020206   Yazar H R (NO, , 2000 Evler Mah., Zubeyde Hanim Cad., Nevsehir Universitesi, Faculty of Art & Science, 50300, Nevsehir, Turkey, Email: yazar@nevsehir.edu.tr) : Low-lying (K<. Pramana J Phys 2013, 81(4), 579-85.

The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA model showed that the constructed Hamiltonian can successfully describe the strong octupole correlations in the deformed nuclei. We showed that the interacting boson approximation may account for many of these K^π = 0⁺ states. It was found that the calculated energy spectra of the gadolinium isotopes agree quite well with the experimental data. The observed B(E2) values were also calculated and compared with the experimental data.

2 illus, 1 table, 16 ref

020205   Yan H;Huang D C (Electronic Information and Physics Dep, Changzhi Univ, Changzhi, P.R. China, Email: yanh2010sx@yahoo.com.cn) : Molecular dynamics simulation of cylindrical droplets. Asian J Chem 2012, 24(4), 1508-10.

Study of the surface properties is of great interest from the standpoint of both fundamental and practice. In this paper cylindrical droplets in nanoscale are investigated. A method to determine the surface tension is given by Gibbs theory of capillarity. The scheme is carried out by molecular dynamics simulation. The effect of temperature and cutoff distance are studied. It is find that surface tension decreases with increasing temperature and corresponding quantities sensitively depend on the interaction potential.

3 illus, 2 tables, 11 ref

020204   Xiao W;Xiao J L (Basic Sciences Dep, Informational Science and Technology of Beijing Univ, Beijing 100101, China, Email: xiaojlin@126.com) : Magnetic field effect on state energies and transition frequency of a strong-coupling polaron in an anisotropic quantum dot. Pramana J Phys 2013, 81(5), 865-71.

By employing a variational method of the Pekar-type, which has different variational parameters in the x-y plane and the z-direction, we study the ground and the first excited state energies and transition frequency between the ground and the first excited states of a strong-coupling polaron in an anisotropic quantum dot (AQD) under an applied magnetic field along the z-direction. The effects of the magnetic field and the electron-phonon coupling strength are taken into account. It is found that the ground and the first excited state energies and the transition frequency are increasing functions of the external applied magnetic field. The ground state and the first excited state energies are decreasing functions, whereas transition frequency is an increasing function of the electron-phonon coupling strength. We find two ways of tuning the state energies and the transition frequency: by adjusting (1) the magnetic field and (2) the electron-phonon coupling strength.

3 illus, 29 ref

020203   Wu R;Cao D (School of Mathematics, Anhui Univ, Hefei-230039, Anhui Province, China, Email: rcwu@ahu.edu.cn) : Lag synchronization of chaotic systems with time-delayed linear terms via impulsive control. Pramana J Phys 2013, 81(5), 727-35.

In this paper, the lag synchronization of chaotic systems with time-delayed linear terms via impulsive control is investigated. Based on the stability theory of impulsive delayed differen-tial equations, some sufficient conditions are obtained guaranteeing the synchronized behaviours between two delayed chaotic systems. Numerical simulations on time-delayed Lorenz and hyper-chaotic Chen systems are also carried out to show the effectiveness of the proposed scheme. Note that under the scheme the chaotic system is controlled only at discrete time instants, and so it reduces the control cost in real applications.

4 illus, 17 ref

020202   Wang Y H;Chen Y (Shanghai Key Laboratory of Trustworthy Computing, East China Normal Univ, Shanghai 200062, People's Republic of China, Email: ychen@sei.ecnu.edu.cn) : Integrability of an extended fifth-order KdV equation with Riccat-type pseudopotential. Pramana J Phys 2013, 81(5), 737-46.

The extended fifth-order KdV equation in fluids is investigated in this paper. Based on the concept of pseudopotential, a direct and unifying Riccati-type pseudopotential approach is employed to achieve Lax pair and singularity manifold equation of this equation. Moreover, this equation is classified into three categories: extended Caudrey-Dodd-Gibbon-Sawada-Kotera (CDGSK) equation, extended Lax equation and extended Kaup-Kuperschmidt (KK) equation. The corresponding singularity manifold equations and auto-Backlund transformations of these three equations are also obtained. Furthermore, the infinitely many conservation laws of the extended Lax equation are found using its Lax pair. All conserved densities and fluxes are given with explicit recursion formulas.

29 ref

020201   Verma M K;Chatterjee A;Reddy K S;Yadav R;Paul S;Chandra M;Samtaney R (Physics Dep, Indian Institute of Technology Kanpur, Kanpur-208 016, Email: mkv@iitk.ac.in) : Benchmarking and scaling studies of pseudospectral code tarang for turbulence simulations. Pramana J Phys 2013, 81(4), 617-29.

Tarang is a general-purpose pseudospectral parallel code for simulating flows involving fluids, magnetohydrodynamics, and Rayleigh-Benard convection in turbulence and instability regimes. In this paper we present code validation and benchmarking results of Tarang. We performed our simulations on 1024³, 2048³, and 4096³ grids using the HPC system of IIT Kanpur and Shaheen of KAUST. Authors observe good 'weak' and 'strong' scaling for Tarang on these systems.

6 illus, 19 ref

020200   Tien C L;Lin T W;Tzeng H D;Jen Y J;Liu M C (Electrical Engineering Dep, Feng Chia Univ, Taichung, Taiwan, Email: cltien@fcu.edu.tw) : Temperature-dependent optical and mechanical properties of obliquely deposited MgF₂ thin films. Indian J pure appl Phys 2014, 52(2), 117-23.

