953 resultados para Key-term separation principle


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This paper proposes a wind speed forecasting model that contributes to the development and implementation of adequate methodologies for Energy Resource Man-agement in a distribution power network, with intensive use of wind based power generation. The proposed fore-casting methodology aims to support the operation in the scope of the intraday resources scheduling model, name-ly with a time horizon of 10 minutes. A case study using a real database from the meteoro-logical station installed in the GECAD renewable energy lab was used. A new wind speed forecasting model has been implemented and it estimated accuracy was evalu-ated and compared with a previous developed forecast-ing model. Using as input attributes the information of the wind speed concerning the previous 3 hours enables to obtain results with high accuracy for the wind short-term forecasting.

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Load forecasting has gradually becoming a major field of research in electricity industry. Therefore, Load forecasting is extremely important for the electric sector under deregulated environment as it provides a useful support to the power system management. Accurate power load forecasting models are required to the operation and planning of a utility company, and they have received increasing attention from researches of this field study. Many mathematical methods have been developed for load forecasting. This work aims to develop and implement a load forecasting method for short-term load forecasting (STLF), based on Holt-Winters exponential smoothing and an artificial neural network (ANN). One of the main contributions of this paper is the application of Holt-Winters exponential smoothing approach to the forecasting problem and, as an evaluation of the past forecasting work, data mining techniques are also applied to short-term Load forecasting. Both ANN and Holt-Winters exponential smoothing approaches are compared and evaluated.

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In competitive electricity markets it is necessary for a profit-seeking load-serving entity (LSE) to optimally adjust the financial incentives offering the end users that buy electricity at regulated rates to reduce the consumption during high market prices. The LSE in this model manages the demand response (DR) by offering financial incentives to retail customers, in order to maximize its expected profit and reduce the risk of market power experience. The stochastic formulation is implemented into a test system where a number of loads are supplied through LSEs.

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The forthcoming smart grids are comprised of integrated microgrids operating in grid-connected and isolated mode with local generation, storage and demand response (DR) programs. The proposed model is based on three successive complementary steps for power transaction in the market environment. The first step is characterized as a microgrid’s internal market; the second concerns negotiations between distinct interconnected microgrids; and finally, the third refers to the actual electricity market. The proposed approach is modeled and tested using a MAS framework directed to the study of the smart grids environment, including the simulation of electricity markets. This is achieved through the integration of the proposed approach with the MASGriP (Multi-Agent Smart Grid Platform) system.

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Wind speed forecasting has been becoming an important field of research to support the electricity industry mainly due to the increasing use of distributed energy sources, largely based on renewable sources. This type of electricity generation is highly dependent on the weather conditions variability, particularly the variability of the wind speed. Therefore, accurate wind power forecasting models are required to the operation and planning of wind plants and power systems. A Support Vector Machines (SVM) model for short-term wind speed is proposed and its performance is evaluated and compared with several artificial neural network (ANN) based approaches. A case study based on a real database regarding 3 years for predicting wind speed at 5 minutes intervals is presented.

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Transthyretin (TTR) protects against A-Beta toxicity by binding the peptide thus inhibiting its aggregation. Previous work showed different TTR mutations interact differently with A-Beta, with increasing affinities correlating with decreasing amyloidogenecity of the TTR mutant; this did not impact on the levels of inhibition of A-Beta aggregation, as assessed by transmission electron microscopy. Our work aimed at probing differences in binding to A-Beta by WT, T119M and L55P TTR using quantitative assays, and at identifying factors affecting this interaction. We addressed the impact of such factors in TTR ability to degrade A-Beta. Using a dot blot approach with the anti-oligomeric antibody A11, we showed that A-Beta formed oligomers transiently, indicating aggregation and fibril formation, whereas in the presence of WT and T119M TTR the oligomers persisted longer, indicative that these variants avoided further aggregation into fibrils. In contrast, L55PTTR was not able to inhibit oligomerization or to prevent evolution to aggregates and fibrils. Furthermore, apoptosis assessment showed WT and T119M TTR were able to protect against A-Beta toxicity. Because the amyloidogenic potential of TTR is inversely correlated with its stability, the use of drugs able to stabilize TTR tetrameric fold could result in increased TTR/ABeta binding. Here we showed that iododiflunisal, 3-dinitrophenol, resveratrol, [2-(3,5-dichlorophenyl)amino] (DCPA) and [4- (3,5-difluorophenyl)] (DFPB) were able to increase TTR binding to A-Beta; however only DCPA and DFPB improved TTR proteolytic activity. Thyroxine, a TTR ligand, did not influence TTR/A-Beta interaction and A-Beta degradation by TTR, whereas RBP, another TTR ligand, not only obstructed the interaction but also inhibited TTR proteolytic activity. Our results showed differences between WT and T119M TTR, and L55PTTR mutant regarding their interaction with A-Beta and prompt the stability of TTR as a key factor in this interaction, which may be relevant in AD pathogenesis and for the design of therapeutic TTR-based therapies.

