015101   Jangid R A (Microwave Research Lab, Physics Dep, Raj Rishi Government P.G. College, Alwar-301 001, Email: rajangid@yahoo.co.in) : Dielectric study of particulate material in e.m. field at microwave frequencies. Indian J Phys 2008, 82(7), 833-41.

Investigation aims at finding out the extent upto which microwaves can be used as a probe to estimate the presence of conducting impurity in some powdered materials. Dielectric properties of pure polyvinyl chloride (PVC) powder and mixtures of pure PVC with different percentages of copper, aluminium and magnesium powders as impurity varying from five to eighty and fifty percent by weight are studied at microwave frequency 10.17 GHz and temperature 34.5°C. Presence of metal modifies dielectric behaviour of pure PVC powder to a great extent. These studies may be useful for estimating quantitatively and qualitatively the percentage of metal in natural ore samples and mineral rocks.

4 illus, 11 ref

015100   Bhunia S;Biswas S;Sarkar D;Sarkar P P (NO, Academy of Technology, Hooghly-712 121, Email: parthabe91@yahoo.co.in) : Experimental investigation on single layer single-feed dual frequency (dual band) reduced sized slotted square microstrip patch antenna. Indian J Phys 2008, 82(7), 829-32.

Novel, compact, single probe-feed square microstrip patch antenna for operation in dual frequency can be achieved by cutting a circular slot having an inner square patch at its centre. From the experimental results obtained, the antenna size using the proposed design method can be reduced by about 70% compared to what is achieved in conventional design method using a simple square patch without the slot. Focuses about the typical results obtained experimentally.

3 illus, 9 ref

015099   Barman J;Sarma K C (Instrumentation and USIC Dep, Gauhati University, Guwahati-781 014, Email: kanak_sarma50@rediffmail.com) : Structural and optical properties of CdS nanoparticles. Indian J Phys 2008, 82(7), 855-62.

II-VI semiconductor nanoparticles have attracted a lot of attention due to the possibility of their applications in various devices. Among the materials used for fabrication of quantum dots (QD) and nanocrystals, cadmium sulphide (CdS) has drawn wide attention because of its potential for applications and availability of a variety of methods for its preparation. In the study, chemical method has been used for synthesis of CdS nanoparticles in polyvinyl alcohol (PVA) as a matrix. X-Ray diffraction and electron microscopy (TEM) were used to determine the phase, shape and size of quantum dots. UV-VIS spectrophotometer and PL-study shows the blue shift and defect level formation within the band gap. Particle size was found to be between 4 and 7 nm.

7 illus, 1 table, 31 ref

015098   Al Zier A;Allahham A;Allaf A W (Chemistry Dep, Atomic Energy Commission, P.O. Box 6091, Damascus, Syria) : Optical limiting action in poly (dimethylacetylendicarboxylate). Curr Sci 2008, 95(1), 75-8.

Attempt has been made to investigate the optical limiting action of poly(dimethylacetylendicarboxylate) for the first time with laser pulses at 532 nm in three different organic solvents: 1,2-dichloroethane, chloroform and tetrachlorocarbon with a concentration of 10^-3 M. The threshold limiting fluence was observed at about 20 J/cm² with a transmission of 77% with CCl₄ solvent. The observed data show that poly(dimethylacetylendicarboxylate) has the potential for use as optical limiting material for future applications.

2 illus, 15 ref

014030   Yadav R P;Arvind Kumar;Kumar K;Akhilesh Kumar (Physics Dep, Agra College, Agra, Uttar Pradesh, Email: rpyadav93pphysics@yahoo.co.in) : Effect of overtaking disturbances on the motion of strong shock waves in highly viscous medium. Bull pure appl Sci-Sect D 2008, 27(2), 293-302.

The effect of overtaking disturbances on the motion of strong shock waves in highly viscous uniform medium has been investigated. Chester-Chisnell-Whitham method is applied to obtain the analytical relations for shock velocity and shock strength for freely propagation of shock. These relations are modified in presence of overtaking disturbances. The effect of overtaking disturbances is included by Yadav(1992) approach. The obtained relations are computed and discussed through tables. Comparison between the results for freely and for overtaking disturbances is made. It is found that the shock velocity and shock strength both decreases as shock advances form low viscous region to the high viscous region of a medium. A very large change in viscosity coefficient leads to very small perturbation in flow variables. This is due to the large dissipation of energy in the highly viscous medium.

7 illus, 5 ref

014029   Vikas Kumar;Prasad B;Prasad R;Sharma A;Verma D K (Physics Dep, R.D.S. College, Muzaffarpur, Bihar) : Phase diagram of an extended one dimensional hubbard model coupled to optical bond phonons. Bull pure appl Sci-Sect D 2008, 27(2), 225-8.

Studied that the stochastic series expansion technique can be used for large electron-phonon chains to compute several different quantities that the signal the opening of the spin gap at the Mqtt-Peierls transition. The phase diagrams obtained in this i.e. in the Hubbard model coupled to optical bond phonons were in good agreement with previously obtained results.

2 illus, 11 ref

014028   Thirumaran S;Sugumaran R;Sathish K (Physics (DDE) Dep, Annamalai Univ, Annamalainagar-608 002, Email: thirumaran64@gmail.com) : Molecular interaction studies in binary liquid mixtures by ultrasoic velocity measurements. Bull pure appl Sci-Sect D 2008, 27(2), 281-92.

The ultrasonic velocity, density and viscosity have been measured for the binary mixtures of m-xylene with substituted benzenes such as chlorobenzene, bromobenzene and nitrobenzene at 303K. The experimental data have been used to calculate the acoustical parameters namely adiabatic compressibility (β), freelength (L_f), free volume (V_f), internal pressure (π_i), and acoustic impedance (Z). The excess values of some the above parameters are also evaluated and discussed in the light of molecular interaction in the mixtures. It is observed that there exists a strong molecular interaction present in the liquid mixtures. The molecular association comparatively stronger in m-xylene - nitrobenzene system. This shows that the nitrobenzene is probably a more effective diluent in the mixtures.

