006175   Yadav R P;Anil Kumar;Anshu Rani;Akhilesh Kumar (Dep of Phys, Govt. P.G. Coll, Bisalpur (Pilibhit)-262 201) : Overtaking disturbances and rotating spherical shock wave in uniform medium. Ultra Scient phys Sci 2006, 18(1), 83-92.

Flow variables behind the spherical shock propagating in rotating medium has been investigated for two cases, viz (1) when shock waves are strong and (ii) when they are weak. Analytical relations for shock velocity and shock strength have been obtained by CCW method. The effect of overtaking disturbances on CCW shock is included. Medium in supposed to be uniform, though it is rotating. The results obtaind here are compared with though obtained elsewhere.

17 illus, 13 ref

006174   Verma A K;Saxena S (Dep of Phys, Bareilly Coll, Bareilly-243 001) : Charged particles (e±) excitation of hydrogen atom. Ultra Scient phys Sci 2006, 18(1), 47-52.

Applies the close coupling approximation for positron (electron) impact excitation of HYDROGEN atom. The differential scattering cross section (DCS), integral cross section (ICS) and collision strength (Ω) have been computed. The calculated values are compared with other theoretical calculation (S-model calculation, 33-state calculation and 24-pseudostate model calculation) and experimental data (wherever available). These cross sections are in good agreement with experimental result. More calculations are still in progress and may be seen in near future publications.

3 illus, 14 ref

006173   Vasanto Rao T (Dep of Phys, Lakireddy Balireddy Coll of Engng, Mylavaram-521 230) : Two loop beta functions and estimation of unification mass. Ultra Scient phys Sci 2006, 18(1), 65-70.

Predicts the values of electroweak mixing angle and unification mass for the E₆ GUT group by using Two loop analysis. Two loop β functions are estimated.

13 ref

006172   Trnka D (NO, II. Physikalisches Institut Univ of Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany, Email: David.Trnka@exp2.physik.uni-giessen.de) : Investigation of in-medium omega photoproduction. Pramana J Phys 2006, 66(5), 915-20.

Recent experimental results on the in-medium modification of the ω meson are discussed. The experiment described was performed at the ELSA accelerator facility in Bonn using the combined detector system of Crystal Barrel and TAPS. The ω-meson was identified via the reaction γ + A → ω + X → π⁰ γ + X.

4 illus, 21 ref

006171   Sodaye S;Tomar B S;Goswami A (Div of Radiochemistry, Bhabha Atom Res Cent, Mumbai-400 085, Email: agoswami@barc.gov.in) : Effect of entrance channel parameters on the fusion of two heavy ions: Excitation functions of reaction products in <. Pramana J Phys 2006, 66(6), 985-97.

Excitation functions of reaction products in ¹⁶O+ ⁶⁶Zn and ³⁷cl + ⁴⁵Sc systems, leading to the same compound nucleus, ⁸²Sr, were measured using recoilcatcher technique and off-line γ-ray spectrometry. The contribution of non-compound processes like transfer and incomplete fusion (ICF) reactions to the cross-sections of different evaporation residues were delineated by comparing the experimental data with the predictions of Monte Carlo simulation code PACE2. The results show that non-compound processes become a significant fraction of the total reaction cross-section in ¹⁶O + ⁶⁶Zn systems in the beam energy range studied, while ³⁷Cl + ⁴⁵Sc gives mainly compound nucleus products. The mass asymmetry dependence of the fusion and non-compound cross-sections have been analysed in terms of the static fusion model and sum rule model.

5 illus, 2 tables, 32 ref

006170   Shende S V;Castelijns R;Bacelar J C S;Lohner H;Messchendorp J (NO, Kernfysisch Versneller Instituut, Zernikelaan 25, 9747 AA Groningen, The Netherlands, Email: shende@KVI.nl) : Nucleon resonance decay by the K<. Pramana J Phys 2006, 66(5), 931-6.

The strange meson production on a proton target in the K⁰Σ⁺ channel is sensitive to nucleon resonance contributions. The K⁰ production on a deuteron target can provide information on the hyperon-nucleon final-state interaction. The experiments γp → K^øΣ⁺ and γd →K⁰Σ⁺ n have been carried out at the ELSA facility at Bonn. Reports the preliminary results of both experiments.

4 illus, 7 ref

006169   Sharma R;Nandy S;Bhattacharyya S P (Dep of Phys Chem, Indian Ass for the Cultivation of Sci, Jadavpur, Kolkata-700 032, Email: pcspb@mahendra.iacs.res.in) : On solving energy-dependent partitioned eigenvalue problem by genetic algorithm: The case of real symmetric Hamiltonian matrices. Pramana J Phys 2006, 66(6), 1125-30.

An energy-dependent partitioning scheme is explored for extracting a small number of eigenvalues of a real symmetric matrix with the help of genetic algorithm. The proposed method is tested with matrices of different sizes (30 x 30 to 1000 x 1000). Comparison is made with Lowdin's strategy for solving the problem. The relative advantages and disadvantages of the GA-based method are analyzed.

2 illus, 2 tables, 12 ref

006168   Sharma A;Singh M;Mittal R (Dep of Phys Nuclear Sci Laboratories, Punjabi Univ, Patiala-147 002, Email: rmsingla@yahoo.com) : Study of photon-induced L3 vacancy alignment for elements La to U. Pramana J Phys 2006, 66(6), 1111-17.

