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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.
1

Characterization of a three-phase medium with a large and negative parameter of nonlinearity

Pauly, Olivier 05 1900 (has links)
No description available.
2

APPLICATION OF RUTHERFORD BACKSCATTERING SPECTROMETRY IN NONDESTRUCTIVE ANALYSIS.

ROLLINS, DAVID. January 1985 (has links)
A Rutherford backscattering spectrometry facility has been designed and built at the University of Arizona. Initial calibration and testing has been carried out in order to accurately characterize the system and make it ready to perform reliable analyses. Also, an explanation of basic RBS principles has been presented to enable persons unacquainted with the technique to determine its applicability for various types of analytical problems. A method for determining the concentration profile of Ag in an SiO₂ matrix is carefully explained. Calculations derived from basic principles are demonstrated for this analysis and can be applied in a number of similar circumstances. Several other examples of analyses of utilizing various operating parameters are explained and illustrated. Some examples of unusual samples are shown to be feasible for analysis by this technique. RBS is shown to be a very useful analytical tool for a wide variety of samples. It has the capability of performing quantitative depth profiles without standards. The vast potential for its use by analytical chemists is demonstrated, and future improvements for this particular facility are discussed.
3

DYNAMIC ANALYSIS OF POROUS MEDIUM PROBLEMS BY THE FINITE ELEMENT METHODS.

WU, JAMES SHIH-SHYN. January 1984 (has links)
General anisotropic constitutive laws and relevant dynamic equations of motion for porous media are described. The accuracy of various discretization algorithms in space and in time was surveyed. Results of these models and algorithms were compared to the exact solutions. Appropriate models and algorithms for further studies of spinal motion segments were then determined. Poroelastic axisymmetric finite element models, simulating spinal motion segments were analyzed and studied. Material properties of the intervertebral disc were derived by fitting experimental data based on porous medium theory using one-dimensional mathematical models. Structural models for the normal and degenerative processes were simulated for investigation of nutritional supply routes in the disc. Detailed structural anaalyses and failure conditions in various spinal motion segments were studied. Results of finite element analyses were consistent with the experimental observations. Nonlinear elastic material behavior of the solid skeleton was assumed and relevant formulas in creep were derived and examined. Preliminary results indicated that the nonlinear poroelastic material law used here may be useful in future analysis of the disc in finite element models of spinal motion segments.
4

An SEM and Microanalysis Examination of a Marquis de Lafayette Terracotta Portrait Bust

Zajac, Lauren Elizabeth January 2011 (has links)
Thesis advisor: Gregory McMahon / Thesis advisor: Barbara Adams Hebard / A terracotta portrait bust of the Marquis de Lafayette with the signature “houdon an. 1790”, now broken, was given to Boston College by Edward S. Ryan in 1966. The two objectives of this study were: (1) To determine the methods used to create this bust and (2) whether or not it could have been made in the studio of Jean-Antoine Houdon. A materials analysis using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) was performed on five representative samples from different regions of the bust. Three samples were unpolished and two were polished using an argon beam milling technique, completely preserving the heterogeneous samples. It was found that the bust was created by pressing wet clay into piece mold, the waxy surface is not original to the sculpture, and the pink layer is the result of a higher iron particle concentration. It is almost impossible to absolutely determine whether or not Houdon made the bust, due to uncertainties in provenance and the large number of busts made by, and copied from, Houdon. However, it is clear that the materials original to the sculpture correlate with the time Houdon lived and the methods he used. / Thesis (BS) — Boston College, 2011. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: College Honors Program.
5

Using surface plasmon resonance spectroscopy to characterize thin composite films

Shinall, Brian Darnell 12 1900 (has links)
No description available.
6

Genusmedvetenhet i dagens religionsläroböcker : En läromedelsanalys med ett genusperspektiv i religionskunskap för gymnasieskolan

Metry, Mina January 2015 (has links)
The essay is based on textbook analysis with a qualitativ method from a gender perspective. The essay analyzes three selected textbooks which are all written after the latest release of the curriculum named GY11. In the essay have I been using a analysisinstrument called ”the genderstaircase”. The purpose of the study have been to examine what point of gender awarness the selected learning materials has with the help of the genderstaircase. My ambition is to complete the genderstaircase with other theories to enhance the results. The result showed that two of three textbooks passed the demands of the curriculum GY11.
7

