1000 resultados para 165-999A


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The assessment of wind energy resource for the development of deep offshore wind plants requires the use of every possible source of data and, in many cases, includes data gathered at meteorological stations installed at islands, islets or even oil platforms—all structures that interfere with, and change, the flow characteristics. This work aims to contribute to the evaluation of such changes in the flow by developing a correction methodology and applying it to the case of Berlenga island, Portugal. The study is performed using computational fluid dynamic simulations (CFD) validated by wind tunnel tests. In order to simulate the incoming offshore flow with CFD models a wind profile, unknown a priori, was established using observations from two coastal wind stations and a power law wind profile was fitted to the existing data (a=0.165). The results show that the resulting horizontal wind speed at 80 m above sea level is 16% lower than the wind speed at 80 m above the island for the dominant wind direction sector.

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In 2014, the wind energy sector achieved a maturity status within the Portuguese power system. While it still experienced some additional capacity deployment (222 MW), after 15 years of intense deployment Portugal reached 4, 953 MW of installed wind power capacity by the end of 2014. Wind power represents 25% (considering only mainland Portugal) of the total operational capacity and 42% of renewable energy capacity in the country. In 2014, Portuguese wind parks produced 12.1 TWh maintaining a wind energy contribution of 24% of the annually electricity consumption. This high wind penetration was influenced by the favorable wind conditions observed in the first three months of the year over central and northern regions of mainland Portugal that also correspond to the largest concentration of installed wind capacity.

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The evolution of receiver architectures, built in modern CMOS technologies, allows the design of high efficient receivers. A key block in modern receivers is the oscillator. The main objective of this thesis is to design a very low power and low area 8-Phase Ring Oscillator for biomedical applications (ISM and WMTS bands). Oscillators with multiphase outputs and variable duty cycles are required. In this thesis we are focused in 12.5% and 50% duty-cycles approaches. The proposed circuit uses eight inverters in a ring structure, in order to generate the output duty cycle of 50%. The duty cycle of 1/8 is achieved through the combination of the longer duty cycle signals in pairs, using, for this purpose, NAND gates. Since the general application are not only the wireless communications context, as well as industrial, scientific and medical plans, the 8-Phase Oscillator is simulated to be wideband between 100 MHz and 1 GHz, and be able to operate in the ISM bands (447 MHz-930 MHz) and WMTS (600 MHz). The circuit prototype is designed in UMC 130 nm CMOS technology. The maximum value of current drawn from a DC power source of 1.2 V, at a maximum frequency of 930 MHz achieved, is 17.54 mA. After completion of the oscillator layout studied (occupied area is 165 μm x 83 μm). Measurement results confirm the expected operating range from the simulations, and therefore, that the oscillator fulfil effectively the goals initially proposed in order to be used as Local Oscillator in RF Modern Receivers.

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Introduction Knowledge of the prevalence and risk factors for Toxoplasma gondii dissemination among pregnant women is relevant because the parasite can be spread from mother to infant. The objective of this study was to assess the epidemiology and risk factors of toxoplasmosis in pregnant women from Gurupi, State of Tocantins, Brazil, from February 2012 to June 2013. Methods The study population included 487 pregnant women. Sociodemographic, dietary and cultural data were collected using a standardized and validated form. Peripheral blood was collected for serologic testing using the ELISA test (IgM/IgG antibodies). The data were analyzed by comparing seropositivity with risk factors using crude and adjusted odds ratios. Results The prevalence rate for IgG and IgM antibodies was 68.7% and 5.7%, respectively. Sociodemographic characteristics associated with toxoplasmosis risk included the following: education level ≤ 8 years (OR: 6.612; CI: 1.450-30.144), age ≥ 30 years (OR: 5.273; CI: 1.166-23.844), working outside the home (OR: 1.604; CI: 1.015-2.536), and family income of two minimum wages or lower (OR: 2.700; CI: 1.891-8.182). Regarding dietary habits, there was a significant association of seropositivity with meat intake (OR: 1.78; CI: 1.149-4.080), cutting vegetables without washing the cutting board beforehand (OR: 2.051; CI: 1.165-3.614), frequent intake of vegetables (OR: 2.051; CI: 1.368-3.006) and in natura milk intake (OR: 2.422; CI: 1.014-5.785). Conclusions The high prevalence rates of toxoplasmosis in Gurupi are related to age, raw meat and in natura milk intake, as well as education level, working outside the home, and poor hygienic habits during meal preparation.

