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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.
271

Test Specimen Design to Identify the Characteristic Length of a CuAlloy Based on Shear Band Formation

Spieker, Klara Anneliese January 2021 (has links)
This thesis deals with the design process of a tensile test specimen geometry with the intention that the specimen will show failure in a shear band during a tensile test. The triggered shear band is linked to a characteristic length lc, which is required for a nonlocal approach to continuum damage mechanics that predicts the life expectancy of a combustion chamber independent of the FEM mesh size. To predict if a specimen will fail in the preferred manner, numerical simulations have been performed and were analysed with the newly defined failure-in-shear-band indicator. Ductile failure modes and the fracture process depend strongly on the stress state. Therefore the indicator is formulated as a function of the Lode parameter and the stress triaxiality. Several double-notched bar specimens have been designed with different notch radii and notch depths. The failure-in-shear-band indicator implies promising values for a small notch radius and larger notch depth. Tensile tests were performed on four specimens which successfully failed in a shear band. Furthermore, a first statement on the magnitude of the characteristic length of CuAgZr is given. / Detta arbete behandlar designprocessen för en dragprovstavskonfiguration framtagen för att uppvisa brott i ett skjuvband under draghållfasthetsprovning. Initiering av skjuvbandet är kopplat till en karakteristisk längd lc, som krävs för att kunna använda en icke lokal metod för att analysera kontinuerlig skademekanik oberoende av maskstorleken i den numeriska modellen. Metoden är utvecklad för att kunna uppskatta den förväntade livslängden för en förbränningskammare. För att förutsäga om ett provobjekt kommer att gå sönder på det sätt som önskashar datorsimuleringar utförts och analyserats med den nyligen definierade indikatorn för skjuvbrott. Plastisk deformation, och så småningom brott, är starkt beroende avspänningstillståndet. Indikatorn är därför formulerad som en funktion av en s.k. Lode parametern och det treaxliga spänningstillståndet. Flera provstavsgeometrier har utformats med dubbla brottanvisningar vars radie och storlek varierats. Indikatorn för skjuvbrott ger lovande värden för små radier och ett större anvisningsdjup. Draghållfasthetsprovning utfördes på fyra provkroppar som uppvisade önskat skjuvbrott. Dessutom erhölls en första indikation om storleken på den karakteristiska längden för CuAgZr.
272

Etude expérimentale sur la localisation des déformations dans les grès poreux

Charalampidou, Elli maria 03 May 2011 (has links) (PDF)
Cette étude expérimentale traite la localisation des déformations sur un grès poreux: le grès de Vosges. Un nombre des essais triaxiaux sont effectués sous des pressions de confinement (i.e., 20 MPa - 190 MPa) et des déformations axiales différentes pour mieux comprendre la réponse mécanique de ce grès. La localisation des déformations a été étudiée dans des différentes échelles en appliquant une variation de mesures de champs (full-field methods) comme la Tomographie Ultrasonore (en 2D), les Emissions Acoustiques (en 3D), les Rayons X (en 3D), et la Corrélation des Images (en 3D). Les méthodes expérimentales ont été appliquées avant, pendant et après les essais triaxiaux. Des coupes fine ont été observées sous le microscope optique et électronique (SEM). La combinaison des multiples techniques expérimentales, qui ont des différentes sensitivités et résolutions, a décrit la procédure de la formation et l'évolution des bands de déformation observées sur le grès de Vosges. Des bandes de cisaillement ont été formées sous des pressions intermédiaires et des bandes de compaction sous des pressions élevées. Des bandes de compactions pure n'ont pas été observées.Les bandes de déformations observées se sont caractérisées comme des zones de déformation de cisaillement localisée et/ou de compaction. En plus, elles se sont caractérisées comme des structures de fable vitesse ultrasonore, des places d'origine des fissures inter- ou intra- granulaires, et des places des densités de matériel élevées.Deux mécanismes principales ont été observées au niveau de grain dans les bandes de cisaillement et de bandes de compaction (shear-enhanced compaction bands): d'un cote c'est la fissuration des grains (endommagement) et de l'autre cote c'est la réduction de porosité (sur la forme de compaction). Les deux mécanismes i présent différences sur leurs proportions et leur ordre d'occurrence dans le temps.
273

An Attributional Analysis of the Causes Cited by Junior High School Band Directors for Success and Failure at U.I.L. Concert/Sightreading Contest and Their Attitudes Towards Contest

