Plasmon Annihilation into Kaluza-Klein Graviton: New Astrophysical Constraints on Large Extra Dimensions

In large extra dimensional Kaluza-Klein (KK) scenario, where the usual Standard Model (SM) matter is confined to a 3+1-dimensional hypersurface called the 3-brane and gravity can propagate to the bulk (D=4+d, d being the number of extra spatial dimensions), the light graviton KK modes can be produced inside the supernova core due to the usual nucleon-nucleon bremstrahlung, electron-positron and photon-photon annihilations. This photon inside the supernova becomes plasmon due to the plasma effect. In this paper, we study the energy-loss rate of SN 1987A due to the KK gravitons produced from the plasmon-plasmon annihilation. We find that the SN 1987A cooling rate leads to the conservative bound $M\_D$ > 22.9 TeV and 1.38 TeV for the case of two and three space-like extra dimensions.Comment: 13 pages, 1 ps figure, text is modified a little bit, conclusion unchanged, new references are added, version accepted for publication in PR

Development of Shelf-Stable Brined Vegetables by Lactic Acid Fermentation

Preservation of vegetables, viz., bitter gourd, carrot, capsicum, cucumber, French bean and gherkin by lactic acid fermentation was attempted. Properly prepared vegetables, packed in brine containing 2.5% equilibrated salt with additives, were allowed to undergo fermentation by their natural flora and this was compared with pure culture fermentation by Lactobacillus plantarum. Fermented vegetables had 0.5 to 1.31% lactic acid, with pH values ranging from 2.97 to 4.02, at the end of 4 weeks of fermentation at 20 ± 2°C. In general, fermentation by L. plantarum resulted in a slightly faster rate of acid production compared to that by natural flora. Mustard powder at 1% concentration was found to be useful as alternate preservative in vegetable fermentation. Fermented vegetables had acceptable quality in terms of colour, texture, flavour, taste and were microbiologically stable for six months of storage at room temperature (25 ± 8°C)

Remediation of Contaminated Soils by Solvent Flushing

Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the release rates of the contaminants. A simulation model is developed to predict contaminant elution curves during solvent flushing for the case of one‐dimensional, steady flow through a contaminated medium. Column experiments are conducted with a Eustis fine sand that is initially equilibrated with an aqueous naphthalene solution, and then eluted with different methanol‐water mixtures to remove the naphthalene. The model simulations, based on parameter values estimated from literature data, agree well with the measured elution profiles. Solvent flushing experiments, where the soil was initially equilibrated with a solution of naphthalene and anthracene, show that compounds with different retardation factors are separated at low cosolvent contents, while coelution of the compounds occurs at higher contents. In general, the smaller the retardation factor in water and the higher the cosolvent fraction, the faster the contaminant is recovered. The presence of nonequilibrium conditions, soil heterogeneity, and type of cosolvent will influence the time required to recover the contaminant.\u

Antimicrofouling activity of Calotropis gigantea (L). R. Br.

1843-1848Milkweed or Calotropis gigantea belongs to Asclepiadaceae family having many curative principles in it. This present work aimed to study the phytochemicals prevailing in the Calotropis gigantea during the summer season by GCMS method and some of these phytochemicals tested against the collagen-binding matrix protein (4CN8) produced by the bacterial foulant through computational method. The result of GCMS analysis revealed that the prevalence of stigmasterol, alpha-amyrin, urs-12-en-24-oic acid, 3-oxo-, methyl ester, (+)-, 2(1H) Naphthalenone, 3,5,6,7,8, 8a-hexahydro-4, 8a-dimethyl-6-(1-ethylethenyl)-, Beta.-Amyrin, Bicyclo [3.1.1] heptane,2,6,6-trimethyl-, 1R-(1.alpha., 2.beta., 5.alpha.) -and 1H-Indene, 5-butyl-6-hexyloctahydro-, 2-[3-(4-tert-Butyl-phenoxy)-2-hydroxy-propylsulfanyl]-4,6-dimethyl-nicotinonitrile and cyclopropane carboxamide, 2-cyclopropyl-2-methyl-N-(1-cyclopropylethyl)- and pyridine-3-carboxamide, oxime, N-(2-trifluoro methyl phenyl). The in silico study exhibited that all the screened phytochemicals are having remarkably good interaction with the tested 4CN8 and possessing-8 to-11 Kcal/mol docking energy except pyridine-3-carboxamide, oxime, N-(2-trifluoromethylphenyl). Hence, the phytochemicals of Calotropis is a right candidate for further elaborate study to establish an eco-friendly alternative to existing toxic antifouling chemicals