The temperature-dependent optical and mechanical properties of magnesium fluoride (MgF₂) thin films with small columnar angles have been presented. Electron-beam evaporation method was used to prepare MgF₂ thin films with two different columnar angles of 6° and 24°. MgF₂ thin films were deposited on B270 glass substrates and silicon wafers, respectively. The temperature-dependent optical and mechanical behaviour of MgF₂ thin films with different columnar angles were obtained by elevated temperature in the range 30-110°C. The wavelength shift with temperature was measured by a spectrophotometer for evaluating the stability of obliquely deposited MgF₂ films. The microstructure and surface roughness of the MgF₂ thin films have been measured by scanning electron microscope (SEM) and atomic force microscopy (AFM). Characteristics for the temperature-dependent optical properties and biaxial residual stresses of MgF₂ thin films deposited at two different oblique angles have been measured and compared. The residual stress of MgF₂ thin films deposited on the B270 substrates has been plotted against the measurement temperature, both of the samples showed a linear dependence.

7 illus, 20 ref

020199   Singh V;Mathimalar S;Dokania N;Nanal V;Pillay R G;Ramakrishnan S (NO, Homi Bhabha National Institute, Anushaktinagar, Mumbai-400 094, Email: nanal@tifr.res.in) : Cryogen-free dilution refrigerator for bolometric search of neutrinoless double beta decay (0vββ) in <. Pramana J Phys 2013, 81(4), 719-25.

The feasibility study for searching neutrinoless double beta decay in ¹²⁴Sn using cryogenic bolometer has been initiated. For this purpose, a custom-built cryogen-free dilution refrigerator, having a large cooling power of 1.4 mW at 120 mK, has been installed at TIFR, India. This paper describes the design, installation and performance of a cryogen-free dilution refrigerator (CFDR-1200). The performance of CFDR-1200 has been analysed using Takano's model developed for conventional (wet) dilution refrigerators.

4 illus, 21 ref

020198   Shibib K S;Munshid M A;Hubiter K A (Laser and Optoelectronics Engineering Dep, Technology Univ, Baghdad, Iraq, Email: assprofkh@yahoo.com) : Analytical model of transient thermal effect on convectional cooled end-pumped laser rod. Pramana J Phys 2013, 81(4), 603-15.

The transient analytical solutions of temperature distribution, stress, strain and optical path difference in convectional cooled end-pumped laser rod are derived. The results are compared with other works and good agreements are found. The effects of increasing the edge cooling and face cooling are studied. It is found that an increase in the edge cooling has significant effect on reducing the maximum temperature that can be reached in the laser rod but it has no effect on the value of optical path difference. It is also found that increasing this type of cooling significantly reduces the time required to reach the thermal equilibrium with a slight increase in the max. tensile hoop stress that can be reached as the cooling increases. On the other hand, increase in face cooling reduces the response time, optical path difference and the maximum temperature that can be reached in the laser rod but a significant increase in the max. tensile hoop stress is observed. A matching between the advantages of these two type of cooling may be useful for a designer.

7 illus, 1 table, 18 ref

020197   Shi J;Li J;Li S (Center for Nonlinear Science Studies, Kunming Univ of Science and Technology, Kunming, Yunnan 650093, People's Republic of China, Email: sjp0207@163.com) : Analytical travelling wave solutions and parameter analysis for the (2+1)-dimensional Davey-Stewartson-type equations. Pramana J Phys 2013, 81(5), 747-62.

By using dynamical system method, this paper considers the (2+l)-dimensional Davey-Stewartson-type equations. The analytical parametric representations of solitary wave solutions, periodic wave solutions as well as unbounded wave solutions are obtained under different parameter conditions. A few diagrams corresponding to certain solutions illustrate some dynamical properties of the equations.

6 illus, 17 ref

020196   Sharma A;Singh B P;Gathania A K (Physics Dep, National Institute of Technology, Hamirpur-177 005, Email: akgathania@yahoo.com) : Synthesis and characterization of dodecanethiol-stabilized gold nanoparticles. Indian J pure appl Phys 2014, 52(2), 93-100.

Dodecanethiol-stabilized gold nanoparticles of different sizes were synthesized using Bi-phasic reduction method by varying the concentration of stabilizer. These particles were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis). TEM images show the average particle size of different samples ranging from <126>1.7 nm to 5.7 nm. FTIR study confirms the linkage of thiol group and their partial crystalline self assembly onto the surface of nano gold particles. From the UV-Vis spectra, it is noticed that absorption peak position is sensitive to the size of the particles. Theoretical fit for absorbance spectra was obtained using Mie theory and the deviation from experimental results demonstrates the large size and shape distribution. A linear relationship between logarithms of extinction coefficient and particle diameter is obtained, which explains the extinction coefficient dependence on the size of the particle.

7 illu, 1 table, 32 ref

020195   Saleh-Moghaddam R;Zomorrodian M E (Physics Dep, Faculty of Physics, Ferdowsi Univ of Mashhad, 91775-1436, Mashhad, Iran, Email: R_saleh88@yahoo.com) : Coupling constant in dispersive model. Pramana J Phys 2013, 81(5), 775-90.

The average of the moments for event shapes in e⁺e^- → hadrons within the context of next-to-leading order (NLO) perturbative QCD prediction in dispersive model is studied. Moments used in this article are <193>1 - T <209>, <193>ρ<209>, <193>B_T<209> and <193>Bw<209>. We extract α_s, the coupling constant in perturbative theory and α₀ in the non-perturbative theory using the dispersive model. By fitting the experimental data, the values of α_s (M_z⁰) = 0.1171 ± 0.00229 and α₀ (μI = 2GeV) = 0.5068 ± 0.0440 are found. Our results are consistent with the above model. Our results are also consistent with those obtained from other experiments at different energies. All these features are explained in this paper.

11 illus, 4 tables, 23 ref

020194   Saidi S;Trabelsi M;Coulomb J P (Physique Dep, Faculte des Sciences de Bizerte, 7021 Jarzouna Bizerte, Tunisie, Email: mohsen.trabelsi@fsb.rnu.tn) : Thermodynamic study of NO thin films adsorbed on MgO(100). Indian J pure appl Phys 2014, 52(2), 112-16.

