NRI Institute of Research and Technology

Bhopal, India

NRI Institute of Research and Technology

Bhopal, India

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Singh A.,Sadhu Vaswani College | Singh A.,Barkatullah University | Srivastava V.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | And 2 more authors.
Physica B: Condensed Matter | Year: 2010

We report ab initio calculations of pressure-induced structural phase transition and electronic properties of the NaCl-type actinide nitrides namely AnN (An=Np and Cm). The total energy as a function of volume is obtained using the self-consistent tight-binding linear muffin tin orbital (TB-LMTO) method by performing spin and non-spin-polarized calculations. Magnetically the AnN compounds are stable in ferromagnetic (FM) state at ambient condition. From the present study, we predict a structural phase transition from ferromagnetic (FM) NaCl-type (B1 phase) structure to ferromagnetic CsCl-type (B2 phase) structure for these in the pressure range of 80.0-50.0 GPa. The pressure-induced transition is found to be first order. The band structure and density of states (DOS) are reported in both FM-B1 phase and FM-B2 phase. The ground-state properties such as magnetic moment, lattice parameter and bulk modulus are calculated and compared with the available theoretical and experimental results. © 2010 Elsevier B.V. All rights reserved.


Singh A.,Sadhu Vaswani College | Singh A.,Barkatullah University | Srivastava V.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | And 2 more authors.
Journal of Nuclear Materials | Year: 2010

We report an ab initio calculation of pressure-induced structural phase transition and electronic properties of the NaCl-type Cm-based pnictides namely CmX (X = N, P, As, Sb and Bi). The total energy as a function of volume is obtained by means of self-consistent tight-binding linear muffin tin orbital (TB-LMTO) method by performing spin and non-spin polarized calculation. Magnetically the CmX compounds are stable in ferromagnetic (FM) state and their crystal structure is NaCl-type at ambient condition. From the present study, we predict a structural phase transition from ferromagnetic (FM) NaCl-type (B 1 phase) structure to ferromagnetic CsCl-type (B 2 phase) structure for curium pnictides in the pressure range of 51.0-10.0 GPa (CmN to CmBi). The pressure-induced transition is found to be first order. The band structure and density of states (DOS) are plotted in FM-B 1 phase and FM-B2 phase. Apart from this the groundstate properties like magnetic moment, lattice parameter and bulk modulus are calculated and compared with the available theoretical and experimental results. © 2010 Elsevier B.V. All rights reserved.


Thakur M.,NRI Institute of Information and Science Technology | Soni B.B.,NRI Institute of Information and Science Technology | Gaur P.,NRI Institute of Information and Science Technology | Yadav P.,NRI Institute of Research and Technology
2014 International Conference on Communication and Network Technologies, ICCNT 2014 | Year: 2014

Metastability events are common in digital circuits, and synchronizers are necessary to protect us from their deadly effects. Originally synchronizers were necessary when playing an asynchronous input (that is, one synchronized with the clock input so that could change exactly when the sample). Everything changes can easily be metastable. Switch its data input at the same time that the sampling edge of the clock and you get Metastability. The two signals relative duration of each cycle varies a little, and eventually leading to the metastability, close enough to each other switches. This combination of metastability with normal display devices, occur frequently. Recent semiconducting metal oxide progress (CMOS) additionally leads to unprecedented levels of integration in digital logic systems. Due to the propagation delay of the path and timing clock hold time configuration errors failure occurs in digital circuits. Depending on the application, errors are described by number of deferent terms, including 'synchronization failure error' and 'Metastability error'. The underlying mechanism for all of these problems is the same, and these terms 'Metastability error' is the largest, because it describes the failure of the element in the circuit and not to the application. The reference signal may be either a reference voltage on the base, for example a bias voltage or a reference based on the time, as a clock signal. © 2014 IEEE.


Pagare G.,P.A. College | Sen D.,Government Girls College | Srivastava V.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | Sanyal S.P.,Barkatullah University
Journal of Physics: Conference Series | Year: 2010

We have investigated theoretically the high-pressure structural phase transition and cohesive properties of two heavy rare earth mono antimonides (RESb; RE Dy and Lu) by using two body interionic potential with necessary modifications to include the effect of Coulomb screening by the delocalized 4f electrons of the RE ion. The peculiar properties of these compounds have been interpreted in terms of the hybridization of f electrons with the conduction band and strong mixing of f states of RE ion with the p orbital of neighboring pnictogen ion. These compounds exhibit first order crystallographic phase transition from their NaCl (B 1) phase to CsCl (B 2) phase at 23.6 GPa and 25.4 GPa respectively. The bulk modulii of RESb compounds are obtained from the P-V curve fitted by the Birch equation of state. We also calculated the RE-RE distance as a function of pressure. Elastic properties of these compounds have also been studied and their second order elastic constants are calculated. © 2010 IOP Publishing Ltd.


Pagare G.,P.A. College | Srivastava V.,NRI Institute of Research and Technology | Sanyal S.P.,Barkatullah University | Rajagopalan M.,Anna University
Physica B: Condensed Matter | Year: 2011

The ground state electronic structure and thermal properties of B 2-type intermetallic compounds AlRE (RE: Pm, Sm, Eu, Tb, Gd and Dy) have been studied using a self-consistent tight-binding linear muffin-tin orbital (TB-LMTO) method at ambient as well as at high pressure. These compounds show metallic behavior under ambient condition. The band structure, total energy, density of states and ground state properties like lattice parameter, bulk modulus are calculated in the present work. The DebyeGrneisen model is used to calculate the Debye temperature and the Grneisen constant. The calculated results are in good agreement with the reported experimental and other theoretical results. The variation in the Debye temperature with pressure has also been reported. We present a detailed analysis of the role of f electrons of RE in the AlRE system. © 2010 Elsevier B.V. All rights reserved.