3 illus, 4 tables, 20 ref

014027   Thirumaran S;Sathish K (Physics Dep, (DDE), Annamalai Univ, Annamalainagar-608 002, Email: thirumaran64@gmail.com) : Ultrasonic investigation of molecular association in binary liquid mixtures of amides + DMSO at different temperatures. Bull pure appl Sci-Sect D 2008, 27(2), 239-48.

The ultrasonic velocity, density and viscosity have been measured for the binary liquid mixtures of Dimethyl Sulphoxide (DMSO) with amides such as formamide (FA), N-N dimethylacetamide (DMA) and N-N dimethylformamide (DMF) at 303, 308 and 313K. The experimental data have been used to calculate the acoustical parameters namely adiabatic compressibility (β), free length (L_f), free volume (V_f), and internal pressure (π_I). The excess values of the above parameters are also evaluated and fitted to Redlich-kister polynomials. It is observed that mutual disruptive effect formed due to the mixing of DMSO with amides leads to weak interaction between them.

4 tables, 19 ref

014026   Sahaya Baskaran G;Lakshmi Praveen P;Ajeetha N;Ojha D P (Liquid Crystal Research Laboratory, Post-Graduate Dep of Physics, Andhra Loyola College, Vijayawada-520 008, Email: sbalc@rediffmail.com) : Molecular ordering in 5OCB based on quantum mechanics and intermolecular forces-a computational analysis. Bull pure appl Sci-Sect D 2008, 27(2), 229-37.

A Computational analysis of ordering in 4'-n-Pentyloxy-4-Biphenyl Carbonite (5OCB) has been carried out based on quantum mechanics and intermolecular forces. The evaluation of atomic charges and energy has been carried out using the CNDO/2 method. The configuration of energy has been computed using the modified Rayleigh-Schrodinger perturbation method at an interval of 0.1 Angustrum in translation and 10° in rotations. The various possible geometrical arrangements of molecular pairs during the different modes of interactions have been considered, and the most favorable configuration of pairing has been obtained. The present computations are helpful in analyzing the liquid crystalline behavior of 5OCB in terms of molecular forces accounting for mesomorphism.

5 illus, 16 ref

014025   Rao M C;Hussain O M (Physics Dep, Andhra Loyola College, Vijayawada-520 008, Email: raomc72@gmail.com) : Growth and electrochemical properties of pulsed laser deposited LiNi_xCo_1-xI₂ thin films. Bull pure appl Sci-Sect D 2008, 27(2), 261-71.

Thin films of LiNixCoi-xOa were prepared by pulsed laser deposition technique in the temperature range 500 - 700 °C in an oxygen partial pressure of 100 mTorr. The films deposited at 700 °C in an oxygen partial pressure of 100 mTorr exhibited R3m layered structure. The SEM data demonstrated that the films exhibited a smooth surface roughness with spherical droplets. The grain size increased with the increase of substrate temperature. FTIR and Raman measurements confirm the XRD data showing the formation of pure phase LiNi_xCo_1-xO₂. The electrochemical measurements were carried out on Li//LiNi_xCo_1-xO₂ cells with a lithium metal foil as anode and a polycrystalline film as cathode of 1.5 cm² active area using a Teflon home-made cell hardware. The growth of LiNi_xCo_1-xO₂ films were studied in relation to the deposition parameters for their effective utilization as cathode materials in solid state microbattery application. The LiNi_0.2Co_0.8O₂ film grown at 700 °C has delivered a specific capacity of 220 mC/μm cm².

5 illus, 23 ref

014024   Manish Kumar;Mishra N (Univ Dep. of Physics, L.N. Mithila Univ, Darbhanga, Bihar) : Analysis of wideband antenna using neural networks. Bull pure appl Sci-Sect D 2008, 27(2), 187-92.

In recent years, the art of using neural network for antenna and communication has been gaining momentum. Procedures using neural networks are developed for the analysis of a wideband antenna. A multi layer perceptron is used to locate the operational frequency bands of the antenna at different reconfigured conditions. The developed formula is tested on a laboratory prototype antenna.

4 illus, 6 ref

014023   Madan Jee;Bhatt M K;Mishra S K;Sanjiv Kumar; Vikas Kumar (Univ Dep of Physics, B.R.A. Bihar Univ, Muzaffarpur, Bihar) : Behavior of semiconductors in crossed high external electric and magnetic fields.. Bull pure appl Sci-Sect D 2008, 27(2), 213-16.

Studies the behavior of semiconductors in crossed high electric and magnetic fields. The problem of inefficiency of inter electronic collision in quantising magnetic field have been solved by taking into account the mutual drag of electrons and phonons. Mutual drag leads to renormalization of the cyclotron frequency of carriers dressed by the phonons. The phonon generation at high external electric and magnetic fields is a non stationery effect. Non equilibrium equation for the density matrix of phonons interacting with electrons have also been obtained. The distribution of electrons and phonons are obtained as a result of the solutions coupled systems of equation for the density matrix of interacting electrons and phonons for arbitrary heating and drift velocities of phonons. The distribution function of phonons is stationary and has the shifted Plank's distribution function from the effective temperature of phonons.

8 ref

014022   Lo C Y (NO, Applied and Pure Research Institute, 7 Taggart Drive, Unit E, Nashua, NH 03060 USA) : Principle of causality and the cylindrically symmetric metric of Einstein and Rosen. Bull pure appl Sci-Sect D 2008, 27(2), 149-70.

From the Hulse-Taylor binary pulsars experiment, it has been found that the nonexistence of gravitational wave solutions is due to a violation of the principle of causality. Nevertheless, some still believe that the wave solutions exist because singularities in the solution of Einstein & Rosen are removable. It is shown that the violation of causality can be proven from the metric form of Einstein-Rosen type, in addition to explicit cylindrical "waves". Metrics of Einstein-Rosen type violate Einstein's equivalence principle, and violate the principle of causality due to the impossibility of having valid sources. Concurrently, the cylindrical symmetry metric, obtained by G. 't Hooft from combining "waves", is also discussed. There are two fundamental errors, namely: 1) the plane wave has been implicitly extended beyond its physical validity as an idealization, and 2) the integration over the angle cannot be justified with a physical process.