Adsorption isotherms of NO on uniform MgO(100) surface have been measured in a wide range of temperature 92K ≤ T ≤ 138K and a coverage corresponding to two first layering transitions. Thermodynamic properties of the first and the second nitrogen monoxide layers have been reported. Particularly, adsorption heat measured for the first layer adsorbed on MgO Q_st⁽¹⁾ = 5.47 kcal.mol^-1, is 18% greater than that measured on the hexagonal graphite basal plane surface, indicating the large stability of the NO first layer adsorbed on MgO. This suggestion is supported by the bi-dimensional critical temperature which is displaced to the height temperatures range T_2C/T_3C = 0.67. By comparison to NO adsorbed on other substrates, the original result in the present study is the absence of bi-dimensional polymorphism in the explored range of temperature. Suggests a configuration where molecules are laying on the MgO(100) surface.

5 illus, 3 tables, 17 ref

020193   Sadeghi H;Pourimani R;Khalili H (Physics Dep, Faculty of Science, Arak Univ, Arak 38156-8349, Iran) : Asymptotic D-state to S-state ratio of triton. Pramana J Phys 2013, 81(5), 799-806.

At low energies, an effective field theory (EFT) with only contact interactions as well as three-body forces allow a detailed analysis of renormalization in a non-perturbative context and uncovers novel asymptotic behaviour. Triton as a three-body system, based on the EFT have been previously shown to provide representative binding energies, charge radii, S-wave scattering amplitude and asymptotic normalization constants for the ³H bound state system. Herein, EFT predictions of the asymptotic D-state to S-state ratio of triton are calculated to more fully evaluate the adequacy of the EFT model. Manifestly model-independent calculations can be carried out to high orders, leading to high precision.

2 illus, 1 table, 25 ref

020192   Qi C;Sun X (College of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, P.R. China, Email: sxmwch@sdu.edu.cn) : Theoretical studies of the reaction paths and rate constants for SiH₄ + H system. Asian J Chem 2012, 24(4), 1798-1804.

The reaction of SiH₄ with H has been studied using the three ab initio levels. The structure of the potential energy surface includes the reactants, the prior complex, the transition state, the postcomplex and the product, are reported. Along the reaction coordinates, the dynamic potential wells correspond to the Feshbach resonance. The rate constants are calculated using the TST (CVT, ICVT) methods with the SCT correction. Rate constants in the temperature range of 200- 1600 K were reported at the G2HQCISD/6-311+G(df,pd) level and exhibits typical non-Arrhenius behaviour. The viriational effect on the values of rate constant is small and the tunneling correction is important in the calculation of rate constants in the lower temperature range. The three parameters expression in the range 200-1600 K is cm³ mol^-1. The calculated ICVT/SCT rate constants are in good agreement with the available experimental data.

6 illus, 5 tables, 35 ref

020191   Paul B C;Thakur P;Verma M M (Physics Dep, North Bengal Univ, Darjeeling-734 013, Email: bcpaul@iucaa.ernet.in) : Observational constraints on modified Chaplygin gas in Horava-Lifshitz gravity with dark radiation. Pramana J Phys 2013, 81(4), 691-718.

Cosmological models with modified Chaplygin gas (MCG) in the framework of Horava-Lifshitz (HL) theory of gravity, both with and without detailed balance, are obtained. The equation of state (EOS) for a MCG contains three unknown parameters namely, A ∝ B. The allowed values of some of these parameters of the EOS are determined using the recent astrophys-ical and cosmological observational data. Using observational data from H(z)-z, baryon acoustic oscillation (BAO) peak parameter and cosmic microwave background (CMB) shift parameter we study cosmologies in detailed-balance and beyond detailed-balance scenario. Take up the beyond detailed-balance scenario in totality and contribution of dark radiation in detailed-balance scenario on the parameters of the EOS. Explores the effect of dark radiation on the whole range of the effective neutrino parameter (ΔN_v) to constrain matter contributing parameter B in both the detailed-balance and the beyond detailed-balance scenarios. It has been observed that greater the dark radiation less the matter contribution in the MCG in both the scenario considered here. In order to check the validity of beyond detailed-balance scenario we plot supernovae magnitudes (μ) with red-shift of Union2 data and then the variation of state parameter with redshift is studied. It is noted that beyond detailed-balance scenario is suitable for cosmological model in HL gravity with MCG.

9 illus, 4 tables, 64 ref

020190   Patel D;Santra S;Mukherjee S;Nayak B K;Rath P K;Parkar V V;Choudhury R K (Physics Dep, Faculty of Science, The M.S. Univ of Baroda, Vadodara-390 002, Email: dipika.physics@gmail.com) : Elastic scattering and fusion cross-sections in <. Pramana J Phys 2013, 81(4), 587-602.

With an aim to understand the effects of breakup and transfer channels on elastic scattering and fusion cross-sections in the ⁷Li + ²⁷Al reaction, simultaneous measurement of elastic scattering angular distributions and fusion cross-sections have been carried out at various energies (E_lab = 8.0-16.0 MeV) around the Coulomb barrier. Optical model (OM) analysis of the elastic scattering data does not show any threshold anomaly or breakup threshold anomaly behaviour in the energy dependence of the real and imaginary parts of the OM potential. Fusion cross-section at each bombarding energy is extracted from the measured α-particle evaporation energy spectra at backward angles by comparing with the statistical model prediction. Results on fusion cross-sections from the present measurements along with data from the literature have been compared with the coupled-channels predictions. Detailed coupled-channels calculations have been carried out to study the effect of coupling of breakup, inelastic and transfer, channels on elastic scattering and fusion. The effect of In-stripping transfer coupling was found to be significant compared to that of the projectile breakup couplings in the present system.

11 illus, 2 tables, 63 ref

020189   Paras Ram;Sharma K (Mathematics Dep, National Institute of Technology, Kurukshetra-136 119, Email: parasram_nit@yahoo.co.in) : Effect of rotation and MFD viscosity on ferrofluid flow with rotating disk. Indian J pure appl Phys 2014, 52(2), 87-92.

