Overview of human skin challenge models.
\\n\\n
More than half of the publishers listed alongside IntechOpen (18 out of 30) are Social Science and Humanities publishers. IntechOpen is an exception to this as a leader in not only Open Access content but Open Access content across all scientific disciplines, including Physical Sciences, Engineering and Technology, Health Sciences, Life Science, and Social Sciences and Humanities.
\\n\\nOur breakdown of titles published demonstrates this with 47% PET, 31% HS, 18% LS, and 4% SSH books published.
\\n\\n“Even though ItechOpen has shown the potential of sci-tech books using an OA approach,” other publishers “have shown little interest in OA books.”
\\n\\nAdditionally, each book published by IntechOpen contains original content and research findings.
\\n\\nWe are honored to be among such prestigious publishers and we hope to continue to spearhead that growth in our quest to promote Open Access as a true pioneer in OA book publishing.
\\n\\n\\n\\n
\\n"}]',published:!0,mainMedia:null},components:[{type:"htmlEditorComponent",content:'
Simba Information has released its Open Access Book Publishing 2020 - 2024 report and has again identified IntechOpen as the world’s largest Open Access book publisher by title count.
\n\nSimba Information is a leading provider for market intelligence and forecasts in the media and publishing industry. The report, published every year, provides an overview and financial outlook for the global professional e-book publishing market.
\n\nIntechOpen, De Gruyter, and Frontiers are the largest OA book publishers by title count, with IntechOpen coming in at first place with 5,101 OA books published, a good 1,782 titles ahead of the nearest competitor.
\n\nSince the first Open Access Book Publishing report published in 2016, IntechOpen has held the top stop each year.
\n\n\n\nMore than half of the publishers listed alongside IntechOpen (18 out of 30) are Social Science and Humanities publishers. IntechOpen is an exception to this as a leader in not only Open Access content but Open Access content across all scientific disciplines, including Physical Sciences, Engineering and Technology, Health Sciences, Life Science, and Social Sciences and Humanities.
\n\nOur breakdown of titles published demonstrates this with 47% PET, 31% HS, 18% LS, and 4% SSH books published.
\n\n“Even though ItechOpen has shown the potential of sci-tech books using an OA approach,” other publishers “have shown little interest in OA books.”
\n\nAdditionally, each book published by IntechOpen contains original content and research findings.
\n\nWe are honored to be among such prestigious publishers and we hope to continue to spearhead that growth in our quest to promote Open Access as a true pioneer in OA book publishing.
\n\n\n\n
\n'}],latestNews:[{slug:"intechopen-authors-included-in-the-highly-cited-researchers-list-for-2020-20210121",title:"IntechOpen Authors Included in the Highly Cited Researchers List for 2020"},{slug:"intechopen-maintains-position-as-the-world-s-largest-oa-book-publisher-20201218",title:"IntechOpen Maintains Position as the World’s Largest OA Book Publisher"},{slug:"all-intechopen-books-available-on-perlego-20201215",title:"All IntechOpen Books Available on Perlego"},{slug:"oiv-awards-recognizes-intechopen-s-editors-20201127",title:"OIV Awards Recognizes IntechOpen's Editors"},{slug:"intechopen-joins-crossref-s-initiative-for-open-abstracts-i4oa-to-boost-the-discovery-of-research-20201005",title:"IntechOpen joins Crossref's Initiative for Open Abstracts (I4OA) to Boost the Discovery of Research"},{slug:"intechopen-hits-milestone-5-000-open-access-books-published-20200908",title:"IntechOpen hits milestone: 5,000 Open Access books published!"},{slug:"intechopen-books-hosted-on-the-mathworks-book-program-20200819",title:"IntechOpen Books Hosted on the MathWorks Book Program"},{slug:"intechopen-s-chapter-awarded-the-guenther-von-pannewitz-preis-2020-20200715",title:"IntechOpen's Chapter Awarded the Günther-von-Pannewitz-Preis 2020"}]},book:{item:{type:"book",id:"5959",leadTitle:null,fullTitle:"Liposomes",title:"Liposomes",subtitle:null,reviewType:"peer-reviewed",abstract:"Liposomes have received increased attention in recent years. Nevertheless, liposomes, due to their various forms and applications, require further investigation. These structures can deliver both hydrophilic and hydrophobic drugs. Preparation of liposomes results in different properties for these systems. In addition, there are many factors and difficulties that affect the development of liposome drug delivery structure. The purpose of this book is to concentrate on recent developments on liposomes. The articles collected in this book are contributions by invited researchers with a long-standing experience in different research areas. We hope that the material presented here is understandable to a broad audience, not only scientists but also people with general background in many different biological sciences. This volume offers you up-to-date, expert reviews of the fast-moving field of liposomes.",isbn:"978-953-51-3580-7",printIsbn:"978-953-51-3579-1",pdfIsbn:"978-953-51-4622-3",doi:"10.5772/66243",price:139,priceEur:155,priceUsd:179,slug:"liposomes",numberOfPages:326,isOpenForSubmission:!1,isInWos:1,hash:"a9ceb39898197da848c05eb1fb7417b5",bookSignature:"Angel Catala",publishedDate:"October 25th 2017",coverURL:"https://cdn.intechopen.com/books/images_new/5959.jpg",numberOfDownloads:14084,numberOfWosCitations:15,numberOfCrossrefCitations:17,numberOfDimensionsCitations:32,hasAltmetrics:1,numberOfTotalCitations:64,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"November 9th 2016",dateEndSecondStepPublish:"November 30th 2016",dateEndThirdStepPublish:"February 26th 2017",dateEndFourthStepPublish:"May 27th 2017",dateEndFifthStepPublish:"July 26th 2017",currentStepOfPublishingProcess:5,indexedIn:"1,2,3,4,5,6",editedByType:"Edited by",kuFlag:!1,editors:[{id:"196544",title:"Prof.",name:"Angel",middleName:null,surname:"Catala",slug:"angel-catala",fullName:"Angel Catala",profilePictureURL:"https://mts.intechopen.com/storage/users/196544/images/system/196544.jpg",biography:"Angel Catalá was born in Rodeo (San Juan, Argentina). He studied chemistry at Universidad Nacional de La Plata, Argentina, where he received a PhD in Chemistry (Biological Branch) in 1965. From 1964 to 1974, he worked as Assistant in Biochemistry at the School of Medicine at the same university. From 1974 to 1976, he was a fellow of the National Institutes of Health (NIH) at the University of Connecticut, Health Center, USA. From 1985 to 2004, he served as Full Professor of Biochemistry at the Universidad Nacional de La Plata. He is a member of the National Research Council (CONICET), Argentina, and Argentine Society for Biochemistry and Molecular Biology (SAIB). His laboratory has been interested for many years in the lipid peroxidation of biological membranes from various tissues and different species. Dr. Catalá has directed twelve doctoral theses, published more than 100 papers in peer-reviewed journals, several chapters in books, and edited twelve books. He received awards at the 40th International Conference Biochemistry of Lipids 1999 in Dijon (France). He is winner of the Bimbo Pan-American Nutrition, Food Science and Technology Award 2006 and 2012, South America, Human Nutrition, Professional Category. In 2006, he won the Bernardo Houssay award in pharmacology, in recognition of his meritorious works of research. Dr. Catalá belongs to the editorial board of several journals including Journal of Lipids; International Review of Biophysical Chemistry; Frontiers in Membrane Physiology and Biophysics; World Journal of Experimental Medicine and Biochemistry Research International; World Journal of Biological Chemistry, Diabetes and the Pancreas; International Journal of Chronic Diseases & Therapy; and International Journal of Nutrition. He is the co-Editor of The Open Biology Journal and associate Editor for Oxidative Medicine and Cellular Longevity.",institutionString:"National University of La Plata",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"4",totalChapterViews:"0",totalEditedBooks:"6",institution:{name:"National University of La Plata",institutionURL:null,country:{name:"Argentina"}}}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"420",title:"Microbial Physiology",slug:"microbial-physiology"}],chapters:[{id:"55431",title:"Dual Centrifugation - A Novel “in-vial” Liposome Processing Technique",doi:"10.5772/intechopen.68523",slug:"dual-centrifugation-a-novel-in-vial-liposome-processing-technique",totalDownloads:1205,totalCrossrefCites:7,totalDimensionsCites:10,signatures:"Ulrich Massing, Sveinung G. Ingebrigtsen, Nataša Škalko-Basnet\nand Ann Mari Holsæter",downloadPdfUrl:"/chapter/pdf-download/55431",previewPdfUrl:"/chapter/pdf-preview/55431",authors:[{id:"201927",title:"Associate Prof.",name:"Ann Mari",surname:"Holsæter",slug:"ann-mari-holsaeter",fullName:"Ann Mari Holsæter"},{id:"202323",title:"Prof.",name:"Ulrich",surname:"Massing",slug:"ulrich-massing",fullName:"Ulrich Massing"},{id:"202325",title:"Prof.",name:"Natasa",surname:"Skalko-Basnet",slug:"natasa-skalko-basnet",fullName:"Natasa Skalko-Basnet"},{id:"202326",title:"MSc.",name:"Sveinung G.",surname:"Ingebrigtsen",slug:"sveinung-g.-ingebrigtsen",fullName:"Sveinung G. Ingebrigtsen"}],corrections:null},{id:"55826",title:"Phenomenological and Formulation Aspects in Tailored Nanoliposome Production",doi:"10.5772/intechopen.68157",slug:"phenomenological-and-formulation-aspects-in-tailored-nanoliposome-production",totalDownloads:876,totalCrossrefCites:0,totalDimensionsCites:3,signatures:"Sabrina Bochicchio, Gaetano Lamberti and Anna Angela Barba",downloadPdfUrl:"/chapter/pdf-download/55826",previewPdfUrl:"/chapter/pdf-preview/55826",authors:[{id:"140173",title:"Prof.",name:"Anna Angela",surname:"Barba",slug:"anna-angela-barba",fullName:"Anna Angela Barba"},{id:"176104",title:"Prof.",name:"Gaetano",surname:"Lamberti",slug:"gaetano-lamberti",fullName:"Gaetano Lamberti"},{id:"201637",title:"Dr.",name:"Sabrina",surname:"Bochicchio",slug:"sabrina-bochicchio",fullName:"Sabrina Bochicchio"}],corrections:null},{id:"56929",title:"Lipobeads",doi:"10.5772/intechopen.70056",slug:"lipobeads",totalDownloads:1136,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"Sergey Kazakov",downloadPdfUrl:"/chapter/pdf-download/56929",previewPdfUrl:"/chapter/pdf-preview/56929",authors:[{id:"143029",title:"Prof.",name:"Sergey",surname:"Kazakov",slug:"sergey-kazakov",fullName:"Sergey Kazakov"}],corrections:null},{id:"55627",title:"Application of Nuclear Magnetic Resonance Spectroscopy (NMR) to Study the Properties of Liposomes",doi:"10.5772/intechopen.68522",slug:"application-of-nuclear-magnetic-resonance-spectroscopy-nmr-to-study-the-properties-of-liposomes",totalDownloads:1348,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Anna Timoszyk",downloadPdfUrl:"/chapter/pdf-download/55627",previewPdfUrl:"/chapter/pdf-preview/55627",authors:[{id:"200367",title:"Dr.",name:"Anna",surname:"Timoszyk",slug:"anna-timoszyk",fullName:"Anna Timoszyk"}],corrections:null},{id:"55128",title:"Liposomes Used as a Vaccine Adjuvant-Delivery System",doi:"10.5772/intechopen.68521",slug:"liposomes-used-as-a-vaccine-adjuvant-delivery-system",totalDownloads:1305,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Ning Wang, Tingni Wu and Ting Wang",downloadPdfUrl:"/chapter/pdf-download/55128",previewPdfUrl:"/chapter/pdf-preview/55128",authors:[{id:"201744",title:"Prof.",name:"Ting",surname:"Wang",slug:"ting-wang",fullName:"Ting Wang"},{id:"205915",title:"Dr.",name:"Ning",surname:"Wang",slug:"ning-wang",fullName:"Ning Wang"}],corrections:null},{id:"55811",title:"Hydrogels and Their Combination with Liposomes, Niosomes, or Transfersomes for Dermal and Transdermal Drug Delivery",doi:"10.5772/intechopen.68158",slug:"hydrogels-and-their-combination-with-liposomes-niosomes-or-transfersomes-for-dermal-and-transdermal-",totalDownloads:2005,totalCrossrefCites:2,totalDimensionsCites:3,signatures:"Mahmoud Mokhtar Ibrahim, Anroop B. Nair, Bandar E. Aldhubiab\nand Tamer M. Shehata",downloadPdfUrl:"/chapter/pdf-download/55811",previewPdfUrl:"/chapter/pdf-preview/55811",authors:[{id:"202426",title:"Ph.D.",name:"Mahmoud",surname:"Ibrahim",slug:"mahmoud-ibrahim",fullName:"Mahmoud Ibrahim"},{id:"202427",title:"Dr.",name:"Anroop B.",surname:"Nair",slug:"anroop-b.-nair",fullName:"Anroop B. Nair"},{id:"202428",title:"Dr.",name:"Bandar E.",surname:"Aldhubiab",slug:"bandar-e.-aldhubiab",fullName:"Bandar E. Aldhubiab"},{id:"202430",title:"Dr.",name:"Tamer M.",surname:"Shehata",slug:"tamer-m.-shehata",fullName:"Tamer M. Shehata"}],corrections:null},{id:"55377",title:"Thermosensitive Liposomes",doi:"10.5772/intechopen.68159",slug:"thermosensitive-liposomes",totalDownloads:1144,totalCrossrefCites:3,totalDimensionsCites:7,signatures:"Anjan Motamarry, Davud Asemani and Dieter Haemmerich",downloadPdfUrl:"/chapter/pdf-download/55377",previewPdfUrl:"/chapter/pdf-preview/55377",authors:[{id:"201952",title:"Prof.",name:"Dieter",surname:"Haemmerich",slug:"dieter-haemmerich",fullName:"Dieter Haemmerich"},{id:"207116",title:"Mr.",name:"Anjan",surname:"Motamarry",slug:"anjan-motamarry",fullName:"Anjan Motamarry"}],corrections:null},{id:"56546",title:"Liposomal Drug Delivery to the Central Nervous System",doi:"10.5772/intechopen.70055",slug:"liposomal-drug-delivery-to-the-central-nervous-system",totalDownloads:2180,totalCrossrefCites:1,totalDimensionsCites:4,signatures:"Rita Nieto Montesinos",downloadPdfUrl:"/chapter/pdf-download/56546",previewPdfUrl:"/chapter/pdf-preview/56546",authors:[{id:"202685",title:"Dr.",name:"Rita Milagros",surname:"Nieto Montesinos",slug:"rita-milagros-nieto-montesinos",fullName:"Rita Milagros Nieto Montesinos"}],corrections:null},{id:"54725",title:"Liposomal Nanoformulations as Current Tumor-Targeting Approach to Cancer Therapy",doi:"10.5772/intechopen.68160",slug:"liposomal-nanoformulations-as-current-tumor-targeting-approach-to-cancer-therapy",totalDownloads:1068,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"Alina Porfire, Marcela Achim, Lucia Tefas and Bianca Sylvester",downloadPdfUrl:"/chapter/pdf-download/54725",previewPdfUrl:"/chapter/pdf-preview/54725",authors:[{id:"202435",title:"Dr.",name:"Alina",surname:"Porfire",slug:"alina-porfire",fullName:"Alina Porfire"},{id:"202936",title:"Prof.",name:"Marcela",surname:"Achim",slug:"marcela-achim",fullName:"Marcela Achim"},{id:"202937",title:"Dr.",name:"Lucia",surname:"Tefas",slug:"lucia-tefas",fullName:"Lucia Tefas"},{id:"202938",title:"BSc.",name:"Bianca",surname:"Sylvester",slug:"bianca-sylvester",fullName:"Bianca Sylvester"}],corrections:null},{id:"55318",title:"Methotrexate Liposomes - A Reliable Therapeutic Option",doi:"10.5772/intechopen.68520",slug:"methotrexate-liposomes-a-reliable-therapeutic-option",totalDownloads:1066,totalCrossrefCites:2,totalDimensionsCites:2,signatures:"Anne Marie Ciobanu, Maria Bârcă, Gina Manda, George Traian\nAlexandru Burcea Dragomiroiu and Daniela Luiza Baconi",downloadPdfUrl:"/chapter/pdf-download/55318",previewPdfUrl:"/chapter/pdf-preview/55318",authors:[{id:"49037",title:"Dr.",name:"Gina",surname:"Manda",slug:"gina-manda",fullName:"Gina Manda"},{id:"193027",title:"Dr.",name:"George Traian Alexandru",surname:"Burcea Dragomiroiu",slug:"george-traian-alexandru-burcea-dragomiroiu",fullName:"George Traian Alexandru Burcea Dragomiroiu"},{id:"203029",title:"Prof.",name:"Daniela",surname:"Baconi",slug:"daniela-baconi",fullName:"Daniela Baconi"},{id:"203030",title:"Dr.",name:"Anne-Marie",surname:"Ciobanu",slug:"anne-marie-ciobanu",fullName:"Anne-Marie Ciobanu"},{id:"203031",title:"Dr.",name:"Maria",surname:"Barca",slug:"maria-barca",fullName:"Maria Barca"}],corrections:null},{id:"55961",title:"Liposome-Mediated Immunosuppression Plays an Instrumental Role in the Development of “Humanized Mouse” to Study Plasmodium falciparum",doi:"10.5772/intechopen.69390",slug:"liposome-mediated-immunosuppression-plays-an-instrumental-role-in-the-development-of-humanized-mouse",totalDownloads:758,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Kunjal Agrawal, Vishwa Vyas, Yamnah Hafeji and Rajeev K. Tyagi",downloadPdfUrl:"/chapter/pdf-download/55961",previewPdfUrl:"/chapter/pdf-preview/55961",authors:[{id:"201069",title:"Dr.",name:"Rajeev",surname:"Tyagi",slug:"rajeev-tyagi",fullName:"Rajeev Tyagi"},{id:"206218",title:"Ms.",name:"Yamnah",surname:"Hafeji",slug:"yamnah-hafeji",fullName:"Yamnah Hafeji"},{id:"206219",title:"Ms.",name:"Kunjal",surname:"Agrawal",slug:"kunjal-agrawal",fullName:"Kunjal Agrawal"},{id:"206220",title:"Ms.",name:"Vishwa",surname:"Vyas",slug:"vishwa-vyas",fullName:"Vishwa Vyas"}],corrections:null}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},relatedBooks:[{type:"book",id:"2553",title:"Lipid Peroxidation",subtitle:null,isOpenForSubmission:!1,hash:"b39734aa940b2d63ae5e8773d3dd5280",slug:"lipid-peroxidation",bookSignature:"Angel Catala",coverURL:"https://cdn.intechopen.com/books/images_new/2553.jpg",editedByType:"Edited by",editors:[{id:"196544",title:"Prof.",name:"Angel",surname:"Catala",slug:"angel-catala",fullName:"Angel Catala"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5769",title:"Fatty Acids",subtitle:null,isOpenForSubmission:!1,hash:"026ff00026816b4cca7116ca6e1e7fbd",slug:"fatty-acids",bookSignature:"Angel Catala",coverURL:"https://cdn.intechopen.com/books/images_new/5769.jpg",editedByType:"Edited by",editors:[{id:"196544",title:"Prof.",name:"Angel",surname:"Catala",slug:"angel-catala",fullName:"Angel Catala"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8095",title:"Liposomes",subtitle:"Advances and Perspectives",isOpenForSubmission:!1,hash:"02b0d76190d551561ad19af0c80f98f2",slug:"liposomes-advances-and-perspectives",bookSignature:"Angel Catala",coverURL:"https://cdn.intechopen.com/books/images_new/8095.jpg",editedByType:"Edited by",editors:[{id:"196544",title:"Prof.",name:"Angel",surname:"Catala",slug:"angel-catala",fullName:"Angel Catala"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6925",title:"Endoplasmic Reticulum",subtitle:null,isOpenForSubmission:!1,hash:"a9e90d2dbdbc46128dfe7dac9f87c6b4",slug:"endoplasmic-reticulum",bookSignature:"Angel Català",coverURL:"https://cdn.intechopen.com/books/images_new/6925.jpg",editedByType:"Edited by",editors:[{id:"196544",title:"Prof.",name:"Angel",surname:"Catala",slug:"angel-catala",fullName:"Angel Catala"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10143",title:"Molecular Pharmacology",subtitle:null,isOpenForSubmission:!1,hash:"2b2fce4ff393dff0d0f0581c7818087c",slug:"molecular-pharmacology",bookSignature:"Angel Catala and Usama Ahmad",coverURL:"https://cdn.intechopen.com/books/images_new/10143.jpg",editedByType:"Edited by",editors:[{id:"196544",title:"Prof.",name:"Angel",surname:"Catala",slug:"angel-catala",fullName:"Angel Catala"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5614",title:"Gluconeogenesis",subtitle:null,isOpenForSubmission:!1,hash:"380e1674d70172e10365c80902d57edf",slug:"gluconeogenesis",bookSignature:"Weizhen Zhang",coverURL:"https://cdn.intechopen.com/books/images_new/5614.jpg",editedByType:"Edited by",editors:[{id:"102875",title:"Prof.",name:"Weizhen",surname:"Zhang",slug:"weizhen-zhang",fullName:"Weizhen Zhang"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],ofsBooks:[]},correction:{item:{id:"71364",slug:"erratum-the-mechanism-of-misalignment-of-saw-cutting-crack-of-concrete-pavement",title:"Erratum - The Mechanism of Misalignment of Saw Cutting Crack of Concrete Pavement",doi:null,correctionPDFUrl:"https://cdn.intechopen.com/pdfs/71364.pdf",downloadPdfUrl:"/chapter/pdf-download/71364",previewPdfUrl:"/chapter/pdf-preview/71364",totalDownloads:null,totalCrossrefCites:null,bibtexUrl:"/chapter/bibtex/71364",risUrl:"/chapter/ris/71364",chapter:{id:"71109",slug:"the-mechanism-of-misalignment-of-saw-cutting-crack-of-concrete-pavement",signatures:"Chatarina Niken",dateSubmitted:"October 18th 2019",dateReviewed:"January 11th 2020",datePrePublished:"February 14th 2020",datePublished:"September 23rd 2020",book:{id:"7615",title:"Fracture Mechanics Applications",subtitle:null,fullTitle:"Fracture Mechanics Applications",slug:"fracture-mechanics-applications",publishedDate:"September 23rd 2020",bookSignature:"Hayri Baytan Ozmen and H. Ersen Balcioglu",coverURL:"https://cdn.intechopen.com/books/images_new/7615.