015640   Thakur P (Physicsl Dep, Alipurduar College, Alipurduar-736 122, Email: prasenjit_thakur1@yahoo.co.in) : Recent observational constraints on generalized chaplygin gas in UDME scenario. Pramana J Phys 2017, 88(3), 89-96.

Recent observational predictions suggest that our Universe is passing through an accelerating phase in the recent past. This acceleration may be realized with the negatively pressured dark energy. Generalized Chaplygin gas may be suitable to describe the evolution of the Universe as a candidate of unified dark matterenergy (UDME) model. Its EoS parameters are constrained using (i) dimensionless age parameter (H₀t₀) and (ii) the observed Hubble (H(z) - z) data (OHD) + baryon acoustic oscillation (BAO) data + cosmic microwavebackground (CMB) shift data + supernovae (Union2.1) data. Dimensionless age parameter puts loose bounds on the EoS parameters. Best-fit values of the EoS parameters H₀, A_s and α (A_s and α are defined in the energy density for generalized Chaplygin gas (GCG) and in EoS) are then determined from OHD+BAO+CMB+Union2.1 data and contours are drawn to obtain their allowed range of values. The present age of the Universe (t₀) and the present Hubble parameter (H₀) have been estimated with 1σ confidence level. Best-fit values of deceleration parameter (q), squared sound speed (c²_s ) and EoS parameter (ω) of this model are then determined. It is seen that GCG satisfactorily accommodates an accelerating phase and structure formation phase.

4 illus, 7 tables, 55 ref

015639   Tangsrirat W (Faculty of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand, Email: drworapong@yahoo.com) : Compact quadrature oscillator with voltage and current outputs using only single VDTA and grounded capacitors. Indian J pure appl Phys 2017, 55(4), 254-60.

A possible design of the compact sinusoidal quadrature oscillator using single voltage differencing transconductance amplifier (VDTA) and only two grounded capacitors has been presented. The presented quadrature oscillator provides the following attractive properties: (i) canonic form and resistor less structure; (ii) availability of the explicit quadrature voltage outputs and current outputs; (iii) electronic controllability of the oscillation frequency (ω₀); and (iv) low active and passive sensitivities. To support the validity of the oscillator, - 74 - PSPICE simulation results have also been provided.

8 illus, 2 table, 28 ref

015638   Sushil Kumar;Singh S;Sharma J K;Goel A;Kalra K (NO, Maharishi Markandeshwar Univ Mullana, Ambala-133 207, Email: sushil.rathi179@gmail.com) : Signature splitting in two quasiparticle rotational bands of <. Pramana J Phys 2016, 87(1), 1-12.

The signature splittings in K^π=1⁺:7/2[404]_π<165>9/2[624]_v, K^π = 0^-:9/2[514]_π⊕9/2[624]_{v< D> bands of ¹⁸⁰Ta and K^π=0^-:7/2[404]π<165>7/2[503]v, K^π = 1^-: 5/2[402]π⊕3/2[512]v, K^π = 1⁺ 7/2[402]π ⊕9/2[624]v, bands of ¹⁸²Ta are analysed within the framework of two-quasiparticle rotor model. The phase as well as magnitudeof the experimentally observed signature splitting in K^π = 1⁺ band of ¹⁸⁰Ta, which could not be explained in earlier calculations, is successfully reproduced. The conflict regarding placement of a 12⁺ level in K^π = 1⁺:7/2⁺[404]π⊕9/2 ⁺[624]v K^π = ground-state rotational band of ¹⁸⁰Ta is resolved and tentative nature of K^π = 0^-:7/2[404]π⊕7/2[503]<112>, K^π = 0^-:7/2[404]π⊕9/2[624]<112> bands observed in ¹⁸²Ta is confirmed. As a future prediction for experimentalists, these two-quasiparticle structures observed in ¹⁸⁰Ta and ¹⁸²Ta are extended to higherspins.}

6 illus, 6 table, 31 ref

015637   Sudheer K S;Sabir M (Physics Dep, Christ College, Irinjalakuda, Calicut Univ, Thrissur-680 125, Email: sudheersebastian@yahoo.com) : Modified function projective combination synchronization of hyperchaotic systems. Pramana J Phys 2017, 88(3), 1-6.

In this work, a novel combination synchronization scheme in which synchronization of a new combination hyperchaotic drive system formed by combining state variables of the original drive system with appropriate scaling factors with a - 73 - response hyperchaotic system is considered. A self-combination system is constructed from hyperchaotic Lorenz system by combining state variables of the Lorenz system with appropriate scaling factors. Modified function projective synchronization between the newly constructed combination hyperchaotic Lorenz system and hyperchaotic Lu system is investigated using adaptive method. By Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two systems as modified function projective synchronized. Numerical simulations are done to show the validity and effectiveness of the proposed synchronization scheme.

7 illus, 27 ref

015636   Su X (School of Mathematics and Physics, North China Electric Power Univ, Baoding 071 003, China, Email: suxh2005@163.com) : Hall and ion-slip effects on the unsteady MHD mixed convection of Cu-water nanofluid over a vertical stretching plate with convective heat flux. Indian J pure appl Phys 2017, 55(8), 564-73.

The problem of unsteady MHD mixed convective flow of a Cu-water nanofluid over a vertical convectively heated plate has been analyzed. The effects of Hall and ion-slip currents have also been taken into consideration. The governing nonlinear partial differential equations have been reduced to a system of nonlinear coupled similarity equations. The resulting similarity equations have been solved numerically to obtain the axial velocity, transverse velocity and temperature in the corresponding boundary layers. It has been found that the variations of the Hall and ion-slip parameters can remarkably affect the velocity and temperature distributions of the nanofluid. Further, the transfer characteristics of the axial velocity, the transverse velocity and the temperature of Cu-water nanofluid under various values of unsteadiness parameter, magnetic parameter, the boundary convection parameter and the mixed convection parameter have been described and discussed, respectively.

22 illus, 1 table, 27 ref

015635   Sreedevi G;Prasada Rao D R V;Makinde O D; Reddy G V R (Mathematics Dep, K L Univ, Green Fields, Vaddeswaram, Guntur-522 502, Email: sreedevihari2007@gmail.com) : Soret and fufour effects on MHD flow with heat and mass transfer past a permeable stretching sheet in presence of thermal radiation. Indian J pure appl Phys 2017, 55(8), .

An analysis has been carried out to study the combined effects of the magnetic field, Joule heating, thermal radiation absorption, viscous dissipation, Buoyancy forces, thermal-diffusion and diffusion-thermion the convective heat and mass transfer flow of an electrically conducting fluid over a permeable vertically stretching sheet. The boundary layer equations for the fluid flow, heat and mass flux under consideration have been obtained and reduced into a system of non-linear ordinary differential equations by using appropriate similarity transformation. Using shooting method coupled with the fourth order Runge-Kutta integration scheme, the numerically solutions have been obtained and presented graphically. The effects of various embedded thermo-physical parameters on the fluid velocity, temperature, skin friction, Nusselt number and Sherwood number have been determined and discussed quantitatively. A comparison of a special case of our results with the one previously reported in the literature shows a very good agreement. An increase in values of thermal radiation, viscous dissipation, suction/injection coefficient and chemical reaction results in the increase of velocity, temperature and heat-mass transfer rates. It is further noted that the velocity, temperature and heat-mass transfer rates reduces on the boundary layer of a permeable vertical stretching sheet due to increase in the values of Soret or decrease in values of Dufour. Further, this work leads to study different flows of electrically conducting fluid over a permeable vertical stretching sheet problem that includes the two dimensional non-linear boundary equations.

