Accounting as practice

In this paper we seek to debate some of the problems affecting positivist accounting research, and how the adoption of organizational theory grounded on qualitative methods can fruitfully contribute to advance research in the area. To this end we draw on research we have previously conducted in Portuguese public hospitals to discuss how the incorporation of power issues, institutional entrepreneurship, hybridization, institutional logics and institutional work in accounting studies fosters in-depth explanations of accounting practice.info:eu-repo/semantics/publishedVersio

Towards Loop Quantization of Plane Gravitational Waves

The polarized Gowdy model in terms of Ashtekar-Barbero variables is further reduced by including the Killing equations for plane-fronted parallel gravitational waves with parallel rays. The resulting constraint algebra, including one constraint derived from the Killing equations in addition to the standard ones of General Relativity, are shown to form a set of first-class constraints. Using earlier work by Banerjee and Date the constraints are expressed in terms of classical quantities that have an operator equivalent in Loop Quantum Gravity, making space-times with pp-waves accessible to loop quantization techniques.Comment: 14 page

Advanced Directives and Living Will: A Case Report

Descreve-se o caso de uma mulher de 61 anos, com diagnóstico de neoplasia da mama em estadio IV. Na altura, recusou terapêutica. Recorre ao Serviço de Urgência, um ano após o diagnóstico, em mutismo, sendo que os exames complementares de diagnóstico revelaram uma lesão cerebral, interpretada como nova metástase. No seu processo clínico, tem uma diretiva antecipada de vontade. Este é um documento formal que explicita quais os cuidados que pretende ou não receber em final de vida. Apresentamos a descrição do caso, as indicações que a doente deixou expressas neste documento e uma reflexão acerca das diretivas antecipadas de vontade e de como estas devem ser integradas na prática clínica.info:eu-repo/semantics/publishedVersio

Dynamics of axialized laser-cooled ions in a Penning trap

We report the experimental characterization of axialization - a method of reducing the magnetron motion of a small number of ions stored in a Penning trap. This is an important step in the investigation of the suitability of Penning traps for quantum information processing. The magnetron motion was coupled to the laser-cooled modified cyclotron motion by the application of a near-resonant oscillating quadrupole potential (the "axialization drive"). Measurement of cooling rates of the radial motions of the ions showed an order-of-magnitude increase in the damping rate of the magnetron motion with the axialization drive applied. The experimental results are in good qualitative agreement with a recent theoretical study. In particular, a classical avoided crossing was observed in the motional frequencies as the axialization drive frequency was swept through the optimum value, proving that axialization is indeed a resonant effect.Comment: 8 pages, 9 figure

The activation energy for GaAs/AlGaAs interdiffusion

Copyright 1997 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 82, 4842 (1997) and may be found at

Relating Covariant and Canonical Approaches to Triangulated Models of Quantum Gravity

In this paper explore the relation between covariant and canonical approaches to quantum gravity and $BF$ theory. We will focus on the dynamical triangulation and spin-foam models, which have in common that they can be defined in terms of sums over space-time triangulations. Our aim is to show how we can recover these covariant models from a canonical framework by providing two regularisations of the projector onto the kernel of the Hamiltonian constraint. This link is important for the understanding of the dynamics of quantum gravity. In particular, we will see how in the simplest dynamical triangulations model we can recover the Hamiltonian constraint via our definition of the projector. Our discussion of spin-foam models will show how the elementary spin-network moves in loop quantum gravity, which were originally assumed to describe the Hamiltonian constraint action, are in fact related to the time-evolution generated by the constraint. We also show that the Immirzi parameter is important for the understanding of a continuum limit of the theory.Comment: 28 pages, 10 figure

Laser cooling in the Penning trap: an analytical model for cooling rates in the presence of an axializing field

Ions stored in Penning traps may have useful applications in the field of quantum information processing. There are, however, difficulties associated with the laser cooling of one of the radial motions of ions in these traps, namely the magnetron motion. The application of a small radio-frequency quadrupolar electric potential resonant with the sum of the two radial motional frequencies has been shown to couple these motions and to lead to more efficient laser cooling. We present an analytical model that enables us to determine laser cooling rates in the presence of such an 'axializing' field. It is found that this field leads to an averaging of the laser cooling rates for the two motions and hence improves the overall laser cooling efficiency. The model also predicts shifts in the motional frequencies due to the axializing field that are in qualitative agreement with those measured in recent experiments. It is possible to determine laser cooling rates experimentally by studying the phase response of the cooled ions to a near resonant excitation field. Using the model developed in this paper, we study the expected phase response when an axializing field is present.Comment: 22 pages, 7 figure