020191   Barua A G;Hazarika S (Physic Dep, Gauhati Univ, Guwahati-781 014, Email: agohainbarua@yahoo.com) : XRF and FTIR spectra of the areca nut (Areca catechu). Natn Acad Sci Lett 2006, 29(11-12), 455-9.

Area nut or betel nut (areca catechu) is chewed by hundreds of millions of people as narcotics, from Zanzibar to India and in the central pacific. There has been a number of studies on this plantation crop in recent times regarding its role on the development of oral submucous fibrosis (OSF),- a chronic debilitating disease and a pre-malignant condition of the oral cavity. Its X-ray fluorescence (XRF) spectrum sh6ws the presence of a new element sulphur. A vibrational band analysis of the Fourier transform infrared (FTIR) spectra of both raw and ripe areca nuts reveals hitherto undetected SO2 bands. These findings could be expected to help in understanding the mechanism by which OSF occurs.

4 illus, 19 ref

020190   Banerjee P;Matsakis D (National Physical Laboratory, , New Delhi-110 012, Email: pbanerjee@mail.nplindia.ernet.in) : Time transfer through GPS, and the harmonization of GPS, GLONASS and Galileo for timing. MAPAN 2006, 21(4), 229-42.

Global Positioning System (GPS) has become a key component of the world technology, and one measure of its success is that it has inspired enhancements and similar systems. GPS can therefore be considered the prototype of several existing or planned Global Navigation Satellite Systems (GNSS), with which term we also include supporting satellite-based enhancement systems. Describes flow GPS derives its timing, how GNSS systems are used for several means of precise time transfer, how carrier phase can assist time transfer, and haw GNSS systems can cooperatively create improved products. Significant benefits in terms of robustness and precision can result from combining GNSS systems. Applications which may require them are situations involving interference, limited reception as in urban canyons or indoors, or where there is limited time to acquire a signal.

10 illus, 1 table, 22 ref

020189   Bandyopadhyay A K;Yadav S;Dilwar N (National Physical Laboratory, , Dr. K.S. Krishnan Road, New Delhi-110 012, Email: akband@mail.np;omdoa.ernet.in) : Current status of pressure standards at NPLI and our experiences with the key comparison data base (KCDB). MAPAN 2006, 21(3), 27-45.

Describes briefly the results of various systematic studies in the last ten years which were carried out to characterize our primary standards such as controlled clearance pressure gauges (CCPG) and different other secondary standards in the hydraulic pressure,region up to 1 GPa and in the pneumatic pressure region lip to 12 MPa. Discusses the method of characterization of one of the primary standards in the hydraulic pressure region up to 1 GPa by Heydemann and Welch method (1). Following this method, piston fall rates were recorded as a function of the applied jacket pressure (p1) for each of several loads or measured pressures. Authors have plotted the cube root of the fall rate as a function of applied pi and extrapolated the linear portion of the curve to zero fall rate Which provided us the values of p2 for different loads. From the p2. at different loads, we have determined the zero clearance between the piston and cylinder. The uncertainty budgets of the primary standards were also estimated for both the pressure regions. Based on these uncertainty budgets, all the other secondary or transfer standards were characterized. Discusses very briefly the characterization of CCPG in the pneumatic pressure region. In both the pressure regions, a uniform traceability chart for national pressure scale is also discussed. The verification of this national scale is shown from the agreement of the recently concluded International/bilateral key comparisons like CCM.P-K7 (10 MPa to 100 MPa), APMP.M.P-K7 (10 MPa to 100 MPa) and APMP.SIM.M.P-K7 (40 MPa to 200 MPa) in the hydraulic pressure region and APMP.M.P-K1c (0.4 MPa to 4.0 MPa) and APMP.SIM.M.P-K1c (0.4 MPa to 4.0 MPa) and APMP.M.P-K6 (20 kPa to 105 kPa) in the pneumatic pressure region. Concludes with a report on the service to the nation by conducting one Proficiency Test (PT) program in the hydraulic pressure region ( 7 MPa to 70 MPa) under the ageis of NPLI - NABL program.

13 illus, 3 tables, 21 ref

020188   Bakkialakshmi S;Shanthi B;Meharaj Bibi M (Phys Dep, Annamalai Univ, Annamalainagar-608 002) : Analysis of fuorescence specturm of ethylamine in methanol. Acta Cienc Indica-Phys 2006, 32(3), 327-30.

