002282   Nath P P;Sarkar S;Joarder R N (Physics Dep, Jadavpur University, Kolkata-700 032) : Ordering potential-the anomalous structure and properties of liquid LiNa alloy. Indian J Phys-Pt A 2003, 77(6), 609-12.

Using pseudopotential theory the ab initio calculation for ordering potential of liquid LiNa alloy is presented. Taking into account the electronic charge transfer and also charge neutrality condition we find the effective valencies in the alloy. Uses the nodel to obtain the Bhatia-Thornton structure factors, particularly at null alloy concentration (Li = 0.61). The calculations of concentration fluctuation and other related thermodynamic properties shwo that this ordering potential approach works reasonably for this phase-separating (ps) liquid alloy system.

3 illus, 7 ref

002281   Nandan S;Singh K M;Upadhyay P N (Physics Dep, Veer Kunwar Singh University, Ara-802 301, Bihar) : Some decay modes of the top quark (t). Acta Cienc Indica-Phys 2003, 29(2), 199-201.

Presents a brief survey on the decay modes of the heavy top quarks. Theoretical predictions are made in context of SM and SUSY. Results on its decay for dilepton Channel, lepton plus jet channel and hadron channels have been presented. Some of its rare decay have also been included.

1 illus, 17 ref

002280   Nanayakkara A (NO, Institute of Fundamental Studies, Hanthana Road, Kandy, Sri Lanka) : Higher-order semiclassical energy expansions for potentials with non-integer powers. Pramana J Phys 2003, 61(4), 739-47.

Presents a semiclassical eigenenergy expansion for the potential <124>x<124>^α when α is a positive rational number of the form 2n/m (n is a positive integer and m is an odd positive integer). Remarkably, this expansion is found to be identical to the WKB expansion obtained for the potential x^N (N-even), if 2n/m is replaced by N. Taking the limit m → 2 of the above expansion, it obtains an explicit asymptotic energy expansion of symmetric odd power potentials <124>x<124>^2j+1 (j-positive integer). It shows how to develop approximate semiclassical expansions for potentials <124>x<124>^α when α is any positive real number.

4 tables, 8 ref

002279   Murthy M B R;Dyasagar B S;Patil R L (NO, F.E.T. Multimedia University, Melaka, 75450, Malaysia) : Measurements on polar liquids at a microwave frequency - evaluation of molecular parameters - a new method. Pramana J Phys 2003, 61(4), 725-7.

A simple method of estimating the dipole moment (μ) and relaxation time (τ) of polar molecules in liquid state, from a single set of dielectric measurements at high frequency, is proposed by using the concept of dielectric virial coefficients and employing Onsager model. The proposed method is tested in a number of polar liquids and the results are discussed.

1 table, 17 ref

002278   Mishra S K;Yadav R K S;Rai S B;Singh V B (Physics Dep, Udai Pratap Autonomous College, Varanasi-221 002) : Potential energy curve and dissociation energy of Diatomic indium halid. Indian J Phys-Pt B 2003, 77(2), 229-32.

The RKR potential curves are computed for the gournd state XO⁺ and low-lying excited states AO⁺ and B1 of indium monohalides using the most recent molecular constants. The H-H potential function has been shown to reproduce well the RKR curve over a wide range of energies and these potentials are applied to estimate the ground state dissociation energy D",) for these molecules. A brief discussion on the correlation of the low-lying excited states to the different possible dissociation products is also given.

2 tables, 34 ref

002277   Mishra S C;Mishra V (Physics Dep, Kurukshetra University, Kurukshetra-136 119) : Second invariant for two-dimensional classical super systems. Pramana J Phys 2003, 61(4), 633-44.

Construction of superpotentials for two-dimensional classical super system (for N ≥ 2) is carried out. Some interesting potentials have been studied in their super form and also their integrability.

20 ref

002276   Mishra N;Jha L (University Department of Physics, L.N. Mithila University, Darbhanga-846 004, Bihar) : Simple numerical method for the study of microstrip antenna. Acta Cienc Indica-Phys 2003, 29(2), 143-8.