57 ref

014021   Kumar R S;S Sreehari Sastry;T Madhu Mohan (Physics Dep, Acharya Nagarjuna Univ, Nagarjuna Nagar-522 510, Email: rskchaval@gmail.com) : Smectic G phase of liquid crystalline mesogen by intermolecular hydrogen bonding. Bull pure appl Sci-Sect D 2008, 27(2), 217-24.

The invention relates to a method in the preparation of liquid crystalline mesogen involving the mesogen p-n-alkyl benzoic acid and non mesogen hexyl-p-hydroxy benzoate. The mesomorphic properties involve the use of thermal analysis equipment differential scanning calorimetry that provides information about phase transition temperatures and enthalpy. Mesophases are identified by polarizing optical microscope. The extensive nature of intermolecular hydrogen bonding between the two polar groups is convinced by FTIR. The structural conformational studies are attributed by proton NMR studies. The thermal behavior of the bonded mesogens reveals smectic G phase with narrow thermal spans.

4 illus, 3 tables, 15 ref

014020   Jagdeep Singh;Chaurasia B (Chemistry Dep, R.N.A.R. College, Samastipur, Bihar) : Dispersion characteristics of unconventional microstrip lines. Bull pure appl Sci-Sect D 2008, 27(2), 197-205.

Theoretical study of dispersion characteristics of various unconventional microstrip lines such as circular and microstrip lines on a substrate with continuous permittivity profile have been made. The arbitrary shapes and inhomogeneous properties of these structures are analysed using the edge-based infinite elements with three components of the electric field. This approach provides a direct solution for the propagation factor and elements of the spurious solution. Numerical results are given to show the validity and usefulness of this method.

5 illus, 10 ref

014019   Fritzsch H (Physik Dep, Universitat Munchen, Munich, Germany) : Fundamental constants in physics. Punjab Univ Res J Sci 2007, 57, 1-11.

Fundamental constants in the Standard Model of particle physics, in particular possible changes of these constants on the cosmological time scale. The Grand Unification of the observed strong, electromagnetic and weak interactions implies relations between time variations of the finestructure constant α and the QCD scale Λ_c. The astrophysical observation of a variation of a implies a time variation of Λ_c of the order of at least 10^-15/year. Several experiments in Quantum Optics, which were designed to look for a time variation of A_c, are discussed.

20 ref

014018   Dwivedi D K (Physics Dep, D.D.U. Gorakhpur Univ, Gorakhpur-273 009, Email: dwivedidkphys@rediffmail.com) : Thermally stimulated processes-II: evaluation of the trap parameters of TL glow peaks. Bull pure appl Sci-Sect D 2008, 27(2), 303-9.

A new method is described to obtain the trap parameters of thermoluminescence glow peaks namely the order of kinetics K, activation energy E and frequency factor S. The suggested method can be applied to evaluate the trap parameters of experimentally observed TL glow peaks irrespective of the order of kinetics involved.

1 illus, 27 ref

014017   Chunduru V (Physics Dep, Osmania Univ College for Women, Koti, Hyderabad, Email: vardhani_c2001@yahoo.co.in) : Strain optical constants of lithium tantalate optical waveguides. Bull pure appl Sci-Sect D 2008, 27(2), 207-12.

The surface variation of refractive indices and strain optical constants gains prominence especially with the advent of submicron dimension waveguides, would help improve the analysis and understanding of the acoustic -optic Bragg diffraction in planar waveguides. For a given optical wavelength, the diffraction efficiency is a sensitive function of the special distribution of both optical and acoustic waves. This naturally indicates that the "Local" variations of refractive indices and strain optical constants would contribute significantly to the modification of the efficiency of the acoustic optic device. It is possible to predict the directions of acoustic waves for a optimum efficiency of a SAW device.

1 table, 6 ref

014016   Baiju D;Vyas B M (Physics Dep, M.L. Sukhadia Univ, Udaipur-313 001, Email: bmvyas@yahoo.com) : Total ionospheric electron integrated production and effective loss rates over Ahmedabad. Bull pure appl Sci-Sect D 2008, 27(2), 249-59.

The Total Electron Content (TEC) data obtained at Ahmedabad using Faraday rotation of 140 MHz radio beacon satellite signals from ATS-6 Experiment are used to compute the over head integrated production rate and integrate loss coefficient for the period of October 1975 to July 1976. The maximum values of production rates are found in equinox months and minimum values in winter months. Similarly the loss coefficient trends also show the maximum value in equinox and minimum value in winter. There is also some significant dependence of production and loss rates of electrons with solar activity. The findings also confirmed with earlier observations reported over mid and low latitude stations.

2 illus, 16 ref

014015   Ashok Kumar;Jha B K;Mahto D;Prasad U;Jha L K (NO, Univ. Dep of Physics, L.N.M.U., Darbhanga) : Theoretical analysis of thermodynamic properties of hard D-sphere fluid mixtures. Bull pure appl Sci-Sect D 2008, 27(2), 177-86.

Based on physical interpretation of the reciprocal of activity, tried to develop a simple theory for a D-dimensional fluid mixtures of hard D-spheres. Also given an analytic expressions for equation of state, excess Helmholtz free energy etc. for hard D-sphere fluid mixture. Calcuiated the values for equation of state, excess free energy particle for binary mixture of hard D-sphere with 2 ≤ D ≤ 5 as a function of packing fraction for specified values of concentration of molecule of definite diameter.

4 illus, 2 tables, 16 ref

014014   Ashok Kumar;Jha B K;Jha U N (NO, , Prof. Colony. Dighi West, Darbhanga, Bihar-846 004) : Relativistic model for energy release of charged matter. Bull pure appl Sci-Sect D 2008, 27(2), 273-80.