Alignment of photon-induced L₃ vacancies is studied in rare earth and high Z elements at energies of experimental interest, near thresholds to 60 keV, under non-relativistic dipole approximation. Numerical calculations of the matrix element are undertaken to produce theoretical data for comparison with the experimental findings. The A₂ values being <62>0.1 at photoelectron energies <60>20 keV are certainly higher than 5-8% uncertainties quoted in experimental results. Present findings are from a very basic model, hydrogen-like and can further be treated as reference to observe the impact of screening, relativistic, multipole and retardation corrections to the model.

1 illus, 17 ref

006167   Semalty P D;Kapil Dev;Ram P N (Dep of Phys, H N B Garhwal Univ Campus, Badshahithaul, Tehri-Garhwal-249 199, Email: psemalty@sancharnet.in) : Lattice specific heat and local density of states of Ni-based dilute alloys at low temperature. Pramana J Phys 2006, 66(6), 1077-92.

A detailed theoretical study of the low-temperature lattice specific heat of Ni-based dilute alloys has been carried out. Lattice Green's function method has been used to calculate the local density of states of substitutional impurities and lattice specific heat in different alloys. The resonance condition has been investigated for possible occurrence of resonance modes. Except in NiCr and NiMn, low-frequency resonance modes have been obtained in all the alloys. However, no localized mode was obtained. The impurity-induced increase in lattice specific heat is explained on the basis of the obtained resonance modes. The calculation shows an excellent agreement with the measured lattice specific heat in these alloys.

23 illus, 1 table, 24 ref

006166   Schadmand S (NO, Institut fur Kernphysik Forschungszentrum Julich, 52425 Julich, Germany, Email: s.schadmand@fz-juelich.de) : Two-pion production in photon-induced reactions. Pramana J Phys 2006, 66(5), 877-84.

Differences in the photoproduction of mesons on the free proton and on nuclei are expected to reveal changes in the properties of hadrons. Inclusive studies of nuclear photoabsorption have provided evidence of medium modifications. However, the results have not been explained in a model independent way. A deeper understanding of the situation is anticipated from a detailed experimental study of meson photoproduction from nuclei in exclusive reactions. In the energy regime above the Δ(1232) resonance, the dominant double pion production channels are of particular interest. Double pion photoproduction from nuclei is also used to investigate the in-medium modification of meson-meson interactions.

5 illus, 5 tables, 1 ref

006165   Saravanan R (Dep of Phys, The Madura Coll, Madurai-625 011, Email: saragow@dataone.in) : Application of maximum entropy method for the study of electron density distribution in SrS, BaS and PuS using Powder X-ray data. Pramana J Phys 2006, 66(6), 1057-65.

A study of the electronic structure of the three sulphides, SrS. BaS and PuS has been carried out in this work, using the powder X-ray intensity data from JCPDS powder diffraction data base. The statistical approach, MEM (maximum entropy method) is used for the analysis of the data for the electron density distribution in these materials and an attempt has been made to understand the bonding between the metal atom and the sulphur atom. The mid-bond electron density is found to be maximum for PuS among these three sulphides, being 0.584 e/Angstum³ at 2.397 Angstrum. SrS is found to have the lowest electron density at the mid-bond (0.003 e/Angstrum³) at 2.118 Angstrum from the origin leaving it more ionic than the other two sulphides studied in this work. The two-dimensional electron density maps on (100) and (110) planes and the one-dimensional profiles along the bonding direction [111] are used for these analyses. The overall and individual Debye-Waller factors of atoms in these systems have also been studied and analyzed. The refinements of the observed X-ray data were carried out using standard softwares and also a routine written by the author.

3 illus, 4 tables, 9 ref

006164   Salamov D I;Babacan T;Kucukbursa A;Unlu S; Maras I (Dep of Phys, Anadolu Univ, Eskisehir, Turkey, Email: atalay@dumlupinar.edu.tr) : The isospin admixture of the ground state and the properties of the isobar analog resonances in medium and heavy mass nucleis. Pramana J Phys 2006, 66(6), 1105-10.

Within the framework of quasiparticle random phase approximation (QRPA), Pyatov-Salamov method [23] for the self-consistent determination of the isovector effective interaction strength parameter, restoring a broken isotopic symmetry for the nuclear part of the Hamiltonian, is used. The isospin admixtures in the ground state of the parent nucleus, and the isospin structure of the isobar analog resonance (IAR) state were investigated with the inclusion of the pairing correlations between nucleons for the medium and heavy mass regions: 80 <60> A <60> 90, 102 <60> A <60> 124, and 204 <60> A <60> 214. It was determined that the influence of the pairing interaction between nucleons on the isospin admixtures in the ground state and the isospin structure of the IAR state is more pronounced for the light isotopes (N ≈ Z) of the investigated nuclei.

3 illus, 1 table, 26 ref

006163   Sahu P K;Otuka N;Isse M;Nara Y;Ohnishi A (NO, Inst of Phys, Sachivalaya Marg, Bhubaneswar-751 005, Email: pradip@iopb.res.in) : Re-hardening of hadron transverse mass spectra in relativistic heavy-ion collisions. Pramana J Phys 2006, 66(5), 809-16.