A simple numerical method for the study of microstrip antenna is developed. The class of antennas considered is fed through the ground plane by a coax transmission line. The reaction integral equation is formulated by treating the coxial aperture as part of the antenna. The substrate thickness can be arbitrary; therefore, this numerical technique is suitable for high frequency application. The effects of the substrate are also included in the analysis. Numerical results are obtained for the current distribution and input inpedance.

3 illus, 10 ref

002275   Mishra A;Mishra S;Jha L (Physics Dep, L.N. Mithila University, Darbhanga, Bihar) : Fractional image solutions of wedges. Acta Cienc Indica-Phys 2003, 29(3), 313-16.

Fractional calculus is used to obtain the fractional images of the dielectric perfectly conducting wedges.

10 ref

002274   Mishra A K (Physics Dep, Delhi Public School, Dhaligaon, Bongaigaon-783 385, Assam) : Scattering model for estimation of soil moisture for remote sensing using microwave technique. Acta Cienc Indica-Phys 2003, 29(3), 259-62.

Microwave scattering and emission behaviour of the soil depend on its dielectric constant, which is effected by the moisture content in the soil. The knowledge of variability of the soil moisture is important for the agriculture. The properties chiefly the scattering co-efficient and the dielectric constant with respect to moisture content are important for remote sensing data. Therefore, in the investigation an attampt has been made to develop scattering model for estimation of scattering co-efficient with moisture content and frequency. Scattering co-efficient increase with frequency and decreases with moisture content for different look angle both for vertical and horizontal polarization.

2 illus, 7 ref

002273   Mehta A (Physics Dep, Oliver Lodge Lab, Liverpool University, Liverpool, L69 7ZR, UK) : Structure function measurements from HERA. Pramana J Phys 2003, 61(5), 819-26.

Recent measurements of structure functions from the HERA Collaborations are presented.

7 illus, 8 ref

002272   Marco E;Oset E;Singh S K (Departmento de Fisica Teorica and IFIC, , Valencia, Spain) : Nuclear effects in the structure functions. Pramana J Phys 2003, 61(5), 993-9.

By using a relativistic framework and accurate nuclear spectral function the structure functions F_2A and F_3A of deep inelastic charged lepton and neutrino scattering are calculated in nuclei and results are presented.

3 illus, 11 ref

002271   Mandal K;Mandal S;Vazquez M (C K Majumdar Laboratory Dep, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata-700 098) : Annealing effect on the giant magnetoimpedance of amorphous microwire. Indian J Phys-Pt A 2003, 77(6), 599-602.

Giant magnetoimpedance (GMI) effect in positive megnetostrictive glass-coated amorphous Co_83.2Nm_7.6Si_5.8B_3.3 microwire has been studied as a function of a dc magnetic field -140 < H_dc < 140 Oe and frequency 0.1 < f < 12.85 MHz. A maximum change of 43% in MI of the as-quenched sample has been observed around 5 MHz frequency. Heat treatment of the sample by passing a dc current of 50 mA through it enhances the MI value ot a large extent (maximum change~94%) by increasing the outer domain volume and inducing a transverse anisotropy. The magnetization of the as-quenched and heat-treated samples has also been studied to understand the domain strucuture and magnetoimedance results.

3 illus, 10 ref

002270   Mallik S (NO, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata-700 064) : Strong interaction at finite temperature. Pramana J Phys 2003, 61(5), 931-41.

Reviews two methods discussed in the literature to determine the effective parameters of strongly interacting particles as they move through a heat bath. The first one is the general method of chiral perturbation theory, which maybe readily applied to this problem. The other is the method of thermal QCD sum rules. Shows that, when the spectral sides of the sum rules are calculated correctly, they do not lead to any new results, but reproduce those of the vacuum sum rules.

16 ref

002269   Mahurpawar V;Deo S D (Mathematics Dep, Government Autonomous P.G. College, Chhindwara-480 001) : On Bianchi-I cosmic strings coupled with Maxwell fields in bimetric relativity. Pramana J Phys 2003, 61(4), 655-8.

Axially symmetric Bianchi-I model is studied with source cosmic cloud strings coupled with electromagnetic field in Rosen's bimetric theory of relativity and observed that there is no contribution from cosmic strings and Maxwell fields in this theory.

