• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 753
  • 596
  • 257
  • 118
  • 53
  • 17
  • 16
  • 16
  • 16
  • 16
  • 16
  • 16
  • 14
  • 14
  • 10
  • Tagged with
  • 2162
  • 566
  • 467
  • 250
  • 214
  • 214
  • 204
  • 201
  • 175
  • 166
  • 138
  • 133
  • 121
  • 121
  • 106
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
671

Measurement of fiber suspension flow and forming jet velocity profile by pulsed ultrasonic doppler velocimetry.

Xu, Hanjiang. January 2003 (has links)
Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2003.
672

Characterization of a fiber suspension jet in a co-flow dilution process.

Schmidt, Eric Andrew. January 2003 (has links)
Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2003. / Includes Bibliography.
673

Modification of polymeric substrates using surface grafted nanoscaffolds

Thompson, Kimberlee Fay. January 2005 (has links)
Thesis (Ph. D.)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2006. / Carter, W. Brent, Committee Member ; Cook, Fred, Committee Member ; Griffin, Anselm, Committee Member ; Michielsen, Stephen, Committee Chair ; Beckham, Haskell, Committee Member ; Bottomley, Lawrence, Committee Member.
674

Competitive adsorption of poly(1-vinylpyrrolidone-co-styrene) and Kymene 557H onto wood fibers the improved effect of sequential adsorption /

Maurer, Ronald W. January 2006 (has links)
Thesis (M. S.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2007. / Koros, William, Committee Member ; Hsieh, Jeffery, Committee Chair ; Deng, Yulin, Committee Member.
675

A method for winding advanced composites of unconventional shapes using continuous and aligned fibers /

Allen, Abraham Keith, January 2004 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Technology, 2004. / Includes bibliographical references (p. 191-195).
676

Processing mechanics of alternate twist ply (ATP) yarn technology /

Elkhamy, Donia Said. Ko, Frank K. Li, Christopher Yuren. January 2007 (has links)
Thesis (Ph. D.)--Drexel University, 2007. / Includes abstract and vita. Includes bibliographical references (leaves 182-184).
677

Experimental investigation on behavior of steel fiber reinforced concrete (SFRC) : a dissertation submitted to the University of Canterbury in partial fulfillment of the requirements for the degree of Master [of Engineering] /

Wang, Chuanbo. January 1900 (has links)
Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references. Also available via the World Wide Web.
678

Wood and fibre properties of fertilized Norway spruce /

Lundgren, Christina. Persson, Bengt. January 2003 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003. / Thesis documentation sheet inserted. Appendix reprints four papers and manuscripts, one co-authored with Bengt Persson. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
679

Πειραματική και θεωρητική μελέτη αισθητήρων οπτικών ινών με σταδιακά απογυμνωμένα φράγματα Bragg / Experimental and theoretical study of fiber optic sensors with etched Bragg gratings

Πολύζος, Δημήτριος 20 December 2012 (has links)
Το θέμα το οποίο πραγματεύεται η παρούσα διπλωματική είναι οι αισθητήρες οπτικών ινών με φράγματα Bragg προσδιορίζοντας τον δείκτη διάθλασης του περιβάλλοντος υγρού κατά τη βύθιση του οπτικού αισθητήρα μέσα σε αυτό. Στο πρώτο κεφάλαιο θα γίνει αρχικά μια ανάλυση των οπτικών ινών αφού θα αναφερθούν ο τρόπος λειτουργίας τους, οι τύποι οπτικών ινών που υπάρχουν, πλεονεκτήματα και μειονεκτήματα που παρουσιάζουν αλλά και ο λόγος που οδηγήθηκε η τεχνολογία στην κατασκευή τους. Στο δεύτερο κεφάλαιο περιγράφονται τα γενικά χαρακτηριστικά, δηλαδή ο τρόπος κατασκευής καθώς επίσης και ο τρόπος λειτουργίας των φραγμάτων Bragg. Αναφέρονται τα διάφορα είδη φραγμάτων Bragg που υπάρχουν και οι μηχανισμοί φωτοευαισθησίας τους. Στο τρίτο κεφάλαιο δίνεται έμφαση στη χρήση των φραγμάτων Bragg σαν αισθητήρες ταυτοποίησης της φύσης των υγρών στα οποία εισάγονται οι αισθητήρες αλλά και σαν αισθητήρες μέτρησης στάθμης υγρών. Τα φράγματα Bragg χρησιμοποιούνται ευρέως και σαν αισθητήρες πίεσης, θερμοκρασίας, ροής, μετατόπισης στάθμης υγρών, χημικής ταυτοποίησης, PH, ηλεκτρικών πεδίων, μαγνητικών πεδίων καθώς και άλλων φυσικών μεγεθών. Ακόμα γίνεται μια περιγραφή της διαδικασίας χημικής απογύμνωσης (etching), καθώς επίσης και τα τεχνικά χαρακτηριστικά και τρόπους λειτουργίας της πηγής φωτός που χρησιμοποιήθηκε, η οποία είναι ένας ενισχυτής Erbium Doped Fiber Amplifier –EDFA. Το τέταρτο κεφάλαιο πραγματεύεται τα αποτελέσματα των προσομοιώσεων που έγιναν με τη χρήση του προγράμματος COMSOL Multiphysics 4.2. Οι προσομοιώσεις έγιναν για διαφορετικές τιμές δεικτών διάθλασης μιας ποικιλίας υγρών. Στο πέμπτο κεφάλαιο αναλύεται το πειραματικό μέρος της ειδικής ερευνητικής εργασίας. Παρουσιάζονται η πειραματική διάταξη και τα πειραματικά δεδομένα που ελήφθησαν στο εργαστήριο Laser, καθώς επίσης και τα σχετικά σχόλια σύγκρισης με τα αποτελέσματα των αντίστοιχων προσομοιώσεων που έγιναν. / -
680

