878 resultados para plane of reference
Resumo:
O presente trabalho resultou de um estudo antropológico sobre o Museu Severina Paraíso da Silva, dedicado à história e às tradições do grupo de candomblé da nação Xambá, cujo diferencial é estar instalado dentro de uma casa de culto afro brasileiro, o Terreiro de Santa Bárbara Ylê Axé Oyá Meguê, em Olinda, Pernambuco, Brasil. Este é um exemplo de Museu que representa a memória de um grupo social minoritário, criado por seus membros, com o objetivo de preservar seu patrimônio étnico-cultural, o qual é utilizado como categoria política para obtenção de reconhecimento perante a sociedade. Foram analisadas, neste estudo, as inter-relações em torno do Museu, observando-se aspectos como sua criação pelos próprios membros; coleta e utilização dos objetos; público-alvo; espaço físico e objetos, em especial os que não perderam seu poder simbólico, embora expostos no Museu e, principalmente, as mensagens transmitidas para a sociedade. Tais aspectos são importantes fios condutores para entender a postura dos membros do grupo em relação à sociedade e à formação de suas autoconsciências individuais e coletivas, ou seja, como eles elaboram e interpretam a identidade como grupo através do Museu; e entender também a importância do Museu na construção da memória e preservação da identidade étnica do grupo Xambá e da cultura negra em Pernambuco. A questão principal, porém, foi verificar se o Memorial e o Museu, como espaços de preservação, criam em seus membros um sentimento de pertencimento. Para a pesquisa foram coletados dados bibliográficos, documentais, no site do terreiro, na cartilha do grupo, em vídeos, plantas, em entrevistas formais com os criadores do museu e informais com outros membros do grupo, mas principalmente através da observação participante nas visitas dirigidas ao Museu e nos toques. Durante a pesquisa verificou-se que uma parte do grupo se destaca pela busca de sua visibilidade como estratégia de reivindicação de direitos sociais. Busca esta que procura legitimar a tradição usando categorias como autenticidade e pureza e pela presença de pesquisadores e pessoas ilustres, além da afirmação da importância do Museu para a construção do patrimônio cultural do negro no Estado. Um ganho substancial nesta busca pela visibilidade foi a concessão do título de Quilombo Urbano, alguns anos após a criação do Museu, sugerindo que este contribuiu para o reconhecimento do local como espaço de preservação de práticas culturais de descendentes de africanos. Há outros elementos que representam vitórias, na luta pelo reconhecimento, ou seja, um empoderamento para o grupo, como o nome de Xambá, dado ao Terminal Integrado de Passageiros construído próximo ao terreiro dentro do perímetro do Quilombo. Além da visibilidade para o grupo, o Museu trouxe outros ganhos, ele cria uma coesão entre seus membros, que passam a se ver como um grupo, como uma nação.
Resumo:
A method is presented for the digital simulation of multiple degrees-of-freedom lumped parameter vibrating systems with arbitrary constitutive elements in an inertial frame of reference. The geometry of the system is treated independently of the constitutive elements and as a result nonlinear (time domain) or linearised (frequency domain) calculations may be performed using a single input description. The method is used to simulate a 3-axle rigid heavy commercial vehicle for harsh vibrating conditions. Some of the assumptions to which the calculations are sensitive are examined. Agreement between the response of a 3-dimensional whole vehicle model and measurements on the test vehicle is satisfactory.
Resumo:
Resonant tunnelling spectroscopy is used to investigate the energy level spectrum of a wide potential well in the presence of a large magnetic field oriented at angles θ between 0° and 90° to the normal to the plane of the well. In the tilted field geometry, the current-voltage characteristics exhibit a large number of quasiperiodic resonant peaks even though the classical motion of electrons in the potential well is chaotic. The voltage range and spacing of the resonances both change dramatically with θ. We give a quantitative explanation for this behaviour by considering the classical period of unstable periodic orbits within the chaotic sea of the potential well.
Resumo:
A framework has been developed for the UK economy that categorizes companies who provides a more defined perspective on the structure of the economy in order to help decision makers, government and industry to achieve sustained economic growth. The Institute for Manufacturing (IfM) has established a broader definition of manufacturing that equates manufacturing to the full cycle of activities from research and development, through design, production, logistics and services, to end of life management, within an economic and social context. This approach recognizes that manufacturing firms turn ideas into products and services and that they are inventors, innovators, global supply chain managers and service providers. It is hoped that this categorization provides policy-makers with a clear frame of reference for discussing measures to adapt interventions to address the needs of the diverse set of companies.