Deals with the theoretical investigation of the effect of Magnetic Field-Dependent (MFD) viscosity on the revolving axi-symmetric steady laminar flow of viscous incompressible electrically non-conducting ferrofluid with rotating disk by solving the boundary layer equations. The non-linear coupled partial differential equations involved in the problem are solved by asymptotic approximations. The velocity components and pressure profiles are computed numerically and discussed graphically for various values of MFD viscosity parameter (k) along with the variation of Karman's dimensionless parameter (α). Also, we have calculated the displacement thickness of the boundary layer, angle of rotation and an expression for total volume flowing outward the z-axis is given.

6 illus, 1 table, 20 ref

020188   Nityananda R (NO, NCRA-TIFR, Pune-411 007, Email: rajaram.nityananda@gmail.com) : Lifelong quantum quest. Resonance 2013, 18(1), 29-38.

John Wheeler's work over his entire working life coming under the broad heading of quantum mechanics is described - it ranges over very practical issues relating to atomic and nuclear physics (particularly nuclear fission), a far-reaching conceptual framework such as the scattering matrix, and deep foundational issues. His inspiration enabled his students to make outstanding contributions as well.

1 illus, 2 ref

020187   Nisha M R;Jayalakshmy M S;Philip J (Instrumentation and STIC Dep, Cochin Univ of Science and Technology, Cochin-682 022, Email: jp@cusat.ac.in) : Effective thermal conductivity of condensed polymeric nanofluids (nanosolids) controlled by diffusion and interfacial scattering. Pramana J Phys 2013, 81(5), 849-64.

Thermal properties of polymeric nanosolids, obtained by condensing the corresponding nanofluids. are investigated using photothermal techniques. The heat transport properties of two sets of polyvinyl alcohol (PVA) based nanosolids, TiO₂/PVA and Cu/PVA, prepared by condensing the respective nanofluids, which are prepared by dispersing nanoparticles of TiO₂ and metallic copper in liquid PVA, are reported. Two photothermal techniques, the photoacoustic and the photopyro-electric techniques, have been employed for measuring thermal diffusivity, thermal conductivity and specific heat capacity of these nanosolids. The experimental results indicate that thermal conduction in these polymer composites is controlled by heat diffusion through the embedded particles and interfacial scattering at matrix-particle boundaries. These two mechanisms are combined to arrive at an expression for their effective thermal conductivity. Analysis of the results reveals the possibility to tune the thermal conductivity of such nanosolids over a wide range using the right types of nanoparticles and right concentration.

5 illus, 28 ref

020186   Natarajan V (Physics Dep, Indian Institute of Science, Bangalore-560 012, Email: vasant@physics.iisc.ernet.in) : What is a photon?. Resonance 2013, 18(1), 39-50.

Discusses the absorber theory of radiation as put forward by Wheeler and Feynman. We show that it gives a better understanding of the photon compared to the usual quantum electrodynamics (QED) picture.

020185   Narlikar J V (NO, Inter-Univ Centre for Astronomy and Astrophysics Ganeshkhind, Post Bag 4 Pune-411 007, Email: jvn@iucaa.ernet.in) : John archibald wheeler: man with picturesque imagination. Resonance 2013, 18(1), 22-8.

John Archibald Wheeler was a researcher and teacher par excellence who was responsible for popularizing the theory of general relativity amongst the academics in the United States. This article tries to provide glimpses of his contributions to gravitation as also some of the work of his distinguished students.

9 ref

020184   Mohsenabadi S S;Zomorrodian M E (Physics Dep, Ferdowsi Univ of Mashhad, Mashhad 91775-1436, Iran, Email: samira.shoeibi1453@gmail.com) : Next-to-next-to-leading order calculation of the strong coupling constant α_s by using moments of event-shape variables. Pramana J Phys 2013, 81(5), 791-8.

The next-to-next-to-leading order (NNLO) quantum chromodynamics (QCD) correction to the first three moments of the four event-shape variables in electron-positron annihilation, the thrust, heavy jet mass, wide, and total jet broadening, is computed. It is observed that the NNLO correction gives a better agreement between the theory and the experimental data. Also, by using the above observables, the strong coupling constant (α_s) is determined and how much its value is affected by the NNLO correction is demonstrated. By combining the results for all variables at different centre-of-mass energies α_s(M_Z⁰) = 0.1248 ± 0.0009 (exp.)_-0.0144^+0.0283 (theo.) is obtained.

7 illus, 4 tables, 14 ref

020183   Mansuripur M (College of optical Sciences, The Univ of Arizona, Tucson, Arizona 85721, Email: masud@optics.arizona.edu) : On the foundational equations of the classical theory of electrodynamics. Resonance 2013, 18(2), 130-55.

A close examination of the Maxwell-Lorentz theory of electrodynamics reveals that polarization and magnetization of material media need not be treated as local averages over small volumes - volumes that nevertheless contain a large number of electric and/or magnetic dipoles. Indeed, Maxwell's macroscopic equations are exact and self-consistent mathematical relations between electromagnetic fields and their sources, which consist of free charge, free current, polarization, and magnetization. When necessary, the discrete nature of the constituents of matter and the granularity of material media can be handled with the aid of special functions, such as Dirac's delta-function. The energy of the electromagnetic field and the exchange of this energy with material media are treated with a single postulate that establishes the Poynting vector S = E x H as the rate of flow of electromagnetic energy under all circumstances. Similarly, the linear and angular momentum densities of the fields are simple functions of the Poynting vector that can be unambiguously evaluated at all points in space and time, irrespective of the type of material media, if any, that might reside at various locations. Finally, we examine the Einstein-Laub force- and torque-density equations, and point out the consistency of these equations with the preceding postulates, with the conservation laws, and with the special theory of relativity. The set of postulates thus obtained constitutes a foundation for the classical theory of electrodynamics.

4 illus, 25 ref

020182   Khan Z;Kundu A;Pradhan S (NO, Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar-382 428, Email: ziauddin_khan@rediffmail.com) : Experimental study of yttrium barium copper oxide superconducting tape's critical current under twisting moment. Pramana J Phys 2013, 81(4), 667-76.

