017085   Ghosh D;Deb A;Biswas S;Mandal P;Haldar P K (Nuclear and Particle Physics Research Centre, Physics Dep, Jadavpur University, Kolkata-700 032) : Dynamical fluctuation of compound multiplicity in nucleus-nucleus interactions at 4.5 AGeV - evidence of projectile dependence of azimuthal asymmetry. Indian J pure appl Phys 2007, 45(12), 959-64.

Azinmuthal fluctuations in compound multiplicity (pions + target protons) spectrum emitted from nucleus-nucleus interactions initiated by ²⁴Mg-AgBr and ¹²C-AgBr both at 4.5 AgeV have been studied. The data exhibit the existence of emission asymmetry in the azimuthal plane for both the interactions. Asymmetry is found to depend on the number of compound multiplicity produced.

017084   Garg M;Quamara J K (Applied Physics Dep, National Institute of Technology, Kurukshetra-136 119, Email: jkquamara@yahoo.com) : FTIR analysis of high energy heavy ion irradiated kapton-H polyimide. Indian J pure appl Phys 2007, 45(7), 563-8.

FTIR spectroscopy technique has been applied for the analysis of high energy heavy ion irradiated kapton-H polyimide. The kapton-H samples were irradiated with 75 MeV oxygen, 80 MeV nickel and 50 MeV lithium ions at PELLETRON facility, Nuclear Science Centre, New Delhi. A very broad peak in 2500-3500 cm^-1 is due to the presence of absorbed water in irradiated samples. The reduction in the intensity of 1702 cm^-1 peak in irradiated samples as compared to pristine samples is associated to the demerization of carbonyl groups. The increase in the intensity of this peak with increase in fluence is due to the increase in cross-linked structure causing the reduction in demerization of carbonyl groups. The FTIR spectrum is independent of the nature of ion.

017083   Gajbhiye N S;Bhattacharyya S (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: nsg@iitk.ac.in) : Mossbauer and magnetic studies for the coexistence of ε-Fe_3-xNi_xN and γ'-Fe_4-yNi_yN phases in Fe-Ni-N nanoparticles. Indian J pure appl Phys 2007, 45(10), 834-8.

Nanocrystalline ε-Fe_3-xNi_xN (x = 0.5-0.8) particles are synthesized by precursor technique and nitridation of decomposed products in NH₃ (g) at 673 K. A small fraction of fcc γ'-Fe_4-yNi_yN phase (space group: P43m) is precipitated along with the formation of ε-Fe_1-xNi_xN hexagonal structure (space group: P6₃/mmc). The Mossbauer spectrum at room temperature for all the compositions shows the presence of superparamagnetic doublet, which is attributed to ε-Fe_3-xNi_xN phase and two sextets corresponding to the corner Fe (Fe^c) and fcc Fe (Fe^f), in γ-Fe_4-vNi_vN. The added Ni atoms preferentially substitute the Fe^c positions. The isomer shift, quadrupole splitting and hyperfine field values vary with the Ni content. The zero-field cooled (ZFC) and field-cooled (FC) curves indicate strong interparticle interactions and surface spin-glass-like state is realized from the low temperature features. The magnetization curves are saturated at 5 K, due to the dominating ferromagnetic nature of the <103><255>-Fe_4-yNi_yN phase.

017082   Gajbhiye N S (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: nsg@iitk.ac.in) : Electronic, Mossbauer and magnetic studies of self-assembled monodispersed FePt nanoparticles. Indian J pure appl Phys 2007, 45(10), 805-9.

The organic ligand encapsulated and bare 4 nm FePt particles, synthesized by wet chemical processing are studied for their structural, electronic and magnetic properties. The fcc phase is stable even above 833 K without any agglomeration and particle growth. The Mossbauer spectra recorded at 10 K for the as-prepared and annealed FePt nanoparticles reveal the presence of superparamagnetic and ferromagnetic fractions. The superparamagnetic blocking temperature decreases from 55 K to 10 K, after annealing at 623 K, due to the decrease in magnetocrystalline anisotropy and Fe-Pt-C is formed at the surface at elevated temperatures. Two distinct sextets are observed at 10 K with a large magnetic hyperfine field for one of the components. The 2D array of the nanoparticles and also the electronic and magnetic properties of the Fe sites are retained even after removing the organic ligand molecules.

017081   Dolia S N;Prasad A S;Dhawan M S;Subhash Chander;Sharma M P (Physics Dep, University of Rajasthan, Jaipur-302 004, Email: sndolia@uniraj.ernet.in) : Mossbauer study of nanoparticles of Co_0.4Zn_0.6Fe₂O₄. Indian J pure appl Phys 2007, 45(10), 826-9.

Two samples of nanoparticles of Co_0.4Zn_0.6Fe₂O₄ with the average particle sizes of 6 nm and 15 nm have been synthesized by chemical co-precipitation method and followed by heat treatment at 600°C. The cubic spinel structure in single phase has been confirmed by X-ray diffraction. The lattice parameters are 8.39 Å and 8.41 Å, respectively. ⁵⁷Fe Mossbauer spectra were recorded at 300 K and 80 K. Both samples are resolved in two patterns corresponding to two crystalline sites. The Mossbauer spectra and hysteresis curves for the two samples recorded at 300 K show superparamagnetic behaviour. The analysis of Mossbauer spectra reveal that the intensity of Fe³⁺ ions on both sites is nearly the same which indicate that the Zn²⁺ occupies the octahedral site in these samples.

017080   Digpratap S;Sushil K;Singh B P (Physics Dep, Institute of Basic Sciences, Khandari, Agra-282 002, Email: drbps.ibs@gmail.com) : Pressure-volume-temperature relationship for diatomic solids based on inverted and non-inverted equations of state. Indian J pure appl Phys 2007, 45(9), 721-5.

