015117   Dipak Ghosh;Argha Deb;Rupa Das (Nuclear and Paticle Physics Research Centre, Phys Dep, Jadavpur Univ, Kolkata-700 032, Email: dipakghosh_in@yahoo.com) : Void analysis of target residues at SPS energy-evidence of correlation with fractal behaviour. Indian J Phys 2007, 81(12), 1303-14.

An analysis of the target residues in ³²S - AgBr and ¹⁶O - AgBr interactions at 200 AGeV and 60AGeV respectively in terms of fractal moment by Takagi method and void probability scaling. The study reveals a interesting feature of the production process. In ¹⁶O - AgBr interactions multifractal behaviour is present in both hemispheres and void probability does not show a scaling behaviour, but at high energy the situation changes. In ³²S - AgBr interactions for both hemisphere monofractal behaviour is indicated by that data and void probability also shows good scaling behaviour. This suggests that a possible correlation of void probability with fractal behaviour of target residues.

6 illus, 2 tables, 31 ref

015116   Dhara A K;Ghosh S K (Variable Energy Cyclotrom Centre, , Block-AF, Sector-1, Bidhannagar, Kolkata-700 064, Email: akd@veccal.ernet.in) : Operator equation of motion in phase space and path integral solution to time-dependent systems possessing invariants:application to time-dependent harmonic oscillator. Indian J Phys 2007, 81(9), 915-24.

The phase space distribution function provides a basis for discussing quantum phenomena within a classical-like framework. The equation of motion for the Wigner operator in phase space derived earlier and employe here to propose a new approach for obtaining a path integral solution to the phase space distribution function for time-dependent systems possessing invariants. For a time-dependent harmonic oscillator, the solution for the phase space distribution function is obtained by mapping the corresponding results for a free particle using suitable variable transformations. The viability of the phase space route and applicability of the proposed method to the investigation of general time-dependent properties of molecular systems is discussed.

17 ref

015115   Das S S;Mitra M;Panda J P;Satapathy P R (Phys Dep, KBDAV Coll, Nirakarpur, Khurda-752 019, Email: drssd2@yahoo.com ) : Unsteady free convective MHD flow and heat transfer of a second order fluid between two heated vertical plates through a porous medium. J Energy Heat Mass Transfer 2007, 29(2), 137-51.

The problem of unsteady free convective flow of an electrically conducting Rivlin-Ericksen second order fluid in presence of transverse magnetic field between two heated vertical parallel plates through a porous medium has been analyzed. The solutions for velocity and temperature of the flow field and also for heat flux and skin friction are obtained by applying perturbation technique. The effects of the flow parameters, such as magnetic parameter (M), porosity parameter (K_p), elastic parameter (R_c), Grashof number for heat transfer (O_r) and Prandtl number (P_r) on the velocity and temperature of the flow field have been discussed with the help of figures. This problem is significantly relevant to geophysical and cosmical studies.

4 illus, 12 ref

015114   Das C;Bhattacharyya K (Chem Dep, B C Coll, Asansol-713 304, Email: pchemkb@yahoo.com) : Force, quantum mechanics and approximate energy eigenstates. Indian J Phys 2007, 81(10), 1039-59.

The prevalent role of force in traditional quantum mechanics is outlined, with special reference to approximate calculations for stationary states. It will be explored how far this force concept can be made useful in the concerned area. The basic idea is to differentiate the Schrodinger stationary equation once. Thus, one can eliminate the unknown energy as well, and then examine how a force-based approach can be beneficial in providing quickly the nodal information and in assessing the quality of an approximate function. Further, it will be demonstrated how the minimization of a suitable quantity derived from force may constitute a variational principle for bound states. The strategy applies also to Siegert states where traditional energy extremization principle ceases to work. Additionally, the utility of the force concept in semiclassical mechanics will be investigated.

7 illus, 3 tables, 18 ref

015113   Chunduru V;Ethiraj R (Physics Dep, Univ College for Women, Osmania Univ, Hyderabad (A.P.), Email: ID_vardhani-c2001@yahoo.co.in) : Electronic polarizbilities of ions in lithium tantalate (LiTa03) optical wave guide from natural birefringence data. Bull pure appl Sci 2007, 26(2), 131-6.

The ever-increasing demand in the field of signal processing, computing, and communication has ushered in integrated devices in optical systems. Several materials have been used for fabricating optical wave-guides, components and devices adopting a variety of techniques. However, among the many device materials, lithium Tantalate remains one of the prime candidates owing to its excellent piezo electric. Electro-optical and wave guiding properties. The active and passive structures of dielectrics also include two-dimensional optical wave-guides. The field of integrated optics is primarily based on the fact that light can be guided and coupled in very thin films of transparent materials on suitable substrates. Optical wave-guides in Lithium tantalate crystal form the basis of many integrated optical devices In characterizing these devices the refractive index is an important parameter and understanding of this parameter from atomic point of view is very essential . since Rl is due to dipole moments of ions it can be expressed in terms of polarizabilities of the ions and electric field. The Electronic Polarizabilities of ions in Lithium Tamalate (LiTaO₃

2 tables, 6 ref

015112   Chattopadhyay S;Mahapatra U S;Chaudhuri R K (Chem Dep, Bengal Engng and Sci Univ, Shibpur, Howrah-711 103, Email: sudip_chattopadhyay@rediffmail.com) : Study of isolated 1:1 Al<. Indian J Phys 2007, 81(10), 1023-37.