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O instável mas tendencialmente crescente preço dos combustíveis associado a preocupações ambientais cada vez mais enraizadas nas sociedades, têm vindo a despoletar uma maior atenção à procura de combustíveis alternativos. Por outro lado, várias projecções indicam um aumento muito acentuado do consumo energético global no curto prazo, fruto do aumento da população e do nível de industrialização das sociedades. Neste contexto, o biodiesel (ésteres de ácidos gordos) obtido através da transesterificação de triglicerídeos de origem vegetal ou animal, surge como a alternativa “verde” mais viável para utilização em equipamentos de combustão. A reacção de transesterificação é catalisada, por norma com recurso a catalisadores homogéneos alcalinos (NaOH ou KOH). Este tipo de processo, o único actualmente com expressão a nível industrial, apresenta algumas desvantagens que, para além de aumentarem o custo do produto final, contribuem para reduzir a benignidade do mesmo: a impossibilidade de reutilização do catalisador, o aumento do número e complexidade das etapas de separação e a produção de efluentes resultantes das referidas etapas. Com o intuito de minimizar ou eliminar estes problemas, vários catalisadores heterogéneos têm vindo a ser estudados para esta reacção. Apesar de muitos apresentarem resultados promissores, a grande maioria não tem viabilidade para aplicação industrial seja devido ao seu próprio custo, seja devido aos pré-tratamentos necessários à sua utilização. Entre estes catalisadores, o óxido de cálcio é talvez o que apresenta resultados mais promissores. O crescente número de estudos envolvendo este catalisador em detrimento de outros, é por si mesmo prova do potencial do CaO. A realização deste trabalho pretendia atingir os seguintes objectivos principais: • Avaliar a elegibilidade do óxido de cálcio enquanto catalisador da reacção de transesterificação de óleos alimentares usados com metanol; • Avaliar qual a sua influência nas características dos produtos finais; • Avaliar as diferenças de performance entre o óxido de cálcio activado em atmosfera inerte (N2) e em ar, enquanto catalisadores da reacção de transesterificação de óleos alimentares usados com metanol; • Optimizar as condições da reacção com recurso às ferramentas matemáticas disponibilizadas pelo planeamento factorial, através da variação de quatro factores chave de influência: temperatura, tempo, relação metanol / óleo e massa de catalisador utilizado. O CaO utlizado foi obtido a partir de carbonato de cálcio calcinado numa mufla a 750 °C durante 3 h. Foi posteriormente activado a 900 °C durante 2h, em atmosferas diferentes: azoto (CaO-N2) e ar (CaO-Ar). Avaliaram-se algumas propriedades dos catalisadores assim preparados, força básica, concentração de centros activos e áreas específicas, tendo-se obtido uma força básica situada entre 12 e 14 para ambos os catalisadores, uma concentração de centros activos de 0,0698 mmol/g e 0,0629 mmol/g e áreas específicas de 10 m2/g e 11 m2/g respectivamente para o CaO-N2 e CaO-Ar. Efectuou-se a transesterificação, com catálise homogénea, da mistura de óleos usados utilizada neste trabalho com o objectivo de determinar os limites para o teor de FAME’s (abreviatura do Inglês de Fatty Acid Methyl Esters’) que se poderiam obter. Foi este o parâmetro avaliado em cada uma das amostras obtidas por catálise heterogénea. Os planos factoriais realizados tiveram como objectivo maximizar a sua quantidade recorrendo à relação ideal entre tempo de reacção, temperatura, massa de catalisador e quantidade de metanol. Verificou-se que o valor máximo de FAME’s obtidos a partir deste óleo estava situado ligeiramente acima dos 95 % (m/m). Realizaram-se três planos factoriais com cada um dos catalisadores de CaO até à obtenção das condições óptimas para a reacção. Não se verificou influência significativa da relação entre a quantidade de metanol e a massa de óleo na gama de valores estudada, pelo que se fixou o valor deste factor em 35 ml de metanol / 85g de óleo (relação molar aproximada de 8:1). Verificou-se a elegibilidade do CaO enquanto catalisador para a reacção estudada, não se tendo observado diferenças significativas entre a performance do CaO-N2 e do CaO-Ar. Identificaram-se as condições óptimas para a reacção como sendo os valores de 59 °C para a temperatura, 3h para o tempo e 1,4 % de massa de catalisador relativamente à massa de óleo. Nas referidas condições, obtiveram-se produtos com um teor de FAME’s de 95,7 % na catálise com CaO-N2 e 95,3 % na catálise com CaO-Ar. Alguns autores de estudos consultados no desenvolvimento do presente trabalho, referiam como principal problema da utilização do CaO, a lixiviação de cálcio para os produtos obtidos. Este facto foi confirmado no presente trabalho e na tentativa de o contornar, tentou-se promover a carbonatação do cálcio com a passagem de ar comprimido através dos produtos e subsequente filtração. Após a realização deste tratamento, não mais se observaram alterações nas suas propriedades (aparecimento de turvação ou precipitados), no entanto, nos produtos obtidos nas condições óptimas, a concentração de cálcio determinada foi de 527 mg/kg no produto da reacção catalisada com CaO-N2 e 475 mg/kg com CaO-A. O óxido de cálcio apresentou-se como um excelente catalisador na transesterificação da mistura de óleos alimentares usados utilizada no presente trabalho, apresentando uma performance ao nível da obtida por catálise homogénea básica. Não se observaram diferenças significativas de performance entre o CaO-N2 e o CaO-Ar, sendo possível obter nas mesmas condições reaccionais produtos com teores de FAME’s superiores a 95 % utilizando qualquer um deles como catalisador. O elevado teor de cálcio lixiviado observado nos produtos, apresenta-se como o principal obstáculo à aplicação a nível industrial do óxido de cálcio como catalisador para a transesterificação de óleos.

