3,044 research outputs found

    New results on the spectroscopy of XYZ states from LHC experiments

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    The main results from LHC experiments on XYZ charmonium-like candidates are summarized.Comment: to appear in the proceedings of The 5th International Workshop on Charm Physics (Charm 2012

    The First Year of the Large Hadron Collider: A Brief Review

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    The first year of LHC data taking provided an integrated luminosity of about 35/pb in proton-proton collisions at sqrt(s)=7 TeV. The accelerator and the experiments have demonstrated an excellent performance. The experiments have obtained important physics results in many areas, ranging from tests of the Standard Model to searches for new particles. Among other results the physics highlights have been the measurements of the W-, Z-boson and t t-bar production cross-sections, improved limits on supersymmetric and other hypothetical particles and the observation of jet-quenching, elliptical flow and J/Psi suppression in lead-lead collisions at sqrt(sNN) = 2.76 TeV.Comment: 11 pages, 9 figures, invited brief review for Mod. Phys. Lett.

    Influência da corrosão no comportamento ao arrancamento de fibras de aço no betão auto-compactável

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    Quando adicionadas ao bet√£o, a possibilidade de corros√£o das fibras de a√ßo , devido √† penetra√ß√£o de cloretos e a√ß√£o da carbonata√ß√£o, √© um par√Ęmetro de durabilidade no bet√£o auto-compact√°vel refor√ßado com fibras de a√ßo (BACRFA) que requer especial aten√ß√£o. No BACRFA fendilhado, a corros√£o tende a ocorrer nas fibras de a√ßo que atravessam as fissuras, o que pode afetar o seu comportamento √† flex√£o. Deste modo, o estudo do comportamento interfacial fibra/matriz √© importante para a compreens√£o dos efeitos da corros√£o das fibras de a√ßo no comportamento mec√Ęnico e na durabilidade das estruturas de BACRFA. Com o intuito de avaliar estes efeitos, no presente trabalho desenvolveu-se um ensaio experimental de arrancamento de fibras de a√ßo em BAC fendilhado, sujeitas previamente √† a√ß√£o da corros√£o por exposi√ß√£o a um ambiente agressivo de cloretos, sendo a corros√£o avaliada por interm√©dio de t√©cnicas eletroqu√≠micas. Os ensaios eletroqu√≠micos realizados revelaram que a probabilidade de corros√£o das fibras de a√ßo num ambiente com cloretos √© superior a 90%. No mesmo ambiente, a susceptibilidade para a corros √£o das fibras de a√ßo que atravessam uma pseudo-fissura, aumenta com a abertura de fissura provocando um aumento da resist√™ncia ao arranque da fibra em BAC fissuradoQREN, n√ļmero 23024, denominado INOTEC, que envolve a empresa CiviTest e o ISISE/Universidade do Minho. O primeiro autor agradece a bolsa de investiga√ß√£o concedida pelo referido projeto. √Ä Maccaferri e Radmix pelo fornecimento das fibras de a√ßo, √† Sika pelo superplastificante, √† Secil pelo cimento e √† Omya Comital pelo F√≠ler calc√°ri

    Extrapolation of Multiplicity distribution in p+p(\bar(p)) collisions to LHC energies

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    The multiplicity (N_ch) and pseudorapidity distribution (dN_ch/d\eta) of primary charged particles in p+p collisions at Large Hadron Collider (LHC) energies of \sqrt(s) = 10 and 14 TeV are obtained from extrapolation of existing measurements at lower \sqrt(s). These distributions are then compared to calculations from PYTHIA and PHOJET models. The existing \sqrt(s) measurements are unable to distinguish between a logarithmic and power law dependence of the average charged particle multiplicity () on \sqrt(s), and their extrapolation to energies accessible at LHC give very different values. Assuming a reasonably good description of inclusive charged particle multiplicity distributions by Negative Binomial Distributions (NBD) at lower \sqrt(s) to hold for LHC energies, we observe that the logarithmic \sqrt(s) dependence of are favored by the models at midrapidity. The dN_ch/d\eta versus \eta for the existing measurements are found to be reasonably well described by a function with three parameters which accounts for the basic features of the distribution, height at midrapidity, central rapidity plateau and the higher rapidity fall-off. Extrapolation of these parameters as a function of \sqrt(s) is used to predict the pseudorapidity distributions of charged particles at LHC energies. dN_ch/d\eta calculations from PYTHIA and PHOJET models are found to be lower compared to those obtained from the extrapolated dN_ch/d\eta versus \eta distributions for a broad \eta range.Comment: 11 pages and 13 figures. Substantially revised and accepted for publication in Journal of Physics

    Percutaneous balloon mitral valvuloplasty in comparison with open mitral valve commissurotomy for mitral stenosis during pregnancy

