Harmonically Trapped Quantum Gases

We solve the problem of a Bose or Fermi gas in $d$-dimensions trapped by $\delta \leq d$ mutually perpendicular harmonic oscillator potentials. From the grand potential we derive their thermodynamic functions (internal energy, specific heat, etc.) as well as a generalized density of states. The Bose gas exhibits Bose-Einstein condensation at a nonzero critical temperature $T_{c}$ if and only if $d+\delta >2$, and a jump in the specific heat at $T_{c}$ if and only if $d+\delta >4$. Specific heats for both gas types precisely coincide as functions of temperature when $d+\delta =2$. The trapped system behaves like an ideal free quantum gas in $d+\delta$ dimensions. For $\delta =0$ we recover all known thermodynamic properties of ideal quantum gases in $d$ dimensions, while in 3D for $\delta =$ 1, 2 and 3 one simulates behavior reminiscent of quantum {\it wells, wires}and{\it dots}, respectively.Comment: 14 pages including 3 figures and 3 table

Membranas sintéticas impermeables y capas auxiliares separadoras en la cubierta plana invertida. Efecto de la presión sobre la degradación

Flat roofs are inverted when the insulation material is placed over the waterproofing membrane. This widely-used constructive system sets materials which may interact easily with each other causing their deterioration. The incompatibilities and the materials that may interact with each other are not completely described, the elements currently used to separate the materials are not totally efficient to avoid deterioration. This paper intends to enlarge the knowledge regarding the materials that are incompatible for inverted flat roofs, the conditions were interactions take place and the efficiency of some alternative solutions to separate the materials. The ethylene propylene diene monomer (EPDM) waterproofing membranes are incompatible with the extruded polystyrene (XPS). The interactions between incompatible materials increase with the pressure.Las cubiertas planas son invertidas cuando el material aislante se coloca sobre la membrana impermeable. Este sistema constructivo ampliamente utilizado emplea materiales que pueden interactuar con facilidad entre ellos, produciendo deterioro. Las incompatibilidades y los materiales que pueden interactuar no se han descrito completamente, los elementos utilizados actualmente para separar los materiales no son totalmente eficientes para evitar el deterioro. Este artículo pretende aumentar el conocimiento acerca de que materiales son incompatibles en la cubierta invertida plana, las condiciones para que las interacciones se den, y la eficiencia de algunas alternativas para separar materiales. Las membranas impermeables de etileno propileno monómero dieno (EPDM) son incompatibles con el poliestireno extrusionado (XPS). Las interacciones entre materiales incompatibles aumentan con la presión

Estudio comparativo con microscopio electrónico de barrido de la degradación de una lámina impermeable de cloruro de polivinilo plastificado en diferentes condiciones

This paper discusses the analysis of several samples of a plasticized polyvinyl chloride (PVC-P) waterproofing membrane. The samples were extracted from different areas of the same flat roof, which was in service for over 12 years. An original sample of an identical PVC-P membrane that was not installed on the roof was also analyzed. The analysis of the materials was carried out using a scanning electron microscope (SEM). An elemental analysis of every sample was also performed by energy dispersive X-ray spectroscopy (EDS). Micrographs and the elemental composition of the samples were compared with the data obtained in the analysis of the original sample. The results show dehydrochlorination of the polymer in two of the samples studied and great deterioration that was not visible to the naked eye in the sample that was totally exposed to the weather.Este estudio discute el análisis de varias muestras de una membrana impermeable de cloruro de polivinilo plastificado (PVC-P). Las muestras fueron extraídas de diferentes áreas de la misma cubierta plana, que estuvo en servicio durante más de 12 años. Una muestra original de idéntica membrana de PVC-P que no estuvo instalada en la cubierta fue también analizada. El análisis de los materiales se llevó a cabo utilizando un microscopio electrónico de barrido (MEB). Además se realizó un análisis elemental sobre cada una de las muestras mediante espectroscopía de dispersión de energía de rayos X (EDS). Las micrografías, y la composición elemental de las muestras, se comparan con los datos obtenidos en el análisis de la muestra original. Los resultados muestran deshidrocloración del polímero en dos de las muestras estudiadas, y un gran deterioro de la muestra totalmente expuesta a la intemperie, que no era visible a simple vista

Realización de un grafo en recintos rectangulares sobre una planta definida

En este trabajo se analiza el problema de la realización de un grafo en un conjunto de recintos rectangulares que cubran una planta dada, de lados paralelos a dos direcciones perpendiculares. Los grafos pueden representar el esquema básico de una vivienda o de un edificio y en él se muestran distintos requerimientos del proyecto. Para ello, se analiza el problema de la partición de un rectángulo en rectángulos, esto es, dado un grafo, saber si admite una realización de esta clase y, en caso afirmativo, generar automáticamente dichas realizaciones. En ambos aspectos, se propone un procedimiento completo y general. Se trata de un problema de aplicación práctica en áreas tales como proyecto arquitectónico o compactación de circuitos electrónicos, del que no se ha encontrado una solución general en la bibliografía consultada.Peer reviewe

