010040   Behera D;Biswal R;Mohapatra U K;Mishra N C (Physics Dep, National Institute of Technology, Rourkela-769 008, Email: dbehera@nitrkl.ac.in) : Microscopic inhomogeneity induced thermal fluctuation in high temperature superconductors. Indian J Phys 2008, 82(3), 317-25.

Superconducting order parameter fluctuation (SCOPF) region in a set of pristine bulk sinter (YBCO) thick films and YBa₂Cu₃O_7-y/Ag (YBCO/Ag), Y_1-xCa_xBa₂Cu₃O_7-y/Ag composite samples are studied by varying the driving current in the first and Ag content in last two systems. The mesoscopic inhomogeneities that influence the tailing region arises due to most of Ag residing at the grain boundaries in the composites or due to current induced suppression of Josephson tunnelling of supercurrent across grain boundaries. These inhomogeneities in principle should not influence the SCOPF region. Ca doping at yttrium site in the grains of YBCO directly influences the SCOPF region. We observe a strong variation of T_LD with Ag and associated increase in coupling strength. It is observed that SCOPF region is more affected in Ca doped sample as compared to Ag composite one. The SCOPF being basically a precursor to the onset of superconductivity in the grains, the results thus show that the SCOPF is affected due to either Ag diffusing into the grains in the composites or due to Ca occupying Y site in the doped samples.

5 illus, 1 table, 20 ref

010039   Banerjee B;Roy S K (Physics Dep, Visva Bharati Univ, Santiniketan-731 235, Email: binayakbanerjee@rediffmail.com ) : Plausible explanation of non-zero isotope shifts in superconductors. Indian J Phys 2008, 82(3), 333-9.

Proposes to consider a charge Bose liquid model as a phenomenological explanation of three puzzling features of non-zero isotope shifts (α) in superconductors. These features are (i) large value of a (~ 0.5) in normal superconductors; (ii) an overall trend of lower values of a with increasing T_o and (iii) a very striking feature of negative value of α (= - 0.013 in Bi 2:2:2:3 with T_o = 108K) [6] in high 7, superconductors. This phenomenon of non-zero isotope shifts observed in high T_o oxides are explained on the baiss of (bi) polaronic theory.

2 illus, 10 ref

008942   Vasantharani P;Muthu Shailaja S;Kannappan A N;Ezhil Pavai R (Physics Dep, Annamalai Univ, Annamalai Nagar, Tamil Nadu) : Ultrasonic velocity studies on the influence of electrolytes on molecular interactions in aqueous solutions of ethylene glycol. Asian J expl Chem 2008, 3(1-2), 64-9.

Density, viscosity and ultrasonic velocity of manganese sulphate, cobalt sulphate and nickel sulphate in 5,10,15 and 20% ethylene glycol (EG) - water mixtures have been measured at different molalities of the salts at 303,308 and 313K. Using these data, the parameters adiabatic compressibility (β), acoustic impedance (Z), viscosity B-coefficient and solvation number (S_n) have been calculated. The data have been analyzed using the Jone-Dole equation and the obtained parameters have been interpreted in terms of ion-ion and ion-solvent interactions.

2 tables, 23 ref

008941   Suresh S;Prasad M;Upender G;Kamalaker V; Chandra Mouli V (Glassy Materials Research Lab (GMRL), Physics Dep, Osmania University, Hyderabad-500 007, Email: vorucm90@yahoo.com) : ESR, IR, Raman and optical absorption studies of 60 B₂O₃ + 10 TeO₂ +5TiO₂+24 R₂O: 1CuO (where R=Li, Na, K) quaternary glasses. Indian J pure appl Phys 2009, 47(3), 163-9.

ESR, IR, Raman and optical absorption spectra of 60 B₂O₃ + 10 TeO₂ +5TiO₂+24 R₂O (where R = Li, Na and K) quaternary glasses containing Cu²⁺ spin probe have been studied. IR results show the BO₃-BO_4- ring structure interconnected by TeO_3- and TeO_4- groups, where the BO_4- groups are neighbours of the TeO_3-groups. BO₃ → BO₄ transition is also observed, which correlates with the conversion of TeO₄ →TeO₃. From Raman spectra, a weak band recorded at 805 cm^-1 clearly indicates the presence of boroxol rings for potassium boro-tellurite glass alone. From ESR spectra, the three weak parallel components are observed in the low field region. However, the perpendicular components are not resolved leading to an intensive line in the high field region. When one kind of alkali oxide is replaced by another, the Spin Hamiltonian parameters have been found to vary drastically. The spin Hamiltonian parameter values indicate that the ground state of Cu²⁺ is d_x²_-y² and the site symmetry around the Cu²⁺ ion is tetragonally distorted octahedral coordination. Optical absorption peak of Cu^{2+ is found to be a maximum at around 794 nm for Li₂O containing borate rich glasses. This peak shifts towards the lower wavelength side as Li₂O is replaced with Na₂O, K₂O. Bonding parameters indicate a slight covalency for the in-plane σ bonding as compared to in-plane and out-of-plane π bonds.}

008940   Srivastava S K;Sinha P;Panwar M (Computational Intelligence Lab, Institute of Science and Technology, Klawad, Yamunanagar-133 105, Email: sanjeevsrivastava1980@rediffmail.com ) : Thermal expansivity and isothermal bulk modulus of ionic materials at high temperatures. Indian J pure appl Phys 2009, 47(3), 175-9.

The volume expansion and bulk modulus data due to Anderson have been extrapolated by modification of previously used relationships for ionic materials viz. NaCl, KCl, MgO and CaO. The empirically modified relationships provide the non-linear models for the variation of both thermal expansivity and bulk modulus with temperature. The results are found to be in close agreement with the experiment which in turn reveals the validity of present work.

008939   Sreenivasulu A;Prasad T N V K V;Buddhudu S (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: profsb_svuniv@hotmail.com) : Optical analysis of RE<. Proc Indian Acad Sci 2008, 74(1), 1-4.