3 ref

002268   Layek B;Sanyal S;Srivastava A M (NO, Institute of Physics, Sachivalaya Marg, Bhubaneswar-751 005) : Implications of cosmic string-induced density fluctuations at the quark-hadron transition. Pramana J Phys 2003, 61(5), 1039-43.

Shows that cosmic strings moving through the plasma at the time of a first-order quark-hadron transition in the early universe generate baryon inhomogeneities, which can survive till the nucleosynthesis epoch. It finds out how these inhomogeneities actually affect the calculated values of the light element abundances. Recently a wealth of observational data from various experiments have helped to reduce the uncertainties in the values of these abundances. Using these it shows that it is possible to derive constraints in the presence of cosmic strings during the quark-hadron transition.

1 illus, 6 ref

002267   Kumar A;Jha L (University of Department of Physics, L.N. Mithila University, Darbhanga-846 004) : Bandwidth analysis of microstrip antenna. Acta Cienc Indica-Phys 2003, 29(3), 215-20.

A new method based on the back propagation multilayered perception network for calculating the bandwidth of reasonant rectangular microstrip antenna is presented. The method can be used for a wide range of substrate thicknesses and permittivities and is useful for the computer aided design of microstrip antennas. This method may find wide applications in high frequency printed antennas, specially at the millimeter-wave frequency range.

4 illus, 12 ref

002266   Kulkarni V H (NO, Instituto Nacional de Pesquias Espaciais, INPE, Av. Dos Astronautica, 1758-Jd Granja, Sao Jose dos Campos-Sp 12245-970, Brazil) : Generation of field-aligned currents by VLF waves in the magnetosphere. Indian J Radio Space Phys 2003, 32(4), 189-92.

It has been shown that VLF waves can be a source for the high energy electrons of tens of keV, carrying the small scale magnetic field-aligned Birkeland currents of sizes <60> 50 km in the magnetosphere. The dispersion relation for whistler mode waves in a magnetized plasma consisting of cold, warm and hot electrons and a beam of electrons carrying the current is examined. The VLF growth rates in the presence of field-aligned currents are found to be weaker and the current carrying electrons extract energy from the VLF waves. Along with the dependence of file-aligned currents and VLF waves of the magnetic activity, both these parameters also depend on each other directly.

17 ref

002265   Kuchhal P;Dass N (NO, Mody College of Engineering and Technology, Lakshmangarh, Sikar) : New isothermal equation of state of solids applied to high pressures. Pramana J Phys 2003, 61(4), 753-7.

A new two parameter inverted equation of state (EOS) is developed which is found to be working very well in the high-pressure region. To check its success and validity, this EOS has been applied in a number of solids. The computed volume compression is found to be in very good agreement with the experimental data in the whole range of pressure in all the solids. The minimum and the maximum pressure range used in the study is 0-320 kbar and 0-3000 kbar, respectively.

1 table, 26 ref

002264   Khanna R K;Chouhan R C (Plasma and Microwave Laboratory, Physics Dep, Government College, Ajmer-305 001) : Non-linear propagation of laser beam and focusing due to self-action in optical fiber: non-paraxial approach. Pramana J Phys 2003, 61(4), 693-706.

A somewhat more general analysis for solving spatial propagation characteristics of intense Gaussian beam is presented and applied to the laser beam propagation in step-index profile as well as parabolic profile dielectric fibers with Kerr non-linearity. Considering self-action due to saturating and non-linearity in the refractive index, a general theory has been developed without any kind of power series expansion for the dielectric constant as is usually done in other theories that make use of paraxial approximation. Result of the steady state self-focusing analysis indicates that the Kerr non-linearity acts as a perturbation on the radial inhomogeneity due to fiber geometry. Analysis indicates that the paraxial rays and peripheral rays focus at different points, indicating aberration effect.

7 illus, 2 tables, 36 ref

002263   Joglekar S D (Physics Dep, Indian Institute of Technology, Kanpur-208 016) : Some observations on interpolating gauges and non-covariant gauges. Pramana J Phys 2003, 61(5), 949-53.

