479 research outputs found

    Three Dimensional Simulation of Jet Formation in Collapsing Condensates

    Full text link
    We numerically study the behavior of collapsing and exploding condensates using the parameters of the experiments by E.A. Donley et al. [Nature, 412, 295, (2001)]. Our studies are based on a full three-dimensional numerical solution of the Gross-Pitaevskii equation (GPE) including three body loss. We determine the three body loss rate from the number of remnant condensate atoms and collapse times and obtain only one possible value which fits with the experimental results. We then study the formation of jet atoms by interrupting the collapse and find very good agreement with the experiment. Furthermore we investigate the sensitivity of the jets to the initial conditions. According to our analysis the dynamics of the burst atoms is not described by the GPE with three body loss incorporated.Comment: 9 pages, 10 figure

    Measurement of the (90,91,92,93,94,96)Zr(n,gamma) and (139)La(n,gamma) cross sections at n_TOF

    Get PDF
    Open AccessNeutron capture cross sections of Zr and La isotopes have important implications in the field of nuclear astrophysics as well as in the nuclear technology. In particular the Zr isotopes play a key role for the determination of the neutron density in the He burning zone of the Red Giant star, while the (139)La is important to monitor the s-process abundances from Ba up to Ph. Zr is also largely used as structural materials of traditional and advanced nuclear reactors. The nuclear resonance parameters and the cross section of (90,91,92,93,94,96)Zr and (139)La have been measured at the n_TOF facility at CERN. Based on these data the capture resonance strength and the Maxwellian-averaged cross section were calculated

    Measurements of high-energy neutron-induced fission of (nat)Pb and (209)Bi

    Get PDF
    This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0, which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly citedThe CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV

    Prevalence of the metabolic syndrome in Luxembourg according to the Joint Interim Statement definition estimated from the ORISCAV-LUX study

    Get PDF
    ABSTRACT: BACKGROUND: The prevalence of the metabolic syndrome (MS) has been determined in many countries worldwide but never in Luxembourg. This research aimed to 1) establish the gender- and age-specific prevalence of MS and its components in the general adult population of Luxembourg, according to the most recent Joint Interim Statement (JIS) definition, by using both the high and low cut-off points to define abdominal obesity, and 2) compare and assess the degree of agreement with the Revised National Cholesterol Education Programme-Adult Treatment Panel III (R-ATPIII) and the International Diabetes Federation (IDF) definitions. METHODS: A representative stratified random sample of 1349 European subjects, aged 18-69 years, participated to ORISCAV-LUX survey. Logistic regression and odds ratios (OR) were used to study MS prevalence with respect to gender and age. The Framingham risk score (FRS) to predict the 10-year coronary heart disease (CHD) risk was calculated to compare the proportion of MS cases below or above 20%, according to both high and low waist circumference (WC) thresholds. Cohen's kappa coefficient (kappa) was utilized to measure the degree of agreement between MS definitions. RESULTS: The prevalence of the MS defined by the JIS was 28.0% and 24.7% when using the low (94/80) and the high (102/88) WC cut-off points, respectively. The prevalence was significantly higher in men than in women (OR = 2.6 and 2.3 for the low and high WC thresholds), as were all components of the MS except abdominal obesity measured by both thresholds. It also increased with age (OR values in age categories ranging from 2.7 to 28 when compared to the younger subjects for low WC and from 3.3 to 31 for the high WC cut-offs). The 10-year predicted risk of CHD by FRS did not depend on the threshold used. Globally, excellent agreement was observed between the three definitions of MS (kappa= 0.89), in particular between JIS and IDF (kappa = 0.93). Agreement was significantly higher in women than in men, and differed between age groups. CONCLUSION: Regardless of the definition used, the adult population of Luxembourg reveals a high MS prevalence. Our findings contribute to build evidence regarding the definitive construct of the MS, to help selecting the waist circumference thresholds for Europid populations, and to support the need to revise the guidelines for abdominal obesity levels

    A inserção do Brasil no mercado mundial de alumĂ­nio: incorporando contribuiçÔes da Ecologia PolĂ­tica para a SaĂșde Coletiva

    Get PDF
    O presente artigo discute a inserção do Brasil no mercado mundial de alumĂ­nio a partir dos referenciais teĂłricos da ecologia polĂ­tica, da economia polĂ­tica do territĂłrio e da saĂșde coletiva. A conjuntura contemporĂąnea da economia mundial tem sido pautada pela desregulamentação e liberalização, caracterĂ­sticos do ideĂĄrio neoliberal propalado pelas naçÔes centrais. A maior participação do Brasil nesse mercado tem sido realizada a partir do aumento da produção e exportação de commodities agrĂĄrias e metĂĄlicas, como o alumĂ­nio. Nesse sentido, a partir dos paradigmas da ecologia polĂ­tica, o texto propĂ”e uma anĂĄlise das consequĂȘncias socioambientais, assim como sobre novas territorialidades que se produzem e reproduzem dentro de uma lĂłgica econĂŽmica que privilegia as naçÔes centrais. Do mesmo modo, procura-se compreender os dilemas da saĂșde coletiva sob uma perspectiva holĂ­stica e integradora na qual se articula aos modelos de desenvolvimento econĂŽmico. Percebe-se que a produção e exportação de alumĂ­nio primĂĄrio, apesar de apresentar um valor agregado maior, esconde um conjunto difuso de impactos que afetam o ambiente e a saĂșde coletiva
    • 

    corecore