Thermosolutal-convective instability of a stellar atmosphere in the presence of suspended particles     

R. C. Sharma  Anup Rajput 《Astrophysics and Space Science》1991,183(2):183-191

Thermosolutal-convective instability of a stellar atmosphere is considered in the presence of suspended particles. The criteria for monotonic instability are derived which are found to hold good in the presence of uniform rotation and uniform magnetic field, separately, on the thermosolutal-convective instability in the presence of suspended particles.  相似文献   

Thermosolutal-convective instability of a composite plasma in a stellar atmosphere including the effects of finite larmor radius and Hall currents     

K. C. Sharma  Urvashi Gupta  R. C. Sharma 《Astrophysics and Space Science》1991,186(2):179-189

Thermosolutal-convective instability of a composite plasma in a stellar atmosphere is considered to include the effects, separately, due to finite Larmor radius (FLR) and Hall currents in the presence of a uniform horizontal magnetic field. The sufficient conditions for the existence of monotonic instability are derived and are found to hold good both in the presence, separately, of FLR and Hall current effects.  相似文献   

Bianchi Type I Bulk Viscous Stiff Fluid Tilted Cosmological Model in General Relativity     

Raj Bali  Keshav Sharma 《Astrophysics and Space Science》2001,275(4):485-497

Bianchi Type I Bulk viscous fluid tilted cosmological model without shearviscosity is investigated. The behaviour of the model in presence andabsence of bulk viscosity is discussed. The physical and geometricalconsequences of the models are also discussed.  相似文献   

Dissociation constants of protonated cysteine species in seawater media     

Virender K. Sharma  Aurelie Moulin  Frank J. Millero  Concetta De Stefano 《Marine Chemistry》2006,99(1-4):52

The dissociation constants (pK₁, pK₂ and pK₃) for cysteine have been measured in seawater as a function of temperature (5 to 45 °C) and salinity (S = 5 to 35). The seawater values were lower than the values in NaCl at the same ionic strength. In an attempt to understand these differences, we have made measurements of the constants in Na–Mg–Cl solutions at 25 °C. The measured values have been compared to those calculated from the Pitzer ionic interaction model. The lower values of pK₃ in the Na–Mg–Cl solutions have been attributed to the formation of Mg²⁺ complexes with Cys²⁻ anionsThe stability constants have been fitted toafter corrections are made for the interaction of Mg²⁺ with H⁺.The pK₁ seawater measurements indicate that H₃Cys⁺ interacts with SO₄²⁻. The Pitzer parameters β⁰(H₃CysSO₄), β¹(H₃CysSO₄) and C(H₃CysSO₄) have been determined for this interaction. The formation of CaCys as well as MgCys are needed to account for the values of pK₂ and pK₃ in seawater.The consideration of the formation of MgCys and CaCys in seawater yields model calculated values of pK₁, pK₂ and pK₃ that agree with the measured values to within the experimental error of the measurements. This study shows that it is important to consider all of the ionic interactions in natural waters when examining the dissociation of organic acids.  相似文献   

Experimental evaluation of shear strength behaviour of plastic and non-plastic silts     

A. Usmani  K.G. Sharma  A. Nanda 《Geomechanics and Geoengineering》2015,10(3):174-181

Silt is available in many parts of the world in combination with sands and clays. However, due to lack of clear understanding of its engineering behaviour, most of the time it is interpreted in terms of either sands or clays. Structures that are usually built on silty soils are designed to take into account design procedures developed for sandy or clayey soils. Presence of silts in combination with varying amount of sand and clays produces silt that is either plastic or non-plastic in nature. Silt is available in and around the Delhi region, in a majority mixture along with fine sands, which is non-plastic in nature. On the other hand silty deposits found in offshore Bombay High region are found in abundance along with significant amounts of clays and are termed as plastic silts. In this paper a comparison of the stress-strain behaviour of plastic and non-plastic silts is carried out under triaxial compression loading during both drained and undrained conditions. Two representative samples each from Delhi and Bombay High regions were considered for this comparison and results of stress-strain under four sets of confining pressure are discussed in detail. It is observed from this study that behaviour of silts is mainly dependent on the composition and structure of the resultant soil matrix. It is concluded from the results that shear strength parameters as well as volume change/pore pressure response of silty soils is dominated by the constituent soil present along with the silt. It is seen from the comparative behaviour of non-plastic and plastic silts that the presence of sand and clays has a governing effect on pore pressure development and the resultant friction angle. The study also corroborated that the nature of silt is transitional both in the case of plastic and non-plastic forms.  相似文献   

Soil characterization based on land cover heterogeneity over a tropical landscape: an integrated approach using earth observation data-sets     

Diwakar Paudel  Jay Krishna Thakur  Sudhir Kumar Singh  Prashant K. Srivastava 《国际地球制图》2015,30(2):218-241

Soil is a vital part of the natural environment and is always responding to changes in environmental factors, along with the influences of anthropogenic factors and land use changes. The long-term change in soil properties will result in change in soil health and fertility, and hence the soil productivity. Hence, the main aim of this paper focuses on the analysis of land use/land cover (LULC) change pattern in spatial and temporal perspective and to present its impact on soil properties in the Merawu catchment over the period of 18?years. Post classification change detection was performed to quantify the decadal changes in historical LULC over the periods of 1991, 2001 and 2009. The pixel to pixel comparison method was used to detect the LULC of the area. The key LULC types were selected for investigation of soil properties. Soil samples were analysed in situ to measure the physicochemical soil properties. The results of this study show remarkable changes in LULC in the period of 18?years. The effect of land cover change on soil properties, soil compaction and soil strength was found to be significant at a level of <0.05.  相似文献   

Laboratory experiments on the influence of soil pipes on slope failure     

Raj H. Sharma 《Landslides》2015,12(2):345-353

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Exact solutions in (2+1)-dimensional anti-de Sitter space-time admitting a linear or non-linear equation of state     

Ayan Banerjee  Farook Rahaman  Kanti Jotania  Ranjan Sharma  Mosiur Rahaman 《Astrophysics and Space Science》2015,355(2):353-359

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Correcting lateral boundary biases in regional climate modelling: the effect of the relaxation zone     

Rocheta  Eytan  Evans  Jason P.  Sharma  Ashish 《Climate Dynamics》2020,55(9-10):2511-2521

Climate Dynamics - Regional climate models (RCM) are an important tool for simulating atmospheric information at finer resolutions often of greater relevance to local scale climate change impact...  相似文献   

Application of downscaled precipitation for hydrological climate-change impact assessment in the upper Ping River Basin of Thailand     

Devesh Sharma  Mukand S. Babel 《Climate Dynamics》2013,41(9-10):2589-2602

This paper assesses the impacts of climate change on water resources in the upper Ping River Basin of Thailand. A rainfall-runoff model is used to estimate future runoff based on the bias corrected and downscaled ECHAM4/OPYC general circulation model (GCM) precipitation scenarios for three future 5-year periods; the 2023–2027 (2025s), the 2048–2052 (2050s) and 2093–2097 (2095s). Bias-correction and spatial disaggregation techniques are applied to improve the characteristics of raw ECHAM4/OPYC precipitation. Results of future simulations suggest a decrease of 13–19 % in annual streamflow compared to the base period (1998–2002). Results also indicate that there will be a shift in seasonal streamflow pattern. Peak flows in future periods will occur in October–November rather than September as observed in the base period. There will be a significant increase in the streamflow in April with overall decrease in streamflow during the rainy season (May–October) and an increase during the dry season (November–April) for all future time periods considered in the study.  相似文献