996 resultados para twice line frequency


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This communications describes an electromagnetic model of a radial line planar antenna consisting of a radial guide with one central probe and many peripheral probes arranged in concentric circles feeding an array of antenna elements such as patches or wire curls. The model takes into account interactions between the coupling probes while assuming isolation of radiating elements. Based on this model, computer programs are developed to determine equivalent circuit parameters of the feed network and the radiation pattern of the radial line planar antenna. Comparisons are made between the present model and the two-probe model developed earlier by other researchers.

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To evaluate the timing of mutations in BRAF (v-raf murine sarcoma viral oncogene homolog B1) during melanocytic neoplasia, we carried out mutation analysis on microdissected melanoma and nevi samples. We observed mutations resulting in the V599E amino-acid substitution in 41 of 60 (68%) melanoma metastases, 4 of 5 (80%) primary melanomas and, unexpectedly, in 63 of 77 (82%) nevi. These data suggest that mutational activation of the RAS/RAF/MAPK pathway in nevi is a critical step in the initiation of melanocytic neoplasia but alone is insufficient for melanoma tumorigenesis.

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The radio frequency (RF) plasma-modified surfaces of kaolinite were investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) and deuteration techniques to determine the nature of RF plasma-induced surface functional groups, the altered sites in the lattice, and interaction mechanism between RF plasma and the surface of the kaolinite. It has been concluded that the RF plasma-induced infrared (IR) vibration absorption bands at 2805, 3010, and 3100 cm(-1) are attributable to the stretching vibration of hydrogen-bonded hydroxyl groups, and the band at 1407 cm(-1) is attributable to the bending vibration of (HO-)Al-O or (HO-)Si-O groupings with hydrogen-bonded hydroxyl groups. Structural alteration occurred on both the surface and subsurface region of the kaolinite during RF plasma treatment. Further structural alteration or adjustment was also observed on well-modified and well-deuterated kaolinite. There are two types of OD bands visible in the DRIFT spectra of this kaolinite, one type which decreased rapidly as a function of time in moist air, and the other which remained unchanged during the measurement. Furthermore, the appearance of broad IR bands at 3500-3100 cm(-1) as a result of deuteration is evidence of structural disturbance by RF plasma treatment lattice deuteration. An RF plasma-induced hydrogen bonding model on the surface of the kaolinite is proposed.

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Frequency deviation is a common problem for power system signal processing. Many power system measurements are carried out in a fixed sampling rate assuming the system operates in its nominal frequency (50 or 60 Hz). However, the actual frequency may deviate from the normal value from time to time due to various reasons such as disturbances and subsequent system transients. Measurement of signals based on a fixed sampling rate may introduce errors under such situations. In order to achieve high precision signal measurement appropriate algorithms need to be employed to reduce the impact from frequency deviation in the power system data acquisition process. This paper proposes an advanced algorithm to enhance Fourier transform for power system signal processing. The algorithm is able to effectively correct frequency deviation under fixed sampling rate. Accurate measurement of power system signals is essential for the secure and reliable operation of power systems. The algorithm is readily applicable to such occasions where signal processing is affected by frequency deviation. Both mathematical proof and numerical simulation are given in this paper to illustrate robustness and effectiveness of the proposed algorithm. Crown Copyright (C) 2003 Published by Elsevier Science B.V. All rights reserved.

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As survival of patients with CF increases,glucose intolerance and cystic fibrosisrelated diabetes (CFRD),ar e increasingly recognised common complications. CFRD may be preceded by a pre-diabetic state. Using markers identified as being associated with CFRD may improve targeted screening. Aim: To identify features consistently predicting CFRD in paediatric patients. Patients diagnosed with CFRD between January 1997–January 2002 were compared with age and sex matched controls. Clinical,micr obiological, and hospitalisation data was collected at time of CFRD diagnosis,and at six monthly intervals for 3 yr prior to diagnosis. Eight patients with CFRD were identified,mean age 13.7 yr (S.D. 3.49) at time of diagnosis. Control patients underwent OGTT to ensure normal glucose tolerance. Patients with CFRD had a lower FEV1 up to 12 months prior to diagnosis however, this was only significant at diagnosis. There was no difference in weight and height z scores between the 2 groups; however,the decrease in weight and height z scores in the CFRD group over 3 yr prior to diagnosis was significant. Mean number of days in hospital and admissions per patient significantly increased in the CFRD group,6 months prior to diagnosis. No other significant differences were observed between the 2 groups. Conclusions: This study has shown a difference in lung function,gr owth parameters and frequency of hospital admissions between patients with CFRD and controls. These differences may be utilised as tools for targeted screening in the paediatricyadolescent population. Further larger scale studies are required to improve guidelines for targeted screening in this population.