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INTRODUCTION: Occult hepatitis B infection (OBI) is considered to be one of the major risks for patients suffering from end-stage renal disease (ESRD) on regular hemodialysis (HD) and patients with chronic hepatitis C virus (HCV) infection. This study compared the prevalence of OBI among these two high-risk groups in the Suez Canal region, Northeastern Egypt, to obtain a better national overview of the magnitude of OBI in this region. METHODS: Serum samples were collected from 165 HD patients and 210 chronic HCV-infected patients. Anti-HCV antibody, hepatitis B surface antigen (HBsAg), total hepatitis B core (anti-HBc) antibody, and hepatitis B surface antibody (anti-HBs) were detected by enzyme-linked immunosorbent assay (ELISA). HCV RNA was detected using a quantitative real-time RT-PCR assay, and HBV was detected using a nested PCR. RESULTS: All patients were negative for HBsAg. A total of 49.1% and 25.2% of the patients in the HD and HCV groups, respectively, were anti-HBc-positive. In addition, more anti-HBs-positive patients were detected in the HD group compared to the HCV group (52.1% and 11.4%, respectively). Three cases were positive for HBV DNA in the HD group, while eighteen positive cases were detected in the HCV group. Both study groups showed significant differences in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level as well as anti-HBc, anti-HBs and HBV-DNA positivity. CONCLUSIONS: OBI was more prevalent among chronic HCV patients than HD patients in the Suez Canal region, Egypt, with rates of 8.5% and 1.8%, respectively. However, more precise assessment of this infection requires regular patient follow-up using HBV DNA detection methods.

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Ventilator-dependent premature infants are often treated with dexamethasone. Several trials showed that steroids while improve pulmonary compliance and facilitate extubation, some treated infants may have adverse effects, such as alterations of growth curves. We conducted this retrospective study to evaluate the effects of steroids on mechanical ventilation, oxygen therapy, hospital length stay and mortality, in ventilator-dependent infants with bronchopulmonary dysplasia (BPD) (defined as the need of oxygen supplementation at 28 days of life). Twenty-six newborns with BPD were evaluated during 9 -- 42 days postpartum (mean = 31 days) and were divided into two groups: Group I - 14 newborns that did not receive dexamethasone, and Group II - 12 newborns that received dexamethasone at 14 --21 days of life. Dexamethasone was given at a dose of 0.25 mg per kilogram of body weight twice daily intravenously for 3 days, after which the dose was tapered. RESULTS: There were no statistically significant differences in the mean length of mechanical ventilation (Group I - 37 days, Group II - 35 days); oxygen supplementation (Group I - 16 days, Group II - 29 days); hospital stay (Group I - 72 days, Group II - 113 days); mortality (Group I - 35.7%, Group II - 41.6%). At birth, Group II was lighter (BW: Group I - 1154 grams ± 302, Group II - 791 grams ± 165; p < 0.05) and smaller (height: Group I - 37.22 cm ± 3.3, Group II - 33.5 ± 2.4; p< 0.05) than Group I. At 40 weeks, there were no statistically significant differences between groups in relation to anthropometric measurements. CONCLUSIONS: The use of corticosteroids in bronchopulmonary dysplasic infants may influence the somatic growth during its use. However, after its suspension, a recovery seems to occur, suggesting that its influence could be transitory.

