Perturbations in a Bouncing Brane Model

The question of how perturbations evolve through a bounce in the Cyclic and Ekpyrotic models of the Universe is still a matter of ongoing debate. In this report we show that the collision between boundary branes is in most cases singular even in the full 5-D formalism, and that first order perturbation theory breaks down for at least one perturbation variable. Only in the case that the boundary branes approach each other with constant velocity shortly before the bounce, can a consistent, non singular solution be found. It is then possible to follow the perturbations explicitly until the actual collision. In this case, we find that if a scale invariant spectrum developed on the hidden brane, it will get transferred to the visible brane during the bounce.Comment: 15 pages, minor modifications, a few typos correcte

The Cosmology of Massless String Modes

We consider the spacetime dynamics of a gas of closed strings in the context of General Relativity in a background of arbitrary spatial dimensions. Our motivation is primarily late time String Gas Cosmology, where such a spacetime picture has to emerge after the dilaton has stabilized. We find that after accounting for the thermodynamics of a gas of strings, only string modes which are massless at the self-dual radius are relevant, and that they lead to a dynamics which is qualitatively different from that induced by the modes usually considered in the literature. In the context of an ansatz with three large spatial dimensions and an arbitrary number of small extra dimensions, we obtain isotropic stabilization of these extra dimensions at the self-dual radius. This stabilization occurs for fixed dilaton, and is induced by the special string states we focus on. The three large dimensions undergo a regular Friedmann-Robertson-Walker expansion. We also show that this framework for late-time cosmology is consistent with observational bounds.Comment: 15 pages, no figures, references added (again

Target space duality and moduli stabilization in String Gas Cosmology

Motivated by string gas cosmology, we investigate the stability of moduli fields coming from compactifications of string gas on torus with background flux. It was previously claimed that moduli are stabilized only at a single fixed point in moduli space, a self-dual point of T-duality with vanishing flux. Here, we show that there exist other stable fixed points on moduli space with non-vanishing flux. We also discuss the more general target space dualities associated with these fixed points.Comment: 12 pages, 1 figur

Participatory cotton breeding for organic and low input farming in Central India

Up to 80% of world’s organic cotton is produced in India. However, involved producers are facing increased difficulties to find suitable cultivars. Few hybrids selected for high input farming and genetically-modified (GM) cotton, which is explicitly excluded in organic farming, are presently dominating the Indian seed market. In addition farmers have lost their traditional knowledge on seed production and hybrid seed needs to be purchased each season

Two phase detonation studies

An experimental study of the passage of a shock wave over a burning fuel drop is described. This includes high speed framing photographs of the interaction taken at 500,000 frames per second. A theoretical prediction of the ignition of a fuel drop by a shock wave is presented and the results compared with earlier experimental work. Experimental attempts to generate a detonation in a liquid fuel drop (kerosene)-liquid oxidizer drop (hydrogen peroxide)-inert gas-environment are described. An appendix is included which gives the analytical prediction of power requirements for the drop generator to produce certain size drops at a certain mass rate. A bibliography is also included which lists all of the publications resulting from this research grant

Efficient E-Wastage Management in Information Technology for Sustainable Growth

The exponential growth of manufacturing industry is mainly driven by electronic industry which in turn produces e wastage as a by-product. The term "waste" is defined for materials, objects which is dumped by the customer rather than recycled, which includes residue from reuse and recycling operations. Electronic waste [1], or e-waste, is a term coined for electronic products that have turned as unnecessary, non-working, unusable or have become obsolete, and have effectively reached the end of their functional life. As the technology is growing at high speed, much of electronic devices become e-waste after a very short period from the day when the product is manufactured. In fact, the collection of old electronic substances is the largest contributor to the e-waste. E-waste consists of computers, laptops and mobile phones with obsolete hardware and software, monitors, printers, TVs, CD players etc. The management of e-waste is essential and need of the hour as electronic devices often contain dangerous substances which can be life threatening and environmental unfriendly. Solving the e–waste management problem begins with schooling and the habit changes as a result of gaining the knowledge. In this paper an attempt is made to address the problem by an efficient work flow model

Evolution of the Kondo resonance feature and its relationship to spin-orbit coupling across the quantum critical point in Ce2Rh{1-x}CoxSi3

We investigate the evolution of the electronic structure of Ce2Rh{1-x}CoxSi3 as a function of x employing high resolution photoemission spectroscopy. Co substitution at the Rh sites in antiferromagnetic Ce2RhSi3 leads to a transition from an antiferromagnetic system to a Kondo system, Ce2CoSi3 via the Quantum Critical Point (QCP). High resolution photoemission spectra reveal distinct signature of the Kondo resonance feature (KRF) and its spin orbit split component (SOC) in the whole composition range indicating finite Kondo temperature scale at the quantum critical point. We observe that the intensity ratio of the Kondo resonance feature and its spin orbit split component, KRF/SOC gradually increases with the decrease in temperature in the strong hybridization limit. The scenario gets reversed if the Kondo temperature becomes lower than the magnetic ordering temperature. While finite Kondo temperature within the magnetically ordered phase indicates applicability of the spin density wave picture at the approach to QCP, the dominant temperature dependence of the spin-orbit coupled feature suggests importance of spin-orbit interactions in this regime.Comment: 6 figure

FORMULATION AND IN VITROEVALUATION OF FLOATING TABLETS OF CEFPODOXIME PROXETIL

Objective: The objective of research work was to formulate and evaluate the floating drug delivery system containing Cefpodoxime Proxetil using polymer HPMC K4M, Guar Gum.Methods: Effervescent floating tablets containing Cefpodoxime proxetil were prepared by direct compression technique using varying concentrations of different grades of polymer.Results: Physical parameters like hardness, weight variation, thickness and friability were within pharmacopoeial limit. Percentage drug content in all floating tablet formulations was found to be 90% to 110%. The floating time was found to be more than 12 H. floating lag time was found to be 10±2.99 second. Formulation batch F8 was selected as an optimum formulation, as possessing less disintegration time, higher water absorption ratio and good content uniformity i.e. within acceptable limit.% drug release of formulation batch F8 was found to be 96.66% in 0.1 N HCL.Conclusion: The FT-IR studies of batch F8 was carried out which showed the peak values within the spectrum corresponding to the peak values of pure drug

Vibrating Winding Branes, Wrapping Democracy and Stabilization of Extra Dimensions in Dilaton Gravity

We show that, in the context of dilaton gravity, a recently proposed democratic principle for intersection possibilities of branes winding around extra dimensions yield stabilization, even with the inclusion of momentum modes of the wrapped branes on top of the winding modes. The constraints for stabilization massaged by string theory inputs forces the number of observed dimensions to be three. We also discuss consequences of adding ordinary matter living in the observed dimensions.Comment: Added a section discussing the linear and non-linear stability of the equilibrium point of the scale factors of the extra dimensions. Corrected a typo in the original field equations and other typos. Added and changed references. Final version appeared in JHE