The pressure-volume-temperature (P-V-T) relationship using inverted and non-inverted equations of state (EOS) for diatomic solids such as NaCl, MgO and LiH has been studied. It is found that the inverted type EOS due to Roy and Roy [Physica B, 350 (2004) 1945.] yields close agreement with the results obtained from the non-inverted equations due to Rydberg [J Phys, 73 (1932) 376.], Shanker et al.[Physica B, 271 (1999) 158], Hama and Suito [J Phys, 8 (1996) 67.] for isothermal compressions as well as isothermal bulk modulus. The Roy - Roy inverted EOS has been found to have an additional advantage of predicting volumes for a solid at simultaneously elevated pressure and temperature. Uses this EOS to obtain P-V-T results for NaCl and MgO. The calculated values present close agreement with the experimental data.

017079   Digpratap S;Rakesh K;Arunesh K (Physics Dep, Institute of Basic Sciences, Khandari, Agra-282 002) : Analysis of temperature dependence of thermal pressure of solids. Indian J pure appl Phys 2007, 45(8), 654-7.

Thermal pressure is an important physical quantity playing the central role in the evaluation of high temperature equations of state for solids. Recently, Kumar and Singh, [Indian J Phys, 78 (2004) 1225] have studied several formulations for the temperature dependence of thermal pressure demonstrating the inadequacies of the models developed by earlier researchers. It is emphasized in the present work that the method adopted by Kumar and Singh is seriously flawed and inconsistent with the recent findings. The Suzuki formulation for volume thermal expansion has been derived correctly and found to be in close agreement with the experimental data on thermal pressure for various solids considered by Kumar and Singh.

017078   Devi R;Purkayastha P;Kalita P K;Sarma R;Das H L;Sarma B K (Physics Dep, Guwahati College, Guwahati-781 021) : Photoelectric properties of CdS thin film prepared by chemical bath deposition. Indian J pure appl Phys 2007, 45(7), 624-7.

Cadmium sulphide thin films deposited on glass substrates are found to be polycrystalline having hexagonal type structure. The photocurrent-light intensity characteristics show sub-linear and super-linear behaviour which are attributed to the defects . The defect characterization is done from the temperature dependence of dc photoconductivity and rise and decay characteristics of the photocurrent. shallow levels (0.06 to 0.34eV) arising from interstitial cadmium or sulphur vacancies are found to cause extrinsic photoconductivity near room temperature whereas the deep levels dominate the rise and decay characteristics and superlinearity.

017077   Das N C;Lahiri D;Bhattacharyya D (Spectroscopy Div, Bhabha Atomic Res Centre, Mumbai-400 085) : Focusing properties of energy dispersive exafs beamline at indus-2 SRS using additional optical elements. J Optics 2007, 36(1), 8-21.

An extended X-ray Absorption Fine Structure (EXAFS) beamline using a bent crystal polychromator is being developed at INDUS-2 Synchrotron Radiation Facility. One of the proposed activities with this beamline is to record the EXAFS spectra of materials under high pressure. For this purpose x-rays originating from the synchrotron source are to be perfectly focused on the experimental samples having sizes of the order of few micrometers. Extensive ray tracing work has been carried out for studying the imaging properties of this beamline using the software program SHADOW. It has been found that the desired focal spot size can be achieved when some additional mirrors in the form of elliptic cylinders are included in the beamline lay-out.

12 illus, 2 tables, 25 ref

017076   Chitra K;Ravichandran V C (ECE Dep, Coll of Engng, Anna Univ, Chennai-600 025) : Balanced detection of turbo-coded optical PPM CDMA system. J Optics 2007, 36(2), 57-67.

The performance of coherence multiplexed(CM) turbo-coded optical PPM CDMA network is evaluated in terms of bit-error-rate (BER), number of users (K) and for various interleaver lengths (N) taking into account the effects of the thermal noise ad shot noise of APD detectors. For a fixed K (=10), the BER of a CM system is reduced by an order of 10-⁵ than that of the single-ended direct detection system. For a typical data rate of 1 Gb/s, and a specified BER of 10^-6, it is found that the number of simultaneous users increases to 50. Turbo decoding is done using Log-ªMAP algorithm with different interleaver lengths of N=l0, 50, 100 resulting in the reduction of BER to 10^-9, 10^-10 and 10^-11 respectively and by applying performance bounds on the turbo-coded system, the maximum number of iterations to reach a BER of 10^-144 are limited to four in this system.

10 illus, 1 table, 8 ref

017075   Chhantbar M C;Gismelseed A;Modi K B;Baldha G J;Yousif A;Joshi H H (Physics Dep, Saurashtra University, Rajkot-360 005) : <. Indian J pure appl Phys 2007, 45(10), 856-9.

⁵⁷Fe M”ssbauer effect (ME) was studied at 295K and 77K on the polycrystalline samples of the spinel oxide system Li_0.5(1+x)Cr_0.1Fe_2.4-1.5xO4 (x = 0.0 to 0.5) synthesized by double sintering ceramic technique. The chemical stoichiometry of the final products was ascertained by EDAX. The X-ray diffractometry (XRD) showed that all the samples were single-phase cubic spinels. The cell edge parameter, α (Å) for each composition was found by XRD-pattern indexing and using the Nelson-Riley method. The distribution of cations in the spinel was determined through XRD intensity analysis using the computer programme. The saturation magnetization for each composition was recorded using hysteresis loop tracer at the applied field of 4kOe. The Mossbauer spectra exhibit two Zeeman sextets due to different fields at tetrahedral (A) and octahedral (B) Fe³⁺ ions. The ME parameters are deduced using the NORMOS software and the observed hyperfine interaction parameters are explained in the light of cation distribution determined through XRD, magnetization and Mossbauer spectroscopic studies.

017074   Chakraborty B (Res and Development Div, Mecon Ltd, , Ranchi-834 002) : Effect of detector gamma on the brightness scale of a CCD camera. J Optics 2007, 36(3), 153-5.

A simple experiment is performed to observe the relationship between image brightness and the signal produced by a CCD camera interms of gray values. The camera is alternately adjusted for linear and square root gamma mode and the transfer junction relating image brightness and the CCD gray values are found to change accordingly.

