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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.
11

Repulsion : Subjektivitet och frågor kring det sociala

Lagerkranser, Johanna January 2007 (has links)
<p>The scope of this investigation is the conditions under which readings of Repulsion (1965), and its depicted mental illness, took place in Sweden during the censorship debates in 1965, and also how the reception was related to narration and subjectivity in the film. The reason for this is the strong reactions to the images of the main character’s inner state, and concerns about negative effects in the public, that were raised. One major concern is how the film articulates discourses through which meanings are produced; that is, how it works as social technology. My thesis is therefore structured around two levels; textual analysis and discourse analysis. In this way, I try to locate meaning and power relations both within and outside the film. My work draws mostly on Edward Branigan’s cognitive theory of narration and Michel Foucault’s thoughts on power and knowledge. I have partly deployed the approach presented by Annette Kuhn, to study the relations of power that are put into play in specific instances. To draw any conclusions I have studied Swedish newspaper articles from 1965 and a summary of the discussion within the Board of Censors. The major findings of the investigation show how the struggles to locate and regulate the meaning of Repulsion ended in the questioning of the very practice of censorship, which even seemed to suggest a moment of transition for the Swedish Board of Censors. Another important finding shows that concerns about Swedish mental care were raised; however, only regarding hospitalisation and treatment of patients and not about underlying, deeper social problems</p>
12

Repulsion : Subjektivitet och frågor kring det sociala

Lagerkranser, Johanna January 2007 (has links)
The scope of this investigation is the conditions under which readings of Repulsion (1965), and its depicted mental illness, took place in Sweden during the censorship debates in 1965, and also how the reception was related to narration and subjectivity in the film. The reason for this is the strong reactions to the images of the main character’s inner state, and concerns about negative effects in the public, that were raised. One major concern is how the film articulates discourses through which meanings are produced; that is, how it works as social technology. My thesis is therefore structured around two levels; textual analysis and discourse analysis. In this way, I try to locate meaning and power relations both within and outside the film. My work draws mostly on Edward Branigan’s cognitive theory of narration and Michel Foucault’s thoughts on power and knowledge. I have partly deployed the approach presented by Annette Kuhn, to study the relations of power that are put into play in specific instances. To draw any conclusions I have studied Swedish newspaper articles from 1965 and a summary of the discussion within the Board of Censors. The major findings of the investigation show how the struggles to locate and regulate the meaning of Repulsion ended in the questioning of the very practice of censorship, which even seemed to suggest a moment of transition for the Swedish Board of Censors. Another important finding shows that concerns about Swedish mental care were raised; however, only regarding hospitalisation and treatment of patients and not about underlying, deeper social problems
13

A mathematical model for colloidal aggregation [electronic resource] / by Colleen S. O'Brien.

O'Brien, Colleen S. January 2003 (has links)
Title from PDF of title page. / Document formatted into pages; contains 313 pages. / Thesis (M.S.Ch.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The characterization of fine particles is an area of immense significance to many industrial endeavors. It has been estimated that 70% of all industrial processes deal with fine particles at some point in the process. A natural phenomenon occurring in these processes is colloidal aggregation. This study examines aggregation in colloidal systems in order to characterize, examine, and control this occurrence in industrial processes. The study of particle aggregation has been broken into many different areas, such as collision mechanisms, interaction energy etc, but a complete model that integrates these different aspects has never been fully realized. A new model is required to accurately predict the aggregation behavior of colloidal particles. In this work, a new model is developed that integrates Smoluchowski kinetics, total interaction energy between particles, and stability ratios for perikinetic and orthokinetic collision mechanisms. / ABSTRACT: The total particle interaction energy necessary for the calculation of stability ratios is represented by the summation of electrostatic and van der Waals interactions. The electrostatic interactions are modeled using DLVO theory, the linear Poisson-Boltzmann equation, and a numerical solution for the non-linear Poisson-Boltzmann Equation, while the van der Waals interactions are represented by Hamaker theory. The mathematical model is solved using an adjustable discretion technique, which is tested against a specific analytic solution, and yields an assessment of the error intrinsic in the discretization method. The basis of the mathematical model is a population balance framework. The model developed in this study is general in many respects, but could be readily applied to many different aggregation systems with minor modification. / ABSTRACT: A comparison of the mathematical model with previous experiments conducted by Scott Fisher (1998) is carried out for the perikinetic and orthokinetic transport-limited aggregation regimes. The fractal nature of solid-sphere aggregates is considered when comparing the mathematical model predictions with experimental measurements. The previous experiments that are used for comparison utilized polystyrene particles ranging from 100 nm to 500 nm in initial diameter, several initial particle concentrations, and various stirring rates. Zeta potential measurements are presented in order to set the range of transport-limited aggregation. An assessment of the results of the mathematical model with the experimental results show good agreement for transport-limited aggregation within the perikinetic and orthokinetic transport-limited aggregation, with average particle sizes ranging from 100 nm to well over 2 microns. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
14