Critical current (I_c) characteristics of 2G YBCO superconducting tape under the influence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The degradation is largely attributed to the shear stress and torsional shear strain resulting from the twisting. The superconductor to resistive transition index, n, is also found to behave in an identical manner with increase in the twisting. Finite element analysis (FEA) of the tape in the experimental configuration with twisting moment being applied on to it has been carried out in COMSOL. The torsional strain calculated analytically as per the experimental configuration matches closely with that of FEA results, which shows that the critical current degradation is a function of strain.

10 illus, 2 tables, 8 ref

020181   Kanagaraj M;Sathishkumar P;Kalai Selvan G; Phebe Kokila I;Arumugam S (NO, Centre for High Pressure Research, School of Physics, Bharathidasan Un, Tiruchirappalli-620 024, Email: sarumugam1963@yahoo.com) : Structural and magnetic properties of CuFe₂O₄ as-prepared and thermally treated spinel nanoferrites. Indian J pure appl Phys 2014, 52(2), 124-30.

The copper based CuFe₂O₄ nanoferrite was prepared by chemical co-precipitation method and the detailed investigation of structural and magnetic properties was carried out successfully at room temperature. The obtained results from XRD confirm that CuFe₂O₄ has tetragonal structure at room temperature and its crystallite size, lattice strain was found to be varied from 11 to 17 nm and 3.910^-2 to 2.610^-2 for microwave annealed to as-prepared samples calculated using Scherrer equation and Williamson-Hall analysis, respectively. A clear superparamagnetic behaviour was observed in as-prepared and hot air oven annealed nanoferrite samples at RT under the field range of ±2 T. A distorted superparamagnetic curve was determined from isothermal magnetic hysteresis studies for the microwave oven annealed sample. It might be a possible magnetic and non-magnetic cation transformation on the surface of CuFe₂O₄ nanoparticles along with high lattice strain resulting in change of magnetic properties under certain level of applied magnetic field.

7 illus, 3 tables, 24 ref

020180   Jat R N;Rajotia D (Mathematics Dep, Rajasthan Univ, Jaipur-302 004, Email: khurkhuria_rnjat@yahoo.com) : Three dimensional viscous flow and heat transfer due to a permeable shrinking sheet with heat generation/absorption. Indian J pure appl Phys 2014, 52(2), 79-86.

Three dimensional boundary layer flow due to a permeable shrinking sheet with viscous dissipation and heat generation/absorption, has been studied. The governing equations are transformed to ordinary differential equations by using suitable similarity transformations and then solved numerically on computer by standard technique. Numerical results of velocity and temperature profiles are obtained with the effects of various parameters involved such as suction, shrinking, Prandtl number, Eckert number and heat generation coefficient etc. and discussed them graphically in suitable manner such that interesting aspects of the solution can be adopted. Also, the comparison of results of two dimensional case and axisymmetric shrinking sheet case is considered.

1 table, 17 ref

020179   Hu X G;Xiang J;Jiao Z;Liu Y;Xie G Q;Hu K (Physics Dep, Huangshan Univ, Huangshan 245041, Anhui, China) : Boson bound states in the β-Fermi-Pasta-Ulam model. Pramana J Phys 2013, 81(5), 839-48.

The bound states of four bosons in the quantum β-Fermi-Pasta-Ulam model are investigated and some interesting results are presented using the number conserving approximation combined with the number state method. We find that the relative magnitude of anharmonic coefficient has a significant effect on forming localized energy in the model, and the wave number plays an important role in forming different bound states. The signature of the quantum breather is also set up by the square of the amplitudes of the corresponding eigenvectors in real space.

5 illus, 33 ref

020178   Haque A;Joglekar S D (Physics Dep, Birla Institute of Technology and Science Pilani Hyderabad Campus, Hyderabad-500 078, Email: ahaque@hyderabad.bits-pilani.ac.in) : Causality in 1+1-dimensional Yukawa model-II. Pramana J Phys 2013, 81(4), 569-78.

The limits g → large, M → large with (g³/M) = const. of the 1 + 1-dimensional Yukawa model are discussed. The conclusion of the results on bound states of the Yukawa model in this limit (obtained in arXiv:0908.4510v3 [hep-th]) is taken into account. It is found that model reduces to an effective non-local φ³ theory in this limit. Causality violation also is observed in this limit.

9 ref

020177   Hansraj S;Maharaj S D;Mthethwa T (Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Univ of KwaZul, Private Bag X54001, Durban 4000, South Africa, Email: maharaj@ukzn.ac.za) : Incompressible Einstein-Maxwell fluids with specified electric fields. Pramana J Phys 2013, 81(4), 557-67.

The Einstein-Maxwell equations describing static charged spheres with uniform density and variable electric field intensity are studied. The special case of constant electric field is also studied. The evolution of the model is governed by a hypergeometric differential equation which has a general solution in terms of special functions. Several classes of exact solutions are identified which may be considered as charged generalizations of the incompressible Schwarzschild interior model. An analysis of the physical features is undertaken for the uniform case. It is demonstrated that uniform density spheres with constant electric field intensity are not realizable with isotropic pressures. This highlights the necessity of studying the criteria for physical admissability of gravitating spheres in general relativity which are solutions to the Einstein-Maxwell equations.

2 illus, 25 ref

020176   Gupta S P (Physics Dep, College Univ, Kurukshetra Univ, Kurukshetra-136 119, Email: spkuk@rediffmail.com) : Manipulation in single quantum system (quantum measurement revisited). Indian Sci Cruiser 2013, 27(2), 37-42.

"Optical cavity" trapping atoms is a very powerful technique to trap different types of atoms and study the different possible states of matter: insulation, superconductivity, Bose-Einstein condensate. Generally, as the number of atoms trapped in the cavity is generally quite low, one has to cool them to very low temperatures (approaching absolute zero via laser cooling and controlled evaporation) so that the their de Broglie wavelength becomes large allowing the quantum Bose-Einstein and Fermi-Dirac statistics come into play. One uses the Feshbach resonance to vary the interaction between the particles and reach the different states of matter. The most precise optical clock with a relative precision of approaching 10^-18 is based on an optical clock. Moreover, the QM entanglemnt process for a number of particles can be set up and followed. One has gone even farther by studying the dispersion relations and the different-sound velocities in these cavities.

