013882   Sanyal D N (Remote Tooling Section, Technology Development Group, Nuclear Power Corporation of India Ltd., Mumbai-400 094, Email: dnsanyal@npcil.co.in) : Laser applications in nuclear power plants. Pramana J Phys 2014, 82(1), 135-41.

This paper reports the state of the art of using a solid-state Nd: YAG laser for material processing applications such as cutting, welding and drilling of several components of operational nuclear reactors in radioactive environment. We have demonstrated several advantages of laser-based material processing over conventional methods, and these are discussed briefly. At NPCIL, we have used laser techniques to cut stainless steel sheets up to 14 mm thickness and stainless steel weld up to a depth of 3 mm. This remotely operable laser system has been engineered for its robustness with proper fixtures and tooling for various material processing operations on industrial scale.

9 illus, 5 ref

013881   Rizvi I A;Kumar K;Ahmad T;Agarwal A;Chaubey A K (Physics Dep, Aligarh Muslim Univ, Aligarh-202 002, Email: kamalkumar1908@gmail.com) : Energy dependence of pre-equilibrium emission for the (p,xn) reactions in niobium. Indian J Phys 2012, 86(10), 913-8.

Proton induced reactions have been studied in the energy region from ≈ 7.0 to 12.5 MeV for niobium, using the stacked foil activation technique followed by gamma ray spectroscopy. The excitation functions for the production of ^93mMo, ^93mNb and ^89gZr have been determined. The experimental data have been compared with theoretical calculations based on compound reactions in statistical equilibrium as well as on pre-equilibrium reactions.

6 illus, 2 tables, 32 ref

013880   Ravichandran V;Chinnathambi V;Rajasekar S (Physics Dep, Sri K.G.S. Arts College, Srivaikuntam-628 619) : Study of nonescape dynamics in duffing oscillator with four different periodic forces. Indian J Phys 2012, 86(10), 907-11.

The effect of damping and the shape of four different periodic forces on nonescape dynamics in Duffing oscillator with double-hump potential is studied. Particularly, we numerically studied the variation of the amplitude f_e of the external forces above which no attractor exists and the scaling of the size of basin of attraction of bounded motion with damping strength. We found f_e = β e^αd2. The values of a and β are different for different periodic forces. The number of nonescaping initial conditions exhibit power-law variation N = β (f_e -f)^α. For each force different power-law relations are noticed above and below a value of the damping strength. The periodic forces of our interest are sine, modulus of sine, rectified sine and square-waves.

10 illus, 1 table, 24 ref

013879   Rao M C (Physics Dep, Andhra Loyola College, Vijaywada-520 008, Email: raomc72@gmail.com) : Synthesis of bulk LiCoO₂ cathode material for lithium ion batteries. Bull pure appl Sci-Sect D 2011, 30(2), 241-6.

LiCoO₂ bulk cathode is synthesized by sintering a mixture of high purity LiCoO₂ and LbO powder with excess of Li i.e. Li/Co<62> 1.0 by adding Li2O. The X-ray diffraction pattern for LiCoO₂ powder synthesized at 800°C showed a random orientation of three major, well defined reflections of (003), (104) and (101). These peaks were indicated as that polycrystalline structure with R3m layered rock salt structure. The atomic force microscopy data demonstrated that the deposited bulk LiCoO₂ is homogeneous and uniform with regard to the surface topography and thickness. The surface is composed of irregular grains with high root mean square surface roughness. The growth of bulk LiCoO₂ is studied for its effective utilization as cathode material in solid state micro battery application.

013878   Ranjan R K;Vikas Kumar (Physics Dep, Y.N. College, J.P.U. Dighwara, Saran, Chapra, Bihar) : Charge relaxation rate due to acoustic phonon in weakly confined quantum dot systems. Bull pure appl Sci-Sect D 2011, 30(2), 227-30.

Author studied phonon induced single electron relaxation rates in realistic models of weakly confined single and vertically coupled quantum dots. Piezoelectric interaction due to transverse acoustical phonons constituted the major source of scattering for small electron transition energies. For large gaps deformation potential interactions due to longitudinal acoustic phonons was observed. We have observed that proper structure deign made it possible to control the scattering rates of both single quantum dots and coupled quantum dots by orders of magnitudes. If we suppress the scattering rate in single quantum dots can be attained for moderately large lateral confinement. But in the case of coupled quantum dot structures permit to extend it down to fairly weak lateral confinement.

013877   Rani S;Lal J;Singh N (Applied Physics Dep, Shri Krishna Institute of Engineering and Technology, Kurukshetra-136 119, Email: sybuk.lather@gmail.com) : Normal and higher order squeezing in eight-wave mixing process. Indian J Phys 2012, 86(1), 53-9.

Investigated theoretically the generation of squeezed states in spontaneous and stimulated eight wave mixing process. It has been found that squeezing occurs in field amplitude, amplitude-squared, amplitude-cubed and fourth power of amplitude states of fundamental mode in the eight wave mixing process. It is found to be dependent on coupling parameter g interaction time t and phase values of the field amplitude. Eight-wave mixing is a process which involves absorption of three pump photons and emission of four probe photons of same frequency and a signal photon of different frequency. It is shown that squeezing is greater in a stimulated interaction than the corresponding squeezing in spontaneous process. It is found that the degree of squeezing depends upon the photon number in first and higher orders. Author studied the Poissonian behaviour of quantum field in the fundamental mode. It has been found that the field shows sub-Poissonian behaviour in the fundamental mode. The signal to noise ratio has also been studied in different orders and found to be higher in lower orders.

5 illus, 30 ref

013876   Rajesh D;Sunandana C S (NO, School of Physics, Hyderabad Univ, Hyderabad-500 046, Email: sunandana@gmail.com) : Effect of etching on the optical properties of partially iodized commercial silver foils. Indian J Phys 2012, 86(8), 681-6.