Statistical Regularities During Object Encoding Systematically Distort Long-Term Memory

Scotti, Paul S. January 2019 (has links)
No description available.
15

Some Effects of The Atomicity of a Metal On Its Dielectric Response and Its Superconducting State

Ingleby, Michael 05 1900 (has links)
<p> Although the electronic pairing hypothesis of Bardeen, Cooper and Schrieffer is verified by experiment, the lattice polarisation mechanism for over-screening the repulsion between mates in a pair need not be the sole mechanism. </p> <p> Alternatives to the lattice polarisation mechanism are discussed and a new approach to electronic polarisation is developed. Propagator formalism is reworked using a charge density propagator to avoid the Dyson equation for the screened potential. The fermi liquid approach to electrons in a metal is avoided, too, because it misses the correlations which give a solid its atomicity. An atomic picture is contrived instead and used to predict what observable features of a superconductor are influenced by atomic correlations. </p> / Thesis / Doctor of Philosophy (PhD)
16

Role of DSCAM in netrin-1 mediated axon repulsion and neuronal migration

Purohit, Anish A. January 2011 (has links)
No description available.
17

Continuum Modeling Of Adhesive Interaction Based On Interatomic Potentials

Jayadeep, U B January 2014 (has links) (PDF)
Adhesion between solid bodies plays a prominent role in a wide variety of situations ranging from tribological applications to dust coagulation initiating the formation of planets. It can be due to various reasons like capillary, electrostatic, van der Waals, and hydrophobic forces. Among these, adhesion due to van der Waals force| which has its origin in permanent or instantaneous electric dipoles present in all atoms and molecules|is of special significance as it is present in all cases. Computational studies on adhesion due to van der Waals force commonly assume it as a surface force due to its short effective range, which is about a few tens of nanometers, in comparison to the length-scales commonly encountered. However, such restrictions are often violated in various important problems. For example, the characteristic dimensions of asperities| which are the smallest roughness elements interacting to cause friction and wear| are usually of nanometer length-scale. In addition, the assumptions inherent in development of surface force model are exact only when the deformations are small. In all such situations, the van der Waals force must be assumed as distributed over the volume. In this work, a computational model is developed by incorporating van der Waals force and short-range repulsion (steric repulsion or Pauli repulsion) as body forces distributed over the volume in a large deformation, static/transient, finite element framework. First the development of the general formulation is discussed, and then it is specialized for various considerations like handling symmetry and interaction between an elastic body and a rigid half-space, which offer significant computational advantages over the general formulation. The applicability of the model is illustrated by using a number of benchmark and practical problems. The comparison of the analysis results and well-established analytical models are provided, which validates our method. As a specific example, the smooth change of interaction force from a thin-rod model to a at-plate model on increasing the cross-sectional areas of two interacting elastic rods is demonstrated. The impact of elastic bodies in presence adhesion, and the associated energy loss is an important concern in studies regarding the origin of friction. Therefore, adhesive impact of elastic rods and spheres is studied using our formulation. Emphasis of the study is on finding the apparent energy loss during impact, which represents the part of energy lost to elastic stress waves remaining in the body after the impact, and hence not available for rebound motion. In case of impact of elastic rods on a rigid half-space, it is shown that the apparent energy loss is a unique function of the tensile strain energy developed in the rod due to van der Waals attraction. A one-dimensional model is developed for this case to determine the energy loss based on the specified problem parameters, which can be used to predict practically relevant phenomena like capture. In case of impact of elastic spheres, which is often correlated with asperity interactions, the energy loss is found to be significant only if adhesion-induced instabilities occur. The behavior shown by rods and spheres are probably at the two extremes with regards to energy loss during impact of elastic bodies in presence of adhesion. Practical use of the formulation is demonstrated by applying it to the study of amplitude variation and phase shifts in tapping-mode atomic force microscopy. Specifically, the advantage of operating the AFM cantilever just below its natural frequency as compared to operating it just above the natural frequency is demonstrated. Bistable behavior, which is the coexistence of two stable vibration modes under exactly same operating conditions, is shown to be severe when the driving frequency is higher than the natural frequency of AFM cantilever even in the absence of adhesion, which can result in spurious contrast-reversal artifacts during imaging. The hysteresis loop associated with the bistable behavior may lead to erroneous conclusions regarding presence of adhesion. Since this model overcomes the limitations of lumped parameter models and the computational models based on surface force approximation, the results can be used for much more realistic interpretation of experimental data. Computational framework developed in this study achieves the capability for analysis of adhesive contact problems directly from van der Waals interaction and steric repulsion. Such a model can be used for revisiting the fundamental problems in contact mechanics, as well as for providing better insights into experimental observations.
18

