On Generalized Fractional Kinetic Equations

In a recent paper, Saxena et al. [1] developed the solutions of three generalized fractional kinetic equations in terms of Mittag-Leffler functions. The object of the present paper is to further derive the solution of further generalized fractional kinetic equations. The results are obtained in a compact form in terms of generalized Mittag-Leffler functions. Their relation to fundamental laws of physics is briefly discussed.Comment: 10 pages, LaTe

Ontology–based Representation of Simulation Models

Ontologies have been used in a variety of domains for multiple purposes such as establishing common terminology, organizing domain knowledge and describing domain in a machine-readable form. Moreover, ontologies are the foundation of the Semantic Web and often semantic integration is achieved using ontology. Even though simulation demonstrates a number of similar characteristics to Semantic Web or semantic integration, including heterogeneity in the simulation domain, representation and semantics, the application of ontology in the simulation domain is still in its infancy. This paper proposes an ontology-based representation of simulation models. The goal of this research is to facilitate comparison among simulation models, querying, making inferences and reuse of existing simulation models. Specifically, such models represented in the domain simulation engine environment serve as an information source for their representation as instances of an ontology. Therefore, the ontology-based representation is created from existing simulation models in their proprietary file formats, consequently eliminating the need to perform the simulation modeling directly in the ontology. The proposed approach is evaluated on a case study involving the I2Sim interdependency simulator

Vortex-Antivortex Pair Production in a First Order Phase Transition

We carry out numerical simulation of a first order phase transition in 2+1 dimensions by randomly nucleating bubbles, and study the formation of global U(1) vortices. Bubbles grow and coalesce and vortices are formed at junctions of bubbles via standard Kibble mechanism as well as due to a new mechanism, recently proposed by us, where defect-antidefect pairs are produced due to field oscillations. We make a comparative study of the contribution of both of these mechanisms for vortex production. We find that, for high nucleation rate of bubbles, vortex-antivortex pairs produced via the new mechanism have overlapping configurations, and annihilate quickly; so only those vortices survive till late which are produced via the Kibble mechanism. However, for low nucleation rates, bubble collisions are energetic enough to lead to many well separated vortex-antivortex pairs being produced via the new mechanism. For example, in a simulation involving nucleation of 20 bubbles, a total of 14 non-overlapping vortices and antivortices formed via this new mechanism of pair creation (6 of them being very well separated), as compared to 6 vortices and antivortices produced via the Kibble mechanism. Our results show the possibility that in extremely energetic bubble collisions, such as those in the inflationary models of the early Universe, this new mechanism may drastically affect the defect production scenario.Comment: 8 pages, Revtex, 14 figures. Figs.1a,b and 5a,d are included, rest are availaible on reques

Defect Production in Slow First Order Phase Transitions

We study the formation of vortices in a U(1) gauge theory following a first-order transition proceeding by bubble nucleation, in particular the effect of a low velocity of expansion of the bubble walls. To do this, we use a two-dimensional model in which bubbles are nucleated at random points in a plane and at random times and then expand at some velocity $v_{\rm b}<c$. Within each bubble, the phase angle is assigned one of three discrete values. When bubbles collide, magnetic `fluxons' appear: if the phases are different, a fluxon--anti-fluxon pair is formed. These fluxons are eventually trapped in three-bubble collisions when they may annihilate or form quantized vortices. We study in particular the effect of changing the bubble expansion speed on the vortex density and the extent of vortex--anti-vortex correlation.Comment: 13 pages, RevTeX, 15 uuencoded postscript figure

Pt-imbalance in dimuon+jet production as a signal of partonic energy loss in heavy ion collisions at LHC

We consider a hard jet production tagged by a muon pair in ultrarelativistic heavy ion collisions. The process cross section is calculated by the CompHEP Monte-Carlo generator taking into account full gamma*/Z interference pattern at LHC energies. We have found that reasonable statistics, ~1000 events per 1 month of LHC run with lead beams, can be expected for realistic geometrical acceptance and kinematic cuts. The transverse momentum imbalance due to interactions of jet partons in the medium is evaluated for mu+mu-pair+jet correlation, as well as for the correlation between mu+mu- pair and a leading particle in a jet. Theoretical and experimental uncertainties of these observables are discussed.Comment: 17 pages in LaTeX including 5 eps-figure