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    OBJECTIVES We sought to compare the maternal and fetal outcomes of patients with severe mitral stenosis submitted to percutaneous balloon dilation Versus open mitral valve commissurotomy (MVC) during pregnancy.BACKGROUND Heart failure in patients with mitral stenosis complicating pregnancy is a common problem in developing countries. Since 1984, percutaneous dilation of the mitral valve using a balloon catheter has become a therapeutic alternative to open heart surgery. Although the efficacy of percutaneous mitral valve balloon dilation is well established, its results have never before been compared viith the results of commissurotomy during pregnancy.METHODS We compared the clinical and obstetric complications in 45 women who were treated with percutaneous mitral valve balloon dilation (group I, n = 21; from 1990 to 1995) or open MVC (group II, n = 24; from 1985 to 1990) for severe heart failure due to mitral stenosis during pregnancy.RESULTS in our study, percutaneous balloon dilation of the mitral. valve had a success rate of 95% (Gorlin formula) and 90.5% (echocardiographic pressure half-time method), as demonstrated by the final mitral valve area achieved. This improvement was followed by a marked decrease in the mitral valve gradient, left atrial pressure and mean pulmonary artery pressure. Patients in both groups had similar improvements in symptoms. Patients who underwent percutaneous balloon dilation had significantly fewer fetal complications, with a reduction in fetal and neonatal mortality (1 death in group I vs. 8 in group II, p = 0.025).CONCLUSIONS Percutaneous balloon mitral valvuloplasty is safe and effective and appears to be preferable for the fetus, compared with open MVC during pregnancy. (J Am Coil Cardiol 2001;37:900-3) (C) 2001 by the American College of Cardiology.Universidade Federal de S√£o Paulo, Dept Cardiol, S√£o Paulo, BrazilUniversidade Federal de S√£o Paulo, Dept Cardiovasc Surg, S√£o Paulo, BrazilSt Vincents Hosp & Med Ctr, Comprehens Cardiovasc Ctr, New York, NY 10011 USAUniversidade Federal de S√£o Paulo, Dept Cardiol, S√£o Paulo, BrazilUniversidade Federal de S√£o Paulo, Dept Cardiovasc Surg, S√£o Paulo, BrazilWeb of Scienc

    An Elastic Multi-Core Allocation Mechanism for Database Systems

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    During the parallel execution of queries in Non-Uniform Memory Access (NUMA) systems, he Operating System (OS) maps the threads (or processes) from modern database systems to the available cores among the NUMA nodes using the standard node-local policy. However, such non-smart mapping may result in inefficient memory activity, because shared data may be accessed by scattered threads requiring large data movements or non-shared data may be allocated to threads sharing the same cache memory, increasing its conflicts. In this paper we present a data-distribution aware and elastic multi-core allocation mechanism to improve the OS mapping of database threads in NUMA systems. Our hypothesis is that we mitigate the data movement if we only hand out to the OS the local optimum number of cores in specific nodes. We propose a mechanism based on a rule-condition-action pipeline that uses hardware counters to promptly find out the local optimum number of cores. Our mechanism uses a priority queue to track the history of the memory address space used by database threads in order to decide about the allocation/release of cores and its distribution among the NUMA nodes to decrease remote memory access. We implemented and tested a prototype of our mechanism when executing two popular Volcano-style databases improving their NUMA-affinity. For MonetDB, we show maximum speedup of 1.53 √ó , due to consistent reduction in the local/remote per-query data traffic ratio of up to 3.87 √ó running 256 concurrent clients in the 1 GB TPC-H database also showing system energy savings of 26.05%. For the NUMA-aware SQL Server, we observed speedup of up to 1.27 √ó and reduction on the data traffic ratio of 3.70 √ó

    EST√ĀGIO SUPERVISIONADO EM CI√äNCIAS CONT√ĀBEIS: EMPRESA DE PRODU√á√ÉO DE MOLDES DE GARRAFAS PET

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    O Presente trabalho foi apresentado para a conclus√£o do componente curricular do Est√°gio Supervisionado no curso de Ci√™ncias Cont√°beis. Para tanto, constitui-se uma empresa de responsabilidade limitada, com atividade industrial e forma de tributa√ß√£o do Lucro Real, com raz√£o social R&H Moldes Ltda., voltada ao ramo de fabrica√ß√£o de moldes para Ind√ļstria de pl√°sticos, pe√ßas e acess√≥rios, especializada na produ√ß√£o de moldes para garrafa PET. O Objetivo do trabalho foi aliar todo o conhecimento adquirido em sala de aula com a parte pr√°tica da contabilidade. Na primeira etapa da fase do est√°gio, por meio de pesquisa e visitas a empresas do ramo, foi poss√≠vel a elabora√ß√£o da ficha t√©cnica dos produtos e processo produtivo, da estrutura de produ√ß√£o e de pessoal. Tamb√©m buscou-se compreender a legisla√ß√£o espec√≠fica para o produto e para a forma de tributa√ß√£o da pr√≥pria empresa. Ainda, foi necess√°rio identificar os custos com o pessoal, com mat√©ria-prima, gastos gerais e despesas, c√°lculo da margem de contribui√ß√£o, do pre√ßo de venda e do ponto de equil√≠brio. Na segunda etapa do trabalho, foi efetuada toda a escritura√ß√£o cont√°bil do trabalho planejado, afim de apresentar os resultados atrav√©s de demonstrativos cont√°beis no per√≠odo de um trimestre. Desta forma, foi poss√≠vel desenvolver habilidades e compet√™ncias inerentes ao profissional cont√°bil e determinar os resultados de uma empresa que industrializa moldes pelos m√©todos de sopro com base na realidade pesquisada
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