4 ills, 38 ref

020175   Ghosh U N;Chatterjee P;Ghosh D K (Mathematics Dep, Siksha Bhavana, Visva Bharati Univ, Santiniketan-731 235, Email: unghosh1@rediffmail.com) : Effect of nonthermal distributed electrons and temperature on phase shifts during the collision of inward and outward ion-acoustic solitary waves in nonplanar geometry. Pramana J Phys 2013, 81(4), 631-40.

Interaction of nonplanar ion-acoustic solitary waves is an important source of information for studying the nature and characteristics of ion-acoustic solitary waves (lASWs). The head-on collision between two cylindrical/spherical lASWs in un-magnetized plasmas comprising of nonthermal distributed electrons and warm ions is investigated using the extended version of Poincare-Lighthill-Kuo (PLK) perturbation method. How the interactions are taking place in cylindrical and spherical geometries are shown numerically. Analytical phase shifts are derived for nonplanar geometry. The effects of the ion to electron temperature parameter and the nonthermal electrons parameter on the phase shift are studied. It is shown that the properties of the interaction of lASWs in different geometries are very different.

4 illus, 42 ref

020174   Eslamizadeh H (Physics Dep, Persian Gulf Univ 75169, Bushehr, Iran, Email: m_eslamizadeh@yahoo.com) : Fission characteristics of <. Pramana J Phys 2013, 81(5), 807-17.

A Kramers-modified statistical model is used to calculate the cross-section of the evaporation residue, fission cross-section, average pre-fission multiplicities of protons and α-particles for ²¹⁶Ra formed in ¹⁹F+¹⁹⁷ Au reactions and results are compared with the experimental data. To calculate these quantities, the effects of temperature and spin K about the symmetry axis have been considered in the calculations of the potential energy surfaces and the fission widths. It is shown that the results of the calculations using values of the temperature coefficient of the effective potential k = 0.008 ± 0.003 MeV^-2 and scaling factor of the fission-barrier height r_s = 1.004 ± 0.002 are in good agreement with the experimental data.

6 illus, 39 ref

020173   Daoud S;Bioud N;Lebgaa N (Faculte des Sciences et de la Technologie, Universite de Bordj Bou Arreridj, 34000, Algerie, Algeria, Email: salah_daoud07@yahoo.f) : Elastic and piezoelectric properties, sound velocity and debye temperature of (B3) Boron-Bismuth compound under pressure. Pramana J Phys 2013, 81(5), 885-92.

Pseudopotential plane-wave method (PP-PW) based on density functional theory (DFT) and density functional perturbation theory (DFPT) within the Teter and Pade exchange-correlation functional form of the local spin density approximation (LSDA) is applied to study the effect of pressure on the elastic and piezoelectric properties of the (B3) boron-bismuth compound. The phase transition, the independent elastic stiffness constants, the bulk modulus, the direct and converse piezoelectric coefficients, the longitudinal, transverse, and average sound velocities, and finally the Debye temperature under pressure are studied. The results obtained are generally lower than the available theoretical data (experimental data are not available) reported in the literature.

4 illus, 25 ref

020172   Chaurasia S;Leshma P;Munda D S (High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085, Email: pgshivanand@gmail.com) : Development of online quasimonochromatic X-ray backlighter for high energy density physics studies. Pramana J Phys 2013, 81(5), 829-38.

Monochromatic X-ray backlighting has been employed with great success in various laser plasma experiments including inertial confinement fusion (ICF) research. However, implementation of a monochromatic backlighting system typically requires extremely high quality spherically bent crystals which are difficult to manufacture and are also expensive. In this paper, we present a quasimonochromatic X-ray backlighting system using flat thallium acid pthalate (TAP) crystal. The detailed characterization of the system is discussed. The X-ray backlighter spectral range is caliberated using Cu spectrum in the spectral range 7-9 A (1.38-1.77 keV). Gold plasma produces continuous X-ray spectrum (M band) in this range. The spectral, spatial and temporal resolutions of the system measured are 30 mAngstrum, 50 μtm and 1.5 ns respectively. The spectral width of the X-ray pulse is 2 Angstrum (ΔE = 0.39 keV).

5 illus, 25 ref

020171   Bora M P;Sarmah D (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: mpbora@gauhati.ac.in) : Oscillation death in a coupled van der Pol-Mathieu system. Pramana J Phys 2013, 81(4), 677-90.

Reports an investigation of the oscillation death (OD) of a parametrically excited coupled van der Pol-Mathieu (vdPM) system. The system can be considered as a pair of harmonically forced van der Pol oscillators under a double-well potential. The two oscillators are coupled with a cubic nonlinearity. We have shown that the system arrives at an OD regime when coupling strength crosses a threshold value at which the system undergoes saddle-node bifurcation and two limit cycles coalesce onto a fixed point of the system. We have further shown that this nonautonomous system possesses a centre manifold corresponding to the OD regime.

7 illus, 31 ref

020170   Aarya S;Shahabuddin M;Gupta V;Kapil Dev; Basfar A A;Siddhartha (Physics Dep, Ramjas College, Delhi Univ, Delhi-110 007, Email: siddharthasingh1@gmail.com) : Physico-chemical modifications induced by 70 MeV carbon ions in alpha phased polyvinylidene fluoride (α-PVDF) polymer. Indian J pure appl Phys 2014, 52(2), 131-6.