The spectrum of extragalactic radiation and discovery of now phase of Quantum electrodynamics has initiated the modern theoreticians to account for an alternative mechanism for the generation of γ-ray bursts from Neutron stars Charged Boson stars and mixed Fermion-Boson stars for its non-topological solution have been studied by Jetzor (1990a,b) and Friedman et al (1988). Study the structure of the gravitational and electromagnetic field surrounding a macroscopic dyon in the presence of a charged field. A simple model of charged shell surrounding on abeliodyon has been developed. We have constructed a formula for the energy release when a spherical shell of charged matter disposes in the presence of a dyon case.

18 ref

014013   Ahuja G;Randhawa M (Physics Dep, Centre of Advanced Study, P.U., Chandigarh-160 014, Email: gulsheenahuja@yahoo.co.in ) : Constructing the CKM and PMNS matrices. Punjab Univ Res J Sci 2007, 57, 257-63.

The CKM and PMNS matrices have been constructed based on the latest measurements, largely free from theoretical inputs as well as likely New Physics effects in the case of the former. To facilitate the construction of the CKM matrix in the PDG representation as well as in view of the comparatively large error in the measured value of the CP violating phase a, the possibility of its construction from the tree level measured CKM elements has also been explored using the unitarity triangle. In view of the persistent difference between the |V_ub| exclusive and inclusive values, we have carried out separate analyses corresponding to these. The PMNS matrix has been constructed by incorporating the constraints due to solar and atmospheric neutrinos as well as by giving full variation to the Dirac-like CP violating phase 5 and considering different values of s₁₃ having implications for different models of lepton mass matrices. Taking clue from quark mixing phenomenology, an analogous analysis of the leptonic unitarity triangle allows an estimate of the likely presence of CP violation in the leptonic sector.

2 illus, 1 table, 40 ref

013019   Verma M;Gupta V;Nema R K;Mishra U (NO, Integral Univ, Lucknow, Uttar Pradesh, Email: upama.misra@rediffmail.com) : Synthesis of some substituted pyrazole derivatives and their evaluation as antiprotozoal agents. Int J chem Sci 2008, 6(1), 179-84.

Compounds incorporating a pyrazole moiety have attracted a great deal of research owing to its therapeutic utility of the templates as useful drug molecule scaffolding. The synthesis of pyrazoles moiety substituted with anilines at the fifth position of the ring as anti-protozoal lead moiety have been reported. All the compounds were screened for the anti-protozoal activity. The compounds (3a), 3-amino-5-phenylamino-4H-pyrazole-4-carboxylic acid ethyl ester and (3c) 3-amino-5-(-4-methoxy-phenylamino)-4H-pyrazole-4-carboxylic acid ethyl ester showed better antimalarial as well as anti-leishmanial activity with IC₅₀ value of 0.132 μmol/L and 0.150 μmol/L against P.falciparum and IC₅₀ value of 0.132 μmol/L and 0.168 μmol/L against Leishmania donovani. These results open up new avenues in designing novel anti-protozoal drugs as dual inhibitor with utilization of pyrazole template as part of the pharmacophore.

1 sch, 1 tables, 12 ref

013018   Upadhyay A K;Sharma B S (Physics Dep, Institute of Basic Sciences, Khandari, Agra, Email: aupadhyay29@yahoo.in) : Elastic properties of intermetallic compounds under high pressure and high temperature. Indian J pure appl Phys 2009, 47(5), 362-8.

The elastic properties of intermetallic compounds MgB₂, TiB₂ and LiBC under high pressure and high temperature using the Hama-Suito theory of equation of state based on the augmented plane wave (APW) and quantum statistical methods have been studied. The results have been obtained for P-V-T relationship and isothermal bulk modulus at high temperature up to 1000K and down to compression of 50% (V/V₀ = 0.50). The input parameters used in calculation are based on the first-principles method. The importance of extreme compression behaviour has been discussed in terms of the Thomas-Fermi model.

013017   Shukla N;Varma P V;Tiwari M S (Physics & Electronics Dep, Dr H S Gour University, Sagar 470 003, Email: tiwarims@rediffmail.com) : Study on kinetic Alfven wave in inertial regime. Indian J pure appl Phys 2009, 47(5), 350-5.

The effect of electron inertia on kinetic Alfven wave (KAW) has been studied. The inertial Alfven waves propagating in regions of auroral electron acceleration are reported from the FAST spacecraft over its entire altitude range (350-4180), (e.g., Chaston et al., Physics Scripta, T84, (2000) 64). The Vlasov-kinetic theory has been adopted to evaluate the dispersion relation, damping rate and growth length, with respect to the normalized perpendicular wave number (k_⊥c/ω_pe) with different plasma density. It is observed that inertial Alfven wave frequency (ω) is decreasing with (k_⊥c/ω_pe) and plasma density. The growth rate and growth length are evaluated for different (m_e/βm_I), where β is the ratio of electron pressure to the magnetic field pressure, m_i,e are the mass of ion and electron, respectively as β = m_e/βm_I represent boundary between the kinetic and inertial regimes. The effects of electron density on the wave frequency, growth rate and growth length are also given as the wave propagates towards higher density side of the lower ionospheric region. Although, the wave is highly damped, it requires longer distance of propagation as predicted by growth length. Thus, some another mechanism should also be operative to dissipate kinetic Alfven wave energy as the Landau damping mechanism alone is not sufficient due to higher growth length. The results show the scenario of auroral pattern in northern and southern hemisphere (Swift D W, J Geophys Res, 112 (2007) A12207). The significance of the investigation for the auroral acceleration region is also presented.

013016   Padmanabhan T (NO, IUCAA, Pune Univ, Post Bag 4, Campus, Ganeshkhind, Pune-411 007, Email: paddy@iucaa.ernet.in) : Snippets of physics, 11. isochronous potentials. Resonance 2008, 13(11), 998-1008.