Ferroelectric materials Ba₀₉₅RE_0.05TiO₃ (RE=Eu³⁺ Sm³⁺ & Dy³⁺) containing certain rare-earth ions as the luminescent ions were prepared by a conventional solid state method. Structural analysis of these materials has been carried out by using both XRD and FTIR spectral measurements. By measuring the excitation, emission spectra and lifetimes of the prominent emission bands, luminescence performance of these optical materials has been investigated.

8 illus, 1 table, 22 ref

008938   Singh A K;Wasankar K S (NO, Defense Institute of Advanced Technology, Pune) : Microstructure based model for effective thermal conductivity of snow. Indian J pure appl Phys 2009, 47(3), 206-11.

A model to quantitatively relate macroscopic effective thermal conductivity (ETC) of snow with the microscopic interfacial contact area among the components using micro-structural parameters obtained from surface section images of snow samples. Unit cell model of Jackson and Black, based on stereological concept of contiguity, is expanded to include the effect of microstructure of snow, as well as, other parameters to predict the ETC of snow. The model is described by three dominant thermal conductance that account for the heat transfer across solid-solid, solid-liquid, and solid-air interface. The complex structure of snow is described using the primary microstructure parameters: coordination number, grain size, bond size, dendricity and sphericity. The ETC formulations developed, include the effect of these snow parameters besides the characteristics of the phases and temperature dependence of their conductivities. The model predictions agree closely with the measurements made using transient thermal probe method. The ETC values obtained from the present model are in close agreement with the observed values than the results of other existing models.

008937   Sharma R;Singh M;Sonara D;Saradha S;Shukla P; Sarkar B;Saxena Y C (NO, Institute for Plasma Research, Bhat, Gandhinagar, Gujarat-382 428) : Design, development and testing of vacuum compatible seals at cryogenic temperature. Bull Indian Vacuum Soc 2007, 10(3), 9-12.

De-mountable joints are one of the major requirements in cryogenic assembly, especially in hydraulic connection. Different methods have been adopted for this purpose. Some demountable joints are also commercially available, but not economically viable solution for laboratory experiments. Therefore, a cost effective solution have been worked out for routine laboratory experiments, so that permanent joining processes can be avoided in order to save assembly/de-assembly time as well as avoiding permanent damage to the piping. Making a demountable type joint for cryogenic experiments require special skill and technique. The technical requirements for such a de-mountable type joint is very stringent, to mention a few are; Compatibility with cryogenic temperature as per use of cryogenic fluids (Liquid helium 4.2 K, Liquid Nitrogen 77 K), Fluid position with respect to the seal (inside flowing condition, outside bath condition) vacuum compatibility and above all consistency and repeatability of making the demountable joints with high level of operational reliability. The design of such seals also require a reliable analysis as thermal stress developed across the joint, due to differential thermal contraction of dissimilar metals, may lead to fluid leakage in the system, which is not desirable. Indium wire seals have been extensively used at cryogenic temperature for sealing vacuum Cans, mainly because of its fluid flow properties in pressure condition. However, no reference was found where such seals have been used in demountable joints with fluid flow condition in hydraulic lines. The joint developed with indium, as sealing material remains vacuum compatible at liquid nitrogen as well as at liquid helium temperature. The joints even withstood thermal shock test with ten repeated cooling to LN₂ and LHe temperature and consequent warm up to room temperature. The leak rate measurement at 77 K and 4.2 K showed no detectable leak above the helium background level in the order of 1 x 10^-9 mbar- I/sec during testing. The paper will describe the details of design consideration and concept, engineering and special techniques involved as well as test results at 77 K and 4.2 K of the developed seal.

3 illus, 1 table, 3 ref

008936   Sekar R;Vaidyanathan G;Hemalatha R (Mathematics Dep, Pondicherry Engineering College, Puducherry-605 014, Email: hemalatha53@yahoo.co.in) : Effect of horizontal thermal gradient on double-diffusive ferroconvection. Indian J pure appl Phys 2009, 47(3), 192-8.

The effect of horizontal thermal and salinity gradients on ferroconvection of a double diffusive system subjected to two dimensional magnetic fields with compensating horizontal thermal and solutal gradients has been investigated. Assuming that the fluid layer is bounded by free boundaries, the conditions for the onset of stationary and oscillatory instabilities are established using linear theory and normal mode technique. Wide range of values of the ratios of horizontal and vertical gradients with respect to temperature, salinity and the cell size are considered. It has been found that the system stabilizes only through oscillatory mode for ratios of the temperature and salinity gradients which tend to make the cell size greater than 1. Stationary instability is found to occur for the ratios of the temperature and salinity gradients which tend to make the cell shape smaller than 1.

008935   Sahoo S;Das S (Physics Dep, National Institute of Technology, Durgapur-713209, Email: sukadevsahoo@yahoo.com) : Supersymmetric structure of fractional quantum Hall effect in graphene. Indian J pure appl Phys 2009, 47(3), 186-91.

Graphene shows unusual low-energy electronic excitations described in terms of Dirac fermions. The fractional quantum Hall effect in a bilayer graphene in different Landau levels within the supersymmetric formalism has been studied. The quantized Hall conductivity is found to be, where n = 0, 1, 2, 3....

008934   Pradyumnan P P;Shini C (Physics Dep, University of Calicut, Kerala-673 635, Email: drpradyumnan@yahoo.co.in) : Growth characterization and etching studies of calcium tartrate single crystal grown using tamarind extract. Indian J pure appl Phys 2009, 47(3), 199-205.

Calcium tartrate crystals were grown in silica gel by single diffusion method. The reactants used were calcium chloride and extract from tamarind juice. Crude as well as centrifuged tamarind extracts were used. The studies on the growth parameter of the crystal were conducted. The characterization studies such as XRD, FT-IR, TG-DTA of the grown crystals were done and it was then compared with that of calcium tartrate crystals grown using AR grade tartaric acid. The absorption spectral, CHN analysis and etching were also studied.