The fluorescence quenching spectra of ethylamine, using carbon tetrachloride and chloroform as quenchers in methanol has been obtained. The Stern-Volmer constants for all quenching process have been plotted. The regression analysis for Stern-Volmer plot has been carried out. Regression co-efficient (r) and the Stem-Volmer constant (Ksv) were calculated. The Stokes shift, ionization potential, eleclfon affinity and the solvent parameter (z) have also been calculated.

1 illus, 1 table, 13 ref

020187   Bahuguna B P (Phys Dep, Govt P.G. College, Rishikesh-249 201) : Theory of electrical conduction in crystalline solids. Acta Cienc Indica-Phys 2006, 32(3), 377-80.

The electrical conductivity of crystals is one of the most important non-equilibrium property, which shows that how a system relaxes to its equilibrium distribution. The theory of electrical conductivity has been investigated with the help of quantum dynamical approach after considering the model Hamiltonian for the problem which consists of the state of a real crystal containing phonon system, electron system, localized impurities and interactions thereof. The disorder effects include the mass and force constants changes at impurity sites. The expression for electrical conductivity has been derived with the help of Kubo formalism. It is found that electrical conductivity is not simply a function of electron energy but it depends on a large number of scattering events and on crystal characteristics and temperatures. It has been shown that the electron-phonon coupling and defects play prominent role in electron transport-theory.

16 ref

020186   Arjun Kumar (NO, , Adarsh Nagar, Ward No. 9, Madhipura, Bihar) : Critical analysis of wave-particle duality. Acta Cienc Indica-Phys 2006, 32(3), 299-302.

A critical analysis of wave-particle duality has been presented. Although the complementarity principle holds in every situation in which non-commuting observables are involved, in the case of wave-particle duality, Bohr's extension of the principle to the classical concepts of waves and particles holds only in interference experiments because of the quantitative relationship between intrinsic path distinguishability and mutual coherence in quantum mechanics. Bohr's extension cannot therefore be given the status of a general principle. However, all experiments are quite consistent with the Einstein-de Broglie-Bohm version of waveparticle duality in which the position of the particle which is present all the time is guided by the quantum potential determined by the total wave function, as well as with the causal model for the behaviour of light in terms of a quantum field theory. Posser's interpretation photons travel as particles along the lines of energy flow which are modified by boundary conditions (as in a double-slit configuration), resulting in a redistribution corresponding exactly to interference diffraction patterns.

10 ref

020185   Ahmed M G;Ali K (National Inst for Standards (NIS), Thermometry Dep Tersa St., El Haram, , Egypt P.O. Box 136 Giza code 12211, Email: gamal70@yahoo.com) : Realization of gallium triple point at the National Institute for Standards (NIS) in Egypt. MAPAN 2006, 21(3), 177-83.

Cells for the realization of the triple point of gallium were prepared at the thermometry laboratory, National institute for Standards (NIS). The cells were first imported from the National Physical Laboratory (NPL), England as melting point cells according to tile requirements of the International Temperature Scale of 1990 (ITS-90) [1]. The cells were extensively studied as a melting point using the laboratory capabilities [2]. One of the two cells was then prepared as a triple point cell. The results showed that the measured gallium triple point (GaTP) is 2.1 mK higher than the melting point temperature. The expanded uncertainty of realization was 0.32 m K (k=2).

4 illus, 4 tables, 13 ref

019112   Zhang J L;Wang M L (NO, College of Sci, Luoyang, 471003, China, Email: zhangjin6602@163.com) : Exact solutions to a class of nonlinear Schrodinger-type equations. Pramana J Phys 2006, 67(6), 1011-22.

Class of nonlinear Schrodinger-type equations, including the Rangwala-Rao equation, the Gerdjikov-Ivanov equation, the Chen-Lee-Lin equation and the AblowitzªRamani-Segur equation are investigated, and the exact solutions are derived with the aid of the homogeneous balance principle, and a set of subsidiary higher order ordinary differential equations (sub-ODEs for short).

29 ref

019111   Yadav M;Chauhan D S (Physics Dep, Govt. P.G. College, Kotdwara-246149) : Propagation of freely propagating weak hydromagnetic cylindrical shock waves through rotating gas. Acta Cienc Indica-Phys 2006, 32(2), 215-28.