Oscillatory motion of a particle in a one dimensional potential belongs to a class of exactly solvable problems in classical mechanics. Examines some lesser known aspects of the oscillations in some potentials.

ref

013015   Nicklawy M;Hassan A F;Bahrawi M;Farid N; Sanjid A M (NO, Helwan University, Science Faculty, Egypt) : Characterizing surface roughness by speckle pattern analysis. J scient ind Res 2009, 68(2), 118-21.

Speckle photography is a non-destructive technique for making moderate sensitivity measurements for strain, rotation, vibration, plane displacements, and surface texture. Presents characterization of surface roughness by studying speckle patterns correlation and visibility during object displacement.

013014   Misra U D;Chaturvedi S (Physics Dep, Lucknow University, Lucknow-226 007) : Semi-empirical method for obtaining Sommerfeld screening parameter σ₁ in X-ray spectra. Indian J pure appl Phys 2009, 47(5), 340-5.

The method is an effort to reduce the requirement of the amount of input data for the calculation of the screening parameter s1. The method requires the knowledge of no other data except the energy value of the level for the element under consideration. The fresh calculations of the screening parameter σ₁ using the new method for the levels L₁, L₂L₃, M₁, M₂M₃, M₄M₅, N₁, N₂N₃ and N₄N₅ in the atomic numbers range Z=57 to Z=71, have been described in the present paper.

013013   Mishra A;Parsai N;Dagonkar N (School of Physics, Devi Ahilya University, Khandwa Road, Indore-452 001) : Theoretical analysis of EXAFS data of copper (II) complexes of isoxezol series. Indian J pure appl Phys 2009, 47(5), 337-9.

A newly approached method has been employed for analysis of the K-absorption X-ray spectra of mixed ligand complexes and verification of structural parameters obtained experimentally. Extended X-ray absorption fine structure (EXAFS) data is generated using standard EXAFS equation and EXAFS curves are plotted for some copper (II) mixed ligand complexes of isoxezol series. Fourier transform of calculated EXAFS data has been taken to calculate bond lengths theoretically. These bond lengths are compared with bond lengths obtained using other methods from experimental EXAFS data. Imaginary part of Fourier transform is compared with the amplitude of Fourier transform to verify consistency of experimentally obtained phase shift parameter with calculated data.

013012   Khanna K M;Ayodo Y K;Sakwa T W;Rotich S K; Torongey P K;Mbugua W S (Physics Dep, Moi University, Box 1125 Eldoret-Kenya) : Pair distribution function for interacting bosons and the ground-state energy of solid helium-4. Indian J pure appl Phys 2009, 47(5), 325-31.

The pair distribution function g(r) for a system of bosons interacting through a two-body potential composed of a hard core followed by a square well has been obtained using the reaction matrix formalism for the energy excitation spectrum E_k and the fundamental definition relating the structure factor S(k) and g(r) . This has been used in obtaining the ground state energy of solid ⁴He using the kinetic energy and potential energy expressions of Hansen and Levesque. The most stable ground state of solid ⁴He corresponds to a potential width of b=3.8Å ,but the corresponding <193>E<209>/N for the density, ρ, of solid ⁴He is very large compared with the experimental value. However, for b =4.81Å and r=2.8x10²² particles/ cm³, <193>E<209>/N =-11.24 K= -93.4Joule/mol. and for b=4.82Å and r=2.5x10²² particles/cm³, <193>E<209>/N = -6.84 K=56.8 Joule/mol. The experimental value for the ground state energy of solid ⁴He =-59.5J/mol.

013011   Kandiban G;Balachandran V (Physics Dep, Thanthai Hans Roever College, Perambalur-621 212, Email: brsbala@rediffmail.com) : Optical communication using chaos based signal transmission scheme. Indian J pure appl Phys 2009, 47(5), 346-9.

Optical communication system using a chaos based signal transmission scheme has been proposed to transmit digital information signal by using the conventional synchronization of chaos and digital transmission approaches. In this scheme either a chaotic or hyper chaotic system is used to generate a chaotic signal. This signal along with the information digital signal is used to generate the transmitted signal. The transmitted signal is then masked by one of the chaotic signal of the transmitter and is transmitted through the channel to the receiver as well as used to drive the transmitter chaotic system using the concept of self-modulation. At the receiver end, suitable subtractor circuit is constructed for unmasking and the reception rule is used to recover the information signal. The effect of typical perturbing factors like channel noise and parameter mismatch are also included and their corresponding performance analysis has been done. By considering appropriate circuit configuration, the results of experiment are also presented.

013010   Kalaivani T;Krishnan S (Physics Dep, S R M University, Kattankulathur-603 203, Email: tkv_p29@rediffmail.com) : Dielectric relaxation studies of ternary liquid mixtures of aniline and substituted anilines with acrylonitrile in the microwave region. Indian J pure appl Phys 2009, 47(5), 383-5.

Dielectric behaviour of three amines and their mixtures: N-methyl aniline + acrylonitrile, aniline+ acrylonitrile and N, N-dimethyl aniline + acrylonitrile at microwave frequency 9.36GHz has been studied at temperature 303K. Different dielectric quantities like dielectric constant (ε?), dielectric loss (ε?), static dielectric constant (ε_°), and dielectric constant at optical frequency (ε_∞) have been determined. The relaxation time (τ) has been calculated by both Higasi's method and Cole-Cole method. The molar free energy of activation (ΔF_τ) and (ΔF_η) have also been calculated. The complex systems studied show the maximum relaxation time values at 1:1 complex ratio by both Higasi's method and Cole-Cole plot method.

013009   Janarthanan S;Kishore Kumar T;Pandi S;Prem Anand D (Physics Dep, Presidency College, Chennai-600 005) : Growth and spectroscopic studies of L-argininum formate NLO single crystals. Indian J pure appl Phys 2009, 47(5), 332-6.

