Effect of Waste Heat Recovery on Drying Characteristics of Sliced Ginger in a Natural Convection Dryer

AbstractIn the present work, quality drying characteristics of sliced ginger were studied utilizing the concept of waste heat recovery in a biomass operated natural convection dryer with sensible heat storage material (SHSM) and phase change material (PCM). Ginger slices (2 and 4mm thick) were dried from initial moisture content (MC) 88-90% (w.b.) to final moisture content 11-12% (w.b.) with hot air maintained at temperature 600C, air velocity 0.2m/sec, atmospheric average relative humidity 74% and ambient temperature 250C. It was observed that the biomass consumption and melting time of PCM were significantly reduced due to the use of waste heat. The optimum drying time was found to be 5.5h for 2mm thick ginger slices. Color, texture and aroma were found better in treated sample

Flux vacua with approximate flat directions

We present a novel method to obtain type IIB flux vacua with flat directions at tree level. We perform appropriate choices of flux quanta that induce relations between the flux superpotential and its derivatives. This method is implemented in toroidal and Calabi-Yau compactifications in the large complex structure limit. Explicit solutions are obtained and classified on the basis of duality equivalences. In the toroidal case we present solutions with N = 1 and N = 2 supersymmetry and arbitrarily weak coupling. In Calabi-Yaus we find novel perturbatively flat vacua, as well as solutions with non-zero flux superpotential and an axionic flat direction which represent a promising starting point for de Sitter constructions from non-zero F-terms in the complex structure sector. The higher order (perturbative and non-perturbative) effects that can lift these flat directions are discussed. We also outline applications in a wide variety of settings involving the classical Regge growth conjecture, inflation and quintessence, supersymmetry breaking and F-term de Sitter uplifting

Quantification of Fluoride Contamination of Groundwater Sources in Parts of Guwahati City, Assam, India: An Assessment of Hazard to Human Health

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Multiscale interaction with topography and extreme rainfall events in the northeast Indian region

Flash floods associated with extreme rain events are a major hydrological disaster in the northeast Indian (NEI) region because of the unique topographic features of the region as well as increased frequency of occurrence of such events. Knowledge of the spatiotemporal distribution of these events in the region and an understanding of the factors responsible for them, therefore, would be immensely useful for appropriate disaster preparedness. Using daily rainfall data from 15 stations over the region for 32 years (1975-2006), it is shown that the frequency of occurrence of these events is largest not during the premonsoon thunderstorm season but during the peak monsoon months (June-July-August). This fact together with the fact that most of these events occur during long rainy spells indicate that the extreme events in the NEI region largely occur in association with the monsoon synoptic events rather than isolated thunderstorms. We also find that the aggregate of extreme rain events over the region has a significant decreasing trend in contrast to a recent finding of an increasing trend of such events in central India (Goswami et al., 2006). This decreasing trend of extreme events is consistent with observed decreasing trend in convective available potential energy and increasing convective inhibition energy over the region for the mentioned period. Examination of the structure of convection associated with the extreme rain events in the region indicates that they occur through a multiscale interaction of circulation with the local topography. It is found that at all the stations, the events are associated with a mesoscale structure of convection that is embedded in a much larger scale convective organization. We identify that this large-scale organization is a manifestation of certain phases of the tropical convergence zone associated with the northward propagating active-break phases of the summer monsoon intraseasonal oscillation. Further, it is shown that the mesoscale circulation interacting with the local topography generates southward propagating gravity waves with diurnal period. The strong updrafts associated with the gravity waves within the mesoscale organization leads to very deep convective events and the extreme rainfall. The insights provided by our study would be useful when designing models to improve the prediction of extreme events

Unitarity constraints on the stabilized Randall-Sundrum scenario

Recently proposed stabilization mechanism of the Randall-Sundrum metric gives rise to a scalar radion, which couples universally to matter with a weak interaction ($\simeq 1$ TeV) scale. Demanding that gauge boson scattering as described by the effective low enerrgy theory be unitary upto a given scale leads to significant constraints on the mass of such a radion.Comment: 10 page Latex 2e file including 4 postscript figures. Accepted in Journal of Physics