A novel dual-leg DC-DC converter for wide range DC-AC conversion

This paper proposes DC–AC Dual-leg dual-stage Conversion (DDC) and DC–AC Direct single-stage conversions (DSC). Conventional energy conversion system has only two-stage conversion, so it has some drawbacks such as huge power loss, less conversion range and lower power rating. So direct conversion, dual-leg step-up and step-up conversions are the solutions to get wide voltage conversion efficiently. The proposed converter can perform the power conversion from battery DC supply into AC with 1:1 ratio, step-up AC, and step-down AC in both directions. Also, it can perform rectifier operation from grid AC supply into DC with 1:1 ratio, step-down DC, and step-up DC. Step-up, step-down and ideal operations are possible within a single circuit; its operation is similar to solid-state DC–AC/AC–DC transformer. The ideal operation, Step-down to Step-up conversion and Step-up to Step-down conversion are possible on both sides, so this converter can handle a wide range of voltage. Power distribution is achieved with voltage regulation between battery/DC-load and AC-load/grid using the proposed control strategy with proper modulation. A prototype model of a 2-kW power rating validates the advantages and feasibility of the proposed methodology

PROTEUS two-dimensional Navier-Stokes computer code, version 1.0. Volume 2: User's guide

A new computer code was developed to solve the two-dimensional or axisymmetric, Reynolds averaged, unsteady compressible Navier-Stokes equations in strong conservation law form. The thin-layer or Euler equations may also be solved. Turbulence is modeled using an algebraic eddy viscosity model. The objective was to develop a code for aerospace applications that is easy to use and easy to modify. Code readability, modularity, and documentation were emphasized. The equations are written in nonorthogonal body-fitted coordinates, and solved by marching in time using a fully-coupled alternating direction-implicit procedure with generalized first- or second-order time differencing. All terms are linearized using second-order Taylor series. The boundary conditions are treated implicitly, and may be steady, unsteady, or spatially periodic. Simple Cartesian or polar grids may be generated internally by the program. More complex geometries require an externally generated computational coordinate system. The documentation is divided into three volumes. Volume 2 is the User's Guide, and describes the program's general features, the input and output, the procedure for setting up initial conditions, the computer resource requirements, the diagnostic messages that may be generated, the job control language used to run the program, and several test cases

PROTEUS two-dimensional Navier-Stokes computer code, version 1.0. Volume 1: Analysis description

A new computer code was developed to solve the two-dimensional or axisymmetric, Reynolds averaged, unsteady compressible Navier-Stokes equations in strong conservation law form. The thin-layer or Euler equations may also be solved. Turbulence is modeled using an algebraic eddy viscosity model. The objective was to develop a code for aerospace applications that is easy to use and easy to modify. Code readability, modularity, and documentation were emphasized. The equations are written in nonorthogonal body-fitted coordinates, and solved by marching in time using a fully-coupled alternating direction-implicit procedure with generalized first- or second-order time differencing. All terms are linearized using second-order Taylor series. The boundary conditions are treated implicitly, and may be steady, unsteady, or spatially periodic. Simple Cartesian or polar grids may be generated internally by the program. More complex geometries require an externally generated computational coordinate system. The documentation is divided into three volumes. Volume 1 is the Analysis Description, and describes in detail the governing equations, the turbulence model, the linearization of the equations and boundary conditions, the time and space differencing formulas, the ADI solution procedure, and the artificial viscosity models

Coupled-mode theory for periodic side-coupled microcavity and photonic crystal structures

We use a phenomenological Hamiltonian approach to derive a set of coupled mode equations that describe light propagation in waveguides that are periodically side-coupled to microcavities. The structure exhibits both Bragg gap and (polariton like) resonator gap in the dispersion relation. The origin and physical significance of the two types of gaps are discussed. The coupled-mode equations derived from the effective field formalism are valid deep within the Bragg gaps and resonator gaps.Comment: 13 pages, 6 figure

PROTEUS two-dimensional Navier-Stokes computer code, version 1.0. Volume 3: Programmer's reference

A new computer code was developed to solve the 2-D or axisymmetric, Reynolds-averaged, unsteady compressible Navier-Stokes equations in strong conservation law form. The thin-layer or Euler equations may also be solved. Turbulence is modeled using an algebraic eddy viscosity model. The objective was to develop a code for aerospace applications that is easy to use and easy to modify. Code readability, modularity, and documentation were emphasized. The equations are written in nonorthogonal body-fitted coordinates, and solved by marching in time using a fully-coupled alternating-direction-implicit procedure with generalized first- or second-order time differencing. All terms are linearized using second-order Taylor series. The boundary conditions are treated implicitly, and may be steady, unsteady, or spatially periodic. Simple Cartesian or polar grids may be generated internally by the program. More complex geometries require an externally generated computational coordinate system. The documentation is divided into three volumes. Volume 3 is the Programmer's Reference, and describes the program structure, the FORTRAN variables stored in common blocks, and the details of each subprogram