85 research outputs found

    A semiclassical trace formula for the canonical partition function of one dimensional systems

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    We present a semiclassical trace formula for the canonical partition function of arbitrary one-dimensional systems. The approximation is obtained via the stationary exponent method applied to the phase-space integration of the density operator in the coherent state representation. The formalism is valid in the low temperature limit, presenting accurate results in this regime. As illustrations we consider a quartic Hamiltonian that cannot be split into kinetic and potential parts, and a system with two local minima. Applications to spin systems are also presented.Comment: 22 pages, 4 figures new section with applications to spin system

    ANATOMIA DO FÍGADO E VIAS BILÍFERAS DO MUÇUÃ (Kinosternon scorpioides)

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    Twenty livers of adult muçua were analyzed. The samples were obtained through an authorization of IBAMA (license nÂș 006/02, process nÂș 0220120011113/2002/81). The animals were anesthetized with xilazine (1mg/Kg/IM) and ketamine (20mg/Kg/IM). After muscular relaxation, they were sacrificed by means of an injection of sodium thiopental at 2.5% in the lethal doses of 60mg/Kg/IV). The coelomatic cavity was opened and the liver dissected with the aid of a magnifying glass. In all the animals the liver was quite voluminous, brown, rectangular in shape, extending through the whole medium portion of the coelomatic cavity, covering the pancreas, duodenum and stomach. External fissures divided the liver in 5 lobes: right lateral and median; square; left lateral and caudate with a papillae process. The liver is maintained in its anatomical position by the pressing of the coelomatic viscera as well as by the following ligaments: hepatogastric (connecting to the stomach); hepatoduodenopancreatic (connecting to the duodenum and pancreas); hepatopulmonar (connecting to the lung); hepatocoelomatic (connecting to the ventral portion of the coelomatic cavity) and hepatopericardic (connecting to the pericardial bursa). In regard to the bile ducts, it is observed that branches originated from the hepatic lobes pull together forming the main right and left ducts, which, together with the cystic duct derived from the gall bladder vesicle, originate the bile duct. According to these observations we concluded that the liver of the muçua is similar to the domestic mammals regarding the shape, number, characterization and bile draining of the hepatic lobe and differs from the ones of the related species such as salamander, snakes and other reptiles.Foram pesquisados 20 fĂ­gados de muçuĂŁs (Kinosternon scorpiodes) adultos obtidos mediante autorização do IBAMA (licença nÂș006/02 e processo nÂș 022012001113/2002-81). Os animais foram anestesiados com cloridrato de xilazina (1 mg/Kg/IM) e cloridrato de quetamina (20 mg/Kg/IM) e apĂłs relaxamento muscular, foram sacrificados atravĂ©s da aplicação de tiopental sĂłdico a 2,5%, na dose letal de 60 mg/Kg/EV. Em seguida prosseguiu-se com a abertura da cavidade pleuroperitoneal e a dissecação do ĂłrgĂŁo, auxiliada por lupa. Em 100% dos animais estudados aquele ĂłrgĂŁo apresentase como um fĂ­gado bastante volumoso, de formato retangular, coloração marrom, se estendendo por toda a porção mĂ©dia da cavidade pleuroperitoneal, envolvendo o pĂąncreas, duodeno e o estĂŽmago. Apresenta-se dividido, por fissuras externas, em cinco lobos: lateral e medial direitos, quadrado, lateral esquerdo, e caudato, este com o processo papilar. O fĂ­gado encontra-se mantido na posição anatĂŽmica pela pressĂŁo das vĂ­sceras pleuroperitoneais e pelos ligamentos, quais sejam, hepatogĂĄstrico (ligandoo ao estĂŽmago), hepatoduodenopancreĂĄtico (ligando-o ao duodeno e pĂąncreas), hepatopulmonar (ligando-o ao pulmĂŁo), hepatopleuroperitoneal (ligando-o Ă  porção ventral da cavidade pleuroperitoneal) e hepatopericĂĄrdico (ligando-o ao saco pericĂĄrdico). Quanto Ă s vias bilĂ­feras, observa-se que sĂŁo formadas por ramos oriundos dos lobos hepĂĄticos, que se juntam formando os ductos principais direito e esquerdo, os quais, juntamente com o ducto cĂ­stico, oriundo da vesĂ­cula biliar, formam o ducto colĂ©doco. De acordo com as observaçÔes realizadas sobre a morfologia externa, conclui-se que o fĂ­gado do muçuĂŁ assemelha-se ao dos principais mamĂ­feros domĂ©sticos, no que se refere Ă  forma, nĂșmero, caracterização e drenagem biliar dos lobos hepĂĄticos, diferindo, entretanto, do das espĂ©cies mais prĂłximas, como as salamandras, cobras e outros rĂ©pteis
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