Alterações estruturais da matriz extracelular do prepúcio humano causadas pelo tabagismo / Alterações estruturais da matriz extracelular do prepúcio humano causadas pelo tabagismo / Structural alterations of human foreskin caused by chronic smoking may explain high levels of urethral reconstruction failure / Structural alterations of human foreskin caused by chronic smoking may explain high levels of urethral reconstruction failure

João Pedro Gaio Meireles Rosado 12 January 2011 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Os autores têm como objetivo, investigar a matriz extra celular, musculatura lisa e densidade vascular do prepúcio de pacientes tabagistas. Espécimes de prepúcio foram obtidas de 20 jovens adultos (média de idade= 27.2) submetidos a postectomia. Dentre os pacientes analisados, um grupo (n=10) possui história prévia de tabagismo (3 to 13 maços/ano, média = 5.8 3.2), e outro grupo (n=10) formam o grupo controle, não fumantes. A coloração de Tricrômico Masson foi utilizada para quantificar tecido conectivo, musculatura lisa e vasos. A coloração Resorcina-fucsina de Weigert foi utilizada para estabelecer as fibras do sistema elástico e a coloração, Vermelho de Picrosirius para o estudo do colágeno. O estudo estereológico foi realizado utilizando o software Image J, para determinar as densidades volumétricas. Para a análise bioquímica o colágeno total foi determinado em &#956;g de hidroxiprolina por MG de tecido seco. O estudo estatístico foi realizado lançando mão do t-teste (p<0,05). Fibras do sistema elástico de fumantes apresentaram-se aumentadas em 42.5% quando comparado ao grupo controle (p=0,002). Em contraste, musculatura lisa (p=0,42) e densidade vascular (p=0,16) não mostraram nenhuma diferença estatística. Foi realizado uma análise quantitativa utilizando Vermelho de Picrosirius sob luz polarizada, que evidenciou a presença de colágeno tipo I e III, sem diferença estatisticamente significativa. A concentração total do colágeno não mostrou diferença entre tabagistas e o grupo controle. (73.1&#956;g/mg 8.0 vs. 69.2&#956;g/mg 5.9, respectivamente, p=0,23). Tabagismo está associado a um significante aumento de fibras do sistema elástico do tecido prepucial. Estes resultados podem, possivelmente, explicar os altos índices de falha na uretroplastia peniana, com uso de flap de prepúcio em fumantes / It has been speculated by McAninch et al. (1), that smokers might experience worse results after urethral reconstruction. We decided to investigate the extracellular matrix, smooth muscle and vascular density in the foreskin of smoker patients. Foreskin samples were obtained from 20 young adults (ranging in age from 23 to 36 years; mean SD = 27.2 5.8) submitted to circumcision from July 2008 to October 2009. Of the patients analyzed, one group (n=10) had a previous history of chronic smoking (3 to 13 packs/year, mean = 5.8 3.2) i.e., one pack per day for 3 to 13 years. The control group was composed of 10 non-smoker patients. Foreskin samples were studied by histology and biochemistry. Means were compared using the two-tailed t-test (p<0.05). The elastic system fibers in the foreskin of smoker patients increased in 42.5% when compared to the control group. In contrast, the smooth muscle fibers, vascular density and total collagen concentration did not show any significant variation between smokers and controls. Smoking is associated with a significant increase of elastic system fibers in foreskin tissue. These results could possibly explain the high failure rate of penile urethroplasty in smokers by using foreskin flaps

Page generated in 0.0631 seconds