Harnessing the capabilities of spray granulation in the food industry for the production of functional foods

The article is the literature review of a current state of production technologies of powdery foodstuff, concentrates and multicomponent mixes. The need of the food industry for qualitative methods of processing of raw materials of different physical and chemical structure is noted. The authors give the reasons about need and possibility of a choice of granulation as a method of data processing of products. Physical and chemical features of granulation methods of disperse environments of various aggregate states based on the studied regularities and works of other authors are considered. The authors made the assumption of the application prospects of the method of liquid dispersion on the surface of particles in a suspended state for a granulation of foodstuff and they offered the alternative option. The possibility to use whey as binding element is considered. At the end of article authors draw the conclusion about the prospects of use of a method of dispersion of liquid on the surface of particles in a suspended state for a granulation of foodstuff

Measuring Cosmic Defect Correlations in Liquid Crystals

From the theory of topological defect formation proposed for the early universe, the so called Kibble mechanism, it follows that the density correlation functions of defects and anti-defects in a given system should be completely determined in terms of a single length scale $\xi$, the relevant domain size. Thus, when lengths are expressed in units of $\xi$, these distributions should show universal behavior, depending only on the symmetry of the order parameter, and space dimensions. We have verified this prediction by analyzing the distributions of defects/anti-defects formed in the isotropic-nematic phase transition in a thin layer of nematic liquid crystals. Our experimental results confirm this prediction and are in reasonable agreement with the results of numerical simulations.Comment: 15 pages, 4 figures, minor changes, few new references adde

Multiwavelength Observations of Supersonic Plasma Blob Triggered by Reconnection Generated Velocity Pulse in AR10808

Using multi-wavelength observations of Solar and Heliospheric Observatory (SoHO)/Michelson Doppler Imager (MDI), Transition Region and Coronal Explorer (TRACE) 171 \AA, and H$\alpha$ from Culgoora Solar Observatory at Narrabri, Australia, we present a unique observational signature of a propagating supersonic plasma blob before an M6.2 class solar flare in AR10808 on 9th September 2005. The blob was observed between 05:27 UT to 05:32 UT with almost a constant shape for the first 2-3 minutes, and thereafter it quickly vanished in the corona. The observed lower bound speed of the blob is estimated as $\sim$215 km s$^{-1}$ in its dynamical phase. The evidence of the blob with almost similar shape and velocity concurrent in H$\alpha$ and TRACE 171 \AA\ supports its formation by multi-temperature plasma. The energy release by a recurrent 3-D reconnection process via the separator dome below the magnetic null point, between the emerging flux and pre-existing field lines in the lower solar atmosphere, is found to be the driver of a radial velocity pulse outwards that accelerates this plasma blob in the solar atmosphere. In support of identification of the possible driver of the observed eruption, we solve the two-dimensional ideal magnetohydrodynamic equations numerically to simulate the observed supersonic plasma blob. The numerical modelling closely match the observed velocity, evolution of multi-temperature plasma, and quick vanishing of the blob found in the observations. Under typical coronal conditions, such blobs may also carry an energy flux of 7.0$\times10^{6}$ ergs cm$^{-2}$ s$^{-1}$ to re-balance the coronal losses above active regions.Comment: Solar Physics; 22 Pages; 8 Figure

Neutron scattering study of the layered Ising magnet CsDy(MoO₄)₂

The quasi-two-dimensional antiferromagnet CsDy(MoO₄)₂ is studied by neutron diffraction and quasielastic neutron scattering. The crystal structure of two low-temperature phases (below 120 K and below 40 K) is determined. An approximate structure of the magnetically ordered phase (TN = 1.36 K) is proposed. In the ordered state the order-parameter critical exponent β = 0.17(0.01), the in-plane correlation length exponent ν = 0.94(0.07), and the staggered susceptibility critical index γ= 1.01(0.04) were determined. Comparing these results to the exact solution for a 2D Ising magnet we conclude that, although 2D behavior is apparent in CsDy(MoO₄)₂, there are deviations from the simple 2D Ising model

Towards the Theory of Cosmological Phase Transitions

We discuss recent progress (and controversies) in the theory of finite temperature phase transitions. This includes the structure of the effective potential at a finite temperature, the infrared problem in quantum statistics of gauge fields, the theory of formation of critical and subcritical bubbles and the theory of bubble wall propagation.Comment: 50 p