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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.
101

FICST: A Tool for Sensitivity Analysis of SCWR Fuel Isotopic Composition to Nuclear Data

Mostofian, Sara January 2014 (has links)
With an ever-increasing population both in Canada and globally, an improved quality of life will depend on having access to energy. The non-renewable, carbon-based, sources of energy that presently provide a major amount of the world's energy supply are depleting and therefore will be expensive in the future. Nuclear technology is a relatively new technology which can fulfill future energy needs but requires highly specialized skills and knowledge to continue to make it safer, cleaner, more reliable, and more affordable. Thus the nuclear industry puts lots of efforts to develop and improve the next generation of nuclear power plants. The Supercritical Water Reactors (SCWRs) are one of the Generation IV nuclear-reactor systems. The SCWRs, to a large extent, are very similar to light water reactors, but with a simpler design. The main advantage of SCWRs is their higher thermal efficiency. The Canadian SCWR has adopted an innovative fuel concept which is a mixture of plutonium and thorium oxides (Th, Pu) O2. The role of nuclear data in fuel development and reactor-physics analysis is quite significant. With the development of nuclear data files over the years, nuclear cross sections and other parameters are widely available, but their accuracy is still a concern. Also the accuracy of nuclear data is more reliable for uranium-based fuels than for thorium-based fuels. It is not known how the uncertainties in the nuclear data will impact the fuel depletion in a SCWR. Thus a sensitivity analysis tool has been developed to evaluate the impact of uncertainties in the neutron cross-sections of the actinides present in SCWR fuel. This document provides the details on the theory and methodology used to develop this tool (FICST). The objective of this work is to develop a code, not any specific calculation done with it. / Thesis / Master of Applied Science (MASc)
102

Rejection Sensitivity and Support Seeking Among the Stigmatized

LaDuke, S. L., Williams, Stacey L. 01 August 2014 (has links)
No description available.
103

Rejection Sensitivity and Support Seeking Among the Stigmatized

LaDuke, Sheri L., Williams, Stacey L. 01 August 2014 (has links)
No description available.
104

MX908®: Sensitivity and Limit of Detection Evaluation of On Swab and Off Table Samples

Brown, Wyatt 19 December 2022 (has links)
No description available.
105

Whole-Body Vibration and Its Effects on Electromechanical Delay and Vertical Jump Performance

Stevenson, Deja Lee 27 June 2005 (has links) (PDF)
The purpose of this study was to determine the effects of whole-body vibration on electromechanical delay and vertical jump performance. Twenty college aged subjects participated in 10 intervals of whole-body vibration (WBV) at a frequency of 26 Hz and amplitude of 5 mm. Each interval consisted of 60 s of WBV in a half-squat followed by 60 s of rest. After 5 intervals, subjects had 6 min of rest before the final 5 intervals. Each subject also participated in the control which included the same 10 intervals in a half-squat without the WBV. Tests were conducted to assess electromechanical delay (EMD) and vertical jump at baseline, during the 6 min rest period and immediately after the treatment and control. EMD was measured using tibial nerve stimulation and a force plate. EMD was recorded as the lag time between the initiation of gastrocnemeus stimulation and plantar flexion force production. Vertical jump was measured using a force plate and subjects' flight time. The factorial ANOVA results showed no differences between groups, the control and WBV treatment, for both EMD (F (2, 38) = 1.385, p = 0.263) and vertical jump (F (2, 38) = 0.040, p < 0.96). The WBV treatment protocol chosen had no effect on vertical jump. These results suggest that WBV, using this protocol, is not effective for acute vertical jump or EMD enhancement. Also, since there was no effect on EMD, this suggests that the WBV treatment did not enhance muscle spindle sensitivity.
106

Efficient Sensitivity Analysis and Design Optimization of Photonic Devices

Swillam, Mohamed A. 10 1900 (has links)
Pages (41,133,161,209) were omitted from the thesis as they were completely blank pages. / <p> In this thesis, we propose efficient approaches for design optimization of passive and active photonic devices. These approaches are based on utilizing gradient based optimization algorithms for efficient optimization of photonic devices. Some of the proposed approaches obtain the required gradient (sensitivity) information efficiently using adjoint variable method (AVM) applied directly to the exploited numerical techniques. Other approaches are based on formulating the design problem as an optimization problem using convex programming. These approaches utilize the gradient-based interior point method (IPM) for solving the design.</p> <p> The AVM aims at efficiently obtaining the sensitivity information using the numerical technique. This technique requires a solution of an additional simulation of the adjoint system. The information obtained from the original and the adjoint simulation is sufficient to obtain the response and the sensitivity of the response with respect to all the design parameters. The AVM technique differs for different numerical method. </p> <p> The obtained sensitivity using the AVM approach is not only useful for exploiting gradient based optimization for design optimization, but also for yield and tolerance analyses of the newly proposed designs. </p> <p> We proposed a second order accurate approach to obtain the sensitivity information using finite difference time domain (FDTD) technique. This approach utilizes the AVM to efficiently obtain the sensitivity information. This approach is exploited for efficiently obtaining the sensitivity of the power reflectivity and coupling coefficient of various devices. This approach has been also utilized for obtaining the sensitivity of the dispersion characteristics of different guided wave structures.</p> <p> We also introduce a novel approach for sensitivity analysis of photonic devices using the beam propagation method (BPM). This approach is simple and easy to implement. It exploits the existing factorization of the system matrices for efficient calculation of the sensitivity of the required objective function. This approach is also utilized for sensitivity analysis of the vectorial modal properties of different guided wave structures. This approach is also exploited for sensitivity analysis of various surface plasmon devices. </p> <p> This AVM approach is also exploited to propose a novel design of an optical switch with wide working wavelength band and compact size. The switch is based on the self imaging theory in multimode waveguide with a refractive index has approximate parabolic profile. The design problem is formulated as two stage optimization procedure. The optimization algorithm exploits the efficiently obtained sensitivity information from a BPM simulation. The final design has interesting characteristics.</p> <p> An efficient approach is also proposed to obtain the sensitivity of the energy levels and wavefunctions of different quantum structures obtained using time dependent and time independent Schrodinger equation. This approach is exploited for design optimization of different quantum well lasers.</p> <p> We also propose a convex formulation for the design problem of multilayer optical coatings. This formulation allows for efficient design of structures with large number of layers in fractions of a second without an initial design.</p> / Thesis / Doctor of Philosophy (PhD)
107