Development and applications of many-body methods capable of reliable computation of potential energy curves (PEC) containing avoided curve-crossing zone remains a challenging area of activity in electronic structure theory till date. The PEC of the ground state and the corresponding lowest charge transfer state of an isolated 1 : 1 Al⁺³. He complex, calculated using the third order effective valence shell Hamiltonian, H^3rd_v, method (a variant of quasi-degenerate multi-reference perturbation theory) and then analyze the aspect of avoided curve-crossing between these two states of the complex. The published theoretical data of this complex is very limited and to our knowledge no experimental data has been reported yet for the ground and excited electronic states of this complex. Thus, a comprehensive theoretical investigation of such a complex would be very useful to identify its structural properties. In our numerical analysis, a comparison of our findings is made with the results generated via other many-body methods whenever available. The results obtained from our method appear quite promising, implying the efficacy of H^3rd_v method to compute the energy surfaces (with degeneracy/quasi-degeneracy of varying degrees) over a wide range of geometries including the avoided curve-crossing zone. We further report the ground state spectroscopic constants of this complex obtained from the improved virtual orbital-complete active space configuration interaction (IVO-CASCI) based numerical gradient method. The spectroscopic constants predicted by the IVO-CASCI are in agreement with those determined from the state-of-the-art coupled cluster method.

3 illus, 1 table, 27 ref

015111   Chattaraj P K;Giri S (Chem Dep, Indian Inst of Technol, Kharagpur-721 302, Email: pkc@chem.iitkgp.emet.in) : A minimum electrophilicity perspective of the HSAB principle. Indian J Phys 2007, 81(9), 871-9.

Some exchange reactions are studied, both at the gas and the solution phases, at the B3LYP/6-31+G(d) level of theory. The favourable direction of a reaction as dictated by the HSAB principle often produces the least electrophilic species. The average electrophilicity of the products is less than that of the reactants in most cases as would have been predicted by a minimum electrophilicity principle.

6 tables, 23 ref

015110   Chandrasekar M;Shanmugapriya M (Mathematics Dep, Coll of Engng, Anna University, Chennai-600 025, Email: mchandru@annauniv.edu) : Mathematical modeling of free convection flow and boundary layer control. J Energy Heat Mass Transfer 2007, 29(3), 209-25.

Gyarmati's variational principle developed on the thermodynamic theory of irreversible processes is formulated for the problem of heat transfer in free convection boundary layer flow with suction and injection over a non-isothermal flat plate. The velocity and temperature functions inside their respective boundary layer are approximated by simple polynomial functions and the variational principle is formulated The hydrodynamical and thermal boundary layer thicknesses are derived as the Euler-Lagrange equations of the variational principle. The skin friction and heat transfer values were computed for different values of suction and injection parameter, Prandtl number and wall temperature exponent. The obtained analytical solution for different values of Prandtl number, suction and injection parameter and wall temperature exponent is compared with the known solution and the comparison shows in good agreement.

8 illus, 1 table, 19 ref

015109   Boubaker K;Chaouachi A (Laboratoire de Photovoltalque and Materiaux, Semi-conducteurs-L.P.M.S.- Ecole Nationaled', Ingenieurs B.P. 37 Le Belvedere 1002 Tunis, Email: boubaker_karem@yahoo.com) : A continuous solution to heat equation using combined dirichlet-newman boundary conditions - case of spray pyrolysis technique deposited non-uniform layer. J Energy Heat Mass Transfer 2007, 29(1), 13-25.

Proposes a continuous solution to heat equation in a particular case of non-uniform layer deposited by modulated spray pyrolisis technique. Studied model takes into account simultaneously Dirichlet and Newman first-order conditions at system boundaries. An integral calculation method including Bessel and Whittaker-Watson modified Erf functions is performed. Comparison is made upon experimentally yielded temperature response.

4 illus, 1 table, 9 ref

015108   Biswas A K;Gautam M A;Kumar K S;Souvik Sarkar;Subir Kumar Sarkar (Electronics and Communication Engineering Dep, Dr. B.C. Roy Engng Coll, Durgapur-713 209) : Asic VLSI chiop using single electron transistors for traffic control system. Indian J Phys 2007, 81(12), 1257-66.

In integrated circuits devices with low power consumption, high operating speed and high integration density equipment(s) are financially indispensable in modern Electronics. Single Electron Device (SED) is one such device. SEDs are capable of controlling the transport of only an electron or a few electrons. A single electron is sufficient to store a bit of information in the SED. Power consumption in the single electron transistor is significantly low compared to BJT, transistor or CMOS transistor. Power consumption can be drastically reduced by reducing the nodes. The processing speed of SEDs will be nearly close to electronic speed. Noise during processing becomes extremely-low when the mode built with SEDs is in operation.

15 illus, 1 table, 43 ref

015107   Biplab Sarkar;Satrajit Adhikari (Chem Dep, Indian Inst of Technol, Guwahati, Guwalhati-781 039, Email: pcsa@mahendra.iacs.res.in) : Curl equations for an induced rener-teller type model. Indian J Phys 2007, 81(9), 927-45.

When a set of three states appears strongly coupled within the set but interacts very weekly with other states of the Hilbert space, these three states form a sub-Hilbert space and thereby, one can express the non-adiabatic coupling (NAC) elements in terms of adiabatic-diabatic transformation (ADT)/mixing angles obviously representing the same sub-space. It has been possible to demonstrate that those explicit forms of the NAC terms satisfy the Curl equations - the necessary conditions to ensure the adiabatic-diabatic transformation in order to remove the NAC terms (could be singular also at specific point(s) or along a seam in the configuration space) in the adiabatic representation of nuclear SE and to obtain the diabatic one with smooth functional form of coupling elements among the electronic states. While formulating the extended Born-Oppenheimer (EBO) equations for the ground adiabatic state, we demonstrate the necessity for the existence of zero Curls of the NAC terms and discuss briefly about their analytical validity at and around the conical intersection. Considering a three state diabatic Hamiltonian, namely, the so called induced Renner-Teller model, we calculate the NAC terms and their Curls analytically, and explore the nature of these quantities, when the three states are either degenerate at a point or approaching to form three states degeneracy at the same point.

