Noncommutative Black Holes and the Singularity Problem

A phase-space noncommutativity in the context of a Kantowski-Sachs cosmological model is considered to study the interior of a Schwarzschild black hole. Due to the divergence of the probability of finding the black hole at the singularity from a canonical noncommutativity, one considers a non-canonical noncommutativity. It is shown that this more involved type of noncommutativity removes the problem of the singularity in a Schwarzschild black hole.Comment: Based on a talk by CB at ERE2010, Granada, Spain, 6th-10th September 201

Noncommutative Black Holes

One considers phase-space noncommutativity in the context of a Kantowski-Sachs cosmological model to study the interior of a Schwarzschild black hole. It is shown that the potential function of the corresponding quantum cosmology problem has a local minimum. One deduces the thermodynamics and show that the Hawking temperature and entropy exhibit an explicit dependence on the momentum noncommutativity regime and it is shown that the wave function vanishes in this limit.Comment: Based on a talk presented by CB at 1st Mediterranean Conference on Classical and Quantum Gravity 2009, Kolymbari, Crete, 14th-18th September 2009, Greec

Deformation quantization of noncommutative quantum mechanics and dissipation

We review the main features of the Weyl-Wigner formulation of noncommutative quantum mechanics. In particular, we present a $\star$-product and a Moyal bracket suitable for this theory as well as the concept of noncommutative Wigner function. The properties of these quasi-distributions are discussed as well as their relation to the sets of ordinary Wigner functions and positive Liouville probability densities. Based on these notions we propose criteria for assessing whether a commutative regime has emerged in the realm of noncommutative quantum mechanics. To induce this noncommutative-commutative transition, we couple a particle to an external bath of oscillators. The master equation for the Brownian particle is deduced.Comment: 7 pages, Latex file, Based on a talk presented by Joao Prata at D.I.C.E. 2006, Piombino, Ital

Reconfiguration of assembly lines using lean thinking in an electronics components' manufacturer for the automotive industry

This article discusses the reconfiguration and improvement of electronics components assembly lines through the use of Lean Thinking principles. This reconfiguration was undertaken in a project that followed the action-research methodology. There were three main distinct problems related with the outdated assembly lines. The first came from a diagnosis of the assembly line itself, where quality problems and difficulties with compliance with the takt-time were identified, as well as activities that do not added value. The second happened due to an adjustment in demand that requires a reconfiguration of the line and, the third problem, related to the integration in an existing assembly line of a new process for a product pertaining to the same family, forcing the exploitation of synergies in production of these two products. Regarding the improvement proposals, some managed to be implemented in a timely manner, others, despite not having been implemented, their impacts has been predicted. Overall, the level of scrap was reduced by 57% through the implementation of the Lean Six Sigma methodology, and the cycle time of an operation was reduced by 12,5% by eliminating non-value adding operations. Also, gains were obtained by reducing the previous occupation with the project of an assembly line segment dedicated to the new product. With this, a reduction of one employee with the integration of two workstations was achieved.I would like to thank all the company's employees who made this project possible, and for the support given. This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Relação benefício/custo da calagem para o feijão-caupi [Vigna unguiculata (L.) walp]), cv. BR3 Tracuateua, em solo ácido de Salvaterra, Marajó, Pará.

Foi avaliado o efeito de seis doses de calcário na elevação do Índice de Saturação por Bases (V%) a 10%; 25%; 50%; 75%;100% e 125% de um Latossolo Amarelo franco arenoso distrófico, no município de Salvaterra, Marajó, Pará, sobre a produção de grãos de feijão-caupi cultivar BR 3 Tracuateua. Depois de obtida a curva de resposta da cultura à calagem, foi efetuada a derivação da equação de regressão e, posteriormente, foi feita uma análise financeira simples onde o lucro bruto foi comparado com o custo total de produção, para determinação da relação benefício/custo. Os resultados mostraram que a testemunha sem calagem teve a menor produção de grãos (1 314 kg ha-1), com lucro bruto de R$ 1 712,00 e a maior relação benefício/custo, de 6,7. As doses de calcário correspondentes às aplicações de 7,9 t ha-1 e 10,1 t ha-1, embora tenham proporcionado as maiores produções de grãos, de 1 776 kg ha-1 e, 1 816 kg ha-1, respectivamente, apresentaram índices de relação benefício/custo menores que a unidade, ou seja, com aplicação de doses muito elevadas de calcário, a receita gerada foi inferior ao custo de produçã

Fenotipagem de milho para tolerância a deficiência hídrica e ao calor, em Teresina, Piauí.

Trinta e seis híbridos de milho foram avaliados no ano de 2009 no município de Teresina, PI, sendo submetidos ao calor e a dois regimes de irrigação: plena e com deficiência hídrica, no período reprodutivo, objetivando selecionar genótipos que apresentem tolerância à seca e ao calor. O delineamento experimental foi o de blocos casualizados, com três repetições. Foram avaliados o rendimento de grãos, componentes de produção e a eficiência do uso da água. A temperatura média máxima do ar, no campo, durante o período de deficiência hídrica foi de 36,5 oC. O rendimento médio de grãos e a eficiência de uso da água dos ensaios com irrigação plena e com deficiência hídrica foram de 8.029 kg ha-1; 11,4 kg ha-1 mm-1 e 3.718 kg ha-1; 7,0 kg ha-1 mm-1, respectivamente. O decréscimo no rendimento de grãos e na eficiência de uso da água foi, respectivamente, de 53,69 % e 38,6 %. No ensaio com deficiência hídrica dezesseis híbridos produziram acima da média geral (3.718 kg ha-1) com destaque para os híbridos DKB 390, 2 B 707, BRS 1001, BRS 1040, BRS 1031, BRS 2020 com rendimento de grãos acima de 5.000 kg ha-1. Os componentes de produção, número de fileiras de grãos por espiga, número de grãos por fileira, número de espiga por planta, peso de cem grãos foram os mais afetados pela deficiência hídrica e calor

a consensus statement from the Portuguese Pulmonology Society

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by a novel SARS-CoV-2 pathogen. Its capacity for human-to-human transmission through respiratory droplets, coupled with a high-level of population mobility, has resulted in a rapid dissemination worldwide. Healthcare workers have been particularly exposed to the risk of infection and represent a significant proportion of COVID-19 cases in the worst affected regions of Europe. Like other open airway procedures or aerosol-generating procedures, bronchoscopy poses a significant risk of spreading contaminated droplets, and medical workers must adapt the procedures to ensure safety of both patients and staff. Several recommendation documents were published at the beginning of the pandemic, but as the situation evolves, our thoughts should not only focus on the present, but should also reflect on how we are going to deal with the presence of the virus in the community until there is a vaccine or specific treatment available. It is in this sense that this document aims to guide interventional pulmonology throughout this period, providing a set of recommendations on how to perform bronchoscopy or pleural procedures safely and efficiently.proofpublishe