2 illus, 1 ref

017073   Calla O P N;Bohra D;Mishra S K;Alam M; Hazarika D;Ramawat L (NO, International Centre For Radio Science, "OM NIWAS" A-23, Shastri Nagar, Jodhpur-342 003) : Effect of microwave radiation on the electrical parameters of soil. Indian J Radio Space Phys 2007, 36(3), 229-33.

Presents the study of the effect of microwave radiation on dry soil. For this, five different soil samples were collected from various geographical regions of India. The waveguide cell method was employed for the determination of the storage factor (ε') and the loss factor (ε") of the soils. In this paper the methodology of measurement of dielectric constant for unexposed and exposed soils to microwave radiation is given and the results obtained are discussed.

017072   Borah M N;Chaliha S;Sarmah P C;Rahman A (Physics Dep, Regional Research Laboratory, Jorhat-785 006, Email: pratap_sarmah@yahoo.com) : Electrical properties of thermally evaporated doped and undoped films of CdSe. Indian J pure appl Phys 2007, 45(8), 687-91.

Electrical characteristics of Ag-doped and undoped films of CdSe have been reported. The activation energies at lower and elevated temperatures have been found to be 0.22 and 0.6eV, respectively. The Sn/CdSe junction exhibits Schottky barrier characteristics with diode ideality factor deviating from unity. Barrier height obtained from C-V plot and J-V plot are 0.8 and 0.72eV, respectively. The junction has been endowed with high series resistance.

017071   Bhowmik R N;Ranganathan R (Experimental Condensed Matter Physics Div, Saha Institute of Nuclear Physics, Calcutta-700 064) : Mossbauer spectroscopy: an essential tool for nanoparticle magnetism in Co_0.2Zn_0.8Fe₂O₄ ferrite. Indian J pure appl Phys 2007, 45(10), 810-5.

Magnetism in Co_0.2Zn_0.8Fe₂O₄ nanoparticles, prepared by mechanical activated process and chemical (co-precipitation) process has been reported. Experimental data showed that magnetic behaviour in mechanical activated nanoparticles (MANP) is drastically different in comparison with the nanoparticles (CPNP) prepared by chemical route. For example, MANP exhibited enhancement in both magnetization and ferrimagnetic order, whereas CPNP shows the reduction in both magnetization and magnetic order. The magnetic evolution during thermal activated grain growth process is also different for samples with smaller particle size, whereas magnetic behaviour for larger particle size is similar for both nano particles and approaching to the properties of bulk system. Understands the co-existence of various competitive effects during grain growth process employing Mossbauer spectroscopy, dc magnetization and ac susceptibility measurements.

017070   Bhatu S S;Lakhani V K;Tanna A R;Vasoya N H; Buch J U;Sharma P U;Trivedi U N;Joshi H H;Modi K B (Physics Dep, Saurashtra University, Rajkot-360 005, Email: kunalbmodi2003@yahoo.com) : Effect of nickel substitution on structural, infrared and elastic properties of lithium ferrite. Indian J pure appl Phys 2007, 45(7), 596-608.

The structural and elastic properties of Li_0.5(1-x)Ni_xFe_2.5-0.5xO₄ (x = 0.0-1.0) spinel ferrite system have been studied by means of X-ray diffraction and infrared spectroscopic measurements at 300K. The X-ray diffraction data has been used to determine the lattice constant, X-ray density, distributions of cations among the tetrahedral and octahedral sites of spinel lattice, anion parameters, site radii, ionic radii, bond angle and bond length. The nature and change in the position of IR bands have been explained on the basis of cations involved in the system. The force constants have been used to calculate elastic moduli like bulk modulus, rigidity modulus, Young's modulus, Poisson's ratio, Debye temperature and corrected to zero porosity. The observed variation of elastic constants with nickel substitution has been explained on the basis of strength of interatomic bonding. The applicability of heterogeneous metal mixture rule for estimating elastic constants has been tested. The Debye temperature obtained from elastic constant data is higher than that of the X-ray diffraction analysis, mainly due to existence of peaks in the vibrational spectra at lower frequencies.

017069   Bhatt S C;Singh K;Uniyal M;Om Prakash;Singh P K;Saxena R;Semwal B S (Physics Dep, H N B Garhwal University, Srinagar, Srinagar Garhwal,Uttaranchal-246 174) : Temperature dependence of dielectric properties of sodium potassium niobate ceramics. Indian J pure appl Phys 2007, 45(7), 609-12.

Dielectric constant, loss tangent and electrical conductivity of Na_0.5K_0.5NbO₃ (SPN) ceramic pellets have been measured at 10, 100 and 1000 kHz frequencies and at temperature varying from room temperature to 250°C. The dielectric constant increases with increase of temperature up to 190°C at all the three frequencies, and thereafter, it decreases with further increase of temperature, i.e., it shows a structural transition at about 190°C. The loss tangent also shows similar behaviour as dielectric constant shows. Some variations may be due to relaxation effects and impurities etc. around the sensitive transition region, which are seem to play prominent role in this soft mode region. Electrical conductivity increases with increase in temperature at all the three frequencies.

017068   Bhat N V;Nate M M;Bhat R M;Bhatt B C (NO, The Bombay Textile Research Association, L.B.S. Marg, Ghatkopar (W), Mumbai-400 086) : Effect of γ-irradiation on polyvinyl alcohol films doped with some dyes and their use in dosimetric studies. Indian J pure appl Phys 2007, 45(6), 545-8.

Using polyvinyl alcohol (PVA), water-soluble polymer, thin films were prepared by incorporating some dyes. On subjecting these films to γ-radiation, it was found that there is a gradual change in the colour. In case of PVA film containing methyl red sudden discolouration occurs at a dose of 30 kGy, however, optical density change was not very contrasting. In case of acid red-4, there is a gradual fading of the red colour in the dose range 10-55 kGy. The PVA film (control) without dye shows development of brownish shade. These changes can be explained in terms of scission of main chain, liberation of the H and OH radicals and their interactions with the dye molecules. It is shown that these films can be used as cheap, portable and reliable plastic detectors for dosimetry.

017067   Basu J (Applied Optics and Photonics Dep, , 92, A.P.C. Road, Univ of Calcutta) : Study of physical parameters of diffractive optical elements fabricated using single exposure technique. J Optics 2007, 36(2), 98-109.

