007832   Upadhyay T C;Joshi M (Physics Dep, HNB Garhwal Univ, Srinagar (Garhwal), Uttarakhand-246 174, Email: mayankphysics@gmail.com) : Temperature dependence of soft mode frequency, dielectric constant and loss tangent in PbHPO₄ crystal in presence of electric field. Indian J pure appl Phys 2010, 48(8), 550-5.

An extended two sublattice pseudospin lattice coupled mode model by adding third and fourth-order phonon anharmonic interactions terms as well as external electric field term has been considered for lead hydrogen phosphate crystal and its isomorphs. With the help of double-time temperature dependent Green's function method, theoretically, expressions for shift, width, soft mode frequency, dielectric constant and loss tangent are derived. By fitting model values in the theoretical expressions, temperature and electric field dependence of soft mode frequency, dielectric constant and loss tangent is calculated for PbHPO₄ crystal in presence of electric field. The theoretical results compared with experimental results of Smutny and Fousek [Ferroelectrics, 21 (1978) 385] show good agreements.

3 illus, 1 table, 19 ref

007831   Torongey P K;Khanna K M;Ayodo Y K;Sakwa W T; Kanyeki F G;Ekai R T;Kimengichi R N;Rotich S (Physics Dep, Moi Univ, Box 1125- Eldoret-Kenya) : Elastic scattering of <. Indian J pure appl Phys 2010, 48(10), 743-8.

Elastic scattering of ⁴He atoms when they approach the surface of ⁴He liquid, has been studied. The liquid surface is assumed to be uniform and the density profile is the same along and perpendicular to the surface. The incident ⁴He atom will interact with a large number of ⁴He atoms in the liquid near the surface of liquid ⁴He. Hence, the effective interaction of the incident particle will be due to many-body forces. The many-body forces are represented by the t-matrix. In the equation for potential energy per atom in the bulk liquid, the pair potential was replaced by the t-matrix. The Gaussian potential used in calculating the expectation value of the t-matrix is equivalent to the Lennard-Jonnes potential. The results give quantitative agreement with the corresponding experimental values for ⁴⁵He for the various values of X². The potential energy per atom in the bulk liquid obtained in this calculation is -20.130 K. The experimental energy of interaction is -20.81K, which implies that the formula derived by us for the potential energy per atom in the bulk liquid works well.

1 illus, 2 tables, 18 ref

007830   Thorat P P;Banerjee P (National Physical Laboratory, Council of Scientific and Industrial Research, New Delhi-110 012, Email: pranuthorat@gmail.com) : Use of modern telephone network for time transfer: an innovation. Indian J pure appl Phys 2010, 48(9), 676-80.

NPL has started a new time service by transmitting digital time data via telephone network in name of Teleclock service. This is quite different from the usual dial-up service in other countries. This unique service can be accessed by the landline telephone as well as by the mobile telephone network. Both types of receivers have been developed by NPL, New Delhi. The concept of this service has been described in this paper. The important features and uniqueness of this system have also been elaborated.

7 illus, 5 ref

007829   Subbaiah K V;Gopalani D;Gautam C S;Jodha A S; Meghwal L R (NO, AERB-Safety Research Institute, Kalpakkam-603 102, Email: kvs@igcar.gov.in) : Gamma radiation protection factor of building materials-Validation of wall reflections from measurements. Indian J pure appl Phys 2010, 48(11), 774-7.

The gamma radiation (INR and fallout radiations using ⁶⁰Co and ¹³⁷Cs sources, respectively) protection factors for 150 cm of soil (density=1.5 g/cc) followed by 21.5 cm specially prepared concrete (density=2.7 g/cc) have been estimated. Since the measurements are not amenable for such large thickness due to significant contributions from the scattered radiation, experiments are carried out for varying thickness and results are corroborated by Monte Carlo calculations. After ascertaining the calculated accuracy, the protection factors are deduced by Monte Carlo calculations. Simulations could reasonably predict the measurements within a factor of 2 for all the cases measured. It is inferred from the simulations that the dose contributions due to reflected radiations from the wall are significant when the material thickness exceeds 45.5 cm soil plus 21.5 cm concrete. Further, materials have been evaluated against fast neutrons using ²⁵²Cf source.

2 table, 4 ref

007828   Srivastava A;Singh V;Aggarwal P;Schneeweiss F;Scherer U W;Friedrich W (Chemistry & Centre for Advanced Studies in Chemistry Dep, Punjab Univ, Chandigarh-160 014, Email: alok@pu.ac.in) : Optical studies of insulating polymers for radiation dose monitoring. Indian J pure appl Phys 2010, 48(11), 782-6.

