Some Unique Constants Associated with Extremal Black Holes

In recent papers we had developed a unified picture of black hole entropy and curvature which was shown to lead to Hawking radiation. It was shown that for any black hole mass, holography implies a phase space of just one quantum associated with the interior of the black hole. Here we study extremal rotating and charged black holes and obtain unique values for ratios of angular momentum to entropy, charge to entropy, etc. It turns out that these ratios can be expressed in terms of fundamental constants in nature, having analogies with other physical systems, like in condensed matter physics.Comment: "Accepted for publication in Astrophysics & Space Science" 4 pages, 10 equation

Effect of Void Network on CMB Anisotropy

We study the effect of a void network on the CMB anisotropy in the Einstein-de Sitter background using Thompson &Vishniac's model. We consider comprehensively the Sacks-Wolfe effect, the Rees-Sciama effect and the gravitational lensing effect. Our analysis includes the model of primordial voids existing at recombination, which is realized in some inflationary models associated with a first-order phase transition. If there exist primordial voids whose comoving radius is larger than $\sim10h^{-1}$Mpc at recombination, not only the Sachs-Wolfe effect but also the Rees-Sciama effect is appreciable even for multipoles l\lsim1000 of the anisotropy spectrum. The gravitational lensing effect, on the other hand, slightly smoothes the primary anisotropy; quantitatively, our results for the void model are similar to the previous results for a CDM model. All the effects, together, would give some constraints on the configuration or origin of voids with high-resolution data of the CMB anisotropy.Comment: 23 pages, latex, 12 eps figures, some calculations and discussions are added, to appear in ApJ 510 (1999

Visual analysis of global comparative mapping of the practice domains of the nurse practitioner/advanced practice nursing role in respondent countries.

Internationally, there is increasing demand for nurse practitioner (NP) and advanced practice nursing (APN) roles; however, high variability exists in how NP/APN roles are defined and understood. The aim of this research was to improve our understanding of how the NP/APN is defined globally by: 1) examining role definitions, competencies, and standards of practice for advanced practice nurses internationally; 2) describing from a global perspective the core concepts and common features of NP/APN associated with practice domains; and 3) exploring the utility of text mining and visual analytics in identifying the clustered core concepts common to NP/APN roles organized around the five advanced practice domains of the Strong Advanced Practice Model. This article describes the findings of a secondary analysis of an international NP/APN competency mapping project, using innovative text mining and visual analysis techniques to reexamine and summarize the NP/APN role in 19 countries from Africa, Australia, Asia, Europe, and North America. Although weak aggrupation/associations suggest that further work is needed to define the domains of advanced practice with associated model development, visual analysis points to the identification of common concepts and linkages between concepts for each practice domain of advanced practice outlined in the Strong Model. The secondary text mining and visual analysis presented in this article allows for comparison of core elements between advanced practice role descriptions, standards, and competencies globally to ultimately provide a global perspective on the common features of NP/APN roles and areas where further delineation is required

Impactos ambientales del ciclo de vida de las baldosas cerámicas: análisis sectorial, identificación de estrategias de mejora y comunicación (I)

El artículo analiza el impacto ambiental que generan las baldosas cerámicas mediante el Análisis de Ciclo de Vida (AC) a nivel sectorial en el que participaron más de 50 empresas españolas. Los resultados han servido para la redacción de las Reglas de Categoría de Producto (RCP) para los recubrimientos de materiales cerámicos, necesarias para la edición de Declaraciones Ambientales de Producto. (Debido a la extensión del artículo recogeremos en esta edición la primera parte, correspondiente a la definición de objetivos y alcance del estudio y el análisis del inventario. La segunda parte, que consta de la evaluación de impactos e interpretación, la identificación de estrategias de mejora, la comunicación ambiental y las conclusiones se publicarán en el número 236 de Piscinas XXI).The article analyses the environmental impact of ceramic tiles by means of a sector-level Life Cycle Analysis (LCA) involving over 50 Spanish firms. The findings were then used to draw up the Product Category Rules (PCR) for ceramic coverings, which are needed to be able to issue Environmental Product Declarations. (Due to the length of the paper, in this edition we will include only the first part, which covers the definition of the aims and scope of the study, as well as the inventory analysis. The second part, which comprises the evaluation of the impacts and interpretation, the identification of the improvement strategies, environmental communication and the conclusions, will be published in issue 236 of Piscinas XXI.

A Complete Set of Firmware for the TileCal Read-Out Driver

TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The Read-Out Driver (ROD) is the main component of the TileCal back-end electronics. The ROD is a VME 64x 9u board with multiple programmable devices which requires a complete set of firmware. This paper describes the firmware and functionalities of all these programmable devices, especially the DSP Processing Units daughterboards where the data processing takes place

Status of the Optical Multiplexer Board 9U Prototype

This paper presents the architecture and the status of the Optical Multiplexer Board (OMB) 9U for the ATLAS/LHC Tile hadronic calorimeter (TileCal). This board will analyze the front-end data CRC to prevent bit and burst errors produced by radiation. Besides, due to its position within the data acquisition chain it will be used to emulate front-end data for tests. The first two prototypes of the final OMB 9U version have been produced at CERN. Detailed design issues and manufacture features of these prototypes are described. Functional descriptions of the board on its two main operation modes as CRC checking and data ROD injector are explained as well as other functionalities. Finally, the schedule for next year when the production of the OMB will be take place is also presented

"Swiss-Cheese" Inhomogeneous Cosmology & the Dark Energy Problem

We study an exact swiss-cheese model of the Universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We find negligible integrated effect, suppressed by (L/R_{H})^3 (where L is the size of one patch, and R_{H} is the Hubble radius), both perturbatively and non-perturbatively. We disentangle this effect from the Doppler term (which is much larger and has been used recently \cite{BMN} to try to fit the SN curve without dark energy) by making contact with cosmological perturbation theory.Comment: 35 pages, 6 figure

Optical Buffer 1:16

This document is a manual describing the functionality and the operation of the Optical Buffer 1:16 (OB). The OB was specially designed to repeat optical signals during the TileCal Read-Out drivers (ROD) production. The data generated in one Optical Multiplexer Board (OMB) 6U prototypes were repeated with two OB in order to inject data simultaneously to four RODs

On the development of the final optical multiplexer board prototype for the TileCal experiment

This paper describes the architecture of the final optical multiplexer board for the TileCal experiment. The results of the first VME 6U prototype have led to the definition of the final block diagram and functionality of this prototype. Functional description of constituent blocks and the state of the work currently undergoing at the Department of Electronic Engineering, in collaboration with IFIC-Valencia, is presented. As no board is yet produced, no experimental results are presented but, nevertheless, design issues that have been taking into account as component placement and signal integrity issues will be detailed