008933   Prabhakara H R (NO, , Bangalore Plasmatek Pvt.Ltd, 129, Block 14, Jeevanmitra Colony I-Phase, Bangalore-560 078) : Vacuum brazing of ceramics and graphite to metals. Bull Indian Vacuum Soc 2007, 10(3), 15-18.

Joining of metals to ceramics and graphite is important in many applications such as x-ray tubes, microwave devices, nuclear fusion reactors and so on. Some of the basic requirements of such joints are electrical insulation, thermal conduction, vacuum compatibility, mechanical strength etc. Several techniques are in use and new ones are being developed to meet stringent requirements. Moly-manganese metallisation is proven technique for brazing ceramics to metals. Recently the so-called active brazing alloys have been introduced in order to reduce the number of steps involved in Brazing. Another technique, which is used in the present work, is to coat ceramic with titanium and then use conventional brazing alloys. Titanium is deposited on ceramics using a cathodic arc plasma source in vacuum. Indigenously prepared copper silver eutectic alloy foils are used as filler material. Brazing is carried out under high vacuum at about 900°C. These techniques have been used to braze stainless steel-alumina, titanium- alumina, as well as copper-graphite. In all these cases mechanically sturdy joints have been obtained. These techniques can also be used to braze metals to metals and ceramics to ceramics. Some of the results of the work in progress would be presented.

3 illus, 5 ref

008932   Narendra Kumar;Sanyal G S (NO, Raman Research Institute, Bangalore-560 080, Email: nkumar@rri.res.in) : Characterization of radiation as an electromagnetic wave or a particle - a criterion. Proc Indian Acad Sci 2008, 74(1), 19-20.

The wave-particle duality of radiation from a source in the electromagnetic spectrum is well-known. A criterion is proposed to determine when the radiation will predominantly exhibit the properties of a particle and when will it behave as a wave. An experiment is suggested to validate the criterion.

1 illus, 5 ref

008931   Nair K P R;Nair V V;Meera V;Priyamol P E; Issac M (Physics Dep, Cochin Univ of Science and Technology, Cochin, Email: kprnair@gmail.com) : NIR vibrational overtone spectrum of diphenylamine. Asian J Spectrosc 2008, 12(2-3), 83-6.

The near infrared overtone absorption spectrum of liquid phase diphenylamine (C₆H₅)₂NH in the overtone spectral region Δv = 2-6 is reported. The observed spectrum is analyzed using local mode model. It has been found that the mechanical frequency for aryl CH in diphenylamine is comparable to that of aniline.

1 illus, 2 tables, 29 ref

008930   Kukreti A;Ashok Kumar;Naithani U C (Physics Dep, Garhwal University, Pauri Campus, Pauri(Garhwal), Uttarakhand-246 001, Email: ashishkukreti07@gmail.com) : Electric field dependent attenuation constant in Ba_xSr_1-xTiO₃ perovskites. Indian J pure appl Phys 2009, 47(3), 220-7.

A theoretical expression is derived for attenuation constant in para-electric phase in anharmonic Ba_xSr_1-xTiO₃ ferroelectric crystal, using double time temperature dependent Green's function technique. Taking electric field as a parameter, the variation of attenuation constant with frequency and temperature has been studied by considering third and fourth order anharmonic interactions. The mass and force constant change due to the presence of impurity atoms in Silverman-Joseph Hamiltonian augmented with higher order anharmonic terms. The effect of electric field, defect and anharmonicity on stabilization of the soft mode frequency has also been studied. The attenuation constant increases with increasing temperature and frequency in the presence of an electric field. In the vicinity of the Curie temperature, the attenuation constant increases anomalously.

008929   Iyer R;Desai R;Upadhyay R V (Physics Dep, St.Xavier's College, Ahmedabad-380 009) : Low temperature synthesis of nanosized Mn1-_xCd_xFe₂O₄ ferrites. Indian J pure appl Phys 2009, 47(3), 180-5.

Nanosized Mn1-_xCd_xFe₂O₄ mixed ferrite samples were synthesized using the co-precipitation technique. The Cd²⁺ ion was employed as the dopant and the values of χ = 0, 0.1 0.3 and 0.5. The X-ray and IR spectra analysis were carried out to confirm the spinel phase formation as well as to ascertain the cation distribution in the ferrite samples. The magnetic study was carried out to ascertain the effect of the cadmium doping on the Ms Value.

008928   Ikot A N;Akpabio L E;Essien K;Ituen E E;Obot I B (Chemistry Dep, University of Uyo, Nigeria, Email: proffoime@yahoo.com) : Variational principle techniques and the properties of a cut-off and anharmonic wave function. E J Chem 2009, 6(1), 113-19.

The variational principles are very useful analytical tool for the study of the ground state energy of any dynamical system. This work, evaluated the method and techniques of variational principle to derive the ground state energy for the harmonic, cut-off and anharmonic oscillators with a ground state wave function for a one-body Hamiltonian in three dimensions.

14 ref

008927   Himanshu A K;Gupta D C;Dutta A;Sinha T P; Bandyopadhayay S K (NO, Variable Energy Cyclotron Centre, DAE, 1/AF Bidhannagar, Kolkata-700 064, Email: himanshu_ak@yahoo.co.in) : Structural and dielectric behaviour of barium substituted lead zinc niobate ceramics at low temperature. Indian J pure appl Phys 2009, 47(3), 212-9.

