In-medium formation of quarkonium

We confront preliminary RHIC data on J/Psi production in nuclear interactions with expectations which follow in scenarios involving charm quark recombination in a region of color deconfinement. The focus is on transverse momentum and rapidity spectra of the J/Psi, which carry a memory of the spectra of the charm quarks. In such a scenario, one predicts that both spectra will be narrower than those expected without recombination. Preliminary results for the transverse momentum spectra point toward a preference for the recombination picture, while the rapidity spectra do not exhibit any narrowing within present large uncertainties. We present new calculations in the recombination model for the centrality behavior of these signals, which map out the necessary experimental precision required for a definitive test.Comment: Based on invited talk at Strangeness in Quark Matter 2006, UCLA, March 26-31, 2006. Clarifying remarks added in published journal versio

Seismic vulnerability assessment of the old city centre of Seixal, Portugal

The seismic vulnerability assessment of old traditional masonry building stocks, in a seismic risk mitigation perspective, is truly essential not only for buildings with recognized historical and patrimonial value, but also, in relation to regular buildings. In this sense, this paper approaches the issue of the seismic vulnerability assessment of masonry buildings through the application of a simplified methodology to building stock of the old city centre of Seixal, Portugal. This methodology is based on a vulnerability index, suitable in the evaluation of damage and in the creation of large scale loss scenarios (economical and human). Over 500 buildings were evaluated in accordance with the referred methodology and the results obtained were then integrated into a Geographical Information System tool. The integration of this kind of vulnerability and loss results into a GIS tool allows that city councils or regional authorities make their decisions based on a global view of the site under analysis, which led to more accurate and faster decisions either in terms of risk mitigation strategies or rehabilitation plans. This tool can also assumes great importance in the construction of safety and rescue plans

Vulnerability assessment of urban building stock: a hierarchic approach

In the last decades the evaluation of the seismic risk are of rising concern, considered essential in the activity and definition of strategy planning and urban management. The evaluation of the seismic vulnerability of the existent building stock in the perspective of the seismic risk mitigation should not be placed only in relation to the isolated buildings of relevant historical and cultural importance, but also, in relation to the agglomerate of buildings in urban centres. The chronological construction process frequently results in characteristic heterogeneity of masonry and wall connection quality. In addition, buildings do not constitute independent units given that they share the mid-walls with adjacent buildings and the façade walls are aligned. This way, as post-seismic observations proved, buildings do not have an independent structural behaviour, but they interact amongst themselves, mainly for horizontal actions and so the structural performance should be studied at the level of the aggregate and not only for each isolated building. In most cases, for masonry structures there is no need for sophisticated dynamic analyses for seismic resistance verification or vulnerability assessment. This is even more relevant when an assessment at the level of a city centre is pursued. In this work, the results of evaluation of the vulnerability will be presented in accordance to three proposed methodologies based on a vulnerability index that consequently allows the evaluation of damage and creation of loss scenarios (economical and human) not only at the level of the building and its façade walls but also at the level of the aggregates. It will be discussed and evaluated the application of the referred methodologies and its integration in an SIG platform

Exploração mecanizada da floresta tropical úmida sem babaçu.

bitstream/item/33767/1/CPATU-CirTec9.pd

Danos em paredes de alvenaria de fachada em edifícios correntes de betão armado: lições do sismo de Abril de 2009 de L´Áquila, Itália