Photoresists have the property of light sensitivity, which has brought about revolutionary changes in electronics industry, and are now being routinely used in the fabrication of Diffractive Optical Elements (DOEs), for wide spread applications in designing sophisticated optical systems, in optoelectronics and other fields of modem optics. A technique for the fabrication of DOEs is described which combines the principles of colorimetry and computer graphics to fabricate primary masks, that has yielded wonderful results. The physical characteristics like the width and depth of the fine structures fabricated using this method have been analysed to gain insight into the accuracy of the methodology.

5 illus, 3 tables, 8 ref

017066   Basu A (Electronic Materials Div, National Physical Lab, New Delhi-110 012, Email: abasu@mail.nplindia.ernet.in) : Anomaly in optical thickness monitoring of a quarterwave thin film multilayer stack - its cause and how to avoid it. Indian J pure appl Phys 2007, 45(11), 920-5.

During the optical monitoring of a quarterwave thin film optical multilayer stack being deposited sequentially on a substrate in a deposition chamber, the intensity of the light beam transmitted through or reflected from the monitoring plate goes through a series of turning points (maxima and minima). The deposition of a film is stopped at a turning point in order to obtain a quarterwave thick film at the monitoring wavelength. In most of the cases, the maxima and minima occur sequentially. However, during the deposition of some quarterwave multilayer stacks a maximum is not followed by a minimum (or vice versa) during the deposition of successive films. Rather, the intensity may change slightly in the opposite direction to that which is expected or not change appreciably, making the monitoring of the deposited film thickness difficult, if not impossible. This occurs when the effective refractive index of the multilayer stack is very close to the refractive index of the film to be deposited next. Either an alternative method of monitoring the thickness of that particular film has to be adopted, or fresh monitoring plates have to be used at crucial stages during the sequential deposition of the multilayer stack.

017065   Banerjee P;Chatterjee A;Suman (Time and Frequency Section, National Physical Lab, New Delhi-110 012, Email: pbanerjee@mail.nplindia.ernet.i) : Determination of Allan deviation of Cesium atomic clock for lower averaging time. Indian J pure appl Phys 2007, 45(12), 945-9.

Absolute Allan deviation of the Cesium clock for averaging time (τ) of 5 days or more may be calculated from the corresponding data of circular T published by Bureau International des Poids et Mesures (BIPM). For lower values of τ, the Allan deviation may indirectly be found from the extrapolation of these values through τ^-1/2 fit as recommended by CCTF-WGMRA guidelines. Absolute Allan deviation may also be directly found out by inter-comparison of minimum three clocks assuming that the noise in all clocks is fully uncorrelated. This paper analyses the values of Allan deviation determined by the direct method keeping in mind the limitation of the measurement system. These values of Allan deviation tally well with those found from the data of circular T.

017064   Aydinol M (Atomic and Molecular Physics Section, Physics Dep, Faculty of Sciences, University of Dicle, Diyarbakir, Turkey, Email: aydinolm@dicle.edu.tr) : X-ray production and ionisation cross-sections of K shell of argon by electron impact near threshold region. Indian J pure appl Phys 2007, 45(8), 641-6.

Excitation of argon by electron impact yielded characteristic X-rays and bremsstrahlung. They are simultaneously measured and analysed for several electron impact energy values. The X-ray yield ratio, Kα1,3/Ka1,2, for the electron impact energy values of 7 <60> Ee <60> 11 keV is equal to (0.104 ± 0.016) and is in agreement with the given value by Salem et al., Atomic Data Tables, 14 (1974)91. Characteristic X-ray yields of Ka1,2 and Ká1,3 lines of argon, increase rapidly as the electron impact energy values increase from 3,5 to 11 keV. The K shell ionisation cross-section results are compared with an earlier experimental results on argon K shell ionisation given by Dolgov-Savalev and Panchenko [Opt-spectro (1970) 575]. K shell ionisation cross-section dependency to the electron impact energies is found to be similar and shows rapid increase starting from near threshold energy to 11 keV. The effects of simultaneously produced competing radiationless yields on to the Ka1,2 and Ká1,2 X-ray line yields of argon, have been investigated.

017063   Aruna S;Anuradha A;Thomas P C;Mohamed M G; Rajasekar S A;Vimalan M;Mani G;Sagavaraj P (Physics Dep, Loyola College, Chennai-600 034) : Growth, optical and thermal studies of L-arginine perchlorate-a promising non-linear optical single crystal. Indian J pure appl Phys 2007, 45(6), 524-8.

Optically good quality single crystal of L-arginine perchlorate (abbreviated as LARPCL), a promising analog of LAP was successfully grown by slow solvent evaporation technique at room temperature. The grown crystals were characterized by single crystal XRD, FTIR, FT-Raman, optical absorption and SEM studies. The thermal stability of the crystal was studied by TG, DTA and DSC analysis. The scanning electron microscopy (SEM) provides information about the surface morphology of the sample. The SHG efficiency is estimated using Kurtz powder method.

017062   Anand S;Verma H C (NO, Regional Research Laboratory, Bhubaneswar-751 013) : Application of <. Indian J pure appl Phys 2007, 45(10), 800-4.

The ores and concentrates utilized for non ferrous metal extraction through hydrometallurgical processing contain iron in different forms. During processing iron gets distributed in various streams such as leach solution, leach residue and precipitated iron cake/impurities. Many secondary high iron containing materials such as iron scrap, blue dust etc. can be used to produce specific value added products such as ferrites and iron oxides. ⁵⁷Fe Mossbauer spectroscopy can be applied to understand the phases of iron in such processes. Gives a few examples of useful information derived from Mossbauer spectroscopy during studies on conversion of goethite to magnetite, synthesis of hematite and dissolution of Cu, Ni and Co from matte obtained by smelt-reduction of manganese nodules.

017061   Akhare V P;Burghate D K;Deogaonkar V S (NO, Shri Shivaji Science College, Amravati-444 603) : Copolymer formation through ultrasonic and viscosity measurements. Indian J pure appl Phys 2007, 45(12), 984-6.