Commercial silver foils-typically 10 μ thick have surfaces contaminated by ambient air that limit optical reflectivity and chemical reactivity. To overcome this in order to realize surface enhanced raman scattering substrates and (bio)chemical and optical sensors it is mandatory to employ methods such as chemical etching and partial iodization by exposure to a flux of iodine vapors for durations less than 15 min. The latter operation not only modifies the surface microstructure of the Ag foil but also initiates iodization-which could be monitored through Ag surface plasmons and their gradual conversion to excitons.

9 illus, 2 tables, 16 ref

013875   Rai C S (P.G. Centre Physics Dep, Centre for Research in Microwave, Ram Dayalu Singh College, Muzaffarpur-842 002, Email: rajesh3muz@yahoo.com) : Depolarization of millimeter wave due to non-spherical dust particles in storms. Indian J Phys 2012, 86(8), 709-14.

Theoretical investigation has been carried out to estimate the depolarization of millimeter wave by non-spherical dust particles present in sand and dust storms. For this purpose ellipsoidal shape of dust particles is considered. The concept of differential attenuation has been utilized to quantity the depolarization. It has been found that in general depolarization angle, depolarization and loss due to depolarization produced by ellipsoidal dust particles depend heavily on frequency and optical visibility (particle density). The values of depolarization and loss due to depolarization increase with increasing frequency and decrease with increasing visibility. It has been also observed that the values of differential attenuation increase with increasing frequency for particular visibility and thus depends directly on frequency. Similar experimental observation have been made by Cox Arnold and Hoffman in ice and rain at 19 and 28 GHz. Also the reported values by several workers are between 19.4 and 77.5 dB at 10 GHz frequency for 1 km path length. Basir et al., XPD = 77.5 dB, Ghobrial et al., XPD = 30 dB, McEwan et al., XPD = 19.4 dB for 1 km path length and 15 m visibility at 10 GHz.

7 illus, 16 ref

013874   Rahman A;Podder J (Badic Sciences and Humanities (Physics) Dep, University of Asia Pacific, Dhaka-1209, Email: jpodder@phy.buet.ac.bd) : Effect of EDTA on the growth kinetics, structural, optical and mechanical properties of ADP crystal. Indian J Phys 2012, 86(1), 15-21.

The pure ammonium dihydrogen phosphate (ADP) and ethylenediamine tetra acetic acid (EDTA) added ADP crystals were grown by isothermal evaporation method. The solubility of ADP was determined for five different temperatures. Metastable zone width of aqueous solutions of ADP saturated at different temperatures was determined by nucleation method in pure form and adding with 0.5 mol.% EDTA. The induction period τ was measured and experiments were performed at selected degrees of supersaturation (C/C*) and the critical nucleation parameters like interfacial energy (σ), energy of formation of the critical nucleus (ΔG*) were calculated based on the classical theory of nucleation. The grown crystals have been subjected to study the structural, optical and mechanical properties. FTIR analysis has been carried out to characterize the grown crystals. The transmission spectra from (100) planes of the grown crystals show that the transmission increases from 55.86 to 83.23% due to addition of EDTA in the visible region and band gap was found to increase from 1.31 to 1.41 eV. The microhardness test was carried out on (100) plane. The load dependent hardness and work hardening coefficient were measured.

10 illus, 22 ref

013873   Pavan Kumar G V;Danveer Singh;Patra P P; Dasgupta A (Photonics and Optical Nanoscopy Laboratory Physics and Chemistry Dep, Indian Institute of Science Education and Research, Pune-411 008, Email: pavan@iiserpune.ac.in) : Subwavelength propagation and localization of light using surface plasmons: a brief perspective. Pramana J Phys 2014, 82(1), 59-70.

Surface plasmons at the metal-dielectric interface have emerged as an important candidate to propagate and localize light at sub wavelength scales. By tailoring the geometry and arrangement of metallic nanoarchitectures, propagating and localized surface plasmons can be obtained. In this brief perspective, we discuss: (1) how surface plasmon polaritons (SPPs) and localized surface plasmons (LSPs) can be optically excited in metallic nanoarchitectures by employing a variety of optical microscopy methods; (2) how SPPs and LSPs in plasmonic nanowires can be utilized for subwavelength polarization optics and single-molecule surface-enhanced Raman scattering (SERS) on a photonic chip; and (3) how individual plasmonic nanowire can be optically manipulated using optical trapping methods.

8 illus, 25 ref

013872   Pandey S K (Physics Dep, Government Model Science College, Jabalpur-482 001, Email: skpandey.7008@gmail.com) : Optical emission induced by interacting excionic states in quantum well systems. Indian J Phys 2012, 86(8), 739-42.

An extension of the theory of optical emission spectra due to exciton-exciton collisions (in bulk GaAs at nonzero temperatures) for GaAs/AlGaAs quantum well systems has been attempted to understand the physics associated with the optical spectra due to excitonic scattering processes in these novel systems. The four typical processes have been considered to give different spectral shape, peak position, and temperature dependence of the emission spectra. The intensity of emitted light in quantum well systems varies inversely to the square of temperature, whereas in case of bulk materials it simply decreases with the temperature. The results arrived at are purely qualitative in nature.

10 ref

013871   Pakzad H R (Physics Dep, Islamic Azad Univ, Bojnourd Branch, Bojnourd, Iran, Email: ttaranomm83@yahoo.com) : Dust acoustic shock waves in strongly coupled dusty plasmas with kappa-distributed ions. Indian J Phys 2012, 86(8), 743-7.

Dust acoustic shock waves (DASWs) have been studied in an unmagnetized dusty plasma system consisting of coupled negatively charged dust and ions obeying superthermal distribution. Korteweg-deVries-Burger equation (KdV-Burgers) has been derived using small amplitude perturbation expansion method to study the nonlinear propagation of the DASWs. The behavior of the shock waves in the plasma has been investigated. It is found that the coefficients of the KdV-Burgers equation are significantly modified by k-parameter (k is a spectral index for superthermal distribution).

