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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.
301

Evaluating the Potential for Low Impact Development to Mitigate Impacts of Urbanization on Groundwater Dependent Ecosystems using MIKE SHE

Dekker, Peter Andrew 11 January 2013 (has links)
Groundwater dependent ecosystems (GDEs), including wetlands and river baseflow systems, are a topic of substantial scientific study. The degradation of GDEs due to urbanization has been well documented. An altered hydrologic regime, through increased impervious area resulting in a flashier hydrologic regime with lower troughs, higher peaks, and quicker changes, has been recognized as a main factor affecting ecological condition. Yet studies on GDEs rarely include a hydrologic modelling component. In this study, the conjunctive hydrologic model MIKE SHE was used to simulate the Lovers Creek subwatershed near Barrie, ON. The hydrologic regime was simulated for pre-development (natural), current (urbanized), and various low-impact development (LID) land use scenarios. The results were linked to the ecological condition via the TQmean metric, which has been used in the literature to relate the hydrologic and ecological conditions of streams. The highest percentage LID scenario restored, on average, 11% of the reduction in TQmean that occurred from pre-development to urbanized conditions, indicating that LID has the potential to protect GDEs in urbanized watersheds. It is expected that the effect of LID would be amplified if considered on a more local scale within a predominantly high density urban area. Recommendations for future modelling efforts to evaluate GDEs and represent LID are made.
302

Coupling of Stress Dependent Relative Permeability and Reservoir Simulation

Ojagbohunmi, Samuel A. Unknown Date
No description available.
303

Processes of participant engagement with the Edmonton Drug Treatment Court: A grounded theory

Sachs, Robyn A. Unknown Date
No description available.
304

Effect of glucose control on satiation, gut hormones and metabolic response to a meal in type 2 diabetes mellitus

Mourad, Carine J. January 2008 (has links)
Type 2 diabetes mellitus (T2DM) is often characterized with hyperglycemia, delayed gastric emptying time and a blunted response of gut hormones during feeding that may modulate hunger and satiety. We hypothesized that poor diabetes control is associated with greater hunger suppression, satiation and satiety than good control. We studied 9 T2DM men, after an overnight fast and in response to a 689 kcal mixed meal, twice with or without oral antihyperglycemic agents in a crossover design. Untreated, subjects had higher fasting and postprandial glucose, showed prolonged gastric emptying time and higher thermic effect of food; all factors associated with hunger suppression. Treated, glycemia decreased by 24% and postprandially GLP-1 and PYY3-36 , peptides associated with hunger suppression, were higher than without medication. Thus, no differences were observed in satiation scores between studies. However food intake from a buffet offered 5 hours post meal, an index of satiety, related to hunger scores only in the study with medication.
305

A model for time-independent and time-dependent damage evolution and their influence on creep of multidirectional Polymer composite laminates

Asadi, Amir 10 June 2013 (has links)
Application of polymer matrix composites in engineering structures has been steadily increasing over the past five decades. Multidirectional polymer composites are one class of continuous fiber reinforced polymer matrix composites used in aerospace structures, where the desired mechanical performance outweighs the cost. Their modulus and strength degrade with time (known as creep and creep rupture) during the service, owing to the viscos-elasticity of the polymer matrix. Additional contribution to this degradation comes from various damage modes developed in the plies of the composite with time and identified in this thesis as TDD (Time Dependent Damage). These damage modes may also develop due to process-induced residual stresses, and during loading to the service load, identified as TID (Time Independent Damage). TID influences the TDD, the creep and the creep rupture. The objective of this thesis is to develop a model to predict the evolution of TID and TDD in multiple plies of a laminate and their influence on creep. The predominant damage mode, transverse cracking, is modeled in this study. The model consists of four modules, PIS, QSL, SL, and VA. The PIS, QSL, and SL moduli predict changes in ply stresses for incremental change in temperature, stress, and time respectively, using lamination theory and assuming linear elastic behavior of the plies during an incremental step. In parallel, each module predicts the stored elastic energy in each ply after each incremental step and compares it with a critical stored elastic energy criterion to determine if a ply would crack. If fracture is predicted, the VA module based on variational analysis, is invoked to determine the crack density and the perturbation in ply stresses due to cracking. The perturbation stresses are used by the module that invoked the VA module to determine the ply stresses after cracking during the current incremental step. The model predictions for a [±45/90]s laminate, at two test temperatures (80C and 180C) and four stresses in the range of 20–54 MPa, compare very well with experimental results validating the model.
306

Electromagnetic full wave modal analysis of frequency-dependent underground cables

Habib, Md. Shahnoor 01 June 2011 (has links)
In this thesis, a new method has been proposed for calculating the frequencydependent parameters of underground cables. The method uses full wave formulation for calculating the modal electromagnetic fields and corresponding voltages and currents and then extracting frequency-dependent per unit length parameters of underground cables. The proposed method can be used for any cross-sectional shape of cables.
307