Ultrasonic velocity (U), viscosity (η), adiabatic compressibility (β_a) and viscous relaxation time (τ) have been measured in binary mixtures of polyvinyl chloride (PVC) and polyvinyl acetate (PVAc) in tetrahydrofuran (THF) at different temperatures 298, 303, 308, 313 and 318K at frequency 2 MHz. The observed maxima in ultrasonic velocity, viscosity, relaxation time and minima in adiabatic compressibility are attributed to molecular interactions between PVC and PVAc due to proton donor-acceptor interactions.

016096   Venkatram Reddy B;Raman Rao G (Univ P.G. Coll, Kakatiya Univ, Godavarikhani-505 209, Email: bvreddy67@yahoo.com) : Transferable valence force fields:the case of out of plane vibrations of dimethoxybenzenes. Asian J Phys 2007, 16(1), 29-32.

A zero-order normal coordinate analysis of out-of-plane vibrations was made for p-, m- and o- dimethoxybenzenes by transferring the force constants from our earlier work. The observed and calculated frequencies agree with an average error of 13 cm^-1 demonstrating the transferability of the force field. Unambiguous vibrational assignments have been made using the potential energy distributions and eigen vectors, for the three molecules. Several assignments suggested by earlier workers have been revised.

2 tables, 7 ref

016095   Singh K M;Singh T J (Mathematics Dep, Manipur Univ, Canchipur, Imphal-795 003) : Slowly rotating model universes of massive scalar filed in general relativity. Asian J Phys 2007, 16(1), 49-56.

In the course of presentation of some new interesting analytic solutions, the dynamics of slowly rotating model universes of massive scalar field are investigated, and their physical and geometrical properties are studied from all angles. The rotational perturbations of such models are examined in detail in order to substantiate the possibility that the universe is endowed with some rotation. The nature and role of the rotational velocity Ω (r,t) which is related to the local dragging of inertial frames and that of the matter rotation ω(r.t) are studied for uniform and non-uniform motions. Also the effects of the scalar field on the rotational motion are discussed for all possible cases. We find out the restrictions on the radii of the models for real astrophysical situations, and the periods of physical validity of them are also studied. Rotating models which are expanding as well as are obtained here, in which cases the rotational velocities are found to decay with time, and these models may be taken as good examples of real astrophysical situations.

36 ref

016094   Shrivastava P K (Physics Dep, Govt. Model Science College, Rewa-486 001, Email: pankaj_in_2001@rediffmail.com) : Effects of interplanetary coronal mass ejections on cosmic ray intensity variation. Asian J Phys 2007, 16(1), 91-3.

In this study, 69 events of Interplanetary Coronal Mass Ejections (ICMEs) have been used to derive their effects on cosmic ray intensity for the period of 1997 to 2002. Daily values of Kiel neutron monitor have been taken in chree analysis. Results of our analysis suggest that ICMEs produce short-term transient decreases in cosmic ray intensity.

1 illus, 8 ref

016093   Sharma S K;Gupta R S (Physics Dep, Govt PG College, Satna-485 001) : Temperature dependence of lyoluminescence of maltose. Asian J Phys 2007, 16(1), 87-8.

Effect of temperature on the lyoluminescence (LL) of gamma irradiated Maltose (saccharide) has been measured using photomultiplier tube and X-Y recorder with high voltage power supply. It is found that decay time does not depend on the dose. It has also been observed that LL intensity decreases with increasing temperature of solvent. It is concluded that more collisional pairs are formed at higher temperature, leading to non radiative transition and thus LL intensity decreases with increasing temperature of solvent.

2 illus, 3 ref

016092   Salehi M R (Shiraz Technology Univ, Modarres Boulevard, P.O. Box 313, Code 71555, Shiraz, Iran, Email: salehi@sutech.ac.ir) : Analysis of IRIN in microwave optical links. Asian J Phys 2007, 16(1), 57-62.

The direct relative intensity noise (DRIN) is compared with the interferometric relative intensity noise (IRIN) caused by phase-to-intensity (P-I) noise conversion. Presents theoretical calculations and experimental results on conversion of FM noise to intensity noise in an RF-optical link which uses an unbalanced Mach-Zehnder interferometer (UMZI) and a 1550 nm distributed feedback (DFB) laser. The IRIN is derived by considering all effects such as the white noise and optical fiber dispersion The experimental and numerical results of DRIN and IRIN in an optical link are shown with good agreement.

4 illus, 9 ref

016091   Ramakumar B;Babin P (NO, Central Manufacturing Technology Institute, Tumkur Road, Bangalore, Email: brk@cmti-india.net) : Electromagnetic forming. Mfg Technol Today 2007, 6(1), 23-7.

Electromagnetic forming is a process of metal forming using electromagnetic forces, generated by pulsed current passing through a magnetic coil. This article is collective information on this process which has lot of potential in the area of automobile, medical, aerospace, nuclear etc. yet to be fully exploited in the country.

5 illus

016090   Rai B K;Kostova I;Ojha S P;Tomar R;Rastogi V K (Chemistry Dep, LNT College, (BRA Bihar Univ), Muzaffarpur-842 002, Email: binodkr_rai@yahoo.co.in) : Synthesis and spectral studies of Co(II), Ni(II) and Cu(II) complexes with Schiff bases derived from 2-methyl-thioquinazolin-4(3H) one. Asian J Phys 2007, 16(1), 23-7.

Mixed ligand Schiff base complexes of the type [M(MTSC)₂X₂] and [M(MTTSC)₂X₂]. where M = Co(II). Ni(II) and Cu(II), MTSC = 2-methyl-thioqionazolin-4(3H) one semicarbazone. MTTSC = 2-methyl-thioquinazolin-4(3H) one thiosemicarbazone and X = Cl^-, Br^- and I^- have been isolated. The ligands and complexes have been characterised by elemental analysis, infrared and electronic spectra, magnetic susceptibility and conductivity data. On the basis of l.R. spectra, the ligands. MTSC and MTTSC have been proposed to act in a bidentate manner, co-ordinating to the metal ions through the azomethine nitrogen and oxygen/sulphur atoms of either semicarbazone or thiosemicarbazone moiety. The remaining co-ordination sites are occupied by anions such as Cl^-, Br^- and I^-. Electronic spectral and magnetic susceptibility data proposed octahedral geometry of the complexes around the central metal ion. The complexes were found to be non-electrolytic in nature.