Williams, Richard (Richard S.), 1958-2001 12 1900 (has links)
The reasons given by thirty-three junior high school band directors for success and failure at the University Interscholastic League Concert/Sightreading Contest were studied using the methodology of Attribution Theory. All of the subjects attended the same contest and were members of a region which included urban and suburban schools. The subjects responded to a questionnaire which evaluated their attitudes towards the contest, allowed them to make judgments about other directors in hypothetical contest situations, and finally asked them to list the five most important reasons for their success or failure at the contest in an open-response format.
274

Non-parametric modelling of pollution-generating technologies : theoretical and methodological considerations, with an application to the case of greenhouse gas emissions in suckler breeding systems in French grassland areas / la modélisation non paramétrique des technologies génératrices de pollution : considérations théoriques et méthodologiques, avec une application au cas des émissions de gaz à effet de serre dans les systèmes d'élevage allaitant dans les zones de prairies françaises

Dakpo, K. Hervé 15 June 2015 (has links)
La prise en compte des problèmes environnementaux dans la responsabilité sociale des entreprises a généré en économie de nombreuses propositions. Parmi elles, le cadre d’analyse basé sur l’évaluation de la performance en utilisant notamment les techniques d’enveloppement des données (DEA) s’est très vite répandu dans la littérature théorique comme empirique. Ce travail de thèse s’inscrit dans cette logique en mettant l’accent sur la modélisation des technologies polluantes. Par ailleurs, la question des changements climatiques et de la forte contribution de l’agriculture et en particulier de l’élevage dans les émissions de gaz à effet de serre (GES) impose à ce secteur de relever aujourd’hui en plus du défi économique celui de l’amélioration de sa performance environnementale. L’objectif général de cette recherche doctorale est donc de fournir un nouveau cadre d’analyse théorique et empirique dans la modélisation des technologies polluantes afin d’évaluer l’éco-efficience des systèmes productifs, en particulier le cas des émissions de GES en élevage extensif de ruminants. Dans un premier temps, nous montrons les limites théoriques et méthodologiques des modèles existants. Néanmoins, nous insistons sur le fait que les approches basées sur l’estimation de plusieurs sous-technologies indépendantes pour prendre en compte les différents processus présents dans les systèmes productifs sont très prometteuses. Dès lors dans un deuxième temps, nous proposons une nouvelle extension de la méthode « by-production » qui repose sur l’introduction d’interconnections entre les différentes sous-technologies impliquées afin de construire un système plus unifié. Dans un troisième temps, une comparaison empirique utilisant des données d’exploitations de viande ovine de notre extension avec les approches existantes a révélé certaines incohérences de ces dernières. Enfin pour aller plus loin, nous élargissons dans un quatrième temps notre approche afin de prendre en compte les aspects dynamiques et notamment la présence de coûts d’ajustement. Les résultats de l’analyse empirique entreprise avec des données d’exploitations bovines allaitantes (viande) ont révélé la nécessité de prendre en compte ces aspects, mais ont aussi révélé la forte hétérogénéité existante dans les stratégies d’investissements des éleveurs. / The growing importance of environmental matters in social responsibility of firms has generated many frameworks of analysis in the economic literature. Among those frameworks, performance evaluation and benchmarking using the non-parametric Data Envelopment Analysis (DEA) have increased at a very fast rate. This PhD research focuses on models that include undesirable outputs such as pollution in the overall production system, to appraise eco-efficiency of decision making units (DMUs). Besides, the recent awareness on the large contribution of agriculture and particularly livestock farming to global warming, has highlighted for this sector the challenge of reaching both economic and environmental performances. In this line, the overall objective of this dissertation is to provide a theoretical and empirical background in modelling pollution-generating technologies and to suggest theoretical improvements that are consistent with the particular case of greenhouse gas emissions in extensive livestock systems. Firstly, we showed that all existing approaches that deal with undesirable outputs in the non-parametric analysis (i.e. DEA) have some strong drawbacks. However, the models grounded on the estimation of multiple independent sub-technologies offer interesting opportunities. Secondly, I developed a new framework that extends the by-production approach through the introduction of some explicit dependence constraints that link the sub-technologies in order to build a unified system. Thirdly, an empirical comparison, using a sample of French sheep meat farms, of this by-production modelling extension with the existing approaches, revealed some inconsistencies of these latter. Finally, we expanded this new by-production formulation to account for dynamic aspects related to the presence of adjustment costs. The application to the case of French suckler cow farms underlined the necessity of accounting for dynamic aspects and also showed high heterogeneity in investment strategies of these farmers.
275