3 illus, 65 ref

013870   Oli S (NO, B C T Kumaon Engineering College, Almora-263 653, Email: sanjayoli@rediffmail.com) : Interacting and non-interacting two-fluid cosmological models in a Bianchi type VI₀ space-times. Indian J Phys 2012, 86(8), 755-61.

Presented anisotropic, homogeneous two-fluid cosmological models in a Bianchi VI₀ space-time. Obtained classes of cosmological models where the two fluids are in interactive phase and another when the two fluids are non-interacting. These models have one or two distinct real singularities depending upon the sign of the constant of integration. The behavior of associated fluid parameters and kinematical parameters has been discussed in detail.

15 ref

013869   Nundy U (NO, , BH-2-76, Kendriya Vihar, Kharghar, Sector-11, Navi Mumbai-410 210, Email: unundy@yahooc.o.in ) : Benefits of cryogenic cooling on the operation of a pulsed CO₂ laser. Pramana J Phys 2014, 82(1), 147-52.

The paper presents results of a theoretical model of a pulsed electron beam controlled CO₂ laser (EBCL) to investigate the effect of cooling on the laser gas mixture. It is shown that cryogenic cooling can significantly improve the performance of the laser. The efficiency of an EBCL improved from 20% to 25.3% by cooling it to 200 K. The improvement is mainly due to the decrease of thermal population of the CO2 (0 1 0) vibration level.

3 illus, 3 tables, 9 ref

013868   Nourinezhad Z;Mehdipour S H J (NO, Bandaranzali Branch, Islamic Azad Univ, Bandaranzali, Iran, Email: mehdipour@liau.ac.ir) : Different descriptions of energy-momentum density in the context of Bianchi IX cosmological model. Indian J Phys 2012, 86(10), 919-23.

Based on the Bianchi type IX metric, we calculate the energy and momentum density components of the gravitational field for the five different definitions of energy-momentum, namely, Tolman, Papapetrou, Landau-Lifshitz, M011er and Weinberg. The energy densities of M011er and Weinberg become zero for the spacetime under consideration. In the other prescriptions, i.e., Tolman, Papapetrou and Landau-Lifshitz complexes, we find different non-vanishing energy-momentum densities for the given spacetime, supporting the well-known argument in general relativity that the different definitions may lead to different distributions even in the same spacetime background.

50 ref

013867   Nimje N;Dubey S;Ghosh S (NO, School of Studies in Physics, Vikram Univ, Ujjain-456 010, Email: nileshnimje.ssp@gmail.com) : Effect of hot carriers on amplitude modulation and demodulation of an electromagnetic wave in magnetised diffusive semiconductor plasmas. Indian J Phys 2012, 86(8), 749-54.

Using hydrodynamic model of semiconductor plasma, analytical investigations are made for the amplitude modulation as well as demodulation of an electromagnetic wave in magnetised diffusive semiconductor plasma incorporating carrier heating (CH) effects. The consideration of CH effects in present study adds new dimension to the analysis. This problem is analyzed in different wave number regime over a wide range of cyclotron frequency. Numerical estimations are made for III-V semiconductor crystal irradiated by pump wave of frequency 1.6 x 10^-13 s^-1. It is found that incorporation of CH effects effectively modifies the amplitude modulation and demodulation processes. It has also been seen that when kv>a <62> 2k, both the side bands get modulated whereas for k_a <60> 2k both the side bands get modulated as well as demodulated depending upon the relative magnitudes of cyclotron frequency and pump frequency.

4 illus, 30 ref

013866   Neetu;Zulfequar M (Physics Dep, Jamia Millia Islamia, New Delhi-110 025, Email: mzulfe@rediffmail.com) : Photoconductivity of Se_90-xTe₁₀Zn_x thin films. Indian J pure appl Phys 2014, 52(1), 53-9.

Photoconductive properties such as dark conductivity, steady state and transient photoconductivity of a-Se_90-xTe₁₀Zn_x thin films, prepared by thermal vacuum evaporation technique have been studied in temperature range 312-380 K. Analysis of data shows that activation energy of dark current is greater as compared to activation energy of photo current. Activation energy decreases with increase in Zn concentration which may be due to increase in defect density of states. Analysis of intensity dependent photoconductivity shows that bimolecular recombination is predominant. Photosensitivity is found to be maximum for Se₈₈Te₁₀Zn₂ composition after that it decreases with increase in Zn concentration. Carrier lifetime decreases with increase in Zn concentration which also confirms that density of defect states increases. Transient photoconductivity shows that the carrier lifetime decreases with increase in Zn concentration. This decrease is due to transition trapping process.

9 illus, 28 ref

013865   Mottaghizadeh M;Eslami P (Physics Dep, Neyshabur Branch, Islamic Azad University, Neyshabur, Iran, Email: m_mottaghizadeh@yahoo.com) : Cylindrical and spherical ion-acoustic solitons in electron-positive ion-negative ion plasmas. Indian J Phys 2012, 86(1), 71-5.

In the present study cylindrical and spherical ion-acoustic solitons in an unmagnetized three-species plasma system, comprising electron, positive ion and negative ion are investigated. The reductive perturbation technique is employed to derive a cylindrical/spherical Korteweg-de Vries (KdV) equation from the hydrodynamics equations. The numerical solutions of the modified KdV equation are presented for both geometries. The changes of the amplitude and the width of ion-acoustic solitons due to the effect of the geometry, mass and concentration of negative ions are studied by numerical calculation of the cylindrical/spherical KdV equation.

5 illus, 1 table, 36 ref

013864   Mandal T K (NO, Faculty of Science and Technology, The ICFAI Univ, Rajawala Road, Central Hope Town, Selaqui, Dehra Dun-248 197, Email: tapanm@yahoo.com) : X-ray diffraction and scanning electron microscopic studies on the microstructure of laser induced surface alloyed PZT ceramics. Indian J Phys 2012, 86(10), 881-8.