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The reuse of recycled concrete aggregates in new hot-mix asphalt can be a more sustainable method of production, but these mixtures may need a heat treatment before compaction to improve their water sensitivity performance. A direct consequence of this treatment is an increase in the hot-mix asphalt resilient modulus. The aim of this paper is to analyse the effect of ageing on the stiffness of asphalt mixtures with different amounts of recycled concrete aggregates, before and after a heat treatment, which was analysed through the assessment of its bitumen properties. Moreover, this paper also aims to analyse whether the rolling thin-film oven test is able to simulate the ageing effect of the heat treatment. In the laboratory work, a paving grade bitumen B50/70 has been used to produce asphalt mixtures with 0% and 30% recycled concrete aggregates, and the bitumen was later characterised (using penetration, softening point, dynamic viscosity and dynamic shear rheometer tests) in various situations, such as when using virgin bitumen, short-term aged bitumen, aged bitumen after heat treatment (simulated with 4 h of rolling thin-film oven test) and bitumen samples recovered from asphalt mixtures with different production mixes (0% and 30% recycled concrete aggregate) and heat treatment conditions (0 and 4 h of curing time in the oven). Based on the results obtained, it could be concluded that the ageing resulting from the heat treatment is the primary cause of the hot-mix asphalt's increased stiffness, while recycled concrete aggregate content has a small influence. Moreover, it could be concluded that when there is no curing time, the recycled concrete aggregate protects the bitumen against ageing. Additionally, it could be stated that the rolling thin-film test is able to adequately simulate the ageing effect of the heat treatment. Thus, this test is useful for determining the ageing suffered by the bitumen when the recycled concrete aggregate mixture is manufactured using a heat treatment.

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In this work, the fracture mode I parameters of steel fibre reinforced self-compacting concrete (SFRSCC) were derived from the numerical simulation of indirect splitting tensile tests. The combined experimental and numerical research allowed a comparison between the stress-crack width (σ - w) relationship acquired straightforwardly from direct tensile tests, and the σ - w response derived from inverse analysis of the splitting tensile tests results. For this purpose a comprehensive nonlinear 3D finite element (FE) modeling strategy was developed. A comparison between the experimental results obtained from splitting tensile tests and the corresponding FE simulations confirmed the good accuracy of the proposed strategy to derive the σ – w for these composites. It is concluded that the post-cracking tensile laws obtained from inverse analysis provided a close relationship with the ones obtained from the experimental uniaxial tensile tests.

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O objetivo foi analisar a relação entre desempenho motor (DM) e variáveis antropométricas de crianças e adolescentes de escolas públicas de Florianópolis. Metodologia: 300 alunos do 3º ao 5º ano e da 4ª a 6ª série do Ensino Fundamental, entre os 8 e 16 anos. Os resultados vão ao encontro à literatura, que indicam correlações negativas entre DM e variáveis antropométricas em crianças e adolescentes.

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In some regions of Brazil, especially where the water is scarce, drinking water is stored in water storage tanks. This practice gives the consumer the guarantee of available water. The water storage conditions such as the exposure to hot weather when the tanks are on rooftops allow the development of microorganisms and microbial biofilms which can deteriorate the water quality and increase the risk to human health [1,2]. This study describes the filamentous fungi (FF) detected in free water and biofilms in drinking water storage tanks in Recife - Pernambuco, Brazil. Five sampling times in triplicate were performed at two distinct points. Colony-forming units (CFU) of FF fungi were determined with 0.45 µm filtration membranes using peptone glucose rose Bengal agar (PGRBA). From the 30 samples analysed a total of 1136 CFU were obtained. The water biofilms were collected from samplers consisting of polyethylene coupons, previously installed in the reservoirs. These coupons were transferred to PGRBA plates and incubated using with the same conditions described for free FF. For the in situ detection of FF in biofilms the Calcofluor White staining technique was used. This procedure demonstrated FF forming biofilms on the surfaces of the coupons. Brazilian legislation does not define limits for FF in drinking water. However considering the potential risk of fungal contamination, the data obtained in this study will contribute to developing future quantitative and qualitative parameters for the presence of fungi in drinking water distribution systems in Brazil. [1] HageskaL, G, Lima, N, Skaar, I. The study of fungi in drinking water. Mycological Research, 113, 2009, 165-172. [2] Skaar I, Hageskal G. Fungi in Drinking Water. In.: Paterson RRM, Lima N. (Eds.) Molecular Biology of Food and Water Borne Mycotoxigenic and Mycotic Fungi. CRC Press, Taylor & Francis Group, Boca Raton, 2015, 597-606.

