Orientador: Prof. Dr. Germán Lugones / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, 2014. / Neste trabalho, estudamos a transicao de fase de materia hadronica a materia quarks
em estrelas de neutrons e proto-estrelas de neutrons. A transicao comeca com o deconfinamento dos hadrons, que e governado pelas interacoes fortes, e e seguido pelo decaimento fraco dos quarks ate que a materia de quarks atinge o equilibrio quimico. Calculamos a taxa de todos os processos de interacao fraca relevantes na materia quarks quente e densa e resolvemos a equacao de Boltzmann, a fim de obter a escala de tempo de decaimento e a emissividade de neutrinos. Na equacao de estado, analisamos sistematicamente o efeito das interacoes fortes perturbativamente ate primeira ordem em ¿¿c, e o efeito datemperatura finita e massa do quark estranho. Nossos resultados mostram que a transicao aumenta a temperatura da materia quarks ate 60.70 MeV e o equilibrio quimico
e atingido em uma escala de tempo de um nanossegundo. A emissividade de neutrinos
por barion e muito grande, o que leva a emissao de uma energia por barion de 10.60
MeV sob a forma de neutrinos. Finalmente, analisamos as consequencias astrofisicas dos
resultados. / Thermodynamics allows us to analyze the performance of thermal machines, which has
the ability to convert the heat into useful work. Among others, the laws of thermodynamics
(especially the second) impose limits in various processes including information processing
in classical computers. The development of increasingly smaller computing devices, has
raised questions about which would limit the applicability of the laws of thermodynamics,
when they are close to the quantum limit. This type of questioning has linked different
disciplines into a new area of research that has been called quantum thermodynamics. This
dissertation is inserted into this new field of knowledge. Specifically we study the possibility
of implementing a quantum heat engine which operates out of equilibrium, and employs
a single "qubit" as working substance. For this purpose we use the underlying tools of
fluctuations theorems to adequately express quantities such as work and heat (which in the
quantum context are stochastic variables). We describe in detail the thermodynamic cycle for
work extraction in finite time, whose dynamics is controlled by "quenches", or sudden changes in an external field. The proposed protocol can be implemented and fully characterized using the current technology in the context of " Nuclear Magnetic Resonance (NMR)". Finally, we show the regimes of the machine operation
| Identifer | oai:union.ndltd.org:IBICT/oai:BDTD:77184 |
| Date | January 2014 |
| Creators | Gil, Jhon Andersson Rosero |
| Contributors | Lugones, Germán, Marinho, Laura Paulucci, Kemp, Ernesto, Dias, Alex Gomes, Peres, Orlando Luis Goulart |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf, 71 f. : il. |
| Source | reponame:Repositório Institucional da UFABC, instname:Universidade Federal do ABC, instacron:UFABC |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=77184&midiaext=70557, http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=77184&midiaext=70558, Cover: http://biblioteca.ufabc.edu.brphp/capa.php?obra=77184 |
Page generated in 0.0019 seconds