Neste artigo relacionam-se as exigências de desempenho e estabilidade com as técnicas de construção de paredes em alvenaria da envolvente de edifícios correntes de betão armado. Em países europeus, a envolvente vertical dos edifícios é frequentemente constituída por paredes não estruturais de alvenaria, usando blocos perfurados verticalmente, ou ainda mais correntemente tijolos cerâmicos de furação horizontal. Estas paredes são tipicamente apoiadas e confinadas por uma estrutura de betão armado, constituída por pilares/paredes e vigas/lajes. Como estas paredes não têm uma função resistente, a sua influência sobre o comportamento global da estrutura é ignorada no dimensionamento das estruturas dos edifícios. Por outro lado, as suas condições de ligação à estrutura principal, normalmente, carecem de uma adequada pormenorização em projecto e a sua construção é deficiente. Em consequência, este tipo de elementos não-estruturais, são particularmente sensíveis às exigências de deformação e aceleração que lhe são impostas quando os edifícios são sujeitos à acção sísmica. Um das causas mais comuns para a instabilidade e inadequado desempenho das paredes de alvenaria da envolvente exterior face acções sísmicas é o reduzido apoio destas paredes sobre a laje ou viga periférica. Esta reduzida largura de suporte é actualmente uma consequência da necessidade de correcção das pontes térmicas planas. Com esta intenção, os projectistas e construtores revestem a estrutura externa localmente, de modo a aumentar a sua resistência térmica, minimizando o desenvolvimento de patologias. No entanto, se não foram acauteladas as devidas medidas em projecto e obra, comprometem a estabilidade global dos painéis de alvenaria da envolvente, sobretudo aquando da ocorrência de um sismo. No sismo que afectou a região de Abruzzo, em Itália, em 6 de Abril de 2009, os danos não-estruturais foram muito expressivos, principalmente o colapso para fora do plano dos panos exteriores das paredes duplas em alvenaria de tijolo, comprovando o anteriormente exposto. Os documentos técnicos e a normativa internacional (Eurocódigo 6, Eurocódigo 8, FEMA-356 e ATC-40) alertam para a necessidade de aplicação de critérios de verificação das deformações e dano nestas paredes não-estruturais. Neste artigo são propostas medidas para melhoria do desempenho, no plano e fora do plano, das paredes duplas, garantindo a sua integridade e estabilidade face a acções horizontais

Masonry enclosure walls: lessons learnt from the recent Abruzzo Earthquake

This paper approaches the issue of performance requirements and construction criteria for masonry enclosure and infill walls. Vertical building enclosures in European countries include, very often, non-loadbearing masonry walls, using horizontally hollowed clay bricks. These walls are generally supported and confined by a reinforced concrete frame structure of columns, beams or slabs. Since these walls are commonly considered to be non-structural elements, and their influence over the structural response is ignored, their consideration in the design of structures as well as its linkage to the surrounding structure is often negligent or insufficiently detailed. In consequence, non-structural elements, as for wall enclosures, are relatively sensitive to drift and acceleration demands when buildings are subjected to seismic actions. Many international standards and technical documents alert to the need of acceptability criteria for non-structural walls, however they do not specifically indicate how to prevent collapse and severe cracking and how to enhance the overall stability for severe seismic loading. In this paper, appropriate measures are proposed to improve both in-plane and out-of-plane integrity and the performance behaviour under seismic actions of external leaf of double leaf cavity walls as well as premature disintegration of the infill walls

Dimensionamento de sistemas de tratamento (decantador e lagoas) e utilização de dejetos suínos.

Características dos dejetos; Equalizador; Decantador; Lagoas de tratamento; Adubação orgânica.bitstream/item/58411/1/CUsersPiazzonDocuments234.pd

Fractional quantization of ballistic conductance in 1D hole systems

We analyze the fractional quantization of the ballistic conductance associated with the light and heavy holes bands in Si, Ge and GaAs systems. It is shown that the formation of the localized hole state in the region of the quantum point contact connecting two quasi-1D hole leads modifies drastically the conductance pattern. Exchange interaction between localized and propagating holes results in the fractional quantization of the ballistic conductance different from those in electronic systems. The value of the conductance at the additional plateaux depends on the offset between the bands of the light and heavy holes, \Delta, and the sign of the exchange interaction constant. For \Delta=0 and ferromagnetic exchange interaction, we observe additional plateaux around the values 7e^{2}/4h, 3e^{2}/h and 15e^{2}/4h, while antiferromagnetic interaction plateaux are formed around e^{2}/4h, e^{2}/h and 9e^{2}/4h. For large \Delta, the single plateau is formed at e^2/h.Comment: 4 pages, 3 figure

Far Infrared Slab Lensing and Subwavelength Imaging in Crystal Quartz

We examine the possibility of using negative refraction stemming from the phonon response in an anisotropic crystal to create a simple slab lens with plane parallel sides, and show that imaging from such a lens should be possible at room temperature despite the effects of absorption that are inevitably present due to phonon damping. In particular, we consider the case of crystal quartz, a system for which experimental measurements consistent with all-angle negative refraction have already been demonstrated. Furthermore, we investigate the possibility of subwavelength imaging from such materials, and show that it should be possible for certain configurations.Comment: 12 pages, 10 figure