30 illus, 2 tables, 52 ref

015634   Soni K K;Maheshwari K P (Pure & Applied Physics Dep, Kota Univ, Kota-324 005, Email: sonikrishna1490@gmail.com) : Nonlinear interaction of ultraintense laser pulse with relativistic thin plasma foil in the radiation pressure-dominant regime. Pramana J Phys 2016, 87(5), 1-6.

Authors present a study of the effect of laser pulse temporal profile on the energy/momentum acquired by the ions as a result of the ultraintense laser pulse focussed on a thin plasma layer in the radiation pressuredominant(RPD) regime. In the RPD regime, the plasma foil is pushed by ultraintense laser pulse when the radiation cannot propagate through the foil, while the electron and ion layers move together. The nonlinear character of laser-matter interaction is exhibited in the relativistic frequency shift, and also change in the wave amplitude as the EM wave gets reflected by the relativistically moving thin dense plasma layer. Relativistic effects in a highenergy plasma provide matching conditions that make it possible to exchange very effectively ordered kineticenergy and momentum between the EM fields and the plasma. When matter moves at relativistic velocities, the efficiency of the energy transfer from the radiation to thin plasma foil is more than 30% and in ultrarelativisticcase it approaches one. The momentum/energy transfer to the ions is found to depend on the temporal profile of the laser pulse. Our numerical results show that for the same laser and plasma parameters, a Lorentzian pulse canaccelerate ions upto 0.2 GeV within 10 fs which is 1.5 times larger than that a Gaussian pulse can.

6 illus, 21 ref

015633   Singh R P;Joshi P;Chamoli S K;Muralithar S; Mukherjee G;Bhowmik R K;Pancholi S C (NO, Inter Univ Accelerator Centre (IUAC), P.O Box 10502, New Delhi-110 067, Email: rps_inuk@yahoo.com ) : Lifetime measurement in the yrast band of the gamma- soft nuclei <. Pramana J Phys 2016, 87(1), 1-11.

Lifetimes of excited states in the yrast band of the gamma-soft nuclei ¹³¹Ce and ¹³³Pr have been measured using the recoil distance Doppler shift and Doppler shift attenuation methods. The yrast bands in ¹³¹Ce and ¹³³Pr are based on odd decoupled neutron vh_11/2 high Ω and proton πh_11/2 low Ω orbitals, respectively. The triaxiality parameter extracted from the experimentally deduced values of transition quadrupole moments, within the framework of cranked Hartree-Fock-Bogoliubov (CHFB) and total Routhian surface (TRS) calculatons, is γ -80° for the band in ¹³¹Ce at high spins, while for the band in ¹³³Pr, the value of γ is close to 0°. This agrees well with the γ shape polarization property of high and low Ωh_11/2 orbitals in these gamma-soft nuclei.

12 illus, 2 table, 38 ref

015632   Singh C P;Srivastava M (Applied Mathematics Dep, Delhi Technological Univ (Formerly Delhi College of Engineering), Bawana Road, Delhi-110 042, Email: spsphd@rediffmail.com) : Minimally coupled scalar field cosmology in anisotropic cosmological model. Pramana J Phys 2017, 88(2), 7-16.

Authors were study a spatially homogeneous and anisotropic cosmological model in the Einstein gravitational theory with a minimally coupled scalar field. We consider a non-interacting combination of scalar field and perfect fluid as the source of matter components which are separately conserved. The dynamics of cosmic scalar fields with a zero rest mass and an exponential potential are studied, respectively. We find that both assumptions of potential along with the average scale factor as an exponential function of scalar field lead to the logarithmic formof scalar field in each case which further gives power-law form of the average scale factor. Using these forms of the average scale factor, exact solutions of the field equations are obtained to the metric functions which represent a power-law and a hybrid expansion, respectively. We find that the zero-rest-mass model expands with decelerated rate and behaves like a stiff matter. In the case of exponential potential function, the model decelerates, accelerates or shows the transition depending on - 71 - the parameters. The isotropization is observed at late-time evolution of the Universe in the exponential potential model.

2 illus, 55 ref

015631   Singh B P;Rakesh Kumar;Ashwani Kumar;Mahesh Kumar;Joshi A G (Physics Dep, C C S Univ, Meerut-250 004, Email: drbeerpal@gmail.com) : Vacuum thermal deposition of crystalline, uniform and stoichiometric CdS thin films in ambient H₂S atmosphere. Indian J pure appl Phys 2017, 55(7), 463-70.

Crystalline, uniform and stoichiometric thin films of CdS have been fabricated on soda lime glass (SLG) substrates using vacuum thermal deposition method in the presence of hydrogen sulphide (H₂S) atmosphere. The consequence of ambient H₂S on the growth, quality and structure-property relationship of vacuum deposited CdS thin films has been investigated. The deposited films have been characterized by XRD, SEM with EDX analysis, AFM, XPS and optical spectroscopy. The physical characterization of as-deposited CdS films reveals that the films deposited in controlled H₂S ambient are more crystalline, highly uniform and stoichiometric in comparison to films deposited without H₂S atmosphere.

6 illus, 52 ref

015630   Sharma R;Ishak A;Pop I (Mathematics Dep, National Institute of Technology Hamirpur, Hamirpur-177 005, Email: raj.juit@gmail.com) : Dual solution of unsteady seperated stagnation- point flow in a nanofluid with suction: A finite element analysis. Indian J pure appl Phys 2017, 55(4), 275-83.

Unsteady two-dimensional stagnation-point flow of a viscous - 70 - and incompressible fluid filled by a nanofluid over a permeable flat plate with suction has been investigated numerically. The mathematical model used for the nanofluid incorporates the effect of Brownian motion and thermophoresis. The velocity of the ambient (inviscisd) fluid has been assumed to vary linearly with the distance from the stagnation-point. The resulting non-linear governing equations with associated boundary conditions have been solved numerically using finite element method (FEM). The effect of the unsteadiness parameter A, mass suction parameter s, Lewis number Le, the Brownian motion parameter Nb and the thermophoresis parameter Nt on the flow, temperature and nanoparticle concentration in the boundary layer region have been analyzed graphically. The impact of the unsteadiness parameter and mass suction/injection parameter on the skin friction, rate of heat transfer and mass transfer have been examined and discussed. Interesting observation is that dual solutions exist for a certain range of the suction/injection parameter, and this range decreases with increasing values of the unsteadiness parameter.

12 illus, 2 table, 51 ref

015629   Sathiyaraj P;Samuel E J J (Physics Dep, Medical Gel Dosimetry Laboratory. VIT Univ, Vellore-632 014, Email: ejames@vit.ac.in) : Radiological properties of selective monomers of polymer gel dosimeter in radiotherapy application. Asian J Chem 2017, 29(3), 601-4.