The polycrystalline samples of (Pb_1-xBa_x)(Zn_1/3Nb_2/3)O₃ (PBZN) ceramics have been synthesized by the columbite precursor method. X-ray diffraction analysis of PBZN synthesized for x = 0.15, 0.25, 0.35 and 0.50 shows a cubic perovskite phase at room temperature. The changes in the structures are observed with increasing Ba contents in PBZN. The dielectric dispersion of the solid solutions has been studied as a function of temperature in the frequency range 100 Hz-1MHz. The temperature variation of the real components (e›) at different frequencies of the dielectric permittivity shows a broad maximum. The diffuse peaks in e› versus T confirm the relaxor behaviour of PBZN. The changes in the relaxor properties of the compounds are found to be compositional dependent. The frequency dependence of T_m in these compounds with barium substitution is modeled using Vogel-Fulcher relation.

008926   Charles J;Ramkumaar G R;Azhagiri S; Gunasekaran S (Physics Dep, S.S.N. College of Engineering, Old Mahabalipuram Road, Kalavakkam-603 110, Email: juliecharles2005@gmail.com) : FTIR and thermal studies on nylon-66 and 30% glass fibre reinforced nylon-66. E J Chem 2009, 6(1), 23-33.

The study deals with the characterization of the polymeric materials viz., nylon-66 and 30% glass fibre reinforced nylon-66 (GF Nylon-66) by employing FTIR and thermal measurements. The complete vibrational band assignment made available for nylon-66 and GF nylon-66 using FTIR spectra confirm their chemical structure. FTIR spectroscopy provides detailed information on polymer structure through the characteristic vibrational energies of the various groups present in the molecule. The thermal behavior of nylon-66 and GF nylon-66 essential for proper processing and fabrication was studied from TGA and DTA thermograms. The thermal stability of the polymers was studied from TGA and the activation energy for the degradation of the polymeric materials was calculated using Murray-White plot and Coats-Redfern plot. The polymer with high activation energy is more thermally stable. GF nylon-66 is found to be more thermally stable than nylon-66. The major thermal transitions such as crystalline melting temperature (T_m and degradation temperature (T_d) of the polymers were detected from DTA curves. The melting behaviour of the polymer depends upon the specimen history and in particular upon the temperature of crystallization. The melting behaviour also depends upon the rate at which the specimen is heated. The various factors such as molar mass and degree of chain branching govern the value of T_m in different polymers.

8 illus, 7 tables, 26 ref

008925   Beaudry F;Moore R B (Veterinary Medicine Dep, Faculty of Veterinary Medicine, Groupe de Rec, University of Montreal, St-Hyacinthe, Quebec, Canada, , Email: francis.beaudry@umontreal.ca ) : Design of new electrode interface to improve transport of atmospheric pressure ions into a mass spectrometer. E J Chem 2009, 6(1), 39-46.

An intermediate electrode was developed to improve the transfer of ions in atmospheric pressure from a first location, the ion source, to a second location, the mass spectrometer. The new apparatus increase the efficiency of mass analysis of molecular constituents of liquids, including trace analysis of chemical entities, in which an electrospray (ES) or IonSpray^TM (IS) technique is used to produce electrically charged droplets which divide and evaporate to form gaseous ions of the molecular constituents. The gas phase ions are transported to the mass spectrometer by an electric field generated by a new electrode design that separates the two fundamental functions of an electrospray or an IonSpral^TM, which are the nebulization of charged droplets and the transport of ions into the mass analyzer. The results suggest that the new apparatus provide a gain in signal intensity up to 10 compared with the commercial product. A significant improvement in ion transport results in higher precision and accuracy and/or reduction of the amount of material needed for analysis.

10 illus, 10 ref

008924   Bayrakceken F;Bastas S A (Optical Spectroscopy Div, Biomedical Engineering Dep, Yeditepe Univ, Istanbul 34755, Turkey, Email: fubay@yeditepe.edu.tr) : Novel and the new type of giant coherent superfluorescence transitions for the two-level system of spectrosil quartz. Asian J Spectrosc 2008, 12(2-3), 75-81.

The ultraviolet high photon flux light induced high resolution optical discrete absorption and superfluorescence discrete spectra of spectrosil quartz were recorded photographically first time in the ultraviolet region at room temperature. This novel discrete transitions observed experimentally between two electronic energy level system by depopulating the ground state of spectrosil quartz in the solid state phase. The integrated areas of the absorption and emission bands were identical and recorded at the highest-quality images at room temperature. This two-level emission system showed that this pure undoped fiber material is not suitable for optical fiber communications in the ultraviolet region only. It is suitable for the visible region. But it will be a perfect device for optoelectronics, optical spectroscopy, photonics laboratory experiments for transmission lines, power electronics and laser research.

2 illus, 18 ref

008923   Bayrakceken F (Optical Spectroscopy Div, Biomedical Engineering Dep, Yeditepe Univ, Istanbul 34755, Turkey, Email: fubay@yeditepe.edu.tr) : Intermolecular cross energy transfer system of coumarin-benzophenone in solution. Asian J Spectrosc 2008, 12(2-3), 87-97.

The compound benzophenone is acting both as a singlet quencher and triplet sensitizer to the molecule coumarin in polar and non-polar solvents. Collisional and optical energy transfer mechanism of coumarin-benzophenone system is studied in solution at room temperature by flash and laser flash photolysis techniques. Ultraviolet light-induced photophysical and photochemical changes of coumarin studied due to its potential applications in photonics, optoelectronics, quantum electronics, photochemistry, and electronic spectroscopy. An absorption and emission bands around 255.5 and 470 nm, were observed for the photoproduct (cyclobutanes) of coumarin.

24 ref

008922   Baris B;Bayrakceken F;Bastas S A;Tarhancy E; Karaaslan I S (Optical Spectroscopy Div, Biomedical Engineering Dep, Yeditepe Univ, Istanbul 34755, Turkey, Email: fubay@yeditepe.edu.tr) : Determination of nanostructured porous silicon in rock samples by energy dispersive fluorescence spectroscopy. Asian J Spectrosc 2008, 12(2-3), 107-11.

