2,464,118 research outputs found

    Kinetics of Deposition of Oriented Superdisks

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    We use numerical Monte Carlo simulation to study kinetics of deposition of oriented superdisks, bounded by the Lame curves of the form x2p+y2p=1|x|^{2p}+|y|^{2p}=1, on regular planar substrate. It was recently shown that the maximum packing density, as well as jamming density ρJ\rho_{J}, exhibit discontinuous derivative at p=0.5p=0.5, when the shape changes from convex to concave form. By careful examination of the late-stage approach to the jamming limit, we find that the leading term in temporal development is also nonanalytic at p=0.5p=0.5, and offer heuristic excluded-area arguments for this behavior

    In Vitro Fertility of Post-thawed Epididymal Ram Spermatozoa After Storage at 5 °C Before Cryopreservation

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    This study addressed the effects of storage duration of epididymides at 5 °C before sperm collection and their fertility after cryopreservation in vitro. Spermatozoa from one of the testes pairs were immediately collected, evaluated and frozen (control group). The remaining epididymides were cooled to 5 °C and stored for 24, 48, 72, and 96 h (experimental groups), after which spermatozoa were collected and frozen as in the control group. Before and after thawing, sperm motility, sperm viability and plasma membrane integrity were assessed. The fertilizing ability of frozen-thawed spermatozoa of each group was evaluated by in vitro fertilization of matured sheep oocytes. Sperm quality (sperm motility, viability, and plasma membrane integrity) at collection and after cryopreservation decreased as the duration of the epididymal storage interval increase (P < 0.05). The motility decreased steadily along the studied time periods. Although, the fertilizing ability of post-thawed epididymal spermatozoa gradually decreased as the storage period was prolonged, the spermatozoa collected from the cauda epididymides stored at 5 °C for up to 96 h were able to fertilize 16%-65% of oocytes in vitro. Results of the present study showed that ram epididymal spermatozoa survive in storage at 5 °C for up to 96 h. These spermatozoa maintain their fertilizing ability and may be suitable for use in IVF and other assisted reproductive procedures

    3D Jet Tomography of Twisted Strongly Coupled Quark Gluon Plasmas

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    The triangular enhancement of the rapidity distribution of hadrons produced in p+A reactions relative to p+p is a leading order in A^{1/3}/log(s) violation of longitudinal boost invariance at high energies. In A+A reactions this leads to a trapezoidal enhancement of the local rapidity density of produced gluons. The local rapidity gradient is proportional to the local participant number asymmetry, and leads to an effective rotation in the reaction plane. We propose that three dimensional jet tomography, correlating the long range rapidity and azimuthal dependences of the nuclear modification factor, R_{AA}(\eta,\phi,p_\perp; b>0), can be used to look for this intrinsic longitudinal boost violating structure of A+AA+A collisions to image the produced twisted strongly coupled quark gluon plasma (sQGP). In addition to dipole and elliptic azimuthal moments of R_{AA}, a significant high p_\perp octupole moment is predicted away from midrapidity. The azimuthal angles of maximal opacity and hence minima of R_{AA} are rotated away from the normal to the reaction plane by an `Octupole Twist' angle, \theta_3(\eta), at forward rapidities.Comment: 10 Pages, 16 Figures, RevTex, Replaced with Peer reviewed verion for PR

    The ρ±ρ0\rho^{\pm}-\rho^0 Mass Splitting Problem

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    It is discussed the problem of the ρ±ρ0\rho^\pm-\rho^0 mass splitting. It is suggested to use the ϕρπ3π\phi\to\rho\pi\to 3\pi decay to measure the ρ±ρ0\rho^{\pm}-\rho^0 mass splitting.Comment: 7 pages, revtex, a few typos fixed, to be published in Pis'ma v ZHETF, V. 69, No 1, pp. 8-11, 10 January 199

    D=11 supergravity with manifest supersymmetry

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    The complete supersymmetric action for eleven-dimensional supergravity is presented. The action is polynomial in the scalar fermionic pure spinor superfield, and contains only a minor modification to the recently proposed three-point coupling.Comment: 14 pp., plain te

    Weak ferromagnetism and spiral spin structures in honeycomb Hubbard planes

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    Within the Hartree Fock- RPA analysis, we derive the spin wave spectrum for the weak ferromagnetic phase of the Hubbard model on the honeycomb lattice. Assuming a uniform magnetization, the polar (optical) and acoustic branches of the spin wave excitations are determined. The bipartite lattice geometry produces a q-dependent phase difference between the spin wave amplitudes on the two sub-lattices. We also find an instability of the uniform weakly magnetized configuration to a weak antiferromagnetic spiraling spin structure, in the lattice plane, with wave vector Q along the Gamma-K direction, for electron densities n>0.6. We discuss the effect of diagonal disorder on both the creation of electron bound states, enhancement of the density of states, and the possible relevance of these effects to disorder induced ferromagnetism, as observed in proton irradiated graphite.Comment: 13 pages, 7 figure

    A survey on performance analysis of warehouse carousel systems

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    This paper gives an overview of recent research on the performance evaluation and design of carousel systems. We discuss picking strategies for problems involving one carousel, consider the throughput of the system for problems involving two carousels, give an overview of related problems in this area, and present an extensive literature review. Emphasis has been given on future research directions in this area
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