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Nas áreas de produção de sementes de Tectona grandis em Cáceres, MT, ventos fortes podem causar queda precoce de frutos. Diásporos de três lotes de teca, um obtido após a queda natural e os outros dois após queda precoce, foram inicialmente qualificados quanto ao teor de água, massa de mil diásporos, número de diásporos por quilograma, emergência em canteiro e respectivo tempo médio. Essas duas últimas variáveis foram novamente determinadas em intervalos de 50 dias até 331 dias após a colheita com o uso de 200 diásporos divididos em quatro repetições. Para os diásporos de queda natural, a emergência de plântulas e o tempo médio não diferiram nos períodos de análise com média geral de 60,6% e 10,8 dias. Os diásporos dos lotes de colheita precoce apresentaram a emergência inicial de 23,5 e 17,5% e os tempos médios de 19,4 e 22,6 dias, respectivamente. Até 115 dias após a colheita, a emergência aumentou (55,5 e 59,5%) e o tempo médio diminuiu (15,0 e 14,1 dias) e a partir daí ocorreu o inverso. Os diásporos de colheita precoce derrubados pelo vento apresentam maturação e o maior potencial fisiológico aos 115 dias após a colheita. No período de 64 a 269 dias após a colheita, esses diásporos atingem o padrão mínimo estabelecido para a teca e o período entre 115 a 165 dias é o mais adequado para sua utilização.

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Tendo como intervenientes estudantes de ensino superior, realizou-se um estudo de carácter qualitativo (Amado & Ferreira, 2013), mais especificamente um estudo de caso (Yin, 2005), cujos objetivos foram definidos de acordo com orientações internacionais para a educação para a sexualidade (WHO, 2010a; UNESCO, 2009), nomeadamente: (1) perceber relacionamentos privilegiados; e (2) identificar conceções de futuros partilhados. Para a recolha de dados solicitou-se às crianças que representassem pares por meio de desenho e que dialogassem sobre a interação e o amor. A amostra foi constituída por 55 crianças com idades compreendidas entre os 5-12 anos, sendo 33 do género feminino e 22 do género masculino. Os dados recolhidos foram tratados com vista à análise de conteúdo e análise de discurso. Entre outros resultados, clarificou-se que os pares desenhados eram em menor número de membros da “família” (7 raparigas e 7 rapazes), nomeadamente, “casados”, “pai e filho”, “primo/as”, “avós” ou “sobrinha-tia”. Noutra categoria enquadraram-se as relações “não familiares” (23 raparigas e 13 rapazes), de “amizade”, “amor” e “paixão”, definidos os pares de “namorados”, exprimindo “carinho” ou estando “apaixonados”. Como conclusões verificaram-se os desejados finais felizes e foram debatidos os significados do amor, tendo as raparigas afirmado que o amor é “muito bom”, podendo ter como sentido “carinho”, “amizade”, “lealdade” ou “paixão”. Assim, quando uma pessoa gosta de outra, o amor “une-as”, é uma “coisa natural”, para duas meninas, mas vive-se o amor, segundo outra, «quando se anda juntos, dando passeios». Pode o amor ser para rapazes «tipo amigos a dar beijinhos na boca», mas são elas a desenhar o beijar. Um outro rapaz também valorizou o ser «mais do que amigo». Por acréscimo, depois dos 12 anos, foi aludido o “saber amar” quando se é “amigo”.