Silicon atomic fluorescence was excited within a carbon atomiser by high voltage (12 kV) discharge technique. Silicon atoms in different rock samples were excited to the upper electronic energy levels, then excited silicon atoms returned to the ground state by emitting characteristic fluorescence lines. All fluorescence transitions observed were resonance lines. Fluorescence lines of silicon were observed at 250.69, 251.43, 251.61, 252.41 and 252.81 nm, as intense discrete emission lines. These emission lines were calibrated by iron arc and mercury arc emission spectra.

2 illus, 1 table, 25 ref

008921   Ali Y P;Nair G;Narsale A M;Chandrasekaran K S;Arora B M (Physics Dep, Hadaramout University of Science and Technology, Mukalla - Yemen, Email: arunnarsale@yahoo.co.in) : Annealing behaviour of GaAs implanted with 70 MeV<. Indian J pure appl Phys 2009, 47(3), 170-4.

Single crystal GaAs substrates implanted with 70 MeV¹²⁰Sn have been investigated by X-ray diffraction (XRD) and electrical resistance measurements after annealing in the temperature range 373-823 K. XRD measurements for the samples annealed up to 723 K show two peaks, one due to the substrate and another due to the implant damaged layer. The strain parameter from the measured separation between the substrate and layer peaks of several symmetric and asymmetric reflections after each annealing step has been calculated. Strain recovery occurs in two predominant annealing stages, one at about 500 K and the other at about 700 K. Temperature dependence (100-300 K) of resistance of these samples indicates that electrical conduction in the samples annealed up to 723 K, is dominated by variable range hopping. Localized states density at the Fermi level N(EF), estimated from temperature dependence of sample resistance after each annealing step, shows two annealing stages similar to those observed from XRD measurements. Isothermal annealing carried out at two different annealing temperatures (523 and 573 K) indicates the activation energy E_a = 0.16 eV for the first annealing stage.

008920   Al-Adel F F;Dastageerl M A;Bakhtiari I A; Al-Gaashani R (NO, King Fahd Univ of Petroleum and Minerals, Dhahran 31261, Saudi Arabia, Email: ffadel@kfupm.edu.sa) : Application of a new method for evaluating the temperature reduction associated with infrared reduction by films. Asian J Spectrosc 2008, 12(2-3), 69-74.

The importance of energy saving, and pollution reduction for the survival of our planet is tremendous. In order to better characterize the role that may be played by infrared films in this regard, Produced first, photometric spectra for some films, which gives a good idea about their effectiveness in cutting the blackbody radiation from the sun. Second, it is considered that a complementary investigation that would allow us to estimate the temperature reduction due to these films will give a better picture of the energy saving role of these films, keeping in mind the need for an experimental method that may play this role in a selective way. The method should be able to selectively give the temperature reduction from blackbody radiation at the expenses of other contributing processes especially the heat conduction process. Results of these investigations are presented and analyzed. Concluded with some important recommendations.

4 illus, 2 tables, 4 ref

008196   Zatale D A;Bagade S M;Rathod S T;Ghosh S A (Physics Dep, Govt. Institute of Science, Nagpur, Maharshtra) : Molecular interaction in binary mixtures using excess thermo-acoustic parameters at different temperatures. Acta Cienc Indica-Phys 2008, 34(3), 519-24.

Density and ultrasonic velocity for binary liquid mixture of Acetone-Benzene at temperatures 303.15K to 323.15K have been measured to derived several acoustical and thermodynamic parameters such as excess adiabatic compressibility (β_ad^E), excess free volume (V_a^E), excess free length (L_f^E), excess acoustic impedance (Z^E), Rao's constant (R) and Wada's constant (W). The variation of these parameters with respect to mole concentration and elevation of temperatures have been explained on the basis of nature and extend of molecular interaction between the component molecules of the solute-solvent.

6 illus, 2 tables, 12 ref

008195   Yadav M K;Rai A N (Bikaur, Supaul Dist, Bihar) : Sheath and plasma parameters in a magnetized plasma. Acta Cienc Indica-Phys 2008, 34(3), 471-9.

9 illus, 12 tables, 11 ref

008194   Vijayaragavan R;Senthilkumaran B;Janikiraman G;Balachandranmohan M;Viruthagiri G;Rajamannan B (Physics Dep, Arasu Engineering College, Kumbakonam, Tamil Nadu) : Mineralogical studies on some green brick specimens by FT-IR spectroscopic technique. Acta Cienc Indica-Phys 2008, 34(3), 501-5.

The Green brick samples are collected from different areas in Nagai district, Tamilnadu. An attempt has been made to FT-IR Spectroscopic analysis of mineral constituents and well or disorder of Kaolinite structure of the Green brick specimens.

1 illus, 1 table, 11 ref

008193   Verma K D;Sharma S K;Prakash D (Physics Dep, S.V. (P.G.) College, Aligarh-202 001) : Temperature dependence of bulk modulus and second order elastic constants. Acta Cienc Indica-Phys 2008, 34(3), 549-60.

Tallon's model has been modified for determining the bulk modulus and elastic constants for CaF₂, BaF₂, PbF₂ and SrF₂ crystals in the temperature range 300-1200K. The concept of the modified Gruneisen parameter has been adopted to obtain equation of state. The results obtained have been compared with those obtained from Kumar model as well as with the available experimental data. The theoretical predictions as reported in the present paper are well supported by experimental data.

16 illus, 2 tables, 27 ref

008192   Verma K D;Sharma S K (Physics Dep, Sri Varshney (P.G.) College, Aligarh-202 001) : Pressure-volume-temperature relationship for some alkali halide crystals. Acta Cienc Indica-Phys 2008, 34(3), 461-70.

A method has been used for determining the volumes at simultaneously elevated temperatures and pressures for LiF, NaF, NaCl and CsCI crystals upto a pressure of 300 kbar and in the temperature range 298-1073 K. The concept of modified Gruneisen parameter has been adopted to obtain pressure-volume-temperature relationships. The results obtained are found to present close agreement with the available experimental data.

