5,801 research outputs found

    THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

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    This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 microns) with the Her- schel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed PACS (Photoconductor Array Camera and Spectrometer) spectra covering the 55-200 microns range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based inter- face (https://throes.cab.inta-csic.es/) and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS (Infrared Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars.Comment: 38 page

    Smart Demand for Improving Short-term Voltage Control on Distribution Networks

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    Smart grids must involve active roles from end users in order to be truly smart. The energy consumption has to be done in a flexible and intelligent manner, in accordance with the current conditions of the power system. Moreover, with the advent of dispersed and renewable generation, increasing customer integration to aid power system performance is almost inevitable. This study introduces a new type of smart demand side technology, denoted demand as voltage controlled reserve (DVR), to improve short-term voltage control, where customers are expected to play a more dynamic role to improve voltage control. The technology can be provided by thermostatically controlled loads as well as other types of load. This technology is proven to be effective in case of distribution systems with a large composition of induction motors, where the voltage presents a slow recovery characteristic due to deceleration of the motors during faults. This study presents detailed models, discussion and simulation tests to demonstrate the technical viability and effectiveness of the DVR technology for short-term voltage control.3872473

    Herbage Production of Tanzania Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e cv. Tanzania) Submitted to Combinations of Frequencies and Intensities of Grazing by Cattle

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    Animal production from pastures is a complex process comprising three main stages: herbage growth, consumption by grazing animals and conversion into animal products (Hodgson, 1990). Utilisation is the stage where the grazier finds greater flexibility for management, probably because most processes related to harvest of the produced herbage by the grazing animals are very responsive to manipulation and control of defoliation practices. The objective of this study was to evaluate herbage production of a Panicum maximum cv. Tanzania pasture submitted to combinations of frequencies and intensities of grazing

    Estudo do Padrão Avançado de Criptografia AES – Advanced Encryption Standard

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    Este trabalho retrata a implementação do algoritmo criptográfico Advanced Encryption Standard (AES). A escolha do Algoritmo AES se deve ao fato de ser o atual padrão avançado de encriptação sendo selecionado após um longo concurso em que os vários algoritmos foram criptoanalisados por toda a comunidade de criptologia. Além de sua eficiência, o AES também foi projetado para permitir a expansão da chave quando necessário, ser implementado tanto a nível de software quanto a nível de hardware e é disponibilizado livremente, o que permite o seu uso em aplicações diversas sem a necessidade de pagamento de royalties

    Firing temperature determination and thermoluminescence dating of a brick with cuneiform characters found in the ruins of Ancient Babylon

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    Este artigo tem por objetivo estudar um tijolo com inscrições em caracteres cuneiformes cujas sentenças estão praticamente completas. Estudos tipológicos correspondentes aos relatos históricos sugerem que o tijolo foi manufaturado no século VI a.C., durante a dinastia de Nabucodonosor II, grande monarca da Babilônia. A amostra foi estudada através da difração de raios X (DRX), ressonância paramagnética de elétron (RPE), termoluminescência (TL) e técnicas de análise por ativação instrumental com nêutrons (AAIN). Os resultados demonstraram que o tijolo tem 2350 anos de idade (± 40) e queima menor que 400o C.This paper aims to study a brick with inscriptions in cuneiform characters in  which the sentences are almost complete. Typological studies in agreement with historical records suggest that the tablet was manufactured in the 6th century  BCE during the dynasty of Nebuchadnezzar II, Great King of Babylon. The  sample was studied by X-ray diffraction analysis (XRD), electron paramagnetic resonance (EPR), thermoluminescence (TL), and instrumental neutron activation analysis (INAA) techniques. The results showed that the brick is 2350 years old (± 40) and its firing temperature was lower than 400 °C

    AVALIAÇÃO DE CRITÉRIOS DE HETEROGENEIDADE BASEADOS EM ATRIBUTOS MORFOLÓGICOS PARA SEGMENTAÇÃO DE IMAGENS POR CRESCIMENTO DE REGIÕES

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    Avalia-se neste trabalho o impacto de se considerar atributos morfológicos na formulação do critério que governa o crescimento de regiões na segmentação de imagens. Para tanto, uma extensão do algoritmo de segmentação multiresolução proposto por Baatz e Schäpe (2000) foi proposta e implementada, permitindo que se testassem critérios derivados de diferentes atributos morfológicos. O estudo valeu-se de um método supervisionado para medir numericamente a qualidade da segmentação. O resultado ideal da segmentação foi representado por um conjunto de segmentos de referência delineados manualmente para três recortes de imagens Quickbird-2. Para cada critério testado, os valores ótimos para os parâmetros do algoritmo de segmentação foram determinados por um processo estocástico que procurou minimizar a discrepância entre as referências e o resultado de cada segmentação. Uma análise tanto quantitativa quanto qualitativa dos resultados indicou inequivocamente que a inclusão de atributos morfológicos no critério de heterogeneidade, que decide a fusão entre segmentos adjacentes no processo de crescimento de regiões, pode resultar numa substancial melhoria da qualidade da segmentação. O artigo realça ainda a importância de se adotar atributos morfológicos apropriados para cada classe de objetos e tece considerações que orientam a escolha destes atributos

    Key Aspects for Implementing ISO/IEC 17025 Quality Management Systems at Materials Science Laboratories

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    Implementing a quality management system based on the requirements specified in ISO/IEC 17025 standard at materials science laboratories is challenging, mainly due to two main factors: (i) the high technical complexity degree of some tests used for materials characterization and (ii) the fact that most materials science laboratories provide materials characterization tests and also carry out research and development activities. In this context, this chapter presents key subjects while implementing a quality management system at materials science laboratories and some considerations on strategies for effectively implementing such systems
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