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According to the American Cancer Society, Cancer is the second most common cause of death in the United States, only exceeded by heart disease. Over the past decade, deciphering the complex structure of individual cells and understanding the symptoms of cancer disease has been a highly emphasized research area. The exact cause of Cancer and the genetic heterogeneity that determines the severity of the disease and its response to treatment has been a great challenge. Researchers from the engineering discipline have increasingly made use of recent technological innovations, namely the Atomic Force Microscope (AFM), to better understand cell physics and provide a means for cell biomechanical profiling. The presented work's research objective is to establish a fundamental framework for the development of novel biosensors for cell separation and disease diagnosis. By using AFM nanoindentation, several studies were conducted to identify key distinctions in the trends of cell viscoelasticity between healthy, nontumorigenic cells and their malignant, highly tumorigenic counterparts. The possibility of identifying useful 'biomarkers' was also investigated. Due to the lack of an available human ovarian cell line, experiments were done on a recently developed mouse ovarian surface epithelial (MOSE) cell line, which resembles to human cell characteristics and represents early, intermediate, and late stages of the ovarian cancer. Material properties were extracted via Hertz model contact theory. The experimental results illustrate that the elasticity of late stage MOSE cells were 50% less than that of the early stage. Cell viscosity also decreased by 65% from early to late stage, indicating that the increase in cell deformability directly correlates with increasing levels of malignancy. Various cancer treatment and component-specific drugs were used to identify the causes for the changes in cell biomechanical behavior, depicting that the decrease in the concentration levels of cell structural components, predominantly the actin filament framework, is directly associated with the changes in cell biomechanical property. The investigation of MOSE cells being subject to multiple mechanical loads illustrated that healthy cells react to shear forces by stiffening up to 25% of their original state. On the other hand, cancerous cells are void of such response and at times show signs of decreasing rigidity. Finally, deformation studies on MOSE cancer stem cells have shown that these cells carry a unique elasticity profile among other cell stage phenotypes that could allow for their detection. The results herein carry great potential into contributing to cell separation methods and analysis, furthering the understanding of cell mechanism dynamics. While prior literature emphasizes on the elastic modulus of cells, the study of cell viscosity and other key material properties holds a critical place in the realistic modeling of these complex microstructures. A comprehensive study of individual cells holds a great amount of promise in the development of effective clinical research in the fight against cancer. / Master of Science

Ett företag som tillverkar hydrauliska snabbkopplingar har genom regelbundna kvalitetsprover upptäckt att vissa låskulor till snabbkopplingarnas låsmekanism plötsligt fått en bristande kvalité och spricker vid belastning. Låskulorna är gjorda av rostfritt stål och har en viktig funktion i låsmekanismen. Om de spricker vid användning kan det leda till konsekvenser med materiella skador eller personskador. Företaget vill förekomma eventuella kvalitetsproblem och måste därför säkerställa att låskulorna har rätt hållfasthet. Låskulorna köps in från en underleverantör och företaget vill därför utveckla en provmetod som provar låskulornas materialegenskaper när de levereras till fabriken. Arbetet i denna rapport syftar till att hjälpa företaget utveckla en sådan provmetod. Ett första steg är att undersöka orsaken till att låskulorna spricker. Materialanalyser utförs av ett materiallaboratorium för att fastställa vilka faktorer i materialet som orsakar brott i låskulorna. Analyserna visar att låskulorna sannolikt spricker på grund av en ökad sprödhet i materialet. Sprödheten beror på att martensiten i materialet är dåligt anlöpt samt en stor mängd karbider. Med orsaken till sprickorna fastställd undersöks befintliga metoder för materialprovning. En provmetod måste prova materialet i färdigtillverkade låskulor eftersom låskulornas tillverkningsprocess påverkar materialegenskaperna. Många av de standardiserade provmetoderna är dock svåra att tillämpa på låskulorna med anledning av låskulornas geometri och små dimensioner. En form av slagprov och pressprov utförs på låskulorna. Ett av syftena med proven är att undersöka om de är lämpliga att använda som provmetod. Genom proven framträder olika materialegenskaper för olika låskulor. Resultaten är dock inte jämförbara låskulorna emellan och proven anses inte vara lämpliga som provmetod. Även ett utmattningsprov utförs på låskulorna genom en upprepande belastning i en snabbkoppling. Detta prov är inte heller lämpligt att använda som provmetod då provet är mycket tidskrävande samt att det finns vissa osäkerheter kring provresultatet. I detta arbete undersöks även två nyligen framtagna provmetoder för kulor till kullager och möjligheten att tillämpa dessa provmetoder på låskulorna. I undersökningen jämförs de båda provmetoderna med avseende på utförande samt framtagning av provkropp. Även en spänningsanalys av en låskula belastad i en snabbkoppling utförs för att ta reda på i vilket område av låskulan de maximala spänningarna uppstår. Undersökningen ger att enbart en provmetod är intressant för fortsatt arbete.   