Browsing ETDs: Virginia Tech Electronic Theses and Dissertations by Title
Now showing items 6799-6818 of 36127
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D-branes and K-homology
(Virginia Tech, 2013-04-19)In this thesis the close relationship between the topological $K$-homology group of the spacetime manifold $X$ of string theory and D-branes in string theory is examined. An element of the $K$-homology group is given by ... -
D-glucaric acid excretion: its positive association with gender, tobacco, caffeine, marijuana, and vegetarianism in humans
(Virginia Polytechnic Institute and State University, 1982)The urinary excretion of D-glucaric acid (DGA) has been used as a nonspecific measure of the induction of hepatic enzymes associated with drug metabolism in man. A survey of 124 nonmedicated men (18-56 years of age), who ... -
D-q impedance identification in three phase systems using multi-tone perturbation
(Virginia Tech, 2013-05-31)In electric power systems, the existence of constant power loads such as output-regulated power converters may bring instability problem to AC or DC distributed systems. Impedance based stability criteria has been proven ... -
DACS: an interactive computer program to aid in the design and analysis of linear control systems
(Virginia Polytechnic Institute and State University, 1985)DACS is an interactive computer program for the IBM-PC that aids in the design and analysis of linear control systems. Written in compiled basic, DACS includes Root Locus, Bode plots, Nyquist diagrams, Nichols charts, ... -
A Daily Diary Investigation of the Impact of Flexible Work Arrangements on Physical Activity Among University Staff
(Virginia Tech, 2019-06-07)The goal of this investigation was to examine personal and environmental factors that may influence levels of daily physical activity in a sample of university staff employees who use flexible work arrangements (flextime ... -
Daily ration, feeding periodicity and prey selection of sauger (Stizostedion canadense) in the Ohio River
(Virginia Polytechnic Institute and State University, 1982)Predation by saugers was evaluated from stomach contents of 550 saugers collected by gillnetting in the Gallipolis Pool of the Ohio River during June 1980 - August 1981. Abundance of prey items in the river was assessed ... -
Daily Self-Monitoring During the Winter Holiday Period: A Strategy for Holiday Weight Maintenance in Reduced-Obese Older Adults?
(Virginia Tech, 2011-02-23)Weight management is problematic among Americans, as the number of overweight adults has risen to two-thirds of the population (1). Without the identification of successful approaches to promote weight stability, it is ... -
Dairy Food Consumption in Educated, Older Women in Virginia: Use of Focus Groups to Examine Attitudes and Perceptions
(Virginia Tech, 1997-09-04)National studies indicate that older women have a suboptimal intake of calcium, and are not consuming the recommended daily servings of dairy foods. Three focus groups of 5-10 women were conducted to examine older women’s ... -
Dairy rations for Virginia
(Virginia Agricultural and Mechanical College and Polytechnic Institute, 1923) -
A Dam Conundrum: The Role of Impoundments in Stream Flow Alteration
(Virginia Tech, 2018-09-12)Over the past century, the world's rivers have become increasingly impounded to combat water scarcity and fossil-fuel reliance. Large dams have faded from popularity due to their adverse environmental effects, but small ... -
The Dam Fighters: Commons Environmental Rhetoric, Rhetorical Citizenship, and Local Ethos
(Virginia Tech, 2020-11-11)In this dissertation project, I examine the ways in which a grassroots environmental organization, the Upper French Broad Defense Association (UFBDA), was able to contribute knowledge and voice concerns regarding a Tennessee ... -
Damage analysis and mechanical response of as-received and heat-treated Nicalon/CAS-II glass-ceramic matrix composites
(Virginia Tech, 1993-04-05)Experimental results of damage development in and mechanical response of heat-treated NicaloniCAS-II laminates subjected to monotonic flexure and axial loading and to cyclic tensile loading are reported. The specimens were ... -
Damage Detection Based on the Geometric Interpretation of the Eigenvalue Problem
(Virginia Tech, 1997-12-09)A method that can be used to detect damage in structures is developed. This method is based on the convexity of the geometric interpretation of the eigenvalue problem for undamped positive definite systems. The damage ... -
Damage Detection in Aluminum Cylinders Using Modal Analysis
(Virginia Tech, 2002-07-31)Many studies have attempted to detect structural damage by examining differences in the frequency response functions of a structure before and after damage. In an experimental setting, this variation can not be attributed ... -
Damage Development in Static and Dynamic Deformations of Fiber-Reinforced Composite Plates
(Virginia Tech, 2005-12-13)A three-dimensional finite element code to analyze coupled thermomechanical deformations of composites has been developed. It incorporates geometric nonlinearities, delamination between adjoining layers, and damage due to ... -
Damage development under compression-compression fatigue loading in a stitched uniwoven graphite/epoxy composite material
(Virginia Tech, 1991)Damage initiation and growth under compression-compression fatigue loading were investigated for a stitched uniweave material system with an underlying AS4/3501-6 quasi-isotropic layup. Performance of unnotched specimens ... -
Damage identification using inductive learning
(Virginia Tech, 1994)A damage identification method incorporating the use of inductive learning is presented. Inductive learning is the process of learning from examples. The method utilizes as much dynamic-response data as is available, ... -
Damage Reduction Strategies for a Falling Humanoid Robot
(Virginia Tech, 2017-08-29)Instability of humanoid robots is a common problem, especially given external disturbances or difficult terrain. Even with the robustness of most whole body controllers, instability is inevitable given the right conditions. ... -
Damage states in laminated composite three-point bend specimens - an experimental/analytical correlation study
(Virginia Tech, 1990)Damage states in laminated composites were studied by considering the model problem of a laminated beam subjected to three-point bending. A combination of experimental and theoretical research techniques was used to correlate ... -
Dammed If You Don't: The Palmertown Tragedy of 1924 in Collective Memory
(Virginia Tech, 2016-06-24)On December 24, 1924, a wall of water and alkali muck engulfed Palmertown, a small community in Saltville, Virginia. Houses were swept away and by the time all of the bodies were pulled from the wreckage, the death toll ...