Radion effects on unitarity in gauge-boson scattering

The scalar field associated with fluctuations in the positions of the two branes, the ``radion'', plays an important role determining the cosmology and collider phenomenology of the Randall-Sundrum solution to the hierarchy problem. It is now well known that the radion mass is of order the weak scale, and that its couplings to standard model fields are order 1/TeV to the trace of the energy momentum tensor. We calculate longitudinal vector boson scattering amplitudes to explore the constraints on the radion mass and its coupling from perturbative unitarity. The scattering cross section can indeed become non-perturbative at energies prior to reaching the TeV brane cutoff scale, but only when some curvature-Higgs mixing on the TeV brane is present. We show that the coefficient of the curvature-Higgs mixing operator must be less than about 3 for the 4-d effective theory to respect perturbative unitarity up to the TeV brane cutoff scale. Mass bounds on the Higgs boson and the radion are also discussed.Comment: 17 pages, LaTeX, 5 eps figures, uses epsf.sty and axodraw.st

String Thermodynamics In and Out of Equilibrium: Boltzmann Equations and Random Walks

We revisit the study of string theory close to the Hagedorn temperature with the aim towards cosmological applications. We consider interactions of open and closed strings in a gas of D$p-$branes, and/or one isolated D$p$-brane, in an arbitrary number $d$ of flat non-compact dimensions and general compact dimensions. Leading order string perturbation theory is used to obtain the basic interaction rates in a flat background, which are shown to be consistent with the random walk picture of highly excited strings that should apply in more general backgrounds. Using the random walk interpretation we infer the structure of more general semi-inclusive string scattering rates and then write down the corresponding Boltzmann equations describing ensembles of highly excited closed and open strings. We organise the interaction terms in Boltzmann equations so that detailed balance becomes manifest. We obtain the equilibrium solutions and show that they reduce to previously computed solutions for $d=0$. We further study the behaviour of non-equlibrium fluctuations and find explicit analytic expressions for the equilibration rates (and for the number of open strings in $d=0$). Potential implications for an early universe with strings at high temperatures are outlined.Comment: 32 pages + Appendix. 3 figure

Indian Forage Scenario – Region Wise Availability and Deficit

In India, rapid urbanisation, changing food habit and higher purchasing power have increased the demand for animal based food products.Proper feeding strategies using green nutritious fodderis key to increase livestock production and productivity in economical and sustainable way.Three major sources of fodder are crop residues, cultivated fodder from arable land (irrigated and rainfed) and fodder from common property resources like forests, permanent pastures, grazing lands, cultivated wasteland, fallow lands etc. Based on the livestock census, we estimated the green and dry fodder availability vis-a-vis demand and emerging deficit/surplus situation. The state wise livestock population for Cattle, Buffaloes, Goat, Sheep, Yak and Mithun were taken into account and the requirement for green, dry forage and animal feed concentrate was worked out considering factors like age, milking or non-milking state, gender, working nature, feeding practices etc. The availability of green forages was estimated based on cultivated area under forage, cropping intensity, productivity etc., green fodder from fallow land, wasteland, forest fringe areas, social forestry, pasture land. For dry fodder, availability of crop residue for fodder was calculated based on the major utilizable cereals, pulses and oilseed crops, harvest index, production, and utilization pattern. Availability of dry forages from forest, wasteland, fallow land and cultivated field after harvest available for grazing were considered. On all India basis, there is an overall deficit of nearly 11 % in green fodder availability and 23 % in dry fodder availability. To meet the deficit scenario various strategies are proposed which includea national programme in mission mode for accelerating production; grassland and grazing policy; rejuvenation of degraded pastures; targeted research and extension programme; entrepreneurship in commercial venture of fodder production and utilization