2 tables, 24 ref

016089   Rai B K (Chemistry Dep, LNT College, (B R A Bihar Univ), Muzaffarpur-842 002, Email: binodkr_rai@yahoo,co.in) : Synthesis and spectral studies of Co(II), Ni(II)and Cu(II)complexes with 2-methyl-[-3(hydroxy propyl)]-3,1-(4H) quinazolin -4- one semicarbazone and thiosemicarbazone. Asian J Phys 2007, 16(1), 71-5.

Transition metal complexes of Co(II), Ni(II) and Cu(ll) metal ions with 2- methyl - [-3- (hydroxy propyl)]-3. 1-(4H) quinazolin-4-one semicarbazone (MHQS) and 2-methyl [-3-(hydroxy propyl)]-3, 1-(4H) quinazolin-4-one thiosemicarbazone (MHQTS) have been synthesised and characterised by elemental analysis, molar conductance, ir and. electronic spectra and magnetic susceptibility measurements. The elemental analysis data shows that the complexes have 1:2 stiochiometry of the type [M(MHQS)₂] and [M(MHQTS)₂]; where M = Co(II). Ni(II) and Cu(II). The magnetic moment data along with ir and electronic spectral data propose the octahedral geometry of the complexes.

1 illus, 2 tables, 24 ref

016088   Pauly F;Sandfuchs O;Kaiser F;Belic M (Institute for Theoretical Solid State Physics, Kalsruhe Univ, 76128 Karlsrule, Germany) : Modulation depth in photorefractive two wave mixing. Asian J Phys 2007, 16(1), 33-47.

High modulation depth effects in contra-directional two-wave mixing in photorefractive crystals are investigated. A modified two-wave mixing model is used that includes a correction function for the high modulation depth. Transverse instabilities arise when the modulation depth at one side of the crystal is close to unity, hence high modulation depth effects must be taken into account. In the near field transverse running waves appear above the instability threshold. A physical justification for the correction function is presented, by analyzing Kukhtarev's material equations. For static gratings a real and superlinear correction function is found, whereas for running gratings a complex correction function with a sublinear real part is obtained.

9 illus, 27 ref

016087   Pankaj A K;Sinha K K (Univ Chemistry Dep, T M Bhagalpur Univ, Bhagalpur-812 007, Email: kkmsinha@samcjarmet.in) : Mossbaure, EPR,IR and XRD studies of Fe-doped ceramic dielectric. Asian J Phys 2007, 16(1), 83-6.

Polycrystalline ceramics like Pb₁-xFe_xTiO₃, where x = 0.05, 0.1. 0.3 have been synthesised and their Mossbauer, EPR, IR and XRD spectra are recorded at room temperature. The XRD spectral analysis indicates that the product materials are in the orthorhombic structure. The Mossbauer. EPR and IR spectra give information about structural changes, local distorsion and vibrational modes in the materials.

5 illus, 5 ref

016086   Malekfar R;Rezvani Jalal M (Physics Dep, Faculty Basic Sciences, Tarbial Modarres Univ, P.O. Box 14115-175, Tehran.I.R. Iran, Email: Malekfar@Modares.ac.ir) : The study of raman, FT-IR reflection and transmission spectroscopy of acidic α liIO₃ crystal and its birefringence properties. Asian J Phys 2007, 16(1), 11-16.

α LiIO₃ crystal has found wide spread applications in second harmonic generation, nonlinear optics, one dimensional ionic conductors and acousto-optic modulators especially in the visible and near infrared region. This crystal was grown from acidic saturated solution of LilO₃ salt by the method of slow evaporaiion of isothermal solution with about 1 x 1 x 2 cm³ dimensions, In the visible region this crystal is transparent and is a negative uniaxial crystal. The Raman, FT-IR reflection and transmission spectra of this crystal from both surfaces parallel and perpendicular to the crystal optical axis were obtained. With the help of Kramers - Kronig relations of reflection the ordinary and extra- ordinary refractive indices in the 400 - 4000 cm^-1 region were calculated and it was shown that in this range and particularly in the 700 -900 cm^-1 region, this crystal converts to a positive uniaxial crystal. The imaginary part of the refractive index and the electrical susceptibilities of the crystal in the mentioned directions and in the 400 - 1000 cm^-1 region were also calculated.

5 illus, 10 ref

016085   Malekfar R;DaRaei A;Abassi B (Physics Dep, Faculty of Basic Sciences, Tarbiat Modarres Univ, P.O. Box 14115-175, Tehran.I.R. Iran, Email: Malekfar@Modares.ac.ir) : The investigation of phase transitions of TGS crystal doped with cobalt phosphate by Raman scattering spectroscopy at low temperatures. Asian J Phys 2007, 16(1), 17-21.

Authors doped cobalt phosphate to triglycine sulphate (TGS) crystal in order to improve the characteristic properties of this family of crystals. The grown pure and doped TGS crystals with different percentage of doping up to 9% of weight have been investigated by Raman spectroscopy at low temperatures down to 10.3 K. In this paper, we report the Raman data for TGS:PCo (9% w) crystal. By comparing the Raman spectra at low temperatures down to 10.3 K two phase transitions at 100 K and 45 K have been clearly observed. These phase transitions are obvious from the displacements of the Raman peaks at different temperatures The addition of cobalt phosphate in the structure of pure TGS crystal is the main reason for changing the phase transition temperatures from 110 and 60 K to 100 and 45 K in pure and TGS:PCo (9% w) crystals, respectively.

4 illus, 20 ref

016084   Konwar M;Mahanta R;Siam C;Baruah G D (Physics Dep, Dibrugarh Moran College, Sibsagar-785 670, Email: gdbaruah@rediffmail.com) : A study of the fluctuating patterns of Brownian motion using light scattering in some colloidal suspensis. Asian J Phys 2007, 16(1), 63-9.