Analyzes the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of Spectra can be interpreted as a good signature of the quark-gluon plasma information.

3 illus, 1 table, 30 ref

006162   Roy B J;Jha V;Chatterjee A;Machner H (Div Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: bjroy@apsara.barc.ernet.in) : Isospin symmetry violation, meson production and η-nucleus interaction studies. Pramana J Phys 2006, 66(5), 893-901.

Studies isospin symmetry violation in nuclear reactions by measuring simultaneously the cross-section of the following two reactions p + d → ³H π⁺ and p + d → ³He π⁰. The experiment was perfomed at the cooler synchrotron accelerator COSY, Julich at several beam energies close to the corresponding η production threshold. We also have ongoing programmes on η-nucleus final-state interaction studies via p+⁶Li → ⁷Be +η reactions, high resolution search for dibaryonic resonances and lambda-proton final state interaction studies. The experimental details and results obtained so far are presented here.

10 illus, 11 ref

006161   Roy A (Dep of Phys, Indian Inst of Technol Bombay, Mumbai-400 076, Email: ankhi@phy.iitb.ac.in) : Investigations of η → π<. Pramana J Phys 2006, 66(5), 921-30.

Reports the efforts carried out to measure the branching ratio of η → π⁰γγ. The experiment was done using the tagged photon facility at ELSA, Bonn. A nearly full 4π set-up comprising of the Crystal Barrel and TAPS detector system was used. The procedure followed to extract the branching ratio of this rare decay mode of eta. The simulations necessary to establish this procedure are presented first followed by data analysis.

11 illus, 4 ref

006160   Ritman J (NO, Institut fur Kernphysik Forschungszentrum Julich, 52425 Julich, Germany, Email: j.ritman@fz-juelich.de) : QCD physics at hadron storage rings: from COSY to FAIR. Pramana J Phys 2006, 66(5), 857-66.

As a result of the rapid rise of the coupling constant α_s at low momentum transfers, perturbation theory is not an appropriate method to describe the strong interaction. In this kinematic regime other methods such as lattice QCD or effective field theories are more appropriate to investigate the appearance of a still unsettled phenomena: confinement and chiral symmetry breaking. Furthermore, the confinement of quarks and gluons to hadrons allows crucial tests of fundamental symmetries that are inherent to the QCD Lagrangian but are broken in hadronic systems. Thus, high precision measurements of the production and decay of specific hadronic states provides decisive benchmarks to investigate the properties of QCD in this regime. A new series of experiments are being prepared using nearly full acceptance detectors for neutral and charged particles around internal targets in high intensity, phase-space-cooled hadronic beams. Later this year, it is planned to transfer the WASA detector from the CELSIUS to the COSY ring in order to measure the production and various decay channels of the η and η' mesons, thereby investigating the violation of P, C, T, and combinations thereof, as well as isospin violation. The experimental and theoretical techniques employed here will provide an important basis to extend these investigations to the static and dynamical properties of hadrons with charm quark content with the high energy storage ring for antiprotons at the new GSI/FAIR facility. Additional related perspectives will be opened at the new facility ranging from the properties of hadrons in dense nuclear matter to measurements of the nucleon's transverse spin distribution in the valence quark region using polarized antiprotons.

6 ref

006159   Rai A K;Inodkumar P C (Dep of Phys, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: raiajayk@rediffmail.com) : Properties of B_c meson. Pramana J Phys 2006, 66(5), 953-8.

The mass spectrum of cb meson is investigated with an effective quark-antiquark potential of the form α_c/r + Ar^v with v varying from 0.5 to 2.0. The S and P-wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime of B_c meson are computed. The properties calculated here are found to be in good agreement with other theoretical and experimental values at potential index, v = 1.

3 tables, 15 ref

006158   Prince P R;Renuka G (Sch of Technol and Appl Sci, Mahatama Gandhi Univ Regional Cent, Pathanamthitta-689 645, Email: drprprince@yahoo.com) : MT index during substorms. Ultra Scient phys Sci 2006, 18(1), 53-8.

Magnetotail (MT) index is computed for a single magnetospheric substorm and its relationship with the instantaneous magnetospheric configuration is analysed. A strong association between the index and the magnetic field inclination was established during the growth phase of the substorm. MT did not reflect the field orientations at disturbed times of substorm expansion and recovery phases.

4 illus, 11 ref

006157   Pant L M (Div Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: Impant@barc.ernet.in) : Tagged photon facility at centre for advanced technology, Indore: possible scenarios. Pramana J Phys 2006, 66(5), 903-14.

Photoproduction of ω in nuclear medium with the ELSA facility at Bonn is discussed in the context of medium modification of hadronic properties. Utilization of Indus-2 at CAT, Indore for producing tagged bremsstrahlung photons and laser backscat-tered photons has been explored with a comparison between the two techniques for producing tagged high energy photons for the first time in the country with emphasis on the ADSS programme to have a precise information of (γ, η) reactions.

10 illus, 2 tables, 5 ref

006156   Mohapatra A K;Unnikrishnan C S (Fundamental Interactions Lab (Gravitation Group), Tata Inst of Fundamental Res Homi Bhabha Rd, Mumbai-400 005, Email: ashok@.tifr.res.in) : High sensitivity probe absorption technique for time-of-flight measurement on cold atoms. Pramana J Phys 2006, 66(6), 1027-35.