Non-linear optical (NLO) organic crystals of L-argininum formate (LAF) have been grown using low temperature solution growth technique. The cell parameters of the crystal were determined using single crystal X-ray diffraction analysis. FTIR analysis was done to confirm the presence of various functional groups in the LAF crystalline sample. FT-Raman analysis carried out on LAF ascertained the presence of formate ion in the crystal lattice. H¹ NMR spectral analysis revealed its structural identification. The surface morphology of the grown crystal was studied using SEM analysis.

013008   Gharibshahian E;Tafreshi M J;Fazli M (Physics Dep, Semnan University, Semnan, Iran) : Growth of KTiOPO₄ crystals by flux technique and their characterization. Indian J pure appl Phys 2009, 47(5), 356-61.

Single crystals of KTiOPO₄ (KTP) have been grown by flux technique using K₆P₄O₁₃ flux. Crystals up to 3x2x1 mm³ in size were grown by slow cooling and spontaneous nucleation when high temperature solution was cooled down to room temperature with the rate of 7°C/h. The structure and quality of the grown crystals were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Optical Transmission analysis. The surface morphology of the grown crystals was studied by scanning electron microscopy (SEM).

013007   Ghanshyam;Verma R K;Narayan Kumar;Jayaswal S K;Singh B P (Physics Dep, B.I.T., Sindri, Dhanbad-828 123, Email: ghanshyam123@rediffmail.com) : Self-focusing of laser beams in the paraxial ray approximation in collisional inhomogeneous plasmas for arbitrary large magnitude of nonlinearity. Int J chem Sci 2008, 6(2), 1021-31.

Presents an investigation of the self-focusing behaviour of radially symmetrical Gaussian laser beam propagating in an axially inhomogeneous collisional plasma-. Considering the non-linearity to arise from the redistribution of electrons, due to thermal conduction across the cross-section of the beam and following the extended version of Sodha et al. theory based on the WKB and paraxial -ray approximation, the self-focusing behaviour has been investigated in some detail. The effect of different types of axial inhomogeneities in plasma, on the self-focusing of laser beam has been studied for arbitrary large magnitude of nonlinearity. The self-focusing is found to depend on type of axial inhomogeneity as well as characteristic scale length of axial inhomogeneity. When thermal conduction is the dominant mechanism of nonlinearity of dielectric constant, the critical power P_cr of the beam is seen to be the same as that given by the small nonlinearity theory. When power of the beam P > P_cr, the medium behaves as an oscillatory wave-guide.

1 illus, 9 ref

013006   Das K;Ray S;Chaudhuri S;Maity A B (Materials Science Dep, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, Email: abm_hit@yahoo.com) : Structural and luminescence properties of sol-gel derived Cu doped ZnO films. Indian J pure appl Phys 2009, 47(5), 377-82.

Well crystallized Cu doped (1, 3 and 5 molar %) ZnO films have been deposited on quartz substrates by sol-gel technique. The microstructural, optical and photoluminescence properties of the films have been studied. It has been observed that the band gap (3.38 eV) of ZnO films did not vary up to 5 molar % of Cu doping. The preferred orientation along (002) was observed for all the films. The X-ray diffraction (XRD) measurement confirmed the decrease of degree of orientation of (002) plane with increasing molar % of Cu in the films. The atomic force microscopy (AFM) measurements have also been performed to examine the surface morphologies of the films. It has been observed that the surface roughness of 1 molar % Cu doped film is smaller (~ 6 nm) than those of 3 and 5 molar % of Cu. The photoluminescence of the films shows prominent peaks between 2.27 to 3.11 eV due to excitonic as well as defect related transitions. A possible mechanism of carrier transitions between shallow and deep impurity levels in the photoluminescence has also been studied.

013005   Bhattacharyya S S;Mukherjee A;Chaudhuri B K; Wu S L (Solid State Physics Dep, Indian Association for the Cultivation of Science, Kolkata-700 032, Email: sspbkc@rediffmail.com) : Polarization-tilt coupling for surface stabilized ferroelectric liquid crystal. Indian J pure appl Phys 2009, 47(5), 372-6.

A ferroelectric liquid crystal (FLC) material in surface stabilized geometry has been characterized by polarized optical microscopic technique and detailed study of temperature dependent spontaneous polarization (PS) and tilt angle (q) have been carried out. The tilt angle (q) has been measured in a newly developed electro-optic method. The coupling coefficient between molecular polarization (PS) and tilt (q) has been determined in accordance with extended Landau theory.

013004   Ananda Kumari R (Physics Dep, Sree Siddaganga College for Women, Tumkur-572 101, Email: ranandakumari61@yahoo.com) : Growth and characterization of NLO crystal. Indian J pure appl Phys 2009, 47(5), 369-71.

Pure ammonium dihydrogen orthophosphate (ADP) crystals and ADP crystals doped with nitrite tri-acetic acid and ethylene diamine tetra acetic acid (EDTA) have been grown by slow evaporation technique. Grown crystals have been characterized using X-ray diffraction and energy dispersive X-ray spectroscopy (EDAX). Second harmonic generation (SHG) efficiency measurements are carried out by Kurtz method. It has been found that the ADP crystals containing nitrite tri acetic acid and EDTA have resulted appreciable increase in SHG efficiency as compared to pure ADP crystals. Dielectric constant and dielectric loss are measured as a function of frequency. Study confirms the contribution of space charge polarization.

013003   Abdul Salim M;Raveendran R (Physics Dep, T.K.M. College of Arts and Science, Kollam-691 005, Email: salim1001@sancharnet.in) : Microhardness variation of cobalt doped cadmium oxalate single crystals due to dopant's concentration. Int J chem Sci 2008, 6(1), 157-65.

Pure and cobalt doped cadmium oxalate single crystals were grown by gel technique. These were characterized and undergone ICPAES and microhardness measurements. Characteristics such as powder XRD and FTIR are taken. The crystals are of few mm in size. XRD patterns of the samples reveal their crystalline nature. The FTIR spectrum shows the presence of water molecules and carboxylic acid. ICPAES measures the quantity of dopant in the pure crystal. The hardness measurement shows the variation of hardness values with load and dopant's concentration.