4 illus, 1 table, 26 ref

008191   Tiwari S N;Shukla S N;Dwivedi A K (Physics and Electronics Dep, Dr. R.M.L. Avadh Univ, Faizabad-224 001) : Rectifying properties of the series and parallel combination of like diodes. Acta Cienc Indica-Phys 2008, 34(3), 357-63.

PN-diodes have- been proved very useful due to its wide range of applications. Studied the rectifying nature of pn-diodes (1N4002) connected in series and parallel in Half-wave, Full-wave and Bridge rectifier circuits. It has been observed that parallel diodes did not affect the circuit performance while series diodes generate the capacitive effect responsible to subside or remove ripples at output. All the studies are made by PSpice circuit simulation software (version 9.2).

6 illus, 4 tables, 9 ref

008190   Tirpude M P;Katre M B;Meshram B S;Kakde A S; Suryavanshi B M (Physics Dep, Govt. Institute of Science, R.T. Road, Nagpur-440 001) : Electrical conduction studies of MgSe thin film. Acta Cienc Indica-Phys 2008, 34(3), 365-8.

MgSe thin film was deposited using spray method. Transport properties of MgSe thin film material has been reported. The measurements of resistivity of the sample and its variation with temperature range between 300K - 500K has been carried out for MgSe thin film. The electrical conductivity (σ) in the range of 10^{-9Ω cm, the activation energy (E_a) 1.389 eV and the intergrain barrier potentials (φ_B) 0.017eV was found for MgSe thin film.}

5 illus, 10 ref

008189   Thakur K;Surya Prakash K V R (Physics Dep, R.S. Univ, Raipur, Chhatisgarh) : Measurement of formant power from speech signal for identification of conceptual disorder persons. Acta Cienc Indica-Phys 2008, 34(3), 507-10.

1 illus, 4 tables, 9 ref

008188   Srivastava A;Mishra L K (Physics Dep, J.D. Women's College, Patna, Bihar) : Evaluation of sound velocity as a function of condensate peak density in large Na/a_ho limit and the frequencies of the monopole and quadrupole of a condensate as a function of the parameter Na/a_ho. Acta Cienc Indica-Phys 2008, 34(3), 387-98.

Presented a method of evaluation of speed of sound 'C' as a function of condensate peak density in large Na/a_ho limit. Also calculated the freuquency of monopole and quadrupole excitation of the condensate in a spherical trap as a function of parameter Na/a_ho where a has positive and negative value. Our theoretical results are in very good match with the experimental data. The local sound velocity increase with n (0) as per experimental finding. From equation (hω)² = m₁/M_-1, the ratio between (m₁/m_-1 moments of the strength distribution function S_F(W) provides a rigorous upper bound to the lowest monopole frequency. The strength distribution of monopole operator F almost coincides with the s-function located at the energy of the lowest compressional mode. Unlike monopole frequency, quadrupole frequency increases with N when a < 0 due to increase in the kinetic energy of the condensate.

1 illus, 3 tables, 23 ref

008187   Srivastava A;Mishra L K (Physics Dep, J.D. Women's College, Patna, Bihar) : Excitation of the condensate using time dependent Gross-Pitaevskii equation and evaluation of frequency of the lowest collective modes. Acta Cienc Indica-Phys 2008, 34(3), 375-86.

Studied the excitation of condensate using Gross-Pitaevskii equation. Evaluated the frequency (in units of ω⊥ of the lower collective modes of even parity m = 0 and m = 2 for N Rubidium atom. From results, it is clear that frequency of the lowest collective mode first decreases very fast and then attains a constant value.

3 illus, 2 tables, 45 ref

008186   Singh D D;Mishra P K (Univ Dep of Physics, L.N. Mithila Univ, Darbhanga-846 004) : Antenna array synthesis of patterns. Acta Cienc Indica-Phys 2008, 34(3), 545-8.

Synthesis of antenna array patterns involving optimization with linear and nonlinear constraints is considered. The general solution for the composite weight vector can be decomposed into a part which satisfies the linear constraints and another lying orthogonal to it. This decomposition is shown to yield simple solutions to several beam optimization problems including some with nonlinear constraints. A geometrical derivation of this result is presented which also provides new insights into the mechanism of null-steering via linear constraints. Application of this approach in conjunction with some search algorithms to the synthesis of optimum array patterns with prescribed narrow or broad nulls is shown to yield interesting and useful solutions. The results are illustrated by considering the design of circular and arc arrays.

1 illus, 1 table, 6 ref

008185   Sathi Reddy K;Linga Reddy D (Physics Dep, S.P. College, Secunderabad-500 025) : Ultrasonic and refractive studies of binary mixtures of aniline in different esters at 300.15 K temperatures. Acta Cienc Indica-Phys 2008, 34(3), 435-40.

Ultrasonic velocity (v), density (ρ), viscosity (η) and refractive index (n) for binary mixtures of Aniline with Methyl acetate, Ethyl acetate and Amyl acetate have been measured at room temperature of about 300.15 K, over entire volume component percentage range. The ultrasonic velocity (v) is measured, using ultrasonic Pulse Echo Overlap (PEO) technique, at a frequency of 2MHz, on Methyl acetate, Ethyl acetate and Amyl acetate, over entire volume component range. It is found that ultrasonic velocities are found to be increase in chain length of esters in binary mixtures of Aniline-Methyl acetate, Aniline- Ethyl acetate and Aniline-Amyl acetate. The relative merits are discussed in detail.

4 illus, 3 tables, 12 ref

008184   Rajnikant;Dinesh;Kamni;Sharma B;Lotus S;Gupta K (Condensed Matter Physics Group, Physics Dep, University of Jammu, Jammu Tawi-180 006) : A comparative crystallographic analysis of the X-ray structure of three cholest-based steroidal molecules. Indian J Chem-Sect B 2007, 46(11), 1855-9.