Reports on a phase-sensitive probe absorption technique with high sensitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms. Demonstrates the high sensitivity and figure of merit of the simple method by measuring the time-of-flight of atoms moving upwards from a magneto-optical trap released in the gravitational field.

4 illus, 16 ref

006155   Metag V (NO, II. Physikalisches Institut Univ of Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany, Email: Volker.Metag@exp2.physik.uni-giessen.de) : In-medium properties of hadrons-Recent experimental results and perspectives. Pramana J Phys 2006, 66(5), 833-56.

Recent experimental results on the modification of hadron properties in a nuclear medium are discussed. Experiments using hadron, heavy-ion and photon beams are described. Particular emphasis is given to the photonuclear production of light vector mesons and scalar mesons off nuclei. Recent results on the search for meson-nucleus bound states are presented. Perspectives for extending these studies to the charm sector are outlined.

25 illus, 175 ref

006154   Mehta N (Dep of Phys, Pranveer Singh Inst of Technol, Kanpur, Email: neeraj_mehta28@yahoo.com) : Applications of chalcogenide glasses in electronics and optoelectronics. J scient ind Res 2006, 65(10), 777-86.

Following the development of the glassy chalcogenide field, new optoelectronic materials based on these materials have been discovered. Several non-oxide glasses have been prepared and investigated in the last several decades, thus widening the groups of chalcogen materials used in various optical electronic and optoelectronic glasses. Development of chalcogenide glasses, their physical properties and applications in electronics and optoelectronics. The glassy, amorphous and disordered chalcogenide materials, important for optoelectronic applications, are discussed. The main electronic and optoelectronic phenomena, specific to these materials are described, and the applications based on these phenomena are evidenced.

8 illus, 1 tables, 66 ref

006153   Machner H (Institut fur Kernphysik Forschungszentrum Julich, , 52425 Julich, Germany, Email: h.machner@fz-juelich.de) : Recent physics at COSY. Pramana J Phys 2006, 66(5), 867-76.

The COSY accelerator in Julich is presented together with its internal and external detectors. The physics program performed recently is discussed with emphasis on strangeness physics and precision experiments.

8 illus, 45 ref

006152   Kulhar V S (Dep of Phys, Univ of Raj, Jaipur-302 004, Email: Kulhar-vs@uniraj.ernet.in) : Excited states of muonium in atomic hydrogen. Pramana J Phys 2006, 66(6), 1017-25.

Muonium formation in excited states in muon-hydrogen charge-exchange collision is investigated using a method developed in a previous paper. Differential cross-section results are found to resemble positronium formation cross-section results of positron-hydrogen charge-exchange problem. Forward differential and integrated cross-sections are computed for muon energy of 2 keV and higher. Total muonium formation cross-sections are computed using Jackson and Schiff scaling rules. Muonium formation cross-section results obtained from proton-hydrogen charge-exchange cross-section results, using velocity scaling are compared with the results of the present calculation.

4 illus, 4 tables, 15 ref

006151   Jha V;Roy B J;Chatterjee A;Machner H (Div of Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: vjha099@yahoo.com) : Study of η-nucleus interaction through the formation of η-nucleus bound state. Pramana J Phys 2006, 66(5), 943-6.

The question of possible existence of η-mesic nuclei is quite intriguing. Answer to this question will deeply enrich our understanding of η-nucleus interaction which is not so well-understood. Reviews the experimental efforts for the search of η-mesic nuclei and describe the physics motivation behind it. Presents the description of an experiment for the search of η nucleus bound state using the GeV proton beam, currently being performed at COSY.

1 illus, 1 table, 9 ref

006150   Jain A K (Div of Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: arunjain@magnum.barc.ernet.in) : Search for non-strange dibaryons. Pramana J Phys 2006, 66(5), 937-42.

Inspite of tremendous interest there has been sporadic searches for dibaryon resonances in the past few decades. The main hurdle one faces in this search is their identification, their signature and practically no guide to their location. With the identification of the pentaquark-θ⁺ resonance one is encouraged to look for the discovery of strange dibaryons also. However where and how to look for non-strange dibaryons is not clear. The transition from a bipolar to a unipolar non-strange dibaryon may possibly be seen in the (p, 2p) reactions on heavy nuclei. The change of the finite size of the p-p interaction vertex can be identified as a sudden change in the extracted DWIA spectroscopic factor. The DWIA anomalies are to be searched for in the existing (p, 2p) reaction data for the identification of non-strange dibaryons.

2 illus, 12 ref

006149   Hamed A M (Dep of Phys Fac of Sci, Ain Shams Univ Cairo, Egypt, Email: amhamed73@hotmail.com) : Computation of the lateral and axial point spread functions in confocal imaging systems using binary amplitude mask. Pramana J Phys 2006, 66(6), 1037-48.