The goal of this study is to calculate the electron density, effective atomic number, mass attenuation and mass energy absorption co-efficient and kinetic energy released per unit mass for five different monomers, which are used in the polymer gel dosimeter in radiotherapy application. Power law method and Auto-Z_eff software were used to calculate the effective atomic number. National Institute of Standard and Technology (NIST) database was used to calculate mass attenuation and energy absorption coefficient. Electron density of the acrylamide was higher (3.40E + 23 e/cm³) than other monomers and N-isopropyal acrylamide has least electron density (2.76E + 23 e/cm³). Each monomer has an identical effective atomic number over the energy range from 0.01 to 20 MeV. The rapid fall occurred in the kinetic energy released per unit mass at low energy. At low energy region kinetic energy released per unit mass of acrylic acid was higher than others and it was opposite in higher energy region. The behaviour of kinetic energy released per unit mass and effective atomic number similar with function of energy. Effective atomic number of n-vinyalpyrrolidine has good agreement with water (0.003 % discrepancy).

6 illus, 3 tables, 28 ref

015628   Sarkar D;Paul N;Bhattacharya K;Ghosh T K (NO, Inter-Univ Center for Astronomy and Astrophysics, Ganeshkind, Pune-411 007, Email: debajyoti@iucaa.in) : Effective hamiltonian approach to quantum random walk. Pramana J Phys 2017, 88(3), 35-48.

In this article authors present an effective Hamiltonian approach for discrete time quantum random walk. A form of the Hamiltonian for one-dimensional quantum walk has been prescribed, utilizing the fact that Hamiltoniansare generators of time translations. Then an attempt has been made to generalize the techniques to higher dimensions. We find that the Hamiltonian can be written as the sum of a Weyl Hamiltonian and a Dirac comb potential. The time evolution operator obtained from this prescribed Hamiltonian is in complete agreement with that of the standard approach. But in higher dimension we find that the time evolution operator is additive, instead of being multiplicative (see Chandrashekar, Sci.RepSci.Rep. 3, 2829 (2013)). We showed that in the case of two-step walk, the time evolution operator effectively can have multiplicative form. In the case of a square lattice, quantum walk has been studied computationally for different coins and the results for both the additive and the multiplicative approaches have been compared. Using the graphene Hamiltonian, the walk has been studied on a graphene lattice and we conclude the preference of additive approach over the multiplicative one.

14 illus, 33 ref

015627   Sanjay Kumar;Sharma S K;Pandey O P (NO, Thpar Univ, Patiala, Punjab-147 004, Email: sanjay2076@gmail.com) : Analysis of volume dependence of thermal expansivity for NaCl. Indian J pure appl Phys 2017, 55(4), 293-6.

In the paper, a suitable model to evaluate the volume dependence of thermal expansivity a by using the reciprocal form of volume dependence of Anderson-Gruneisen parameter (δ_T) has been proposed. The newly developed relationship has satisfied the constraints of infinite pressure behavior, i.e., P → ∞ or V → 0. The results obtained through the present model show the consistency with the experimental data for NaCl.

1 illus, 28 ref

015626   Saha A;Talukdar B;Das U;Chatterjee S (Physics Dep, Visva Bharati Univ, Santiniketan-731 235, Email: binoy123@bsnl.in) : Solitons, compactons and undular bores in Benjamin-Bona-Mahony-like systems. Pramana J Phys 2017, 88(2), 63-76.

Authors examine the effect of dissipation on travelling waves in nonlinear dispersive systems modelled by Benjamin-Bona-Mahony (BBM)-like equations. In the absence of dissipation, the BBM-like equations are found to support soliton and compacton/anticompacton solutions depending on whether the dispersive term islinear or nonlinear. We study the influence of increasing nonlinearity of the medium on the soliton and compacton dynamics. The dissipative effect is found to convert the solitons either to undular bores or to shock-like waves depending on the degree of nonlinearity of the equations. The anticompacton solutions are also transformed to undular bores by the effect of dissipation. But the compactons tend to vanish due to viscous effects. The local oscillatory structures behind the bores and/or shock-like waves in the case of solitons and anticompactons are found to depend sensitively both on the coefficient of viscosity and solution of the unperturbed problem.

34 illus, 24 ref

015625   Rupini B;Kumar Y;Akdag H;Varlikli C;Shulga Y M;Shulga N Y;Kasana V K (School of Interisciplinary and Transdisciplinary Studies, Indira Gandhi National Open Univ, New Delhi-110 068, Email: ykbssi@gmail.com) : Physico-chemical properties of some polymer blended task specific novel S-(+)-2-3-dihydroxy-N, N, N-tributyl-propanaminiumtriflate and - 68 - 1-(2-propoxy)-3-methylimdazolium-borohydride room temperature ionic liquids. Indian J pure appl Phys 2017, 55(7), 503-11.

Two novel chiral ionic liquids S-(+)-2-3-dihydroxy-N, N, N-tributyl-propanaminiumtriflate and 1-(2-propoxy)-3-methylimdazolium-borohydride have been prepared using conventional metathesis reaction. These ionic liquids have been subjected to solution cast method followed by ultrasonication to obtain the corresponding ionic liquid gel polymer electrolytes with poly (vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP), free-standing, rubbery, dimensionally stable films with a high degree of transparency have been obtained. Thermo-gravimetric analysis confirms that the intermediate solvent, acetone used for mixing PVDF-HFP polymer with ionic liquid is completely evaporated after gelation and drying process. Further thermal properties have been analyzed by differential scanning calorimetry. Scanning electron microscopy micrographs show the different surface morphology of the gel electrolytes according to nature of the ionic liquid. The structural information has been extracted by X-ray diffraction. The ionic conductivities of both polymer-ionic liquid blends are in the order of 10^-3 to 10^-5 S cm^-1. Electrochemical stability window of these polymer electrolytes ranges from 4.0 to 5.0 V. Various physicochemical properties and fast ion conduction in the gel polymer membranes show their promising characteristics as electrolytes in different ionic devices.

10 illus, 30 ref

015624   Ray H (NO, , Study Centre, S-1/407/6, B.P. Township, Kolkata-700 094, Email: hasi_ray@yahoo.com) : Dependence of scattering length on van der waals interaction and reduced mass of the system in two-atomic collision at cold energies. Pramana J Phys 2016, 87(1), 1-5.

The static exchange model (SEM) and the modified static exchange model (MSEM) recently introduced by Ray in {it Pramana - J. Phys.} 83, 907 (2014) are used to study the elastic collision between two hydrogen-like atoms when both are in ground states by considering the system as a four-body Coulomb system in the centre of mass frame, in which all the Coulomb interaction terms in direct and exchange channels are treated exactly. The SEM includes the non-adiabatic short-range effect due to electron exchange. The MSEM added init, the long-range effect due to induced dynamic dipole polarizabilities between the atoms e.g., the van der Waals interaction. Applying the SEM code in different H-like two-atomic systems, a reduced mass (μ) dependence on the scattering length is observed. Again, applying the MSEM code on H(1s)-H(1s) elastic scattering and varying the minimum values of interatomic distance R₀, the dependence of scattering length on the effective interatomic potential consistent with the existing physics is observed. Both these basic findings in low and cold energy atomic collision physics are quite useful and are being reported for the first time.

