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  • 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.
71

EXPLORING THE USE OF MICROSTRUCTURED FIBRES AS A STATIONARY PHASE SUPPORT FOR OPEN TUBULAR LIQUID CHROMATOGRAPHY

IRVING, RYAN 15 September 2011 (has links)
With the rise of capillary HPLC systems, open tubular liquid chromatography (OTLC) has been garnering more attention due to the possible fundamental advantages of open tubular systems over conventional packed or monolithic systems. Performance has yet to reach its potential due in part to a variety of technical challenges, resulting in the need for very small injection volumes and sensitive detection. In this work, we have shown that with modern HPLC sample introduction and detection systems, along with careful fabrication of polymer stationary phases, that reverse phase open tubular liquid chromatography may be within reach. We have shown that, with small diameter (i.d. 30m) open tubular columns, complex multi-component mixtures (EPA 610, in-house drug mixture) can be separated. We have also shown that these columns are robust and can function over a wide range of flow rates (200-1000 nl/min), and may be useful for general reverse phase separation in the future. However, currently, more stationary phase development and procedure refinement is needed. Microstructured fibres (MSFs), a relatively new class of optical fibre which confine light within fibres through a refractive index change caused by the use of parallel air channels running throughout the length of the fibre, are explored as a new support material for open tubular liquid chromatography. The fine channel structures of MSFs enable reasonable sample volumes to be used compared to conventional open tubular systems, while offering a similar plug-like flow profile through the fibre. With current sample introduction and flow technologies, we have shown that the potential advantages of MSF columns is great even when simple C18 stationary phases are used; this was able to separate a four PAH mixture. However, a distribution in channel sizes caused by current manufacturing standards and a limited ability to evenly deposit polymer stationary phases in the fibres has kept MSF columns from reaching their full potential. / Thesis (Master, Chemistry) -- Queen's University, 2011-09-14 11:52:41.23
72

Experimental investigation of steel tubed reinforced concrete columns

Machado, Rafael Ignacio 05 1900 (has links)
No description available.
73

Adhesion of Two Cylindrical Particles to a Soft Membrane Tube

Mkrtchyan, Sergey January 2012 (has links)
The interaction of nanoparticles with biological systems, especially interactions with cell membranes, has been a subject of active research due to its numerous applications in many areas of soft-matter and biological systems. Within only a few relevant physical parameters profound structural properties have been discovered in the context of simple coarse-grained theoretical models. In this Thesis we study the structure of a tubular membrane adhering to two rigid cylindrical particles on a basis of a free-energy model that uses Helfrich energy for the description of the membrane. A numerical procedure is developed to solve the shape equations that determine the state of lowest energy. Several phase transitions exist in the system, arising from the competition between the bending energy of the membrane and the adhesion energy between the membrane and the particles. A continuous adhesion transition between the free and bound states, as well as several discontinuous shape transitions are identified, depending on the physical parameters of the system. The results are then generalized into a single phase diagram separating free, symmetric- and asymmetric-wrapping states in the phase space of the size of the particles and the adhesion energy. We show that for a relatively small size of the membrane tube the interaction between the cylinders becomes attractive in the strong curvature regime, leading to aggregation of the particles in the highly curved area of the tube that is characteristically different from the aggregation in a related three-dimensional system. For a relatively large membrane tube size the cylinders prefer to have a non-zero separation, even in the completely engulfed state. This indicates that, i) the spontaneous curvature of the membrane may play a role in the sign of the interaction of two colloidal particles adhered to a membrane and ii) cylindrical particles can aggregate on membrane tubes and vesicles if the curvature of the membrane around the aggregation region is sufficiently large.
74

Investigation into aspects of the biology of tubular black thrips, Haplothrips victoriensis Bagnall (Thysanoptera: Phlaeothripidae) in South Australia.