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O Educacenso ?? um sistema eletr??nico de coleta de informa????es educacionais composto por um aplicativo web, que permite a coleta, migra????o e altera????o de dados educacionais das escolas em todo o territ??rio nacional, e por um banco de dados relacional, que armazena de forma sistem??tica todas estas informa????es. O Educacenso representa uma inova????o, pois se trata de um banco de dados ??nico, de base nacional, alimentado por dados e informa????es que v??m diretamente das escolas, por meio da internet. Constitui-se no mais completo cadastro de escolas, alunos e docentes do pa??s. A constru????o de um banco de dados com informa????es individualizadas amplia as possibilidades de comunica????o com outras bases de dados do governo federal. O novo desenho metodol??gico e a utiliza????o de recursos de tecnologia da informa????o permitiram ampliar a precis??o e a fidedignidade dos dados do Censo Escolar, o que possibilita realiza????o de ajustes na pol??tica educacional e maior efetividade do gasto p??blico com a educa????o b??sica

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Os Postos de Seguro Social do INSS processavam os dados dos segurados da Previd??ncia em lotes, acarretando demora na Concess??o de Benef??cios e perda de tempo por parte dos segurados, com muitas idas e vindas aos postos. As criticas aos dados eram realizadas uma vez por semana e em conseq????ncia os segurados eram obrigados a voltar ao posto para resolver as pend??ncias posteriormente informadas e at?? que os dados passassem pelas cr??ticas do computador central. Havia necessidade de implantar um novo sistema para melhorar o atendimento no INSS. Foi implementado no Paran?? um projeto piloto, desenvolvido pela Dataprev e a pedido de seu cliente INSS, denominado ???Concess??o de Benef??cios On Line???. Com a utiliza????o desta tecnologia, por exemplo, passou a ser poss??vel entrar com um pedido de aposentadoria e imprimir imediatamente a Carta de Concess??o, informando o valor e o banco em que ser??o feitos os pagamentos ao Segurado da Previd??ncia Social. O novo sistema ap??ia a melhoria no atendimento do segurado do INSS, porque permite informar ao Segurado imediatamente se o Benef??cio est?? concedido ou se h?? pend??ncias que devam ser atendidas

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Este documento trata de: a educa????o continuada do servidor p??blico, desenvolvimento de compet??ncias nas organiza????es p??blicas, o papel das escolas de governo na forma????o do servidor p??blico, a EaD como estrat??gia de educa????o continuada, educa????o a dist??ncia na Enap, bases de atua????o da cgead, o desenvolvimento das compet??ncias de tutoria

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Este documento trata de M??dulo 2 - o professor-tutor, Introdu????o, as tecnologias da intelig??ncia e o ciberespa??o, mapeando as tecnologias da educa????o a dist??ncia, ambientes virtuais de aprendizagem (AVA) e sistemas de gerenciamento de aprendizagem (SGA), o Moodle, compet??ncias tecnol??gicas da tutoria, refer??ncias, finalizando o m??dulo

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Este documento trata de m??dulo 3 - O professor-tutor e os aprendizes, objetivos do m??dulo, introdu????o, a evolu????o da educa????o a dist??ncia e as novas possibilidades de intera????o, o perfil do aluno da educa????o a dist??ncia, implica????es pr??ticas para o trabalho do professor-tutor, compet??ncias sociais do professor tutor da Enap, refer??ncias, finalizando o m??dulo

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Este documento trata de M??dulo 4 - o professor-tutor e a aprendizagem, objetivos do m??dulo, introdu????o, articulando teorias e m??todos com o contexto educacional mais amplo, a perspectiva construtivista da aprendizagem, contribui????es da heutagogia e do conectivismo, implica????es para a atua????o do tutor, a avalia????o da aprendizagem, compet??ncias pedag??gicas do professor-tutor da Enap, refer??ncias, finalizando o m??dulo

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Este documento trata de M??dulo 5 - o professor-tutor e a institui????o, objetivos do m??dulo, introdu????o, aprendizagem organizacional, comunidades de pr??tica, o profissional reflexivo, implica????es para a atua????o do professor-tutor, programa de forma????o de professores-tutores para educa????o continuada a dist??ncia, compet??ncias gerenciais do professor-tutor da Enap, refer??ncias, finalizando o m??dulo