27,768 research outputs found

    Response to Comment on "Pairing and Phase Separation in a Polarized Fermi Gas"

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    Zwierlein and Ketterle rely on subjective arguments and fail to recognize important differences in physical parameters between our experiment and theirs. We stand by the conclusions of our original report

    Entanglement enhancement and postselection for two atoms interacting with thermal light

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    The evolution of entanglement for two identical two-level atoms coupled to a resonant thermal field is studied for two different families of input states. Entanglement enhancement is predicted for a well defined region of the parameter space of one of these families. The most intriguing result is the possibility of probabilistic production of maximally entangled atomic states even if the input atomic state is factorized and the corresponding output state is separable.Comment: accepted for publication in J. Phys.

    Mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter within the relativistic impulse approximation

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    The mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter are investigated using the nucleon optical potential obtained within the relativistic impulse approximation with the empirical nucleon-nucleon scattering amplitudes and the nuclear densities obtained in the relativistic mean field model. It is found that the isospin-splitting of nucleon mean free paths, sensitive to the imaginary part of the symmetry potential, changes its sign at certain high kinetic energy. The in-medium nucleon-nucleon cross sections are analytically and numerically demonstrated to be essentially independent of the isospin asymmetry of the medium and increase linearly with density in the high energy region where the relativistic impulse approximation is applicable.Comment: 13 pages, 6 figure

    Analysis of Non Value Added Activity on Ship Production Process Approach Concept of Value Stream Mapping Case Study at PT. Dumas Tanjung Perak Shipyard Surabaya

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    Competition of shipyard industry market in this globalization era encourages companies to realize the importance of improving the effectiveness and efficiency so that, able to compete in terms of quality, cost and on time delivery. Production effectiveness is one effort that must be achieved by a shipbuilding industry to survive amid the competition in seizing market share. Production effectiveness is done with the aim of producing economically, continuously and on time to the customer, so that the company's survival can be guaranteed. This study aims to identify the activities that are classified as waste in the process of ship building at PT. Dumas Tanjung Perak Shipyard Surabaya so as to minimize production time in shipyard industry. The results showed the effectiveness of PT. DUMAS currently reaches 84.96%. In the process of improvement with the application of value stream mapping effectiveness value reached 92%. The conclusion of this research is a value stream mapping method can be applied measuring instrument and can describe the flow of production process in shipyard so that can explain in detail activity that give value added or non value added activity

    Probing the isospin dependence of the in-medium nucleon-nucleon cross sections with radioactive beams

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    Within a transport model we search for potential probes of the isospin dependence of the in-medium nucleon-nucleon (NN) cross sections. Traditional measures of the nuclear stopping power are found sensitive to the magnitude but they are ambiguous for determining the isospin dependence of the in-medium NN cross sections. It is shown that isospin tracers, such as the neutron/proton ratio of free nucleons, at backward rapidities/angles in nuclear reactions induced by radioactive beams in inverse kinematics is a sensitive probe of the isospin dependence of the in-medium NN cross sections. At forward rapidities/angles, on the other hand, they are more sensitive to the density dependence of the symmetry energy. Measurements of the rapidity/angular dependence of the isospin transport in nuclear reactions will enable a better understanding of the isospin dependence of in-medium nuclear effective interactions.Comment: 19 pages including 7 figures, submitted to Phys. Rev.

    Effect of symmetry energy on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei

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    Using an isospin-dependent transport model, we study the effects of nuclear symmetry energy on two-nucleon correlation functions in heavy ion collisions induced by neutron-rich nuclei. We find that the density dependence of the nuclear symmetry energy affects significantly the nucleon emission times in these collisions, leading to larger values of two-nucleon correlation functions for a symmetry energy that has a stronger density dependence. Two-nucleon correlation functions are thus useful tools for extracting information about the nuclear symmetry energy from heavy ion collisions.Comment: Revised version, to appear in Phys. Rev. Let

    τρππν\tau\to\rho\pi\pi\nu decays

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    Effective chiral theory of mesons is applied to study the four decay modes of τρππν\tau\to\rho\pi\pi\nu. Theoretical values of the branching ratios are in agreement with the data. The theory predicts that the a1a_{1} resonance plays a dominant role in these decays. There is no new parameter in this study.Comment: 12 pages and one figur

    Effet des prétraitemetns auxiniques sur la croissance des plants de gombo au Gabon

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    Le gombo est une plante maraîchère à usage alimentaire et médicinal au Gabon. La présente étude a été réalisée en vue d'induire la croissance de ce légume et d'accroitre la production. Des graines de gombo ont été prétraitées pendant 24 h dans 6 solutions d'auxine de concentrations entre 1 et 10-5M. Elles ont ensuite été mises en culture sous serre pendant 30 j. Les paramètres morphologiques de croissance suivants ont été évalués : la germination des graines, la croissance primaire et secondaire des tiges, ainsi que la surface foliaire des plants. Les résultats ont montré que les concentrations élevées d'auxine supérieures à 10-2M ont inhibé tous les paramètres morphométriques étudiés. Les doses auxiniques inférieures ou égales à 10-2M ont, par contre, stimulé la croissance de cette plante, proportionnellement à la concentration auxinique. Les traitements auxiniques de concentrations 10-2M peuvent donc être envisagés dans l'amélioration de la croissance des plants de gombo au Gabon.Okra is a nutritional and medicinal plant, widely cultivated in Gabon. The present study is undertaken in order to improve biomass' production. Hence, okra's seeds were pretreated by immersion in 6 auxin solutions during 24 h and cultivated under greenhouse conditions. Growth parameters, estimated 30 days after sowing, were: seed germination, longitudinal and diametric growths of the stem and leaf area. Results show that high concentrations of auxin (>10-2M) reduced the morphometric parameters of okra. But lowest concentrations (10-2M to 10-5M) increase all parameters measured proportionally to the level of the compound. Therefore, the use of auxin, at the lowest concentrations, of about 10-2M, may be envisioned in order to improve okra production in Gabon.Keywords : Auxin, okra, pretreatments, morphometric parameters, improvement, growth, Gabo

    Essai d’amélioration de la durée de conservation des aubergines aux températures ambiantes au Gabon

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    La conservation des fruits, particulièrement celle des aubergines, est difficile au Gabon, par manque de techniques d’entreposage appropriées. Les rares procédés utilisés sont coûteux et peu accessibles à la majeure partie de la population. La présente étude a été proposée pour tester l’efficacité de quelques méthodes simples susceptibles de servir d’alternative. Ce sont : les traitements des aubergines à la poudre des cendres et aux solutions de GA-3, de NaCl et d’huile d’arachide. Les paramètres de conservation étudiés étaient : la durée de stockage, les pertes de masse, de dureté et d’intégrité des organes. Les résultats ont montré que les traitements à l’huile d’arachide produisaient les meilleures conditions de conservation, avec des rallongements significatifs de durée de +18 jours, et des atténuations des pertes de masse, de dureté et d’intégrité. L’usage de cette technique peut donc être conseillé comme méthode de conservation valable des fruits d’aubergine.Mots clés: Fruits, traitements, huile d’arachide, durée, stockag
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