The application of nuclear microprobe analysis in materials science

Mars, Johan Andre January 2003 (has links)
Thesis (DTech (Science))--Peninsula Technikon, Cape Town, 2003. / The impetus for the refinement and renewal of daily-used products has spurred international interest in investigating the small in homogeneities that might exist in these products. This interest has become an important part in the design philosophy, which is based on structural information gained by the analysis of these products. It is this drive that initiated the study to investigate the simultaneous use of novel nuclear analytical techniques such as micro proton induced X-ray emission( u-PlXE), micro proton induced gamma-ray emission (u-PlGE) and micro proton backscattering (u-RBS) to achieved a broader and yet deeper insight into the fine structure of products. The fundamental underlying physical principles of these techniques are discussed to gain in-depth knowledge on how to them to obtain the desired information. Also determined was the degree of accuracy that could be attained in the application of this knowledge. These principles were evaluated in conjunction with the instrumentation with which the applicability of these techniques could then be further extended. More so is the use of sophisticated software that facilitated the use of both physical and instrumental parameters. After describing the necessary implements to achieve this further know-how, products of industrial origin were investigated to determine in homogeneities that existed in those products and compared those theoretical values. The first application was made to ceramic-based sorption electrodes to be used in the purification of wastewater.
8

Structure/property behavior of inorganic/organic sol-gel derived hybrid materials

Brennan, Anthony Bartholomew 16 September 2005 (has links)
A novel class of inorganic/ organic hybrid materials referred to as CERAMERs have been successfully prepared by a sol-gel process using a polymeric acid catalyst, poly(styrene sulfonic acid), to form a network from tetraethylorthosilicate (TEOS) and triethoxysilane end capped oligomers of poly( tetramethylene oxide) (PTMO). The structure-property relationships were determined for these hybrid networks from their dynamic mechanical behavior, mechanical properties, and SAXS behavior. Thermal gravimetric data coupled with FfIR analysis were used to obtain a qualitative measure of the extent of conversion of the metal alkoxides as a function of acid catalyst. Another new class of CERAMERs was successfully developed by the sol-gel processing of three different metal alkoxides in conjuction with the triethoxy silane end capped PTMO oligomers. The first novel hybrid is based upon complexes of aluminum tri-n-butoxide with ethyl acetoacetonate or titanium tetra-iso-propoxide with ethyl acetoacetate reacted with the triethoxysilane end capped PTMO. The hybrid networks were optically clear and could be easily formed as relatively large monoliths. A novel method of preparation of stable sols without the use of ethyl acetoacetate, developed by Dr. Bing Wang in this laboratory, led to more stable CERAMERS of titanium tetra-iso-propoxide (TiOPr) reacted with the functionalized P'TMO as well as a fourth inorganic/organic hybrid material based upon zirconium tetra-n-propoxide and PTMO. Indeed, the mechanical properties of the TiOPr/P'TMO CERAMERs and ZrOPr/P'TMO CERAMERs were significantly enhanced over the TEOS/PTMO CERAMERs in terms of both Young's modulus and stress at break. The structure-property relationships of these materials were adequately described by the morphological model originally developed for the CERAMERs based upon TEOS/PTMO. / Ph. D.
9

A Lithium-ion Test Cell for Characterization of Electrode Materials and Solid Electrolyte Interphase

Goel, Ekta 03 May 2008 (has links)
The research discussed is divided into two parts. The first part discusses the background work involved in preparation of the Li-ion cell testing stage. This includes the preparation of anodes using the doctor blade and a calendar mill, electrolyte preparation, test cell assembly, the Li-ion test cell design, and experiments performed to troubleshoot the cell. The second part deals with the cell testing experiments. Li-ion batteries are amongst the most promising rechargeable battery technology because of their high capacity and low weight. Current research aims at improving the anode quality to increase the capacity. The experiments discussed evaluate the traditional anode materials like SFG44 graphite and conducting grade graphite against the novel ones– and tin oxide (SnO2) based and carbon encapsulated tin based anodes. The solid electrolyte interphase formed on each anode was analyzed to understand the initial capacity fade leading to conditioning of the cell thus stabilizing its performance.
10

”Clint Eastwood med disktrasa” : En narrativ innehållsanalys av läromedel utifrån ett genusperspektiv

Björkman, Dawid Leonard January 2016 (has links)
The aim of this study is to examine how the male characters are portrayed in the television series »Livet i bokstavslandet« based on Connels (1995) theory hegemonic »masculinity« and Butlers theory »gender performativity« and examine if the male characters challenge or maintain gender. The study proceed from the following questions: Does the male characters in »Livet i bokstavslandet« challenge or reproduce traditional gender roles? Are the male characters »participant«, »subordinated« or »marginalized« based on Connells hegemonic masculinity theory? A narrative content analysis has been conducted. The theoretical framework of the examination is based on men and masculinities studies, from a post-modern influenced perspective. Butler's concepts of performativity are of importance in this study. The results of shows, in conclusion, that »Livet i bokstavslandet« does neither challenge nor negotiate new gender roles. From a performativity point of view, the conclusion is that the series maintains prevailing gender roles.

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