The optical study carried out on insulating polymers namely polyethyleneterephthalate (PET) and polyvinylchloride (PVC) has been described. The polymers are exposed to different radiation doses by exposing them to swift heavy ions of carbon (90 MeV), silicon (120 MeV) and nickel (100 MeV) which influence on their optical properties. The studies show that amongst the investigated polymers, PVC and PET have potential for application as dosimeter beyond a threshold dose which is strongly dependent on the nature of the material and the radiation type. The optical micrographs show a distinct change in colour of the sample with increase in radiation dose.

4 illus, 2 table, 23 ref

007827   Sreenath Reddy M;Gopal Reddy C;Yadagri Reddy P;Rama Reddy K (Physics Dep, Osmania Univ, Hyderabad-500 007, Email: yadagirireddy@yahoo.com) : Natural background gamma radiation levels in Hyderabad and its surroundings, Andhra Pradesh, India. Indian J pure appl Phys 2010, 48(11), 778-81.

The natural background gamma radiation levels were measured in the dwellings of urban Hyderabad and its surroundings using thermoluminescence (TL) dosimeters and Geiger-Muller based μR-survey meter. The measured minimum, maximum and average radiation levels were found to be 226, 506 and 314+47 nGyh^-1 for urban Hyderabad and 190, 462 and 309+ 81 _nGyh^-1 for surroundings of Hyderabad. In this study, the natural background gamma radiation levels in different dwellings with types of constructions have been correlated. It was found that these levels are higher in the constructions made by mud, which is of local soil. The annual effective dose due to natural background gamma radiation exposure in the Hyderabad and its surroundings is calculated and found to be 1.54+0.23 _mS_v and 1.52+0.40 _mS_v, respectively.

2 illus, 3 table, 15 ref

007826   Soosen Samuel M;Koshy J;Chandran A;George K C (Physics Dep, S B College, Changanassery, Kerala-686 101, Email: drkcgeorge@gmail.com) : Optical phonon confinement in ZnO nanorods and nanotubes. Indian J pure appl Phys 2010, 48(10), 703-8.

The structure and morphology of ZnO nanorods and nanotubes synthesized by hydrothermal method were studied by TEM, XRD and Raman spectroscopy. The Raman scattering spectra at room temperature were excited by He-Ne laser with wavelength 633 nm. The perfect wurtzite structures of ZnO nanorods and nanotubes were verified by the intense E₂ (high) mode. The strong red shifts of phonon frequencies, broadening of the FWHM of Raman peaks and asymmetry of line shapes were attributed to phonon confinement effect. An optical phonon confinement model was used for calculating the theoretical line shapes, asymmetric broadening and shift of the optical phonons. The results were in good agreement with the experimental values. Besides the fundamental phonon modes, overtone and combination modes were also observed because of the anharmonicity effect. From this study, it was found that the phonon confinement effect was more obvious in ZnO nanotubes as compared to nanorods.

7 illus, 2 tables, 21 ref

007825   Sivaiah K;Hemalatha Rudramadevi B;Buddhudu S (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502) : Structural, thermal and optical properties of Cu<. Indian J pure appl Phys 2010, 48(9), 658-62.

Spectral characterization of Cu²⁺ and Co²⁺: PVP polymer films has been carried out from the measurement of their absorption, excitation and emission spectra in order to understand their optical performance as the visible colour displaying luminescent materials. Transparent and very clear natured reference PVP polymer film has also been developed by employing a solution cast method to measure the profiles of XRD, FTIR and Raman spectra in exploring its structural details. Besides, we have also reported its thermal properties based on the measurement of TG-DTA profiles.

9 illus, 25 ref

007824   Shinde S;Pandya A;Jha P K (Physics Dep, Institute of Technology, Nirma Univ, Ahmedabad-382 481, Email: satyamshinde@yahoo.com) : Pressure induced phonon stiffening and softening in III-V phosphides. Indian J pure appl Phys 2010, 48(8), 543-9.

A lattice dynamical study of InP, GaP and BP under pressure is reported by using two lattice dynamical model theories namely, the rigid ion and deformation bond approximation models. It is observed that the energies of the optical phonons and longitudinal acoustic phonons stiffen with pressure, while the transverse acoustic phonon frequency softens. The phonon density of states shows pronounced shift in the frequency spectra with pressure. The mode Griineisen parameter indicates that the TA phonon modes have negative values and responsible for the lattice softening. The lattice specific heat at constant volume, C_v increases with pressure. The obtained results are, in general, good agreement with available data.

3 illus, 4 tables, 37 ref

007823   Sheikh M R;Acharya B S;Gartia R K (Physics Dep, D M College of Science, Imphal, Manipur) : Characterization of iron slag of Kakching, Manipur by X-ray and optical spectroscopy. Indian J pure appl Phys 2010, 48(9), 632-4.

The mineral and elemental constitutional analysis of the slag obtained from Kakching area of Thoubal district, Manipur have been carried out. The techniques used for characterization are X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT1R) and optical microscopy. The age of the slag is determined to be 400 AD by thermoluminescence dating technique.