4 illus, 26 ref

015106   Bhattacharjee J K;Mallik A K;Chakraborty Sagar (Theoretical Phys Dep, Indian Association for the Cultivation of Science, 2A & 2B Raja S C Mullick Road, Kolkata-700 032) : An introduction to nonlinear oscillators : a pedagogical review. Indian J Phys 2007, 81(11), 1115-75.

Oscillators are omnipresent; most of them are inherently non-linear. Though a non-linear equation mostly does not yield an exact analytical solution for itself, plethora of elementary yet practical techniques exist for extracting important information about the solution of equation. The purpose of this review is to Introduce the readers to such techniques which are carefully illustrated using mainly the examples of anharmonic oscillator, Van-der-Poi oscillator and Duffing's oscillator.

^ccr3 illus, 11 ref

015105   Bhardwaj S et al (Nanotechnology Research Center, Birla College, Kalyan-421 304) : Carbon nanomaterial from tea leaves as an anode in lithium secondary batteries. Asian J expl Sci 2008, 22(2), 89-93.

Carbon nanqmaterials have been synthesized by pyrolysis of plant based precursors (i.e. Tea leaves), without using any catalyst. These materials are characterized by SEM, Raman and XRD. Carbon nanomaterials are utilized as the anode in Li secondary batteries. The charging/discharging of the lithium batteries are studied. The carbon obtained shows the highest capacity of 63.31mAh/gm.

5 illus, 5 ref

015104   Bessaih R;Soudani A (Laboratoire d'Energetique Apppliquee et de Pollution, Departement de G, Universite Mentouri-Constantine, Route d'Ain El. Bey, Constantine 25000, Algeria) : Numerical simulation of turbulent natural convection air cooling of heated sources mounted on a vertical plate. J Energy Heat Mass Transfer 2007, 29(2), 95-117.

Summarizes computational results of natural convection air cooling of 10 cubic altumium heated sources (blocks), simulating electronics components, mounted on a vertical insulating plate. A three-dimensional, conjugate heat transfer model, and a high-Reynolds number (k-ε) turbulence model with appropriate boundary conditions, were used in this work. The governing equations were solved by a finite volume method throughout the entire physical domain (solid and fluid). Calculations were made for a wide range of independent parameters (Ra, kS/kair. and S/Ly). Consideration was given only to airflow. The results are compared with the experimental data obtained with similar parameters.

12 illus, 24 ref

015103   Belkacem A;Rebhi M;Toahami A;Zeghmati B (NO, Institut de Genie Mecanique, Centre Universitaire de Bechar, BP 417 Bechar 08000, Algerie, Email: zeghmati@univ-perp.fr) : Laminar natural convection in a vertical channel with a heated sinusoidal protuberance. J Energy Heat Mass Transfer 2007, 29(3), 175-90.

A numerical analysis is performed to study thermal laminar natural convection in a vertical channel with an extended surface located on one of the walls . The extended surface is a protuberance described by a sinusoidal profile and is subjected to a uniform heat flux. The wall here and there the protuberance and the wall facing it are supposed to be adiabatic. The governing elliptic equations are discretized using the finite-volume method with non-staggered variables arrangement. The linkage between the velocity and the pressure field is handled by the PISO algorithm. Simulations are carried out to analyze the effect of the amplitude of the sinusoidal profile, the heat flux density, the thermal conductivity of the material protuberance on the temperature field, the flow structure and the local and average Nusselt numbers.

10 illus, 2 tables, 21 ref

015102   Bansod V J;Jadhav R K (Mathematics Dep, Dr. B.A. Technol Univ, Lonere 402 103) : Series solution for heat and mass transfer from an horizontal hot surface in a non-darcy semi-infinite porous region. J Energy Heat Mass Transfer 2007, 29(4), 311-23.

An analysis is performed for non-Darcy free convection flow over an impermeable horizontal plate embedded in a fluid-saturated porous medium for the case of constant wall temperature and concentration. The governing problem is transformed into an infinite sets of non-linear differential equations in terms of non-Darcy parameters (perturbation junction). Three sets of coupled non-linear equations are solved using Shooting technique. Results are presented for local Nusselt number and local Sherwood number for the values of different controlling parameters.

6 illus, 18 ref

015101   Ayisha Begam A;Rugmini Radhakrishnan S (Faculty of Engnmg, Avinashilingam Univ for Women, Coimbatore-641 043) : Structure and optical characteristics of spin coated polyaniline-nanocomposite films. Res Highlight 2008, 18(2), 98-101.

5 illus, 5 ref

015100   Aradhana Kimothi;Tiwari V K;Saxena V K;Saini J S;Bhatnagar D (Microwave Laboratory, Phys Dep, Univ Rajasthan, Jaipur-302 004, Email: dbhatnagar_2000@rediffmail.com) : Theoretical analysis on the performance of a circular sector microstrip antenna under re-entry conditions. Indian J Phys 2007, 81(12), 1247-56.

Expressions of the field intensities for electromagnetic and electroacoustic modes for a circular sector microstrip patch antenna mounted on a re-entry vehicle are derived by applying linearized hydrodynamic theory coupled with vector function technique. The contribution of both electrons and ions is considered during the theoretical analysis of antenna is plasma medium. Radiation resistance, directivity, bandwidth, quality factor and radiation efficiency of antenna are obtained for different plasma parameter (ζ) values. A comparison between the radiation intensity of antenna under different plasma conditions (different ζ values) indicates that it decreases drastically on decreasing plasma parameter value. The overall performance of antenna is very poor when plasma parameter (ζ) approaches below 0.2 or in other words when plasma frequency is much higher than source frequency.

7 illus, 1 table, 11 ref

015099   Anurag Tewari A;Khanna K N (Phys Dep, VSSD Coll, Kanpur-208 026, Email: knkanna@rediffmail.com) : Shear viscosity of square-well fluid. Indian J Phys 2007, 81(12), 1295-1302.