Den provmetod som föreslås i detta arbete kallas "the notched ball test" (NBT). Provmetoden innebär att en djup och smal skåra bearbetas i en låskula som sedan belastas med en tryckande kraft vinkelrätt mot skåran tills brott uppstår. Den maximala spänningen som verkar vid brottet beräknas med en enkel ekvation och används som mått för låskulans hållfasthet. Provmetoden är lämplig då den går att utföra med befintlig utrustning på företaget, den provar materialet i färdigtillverkade låskulor samt i samma område som de maximala spänningarna i en låskula belastad i en snabbkoppling uppstår. NBT nyttjar även dragspänningar vilket är fördelaktigt när sprödhet ska upptäckas i ett material. För att fastställa hur olika materialegenskaper samt geometrier för provkroppen påverkar provresultaten utförs en djupare analys av provmetoden. Analysen ger även vilka geometrier som bör användas vid utförandet av NBT samt värdet för den konstant som används vid beräkning av brottspänningen. Praktiska prov av NBT utförs inte i detta arbete men rapporten innefattar slutsatser om provmetoden och rekommendationer till företaget hur ett fortsatt arbete med NBT kan utföras. / A company that manufactures hydraulic quick-couplings has discovered through regular quality checks that the quality of some of the locking balls for the locking mechanism in the quick couplings suddenly has become insufficient and the locking balls rupture under load. The locking balls are made of stainless steel and if they rupture during usage the consequences can be material damage or even personal injury. The company wants to prevent any quality problems and must therefore ensure that the strength of the locking balls is sufficient. The locking balls are purchased from a subcontractor and the company would therefore like to develop a method for strength testing locking balls delivered to the factory. This thesis aims to help the company in developing such a method.  A first step is to investigate the cause of the locking balls rupture. Material analyses are executed by a material laboratory in order to determine what features in the material that causes the ruptures. The analyses shows that rupture is probably caused by an increased brittleness in the material and the brittleness is a consequence of less tempered martensite and a high amount of carbides. With the cause of rupture determined, existing methods for testing material properties is studied. It is important that strength testing is carried out with test specimens prepared from the actual locking balls. Otherwise the influence of the locking balls manufacturing process on the material properties is not taking into account. Many of the standardized methods for testing material properties, however, are hard to apply to the locking balls due to the geometry and small dimensions of the locking balls. A kind of impact test and compression test is performed. One of the purposes with the tests is to investigate if they are adequate for strength testing the locking balls. The results of the tests, however, are not suitable for comparison. Also, a fatigue test of the locking balls is performed by a repetitive loading of a quick coupling. The fatigue test is, however, time consuming and there are uncertainties in the test results. None of these tests is considered suitable as a strength testing method. In this thesis, two recently developed methods for strength testing ceramic balls and the possibility to apply these methods on the locking balls is studied. The study includes an analysis of the stress distribution in a locking ball under load to determine in which region the highest stresses occur. The study provides that only one of the methods is suitable for the locking balls due to differences in preparing the test specimen and which region of the locking ball that is tested in each method. The strength testing method that is proposed in this thesis is called the notched ball test (NBT). In NBT a long and narrow notch is cut in a locking ball which is then loaded in compression perpendicular to the notch until rupture occurs. The maximum stress acting at the rupture is calculated and used to determine the strength of the locking ball. NBT is suitable because it can be performed with existing equipment at the company, the test specimen is prepared from actual locking balls and the test uses tensile stresses which is an advantage when brittleness is to be detected in a material. An analysis of NBT is performed to determine how material properties and different notch geometries is affecting the test results. The analysis also gives some recommendations for notch geometries that should be used when performing NBT as well as a constant that is used when calculating the maximum stress. Practical experiments of NBT are not carried out in this thesis. Instead, conclusions regarding NBT and recommendations for the company on how they should proceed with NBT are given.