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"198122",title:"Dr.",name:"Hayri Baytan",middleName:null,surname:"Ozmen",slug:"hayri-baytan-ozmen",fullName:"Hayri Baytan Ozmen"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:[{id:"313776",title:"Dr.",name:"Chatarina",middleName:null,surname:"Niken",fullName:"Chatarina Niken",slug:"chatarina-niken",email:"chatarinaniken@yahoo.com",position:null,institution:null}]}},chapter:{id:"71109",slug:"the-mechanism-of-misalignment-of-saw-cutting-crack-of-concrete-pavement",signatures:"Chatarina Niken",dateSubmitted:"October 18th 2019",dateReviewed:"January 11th 2020",datePrePublished:"February 14th 2020",datePublished:"September 23rd 2020",book:{id:"7615",title:"Fracture Mechanics Applications",subtitle:null,fullTitle:"Fracture Mechanics Applications",slug:"fracture-mechanics-applications",publishedDate:"September 23rd 2020",bookSignature:"Hayri Baytan Ozmen and H. Ersen Balcioglu",coverURL:"https://cdn.intechopen.com/books/images_new/7615.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"198122",title:"Dr.",name:"Hayri Baytan",middleName:null,surname:"Ozmen",slug:"hayri-baytan-ozmen",fullName:"Hayri Baytan Ozmen"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:[{id:"313776",title:"Dr.",name:"Chatarina",middleName:null,surname:"Niken",fullName:"Chatarina Niken",slug:"chatarina-niken",email:"chatarinaniken@yahoo.com",position:null,institution:null}]},book:{id:"7615",title:"Fracture Mechanics Applications",subtitle:null,fullTitle:"Fracture Mechanics Applications",slug:"fracture-mechanics-applications",publishedDate:"September 23rd 2020",bookSignature:"Hayri Baytan Ozmen and H. Ersen Balcioglu",coverURL:"https://cdn.intechopen.com/books/images_new/7615.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"198122",title:"Dr.",name:"Hayri Baytan",middleName:null,surname:"Ozmen",slug:"hayri-baytan-ozmen",fullName:"Hayri Baytan Ozmen"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}}},ofsBook:{item:{type:"book",id:"8368",leadTitle:null,title:"Computer and Network Security",subtitle:null,reviewType:"peer-reviewed",abstract:"In the era of Internet of Things (IoT), and with the explosive worldwide growth of electronic data volume and the associated needs of processing, analyzing, and storing this data, several new challenges have emerged. Particularly, there is a need for novel schemes of secure authentication, integrity protection, encryption, and non-repudiation to protect the privacy of sensitive data and to secure systems. Lightweight symmetric key cryptography and adaptive network security algorithms are in demand for mitigating these challenges. This book presents state-of-the-art research in the fields of cryptography and security in computing and communications. It covers a wide range of topics such as machine learning, intrusion detection, steganography, multi-factor authentication, and more. It is a valuable reference for researchers, engineers, practitioners, and graduate and doctoral students working in the fields of cryptography, network security, IoT, and machine learning.",isbn:"978-1-83880-855-6",printIsbn:"978-1-83880-854-9",pdfIsbn:"978-1-83880-856-3",doi:"10.5772/intechopen.78497",price:119,priceEur:129,priceUsd:155,slug:"computer-and-network-security",numberOfPages:176,isOpenForSubmission:!1,hash:"40b3cd1cd3de504736186805106eed6b",bookSignature:"Jaydip Sen",publishedDate:"June 10th 2020",coverURL:"https://cdn.intechopen.com/books/images_new/8368.jpg",keywords:null,numberOfDownloads:3254,numberOfWosCitations:0,numberOfCrossrefCitations:1,numberOfDimensionsCitations:3,numberOfTotalCitations:4,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"July 10th 2018",dateEndSecondStepPublish:"July 31st 2018",dateEndThirdStepPublish:"September 29th 2018",dateEndFourthStepPublish:"December 18th 2018",dateEndFifthStepPublish:"February 16th 2019",remainingDaysToSecondStep:"2 years",secondStepPassed:!0,currentStepOfPublishingProcess:5,editedByType:"Edited by",kuFlag:!1,biosketch:null,coeditorOneBiosketch:null,coeditorTwoBiosketch:null,coeditorThreeBiosketch:null,coeditorFourBiosketch:null,coeditorFiveBiosketch:null,editors:[{id:"4519",title:"Prof.",name:"Jaydip",middleName:null,surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen",profilePictureURL:"https://mts.intechopen.com/storage/users/4519/images/system/4519.jpeg",biography:"Professor Jaydip Sen has worked for many reputed organizations, including Oil and Natural Gas Corporation Ltd., India; Oracle India Pvt. Ltd.; Akamai Technology Pvt. Ltd.; Tata Consultancy Services Ltd.; and National Institute of Science and Technology, India. Prior to joining the NSHM Knowledge Campus, India, in December 2018 as the head of the Data Science and Computing School, Prof. Sen worked with Praxis Business School as a Professor of Business Analytics. Prior to that, he was a lead scientist in the Innovation Lab of Tata Consultancy Services, Kolkata, India, where he was involved in research and development in security and privacy aspects in wireless networks and Internet of Things. His research areas include security in wired and wireless networks, intrusion detection systems, secure routing protocols in wireless ad hoc and sensor networks, secure multicast and broadcast communication in next-generation broadband wireless networks, trust- and reputation-based systems, quality of service in multimedia communication in wireless networks and cross-layer optimization-based resource allocation algorithms in next-generation wireless networks, sensor networks, and privacy issues in ubiquitous and pervasive communication, big data analytics, R, Python, Spark, Hadoop and MapReduce programming. Currently, he is active in the fields of applied statistical modelling, data mining and machine learning, data warehousing and multi-dimensional modelling, social media and mobile analytics, Artificial Intelligence, and Deep Learning. He has more than 200 publications in reputed international journals and referred conference proceedings (IEEE Xplore, ACM Digital Library, Springer LNCS etc.), and eight chapters in books published by internationally renowned publishing houses. He has delivered expert talks and keynote lectures at various international conferences and symposia. He is a senior member of ACM, a member of IEEE, and a lifetime member of Indian Society of Technical Education (ISTE). He was also an active member of the security group of IEEE 802.16 standard body and European Telecommunication Standards Institute (ETSI). His biography has been listed in Marquis Who’s Who in the World annually since 2008. He has delivered invited talks at many prestigious international conferences both in India and abroad and has conducted a number of training programs for teachers of Computer Science and Engineering and Data Science at various universities.",institutionString:"Praxis Business School",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"7",totalChapterViews:"0",totalEditedBooks:"6",institution:null}],coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"537",title:"Network Security",slug:"network-security"}],chapters:[{id:"71876",title:"Introductory Chapter: Machine Learning in Misuse and Anomaly Detection",slug:"introductory-chapter-machine-learning-in-misuse-and-anomaly-detection",totalDownloads:286,totalCrossrefCites:0,authors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"},{id:"320071",title:"Dr.",name:"Sidra",surname:"Mehtab",slug:"sidra-mehtab",fullName:"Sidra Mehtab"}]},{id:"64741",title:"A New Cross-Layer FPGA-Based Security Scheme for Wireless Networks",slug:"a-new-cross-layer-fpga-based-security-scheme-for-wireless-networks",totalDownloads:343,totalCrossrefCites:0,authors:[{id:"267173",title:"Dr.",name:"Michael",surname:"Ekonde Sone",slug:"michael-ekonde-sone",fullName:"Michael Ekonde Sone"}]},{id:"67618",title:"Anomaly-Based Intrusion Detection System",slug:"anomaly-based-intrusion-detection-system",totalDownloads:876,totalCrossrefCites:1,authors:[{id:"269941",title:"Mrs.",name:"Jyothsna",surname:"Veeramreddy",slug:"jyothsna-veeramreddy",fullName:"Jyothsna Veeramreddy"},{id:"321710",title:"Dr.",name:"Koneti Munivara",surname:"Prasad",slug:"koneti-munivara-prasad",fullName:"Koneti Munivara Prasad"}]},{id:"69755",title:"Security in Wireless Local Area Networks (WLANs)",slug:"security-in-wireless-local-area-networks-wlans-",totalDownloads:307,totalCrossrefCites:0,authors:[{id:"267784",title:"Dr.",name:"Rajeev",surname:"Singh",slug:"rajeev-singh",fullName:"Rajeev Singh"},{id:"268313",title:"Dr.",name:"Teek Parval",surname:"Sharma",slug:"teek-parval-sharma",fullName:"Teek Parval Sharma"}]},{id:"71146",title:"Analysis of Network Protocols: The Ability of Concealing the Information",slug:"analysis-of-network-protocols-the-ability-of-concealing-the-information",totalDownloads:233,totalCrossrefCites:0,authors:[{id:"297965",title:"Mr.",name:"Anton",surname:"Noskov",slug:"anton-noskov",fullName:"Anton Noskov"}]},{id:"69777",title:"Multifactor Authentication Methods: A Framework for Their Comparison and Selection",slug:"multifactor-authentication-methods-a-framework-for-their-comparison-and-selection",totalDownloads:255,totalCrossrefCites:0,authors:[{id:"269010",title:"Ph.D.",name:"Angelica",surname:"Caro",slug:"angelica-caro",fullName:"Angelica Caro"},{id:"269446",title:"Dr.",name:"Alfonso",surname:"Rodriguez",slug:"alfonso-rodriguez",fullName:"Alfonso Rodriguez"},{id:"269447",title:"M.Sc.",name:"Ignacio",surname:"Velásquez",slug:"ignacio-velasquez",fullName:"Ignacio Velásquez"}]},{id:"64915",title:"Secure Communication Using Cryptography and Covert Channel",slug:"secure-communication-using-cryptography-and-covert-channel",totalDownloads:155,totalCrossrefCites:0,authors:[{id:"267294",title:"Dr.",name:"Tamer",surname:"Fatayer",slug:"tamer-fatayer",fullName:"Tamer Fatayer"}]},{id:"67728",title:"High-Speed Area-Efficient Implementation of AES Algorithm on Reconfigurable Platform",slug:"high-speed-area-efficient-implementation-of-aes-algorithm-on-reconfigurable-platform",totalDownloads:371,totalCrossrefCites:0,authors:[{id:"269944",title:"Mr.",name:"Altaf",surname:"Mulani",slug:"altaf-mulani",fullName:"Altaf Mulani"},{id:"283911",title:"Dr.",name:"Pradeep",surname:"Mane",slug:"pradeep-mane",fullName:"Pradeep Mane"}]},{id:"64945",title:"Hybrid Approaches to Block Cipher",slug:"hybrid-approaches-to-block-cipher",totalDownloads:437,totalCrossrefCites:0,authors:[{id:"268738",title:"Dr.",name:"Roshan",surname:"Chitrakar",slug:"roshan-chitrakar",fullName:"Roshan Chitrakar"},{id:"278441",title:"Mr.",name:"Roshan",surname:"Bhusal",slug:"roshan-bhusal",fullName:"Roshan Bhusal"},{id:"278442",title:null,name:"Prajwol",surname:"Maharjan",slug:"prajwol-maharjan",fullName:"Prajwol Maharjan"}]}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"},personalPublishingAssistant:{id:"205697",firstName:"Kristina",lastName:"Kardum Cvitan",middleName:null,title:"Ms.",imageUrl:"https://mts.intechopen.com/storage/users/205697/images/5186_n.jpg",email:"kristina.k@intechopen.com",biography:"As an Author Service Manager my responsibilities include monitoring and facilitating all publishing activities for authors and editors. From chapter submission and review, to approval and revision, copyediting and design, until final publication, I work closely with authors and editors to ensure a simple and easy publishing process. I maintain constant and effective communication with authors, editors and reviewers, which allows for a level of personal support that enables contributors to fully commit and concentrate on the chapters they are writing, editing, or reviewing. I assist authors in the preparation of their full chapter submissions and track important deadlines and ensure they are met. I help to coordinate internal processes such as linguistic review, and monitor the technical aspects of the process. As an ASM I am also involved in the acquisition of editors. Whether that be identifying an exceptional author and proposing an editorship collaboration, or contacting researchers who would like the opportunity to work with IntechOpen, I establish and help manage author and editor acquisition and contact."}},relatedBooks:[{type:"book",id:"3412",title:"Theory and Practice of Cryptography and Network Security Protocols and Technologies",subtitle:null,isOpenForSubmission:!1,hash:"edbd5d0f991597aa78defb420d03f547",slug:"theory-and-practice-of-cryptography-and-network-security-protocols-and-technologies",bookSignature:"Jaydip Sen",coverURL:"https://cdn.intechopen.com/books/images_new/3412.jpg",editedByType:"Edited by",editors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"2263",title:"Applied Cryptography and Network Security",subtitle:null,isOpenForSubmission:!1,hash:"07634e142c90c16ba2a873e2e45d2cd0",slug:"applied-cryptography-and-network-security",bookSignature:"Jaydip Sen",coverURL:"https://cdn.intechopen.com/books/images_new/2263.jpg",editedByType:"Edited by",editors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1778",title:"Cryptography and Security in Computing",subtitle:null,isOpenForSubmission:!1,hash:"62c15d873f53e3d996a21ab0821688f3",slug:"cryptography-and-security-in-computing",bookSignature:"Jaydip Sen",coverURL:"https://cdn.intechopen.com/books/images_new/1778.jpg",editedByType:"Edited by",editors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5416",title:"Cloud Computing",subtitle:"Architecture and Applications",isOpenForSubmission:!1,hash:"8ae44907e10133e5796c0dcd01234da8",slug:"cloud-computing-architecture-and-applications",bookSignature:"Jaydip Sen",coverURL:"https://cdn.intechopen.com/books/images_new/5416.jpg",editedByType:"Edited by",editors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6462",title:"Internet of Things",subtitle:"Technology, Applications and Standardization",isOpenForSubmission:!1,hash:"0db33037b03f025bd97ce988f4ab90c2",slug:"internet-of-things-technology-applications-and-standardization",bookSignature:"Jaydip Sen",coverURL:"https://cdn.intechopen.com/books/images_new/6462.jpg",editedByType:"Edited by",editors:[{id:"4519",title:"Prof.",name:"Jaydip",surname:"Sen",slug:"jaydip-sen",fullName:"Jaydip Sen"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7623",title:"Coding Theory",subtitle:null,isOpenForSubmission:!1,hash:"db1156342e3a1a46ff74cad035a3886b",slug:"coding-theory",bookSignature:"Sudhakar Radhakrishnan and Muhammad Sarfraz",coverURL:"https://cdn.intechopen.com/books/images_new/7623.jpg",editedByType:"Edited by",editors:[{id:"26327",title:"Dr.",name:"Sudhakar",surname:"Radhakrishnan",slug:"sudhakar-radhakrishnan",fullName:"Sudhakar Radhakrishnan"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},chapter:{item:{type:"chapter",id:"66350",title:"Pharmacological Challenge Models in Clinical Drug Developmental Programs",doi:"10.5772/intechopen.85352",slug:"pharmacological-challenge-models-in-clinical-drug-developmental-programs",body:'\n
Drug development programs are well-established and long-lasting processes, taking between 10 and 15 years, from discovery to market availability. Clinical trials with drug candidates are the final stage in drug development programs [1, 2]. These clinical trials are often classified into four stages of experimentation, phase I—IV, which are used as a general guideline in clinical trial research for development of a new treatment in specific diseases, i.e., skin diseases [3]. In general, safety, tolerability and pharmacokinetic properties are assessed in healthy volunteers during phase I. The candidate drug will move on to phase II when the initial safety and tolerability has been determined. The main aim of phase II is to establish the safety and efficacy of the drug in the target population. Phase III studies involve large-scaling testing to provide more and extended information on the effectiveness of the drug and on the benefits and possible adverse events. The last phase, IV, also known as the post marketing surveillance trials, is executed after the drug enters the market. The main purpose of this monitoring phase is to determine the long-term effectiveness and patient’s quality of life and cost-effectiveness [4, 5].