High Sensitivity Studies Using a Tandem Mass Spectrometer

Heyland, Gunter Rolf 05 1900 (has links)
<p> A description of the McMaster tandem mass spectrometer is given and the usefulness of this instrument in high sensitivity applications is discussed.</p> <p> The pulse characteristics of the 17 stage Allen type electron multiplier which is used on the two stage mass spectrometer were determined and possible means of achieving an improved response in counting applications are discussed.</p> <p> An ion source of the crucible variety was constructed which made possible the detection of 10^-9 grams of a tin isotope. This source was used to detect sub microgram quantities of an enriched tin sample and was also used for the qualitative analysis of a sample which contained tin extracted from a reactor irradiated fuel rod.</p> / Thesis / Master of Science (MSc)
108

A Role for CEACAM2 in Insulin Homeostasis and Action

Patel, Payal R. 23 August 2010 (has links)
No description available.
109

Investigating the potential anti-diabetic effect of sulforaphane

Luo, Jing 01 July 2014 (has links)
Type 2 diabetes (T2D) is a major public health issue worldwide and it currently affects nearly 26 million people in the United States. It is estimated that one third of Americans will have diabetes by 2050. T2D is a result of chronic insulin resistance and loss of beta-cell mass and function. Both in experimental animals and people, obesity is a leading pathogenic factor for developing insulin resistance, which is always associated with the impairment in energy metabolism, causing increased intracellular fat content in skeletal muscle, liver, fat, as well as pancreatic islets. Constant insulin resistance will progress to T2D when beta-cells are unable to secret adequate amount of insulin to compensate for decreased insulin sensitivity. In the present study, I investigated whether sulforaphane, a natural compound derived from cruciferous vegetables, can prevent high-fat (HF) diet-induced obesity and diabetes in C57BL/6 mice. Dietary intake of sulforaphane (250 mg/kg diet) prevented hyperglycemia and increased insulin sensitivity in HF diet-induced obese mice. Mice treated with sulforaphane had significant lower serum insulin levels (1.93±0.11 μg/dl) as compared to those without treatment (3.09±0.27 μg/dl, P<0.05). In second study, administration of sulforaphane (40 mg/kg body weight daily via gavage) in obese mice enhanced body weight loss and improved insulin sensitivity. Moreover, sulforaphane increased pyruvate oxidation by 28.85% (P<0.05) and enhanced fatty acid oxidation efficiency by 2.2 fold (P<0.05) in primary human muscle cells. These results suggest that sulforaphane may be a naturally occurring insulin-sensitizing agent that is capable of preventing T2D. / Master of Science
110

Practical Analysis of the Dynamic Characteristics of JavaScript

Wei, Shiyi 05 October 2015 (has links)
JavaScript is a dynamic object-oriented programming language, which is designed with flexible programming mechanisms. JavaScript is widely used in developing sophisticated software systems, especially web applications. Despite of its popularity, there is a lack of software tools that support JavaScript for software engineering clients. Dataflow analysis approximates software behavior by analyzing the program code; it is the foundation for many software tools. However, several unique features of JavaScript render existing dataflow analysis techniques ineffective. Reflective constructs, generating code at runtime, make it difficult to acquire the complete program at compile time. Dynamic typing, resulting in changes in object behavior, poses a challenge for building accurate models of objects. Different functionalities can be observed when a function is variadic; the variance of the function behavior may be caused by the arguments whose values can only be known at runtime. Object constructors may be polymorphic such that objects created by the same constructor may contain different properties. In addition to object-oriented programming, JavaScript supports paradigms of functional and procedural programming; this feature renders dataflow analysis techniques ineffective when a JavaScript application uses multiple paradigms. Dataflow analysis needs to handle these challenges. In this work, we present an analysis framework and several dataflow analyses that can handle dynamic features in JavaScript. The first contribution of our work is the design and instantiation of the JavaScript Blended Analysis Framework (JSBAF). This general-purpose and flexible framework judiciously combines dynamic and static analyses. We have implemented an instance of JSBAF, blended taint analysis, to demonstrate the practicality of the framework. Our second contribution is an novel context-sensitive points-to analysis for JavaScript that accurately models object property changes. This algorithm uses a new program representation that enables partial flow-sensitive analysis, a more accurate object representation, and an expanded points-to graph. We have defined parameterized state sensitivity (i.e., k-state sensitivity) and evaluated the effectiveness of 1-state-sensitive analysis as the static phase of JSBAF. The third contribution of our work is an adaptive context-sensitive analysis that selectively applies context-sensitive analysis on the function level. This two-staged adaptive analysis extracts function characteristics from an inexpensive points-to analysis and uses learning-based heuristics to decide on an appropriate context-sensitive analysis per function. The experimental results show that the adaptive analysis is more precise than any single context-sensitive analysis for several programs in the benchmarks, especially for those multi-paradigm programs. / Ph. D.

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