Laser induced surface modification has been carried out in commercially available lead zirconate titanate (PZT) ceramics for the potential use in microelectronics and microsystem technology applications. The modification of surface has been achieved by the localized remelting of PbO precoated PZT substrate, using infrared laser irradiation of CO₂, followed by solidification of the alloyed surface. PZT has been found to evaporate as PbO during its remelting, leading to a significant loss of the material. Precoating of PbO on the PZT substrate has been observed to compensate this material loss. The microstructures of the laser-modified surfaces have been studied with X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis.

5 illus, 2 tables, 38 ref

013863   Mahalakshmi S;Mohamed R R;Kannappan V; Sathyanarayanamoorthi V (Physics Dep, Aarupadai Veedu Institute of Technology, Chennai-603 104, Email: kannappan48@gmail.com) : Polarizable continuum solvation model analysis of halogen substituted 6-nitropyridines. Indian J pure appl Phys 2014, 52(1), 19-23.

The conductor-like Polarizable Continuum Solvation Model (C-PCM) is applied to industrially important two halogen substituted pyridine derivatives, namely 2-chloro-6-nitropyridine and 2-bromo-6-nitropyridine in ten solvents with wide range of dielectric constants. The physical properties of the systems, such as free energies of solution, electrostatic interaction, dispersive energies, repulsive energies, dipole moments (μ) and first hyperpolarizability (β) of solute in pure state and in the presence of solvents are computed and discussed for these systems.

4 illus, 4 tables, 21 ref

013862   Lo C Y;Wong C (NO, Applied and Pure Research Institute, 7 Taggart Drive, Unit E, Nashua, NH-03060, USA) : Experimental verifications of the Einstein equation and consequences of the charge-mass repulsive force. Bull pure appl Sci-Sect D 2011, 30(2), 177-94.

Einstein gives three accurate predictions. However, the Einstein equation has not been confirmed beyond what the Maxwell-Newton Approximation can do. As Gullstrand suspected, it has been proven that there is no dynamic solution and thus the perihelion of Mercury cannot be derived with perturbation from the Einstein equation. So far, the only exception is the derivation of the metric for a charged particle. Because the electromagnetic energy-stress tensor is involved, the Einstein equation is beyond the MaxwellNewton Approximation. It has been shown that this metric implies a repulsive force mq²/r³ between a charge q and a mass m, separated with a distance r. Although it has been shown experimentally that a metal ball becomes lighter after charged with electrons, more detailed data are needed to confirm this force and distinguish its formula from claims of other theories. Due to its 1/r³dependence and repulsiveness, this long range neutral force would be important in astrophysics. Moreover, in contrast to the claim of Einstein, a heated metal would have a reduced weight because of the charge-mass interaction.

013861   Lakshmi Devi V;Jyothi I;Rajagopal Reddy V (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: reddy_vrg@rediffmail.com) : Electrical transport properties of Ru/Cu/n-InP schottky barrier diode based on temperature-dependent I-V and C-V measurements. Indian J Phys 2012, 86(8), 687-95.

Schottky diodes are fabricated on n-InP using Ru/Cu metallization scheme and studied the electrical properties in the temperature range of 260-420 K in steps of 20 K. The I-V-T characteristics of Ru/Cu Schottky contacts are analyzed in terms of thermionic emission theory by incorporating the concept of barrier inhomogenities through a Gaussian distribution function. The estimated barrier heights (BHs) of the Ru/Cu/n-InP Schottky barrier diodes (SBDs) are varied from 0.45 eV (I-V), 0.84 eV (C-V) at 260 K to 0.63 eV (I-V), 0.64 eV (C-V) at 420 K. The ideality factors n are varied from 2.50 at 260 K to 1.67 at 420 K. The calculated series resistance (R_s) of the Ru/Cu/n-InP SBD is in the range of 2,703 Ω at 260 K to 134 Ω at 420 K. From the above observations, Φ_b0, n and R_s are strongly temperature dependent. A laterally homogeneous BH value of approximately 0.77 eV for the linear relationship between experimental effective BHs and ideality factors that can be explained by lateral inhomogenities. Furthermore, the mean BH and the Richardson constant values are obtained to be 0.91 eV and 8.41 A K^-2 cm^-2, respectively, by means of the modified Richardson plot ln(I₀/T²) - (q²σ²₀2k²T²) vs. 1,000/T. The inconsistency between BHs obtained from I-V and C-V measurements is also interpreted.

1 table, 12 illus, 57 ref

013860   Kumbakhar M;Hahnel D;Gregor I;Enderlein J (Radiation and Photochemistry Div, Chemistry Group, Bhabha Atomic Research Centre, Mumbai-400 085, Email: manojbarc@yahoo.co.in) : Feedback-controlled electro-kinetic traps for single-molecule spectroscopy. Pramana J Phys 2014, 82(1), 121-34.

A principal limitation of single-molecule spectroscopy in solution is the diffusion-limited residence time of a given molecule within the detection volume. A common solution to this problem is to immobilize molecules of interest on a passivated glass surface for extending the observation time to obtain reliable data statistics. However, surface tethering of molecules often introduces artifacts, particularly when studying the structural dynamics of biomolecules. To circumvent this limitation, author investigated alternative ways to extend single-molecule observation times in solution without surface immobilization. Among various possibilities, the so-called anti-Brownian electro-kinetic trap (or ABEL trap) seems best suited to achieve this goal. The essential part of this trap is a feedback-controlled electro-kinetic steering of a molecule's position in reaction to its diffusive Brownian motion which is monitored by fluorescence, thus keeping the molecule within a sub-micron sized detection volume. Fluorescence trace recordings of over thousands of milliseconds duration on individual dye molecules within an ABEL trap have been reported. In this short review, author discussed the principle and some results of ABEL trapping of individual molecules with possible extensions to future works.

6 illus, 95 ref

013859   Kulkarni A P;Jain S;Kamath M P;Joshi A S;Naik P A;Gupta P D;Annapurna K;Mandal A K;Karmakar B;Sen R (Laser Plasma Div, Raja Ramanna Centre for Advanced Technology, Indore-452 013) : Measurement of the figure of merit of indigenously developed Nd-doped phosphate laser glass rods for use in high power lasers. Pramana J Phys 2014, 82(1), 159-63.

