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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.
181

Lectures on Differentials, Generalized Differentials and on some

Michel Dubois-Violette, patricia@osiris.th.u-psud.fr 02 October 2000 (has links)
No description available.
182

Dynamic Testing of Soft and Ultra-soft Materials

Huang, Sheng 20 January 2010 (has links)
A modified Split Hopkinson Pressure Bar (SHPB) system is used to determine the mechanical properties of soft and ultra-soft materials. An aluminum bar is introduced to reduce the impedance mismatch between the test system and sample. The small signal of the forces was measured by a quartz crystal gauge system. The high precision Laser gap gauge (LGG) system was used to measure the deformation of samples. The compressive tests of Cemented Paste Backfill (CPB), fresh CPB and Polymethylmethacrylate (PMMA) and the fracture toughness tests of PMMA were conducted to approve the legitimacy of our modified SHPB system. From these experiments, the efficiency and economy of the modified SHPB system were attested.
183

Temperament in beef cattle : methods of measurement, consistency and relationship to production

Sebastian, Thomas 14 December 2007
Two behavioural studies were conducted at the University of Saskatchewan beef feedlot. In the first study, the temperament of 400 steers was determined using both objective and subjective measures. The consistency of temperament, over repeated tests and between different measures, was also tested. The objective behavioural tests were conducted during the individual restraint of the steers using strain gauges and an MMD (movement-measuring-device). The time required for the steers to exit the area was also recorded. Subjective assessment of animals responsiveness during restraint was recorded on a scale of 1-5 (calm to wild). The consistency of individual differences in a steers response within the evaluation series and across repetitions, shows that this trait may represent a stable personality of the animal. The significant relationship between objective and subjective measures demonstrates that objective measures of temperament can be used to replace the traditional subjective scale as it has the added advantage of reducing inter- and intra-observer variability. The positive relationship of subjective scores and MMD values with the steers performance (average daily weight gain) shows not only that a calm temperament is conducive to productivity, but also that objective measures can replace subjective techniques for assessing temperament for performance evaluation. In the second study the reactivity of a subset of the original 400 steers (262 animals from 8 pens) to a novel stimulus was assessed. The purpose of this experiment was to determine if a steers behavioural response in the novel test was correlated to its temperament assessment determined in the first study. A remote controlled ball was dropped from the ceiling of a salt feeder while a steer licked the salt. Two overhead cameras connected to a monitor through a VCR and time lapse recorder permitted us to observe and document the response. A lack of correlation between measures of handling and novelty measures show that reactivity of animals in the handling chute and their responsiveness to the novel stimulus do not represent one and the same trait.
184

Dynamic Testing of Soft and Ultra-soft Materials

Huang, Sheng 20 January 2010 (has links)
A modified Split Hopkinson Pressure Bar (SHPB) system is used to determine the mechanical properties of soft and ultra-soft materials. An aluminum bar is introduced to reduce the impedance mismatch between the test system and sample. The small signal of the forces was measured by a quartz crystal gauge system. The high precision Laser gap gauge (LGG) system was used to measure the deformation of samples. The compressive tests of Cemented Paste Backfill (CPB), fresh CPB and Polymethylmethacrylate (PMMA) and the fracture toughness tests of PMMA were conducted to approve the legitimacy of our modified SHPB system. From these experiments, the efficiency and economy of the modified SHPB system were attested.
185

Relativistic lagrangian non-linear field theories supporting non-topological soliton solutions