3 illus, 1 table, 15 ref

007822   Shastri N;Vyas P R;Gupta S J (NO, Sarvajanik College of Engineering & Technology, M T B College Campus, Athwalines, Surat-395 001) : Physical properties of mixed liquid crystal at phase transition. Indian J pure appl Phys 2010, 48(8), 556-61.

The physical properties of the mixture of two non-mesomorphic compounds which give considerable insight into the mesomorphic state of the compound, have been studied. The mesomorphic states of mixture of cholesterol (non-mesomorphic compound) and tetradecanol (non-mesomorphic compound) have been studied which give twisted nematic phase or cholestric phase and have wide applications in optical devices or display devices. The thermal behaviour of ultrasonic velocity, specific volume, adiabatic compressibility and molar compressibility in the mixture at phase transition and their interpretation have been investigated. The results using Fabry Perrot Scattering Studies [FPSS] are also presented.

9 illus, 1 table, 12 ref

007821   Sharma U D;Joshi H;Kumar M (Physics Dep, G B Pant Agriculture and Technology Univ, Pantnagar-263 145, Email: munish_dixit@yahoo.com) : Effect of pressure and temperature on C₆₀ fullerite. Indian J pure appl Phys 2010, 48(9), 663-7.

Simple model has been developed to study the effect of pressure and temperature on C₆₀ solid. Pressure and temperature dependence of volume V/V_o bulk modulus B, and coefficient of volume thermal expansion a has been investigated by varying the temperature from room temperature to 2000 K, and pressures from room pressure to 200 kbar. The results have been compared with the available experimental data as well as different theoretical approaches. The good agreement between theory and available experimental data supports the validity of the simple model proposed for C₆₀ solid.

4 illus, 2 tables, 20 ref

007820   Sharma S;Rana S;Pal K (Physics and Electronics Dep, Jammu Univ, Jammu-180 006) : Realization of variable Q bandpass filter using low-voltage CCII. Indian J pure appl Phys 2010, 48(8), 600-2.

A voltage-mode bandpass filter with variable Q, realized using a single FGMOS based second generation current conveyor (CCII) that operates with + 0.75 V supply voltage, has been presented. The Q and pass band gain (K) can be adjusted for desired values within some limits by selecting the various passive components used in the circuit. The workability of this circuit has been verified by PSpice simulations using 0.5 μm technology parameters.

3 illus, 1 table, 22 ref

007819   Sharma M K;Joshi D P (NO, Govt Sr Secondary School, Kolar, Sirmour, Himachal Pradesh, Email: dr.manojsharma266@rediffmail.com) : Effect of grain boundaries on photovoltaic properties of PX-GaAs films. Indian J pure appl Phys 2010, 48(8), 575-80.

A new relation for the effective diffusion length of minority carriers has been presented and the performance of polycrystalline GaAs solar cells has been studied theoretically. It has been found that in the very small grain size range, the diffusion length of minority carriers in these devices is controlled not only by the grain boundary (GB) recombination processes but also by the GB recombination processes in the junction space charge region. In the very small grain size range, the efficiency of these solar cells has been found to be very sensitive to the grain size as compared to that observed for PX-Si solar cells. A good agreement has been found between the theoretical predictions and the available experimental data.

7 illus, 1 table, 17 ref

007818   Sehgal T;Rattan S (Chemistry Dep, Amity School of Engineering and Techonology, Palam Vihar Road, Bijwasan, New Delhi-110061, Email: teenakrishna@yahoo.co.in) : Graft-copolymerization of N-viny1-2-pyrrolidone onto isotactic polypropylene film by gamma radiation using peroxidation method. Indian J pure appl Phys 2010, 48(11), 823-9.

Isotactic polypropylene (IPP) films were modified through radiation-induced grafting of N-vinyl-2-pyrrolidone (NVP) with the aim of preparing hydrogels. The radioactive isotope cobalt-60 was used as the source of gamma radiation. A plausible mechanism of grafting has been proposed. The grafting conditions were optimized with respect to monomer concentration, time, temperature and amount of solvents. The structures of grafted films were characterized by FTIR, AFM and SEM studies. IPP-g-NVP films were investigated for their swelling behaviour as a function of different pH solutions. The prepared grafted films can have potential applications in the fields of controlled drug delivery systems.

9 illus, 1 table, 17 ref

007817   Santosh Kumar;Mishra L K (NO, , Sundarma Sadan, Road No.-12/B, Magadh Colony, Gaya-823 001) : Evaluation of long-wavelength surface plasmon dispersion coefficient α for various simple metal surfaces. Int J chem Sci 2010, 8(1), 223-9.

Presents an evaluation of long wavelength surface plasmon dispersion coefficients a (A) for various simple metal surfaces using various models (HD, SRM, IBM, RPA and ALDA). It was observed that the surface plasmon dispersion coefficient α evaluated using RPA and ALDA models are negative as per experimental observation but the magnitude is large. On the other hand, α calculated from HD and SRM models are positive but the magnitude matches with experimental data.