Few-body interactions in cold Rydberg atoms / Interaction à quelques corps entre atomes de Rydberg

Faoro, Riccardo 03 December 2015 (has links)
L’objectif de cette thèse est l’étude des différents aspects de l’interaction à quelques corps entre des atomes de Rydberg froids. Cette thèse a été réalisée dans le cadre d’une cotutelle entre l’Université Paris-Saclay et l’Université de Pise en travaillant sur deux différents montages expérimentaux sur des atomes de Rydberg froids : respectivement sur le Cs au Laboratoire Aimé Cotton et sur le Rb au département de Physique de l’Université de Pise. Au Laboratoire Aimé Cotton nous avons démontré l’existence des nouvelles interactions à quelques corps dans un gas gelé d’atomes de Rydberg. Ces nouvelles résonances sont la généralisation des résonances de Förster bien connues dans le domaine des atomes de Rydberg. Ces résonances agissent sur les degrés de liberté interne des atomes de Rydberg et ont l’effet d’un transfert résonant d’énergie et de population comme dans le cas des FRET (Fluorescence Resonance Energy Transfer). Comme dans le cas de la résonance de Förster à deux corps, les résonances FRET à trois corps sont accordées à la résonance avec un champ électrique externe et peuvent être observées pour différents nombres quantique principaux. Les effets à trois corps sont observés en absence de tout effet à deux corps et sont qualifiés de Borroméens. La présence d’un champ externe peut générer d’autres résonances entre atomes de Rydberg qui sont interdites en absence de champ électrique. Ces résonances, qu’on peut qualifier des résonances quasi-interdites, sont dues à un couplage dipole-dipole de type Förster. Nous avons identifié toutes ces résonances liées au couplage entre les niveaux de multiplicité de n différents.Dans le montage expérimental à Pise on a étudié les effets mécaniques liés à la répulsion van der Waals entre atomes de Rydberg. Nous avons étudié l’expansion due à l’interaction van der Waals dans une chaîne 1D des atomes de Rydberg de Rb qui ont étés excités avec une excitation laser hors résonance. La comparaison entre les différents désaccords de l’excitation laser démontre le rôle central joué par l’interaction van der Waals. / The aim of this thesis is to investigate different aspects of few-body interactions in cold Rydberg atoms. It has been realized in a co-tutelle program between the University of Paris-Saclay and the University of Pisa working on two different experimental set ups: one at Laboratoire Aimé Cotton on cold Cs Rydberg atoms and a second at Physics Department of Pisa on cold Rb Rydberg atoms. In Laboratoire Aimé Cotton we demonstrated the existence of new few-body interactions we observed in a frozen Rydberg gas of Cs atoms. These new resonances are a generalization of already known two-body Förster resonances. They act on the internal degrees of freedom of the Rydberg atoms leading to a resonant energy transfer analogous to the one in FRET (Fluorescence Resonance Energy Transfer). In analogy with Förster resonance, three-body FRETs are tuned with an external electric field and can be observed for different principal quantum number. The three-body interaction appeared in the absence of any two-body ones and for this reasons it has a Borromean character. The presence of this external electric field leads to additional resonances between Rydberg atoms supposedly forbidden. These resonances, we call quasi-forbidden Förster resonances, are due to dipole-dipole interaction as in the case of Förster resonance. We investigated these resonances finding a large number close to the allowed two-body and three-body FRET. A precise study was necessary in order to identify and discriminate these resonances from the allowed ones.In the experiment in Pisa we instead focus our attention on the mechanical effect of van der Waals repulsion between Rydberg atoms. We studied the spatial expansion due to a van der Waals interaction in a 1D chain of Rb Rydberg atoms excited with an off-resonant laser excitation. The comparison of the spatial expansion for different detuning of the laser excitation reveals the central role of the van der Waals interaction whose strength is equal to the detuning of the laser excitation.
19