Using CCW method an attempt has been made to study the propagation of freely propagating weak hyromagnetic cylindrical shock waves taking into account constant axial magnetic field through an ideal and rotating gas at permissible shock front locations for an arbitrary varying initial density distribution of the form, say, ρ₀ = ρ' = log (1 + λr), where ρ is the density at the axis of symmetry and λ is non-dimensionalyzing constant. The numerical estimate of the flow variables have been computed at only on those values of propagation distance r which are permitted by the initial entropy distribution condition. Thus the result obtained has been presented through graphs and compared with earlier work.

6 illus, 8 table, 18 ref

019110   Verma M K;Krishna Kumar;Kamble B (Phys Dep, Indian Institute of Technology Kanpur, Kanpur-208 016, Email: mkv@iitk.ac.in) : Mode-to mode energy transfers in convective patterns. Pramana J Phys 2006, 67(6), 1129-40.

Investigates the energy transfer between various Fourier modes in a low-dimensional model for thermal convection. Used the formalism of mode-to-mode energy transfer rate in our calculation. The evolution equations derived using this scheme is the same as those derived using the hydro dynamical equations for thermal convection in Boussinesq fluids. Numerical and analytical studies of this model show that convective rolls appear as the Rayleigh number R is raised above its critical value R_c. Further increase of Rayleigh number generates rolls in the perpendicular directions as well, and obtained a dynamic asymmetric square pattern. This pattern is due to Hopf bifurcation. There are two sets of limit cycles corresponding to the two competing asymmetric square patterns. When the Rayleigh number is increased further, the limit cycles become unstable simultaneously, and chaotic motion sets in. The onset of chaos is via intermittent route. The trajectories wander for quite a longtime almost periodically before jumping irregularly to one of the two ghost limit cycles.

5 illus, 19 ref

019109   Verma K K;Soni K R (Microwave Lab, Phys Dep, Malaviya National Inst of Technol, Jaipur-302 017, Email: kkvermaphd@rediffmail.com) : Theoretical study of 2 x 2 planar array of equilateral triangular patch microstrip antenna on ferrite substrate. Indian J Phys 2006, 80(10), 1005-10.

Presents theoretical investigations of the radiation properties of a 2x2 element planar array of equilateral triangular patch microstrip antenna built up on a magnetized ferrite substrate Ni_1.062Co_0.02Fe_1.948O₄ in the presence of plasma medium. The far zone EM-mode and Pª mode radiation fields are derived using vector wave function techniques and pattern multiplication approaches. The results are obtained both in plasma medium and in free space. Computation of maximum field intensity, half power beam width (HPBW), full null beam width (FNBW) and other important antenna parameters such as radiation conductance, directivity and quality factor has been made for the plasma and the free space medium. The results of this theoretical analysis suggest that due to ferrite substrate, this planar array antenna can be operated at lower frequency range and there is reduction of size of such antenna when designed on NiCoFeO₄ ferrite substrate.

5 illus, 5 tables, 12 ref

019108   Verma K D;Singh S P;Prakash D (Physics Dep, S V College, Aligarh-202 001) : Temperature dependence of bulk modulus and second order elastic constants. Acta Cienc Indica-Phys 2006, 32(2), 121-30.

A simple theoretical model is developed to investigate the temperature dependence of the bulk modulus and second order elastic constants. The method is based on Tallon's model using the concept of modified Gruneisen parameters. The results obtained for a number of crystals viz., MgO, CaO and Mg₂SiO₄ are discussed and compared with those obtained from O.L Anderson model as well as with available experimental data. It is concluded that the Tallon's model is far better than the Anderson model for bulk modulus for all the crystals except Mg₂SiO₄ and the Anderson model has the better agreement for second order elastic constants except C₁₁ of MgO.

4 illus, 2 table, 13 ref

019107   Verma A S;Rathi S K;Sharma D;Bhardwaj S R (Physics Dep, B.S.A. College, Mathura-281 004) : Structural properties of europium monochalcogenides. Acta Cienc Indica-Phys 2006, 32(2), 137-9.

Present optical and electronic properties such as homopolar gaps (E_h), average energy gaps (E_g), crystal ionicity (f_i), dielectric constants (ε_∞) and plasmon energy (hω_p). In the present research paper we have made an attempt to understand average energy gap (E_g), ionic gap (E_c), plasmon energy (hω_p) and crystal ionicity (f_i) trends in these materials using modified P.V.V. theory and other related models, A discussion based on P.V.V. theory has been presented for the derived homopolar gap (E_h), ionic gap (E_c), average energy gap (E_g), Penn gap (E_p) correlating ionicity with E_c and E_g as well as with various hyperfine interactions.