Discusses the viability of using interpolating gauges to define the non-covariant gauges starting from the covariant ones. Draws attention to the need for a very careful treatment of boundary condition defining term. Shows that the boundary condition needed to maintain gauge-invariance as the interpolating parameter θ varies, depends very sensitively on the parameter variation. Also considers the Lagrangian path-integrals in Minkowski space for gauges with a residual gauge-invariance. Points out the necessity of inclusion of an ε-term (even) in the formal treatments, without which one may reach incorrect conclusions. Further points out that the ε-term can contribute to the BRST WT-identities in a non-trivial way (even as ε → 0). Points out that these contributions lead to additional constraints on Green's function that are not normally taken into account in the BRST formalism that ignores the ε-term, and that they are characteristic of the way the singularities in propagators are handled. Argues that a prescription, in general, will require renormalization; if at all it is to be viable.

13 ref

002262   Jha A N;Jha L (University Department of Physics, L.N. Mithila University, Darbhanga-846 004) : Study of the radar cross section of a rectangular microstrip antenna. Acta Cienc Indica-Phys 2003, 29(3), 327-30.

The Radar Cross Section of a rectangular microstrip patch on a lossy biased ferrite substrate is investigated. The analysis is based on a full-wave integral equation formulation in conjunction with the method of moments. In the analysis the direction of the bias is not prescribed. The RCS characteristics, especially the resonance behaviour of a patch with various biasing conditions, are studied and compared to the case of an unbiased ferrite.

2 illus, 6 ref

002261   Jayasree CX S;Renuka G;Venugopal C (Physics Dep, University of Kerala, Kariavattom, Trivandrum-695 581) : Destabilization of EIC waves and heating of HPT ions. Indian J Radio Space Phys 2003, 32(3), 127-34.

The electrostatic ion cyclotron (REIC) instability of hot plasma torus (HPT) particles in the auroral region due to field aligned current (FAC) has been studied. The value of FAC density is estimated from the high time resolution magnetic field data of DE-1 spacecraft at altitudes ranging from 600 km to 2500 km during the magnetic storm of 21 Mar. 1990 during 0001-2000 hrs UT. The FAC destabilizes the EIC wave and the resultant electrostatic turbulence creates an anomalous resistivity. The current driven resistivity produces parallel electric field and high power dissipation. The growth rate of EIC wave decreases as the electron to ion temperature ratio T_e/T_ie/T_i increases. When the instability is almost shut off, the ion heating and transversely accelerated ions (TAI) are sharply reduced.

9 illus, 28 ref

002260   Jain V K (Phys Dep, M.D. Univ, Rohtak-124 001) : Superposition model analysis of zero-field splitting of Mn<. Bull pure appl Sci-Sect D 2003, 22(1), 91-3.

The Newman superposition model has been applied to the secon - order zero-field splitting parameter b⁰₂ for Mn²⁺ in Ce₂Zn₃(NO₃)₁₂.24H₂O single crystals at both the sites. It is shown that calculated values of b⁰₂ are in agreement with the experimental values if local relaxation efects are taken in to account.

8 red

002259   Jain V K (Phys Dep, M. D. Univ, Rohtak-124 001) : Electron paramagnetic resonance of atomic hydrogen in X-irradiated sulfates. Bull pure appl Sci-Sect D 2003, 22(1), 51-3.

The electron paramagnetic resonance spectra of the X-ray irradiated thermally annealed Gypsum and barium sulfate is studied at 285 K. The Gypsum and Coelstine are obtained from various locations while barium sulfate was prepared under controlled conditions. The spin-Hamiltonian parameters are evaluated. It is observed that atomic hydrogen is originated from stoichiometric constituents.

1 illus, 2 tables, 3 ref

002258   Jain P;Ralston J P (Physics Dep, Indian Institute of Technology, Kanpur-208 016) : Proton electromagnetic form factor F₂ and quark orbital angular momentum. Pramana J Phys 2003, 61(5), 987-92.

Analyses the proton electromagnetic form factor ratio R(Q²) = QF₂(Q²)/F₁(Q²) as a function of momentum transfer Q² within perturbative QCD. Finds that the prediction for R(Q²) at large momentum transfer Q depends on the exclusive quark wave functions, which are unknown. For a wide range of wave functions it finds that QF₂/F₁ <126> const. at large momentum transfer, which is in agreement with recent JLAB data.

2 illus, 16 ref

002257   Jain B K (Physics Dep, Mumbai University, Mumbai-400 076) : Nuclear physics at small distances. Pramana J Phys 2003, 61(5), 1001-8.