The molecular and crystal structures of (+)-4-cholsten-3-one 1 cholesteryl-chloroformate 2 and cholesteryl-caprylate 3 have been determined by using X-ray crystallographic and computational techniques. All the three compounds crystallize in the monoclinic space group P2₁ with unit cell parameters: a=10.683(5)Å, b=7.861(2), c=14.616(2), β=105.8(2)° for [1], a=12.294(2)%, b=9.399(8), c=12.787(2), °=113.3(1)° for [2] and a=12.778(9), b=9.201(4), c=14.063(6)Å, β=93.85(4)° for [3]. the number of molecules per unit cell in case of each structure is 2. The final R-factor for [1] is 0.054, [2] 0.077 and [3] 0.068. Besides some interesting geometrical and structural features, all the three molecules exhibit C-H...O hydrogen bonding. A comparative crystallographic analysis of all the three molecules has been reported.

2 illus, 2 tables, 16 ref

008183   Patra S (Physics Dep, G.B. Pant Univ of Agriculture and Technology, Pantnagar-263 145) : "Kubo formalism" a pedagogical theoretical approach to study the bulk properties of materials in the present day context. Acta Cienc Indica-Phys 2008, 34(3), 399-418.

Different methods are discussed to calculate the electrical resistivity of metals and dilute alloys incorporating the contribution of the electron-phonon interaction and also of the anharmonic processes. It is found that the electrical resistivity as calculated from the various methods may give rise to the additional terms depending on the decoupling approximations but it's temperature dependence remains the same. The simultaneous presence of the different scattering processes yields interference terms which may analyse the deviation from the Mattheissen's rule and it was applied to several physical phenomena.

6 illus, 37 ref

008182   Parivathini K;Bakkialakshmi S (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002) : On fluorescence quenching of pyrene by N, N-dimethylaniline (DMA) in sodium dodecyl sulfate (SDS). Acta Cienc Indica-Phys 2008, 34(3), 525-33.

In Application of fluorescence methods to study the fluorescence quenching of pyrene by N, N-dimethylaniline (DMA) in sodium dodecyl sulfate (SDS) at steady state condition have been carried out. The fluorescence quenching analysis reveals the binding of DMA with the surfactant micelles. The absorption and fluorescence spectra of pyrene with various quencher and surfactant concentrations were recorded successfully. The Stern-Volmer constant (Ksv) and the regression coefficient (r) have been evaluated from the plot. The Stern-Volmer plots for the quenching of pyrene by DMA is found to be linear and the constants (Ksv) depend on the micellar concentration. From the spectroscopic study it was observed that the Stern-Volmer plots are in linear and the regression analysis of the curves are in good correlation. Also the fluorescence quenching of pyrene is dynamic in nature. The important physico-chemical constants such as charge transfer energy, ionization potential, electron affinity, Stoke's shift and solvent parameter have also been evaluated from the spectra.

7 illus, 2 tables, 15 ref

008181   Pal M L;Singh V (Physics Dep, T.D.P.G. College, Jaunpur, Uttar Pradesh) : P-string solutions in the absence of magnetic field. Acta Cienc Indica-Phys 2008, 34(3), 431-4.

Consider a string-dust system in the absence of the magnetic field, in which case the field equations take the other form.

10 ref

008180   Kumar A (Physics Dep, M.L.S.M. College, Darbhanga-846 004) : Analysis of dielectric loaded spiral antenna. Acta Cienc Indica-Phys 2008, 34(3), 535-8.

In infinitesimally thin spiral antenna, sandwiched by bottom and top dielectric layers having the same relative permittivity, is analyzed under the condition that the dielectric layers are of finite extent and the antenna is backed by an infinite conducting plane. As the thickness of the top dielectric layer increases, the input impedance and axial ratio (AR) vary in an oscillatory fashion, with a period slightly larger than one-half of the guided wavelength of a wave propagating in an unbounded dielectric material. These oscillatory variations are reduced by adding a layer, called the "anti-reflection layer (ARL)", to the top dielectric layer. A representative spiral antenna with an ARL, shows a frequency bandwidth of approximately 11 % for a 3-dB AR criterion, having a gain of approximately 13 dBi and a voltage standing wave ratio of less than 1.2.

2 illus, 9 ref

008179   Karunakaran V;Ramanathan R (Physics Dep, Government Arts College, Ariyalur-621 713) : Fundamental acoustical parameters and intermolecular free length of L-glutamic acid in water. Acta Cienc Indica-Phys 2008, 34(3), 495-9.

The fundamental acoustical parameters which are ultrasonic velocity; density and viscosity are measured at 303K, 313K and 323K and its intermolecular free length is calculated at these temperatures for L-Glutamic acid which is a non essential amino acid. L-Glutamic acid exists in two polymorphic forms which are alpha and beta and if dissolved in water, these two forms co-exists and there is a transformation from alpha form to beta form. There is aggregation of these forms in aqueous medium and their aggregation is chaotic.

4 illus, 4 ref

008178   Karthikeyan S;Krishnamoorthy P;Rajasekaran R; Karthik S (Physics Dep, St. Joseph's College of Engineering, Chennai-600 119) : Spectroscopic study of characterisation of commercial drug paracetamol. Acta Cienc Indica-Phys 2008, 34(3), 419-26.

Paracetamol is chemically 4-hydroxy acetanilide or acetaminophen. It occurs as a white, crystalline solid having bitter taste. It is one of the best drugs to be used as antipyretic. Paracetamol is one of the most commonly used analgesic for headache, musculoskeleton pain, dysmenorrhea etc, where antiflammatory action is not required. An attempt has been made to study qualitative/quantitative analysis of pharmaceutical formulation using FT-IR and NMR spectroscopy. The intensity ratios of the sample, which characterize the polymorphism of the drug are well presented. The data's obtained from the study are supported with Nuclear Magnetic Resonance Spectroscopy (NMR). From the chemical shifts in the NMR spectra, the acetyl group, methoxy group and NH group attached to aromatic group have been confirmed. The study indicates that monoclinic form is dominant in the case of liquid form of paracetamol when compared to solid form of drug usage.