\nTranslational research focuses on the transcription of the animal model into humans, also known as first-in-human-dose. In general, efficacy, safety and tolerability are examined in the early phases of clinical research. However, the absence of the disorder in healthy volunteers may hamper investigation of the above-mentioned hallmarks of drug development. Inflammation, for example, plays an important role in diseases and is often an indication for a certain skin disease. Difficulties occur when testing drugs against inflammation in volunteers who do not have this condition. Therefore, pharmacological challenge models have been established to mimic physiological and pathophysiological conditions of several skin diseases. These models distort the physiological condition and lead to temporary effects that mimic the pathophysiology of the disease.
\nTable 1 gives an overview of established skin challenge models.
\nChallenge | \nApplication | \nMode of action | \nCondition induced | \nImmune response | \nReference | \n
---|---|---|---|---|---|
Inflammation | \n|||||
BCG | \nIntradermal | \nTLR 4, 9 agonist | \nLocal inflammation, systemic immune response | \nAdaptive | \n[6, 7, 8] | \n
Imiquimod | \nLocal under occlusion | \nTLR7 agonist | \nLocal inflammation | \nInnate + adaptive | \n[9, 10, 11, 12, 13] | \n
LPS challenge + Al(OH)3 | \nIntra dermal | \nTLR 4 agonist | \nInflammatory response | \nInnate + adaptive | \n[14, 15] | \n
Cantharidin | \nPaper disc with cantharidin | \nNeutrophils | \nLocal inflammation | \nInnate | \n[14, 16] | \n
Injected UV killed E. coli | \nIntradermal | \nNeutrophils | \nErythema, heat, swelling and pain | \nInnate | \n[14, 17] | \n
KLH | \nIntradermal, Intramuscular | \nNeo-antigen | \nLocal inflammation, systemic immune response | \nAdaptive | \n[18, 19, 20, 21, 22] | \n
ITCH | \n|||||
Capsaicin | \nIntradermal, intra muscular, topical | \nTRPV 1 receptor | \nItch | \nInnate | \n[23, 24, 25] | \n
Histamine | \nIntradermal, intramuscular | \nH1, 2, 3, 4 receptor CMIA fibers | \nItch | \nInnate | \n[26, 27, 28, 29, 30, 31, 32, 33] | \n
Cowhage | \nCutaneous | \nCMH-fibers | \nItch Burning | \nUnknown | \n[34, 35] | \n
UV-exposure | \n|||||
UV-B irradiation | \nLocal thermode | \nPI3K/AKT/mTOR-upregulation | \nPain, pigmentation, erythema, inflammation | \nInnate Adaptive | \n[23, 36, 37, 38, 39, 40, 41] | \n
Overview of human skin challenge models.
BCG: Bacillus Calmette-Guérin; LPS challenge: lipopolysaccharide; injected UV killed E. coli: Injected ultraviolet killed Escherichia coli; KLH: keyhole limpet hemocyanin; UV-B: Ultraviolet B.
This approach includes translating basic scientific discoveries into clinical applications. Several recent developments in plaque psoriasis are noteworthy, which serve as an example of research with many translational aspects [42, 43]. Psoriasis is a chronic, inflammatory skin disease that is characterized by erythematous, itchy plaques covered by course scales on the extensor surface of the elbows and knees, as well as the scalp, dorsal hands and lumbar area. Also, the nails and joints (psoriatic arthritis) can be affected [44, 45]. Psoriasis is a multifactorial disease but the hallmarks of pathophysiological pathways (Th1/Th17) with interleukin-12/23 and IL-17 have been clearly established as most important players. Over the last decade many new compounds have been in development for psoriasis yielding a total of 11 registered, targeted monoclonal antibodies today. In these drug development programs in vivo models in mice are of great importance for the setup of clinical programs. These mouse models needed to be made suitable to display certain features of psoriasis, since mice are unable to develop psoriasis themselves [10]. This research resulted in development of diverse mouse models i.e., spontaneous mutation model, genetically engineered model, cytokine injection model and transplantation model. All of the mentioned animal approaches represent more or less psoriasis-like cutaneous characteristics. Despite expression of psoriasis like features, the models also have some limitations including the need for special experimental facilities and lack of effectiveness of anti-psoriatic drugs [46, 47, 48, 49]. In general, animal models are far from perfect especially in terms of pharmaco- and toxicokinetics.
\nAnimals are not able to predict health effects in humans better than humans themselves. Monkeys reflects the human being the best, however, even they can differ as became clear in 2016. An anti-CD28 antibody caused multiple organ failures in six healthy volunteers within hours, despite multiple normal tests in monkeys. This shows that animal models may have limited predictability for safety in humans. Ethical concerns with regard to need for animal testing may also be a factor underlining the need for pharmacological challenge models in humans [50].
\nThis chapter will provide a detailed overview of four different, local inflammation models: inflammation by Toll-like receptor agonists such as imiquimod (inflammation), UV-B irradiation (inflammation and pain), histamine provocation (itch) and KLH challenge (delayed type hypersensitivity).
\nSkin inflammation is a common response of our immune system to penetrating pathogens, skin trauma, exposure of xenobiotics, microbes and parasites [51, 52, 53]. Inflammation is clinically recognizable by erythema, pain, heat and swelling [54]. Generally, in inflamed skin, various immune cells, of both the innate and adaptive system are involved to combat the pathogens. However, imbalance of these immune cells may lead to chronic skin diseases such as psoriasis vulgaris, atopic dermatitis and acne vulgaris. Currently, many investigations are addressing the biomolecular mechanisms of inflammation; however, the pathophysiology of the skin remains complex and needs further investigation [55, 56].
\nHence, various models in healthy volunteers were developed that mimic inflamed skin conditions [57]. One of the examples is the challenge model with topical application of imiquimod, the active ingredient of Aldara cream. Imiquimod is a small molecule with a low molecular weight and high lipophilicity which is preferable for absorption in the skin after topical administration. This small molecule is also a ligand for toll-like receptor seven and eight (TLR), which belongs to the class of immunomodulatory agents and is able to induce the production of several cytokines (interferon-1 response) with antiviral and tumoricidal properties. The mechanism of action of imiquimod is complex and three main pathways are required including TLR signaling, inflammasome activation and inhibition of the adenosine receptor. However, limited information is available on the mechanism of imiquimod on the adenosine receptor. The first pathway is TLR dependent and activates nuclear factor kappa B (NF-κB) signaling via My-D88, which is important in an early immune response. Herewith, activation of c-Junk and IRAK pathways occur which are involved in the production of several pro-inflammatory cytokines. The second pathway is TLR independent. Imiquimod is able to activate the inflammasome via the NALP3 pathway, which also triggers an immune response and leads to production of interleukin-1β (IL-1β, a pro-inflammatory cytokine) [10, 11, 13, 58, 59, 60].
\nAldara 5% cream is registered as a topical product that is indicated for the treatment of superficial basal cell carcinoma, actinic keratosis and genital and peri-anal warts (condyloma acuminata). Topical administration of imiquimod appears to be safe and reasonably tolerated according to the mouse model. This murine imiquimod challenge model has been widely used to examine the mechanisms involved in psoriasis vulgaris, since it is simple, inexpensive and develops an acute inflammatory response with psoriasiform features. However, in general, the main limitation of murine models is that no single mouse model is able to reflect human disease precisely, as the physiology and the pathophysiology of the skin differs in both species [61]. Therefore, recently, human studies been conducted that study skin inflammation after topical application of imiquimod.
\nVinter et al. successfully developed an imiquimod-induced psoriasis- like skin inflammation model in humans by applying imiquimod topically under occlusion on non-lesional psoriatic skin of the lower back. A group of patients (n = 7) received the treatment and vehicle for 2 days, while the other group (n = 3) received the same treatment for 7 days. All the treatments were applied on tape stripped skin resulting in perturbation of the skin barrier. After 2 days of treatment with imiquimod, a significant upregulation in mRNA expression was observed for the pro- inflammatory cytokines tumor necrosis factor a (TNF-a), IL-1β and IL-6, whereas TNF-a and IL-6 are keratinocyte driven cytokines. Additionally, a high level of IFN-γ and IL-10 was found, the latter has an important role in suppression of the inflammatory response in the skin, as it influences the regulatory T-cells. In this model, inflammation and psoriasis-like characteristics were induced; however, typical psoriasis lesions were not observed and therefore appear to be the main limitation of the study.
\nA different approach to study skin inflammation was established by Van der Kolk et al. by applying imiquimod topically to healthy volunteers under occlusion. A distinction between the two groups was made. The first cohort received a topical treatment for 24, 48 and 72 hours on the intact skin barrier, while the second cohort received exactly the same treatment on a compromised skin barrier, through tape stripping (Figure 1). In this open label, dose-ranging study, erythema and blood perfusion were monitored by means of erythema index photo analysis, erythema colorimetry, erythema visual grading and laser speckle contrast imaging (LSCI). A dose-dependent increase in erythema was observed for all measurements, with a more rapid and pronounced effect in the tape stripped group. This model showed no clear differences in erythema intensity between the treatments after 48 and 72 hours, which is in concordance with observations in the murine model [9, 13]. Additionally, an increased skin perfusion was found after treatment with imiquimod, however this was only observed in the tape stripped cohort. A similar effect was found for the biomarkers in skin biopsies. Tape-stripping combined with imiquimod treatment resulted in an upregulation of gene expression of CXCL10, MX-A, ICAM-1 and hBD-2 after 48 and 72 hours. The same results were observed after treatment with imiquimod only compared to vehicle, however to a lesser extent. Imiquimod has a three-step mechanism, which entails an initial (24 hour), intermediate (24–72 hour) and late phase (>72 hour). In the intermediate phase of imiquimod, activation of both the innate and adaptive immune response takes place, which is characterized by infiltration of neutrophils, lymphocytes, and macrophages, based on the findings reported in the review of translational imiquimod skin inflammation models [59]. In addition, histologically, infiltration of CD11+, HLA-DR, CD4+ and CD8+ into the dermis was observed. Increased infiltration was more pronounced in the tape stripped cohort, however, no differences were observed between 48 and 72 hours of treatment [9].
\nOverview of the treatment schedule. (a) Treatment areas 1, 2 and 3 were treated with 5 mg imiquimod respectively for 24, 48 and 72 hours. All treatments were applied under occlusion by a 12 mm Finn chamber. (b) Clinical impression of site 3 of the tape stripped cohort after 72 hours of imiquimod treatment [9]. Permitted for non-profit use.
This chapter focuses mainly on translating skin inflammation into a model that can be used in healthy human volunteers. In the past decades, a lot of research has been performed in this field; however, murine models remained the gold standard. Since skin inflammation plays a crucial role in skin diseases such as psoriasis and atopic dermatitis, Vinter et al. established a human counterpart to the mouse model of imiquimod- induced psoriasis like skin inflammation [13]. Despite the expression of different pro-inflammatory cytokines and the presence of psoriasis-like features, typical psoriasis lesions were not observed. However, this study formed the base to the inflammation model developed by Van der Kolk et al. where imiquimod has been applied under occlusion to challenge the skin. This model resulted in expression of certain cytokines and chemokines that are involved in activation of innate as well as adaptive immune system. Chemokines such as CXCL10 are expressed through activation of keratinocytes in inflamed skin. Expression of MX-A, a downstream interferon, which corresponds with the activation of plasmacytoid dendritic cells (pDCs), was also upregulated in the tape stripped cohort. The presence of interferons reflects the antiviral response, which is in concordance with the antiviral characteristics of imiquimod, used for HPV-induced diseases [62, 63]. Based on these findings, the murine imiquimod skin inflammation model was translated to a safe, human model in healthy volunteers. Skin erythema, skin perfusion and expression of cytokines had high intensity in the tape stripped cohort due to the enhanced transepidermal drug delivery. This model is suitable as a challenge model and can be used in drug developmental programs where TLR 7 is involved. Currently, several drugs are under development targeting TLR7/8 that have anti-tumor characteristics with more than 30 leads to be explored within the next years [64, 65].
\nItch, interchangeably used as pruritus, is a common skin sensation and together with pain are crucial symptoms in many chronic and allergic skin diseases. Itch can be induced by mechanical, thermal and chemical stimuli. Additionally, itch can lead to impairment of the skin and thereby affect a person’s quality of life. Yosipovitch et al. defined different types of pruritus that are involved in chronic itch including pruriceptive, neuropathic, neurogenic and psychogenic itch. Skin inflammation, dryness, or other skin damage are the main factors causing pruriceptive itch and are found in diseases such as scabies, urticaria and insect bite reactions [66, 67]. Neuropathic itch, is usually caused by nerve injury and can arise at any point along the afferent pathway of the neurons. This itch is observed for example after a varicella zoster infection or nerve trauma. Itch that is originated from activation of the central nervous system is called neurogenic itch. The underlying mechanism is complex since it involves pruriceptive itch as well. This itch is often observed in visceral disease states such as end state renal disease or kidney failure. The last subtype of itch is termed psychogenic itch. This type of itch arises with somatization and the delusional state of parasitophobia [66, 67, 68]. In this chapter, we will focus on pruriceptive itch and the translational model for it.
\nGenerally, theories have been proposed that explained the relation between itch and pain. Itch is mediated through weak activation of nociceptors and stronger activation would result in weak pain. This is also called, the intensity theory. However, further research has elucidated new aspects that explain pruriceptive sensory mechanism in the nervous system. This resulted in two main pathways including specificity and pattern theories. The specificity theory, explains that there are different sets of neuron fibers transferring information to the central nervous system which send responsive signals including itch and pain [25, 35]. The pattern theory stipulates that many sensory receptors and spinal cord neurons are involved in sensation of itch [69]. Although, the neural mechanism of pruritus has been investigated extensively, there remains much to be learned. Therefore, studies that use chemical agents to induce itch have been designed to study the sensory patterns of itch and pain in humans.
\nOne of the most frequently and widely used pruritic agent, that evokes itch, is histamine [70]. Originally, histamine is a neurotransmitter that is associated with pathological processes such as inflammation, pruritus and vascular leak. Histamine is stored in several immune cells, basophils and mast cells and is quickly released after stimulation. Stimulation with histamine, triggers the unmyelinated nerve fibers, also known as C-fibers. A subset of C-fibers (CMi or CMh) is stimulated according the intensity of the stimulus. In case of histamine stimulation, sustained response of CMi occurs [71]. Histidine decarboxylase (HDC), an enzyme that is responsible for histamine production, increases through stimulation with certain mediators that are found in skin lesions of patients with atopic dermatitis. Hence, this enhancement is associated with upregulated histamine release and thus with increased itch sensitivity [28, 70].
\nHistamine has been used in literature as an important inflammatory mediator that is responsible for vascular and inflammatory effects [33]. In the early 1900s the first studies were conducted regarding the potential vascular role of histamine in vivo, however, only a couple of years ago a clinical study was conducted that investigated the cutaneous inflammatory response in human skin. Falcone et al. has developed an easy-to-use model to study the early stages of skin inflammation. Eighteen (18) subjects with Fitzpatrick skin type II and III received topically applied histamine after performing histamine iontophoresis. The subject had to rate their perceived itch on visual analog scale (VAS) with 3 being the threshold for willingness to scratch the skin. Additionally, different skin assessments were performed including trans-epidermal water loss, skin redness and punch biopsy to process immunohistochemistry. Itch was observed up to 30 minutes after stimulation with histamine iontophoresis and was above the itch threshold (VAS > 3). Immunohistochemistry showed an increase of the epidermal thickness, after 72 hours of histamine iontophoresis challenge. In summary, this model can be used as an in vivo model to provoke local and acute skin inflammation, without having an impact on the barrier function. However, no data are available on cell level or cytokine expression profiles [29].
\nAs was earlier described, increased production of histamine has been related to several skin diseases including atopic dermatitis. In addition, histamine has been the main prototypical pruritogen that has been used for experimental purposes. The working mechanism of histamine is going via G- protein coupled receptors: H1 up and till H4. It appears that the H1 and H4 receptors play a role in the histamine involved itch response in mice. In humans, the involvement of other receptor subtypes (H2 and H3) in itch is not well-examined in literature [31, 32]. Generally, the classical anti-histamines bind to H1 receptor and are prescribed in patients suffering from atopic dermatitis. However, recent research clarifies that histamine pathway is not playing a major role in atopic dermatitis. Also, the clinical use of anti-histamines in atopic dermatitis population has been ineffective and questionable which corroborates these findings [27, 32, 72].