Reports the study of meson and resonance production in nuclear collisions near the threshold. Because of the large momentum transfer, these reactions occur at length scales less than the size of the hadrons. Explores whether they are best described in terms of the quark-gluon picture or the meson-exchange picture. Comparing the results with the available experimental data concludes that the spin-averaged cross-sections are best described in meson-exchange picture. The description of the observed nucleon-nucleus and hyperon-nucleus spin-orbit potentials are found to be consistent with the quark-gluon exchange picture.

7 illus, 14 ref

002256   Jain A;Ravishankar V (Physics Dep, Indian Institute of Technology, Kanpur-208 016) : Phase space description of the production of quark gluon plasma in heavy-ion collisions. Pramana J Phys 2003, 61(5), 1045-9.

A new source term is proposed to describe the production of quark gluon plasma in heavy-ion collisions.

3 illus, 14 ref

002255   Jain A;Gupta C B (Physics Dep, B.S.A. College of Engg. & Tech., Mathura, U.P.) : Effect of free convection on boundary layer flow of Rivlin-Ericksen fluid through porous medium over a continuous porous surface moving in an oscillating free stream and heat transfer. Acta Cienc Indica-Phys 2003, 29(2), 158-64.

An analysis of the effect of free convection on boundary layer flow of Rivlin-Ericksen fluid through porous medium past a continuous porous moving flat surface with constant suction has been considered when free stream velocity oscillate in time about a constant mean. Expression for mean velocity, mean temperature, transient velocity, transient temperature, fluctuating part of velocity U_r and U_i the mean skin friction and mean rate of heat transfer, the amplitude and phase of skin friction and the rate of heat transfer have been obtained and discussed graphically.

2 illus, 2 tables, 6 ref

002254   Jain A;Gupta C B (NO, B.S.A. College of Engg & Tech, Mathura) : Hydromagnetic free convective flow through a porous medium with variable permeability and mass transfer. Acta Cienc Indica-Phys 2003, 29(1), 77-86.

A theoretical analysis of the effect of mass transfer on free convective two dimensional unsteady flow of a viscous incompressible fluid through a porous medium bounded by an infinite vertical porous plat subjected to a uniform suction is presented under the influence of a uniform transverse magnetic field. The permeability of the porous medium fluctuated in time about a constant mean. Evaluates the velocity distribution u, fluctuating part of velocity profiles M_r, M_i and the skin friction at the plate by using the perturbation technique. Investigates the effects of G_c (Modified Grashoff No.) and S_c (Schmidt No.) on velocity and skin friction τ with help of Graphs.

3 illus, 4 tables, 14 ref

002253   Harris F E (Physics Dep, University of Utah, Salt Lake City, UT 84112, USA) : Comment: On the computation of molecular auxiliary functions A_n and B_n. Pramana J Phys 2003, 61(4), 779-80.

Guseinov, Mamedov, Kara and Orbay propose methods for evaluating the molecular auxiliary functions A_n(p) and B_n(pt) for range 17≤n≤60 and 25≤pt≤60. However, their procedure for A_n(p) is not new, and that for B_n(pt) is less efficient for their target range than another well-known method. Their approach does have merit for smaller non-zero values of pt.

4 ref

002252   Harikumar E;Mitra I;Sharatchandra H S (NO, The Institute of Mathematical Sciences, C.I.T. Campus, Chennai-600 113) : Half-monopoles in the Yang-Mills theory. Pramana J Phys 2003, 61(5), 961-5.

Using a gauge-invariant characterization of monopoles defined via their centres it investigates the generic topological field pattern for the three-dimensional Yang-Mills theory. This leads to field patterns with one-half winding number. After presenting the main features through the simpler case of half-vortices, it considers half-monopoles in detail.

2 illus, 10 ref

002251   Harikumar E;Mitra I;Sharatchandra H S (NO, The Institute of Mathematical Sciences, C.I.T. Campus, Chennai-600 113) : Topological field patterns in the Yang-Mills theory. Pramana J Phys 2003, 61(5), 955-9.

Presents a formalism where the topological configurations of pure Yang-Mills theory are characterised using gauge fields alone. Obtains an expression for the charges of these topological SO(3) gauge field configurations in terms of the Abelian vector potentials. In this formalism it analyses the 't Hooft-Polyakov monopole solution.