A novel aperture based on Tolardo concept composed of a central clear disc surrounded by a series of black and white (B/W) concentric annuli of equal transmittance is presented. Different apodized apertures of different number of B/W annuli are suggested in order to improve further the three-dimensional resolving power of confocal imaging systems. Both the axial and lateral point spread functions (PSF) and the corresponding irradiances are computed in both cases of conventional and confocal scanning microscopes for the above-mentioned amplitude filters. These results of axial and lateral irradiances are graphically represented by constructing a computer program using MATLAB. The obtained results are compared with that obtained in case of circular, annular, and Martinez-Corral apodized aperture.

11 illus, 27 ref

006148   Guo Z Z;Wu X W;Wang C A (Phys Dep, Inner Mongolia Norm Univ, Huhhot 010022, Email: zzguo@imnu.edu.cn) : Damage spreading on the 3-12 lattice with competing Glauber and Kawasaki dynamics. Pramana J Phys 2006, 66(6), 1067-75.

The damage spreading of the Ising model on the 3-12 lattice with competing Glauber and Kawasaki dynamics is studied. The difference between the two kinds of nearest-neighboring spin interactions (interaction between two 12-gons, or interaction between a 12-gon and a triangle) are considered in the Hamiltonian. It is shown that the ratio of the interaction strength F between the two kinds of interactions plays an important role in determining the ciritical temperature T_d of phase transition from forzen to chaotic. Two methods are used to introduce the bond dilution on the Ising model on the 3-12 lattice: regular and random. The maximum of the average damage spreading (D)_max can approach values lower than 0.5 in both cases and the reason can be attributed to the `survivors' among the spins. We have also, for the first time, presented the phase diagram of the mixed G-K dynamics in the 3-12 lattice which shows what happens when going from pure Glauber to pure Kawasaki.

7 illus, 18 ref

006147   Gill T S;Harvinder Kaur;Saini N S (Dep of Phys, Guru Nanak Dev Univ, Amritsar-143 005, Email: nspst99@yahoo.com) : Ion-acoustic solitons in multispecies spatially inhomogeneous plasmas. Pramana J Phys 2006, 66(6), 1049-56.

Ion-acoustic solitons are investigated in the spatially inhomogeneous plasma having electrons-positrons and ions. The soliton characteristics are described by Korteweg-de Vries equation which has an additional term. The density and temperature of different species play an important role for the amplitude and width of the solitons. Numerical calculations show only the possibility of compressive solitons. Further, analytical results predict that the peak amplitude of soliton decreases with the decrease of density gradient. Soliton characteristics like peak amplitude and width are substantially different from those based on KdV theory for homogeneous plasmas.

45 ref

006146   Dasgupta S;Kushwaha T;Goswami D (Dep of Chem, Indian Inst of Technol, Kanpur-208 016, Email: dgoswami@iitk.ac.in) : Dependence of adiabatic population transfer on pulse profile. Pramana J Phys 2006, 66(6), 999-1015.

Control of population transfer by rapid adiabatic passage has been an established technique wherein the exact amplitude profile of the shaped pulse is considered to be insignificant. Studies the effect of ultrafast shaped pulses for two-level systems, by density-matrix approach. However finds that adiabaticity depends simultaneously on pulse profile as well as the frequency modulation under non-resonant conditions.

12 illus, 15 ref

006145   Das S (Div of Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: swapand@apsara.barc.ernet.in) : (γ,π<. Pramana J Phys 2006, 66(5), 947-52.

π⁰γ invariant mass distribution spectrum has been calculated for the (γ,π⁰γ) reaction on ¹²C nucleus at 2.5 GeV beam energy. These π⁰ and 7 are assumed to originate due to the decay of vector mesons produced in the photonuclear reaction. The nuclear medium effect on vector mesons and the effect of π⁰ rescattering on the π⁰γ invariant mass spectrum have been investigated.

5 illus, 8 ref

006144   Chatterjee A;Roy B J;Jha V;Shukla P;Machner H (Div of Nuclear Phys, Bhabha Atom Res Cent, Mumbai-400 085, Email: drambar@gmail.com) : Enstar detector for η-mesic studies. Pramana J Phys 2006, 66(5), 885-92.

Initiates a search for a new type of nuclear matter, the η-mesic nucleus, using beams from the multi-GeV hadron facility, COSY at Juelich, Germany. A large acceptance scintillator detector, ENSTAR has been designed and built at BARC, Mumbai and fully assembled and tested at COSY. A test run for calibration and evaluation has been completed. Presents the design and technical details of the ENSTAR detector and how it will be used to detect protons and pions (the decay products of η-mesic bound state). The detector is made of plastic scintillators arranged in three concentric cylindrical layers. The readout of the detectors is by means of optical fibres. The layers are used to generate ΔE - E spectra for particle identification and total energy information of stopped particles. The granularity of the detector allows for position (θ and φ) determination making the event reconstruction kinematically complete.

4 illus, 4 tables, 9 ref

006143   Chakraborty S;Chanda P K (Cent Drugs Lab, , 3 Kyd Street, Kolkata-700 016, Email: susa_chak@yahoo.com) : On a revisit to the painleve test for integrability and exact solutions for Yang's self-dual equations for SU (@) gauge fields. Pramana J Phys 2006, 66(6), 971-83.

