2,717 research outputs found
A semiclassical model of light mesons
The dominantly orbital state description is applied to the study of light
mesons. The effective Hamiltonian is characterized by a relativistic kinematics
supplemented by the usual funnel potential with a mixed scalar and vector
confinement. The influence of two different finite quark masses and potential
parameters on Regge and vibrational trajectories is discussed.Comment: 1 figur
Filling and wetting transitions of nematic liquid crystals on sinusoidal substrates
Close to sinusoidal substrates, simple fluids may undergo a filling
transition, in which the fluid passes from a dry to a filled state, where the
interface remains unbent but bound to the substrate. Increasing the surface
field, the interface unbinds and a wetting transition occurs. We show that this
double-transition sequence may be strongly modified in the case of ordered
fluids, such as nematic liquid crystals. Depending on the preferred orientation
of the nematic molecules at the structured substrate and at the
isotropic-nematic interface, the filling transition may not exist, and the
fluid passes directly from a dry to a complete-wet state, with the interface
far from the substrate. More interestingly, in other situations, the complete
wetting transition may be prevented, and the fluid passes from a dry to a
filled state, and remains in this configuration, with the interface always
attached to the substrate, even for very large surface fields. Both transitions
are only observed for a same substrate in a narrow range of amplitudes
H1N1 disseminated infection in a 3-month-old boy
Earlier this year a new influenza virus emerged. In children, the clinical manifestations of H1N1 infection are similar to those reported during periods of seasonal influenza. We report on a 3-month-old boy with an upper respiratory tract infection who presented enteropathy, coagulopathy and encephalitis related to H1N1. The infection was confirmed in nasopharyngeal aspirate, stools and cerebrospinal fluid by real-time PCR. Treatment with oseltamivir was started.info:eu-repo/semantics/publishedVersio
Pentaquarks in the Jaffe-Wilczek approximation
The masses of , and pentaquarks are
evaluated in a framework of both the Effective Hamiltonian approach to QCD and
spinless Salpeter using the Jaffe--Wilczek diquark approximation and the string
interaction for the diquark--diquark--antiquark system. The pentaquark masses
are found to be in the region above 2 GeV. That indicates that the Goldstone
boson exchange effects may play an important role in the light pentaquarks. The
same calculations yield the mass of pentaquark 3250 MeV
and pentaquark 6509 MeV.Comment: 14 pages, 2 tables, LaTeX2e. References correcte
Structural and Microanalytical Studies of CrO2 Thin Films on c-Sapphire by High Resolution Electron Microscopy Methods
Chromium dioxide (CrO2) has been extensively used in the magnetic recording industry. However, it is its ferromagnetic half-metallic nature that has more recently attracted much attention, primarily for the development of spintronic devices. CrO2 is the only stoichiometric binary oxide theoretically predicted to be fully spin polarized at the Fermi level. It presents a Curie temperature of ∼ 396 K, i.e. well above room temperature, and a magnetic moment of 2 mB per formula unit. However an antiferromagnetic native insulating layer of Cr2O3 is always present on the CrO2 surface which enhances the CrO2 magnetoresistance and might be used as a barrier in magnetic tunnel junctions
Quantum repeaters and quantum key distribution: analysis of secret key rates
We analyze various prominent quantum repeater protocols in the context of
long-distance quantum key distribution. These protocols are the original
quantum repeater proposal by Briegel, D\"ur, Cirac and Zoller, the so-called
hybrid quantum repeater using optical coherent states dispersively interacting
with atomic spin qubits, and the Duan-Lukin-Cirac-Zoller-type repeater using
atomic ensembles together with linear optics and, in its most recent extension,
heralded qubit amplifiers. For our analysis, we investigate the most important
experimental parameters of every repeater component and find their minimally
required values for obtaining a nonzero secret key. Additionally, we examine in
detail the impact of device imperfections on the final secret key rate and on
the optimal number of rounds of distillation when the entangled states are
purified right after their initial distribution.Comment: Published versio
Cardiopulmonary complications in a patient with bezoar
We report a case of a 17-year-old institutionalised male with a medical history of fragile X syndrome, bilateral congenital glaucoma, cataracts and pica disorder. He was transferred to our paediatric intensive care unit owing to respiratory failure and hypotension. On transoesophageal echocardiogram, he presented left atrium compression. A CT of the thorax and mediastinum revealed an unknown heterogeneous material in the lumen of the stomach and oesophagus, with a lung parenchyma suggestive of alveolar foreign material. Endoscopic evaluation showed diaper fragments inside the oesophagus and stomach. Fragmentation and suction of diaper material was made. Medical treatment was performed with inotropic support, conventional mechanical ventilation and antibiotics
Punctuated equilibrium theory in Brazilian public policy: the case of Ceará
Este artigo faz uma análise do processo de decisão orçamental dos municÃpios do Estado do Ceará. Através deste estudo, procura-se perceber em que medida a distribuição dos orçamentos aos governos locais sofrem (ou não) variações. Já em um segundo momento, tenta-se depreender quais as receitas de cada um dos municÃpios (as variáveis independentes) que melhor descrevem e auxiliam a opção polÃtica de investimento local (esta será a variável dependente). Considerando o perÃodo de 2006 a 2010 e fazendo uso de um desenho de pesquisa de tipo transversal, conclui-se que nos governos locais do Ceará o investimento público apresenta perÃodos de estabilidade seguido por perÃodos de grande alteração dos orçamentos – confirmando a hipótese de pesquisa. Estas conclusões confirmam os pressupostos da teoria do equilÃbrio pontuado. Conclui-se igualmente que o investimento público que vem sendo realizado é dependente das transferências que a União faz para os governos locais do Estado do Ceará e das receitas de capital. Face a estas condições, é pertinente equacionar até que nÃvel e grau o endividamento pode ocorrer em virtude da escassez cada vez maior do financiamento público.This research aims to analyze the budget decision process in
Ceará municipalities in order to understand in which
way budget distributions change (or not) during the research period under consideration. This research also aims
to understand which revenues (the independent variables) of each municipality better expla
in the political choices
for local government investments (the dependent variable). Making use of data from 2006 to 2010 and using a
cross
-
sectional research design, the study concludes a stability in local government investments periods of stress
where su
ch investments have both positive and negative significant fluctuations
–
confirming our working
hypothesis. These results confirm punctuated Equilibrium Theory assumptions and also find that local government
public investment is dependent on money transfe
rs from the central government and also from capital revenues.
Thus, it is important to question to what degree public indebtedness should be allowed, due to a scarcity of public
fundsinfo:eu-repo/semantics/publishedVersio
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