6 ref

002250   Gupta V K;Gupta A;Singh S;Anand J D (Physics and Astrophysics Dep, University of Delhi, Delhi-110 007) : Radial oscillations of magnetized proto strange stars in temperature- and density-dependent quark mass model. Pramana J Phys 2003, 61(4), 659-68.

Reports the mass-radius (M-R) relation and the radial oscillations of magnetized proto strange stars. For the quark matter it has employed the very recent modification, the temperature- and density-dependent quark mass model of the well-known density-dependent quark mass model. It finds that the effect of magnetic field, both on the maximum mass and radial frequencies, is rather small. Also a proto strange star, whether magnetized or otherwise, is more likely to evolve into a strange star rather than transform into a black hole.

5 illus, 28 ref

002249   Gupta S (Theoretical Physics Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005) : Quark gluon plasma: lattice computations put to experimental test. Pramana J Phys 2003, 61(5), 877-88.

Describes how lattice computations are being used to extract experimentally relevant features of the quark gluon plasma. Deals specifically with relaxation times, photon emissivity, strangeness yields, event-by-event fluctuations of conserved quantities and hydrodynamic flow. Finally gives evidence that the plasma is rather liquid-like in some ways.

4 illus, 67 ref

002248   Gupta P;Gadhavi H;Jayaraman A (School of Physics, Devi Ahilya University, Indore-452 001) : Aerosol optical depth variation observed using sun-photometer over Indore. Indian J Radio Space Phys 2003, 32(4), 229-37.

Columnar aerosol optical depth measurements have been made over Indore (22.7°N, 75.9°E) during May 2001-March 2002 at four spectral bands centred around 400, 499, 668 and 858 nm using a hand-held sun-photometer. The aerosol optical depth (AOD) shows seasonal variation with high values in summer and low values in winter. The summer-increase is found to be due to the high wind speed producing larger amount of wind-deroved dust particles. As the summe monsoon sets in at the end of June there is an appreciable decrease in the AOD values. The AOD values decrease further in winter and the decrease is more at higher wavelengths indicating that there is a general reduction in the number of bigger particles. Also during wintr months the wind direction changed to southerly and south-easterly which brings air that is more rural to the measurement site. The amplitude of the observed high AOD values in summer and low during winter, is higher for longer wavelengths which shows that the coarse particles contribute more to the observed variation is compared to sub-micron particles. Comparison of the AOD values over Indore with that of Trivandrum and Visakhapatnam shows that the Indore values are comparable to that of Visakhapatnam, but much higher than the Trivandrum values indicating the influence of industrialization and higher population.

8 illus, 3 tables, 18 ref

002247   Gupta L;Rath S;Abbi S C;Jain F C (Physics Dep, Indian Institute of Technology, New Delhi-110 016) : Temperature dependence of the fundamental band gap parameters in cadmium-rich Zn_xCd_1-xSe using photoluminescence spectroscopy. Pramana J Phys 2003, 61(4), 729-37.

Thin films of ternary Zn_xCd_1-xSe were deposited on GaAs (100) substrate using metal-organic-chemical-vapour-deposition (MOCVD) technique. Temperature dependence of the near-band-edge emission from these Cd-rich Zn_xCd_1-xSe (for x = 0.025, 0.045) films has been studied using photoluminescence spectroscopy. Relevant parameters that describe temperature variation of the energy and broadening of the fundamental band gap have been evaluated using various models including the two-oscillator model, the Bose-Einstein model and the Varshni model. While all these models suffice to explain spectra at higher temperatures, the two-oscillator model not only explains low temperature spectra adequately but also provides additional information concerning photon dispersion in these materials.

3 illus, 3 tables, 24 ref

002246   Guideinov I I (Physics Dep, Faculty of Arts and Science, Onsekiz Mart University, Canakkale, Turkey) : Response to the comment: On the computation of molecular auxiliary functions A_n and B_n. Pramana J Phys 2003, 61(4), 781-3.

The comment `on the computation of auxiliary functions A_n(p) and B_n(pt)' is analysed in the arbitrary range of parameters n, p and pt. It is shown that our downward recursion approach for B_n(pt) in the range (n/pt) <62> 1 is more efficient than the well-known upward recursion method, and the upward recursion procedure for A_n(p) does not have merit for smaller non-zero values of p (p<60>0.01).