Srivastava V.,NRI Institute of Research and Technology | Srivastava V.,Barkatullah University | Bhajanker S.,NRI Institute of Research and Technology | Bhajanker S.,Barkatullah University | Sanyal S.P.,NRI Institute of Research and Technology
Physica B: Condensed Matter | Year: 2011

The structural and mechanical properties of LnO (Ln=Sm, Eu, Yb) compounds have been investigated using a modified interionic potential theory, which includes the effect of Coulomb screening. We predicted a structural phase transition from NaCl (B 1)- to CsCl (B 2)-type structure and elastic properties in LnO compounds at very high pressure. The anomalous properties of these compounds have been correlated in terms of the hybridisation of f-electrons of the rare earth ion with conduction band and strong mixing of f-states of lanthanides with the p-orbital of neighbouring chalcogen ion. For EuO, the calculated transition pressure, bulk modulus and lattice parameter are close to the experimental data. The nature of bonds between the ions is predicted by simulating the ionion (LnLn and LnO) distances at high pressure. The second order elastic constants along with shear modulus and Youngs modulus, elastic anisotropy and Poissons ratio are also presented for these oxides. © 2011 Elsevier B.V. All rights reserved.


Bhajanker S.,NRI Institute of Research and Technology | Bhajanker S.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | Srivastava V.,Barkatullah University | Sanyal S.P.,Barkatullah University
Physica B: Condensed Matter | Year: 2012

The high pressure structural, elastic and thermal properties of holmium pnictides HoX (X=N, P, As and Bi) were investigated theoretically by using an inter-ionic potential theory with modified ionic charge parameter. We have predicted a structural phase transition from NaCl (B 1) to CsCl (B 2)-type structure at pressure of 139 GPa for HoN, 52 GPa for HoP, 44 GPa for HoAs and 26 GPa for HoBi. Other properties, such as lattice constant, bulk modulus, cohesive energy, second and third-order elastic constants were calculated and compared with the available experimental and theoretical data. In order to gain further information the brittle behaviour of these compounds was observed. Some other properties like Shear modulus (G), Youngs modulus (E), Poissons ratio (ν), anisotropy factor (A), sound velocities, Debye temperature (θ D) were calculated. The variation of elastic constants (C 11 and C 44) and Debye temperature (θ D) with pressure was also presented. © 2012 Elsevier B.V. All rights reserved.


Bhajanker S.,NRI Institute of Research and Technology | Bhajanker S.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | Srivastava V.,Barkatullah University | And 2 more authors.
Journal of Physics: Conference Series | Year: 2012

The mechanical and thermal properties of praseodymium monochalcogenides and monopnictides are calculated using elastic constants, those have been derived from two body inter- ionic potential theory. We have calculated the Young's modulus (E), Poisson's ratio (v), anisotropy factors (A), sound velocities and Debye temperature (θ D) for these compounds. The bulk modulus to shear modulus ratio (B/G) lies between 1.75-1.92 for all these compounds, which shows that all compounds are ductile in nature. Young's modulus shows that PrS and PrAs are stiffer than the other monochalcogenides and monopnictides of praseodymium. The variation of elastic constants (C 11, C 44) with pressure and the variation of Debye temperature with pressure are also presented for these compounds.


Khan A.A.,Sagar Institute of Science and Technology and Engineering | Khan A.A.,Barkatullah University | Srivastava V.,Barkatullah University | Srivastava V.,NRI Institute of Research and Technology | And 2 more authors.
Journal of Physics: Conference Series | Year: 2012

The structural and electronic properties of B2-cadmium lanthanide (RE), CdLn (Ln=La, Ce and Pr) intermetallics have been calculated at T=0K at ambient and at high pressure by using tight binding linear muffin tin orbital method. We have estimated lattice parameter, bulk modulus, density of states for the three CdLn intermetallics. The f-electrons present in the -Ln, play important role. The variation in density of states under compression is calculated due to Pr-f effect in CdPr, which opens a possibility of structural instability.


Lohi S.A.,NRI Institute of Research and Technology | Motwani A.,NRI Institute of Research and Technology
Proceedings - 2014 4th International Conference on Communication Systems and Network Technologies, CSNT 2014 | Year: 2014

Information in the form of textual documents would have a huge growth due to the factors like digitization of libraries, exponential rise in internet usage, use of e-mail for various reasons, acceptability of soft copies for many works even critical financial work and other things. In view of these reasons, this paper discusses a new approach for Documentation Taxonomy (DT) based on combining efficient algorithms to be used for english language. The important aspect of automatically classifying and providing taxonomy to a set of documents into any taxonomical structure with the help of predefined categories is termed as Documentation Taxonomy. Automated Documentation Taxonomy is gaining prominence since it frees organizations from the frantic and time consuming need of manually organizing documents. This manual process can be expensive and given the time constraints of the application or the number of documents involved, simply not feasible. In terms of accuracy, modern documentation taxonomy systems proves better than that of trained human professionals, which is made possible by a combination of information retrieval technology and machine learning technology. This research put forwards a mechanism that shows that the use of combination of different algorithms brings down the ambiguity in taxonomical issues. There are numerable useful applications of this approach spanning various scientific and general fields of work. © 2014 IEEE.

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