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This paper tries to remove what seems to be the remaining stumbling blocks in the way to a full understanding of the Curry-Howard isomorphism for sequent calculus, namely the questions: What do variables in proof terms stand for? What is co-control and a co-continuation? How to define the dual of Parigot's mu-operator so that it is a co-control operator? Answering these questions leads to the interpretation that sequent calculus is a formal vector notation with first-class co-control. But this is just the "internal" interpretation, which has to be developed simultaneously with, and is justified by, an "external" one, offered by natural deduction: the sequent calculus corresponds to a bi-directional, agnostic (w.r.t. the call strategy), computational lambda-calculus. Next, the duality between control and co-control is studied and proved in the context of classical logic, where one discovers that the classical sequent calculus has a distortion towards control, and that sequent calculus is the de Morgan dual of natural deduction.

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O presente estudo teve como objetivo caracterizar a composição florística e fitossociológica de uma floresta nativa no município de Caracaraí, Roraima, Brasil. Foram inventariadas todas as árvores com DAP > 10 cm em 9 parcelas permanentes de 100 x 100 m (1 ha cada). Foram observados 4.724 indivíduos (525ind.ha-1), distribuídos em 42 famílias botânicas, 111 gêneros e 165 espécies. As famílias com maior número de indivíduos foram Fabaceae (1.883), Lecythidaceae (609) e Sapotaceae (434), perfazendo 52% do total de indivíduos amostrados. O grupo composto por espécies pioneiras apresentou maior número de indivíduos (219ind.ha-1), seguido das secundárias (193ind.ha-1) e climácicas (113ind.ha-1). No entanto, as secundárias obtiveram maior número de espécies (95), em detrimento de climácicas (44) e pioneiras (26). O índice de diversidade de Shannon (H' = 3,27) e o valor de equabilidade de Pielou (J = 0,64) foram inferiores aos obtidos em outros inventários florísticos na Amazônia Legal, contribuindo para isso o tamanho populacional de Pentaclethra macroloba. As espécies Pentaclethra macroloba (52,1), Eschweilera bracteosa (23,7) e Pouteria caimito (8,1) apresentaram os maiores valores de importância, perfazendo 28% do VI total. A maior parte dos indivíduos amostrados (71,3% = 374ind.ha-1) foram registrados no estrato médio (12,4 m < altura < 26,5 m) da floresta. A comunidade florestal pode ser considerada bem estruturada, madura e diversa, portanto em bom estado de conservação.

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OBJECTIVE: To assess whether female sex is a factor independently related to in-hospital mortality in acute myocardial infarction. METHODS: Of 600 consecutive patients (435 males and 165 females) with acute myocardial infarction, we studied 13 demographic and clinical variables obtained at the time of hospital admission through uni- and multivariate analysis, and analyzed their relation to in-hospital death. RESULTS: Females were older (p<0.001) and had a higher incidence of hypertension (p<0.001). Males were more frequently smokers (p<0.001). The remaining risk factors had a similar incidence among both sexes. All variables underwent uni- and multivariate analysis. Through univariate analysis, the following variables were found to be associated with in-hospital death: female sex (p<0.001), age >70 years (p<0.001), the presence of previous coronary artery disease (p=0.0004), previous myocardial infarction (p<0.001), infarction in the anterior wall (p=0.007), presence of left ventricular dysfunction (p<0.001), and the absence of thrombolytic therapy (p=0.04). Through the multivariate analysis of logistic regression, the following variables were associated with in-hospital mortality: female sex (p=0.001), age (p=0.008), the presence of previous myocardial infarction (p=0.02), and left ventricular dysfunction (p<0.001). CONCLUSION: After adjusting for all risk variables, female sex proved to be a variable independently related to in-hospital mortality in acute myocardial infarction.