Black hole formation in bidimensional dilaton gravity coupled to scalar matter systems

This work deals with the formation of black hole in bidimensional dilaton gravity coupled to scalar matter fields. We investigate two scalar matter systems, one described by a sixth power potential and the other defined with two scalar fields containing up to the fourth power in the fields. The topological solutions that appear in these cases allow the formation of black holes in the corresponding dilaton gravity models.Comment: Latex, 9 pages. Published in Mod. Phys. Lett. A14 (1999) 268

¿Aplican los estudiantes de maestría en contabilidad y finanzas la teoría de la perspectiva?

This study aims to question the assumptions of prospect theory using a sample of students enrolled in a master’s course on accounting and finance at a Portuguese polytechnic institution. Such theory has stood out among others developed in the field of Behavioural Finance due to the debate and investigation it has generated. To achieve this aim, we applied a questionnaire four consecutive years (2012–2015). The instrument included a set of alternative response questions that seek to unveil respondents’ preferences regarding the situations they were presented with. Bibliographic and descriptive research was carried out and the results were compared with those obtained by other authors but they were not always consistent. Thus, the isolation effect was confirmed; the reflection effect was almost always confirmed; and the certainty effect was not always confirmed. Regarding attitude toward risk, the assumptions of risk aversion, and importance given to changes in wealth (at the expense of wealth states), our results are in line with those obtained by said authors. Hence, this study contributes to support prospect theory with its results and the confirmation of the isolation effect.El objetivo de este estudio es verificar los supuestos de la teoría de la perspectiva en una muestra compuesta por estudiantes que asistieron a un curso de maestría en contabilidad y finanzas en una institución politécnica en Portugal. Esta teoría se ha destacado entre otras desarrolladas en el campo de las finanzas conductuales por el debate y la investigación que ha generado. Para lograr el objetivo mencionado, adaptamos el cuestionario de los autores de la teoría de la perspectiva. El cuestionario se aplicó cuatro años consecutivos (de 2012 a 2015) e incluyó un conjunto de preguntas de respuesta alternativa que buscan conocer las preferencias de los encuestados frente a las situaciones que se exponen. También se realizó una investigación bibliográfica y descriptiva y se compararon los resultados con los obtenidos por otros autores. Los resultados no siempre fueron consistentes con los de dichos autores. Se verificó el efecto de aislamiento, el efecto de reflexión (casi siempre) y el efecto de certeza (no siempre). Adicionalmente, en cuanto a la actitud hacia el riesgo, los supuestos de aversión al riesgo y la importancia dada a los cambios en la riqueza (a expensas de estados de riqueza), nuestros resultados están en la misma línea que los de tales autores. Con estos últimos resultados y la confirmación del efecto de aislamiento, este estudio hace una contribución a la teoría de la perspectiva

Quantum radiation reaction force on a one-dimensional cavity with two relativistic moving mirrors

We consider a real massless scalar field inside a cavity with two moving mirrors in a two-dimensional spacetime, satisfying Dirichlet boundary condition at the instantaneous position of the boundaries, for arbitrary and relativistic laws of motion. Considering vacuum as the initial field state, we obtain formulas for the exact value of the energy density of the field and the quantum force acting on the boundaries, which extend results found in previous papers. For the particular cases of a cavity with just one moving boundary, non-relativistic velocities, or in the limit of infinity length of the cavity (a single mirror), our results coincide with those found in the literature.Comment: 6 pages 9 figure

An Optical Approach to the Dynamical Casimir Effect

We recently proposed a new approach to analyze the parametric resonance in a vibrating cavity based on the analysis of classical optical paths. This approach is used to examine various models of cavities with moving walls. We prove that our method is useful to extract easily basic physical outcome.Comment: 9 page

Comparação dos efeitos secundários agudos da Radioterapia por intensidade modulada com a Radioterapia tridimensional conformada no carcinoma de próstata

Introdução: Este trabalho tem como principal objectivo comparar os efeitos secundários agudos da Radioterapia por Intensidade Modulada (IMRT) e a Radioterapia Tridimensional Conformada (3 D-CRT) no carcinoma de Próstata; Materiais e métodos: Foram observados os processos clínicos de 30 doentes e analisados os efeitos colaterais da RT ocorridos no decurso do tratamento. Resultados: A percentagem de toxicidade aguda dermatológica foi superior no grupo tratado com 3D-CRT. Nenhum doente apresentou toxicidade aguda grave. Conclusões: O tamanho reduzido da amostra e a ausência de valores estatisticamente significativos, não permite concluir a influência da técnica de RT no desenvolvimento de efeitos secundários agudos.Introduction: This study has as main objective to compare the acute side effects for Intensity Modulated Radiotherapy (IMRT) and Tridimensional Conformal Radiotherapy (3D-CRT) in prostate cancer; Materials and methods: We observed the clinical files of 30 patients and analyzed the side effects of RT occurred in the course of treatment. Results: The percentage of acute dermatological toxicity was higher in the group treated with 3D-CRT. No patient showed severe acute toxicity. Conclusions: The small sample size and lack of statistically significant values, does not suggest the influence of RT on the development of acute side effects

Large deviations for non-uniformly expanding maps

We obtain large deviation results for non-uniformly expanding maps with non-flat singularities or criticalities and for partially hyperbolic non-uniformly expanding attracting sets. That is, given a continuous function we consider its space average with respect to a physical measure and compare this with the time averages along orbits of the map, showing that the Lebesgue measure of the set of points whose time averages stay away from the space average decays to zero exponentially fast with the number of iterates involved. As easy by-products we deduce escape rates from subsets of the basins of physical measures for these types of maps. The rates of decay are naturally related to the metric entropy and pressure function of the system with respect to a family of equilibrium states. The corrections added to the published version of this text appear in bold; see last section for a list of changesComment: 36 pages, 1 figure. After many PhD students and colleagues having pointed several errors in the statements and proofs, this is a correction to published article answering those comments. List of main changes in a new last sectio

Zygosaccharomyces bailii strain talf1 inulinases: a versatile tool for bioprocesses

Fructans are one of the most abundant non-structural polysaccharides found in a wide range of plants. Inulin is a polydisperse fructan polymer composed by linear chains of b-2, 1-linked D-fructofuranose molecules terminated by a glucose residue through a sucrose-type linkage at the reducing end. Inulin or inulin-rich materials can be actively hydrolyzed into fermentable sugars (glucose and fructose) using inulinases and then further used within bioprocesses

Zeeman splittings of the 5D0–7F2 transitions of Eu3+ ions implanted into GaN

We report the magnetic field splittings of emission lines assigned to the 5D0–7F2 transitions of Eu3+ centres in GaN. The application of a magnetic field in the c-axis direction (B||c) leads to a splitting of the major lines at 621 nm, 622 nm and 622.8 nm into two components. The Zeeman splitting is linear with magnetic field up to 5 Tesla for each line. In contrast, a magnetic field applied in the growth plane (B┴c) does not influence the photoluminescence spectra. The estimated g-factors vary slightly from sample to sample with mean values of g|| ~2.8, ~1.5 and ~2.0 for the emission lines at 621 nm, 622 nm and 622.8 nm respectively