3,000 research outputs found
New results on the spectroscopy of XYZ states from LHC experiments
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
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
Quando adicionadas ao betão, a possibilidade de corrosão das fibras
de aço , devido à penetração de cloretos e ação da
carbonatação, é um parâmetro de durabilidade no betão auto-compactável reforçado com fibras de aço (BACRFA) que requer especial atenção.
No BACRFA fendilhado, a corrosão tende a ocorrer nas fibras de aço que atravessam as
fissuras,
o que pode afetar o seu comportamento à flexão.
Deste modo, o
estudo do comportamento interfacial
fibra/matriz é importante para a compreensão dos efeitos da corrosão das fibras de aço no comportamento mecânico 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 aço em BAC fendilhado, sujeitas
previamente
à ação da corrosão
por exposição a um ambiente agressivo de cloretos, sendo
a corrosão
avaliada por intermédio de técnicas
eletroquímicas.
Os ensaios
eletroquímicos
realizados revelaram
que
a probabilidade de
corrosão das fibras de aço num
ambiente com cloretos é superior a 90%. No mesmo ambiente, a susceptibilidade para a corros
ão das fibras de aço que
atravessam uma pseudo-fissura, aumenta com a abertura de fissura
provocando um aumento da
resistência ao arranque
da fibra em BAC fissuradoQREN, número 23024, denominado INOTEC, que envolve a empresa
CiviTest e o ISISE/Universidade do Minho. O primeiro autor agradece a bolsa
de investigação concedida pelo referido projeto. À Maccaferri e Radmix pelo fornecimento das fibras de aço, à Sika pelo superplastificante, à Secil pelo cimento e à Omya Comital pelo Fíler calcári
Extrapolation of Multiplicity distribution in p+p(\bar(p)) collisions to LHC energies
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
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 São Paulo, Dept Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, São Paulo, BrazilSt Vincents Hosp & Med Ctr, Comprehens Cardiovasc Ctr, New York, NY 10011 USAUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, São Paulo, BrazilWeb of Scienc
An Elastic Multi-Core Allocation Mechanism for Database Systems
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 × , due to consistent reduction in the local/remote per-query data traffic ratio of up to 3.87 × 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 × and reduction on the data traffic ratio of 3.70 ×
ESTÁGIO SUPERVISIONADO EM CIÊNCIAS CONTÁBEIS: EMPRESA DE PRODUÇÃO DE MOLDES DE GARRAFAS PET
O Presente trabalho foi apresentado para a conclusão do componente curricular do Estágio Supervisionado no curso de Ciências Contábeis. Para tanto, constitui-se uma empresa de responsabilidade limitada, com atividade industrial e forma de tributação do Lucro Real, com razão social R&H Moldes Ltda., voltada ao ramo de fabricação de moldes para Indústria de plásticos, peças e acessórios, especializada na produção de moldes para garrafa PET. O Objetivo do trabalho foi aliar todo o conhecimento adquirido em sala de aula com a parte prática da contabilidade. Na primeira etapa da fase do estágio, por meio de pesquisa e visitas a empresas do ramo, foi possível a elaboração da ficha técnica dos produtos e processo produtivo, da estrutura de produção e de pessoal. Também buscou-se compreender a legislação específica para o produto e para a forma de tributação da própria empresa. Ainda, foi necessário identificar os custos com o pessoal, com matéria-prima, gastos gerais e despesas, cálculo da margem de contribuição, do preço de venda e do ponto de equilíbrio. Na segunda etapa do trabalho, foi efetuada toda a escrituração contábil do trabalho planejado, afim de apresentar os resultados através de demonstrativos contábeis no período de um trimestre. Desta forma, foi possível desenvolver habilidades e competências inerentes ao profissional contábil e determinar os resultados de uma empresa que industrializa moldes pelos métodos de sopro com base na realidade pesquisada
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