A formula for the shear viscosity of the square well fluids is proposed through the modified pair correlation function in hard sphere system. The results are compared with the expressions of the viscosity and diffusion coefficients derived by Nigra and Evans for square-well fluid, the diffusion coefficient is changed into viscosity coefficient by employing Stokes- Einstein relation. The numerical results of the viscosity obtained by employing Stokes - Einstein relation. The numerical results of the viscosity obtained by employing Stokes -Einstein relation are found poor at low temperatures.

3 illus, 12 ref

015098   Alam M;Begum D;Yamamoto K (Mathematies Discipline, Khulna Univ, Khulna 9208, Bangladesh, Email: alam_mahmud2000@yahoo.com) : Flow through a rotating straight pipe with large aspect ratio. J Energy Heat Mass Transfer 2007, 29(2), 153-73.

A numerical study of the laminar flow of an incompressible viscous fluid in a rotating straight pipe is investigated to examine the combined effects of rotation (Coriolis force) and aspect ratio. The flow depends on the rotation parameter R = (2a² /v), the pressure driven parameter D_n = (Ga³/v² p), and aspect ratio γ = b/ a where a is the half width of the pipe cross-section, b the half of the pipe height, Ω the angular velocity, μ the viscosity, v the kinematics viscosity and G the constant pressure gradient along the pipe axis. The dimensionless non-linear equations of motion are solved by Spectral Method and using Chebyshev polynomial as a tool. The calculation are carried out for -140 ≤ R ≤ 140 and aspect ratio γ ≥ 1 at D_n ≥ 100. At weak moderate rotation rates. a double vortex secondary flow appears in the transverse plane of the pipe. The secondary flow starts as a double vortex configuration that is strongly compressed against the upper and lower walls of the pipe for strong rotation rate. The number of roll-cells that appeared would of course, depends on the aspect ratio of the pipe. The maximum number of roll-cells that appeared is ten.

18 illus, 14 ref

015097   Al-Hajri M;Witery A (Mechanical Power and Refrigeration Engng Technol, Coll of Technol Studies, The Public Authority for Applied Education an, P.O. Box 23167, Safat, 13092 Kuwait, Email: hajeri@paaet.edu) : Numerical investigations of heat transfer in channel plate heat exchangers. J Energy Heat Mass Transfer 2007, 29(4), 255-69.

Presents a computational study of fluid flow and heat transfer for a channel plate heat exchanger over medium ranges of Reynolds numbers on shell and tube sides. The thermal plates are manufactured using the Aluminum roll-bonding technique to produce economical heat exchanger plates. The tube side passage in these plates has five of doubly split 180° bends with an internal cross section of a benzene ring and the plates were spaced at 40 mm pitch. The CFD code employed is Fluent using the Re-Normaliazation Group (RNG) turbulence model and the two layer zonal model for near wall areas. Four models were considered in this paper, two for each side tube and shell: 2D full tube for one plate, 3D local tube representation and 3D shell side for outgoing and incoming flow. The study shows that pressure drop in the 1800 split bends is reduced compared with the bend without it.

17 illus, 1 table, 7 ref

015096   Akyuz T;Mukhamedshina N;Basaran S;Akyuz S; Mirsagatova A A;Bolcal C;Gulec A (Physics Dep, Science Faculty, Istanbul Univ, Vezneciler, 34134, Istanbul, Turkey, Email: sakyuz@istanbul.edu.tr) : Neutron activation analysis of the metals from ancient coins dating back to roman age. Asian J Chem 2007, 19(3), 1832-6.

Concentration levels of various elements have been estimated in ancient coins dating back to Roman age. which have been found in a sewage system of the ancient Ainos (Enez. Turkey). The coins are distributed into two groups on the basis of elemental composition: Pb and Cu based or Fe and Mn based coins indicating that two different ore deposits were used for issuing these coins. Other minor elements present in varying proportions are Ca, As and Sn. Besides to these major and minor elements, the coins were found to contain Na, K. Sc, Cr. Co, Ni, Zn. Br, Ag, Sb, Ba, Au as impurities.

3 illus, 2 tables, 7 ref

014066   Venkata Subba Reddy K;Sreedhara Reddy P;Klein A;Venkata Rao G;Uthanna S (Physics Dep, Sri Venkateswara University, Tirupati-517 502) : Growth and characterization of Cu₃N films deposited by dc magnetron sputtering. Indian J Phys 2007, 81(5-6), 547-54.

Copper nitride thin films were deposited on glass substrates by dc magnetron sputtering technique by sputtering of metallic copper target under different nitrogen partial pressures in the range 5x10^-4 - 5x10^-3 mbar and substrate bias voltages from 0 V to - 80 V. The films were characterized by studying the chemical binding configuration, crystallographic structure and electrical properties. The influence of nitrogen partial pressure and substrate bias voltage on the physical properties was systematically studied. Single phase polycrystalline films of Cu₃N were obtained at nitrogen partial pressure of 1x10^-3 mbar. The crystallographic structure and orientation of the crystallites were strongly influenced by the substrate bias voltage. The films formed at the nitrogen partial pressure of 1x10^-3 mbar and substrate bias voltage of - 45 V exhibited low electrical resistivity of 3.2x10² Ωcm, high Hall mobility of 15.8 cm²/V.sec and electron concentration of 1.1 x10¹⁹ cm^-3.

4 illus, 1 table, 23 ref

014065   Ubale A U;Mankar R B;Daryapurkar A S;Raut R R;Sangawar V S (Thin Film Physics Lab, Physics Dep, Government Vidarbha Institute of Science and Humanities, Amravati-444 604) : Structural and optical properties of nanostrucutred PbS thin film chemically deposited at room temperature. Indian J Phys 2007, 81(5-6), 555-65.