High energy, high power (HEHP) Nd: glass laser systems are used for inertial confinement fusion and equation of state (EOS) studies of materials at high temperature and pressure. A program has been undertaken for the indigenous development of Nd-doped phosphate laser glass rods and discs for HEHP lasers. In this paper, we report the characterization of the Nd-doped phosphate laser glass rods produced under this program and compare the indigenously developed laser glass to LHG-8 laser glass of M/s Hoya, Japan. We experimentally measured the values of the stimulated emission cross-section (a) and coefficient of intensity-dependent refractive index (n₂) and hence the figure of merit F = σ/n₂ of the indigenous phosphate laser glass rods. This value of figure of merit is found comparable to the reported value of identically doped Nd:glass rods.

3 illus, 1 table, 7 ref

013858   Kodi Pandyan R;Seenithurai S;Mahendran M (Physics Dep, Smart Materials Laboratory, Thiagarajar College of Engineering, Madurai-625 015, Email: manickam-mahendran@tce.edu) : Carbon monoxide adsorption on transition element-doped single wall carbon nanotube. Indian J Phys 2012, 86(8), 677-80.

The present work focuses on the carbon monoxide (CO) gas adsorption on transition element doped (8, 0) zigzag single wall carbon nanotube (SWCNT) and pure SWCNT. Density functional theory studies show that Sc, Ti and V doped SWCNTs adsorb CO molecules effectively compared to pure SWCNT. The binding energy of Sc, Ti and V doped SWCNT is 1.31, 1.81 and 0.95 eV, respectively, which is much higher than pure SWCNT. The band structures and density of states of these transition elements show dramatic changes in their structures on doping CO molecules. The band gap of pure SWCNT is 0.7 eV while on doping transition elements and on absorbing CO molecules, it reduces up to 0.35 eV. This study shows that the transition element doped SWCNTs can be used as a good CO molecule absorber at room temperature.

5 tables, 40 ref

013857   Karan S;Dutta Majumder D;Goswami A (NO, Institute of Radiophysics and Electronics, Calcutta Univ, 92, APC Road, Kolkata-700 009, Email: duttamajumder.isi@gmail.com) : Mathematical formalism of self assembly for design and fabrication of nanostructured materials: a new paradigm for nanotechnology. Indian J Phys 2012, 86(8), 667-76.

The molecular nanotechnology is the concept of functional mechanical system at the molecular scale, i.e., machines at the molecular scale, designed and built atom by atom. This idea along with self recognition (self assembly) can be used in the development of intelligent nanoparticles (NPs). Presents a mathematical formalism of force balance and self assembly along with a quantum mechanical algorithmic approach for avoiding uncertainty relations in a limited range, where tiny nano particle (1-100 nm), constitute an elementary unit. Explains the natural self organization, where, the system organizes itself, but there is no known agent inside the system doing the organizing. Thiol, aspartic acid, citrate and bovine serum albumin capped gold NPs were synthesised in the laboratory with potentially useful size and shape dependent properties. Used colloidal method for synthesis of NPs confinement at 2, 5, 10 and 20 nm. The particle shape contours were measured by transmission electron microscope with high resolution field emission scanning electron microscope (FE-SEM, FEI Quanta 200F). AFM (AFM-STM, Ntegra Ts-150) study was performed to see the surface topology and confinement. SPR spectra study including pH stability analysis is used to study the properties of quantum confinement.

6 illus, 3 tables, 27 ref

013856   Jha L;Singh N K;Manish Kumar (Physics Dep, L.N. Mithila Univ, Darbhanga-846 004, Email: jlnphylnmu@yahoo.com) : Smith chart and its importance in antenna technology. Bull pure appl Sci-Sect D 2011, 30(2), 217-22.

This paper presents Smith Chart as a graph based method of simplifying the complex math needed to describe the characteristics of microwave components. Smith Chart can look imposing; it's nothing more than a special type of 2-D graph, much as pola rand semilog log-log scales constitute special types of 2-D graphs. We have shown the utility of Smith Chart with the help of different graphs and figu res.

013855   Jadhav U M;Shinde M S;Patel S N;Patil R S (NO, P S G V P M'S Arts, Science & Commerce College, Shahada, Dist, Nandurbar-425 409, Email: spatil_shahada@yahoo.co.in) : Structural, optical and electrical properties of nanocrystalline cadmium sulphide thin films deposited by novel chemical route. Indian J pure appl Phys 2014, 52(1), 39-43.

Nanocrystalline semiconducting cadmium sulphide(CdS) thin films have been deposited on glass substrate by relatively simple, quick and cost effective chemical bath route. The deposition kinetics played important role to get good quality nanocrystalline films with uniform thickness. Hence, the preparative parameters such as concentration, temperature, deposition time, pH of solution have been optimized. The characterization of as deposited thin films was carried out for the structural, compositional, surface morphological, optical and electrical properties using X-ray diffraction (XRD), EDAX, Scanning electron microscopy (SEM), UV-VIS Spectra and dc two point probe method.

9 illus, 19 ref

013854   Indulal C R;Vaidyan A V;Sajeev Kumar G; Raveendran R (Physics Dep, S.N. College, Kollam, Kerala-691 001, Email: cr_indulal@yahoo.com) : Ion exchange properties of nanosized cerium molybdo iodate and cerium phospho iodate. J Metall Mater Sci 2012, 54(4), 299-302.

Nanoparticles of cerium molybdo iodate and cerium phospho iodate, tetravalent metal acid (TMA) salts were prepared by chemical co-precipitation method. The protons present in the structural hydroxyl groups indicate good potential for TMA salts to exhibit solid state proton conduction. The samples in its protonated form were subjected to ion exchange capacity studies. The data revealed that the samples act as a good ion exchangers.

1 illus, 1 table, 5 ref

013853   Hussain A;Begum A;Rahman A (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: hussainmakak@gmail.com) : Electrical and optical properties of nanocrystalline lead sulphide thin films prepared by chemical bath deposition. Indian J Phys 2012, 86(8), 697-701.