2 table, 14 ref

019106   Verma A K;Saxena S (Physics Dep, Bareilly college, Barielly-243 001, (U.P)) : Positron (electron) impact excitation of xenon. Acta Cienc Indica-Phys 2006, 32(2), 131-6.

Apply the close coupling approximation for positron (electron) impact excitation of inert XENON atom. The differential scattering cross section (DCS), Integral cross section (ICS), collision strength (Ω) and effective collision strength (γ) have been calculated. The calculated value are compared with other theoretical calculation (DWBA) 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.

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019105   Vasantharani P;Kannappan A N (Physics Dep, Annamalai Univ, Annamalainagar-608 002) : Acoustical studies on aqueous ternary electrolytes at different temperatures. Acta Cienc Indica-Phys 2006, 32(2), 163-8.

Measurements have been made on ultrasonic velocity, viscosity and density of sodium chloride, sodium formate and sodium acetate in 10, 20 and 30% of formamide-water mixtures at different molalities of salts at 303, 308 and 313 K. The derived acoustical parameters viz., adiabatic compressibility, apparent molal compressibility, apparent molal volume and the limiting apparent molal compressibility, limiting apparent molal volume as well as the constants S_k and S_v have also been calculated. The variation in these parameters with respect to the molality has been explained on the basis of ion-solvent interaction and structure making/breaking tendency of the electrolyte.

3 table, 15 ref

019104   Varma S V K;Syam Babu M;Subramanyam D; Prabhakar Reddy N (Mathematics Dep, S V Univ, Tirupati-517 502, Email: prasannadsm@yahoomail.com) : Unsteady MHD flow of viscous incompressible immiscible fluids in a rotating channel bounded by permeable beds. Ultra Scient phys Sci 2006, 18(3M), 501-8.

Unsteady laminar flow of two electrically conducting, viscous incompressible and immiscible fluids in a rotating channel bounded by permeable media of different permeabilities under the influence of a uniform transverse magnetic field is studied by taking the pressure gradient to vary exponentially with respect to time. Analytical solutions of the equations of motion are obtained for velocities and mass flow rates. The effects of magnetic parameter M, Reynolds number Re, permeability parameters σ₁ and σ₂ and height h₂ of the upper fluid on velocities and mass flow rates are studied through graphs.

5 illus, 14 ref

019103   Tak S S;Vyas M K (Mathematics and Staticstics Dep, J N V Univ, Jodhpur-342 005, Email: takssjnvu@sify.com) : Analysis of three dimensional couette flow and heat transfer in porous medium between two permeable plates with sinusoidal temperature. Ultra Scient phys Sci 2006, 18(3M), 489-500.

Three dimensional Couette flow and heat transfer through a porous medium between two parallel infinite porous plates is considered. The stationery plate is subjected to a slightly sinusoidal surface temperature with transverse sinusoidal suction velocity while the moving plate is isothermal with uniform injection velocity. The expressions for components of skin friction and rate of heat transfer at the stationery plate and recovery factor at the insulated plate are obtained. These parameters are plotted against Reynolds numbers for various values of other parameters and discussed in detail.

12 ref

019102   Szewvzyk R (NO, Institute of Metrology and Measuring Systems, Warsaw University of Tec, Sw. A. Boboli 8, 02-525 Warsaw, Poland, Email: rszewczyk@onet.pl) : Modelling of the magnetic and magnetostrictive properties of high permeability Mn-Zn ferrites. Pramana J Phys 2006, 67(6), 1165-71.

Presents the results; of modellilig of both magnetic and magne-tostrictive properties of high permeability Mn_0.51Zn_0.44Fe_2:05O₄ ferrittes. The parameters of energy-based Jiles-Atherton-Sablik (J-A-S) model were talculated for ,each experimental hysteresis loop on the basis of evolutionary strategies and Hook-Jevis optimizaªtion method. Finally high conformity between experimental and modelling results was achieved. This high conformity indicates that the presented results create new opportuªnity of modelling of the properties of inductive component based on ferrites as well as quantitative description of magnetization. process.

