9,399 research outputs found

    Measured unsteady transonic aerodynamic characteristics of an elastic supercritical wing with an oscillating control surface

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    Transonic steady and unsteady aerodynamic data were measured on a large elastic wing in the NASA Langley Transonic Dynamics Tunnel. The wing had a supercritical airfoil shape and a leading-edge sweepback of 28.8 deg. The wing was heavily instrumented to measure both static and dynamic pressures and deflections. A hydraulically driven outboard control surface was oscillated to generate unsteady airloads on the wing. Representative results from the wind tunnel tests are presented and discussed, and the unexpected occurrence of an unusual dynamic wing instability, which was sensitive to angle of attack, is reported

    Differentiating the effects of negative state on optimism and the implicit perception of everyday injury risk

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    To date no research has examined the effects of negative state on the perception of everyday injury risk. Instead, studies have focussed more broadly on the relationship between mood and self- reported optimism. The present study had two aims. Firstly, to assess the effect of incidental anxiety on implicit injury risk perception using a modified Implicit Association Test (IAT). Secondly, it sought to compare any effect with that on a conventional measure of risk perception (optimism). In line with previous research, anxious participants perceived more risk (were less optimistic). In contrast, there was no significant correlation between anxiety and the implicit perception of everyday injury risk. Theoretical and practical implications are discussed

    Some Volatile Aroma Components of Vitis Vinifera L. cv. Sauvignon blanc

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    Volatile aroma components of Vitis vinifera L. cv. Sauvignon blanc grapes were studied to identify the components responsible for the characteristic aroma of this grape cultivar. Thirty three volatile components were identified. Amongst these methional and trans-2, cis-6-nonadienal are reported present in Vitis for the first time. Evidence is also presented for the presence of three methoxypyrazines which are believed to be key substances responsible for the typical aroma present in grapes and wines of this cultivar

    Estudo das relações de troca do melão produzido na região do Submédio São Francisco.

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    O estudo teve como objetivo determinar a relação de troca do melão produzido e comercializado na região do Submédio São Francisco e do fertilizante superfosfato simples que é um dos insumos utilizado em maior quantidade na sua exploração. Os valores da série histórica que corresponde ao período de 1999 a 2005, foram corrigidos pelo Índice Geral de Preços da Fundação Getúlio Vargas. Os resultados do estudo revelaram que de março até junho as relações de troca produto/insumo são favoráveis ao produtor, o contrário, ocorrendo durante todos os demais meses do ano. O Mês de maio registrou o maior ganho para o produtor, enquanto em dezembro ocorre a relação mais desfavorável. A análise global da série histórica revela que praticamente não há perda nem ganho no poder de compra do produtor de melão, visto que, o índice médio geral da relação de troca do período está apenas 0,9% acima do índice do ano critério do estudo, que é o ano inicial da série.Edição dos Anais do 47. Congresso Brasileiro de Olericultura; 4. Simpósio Brasileiro sobre Cucurbitáceas, Porto Seguro, ago. 2007

    Wind Energy Potential in Nigeria

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    Wind energy is one of the fastest growing technologies in energy generation industry nowadays. The erratic and epileptic state of power in this country and the concern about global warming should be a great concern for all and should drive us into strong demand for wind generation. The main advantages of electricity generation from wind are the absence of harmful emissions, very clean and the almost infinite availability of the wind that is converted into electricity. In Nigeria, where the wind power prospect is estimated to be high or moderate has not connected this renewable resources to the grid. It is not just enough to say that the wind turbines should be connected to the grid because there are sufficient wind speeds to drive the wind turbine. Mostly, the stability and reliability studies must be carried out whenever wind power is to be connected to power system to predict severe consequences on the power system to which the wind generators will be connected. This paper therefore describes the wind energy potential in Nigeria and specifies the conditions to be met before the wind generator can be connected to the existing grid and how it can be connected. The paper also shows that short-circuit power at Point of Common Coupling (PCC) is the crucial value for the permissible installed power ratings of the turbine

    Study of Charmonia near the deconfining transition on an anisotropic lattice with O(a) improved quark action

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    We study hadron properties near the deconfining transition in the quenched lattice QCD simulation. This paper focuses on the heavy quarkonium states, such as J/ψJ/\psi meson. In order to treat heavy quarks at T>0T>0, we adopt the O(a)O(a) improved Wilson action on anisotropic lattice. We discuss ccˉc\bar{c} bound state observing the wave function and compare the meson correlators at above and below TcT_c. Although we find a large change of correlator near the TcT_c, the strong spatial correlation which is almost the same as confinement phase survives even T1.5TcT\sim 1.5T_c.Comment: 19 pages, 10 figure

    Expression of schizophrenia in black Xhosa-speaking and white English-speaking South Africans

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    Objective. To inv:estigate whether schizophrenia manifests itself differently in  Xhosa-speaking South Africans, compared with English-speaking white South  Africans.Design. A comparative study ·of the presentation of schizophrenia in two groups of patients.Settings and subjects. A sample of 63 patients (43 Xhosaspeaking and 20 English-speaking) admitted to a large psychiatric hospital for the first time with a diagnosis of schizophrenia.Outcome measures. The Present State Examination (PSE) was used to confirm the clinical diagnosis of schizophrenia. The Relatives' Rating of Symptoms and Social Behaviour (KAS-R) was used to obtain information on the behavioural and emotional expression of schizophrenia.Results. A significantly higher prevalence of aggressive and disruptive behaviour was reported by relatives of Xhosaspeaking patients with schizophrenia of recent onset compared with English-speaking patients. The PSE elicited significantly more delusions of persecution, sexual and fantastic delusions, self-neglect and irritability in the Xhosaspeaking patients.Canclusion. Significant differences in the presentation of schizophrenia, but not its core symptoms, were identified in . Xhosa-speaking blacks and English-speaking whites
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