\nTherefore, there was a need to establish an alternative itch model, relating to another pathway. The pruritus pathway has physiological functions such as skin barrier homeostasis, inflammation, itch and pain and is the protease-activated receptor (PAR) pathway. PARs are classified as G-protein-coupled receptors and consist of four members, PAR-1, PAR-2, PAR-3 and PAR-4, whereas PAR-2 pathway is mainly associated with skin diseases such as atopic dermatitis [26]. Papoiu et al. established a simple human model based on exogenously stimulation of the PAR-2 pathway in order to provoke itch by applying Cowhage spicules. Additionally, the Cowhage model was compared to the traditional histamine iontophoresis model and the effect of the combined model (histamine iontophoresis and Cowhage) was observed. VAS rating was increased in both atopic dermatitis patients and healthy volunteers, the Cowhage and combination model compared to the histamine model, resulting in no synergy between the Cowhage and the combined model. This finding suggests that Cowhage was the major contributor of itch after stimulation of both pathways simultaneously [34]. The Cowhage model is simple and easy to use and could serve to study itch related skin diseases such as atopic dermatitis. On the other hand, less is known about this pathway and more research is required to examine the mechanism behind this model.
\nIn conclusion, two main skin challenge models were described to provoke itch: histamine iontophoresis and Cowhage. Both models are suitable to use, however, both have a different underlying mechanism to elicit the itch sensation. Evidence-based, induction of the PAR-2 pathway plays a major role in atopic dermatitis, causing pruritus, compared to the histamine model. Therefore, from a therapeutic point of view, drugs that inhibit PAR-2 itch pathway, could be promising, leading to development of a new treatment for chronic pruritus. Since less is known about the underlying cellular mechanism of Cowhage, it would we useful to examine biomarker expression, conduct different skin photography assessments and look at the skin vascularity flow. Furthermore, an advanced challenge study is required in healthy volunteers and patients with atopic dermatitis to examine and monitor the inflammation of both models. In addition, the efficacy of anti-histamine agents and PAR-2 antagonists could be evaluated as well.
\nUltraviolet (UV) radiation is classified as a carcinogenic compound since it has the ability to initiate and promote malignant skin tumors. Additionally, increased exposure to UV radiation can lead to other skin problems such as inflammation and degenerative aging. UV energy is subdivided into three main classes based on physical properties: UV-A, UV-B and UV-C. UV-B can cause physiological skin alterations leading to a cascade of cytokine activation and resulting in an inflammatory response, so called “sunburn”. Furthermore, exposure to UV-B is related to the accumulation of epidermal keratinocytes and thereby increases the epidermal thickness. UV-B radiation has an additional effect on the skin, it is able to up-regulate the production and the accumulation of melanin in the skin and is also linked to cancer susceptibility.
\nIn well-controlled clinical settings, exposure to UV-B is widely used as a human and animal challenge model to induce local cutaneous hyperalgesia (pain) and inflammation. Primary hyperalgesia is induced after 24 hours and remains for more than 48 hours which makes the model suitable for studies where multiple dosing is required. The amount of UV-B radiation applied to the skin needs to be adjusted to a subject’s skin type, according the classification of Fitzpatrick Skin Type [73, 74]. Hereafter, prior the start of the challenge, the Minimal Erythema Dose (MED) is determined and subsequently a one-, two- or threefold multiple of this dose is applied to the skin. After 24 hours, skin inflammation occurs.
\nThis UV model is one of the pain models that can be used as a screening tool for early stage clinical drug development. However, in research, the UV model is used to examine the effects of anti-analgesic or local anesthetics [75, 76]. Recently, an article was published where the UV-B model was one of the models that was applied to compare the effects of several analgesic to placebo. The following analgesic compounds were investigated in the first part: fentanyl, phenytoin, (S)-ketamine and placebo. For the second part of the study imipramine, pregabalin, ibuprofen and placebo were examined. Different pharmacodynamic (PD) assessments were performed which are part of the pain cart including thermal grill, thermode testing and UV-B, electrical stimulation test, pressure stimulation and cold pressure test [41]. Whilst, this study was performed to examine systemic effects of analgesic compounds, the topical effect of UV-B radiation was not determined. One article published the effects of single doses of UV-A, UV-B and UV-C on skin blood flow and barrier function by laser-Doppler flowmeter and evaporimetry. Radiation with various UV light resulted in skin inflammation characterized by erythema, however, assessed visually. Visual perception of erythema correlated with the increase in blood flow assessed by laser-Doppler flowmeter. However, UV radiation has not damaged the skin barrier function, since the trans- epidermal water loss was not increased. An exception formed the three MED, an increase in blood flow was observed after 2 weeks [38]. This study has examined the effects of analgesics on UV-B radiation and other models evoking pain, while skin inflammation occurs as well. Only a few in vivo studies attempted to examine the effect of UV-B radiation on skin inflammation. In general, UV-B radiation triggers the production of inflammatory cytokines in the human keratinocyte cell line HaCaT, including IL-1, IL-6, IL-8, IL-10 and TNF-a, which are leading to alterations of immune cells of the skin [39]. However, involvement of immune cells in skin inflammation after UV-B radiation has not yet been examined and monitored in healthy volunteers.
\nFor future perspectives, the UV-B challenge model could be applied to induce temporarily skin inflammation that could be monitored with additional dermatological tests, such as multispectral imaging, thermography and laser speckle contrast imaging.
\nChallenge models that are described in this chapter, were mostly initiating an innate response, except the imiquimod challenge model. However, in auto-immune skin diseases, activation of the adaptive immune system is crucial as well as the involvement of T-cells [77]. It is quite challenging to evaluate the efficacy of novel drugs in healthy volunteers that target T-lymphocytes, since these are in the resting phase. Hence, challenge models could provide the desirable solution by activating autoreactive T-cell pathways in healthy volunteers. Earlier research investigated keyhole limpet hemocyanin (KLH) as a potential immunization candidate for studying the cell- mediated immune response [78]. KLH is a large molecule (~8000 kDa) consisting of several subtypes and has been widely used in animal and human research for more than 40 years to outline cellular and humoral responses [79, 80, 81]. Additionally, KLH can be used as a carrier protein for cancer vaccines and for bladder cancer immunotherapy [20, 82]. Because of the xenogeneic properties to the human immune system, KLH is able to promote a reliable primary immune response. The following administration routes are known and have been used in earlier research—intradermal, subcutaneous, intramuscular and inhalational [21, 22, 83, 84, 85, 86, 87]. Furthermore, KLH is considered to be clinically safe, since no reports are available on significant adverse events as reported in the comprehensive review by Harris & Markl. Only mild adverse events were reported including itch, rash and mild injection site reactions (soreness) [19, 88]. In summary, single dose immunization with KLH evokes a predictable primary T-cell dependent immune response. An additional intradermal dose of KLH will result in an additional immune response and thereby induces a delayed type IV hypersensitivity reaction around the site of injection [78].
\nPresence of erythema and induration are features of a cell-mediated immune response and are generally scored by visual inspection, which is a subjective method and may lead to significant interrater variability. Saghari et al. established a challenge model to activate T-cells in healthy volunteers after immunization with KLH, whereas both the cellular response and the delayed type hypersensitivity are objectively quantified. Adaptive immunity was measured by anti-KLH IgM and IgG blood serum level titers. Additionally, cutaneous blood perfusion, erythema and swelling were objectively measured by respectively laser speckle contrast imaging (LSCI), multispectral imaging and colorimetry. An increase in anti-KLH IgM and IgG was observed after intramuscular KLH administration compared to placebo. This was the case for the cutaneous blood perfusion quantified by LSCI and for the erythema and swelling quantified by multispectral imaging and colorimetry. So far, none of the studies have quantified induration and erythema response by using non-invasive instruments. This model is developed as proof-of-concept to determine the feasibility and to quantify the features of cell-mediated response [89]. Therefore, the delayed type hypersensitivity model can serve as a candidate to study the pharmacological and pharmacodynamic effects of immunomodulators in healthy volunteers.
\nGenerally, in vivo mice models are a crucial part in pre-clinical drug developmental programs, assessing safety. However, often animal models lack the disease or differ in morphological and physiological properties. Ethical concerns with regard to animal studies are an additional issue which prompts to search for new solutions. Currently, safety is assessed in healthy volunteers who hamper the disease. Therefore, challenge models that mimic the disease temporarily, could provide a possible solution and act as translational models. This chapter has provided an overview (Table 1) of various challenge models that are known to initiate skin inflammation by triggering the human immune system. First, the human imiquimod challenge model was introduced as a safe and well-tolerated model to study temporarily induced skin inflammation by targeting the TLR7/8 receptor. The effect on erythema, cutaneous perfusion and biomarker expression was more pronounced in the group with the perturbed skin barrier due tape stripping. Nowadays, this imiquimod model can be applied to test agents that target TLR7/8 receptor with anti-tumor characteristics.
\nFurthermore, two models for pruritus were described focusing on two different mechanisms. The first model used histamine as pruritogen to evoke itch via a subset of C-fibers. An upregulation of HDC is associated with an increase in histamine release and is found in the lesions of patients suffering from atopic dermatitis. Anti-histamines are often prescribed against itch in patients with atopic dermatitis even though they are ineffective. Therefore, an alternative model was developed targeting the PAR-2 pathway. In this model, itch was initiated by applying Cowhage spicules to the forearm of healthy volunteers and patients with atopic dermatitis. The itch sensation was based on VAS score and EASI (in patients with atopic dermatitis), both giving qualitative measures.
\nAnother model that has been described in this chapter is the UV-B radiation model, which is used to induce pain stimulus in healthy volunteers. A couple of studies elucidates the occurrence of skin inflammation after UV-B radiation. However, no research has been done that focuses on skin inflammation in humans after using UV-B radiation.
\nThe last model of this chapter triggering neo-antigen, is the KLH challenge model in healthy volunteers. KLH caused a delayed type IV immune response. An increase in cutaneous blood perfusion, erythema and swelling was observed after administration of KLH. This model could be used for proof-of-concept studies.
\nIn general, all the challenge models that have been developed could be optimized by assessing pharmacodynamic endpoints focusing on the four pillars imaging, biophysical, clinical and cellular/molecular that together constitute a so-called ‘dermatological toolbox’. For imaging, various tools can be used such as multispectral imaging, 2D/3D imaging, colorimetry and optical coherence tomography. Laser speckle contrast imaging, trans-epidermal water loss, thermography, transdermal analysis patch and microbiome analyses are able to provide objective information on biophysical condition of the skin. For completeness of the derma toolbox it is recommended to include the NRS pain/itch or VAS as well as the skin histology, immunohistochemistry and mRNA expression. This toolbox will allow us to develop and monitor advanced human skin challenge models that will provide a more holistic view and to move a step closer towards ‘systems dermatology’.
\nNo conflicts of interest.
\nAll fusion welds involve the melting and subsequent solidification of the base metal. The geometry of the weld bead is a good indicator of the melting and solidifying process. Generally, weld inspection starts by evaluating this weld bead geometry and is followed by further inspection of the mechanical properties and metallurgical structures [1]. Many resources and time are employed in the final inspection of the weld bead, which is conducted when the part is finished. At that time, the problem usually has no solution or the solution is very expensive. This is one of the reasons why the control of the weld pool geometry is imperative to improve the quality in the weld and to reduce the cost of welded components.
Research and development in this area have increased in the last five decades, starting from simple control methods and analogical devices, as shown in [2], to complex algorithms and digital devices and computers, as shown in [3, 4]. But, in the literature analyses made in [5], it is possible to observe that most of the cases (90%) of the developments work in horizontal position and only 10% work in orbital welding, despite the importance of orbital welding for the industry. It is important to note that this type of welding imposes strong challenges in the use of sensors due to orbital movement (which can be quite irregular) around the piece. The main challenges are in the size and portability of the sensor, flexibility in the communication lines, continuous changes in position and lighting conditions (for optical sensors), and the effects of the force of gravity. These statistical data are shown in Figure 1a.
Statistical information of publications about control systems of the weld bead geometry: (a) welding positions; (b) model types; (c) control type.
In addition, most cases apply static models, do not control all parameters of the bead geometry, and do not apply multivariable techniques, as shown in Figure 1b and c. The dynamic models can be a better representation of the process, producing better prediction results. The research where these models were used represents only 13% of the total, as analyzed in [5]. The black box model approach is widely used. Because of the complex characteristics of the process, a physic model approach is very difficult and needs extensive research and resources.
In this chapter the principal control loops and techniques used for online control of the weld bead geometry are discussed. The more usual variables, control, and techniques to modeling, used in welding power sources and welding robotic systems, are critically discussed. Some examples of singled and multivariable control loops are shown. A decoupling technique for multivariable loops is also explained. The dead time and disturbances that can affect the processes and some techniques to determine them are also explained. A special topic about the embedded systems in the welding process was included.
This chapter aims to create a knowledge base necessary to understand the main control systems in welding processes before addressing more complex control techniques. Its main contributions are the exhaustive literature review that is critically discussed and the solutions provided for the control of each part of the process, especially the control of the weld bead geometry for electric arc welding processes.
A typical automatic closed-loop control is composed of a controller or control system, an actuator system, and a measurement system or sensor, as shown in Figure 2a. The controller calculates the control law based on the control error, which is the difference between the set point value and the measurement of the controlled variable. The actuator modifies the process state, based on controller output (manipulate variable), to bring the controlled variable to the desired value. In sequence, to close the loop, the measurement system obtains the value of the controlled variable and sends it to the controller. An open-loop control does not have a measurement system, or the controller does not use its feedback as shown in Figure 2b.
Representation of a typical automatic control system: (a) closed-loop control; (b) open-loop control.
The selection of variables to the control loop is a very important task. For this, it is necessary to analyze and quantify the influence of all process variables on the variable to be controlled. A statistical tool to quantify these relationships is the cross-correlation, using experimental data series of these variables and the variable to be controlled. Other factors must also be considered, such as the actual possibility of modifying each of these variables and how these modifications affect other control loops. These correlations are mentioned in the literature, but often they are not totality quantified, indicating that there is still a wide-open field of research in modeling these processes.
The dead time (transportation lag or time delay) is another important parameter that can be obtained from cross-correlation analysis too [6]. The sampling time for digital control systems must be selected based on the process dynamic, and autocorrelation techniques can be useful.
An important input to be considered on the control loop is the disturbance. This signal (or signals) can affect the process response and must be compensated by the controller. The open-loop controller cannot compensate for the disturbance action because it does not have a feedback signal. An example of disturbance is small variations in the height of the base metal surface product of heat. These variations change the contact tip to work distance and consequently the arc conditions. If the disturbance is measurable, some techniques can be used to improve the response of the controller, as shown in [6].
The model or process can be obtained using white or black box techniques. The first modeling technique required great knowledge of the process and its manufacture parameters to be able to create the equations that satisfactorily describe the process, actuator, and sensor. It is important to keep in mind that these parameters may change during the life of the equipment. Then if you use the parameters defined by the manufacturer, you can make the model inaccurate or useless. Because of this aspect and because of the development of powerful methods and tools for modeling, the black box techniques are more used.
To create a black box model of process for simulation, estimation, prediction, or control purposes, it is necessary that an actuator system and a measurement system modify the state of the process and see its response. With the process input and output values, it is possible to obtain statics or dynamic models of the process, but the actuator and sensor are included in the process model, as shown in Figure 2a. This becomes more evident in dynamic models when the dynamic response of the actuator and sensor affects the dynamic of the set. In static models, the use of a different sensor (or actuator), but with the same static gain, does not affect the model.
Other types of control algorithms are the logic control; those are classified as combinational and sequential. The response of the combinational logic algorithm depends on the inputs on current sampling time only, for example, the torch travel limit was reached, the robot must stop, and the arc must close. On sequential control the response depends on the previous sampling time inputs also, for example, in seam tracking control, it is important to know the last positions reached by the torch to calculate the next position.
In welding processes it is possible to find several control loops with different complexities and purposes. Each control loop has a set point or desired value of the controlled variable (supply by the operator or by a higher-level controller), a controlled variable (obtained from measurement system), a manipulated variable (supplied to the actuator by the control system), and disturbances. For example, on GMAW conventional welding power sources with the constant voltage, you can find an arc controller loop that tries to keep the voltage, the wire feed speed controller, and the gas flow controller (commonly included in the sequential logic controller) constant. The more complex processes have other control loops and sequential controllers to generate the arc signal form.
In welding robotic systems, you can find several control loops too but related with the torch or piece position and torch or piece travel. The combination of several controllers makes possible the control of the geometry of the weld bead, for example, a loop that changes the set point of voltage input in the welding power source to control the weld bead width based on profile sensor or video camera. Another example is a control loop that changes the wire feed speed in the welding power source and the welding speed in the welding robot to control the weld bead penetration.
These several controllers and actuators, which modify the same process at the same time to reach the manufacture objectives, will also cause interactions between the loops and its strongly coupled variables. A change in a control loop may affect other loops as disturbance and turns the process unstable. In these cases, a multivariable control loop must be considered. In the next sections, examples of control loops used in arc welding processes are shown.
If the torch trajectory is known, two open-loop controls can be used to govern the torch movement in two axes of the flat welding robotic system that uses stepper motors as actuator elements. In this system, the
Blocks diagram of the welding speed and seam tracking control loops.
The welding speed controller reads a lookup table with the speed set points (
On the other hand, the seam tracking controller receives the
To reduce the amount of data in the lookup tables, it is possible to save only the significant changes of welding speed and trajectory and hold the last value in the output until the new value is found.
To obtain the correct torch trajectory, the weld joint can be scanned before the welding process starts and the center joint can be calculated in all the points of the torch trajectory. With this data, it is possible to define the correct trajectory for the torch and move the seam tracking stepper motor accordingly.
The seam tracking loop can be transformed on closed-loop, but it is necessary for a profile sensor (e.g., a laser profilometer) to obtain online the joint profile and to make the trajectory analysis. The same control strategy can be used to substitute the lookup table by the algorithm that analyzes the profilometer data. This control strategy is better if the pieces are expected to move or deform during welding, but more calculation resources are needed.
The contact tip to work distance (
Blocks diagram of the contact tip to work distance control loop.
Due to the advanced position of the sensor, the CTWD measurement is in advanced time (
The principal variables that affect the bead geometry in the conventional arc welding process are the welding voltage, the welding current, the wire feed speed, the contact tip to work distance, and the welding speed. The most common relation found in the scientific literature shows that increasing the electric current by increasing the wire feed speed, for the same welding speed, results in a greater weld bead depth and welding pools with greater volume and production. An increase in electric current, accompanied by a proportional increase of the welding speed (wire feed speed/welding speed = constant), also results in greater penetration, but the welding pool keeps the same volume. Then, the same welding joint volume can be filled (maintaining production) and ensure its integrity by full penetration (good quality) at the same time [7].
