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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.
21

Simetrias de paridade e de reversão temporal no Efeito Hanbury Broen-Twiss

Silva, Erick Rodrigues 03 August 2015 (has links)
Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2016-05-02T10:49:21Z No. of bitstreams: 1 arquivototal.pdf: 1791577 bytes, checksum: ecd7a6eb8a18230d0145c24932d9e248 (MD5) / Made available in DSpace on 2016-05-02T10:49:22Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1791577 bytes, checksum: ecd7a6eb8a18230d0145c24932d9e248 (MD5) Previous issue date: 2015-08-03 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The Hanbury Brown-Twiss experiment is very well established in quantum optics literature, so we devoted this dissertation in order to embed the parity and temporal reversal symmetry in the former experiment. Therefore, we developed the scattering matrix formalism which allow us use some techniques such as the scattering matrices' concatenation of di erent sections in terms of one matrix and the scattering problem of a parity and temporal reverse symmetric system. In this manner, we could derive the scattering matrix of a parity and temporal reverse symmetric Hanbury Brown- Twiss experiment(HBT-PT). With the possession of this matrix, we proposed a theoretical model which provides how to measure the symmetry of this system, which we called correlation functions formalism. In order to stablish the former formalism, we studied B uttiker formalism, which we veri ed how the correlation between 2 incident particles in a system relates to the noise due transport of this particles and what kind of noise we are treating in a given regime which the system is operating. Then, we found the input states in terms of the output states of two particles inciding in a multiterminal system, which we used it's scattering matrix to stablish the relation between the states. Thereat, we derived all the possibles correlations(therefore, the noise) of two incident particles in the former system. Thereby, we analysed the extreme cases of a barrier coupled to the HBT-PT experiment for the purpose of stablish which regime the experiment is symmetric adjusted, so, demonstrating the Hanbury Brown-Twiss E ect with parity and temporal reverse symmetries. / Sendo o experimento Hanbury Brown-Twiss bem estabelecido na literatura da otica quântica, dedicamos esta dissertação a embutir no mesmo experimento a questão da simetria por paridade e reversão temporal. Para tanto, abrimos mão do formalismo da matriz de espalhamento que permitiu nos utilizar tecnicas como a concatenação de matrizes de espalhamento de sec ções diferentes em termos de apenas uma matriz e o problema do espalhamento em um sistema simétrico por paridade e reversão temporal. Dessa forma, pudemos derivar a matriz de espalhamento para o experimento Hanbury Brown-Twiss com simetria de paridade e revers~ao temporal(HBT-PT). De posse dessa matriz, propusemos um modelo teórico que propicia a medição experimental a simetria desse sistema, o qual chamamos de formalismo das fun c~oes de correla c~ao. Para estabelecermos o formalismo supracitado, estudamos o formalismo de Buttiker, onde veri case como a correlaçãao entre 2 partículas incidentes em um sistema relaciona-se com o ru do devido ao transporte dessas part culas e que tipo de ru do estamos tratando, dado o regime em que o sistema está operando. Em seguida, encontramos os estados de entrada em termos dos estados de saída de 2 partículas incidindo em um sistema multiterminal, onde utilizamos a sua matriz de espalhamento para estabelecer a rela c~ao entre os estados. Com isso, derivamos todas as possíveis correlações (e, por conseguinte, o ruído) de 2 partículas incidentes nesse sistema. Assim, analisamos os casos extremos de uma barreira acoplada ao experimento HBT-PT, a m de estabelecer o regime em que o experimento está simetricamente ajustado e demonstramos o Efeito Hanbury Brown-Twiss por paridade e reversão temporal.
22

