5,179 research outputs found
The Einstein-Boltzmann Relation for Thermodynamic and Hydrodynamic Fluctuations
When making the connection between the thermodynamics of irreversible
processes and the theory of stochastic processes through the
fluctuation-dissipation theorem, it is necessary to invoke a postulate of the
Einstein-Boltzmann type. For convective processes hydrodynamic fluctuations
must be included, the velocity is a dynamical variable and although the entropy
cannot depend directly on the velocity, will depend on velocity
variations. Some authors do not include velocity variations in ,
and so have to introduce a non-thermodynamic function which replaces the
entropy and does depend on the velocity. At first sight, it seems that the
introduction of such a function requires a generalisation of the
Einstein-Boltzmann relation to be invoked. We review the reason why it is not
necessary to introduce such a function, and therefore why there is no need to
generalise the Einstein-Boltzmann relation in this way. We then obtain the
fluctuation-dissipation theorem which shows some differences as compared with
the non-convective case. We also show that is a Liapunov
function when it includes velocity fluctuations.Comment: 13 Page
Factors that influence the process of formation of the olympic judokas
Con el objetivo de analizar los factores que influyen en el proceso de formaciĂłn deportiva de los judokas españoles olĂmpicos, se aplicĂł una entrevista semiestructurada de 52 preguntas agrupadas en 6 dimensiones (Contexto Deportivo, Contexto Social, Proceso de FormaciĂłn, PsicolĂłgica, TĂ©cnico-tĂĄctica, CondiciĂłn FĂsica). Los resultados muestran que los judokas olĂmpicos se iniciaron en la prĂĄctica del Judo a los 6,90 ± 3,02 años, concretamente las mujeres a los 6,80 ± 2,88 años y los hombres algo mĂĄs tarde, a los 7 ± 3,42 años, el 95% (n=19) influenciados, fundamentalmente, por un familiar. AdemĂĄs, destaca que ninguno de los entrevistados consiguiĂł medalla en categorĂas inferiores. Para el 75% (n=15) de los judokas olĂmpicos es muy importante llevar una sincronizaciĂłn del entrenamiento tĂ©cnico-tĂĄctico, de la condiciĂłn fĂsica y de los aspectos psicolĂłgicos de forma integradaWith the aim of analizing the factors that have an influence on the sports training process of the olympic Spanish judokas, a semistructured interview of 52 questions grouped in 6 aspects was carried out: Sports Context, Social Context, Training Process, Psychological Condition, Technical-Tactical Condition and Physical Conditon). The results show that olympic judokas began practising judo at the age of 6.90 ± 3.02 years. Specifically, women started at the age of 6.80 ± 2.88, and men slightly later, at the age of 7 ± 3.42 years. 95% (n=19) of them were mainly influenced by a relative. Moreover, it is to be highlighted that none of the interviewees won a medal in low categories. For 75% (n=15) of the olympic judokas, it is very important that technical-tactical training, physical condition training and psychological aspects be synchronised in an integrated wa
Identidad taxonómica de algunos taxones del género endémico ibérico Iberus Montfort, 1810 (Gastropoda, Helicidae)
Se revisan las series tipo de las especies de Iberus descritas por RossmĂ€ssler (1854) y depositadas en el Senckenberg Forschungsinstitut und Naturmuseum de Frankfurt, Alemania. Se concluye que Helix alcarazana (actualmente Iberus alcarazanus) es sinĂłnimo posterior de Iberus alonensis (FĂ©russac, 1821). Se discuten y modifican las localidades tipo de Helix y de Helix alcarazana y se designan lectotipos para Helix guiraoana, Helix guiraoana var. angustata, Helix alcarazana y Helix loxana. AdemĂĄs, se revisa la serie tipo de Helix alonensis (FĂ©russac, 1821) (actualmente Iberus alonensis) depositada en el MusĂ©um national dâHistoire naturelle de ParĂs, Francia. Se selecciona el lectotipo y se designa âAlicanteâ como localidad tipo restringida.To determine the taxonomic identity of some of the species included in the genus Iberus, we reviewed the type series described by RossmĂ€ssler (1854) and deposited at the Senckenberg Forschungsinstitut und Naturmuseum of Frankfurt (Germany). We concluded that Helix alcarazana (currently Iberus alcarazanus) is a junior synonym