Var kommer mina kläder ifrån? : En kvalitativ studie om hur uppfattningen och informationen om Country of Manufacture påverkar konsumenters köpbeslut / Where do my clothes come from? : A qualitative study of how the perception and information about Country of Manufacture affects consumers' purchasing decisions

Campoverde Morales, Melina, Khusnuddinova, Dilnoza January 2021 (has links)
Syfte: Denna studie syftar till att undersöka hur konsumenters köpbeslut påverkas utifrån deras kunskap och uppfattning om produkters tillverkningsland (Country of Manufacture). Metod: I denna studie används den kvalitativa forskningsmetoden där datainsamlingen utfördes genom 10 kvalitativa semistrukturerade intervjuer via telefonsamtal och Zoom-möten. Slutsatser: Informationen om ett tillverkningsland används i konsumenternas utvärdering av alternativ i form av stereotyper om länder, vilket även påverkar deras förväntningar av produktens inre värden. Påverkan av informationen om tillverkningslandet är större vid personliga och känslomässiga aspekter i form av fientlighet, affinitet och etnocentrism. Bakomliggande faktorerna till dessa aspekter är politik, hållbarhet och religion vilket uppstår på kollektiv och individuell nivå utifrån deras livssituation och tidigare erfarenheter. Dessutom tar konsumenten ställningstaganden över om de ska genomföra ett köp eller inte utifrån dessa aspekter. / Purpose: This study aims to investigate how consumers purchasing decisions are affected based on their knowledge and perception of the Country of Manufacture of products. Method: This study has a qualitative research method where collection of data was performed through 10 qualitative semi-structured interviews via telephone conversations and Zoom meetings. Conclusions: The information about a Country of Manufacture is used in consumers' evaluation of alternatives in the form of stereotypes about countries, which also affects their expectations of the product's intrinsic values. The influence of the information about the Country of Manufacture is greater in personal and emotional aspects in the form of animosity, affinity and ethnocentrism. The underlying factors to these aspects are politics, sustainability and religion, which arises on a collective and individual level based on their life situation and previous experiences. In addition, the consumer takes a stand on whether or not to make a purchase based on these aspects.
20

Estrutura taxonômica, filogenética e funcional de metacomunidades de pequenos mamíferos não-voadores de ecótonos campo-floresta no sul do Brasil