Nanostructured PbS thin films were deposited on to glass, by a chemical deposition method, Successive Ionic Layer Adsorption and Reaction (SILAR) at room temperature. For deposition of PbS thin films, lead acetate was used as cationic and thioacetamide as anionic precursor in aqueous medium. The structure and surface morphology of the films were characterized by X-ray diffraction and Scanning electron microscopy. The optical investigation showed that depending on thickness, films have direct allowed transitions in the range 1.86-2.36 eV. The decrease in dc dark resistivity with increase in grain size was also examined.

10 illus, 28 ref

014064   Sinha A K;Pathan B M;Vohat P (NO, Indian Institute of Geomagnetism, Navi Mumbai-410 218, Email: ashwini@iigs.iigm.res.in) : Low latitude Pc1 pulsation as observed from ground based search coil magnetometer. Bull Astr Soc India 2007, 35(4), 533-8.

Magnetic data from searchcoil magnetometer in the Indian sector have been analyzed to study geomagnetic pulsations in the near equator low latitude region (geomag. lat.<60> 20°). Apart from normal Pc4 pulsations (which is expected at such location), we observe the presence of Pel oscillations (frequency <126> 4 Hz) which are very unlikely at these latitudes. The interesting aspect of these observed pulsations is that they follow a broad-band spike during post-sunset and pre-dawn hours, whereas during day time the absence of broad band spike and simultaneous enhancement in the power of Schumann resonance was observed. Observations suggest that these two types of Pcl pulses are sustained by different energy sources.

3 illus, 1 table, 9 ref

014063   Sastri J H (NO, Indian Insitute of Astrophysics, Bangalore-560 034) : Physical processes underlying the geomagnetic effects of solar wind dynamic pressure (Pd) variations. Bull Astr Soc India 2007, 35(4), 549-60.

A concise review of recent studies of the ground-level geomagnetic storm sudden commencements (ssc's)/positive sudden impulses (si's) observed in the dip equatorial region and at low latitudes is presented highlighting the incremental additions to our empirical knowledge of the characteristics of ssc's/si's and understanding of the physical processes responsible for them.

4 illus, 40 ref

014062   Sarkar S K;Anil Kumar;Ahmed I;Gupta M M; Prasad M V S N;De A K;Das J (Radio and Atmospheric Sciences Div, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110 012, Email: aksarkar@mail.nplindia.ernet.in) : Rain attenuation at 13 GHz overthe line of sight path situated between Panihati and Barrackpore in eastern India. Indian J Phys 2007, 81(7), 647-53.

Results on attenuation measurements at 13 GHz under rainy conditions over another microwave link propagation path (Panihati-Barackpore) located over Kolkata have been presented. The link suffers large attenuation due to heavy rain. The communication link belongs to an operational agency. The microwave amplitude variation was monitored and rain rate measurements were made on twenty four-hour basis by a fast response rain gauge in the monsoon months during 2005. The observed microwave radio signal was characterized with a steady signal level <126> -42 to -43 dBm with fade depth -1 to 2 dB under non-precipitation condition. The results on attenuation have been studied in the light of simultaneous rain rate observations. The results on attenuation of radio wave under rainy condition are useful to design and installation of future communication links both for terrestrial and earth space paths in the regions in India where there is rain characteristics similar to Indian eastern coastal station. The probability distribution of attenuation and rain rates have been deduced from measured observations.

6 illus, 1 table, 10 ref

014061   Sahoo S;Maharana L;Behera B R (Physics Dep, National Institute of Technology, Durgapur-713 209, Email: sukadevsahoo@yahoo.com) : Effect of both Z and Z'-mediated flavor-changing neutral currents on B_s → μ<. Indian J Phys 2007, 81(5-6), 597-605.

Effect of both Z and Z'-mediated flavor-changing neutral currents (FCNCs) on the B_s → μ⁺ μ^- rare decay process has been studied. Mixing between ordinary and exotic left-handed quarks induces Z -mediated FCNC whereas mixing of right-handed ordinary and exotic quarks induces Z' -mediated FCNC. Finds the branching ratio is enhanced from its standard model (SM) value due to the effect of both Z and Z' -mediated FCNCs.

1 illus, 32 ref

014060   Rajendran S;Ravishanker Babu;Kanimozhi K (Physics Dep, Alagappa University, Karaikudi-630 003, Email: sraj54@yahoo.com) : Solid polymer electrolyte based on PEO/PCV blends. Indian J Phys 2007, 81(5-6), 539-45.

Novel polymer blend electrolyte was prepared using poly (ethylene oxide), poly(vinyl chloride) and lithium perchlorate (LICIO₄) as the complexing salt by employing solvent casting technique. The prepared films were subjected to XRD, FTIR, a.c impedance spectroscopy and thermogravimetry / differential thermal analysis (TG/DTA). Quantitative analysis of the FTIR spectra provides the specific interactions between the constituents. The thermal stability of the film is found using TG/DTA studies. The maximum conductivity value of PVC (25)-PEO(75)-LiCIO₄(8) film is found as 1.32 x 10^-5 Stcm at room temperature. As the PVC concentration increases in the electrolyte, the conductivity is found to decrease. The temperature dependent ionic conductivity is also carried out in the temperature range 303-333K and the results are discussed.

4 illus, 1 table, 21 ref

014059   Radhi R A;Hamoudi A K;Jassim K S (Physics Dep, College of Science, University of Baghdad, Baghdad, Iraq, Email: raadradhi@yahoo.com) : Calculations of longitudinal form factors of p-shell nuclei, using enlarged model space including core-polarization effects with realistic two-body effective interaction. Indian J Phys 2007, 81(7), 683-95.