of Iberus alonensis (FĂ©russac, 1821). The type localities of Helix guiraoana and Helix alcarazana were discussed and modified and the lectotypes of Helix guiraoana, Helix guiraoana var. angustata, Helix alcarazana and Helix loxana were designated. In addition, we reviewed the type series of Helix alonensis FĂ©russac, 1821 (currently Iberus alonensis) deposited at the MusĂ©um national dâHistoire naturelle of Paris, France and we selected its lectotype. The locality of Alicante has been designated as the restricted type locality of this species.Se revisan las series tipo de las especies de Iberus descritas por RossmĂ€ssler (1854) y depositadas en el Senckenberg Forschungsinstitut und Naturmuseum de Frankfurt, Alemania. Se concluye que Helix alcarazana (actualmente Iberus alcarazanus) es sinĂłnimo posterior de Iberus alonensis (FĂ©russac, 1821). Se discuten y modifican las localidades tipo de Helix y de Helix alcarazana y se designan lectotipos para Helix guiraoana, Helix guiraoana var. angustata, Helix alcarazana y Helix loxana. AdemĂĄs, se revisa la serie tipo de Helix alonensis (FĂ©russac, 1821) (actualmente Iberus alonensis) depositada en el MusĂ©um national dâHistoire naturelle de ParĂs, Francia. Se selecciona el lectotipo y se designa âAlicanteâ como localidad tipo restringida
Decoherence in an accelerated universe
In this paper we study the decoherence processes of the semiclassical
branches of an accelerated universe due to their interaction with a scalar
field with given mass. We use a third quantization formalism to analyze the
decoherence between two branches of a parent universe caused by their
interaction with the vaccum fluctuations of the space-time, and with other
parent unverses in a multiverse scenario.Comment: 11 pages, 2 figure
A dark energy multiverse
We present cosmic solutions corresponding to universes filled with dark and
phantom energy, all having a negative cosmological constant. All such solutions
contain infinite singularities, successively and equally distributed along
time, which can be either big bang/crunchs or big rips singularities.
Classicaly these solutions can be regarded as associated with multiverse
scenarios, being those corresponding to phantom energy that may describe the
current accelerating universe
Quantum state of the multiverse
A third quantization formalism is applied to a simplified multiverse
scenario. A well defined quantum state of the multiverse is obtained which
agrees with standard boundary condition proposals. These states are found to be
squeezed, and related to accelerating universes: they share similar properties
to those obtained previously by Grishchuk and Siderov. We also comment on
related works that have criticized the third quantization approach.Comment: 15 pages, 2 figure
Differences of the game between the football Spanish team and its rivals.
El objeto de este estudio, analizando la accioÌn de juego en fuÌtbol, describe el uso de los contextos de interaccioÌn que la seleccioÌn espanÌola de fuÌtbol y sus rivales hicieron en los campeonatos internacionales. Para ello, 13 partidos fueron observados y codificados (seis de la Eurocopa 2008 y siete del Mundial 2010) gracias a un sistema taxonoÌmico ad hoc previamente definido. Los datos fueron registrados usando un software especiÌfico. DespueÌs, coordenadas polares fueron desarrolladas usando soÌlo como conductas criterio los contextos de interaccioÌn. Los resultados obtenidos describen que EspanÌa y sus oponentes no hicieron el mismo uso del espacio de juego en sus partidos (maÌs ofensivo para los primeros), mostrando la dimensioÌn diacroÌnica de los eventos y combinando las perspectivas prospectiva y retrospectiva. Esto nos permite saber el componente estrateÌgico del uso de los contextos de interaccioÌn hechos por los equipos en la competicioÌn y optimizar programas de entrenamiento especiÌficos.Este estudio es parte del proyecto titulado Avances TecnoloÌgicos y MetodoloÌgicos en la AutomatizacioÌn de Estudios observacionales en deporte, financiado por DireccioÌn General de InvestigacioÌn de EspanÌa, Ministerio de Ciencia e InnovacioÌn (PSI2008-01179) en el periÌodo 2008-2011. No existen conflictos de intereses para esta investigacioÌn
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