Describes the nature of Brownian movement exhibited by colloidal suspensions. In the experiment we have used 5mW He-Ne laser light at 6328A and also Ar⁺ laser light (green) to illuminate a sample cell containing the liquid with colloidal suspensions of medicinal plants. The intensity fluctuations of the Brownian movements are measured with the help of silicon photodiodes placed at particular positions and connected to a sensitive digital multimeter. The readings are recorded with the help of a video camera [Model DCR-TRV 460 E Sony]. The records of the fluctuations are taken for about two minutes and are transferred to a computer. The fluctuating patterns per second are worked out with the help of a computer and they indicate the nature of particular colloidal suspensions. A computer software has been used to work out the intensity patterns in both two and three dimensions. The intensity fluctuating patterns per second also exhibit the time dependence of the random force F_y(t), which are characteristics of Brownian motion. The sizes of the colloidal particles responsible for random motion are estimated.

4 illus, 5 ref

016083   Kariyappa R;Varghese B A;Dame L (Indian Inst of Astrophys, , Bangalore-560 034, Email: rkari@iiap.res.in) : Variation in area and intensity of the solar chromaospheric network elements and their contribution to UV irradiance variability. Asian J Phys 2007, 16(1), 1-9.

Segregats (i) plages, (ii) magnetic network, and (iii) intranetwork + the background regions from the Call K spectroheliograms of-1980-and 1992, observed at the National Solar Observatory at Sacramento Peak, using their histograms taken for the full-disk. The different parameters like the intensity and area of the chromospheric features, the full-disk intensity (spatial K index), and the full width at half maximum (FWHM) of the histograms [1], have been derived from the images. The spatial K index, FWHM, and the intensity of various features have been compared to the UV irradiance measured in the Mgll h and k lines by the Nimbus7 and NOAA9 satellites and it has been found that they are correlated with the Mgll h and k c/w ratio. We established, for the first time, from the results of 1992 images [1] and of 1980 that the FWHM can be used as a good index for measuring and describing the chromospheric activity in the K-line. The results of both 1980 and 1992 images show an anticorrelation between the intensity and area of the network elements, which confirm the earlier findings derived entirely from different data set from Kodaikanal Call K spectroheliograms analyzed for the center of the solar disc in a quiet regions for a longer time interval of 1957 to 1983 [2]. During solar minimum the network is fainter but covers a larger area than during solar maximum. These results suggest that the variations in both the intensity and area of the various chromospheric features have to be taken into account in irradiance models.

5 tables, 24 ref

016082   Joseph B;Menon C S (School of Pure and Applied Physics, Mahatma Gandhi Univ, Kottayam-686 560, Email: bennyanugraha@yahoo.com) : Studies on the optical properties and surface morphology of cobalt phthalocyanine thin films. E J Chem 2008, 5(1), 86-92.

Thin films of Cobalt Phthalocyanine (CoPc) are fabricated at a base pressure of 10^-5 rabar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. The present studies reveal that the optical band gap energies of CoPc thin films are almost same on substrate temperature variation. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM), which show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM) intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are needle like, which are interconnected at high substrate temperatures. The optical band gap energy is almost same on substrate temperature variation. Trap energy levels are also observed for these films.

5 illus, 3 tables, 25 ref

016081   Irimia A (Physics and Astronomy Dep, Vanderbilt Univ, Nashville, Tennessee, 37235, USA) : Forbidden transition probabilities of astrophysical interest among low-lying states of V III. J Astrophys Astr 2007, 28(2-3), 157-66.

Electric and magnetic multi pole transitions among lowªlying states of doubly ionized vanadium were computed using the multi-configuration Hartree-Fock (MCHF) method with Breit-Pauli (BP) corrections to a non-relativistic Hamiltonian. Energy levels were deterªmined up to and including 3d² (¹G)4s b ²G_7/2 and computed energies were found to be in good agreement with experiment and other theories. In addition to Einstein A_ki coefficients for some E2 and Ml transiªtions, lifetime data and selected weighted oscillator strengths are also reported.

5 tables, 37 ref

016080   Herczfeld P R;Tewari D P;Fischer M (Electrical Engineering Dep, Drexel University, Philadelphia, Pa 19104, USA) : Study of passive cooling by water evaporation on a roof assisted by forced convection. Asian J Phys 2007, 16(1), 95-6.

2 ref

016079   Dehingia N;Changmai R;Baruah G D (Physics Dep, Dibrugarh Univ, Dibrugarh-786 004) : On the nature scatting of some tea samples of Assam. Asian J Phys 2007, 16(1), 80-2.

Scattered radiation at wavelength 6328 Angstrom from nine samples of blended tea solutions of different qualities have been investigated. Intensity measurements of the radiations indicate a possible correlation with the quality of the sample.

1 illus, 1 table, 3 ref

015174   Wadehra A;Deb B M (Physics Dep, Ohio State Univ, Columbus, OH 43210, Email: bmdeb@yahoo.co.in) : Time-dependent quantum fluid density functional theory of hydrogen molecule under intense laser fields. J chem Sci 2007, 119(5), 335-41.

A time-dependent generalized non-linear Schrodinger equation (GNLSE) of motion was earlier derived by combining density functional theory and quantum fluid dynamics in three-dimensional space. In continuation of the work reported previously, the GNLSE is applied to provide additional knowledge on the femtosecond dynamics of the electron density in the hydrogen molecule interacting with high-intensity laser fields. For this purpose, the GNLSE is solved numerically for many time-steps over a total interaction time of 100 fs, by employing a finite-difference scheme. Various time-dependent (TD) quantities, namely, electron density, ground-state survival probability and dipole moment have been obtained for two laser wavelengths and four different intensities. The high-order harmonics generation (HHG) is also examined. The present approach goes beyond the linear response formalism and, in principle, calculates the TD electron density to all orders of change.