Le, Luong Cao January 2010 (has links)
Haplothrips victoriensis Bagnall (Thysanoptera: Phlaeothripidae) is an indigenous thrips of southern Australia. It is known as a predator of two-spotted mite. This project investigated various biological characteristics of H. victoriensis as a precursor to its potential use in biological control. In addition, H. victoriensis is very difficult to distinguish from other Haplothrips species in terms of morphology, especially as there are no keys to larvae. DNA barcoding and morphology of the larval stages are used to address these issues. The thesis is divided into seven chapters comprising an introduction, four main research chapters, conclusion and reference chapters. Chapter 2 covers the culturing techniques for H. victoriensis. Some new cases and rearing processes were designed to culture H. victoriensis and its prey. These were following series of rearing techniques investigated including rearing H. victoriensis for egg collection, H. victoriensis larvae and adults for biological and morphological observations, mass rearing of H. victoriensis, WFT and Tyrophagus mites, and rearing WFT for egg collection. Predatory H. victoriensis was reared in the laboratory with various diets of honey, pollen, Tyrophagus mites and western flower thrips (WFT). Chapter 3 investigates the biological development of H. victoriensis, including egg, larva, prepupa, pupa and adult stages. Haplothrips victoriensis fed with 10% honey solution, mixed pollen and Tyrophagus eggs took about 16-22 days to develop from eggs to adults at 25 oC. Developmental times of immature H. victoriensis varied when fed on different food sources. The longevity of H. victoriensis was significantly different with different diets. Chapter 4 examines predatory and cannibalistic characteristics and consumption of H. victoriensis on various prey. Haplothrips victoriensis was found to feed on many kinds of common prey; Two spotted mite (TSM), Tyrophagus mite, WFT, spotted alfalfa aphid, greenhouse whitefly and diamond back moth but not on ash whitefly. Importantly, H. victoriensis was also found to be cannibalistic which might affect population fluctuations in the laboratory and in the field. Chapter 5 examines the ecology and hosts of H. victoriensis in South Australia and taxonomy of H. victoriensis and some other Haplothrips species being similar to H. victoriensis. Haplothrips victoriensis was found to live on flowers from a range of different plant families. Morphological characteristics of the immature stages of H. victoriensis and a key developed to separate common Haplothrips in S.A. As well, COI was used to possibly identify H. victoriensis and its morphologically similar taxa and investigate whether H. victoriensis is a single species or perhaps contains cryptic species. None of the specimens of H. victoriensis included in the analyses showed any variation in COI indicating a single species for horticultural areas in S.A. Chapter 6 provides an overall discussion of the main results and indicates areas of future research. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1522174 / Thesis (M.Sc.) -- University of Adelaide, School of Earth and Environmental Sciences, 2010
75

Renal proximal tubular handling of nucleosides by human nucleoside transporter proteins

Elwi, Adam Nader. January 2009 (has links)
Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Oncology. Title from pdf file main screen (viewed on August 1, 2009). Includes bibliographical references.
76

Design of welded tubular connections basis and use of AWS code provisions /

Marshall, Peter William. January 1992 (has links)
Originally presented as the author's Thesis (Ph. D.)--University of Kumamoto. / Includes bibliographical references and index.
77

Efeito dos parâmetros de pulso sobre as características geométricas e desempenho da soldagem com arame tubular autoprotegido e corrente pulsada

Corrêa, Fábio Ricardo Torrano [UNESP] 20 January 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-20Bitstream added on 2014-06-13T20:17:59Z : No. of bitstreams: 1 correa_frt_me_bauru.pdf: 1326371 bytes, checksum: a4dd5287d93dc0ae01a81f1278a10ffd (MD5) / No presente trabalho buscou-se determinar o comportamento das características geométricas do cordão da solda e o desempenho da soldagem, através do processo de soldagem com arame tubular autoprotegido e corrente pulsada. As características geométricas estudadas foram largura do cordão, penetração da solda e altura do reforço. Para definir o desempenho da soldagem analisou-se o rendimento de deposição e a taxa de deposição. Como metal de base utilizou-se o aço ABNT 1010 de espessura 6,35mm. O arame utilizado foi o AWS E71T-11 com diâmetro 1,1mm. A soldas foram realizadas por simples deposição, utilizando-se uma fonte de solda microprocessada, mantendo-se a velocidade de soldagem e a distancia tocha/peça constante. Durante o processo de soldagem os parâmetros de pulso analisados foram a corrente de pico (Ap), corrente de base (Ab), freqüência de pulso (F) e tempo de pico (Tp). Para coleta dos dados foi utilizada uma placa de aquisição de dados com interface a um microcomputador. De posse dos dados, foi aplicada a técnica de ANOVA, com o objetivo de identificar, quantificar e localizar a significância das dispersões. Verificou-se que a tensão média tem grande influência nas características geométricas do cordão de solda e de desempenho da soldagem. Para cada incremento de F provocou uma redução da largura do cordão de solda e aumento da penetração, altura do reforço, taxa de deposição e rendimento de deposição. O incremento Tp acarretou a formação de cordões mais largos, como também a redução na altura do reforço, penetração, taxa de deposição e rendimento de deposição. A variação de Ap não teve influência sobre largura do cordão, a altura do reforço, taxa de deposição e rendimento de deposição. / In the present work one searched to determine the behavior of the geometric characteristics of the bead weld and the performance of the welding, through the process self-shielded flux cored arc welding and pulsed current. The studied geometric characteristics had been width of bead, penetration of the weld, height of the reinforcement. To define the performance of the welding one analyzed the deposition efficiency and the deposition rate. As metal base was used steel ABNT 1010 with thickness 6, 35 mm. The used wire was the AWS E71T-11 with diameter 1,1 mm. The welds had been carried through by simple deposition, using themselves a microprocessed weld power source, remaining constant it welding speed and the stick-out. During the welding process the analyzed parameters of pulse had been the peak current (Ap), base current (Ab), pulse frequency (F) and peak duration (Tp). For collection of the data a plate of acquisition of data with interface to a microcomputer was used. Of ownership of the data, the ANOVA technique was applied, with the objective to identify, to quantify and to locate the significance of the dispersions. It was verified that the mean voltage has great influence in the geometric characteristics of the bead weld and the performance of the welding. For each increment of F it provoked a reduction of the width of the bead weld and increase of the penetration, height of the reinforcement, deposition rate and deposition efficiency. The Tp increment caused the wider bead weld formation, as also the reduction in the height of the reinforcement, penetration, deposition rate and deposition efficiency. The variation of Ap did not have influence on width of the bead weld, the height of the reinforcement, deposition rate and deposition efficiency.
78