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Dissertação apresentada para obtenção do Grau de Doutor em Ciências do Ambiente, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia.

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A case of sporotrichosis in a woman presenting 63 cutaneous lesions distributed all over the tegument is related. The patient had both humoral (Immunoglobulins) and cellular (Lymphocytes subpopulations) immunity within normal limits, but was under treatment with steroid during a long time (Prednisone 10 mg daily for 2 years), due to a sciatic pain. In addition a review of the Brazilian literature on this type of lesions was carried out and commented.

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The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-a) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-a, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0.005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-a therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.

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To be published at Krings, Bettina-J. ed. (2011), Brain Drain or Brain Gain? Changes of Work in Knowledge-based Societies, Berlin, Ed. Sigma. The author wants to thanks the comments and suggestions from Bettina Krings and Sylke Wintzer. They are not, however, responsible for the final result.

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Nosocomial infection among male patients in a public psychiatric hospital was studied and the definitions for use in long-term care facilities were employed for diagnosis. The overall nosocomial infection rate was 6.7 per 1,000 day inpatients; 55.6% of these infections were identified in the respiratory tract, 50% of them being respiratory viral diseases; 38.9% of the nosocomial infections involved the eyes, ears, nose, throat and mouth, and 5.6% involved the skin and soft tissues. The epidemiological characteristics and the main clinical alterations of these inpatients were also identified.