The illegal reptile trade - a criminological perspective

Herbig, Friedo Johann Willem 30 June 2003 (has links)
The illegal reptile trade quandary in the Western Cape province is strategically and chronologically addressed in this thesis with the implicit intention of revealing its gamut and underlying dynamics, developing a pragmatic, parsimonious and authentic conservation crime category with clearly delineated parameters, and formulating an integrated theoretical explanation regarding its aetiology that will adequately explicate herpetological, and hopefully also other forms of natural resource, crime and deviance. The thesis, by essentially transcending traditional, stereotypical edicts, throws new light on a severely neglected and underestimated form of natural resource exploitation, highlighting the need for reptiles, as the sentinels of the state of our environmental health to be preserved and perpetuated for, in the final analysis, the benefit of human kind. Through an essentially explorative enquiry, utilising an integrated qualitative -quantitative research approach, the concept of conservation crime, as a vanguard to an innovative and unified conservation criminology, is introduced in this thesis in the form of unambiguous adjunct of the mainstream criminological discipline. It is, furthermore, utilised as a conduit within the herpetological crime framework to enrich the criminological discipline as a whole, broaden its frontiers, promote effective and focussed intervention/mitigation initiatives, as well as stimulate interest for further investigation in this field. Fragmented, antiquated and nebulous legislation, deficient conservation and related role-player organisational capacity and inconsistent penalties, in concert with apathetic (and decidedly generic) societal attitudes and traditional pessimistic rubric regarding reptiles, emerge as fundamental proclivities impeding the effective intercession and management of the natural resources embodied in this sphere. Injudicious manipulation of the Western Cape's scarce and specialised reptile resources and the biodiversity ramifications such exploitation realises portend the intensification and diversification potential of such criminality. Conservation criminology, as developed and presented in this thesis, underscores the significant contribution this field of criminology can make in comprehending the illegal manipulation/exploitation of herpetological and other natural resources, expanding and enhancing its theoretical constructs and implementing justice through decisive, dedicated and holistic intervention programmes/strategies in order to defend the inherent right to the continued existence of all reptile species. / Crimonology / D. Litt et Phil. (Criminology)
23

The illegal reptile trade - a criminological perspective

Herbig, Friedo Johann Willem 30 June 2003 (has links)
The illegal reptile trade quandary in the Western Cape province is strategically and chronologically addressed in this thesis with the implicit intention of revealing its gamut and underlying dynamics, developing a pragmatic, parsimonious and authentic conservation crime category with clearly delineated parameters, and formulating an integrated theoretical explanation regarding its aetiology that will adequately explicate herpetological, and hopefully also other forms of natural resource, crime and deviance. The thesis, by essentially transcending traditional, stereotypical edicts, throws new light on a severely neglected and underestimated form of natural resource exploitation, highlighting the need for reptiles, as the sentinels of the state of our environmental health to be preserved and perpetuated for, in the final analysis, the benefit of human kind. Through an essentially explorative enquiry, utilising an integrated qualitative -quantitative research approach, the concept of conservation crime, as a vanguard to an innovative and unified conservation criminology, is introduced in this thesis in the form of unambiguous adjunct of the mainstream criminological discipline. It is, furthermore, utilised as a conduit within the herpetological crime framework to enrich the criminological discipline as a whole, broaden its frontiers, promote effective and focussed intervention/mitigation initiatives, as well as stimulate interest for further investigation in this field. Fragmented, antiquated and nebulous legislation, deficient conservation and related role-player organisational capacity and inconsistent penalties, in concert with apathetic (and decidedly generic) societal attitudes and traditional pessimistic rubric regarding reptiles, emerge as fundamental proclivities impeding the effective intercession and management of the natural resources embodied in this sphere. Injudicious manipulation of the Western Cape's scarce and specialised reptile resources and the biodiversity ramifications such exploitation realises portend the intensification and diversification potential of such criminality. Conservation criminology, as developed and presented in this thesis, underscores the significant contribution this field of criminology can make in comprehending the illegal manipulation/exploitation of herpetological and other natural resources, expanding and enhancing its theoretical constructs and implementing justice through decisive, dedicated and holistic intervention programmes/strategies in order to defend the inherent right to the continued existence of all reptile species. / Crimonology / D. Litt et Phil. (Criminology)

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