Photodisintegration of 3He with Double Polarizations

Laskaris, Georgios January 2015 (has links)
<p>The first measurements of the two- and three-body photodisintegration of longitudinally</p><p>polarized 3He with a circularly-polarized gamma-ray beam were carried out at the High Intensity gamma-ray Source facility located at Triangle Universities Nuclear Laboratory (TUNL). A high pressure 3He target, polarized via spin exchange optical pumping with alkali metals, was used in the experiments. The protons from the two-body photodisintegration experiment were detected using seventy two silicon surface barrier detectors of various thicknesses while the neutrons from the three-body photodisintegration were detected with sixteen 12.7 cm diameter liquid scintillator detectors. The spin-dependent cross sections and the contributions from the two- and three-body photodisintegration to the 3He Gerasimov-Drell-Hearn sum rule integrand were extracted and compared with state-of-the-art three-body calculations at the incident photon energies of 29.0 MeV (two-body) and 12.8, 14.7, and 16.5 MeV (three-body).</p><p>These are the first measurements of the contributions of the two- and three-body photodisintegration of 3He to the GDH integrand. These measurements were found to be in good agreement with the theoretical calculations which include the Coulomb interaction between protons in the final state. They also reveal-for the first time-the importance of the three-nucleon forces and the relativistic single-nucleon charge corrections which are responsible in the calculations for the observed difference</p><p>between the spin-dependent cross sections.</p> / Dissertation
308

Influence of landscape scale and habitat distribution on individual bat species and bat species richness

Brüsin, Martin January 2013 (has links)
Habitat fragmentation is one of the most important factors affecting species extinction and biodiversity loss, Species habitat response expects to differ with habitat feature at different spatial scales and this study was to identify how bat diversity and individual bat species respond to different habitat amounts. The local bat species richness was observed in 156 different locations in Östergötland and the proportion of different habitats were calculated for circular areas with diameters ranging from 400 m. to 12 km. from each location. Although we found that the individual bat species responded differently to the amount of each habitat at different spatial scales, the bat species richness showed a decreasing response with increasing spatial scale. The strongest response of bat species richness to habitat characteristics was at a scale of 939 m.
309

The metabolic response to acute exercise in adolescent boys with NIDDM relatives

Hanna, Lauren E. January 2008 (has links)
Individuals with NIDDM and low insulin sensitivity (Si) have altered fuel use, which may appear in NIDDM relatives. Adolescent males, six with NIDDM relatives (POS) and six controls (CON), matched for fitness and fatness, participated. Peak oxygen uptake (V02pea), ventilatory threshold (VT) and body composition were measured. Insulin and glucose values were used for Si estimates. Oxygen consumption (V02) and respiratory exchange ratio (RER) measurements were made at rest and during exercise at 80,100 and 120% of VT for substrate use. No group differences were found in anthropometric data, V02pea, VT or blood measurements, although fat free mass (FFM) tended to be greater in CON. CON tended to use a higher percentage carbohydrate and a lower percentage of fat than POS, but differences were no longer present after normalization to FFM. Trends towards fuel use differences may suggest metabolic abnormalities are present in POS, but further investigation is necessary. / School of Physical Education, Sport, and Exercise Science
310

Creating chimeras of human G-protein coupled receptors (HGPR40/43) for diabetic drug development

Acharya, Deepak. January 2009 (has links)
Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder of global concern that is primarily characterized by insulin resistance, relative insulin deficiency, and hyperglycemia. G- Protein Coupled Receptors (GPCRs), important mediators of cellular signaling responses, have been prime targets of drug discovery efforts in various therapeutic areas. Human G-Protein Receptor 40 (HGPR40) is highly expressed in the pancreas and has been implicated in the regulation of glucose metabolism and pathophysiology of T2DM. For effective control of diabetes, combination therapy is being considered because no single drug can completely control diabetes and its associated complications. This necessitates the identification of novel drug targets including HGPR40 which might permit development of drugs which function differently from existing drugs. This project focused on the construction of two chimeric receptor proteins named HGPR40.1-715_43.709-1013 (Chimera I) and HGPR40.1-431_43.389-1013 (Chimera II) which were made by exchanging domains within trans-membranes regions 6 and 4, of HGPR40 and HGPR43 DNA, homologous receptors which vary in amino acid sequence but which have the same three-dimensional structure. After PCR amplification of sufficient quantities of the desired gene fragments they were ligated together to form the desired recombinant chimeric proteins which were cloned into the expression vector pcDNA3.1 in two successive cloning steps. The vector contains CMV promoter, multiple cloning sites, neomycin resistance gene etc for high-level expression in a wide range of mammalian cells. The two full-length chimeras were designed to be 6452 bp and 6483 bp by exchanging either the first or the first two external domains of HGPR40 with those of HGPR43. The creation of the correct chimeras was verified by both agarose gel electrophoresis and PCR analysis. Then chimeric DNA was transformed into Escherichia coli to obtain sufficient amounts of DNA for sequencing verification of the desired construct. Upon verification, the cloned DNA was to be transfected into cultured mammalian kidney (HEK293) cells for expression of the chimeric proteins. A (FLIPR) Fluorometric Imaging Plate Reader analysis by our collaborators at Eli Lilly would have been used to measure the extent of Ca2+ efflux from the endoplasmic reticulum testing a variety of stimulatory molecules to obtain an indication of which would activate the receptor. Activation would initiate the internal (second messenger cascade) G-protein signaling pathway and result in the secretion of insulin. However, transformation of the chimeric membrane receptors into E. coli resulted in altered sequences which could not be used for the FLIPR analysis. Expression of membrane proteins in E. coli can lead to such gene rearrangements. These experiments will be repeated in the future using another type of competent cell designed to prevent genetic re-arrangements. Construction of stable clones will permit us to test numerous potential ligands to aid in development of novel therapeutic drugs targeting HGPR40 to aid in combating diabetes. / Department of Biology

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