Nanocrystalline lead sulphide thin films were deposited on clean glass substrates by chemical bath deposition technique using lead acetate and thiourea as Pb⁺² and S^-2 ions source respectively. Films of five different molarities (0.05 M-0.150 M) of same pH value 10.5 were prepared at 318 K. Characterization was carried out using X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy, optical absorption and electrical conductivity measurements. Average crystallite size calculated from the XRD spectra using Scherrer's formula were between 13 and 18 nm. The optical absorption spectra shifted towards the lower wavelength. The band gap energy of 2.13-2.44 eV was determined from the optical absorption spectra. The electrical conductivity measured using two co-planar Aluminium electrodes was found to increase with increase in temperature showing semiconducting nature of the films. The electrical conductivity at room temperature was found to be of the order of 10^-4 Ω^-1 cm^-1.

6 illus, 1 table, 29 ref

013852   Han L A;Chen C L (Applied Physics Dep, Xi'an Science and Technology Univ, Xi'an-710 054, China, Email: hanlianvivian@sohu.com) : Transport properties and laser irradiation effect in Ca_0.8Ce_0.2MnO₃ film. Indian J Phys 2012, 86(10), 877-80.

Using magnetron sputtering method, a-axial oriented Ca_0.88Ce_0.2 MnO₃ epitaxial film with the thickness of 138 nm has been deposited on LaAlO₃ (100) substrate, transport properties and laser irradiation effect on the resistance change have been investigated. The film shows a semiconductive behavior and the transport mechanism is satisfied with Mott's variable range hopping model. Laser irradiation results in a decrease of the resistance in the whole temperature range measured, which is due to the photogenerated electron-hole pairs and the cooperative effect of the electron hopping from the valence band to the conduction band.

4 illus, 28 ref

013851   Gurram S;Kuruvilla A;Singh R;Ekka B;Upadhyay B N;Binda K S;Oak S M (NO, Raja Ramanna Centrev for Advanced Technology, Indore-452 013, Email: srikanth@rrcat.gov.in) : Erbium-ytterbium fibre laser emitting more than 13 W of power in 1.55 μm region. Pramana J Phys 2014, 82(1), 143-6.

Reported the work on erbium:ytterbium-doped double clad fibre laser (EYDFL), that is pumped at 976 nm. The maximum output power generated is 13.6 W in 1550 nm region with a slope efficiency of about 21%. To the best of our knowledge, this is the highest power reported from an EYDFL, that uses commercially available off-the-shelf large mode area Er:Yb-doped double-clad fibre.

3 illus, 6 ref

013850   Gupta S;Munirathnam K (Physics Dep, The Oxford College of Engineering, Bangalore, Email: nigdha.gupta@rediffmail.com) : Synthesis and characterization of sputtered Cd1-xMgxTe alloy and their applications in solar cells. Indian J pure appl Phys 2014, 52(1), 44-52.

Cd-xMgxTe, a potential optoelectronic material is an attractive II-VI semiconductor alloy candidate for obtaining energy gaps wider than 1.5 eV of CdTe needed for the top junction absorber layer in a polycrystalline thin film tandem solar cell. These alloy films can easily be prepared by sputtering. In the present paper, the optical absorption, morphology (SEM/AFM), XPS of between CdS and CdMgTe interface, crystallographic structure (XRD) and film stoichiometry by EDS of CdMgTe alloy, have been studied. Results were obtained as a function of rfsputter power and Ar sputter gas pressure. The film stability due to post-deposition vapour chloride treatment and the possibility of cell performance of CdS/CdMgTe as a top junction tandem cell have been explored. The cells made from 20 wt% Mg containing target showed better performance than that of 40 wt% Mg containing target. The best device obtained from a cell showed an open circuit voltage of 606 mV and efficiency of 1.93% and for another case the cell performance was further improved and the cell showed the open circuit voltage of 500 mV and efficiency of 2.26%.

10 illus, 4 tables, 31 ref

013849   Gupta G P;Tayal V;Msezane A Z (Physics Dep, S.D. (Postgrauate) College, Muzaffarnagar-251 004, Email: tayalvikas11@rediffmail.com) : Fine-structure energy levels and radiative rates in Si-like chlorine. Indian J Phys 2012, 86(1), 1-8.

Excitation energies and radiative rates for electric dipole (E1) transitions among the 86 fine-structure levels belonging to the configurations (1s ²2s ²2p⁶)3s ²3p ², 3s3p ³, 3s ²3p3d, 3p ⁴, 3s ²3p4s, 3s ²3p4p, 3s3p ²(² S)4s, 3s3p ²(² P)4s, 3s3p ²(⁴ P)4s, 3s3p ²(² D)4s, 3s ²3p4d and 3s ²3p4f of Cl IV are calculated using extensive configuration-interaction (CI) wave functions obtained with the CIV3 computer code of Hibbert. The relativistic effects in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian. In order to keep the calculated energy splittings close to the energy values of the National Institute for Standards and Technology, author have made small adjustments to the diagonal elements of the Hamiltonian matrices. Calculated energy levels, including their orderings, are in excellent agreement with the available NIST values. The mixing among several fine-structure levels is found to be very strong. From radiative rates author have also calculated radiative lifetimes of the fine-structure levels. Significant differences between calculated lifetimes and those from a sophisticated calculation for a few low lying levels are noted and discussed. In this calculation, also predicted new data for several fine-structure levels where no other theoretical and/or experimental results are available.

3 tables, 32 ref

013848   Ghosh D;Deb A;Pal S;Mondal M;Mondal A;Alam N (Nuclear and Particle Physics Research Centre, Physics Dep, Jadavpur Univ, Kolkata-700 032, Email: argha_deb@yahoo.com) : Assessment of erratic fluctuations of pions and protons in hadron-nucleus interactions. Indian J Phys 2012, 86(10), 925-30.