Analyse de la cinétique de transformation et des instabilités de déformation dans des aciers TRIP "Moyen Manganèse" de 3ème génération / Analysis of transformation kinetics and strain instabilities in 3rd generation medium manganese TRIP Steels

Callahan, Michael 21 November 2017 (has links)
Cette thèse caractérise un acier Moyen Mn à 0.2C-5Mn-2.5Al qui montre un écrouissage très fort au cours de la déformation plastique dû à l’effet TRIP. Pendant TRIP, l’austénite résiduelle paramagnétique se transforme en martensite ferromagnétique sous déformation plastique, ce qui conduit à un fort écrouissage. Le taux de cet écrouissage dépend des paramètres de fabrication et surtout la température de recuit intercritique. Ces aciers ont aussi des fois le tendance de se déformer de façon hétérogène par des bandes de Lüders ou PLC.Dans cette thèse, une méthode de caractérisation de la cinétique de transformation de phase est développée sur la base des mesures de l’aimantation saturée de l’acier. La méthode magnétique est unique dans son implémentation in-situ sans aucun effet sur l’essai de traction. Une correction pour les effets de la contrainte appliquée sur l’aimantation est aussi introduite pour la première fois avec une base physique. Les résultats des mesures magnétiques ont été comparés contre des caractérisations des bandes de déformation pour montrer que la transformation de phase coïncide avec le passage des bandes de déformation. La sensibilité à la vitesse de déformation est analysée et une caractérisation de la présence et type de bande PLC est présentée en fonction de la cinétique de transformation de phase. / This thesis studies the mechanical behavior of a 0.2C-5Mn-2.5Al Medium Mn steel that exhibits a very high degree of work hardening due to transformation-induced plasticity (TRIP) during plastic deformation. During TRIP, paramagnetic retained austenite is transformed to ferromagnetic martensite with the application of plastic strain and generates a significant amount of work hardening. The rate of work hardening is seen to vary greatly depending on processing parameters—notably the intercritical annealing temperature. These steels also often deform heterogeneously through the propagation of Lüders or PLC strain bands.This research develops a method to characterize the kinetics of the TRIP effect through measurements of the samples magnetic properties. The method is novel in that it is performed in-situ with no effect on the tensile test and is able to correct for the effects of the applied stress on the magnetic properties. The results of these experiments were compared to characterizations of the strain bands to demonstrate that TRIP coincides with the passage of a Lüders or PLC band. The strain rate sensitivity of the steels is analyzed and the presence and type of PLC bands are characterized with respect to the transformation kinetics.
276

"Local Band Does O.K.": A Case Study of Class and Scene Politics in the Jam Scene of Northwest Ohio

Brown, Katelen Elyse 24 July 2018 (has links)
No description available.
277

An Analysis of the Course of Study for Instrumental Music Courses in the High Schools of Texas

Howard, William Harmon 06 1900 (has links)
The purpose of this survey was to analyze the course of study in instrumental music prescribed by the Texas State Department for the high schools of the state and to determine whether or not a coordinated and well-rounded program of education in instrumental music is being offered in the schools of Texas. It was hoped, furthermore, that, by comparing this program with others elsewhere, this analysis might show whether or not Texas is following any general trend in instrumental music education.
278

Articulation of the Primary with the Secondary Instrumental Band Program in the Public Schools

Olivadoti, Joseph, 1893-1977 08 1900 (has links)
The purpose of this thesis is to acquaint future band and orchestra directors with a successful, thoroughly "tried and tested" plan of building an instrumental program within the music department. This thesis presents the technique of instrumentating the senior high school band by planning an instrumental program from the first grade to the time the band student reaches the senior high school level.
279

Efeito da aplicação do lodo de esgoto e de fertilização mineral no crescimento e propriedades da madeira de árvores de Eucalyptus grandis W. Hill ex. Maiden / Effect of the application of the sewage sludge and mineral fertilization in the growth and the wood properties of Eucalyptus grandis trees W. Hill. ex. Maiden