2 illus, 2 table, 18 ref

015623   Qi X;Lin W (School of Physical Science and Technology, Southwest Jiaotong Univ, Chengdu 610031, China, Email: wl@swjtu.edu.cn) : Filamentation of ultrashort laser pulses of different wavelengths in Argon. Pramana J Phys 2017, 88(2), 125-128.

Author investigate the filaments formed by the ultrashort laser pulses with different wavelengths of 400 nm, 586 nm and 800 nm propagating in argon. Numerical results show that, when the input power or the ratio of the input power to the critical power is given, the pulse with 400 nm wavelength has the largest on-axis intensity, as well as the narrowest filament and the most stable beam radius. These results indicate that the pulse with shorter wavelength is more suitable for the long-range propagation in argon.

2 illus, 1 table, 31 ref

015622   Pratiwi B N;Suparmi A;Cari C;Husein A S (Physics Dep, Graduate Program, Sebelas Maret Univ, Jl.Ir. Sutami 36A Kentingan Surakarta 57126, Indonesia, Email: namakubetanurpratiwi@gmail.com) : Asymptotic iteration method for the modified poschl-teller potential and trigonometric scarf II non-central potential in the dirac equation spin symmetry. Pramana J Phys 2017, 88(2), 31-39.

Analytical solution of the Dirac equation for the modified Poschl-Teller potential and trigonometric Scarf II non-central potential for spin symmetry is studied using asymptotic iteration method. One-dimensional Dirac equation consisting of the radial and angular parts can be obtained by the separation of variables. By usingasymptotic iteration method, the relativistic energy equation - 67 - and orbital quantum number (l) equation can be obtained, where both are interrelated. Relativistic energy equation is calculated numerically by the Matlab software. The increase in the radial quantum number n_r

3 illus, 3 tables, 33 ref

015621   Prasad Y B S R;Barnwal S;Naik P A;Yadav Y; Patidar R;Kamath M P;Upadhyay A;Bagchi S;Kumar A;Joshi A S;Gupta P D (Laser Plasma Div, Raja Ramanna Centre for Advanced Technology, Indore-452 013, Email: yprasad@rrcat.gov.in) : Shock wave propogation in soda lime glass using optical shadowgraphy. Pramana J Phys 2016, 87(1), 1-8.

Propagation of shock waves in soda lime glass, which is a transparent material, has been studied using the optical shadowgraphy technique. The time-resolved shock velocity information has been obtained (1) in single shot, using the chirped pulse shadowgraphy technique, with a temporal resolution of tens of picoseconds and (2) in multiple shots, using conventional snapshot approach, with a second harmonic probe pulse. Transient shock velocities of (5-7) x 10⁶ cm/s have been obtained. The scaling of the shock velocity with intensity in the 2 x 10¹³ - 10¹⁴ W/cm² range has been obtained. The shock velocity is observed to scale with laser intensity as I^0.38. The present experiments also show the presence of ionization tracks, generated probably due to X-ray hotspots from small-scale filamentation instabilities. The results and various issues involved in these experiments are discussed.

7 illus, 1 table, 29 ref

015620   Prajapati A N (Applied Physics Dep, The Maharaja Sayajirao Univ of Baroda, Vadodara-390 002, Email: anprjapati2006@yahoo.co.in) : Acoustic and refractometric study of binary mixtures of 1-propanol +Benzonitrile at 313K. Indian J pure appl Phys 2017, 55(4), 297-303.

Ultrasonic speed (U), refractive index (n) and density (ρ) for binary mixtures of various concentrations of 1-Propanol (1-PrOH) with Benzonitrile (BN) have been measured at constant temperature 313 K. Various acoustic and optical parameters have been determined from the measured values of ultrasonic speed, refractive index and density of binary liquid mixtures. Excess of measured acoustic and optical parameters have been evaluated and fitted in R-K polynomial. The deviations in the sign and values of these parameters from the ideal mixing reveal inter-molecular interactions in the liquid mixture. Several theoretical mixing relations for ultrasonic speed and refractive index for the binary mixtures have been applied and verified for the same.

3 illus, 6 table, 27 ref

015619   Pradhan P (Physics Dep, Vivekananda Satavarshiki Mahavidyalaya, Manikpara, Jhargram, West Midnapur-721 513, Email: ppradhan77@gmail.com) : Stability analysis and quasinormal modes of Reissner-Nordstrom space -time via lyapunov exponent. Pramana J Phys 2016, 87(1), 1-9.

Explicitly derive are The proper-time (τ) principal Lyapunov exponent (λ_p) and coordinate-time (t) principal Lyapunov exponent (λ_c) for Reissner-Nordstrom (RN) black hole (BH). Also their ratio computed. For RN space-time, it is shown that the ratio is (λ_p/λ_c)=r₀/<18 2>r²₀ - 3Mr₀ + 2Q² for time-like circulargeodesics and for Schwarzschild BH, it is (λ_p/λ_c) = √r₀/√r₀ - 3M. We further show that their ratio λ_p/λ_c may vary from orbit to orbit. For instance, for Schwarzschild BH at the inner most stable circular orbit (ISCO), the ratio is may vary from orbit to orbit. For instance, for Schwarzschild BH at the innermost stable circular orbit(ISCO), the ratio is (λ_p/λ_c)|_{rISCO=6M< D> = √2 and at marginally bound circular orbit (MBCO) the ratio is calculated to be (λp/λc)|rmb=4M = 2. Similarly, for extremal RNBH, the ratio at ISCO is (λp/λc)|rISCO=4M< D> = 2√2/√3. We also further analyse the geodesic stability via this exponent. By evaluating the Lyapunov exponent, it is shown that in the eikonal limit, the real and - 66 - imaginary parts of the quasinormal modes of RN BH is given by the frequency and instability time-scale of the unstable null circular geodesics.}

1 illus, 35 ref

015618   Pandey A;Verma M K;Chatterjee A G;Dutta B (Physics Dep, Indian Institute of Technology, Kanpur-208 016, Email: ambrishiitk@gmail.com) : Similarities between 2D and 3D convection for large Prandtl number. Pramana J Phys 2016, 87(1), 1-10.

Using direct numerical simulations of Rayleigh-Benard convection (RBC), we perform a comparative study of the spectra and fluxes of energy and entropy, and the scaling of large-scale quantities for large and infinite Prandtl numbers in two (2D) and three (3D) dimensions. We observe close similarities between the 2D and 3D RBC, in particular, the kinetic energy spectrum E^u(k) <126> k^-13/3, and the entropy spectrum exhibits a dual branch with a dominant k^-2 spectrum. We showed that the dominant Fourier modes in 2D and 3D flows are very close. Consequently, the 3D RBC is quasi-two-dimensional, which is the reason for the similarities between the 2D and 3D RBC for large and infinite Prandtl numbers.

13 illus, 2 table, 21 ref

015617   Nikhil Raj;Singh A K;Gupta A K (Computer and Communication Engineering Dep, Manipal Univ, Jaipur-302 006, Email: nikhilpub@gmail.com) : Low voltage high bandwidth self-biased high swing cascode current mirror. Indian J pure appl Phys 2017, 55(4), 245-53.