Erraticity analysis using the gap moment method is performed using the experimental data of π -AgBr interactions at 200 and 350 GeV both for pions and compound hadrons (pions + protons). The entropy like quantity S_q has been calculated at two different energies. The variation of S_q with q and their dependence on multiplicity of charged particles are investigated also. The study reveals the positive indication of the presence of erratic nature of event-by-event fluctuations of gap distributions of produced pions and compound hadrons in emission angle (cos θB) space in relativistic hadron-nucleus interaction.

4 illus, 3 tables, 37 ref

013847   Ghanshyam (Physics Dep, BIT Sindri, Dhanbad-828 123, Email: ghanshyam123@gmail.com) : Simulated Raman scattering instability of laser beam in a plasma channel. Indian J Phys 2012, 86(8), 731-8.

A high power laser beam propagating through collisional plasma creates a low density channel through which it propagates self-guided. This equilibrium, however, is unstable to stimulated Raman back scattering above a threshold power. The self focusing, leads to enhancement of wave intensity, elevation of electron temperature and reduction of local electron density, leading to diminished attenuation rate. Stimulated Raman scattering instability is treated for laser beam propagating through collisional plasma with thermal conduction in a self-focused filament. Thermal conduction could play a dominant role in determining the energy dissipation of electrons. Inside a filament, the laser undergoes stimulated Raman backscattering. Since the temperature inside a filament is higher and density lower than those outside, the collisional damping rates of the decay waves are lowered and hence the threshold power for B-SRS is reduced. It remains an important process in laser produced plasma. It is also a limiting process in a plasma- loaded free electron laser.

1 illus, 22 ref

013846   Farjami Shayesteh S;Kolahi S; Azizian-Kalandarragh Y (Physics Dep, University of Guilan, Rasht, Iran, Email: saber@guilan.ac.ir) : Effect of pH on the structural and optical properties of ZnS nanoparticles embedded in PVA matrix. Indian J pure appl Phys 2013, 51(11), 780-3.

ZnS nanoparticles embedded in polyvinyl alcohol (PVA) matrix have been synthesised with different pH by using wet chemical methods at room temperature. X-ray diffraction (XRD) pattern indicated that prepared nanoparticles with different pH show cubic phase. The average size variation of nanoparticles with pH estimated from the Debye-Scherrer equation and varying optical size by using absorption edge. Also, UV-Vis absorption results show a blue shift by variation of pH. The intensity of PL emission was found to be dependent on the pH of precursors and maximum of intensity related to pH=6. As a conclusion, pH plays vital role in improving PL intensity. It is also observed that particle size depends on the pH and a decrease in the size of particles is observed with the decrease of pH.

5 illus, 3 tables, 23 ref

013845   Elangovan S;Mullainathan S (Physics Dep, Easwari Engineering College, Chennai-600 089, Email: elangovan.physics@rediffmail.com) : Ultrasonic study of intermolecular interaction in ternary mixture of ethyl formate + 1-propanol + benzene at 303 K. Indian J Phys 2012, 86(8), 727-30.

Density (ρ), viscosity (η) and ultrasonic velocity (U) have been measured for a ternary mixture composed of ethyl formate, 1-propanol and benzene have been determined at 303 K. The adiabatic compressibility (β), free length (L_f), free volume (V_f) and internal pressure (π_i) have been calculated. The excess values of adiabatic compressibility (β^E), excess free length (L_f^E), free volume (V_f^E) and internal pressure (π_i^E) have also been computed by using the experimental data at 303 K. The deviation in the excess values reveal that intermolecular interactions obtaining in the solution.

2 illus, 3 tables, 21 ref

013844   El-Brolossy T A (Physics Dep, Faculty of Science, King Faisal University, Al-Sassa, Saudi Arabia, Email: elbrolosyta@yahoo.com) : Photoacoustic measurements of optical energy gap of porous silicon as a two layer opaque material. Indian J Phys 2012, 86(1), 39-4.

Photoacoustic (PA) technique was applied to study the optical absorption and measure the optical energy gap of porous silicon (PSi) as a suitable example of the two layer samples (porous layer and Si substrate). The PSi layers were prepared by the electrochemical anodization etching process with different current density of p-type silicon wafers. The formation of the porous layer has been identified by photoluminescence (PL) and AFM measurements. Thermal diffusivity of the prepared samples was also measured to confirm thermal isolation properties of the formed PSi. The optical absorption, energy gap, and thermal diffusivity of PSi were investigated by analyzing the experimental data from PA measurements. The values of energy gap have been found to be porosity-dependent. In contrast to the conventional techniques, PA measures the energy band gap of both layers simultaneously with high accuracy. In the range of porosity (27-52%) of the studies, our results show that the optical band-gap energy of p-type PSi (1.7-1.92 eV) was higher than that obtained for silicon substrate (1.11 eV). These energies were used to obtain the diameter of the Si quantum dots in the porous layer. These results introduce PA technique as a suitable candidate for optical depth profile analysis of multilayer solids. Moreover, PA technique can be used for particles size estimation of low dimensional materials.

9 illus, 27 ref

013843   Dwivedi O K;Mishra M;Shukla A K (Amorphous Semiconductor Research Laboratory, Physics Dep, M.M.M. Engineering College, Gorakhpur-273 010, Email: dwivedidkphys@rediffmail.com) : Structural and electrical studies of ZnTe thin film on glass substrate by vacuum evaporation technique. Bull pure appl Sci-Sect D 2011, 30(2), 237-40.

ZnTe thin films were grown on glass substrate by using vacuum evaporation technique. Hall effect measurement indicates that the ZnTe film was p-type. Dielectric studies such as dielectric constant and loss tangent (tan d) as a function of frequency were performed for ZnTe films. Carrier concentration, mobility and dielectric constant have been calculated.

013842   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Spontaneous largescale momentum exchange by microinstabilities: an analogy between Tokamaks and space plasmas. Bull pure appl Sci-Sect D 2011, 30(2), 423-31.