[pt] Do impulso ao mergulho numa paisagem submersa, este almanaque propõe uma reflexão sobre surdez e escuta. A escrita conduz o pensamento através da observação de imagens submarinas, seguindo um percurso que cruza fronteiras; entre o lúdico e os dados científicos, a teoria e a intuição, a certeza e incerteza, humano e bicho, natural artificial. Num caminho que deseja chegar ao abismo, para conhecer seus monstros e sua pluralidade. / [en] From impulse to diving in a submerged landscape, this almanac proposes a reflection on deafness and listening. Writing leads thought through the observation of under-water images, following a route that crosses borders; between ludic and scientific data, theory and intuition, certainty and uncertainty, human and animal, natural and artificial. In a path that wants to reach the abyss, to know its monsters and plurality.

Parmi tous les composants mécaniques présents dans un moteur d'avion, les roulements tiennent une place majeure puisqu'ils assurent la liaison entre les parties tournantes, les rotors, et les parties fixes, les stators. Pour assurer leur bon fonctionnement, un jeu radial interne est nécessaire. Les roulements présentent de ce fait une non-linéarité forte qui peut affecter le comportement vibratoire de la structure. L'objectif de cette thèse, réalisée en collaboration avec la société Snecma Moteurs, est d'étudier l'influence de ce jeu fonctionnel sur la dynamique rotor. A cette fin, un banc expérimental, dénommé banc Dynamique D'Ensemble, a été réalisé. Dans un premier temps, l'aspect modélisation des roulements sera traité. Le modèle proposé, qui prend en compte le jeu radial et considère le contact bille/bague comme hertzien, nécessite cependant des outils de calcul appropriés. Nous présenterons alors la méthode de tir multiple et la méthode des éléments finis en temps avant de montrer les résultats de calculs effectués sur divers exemples. Dans un second temps, nous présenterons le banc Dynamique D'Ensemble qui permettra de valider expérimentalement les modèles de roulements utilisés. Ce banc a été conçu pour être le plus simple possible, tout en restant le plus représentatif d'un moteur d'avion. Nous exposerons tout d'abord les aspects dimensionnement et recalage, puis les premiers résultats obtenus sur banc tournant.

Made available in DSpace on 2016-04-28T14:16:12Z (GMT). No. of bitstreams: 1 Arthur Issa Mangili.pdf: 986316 bytes, checksum: 5bd8636e8f419fb55e6f9132606a92dc (MD5) Previous issue date: 2011-05-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to analyze the experiments made by Heinrich Rudolph Hertz about the photoelectric effect. To this end, we consulted the work Electric Waves: Being Researches On The Propagation Of Electric Action With Finite Velocity Through Space, mainly the part in which the experiment that refers to the photoelectric effect is described. So we want to understand in which context such effect is discussed, looking for evidence that has arisen its discovery / Este estudo teve por objetivo analisar os experimentos realizados por Heinrich Rudolph Hertz relativos ao efeito fotoelétrico. Para tanto, consultamos a obra Electric Waves: Being Researches on the Propagation of Electric Action With Finite Velocity Through Space, principalmente a parte em que o experimento que se refere ao efeito fotoelétrico é descrito. Buscamos assim compreender em que contexto tal efeito é abordado, procurando indícios que sugiram a sua descoberta

There are various situations in which electrical energy is desired but cannot by conveniently supplied. Since the days of Hienrich Hertz and Nikola Tesla, scientists have tried to solve this problem using different methods of wireless power transfer. Today, wireless power transfer has only been commercially demonstrated at small distances through use of induction. This thesis demonstrated the transfer of wireless power at relatively large distances through radio frequencies in the development of a prototype for a commercial product - a wireless household lamp.

