1,676 research outputs found

    Casimir Energy for a Wedge with Three Surfaces and for a Pyramidal Cavity

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    Casimir energy calculations for the conformally coupled massless scalar field for a wedge defined by three intersecting planes and for a pyramid with four triangular surfaces are presented. The group generated by reflections are employed in the formulation of the required Green functions and the wave functions.Comment: Latex, 9 page

    slq(2)sl_q(2) Realizations for Kepler and Oscillator Potentials and q-Canonical Transformations

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    The realizations of the Lie algebra corresponding to the dynamical symmetry group SO(2,1) of the Kepler and oscillator potentials are q-deformed. The q-canonical transformation connecting two realizations is given and a general definition for q-canonical transformation is deduced. q-Schr\"{o}dinger equation for a Kepler like potential is obtained from the q-oscillator Schr\"{o}dinger equation. Energy spectrum and the ground state wave function are calculated.Comment: 12 pages, Latex twice, (Comparison with the other approaches and some refs. added. The version which will appear in J. Phys. A

    Implications of Geographic Information System in Mapping Solid Waste Collection Points in New Owerri, Imo State

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    The unsanitary condition in which solid waste is temporarily dumped and disposed of has generated environmental concern through pollutions and health hazards. This calls for a need to map out suitable collection points and disposal point for effective and efficient management of solid waste to promote hygienic environment. Therefore, GIS offers solution in this regard as a decision support system for most suitable site selection. Consequently, different layers (roads, stream and land use) were created to serve the purpose of manipulation and analyses to procure most suitable site for collection point of solid waste generated in New Owerri, Imo State using Arc view 3.2a software

    Macroscopic Quantum Tunneling of a Bose Condensate

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    We study, by means of a variational method, the stability of a condensate in a magnetically trapped atomic Bose gas with a negative scattering length and find that the condensate is unstable in general. However, for temperatures sufficiently close to the critical temperature the condensate turns out to be metastable. For that case we determine in the usual WKB approximation the decay rate of the condensate due to macroscopic quantum fluctuations. When appropriate, we also calculate the decay rate due to thermal fluctuations. An important feature of our approach is that (nonsingular) phase fluctuations of the condensate are taken into account exactly.Comment: Invited paper for the Journal of Statistical Physic

    Boundary Shape and Casimir Energy

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    Casimir energy changes are investigated for geometries obtained by small but arbitrary deformations of a given geometry for which the vacuum energy is already known for the massless scalar field. As a specific case, deformation of a spherical shell is studied. From the deformation of the sphere we show that the Casimir energy is a decreasing function of the surface to volume ratio. The decreasing rate is higher for less smooth deformations.Comment: 12 page

    Are Leaf Traits Stable Enough to Rank Native Grasses in Contrasting Growth Conditions?

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    The growing interest in classifying species in response groups relating to variations in environmental factors has triggered the search for functional traits that express differences in ecological behaviour among plant species (Lavorel & Garnier, 2002). Specific leaf area (SLA) and leaf dry matter content (LDMC) reflect a fundamental trade-off in plant functioning between a fast growth rate (high SLA, low LDMC species) and nutrient conservation (low SLA, high LDMC species). This study aimed to analyse the stability of ranking native grasses by SLA and LDMC values under different plant growing conditions

    Exact propagators for atom-laser interactions

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    A class of exact propagators describing the interaction of an NN-level atom with a set of on-resonance δ\delta-lasers is obtained by means of the Laplace transform method. State-selective mirrors are described in the limit of strong lasers. The ladder, V and Λ\Lambda configurations for a three-level atom are discussed. For the two level case, the transient effects arising as result of the interaction between both a semi-infinite beam and a wavepacket with the on-resonance laser are examined.Comment: 13 pages, 6 figure

    Extraction of isoflavones from different raw sources using natural deep eutectic solvents

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    This research was partially supported by RFBR 17-03-00641 and the Ministry of Education of the Russian Federation within the framework of the basic part of the state task, Project No. 4.9514.2017 / 8.9
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