On the other hand, laser welding has an additional set of parameters, such as the laser power and optical adjustments of the laser beam, but it is restricted by the availability of the equipment and difficult to make online adjustment in welding parameters. Shortly, the controllable parameters will become diversified, but right now the focus adjustment can be made by changing the position of focus lens inside the laser head. A review of these topics is shown in [8].
It is important to note that the relations between variables are more complex and multivariable techniques are necessary to describe them. With the multivariable techniques, it is possible to consider the interactions between variables in the process and reduce their effect in the control loop, but the implementation is difficult because of the complexity of the modeling and the control algorithm adjustment. In the literature analysis made in [5], only 9% of the papers use multivariable control loops.
A generic diagram of a multivariable control loop of the weld bead geometry for the GMAW process is shown in Figure 5. It used the main variables that affect the process, to control the bead geometry, but it should be noted that due to the interdependence between them, setting the controller parameters and the use of uncoupling become difficult.
Main variables used in the weld bead geometry control in GMAW process.
The GMAW conventional process can be represented as a multiple-input multiple-output (MIMO) process with three inputs and two outputs, as shown in Figure 6. The pairing of controlled and manipulated variables is shown too, and the other variables are considered as disturbances or controlled by other control loops. This selection is based on the bibliographic review and requires the analysis of the relative gains defined in [9].
Arc welding process represented as a multiple-input multiple-output system, with the depth and width of the weld bead controlled by PID algorithms.
It is important to note that the orbital welding adds more complexity to control, due to the effect of gravity on the transfer of material, the weld pool, and the weld bead formation, in addition to other requirements. So, it is important to consider the orbital angle as a measurable disturbance.
Control strategies proposed in [5] are based on a PID controller improved with a decoupling method, a Smith predictor, and a fuzzy self-adaptive algorithm. In the PID control strategy, shown in Figure 6, the welding voltage (
The weld bead depth value (
While many control algorithms have been proposed, in which approaches are theoretically elegant, most of the industrial processes nowadays are still controlled by proportional-integral-derivative controllers [10, 11, 12]. Conventional PID controllers have been widely applied in industrial process control for about half a century because of their simple structure and convenience of implementation [13]. However, a conventional PID controller can have poor control performance for nonlinear and complex systems for which there are no precise mathematical models. Numerous variants of conventional PID controller, such as self-tuning, auto-tuning, and adaptive PID controllers, have been developed to overcome these difficulties. Several online self-tuning or adaptive algorithms are based on fuzzy inference systems that were developed in [11, 12, 14, 15, 16, 17, 18, 19].
The weld bead width measure dead time problem can be solved using a modified Smith predictor as shown in [5]. In the same work, the nonlinear is solved using a fuzzy self-adaptive algorithm for PID tuning. But the control strategy still has a problem, the interdependence between the process variables.
To improve the controller behavior, the decoupling structures can be incorporated for reducing the interaction between the loops. In this case, the decoupling used is based on feedforward control. These decoupling techniques are useful when the process is affected by strong measurable disturbances. This strategy can help improve the behavior of the controller in the face of this disturbance, but it cannot replace the feedback control [20]. The typical feedforward control is shown in Figure 7.
Typical feedforward control in a single control loop. Adapted from [5].
The feedforward control tries to anticipate the effect of the disturbance (d). The control action is applied directly to the control loop drive element, before the disturbance can affect the controlled variable [6, 20]. Eqs. (1) and (2) usually define the necessary conditions to it, while the feedforward model is obtained in Eq. (3).
If
where the terms
then the feedforward transfer function is
where
Sometimes only the steady value is compensated, and the dynamic is depreciated in which case the transfer function of the feedforward block is
If the interactions between loops are considered as disturbances, the same feedforward scheme can be used to decoupling the weld bead width and penetration control loop in our welding process. Figure 8 shows the block diagram with decouples.
Weld bead width and depth penetration controller with decouples.
Decouples
The design and synthesis of PID controllers and fuzzy algorithms in FPGA or microcontroller devices are possible, and the resource consumption is very low, as is shown in [23]. But many other scientific researchers are being developed and tested to solve and improve the control of the welding process. In the next section, some of them will be described.
The welding process is characterized as multivariable, nonlinear, and time-varying, with stochastic behavior and having a strong coupling among welding parameters. For this reason, it is very difficult to find a reliable mathematical model to design an effective control scheme by conventional modeling and control methods.
Due to these characteristics, the use of adaptive techniques has spread in the last decades with favorable results, only overcome by a proportional-integral-derivative controller. The adaptive control has been implemented in some researchers to cope with the problem of the high dependence of process parameters to its operating condition. The main drawback of this method is that it requires online estimation or tuning of the parameters, which is usually a time-consuming operation. The single implementation of PID and low computational resources make it still the most used, as in the rest of industrial applications. A graphic summary is shown in Figure 9, and Table 1 shows the document references analyzed.
Graphic summary about the main methods or techniques used for control of the weld bead geometry, including the quantity of references and the percentage they represent in the total papers consulted.
Control technique or control model | References |
---|---|
On/off, classic PID, or PID combined with other method | [2, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37] |
Adaptive | [26, 29, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50] |
Neural network and fuzzy logic or neuro-fuzzy | [3, 4, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60] |
Neural network | [27, 61, 62, 63] |
Fuzzy logic | [39, 64, 65] |
Autoregressive moving average (ARMA or similar) | [29, 66, 67] |
Expert systems | [38, 53, 40] |
State space | [1, 68] |
Model-free adaptive | [68, 69] |
First- or second-order model | [70, 71] |
Support vector machine | [64] |
Finite elements | [52] |
References classified according to the methods or techniques used for control of the weld bead geometry.
Neural networks, fuzzy methods, and their combinations also stand out. Note that the magnificent behavior of the neural network can be clouded by a slow convergence because of the excessive quantity of neurons or hidden layers. Many research efforts use this approach but neglected the need for the quick response of the control system.
Statistical methods, such as the classic autoregressive moving-average and expert systems, are represented too. Other less used techniques include state space, model-free adaptive, first- and second-order model, support vector machine, and finite elements.
Developments in the field of automatic control of the geometry in the arc welding process have been intense in the last four decades. The most representative research efforts found in the literature are in this area in the last two decades. In this section, some relevant works are discussed in chronological order.
In 1986, Nied and Baheti [46] registered a patent in which a robotic welding system has an integrated vision sensor to obtain images and analyze the welding scene in real-time. It used an adaptive feedback control to assure the full penetration, the weld puddle area, and the maximum width in the TIG process. The adaptive control system determines a puddle geometry error and uses the nominal welding current to change the heat input to the weld pool, regulating the combination of puddle area and width. Arc voltage is modulated to reflect changes in welding current and maintain a constant arc length.
In 1989 Edmund R. Bangs and others [38] registered a patent that described a system for real-time welding adaptive control using infrared images, artificial intelligence (expert system), and distributed processors.
Already in 1990, Andersen designed a control system for the GMAW process [24]. As shown in Figure 10, a neural network set point selector defines the start parameters of welding speed (
Control loop proposed for Andersen [24] when the initial set point conditions are defined by neural network and the penetration are estimated. Adapted from [73].
Zhang et al. [74] developed an adaptive control of full penetration for GTAW processes, based on the generalized predictive control (GPC) algorithm presented by Clarke [75, 76, 77]. The controlled variables are the width and reinforcement of the weld bead, measured by a vision system and a laser stripe. The control or manipulated variables are the welding current and arc length. The sampling interval of the control system was 0.5 s. The process has been described by a moving-average model with a predictive decoupling algorithm. The system is not controlling the penetration directly but has a satisfactory performance in the weld quality control.
Brown et al. [26] developed a control loop with a PID controller and an adaptive dead-time compensator for GMAW processes in a horizontal welding position. The controlled variable is the weld pool width and the welding speed is manipulated. The simulation results show an acceptable response.
A dynamic model, based on neural network, was designed in [53] to predict the maximum backside width in pulsed GTAW processes. Also, a self-learning fuzzy neural network controller was developed for controlling the maximum backside width, and the fuzzy rules were modified online. Another intelligent multivariable controller, type double-input and double-output (DIDO), based on a neuro-fuzzy algorithm and combined with an expert system, was developed to control the maximum backside width and the shape of the weld pool. Experimental results showed the best behavior using the DIDO intelligent controller.
In [55], a neuro-fuzzy controller was designed for the GTAW process. This method overcomes the dependency of human experts for the generation of fuzzy rules and the non-adaptive fuzzy set. The adaptation of membership function and the fuzzy rule self-organization are carried out by the self-learning and competitiveness of the neural network with three hidden layers. The simulation test got promising behavior.
Chin [28] developed a system for infrared image sense and PID control of the SAW process. Several tests were executed with diverse conditions in the control variables. Similarly, an infrared point sensor (pyrometer) is used in [36] to estimate the weld bead depth in GTAW and SAW processes. The penetration is controlled indirectly (using the infrared emission) by a PI regulator, which changes the welding current in the GTAW process and the welding voltage and welding speed in the SAW process. A satisfactory result is obtained under laboratory conditions.
Moon and Beattie [45] developed an adaptive fill control for multi-torch multi-pass SAW processes. The system measures the joint geometry with laser seam tracking and calculates the total area of the joint, computing by numerical integration based on the actual joint profile. With the area ratio of the joint, the welding current/voltage combination is obtained, and the welding speed is adjusted inversely in proportion to the area to be filled. The control significantly improves weld bead quality. This technology has been used in the manufacture of longitudinal and spiral pipes and pressure vessels.
In [66], two simultaneous but independent control loops are used. The first loop monitors the temperature with an infrared camera and controls the trajectory of the torch. The second loop monitors the geometric profile with the laser stripe and manipulates the welding speed and the wire feed speed. A variable delay Smith predictor is used for reducing the dead-time effect of laser strip sensor, as shown in Figure 11. The author tested a SISO closed loop with a PI controller and a MIMO GOSA. The last one obtains the best result.
SISO (a) and DIDO (b) control loops that employ infrared information. Adapted from [66].
An H-infinity robust control system in [1] is proposed to control the length and width of the weld pool, manipulating welding current and weld speed. The simulation shows an effective robust method to control processes with large uncertainties in the dynamics. However, the complexity of the H-infinity control algorithm can make the implementation of embedded devices difficult. Also, it needs an effective description of the uncertainties of the welding process dynamics, and it is difficult under conditions of the real processes.
A weld pool imaging system, with a LaserStrobe high shutter speed camera, is used in [58] to obtain contrasting images and eliminate the arc interference. Image processing algorithms, based on edge detection and connectivity analysis, extract information about the weld pool length and width online. A neuro-fuzzy controller, based on human experience and experimental results, manipulate the welding voltage and speed in real-time based on weld pool dimensions. A welding speed closed-loop control is used to reach the set point of the weld pool geometry. The simulation results are satisfactory, but the response may be slow due to the time required for image processing and fuzzy calculation.
In [31], the difficulty to tune the PI controller parameters to achieve the desired performance, across the entire range of the process operation, is shown. Therefore, the design and implementation of more complex controllers are required to obtain better control of the welding process.
A method developed by Casalino in [52] defines an automated methodology for selecting the weld process parameters based on artificial intelligence. While there are many methods available to improve the reliability of traditional open-loop control schemes, these can only be used with a particular welding power source and a specific welding arrangement.
Lu et al. [43] developed a non-transferred plasma charge sensor-based vision system to measure the depth of the weld pool surface in orbital GTAW processes. The sensor measures the welding voltage when the welding current is off and calculates the arc distance by an inversely linear relation. An insulated gate bipolar transistor (IGBT) power module is utilized to temporarily switch off the main power supply. During this period, the large arc pressure associated with the main arc is not present, the depth of the weld pool surface decreases, and the sensor output increases, obtaining the arc measurement. An adaptive interval algorithm controls the depth of the weld pool surface, regulating the main-arc-on period. Four experiments were executed under different conditions and show a satisfactory response.
Smith et al. [34] use two independent PIs to control a pulsed TIG process in a horizontal position. Both controllers use the control error of the top face weld pool width as input. The independent outputs are the welding current and the wire feed speed. The active adjustment of the welding current and the wire feed speed allows compensating variations on the weld pool size. A camera and image processing algorithm measures the top face weld pool width. The controllers and image processing algorithms run concurrently on a PC. The controllers use CAN serial communication protocol to adjust the outputs in two distributed actuator nodes, based on a microcontroller system. A step-change in plate thickness was used to test the controller system. The experimental results produced welds with a more consistent profile when faced with variations in process conditions.
In [63], a three-dimensional vision system is used for obtaining the geometrical parameters of the weld joint. A closed-loop neuronal-network controller is developed to control the width and depth of the weld joint, by regulating the welding voltage, welding speed, and wire feed speed. The neuronal model has two hidden layers with six and four neurons, respectively, as shown in Figure 12. The experimental results, using the neural network learning data and the error range of width and depth, are within 3%.
Neural network to determine welding parameters. Adapted from [63].
Fuzzy and PID controllers are employed in [65] to control the geometry stability in a GTAW process, by regulating the welding current (
Block diagram of the geometry stability controller for GTAW process, developed in [65].
In [78] two SISO subsystems are developed to control a double-electrode GMAW process. The control structure is selected for convenient implementation and design. One system controls the welding current of the main torch by manipulating the wire feed speed. The other system controls the welding voltage of the bypass torch by manipulating the welding current. Two interval models have been obtained, based on experimental data from step-response experiments under different manufacturing conditions. These simple controllers show an acceptable behavior to control this relatively complex process.
Chen solved the full penetration detection, in orbital the GTAW process, with a vision system over the topside pool and a neural network model for estimating the backside weld bead width in [39]. The neural network has 17 neurons in the input layer, 40 in the hidden layer, and 1 in the output. An adaptive controller receives the backside weld bead width, estimated by the neural network, and regulates the peak current. A fuzzy controller received the gap state and controlled the wire feed speed. The experimental results, examined in X-ray, have shown a uniform backside of the weld bead.
An adaptive inverse control based on support vector machine-based fuzzy rules acquisition system is proposed by [64] for pulsed GTAW process. This method extracts the control rules automatically from the process data, using an adaptive learning algorithm and a support vector machine to adjust the fuzzy rules. The controlled variable is the backside weld width, and the manipulated variable is the peak current of the pulse. A double-side visual sensor system captures the topside and backside images of the weld pool simultaneously. The data for model identifying is obtained experimentally. The control is simulated and shows satisfactory results.
Lü et al. [69] developed a MISO algorithm for the control of the width of the weld pool backside in the GTAW process. The vision sensing technology and model-free adaptive control (MFC) are used. The welding current and wire feed speed are selected as the manipulated variables, and the backside width of the weld pool is the controlled variable. The main difficulty was the availability of computational resources to maintain the control period and the image processing speed within acceptable values. It has the disadvantage of using complex optical systems for obtaining the image of the back- and the front side of the weld pool.
In [68] a space state model of the GMAW process is obtained to compare the behavior of three controllers: ARMarkov-PFC (based MPC controller), PI, and feedback linearization based on the PID (FL-PID). The controller outputs are the wire feed motor voltage and the welding voltage. The controlled variables are the welding current and voltage. The simulation results show that the ARMarkov-PFC outperformed other controllers from the viewpoints of the transient response, desired output tracking, and robustness against the process parameter uncertainties but require more computational resources. The FL-PID controller was sensitive to the process parameter variations, presence of noise and disturbance, and results in an improper performance. The PI controller produced an inappropriate transient response and inadequate interaction reduction despite good tracking performance, low sensitivity to parameter variations, and low computational resource requirements.
The main advantages of MPC over structured PID controllers are its ability to handle constraints, non-minimum phase processes, changes in system parameters (robust control), and its straightforward applicability to large, multivariable, or multiple-input multiple-output processes. Despite having many advantages, a noticeable drawback of an MPC is that it requires higher computation capability, as is shown in [79].
The change in arc voltage during the peak current is used in [49] to estimate the weld penetration depth in the pulsed GMAW process. An adaptive interval model control system is implemented, but, contrary to the author’s comment, the control accuracy is not good.
Lui et al. [60] developed a model-based predictive control for the orbital GTAW process. The control input is the backside weld bead width, and the outputs are the welding current and welding speed. A nonlinear neuro-fuzzy (ANFIS) model is utilized to estimate the backside weld bead width (related with weld depth penetration) using the front-side weld pool characteristic. Figure 14 shows a block diagram of this approach.
Model-based predictive control to orbital GTAW process. Adapted from [60].
In [67] the GMAW LAM process is modeled using the recursive least squares algorithm for system identification. An image processing algorithm is employed for obtaining the nozzle to top surface distance. An adaptive controller adjusts the deposition rate and keeps the nozzle to top surface distance constant. The precision range of the control system is limited within ±0.5 mm.
A segmented self-adaptive PID controller was developed in [30] for controlling the arc length and monitoring the arc sound signal in the pulsed GTAW process for the flat and arched plate. The experiments show that the controller has acceptable accuracy.
Lui and Zhang [4] developed a machine-human cooperative control scheme to perform welder teleoperation experiments in the orbital GTAW process. They developed an ANFIS model of the human welder’s adjustment on the welding speed. The welder sees the weld pool image overlaid with an assistant visual signal and moves the virtual welding torch accordingly. The robot follows the welder’s movement and completes the welding task. The experimental data is used to obtain the model. Later, they transfer this model to the welding robot controller to perform automated welding. The controller receives the three-dimensional weld pool characteristic parameters (weld pool length, width, and convexity) and changes the welding speed.
In other similar work [3], a human intelligence model based on a neuro-fuzzy algorithm is proposed to implement an intelligent controller to maintain a full penetration manipulating the welding current. These works establish a method to rapidly transform human welder intelligence into welding robots by using three-dimensional weld pool surface sense, fitting the human welder response to the information through a neuro-fuzzy model, and using the neuro-fuzzy model as a replacement for human intelligence in automatic systems. In previous works [56, 57], the skilled human welder response to the fluctuating three-dimensional weld pool surface is correlated and compared with a novice welder.
Embedded systems, especially the FPGA and system on chip (SoC), are used in a multitude of technological processes in various industries, covering hazardous areas such as medical, aerospace, and military or even the most common household appliances. With the increase in processing capabilities of these systems, based on microcontrollers and new processor generation, it is possible to obtain remarkably improved measurement and control systems with the use of advanced algorithms for processing information provided by the sensors. The parallel processing capabilities of the FPGA (into the SoC) allow lower execution times than in processors or microcontrollers. These capabilities are important to estimators based on neural networks (parallel execution) and to control systems in real-time that need to attend several sensors and actuators.