abstract: Current trends in the Computer Aided Engineering (CAE) involve the integration of legacy mesh-based finite element software with newer solid-modeling kernels or full CAD systems in order to simplify laborious or highly specialized tasks in engineering analysis. In particular, mesh generation is becoming increasingly automated. In addition, emphasis is increasingly placed on full assembly (multi-part) models, which in turn necessitates an automated approach to contact analysis. This task is challenging due to increases in algebraic system size, as well as increases in the number of distorted elements - both of which necessitate manual intervention to maintain accuracy and conserve computer resources. In this investigation, it is demonstrated that the use of a mesh-free B-Spline finite element basis for structural contact problems results in significantly smaller algebraic systems than mesh-based approaches for similar grid spacings. The relative error in calculated contact pressure is evaluated for simple two dimensional smooth domains at discrete points within the contact zone and compared to the analytical Hertz solution, as well as traditional mesh-based finite element solutions for similar grid spacings. For smooth curved domains, the relative error in contact pressure is shown to be less than for bi-quadratic Serendipity elements. The finite element formulation draws on some recent innovations, in which the domain to be analyzed is integrated with the use of transformed Gauss points within the domain, and boundary conditions are applied via distance functions (R-functions). However, the basis is stabilized through a novel selective normalization procedure. In addition, a novel contact algorithm is presented in which the B-Spline support grid is re-used for contact detection. The algorithm is demonstrated for two simple 2-dimensional assemblies. Finally, a modified Penalty Method is demonstrated for connecting elements with incompatible bases. / Dissertation/Thesis / Ph.D. Mechanical Engineering 2010

Made available in DSpace on 2014-12-17T14:54:56Z (GMT). No. of bitstreams: 1 Tese_Cristhianne.pdf: 1342088 bytes, checksum: 1c3372509a24d25d30a4e89f11cd641e (MD5) Previous issue date: 2010-04-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In general, the materials used as substrates in the project of microstrip antennas are: isotropic, anisotropic dielectrics and ferrimagnetic materials (magnetic anisotropy). The use of ferrimagnetic materials as substrates in microstrip patch antennas has been concentrated on the analysis of antennas with circular and rectangular patches. However, a new class of materials, called metamaterials, has been currently the focus of a great deal of interest. These materials exhibit bianisotropic characteristics, with permittivity and permeability tensors. The main objective of this work is to develop a theoretical and numerical analysis for the radiation characteristics of annular ring microstrip antennas, using ferrites and metamaterials as substrates. The full wave analysis is performed in the Hankel transform domain through the application of the Hertz vector potentials. Considering the definition of the Hertz potentials and imposing the boundary conditions, the dyadic Green s function components are obtained relating the surface current density components at the plane of the patch to the electric field tangential components. Then, Galerkin s method is used to obtain a system of matrix equations, whose solution gives the antenna resonant frequency. From this modeling, it is possible to obtain numerical results for the resonant frequency, radiation pattern, return loss, and antenna bandwidth as a function of the annular ring physical parameters, for different configurations and substrates. The theoretical analysis was developed for annular ring microstrip antennas on a double ferrimagnetic/isotropic dielectric substrate or metamaterial/isotropic dielectric substrate. Also, the analysis for annular ring microstrip antennas on a single ferrimagnetic or metamaterial layer and for suspended antennas can be performed as particular cases / Em geral, os materiais utilizados como substratos no projeto de antenas de microfita s?o: diel?tricos isotr?picos, diel?tricos anisotr?picos e ferrimagn?ticos (anisotr?picos magn?ticos). No entanto, o uso de materiais ferrimagn?ticos em substratos de antenas de microfita do tipo patch tem-se concentrado em an?lises que utilizam geometrias circulares e retangulares. Na ?ltima d?cada, uma nova classe de materiais com caracter?sticas bianisotr?picas, apresentando permissividade e permeabilidade tensoriais, tem surgido e despertado bastante interesse, sendo denominados metamateriais. Portanto, este trabalho apresenta uma an?lise te?rica e num?rica das caracter?sticas ressonantes de uma antena de microfita com