5 illus, 4 tables, 11 ref

012039   Zoliana B;Thapa R K (Electronics Dep, Govt. Zirtiri Residential Science College, Aizawl, Mizoram-796 001, Email: bzoliana@yahoo.com) : Application of projection operator method to define basis functions for use in photoemission calculations. Indian J Phys 2008, 82(6), 729-34.

Applied projection operator method of group theory in deriving the symmetry adapted wavefunctions defined by ψi which represents the surface electronic states in the case of a strong periodic potential. The method involves the defining of basis function pertaining to a particular symmetry point of Cu(110), from which ψ_i is formulated by the LCAO method. This has been applied to calculate photocurrent from Cu (110) surface state. We have also used this method of calculation for a metal like Al.

3 illus, 9 ref

012038   Yadav M;Chauhan D S (Physics Dep, Govt. P.G. College Kotdwara, Pauri Garhwal, Uttaranchal-246 149) : Propagation of weak cylindrical shock waves under the influences of overtaking distrubances. Indian J Theor Phys 2007, 55(3), 185-95.

Inclusion of effects of disturbances behind the shock waves moving in uniform and non-uniform medium modifies the approximate method used to investigate their propagation. The numerical estimates of the flow variable have been computed at the permissible shock front locations. The result has been presented through graphs and compared with the earlier results also.

5 illus, 12 ref

012037   Wary G;Rahman A (Physics Dep, Cotton College, Guwahati-781 001, Email: ganesh_wary@yahoo.co.in) : Comparative studies on optical parameters of CdTe and ZnO thin films. Indian J Phys 2008, 82(6), 723-8.

The optical parameters of vacuum evaporated (p)CdTe and (n)ZnO thin films were studied and compared using uv-visible spectrophotometer equipped with an integrating sphere. The main optical parameters studied are: transmittance, reflectance, absorbance, refractive index, extinction co-efficient etc. Comparison at wavelength 500 nm shows that refractive index 'n' as well as imaginary part of dielectric constant, 'ε" 'of (n)ZnO films are smaller than that of (p) CdTe films which indicates the more transparency of (n)ZnO films and more efficient semiconductor for using as transparent conducting oxide (TCO) in most of the junction devices. Static (dc) electrical conductivity is observed to increase slowly towards the IR spectrum as imaginary part of refractive index 'k' increases towards higher wavelength.

2 illus, 3 tables, 12 ref

012036   Srivastava S K;Kar M;Ravi S (Physics Dep, Indian Institute of Technology, Guwahati, Guwahati-781 039, Email: sravi@iitg.ernet.in) : Electrical transport and magnetic properties of La_0.85Ag_0.15(Mn_1-yAl_y)O₃ compounds. Indian J Phys 2008, 82(6), 695-9.

La_0.85Ag_0.15Mn_1-yAl_yO₃ compounds were prepared for y = 0, 0.05 and 0.10 by solid-state route. XRD patterns show that all the samples are in single phase form. Temperature variations of ac susceptibility down to 25K were measured at an ac field amplitude of 6Oe. All the above samples exhibit paramagnetic to ferromagnetic transitions with a decrease in ferromagnetic transition temperature (T_c) with an increase in Al doping. Temperature variation of DC electrical resistivity was measured down to 25K for all the samples. Metal-insulator (M-l) transition has been observed in all the samples with maximum transition temperature (T_p) at 285K for y= 0 sample.

3 illus, 1 table, 17 ref

012035   Singh K K;Shubha Singh;Patel R P;Jaipal Singh;Singh A K;Singh A K;Singh R P;Lalmani (Atmospheric Research Lab, Physics Dep, Banaras Hindu University, Varanasi-221 005, Email: singhshubhabhu@gmail.com) : Estimation of magnetospheric electron densities from low latitude whistlers. Indian J Phys 2008, 82(4), 379-86.

Dispersion analysis of whistler waves recorded at the low latitude stations have been used to estimate electron density in the equatorial region and electron contents in the flux tube aligned along the dipolar geomagnetic fields lines. This is possible only when waves have propagated along the field lines. Reports some examples of whistler waves recorded at the ground station Jammu (geom. lat. 22° 26' N, L = 1.17), India, whose analysis yield path of propagation in the range 1.62 ≤ L ≤ 4.39. The matched filtering and parameter estimation technique has been used to analyze these whistlers and the error in estimating the path of propagation is less than 3%. However, the computed electron densities and electron tube contents based on the analysis of these whistlers are found to be one order of magnitude smaller than the values reported by the other workers. This shows that the matching of simulated and observed dynamic spectra need not necessarily yield correct path of propagation and hence correct value of electron density. As a result either the propagation mechanism at low latitude or the analysis method of whistlers recorded at low latitudes has to be reconsidered.

3 illus, 1 table, 31 ref

012034   Singh K K;Das H L (Physics Dep, T.M. College, Oinam-795 134, Email: kunjabali@yahoo.com) : Microstructures, stress, strain and surface characterization of TD polycrystalline CdS thin films. Indian J Phys 2008, 82(6), 685-93.

Reports in this paper the effects of substrate temperature (Ts) and film thickness (T_f) on the microstructures, stress, strain and the surface morphology in thermally deposited (TD) polycrystalline CdS thin films using XRD and SEM techniques. The XRD and the SEM results reveal that the quality of polycrystalline nature of CdS films grown under identical film growth conditions were observed significantly improved with Ts and T_f The structural phases of the films were observed to possess two phase structures. Films grown at Ts ≤ 423K were found f.c.c. cubic ZnS structure with (111), (220) and (311) planes, and hexagonal phase structure at Ts ≥ 443K with (002) and (112) planes. The evaluated lattice parameters in cubic and hexagonal phases were found with close agreements with their standard values. The films were observed to contain a large regions of localized micro-strains, the sizes of which were observed to decrease as Ts increases from 373K to 473K in films of 2500Angustrum thickness, and T_f increases from 1500A to 4000 A at 473K (Ts). The films grown from 300K to 423K (Ts) were found to be unstressed, and fairly stressed at elevated Ts. The stresses were remarkably increased with increasing T_f.