Painleve test for integrability for the Yang's self-dual equations for SU(2) gauge fields has been revisited. Jimbo et al analysed the complex form of the equations with a rather restricted form of singularity manifold. They did not discuss exact solutions in that context. The analysis has been done starting from the real form of the same equations and keeping the singularity manifold completely general in nature. It has been found that the equations, in real form, pass the Painleve test for integrability. The truncation procedure of the same analysis leads to non-trivial exact solutions obtained previously and auto-Backlund transformation between two pairs of those solutions.

21 ref

006142   Chakraborty S;Chanda P K (Cent Drugs Lab, , 3 Kyd Street, Kolkata-700 016, Email: susa_chak@yahoo.com) : Painleve test for integrability and exact solutions for the field equations for Charap's chiral invariant model of the pion dynamics. Pramana J Phys 2006, 66(6), 961-9.

It has been shown that the field equations for Charap's chiral invariant model of the pion dynamics pass the Painleve test for complete integrability in the sense of Weiss et al. The truncation procedure of the same analysis leads to auto-Backlund transformation between two pairs of solutions. With the help of this transformation non-trivial exact solutions have been rediscovered.

19 ref

006141   Bedir M;Bakkaloglu O F;Karahan I H;Oztas M (Dep of Engng Phys, Univ of Gaziantep, 27310-Gaziantep, Turkey, Email: bedir@gantep.edu.tr) : A study on electrodeposited Ni_xFe_1-x alloy films. Pramana J Phys 2006, 66(6), 1093-1104.

Ni_xFe_1-x (0.22 ≤ x ≤ 0.62) alloy films were grown by electrodeposition technique. A shift in diffraction peaks of NiFe and Ni₃Fe was detected with increasing Ni content. The highest positive magnetoresistance ratio was detected as 5% in Ni_0.5Fe_0.49. Positive and negative anisotropic magnetoresistance were observed in longitudinal and transverse geometries respectively. The highest anisotropic magnetoresistance ratio of 9.8% was also detected in Ni_0.51Fe_0.49. The angular variation of magnetoresistance was studied. Magnetisation loop curves show that NiFe alloy films have a linear decreasing anisotropy constant with increasing Ni deposit content and show a decreasing behavior of coercivity which indicates soft magnetic property with increasing Ni deposit content.

9 illus, 25 ref

006140   Bandyopadhyay D (NO, Saha Inst of Nuclear Phys, 1/AF Bidhan Nagar, Kolkata-700 064, Email: deba@theory.saha.ernet.in ) : Hadrons in compact stars. Pramana J Phys 2006, 66(5), 817-25.

Discussed β-equilibrated and charge neutral matter involving hyperons and K condensates within relativistic models. It is observed that populations of baryons are strongly affected by the presence of antikaon condensates. Also, the equation of state including K condensates becomes softer resulting in a smaller maximum mass neutron star.

2 illus, 11 ref

006139   Awasthi O N;Pundhir V K (Dep of Phys, Regional Inst of Educ Natn Coun of Educ Res & Training, Shyamla Hills, Bhopal-462 013, India) : Electron-electron interactions and the electrical resistivity of copper at low temperatures. Ultra Scient phys Sci 2006, 18(1), 43-6.

The low temperature electrical resistivity in copper has been re-examined keeping in view the recent technological developments. Studies the electrical resistivity of copper at very low temperatures-below 2K. The low-temperature electrical resistivity of copper has been analyzed by different authors in terms of electron-phonon and electron-electron interaction processes. It is observed that theoretical resistivity of copper at low temperatures contains a T² term. Evaluates the T² term in terms of electron-electron interaction processes. The contribution of this T² term due to the electron-electron umklapp scattering processes in the electrical resistivity of copper at low temperatures has been evaluated using a simplified spherical Fermi surface model with isotropic transition probability. The values of the electrical resistivity so obtained compare fairly well with the experimental results.

1 illus, 1 table, 13 ref

006138   Anand R K (Dep of Phys, Univ of Allahabad, Allahabad-211 003) : Motion of strong converging shock waves in uniform medium. Ultra Scient phys Sci 2006, 18(1), 105-7.

Chester - Chisnell - Whitham method has been used to investigate the motion of strong converging shoek waves in an ideal gas. The analytical expressions for flow variables immediately behind the shock has been obtained. It is found that the plane shock wave moves with a constant shock strength.

^ssc 7 ref

006137   Alfaz Uddin M;Haque A K F;Mahbub M S;Karim K R;Basak A K (Dep of Phys, Univ of Rajshahi, Rajshahi, Bangladesh, Email: mauddin@ru.ac.bd) : Electron impact single ionization of mono-and di-positive ions. Pramana J Phys 2006, 66(6), 1119-24.

The electron impact ionization cross-sections of mono- and di-positive ionic targets are calculated using a second version of the modified binary-encounter-dipole (MBED) model. The present version differs from the previous one in the scale factor of the Burgess denominator and is applicable to targets with charges q = 1 and 2. The MBED in the present form is found to work well for 11 ionic targets ranging from Be⁺ to K⁺ and complements its previous version valid for targets with q <62> 2.

3 illus, 26 ref

006136   Abbas A (Inst of Phys, , Sachivalaya Marg, Bhubaneswar-751 005, Email: afsar@iopb.res.in) : A new 'hidden colours hypothesis' in hadron physics. Pramana J Phys 2006, 66(5), 827-32.