2 tables, 36 ref

007816   Sannapa J;Ningappa C;Prakash Narasimha K N (Yuvaraja's College, Mysore Univ, Mysore-570 005, Email: sannappaj@yahoo.co.in) : Natural radioactivity levels in granite regions of Karnataka State. Indian J pure appl Phys 2010, 48(11), 817-19.

The activities of ²³⁶Ra, ²³²Th and ⁴⁰K and natural radiation levels have been measured at granite regions of Karnataka State, India using HPGe detector and scintillometer. In granite region ²³²Th activity is high compared to ²²⁶Ra. The data shows that the activities of ²²⁶Ra, ²³²Th and ⁴⁰K and ambient y-radiation level were found to be high in comparison to global and Indian average.

1 table, 12 ref

007815   Samuel Selvaraj R;Gopinath T;Jayalakshim K (Physics Dep, Presidency College, Chennai-600 005, Email: samuelselvaraj.r@rediffmail.com) : Statistical relationship between surface ozone and solar activity in a tropical rural coastal site, India. Indian J Sci Technol 2010, 3(7), 792-4.

Surface ozone has been measured at Tranquabar (11°N, 79°9'E), a tropical rural site on the east coast of south India, during the years 1996 to 2004. The sunspot data were collected from Udaipur solar observatory during the same I period. The relationship between annual mean smoothed sunspot number and annual mean surface ozone levels are studied by Pearson product moment correlation coefficient and that is found to be a high value 0.94. High positive rank correlation coefficients 0.76 and 0.62 obtained for the years 2000 and 2002 indicates the influence of higher solar activity over the surface ozone levels.

3 illus, 2 tables, 11 ref

007814   Saka I;Gumus S;Gencten A (Physics Dep, Faculty of Arts and Sciences, Ondokuz Mayis Univ, Samsun, Turkey, Email: isaka@omu.edu.tr) : Spectral editing with 2D E-HMQC NMR spectroscopy for CDN groups: a theoretical study. Indian J pure appl Phys 2010, 48(9), 626-31.

In order to get the simplified spectra for separation of carbonyl groups, the spectral editing of NMR signals has become a useful technique for complex molecules. E-HMQC is a '¹-dedected, edited-pulse angle and two-dimensional NMR experiment which allows the selective detection of CH, CH₂ and CH₃ signals. The product operator theory is widely used for analytical description of the spectral editing NMR experiments for weakly coupled spin systems. In the present study, analytical descriptions of the 2D ²H-dedected E-HMQC NMR experiment have been presented for weakly coupled IS_n, (I=1/2; 5=1; n=1, 2, 3) spin systems by using the product operator theory. By using obtained FID values, theoretical discussion and experimental suggestions for sub-spectral editing of CD, CD₂ and CD₃ groups have been made.

2 illus, 2 tables, 30 ref

007813   Sahoo S N;Panda J P;Dash G C (Mathematics Dep, Institute of Technical Education and Research, Siksha 'O' Anusandhan U, Khandagiri Square, Bhubaneswar-751 030, Email: sachi.sahoo@yahoo.com) : Hydromagnetic oscillatroy flow and heat transfer of a viscous liquid past a vertical porous plate in rotating medium. Indian J Sci Technol 2010, 3(7), 817-21.

Unsteady oscillatory flow of an incompressible, electrically conducting viscous liquid through a porous medium past an infinite vertical porous plate with constant suction has been studied. A transverse uniform magnetic field has been applied in a rotating frame of reference. The porous medium is bounded by a vertical plane surface. The temperature on the vertical surface fluctuates in time about a non-zero constant mean. The analytical expressions for the velocity, temperature, skin friction and Nusselt number are presented showing the effects of pertinent parameters. It is observed that steady part of the velocity field has two layers character viz thermal layer and suction layer, while the oscillatory part exhibits a multilayer character.

4 illus, 2 tables, 15 ref

007812   Sahoo S (Physics Dep, National Institute of Technology, Durgapur-713 209, Email: sukadevsahoo@yahoo.com) : Mass of the neutrino. Indian J pure appl Phys 2010, 48(10), 691-6.

In the standard model (SM) of particle physics, neutrinos are massless and neutral spin 1/2 particles. But from recent experiments, it is found that neutrinos undergo flavour oscillations, violating lepton flavour conservation which implies that neutrinos have non-zero mass. The absolute scale of neutrino masses is very important for understanding the evolution and the structure formation of the Universe as well as for nuclear and particle physics beyond the present standard model. In this review article, first we have tried to put some logical arguments to support that neutrinos have mass. Then various ways of determining the neutrino masses are briefly discussed and their sensitivities are compared. Neutrino mass is a window for new physics beyond the SM.