3 illus, 3 tables, 19 ref

008177   Jha B S;Jha H K (Univ Dep of Physics, L.N. Mithila Univ, Darbhanga, Bihar) : Analysis of the small fractal koch monopole antenna. Acta Cienc Indica-Phys 2008, 34(3), 441-6.

Fractal objects have some special geometrical properties. It can enclose in a finite area, an infinitely long curve. The resulting curve is highly convoluted being no where differentiable. The behaviour of the koch monopole is numerically analyzed. The results show that as the number of iterations on the small koch monopole are increased, the quality factor (Q) of the antenna approaches the fundamental limit for small antennas.

2 illus, 11 ref

008176   Jha B N;Ray K M;Thakur A K (Physics Dep, M.S.S.G. College, Areraj, Bihar) : Effect of weakly ionized plasma on radiation characteristics of circular microstrip antenna. Acta Cienc Indica-Phys 2008, 34(3), 511-18.

Theoretical investigation has been carried out to study the effect of plasma parameters on the radiation characteristics of circular microstrip antenna. For this purpose the array of circular microstrip antenna has been taken into account and the expression for E-plane and H-plane pattern has been developed in terms of plasma frequency. It has been found that the weakly ionized plasma has significant effect on directivity of antenna, however slight effect on radiation characteristics of array has also been found. The radiation starts to flap within certain solid angle with increasing value of ^ωp/ω.

3 illus, 8 ref

008175   Jayabharathi J;Shanthi B;Bakkialakshmi S (Chemistry Dep, Annamalai Univ, Annamalainagar-608 002) : Synthesis and spectral studies of t(3)ethyl-r(2), c(6)-DI-2' furylpiperidin-4-one and its oxime. Acta Cienc Indica-Phys 2008, 34(3), 369-73.

The IR, ¹H, ¹³C NMR and fluorescence spectra have been recorded for t(3)-ethyl-(2), c(6)-di-2'-furylpiperidine-4-one (1) and /(3)-ethyl-r(2), c(6)-di-2'-furylpiperidin-4-one(2) oxime. From the ¹H and ¹³C spectral data, the chair confirmation has been proposed for synthesis and spectral studies of t(3)-ethyl-r(2), c(6)-di-2' furylpiperidin-4-one(1) and its oxime(2). The effect of oximation on the chemical shifts have been discussed in detail and fluorescence spectra of <(3)-ethyl-r(2), c(6)-di-2' furylpiperidin-4-one and its oxime(2) have been studied.

5 illus, 1 table, 5 ref

008174   Gupta R N;Dubey S P;Jaiswal N;Yadava S;Gupta G K (Physics Dep, D.D.U. Gorakhpur Univ, Gorakhpur, Uttar Pradesh) : Temperature dependance of dielectric constant of potassium hexacyanoferrate trihydrate (II). Acta Cienc Indica-Phys 2008, 34(3), 341-4.

Temperature variation of dielectric constant of Potassium Hexacyanoferrate Trihydrate (II) has been measured by a capacitance bridge model Zenith M92A at a frequency of 1000Hz. The sample was kept in a furnace whose temperature was controlled at an accuracy of 1 C. The properly annealed sample shows a graded small peak at 57°C (ε = 158) and abrupt two adjacent peaks at the temperature of 154°C (ε = 1050) and 157°C (ε =1312) for the value of the dielectric constant. The stability of ferroelectric phase and the transition temperature of potassium hexacyanoferrate trihydrate (II) are very sensitive to mechanical stresses. The cooling curve however shows a similar nature for the value of the dielectric constant, of course much diminished value.

2 illus, 11 ref

008173   Gupta R N;Dubey S P;Jaiswal N (Physics Dep, D.D.U. Gorakhpur Univ, Gorakhpur, Uttar Pradesh) : Temperature variation of dielectric constant of mercuric acetate. Acta Cienc Indica-Phys 2008, 34(3), 427-30.

Variation of dielectric constant of Mercuric Acetate with temperature has been recorded from room temperature to high temperature (≈ 130°C) using a capacity bridge (model Zenith M92A) at a frequency of 1000 Hz. The sample was kept in a suitable furnace whose temperature was controlled with an accuracy of 1°C. It has been found that dielectric constant of the compound increases from low value (ε = 3) at 37°C to the high value (ε = 32) at 58°C. After that dielectric constant decreases and attains a value of 4 at temperature of 90°C. A slow fall in dielectric constant was observed thereafter upto the higher temperature of measurement. In cooling cycle however, the compound shows the low dielectric constant nearly 4 to 2 with small variation. The result of heating cycle can be explained on the basis of relaxor system in which the dielectric response has a broad peak as a function of temperature, rather than a sharp peak in the normal ferroelectrics. This class of ferroelectrics termed as relaxor ferroelectrics and their origin is very controversial and most likely due to hetrovalent behaviour.

1 illus, 16 ref

008172   Choudhary R (P.G. Dep of Physics, C.M. Science College, Darbhanga-846 004) : Aperture field of H-plane sectoral hollow dielectric horn antenna. Acta Cienc Indica-Phys 2008, 34(3), 481-7.

Theoretical analysis of the H-plane sectoral hollow dielectric horn antenna for the aperture fields has been presented. The exact determination of the aperture fields of the dielectric horn antenna is rather complicated due to complex nature of its boundary. The aperture field components have been obtained by solving the wave equation using the separation of variable technique and applying proper boundary conditions. Several simplifying assumptions have been made in order to get aperture fields of the Dielectric horn antenna. Theoretical value of one of electric field components (E_y1) over the front aperture has been computed and shown in graphs.

2 illus, 7 ref