A new 'hidden colour hypothesis' within the framework of QCD, as an extension of and in keeping with the spirit of the 'colour singlet hypothesis' is hereby proposed. As such it should play a role in a consistent description of exotic hadrons, such as diquonia, pentaquarks, dibaryons etc. How these exotic hadrons are affected by this new hypothesis is discussed here. This new hypothesis suggests that the experimentalists may not be looking for single exotics but for composites of two or more of the same.

1 table, 8 ref

005136   Selvanayagam S;Velmurugan D;Yamane T (Dep of Crystallography and Biophys, Univ of Madras Guindy Campus, Chennai-600 025, Email: d_velu@yahoo.com) : Iterative ACORN as a high throughput tool in structural genomics. Indian J Biochem Biophys 2006, 43(4), 211-6.

High throughput macromolecular structure determination is very essential in structural genomics as the available number of sequence information far exceeds the number of available 3D structures. ACORN, a freely available resource in the CCP4 suite of programs is a comprehensive and efficient program for phasing in the determination of protein structures, when atomic resolution data are available. ACORN with the automatic model-building program ARP/wARP and refinement program REFMAC is a suitable combination for the high throughput structural genomics. ACORN can also be run with secondary structural elements like helices and sheets as inputs with high resolution data. In situations, where ACORN phasing is not sufficient for building the protein model, the fragments (incomplete model/dummy atoms) can again be used as a starting input. Iterative ACORN is proved to work efficiently in the subsequent model building stages in congerin (PDB-ID: 1is3) and catalase (PDB-ID: 1gwe) for which models are available.

3 illus, 2 tables, 15 ref

005135   Naveen Kumar;Singh P;Satish Kumar (Div of Surgery, Indian Vet Res Inst, Izatnagar (U.P.)-243 122, Email: naveen@ivri.up.nic.in) : Physical, X-ray diffraction and scanning electron microscopic studies of uroliths. Indian J Biochem Biophys 2006, 43(4), 226-32.

Identification of chemical constituents of calculus is important in the diagnosis and management of urolithiasis. The compositional variability of uroliths has different etiologies and requires various modes of treatment and prophylaxis. Reports the chemical compositional analyses of calculi recovered from buck and bullock by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) techniques and ultra-structure examination by scanning electron microscopy (SEM), XRD and EDX investigations conclusively established the chemical compositions of urinary calculi under investigation. The calculus from buck (sample I) had calcium oxalate monohydrate, a dominant salt phase and magnesium compound in significant amount. The calculus from bullock (sample II) had magnesium ammonium phosphate phase, with significant amount of calcium in apatite form and K⁺ ions. SEM study at higher magnification (X1000) showed bipyramidal crystals in external zones of urolith (sample I). The struvite apatite calculus showed that basic unit of structure was lamination and the laminitis appeared to be made up of fine granules and high porosity. The bio-mineralization process of calculus formation was also studied, with a view to take preventive and therapeutic measures for amelioration of urinary stone diseases in animals and humans.

4 illus, 3 tables, 39 ref

005134   Dwivedi B N (Appl Phys, Inst of Technol Banaras Hindu Univ, Varanasi-221 005, Email: bholadwivedi@yahoo.com) : The source region of the solar wind. Curr Sci 2006, 90(4), 482-4.

4 illus, 7 ref

004109   Ubale A U;Dhokne R J;Chikhlikar P S;Sangawar V S;Kulkarni D K (Dep of Phys, Govt. Vidarbha Inst of Sci and Humanities, Amravati-444 604, Email: ashokuu@yahoo.com) : Characterization of nanocrystalline cadmium telluride thin films grown by successive ionic layer adsorption and reaction (SILAR) method. Bull Mater Sci 2006, 29(2), 165-8.

Structural, electrical and optical characteristics of CdTe thin films prepared by a chemical deposition method, successive ionic layer adsorption and reaction (SILAR), has been described. For deposition of CdTe thin films, cadmium acetate was used as cationic and sodium tellurite as anionic precursor in aqueous medium. In this process hydrazine hydrate is used as reducing agent and NH₄OH as the catalytic for the decomposition of hydrazine. By conducting several trials optimization of the adsorption, reaction and rinsing time duration for CdTe thin film deposition was done. The structural, optical and electrical properties of CdTe film are reported. The XRD pattern shows that films are nanocrystalline in nature. The resistivity is found to be of the order of 4.11 x 10³ <87>?-cm at 523 K temperature with an activation energy of <126> 0.2 eV. The optical absorption studies show that films have direct band gap (1.41 eV).

5 illus, 1 table, 11 ref

004108   Tiwari R K;Upadhyay M;Shukla S R;Pandey D N; Tripathi A (Dep of Phys & Electron, Dr. R.M.L. Avadh Univ, Faizabad-224 001, Email: mupadhyaya@rediffmail.com) : Electric and magnetic polarization for various tunneling model in presence of electric and magnetic field separately and their comparison. Bull pure appl Sci-Sect D 2006, 25(1), 21-4.

