Entanglement of Two Impurities through Electron Scattering

We study how two magnetic impurities embedded in a solid can be entangled by an injected electron scattering between them and by subsequent measurement of the electron's state. We start by investigating an ideal case where only the electronic spin interacts successively through the same unitary operation with the spins of the two impurities. In this case, high (but not maximal) entanglement can be generated with a significant success probability. We then consider a more realistic description which includes both the forward and back scattering amplitudes. In this scenario, we obtain the entanglement between the impurities as a function of the interaction strength of the electron-impurity coupling. We find that our scheme allows us to entangle the impurities maximally with a significant probability

Nonlinear modeling of the cyclic response of RC columns

Cyclic load reversals (like those induced by earthquakes) result in accelerated bond degradation, leading to significant bar slippage. The bond-slip mechanism is reported to be one of the most common causes of damage and even collapse of existing RC structures subjected to earthquake loading. RC structures with plain reinforcing bars, designed and built prior to the enforcement of the modern seismic-oriented design philosophies, are particularly sensitive to bond degradation. However, perfect bond conditions are typically assumed in the numerical analysis of RC structures. This paper describes the numerical modeling of the cyclic response of two RC columns, one built with deformed bars and the other with plain bars and structural detailing similar to that typically adopted in pre-1970s structures. For each column, different modeling strategies to simulate the column response were tested. Models were built using the OpenSees and the SeismoStruct platforms, and calibrated with the available tests results. Within each platform, different types of nonlinear elements were used to represent the columns. Bond-slip effects were included in the OpenSees models resorting to a simple modeling strategy. The models and the parameters adopted are presented and discussed. Comparison is established between the most relevant experimental results and the corresponding results provided by the numerical models. Conclusions are drawn about the capacity of the tested models to simulate the columns response and about the influence of considering or not considering the effects of bars slippage

The Portuguese Severe Asthma Registry: Development, Features, and Data Sharing Policies

The Portuguese Severe Asthma Registry (Registo de Asma Grave Portugal, RAG) was developed by an open collaborative network of asthma specialists. RAG collects data from adults and pediatric severe asthma patients that despite treatment optimization and adequate management of comorbidities require step 4/5 treatment according to GINA recommendations. In this paper, we describe the development and implementation of RAG, its features, and data sharing policies. The contents and structure of RAG were defined in a multistep consensus process. A pilot version was pretested and iteratively improved. The selection of data elements for RAG considered other severe asthma registries, aiming at characterizing the patient's clinical status whilst avoiding overloading the standard workflow of the clinical appointment. Features of RAG include automatic assessment of eligibility, easy data input, and exportable data in natural language that can be pasted directly in patients' electronic health record and security features to enable data sharing (among researchers and with other international databases) without compromising patients' confidentiality. RAG is a national web-based disease registry of severe asthma patients, available at asmagrave.pt. It allows prospective clinical data collection, promotes standardized care and collaborative clinical research, and may contribute to inform evidence-based healthcare policies for severe asthma.info:eu-repo/semantics/publishedVersio

tt* Geometry and Closed String Tachyon Potential

We propose a closed string tachyon action including kinetic and potential terms for non-supersymmetric orbifolds. The action is given in terms of solutions to $tt^*$ equations which captures the geometry of vacua of the corresponding N=2 worldsheet theory. In certain cases the solutions are well studied. In case of tachyons of ${\bf C}/Z_n$, solutions to affine toda equations determine the action. We study the particular case of ${\bf C}/Z_3\to {\bf C}$ in detail and find that the Tachyon action is determined in terms of a solution to Painleve III equation.Comment: 10 page

Amostragem para inventário florestal com probabilidade de superposição de parcelas circulares.

Este trabalho teve o propósito de avaliar uma metodologia de amostragem que propõe o uso de parcelas circulares superpostas em inventários florestais, comparada à amostragem simples ao acaso convencional. Compararam-se os métodos com parcelas retangular e circular de raio fixo e variável (Bitterlich). Os resultados mostraram que o método de parcelas circulares superpostas pode ser aplicado com os estimadores da amostragem simples ao acaso, e o método de Bitterlich pode ser uma alternativa à parcela circular de raio fixo

Effective restoration of chiral and axial symmetries at finite temperature and density

The effective restoration of chiral and axial symmetries is investigated within the framework of the SU(3) Nambu-Jona-Lasinio model. The topological susceptibility, modeled from lattice data at finite temperature, is used to extract the temperature dependence of the coupling strength of the anomaly. The study of the scalar and pseudoscalar mixing angles is performed in order to discuss the evolution of the flavor combinations of $q \bar q$ pairs and its consequences for the degeneracy of chiral partners. A similar study at zero temperature and finite density is also realized.Comment: 5 pages, 1 figure. Talk given at Strange Quark Matter 2004, Cape Town, South Africa, 15-20 September, 200

Base de dados climáticos.

Um repositório organizado de dados é uma exigência em qualquer empresa, como componente de eficiência, e a forma adequada para isto é utilizar uma ferramenta de banco de dados. Focando a pesquisa agropecuária, que necessita de dados climáticos como um dos componentes do ambiente que condicionam a produção, ter esses dados atualizados e disponíveis para acesso é uma necessidade para a empresa. A primeira ferramenta de banco de dados surgiu na IBM como forma de reduzir trabalho e custo no armazenamento e organização de dados, e o modelo relacional de banco de dados, utilizado neste documento, surgiu na década de 70, e até hoje é um dos mais utilizados, com a Linguagem Estruturada de Consulta – SQL, desenvolvida na década de 80, e adotada universalmente. Desta forma, o produto apresentado nesta publicação é uma forma de permitir o acesso aos usuários a toda base climática disponível na Unidade até 2011, ao mesmo tempo popularizando um sistema de banco de dados para o grupamento de pesquisa, por meio de um passo a passo.bitstream/item/70054/1/doc-141.pd