The FPGA has numerous digital inputs and outputs, with the possibility of adding several analogs and other peripherals. Many of them have a hard processor, with one or more cores and various peripherals for communication, video, sound, and large random access memory (RAM) capacity, where you can run a standard operating system interconnected with the FPGA. These features and the small size, low power consumption, low heat dissipation, and reconfigurable architecture make it an ideal tool for monitoring and control systems with real-time requirements. For all these good reasons, we must pay special attention to these devices.
The modern welding power sources are controlled by embedded systems. These systems provide communication, data acquisition, and control functions for different welding processes, but their most important specialization is the control of the electric arc, laser signal, and other methods to transfer the energy to the base material. This specialization permitted the substitution of big transformer and switches to select the welding parameters such as the voltage, current, and inductance, by a smaller transformer and high-frequency switching semiconductors governed by a microcontroller. With these changes it was possible to generate various types of waveforms on the output of the welding power source, improving the conventional processes and creating new processes and new control algorithms.
In these systems, the embedded controller emulates the impedance of the old transformer and keeps the set points of welding voltage and current with more accuracy. The configuration of welding parameters, data acquisition, and set point changes can be made using a communication protocol, defined by the manufacturer. The integration with a supervisory or higher control system is possible using this communication protocol.
The literature review does not show an extensive application of FPGA to bead geometry control in the arc welding process. But other works have shown applications related with wire feed control [80], defect detection [81, 82, 83], and arc signal monitoring [84, 85]. A graphical summary is shown in Figure 15.
Graphical summary of the applications of embedded devices in welding processes found in the literature review.
Based on the literature review and the experimental experience about the control of the welding bead geometry, it is possible to observe the great complexity of the welding process and the many efforts to control it. The proposed solutions range from simple open-loop controllers to complex intelligent control algorithms, highlighting the legendary PID combined with other techniques, adaptive methods, and the neural network and fuzzy algorithms.
Despite the arduous research efforts, few of these algorithms are being applied in the industry, in some cases due to its complexity but others due to commercial interests and its cost of implementation. For these reasons, the control of welding processes is an open topic for research and especially for the development of feasible solutions to be used in the industry.
Scientific research and the slow but continuous application of its results in the welding industry show a tendency for modeling and control of these processes to be carried out using methods of artificial intelligence. These methods, in addition to including classic artificial intelligence techniques, are incorporating bioinspired algorithms, deep learning techniques, big data and data mining for the analysis of the measurements, the adjustment of the controllers, and even the implementation of the controller itself.
Undoubtedly, the current development of embedded systems and the small and smart sensors is allowing the implementation of many algorithms proposed decades ago and new algorithms that make extensive use of the calculation capabilities of these systems. The use of multivariable control and dynamic models of the process will be possible and will allow a notable improvement in the quality of the welds and the number of parts rejected in the production process.
But the advantages of these technologies will not be accepted and exploited efficiently without adequate training of the technical staff that directs and operates the industries. Many of these modeling and control techniques are still unknown or their advantages are poorly disclosed. This is a problem when it is compared in terms of ease of use and productivity against classical techniques with decades of use in the industry. In this sense, we try to contribute to the dissemination of this knowledge throughout this chapter.
Customer Satisfaction is of paramount importance at IntechOpen and we take all complaints very seriously. Our Authors, their institutions, and other purchasers, if dissatisfied with the service provided, or the product purchased, can file a written complaint to IntechOpen, 5 Princes Gate Court, London, SW7 2QJ, UK or via the following e-mail address: info@intechopen.com.
',metaTitle:"Customer Complaints",metaDescription:"Our authors, their institutions and other purchasers, if unsatisfied with the service provided or the product purchased, can file a written complaint at IN TECH d.o.o offices at Janeza Trdine 9, 51000 Rijeka, Croatia, or via the following e-mail address: info@intechopen.com.",metaKeywords:null,canonicalURL:null,contentRaw:'[{"type":"htmlEditorComponent","content":"Receipt of complaints will be acknowledged in writing and Intech Limited will respond fully to concerns within 15 business days.
\\n\\nCustomers have the right to terminate the contract without giving any reason (written notice of termination). The deadline for said termination is fourteen (14) days from the date of receipt of goods. Returns are at the expense of the Customer and must be made within the fourteen (14) days from the date of the written notice of termination. Intech Limited will process refunds to the Customer without undue delay.
\\n\\nIn the event that the Publisher ships damaged or misbound copies of products, or duplicate or incorrect copies of the products are received by the Customer, the Publisher will accept returns at the Publisher's expense, provided notice of such damaged or incorrect shipment is given to the Publisher within fourteen (14) working days from the date of receipt.
\\n\\nPublishing errors, including but not limited to typographical errors, having no significant effect on the editorial content or design characteristics of the products, cannot be considered a reason for rejecting payment or, as the case may be, modifying the agreed price.
\\n\\nAt the Publisher's request, the customer should provide evidence of the damaged or incorrect shipment. The Publisher will refund or ship the ordered products without delays.
\\n"}]'},components:[{type:"htmlEditorComponent",content:"Receipt of complaints will be acknowledged in writing and Intech Limited will respond fully to concerns within 15 business days.
\n\nCustomers have the right to terminate the contract without giving any reason (written notice of termination). The deadline for said termination is fourteen (14) days from the date of receipt of goods. Returns are at the expense of the Customer and must be made within the fourteen (14) days from the date of the written notice of termination. Intech Limited will process refunds to the Customer without undue delay.
\n\nIn the event that the Publisher ships damaged or misbound copies of products, or duplicate or incorrect copies of the products are received by the Customer, the Publisher will accept returns at the Publisher's expense, provided notice of such damaged or incorrect shipment is given to the Publisher within fourteen (14) working days from the date of receipt.
\n\nPublishing errors, including but not limited to typographical errors, having no significant effect on the editorial content or design characteristics of the products, cannot be considered a reason for rejecting payment or, as the case may be, modifying the agreed price.
\n\nAt the Publisher's request, the customer should provide evidence of the damaged or incorrect shipment. The Publisher will refund or ship the ordered products without delays.
\n"}]},successStories:{items:[]},authorsAndEditors:{filterParams:{sort:"featured,name"},profiles:[{id:"6700",title:"Dr.",name:"Abbass A.",middleName:null,surname:"Hashim",slug:"abbass-a.-hashim",fullName:"Abbass A. Hashim",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/6700/images/1864_n.jpg",biography:"Currently I am carrying out research in several areas of interest, mainly covering work on chemical and bio-sensors, semiconductor thin film device fabrication and characterisation.\nAt the moment I have very strong interest in radiation environmental pollution and bacteriology treatment. The teams of researchers are working very hard to bring novel results in this field. I am also a member of the team in charge for the supervision of Ph.D. students in the fields of development of silicon based planar waveguide sensor devices, study of inelastic electron tunnelling in planar tunnelling nanostructures for sensing applications and development of organotellurium(IV) compounds for semiconductor applications. I am a specialist in data analysis techniques and nanosurface structure. I have served as the editor for many books, been a member of the editorial board in science journals, have published many papers and hold many patents.",institutionString:null,institution:{name:"Sheffield Hallam University",country:{name:"United Kingdom"}}},{id:"54525",title:"Prof.",name:"Abdul Latif",middleName:null,surname:"Ahmad",slug:"abdul-latif-ahmad",fullName:"Abdul Latif Ahmad",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"20567",title:"Prof.",name:"Ado",middleName:null,surname:"Jorio",slug:"ado-jorio",fullName:"Ado Jorio",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Universidade Federal de Minas Gerais",country:{name:"Brazil"}}},{id:"47940",title:"Dr.",name:"Alberto",middleName:null,surname:"Mantovani",slug:"alberto-mantovani",fullName:"Alberto Mantovani",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"12392",title:"Mr.",name:"Alex",middleName:null,surname:"Lazinica",slug:"alex-lazinica",fullName:"Alex Lazinica",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/12392/images/7282_n.png",biography:"Alex Lazinica is the founder and CEO of IntechOpen. After obtaining a Master's degree in Mechanical Engineering, he continued his PhD studies in Robotics at the Vienna University of Technology. Here he worked as a robotic researcher with the university's Intelligent Manufacturing Systems Group as well as a guest researcher at various European universities, including the Swiss Federal Institute of Technology Lausanne (EPFL). During this time he published more than 20 scientific papers, gave presentations, served as a reviewer for major robotic journals and conferences and most importantly he co-founded and built the International Journal of Advanced Robotic Systems- world's first Open Access journal in the field of robotics. Starting this journal was a pivotal point in his career, since it was a pathway to founding IntechOpen - Open Access publisher focused on addressing academic researchers needs. Alex is a personification of IntechOpen key values being trusted, open and entrepreneurial. Today his focus is on defining the growth and development strategy for the company.",institutionString:null,institution:{name:"TU Wien",country:{name:"Austria"}}},{id:"19816",title:"Prof.",name:"Alexander",middleName:null,surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/19816/images/1607_n.jpg",biography:"Alexander I. Kokorin: born: 1947, Moscow; DSc., PhD; Principal Research Fellow (Research Professor) of Department of Kinetics and Catalysis, N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow.\r\nArea of research interests: physical chemistry of complex-organized molecular and nanosized systems, including polymer-metal complexes; the surface of doped oxide semiconductors. He is an expert in structural, absorptive, catalytic and photocatalytic properties, in structural organization and dynamic features of ionic liquids, in magnetic interactions between paramagnetic centers. The author or co-author of 3 books, over 200 articles and reviews in scientific journals and books. He is an actual member of the International EPR/ESR Society, European Society on Quantum Solar Energy Conversion, Moscow House of Scientists, of the Board of Moscow Physical Society.",institutionString:null,institution:{name:"Semenov Institute of Chemical Physics",country:{name:"Russia"}}},{id:"62389",title:"PhD.",name:"Ali Demir",middleName:null,surname:"Sezer",slug:"ali-demir-sezer",fullName:"Ali Demir Sezer",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/62389/images/3413_n.jpg",biography:"Dr. Ali Demir Sezer has a Ph.D. from Pharmaceutical Biotechnology at the Faculty of Pharmacy, University of Marmara (Turkey). He is the member of many Pharmaceutical Associations and acts as a reviewer of scientific journals and European projects under different research areas such as: drug delivery systems, nanotechnology and pharmaceutical biotechnology. Dr. Sezer is the author of many scientific publications in peer-reviewed journals and poster communications. Focus of his research activity is drug delivery, physico-chemical characterization and biological evaluation of biopolymers micro and nanoparticles as modified drug delivery system, and colloidal drug carriers (liposomes, nanoparticles etc.).",institutionString:null,institution:{name:"Marmara University",country:{name:"Turkey"}}},{id:"61051",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"100762",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"St David's Medical Center",country:{name:"United States of America"}}},{id:"107416",title:"Dr.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Texas Cardiac Arrhythmia",country:{name:"United States of America"}}},{id:"64434",title:"Dr.",name:"Angkoon",middleName:null,surname:"Phinyomark",slug:"angkoon-phinyomark",fullName:"Angkoon Phinyomark",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/64434/images/2619_n.jpg",biography:"My name is Angkoon Phinyomark. I received a B.Eng. degree in Computer Engineering with First Class Honors in 2008 from Prince of Songkla University, Songkhla, Thailand, where I received a Ph.D. degree in Electrical Engineering. My research interests are primarily in the area of biomedical signal processing and classification notably EMG (electromyography signal), EOG (electrooculography signal), and EEG (electroencephalography signal), image analysis notably breast cancer analysis and optical coherence tomography, and rehabilitation engineering. I became a student member of IEEE in 2008. During October 2011-March 2012, I had worked at School of Computer Science and Electronic Engineering, University of Essex, Colchester, Essex, United Kingdom. In addition, during a B.Eng. I had been a visiting research student at Faculty of Computer Science, University of Murcia, Murcia, Spain for three months.\n\nI have published over 40 papers during 5 years in refereed journals, books, and conference proceedings in the areas of electro-physiological signals processing and classification, notably EMG and EOG signals, fractal analysis, wavelet analysis, texture analysis, feature extraction and machine learning algorithms, and assistive and rehabilitative devices. I have several computer programming language certificates, i.e. Sun Certified Programmer for the Java 2 Platform 1.4 (SCJP), Microsoft Certified Professional Developer, Web Developer (MCPD), Microsoft Certified Technology Specialist, .NET Framework 2.0 Web (MCTS). I am a Reviewer for several refereed journals and international conferences, such as IEEE Transactions on Biomedical Engineering, IEEE Transactions on Industrial Electronics, Optic Letters, Measurement Science Review, and also a member of the International Advisory Committee for 2012 IEEE Business Engineering and Industrial Applications and 2012 IEEE Symposium on Business, Engineering and Industrial Applications.",institutionString:null,institution:{name:"Joseph Fourier University",country:{name:"France"}}},{id:"55578",title:"Dr.",name:"Antonio",middleName:null,surname:"Jurado-Navas",slug:"antonio-jurado-navas",fullName:"Antonio Jurado-Navas",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/55578/images/4574_n.png",biography:"Antonio Jurado-Navas received the M.S. degree (2002) and the Ph.D. degree (2009) in Telecommunication Engineering, both from the University of Málaga (Spain). He first worked as a consultant at Vodafone-Spain. From 2004 to 2011, he was a Research Assistant with the Communications Engineering Department at the University of Málaga. In 2011, he became an Assistant Professor in the same department. From 2012 to 2015, he was with Ericsson Spain, where he was working on geo-location\ntools for third generation mobile networks. Since 2015, he is a Marie-Curie fellow at the Denmark Technical University. His current research interests include the areas of mobile communication systems and channel modeling in addition to atmospheric optical communications, adaptive optics and statistics",institutionString:null,institution:{name:"University of Malaga",country:{name:"Spain"}}}],filtersByRegion:[{group:"region",caption:"North America",value:1,count:5699},{group:"region",caption:"Middle and South America",value:2,count:5172},{group:"region",caption:"Africa",value:3,count:1689},{group:"region",caption:"Asia",value:4,count:10243},{group:"region",caption:"Australia and Oceania",value:5,count:888},{group:"region",caption:"Europe",value:6,count:15652}],offset:12,limit:12,total:117315},chapterEmbeded:{data:{}},editorApplication:{success:null,errors:{}},ofsBooks:{filterParams:{sort:"dateendthirdsteppublish"},books:[],filtersByTopic:[{group:"topic",caption:"Agricultural