Sette Junior, Carlos Roberto 18 June 2007 (has links)
As plantações sustentáveis e de alta produtividade de espécies de eucalipto podem contribuir para a solução dos desafios ligados a oferta de madeira para os diversos segmentos industriais, bem como os de ordem ambiental e social existentes no Brasil e no mundo. As pesquisas experimentais têm demonstrado que as fertilizações mineral e orgânica (biossólidos) aumentam a taxa de crescimento das árvores de eucalipto sendo, contudo, escassas as informações sobre as propriedades da madeira. A partir de dois experimentos de campo instalados na Estação Experimental de Itatinga-SP, foram realizadas avaliações da dinâmica do crescimento em diâmetro do tronco e das propriedades anatômicas e físicas do lenho de árvores de Eucalyptus grandis. As árvores de eucalipto foram plantadas no espaçamento de 3x2 m e fertilizadas com nitrogênio (plantio, 6, 12, 18 meses) e lodo de esgoto (plantio, 8 meses) no Experimento A e potássio e sódio (plantio, 6, 12 meses) no Experimento B. Nos dois experimentos foram selecionadas, de acordo com as classes de área basal, as árvores de eucalipto com idade de 22 meses e instaladas faixas dendrométricas para o monitoramento do incremento em diâmetro do tronco no período de fevereiro de 2006 a janeiro de 2007. Árvores de eucalipto selecionadas em classes de área basal foram cortadas com a idade de 24 meses e coletadas amostras do lenho em diferentes porcentagens da sua altura total. De cada tratamento, foram analisadas as propriedades anatômicas e físicas da madeira, sendo (i) variação radial das dimensões das fibras, vasos e da densidade aparente do lenho por densitometria de raios X e (ii) variação longitudinal da densidade básica do lenho. Nos dois experimentos detectou-se o efeito da sazonalidade climática no incremento em diâmetro do tronco das árvores, com períodos de máximo (fevereiromaio) e de mínimo (julho-agosto) crescimento. Foram, também, encontradas diferenças significativas entre os tratamentos de fertilização e as classes de área basal das árvores para o crescimento e para alguns parâmetros de densidade do lenho e dimensões das fibras e vasos. O modelo de variação da densidade aparente do lenho se caracterizou por valores elevados na região da medula, decrescendo e estabilizando em direção a casca. A densidade básica do lenho decresceu e/ou estabilizou da base até 25% da altura das árvores; aumentou entre 25 e 75% da altura e decresceu até o topo. A variação radial (medula-casca) foi caracterizada pelo aumento da largura, diâmetro do lume e comprimento e a diminuição da espessura da parede celular das fibras e pelo aumento do diâmetro tangencial e da área ocupada e redução da freqüência dos vasos. / The sustainable and high productivity plantations of eucalyptus species can contribute to the solution of the challenges regarding the wood for the several industrial sectors, as well as the environmental and social aspects in Brazil and in the world. The researches experimental have been demonstrating that the mineral and organic fertilizations (biosolids) increase the growth rate of the eucalypt trees being, however, scarce the information on the wood properties. From two field experiments installed in the Experimental Station of Itatinga-SP, evaluations were done one the growth dynamics in of trees diameter and the anatomical and physical wood properties of Eucalyptus grandis. The eucalypt trees were planted in the spacing 3x2 m and fertilized with nitrogen (planting, 6, 12, 18 months) and sewage sludge (planting, 8 months) in the Experiment A and potassium and sodium (planting, 6, 12 months) in the Experiment B. In the two experiments were selected, according with the classes of basal area, the eucalypt trees with 22 months old and installed dendrometer bands for the monitoring of the increment in trees diameter from February 2006 to January 2007. Eucalypt trees selected in classes of basal area were cut with 24 months old and wood samples were collected in different % of the total height. The anatomical and physical wood properties were analyzed, being (i) the radial variation of the fibers, vessels and the wood apparent density by of X-ray densitometry and (ii) longitudinal variation of the wood basic density. In the two experiments the effect of the climatic seasonality was detected in increment of the trees diameter, with laugher grow periods (February-May) and lower periods (July- August). Significant differences between the treatments and classes of basal area of the trees for the growth and some parameters of wood density and fibers and vessels were also detected. The model of variation of the wood apparent density was elevated near to pith and decreased/stabilizes in bark direction. The wood basic density decreased and/or it stabilized of the base until 25%; increased up to 75% and decreased up to 100% of the trees height. The radial variation was characterized by the increase of the width, lumen diameter and length and the decrease of the cell wall thickness of the fibers and for the increase of the tangential diameter and the area and reduction of the frequency of the vessels.
280

A guide for incorporating corps-style percussion

Lindblom, Daniel Lee January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries / Department: Music.

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