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The field survey was undertaken by NaFIRRI technical staff. The terms of reference for the survey were to make an assessment of the lake for possible cage fish farming. The survey was undertaken on the 26 August 2010 by a team composed of the several. The lake supports small subsistence fishing activities by the local communities living around it. Information from the local community indicates that the fish species/types occurring in the lake include the Ngege, Nile perch, the African catfish and the lung fish. The fishing crafts in operation are largely Dug-out and Bao Tatu canoes and the main fishing gears are nylon and monofilament gillnets, hooks and beach seines.
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Liquid crystal (LC) adaptive optical elements are described, which provide an alternative to existing micropositioning technologies in optical tweezing. A full description of this work is given in [1]. An adaptive LC prism supplies tip/tilt to the phase profile of the trapping beam, giving rise to an available steering radius within the x-y plane of 10 μm. Additionally, a modally addressed adaptive LC lens provides defocus, offering a z-focal range for the trapping site of 100 μm. The result is full three-dimensional positional control of trapped particle(s) using a simple and wholly electronic control system. Compared to competing technologies, these devices provide a lower degree of controllability, but have the advantage of simplicity, cost and light efficiency. Furthermore, due to their birefringence, LC elements offer the opportunity of the creation of dual optical traps with controllable depth and separation.
Resumo:
An MPhil programme, delivered by the Engineering Department at the University of Cambridge, claims to be excellent at preparing graduates for manufacturing industry careers. The course uses a combination of different educational experiences, including industry-based assignments, industrial visits and practical exercises. This research explores how problem solving skills are developed during the first module, Induction, which is designed to enable students to undertake their first industrial assignment. From the literature, four conditions necessary for skill development were identified: Provision of a skill description, making explicit key components A number of different experiences with a range of contextual variables A teaching process which includes regular feedback and student reflection Students motivated to learn. These were used to construct a skill development framework (SDF). Using a case study research design, multiple types of evidence were collected to test for the above conditions using both classroom observation and questionnaire methods. The results confirmed the presence of the SDF conditions at different levels, with reflection aspects considered the weakest. Conflicting results were obtained regarding the students' self-awareness of skill levels. A plausible explanation is a change in the students' frame of reference. This initial study set out to develop a better understanding of the process of skill development. Whilst the SDF appears reasonable, there is a need for further work in three broad areas of defining skills, assessing skills and developing reflection skills.
Resumo:
For established axisymmetric turbulent miscible Boussinesq fountains in quiescent uniform environments, expressions are developed for the fluxes of volume, momentum and buoyancy at the outflow from the fountain: the outflow referring to the counterflow at the horizontal plane of the source. The fluxes are expressed in terms of the fountain source conditions and two dimensionless functions of the source Froude number, Fr0: a radial function (relating a horizontal scale of the outflow to the source radius) and a volume flux function (relating the outflow and source volume fluxes). The forms taken by these two functions at low Fr0 and high Fr0 are deduced, thereby providing the outflow fluxes and outflow Froude number solely in terms of the source conditions. For high Fr0, the outflow Froude number, Frout, is shown to be invariant, indicating (by analogy with plumes for which the 'far-field' Froude number is invariant with source Froude number) that the outflow may be regarded as 'far-field' since the fluxes within the fountain have adjusted to attain a balance which is independent of the source conditions. Based on Frout, the fluxes in the plume that forms beyond the fountain outflow are deduced. Finally, from the results of previously published studies, we show that the scalings deduced for fountains are valid for 0.0025 ≲ Fr0 ≲ 1.0 for low Fr0 and Fr0≳ 3.0 for high Fr0. © 2014 Cambridge University Press.
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Atomic configurations and formation energies of native defects in an unsaturated GaN nanowire grown along the [001] direction and with (100) lateral facets are studied using large-scale ab initio calculation. Cation and anion vacancies, antisites, and interstitials in the neutral charge state are all considered. The configurations of these defects in the core region and outermost surface region of the nanowire are different. The atomic configurations of the defects in the core region are same as those in the bulk GaN, and the formation energy is large. The defects at the surface show different atomic configurations with low formation energy. Starting from a Ga vacancy at the edge of the side plane of the nanowire, a N-N split interstitial is formed after relaxation. As a N site is replaced by a Ga atom in the suboutermost layer, the Ga atom will be expelled out of the outermost layers and leaves a vacancy at the original N site. The Ga interstitial at the outmost surface will diffuse out by interstitialcy mechanism. For all the tested cases N-N split interstitials are easily formed with low formation energy in the nanowires, indicating N-2 molecular will appear in the GaN nanowire, which agrees well with experimental findings.