Slow and fast micro-field components in warm and dense hydrogen plasmas

The aim of this work is the investigation of the statistical properties of local electric fields in an ion-electron two component plasmas for coupled conditions. The stochastic fields at a charged or at a neutral point in plasmas involve both slow and fast fluctuation characteristics. The statistical study of these local fields based on a direct time average is done for the first time. For warm and dense plasma conditions, typically $N_{e}\approx 10^{18}cm^{-3}$, $$, well controlled molecular dynamics (MD) simulations of neutral hydrogen, protons and electrons have been carried out. Relying on these \textit{ab initio} MD calculations this work focuses on an analysis of the concepts of statistically independent slow and fast local field components, based on the consideration of a time averaged electric field. Large differences are found between the results of these MD simulations and corresponding standard results based on static screened fields. The effects discussed are of importance for physical phenomena connected with stochastic electric field fluctuations, e.g., for spectral line broadening in dense plasmas.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

METHODOLOGICAL APPROACH TO INTEGRATE A GIS-BASED ANALYSIS INTO THE DESIGN OF CULTURAL ITINERARIES IN THE FRAMEWORK OF AN INTEGRATED PLAN FOR TERRITORY

Abstract. The historical concept of heritage, which mostly comprised physical architectural and archaeological evidences, has been extended to the surrounding landscape in the last decades. This tendency has been corroborated by a series of International Charters and the European Landscape Convention of 2000. Landscape, understood as the perceptible part of territory that supports the contingencies throughout history, is subject to protection, management and planning. However, some inherent aspects of territory have been disregarded because of the frantic enlargement of cities throughout the twentieth century at the expense of the rural areas. Territorial heritage, which is fundamental to cultural landscape formation, is currently considered a strategic resource able to guarantee self-sustaining development of peri-urban and rural zones. In many cases, urban investments and planning associated to the enlargement of the metropolitan areas have overlooked this fruitful territorial heritage, making cultural landscapes illegible. This is the case of the cultural landscapes in the buffer zones of the archaeological sites, which are part of a diffuse territorial heritage that requires to be assessed by means of some innovative approaches. Cultural itineraries are presented as a landscape architecture strategy for valorising territorial heritage. Well-targeted design of these itineraries can also contribute to restore the dynamics of cultural landscape formation and to regenerate peri-urban and rural areas by promoting its self-sustaining development. To that end, the conceptualisation and hypotheses posed by some authors of the Società dei Territorialisti/e are used as references. A work methodology to design cultural itineraries is suggested in line with the presumptions of an integrated plan for territory aimed to valorise the territorial heritage. This paper explores in which way a GIS-based analysis can be integrated into the design of a landscape architecture like the cultural itinerary

Infección por el virus de la leucemia felina (FeLV) y linfomas mediastínicos : dos casos clínicos

Se describen los hallazgos clínicos, radiológicos y analíticos en dos casos de gatos menores de dos años, que se presentaron con un cuadro clínico de caquexia, vómitos y disnea. En ambos casos las radiografías evidenciaron la presencia de masas intratorácicas; la analítica basada en test ELISA para FeLV y FIV y las necropsias efectuadas, parecen demostrar la relación existente entre gato joven, FeLV y el desarrollo de masas tumorales mediastínicas.The clinical, radiologycal and analytic discovery, are described in two cases of cats under two years of age which were presented with dyspnea, vomiting and caquexia. In both cases the radiographs showed the presence of intrathoracic masses; ELISA test for FeLV and FIV and the necropsy demostrated the relation of young cat and FeLV with the development of mediastinic tumoral masses

Planktonic Chlorophyceae from the lower Ebro River (Spain)

On samples obtained in 4 seasonal periods between April 1999 and February 2000 from the last 18 km of Ebro River (Spain) some interesting planktonic coccal green algae (Chlorophyceae) were found. This paper offers comments and taxonomical observations on 60 taxa. Crucigenia smithii (Kirchner) W. et G. S. West, Crucigeniella pulchra (W. et G.S.West) Komárek, Elakatothrix genevensis (Reverdin) Hindák, E. subacuta Koršikov, Nephrocytium schilleri (Kammerer) Comas, Oocystidium ovale Kor{ikov, Pseudoschroederia antillarum (Komárek) Hegewald et Schnepf, Scenedesmus denticulatus var. fenestratus (Teiling) Uherkovich, S. pannonicus Hortobágyi, Siderocelis ornata (Fott) Fott, Tetrachlorella alternans (G.M. Smith) Koršikov and Tetrastrum komarekii Hindák were found for the first time in this country. The best represented genus was Scenedesmus, with 16 taxa