6 illus, 5 tables, 24 ref

012033   Singh K D;Mathew A (Mathematics Dep (ICDEOL), Himachal Pradesh University, Shimla-171 005, Email: kdsinghshimla@gmail.com) : Injection/suction effect on an oscillatory hydromagnetic flow in a rotating horizontal porous channel. Indian J Phys 2008, 82(4), 435-45.

Studies the effects of injection/suction on an oscillatory flow of a viscous incompressible ftuid in a porous channel. The porous channel with constant injection/suction rotates about an axis perpendicular 10 the plates of the channel. A magnetic field of uniform strength is also applied perpendicular to the plates. The upper plate is allowed to oscillate in its own plane with the velocity U^*(t^*) whereas the lower plate is at rest. The effects of coriolis force and the magnetic field on the flow are studied.

3 illus, 1 table, 14 ref

012032   Sheikh A H;Verma S C;Amod Kumar (Snow and Avalanche Study Establishment, Research and Development Centr, DRDO, Himparisar, Chandigarh-160 036, Email: ansarhamidf@yahoo.co.in) : Interaction of retarding structures with simulated avalanches in snow chute. Curr Sci 2008, 94(7), 916-21.

Series of experiments were conducted in a 61-m long snow chute to investigate the interaction of the flowing snow mass with obstacles (friction blocks) of different geometries. The flows generated are approximated as avalanche-like flows as they show typical features such as a steady velocity along the track, longitudinal spreading and almost fluidized flowing characteristics, despite the smooth chute surface. Reports a series of experiments on model control structures in the form of mounds and a blunt body of similar projection area which are of a comparable height to the flow depth. The retarding effects were investigated by a direct measurement of the velocity of flow at various sections using CCD cameras, its runout length and location of centre of mass of the final debris deposited. The experiments show that the avalanche currents generated in the snow chute detach from the top of the obstacles in the form of a jet and a granular jump is created, which results in a sufficient dissipation of the energy and a possibility of a shock wave travelling in the upstream direction. It was observed that mounds with height more than two times the flow depth, can lead to a significant reduction in the runout length. However, at low flow depths the effectiveness of the blunt body is more because the avalanching snow splits into different segments and the flow profile is close to the bed slope. On the contrary, when the flow depth is of the same order of magnitude as the obstacle height, the mound becomes more effective as the flow detaches from the top of the blunt body and travels a much larger distance at high velocity, while as in case of mounds a jet is formed both in horizontal and vertical directions, and travels a comparatively less distance. The study of the jet traverse in the vertical direction becomes useful in determining the effective distance between rows of retarding structures.

6 illus, 4 tables, 9 ref

012031   Shashikumar T S;Ragini N;Chandrashekara M S; Paramesh L (Studies in Physics Dep, University of Mysore, Manasagangotri, Mysore-570 006, Email: lp@physics.uni-mysore.ac.in) : Radon in soil, its concentration in the atmosphere and gamma exposure rate around Mysore city, India. Curr Sci 2008, 94(9), 1180-5.

Concentrations of radon in soil, rate of its exhalation from the ground surface and its concentration in the atmospheric air have been studied in and around Mysore city (12°N and 76°E). Variation of radon concentration in the soil-gas under dry and wet conditions at different depths was also studied. Radon in soil-gas was found to increase with depth and decrease with increase in moisture content of the soil. Radon in soil varies from 0.11 to 11.85 kBq m<^-3 with a median of 1.92 kBq m³. The annual average values of radon and its progeny concentrations in the atmosphere vary from 15.33 to 47.81 Bq m^-3 with a median value of 24.36 Bq m^-3 and 0.08 to 3.54 mWL with a median value of 0.33 mWL respectively. Good correlations were observed between radon in soil, radon exhalation rate from the ground surface and radon concentration in the atmosphere in these locations. ²²⁶Ra in soil at these locations was also estimated using the HPGe detector. The activity of ²²⁶Ra varies from 11.3 to 74.2 Bq kg^-1. Radon concentration in soil-gas shows good correlation with the activity of ²²⁶Ra in soil. The correlation coefficient was 0.76.

3 illus, 3 tables, 25 ref

012030   Sarma S;Srinivasan A (Physics Dep, Indian Institute of Technology, Guwahati, Guwahati-781 039, Email: sida@iitg.ernet.in) : Influence of cooling rate on the properties of ferromagnetic shape memory alloy. Indian J Phys 2008, 82(6), 701-6.

Polycrystalline Co₄₅Ni₂₅Ga₃₀ alloys were prepared by arc melting method, followed by the quenching separately into liquid nitrogen, ice cold water and air, respectively. The powder X-ray diffraction pattern of slow cool alloys showed a mixed phase structure, whereas the quenched alloys revealed a single phase structure. No marked structural difference was observed in the X-ray diffraction patterns of the air cooled, ice quenched and liquid nitrogen quenched samples. However, the martensitic and austenite transformation parameters observed by Differential scanning calorimeter (DSC) showed appreciable change in quenched samples. The slow cooled sample did not show any signature of martensitic transformation. The surface relief due to martensitic transformation was observed in optical microscope for all three quenched samples. The thickness of the twin lines increased for samples cooled at higher rates. The Curie temperature of the three samples shows subtle variations.

4 illus, 1 table, 6 ref

012029   Sarkar N K;Choudhury J;Bhattacharjee R (Physics Dep, Karimganj College, Karimganj-788 710, Email: nks_sds@rediffmail.com) : Algebraic approach : study of vibrational spectra of some linear triatomic molecules. Indian J Phys 2008, 82(6), 767-72.

Using the Lie algebraic method the vibrational energy levels of OCS and HCN are calculated for 35 vibrational bands each using the local Hamiltonian. A comparative study is made between the two. It has been shown that local Hamiltonian gives a much better fit to the HCN in comparison to that of OCS. Better result for HCN compared to those published earlier also has been reported.

2 tables, 14 ref