Rubiera García, Diego 17 December 2008 (has links)
En el contexto de la teoría de campos el interés en soluciones extendidas describiendo campos asociados a partículas puntuales data de los años 30, con los intentos de Born e Infeld para construir una electrodinámica no-lineal cuyas soluciones electrostáticas a simetría esférica eliminaran la divergencia de la autoenergía del electrón en Electrodinámica Clásica.En esta tesis realizamos un amplio estudio de una extensa clase de teorías relativistas de campos que contienen soluciones de tipo solitón no-topológico en tres dimensiones espaciales. Específicamente estudiamos campos (multi) escalares que surgen en teorías cuyos lagrangianos están definidos como funciones generales del término cinético habitual, y campos de gauge (abelianos y no-abelianos) en teorías gauge generalizadas con lagrangianos funciones de los dos invariantes cuadráticos del campo habituales. En el caso escalar hemos obtenido una completa caracterización de las soluciones estáticas a simetría esférica con energía finita, definida positiva, y que además son estables. Para el caso gauge se ha realizado un estudio general que conduce también en este caso a un completa caracterización de las soluciones electrostáticas a simetría esférica cuyas formas y energías pueden ponerse en relación con sus contrapartidas (multi) escalares. En todo este estudio la condición de "admisibilidad", que corresponde a la imposición de una serie de restricciones para obtener teorías físicamente admisibles, lleva una descripción exhaustiva de esta clase de teorías no-lineales.A partir de principios variacionales sobre la energía y del estudio de la evolución dinámica de las perturbaciones de estas soluciones en las ecuaciones de campos se han obtenido condiciones necesarias y suficientes para que estas soluciones (multi) escalares y gauge sean estables en el sentido "débil", es decir, frente a pequeñas perturbaciones que conserven la carga de cada campo. Asimismo, se introducen ejemplos explícitos de lagrangianos que pueden tener interesantes consecuencias fenomenológicas en varias áreas. Dichos lagrangianos se han estudiado con detalle, obteniendo una completa descripción de sus energías y otras propiedades físicamente relevantes. Un ejemplo particular de esta clase de modelos sería la teoría de Born-Infeld. Finalmente se han estudiado las aplicaciones que dichos lagrangianos con soluciones solitón no-topológico pueden tener en diversos ámbitos, tales como los lagrangianos efectivos en Electrodinámica Cuántica, o la descripción de la estructura interna de los hadrones.
186

Lastcells applikation : Verktyg för montering av trådtöjningsgivare i lastcell

Stumle, Joakim January 2007 (has links)
Ett verktyg för applicering av trådtöjningsgivare har tagits fram på uppdrag av AED AB i Växjö. Verktyget skall användas för färdigställning/slutmontering av lastceller som i sin tur skall användas till att mäta vilka krafter som påverkar en skogsmaskin när denna lastas med sin givna maxlast. Verktyget skall föras in i ett 25 mm brett hål där det skall hålla fast och lägga tryck på fyra trådtöjningsgivare, en i vardera riktning, vilka bestrykts med lim. Verktyget skall hålla ett tryck på tre till fyra kiloPond medan lastcellen värms till 150° C då limmet härdar. Verktyget består av fyra ben, ett i vardera riktning. De är ledande i en änden. Andra änden på benen är avfasad och bildar en öppning. När en kula trycker mot benens avfasade ytor expanderar dem utåt och trycker därmed den limbestrukna trådtöjningsgivaren mot hålets vägg. / A tool for the application of strain gauges have been constructed by the commission of AED AB in Växjö. The tool shall be used for the assembling of loadcells which then will be used for measuring forces that affects a loggingmachinery when loaded with its maximum load. The tool shall be inserted in a 25 mm wide hole where it is supposed to hold and apply load to four strain gauges, one in each direction, which has been smeared with glue. The tool shall maintain a pressure of three to four kiloPond while the loadcell is heated to 150 C until the glue has hardened. It consists of four legs with a joint in one end and a slant surface by the other. When a ball is pushed against the slant surfaces, the legs will expand and push the glue smeared strain gauges against the wall of the hole.
187

Temperament in beef cattle : methods of measurement, consistency and relationship to production

Sebastian, Thomas 14 December 2007 (has links)
Two behavioural studies were conducted at the University of Saskatchewan beef feedlot. In the first study, the temperament of 400 steers was determined using both objective and subjective measures. The consistency of temperament, over repeated tests and between different measures, was also tested. The objective behavioural tests were conducted during the individual restraint of the steers using strain gauges and an MMD (movement-measuring-device). The time required for the steers to exit the area was also recorded. Subjective assessment of animals responsiveness during restraint was recorded on a scale of 1-5 (calm to wild). The consistency of individual differences in a steers response within the evaluation series and across repetitions, shows that this trait may represent a stable personality of the animal. The significant relationship between objective and subjective measures demonstrates that objective measures of temperament can be used to replace the traditional subjective scale as it has the added advantage of reducing inter- and intra-observer variability. The positive relationship of subjective scores and MMD values with the steers performance (average daily weight gain) shows not only that a calm temperament is conducive to productivity, but also that objective measures can replace subjective techniques for assessing temperament for performance evaluation. In the second study the reactivity of a subset of the original 400 steers (262 animals from 8 pens) to a novel stimulus was assessed. The purpose of this experiment was to determine if a steers behavioural response in the novel test was correlated to its temperament assessment determined in the first study. A remote controlled ball was dropped from the ceiling of a salt feeder while a steer licked the salt. Two overhead cameras connected to a monitor through a VCR and time lapse recorder permitted us to observe and document the response. A lack of correlation between measures of handling and novelty measures show that reactivity of animals in the handling chute and their responsiveness to the novel stimulus do not represent one and the same trait.
188

Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges

Castillo, Davis 2011 May 1900 (has links)
New measuring methods continue to be developed in the field of wind anemometry for various environments subject to low-speed and high-speed flows, turbulent-present flows, and ideal and non-ideal flows. As a result, anemometry has taken different avenues for these environments from the traditional cup model to sonar, hot-wire, and recent developments with sphere anemometers. Several measurement methods have modeled the air drag force as a quadratic function of the corresponding wind speed. Furthermore, by incorporating non-drag fluid forces in addition to the main drag force, a dynamic set of equations of motion for the deflection and strain of a spherical anemometer's beam can be derived. By utilizing the equations of motion to develop a direct relationship to a measurable parameter, such as strain, an approximation for wind speed based on a measurement is available. These ODE's for the strain model can then be used to relate directly the fluid speed (wind) to the strain along the beam’s length. The spherical anemometer introduced by the German researcher Holling presents the opportunity to incorporate the theoretical cantilevered Euler-Bernoulli beam with a spherical mass tip to develop a deflection and wind relationship driven by cross-area of the spherical mass and constriction of the shaft or the beam's bending properties. The application of Hamilton's principle and separation of variables to the Lagrangian Mechanics of an Euler-Bernoulli beam results in the equations of motion for the deflection of the beam as a second order partial differential equation (PDE). The boundary conditions of our beam's motion are influenced by the applied fluid forces of a relative drag force and the added mass and buoyancy of the sphere. Strain gauges will provide measurements in a practical but non-intrusive method and thus the concept of a measuring strain gauge is simulated. Young's Modulus creates a relationship between deflection and strain of an Euler-Bernoulli system and thus a strain and wind relation can be modeled as an ODE. This theoretical sphere anemometer's second order ODE allows for analysis of the linear and non-linear accuracies of the motion of this dynamic system at conventional high speed conditions.
189

Lastcells applikation : Verktyg för montering av trådtöjningsgivare i lastcell

Stumle, Joakim January 2007 (has links)
<p>Ett verktyg för applicering av trådtöjningsgivare har tagits fram på uppdrag av AED AB i Växjö. Verktyget skall användas för färdigställning/slutmontering av lastceller som i sin tur skall användas till att mäta vilka krafter som påverkar en skogsmaskin när denna lastas med sin givna maxlast. Verktyget skall föras in i ett 25 mm brett hål där det skall hålla fast och lägga tryck på fyra trådtöjningsgivare, en i vardera riktning, vilka bestrykts med lim. Verktyget skall hålla ett tryck på tre till fyra kiloPond medan lastcellen värms till 150° C då limmet härdar. Verktyget består av fyra ben, ett i vardera riktning. De är ledande i en änden. Andra änden på benen är avfasad och bildar en öppning. När en kula trycker mot benens avfasade ytor expanderar dem utåt och trycker därmed den limbestrukna trådtöjningsgivaren mot hålets vägg.</p> / <p>A tool for the application of strain gauges have been constructed by the commission of AED AB in Växjö. The tool shall be used for the assembling of loadcells which then will be used for measuring forces that affects a loggingmachinery when loaded with its maximum load. The tool shall be inserted in a 25 mm wide hole where it is supposed to hold and apply load to four strain gauges, one in each direction, which has been smeared with glue. The tool shall maintain a pressure of three to four kiloPond while the loadcell is heated to 150 C until the glue has hardened. It consists of four legs with a joint in one end and a slant surface by the other. When a ball is pushed against the slant surfaces, the legs will expand and push the glue smeared strain gauges against the wall of the hole.</p>
190

A model study of the deconfining phase transition

Velytsky, Alexander. Berg, Bernd A. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Bernd A. Berg, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed June 16, 2004). Includes bibliographical references.

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