A low voltage self-biased high swing cascode current mirror (SHCCM) with improved bandwidth has been proposed. The recently reported SHCCM architecture use the bulk-driven quasi-floating gate (BDQFG) MOS transistors to enhance the effective transconductance which improves the current mirror input resistance and bandwidth range over the same architecture realized using bulk-driven MOS transistors. To further improve the bandwidth the proposed BDQFG based SHCCM uses two resistances which makes the current mirror frequency response free from input capacitors and also reduces the parasitic capacitance effect which - 65 - results in increased bandwidth with an advantage of having no degradation in other performance parameters of current mirror. The proposed current mirror operates well for input current range from 0 to 200 μA with good linearity and shows the bandwidth of 298 MHz (i.e., 1.6 times over prior reported BDQFG based SHCCM). The observed input and output resistance is 306 O and 165 ΩO, respectively. Further, the THD analysis is carried to prove the robustness of proposed current mirror. The complete analysis is performed on UMC 0.18 μm technology using HSpice.

18 illus, 3 table, 27 ref

015616   Mukesh Kumar;Sawhney N;Sharma A K;Sharma M (Chemistry Dep, Jammu Univ, Jammu-180 006, Email: mlakhanpal123@gmail.com ) : Study of acoustical parameters of cupric oxide nanoparticles dispersed in aqueous solutions of various glycols. Indian J pure appl Phys 2017, 55(8), 574-82.

In this study cupric oxide (CuO) nanoparticles have been synthesised by precipitation method using cupric acetate dihydrate [Cu(CH₃COO)₂.2H₂O] as a starting material. The synthesised nanoparticles have been characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). These nanoparticles have been dispersed in three different base fluids which are 10% aqueous solutions of ethylene glycol (EG), propylene glycol (PG) and hexylene glycol (HG). Ultrasonic velocity (U), density (ρ) and viscosity (η) of these nanofluids have been measured at different concentrations of CuO nanoparticles as a function of temperatures (T = 303.15 K, 308.15 K and 313.15 K). Using these values various acoustical parameters such as adiabatic compressibility, intermolecular free length, relaxation time, acoustic impedance and attenuation coefficient have been evaluated.

19 illus, 4 tables, 34 ref

015615   Mugemana A;Moolla S;Lazarus I J (School of Chemistry and Physics, KwaZulu-Natal Univ, Durban 4000, South Africa, Email: Moollas@ukzn.ac.za) : Nonlinear waves in electron-positron-ion plasmas including charge separation. Pramana J Phys 2017, 88(2), 17-24.

Nonlinear low-frequency electrostatic waves in a magnetized, three-component plasma consisting of hot electrons, hot positrons and warm ions have been investigated. The electrons and positrons are assumed to have Boltzmann density distributions while the motion of the ions are governed by fluid equations. The system is closed with the Poisson equation. This set of equations is numerically solved for the electric field. The effects of the driving electric field, ion temperature, positron density, ion drift, Mach number and propagation angle are investigated. It is shown that depending on the driving electric field, ion temperature, positron density, ion drift, Mach number and propagation angle, the numerical solutions exhibit waveforms that are sinusoidal, sawtooth andspiky. The introduction of the Poisson equation increased the Mach number required to generate the waveforms but the driving electric field E0 was reduced. The results are compared with satellite observations.

6 illus, 27 ref

015614   Mousavi M;Shojaei M R (Physics Dep, Shahrood Univ of Technology, P.O. Box 3619995161-316, Shahrood, Iran, Email: nuclear.physics2020@gmail.com) : Bound-state energy of double magic number plus one nucleon nuclei with relativistic mean-field approach. Pramana J Phys 2017, 88(2), 1-5.

In this work, we have obtained energy levels and charge radius for the β-stability line nucleus, in relativistic shell model. In this model, we considered a close shell for each nucleus containing double magicnumber and a single nucleon energy level. Here we have taken ⁴¹Ca with a single neutron in the ⁴⁰Ca core as an illustrative example. Then we have selected the Eckart plus Hulthen potentials for interaction between the coreand the single nucleon. By using parametric Nikiforov-Uvarov (PNU) method, we have calculated the energy values and wave function. Finally, we have calculated the charge radius for ¹⁷O, ⁴¹Ca, ⁴⁹Ca and ⁵⁷Ni. The results are in agreement with experimental values and hence this model can be applied for similar nuclei.

2 tables, 46 ref

015613   Mohamed M;Dib A S A;Belbachir A H (Physics Dep, Univ of Blida 1, Blida, Algeria, Email: ouldmohamedmounir79@gmail.com) : Energy distribution of cosmic rays in the earth's atmosphere and avionic area using Monte Carlo codes. Pramana J Phys 2016, 87(1), 1-5.

Cosmic rays cause significant damage to the electronic equipments of the aircrafts. In this paper, we have investigated the accumulation of the deposited energy of cosmic rays on the Earth's atmosphere, especially in the aircraft area. In fact, if a high-energy neutron or proton interacts with a nanodevice having only a few atoms, this neutron or proton particle can change the nature of this device and destroy it. Our simulation based on Monte Carlo using Geant4 code shows that the deposited energy of neutron particles ranging between 200 MeV and 5 GeV are strongly concentrated in the region between 10 and 15 km from the sea level which is exactly the avionic area. However, the Bragg peak energy of proton particle is slightly localized above the avionic area.

5 illus, 1 table, 20 ref

015612   Moghtader Dindarlu M H;Kavosh Tehrani K; Saghafifar H;Maleki A;Solookinejad G H;Jabbari M (Physics Dep, Marvdasht Branch, Islamic Azad Univ, Marvdasht, Iran, Email: elsa27m@gmail.com) : Influence of absorbed pump profile on the temperature distribution within a diode side-pumped laser rod. Pramana J Phys 2017, 88(2), 129-134.

In this paper, an analytical model for temperature distribution of the side-pumped laser rod is extracted. This model can be used for side-pumped laser rods whose absorbed pump profile is a Gaussian profile. Then, it is validated by numerical results which exhibit a good agreement with the analytical results. Afterwards, by considering a general expression for super-Gaussian and top-hat profiles, and solving the heat equation, the influence of profile width and super-Gaussian exponent of the profile on temperature distribution are investigated.Consequently, the profile width turns out to have a greater influence on the temperature compared to the type of the profile.

5 illus, 2 tables, 25 ref

015611   Mirmoeini S R;Elahi A S;Ghoranneviss M (NO, Plasma Physics Research Center, Science and Research Branch, Islamic, Tehran, Iran, Email: Salari_phy@yahoo.com) : Analysis of tokamak plasma confinement modes using the fast fourier transformation. Pramana J Phys 2016, 87(5), 1-6.

The Fourier analysis is a satisfactory technique for detecting plasma confinement modes in tokamaks. The confinement mode of tokamak plasma was analysed using the fast Fourier transformation (FFT). For this purpose, we used the data of Mirnov coils that is one of the identifying tools in the IR-T1 tokamak, with and without external field (electric biasing), and then compared it with each other. After the Fourier analysis of Mirnov coil data, the diagram of power spectrum density was depicted in different angles of Mirnov coils in the 'presenceof external field' as well as in the 'absence of external field'. The power spectrum density (PSD) interprets the manner of power distribution of a signal with frequency. In this article, the number of plasma modes and the safety factor qq were obtained by using the mode number of q = m/n (mm is the mode number). The maximum MHD activity was obtained in 30-35 kHz frequency, using the density of the energy spectrum. In addition, the number of different modes across 0-35 ms time was compared with each other in the presence and absence of theexternal field.