and Biological Sciences",value:5,count:9},{group:"topic",caption:"Biochemistry, Genetics and Molecular Biology",value:6,count:15},{group:"topic",caption:"Business, Management and Economics",value:7,count:2},{group:"topic",caption:"Chemistry",value:8,count:6},{group:"topic",caption:"Computer and Information Science",value:9,count:10},{group:"topic",caption:"Earth and Planetary Sciences",value:10,count:4},{group:"topic",caption:"Engineering",value:11,count:15},{group:"topic",caption:"Environmental Sciences",value:12,count:2},{group:"topic",caption:"Immunology and Microbiology",value:13,count:4},{group:"topic",caption:"Materials Science",value:14,count:4},{group:"topic",caption:"Mathematics",value:15,count:1},{group:"topic",caption:"Medicine",value:16,count:56},{group:"topic",caption:"Neuroscience",value:18,count:1},{group:"topic",caption:"Pharmacology, Toxicology and Pharmaceutical Science",value:19,count:5},{group:"topic",caption:"Physics",value:20,count:2},{group:"topic",caption:"Psychology",value:21,count:3},{group:"topic",caption:"Robotics",value:22,count:1},{group:"topic",caption:"Social Sciences",value:23,count:3},{group:"topic",caption:"Technology",value:24,count:1},{group:"topic",caption:"Veterinary Medicine and Science",value:25,count:2}],offset:0,limit:12,total:null},popularBooks:{featuredBooks:[{type:"book",id:"7802",title:"Modern Slavery and Human Trafficking",subtitle:null,isOpenForSubmission:!1,hash:"587a0b7fb765f31cc98de33c6c07c2e0",slug:"modern-slavery-and-human-trafficking",bookSignature:"Jane Reeves",coverURL:"https://cdn.intechopen.com/books/images_new/7802.jpg",editors:[{id:"211328",title:"Prof.",name:"Jane",middleName:null,surname:"Reeves",slug:"jane-reeves",fullName:"Jane Reeves"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8545",title:"Animal Reproduction in Veterinary Medicine",subtitle:null,isOpenForSubmission:!1,hash:"13aaddf5fdbbc78387e77a7da2388bf6",slug:"animal-reproduction-in-veterinary-medicine",bookSignature:"Faruk Aral, Rita Payan-Carreira and Miguel Quaresma",coverURL:"https://cdn.intechopen.com/books/images_new/8545.jpg",editors:[{id:"25600",title:"Prof.",name:"Faruk",middleName:null,surname:"Aral",slug:"faruk-aral",fullName:"Faruk Aral"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9961",title:"Data Mining",subtitle:"Methods, Applications and Systems",isOpenForSubmission:!1,hash:"ed79fb6364f2caf464079f94a0387146",slug:"data-mining-methods-applications-and-systems",bookSignature:"Derya Birant",coverURL:"https://cdn.intechopen.com/books/images_new/9961.jpg",editors:[{id:"15609",title:"Dr.",name:"Derya",middleName:null,surname:"Birant",slug:"derya-birant",fullName:"Derya Birant"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9157",title:"Neurodegenerative Diseases",subtitle:"Molecular Mechanisms and Current Therapeutic Approaches",isOpenForSubmission:!1,hash:"bc8be577966ef88735677d7e1e92ed28",slug:"neurodegenerative-diseases-molecular-mechanisms-and-current-therapeutic-approaches",bookSignature:"Nagehan Ersoy Tunalı",coverURL:"https://cdn.intechopen.com/books/images_new/9157.jpg",editors:[{id:"82778",title:"Ph.D.",name:"Nagehan",middleName:null,surname:"Ersoy Tunalı",slug:"nagehan-ersoy-tunali",fullName:"Nagehan Ersoy Tunalı"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8686",title:"Direct Torque Control Strategies of Electrical Machines",subtitle:null,isOpenForSubmission:!1,hash:"b6ad22b14db2b8450228545d3d4f6b1a",slug:"direct-torque-control-strategies-of-electrical-machines",bookSignature:"Fatma Ben Salem",coverURL:"https://cdn.intechopen.com/books/images_new/8686.jpg",editors:[{id:"295623",title:"Associate Prof.",name:"Fatma",middleName:null,surname:"Ben Salem",slug:"fatma-ben-salem",fullName:"Fatma Ben Salem"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7434",title:"Molecular Biotechnology",subtitle:null,isOpenForSubmission:!1,hash:"eceede809920e1ec7ecadd4691ede2ec",slug:"molecular-biotechnology",bookSignature:"Sergey Sedykh",coverURL:"https://cdn.intechopen.com/books/images_new/7434.jpg",editors:[{id:"178316",title:"Ph.D.",name:"Sergey",middleName:null,surname:"Sedykh",slug:"sergey-sedykh",fullName:"Sergey Sedykh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9839",title:"Outdoor Recreation",subtitle:"Physiological and Psychological Effects on Health",isOpenForSubmission:!1,hash:"5f5a0d64267e32567daffa5b0c6a6972",slug:"outdoor-recreation-physiological-and-psychological-effects-on-health",bookSignature:"Hilde G. Nielsen",coverURL:"https://cdn.intechopen.com/books/images_new/9839.jpg",editors:[{id:"158692",title:"Ph.D.",name:"Hilde G.",middleName:null,surname:"Nielsen",slug:"hilde-g.-nielsen",fullName:"Hilde G. Nielsen"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9208",title:"Welding",subtitle:"Modern Topics",isOpenForSubmission:!1,hash:"7d6be076ccf3a3f8bd2ca52d86d4506b",slug:"welding-modern-topics",bookSignature:"Sadek Crisóstomo Absi Alfaro, Wojciech Borek and Błażej Tomiczek",coverURL:"https://cdn.intechopen.com/books/images_new/9208.jpg",editors:[{id:"65292",title:"Prof.",name:"Sadek Crisostomo Absi",middleName:"C. Absi",surname:"Alfaro",slug:"sadek-crisostomo-absi-alfaro",fullName:"Sadek Crisostomo Absi Alfaro"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9139",title:"Topics in Primary Care Medicine",subtitle:null,isOpenForSubmission:!1,hash:"ea774a4d4c1179da92a782e0ae9cde92",slug:"topics-in-primary-care-medicine",bookSignature:"Thomas F. Heston",coverURL:"https://cdn.intechopen.com/books/images_new/9139.jpg",editors:[{id:"217926",title:"Dr.",name:"Thomas F.",middleName:null,surname:"Heston",slug:"thomas-f.-heston",fullName:"Thomas F. Heston"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9343",title:"Trace Metals in the Environment",subtitle:"New Approaches and Recent Advances",isOpenForSubmission:!1,hash:"ae07e345bc2ce1ebbda9f70c5cd12141",slug:"trace-metals-in-the-environment-new-approaches-and-recent-advances",bookSignature:"Mario Alfonso Murillo-Tovar, Hugo Saldarriaga-Noreña and Agnieszka Saeid",coverURL:"https://cdn.intechopen.com/books/images_new/9343.jpg",editors:[{id:"255959",title:"Dr.",name:"Mario Alfonso",middleName:null,surname:"Murillo-Tovar",slug:"mario-alfonso-murillo-tovar",fullName:"Mario Alfonso Murillo-Tovar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8697",title:"Virtual Reality and Its Application in Education",subtitle:null,isOpenForSubmission:!1,hash:"ee01b5e387ba0062c6b0d1e9227bda05",slug:"virtual-reality-and-its-application-in-education",bookSignature:"Dragan Cvetković",coverURL:"https://cdn.intechopen.com/books/images_new/8697.jpg",editors:[{id:"101330",title:"Dr.",name:"Dragan",middleName:"Mladen",surname:"Cvetković",slug:"dragan-cvetkovic",fullName:"Dragan Cvetković"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7831",title:"Sustainability in Urban Planning and Design",subtitle:null,isOpenForSubmission:!1,hash:"c924420492c8c2c9751e178d025f4066",slug:"sustainability-in-urban-planning-and-design",bookSignature:"Amjad Almusaed, Asaad Almssad and Linh Truong - Hong",coverURL:"https://cdn.intechopen.com/books/images_new/7831.jpg",editors:[{id:"110471",title:"Dr.",name:"Amjad",middleName:"Zaki",surname:"Almusaed",slug:"amjad-almusaed",fullName:"Amjad Almusaed"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:12,limit:12,total:5145},hotBookTopics:{hotBooks:[],offset:0,limit:12,total:null},publish:{},publishingProposal:{success:null,errors:{}},books:{featuredBooks:[{type:"book",id:"9208",title:"Welding",subtitle:"Modern Topics",isOpenForSubmission:!1,hash:"7d6be076ccf3a3f8bd2ca52d86d4506b",slug:"welding-modern-topics",bookSignature:"Sadek Crisóstomo Absi Alfaro, Wojciech Borek and Błażej Tomiczek",coverURL:"https://cdn.intechopen.com/books/images_new/9208.jpg",editors:[{id:"65292",title:"Prof.",name:"Sadek Crisostomo Absi",middleName:"C. Absi",surname:"Alfaro",slug:"sadek-crisostomo-absi-alfaro",fullName:"Sadek Crisostomo Absi Alfaro"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9139",title:"Topics in Primary Care Medicine",subtitle:null,isOpenForSubmission:!1,hash:"ea774a4d4c1179da92a782e0ae9cde92",slug:"topics-in-primary-care-medicine",bookSignature:"Thomas F. Heston",coverURL:"https://cdn.intechopen.com/books/images_new/9139.jpg",editors:[{id:"217926",title:"Dr.",name:"Thomas F.",middleName:null,surname:"Heston",slug:"thomas-f.-heston",fullName:"Thomas F. Heston"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8697",title:"Virtual Reality and Its Application in Education",subtitle:null,isOpenForSubmission:!1,hash:"ee01b5e387ba0062c6b0d1e9227bda05",slug:"virtual-reality-and-its-application-in-education",bookSignature:"Dragan Cvetković",coverURL:"https://cdn.intechopen.com/books/images_new/8697.jpg",editors:[{id:"101330",title:"Dr.",name:"Dragan",middleName:"Mladen",surname:"Cvetković",slug:"dragan-cvetkovic",fullName:"Dragan Cvetković"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9343",title:"Trace Metals in the Environment",subtitle:"New Approaches and Recent Advances",isOpenForSubmission:!1,hash:"ae07e345bc2ce1ebbda9f70c5cd12141",slug:"trace-metals-in-the-environment-new-approaches-and-recent-advances",bookSignature:"Mario Alfonso Murillo-Tovar, Hugo Saldarriaga-Noreña and Agnieszka Saeid",coverURL:"https://cdn.intechopen.com/books/images_new/9343.jpg",editors:[{id:"255959",title:"Dr.",name:"Mario Alfonso",middleName:null,surname:"Murillo-Tovar",slug:"mario-alfonso-murillo-tovar",fullName:"Mario Alfonso Murillo-Tovar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9785",title:"Endometriosis",subtitle:null,isOpenForSubmission:!1,hash:"f457ca61f29cf7e8bc191732c50bb0ce",slug:"endometriosis",bookSignature:"Courtney Marsh",coverURL:"https://cdn.intechopen.com/books/images_new/9785.jpg",editors:[{id:"255491",title:"Dr.",name:"Courtney",middleName:null,surname:"Marsh",slug:"courtney-marsh",fullName:"Courtney Marsh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7831",title:"Sustainability in Urban Planning and Design",subtitle:null,isOpenForSubmission:!1,hash:"c924420492c8c2c9751e178d025f4066",slug:"sustainability-in-urban-planning-and-design",bookSignature:"Amjad Almusaed, Asaad Almssad and Linh Truong - Hong",coverURL:"https://cdn.intechopen.com/books/images_new/7831.jpg",editors:[{id:"110471",title:"Dr.",name:"Amjad",middleName:"Zaki",surname:"Almusaed",slug:"amjad-almusaed",fullName:"Amjad Almusaed"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9376",title:"Contemporary Developments and Perspectives in International Health Security",subtitle:"Volume 1",isOpenForSubmission:!1,hash:"b9a00b84cd04aae458fb1d6c65795601",slug:"contemporary-developments-and-perspectives-in-international-health-security-volume-1",bookSignature:"Stanislaw P. Stawicki, Michael S. Firstenberg, Sagar C. Galwankar, Ricardo Izurieta and Thomas Papadimos",coverURL:"https://cdn.intechopen.com/books/images_new/9376.jpg",editors:[{id:"181694",title:"Dr.",name:"Stanislaw P.",middleName:null,surname:"Stawicki",slug:"stanislaw-p.-stawicki",fullName:"Stanislaw P. Stawicki"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7769",title:"Medical Isotopes",subtitle:null,isOpenForSubmission:!1,hash:"f8d3c5a6c9a42398e56b4e82264753f7",slug:"medical-isotopes",bookSignature:"Syed Ali Raza Naqvi and Muhammad Babar Imrani",coverURL:"https://cdn.intechopen.com/books/images_new/7769.jpg",editors:[{id:"259190",title:"Dr.",name:"Syed Ali Raza",middleName:null,surname:"Naqvi",slug:"syed-ali-raza-naqvi",fullName:"Syed Ali Raza Naqvi"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9279",title:"Concepts, Applications and Emerging Opportunities in Industrial Engineering",subtitle:null,isOpenForSubmission:!1,hash:"9bfa87f9b627a5468b7c1e30b0eea07a",slug:"concepts-applications-and-emerging-opportunities-in-industrial-engineering",bookSignature:"Gary Moynihan",coverURL:"https://cdn.intechopen.com/books/images_new/9279.jpg",editors:[{id:"16974",title:"Dr.",name:"Gary",middleName:null,surname:"Moynihan",slug:"gary-moynihan",fullName:"Gary Moynihan"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7807",title:"A Closer Look at Organizational Culture in Action",subtitle:null,isOpenForSubmission:!1,hash:"05c608b9271cc2bc711f4b28748b247b",slug:"a-closer-look-at-organizational-culture-in-action",bookSignature:"Süleyman Davut Göker",coverURL:"https://cdn.intechopen.com/books/images_new/7807.jpg",editors:[{id:"190035",title:"Associate Prof.",name:"Süleyman Davut",middleName:null,surname:"Göker",slug:"suleyman-davut-goker",fullName:"Süleyman Davut Göker"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],latestBooks:[{type:"book",id:"7434",title:"Molecular Biotechnology",subtitle:null,isOpenForSubmission:!1,hash:"eceede809920e1ec7ecadd4691ede2ec",slug:"molecular-biotechnology",bookSignature:"Sergey Sedykh",coverURL:"https://cdn.intechopen.com/books/images_new/7434.jpg",editedByType:"Edited by",editors:[{id:"178316",title:"Ph.D.",name:"Sergey",middleName:null,surname:"Sedykh",slug:"sergey-sedykh",fullName:"Sergey Sedykh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8545",title:"Animal Reproduction in Veterinary Medicine",subtitle:null,isOpenForSubmission:!1,hash:"13aaddf5fdbbc78387e77a7da2388bf6",slug:"animal-reproduction-in-veterinary-medicine",bookSignature:"Faruk Aral, Rita Payan-Carreira and Miguel Quaresma",coverURL:"https://cdn.intechopen.com/books/images_new/8545.jpg",editedByType:"Edited by",editors:[{id:"25600",title:"Prof.",name:"Faruk",middleName:null,surname:"Aral",slug:"faruk-aral",fullName:"Faruk Aral"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9569",title:"Methods in Molecular Medicine",subtitle:null,isOpenForSubmission:!1,hash:"691d3f3c4ac25a8093414e9b270d2843",slug:"methods-in-molecular-medicine",bookSignature:"Yusuf Tutar",coverURL:"https://cdn.intechopen.com/books/images_new/9569.jpg",editedByType:"Edited by",editors:[{id:"158492",title:"Prof.",name:"Yusuf",middleName:null,surname:"Tutar",slug:"yusuf-tutar",fullName:"Yusuf Tutar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9839",title:"Outdoor Recreation",subtitle:"Physiological and Psychological Effects on Health",isOpenForSubmission:!1,hash:"5f5a0d64267e32567daffa5b0c6a6972",slug:"outdoor-recreation-physiological-and-psychological-effects-on-health",bookSignature:"Hilde G. Nielsen",coverURL:"https://cdn.intechopen.com/books/images_new/9839.jpg",editedByType:"Edited by",editors:[{id:"158692",title:"Ph.D.",name:"Hilde G.",middleName:null,surname:"Nielsen",slug:"hilde-g.-nielsen",fullName:"Hilde G. Nielsen"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7802",title:"Modern Slavery and Human Trafficking",subtitle:null,isOpenForSubmission:!1,hash:"587a0b7fb765f31cc98de33c6c07c2e0",slug:"modern-slavery-and-human-trafficking",bookSignature:"Jane Reeves",coverURL:"https://cdn.intechopen.com/books/images_new/7802.jpg",editedByType:"Edited by",editors:[{id:"211328",title:"Prof.",name:"Jane",middleName:null,surname:"Reeves",slug:"jane-reeves",fullName:"Jane Reeves"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8063",title:"Food Security in Africa",subtitle:null,isOpenForSubmission:!1,hash:"8cbf3d662b104d19db2efc9d59249efc",slug:"food-security-in-africa",bookSignature:"Barakat Mahmoud",coverURL:"https://cdn.intechopen.com/books/images_new/8063.jpg",editedByType:"Edited by",editors:[{id:"92016",title:"Dr.",name:"Barakat",middleName:null,surname:"Mahmoud",slug:"barakat-mahmoud",fullName:"Barakat Mahmoud"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10118",title:"Plant Stress Physiology",subtitle:null,isOpenForSubmission:!1,hash:"c68b09d2d2634fc719ae3b9a64a27839",slug:"plant-stress-physiology",bookSignature:"Akbar Hossain",coverURL:"https://cdn.intechopen.com/books/images_new/10118.jpg",editedByType:"Edited by",editors:[{id:"280755",title:"Dr.",name:"Akbar",middleName:null,surname:"Hossain",slug:"akbar-hossain",fullName:"Akbar Hossain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9157",title:"Neurodegenerative Diseases",subtitle:"Molecular Mechanisms and Current Therapeutic Approaches",isOpenForSubmission:!1,hash:"bc8be577966ef88735677d7e1e92ed28",slug:"neurodegenerative-diseases-molecular-mechanisms-and-current-therapeutic-approaches",bookSignature:"Nagehan Ersoy Tunalı",coverURL:"https://cdn.intechopen.com/books/images_new/9157.jpg",editedByType:"Edited by",editors:[{id:"82778",title:"Ph.D.",name:"Nagehan",middleName:null,surname:"Ersoy Tunalı",slug:"nagehan-ersoy-tunali",fullName:"Nagehan Ersoy Tunalı"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9961",title:"Data Mining",subtitle:"Methods, Applications and Systems",isOpenForSubmission:!1,hash:"ed79fb6364f2caf464079f94a0387146",slug:"data-mining-methods-applications-and-systems",bookSignature:"Derya Birant",coverURL:"https://cdn.intechopen.com/books/images_new/9961.jpg",editedByType:"Edited by",editors:[{id:"15609",title:"Dr.",name:"Derya",middleName:null,surname:"Birant",slug:"derya-birant",fullName:"Derya Birant"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8686",title:"Direct Torque Control Strategies of Electrical Machines",subtitle:null,isOpenForSubmission:!1,hash:"b6ad22b14db2b8450228545d3d4f6b1a",slug:"direct-torque-control-strategies-of-electrical-machines",bookSignature:"Fatma Ben Salem",coverURL:"https://cdn.intechopen.com/books/images_new/8686.jpg",editedByType:"Edited by",editors:[{id:"295623",title:"Associate Prof.",name:"Fatma",middleName:null,surname:"Ben Salem",slug:"fatma-ben-salem",fullName:"Fatma Ben Salem"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},subject:{topic:{id:"11",title:"Engineering",slug:"engineering",parent:{title:"Physical Sciences, Engineering and