The physico-chemical changes induced by 70 MeV carbon ions (¹²C⁺⁵) have been investigated in PVDF using UV-Visible, FTIR, XRD and HFIA techniques. The induced changes have been studied with respect to their optical, chemical, structural and electrical response. The polymer samples have been irradiated in the ion fluence ranging from 1x10¹¹ to 3x10¹² ions cm^-2. The UV-visible spectra show that the optical absorption increases with increasing ion fluence. Two new dips at 482 nm and 654 nm were appeared in the irradiated sample which may be due to the fluorinated defects created due to irradiation. In the FTIR spectra, it was found that transmittance intensity decreases with increasing ion fluence in the range 1500-4000 cm^-1. The diffraction pattern of PVDF indicates that crystallinity decreases with increasing ion fluence but the crystallite size is found to increase due to carbon ion irradiation. The variation of dielectric constant and dielectric loss for virgin and irradiated films have been studied in the frequency range 10 mHz-10 MHz at ambient temperature. There is an exponential increase in ac conductivity with increasing frequency and the effect of irradiation is significant at higher fluence. The dielectric constant and dielectric loss changed significantly due to ion beam irradiation, meanwhile the frequency exponents decreased with increasing ion fluence. It was found that dielectric response in both virgin as well as irradiated samples obey the Jonscher's power law.

6 illus, 31 ref

019145   Yang Z;Hu C;Meng Q (Jiangsu Xuzhou Construction Machinery Research Institute, Intelligent Control Lab, Xuzhou-221 004, China, Email: yangzhiwen2008@126.com) : Nonequilibrium green's function techniques in current-voltage calculations of nanoscale materials. Indian J Phys 2012, 86(11), 977-87.

Nonequilibrium Green's function techniques are today a vital tool for investigating electrical properties of nanoscale materials. In this review paper, recent works addressed on comprehend nanomaterials have been reviewed. A brief description of the theoretical basis of nonequilibrium Green's function and its application in deducing the current formula for a two probe model are given. Applications of nonequilibrium Green's functions in hunting electronic transport properties of nanoscale materials have been presented. A short conclusion and prospects on two probe model calculations are discussed.

8 illus, 129 ref

019144   Yan H;Zhou X (Electronic Information and Physics Dep, Changzhi Univ, Changzhi-046 011, P.R. China, Email: yanh2010sx@yahoo.com.cn) : Determination of surface tension of nanoscale liquid threads. Asian J Chem 2013, 25(17), 9785-8.

For the determination of surface tension of liquid threads by molecular dynamics simulations, the most time-consuming part is the calculation of pressure tensor in the transition layer, which makes it difficult to enhance the precision of the computation. A new method for the calculation of surface tension of liquid threads to decrease the calculation quantity of pressure tensor in transition layer to the least is proposed in this paper. Four thousand eight hundred particles are taken to show how to carry out our scheme.

2 illus, 1 table, 10 ref

019143   Vijayakumar S;Ganesan S (Physics Dep, Sri Ramakrishna Institute of Technology, Pachapalayam, Perurchettipalaym post, Coimbatore-641 010, Email: vijaysk.research@gmail.com) : Preparation and stability of gold nanoparticles. Indian J Phys 2012, 86(11), 989-95.

Study a prechosen size of gold nanoparticles prepared by chemical reduction method and has been found to be highly stable under a range of different experimental conditions explored. The gold nanoparticles have been characterized by UV-vis spectroscopy and transmission electron microscopy. The stability of citrate stabilized gold nanoparticles has been investigated as a function of pH by UV-visible absorption spectroscopy and Zeta-potentiometer and has shown good stability over the experimental methods adopted.

4 illus, 1 table, 56 ref

019142   Rudramadevi B H;Thilagavathi K;Buddhudu S (Physics Dep, School of Physics, Madurai Kamaraj Univ, Madurai-625 021, Email: bh.rudramadevi@gmail.com) : Structural, dielectric and conductivity properties of Mn<. Indian J Phys 2012, 86(11), 997-1001.

Poly (N-vinyl pyrrolidone) (PVP) and Mn²⁺ and Ni²⁺ :PVP polymer films have been prepared by a solution casting method. The amorphous nature of the polymer electrolytes has been confirmed based on the X-ray diffraction analysis. The Fourier Transform Infrared Spectra confirm the complex formation of the polymer with the dopant transition metal ions. The conductivity analysis of doped polymer films has revealed a high ionic conductivity and it has been found to be 1.3 x 1(P^-4 S cm^-1, at room temperature. The conductivity of the films increases with an increase in the frequency and temperature. The dielectric measurements of the sample have been performed in the frequency range 1 Hz-1 MHz and in the temperature range of 273-373 K. Dielectric properties, such as dielectric constant, dielectric loss, electric modulus and conductivity of the PVP:Mn²⁺and PVP:Ni²⁺ films have been studied. The dielectric behavior has been analyzed using dielectric permittivity, and electric modulus of the samples.

5 illus, 2 tables, 30 ref

019141   Miller D E;Tawfik A (NO, Fakultat fur Physik, Bielefeld Univ, 33501 Bielefeld, Germany, Email: a.tawfik@eng.mti.edu.eg) : Effects of quantum entropy on bag constant. Indian J Phys 2012, 86(11), 1021-6.

The effects of quantum entropy on the bag constant are studied at low temperatures and for small chemical potentials. The inclusion of the quantum entropy of the quarks in the equation of state provides the hadronic bag with an additional heat which causes a decrease in the effective latent heat inside the bag. Considered two types of baryonic bags, Δ and Ω^-. In both cases we have found that the bag constant without the quantum entropy almost does not change with temperature and quark chemical potential. The contribution from the quantum entropy to the equation of state clearly decreases the value of the bag constant. Furthermore, we construct states densities for quarks using the "Thomas-Fermi model" and take into consideration a thermal potential for the interaction.

2 illus, 28 ref

019140   Madhavi Latha T;Peddi Naidu P;Madhusudhana Rao D N;Indira Devi M (Physics Dep, M.R.P.G. College, Vizianagaram-535 002, Email: indiramalladi@yahoo.com) : Theoretical study of diurnal shift in reflection height of VLF waves using IRI electron density model. Indian J Phys 2012, 86(11), 947-50.