Based on a recent theory of spontaneous toroidal rotation in tokamaks and in astrophysical accretion disks, Author proposed that an analogous process could be at play also in the Earth space environment. Used fully kinetic simulations to study the evolution of drift instabilities and show that indeed a macroscopic velocity shear is generated spontaneously in the plasma. As in tokamaks, the microscopic fluctuations remain limited to the edge of the plasma channel but the momentum spreads over the whole macroscopic system.

013841   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Field theoretic description of ultra relativistic electron-position plasma. Bull pure appl Sci-Sect D 2011, 30(2), 403-21.

Ultra relativistic electron-positron plasma can be produced in highintensity laser fields and play a role in various astrophysical situations. Their properties can be calculated using QED at finite temperature. Used perturbative QED at finite temperature for calculating various important properties, such as the equation of state, dispersion relations of collective plasma modes of photons and electrons, Debye screening damping rates, of Ultrarelativistic electron-positron plasma. Author will focus on electron-positron plasma produced with ultra-strong lasers.

013840   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Currents in a tokamak. Bull pure appl Sci-Sect D 2011, 30(2), 397-401.

A self-consistent analysis of the currents in a tokamak yields the result that the parallel neutralizing current is given simply by the sum of currents commonly called the bootstrap current and the Pfirsch-Schluter current. An expression is given relating the parallel and perpendicular pressure gradient induced species flow velocities to the total current.

013839   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Charge fluctuation of dust grain and its impact on dusty acoustic wave damping. Bull pure appl Sci-Sect D 2011, 30(2), 275-9.

Considered the influence of dust charge fluctuations on damping of the dust-ion-acoustic waves. It is assumed that all grains have equal masses but charges are not constant in time -they may fluctuate in time. The dust charges are not really independent of the variations in the plasma potentials; all modes will influence the chiming mechanism, and feedback will lead to several new interesting and unexpected phenomena. The charging of the grains depends on local plasma characteristics. If the waves disturb these characteristics, then charging of the grains is affected and the grain charge is modified, with a resulting feedback on the wave mode. In the case considered here, when the temperature of electrons is much greater than the temperature of the ions and the temperature of electrons is not great enough for further ionization of the ions, it is shown that attenuation of the acoustic wave depends only on one phenomenological coefficient.

013838   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Stability dust-ion-acoustic wave in dusty plasma with stream-influence of charge fluctuation of dust grains. Bull pure appl Sci-Sect D 2011, 30(2), 269-73.

There is a rapidly increasing wealth of experimental data on socalled dusty plasma i.e. ionized gases or usual plasmas that contain micron-sized charged particles. Interest in these structures is driven both by their importance in many astrophysical as well as commercial situations. Among them are linear and non-linear wave phenomena. Considered the influence of dust charge fluctuations on stability of the ion-acoustic waves when the stream of particles is present. It is assumed that all grains of dust have equal masses but charges are not constant in time -they may fluctuate in time. The dust charges are not really independent of the variations of the plasma potentials. All modes will influence the charging mechanism, and feedback will lead to several new interesting and unexpected phenomena. The charging of the grains depends on local plasma characteristics. If the waves disturb these characteristics, then charging of the grains is affected and the grain charge is modified, with a resulting feedback on the wave mode. In the case considered here, when the temperature of the electron is much greater then the temperature of the ions and the temperature of electrons is not great enough for further ionization of the ions, it is shown that stability of the acoustic wave depends only on phenomenological coefficient and relation between.

013837   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Damping of plasma-electron oscillations and waves in low-collision electron-ion plasmas. Bull pure appl Sci-Sect D 2011, 30(2), 261-8.

Previously developed methods for finding asymptotic solutions of Vlasov equations using two-dimensional (in coordinate x and time t) Laplace transform is applied to low-collision electron-ion plasma.

013836   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Damping of electromagnetic waves in low-collision electron-ion plasma. Bull pure appl Sci-Sect D 2011, 30(2), 255-60.

Using previously developed methods of two-dimensional Laplace transform, obtained the characteristic equations k(?) for electromagnetic waves in low-collision fully ionized plasma in a plane geometry. Applied here a new technique, different from the one used in iteration procedure of taking into account the Coulomb collisions. The kinematical waves are collisionally damped to the same extent as the electromagnetic waves. Despite the difference in appearance of the dispersion (poles) equation, the obtained decrements for fast and slow wave modes coincide with the results obtained if one neglects the terms of higher orders in V²_x/c², (V_x and C are electron and light velocities). Pointed out how one can determine mutually dependent boundary conditions, allowing us to eliminate simultaneously both the backward and kinematical waves for transverse as well as for longitudinal oscillations.

013835   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Entanglement phenomenon: a physical explanation. Bull pure appl Sci-Sect D 2011, 30(2), 251-3.

Coherency and entanglement are the myths of quantum mechanics. Its important property, unrecognized until now, is inequality of forward and reversed processes. The existent experimental proofs and suggested experiments are discussed.

013834   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : General relativity requires absolute space and time. Bull pure appl Sci-Sect D 2011, 30(2), 247-50.

Examined two far-reaching and somewhat heretic consequences of General Relativity, It requires a cosmology which includes a preferred rest frame, absolute space and time, A rotating universe and time travel are strict solutions of General Relativity.

013833   Devi G;Sarma K K;Datta P;Mahanta A K (Physics Dep, Lalit Chandra Bharali College, Guwahati-781 011, Email: gitanjalilcb@gmail.com) : Prediction of high energy particle shower sizes and core location using artificial neural networks. Indian J Phys 2012, 86(1), 77-8.

Traditionally Artificial Neural Network (ANN)s, as non-parametric prediction tools, are used for pattern recognition and related applications but can be modeled for High Energy Particle shower size and core location prediction. The present work describes the use of an ANN based system which has been configured to predict shower sizes in the range 10^10.5-10^20.5 eV and core locations of twenty events. The system receives density values as inputs and generates shower sizes for 20 core positions and predicts the coordinates of the locations. The results derived with variations of input upto 50% show success rates in the range of 90s.

11 illus, 4 tables, 11 ref