2 tables, 6 ref

002245   Goyal D R;Maan A S (Phys Dep, Maharshi Dayanad Univ, Rohtak-124 001) : A.C. conductivity in amorphous InSeTe alloys. Bull pure appl Sci-Sect D 2003, 22(1), 75-9.

An account of the a.c. conductivity of In4_oSe_xTe_60-x

4 illus, 1 table, 15 ref

002244   Goyal D R;Maan A S (Phys Dep, Maharashi Dayanand Univ, Rohtak-124 001) : Calorimeteric studies in glassy Sb-Se alloys. Bull pure appl Sci-Sect D 2003, 22(1), 65-8.

DSC technique has been employed to study the kinetics of glass transition and crystallization in Sb-Se glasses. The shifting of endothermic peak of glass transition and exothermic peak of crystallization with heating rate has been used to calculate the activation energy for structural relaxation, activation energy for crystallization and the order parameter. There is consistent change in both the activation energies with Sb contents.

4 illus, 1 table, 15 ref

002243   Giri V S;Akhour B P (Physics Dep, Ranchi University, Ranchi-834 008, Jharkhand) : Constant parameter of hard convex fluid. Indian J Phys-Pt B 2003, 77(2), 233-6.

The isotropic-symmetric and orientational co-relations for hard convex body (HCB's) model, exhibit simpler behviour in the surface-to-surface than in the more customary center-to-center coordinate representation. It is the support function h(x) which defines the analtytical properties of this model. The intermolecular potential field has been proposed in terms of the support function. The intermolecular potential for HCB's reduces to hard sphere (HS) intermolecular potential for major and minor axis ratio equal to one and has exactly the same surface-to-surface distribution as for HCB's. The constant parameters of the potential function have been determined empirically by fitting the theoretical virial coefficient with quantum correction to experimental virial coefficient data. The resulting second virial coefficients agree well with the available experimental data.

1 illus, 1 table, 9 ref

002242   Giri D;Mishra P K;Kumar S (NO, Centre for Theoretical Studies, Indian Institute of Technology Kharagp, Kharagpur-721 302) : Critical behaviour of stiff polymer near the surface. Indian J Phys-Pt A 2003, 77(6), 561-3.

The self-avoiding walk models to investigate the adsorption transition of semi-flexible homopolymer chain in two and three dimesions. The exact-enumeration method has been used to locate the transition points. The results obtained from this method have been compared with the exact results found for the directed walk model of semi-flexible polymer.

3 illus, 12 ref

002241   Giri B P;Jha L (Physics Dep, L.N. Mithila University, Darbhanga, Bihar) : Study of hemispherical dielectric-resonator antenna. Acta Cienc Indica-Phys 2003, 29(1), 1-6.

A detailed study of the hemispherical Di-electric resonator antenna excited by a coaxial probe is made using the dyadic Green's functions pertaining to an electric current source located in dielectric sphere. The integral equation for the dielectric resonator antenna excited by a co-axial probe is obtained. The integral equation is solved using the method of moments. The antenna characteristics such as input impedance radiation patterns, directivity and efficiency are computed numerically, around the resonant frequency. The computed input impedance is compared with numerical and experimental data available in the literature.

4 illus, 11 ref

002240   Ghosh U K;Sen S N;Prasad R R;Singh R P;Mishra L K (Physics Dep, D.A.V. School, Aurangabad) : Evaluation of plasmon frequency associated with charge carriers and the temperature dependence resistivity of heavy electron systems. Acta Cienc Indica-Phys 2003, 29(1), 59-64.

Evaluates the plasmon frequency of various heavy electron systems. The evaluated values of resistivity ρ(T) for Ceal₃ and UPt₃ are in good agreement with that of the experimental data.

3 tables, 18 ref

002239   Ghosh S;Rishi M P (NO, School of Studies in Physics, Vikram University, Ujjain-456 010) : Amplitude modulation and demodulation of electromagnetic wave in magnetised diffusive semiconductor. Indian J Phys-Pt B 2003, 77(2), 223-7.