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Our objective was to compare food intake and nutritional status of Pemphigus Foliaceus patients (PG) on long term glucocorticoid therapy to a Control Group (CG). Fourteen PG female inpatients receiving prednisone (0.33 ± 0.22mg/kg) for at least 12 months and twelve CG subjects were submitted to nutritional evaluation, including anthropometry, urinary creatinine determination and serum biochemical measurements, besides 48-h-based food intake records. Groups were compared by Chi-square, Mann-Whitney and "t" tests. PG patients and CG were paired, respectively, in relation to age (24.7 ± 14.1 vs. 22.0 ± 12.0 years), body mass index (25.8 ± 6.4 vs. 24.0 ± 5.6kg/m2), daily protein intake (132.9 ± 49.8 vs. 95.2 ± 58.9g), and serum albumin (median; range) (3.8; 3.5-4.1 vs. 3.8; 3.6-5.0g/dl). However, PG patients had lower height-creatinine index (64.8 ± 17.6 vs. 90.1 ± 33.4%), and higher daily energy (3080 ± 1099 vs. 2187 ± 702kcal) and carbohydrate (376.8 ± 135.8 vs. 242.0 ± 80.7g) intakes. Despite high food, protein and energy consumption, PG patients on long term glucocorticoid therapy had lower body muscle mass than controls, while showing high body fat stores. These findings are possibly related to combined metabolic effects of long term corticotherapy and inflammatory disease plus corticosteroid-induced increased appetite.

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RESUMO - A Paralisia Cerebral (PC) deve ser olhada como uma patologia do neurodesenvolvimento: a infância é um período de actividade exploratória por essência, a restrição motora condiciona as várias áreas do desenvolvimento. Contextos, apoios, oportunidades e experiências de vida serão determinantes no desenvolvimento de todo o seu potencial. Objectivos/finalidade: Identificar, descrever, comparar e analisar factores de risco associados à PC, sua caracterização multidimensional e integração escolar aos 5 e 10 anos. Procurou‐se contribuir para a sua prevenção primária e secundária, e obter dados para planeamento e implementação dos programas de apoio. Métodos: Adoptou‐se a abordagem do Programa Nacional de Vigilância da Paralisia Cerebral (PNVPC) e da Surveillance of Cerebral Palsy in Europe (SCPE). Analisaram‐se factores de risco, competências funcionais, défices associados, severidade e integração escolar de duas populações de Lisboa e Vale do Tejo, (nascimento 1996/1997‐2001/2002 e prevalência aos 5 e 10 anos). Descreveram‐se os dados, efectuaram‐se correlações, aplicaram‐se testes de independência e compararam‐se com dados dos nadovivos, dados nacionais e europeus. Analisaram‐se os factores que influenciaram a integração escolar através de métodos de regressão logística. Resultados/Conclusões/Recomendações: 1,65‰ e 1,57‰ dos nadovivos desenvolveram PC; a prevalência aos 5 anos foi de 1,7‰ e de 1,48‰; 5,9% e 7,9% faleceram antes dos 5 anos. Em 2001/2002 verificou‐se aumento de: PC espástica bilateral‐2/3membros, prematuridade, causa pos‐neonatal, níveis funcionais ligeiros e graves; percentil estaturo‐ponderal <3 (5‐anos). Diminuição de: disquinésia, anóxia e alguns défices associados. Destacaram‐se as associação: prematuridade e PC espástica bilateral‐ 2/3membros; nascer de termo e anóxia, disquinésia, primíparas, défices associados e severidade; infecção pré‐natal e QI<50, epilepsia e severidade; causa pos‐neonatal e PC espástica bilateral‐4membros e múltiplos défices. Aos 5 anos, as variáveis explicativas para a não inclusão escolar foram: QI<50 e epilepsia; uma elevada percentagem de crianças com PC moderada/grave encontrava‐se integrada; 75% das que se encontravam desintegradas mantiveram‐se nesta situação aos 10. Nesta idade, as variáveis explicativas para a não inclusão escolar foram: QI<50 e motricidade fina; 35,1% encontrava‐se fora do ensino regular; 4,5%, embora em idade de escolaridade obrigatória, não frequentavam qualquer estabelecimento escolar. Informação sistematizada, abrangente, objectiva, simples e acessível, sobre novos casos de PC, factores de risco, prevalência em idades‐chave e caracterização multidimensional constitui uma ferramenta clínica e epidemiológica, que deve sustentar as políticas de saúde, educacionais e sociais, contribuindo para a permanência destas crianças no ensino regular, trazendo às crianças e famílias o suporte que as encorajem e sustentem nestes processos. ABSTRACT ------- Cerebral Palsy (CP) must be recognized as a neurodevelopmental disorder: childhood is, on its nature, a period for exploring the environment and therefore motor deficit interferes with all developmental areas. The context, support, opportunities and life experiences are determinants for the development of his full potential. Objective/Aim: To identify, describe, compare and analyze CP risk factors the multidimensional characterization and school integration levels at the age of 5 and 10 years. We aim to contribute to CP primary and secondary prevention and provide information for service planning and implementation of support programs. Methods: The approach of National Cerebral Palsy Surveillance Programme (NCPSP) and Surveillance of Cerebral Palsy in Europe (SCPE) were used. For two groups of children from Lisboa e Vale do Tejo region, birth data 1996/1997‐2001/2002 and prevalence at 5 and 10 years, were analyzed: CP risk factors, functional ability, associated impairments, severity and school integration settings. Data collected was described, analyzed using correlations, applied tests of independence and compared with new born data, national data and european data. To analyze the factors related to school inclusive settings, logistic regression was appealed. Results/Conclusions/Recommendations: 1,65% and 1,57‰ of the new‐born alive developed CP. The prevalence at 5 years was 1,7‰ and 1,48‰ 5,9% and 7,9% died before their 5th birthday. Bilateral spastic CP 2/3limb, preterm birth, cases of post‐neonatal origin, mild and sever functional impairment; weight and height percentile <3 at 5 years old Increased in 2001. Decreased dyskinetic CP, anoxia and some additional imparments. Were identified among other the association between prematurity and spastic bilateral CP‐2/3 members; born at term and anoxia, dyskinetic CP, first child, associated impairments and severity; prenatal infection and IQ<50, epilepsy and severity; post‐neonatal cause and spastic bilateral CP‐4 members and associated impairments. At 5‐years‐old the more explanatory variables for not be in a school inclusive settings were IQ<50 and epilepsy, a high percentage of children with moderate/severe CP was attending regular school, but most children who were out of inclusive settings at 5 years continue on this situations at 10‐years‐old. At this age the more explanatory variables for not be in a school inclusive settings were: IQ<50 and upper limb function; 35,1% were out of regular school; 4,5%, even in compulsory school age, are out of school. Standardized comprehensive, objective, simple and accessible information about CP new cases, risk factors, prevalence in the key‐age and children multidimensional characterization constitutes a clinical and epidemiological tool that should sustain health, educational and social policy. This would support the continuity of these children in regular schools, encouraging g them and their families in these processes.

