Geodesic analysis, absorption and scattering in the static Hayward spacetime

We investigate the propagation of massless particles and scalar fields in the background of Hayward regular black holes. We compute the absorption and scattering cross sections and compare our numerical results with some analytical approximations, showing that they are in excellent agreement. We show that some of the absorption and scattering results of Reissner-Nordstr\"om black holes can be mimicked by Hayward regular black holes, for appropriate choices of the charge of the two different black holes.Comment: 10 pages, 13 figures. To appear in the volume "Tribute to Ruben Aldrovandi", F. Caruso, J.G. Pereira and A. Santoro (Eds.) (Editora Livraria da F\'isica, S\~ao Paulo, 2024

Scattering properties of charged black holes in nonlinear and Maxwell's electrodynamics

We investigate the scattering properties of a massless scalar field in the background of a charged Ay\'on-Beato-Garc\'ia regular black hole solution. Using a numerical approach, we compute the differential scattering cross section for arbitrary values of the scattering angle and of the incident wave frequency. We compare our results with those obtained via the classical geodesic scattering of massless particles, as well as with the semiclassical glory approximation, and show that they present an excellent agreement in the corresponding limits. We also show that Ay\'on-Beato-Garc\'ia and Reissner-Nordstr\"om black hole solutions present similar scattering properties, for low-to-moderate values of the black hole electric charge, for any value of the scattering angle.Comment: 11 pages, 14 figures, published in European Physical Journal Plu

Perfect category-graded algebras

In a perfect category every object has a minimal projective resolution. We give a criterion for the category of modules over a categorygraded algebra to be perfect.Comment: A sufficient condition is replaced by a criterion. Several references added. 17 page

Aplicação da metodologia definida pela OCDE para o cálculo de população urbana e rural nos municípios do Brasil

Não existe, à escala internacional, um consenso sobre a definição do conceito de “rural”, apesar de ser usado quer pelo senso comum quer pelos cientistas das ciências sociais. Com o objetivo de aplicar o critério de delimitação do rural da OCDE no território brasileiro, a presente comunicação utilizou dados do censo demográfico brasileiro de 2010, fornecidos pelo IBGE. Procurando seguir a tipologia da OCDE foi determinada a densidade demográfica de cada um dos 314.018 setores censitários e classificados como urbano ou rural. Com esses dados os 5.565 municípios foram qualificados como Região Predominantemente Rural; Região Intermediária e Região Predominantemente Urbana. Os resultados apontam para a maioria das cidades brasileiras como sendo consideradas regiões intermediárias

ALTERNATIVE DESIGN AND ECONOMIC FEASIBILITY OF AN EXPERIMENTAL WHR FOR INTAKE AIR CONDITIONING OF A LARGE INTERNAL COMBUSTION ENGINE

This work presents an alternative design for an experimental waste heat recovery thermal system to be coupled to a large turbocharged internal combustion engine for combustion air conditioning. The goal is to carry out a design of a new thermal system under restricted economic requirements for one of the generators set of Luiz Oscar Rodrigues de Melo Thermoelectric Power Plant. Thereby, a comparison with the original proposal from previous works is also developed in order to demonstrate the differences in terms of thermo-economic design parameters. The waste recovery thermal system produces sufficient chilled water through a single-effect absorption chiller, powered by hot water which is produced by recovering the exhaust gases residual heat to supply cooling applications on the combustion air. The results showed a significant reduction for the chiller capacity demand, from 550 to 185 RT, that would be enough to provide chilled water for 98.72% of the analyzed operation historical period. The economic feasibility indicators reveal the proposal for the alternative waste heat recovery system as the best financial option, presenting a lower investment cost (US$316,793.27 of savings) and a time for capital recovery of 2.14 years, 1.61 years shorter when compared with the initial WHR system

The use of organizational assessments in improving patient and staff experiences in the ambulatory care setting

As the needs of patients evolve, healthcare organizations must diversify their approach to improving patient experience. Their programs should encompass the medical, mental, spiritual, and emotional needs of patients and their family members and the staff who care for patients. This case study examines the results of the evaluation to assess the effectiveness of organizational patient experience efforts. The Beryl Institute’s Experience Assessment was the evaluation tool administered and revealed the areas in which the organization was performing well and where improvements were needed. In collaboration with Ambulatory Care and Finance, the Office of Patient Experience targeted the Adult Primary Care and Orthopedic outpatient clinics for this assessment and followed-up with improvement projects to address the areas of opportunities identified. We administered the Extended DiSC® Assessment to the leaders in all departments that function within Ambulatory Care, to support the success of the improvement projects. The DiSC® assessment enables each leader to understand their communication style and gain an understanding of the ways they could improve communication with the leaders they collaborated with, who have different communication styles. Both assessments are geared towards self-examination and prodded the organization towards taking an honest look at how they functioned collectively and on an individual level and helped to clarify their perspective and reiterate their core values as a patient experience organization. The use of the Experience Assessment enabled an objective evaluation of the team’s readiness for patient experience improvements, in conjunction with the insights gleaned from the Extended DiSC® assessment. Experience Framework This article is associated with the Staff & Provider Engagement lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this lens

A consistent scalar-tensor cosmology for inflation, dark energy and the Hubble parameter

The authors are grateful for financial support to the Cruickshank Trust (CW), EPSRC/GG-Top (CW, JR), Omani Government (MA), Science Without Borders programme, CNPq, Brazil (DR), and STFC/CfFP (CW, AM, RB, JM). CW and AM acknowledge the hospitality of CERN, where this work was started. The University of Aberdeen and University of Edinburgh are charitable bodies registered in Scotland, with respective registration numbers SC013683 and SC005336.Peer reviewedPostprin

Indicadores de produtividade de cultivares de amora preta em dois sistemas de cultivo.

O objetivo do trabalho foi avaliar a produtividade, peso médio dos frutos e número de frutos para três cultivares de amora preta.Resumo