Analytical investigations are made for the amplitude modulation as well as demodulation of electromagnetic wave propagating in a diffusive semiconductor medium. Using hydrodynamical model of semiconductor plasmas the value of modulation indices has been found for both side band modes. Analyses are made in different wave number regions over a wide range of cyclotton frequency. It has been seen that diffusion of charge carriers modifies amplitude modulation and demodulation process effectivley. Numerical estimations are made for n-InSb crystal irradiated by pump wave of frequency 1.6 Tera sec^-1. Complete absorption of the waves takes place in all the possible wave length regimes when the cyclotron frequency w becomes exactly equal to carrier frequency provided one neglects the collision term in modulation/demodulation indices.

4 illus, 17 ref

002238   Ghosh A K;Munshi T K (Physics Dep, Kalna College, Kalna, Burdwan-713 409) : Piezoelectricity and electron mobility in ZnO. Indian J Phys-Pt A 2003, 77(6), 637-9.

Piezoelectric scattering mobility of electrons for the zinc blends structure is found to vary as T^-1/2for all range of low temperatures. This signifies a very high conductivity of the sample and a very high velocity of electrons in it at suitable low temperatures. So substances like ZnO have enormous prospect in searching for room temperature super conductivity.

4 ref

002237   Ghosh A K;Munshi T K (Physics Dep, Kalna College, Kalna, Burdwan-713 409, West Bengal) : Sensitivity of piezoelectric transducer. Indian J Phys-Pt A 2003, 77(6), 633-5.

A theoretical analysis based on an established transducer model has revealed a mathematical expression for sensitivity (e.g., volts. per unit signal force) of piezoelectirc plate transducer operating in its thickness mode and air as its surrounding medium. The sensitivity is found to be a strong function of frequency, with the principal peak being at the plate's fundamental thickness resonance. Other peaks of sensitivity are found to be at the odd multiples of this fundamental resonance frequency, whereas at even multiples of this frequency, the sensitivity is practically zero.

1 illus, 5 ref

002236   George R K;Shah R C (App Math Dep, Facl of Technol Eng, M.S. Univ of Baroda, Vadodra-390 001) : Solvability and controllability of controlled Lienard system. Indian J Math 2003, 45(1), 59-69.

Solvability and controllability of the Lienard equation has been investigated. For solvability analysis a more general Lienard system which was recently studied by Huang for boundedness of solution has been used. Sufficient conditions on the nonlinear function in the Lienard system has been given which will ensure the solvability and controllability of the system. In the analysis use of the Banach contraction principle and theory of Lipschitz continuous operators have been made. Also obtain algorithm for the computations of the seteering control has been obtained.

5 ref

002235   Gavai R V (Theoretical Physics Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005) : Lattice quantum chromodynamics: some topics. Pramana J Phys 2003, 61(5), 889-99.

Reviews some topics in lattice quantum chromodynamics, focusing more on the recent results. These include: the QCD phase diagram in the μ-T plane, the quark number susceptibilities, and the screening lengths.

9 illus, 13 ref

002234   Gao H (Physics Dep, Duke University, Durham, NC 27708, USA) : Exclusive processes at Jefferson Lab. Pramana J Phys 2003, 61(5), 837-46.

Mapping the transition from strongly interacting, non-perturbative quantum chromodynamics, where nucleon-meson degrees of freedom are effective to perturbative QCD of quark and gluon degrees of freedom, is one of the most fundamental, challenging tasks in nuclear and particle physics. Exclusive processes such as proton-proton elastic scattering, meson photoproduction, and deuteron photodisintegration have been pursued extensively at many laboratories over the years in the search for such a transition, particularly at Jefferson Lab in recent years, taking the advantage of the high luminosity capability of the CEBAF facility. Reviews recent results from Jefferson Lab on deuteron photodisintegration and photopion production processes and the future 12 GeV program.

3 illus, 42 ref

002233   Dwivedi A K (Physics Dep, R.S.K.D.P.G. College, Jaunpur-222 002) : Shock wave rotating gas with radiation heat flux. Acta Cienc Indica-Phys 2003, 29(3), 267-72.

Studies the propagation of shock wave in rotating non-uniform atmosphere taking radiative heat flux into consideration using Chester [1] - Chisnell [2] - Whitham [3] method.

3 tables, 7 ref