patch em anel, utilizando como substratos materiais ferrimagn?ticos e metamateriais. A an?lise utiliza o formalismo de onda completa atrav?s da aplica??o do m?todo dos potenciais vetoriais de Hertz, no dom?nio da transformada de Hankel. A defini??o dos potenciais vetoriais de Hertz e a imposi??o das condi??es de contorno adequadas ? estrutura permitem determinar as fun??es di?dicas de Green, relacionando as componentes da densidade de corrente no patch com as componentes tangenciais do campo el?trico. O m?todo de Galerkin ? ent?o usado para obter a equa??o matricial, cuja solu??o n?o trivial fornece a freq??ncia de resson?ncia da antena. A partir da modelagem, ? poss?vel obter resultados para a freq??ncia de resson?ncia em fun??o de v?rios par?metros da antena de microfita com patch em anel, para diferentes configura??es e substratos, al?m do diagrama de radia??o, perda de retorno e da largura de banda. S?o consideradas estruturas de antenas de microfita com patch em anel sobre m?ltiplas camadas ferrimagn?tica/metamaterial sobre diel?trico isotr?pico. A an?lise num?rica para antenas com uma ?nica camada ferrimagn?tica ou metamaterial e para antenas suspensas s?o obtidas como casos particulares

Made available in DSpace on 2014-12-17T14:55:23Z (GMT). No. of bitstreams: 1 MiltonLCGN_Capa_ate_pag14.pdf: 8498531 bytes, checksum: 98bb761f871446c2506a2971dd59c5eb (MD5) Previous issue date: 2004-04-06 / This work presents a theoretical and numerical analysis of Frequency Selective Surfaces (FSS) with elements as rectangular patch, thin dipole and crossed dipole mounted on uniaxial anisotropic dielectric substrate layers for orientations of the optical axis along x, y and z directions. The analysis of these structures is accomplished by combination of the Hertz vector potentials method and the Galerkin's technique, in the Fourier transform-domain, using entire?domain basis functions. This study consists in the use of one more technique for analysis of FSS on anisotropic dielectric substrate. And presents as the main contribution the introduction of one more project parameter to determinate the transmission and reflection characteristics of periodic structures, from the use of anisotropic dielectric with orientations of the crystal optical axis along x, y and z directions. To validate this analysis, the numerical results of this work are compared to those obtained by other authors, for FSS structures on anisotropic and isotropic dielectric substrates. Also are compared experimental results and the numerical correspondent ones for the FSS isotropic case. The technique proposed in this work is accurate and efficient. ln a second moment, curves are presented for the transmission and reflection characteristics of the FSS structures using conducting patch elements mounted on uniaxial anisotropic dielectric substrate layers with optical axis oriented along x, y and z directions. From analysis of these curves, the performance of the considered FSS structures as function of the optical axis orientation is described / Este trabalho apresneta uma an?lise te?rica e num?rica de superf?cies seletivas de freq??ncia, ou Frequency Secective Surface (FSS) com elementos do tipo patch retangular, dipolo fino e dipolo cruzado sobre camadas de substratos diel?tricos anisotr?picos uniaxiais para orienta??es de eixo ?ptico nas dire??es x, y e z. A an?lise destas estruturas ? realizada atrav?s do m?todo dos potenciais vetoriais de Hertz em combina??o com a t?cnica num?rica de Galerkin , no dom?nio da transforma de Fourier, utilizando-se fun??es de base de dom?nio inteiro. Este estudo consiste no emprego de mais uma t?cnica para an?lise de FSS sobre substratos diel?trico anisotr?picos. E apresenta com o principal constribui??o a introdu??o de mais um par?metro de projeto para determina??o das caracter?sticas de transmiss?o e reflex?o das estruturas peri?dicas, a partir da utiliza??o de diel?tricos anisotr?picos com orienta??es de eixo ?ptico nas dire??es x, y e z do sistema de coordenadas cartesianas. Com o objetivo de validar a t?cnica utilizada, s?o realizadas compara??es entre os resultados num?ricos obtidos neste trabalho e os resultados apresentados por outros autores, para o caso de estruturas de FSS com substratos diel?tricos anisotr?picos e isotr?picos. Tamb?m s?o feitas confronta??es entre resultados experimentais e os num?ricos correspondentes para o caso de FSS com material isotr?picos. O m?todo de an?lise proposto mostrou-se bastante eficiente e preciso. Em um segundo momento, s?o apresentadas as curvas das caracter?sticas de transmiss?o e reflex?o de FSS usando patches condutores sobre uma camada diel?trica anisotr?pica uniaxial com eixo ?pitco orientado nas dire??es x, y e z. A partir da an?lise destas curvas, o desempenho das estgruturas de FSS consideradas em fun??o da orienta??o do eixo ?ptico ? descrito