3 illus, 2 tables, 12 ref

019101   Srivastava N K;Singh Y P (National Physical Laboratory, , New Delhi-110 012, Email: ypsingh@mail.nplindia.ernet.in) : Uncertainty with its components and application in degree of equivalence in calibration of strip-lamp & optical-pyrometer. MAPAN 2006, 21(2), 91-101.

The calibration of Srtip-Lamp or an Optical-Pyrometer in two sets observations expected a problem towards consistency of measurements ill a laboratory as compared to a reference laboratory & in definition of suitable reference standards. The degree of equivalence (D_ij) between Key-Comparison Reference Value (KCRV) & a Laboratory measurement or measurements of two laboratories helped to express inter-changeability of laboratory standards or compatibility/consistency of measurement standards. To relate two independent core-functions ill two sets of data of a single-(fixed-)valued parameter on the first hand, helped to establish Traceability of measurements with analysis of associated uncertainty. On the other hand, expression of standards with its deviations and associated uncertainties led to expression of mutual confidence of two involved laboratories. Consistency could be defined as appropriate ill measurement when its Systematic and random-uncertainty components were of equal order of magnitude in d_jj and h_jj. Reference Standard defined as appropriate and of good quality if systematic-type uncertainty of long-term drifts were less than short-term drifts or random-type uncertainty in a calibratian-process. Drifts in calibration could be minimized during repeated electrical heating stability anneals to Strip-Lamps, etc. In connection with standards, traceability of j^th laboratory could be treated as appropriate, if uncertainty, u_j was less than unceratainty, μ_i of i^th laboratory, or in other words, when uncertainty on input-side (u_ci), of a measurement was less than uncertainty on out-put side (u_co).

5 ref

019100   Srivastava A K;Gupta B R K (Physics Dep, G.B. Univ of Agric and Technology, Pantnagar-263 145, Email: brkg@rediffmail.com) : Compression behaviour of single wall carbon nanotube under high pressure. Indian J Phys 2006, 80(10), 983-7.

Analyzeds the pressure dependence of compressional behaviour of nanotube bundle and individual tube within the bundle of single wall car nanotube. For thts purpose useses usual Tait's Equation of State to predict the change in unit cell volume as a function of pressure. Also predictes the variation of isotherma bulk modulus and specific heat with pressure for nanotube. The results achieved from usual Tait's Equation of State are found in good agreement with the available experimental data. It is concluded that the individual carbon nanotube is less compressible than the bundle of carbon nanotube.

6 illus, 1 table, 29 ref

019099   Souradeep T (NO, Inter-Univ Centre for Astronomy and Astrophys, Post Bag 4, Graneshkhind, Pune-411 007, Email: tarun@iucaa.ernet.in) : Spectroscopy of cosmic topology. Indian J Phys 2006, 80(11), 1063-9.

Einstein's theory of gravitation that governs the geometry of space-time, coupled with spectacular advance in cosmological observations, promises to deliver a 'standard model' of cosmology in the near future. However, local geometry of space constrains, but does not dictate the topology of the cosmos. Hence, cosmic topology has remained an enigmatic aspect of the `standarc model' of cosmology. Recent advance in the quantity and quality of observations has brought this issue within the realm of observational query. The breakdown of statistical homogeneity and isotropy of cosmic perturbations is a generic consequence of non trivial cosmic topology arising from to the imposed 'crystallographic' periodicity on the eigenstates of the Laplacian. The sky maps of Cosmic Microwave Background (CMB) anisotropy and polarization are the most promising observations that could carry signatures of a violation of statistical isotropy and homogeneity. Hence, a measurable spectroscopy of cosmic topology is made possible using the Bipolar power spectrum (BiPS) of the temperature and polarization that quantifies violation of statistical isotropy.

3 illus, 39 ref

019098   Singh U N;Mishra L K (Physics Dep, Magadh Univ, Bodh-Gaya-824 234) : Radiative recombination and shockley read recombination and evaluation of lifetime as a function of temperature of P-Hg_1-xCd_x Te. Acta Cienc Indica-Phys 2006, 32(2), 145-52.

Evaluation of radiative lifetime as a function of temperature for different carrier concentration and lifetime for acceptron (change carriers) for Auger recombination, radiative recombination and combined recombination for p-Hg_{1 -x}Cd_x T_e have been performed. Evaluated results are is good agreement with those of the other workers.

4 table, 5 ref