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The aim of this article is to present an investigation of cure rate, after long follow up, of specific chemotherapy with benznidazole in patients with both acute and chronic Chagas disease, applying quantitative conventional serological tests as the base of the criterion of cure. Twenty one patients with the acute form and 113 with one or other of the various chronic clinical forms of the disease were evaluated, after a follow up period of 13 to 21 years, for the acute, and 6 to 18 years, for the chronic patients. The duration of the acute as well as the chronic disease, a condition which influences the results of the treatment, was determined. The therapeutic schedule was presented, with emphasis on the correlation between adverse reactions and the total dose of 18 grams, approximately, as well as taking into consideration precautions to assure the safety of the treatment. Quantitative serological reactions consisting of complement fixation, indirect immunofluorescence, indirect hemagglutination, and, occasionally, ELISA, were used. Cure was found in 76 per cent of the acute patients but only in 8 per cent of those with chronic forms of the disease. In the light of such contrasting results, fundamentals of the etiological therapy of Chagas disease were discussed, like the criterion of cure, the pathogenesis and the role of immunosuppression showing tissue parasitism in long standing chronic disease, in support of the concept that post-therapeutic consistently positive serological reactions mean the presence of the parasite in the patient's tissues. In relation to the life-cycle of T. cruzi in vertebrate host, there are still some obscure and controversial points, though there is no proof of the existence of resistant or latent forms. However, the finding over the last 15 years, that immunosuppression brings about the reappearance of acute disease in long stand chronic patients justifies a revision of the matter. Facts were quoted in favor of the treatment of chronic patients.