University, Diss., 2004--Würzburg.

München, Techn. Universiẗat, Diss., 2002.

Neste trabalho estudamos quatro tópicos. Nos dois primeiros calculamos a emisssão de momentum angular até a ordem de quadrupolo elétrico, primeiro através do fluxo dos campos e depois trabalhando nas próprias fontes. Os outros dois referem-se à massa eletromagnética. No primeiro a analisamos seguindo o trabalho de Dirac. No segundo a analisamos no contexto da eletrodinâmica não-linear de Born-Infeld mostrando que é igual à energia eletrostática dividida por c2 para um sistema qualquer, pontual ou não. / In this work we have studied four topics. In the first two we have calculated the emission of angular momentum up to electric quadrupole order, first through the flux of fields and afterwards working an the sources themselves. The other two refer to the electromagnetic mass. In the first one we have analysed it following Dirac\'s work. In the second one we have ana1ysed it in the context of the Born-Infeld\'s nonlinear electrodynamics showing that it is equal to the electrostatic energy divided by c2 far any system, paint like or not.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 158-176). Available also in a digital version from Dissertation Abstracts.

Inauguraldiss. Phil.-hist. Fak. Bern, 1985. / Im Buchh.: Erlangen: Palm & Enke.

Submitted by DERICK DOS SANTOS ROSA null (derick@ift.unesp.br) on 2016-09-27T19:10:43Z No. of bitstreams: 1 dissertacao.pdf: 2019409 bytes, checksum: 0be92a2b52e4578cd4fe399bc8639856 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-29T16:36:56Z (GMT) No. of bitstreams: 1 rosa_ds_me_ift.pdf: 2019409 bytes, checksum: 0be92a2b52e4578cd4fe399bc8639856 (MD5) / Made available in DSpace on 2016-09-29T16:36:56Z (GMT). No. of bitstreams: 1 rosa_ds_me_ift.pdf: 2019409 bytes, checksum: 0be92a2b52e4578cd4fe399bc8639856 (MD5) Previous issue date: 2016-07-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesta dissertação vamos estudar um problema de três corpos via aproximação de Born-Oppenheimer em duas dimensões para um sistema constituído de duas partículas pesadas e uma leve. Considerando uma interação de contato entre a partícula leve e as pesadas e desconsiderando a interação entre as pesadas, estudamos o efeito do momento angular e da diferença de massa entre as partículas. Notamos que diminuindo a diferença de massa entre as partículas encontramos um número menor de estados ligados. Conforme aumentamos o momento angular observamos um número menor de estados ligados, isto porque o momento angular soma ao sistema um potencial repulsivo, tornando o sistema mais fracamente ligado. Considerando um potencial gaussiano entre as partículas pesadas calculamos a energia de três corpos e o raio quadrático médio. Observamos que a introdução deste potencial torna possível o rompimento do sistema de três corpos e o fenômeno de tunelamento. Estudando o raio quadrático médio percebemos que na região de tunelamento o tamanho do sistema varia consideravelmente, tornando esta região interessante de ser detectada experimentalmente. / In this thesis we study mass-imbalanced three-body system in two dimensions using BornOppenheimer approximation. Considering the heavy-light particle system interacting through zero-range interaction and disregarding interaction between the heavy-heavy, we study effects the angular momentum and mass ratio difference. Decreasing the mass difference between the heavy and the light particles a smaller number of bound states is found. Increasing the angular momentum we add to the system a repulsive potential, making the system weakly bounded, in this case a small number of bound states are expected. Considering a gaussian potential between the heavy-heavy particles it is possible to unbounded the system and observe tunneling phenomena. The considerable change in the tunneling region for the mean square radii indicates an increase in the system size, making this region interesting to be experimentally detected. / CNPq: 147716/2014.4

Neste trabalho estudamos quatro tópicos. Nos dois primeiros calculamos a emisssão de momentum angular até a ordem de quadrupolo elétrico, primeiro através do fluxo dos campos e depois trabalhando nas próprias fontes. Os outros dois referem-se à massa eletromagnética. No primeiro a analisamos seguindo o trabalho de Dirac. No segundo a analisamos no contexto da eletrodinâmica não-linear de Born-Infeld mostrando que é igual à energia eletrostática dividida por c2 para um sistema qualquer, pontual ou não. / In this work we have studied four topics. In the first two we have calculated the emission of angular momentum up to electric quadrupole order, first through the flux of fields and afterwards working an the sources themselves. The other two refer to the electromagnetic mass. In the first one we have analysed it following Dirac\'s work. In the second one we have ana1ysed it in the context of the Born-Infeld\'s nonlinear electrodynamics showing that it is equal to the electrostatic energy divided by c2 far any system, paint like or not.

Promoting physical activity in older adults is an important part of healthy aging. With an increasing older foreign-born population in the United States, there is limited information on physical activity participation in this group and even less for those experiencing difficulties in physical functioning and chronic illnesses. The primary objective of the study was to determine how physical factors, psychological issues, chronic illnesses, pain symptoms, perceived health status, and number of years living in the U.S. influence physical activity participation in older foreign-born respondents. The secondary objective was to identify the difference of predictors of physical activity participation between older foreign-born and older native-born respondents. The study is based on data collected from the National Health Interview Survey (NHIS) conducted from 2002 to 2009 for adults aged 50 or older. Ordinal logistic regression analysis was used to predict and explain the physical activity participation in older foreign-born respondents. Factors associated with more physical activity participation included a higher level of education, more time living in the U.S., more positively perceived health status, and having at least one chronic illnesses, or pain symptoms. Having more difficulties in physical functioning caused older foreign-born respondents to participate less in physical activity. This study provides the most recent evidence to health-care professionals to develop and implement policies and strategies to facilitate physical activity programs that will be beneficial to elderly immigrants living in the U.S.

Birth order may represent one of the most influential environmental factors that directly impacts personality development and even life outcomes. The present study sought to expand upon the existing literature by examining the motivational and dispositional differences between first born and second born individuals. Research indicates that first born children show significantly higher levels of academic achievement and lifelong attainment due to experiencing higher parental expectations as well as increased financial support. As a result, the second born child is likely to compare him/herself with the first born sibling and develop a greater level of competitiveness. Additionally, this desire to surpass the first born may lead to the development of extrinsically motivated goals. Few research endeavors to date have explored the specific motivational disposition of the second born child with no future siblings. By engaging in this research, a better understanding of the complex interaction between siblings can be ascertained as well as a deeper appreciation for how the familial environment impacts development. Such information can be applied to the educational setting to develop programs more rewarding and salient to second-born individuals, thus increasing their level of academic achievement. Seventy-two male and female participants took part in the present experiment. Research validated scales were used to assess overall competitiveness in addition to intrinsic and extrinsic motivation. A paired-t test was used to evaluate the data and compare the differences between the two groups. Although the results do not support the hypotheses, there were a number of limitations that may have served to restrict the scope of the data. The theoretical implications of the results and suggestions for future research will be discussed.

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