Longitudinal form factors for electron scattering have been calculated for p-shell nuclei using enlarged model space includes all orbits in 1p and 2s-1 d shells. The two-body Cohen-Kurath interaction is used for the p-shell orbits while Preedam-Wildenthal for the sd-shell orbits. The two body Milliner-Kurath interactions are used for the psd orbits. The two-body Kuo-normalized G-matrix between the p-shell orbits and the sd-shell orbits are adopted. Core-polarization effects are taken into consideration through excitations of nucleons from the 15 core orbits and also from the valence 1p and 2s-1 d orbits into higher shells, with 6h ω excitations. The two-body Michigan three Yakawa (M3Y) interaction is used for the core-polarization matrix elements. Coreªpolarization effects improve the agreement with the experimental data remarkably well and play an essential role for electromagnetic transitions and electron scattering form factors.

9 illus, 32 ref

014058   Pandey V S;Dwivedi B N (Applied Physics Dep, Insitute of Technology, Banaras Hindu Univ, Varanasi-221 005, Email: pandey_vs@yahoo.com) : Dispersion relation for MHD waves in homogeneous plasma. Bull Astr Soc India 2007, 35(4), 465-71.

Authors consider viscosity and. thermal conductivity as dissipation mechanisms to derive a general dispersion relation for MHD waves propagating in a homogeneous plasma. Also show that the actual dispersion relation for MHD waves in a homogeneous medium must be six-order. The finding is in agreement (except some coefficients) with the results of Porter et al. (1994) but it is in disagreement with the previous results obtained by Kumar et al. (2006).

13 ref

014057   Panda S K;Rout G C (NO, K.D. Science College, Pochilima, Hinjilicut-761 101, Email: skp@iopb.res) : Interplay of charge density wave and spin density wave in cuprate systems. Indian J Phys 2007, 81(5-6), 619-26.

Microscopic model is proposed to study the co-existence of charge density wave (CDW) and spin density wave (SDW) effects in high- T_c super- conductors in normal state under underdoping condition before the onset of super-conductivity. The one particle electron Green's functions are calculated by Zubarev's technique. The CDW and SDW gap parameters are calculated from their correlation functions and solved selfª-consistently taking into account the position of the impurity levels and the hybridisation between .the impurity electron and the copper d-electrons.The temperature dependence of CDW and SDW gap parameters are studied for different model parameters of the system.

4 illus, 14 ref

014056   Ozdemir L;Karacoban B;Urer G (Physics Dep, Sakarya University, 54140, Sakarya, Turkey, Email: lozdemir@sakarya.edu.tr ) : Electric dipole transitions for some excited states in neutral silver. Indian J Phys 2007, 81(7), 705-15.

For some excited levels, transition energies, wavelengths, oscillator strengths and transition probabilities calculations in neutral silver (Ag I) have been calculated within the framework multiconfiguration Hartree-Fock approximation with relativistic corrections (Breit-Pauli Hamiltonian). The wavefunctions and some relativistic corrections have been obtained using MCHF + BP atomic package. Comparisons with other some calculations and experiments are presented.

1 table, 36 ref

014055   Nandan H (Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur-721 302, Email: hnandan@cts.iitkgp.ernet.in) : Dual gluon propagator and confinement potential in SU (2) QCD. Indian J Phys 2007, 81(5-6), 585-95.

In order to study the response of dual QCD vacuum in non-perturbative regime, the dual gluon propagator is evaluated by calculating a non-local quark current-current correlation relation in the dynamically broken phase of the magnetic symmetry. The linearly rising potential is then shown to be responsible for the absolute colour confinement in the low energy regime with.a constant restoring colour force between a quark-pair of a flux tube in SU(2) dual QeD vacuum.

2 illus, 32 ref

014054   Mandal B K;Bhattacharya N;Neogy C;Deb S K;Nag A (Physics Dep, University of Kalyani, Kalyani-741 235) : AC transport processes in RE (Y,Sm,Nd,Dy) BCO HTSC samples in the normal state. Indian J Phys 2007, 81(7), 655-64.

Using a contactless method, the ac response given by σ ₂(ω) / σ₁(ω), the ratio of the real (σ₁) and imaginary (σ₂) parts of conductivity, was measured over wide frequency (0.1 to 10 MHz) and temperature (80 to 300 K) ranges for HTSCs(RE)BCO (RE = Y, Sm, Nd, Dy). Analysis of ac response in the normal state clearly indicates that both tunnelling and hopping of carriers are responsible for ac transport and relaxation in these materials. A master curve is obtained for each material when <157> σ₂/ σ₁<157> is scaled against reduced frequency ω /T^α and the shape of the master curve is similar for all the materials.

6 illus, 1 table, 17 ref

014053   Mahapatra S (Physics Dep, St. Paul's Cathedral Mission College, 33/1 Raja Rammohan Roy Sarani, Kolkata-700 009, Email: s.mahapatra@rediffmail.com) : Low-lying stages of <. Indian J Phys 2007, 81(7), 697-703.

Calculation of low-lying resonance states of two halo nuclei ¹¹Be and ¹⁵C is performed in a two-body model (¹⁰Be+n and ¹⁴C+n respectively for the two nuclei ¹¹Be and ¹⁵C) using standard Woods-Saxon potential. This potential develops a well followed by a barrier which can temporarily trap the particle and give rise to resonance states. Obtains 5⁺/2 resonance for ¹¹Be at 1.281 MeV and 3⁺/2 resonance for ¹⁵C at 3.337 Mev, which are in agreement with the experimental results.

4 illus, 4 tables, 17 ref

014052   Liakath Ali Khan F;Sivagurunathan P;Shakil Muhammad G;Mehrotra S C (Physics Dep, Annamalai University, Annamalai Nagar-608 002) : Dielectric relaxation studies of higher order alcohol complexes with alkyl acrylates using time domain reflectometry. Indian J Phys 2007, 81(7), 665-72.

