1,095 research outputs found

    Equilibrium Relativistic Mass Distribution

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    The relativistic Maxwell-Boltzmann distribution for the system of NN events with motion in space-time parametrized by an invariant ``historical time'' τ\tau is considered without the simplifying approximation m2M2m^2\cong M^2, where MM is a given intrinsic property of the events. The relativistic mass distribution is obtained and the average values of mm and m2m^2 are calculated. The average value of the energy in nonrelativistic limit gives a correction of the order of 10\% to the Dulong-Petit law. Expressions for the pressure and the density of events are obtained and the ideal gas law is recovered.Comment: TAUP-2048-9

    Grid approximation of a singularly perturbed boundary value problem modelling heat transfer in the case of flow over a flat plate with suction of the boundary layer

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    AbstractIn the present paper we consider a boundary value problem on the semiaxis (0,∞) for a singularly perturbed parabolic equation with the two perturbation parameters ε1 and ε2 multiplying, respectively, the second and first derivatives with respect to the space variable. Depending on the relation between the parameters, the differential equation can be either of reaction–diffusion type or of convection–diffusion type. Correspondingly, the boundary layer can be either parabolic or regular. For this problem we consider the case when the boundary layer can be controlled by continuous suction of the fluid out of the boundary layer (model problems of this type appear in the mathematical modelling of heat transfer processes for flow past a flat plate). Errors in the approximations generated by standard numerical methods can be unsatisfactorily large for small values of the parameter ε1. We construct a monotone finite difference scheme on piecewise uniform meshes which generates numerical solutions converging ε-uniformly with order O(N−1lnN+N0−1), where N0 is the number of nodes in the time mesh and N is the number of meshpoints on a unit interval of the semiaxis in x. Although the solution of problem has a singularity only for ε1→0, the character of the boundary layer depends essentially on the vector-valued parameter ε=(ε1,ε2). This prevents us from constructing an ε-uniformly convergent scheme having a transition parameter which is independent of the parameter ε2

    Mcl-1 and bax in the fetal ovary: studies of the undernourished pregnant ewe

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    Mcl-1 and bax in the fetal ovary: studies of the undernourished pregnant ewe

    Nucleation versus Spinodal decomposition in a first order quark hadron phase transition

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    We investigate the scenario of homogeneous nucleation for a first order quark-hadron phase transition in a rapidly expanding background of quark gluon plasma. Using an improved preexponential factor for homogeneous nucleation rate, we solve a set of coupled equations to study the hadronization and the hydrodynamical evolution of the matter. It is found that significant supercooling is possible before hadronization begins. This study also suggests that spinodal decomposition competes with nucleation and may provide an alternative mechanism for phase conversion particularly if the transition is strong enough and the medium is nonviscous. For weak enough transition, the phase conversion may still proceed via homogeneous nucleation.Comment: LaTeX, 10 pages with 7 Postscript figures, more discussions and referencese added, typos correcte

    Detection of relic gravitational waves in the CMB: Prospects for CMBPol mission

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    Detection of relic gravitational waves, through their imprint in the cosmic microwave background radiation, is one of the most important tasks for the planned CMBPol mission. In the simplest viable theoretical models the gravitational wave background is characterized by two parameters, the tensor-to-scalar ratio rr and the tensor spectral index ntn_t. In this paper, we analyze the potential joint constraints on these two parameters, rr and ntn_t, using the potential observations of the CMBPol mission, which is expected to detect the relic gravitational waves if r0.001r\gtrsim0.001. The influence of the contaminations, including cosmic weak lensing, various foreground emissions, and systematical errors, is discussed.Comment: 26 pages, 19 figures, 4 tables; JCAP in pres

    Stem cell factor (SCF) and c-kit in the ovine fetal testis in normal and nutrition perturbed pregnancies

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    Stem cell factor (SCF) and c-kit in the ovine fetal testis in normal and nutrition perturbed pregnancie

    A New Relativistic High Temperature Bose-Einstein Condensation

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    We discuss the properties of an ideal relativistic gas of events possessing Bose-Einstein statistics. We find that the mass spectrum of such a system is bounded by μm2M/μK,\mu \leq m\leq 2M/\mu _K, where μ\mu is the usual chemical potential, MM is an intrinsic dimensional scale parameter for the motion of an event in space-time, and μK\mu _K is an additional mass potential of the ensemble. For the system including both particles and antiparticles, with nonzero chemical potential μ,\mu , the mass spectrum is shown to be bounded by μm2M/μK,|\mu |\leq m\leq 2M/\mu _K, and a special type of high-temperature Bose-Einstein condensation can occur. We study this Bose-Einstein condensation, and show that it corresponds to a phase transition from the sector of continuous relativistic mass distributions to a sector in which the boson mass distribution becomes sharp at a definite mass M/μK.M/\mu _K. This phenomenon provides a mechanism for the mass distribution of the particles to be sharp at some definite value.Comment: Latex, 22 page

    Cationic lipid-based nanoparticles mediate functional delivery of acetate to tumor cells in vivo leading to significant anticancer effects

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    Metabolic reengineering using nanoparticle delivery represents an innovative therapeutic approach to normalizing the deregulation of cellular metabolism underlying many diseases, including cancer. Here, we demonstrated a unique and novel application to the treatment of malignancy using a short-chain fatty acid (SCFA)-encapsulated lipid-based delivery system – liposome-encapsulated acetate nanoparticles for cancer applications (LITA-CAN). We assessed chronic in vivo administration of our nanoparticle in three separate murine models of colorectal cancer. We demonstrated a substantial reduction in tumor growth in the xenograft model of colorectal cancer cell lines HT-29, HCT-116 p53+/+ and HCT-116 p53-/-. Nanoparticle-induced reductions in histone deacetylase gene expression indicated a potential mechanism for these anti-proliferative effects. Together, these results indicated that LITA-CAN could be used as an effective direct or adjunct therapy to treat malignant transformation in vivo

    Homogeneous nucleation of quark-gluon plasma, finite size effects and long-lived metastable objects

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    The general formalism of homogeneous nucleation theory is applied to study the hadronization pattern of the ultra-relativistic quark-gluon plasma (QGP) undergoing a first order phase transition. A coalescence model is proposed to describe the evolution dynamics of hadronic clusters produced in the nucleation process. The size distribution of the nucleated clusters is important for the description of the plasma conversion. The model is most sensitive to the initial conditions of the QGP thermalization, time evolution of the energy density, and the interfacial energy of the plasma-hadronic matter interface. The rapidly expanding QGP is first supercooled by about ΔT=TTc=46\Delta T = T - T_c = 4-6 %. Then it reheats again up to the critical temperature T_c. Finally it breaks up into hadronic clusters and small droplets of plasma. This fast dynamics occurs within the first 510fm/c5-10 fm/c. The finite size effects and fluctuations near the critical temperature are studied. It is shown that a drop of longitudinally expanding QGP of the transverse radius below 4.5 fm can display a long-lived metastability. However, both in the rapid and in the delayed hadronization scenario, the bulk pion yield is emitted by sources as large as 3-4.5 fm. This may be detected experimentally both by a HBT interferometry signal and by the analysis of the rapidity distributions of particles in narrow p_T-intervals at small p_T on an event-by-event basis.Comment: 29 pages, incl. 12 figures and 1 table; to be published in Phys. Rev.
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