Electron density profiles for the International Reference Ionosphere (IRI) 2001 and 2007 models have been utilized in evaluating the D-region conductivity parameter in earth ionosphere wave guide calculations. The day to night shift in reflection height of very low frequency (VLF) waves has been calculated using D-region conductivities derived from IRI models and the results are compared with those obtained from phase variation measurements of VLF transmissions from Rugby (England) made at Visakhapatnam (India). The values derived from the models are found to be much lower than those obtained from the experimental measurements. The values derived from the IRI models are in good agreement with those obtained from exponential conductivity model.

2 tables, 21 ref

019139   Liu R;Zhang Z;Huang J;Li H (NO, School of Physics Science, Jinan Univ, Jinan-250 022, Shandong Province, P.R. China, Email: ss_zhangz@ujn.edu.cn) : Optical properties of Indium-doped ZnO nano-films prepared by spray pyrolysis and hydrothermal synthesis. Asian J Chem 2013, 25(17), 9601-4.

Zinc oxide and indium-doped ZnO nano-films are prepared by two-step method on the quartz glass substrate. The growth orientation along c-axis of ZnO nano rods is changed by indium doping and with the increase of indium proportion, the orientation along (101) plane increase. The structure changes from prism-like nano rods to nanofilms due to the different indium proportion. New energy levels are introduce into ZnO causing a blue shift in the green emission region and more oxygen vacancies that results a better blue emission at 404 nm.

5 illus, 22 ref

019138   Javidan K;Pakzad H R (Physics Dep, Ferdowsi Mashhad Univ, 9177 1436 Mashhad, Iran, Email: pakzad@bojnourdiau.ac.ir) : Ion acoustic solitary waves in high relativistic plasmas with superthermal electrons and thermal positrons. Indian J Phys 2012, 86(11), 1037-42.

Propagation of ion acoustic waves in plasmas containing superthermal electrons, thermal positrons and high relativistic ions is investigated. It is shown that the Korteweg-de Vries (KdV) equation describes the nonlinear waves in such plasmas. The effects of relativistic ions and superthermal electrons on the soliton identifications are discussed.

4 illus, 59 ref

019137   Gairola S C (Physics Dep, H N B Garhwal Univ, Pauri Campus, Pauri-246 001, Email: dgsureshc@yahoo.co.in) : Electronic heat capacity of an isotopically disordered semiconductor crystals. Indian J Phys 2012, 86(11), 967-70.

An interaction of an electron with phonon in a crystal shows the dependence of electronic heat capacity on temperature in low temperature limit. It is also found from theory that electronic heat capacity is a linear as well as nonlinear function of electron-phonon coupling constant, linear function of force constant change parameter and polaron state upto second order. An electron Green's function has been evaluated using equation of motion technique of quantum dynamics. The response function has been obtained from electron Green's function to give electron-phonon linewidth and shift. This electron-phonon linewidth has been responsible for electron density of states.

27 ref

019136   Feng X C;Chang T Q (Technology and Physics Dep, Zhengzhou Light Industry Univ, Zhengzhou-450 002, China, Email: fxchao@zzuli.edu.cn) : On the problem of isodoublet of 1<. Indian J Phys 2012, 86(11), 1033-6.

In the framework of meson-meson mass mixing, investigates the mass of isodoublet of the 1³ P₁ meson nonet in the presence of a₁(1260), f₁ (1285) and f₁ (1420) being the 1³P₁ meson state and the decays of the states f₁(1285) and f₁(1420). The results are in agreement with the values predicted by other theoretical approaches and the experimental data. As a byproduct, with the help of the mass of isodoublet of the 1³P₁ meson nonet, we obtain the mixing angle between the K₁(1270) and K₁(1400) mesons. Our results should be tested in the experiment in the future.

1 tables, 34 ref

019135   Dehghan Nezhad A;Moosavi Nejad S M; Nadjafikhah M;Davvaz B (Mathematics Dep, Yazd Univ, Yazd, Iran, Email: davvaz@yazduni.ac.ir) : Physical example of algebraic hyperstructures: leptons. Indian J Phys 2012, 86(11), 1027-32.

Algebraic hyperstructures represent a natural extension of classical algebraic structures in which the composition of two elements of a set is a set, instead of an element. The main purpose of this paper is to provide, for the first time, a physical example of hyperstructures associated with the elementary particle physics, Leptons. We have considered this important group of the elementary particles and shown that this set along with the interactions between its members can be described by the algebraic hyperstructures.

10 tables, 16 ref

019134   Chandra Shekar N V;Sahu P C;Kathirvel V; Chandra S (Condensed Matter Physics Div, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Email: chandru@igcar.gov.in) : Electronic structure of UAl₂ and UGa₂. Indian J Phys 2012, 86(11), 971-6.

To understand and compare the structural stability of UA12 and UGa₂ at room pressure, calculation of electronic structure using full potential linear augmented plane wave (FP-LAPW) method have been performed. The results of calculations with and without including spin-orbit interaction were compared and contrasted. In general, it has been observed that the density of states at the Fermi level E_F increased when the calculations are performed with the inclusion of spin orbit interaction. The spin polarized calculations for UGa₂ have shown that the Fermi level E_F is positioned near a sharp peak in the density of states curve on the antibonding side. On the other hand, in the case of UA12, the E_F lies on the slope of a peak in the density of states curve in the bonding side. The position of the Fermi level and the structural stability under high pressure are correlated.

8 illus, 26 ref

019133   Bassi M;Baluja K L (Physics Dep, Kalindi College, Delhi Univ, New Delhi-110 008, Email: drmonikabassi123@yahoo.co.in) : Polarizability of screened coulomb potential. Indian J Phys 2012, 86(11), 961-6.

Obtained the co-ordinate space wavefunction by the inverse Fourier transform of the momentum space wavefunction for the screened Coulomb potential, V(r) = -e^-μr/r, problem. The dipole polarizability α_d is evaluated in the closure approximation.

2 illus, 2 tables, 23 ref