6 illus, 2 tables, 33 ref

015610   Min D;Yu K;Li H J (School of Computer Science and Engineering, Xinjiang Univ of Finance and Economics, Urumqi, Xinjiang 830001, China, Email: yukai.dlut@163.com) : Refinement of the community detection performance by weighted relationship coupling. Pramana J Phys 2017, 88(3), 27-34.

The complexity of many community detection algorithms is usually an exponential function with the scale which hard to uncover community structure with high speed. Inspired by the ideas of the famous modularity optimization, in this paper, we proposed a proper weighting scheme utilizing a novel k-strength relationship whichnaturally represents the coupling distance between two nodes. Community structure detection using a generalized weighted modularity measure is refined based on the weighted k-strength matrix. We apply our algorithm on both the famous benchmark network and the real networks. Theoretical analysis and experiments show that the weighted algorithm can uncover communities fast and accurately and can be easily extended to large-scale real networks.

6 illus, 2 tables, 36 ref

015609   Medhat M E;Shirmardi S P;Singh V P (Experimental Nuclear Physics Dep, Nuclear Research Centre, P.O. 13759, Cairo, Egypt, Email: kudhphyvps@rediffmail.com) : Monte carlo simulation for the estimation of iron in human whole blood and comparison with experimental data. Pramana J Phys 2017, 88(3), 75-79.

Monte Carlo N-particle (MCNP) code has been used to simulate the transport of gamma photon rays of different energies (22, 31, 59.5 and 81 keV) to estimate the iron content in solutions. In this study, MCNP simulation results are compared with experiment and XCOM theoretical data. The simulation shows that theobtained results are in good agreement with experimental data, and better than the theoretical XCOM values. The study indicates that MCNP simulation is an excellent tool to estimate the iron concentration in the blood samples. The MCNP code can also be utilized to estimate other trace elements in the blood samples.

2 illus, 5 tables, 12 ref

015608   Madhok V;Riofrio C A;Deutsch I H (Zoology Dep, British Columbia Univ, 6270 Univ Boulevard, Vancouver, V6T 1Z4, Canada, Email: vmadhok@gmail.com) : Characterizing and quantifying quantum chaos with quantum tomography. Pramana J Phys 2016, 87(5), 1-13.

We explore quantum signatures of classical chaos by studying the rate of information gain in quantum tomography. The tomographic record consists of a time series of expectation values of a Hermitian operator evolving under the application of the Floquet operator of a quantum map that possesses (or lacks) time-reversal symmetry. We find that the rate of information gain, and hence the fidelity of quantum state reconstruction, depends on the symmetry class of the quantum map involved. Moreover, we find an increase in informationgain and hence higher reconstruction fidelities when the Floquet maps employed increase in chaoticity. We make predictions for the information gain and show that these results are well described by random matrix theory inthe fully chaotic regime. We derive analytical expressions for bounds on information gain using random matrix theory for different classes of maps and show that these bounds are realized by fully chaotic quantum systems.

^iia7 illus, 49 ref

015607   Lone M Q (Physics Dep, Kashmir Univ, Srinagar-190 006, Email: lone.muzzafar@gmail.com) : Entanglement dynamics of two interacting qubits under the influence of local dissipation. Pramana J Phys 2016, 87(1), 1-7.

The dynamics of entanglement given by the concurrence of a two-qubit system in the non-Markovian setting are investigated. A quantum master equation is derived, which is solved in the eigenbasis of the system Hamiltonian for X-type initial states. A closed formula for time evolution of concurrence is presented for a pure state. It is shown that under the influence of dissipation non-zero entanglement is created in unentangled twoqubit states which decay in the same way as pure entangled states. We also show that under real circumstances,the decay rate of concurrence is strongly modified by the non-Markovianity of the evolution.

1 illus, 34 ref

015606   Li P;Zhang C;Ren F d;Cao Q;Li X J;Cao R l (College of Chemistry and Chemical Engineering, Taiyuan Univ of Technology, Teaiyuan 030 024, China, Email: fxp12481248@hotmail.com) : Theoretical insight into the structure and stability of TNT and RDX in external electric field. Indian J pure appl Phys 2017, 55(8), 604-15.

A comparison of the effect of external electric field on the C-NO₂ or N-NO₂ bonds with - 61 - the C-H and N-O bonds in 2,4, 6-trinitrotoluene (TNT)or hexahydro-1,3,5-trinitro-s-triazine (RDX) has been carried out using the M06-2x method with the 6-311++G** and aug-cc-pVTZ basis sets. The result shows that for TNT the fields have a minor effect on the C-NO₂ and C-H bonds but a major effect on the N-O bonds, while in RDX the fields greatly affect the N-NO₂ bond but the N-O and C-H bonds are slightly affected. Thus, in TNT the N-O bond can be the trigger bond, and in RDX the N-NO₂ bond is always the trigger bond in electric fields. The explosive sensitivities may be reduced and the stabilities may be increased under the external electric fields in the negative direction along the C-NO₂ bond axis for TNT and in the positive direction along the N-NO₂ or N-O bond axis for RDX. The opposite trends can be suggested in the fields of the opposite directions along above bond axes. The introduction of external electric field into energetic material may be an available way to adjust explosive sensitivity. The analyses of AIM (atoms in molecules) and frequencies support the above viewpoints. The linear correlations between the field strengths and the changes of N-O/N-N bond lengths, ρ_(N-O/N-N) values, or stretching frequencies of the N-O/N-N bonds have been found.

4 illus, 4 tables, 31 ref

015605   Lamba V K;Engles D;Dhariwal S;Ajay Kumar (NO, Global College of Engineering & Technology, Kahnpur Khui-140 117, Email: lamba_vj@hotmail.com) : Study on the effect of bending on CNT's flexible antennas. Indian J pure appl Phys 2017, 55(7), 518-24.

With the development and an increasing interest in flexible electronics for different applications, a patch antenna has been designed and fabricated using carbon nano tube-polymer ink on fabrics. The antenna has been fabricated on cotton and songket fabric which have permittivity of ε_r ≈ 1.5, and 1.6, respectively. The thickness of the fabric substrate has been varied to study the effect on antenna performance in a range of 1.5 mm to 2.2 mm. Measured and simulation results show that bandwidth depends on thickness and type of fabrics used.

10 illus, 3 tables, 34 ref

015604   Kulkarni N S;Dhingra R;Vinit Kumar (Accelerator and Beam Physics Laboratory, Materials and Advanced Accel, Raja Ramanna Centre for Advanced Technology, Indore-452 013, Email: nita@rrcat.gov.in) : Physics design of a 10 MeV, 6 k W travelling wave electron linac for industrial applications. Pramana J Phys 2016, 87(5), 1-16.

Authors present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear accelerator (linac), which has been recently built and successfully operated at Raja Ramanna Centre for Advanced Technology, Indore. The accelerating structure is a 2π/3 mode constant impedance travelling wave structure, which comprises travelling wave buncher cells, followed by regular accelerating cells. The structure is designed to accelerate 50 keV electron beam from the electron gun to 10 MeV. This paper describes the details of electromagnetic design simulations to fix the mechanical dimensions and tolerances, as well as heat loss calculations in the structure. Results of design simulations have been compared with those obtained using approximate analytical formulae. The beam dynamics simulation with space charge is performed and the required magnetic field profile for keeping the beam focussed in the linac has been evaluated and discussed. An important feature of a travelling wave linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Threedimensional transient simulations of the accelerating structure along with the input and output couplers have beenperformed using the software CST-MWS to explicitly demonstrate this feature.