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Microtwins in the 3C-SiC films grown on Si(001) by APCVD were analyzed in detail using an X-ray four-circle diffractometer. The empty set scan shows that 3C-SiC films can grow on Si substrates epitaxially and the epitaxial relationship is revealed as (001)(3C-SiC)//(001)(Si), [111](3C-SiC)//[111](Si). Other diffractions emerged in the pole figures of the (111) 3C-SiC. We performed the (10 (1) over bar0) h-SiC and the reciprocal space mapping of the (002) plane of twins for the first time, finding that the diffractions at chi = 15.8 degrees result from not hexagonal SiC but microtwins of 3C-SiC, and twin inclusions are estimated to be 1%.
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Compact and efficient triple-pass optical parametric chirped pulse amplification in a single crystal has been demonstrated. The signal was triple-pass amplified in a single nonlinear crystal by a nanosecond pump pulse. The first-pass optical parametric amplification is completely phase matched in the plane of the maximum effective nonlinearity, and the other two passes work symmetrically near to the first-pass optical parametric amplification plane. This architecture efficiently increases the overall gain, overcomes the optical parametric fluorescence, and clearly simplifies the amplification scheme.
Resumo:
This paper describes the design of an interference imaging spectrometer. A static Polarization Imaging Spectrometer (PIS) based on a single Savart polariscope has been developed. It produces the interferogram and target's image in the spatial domain which are recorded by using a two-dimensional (2D) CCD detector. Imaging lens localizes the interference fringes and target's image coincident with the plane of detector, thereby facilitating an extremely compact design. The spectrum of the input light is reconstructed through the Fourier-transform of the interferogram. The total optics is as small as 20 x 6 cm phi in size and the spectral resolution of the prototype system is 97.66 cm(-1) between 25,000 and 10, 000 cm(-1). The polarization interference imaging device has advantages of ultra-compact size, wide field of view, high throughput and without any moving parts. (C) 2002 Published by Elsevier Science B.V.
Resumo:
采用0.05mol.L-1的EDTA作为萃取剂,在一定的萃取条件下,对2种尾矿土壤中重金属进行土壤柱萃取实验,并采用优化的BCR(European Community Bureau of Reference)连续萃取方案对萃取前后的Pb、Zn、Cu和Cd进行形态分析.研究EDTA对4种金属的萃取效率及萃取前后的形态变化特征.结果表明,EDTA能有效的从土壤中萃取该4种金属,萃取效率依次为:Cd>Zn>Cu>Pb;金属的4种形态均能被EDTA萃取;在浅层土壤中,EDTA对酸可提态的金属的萃取效果尤为显著;在深层土壤中,酸可提取态、氧化物结合态、有机结合态和残余态4种形态的金属萃取效果,随着土壤柱深度的增加而降低.
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Eye detection plays an important role in many practical applications. This paper presents a novel two-step scheme for eye detection. The first step models an eye by a newly defined visual-context pattern (VCP), and the second step applies semisupervised boosting for precise detection. VCP describes both the space and appearance relations between an eye region (region of eye) and a reference region (region of reference). The context feature of a VCP is extracted by using the integral image. Aiming to reduce the human labeling efforts, we apply semisupervised boosting, which integrates the context feature and the Haar-like features for precise eye detection. Experimental results on several standard face data sets demonstrate that the proposed approach is effective, robust, and efficient. We finally show that this approach is ready for practical applications.
Resumo:
Seven compounds, four flavones and three triterpenoids from Glycyrrhiza uralensis Fisch. extract are identified by high performance liquid chromatography coupled with electrospray ionization multi-tandem mass spectrometry (HPLC-ESI-MSn). The fragmentation pathways of these compounds are investigated by ESI-MSn and Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (FT-ICR-MSn). Comparing the retention times (t(R)) and mass spectra with those of reference compounds, seven components are identified in Glycyrrhiza uralensis Fisch. and their MSn data proposed plausible schemes for their fragmentation. All the experimental results show that ESI-MSn and FT-ICR-MSn are powerful tools for the structural characterization of triterpenoids and flavones