58 ref

007811   Rupesh Kumar;Mahur A K;Singh H;Sonkawade R G; Swarup R (Physics Dep, D S College, Aligarh, Email: ayaymahur345@rediffmail.com) : Radon levels in some dwellings around the international monumet Taj Mahal, Agra using SSNTDs. Indian J pure appl Phys 2010, 48(11), 802-4.

The Taj Mahal, Agra had been on top priority of India and safe guarded by Taj Mahal Corridor. All the gaseous industrial discharges as well as fluid chemicals and water due to rain and river Yamuna toxic polluting entities had been ' taken into account while maintaining the beauty of Taj and purity of environment around it's rural areas. Indoor radon V concentration depends in a complex way on the characteristic of the soil, the type of building structure, ventilation condition j| and occupant's behaviour. LR-115 Type II Solid State Nuclear Track Detectors (SSNTD's) have been used to measure the airborne radon levels in some dwellings near Taj Mahal, Agra. Radon concentrations were found to vary from 98 to 305 Bqirf^-3 with an average value of 213 Bqirf^-3. Annual effective dose in these dwellings were found to vary from 1.3 to 4.4 mSv.

1 table, 14 ref

007810   Rosangliana;Lalmuanpuia;Zoliana B;Thapa R K (Physics Dep, Govt Zirtiri Residential Science College, Aizawl-796 001, Email: r.k.thapa@gmail.com) : Calculation of photofield emission current in tungsten by using transfer Hamiltonian method. Sci Vision 2010, 10(4), 133-6.

Results of the calculations of photofield emission current have been presented. Free electron potential model was used to describe crystal potential to derive wave functions. Transfer Hamiltonian method was applied for calculation of the transition probability. Photofield emission current is calculated from tungsten. Variation of photofield emission current is explained from the result.

2 illus, 6 ref

007809   Rohmingliana P C;Vanchhawng L;Thapa R K;Sahoo B K;Mishra R;Zoliana B;Mayya Y S (Physics Dep, Mizoram University, Aizawl-796 009, Email: bzoliana@rediffmail.com) : Measurement of indoor concentrations of radon and thoron in Mizoram, India. Sci Vision 2010, 10(4), 148-52.

Radon, thoron and their progenies as a natural radiation hazards to human health is well known. These gases are present in the environment and their level of concentration depends upon geographical and geological conditions, meteorological factors, etc. The indoor radon/thoron concentration is also influenced by building materials, ventilating system and soil gas diffusion. Measurement of radon/thoron concentration in Mizoram is reported in this paper covering three districts, namely Aizawl, Kolasib and Champhai. In this study, we used solid-state nuclear track detectors to obtain the time integrated concentration levels of indoor radon/thoron. The study was conducted by measuring the cumulative exposure for a period of about 90 days each in 149 houses during rainy season (May-August). Houses were selected on the basis of geological characteristics of the area and the construction types in order to determine variation of concentrations of radon and thoron due to these factors. Among the three districts, Champhai District had the highest radon/thoron concentraªtions, while Kolasib District had the maximum thoron concentration. Among the different types of houses, concrete building had the average maximum concentration of radon followed by Assam type building with G.I. Sheet walls while the contribution due to asbestos walls of Assam type building was found to be lowest.

3 illus, 13 ref

007808   Parekh K (Physics Dep, Indian Institute of Technology Gandhinagar, Chandkheda, Ahmedabad, Email: pkinnarih@rediffmail.com) : Effect of preparative conditions on magnetic properties of CoFe₂O₄ nanoparticles. Indian J pure appl Phys 2010, 48(8), 581-5.

Nanomagnetic particles of CoFe₂O₄ have been synthesized using chemical co-precipitation technique followed by annealing, characterized and investigated by powder XRD and magnetic measurement tools. All samples of nano ferrites synthesized at different annealing temperatures show single phase cubic spinel structure with particle size changes from 9.5 to 2! nm. The virgin curve of magnetic measurement exhibits superparamagnetic behaviour at room temperature which changes to 'S' shape with increasing annealing temperature indicating change in soft magnet to pinning-type magnet. The coercivity of the nano-cobalt ferrite particles has been found to increase with increase in annealing temperature.

5 illus, 1 table, 14 ref

007807   Panwar L;Choudhary H S;Vaijapurkar S G;Bohra D;Bhatnagar P K (NO, Defence Laboratory, Ratanada Palace, Jodhpur-342 001, Email: Panwar_lalit@rediffmail.com) : Silicon PIN diode neutron dosimetry. Indian J pure appl Phys 2010, 48(11), 813-16.

Silicon PIN neutron dosimeter has been developed by Defence Laboratory, Jodhpur. The device is a wide base, conductivity modulated PIN diode that response to fast neutrons in the range of interest (1 _cGy to 1000 _cGy). The study carried out at Defence Laboratory to evaluate different characteristics of the PIN diode as a neutron dosimeter has been presented.