20 illus, 9 tables, 17 ref

015603   Konou K N;Haris M;Lare Y;Baneto M;Napo K (Laboratoire sur I Energie Solaire, Univ de Lome, BP 1515, Lome-Togo, Email: harismuthiah@gmail.com) : Effect of barium doping on the physical properties of zinc oxide nanoparticles elaborated via sonochemical synthesis method. Pramana J Phys 2016, 87(1), 1-7.

The aim of this work is to study the effect of barium (Ba) doping on the optical, morphological and structural properties of ZnO nanoparticles. Undoped and Ba-doped ZnO have been successfully synthesized via sonochemical method using zinc nitrate, hexamethylenetetramine (HMT) and barium chloride as startingmaterials. The structural characterization by XRD and FTIR shows that ZnO nanoparticles are polycrystalline with a standard hexagonal ZnO wurtzite crystal structure. Decrease in lattice parameters from diffraction data shows the presence of Ba²⁺ in the ZnO crystal lattice. The morphology of the ZnO nanoparticles has been determined by scanning electron microscopy (SEM). Incorporation of Ba was confirmed from the elemental analysis using EDX. Optical - 60 - analysis depicted that all samples exhibit an average optical transparency over 80%, in the visible range. Room-temperature photoluminescence (PL) spectra detected a strong ultraviolet emission at 330 nmand two weak emission bands were observed near 417 and 560 nm. Raman spectroscopy analysis of Ba-doped samples reveals the successful doping of Ba ions in the host ZnO.

7 illus, 1 table, 40 ref

015602   Khordad R;Bahramiyan H (Physics Dep, College of Sciences, Yasouj Univ, Yasouj, Iran, Email: rezakh2025@yahoo.com) : Effects of electron-phonon interaction and impurity on optical properties of hexagonal-shaped quantum wires. Pramana J Phys 2017, 88(3), 81-88.

Authors have investigated the influence of electron-phonon (e-p) interaction and hydrogenic donor impurity simultaneously on energy difference, binding energy, the linear, nonlinear and total refractive index changes and absorption coefficients of a hexagonal-shaped quantum wire. For this goal, we have used finite-elementmethod (FEM), a compact density matrix approach and an iterative procedure. It is deduced that energy difference and binding energy decrease by changing the impurity position with and without e-p interaction. The dipole matrix elements have complex behaviours in the presence of impurity with and without e-p interaction. The refractive index changes and absorption coefficients increase and shift towards lower energies by enhancing a1a1 with central impurity. In the presence of central impurity, the absorption coefficients and refractive index changes enhance and shift toward higher energies when e-p interaction is considered.

11 illus, 36 ref

015601   Khanday F A;Beigh I N;Psychalinos C (Electronics and Instrumentation Technology Dep, Kashmir Univ, Srinagar-190 006, Email: farooqsnn20@yahoo.co.in) : 0.5 V log-domain realization of tinnitus detection system. Indian J pure appl Phys 2017, 55(8), 595-603.

A low-voltage tinnitus detection system using log-domain technique has been introduced in this paper. The design offers the advantages of resistorless design, electronic tunability of performance characteristics, and less complexity than the reported ones. The performance of the tinnitus detector has been verified by HSPICE simulation software using the parameters of TSMC CMOS 130 nm process.

24 illus, 6 tables, 27 ref

015600   Khan A;Khattar D;Prajapati N (Mathematics Dep, Jamia Millia Islamia, Delhi-110 025, Email: nitishprajapati499@gmail.com) : Multiswitching combination-combination synchronization of chaotic system. Pramana J Phys 2017, 88(3), 59-67.

In this paper, a novel synchronization scheme is investigated for a class of chaotic systems. Themultiswitching synchronization scheme is extended to the combination-combination synchronization scheme such that the combination of state variables of two drive systems synchronize with different combination of state variables of two response systems, simultaneously. The new scheme, multiswitching combination-combination synchronization (MSCCS), is a notable extension of the earlier multiswitching schemes concerning only the single drive-response system model. Various multiswitching modified projective synchronization schemes are obtained as special cases of MSCCS, for a suitable choice of scaling factors. Suitable controllers - 59 - have been designed and using Lyapunov stability theory sufficient condition is obtained to achieve MSCCS between four hyperchaotic systems and the corresponding theoretical proof is given. Numerical simulations are performed to validate the theoretical results.

5 illus, 37 ref

015599   Katore S D;Kapse D V (Mathematics Dep, Sant Gadge Baba Amravati Univ, Amravati-444 602, Email: dipti.kapse@gmail.com) : Dynamics of Bianchi type-VI₀ Holographic Dark energy models in general relativity and Lyra's geometry. Pramana J Phys 2017, 88(2), 87-94.

In this paper, we have studied the anisotropic and homogeneous Bianchi type-VI00 Universe filled with dark matter and holographic dark energy components in the framework of general relativity and Lyra's geometry. The Einstein's field equations have been solved exactly by taking the expansion scalar (θ) in the model is proportional to the shear scalar (σ). Some physical and kinematical properties of the models are also discussed.

41 ref

015598   Karthikeyan S;Vizhiselvi K (Physics Dep, Dr Ambedkar Government Arts College, Chennai-600 039, Email: physicskarthik@gmail.com) : Fourier self deconvolution and principle components analysis of spirulina based food products in quality - 58 - assessment. Indian J pure appl Phys 2017, 55(7), 525-31.

Biochemical constituent's change in the spirulina based substance items have been studied utilizing Fourier transform infrared spectroscopy (FTIR). The FTIR spectra demonstrate the changes in band area, and intensity which have been used to find both qualitative and quantitative changes in carbohydrate, lipid and protein in the given sample. The quantitative changes in biochemical composition have been studied by measuring the intensity ratio of the chosen band I₂₉₂₄/I₂₈₅₃, I₂₉₂₅/I₁₆₁₅, I₁₅₄₅/I₁₆₅₇ and I₂₉₆₀/I₂₈₇₃. The lipid/protein ratio (I₂₉₂₅/I₁₆₁₅) increments from the chosen commercial samples examined recommending spirulina have regular antioxidative agents. The band area ratio of the methyl, methylene group (usCH₃/uasCH₂+usCH₂) has been computed for a change in fatty acids compositions. Fourier self deconvolution has been utilized to study the biochemical composition changes in commercial samples. The increases in the secondary structure of proteins such as α helix, β turn and β sheet have been seen among the sample. Further the changes in the band area of glycogen, lactic acid have been seen in the spectra after deconvolution. The utilization of principle components analysis (PCA) helps us to find a distinct variation in the sample. PCA demonstrates the prominent band appeared to be highly influenced is amide I and glucose. It has been found that FTIR with PCA can be utilized as a part of subjective and quantitative examination of spirulina based food products.

