Sri Sathya Sai College for Women

Bhopal, India

Sri Sathya Sai College for Women

Bhopal, India
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Nautiyal P.,Hemwati Nandan Bahuguna Garhwal University | Mishra A.S.,Hemwati Nandan Bahuguna Garhwal University | Verma J.,Allahabad University | Agrawal A.,Sri Sathya Sai College for Women
Aquatic Ecosystem Health and Management | Year: 2017

This study reveals the relationship of biotic assemblages to their environments in the Central Highland Ecoregion rivers (Ken, Paisuni and Tons). Such knowledge will enhance our predictive abilities in the ecological studies and resource management in the concerned region. Rivers of an ecoregion are expected to harbour similar flora, fauna, and communities. This hypothesis was examined by tracking the spatial variation in richness, density, and taxonomic composition of benthic diatom and macroinvertebrate assemblages in three Plateau rivers whose course lay within 3°N latitude. Taxonomic richness and density decreased with the reduction of substrate size from the headwaters to the lowlands. Cluster and ordination analyses indicate prevalence of intrabasin rather than interbasin gradients of abundance. In both assemblages, the most abundant taxon is rarely similar longitudinally or across the river sections in the ecoregion. Hence, proximate factors govern the assemblages rather than ecoregional properties (latitude, altitude). This, and the high richness of diatom flora, points to diverse assemblages from the headwater to the lowland section in each river and among the rivers of the ecoregion. Copyright © 2017 AEHMS.


Srivastava A.,Sri Sathya Sai College for Women | Thakur R.,Barkatullah University | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2017

We present the specific heat (Cv) and thermal expansion (α) of lightly doped Sr1-xCexCoO3-δ (x=0.0-0.15) using Modified Rigid Ion Model (MRIM) and a novel atomistic approach of Atom in Molecules(AIM) theory. We partial replaced the A-site Strontium cation by other element (Cerium) of different size, valence and mass. The effect of Cerium doping on lattice specific heat (Cv)lat, thermal expansion(α) of Sr1-xCexCoO3-δ (x = 0.0-0.15) as a function of temperature (20K≤T≤ 1000K) is reported probably for the first time. The results indicate better thermal compatibility of Sr0.95Ce0.05CoO3 with Samaria doped Ceria (SDC) electrolyte than other studied compounds. The Debye temperature of these perovskite material as cathode for Intermediate Range Solid Oxide Fuel Cell (IR-SOFC) is also predicted. © 2017 Author(s).


Srivastava A.,Sri Sathya Sai College for Women | Gaur N.K.,Barkatullah University
Key Engineering Materials | Year: 2013

With the objective of exploring the unknown thermodynamic phase diagram of Bi1- xSrxMnO3 family, we present here an investigation of the temperature-dependent (10K < T < 900K) thermodynamic behavior of Bi1-xSrxMnO3 (x=0.25, 0.30, 0.50). We report here probably for the first time the thermal expansion and specific heat along with other thermal properties of strontium doped perovskite manganite BiMnO3. The specific heat values revealed by using RIM are in closer agreement with the available experimental data for some concentrations (x) of Bi1-xSrxMnO3. In addition, the results on the cohesive energy (φ) in orthorhombic perovskite phase, molecular force constant (f), Reststrahlen frequency (vo) and Gruneisen parameter (γ) are also presented. Copyright © 2013 Trans Tech Publications Ltd.


Srivastava A.,Sri Sathya Sai College for Women | Thakur R.,Barkatullah University | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2014

Specific heat (Cp) thermal expansion (α) and Bulk modulus (BT) of lightly doped Rare Earth manganites (La0.3Pr0.7)0.65Ca0. 35Mn1-xBxO3 (B3+=Fe3+,Cr3+,Ga3+,Al3+,Ru4+); (0.3


Thakur R.,Barkatullah University | Srivastava A.,Sri Sathya Sai College for Women | Thakur R.K.,Barkatullah University | Gaur N.K.,Barkatullah University
Journal of Alloys and Compounds | Year: 2012