Luza, André Luís January 2013 (has links)
Ecótonos campo-floresta no sul do Brasil são originados pela expansão de ecossistemas florestais sobre os campestres, um processo natural gerado por mudanças climáticas de larga escala espacial e temporal. Este processo provoca mudanças vegetacionais que consequentemente modificam os padrões de distribuição, composição e riqueza faunística. Assim, ecótonos campo-floresta são sistemas adequados para inferir sobre a influência de processos históricos, biogeográficos e ecológicos na estruturação de comunidades. Para respondermos questões relacionadas a processos agindo em diferentes escalas espaciais, distribuímos as amostragens de modo a obtermos um panorama espacial da estrutura das assembléias. Assim, a proposta de estudo desenvolvido no Capítulo I foi avaliar o papel do ambiente e de dinâmicas espaciais sobre a composição, riqueza de espécies e número de indivíduos em metacomunidades de pequenos mamíferos não-voadores de ecótonos campo-floresta. Os resultados demonstram que os componentes ambiental, espacial e a estrutura espacial do ambiente contribuem igualmente na explicação da variância na composição de espécies, enquanto o ambiente foi mais importante em explicar mudanças na riqueza de espécies e número de indivíduos. Assim, concluímos que requerimentos de nicho das espécies e processos regionais como a limitação da dispersão, o distanciamento de centros de especiação e distribuição geográfica e o processo de expansão florestal conjuntamente explicam variações na estrutura de metacomunidades de pequenos mamíferos não-voadores em ecótonos campo-floresta no Sul do Brasil. No Capítulo II, inferimos sobre os processos gerando os padrões de coexistência de pequenos mamíferos não-voadores em assembléias baseando-se em afinidades filogenéticas e funcionais. Considerando estas similaridades, avaliamos se a diferenciação de nicho ou os filtros ambientais compõem processos importantes para explicar os padrões de coexistência em escalas de hábitat, paisagem e região. Os resultados apontam um padrão de agrupamento filogenético e funcional em todas as escalas avaliadas, embora um padrão de repulsão foi registrado no interior florestal, atestando a influência da diferenciação de nicho estruturando as assembléias de pequenos mamíferos não-voadores nesta porção do gradiente campo-floresta. A predominância do padrão de agrupamento filogenético e funcional afirma a ação de filtros ambientais como processos majoritariamente importantes em explicar os padrões de coexistência de espécies e indivíduos de pequenos mamíferos não-voadores nas escalas avaliadas. Desta forma, o estudo compõem uma das primeiras tentativas para definir os processos de estruturação de assembléias de pequenos mamíferos não-voadores neotropicais combinando aspectos taxonômicos, funcionais e filogenéticos, levantando também questões de conservação da biodiversidade nos sistemas ecológicos estudados. / Grassland-forest ecotones in southern Brazil are originated by forest expansion on grasslands, a natural process generated by climate shifts in large spatial and temporal scales, which causes vegetation changes and likely affects distribution, composition and faunal richness patterns. Thus, grassland-forest ecotones in southern Brazil are suitable systems to infer about influence of historical, biogeographical and ecological processes structuring communities. In order to make these inferences, we spatially sampled non-flying small mammals to characterize the spatial structure of species assemblages. The study proposal of Chapter I was to evaluate the role of environment and spatial dynamics on the composition, species richness and individuals number of nonflying small mammals metacommunities in grassland-forest ecotones. The results shows that environment, space and spatial structure of environment explained equally variations in species composition, while environment variables was the most important component explaining changes in species richness and number of individual. Thus, we conclude that niche requirements and regional processes like dispersal limitation, increase in distance of speciation cores and geographic distribution centers and the forest expansion process explain together variation in metacommunities structure of non-flying small mammals in grassland-forest ecotones at southern Brazil. In Chapter II, we inferred the coexistence patterns of non-flying small mammals based on phylogenetic and functional affinities. Considering these ecological similarities, we evaluate whether niche differentiation or environmental filters processes are responsible for patterns of species coexistence in habitat, landscape and regional scales. Results indicated a phylogenetic and functional cluster across all evaluated scales, although phylogenetic and functional repulsion was registered at forest interior, proving the importance of niche differentiation structuring non-flying small mammals assemblages in this grassland-forest gradient portion. Prevalence of phylogenetic and functional cluster across all scales attests environmental filters as important processes explaining species and individual coexistence patterns in habitat, landscape and regional scales. Therefore, this study comprises one of first attempts to define processes underlying the structure of neotropical non-flying small mammals assemblages combining taxonomic, functional and phylogenetic aspects, concurrently addressing important questions to biodiversity conservation in the ecological systems under study.

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