1,947 research outputs found

    Effect of Dust Particles on Rotating Micropolar Fluid Heated From Below Saturating a Porous Medium

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    This paper deals with the theoretical investigation of the effect of dust particles on a layer of rotating micropolar fluid heated from below saturating a porous medium. A dispersion relation is obtained for a flat fluid layer contained between two free boundaries using a linear stability analysis theory and normal mode analysis. The principle of exchange of stabilities is found to hold true for the micropolar fluid saturating a porous medium heated from below in the absence of dust particles, rotation and micropolar heat conduction parameter. The oscillatory modes are introduced due to the presence of the dust particles and rotation, which were non-existence in their absence. The presence of micropolar heat conduction parameter may also introduce oscillatory modes. For the case of stationary convection, the effect of various parameters like medium permeability, rotation, dust particles, coupling parameter, micropolar coefficient (A) and micropolar heat conduction parameter has been analyzed. The thermal Rayleigh number for the onset of instability is also determined numerically and results are depicted graphically. In the present paper, an attempt is also made to obtain the sufficient conditions for the non-existence of overstability

    Effect of Damping and Thermal Gradient on Vibrations of Orthotropic Rectangular Plate of Variable Thickness

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    In this present paper, damped vibrations of an orthotropic rectangular plate resting on elastic foundation with thermal gradient is modeled, considering variable thickness of plate. Following Le`vy approach, the governed equation of motion is solved numerically using quintic spline technique with clamped and simply supported edges. The effect of damping parameter and thermal gradient together with taper constant, density parameter and elastic foundation parameter on the natural frequencies of vibration for the first three modes of vibration are depicted through Tables and Figures, and mode shapes have been computed for fixed value of plate parameter. It has been observed that the rate of decrease of frequency parameter with damping parameter Dk for C-SS plate is higher than that for C-C plate keeping all other parameter fixed

    Effect of bio-composts on soil fertility status and productivity of organic farm: An approach to promote sustainable agriculture

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    The findings of this research provide information on various approaches to manage and maintain soil fertility for organic crop production through composting. The initial recorded data pertaining to various conventional farming practices showed very low soil fertility status, low productivity before the initiation of organic farming. In the year prior to 2006 pH was low (4.10) and it increased to 5.40 by 2006-07. Organic carbon percentage increased to 1.35 in 2006-07 and the value of phosphorus was very low in the previous year but increased in the year 2006-07 (6.00 Kg/ha) while Potassium value increased in the year 2006-07 (395.00 Kg/ha). Input use pattern of various composts was also evaluated and it was observed that higher rates of FYM was used in case of maize-wheat+gram (614.31q/ha) in 2006-07 while higher rates of vermicompost was used in case of soybean-pea system i.e 111.11 q/ha for the year 2006-07. It was found that in the year 2006-07, among the cereals, yield of wheat was the highest (15.56 q/ha), among pulses soybean dominated (13.04 q/ha). The yield of potato (74.88 q/ha) was the highest among vegetable crops. For the year 2007-08, the yield of wheat+ lentil was the highest (10.86 q/ha). Among the pulses again yield of soybean was the highest (6.14 q/ha) and potato showed the highest yield among vegetables (73.88 q/ha). It showed that the application of compost had direct effect on productivity as the application of compost in the year 2007-08 decreased the productivity decreased subsequently as compared to initial year i.e 2006-07

    Retroperitoneal germ cell tumor

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    The R-Process Alliance: A Comprehensive Abundance Analysis of HD 222925, a Metal-Poor Star with an Extreme R-Process Enhancement of [Eu/H] = -0.14

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    We present a detailed abundance analysis of the bright (V = 9.02), metal-poor ([Fe/H] = -1.47 +/- 0.08) field red horizontal-branch star HD 222925, which was observed as part of an ongoing survey by the R-Process Alliance. We calculate stellar parameters and derive abundances for 46 elements based on 901 lines examined in a high-resolution optical spectrum obtained using the Magellan Inamori Kyocera Echelle spectrograph. We detect 28 elements with 38 <= Z <= 90; their abundance pattern is a close match to the Solar r-process component. The distinguishing characteristic of HD 222925 is an extreme enhancement of r-process elements ([Eu/Fe] = +1.33 +/- 0.08, [Ba/Eu] = -0.78 +/- 0.10) in a moderately metal-poor star, so the abundance of r-process elements is the highest ([Eu/H] = -0.14 +/- 0.09) in any known r-process-enhanced star. The abundance ratios among lighter (Z <= 30) elements are typical for metal-poor stars, indicating that production of these elements was dominated by normal Type II supernovae, with no discernible contributions from Type Ia supernovae or asymptotic giant branch stars. The chemical and kinematic properties of HD 222925 suggest it formed in a low-mass dwarf galaxy, which was enriched by a high-yield r-process event before being disrupted by interaction with the Milky Way.Comment: Accepted for publication in the Astrophysical Journal (17 pages, 4 figures, 3 tables

    A study on phenological traits of Abies pindrow (Royle) Spach. in the different sites of Garhwal Himalayas, India

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    Phenology, the timing of various events in a species life cycle, is an important life history trait for both plants and animals. Dharali site situated in the highest altitudinal range i.e. 2800-3300 m above msl and showed the initiation of all the phenological characteristics i.e. leaf fall, leaf emergence, appearance of male and female strobili, pollination, cone maturation and seed dispersal in advance as compared to all the other sites. The comparison of the two years phenological data in all the sites (Mundali, Bhukki, Dheoban, Dharali) showed that in the year 2013 early leaf emergence, prolonged cone maturity and early seed dispersal were observed. Rise in temperature and change in climate in mountainous regions has caused the tree line to advance to higher elevations as temperatures have increased over the past few decades. In addition to changing their spatial distributions, plants are also chang-ing their temporal niches

    A robust liposomal platform for direct colorimetric detection of sphingomyelinase enzyme and inhibitors

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    The enzyme sphingomyelinase (SMase) is an important biomarker for several diseases such as Niemann Pick’s, atherosclerosis, multiple sclerosis, and HIV. We present a two-component colorimetric SMase activity assay that is more sensitive and much faster than currently available commercial assays. Herein, SMase-triggered release of cysteine from a sphingomyelin (SM)-based liposome formulation with 60 mol % cholesterol causes gold nanoparticle (AuNP) aggregation, enabling colorimetric detection of SMase activities as low as 0.02 mU/mL, corresponding to 1.4 pM concentration. While the lipid composition offers a stable, nonleaky liposome platform with minimal background signal, high specificity toward SMase avoids cross-reactivity of other similar phospholipases. Notably, use of an SM-based liposome formulation accurately mimics the natural in vivo substrate: the cell membrane. We studied the physical rearrangement process of the lipid membrane during SMase-mediated hydrolysis of SM to ceramide using small- and wide-angle X-ray scattering. A change in lipid phase from a liquid to gel state bilayer with increasing concentration of ceramide accounts for the observed increase in membrane permeability and consequent release of encapsulated cysteine. We further demonstrated the effectiveness of the sensor in colorimetric screening of small-molecule drug candidates, paving the way for the identification of novel SMase inhibitors in minutes. Taken together, the simplicity, speed, sensitivity, and naked-eye readout of this assay offer huge potential in point-of-care diagnostics and high-throughput drug screening
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