6 illus, 4 ref

007806   Pandey M K;Lalan Prasad;Gariya S (Physics Dep, M B Govt P G College, Haldwani, Nainital-263 141, Email: iprasad@iucaa.ernet.in) : Coronal heating by coupling of the magnetosonic and phase-mixed alfven waves. Indian J Radio Space Phys 2010, 39(5), 280-3.

The interaction of phase-mixed Alfven waves with an inhomogeneous cold plasma density, transverse to magnetic field, may excite the non-linear fast magnetosonic waves. Phase mixing of the Alfven waves produce strong transversal gradients in the amplitude. The strong transversal gradients in amplitude of the Alfven wave leads to the dissipation of Alfven wave energy. The dissipation of the phase-mixed Alfven wave in inhomogeneous cold plasma is conversion to the non-linear excitation of the fast magnetosonic waves. The linear coupling of the phase-mixed Alfven waves and fast magnetosonic waves may be a possible mechanism of solar coronal heating. Here, this heating mechanism has been considered with viscosity, resistivity and thermal conductivity in an inhomogeneous plasma medium.

18 ref

007805   Palani R;Balakrishnan S (Physics Dep, DDE, Annamalai Univ, Annamalainagar, Tamil Nadu, Email: palani_physics06@yahoo.co.in) : Acoustical properties of ternary mixtures of 1-alkanols in di-isoprophyl ether and 2,2,2-trifluoroethanol mixed solvent. Indian J pure appl Phys 2010, 48(9), 644-50.

Ultrasonic velocity ((U), density (p) and viscosity (η) for the ternary liquid mixtures of diisopropyl ether+2,2,2-trifluoroethanol+1-propanol, diisopropyl ether+2,2,2-trifluoroethanol+l-butanol and diisopropyl ether+2,2,2-trifluoro-ethanol+1-pentanol have been measured as a function of the composition at 303, 308 and 313 K. The experimental data have been used to calculate some excess thermodynamical parameters such as viscosity (η^e), adiabatic compressibility (β^E), free length (L^E_f), free volume (V^E_f), internal pressure (π^E_i) and Gibb's free energy (ΔG^E). The results have been discussed and interpreted in terms of structural and specific interaction predominated by hydrogen bonding.

1 illus, 4 tables, 28 ref

007804   Natarajan V;Sivanesan T;Pandi S (Physics Dep, Rajalakshmi Institute of Technology, Kunthampakkam-602 124, Email: hinatarajan@gmail.com) : Third order non-linear optical properties of L-arginine hydrochloride monohydrate single crystals by Z-scan technique. Indian J Sci Technol 2010, 3(8), 897-9.

L-arginine hydrochloride monohydrate (L-arginine hydrochloride monohydrate) was synthesized by the reaction between hydrochloric acid and the strongly basic amino acid, L-arginine taken in the ratio of 1:1. The crystal structure of the sample was studied by single X-ray diffraction. The UV transmittance spectra of the grown crystals indicate a good transparency between 200 and 1000 nm. The nonlinear refractive index n₂ and susceptibility x⁽³⁾ have been measured through the Z-scan technique. The results indicate that the compound exhibits reverse saturation absorption and self-defocusing performance. Non-linear absorption co-efficient is determined as 9.2194 x 10^-4 cm/w. The non-linear refractive index of the L-arginine hydrochloride single crystals were found to be 1.7129 x 10^-7 cm ²/w. The real and imaginary pars of non-linear susceptibility x⁽³⁾ have been measured at 632.8 nm and found to be 1.1573 x 10^-5 esu and 3.1382 x 10 esu. respectively.

4 illus, 1 table, 17 ref

007803   Narayan P;Meghwal L R;Songara K C;Vaijapurkar S G;Bhatnagar P K (NO, Defence Laboratory, Jodhpur-342 011, Email: pradeep_narayan@rediffmail.com) : Radiological safety aspects in Californium-252 source transfer operation. Indian J pure appl Phys 2010, 48(11), 798-801.

The methodology, radiological safety planning and technical experiences gained during the transfer of 1 mg of ²⁵²Cf neutron source from transport container to exposure facility have been reported. Hot mockups with dummy sources and radiation safety planning in advance have been observed as the main contributing factor in personal dose reduction and to increase the confidence level in radioactive source transfer in open condition. The doses received by the personnel during this procedure are in the range 0.15-0.30 mSv, which are well within the planned dose limit during operation (5 mSv). No accidental or emergency situation had arisen during the course of this task. Before any new high strength source expected to arrive in any institution, a full-scale mockup should be performed to ensure all members of the work team to understand their parts in the operation. Minimum possible persons should be involved in source transfer. Too many minds at a time should not be applied in such a hazardous operation. There should be only one supervisor at the site and no one except the supervisor should be allowed to give instructions and suggestions during the source loading or transfer procedure. Only expert and experienced radiation safety personnel with high confidence level should undertake such operations. All technical aspects and challenges faced during the source transfer have been highlighted.