We have reported the temperature dependence (5 K ≤ T ≤ 1000 K) of the lattice contribution to the specific heat of rhombohedral LaCoO 3 and orthocobaltates RCoO 3 (R = Pr and Nd). The strong electron phonon interactions are present in these compounds and lattice distortions can affect them substantially. Thus Rigid Ion Model (RIM) is used for the first time to study the cohesive and thermal properties of the cobaltates RCoO 3 with rare earth cation (R = La, Pr and Nd). The values of specific heat calculated by us have shown remarkably good agreement with corresponding experimental data. In addition, the results on the temperature dependence of cohesive energy (φ), molecular force constant (f), Reststrahlen frequency (υ), Debye temperature (θ D) and Gruneisen parameter (γ) are also reported. © 2011 Elsevier B.V. All rights reserved.


Srivastava A.,Sri Sathya Sai College for Women | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2011

With the objective of exploring the unknown thermodynamic phase diagram of Pr1-xSrxMnO3 perovskite family around the half doping levels and above, we present here an investigation of the temperature-dependent (20 K


Srivastava A.,Barkatullah University | Srivastava A.,Sri Sathya Sai College for Women | Gaur N.K.,Barkatullah University
Journal of Physics: Conference Series | Year: 2010

The elastic and thermal properties of perovskite manganites La 1-xSrxMnO3 (x = 0.165, 0.185, 0.20, 0.40, 0.70, 0.80, 0.90, 1.0) have been studied as a function of temperature (1K≤T≤300K) by means of Atoms in Molecules (AIM) theory and a Modified Rigid Ion Model (MRIM) respectively. The specific heat values (Cv) and the Debye temperatures obtained by us from the lattice contributions are in reasonably good agreement with the available experimental data for some concentrations (x) of La1-xSrxMnO3. In addition, the results on the Bulk Modulus (BT), cohesive energy (φ), molecular force constant (f), Reststrahlen frequency (vo) and Grüneisen parameter (γ) are also analysed. © 2010 IOP Publishing Ltd.


Srivastava A.,Sri Sathya Sai College for Women | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2012

Silver-doped manganites are known for their huge magnetocaloric effect; hence their thermodynamic behaviour is mapped here with reference to the changed local environment at A-site due to silver doping. We present here, the theoretical formulation to calculate the temperature-dependent (2K < T < 350K) thermal expansion and specific heat of La1-xAg xMnO3 (x=0.05-0.50) using modified Rigid Ion Model (RIM) and AIM theory. The obtained results suggest that higher silver doping (x∼0.5) is favourable for the magnetocaloric application of manganites. © 2012 American Institute of Physics.


Srivastava A.,Sri Sathya Sai College for Women | Thakur R.,Barkatullah University | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2013

Specific heat (Cp), thermal expansion (α) and bulk modulus of sodium doped Rare Earth manganites R1-xNaxMnO 3(R3+=La,Pr,Tb) has been studied by means of a Modified Rigid Ion Model (MRIM) and AIM theory. The partial replacement of rare earth cation by sodium introduces large size and charge mismatch at A-site affecting the bulk modulus and thermal properties. Lattice specific heat (Cp) of Pr0.8Na0.2MnO3 as a function of temperature (1K≤T≤350K) is found to be in agreement with the published data. The trend of variation of Debye temperature with A-site cationic radius is predicted probably for the first time for the doped rare earth manganites. © 2013 AIP Publishing LLC.


Srivastava A.,Sri Sathya Sai College for Women | Thakur R.,Barkatullah University | Gaur N.K.,Barkatullah University
AIP Conference Proceedings | Year: 2013

The Specific heat of orthorhombic rare earth manganites RMnO3 (R = La-Dy) with 50% Calcium in the perovskite structure at A-site has been studied by means of a Modified Rigid Ion Model (MRIM). This replacement introduces large cation variance at A-site and change spin-ordering at B-site hence the specific heat increases appreciably. The lattice specific heat (C v) of Sm0.5Ca0.5MnO3 as a function of temperature (1K≤T≤ 300K) is found to be in agreement with the published data. The trend of variation of Debye temperature with A-site cation variance is predicted probably for the first time for the doped rare earth manganites. © 2013 AIP Publishing LLC.

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