The knowledge of Polarization plays an important role in understanding the nature of molecular interactions in various types of solids, liquid and liquid mixtures. Many attempt have been made by various workers ( Bayelar 1972, Gomez et al 1967 . Quingley and Das 1973 . Rollefson 1972 . Pandey et al 1986). Polarization by applying Electric Field for various tunneling models and get sucess to explain various electrical and optical properties but less attempt has been made to study various properties with the applied magnetic field for above tunneling models. So an attempt has been made to find out expression for polarization by applying magnetic field in <100> direction for <100>, <110>, <100>+<111> and <110>+<111> tunneling models and expression lor magnetic polarization and magnetic susceptibility have been obtained and obtained results are compared with results of electric field giving good agreement.

12 ref

004107   Tanwar A;Gupta K K;Singh P J;Vijay Y K (Dep of Phys, M.S.J. Coll, Bharatpur-331 001, Email: tanwar17msj@yahoo.com) : Dielectric measurements on PWB materials at microwave frequencies. Bull Mater Sci 2006, 29(2), 181-5.

In quest of finding new substrate for printed wiring board (PWB) having low dielectric constant, have made PSF/PMMA blends and evaluated the dielectric parameters at 8.92 GHz frequency and at 35°C temperature. Incorporating PMMA in PSF matrix results in reduced dielectric constant than that of pure PSF. The dielectric parameters of pure PMMA and PSF films of different thicknesses have also been obtained at microwave frequencies. Dielectric data at microwave frequencies. Dielectric data at microwave frequencies has been used as a tool to evaluate optical constants, absorption index 'K' and refractive index 'n'. The blends of PSF/PMMA may be used as base materials for PWBs.

2 illus, 2 tables, 18 ref

004106   Syed Ali K S;Saravanan R;Israel S;Rajaram R K (Dep of Phys, Yadava Coll, Madurai-625 014, Email: saragow@dataone.in) : Electron density distribution and bonding in ZnSe and PbSe using maximum entropy method (MEM). Bull Mater Sci 2006, 29(2), 107-14.

Study of electronic structure of materials and bonding is an important part of material characterization. The maximum entropy method (MEM) is a powerful tool for deriving accurate electron density distribution in crystalline materials using experimental data. Attention is focused on producing electron density distribution of ZnSe and PbSe using JCPDS X-ray powder diffraction data. The covalent/ionic nature of the bonding and the interaction between the atoms are clearly revealed by the MEM maps. The mid bond electron densities between atoms in these systems are found to be 0-544 e/Angstrum³ and 0-261 e/Angstrum³, respectively for ZnSe and PbSe. The bonding in these two systems has been studied using two-dimensional MEM electron density maps on the (100) and (110) planes, and the one-dimensional electron density profiles along [100], [110] and [111] directions. The thermal parameters of the individual atoms have also been reported in this work. The algorithm of the MEM procedure has been presented.

8 illus, 3 tables, 21 ref

004105   Sinha N;Sinha T K (Dep of Phys, K.S.R. Coll, Sarairanjan, Samastipur-848 101) : Classification of parallel tensors and its application in general relativity. Bull pure appl Sci-Sect D 2006, 25(1), 25-9.

Solution of Einstein field equations in general relativity (Fischer et.al, 1972) represent a system in space- time which is valid lor both gravitational and electromagnetic waves. Main purpose is to discuss some characteristic properties of space-time with respect to parallel tensors in a n-dimensional space. The main thrust here on spherically symmetric structure of space-times (Ebin, 1970).

8 ref

004104   Sinha N;Sinha T K (Dep of Phys, K.S.R. Coll, Sarairanjan, Samastipur-848 101) : Tetrade fromalism in general theory of relativity. Bull pure appl Sci-Sect D 2006, 25(1), 9-13.

In general theory of Relativity, laws of nature remain invariant with respect to any space-time coordinates systems. Main aim here is to derive dyadic properties of curvature- Weyl tensor ( Neumann. et al 1963). Split the strangled components of curvature tensor and Weyl tensor in terms of orthonormal tetrad to derive a modified version of the classical solutions of Einstein field equations based on spinors.

6 ref

004103   Sajeev U S;Joseph Mathai C;Saravanan S; Ashokan R R;Venkatachalam S;Anantharaman M R (Dep of Phys, Cochin Univ of Sci and Technol, Cochin-682 022, Email: mraiyer@yahoo.com) : On the optical and electrical properties of rf and a.c. plasma polymerized aniline thin films. Bull Mater Sci 2006, 29(2), 159-63.

Polyaniline is a widely studied conducting polymer and is a useful material in its bulk and thin film form for many applications, because of its excellent optical and electrical properties. Pristine and iodine doped polyaniline thin films were prepared by a.c. and rf plasma polymerization techniques separately for the comparison of their optical and electrical properties. Doping of iodine was effected in situ. The structural properties of these films were evaluated by FTIR spectroscopy and the optical band gap was estimated from UV-vis-NIR measurements. Comparative studies on the structural, optical and electrical properties of a.c. and rf polymerization are presented. It has been found that the optical band gap of the polyaniline thin films prepared by rf and a.c. plasma polymerization techniques differ considerably and the band gap is further reduced by in situ doping of iodine. The electrical conductivity measurements on these films show a higher value of electrical conductivity in the case of rf plasma polymerized thin films when compared to the a.c. plasma polymerized films. Also, it is found that the iodine doping enhanced conductivity of the polymer thin films considerably. The results are compared and correlated and have been explained with respect to the different structures adopted under these two preparation techniques.

6 illus, 1 table, 13 ref