1 table, 3 ref

007802   Mohanraj K;Sivkumar G;Barathan S (Physics Dep, Manonmanian Sundaranar Univ, Tirunelveli-627 012, Email: km_aup@yahoo.co.in) : Hydration process of fly ash blended cement composite. Int J chem Sci 2010, 8(1), 589-601.

In the investigation, to evaluate the performance of a 25% cement replacement by fly ash (FA), blended composite and control (without FA) was hydrated with sea water (SW) with the water to binder ratio 0.4. Intervals of the hydrated samples are 1 hour, 6 hours, 7 hours, 1 day, 7 days, 28 days, 90 days and 180 days. Setting time and compressive strength of control and blended composites were carried out. The hydrated samples were subjected to FTIR and SEM with EDS analysis. This study reveals that the control (without fly ash) pastes can accelerate the early stage of hydration due to higher amounts of ettringite formation and retarded hydration process in later periods due to Ca(OH)₂ product reacting with sodium, magnesium and chloride ions to form recrystallised gypsum and Mg(OH)₂. These products are deteriorating in control paste. In blended composite, these products are free due to pozzolanic reaction of fly ash consuming Ca(OH)₂. Also, the A1₂O₃ rich in fly ash reacts with chloride to form Friedel's salt (Ca₃.CaCl₂.10H₂O). This reduces the amount of free chlorides and hence, the blended composite has higher strength than control in later periods and increase the resistance to sulphate attack.

6 illus, 1 table, 31 ref

007801   Mehra R;Badhan K;Sonkawade R G;Kansal S;Singh S (Physics Dep, Dr B R Ambedkar National Institute of Technology, Jalandhar, Email: rohit_mimit@rediffmail.com) : Analysis of terrestrial natural radionuclides in soil samples and assessment of average effective dose. Indian J pure appl Phys 2010, 48(11), 805-8.

Radionuclides that are present in soil significantly affect terrestrial gamma radiation levels which in turn can be used for the assessment of terrestrial gamma dose rates. Natural radioactivity analysis has been done for the soil samples collected from different villages/towns of Hoshiarpur district of Punjab, India. The measurements have been carried out using HPG_e detector based on high-resolution gamma spectrometry system. The calculated activity concentration values for terrestrial gamma viz. ²³⁸U, ²³²Th and ⁴⁰ K have been found to vary from 8.89 to 56.71 Bq kg^-1, from 137.32 to 334.47 Bq kg^-1 and from 823.62 to 1064.97 Bq kg^-1, respectively. The total average absorbed dose rate in the study areas is 185.32nGyh^-1. The calculated value of average radium equivalent activity (401.13 Bq kg^-1) exceeds the permissible limit (370 Bqkg^-1) recommended by Organization for Economic Corporation and Development (OECD). The calculated average value of external hazard index (H_ex) is 1.097. The calculated values of Indoor and Outdoor annual effective doses vary from 0.61 to 1.28 mSv and from 0.15 to 0.32 mSv, respectively. A positive correlation (R²=0.7l) has also been observed for concentration of ²³²Th and ⁴⁰K.

1 illus, 3 table, 13 ref

007800   Madhu Sahu K B;Amarnath J (NO, Aditya Institute of Technology and Management, Tekkali-532 201, Email: kbmadhsahu44@gmail.com) : Movement of meatallic particle contamination in a gas insulated busduct under dielectric coated enclosure with electromagnetic field effect. Indian J Sci Technol 2010, 3(7), 764-9.

The purpose of coating the inside surface of gas insulated busduct (GIB) enclosure with a dielectric material reduces I the deleterious effect of electrode surface roughness, impedes the development of metallic particle initiated micro I discharges, increases the field required to lift particles, and reduces the charge acquired by particles. The performance I of particle contaminated compressed gas systems with dielectric coated electrodes are analyzed in this paper. The I equations governing the motion of the particle due to its electromagnetic field effect has been formulated to obtain the particle trajectories. Hence simulation has been carried out to study the effect of fields on the motion of the particle with and without electromagnetic field effect under dielectric coated enclosure. Particle trajectories obtained for various voltages of aluminum, copper, and silver particles of size 12 mm in length and 0.2mm as radius present on the enclosure. The simulation results have been presented and analyzed.

12 illus, 1 table, 7 ref

007799   Madhu Mohan T;Sreehari Sastry S;Murthy V R K (Physics Dep, Acharya Nagarjuna Univ, Nagarjunanagar-522 510, Email: ssreeharisastryanu@gmail.com) : Microwave dielectric relaxation thermodynamic and conformational studies of hydrogen bond binary mixtures of propan-1-ol with methyl benzoate and ethyl benzoate. Indian J pure appl Phys 2010, 48(9), 668-75.