8 illus, 5 tables, 22 ref

015597   Kaplan M;Bekir A (Mathematics-Computers Dep, Eskisehir Osmangazi Univ, Eskisehir, Turkey, Email: mkaplan@ogu.edu.tr ) : Modified simple equation method for solving some fractional-order nonlinear equations. Pramana J Phys 2016, 87(1), 1-5.

Nonlinear fractional differential equations are encountered in various fields of mathematics, physics, chemistry, biology, engineering and in numerous other applications. Exact solutions of these equations play a crucial role in the proper understanding of the qualitative features of many phenomena and processes in various areas of natural science. Thus, many effective and powerful methods have been established and improved. In this study, we establish exact solutions of the time fractional biological population model equation and nonlinearfractional Klein-Gordon equation by using the modified simple equation method.

2 illus, 31 ref

015596   Joshi B N;Jain A K;Biswas D C;John B V;Gupta Y K;Danu L S;Vind R P;Prajapati G K;Mukhopadhyay S;Saxena A (Nuclear Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: bnjoshi@barc.gov.in) : Search for <. Pramana J Phys 2017, 88(2), 77-85.

In the backdrop of many models, the heavy cluster structure of the ground state of ²⁴Mg has been probed experimentally for the first time using the heavy cluster knockout reaction ²⁴Mg(¹²C, 2¹²C)¹²C in thequasifree scattering kinematic domain. In the (¹²C, 2¹²C) reaction, the direct ¹²C-knockout cross-section was found to be very small. Finite-range knockout theory predictions were much larger for (¹²C, 2¹²C) reaction,indicating a very small ¹²C-¹²C clustering in ²⁴Mg(g.s.). The present results contradict most of the proposed heavy cluster (¹²C+¹²C) structure models for the ground state of ²⁴Mg.

9 illus, 2 tables, 31 ref

015595   Jacob R;Isac J (Physics Dep, C M S College, Kottayam-686 001, Email: reenujacob12@gmail.com) : Dynamic mechanical analysis and thermal degradation of jute fiber reinforced BSFT (Ba_0.6Sr_0.4Fe_xTi_(1-x) O_3-100), (x=0.1)-polypropylene composite. Indian J pure appl Phys 2017, 55(7), 497-502.

Recent research shows that the natural fibers from renewable natural resources have - 57 - greater potential than other man-made fibers. Attempts have been carried out to study the effect of fiber loading and temperature on jute fiber reinforced BSFT (Ba_0.6Sr_0.4Fe_xTi_(1-x) O_3-δ), (x=0.1)-polypropylene composites using DMA and thermal techniques. The intrinsic design and morphology of the components of the system define the dynamic mechanical properties of the composite. For lower temperatures, the storage modulus (E') values are maximum for the neat PP whereas at temperatures above T_g, the E' values have been found to be maximum for composites with higher fiber loading, proving that the incorporation of jute fiber in BSFT-polypropylene matrix induces reinforcing effects at elevated temperatures. The loss modulus and damping peaks have been found to be lowered by the incorporation of fiber. Cole-Cole analysis throws light on the phase behavior of the composite samples. Thermo gravimetric analysis result on the enhanced thermal stability by the incorporation of fibers. The whole study reveals the enhancement in the dynamic, mechanical and thermal properties of the BSFT-PP composite on incorporation of jute fiber.

6 illus, 21 ref

015594   Jacob R;Harikrishnan K P;Mishra R;Ambika G (Physics Dep, The Cochin College, Cochin-682 002, Email: kp_hk2002@yahoo.co.in) : Cross over of recurrence networks to random graphs and random geometric graphs. Pramana J Phys 2017, 88(2), 135-142.

Recurrence networks are complex networks constructed from the time series of chaotic dynamical systems where the connection between two nodes is limited by the recurrence threshold. This condition makes the topology of every recurrence network unique with the degree distribution determined by the probability densityvariations of the representative attractor from which it is constructed. Here we numerically investigate the properties of recurrence networks from standard low-dimensional chaotic attractors using some basic network measuresand show how the recurrence networks are different from random and scale-free networks. In particular, we show that all recurrence networks can cross over to random geometric graphs by adding sufficient amount of noise tothe time series and into the classical random graphs by increasing the range of interaction to the system size. We also highlight the effectiveness of a combined plot of characteristic path length and clustering coefficient in capturing the small changes in the network characteristics.

12 illus, 25 ref

015593   Isik M;Tugay E;Gasanly N (Electrical and Electronics Engineering Dep, Atilim Univ, Ankara 06836, Turkey, Email: mehmet.isik@atilim.edu.tr) : Optical properties of GaS crystals: combined study of temperature-dependent band gap energy and oscillator parameters. Indian J pure appl Phys 2017, 55(8), 583-8.

Optical parameters of gallium sulfide (GaS) layered single crystals have been found through temperature-dependent transmission and room temperature reflection experiments in the wavelength range of 400-1100 nm. Experimental data demonstrates the coexistence of both optical indirect and direct transitions and the shift of the absorption edges toward lower energies by increasing temperature in the range of 10-300 K. Band gap at zero temperature, average phonon energy and electron phonon coupling parameter for indirect and direct band gap energies have been obtained from the analyses of temperature dependences of band gap energies. At high temperatures kT <62><62> ⋅Eph<209>, rates of band gap energy change have been found as 0.56 and 0.67 meV/K for E_gi and E_gd, respectively. Furthermore, the dispersion of refractive index has been discussed in terms of the Wemple-DiDomenico single effective oscillator model. The refractive index dispersion parameters, namely oscillator and dispersion energies, oscillator strength and zero-frequency refractive index, have been found to be 4.48 eV, 24.8 eV, 6.99x10¹³ m^-2 and 2.56, respectively. The results of the present work will provide an important contribution to the research areas related to the characterization and optoelectronic device fabrication using GaS layered crystals.

5 illus, 32 ref

015592   Hazarika B J;Choudhury D K (Centre for Theoretical Studies, Pandu College, Guwahati-781 012, Email: bh53033@gmail.com) : Isgur-wise function in a QCD-inspired potential model with WKB approximation. Pramana J Phys 2017, 88(3), 149-154.

Authors use Wentzel-Kramers-Brillouin (WKB) approximation for calculating the slope and curvature of Isgur-Wise function in a QCD-inspired potential model. This work is an extension of the approximation methods to the QCD-inspired potential model. The approach hints at an effective range of distance for calculating the slope and curvature of Isgur-Wise function. Comparison is also made with those of Dalgarno method and variationallyimproved perturbation theory (VIPT) as well as other models to show the advantages of using WKB approximation.

1 illus, 5 tables, 38 ref

015591   Hajra S (NO, , Indian Physical Society, 2A & SB Raja S.C. Mullick Road, Kolkata-700 032, Email: sankarhajra@yahoo.com) : Spinning earth and its coriolis effect on the circuital light beams: Verification of the special relativity theory. Pramana J Phys 2016, 87(5), 1-5.

Bilger et al (1995), Anderson et al (1994) and Michelson-Gale assisted by Pearson (1925) measure/mention Sagnac effect on the circuital light/laser beams on the spinning Earth. But from the consideration of classical electrodynamics, the effect measured/mentioned by those experimenters is the Coriolis effect, not the Sagnac effect. A simple experiment is suggested here that can easily settle the problem.

2 illus, 7 ref