Using picosecond time domain reflectometry (TDR), dielectric relaxation studies have been carried out for alkyl acrylates (methyl acrylate, ethyl acrylate and butyl acrylate) with higher order alcohols (1-octanol. 1-nonanol and 1-dodecanol) mixtures over the frequency range 10 MHz to 20 GHz at 303 K. Static permittivity ε₀, dielectric constant ε_∞ at high frequency and relaxation time τ were found through dielectric measurements for different concentration of each system. The Kirkwood correlation factor and the excess inverse relaxation time were determined and discussed to yield information on the molecular interaction of the systems. Deviation from the linearity of various models suggest molecular association through hydrogen bonding between the -OH group of alcohols and C=O group of esters. The values of the static dielectric constant and the relaxation time increase with an increase in the percentage of alcohol in alkyl acrylate.

1 illus, 3 tables, 23 ref

014051   Liakath Ali Khan F;Sivagurunathan P;Raja Mohamed Kamil S (Physics Dep, Annamalai University, Annamalai Nagar-608 002) : Infrared studies on hydrogen bonding interaction between alkyl esters and p-cresol in carbon tetrachloride. Indian J Phys 2007, 81(7), 727-36.

Influence of the hydroxyl group in p-cresol on the carbonyl vibration of representative compounds belonging to methyl methacrylate, ethyl methacrylate and butyl methacrylate in carbon tetrachloride has been investigated by means of FTIR spectroscopy. The integrated intensities and change in dipole moments for O-H and C=O bonds were calculated. The formation constants of the 1 : 1 complexes have been calculated using Nash's method. The values of the formation constant and the Gibbs energy vary with ester chain length, which suggests that the strengths of the intermolecular O-H...O=C bonds are dependent on the alkyl group of the acrylic ester and the results show that the proton accepting ability of acrylic esters is in the order methyl methacrylate <60>ethyl methacrylate <60> butyl methacrylate.

5 illus, 2 tables, 27 ref

014050   Jiulin D (Physics Dep, School of Science, Tianjin Univ, Tianjin-300 072, Email: jiulindu@yaqhoo.com.cn) : Property of tsallis entropy and principal of entropy increase. Bull Astr Soc India 2007, 35(4), 691-6.

The property of Tsallis entropy is examined when considering two systems with different temperatures to be in contact with each other and to reach the thermal equilibrium. It is verified that the total Tsallis entropy of the two systems cannot decrease after the contact of the systems. Also derived an inequality for the change of Tsallis entropy in such an example, which leads to a generalization of the principle of entropy increase in the framework of nonextensive statistical mechanics.

11 ref

014049   Jain M (Physics Dep, Maharshi Dayanand University, Rohtak-124 001, Email: liggavansh@yahoo.com) : Superposition model analysis for the zero-field splitting of Mn<. Indian J Phys 2007, 81(5-6), 615-18.

The Newman superposition model has been applied to second-order zero-field splitting parameter b₂⁰ taken from the literature for Mn²⁺ in La₂Co₃(NO₃)₁₂.24H₂O. It is shown that calculated value of b₂⁰ is in agreement with the experimental value if local lattice relaxations are taken into account.

9 ref

014048   Gogoi P;Konwar K;Baishya B (Physics Dep, Dibrugarh University, Dibrugarh-786 004) : Effect of copper interlayer on thermally deposited polycrystalline Ge-thin film transistors fabricted on glass substrates. Indian J Phys 2007, 81(5-6), 567-72.

Reports the performance of Ge-thin film transistors (TFTs) with a copper interlayer in the channel region. All the TFTs are fabricated in staggered electrode structure on perfectly cleaned glass substrates using thermal evaporation process. Rare earth oxide Dy₂O₃ is used as gate insulator. The TFTs are annealed at 370°C at high vacuum. The TFT exhibits a better mobility of 0.646 cm²V^-1s^-1, than the TFT, fabricated without copper interlayer, mobility of which is found as 1.44 X 10^-3 cm²V^-1. The characteristics and some electrical parameters of the TFTs with copper interlayer are evaluated and compared with that of TFTs fabricated without copper interlayer.

5 illus, 1 table, 8 ref

014047   Eichhorn G;Accomazzi A;Grant C S;Kurtz M J; Thompson D M;Murray S S (NO, , Harvard-Smithsonia Center for Astrophysics, Cambridge, MA 02138, USA, Email: guentherieichhorn@springer.com) : Access to the literature and connection to on-line data. Bull Astr Soc India 2007, 35(4), 717-25.

The Astrophysics Data System (ADS) provides access to the astronomical literature through the World Wide Web. It is a NASA funded project and access to all the ADS services is free to everybody world-wide. It can be accessed without login through any web browser. The ADS Abstract Service allows the searching of three databases with abstracts in Astronomy (including Astrophysics, Planetary Sciences, and Solar Physics), Physics/Geosciences, and the arXiv E-prints from Cornell, with a total of over 5 million references. The system also provides access to reference and citation information, links to on-line data, electronic journal articles, and other on-line information. The ADS Article Service contains the full articles for most of the astronomical literature back to volume 1. It contains the scanned pages of all the major Astronomy journals (Astrophysical Journal, Astronomical Journal, Astronomy & Astrophysics, Monthly Notices of the Royal Astronomical Society, and Solar Physics), as well as most smaller journals back to volume 1. In order to improve access from different parts of the world, we have set up 12 mirror sites of the ADS in different countries in Europe, Asia, Australia and the Americas.

2 tables, 14 ref

014046   Disale S D;Niwate Y S;Garje S S (Chemistry Dep, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai-400 098, Email: ssgarje@chem.mu.ac.in) : Growth of semiconductor thin films and nanoparticles using single-source precursors. Bionano Front 2007, 1(1), 1-6.