6 illus, 37 ref

015173   Vijaykumar K C K;Dhandapani S;Srinivasan P S S (Mechanical Engineering Dep, Kongu Enng Coll, Perundurai, Erode-638 052, Email: vijick@yahoo.com) : Energy efficient eco-friendly (E<. J Energy Heat Mass Transfer 2007, 29(1), 27-41.

The study is concerned with the evaluation and comparison of the thermal performance of building roof subject to periodic climatical conditions and solar radiation. Most of the Indian concrete buildings have 150mm thick Reinforced Cement Concrete (RCC) with Weathering Course (WC) having 75 - 100mm thick lime brick mortar. Literature survey reveals that such roofs account for about 40 - 75% of total heat transmitted into the occupant zone depending upon the location and also account for the major portion of electricity bill in air-conditioned buildings. In order to reduce the heat transmission, a new concept has been proposed wherein Hollow Clay Tiles (HCT) are laid over reinforced cement concrete instead of weathering course. The transient heat transmission through various types of roof structures has been analysed for typical Indian climatic conditions. The deviation of experimental results with the numerical results is within 5 - 10%. The energy savings obtained with the use of proposed HCT roof is found to be 38 - 63% when compared with conventional weathering course roof.

9 illus, 3 tables, 18 ref

015172   Venkateswarlu P;Sanyasi Rao S;Kiran Appaji S (Chem Engng Dep, Coll of Engng Andhra Univ6pVisakhapatnam-530 003, , Email: pvlu9@rediffmail.com) : Mass transfer studies in a simultaneously vibrating and rotating cylindrical electrode. J Energy Heat Mass Transfer 2007, 29(4), 323-38.

Vibration or rotation of an electrode increases the turbulence in an electrolytic cell resulting in higher limiting current densities. Limiting current data were obtained at a copper cylindrical electrode simultaneously vibrating and rotating in a rectangular electrolytic cell. The electrolyte consisted of 0.01N potassium ferricyanide. 0.01 N potassium ferrocyanide and 0.5N; sodium hydroxide. The variables studied were vibration frequency, vibration amplitude and rotation speed of the electrode. The mass transfer coefficients were enhanced 16-64. 5 fold with increases in amplitude. frequency and rotation speed.

12 illus, 1 table, 22 ref

015171   Vasantharani P;Karthikeyani K; (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002, Email: pvr2007@gmail.com) : Thermal expansion and acoustical properties of zinc bismuth borate glasses. Bull pure appl Sci 2007, 26(2), 67-72.

Glass systems of the composition xBi₂O₃-(55-x)ZnO-55B₂O₃(where x = 17. 19, 21, 23 and 25 mol%) have been prepared by melt quenching technique Elastic properties have been investigated using sound velocity measurements at 5MHz at room temperature (303K). Elastic moduli reveal trends in their compositional dependence. The bulk modulus and shear modulus increases monotonically with increase of BO₄ units, which increase the dimensionality of the network. The results are discussed have been calculated in view of borate network.

2 illus, 4 tables, 11 ref

015170   Vasantharani P;Kalaimagal P (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002, Email: pvr2007@gmail.com) : Ultrasonic study on BaO-Bi₂-O₃-B₂O₃ ternary glasses. Bull pure appl Sci 2007, 26(2), 103-8.

Ternary Barium glasses in the form (40-x) BaO - x Bi₂O₃ - 60 B₂O₃ have been prepared. Both longitudinal and shear ultrasonic velocities were measured for different compositions of the glass system by using the pulse-echo method at 5MHz frequency at room temperature. The elastic properties of ternary barium glasses were measured as a function of composition. The ultrasonic velocity, density, the calculated elastic moduli and some other physical parameters such as micro-hardness, and Debye temperature depend on the glass composition Addition effect of Bi₂O₃, on the elastic moduli was investigated interms of a number of network bonds and the mean cross-link density of the glass systems.

4 illus, 3 tables, 9 ref

015169   Varma H R;Banerjee T;Deshmukh P C (Phys Dep, Manipal Inst of Technol, Manipal-576 104) : Selective interchannel coupling as computational strategy to interpret complex atomic spectrum. Indian J Phys 2007, 81(10), 1069-77.

Selective interchannel coupling has been used in the present work as an effective computational strategy to identify specific autoionization resonances and other correlation effects in the photoionization angular distribution asymmetry parameter for the case of valence ns subshell photoionization of atomic krypton and mercury. It is found that in the case of 6s photoionization of Hg, deviation of β from the non-relativistic value 2 in the energy region below the 5d ionization thresholds is a cumulative effect of the Cooper minimum in 6s photoionization and resonant excitations from the 5d subshells.

7 illus, 2 tables, 16 ref

015168   Srinivas T;Gupta A V S S K S; (Mechanical Engng Dep, Gudlavalleru Engn Coll, Gudlavalleru-521 356, Email: srinivastpalli@yahoo.co.in) : Performance simulation of 210 MW natural gas fired combined cycle power plant. J Energy Heat Mass Transfer 2007, 29(1), 61-82.

Combined cycle power plant with methane as a fuel has been analyzed on the basis of both first law and second law point of view. In this model, gas cycle which is a topping cycle has been separately compared with the effects of intercooling and reheating on the performance of the combined plant. i.e., the performance with and without intercooling, as well as with and without reheating. It is found that at low pressure ratio the performance of combined cycle with simple gas cycle has high performance. Therefore in this analysis, simple gas cycle is selected as a topping cycle due to mechanical considerations of the turbo machines. The bottoming cycle i.e., steam cycle. consists of eight feed water heater, one deaerator and a steam reheater. Single pressure heat recovery steam generator is selected for simplification of this analysis. The effects of parameters related to topping and bottoming cycles are discussed on the performance and exergetic loss of components. These parameters are pressure ratio, maximum temperature of the combined cycle, heat recovery steam generator' steam pressure and steam temperature at steam turbine inlet. For the net output of 210 MW, the requirements of fuel and air along with the flow rates in the plant are determined at the working parameters. The optimum value of the gas pressure ratio is found as 15 to for maximum efficiency of combined cycle.

18 illus, 1 table, 10 ref