Pilares mistos : tubos metalicos com nucleo de concreto de alta resistencia

Bonaldo, Everaldo 28 July 2018 (has links)
Orientador : Luiz Roberto Sobreira de Agostini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-07-28T11:33:10Z (GMT). No. of bitstreams: 1 Bonaldo_Everaldo_M.pdf: 3945351 bytes, checksum: 864d8a2d98add733ff3772d538e714b9 (MD5) Previous issue date: 2001 / Mestrado
79

Behaviour of shearhead system between flat reinforced concrete slab and steel tubular column

Yan, Ping Yu January 2011 (has links)
This thesis presents the results of an experimental, numerical and analytical study to develop a design method to calculate punching shear resistance for a new shearhead system between tubular steel column and reinforced concrete flat slab. This shearhead system enables two of the most popular structural systems, i.e. reinforced concrete flat slab floor and steel tubular column, to be used to produce efficient structures of low cost and short construction time. This research investigates slabs without and with a service hole adjacent to the column. The new shearhead system should not only possess sufficient punching shear resistance, but should also be efficient for construction. The main methodology for this project was based on numerical finite element simulations verified by two full scale tests. These two tests were carried out in the University of Manchester's Structural Testing Laboratory. The two specimens had the same slab size, thickness and reinforcement ratio, but differed in the column shape (rectangular or circular), central reinforcement arrangement (continuous or discontinuous), shearhead position in the slab thickness and shearhead fabrication arrangement. Recorded load-deflection and load-strain relationships, crack development and critical perimeter were used for detailed validation of using the commercial finite element software ABAQUS. The validated ABAQUS model was used to conduct a comprehensive parametric study to investigate the effects of a number of design parameters, including the effect of varied column size, shearhead arm length, shearhead arm cross section, shearhead arm angle, amount of flexural reinforcement, slab thickness, shearhead positions and hole positions. The main conclusion from the parametric study was that the shearhead system could be treated as an enlarged column in normal flat slab structure. The parametric study enabled pressure distribution below the shearhead arms to be approximated for checking whether the shearhead arms would be sufficient for the enlarged column assumption to be valid. The parametric study results were also used to determine the effective depth of the flat slab and critical punching shear perimeter of the slab with and without a service hole.Using the enlarged column assumption, the punching shear resistance of all structures used in the parametric study were re-calculated using Eurocode 2 (EC2), British stand 8110 (BS8110) and American Concrete Institute code 318 (ACI 318). Comparison of calculation results using these three design methods indicates that both EC2 and BS8110 predicted very close value which reached very good agreement with the ABAQUS simulation (normally within 10%). Among these three design methods, ACI 318 was the only code that explicitly considered shearhead system. ACI 318 was not able to predict the slab critical perimeter length with good accuracy, however, its prediction of slab punching shear resistance achieved reasonably good agreement with numerical analysis results and were on the safe side. Based on these studies, a design method for calculating punching resistance of the proposed shearhead system between reinforced concrete flat slab and steel tubular column has been developed in this thesis.
80

Renal tubular mechanisms for creatinine secretion in the guinea pig

Arendshorst, William J. January 1970 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

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