The growth of semiconductor thin films and nanoparticles is an important aspect in view of their technological applications. There are various methods for their growth. However, use of single source precursors offer convenient route for the deposition of thin films and the growth of nanoparticles.ln this review, a brief overview of use of single - source precursors for their growth is given.

5 illus, 31 ref

014045   Choudhury D K;Gogoi R (Physics Dep, Gauhati University, Guwahati-781 014, Email: dkc_phys@yahoo.co.in) : Deep inelastic neutrino scattering and fractal models of nucleon structure functions at small x. Indian J Phys 2007, 81(5-6), 607-14.

Concept of self-similarity in the structure of the proton at small x used successfully in the analysis of recent HERA data, is now extended to deep inelastic neutrino scattering. The fractal models are then tested with the available CCFR neutrino data.

4 illus, 2 tables, 20 ref

014044   Chakrabarti S;Sasmal S;Saha M;Khan R;Bhoumik D;Chakrabarti S K (NO, Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata-700 084) : Unusual behavior of D-region ionization time at 18.2kHz during seismically active days. Indian J Phys 2007, 81(5-6), 531-8.

VTX3 station at Vijyanarayanam which transmits Very Low Frequency (VLF) signal at 18.2 kHz using the Stanford University made receiver stationed at the Centre have been monitored. Observes significant anomalies of the formation time of the D-region of the ionosphere at the Sunrise during the seismically active days. Analyzed this data for over five months (181 November 2006 to 28th April 2007) and have noticed that during or before the earthquakes which took place in the neighboring region, the formation time is very anomalous in comparison to the normal days and therefore this may be used as a precursor to the earthquakes. Suspects that this abnormal behavior is due to the Lithosphere-Ionosphere coupling. This anomalous behaviour has never been reported before.

5 illus, 1 table, 11 ref

014043   Bhattacharjee B;Debnath B;Mukhopadhyay A; Sengupta S (Physics Dep, Gauhati University, Guwahati-781 014, Email: bb_22@rediffmail.com) : Erraticity moment of bin multiplicity and rapidity gap of fast TFs from <. Indian J Phys 2007, 81(7), 717-26.

Reports the emission characteristics of spatial distribution of target associated fast particles from ⁸⁴Kr-Ag/Br interaction at O.95A GeV. The erraticity analysis of bin multiplicity of knocked out protons confirms a power law behavior of the form C_p,q ∞ M^ψα(p). The ψ_q(p) are found to have non zero values confirming erratic behavior of spatial pattern. To further characterise the spatial pattern of emitted fast particles, erraticity moments of rapidity gap between the tracks have also been estimated. The entropy like quantity S_q are found to differ significantly from 1 thereby confirming again the erratic behavior of target associated fast particles. Due to low averaged muliplicity, the conclusions drawn from gap analysis are found to be more convincing than those from erraticity analysis of bin multiplicity.

4 illus, 12 ref

014042   Bhadauriya P (Physics Dep, Institute of Basic Sciences, Khandari, Agra-282 002, Email: preeti_ibs@sity.com) : Equations of state and thermoelastic properties of the Earth's lower mantle. Indian J Phys 2007, 81(5-6), 573-84.

Thermoelastic properties of the lower mantle of the Earth were studied using different equations of state. The values of bulk modulus and its pressure derivative, thermal expansivity, Gruneisen parameter λ and its volume derivatives, q and λ have been calculated for the entire depth of the lower mantle ranging from 670 km to 2891 km. The results obtained in the study are found to compare well with the corresponding values based on the seismological data reported by Stacey and Davis.

6 tables, 20 ref

014041   Bayal N;Chanda A;Mazumdar A (Mechanical Engineering Dep, Haldia Institute of Technology, Haldia, West Bengal, Email: n_bayal@rediffmail.com) : Numerical investigation of hydrodynamic development length of gaseous flow in parallel plate micro channel. Indian J Phys 2007, 81(7), 673-81.

Fluid flows in the entrance region of micro channels have been investigated using fourth order finite difference implicit scheme. Considerations have been given to investigate the compressibility and rarefaction effects assuming slip and no slip on developing laminar flow at very close to the entry. It has been seen that the effect of compressibility is important for higher Reynolds number (Re) and rarefaction is significant for lower reynolds number Re. The result suggests that rarefaction has a significant effect on hydrodynamic development length. A new relation has been proposed for entry length for Reynolds number in between 1 to 400. The proposed relation provides an efficient, practical and accurate toot in predicting the hydrodynamic development length. It has also been observed that due to slip flow mass flow rate increases.

4 illus, 1 table, 10 ref

013029   Yadav R P;Satyendra Kumar;Rawat P S (Physics Dep, GPVT. P.G College, Bilaspur, Pilibhit-262 201) : Freely propagation of shock waves: comparison between Whitham's and Chisnell's method. Acta Cienc Indica-Phys 2007, 33(4), 583-8.

Propagation of strong shock waves in the uniform medium has been investigated by Whitham and Chisnell Methods. The obtained expansions are computed and discussed through tables and graphs. The dependence of Mach number on propagation distance as well as on adiabatic index has also been analyzed for both the cases. It is found that shock decreases faster in case of Whitham Method.

1 illus, 2 ref

013028   Yadav M K;Pradeep Kumar;Seema (Molecular Spectroscopy and Biophysical Lab, Physics Dep, D.N. (P.G.) College, Meerut-250 002) : Solvent effect on electronic absorption spectra of 2-amino-4-chloro-6-nitro phenol. Acta Cienc Indica-Phys 2007, 33(4), 515-18.

Electronic spectra of 2-amino-4-chloro-6-nitro phenol has been recorded in the region 2000Angstrom - 3500Angstrom. The absorption spectra has been recorded in different solvents (viz. ethanol, methanol and water). The effect of solvents on electronic transitions is also studied and discussed.

2 illus, 1 table, 15 ref