Technology",slug:"physical-sciences-engineering-and-technology"},numberOfBooks:844,numberOfAuthorsAndEditors:20050,numberOfWosCitations:23377,numberOfCrossrefCitations:15584,numberOfDimensionsCitations:34695,videoUrl:null,fallbackUrl:null,description:null},booksByTopicFilter:{topicSlug:"engineering",sort:"-publishedDate",limit:12,offset:0},booksByTopicCollection:[{type:"book",id:"8686",title:"Direct Torque Control Strategies of Electrical Machines",subtitle:null,isOpenForSubmission:!1,hash:"b6ad22b14db2b8450228545d3d4f6b1a",slug:"direct-torque-control-strategies-of-electrical-machines",bookSignature:"Fatma Ben Salem",coverURL:"https://cdn.intechopen.com/books/images_new/8686.jpg",editedByType:"Edited by",editors:[{id:"295623",title:"Associate Prof.",name:"Fatma",middleName:null,surname:"Ben Salem",slug:"fatma-ben-salem",fullName:"Fatma Ben Salem"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9208",title:"Welding",subtitle:"Modern Topics",isOpenForSubmission:!1,hash:"7d6be076ccf3a3f8bd2ca52d86d4506b",slug:"welding-modern-topics",bookSignature:"Sadek Crisóstomo Absi Alfaro, Wojciech Borek and Błażej Tomiczek",coverURL:"https://cdn.intechopen.com/books/images_new/9208.jpg",editedByType:"Edited by",editors:[{id:"65292",title:"Prof.",name:"Sadek Crisostomo Absi",middleName:"C. Absi",surname:"Alfaro",slug:"sadek-crisostomo-absi-alfaro",fullName:"Sadek Crisostomo Absi Alfaro"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9279",title:"Concepts, Applications and Emerging Opportunities in Industrial Engineering",subtitle:null,isOpenForSubmission:!1,hash:"9bfa87f9b627a5468b7c1e30b0eea07a",slug:"concepts-applications-and-emerging-opportunities-in-industrial-engineering",bookSignature:"Gary Moynihan",coverURL:"https://cdn.intechopen.com/books/images_new/9279.jpg",editedByType:"Edited by",editors:[{id:"16974",title:"Dr.",name:"Gary",middleName:null,surname:"Moynihan",slug:"gary-moynihan",fullName:"Gary Moynihan"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10224",title:"Safety and Risk Assessment of Civil Aircraft during Operation",subtitle:null,isOpenForSubmission:!1,hash:"d966066f4fa44f6b320cd9b40ed66bbd",slug:"safety-and-risk-assessment-of-civil-aircraft-during-operation",bookSignature:"Longbiao Li",coverURL:"https://cdn.intechopen.com/books/images_new/10224.jpg",editedByType:"Edited by",editors:[{id:"260011",title:"Dr.",name:"Longbiao",middleName:null,surname:"Li",slug:"longbiao-li",fullName:"Longbiao Li"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10025",title:"Numerical and Experimental Studies on Combustion Engines and Vehicles",subtitle:null,isOpenForSubmission:!1,hash:"44d31c0f408772b0e50d89e029f4b14d",slug:"numerical-and-experimental-studies-on-combustion-engines-and-vehicles",bookSignature:"Paweł Woś and Mirosław Jakubowski",coverURL:"https://cdn.intechopen.com/books/images_new/10025.jpg",editedByType:"Edited by",editors:[{id:"119441",title:"Ph.D.",name:"Paweł",middleName:null,surname:"Woś",slug:"pawel-wos",fullName:"Paweł Woś"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10073",title:"Recent Advances in Nanophotonics",subtitle:"Fundamentals and Applications",isOpenForSubmission:!1,hash:"aceca7dfc807140870a89d42c5537d7c",slug:"recent-advances-in-nanophotonics-fundamentals-and-applications",bookSignature:"Mojtaba Kahrizi and Parsoua A. Sohi",coverURL:"https://cdn.intechopen.com/books/images_new/10073.jpg",editedByType:"Edited by",editors:[{id:"113045",title:"Dr.",name:"Mojtaba",middleName:null,surname:"Kahrizi",slug:"mojtaba-kahrizi",fullName:"Mojtaba Kahrizi"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8180",title:"Landslides",subtitle:"Investigation and Monitoring",isOpenForSubmission:!1,hash:"5bfd80e1f39cf25ec7b8c18ed95b74c9",slug:"landslides-investigation-and-monitoring",bookSignature:"Ram Ray and Maurizio Lazzari",coverURL:"https://cdn.intechopen.com/books/images_new/8180.jpg",editedByType:"Edited by",editors:[{id:"202304",title:"Dr.",name:"Ram",middleName:null,surname:"Ray",slug:"ram-ray",fullName:"Ram Ray"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9174",title:"Product Design",subtitle:null,isOpenForSubmission:!1,hash:"3510bacbbf4d365e97510bf962652de1",slug:"product-design",bookSignature:"Cătălin Alexandru, Codruta Jaliu and Mihai Comşit",coverURL:"https://cdn.intechopen.com/books/images_new/9174.jpg",editedByType:"Edited by",editors:[{id:"2767",title:"Prof.",name:"Catalin",middleName:null,surname:"Alexandru",slug:"catalin-alexandru",fullName:"Catalin Alexandru"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7700",title:"Modern Printed-Circuit Antennas",subtitle:null,isOpenForSubmission:!1,hash:"c348dddb91240f82d274524c736108e3",slug:"modern-printed-circuit-antennas",bookSignature:"Hussain Al-Rizzo",coverURL:"https://cdn.intechopen.com/books/images_new/7700.jpg",editedByType:"Edited by",editors:[{id:"153384",title:"Prof.",name:"Hussain",middleName:null,surname:"Al-Rizzo",slug:"hussain-al-rizzo",fullName:"Hussain Al-Rizzo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9266",title:"Machine Tools",subtitle:"Design, Research, Application",isOpenForSubmission:!1,hash:"3def867e2d654b757bb101201bc6d1e6",slug:"machine-tools-design-research-application",bookSignature:"Ľubomír Šooš and Jiri Marek",coverURL:"https://cdn.intechopen.com/books/images_new/9266.jpg",editedByType:"Edited by",editors:[{id:"141212",title:"Prof.",name:"Ľubomír",middleName:null,surname:"Šooš",slug:"ubomir-soos",fullName:"Ľubomír Šooš"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10093",title:"Electromagnetic Propagation and Waveguides in Photonics and Microwave Engineering",subtitle:null,isOpenForSubmission:!1,hash:"1aa3bf83f471bb1591950efa117c6fec",slug:"electromagnetic-propagation-and-waveguides-in-photonics-and-microwave-engineering",bookSignature:"Patrick Steglich",coverURL:"https://cdn.intechopen.com/books/images_new/10093.jpg",editedByType:"Edited by",editors:[{id:"223128",title:"Dr.",name:"Patrick",middleName:null,surname:"Steglich",slug:"patrick-steglich",fullName:"Patrick Steglich"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7414",title:"Modulation in Electronics and Telecommunications",subtitle:null,isOpenForSubmission:!1,hash:"5066fa20239d3de3ca87b3c45c680d01",slug:"modulation-in-electronics-and-telecommunications",bookSignature:"George Dekoulis",coverURL:"https://cdn.intechopen.com/books/images_new/7414.jpg",editedByType:"Edited by",editors:[{id:"9833",title:"Prof.",name:"George",middleName:null,surname:"Dekoulis",slug:"george-dekoulis",fullName:"George Dekoulis"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],booksByTopicTotal:844,mostCitedChapters:[{id:"17237",doi:"10.5772/24553",title:"Hydrogels: Methods of Preparation, Characterisation and Applications",slug:"hydrogels-methods-of-preparation-characterisation-and-applications",totalDownloads:64144,totalCrossrefCites:58,totalDimensionsCites:205,book:{slug:"progress-in-molecular-and-environmental-bioengineering-from-analysis-and-modeling-to-technology-applications",title:"Progress in Molecular and Environmental Bioengineering",fullTitle:"Progress in Molecular and Environmental Bioengineering - From Analysis and Modeling to Technology Applications"},signatures:"Syed K. H. Gulrez, Saphwan Al-Assaf and Glyn O Phillips",authors:[{id:"58120",title:"Prof.",name:"Saphwan",middleName:null,surname:"Al-Assaf",slug:"saphwan-al-assaf",fullName:"Saphwan Al-Assaf"}]},{id:"35261",doi:"10.5772/34233",title:"Anisotropic Mechanical Properties of ABS Parts Fabricated by Fused Deposition Modelling",slug:"anisotropic-mechanical-properties-of-abs-parts-fabricated-by-fused-deposition-modeling-",totalDownloads:6625,totalCrossrefCites:71,totalDimensionsCites:173,book:{slug:"mechanical-engineering",title:"Mechanical Engineering",fullTitle:"Mechanical Engineering"},signatures:"Constance Ziemian, Mala Sharma and Sophia Ziemian",authors:[{id:"89554",title:"Dr.",name:"Mala",middleName:null,surname:"Sharma",slug:"mala-sharma",fullName:"Mala Sharma"},{id:"98759",title:"Dr.",name:"Constance",middleName:null,surname:"Ziemian",slug:"constance-ziemian",fullName:"Constance Ziemian"},{id:"137165",title:"Ms.",name:"Sophia",middleName:null,surname:"Ziemian",slug:"sophia-ziemian",fullName:"Sophia Ziemian"}]},{id:"13254",doi:"10.5772/13474",title:"Insight Into Adsorption Thermodynamics",slug:"insight-into-adsorption-thermodynamics",totalDownloads:6557,totalCrossrefCites:57,totalDimensionsCites:155,book:{slug:"thermodynamics",title:"Thermodynamics",fullTitle:"Thermodynamics"},signatures:"Papita Saha and Shamik Chowdhury",authors:[{id:"13943",title:"Dr.",name:"Papita",middleName:null,surname:"Saha",slug:"papita-saha",fullName:"Papita Saha"},{id:"24184",title:"Mr.",name:"Shamik",middleName:null,surname:"Chowdhury",slug:"shamik-chowdhury",fullName:"Shamik Chowdhury"}]}],mostDownloadedChaptersLast30Days:[{id:"57483",title:"Helicopter Flight Physics",slug:"helicopter-flight-physics",totalDownloads:5831,totalCrossrefCites:2,totalDimensionsCites:2,book:{slug:"flight-physics-models-techniques-and-technologies",title:"Flight Physics",fullTitle:"Flight Physics - Models, Techniques and Technologies"},signatures:"Constantin Rotaru and Michael Todorov",authors:[{id:"206857",title:"Prof.",name:"Constantin",middleName:null,surname:"Rotaru",slug:"constantin-rotaru",fullName:"Constantin Rotaru"},{id:"209010",title:"Prof.",name:"Michael",middleName:null,surname:"Todorov",slug:"michael-todorov",fullName:"Michael Todorov"}]},{id:"49024",title:"Biological and Chemical Wastewater Treatment Processes",slug:"biological-and-chemical-wastewater-treatment-processes",totalDownloads:24505,totalCrossrefCites:18,totalDimensionsCites:27,book:{slug:"wastewater-treatment-engineering",title:"Wastewater Treatment Engineering",fullTitle:"Wastewater Treatment Engineering"},signatures:"Mohamed Samer",authors:[{id:"175050",title:"Prof.",name:"Mohamed",middleName:null,surname:"Samer",slug:"mohamed-samer",fullName:"Mohamed Samer"}]},{id:"48982",title:"A Comprehensive Modeling and Simulation of Power Quality Disturbances Using MATLAB/SIMULINK",slug:"a-comprehensive-modeling-and-simulation-of-power-quality-disturbances-using-matlab-simulink",totalDownloads:11247,totalCrossrefCites:4,totalDimensionsCites:12,book:{slug:"power-quality-issues-in-distributed-generation",title:"Power Quality Issues in Distributed Generation",fullTitle:"Power Quality Issues in Distributed Generation"},signatures:"Rodney H.G. Tan and Vigna K. Ramachandaramurthy",authors:[{id:"152137",title:"Dr.",name:"Vigna",middleName:null,surname:"Ramachandaramurthy",slug:"vigna-ramachandaramurthy",fullName:"Vigna Ramachandaramurthy"},{id:"175327",title:"Dr.",name:"Rodney",middleName:"H.G.",surname:"Tan",slug:"rodney-tan",fullName:"Rodney Tan"}]},{id:"62059",title:"Types of HVAC Systems",slug:"types-of-hvac-systems",totalDownloads:8219,totalCrossrefCites:3,totalDimensionsCites:5,book:{slug:"hvac-system",title:"HVAC System",fullTitle:"HVAC System"},signatures:"Shaimaa Seyam",authors:[{id:"247650",title:"M.Sc.",name:"Shaimaa",middleName:null,surname:"Seyam",slug:"shaimaa-seyam",fullName:"Shaimaa Seyam"},{id:"257733",title:"MSc.",name:"Shaimaa",middleName:null,surname:"Seyam",slug:"shaimaa-seyam",fullName:"Shaimaa Seyam"}]},{id:"72592",title:"Modeling Antecedent Soil Moisture to Constrain Rainfall Thresholds for Shallow Landslides Occurrence",slug:"modeling-antecedent-soil-moisture-to-constrain-rainfall-thresholds-for-shallow-landslides-occurrence",totalDownloads:257,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"landslides-investigation-and-monitoring",title:"Landslides",fullTitle:"Landslides - Investigation and Monitoring"},signatures:"Maurizio Lazzari, Marco Piccarreta, Ram L. Ray and Salvatore Manfreda",authors:[{id:"202304",title:"Dr.",name:"Ram",middleName:null,surname:"Ray",slug:"ram-ray",fullName:"Ram Ray"},{id:"250931",title:"Ph.D.",name:"Maurizio",middleName:null,surname:"Lazzari",slug:"maurizio-lazzari",fullName:"Maurizio Lazzari"},{id:"318565",title:"Dr.",name:"Marco",middleName:null,surname:"Piccarreta",slug:"marco-piccarreta",fullName:"Marco Piccarreta"},{id:"318566",title:"Prof.",name:"Salvatore",middleName:null,surname:"Manfreda",slug:"salvatore-manfreda",fullName:"Salvatore Manfreda"}]},{id:"67558",title:"Polymerase Chain Reaction (PCR): Principle and Applications",slug:"polymerase-chain-reaction-pcr-principle-and-applications",totalDownloads:5386,totalCrossrefCites:1,totalDimensionsCites:3,book:{slug:"synthetic-biology-new-interdisciplinary-science",title:"Synthetic Biology",fullTitle:"Synthetic Biology - New Interdisciplinary Science"},signatures:"Karim Kadri",authors:[{id:"290766",title:"Dr.",name:"Kadri",middleName:null,surname:"Karim",slug:"kadri-karim",fullName:"Kadri Karim"}]},{id:"73317",title:"Remote Sensing Approaches and Related Techniques to Map and Study Landslides",slug:"remote-sensing-approaches-and-related-techniques-to-map-and-study-landslides",totalDownloads:287,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"landslides-investigation-and-monitoring",title:"Landslides",fullTitle:"Landslides - Investigation and Monitoring"},signatures:"Ram L. Ray, Maurizio Lazzari and Tolulope Olutimehin",authors:[{id:"202304",title:"Dr.",name:"Ram",middleName:null,surname:"Ray",slug:"ram-ray",fullName:"Ram Ray"},{id:"250931",title:"Ph.D.",name:"Maurizio",middleName:null,surname:"Lazzari",slug:"maurizio-lazzari",fullName:"Maurizio Lazzari"},{id:"320982",title:"Ms.",name:"Tolulope",middleName:null,surname:"Olutimehin",slug:"tolulope-olutimehin",fullName:"Tolulope Olutimehin"}]},{id:"52822",title:"Non-Orthogonal Multiple Access (NOMA) for 5G Networks",slug:"non-orthogonal-multiple-access-noma-for-5g-networks",totalDownloads:12870,totalCrossrefCites:8,totalDimensionsCites:14,book:{slug:"towards-5g-wireless-networks-a-physical-layer-perspective",title:"Towards 5G Wireless Networks",fullTitle:"Towards 5G Wireless Networks - A Physical Layer Perspective"},signatures:"Refik Caglar Kizilirmak",authors:[{id:"188668",title:"Dr.",name:"Refik Caglar",middleName:null,surname:"Kizilirmak",slug:"refik-caglar-kizilirmak",fullName:"Refik Caglar Kizilirmak"}]},{id:"70874",title:"Social, Economic, and Environmental Impacts of Renewable Energy Resources",slug:"social-economic-and-environmental-impacts-of-renewable-energy-resources",totalDownloads:1663,totalCrossrefCites:4,totalDimensionsCites:6,book:{slug:"wind-solar-hybrid-renewable-energy-system",title:"Wind Solar Hybrid Renewable Energy System",fullTitle:"Wind Solar Hybrid Renewable Energy System"},signatures:"Mahesh Kumar",authors:[{id:"309842",title:"Mr.",name:"Kamlesh",middleName:null,surname:"Kumar",slug:"kamlesh-kumar",fullName:"Kamlesh Kumar"}]},{id:"73582",title:"Introductory Chapter: Importance of Investigating Landslide Hazards",slug:"introductory-chapter-importance-of-investigating-landslide-hazards",totalDownloads:189,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"landslides-investigation-and-monitoring",title:"Landslides",fullTitle:"Landslides - Investigation and Monitoring"},signatures:"Ram L. Ray and Maurizio Lazzari",authors:[{id:"202304",title:"Dr.",name:"Ram",middleName:null,surname:"Ray",slug:"ram-ray",fullName:"Ram Ray"},{id:"250931",title:"Ph.D.",name:"Maurizio",middleName:null,surname:"Lazzari",slug:"maurizio-lazzari",fullName:"Maurizio Lazzari"}]}],onlineFirstChaptersFilter:{topicSlug:"engineering",limit:3,offset:0},onlineFirstChaptersCollection:[{id:"74742",title:"Survey of Some Exact and Approximate Analytical Solutions for Heat Transfer in Extended Surfaces",slug:"survey-of-some-exact-and-approximate-analytical-solutions-for-heat-transfer-in-extended-surfaces",totalDownloads:5,totalDimensionsCites:0,doi:"10.5772/intechopen.95490",book:{title:"Heat Transfer - Design, Experimentation and Applications"},signatures:"Raseelo Joel Moitsheki, Partner Luyanda Ndlovu and Basetsana Pauline Ntsime"},{id:"74895",title:"Nanocomposite and Nanofluids: Towards a Sustainable Carbon Capture, Utilization, and Storage",slug:"nanocomposite-and-nanofluids-towards-a-sustainable-carbon-capture-utilization-and-storage",totalDownloads:7,totalDimensionsCites:0,doi:"10.5772/intechopen.95838",book:{title:"Advances in Micro- and Nanofluidics"},signatures:"Ronald Nguele, Katia Nchimi Nono and Kyuro Sasaki"},{id:"74881",title:"Reducing Emerging Contaminants Ensuing from Rusting of Marine Steel Installations",slug:"reducing-emerging-contaminants-ensuing-from-rusting-of-marine-steel-installations",totalDownloads:5,totalDimensionsCites:0,doi:"10.5772/intechopen.95493",book:{title:"Emerging Contaminants"},signatures:"Karima Hanini, Sameh Boudiba and Merzoug Benahmed"}],onlineFirstChaptersTotal:290},preDownload:{success:null,errors:{}},aboutIntechopen:{},privacyPolicy:{},peerReviewing:{},howOpenAccessPublishingWithIntechopenWorks:{},sponsorshipBooks:{sponsorshipBooks:[{type:"book",id:"10176",title:"Microgrids and Local Energy Systems",subtitle:null,isOpenForSubmission:!0,hash:"c32b4a5351a88f263074b0d0ca813a9c",slug:null,bookSignature:"Prof. Nick Jenkins",coverURL:"https://cdn.intechopen.com/books/images_new/10176.jpg",editedByType:null,editors:[{id:"55219",title:"Prof.",name:"Nick",middleName:null,surname:"Jenkins",slug:"nick-jenkins",fullName:"Nick Jenkins"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:8,limit:8,total:1},route:{name:"chapter.detail",path:"/books/translational-studies-on-inflammation/pharmacological-challenge-models-in-clinical-drug-developmental-programs",hash:"",query:{},params:{book:"translational-studies-on-inflammation",chapter:"pharmacological-challenge-models-in-clinical-drug-developmental-programs"},fullPath:"/books/translational-studies-on-inflammation/pharmacological-challenge-models-in-clinical-drug-developmental-programs",meta:{},from:{name:null,path:"/",hash:"",query:{},params:{},fullPath:"/",meta:{}}}},function(){var e;(e=document.currentScript||document.scripts[document.scripts.length-1]).parentNode.removeChild(e)}()