The dielectric relaxation studies of propan-1-ol with alkyl benzoates (methyl benzoate and ethyl benzoale) have been carried out, for various mole fractions at different temperatures, using LF impedance analyzer, Plunger method and Abbe's refractometer in radio, microwave and optic frequency regions, respectively. Kirkwood effective correlation factor, corrective Kirkwood correlation factor, Bruggeman parameter, relaxation time and thermo dynamical parameters are calculated using the experimental data. Conformational analysis of the formation of hydrogen bond in the equimolar binary mixture systems of propan-1-ol with alkyl benzoates is supported by experimental and theoretical FT-IR values.

8 illus, 7 tables, 38 ref

007798   Lin C S;Ho C W;Yang S W;Chen D C;Yeh M S (Automatic Control Engineering Dep, Feng Chia Univ, Taichung, Taiwan) : Automatic optical inspection system for the image quality of microlens array. Indian J pure appl Phys 2010, 48(9), 635-43.

An automatic optical inspection system for the image quality and light field of a microlens array is presented in this paper. For the inspection of microlens array, XY-Table is used to the positioning of micro-lens array. With a He-Ne laser beam as a probing light, the measured image will be shown on the screen. A CCD camera captures the image of the screen and sends the data to the computer to analyze the luminosity function and uniformity. The noise disturbance of energy fluctuation of light field can be filtered by dividing the reference light intensity by the measured value. The light field measurement system checks the photometric quantity of each check point in sequence by distributing check points and several quality parameters are made for analysis to evaluate the uniformity of light field. The novel quality parameters are used to identify the quality of light field and provide a further understanding of the performance of microlens array.

9 illus, 2 tables, 24 ref

007797   Lalmuanpuia;Rosangliana;Thapa R K (Physics Dep, Mizoram University, Aizawl-796 009, Email: lmprenthlei@gmail.com) : Electronic and optical properties of lead telluride (PbTe) by using FP-LAPW method. Sci Vision 2010, 10(4), 143-47.

A theoretical study of electronic and optical properties of PbTe using the full-potential augmented plane waves (FP-LAPW) within density-functional theory (OFT) was presented as implemented in WIEN2k code. We adopted the dipole approximation in our optical calculations. The dielectric function was calculated in the momentum representation, which requires matrix elements of the momentum between occupied and unoccupied states. We identified the microscopic origin of the main features in the optical spectra and find the factors responsible for most of the optical absorption in this system.

5 illus, 8 ref

007796   Kumar V;Singh J K (Electronics and Instrumentation Dep, Indian School of Mines, Dhanbad-826 004, Email: vkumar52@hotmail.com) : Model for calculating the refractive index of different materials. Indian J pure appl Phys 2010, 48(8), 571-4.

Simple model based on energy gap data, has been proposed for calculating the refractive index of different semiconductors, insulators, oxides and halides. The proposed model is applicable to the whole range of energy gap materials. The calculated values of refractive index are compared with the experimental values and the values reported by other researchers. A fairly good agreement has been obtained between them.

1 tables, 25 ref

007795   Khan M S (NO, , H. No. 49, Al-Farooq Colony, Rawalpora, Srinagar, Kashmir-190 005, Email: shafiqifs@gmail.com) : Ultimate proof of energy theory of matter and cosmology: 'theory of everything'. Indian J Sci Technol 2010, 3(8), 948-54.

A new theory 'Theory of everything' is being proposed. This article should be sufficient proof for correctness of Energy Theory of Matter and Cosmology and besides the article disproves the Special Theory of Relativity, General Theory of Relativity and Big Bang Theory.

2 illus,

007794   Khan M S (NO, , H. No. 49, Al-farooq Colony, Rawalpora, Srinagar, Kashmir-190 005, Email: shafiqifs@gmail.com) : Energy theory of matter and cosmology. Indian J Sci Technol 2010, 3(8), 943-7.

A new theory 'Energy theory of matter and cosmology', as an alternative theory, is proposed which could explain all the problems with different theories of physics; the main cause of which are the theories of relativity and resultantly the Big Bang Theory failed. Since it is established that the basic building substance of matter is energy and it has to under the influence of a scalar force field this energy is converted into the matter. The scalar force field originated from the universal creator and with the initiation of the scalar force field energy; of which the matter is made up of; was converted into matter. During the process of conversion of energy into the particles, the particles attained high energies and collisions of the particles started. These particles in the process of fusion emit radiation which finally takes the form of cosmic background radiation and under the influence of said scalar force field, weak nuclear force, strong nuclear force and electromagnetic forces the atoms started forming. Then these atoms under the influence of gravitational force started clustering and thereby planets, stars and other astronomical bodies came into existence.

4 illus, 1 table

007793   Kerur B R;Rajeshwari T;Sharanabasappa;Anil Kumar S;Narayani K;Rekha A K;Hanumaiah B (Physics Dep, Gulbarga Univ, Gulbarga-585 106, Email: kerurbrk@hotmail.com) : Radioctivity level in rocks of North Karnataka, India. Indian J pure appl Phys 2010, 48(11), 809-12.

Deals with the radioactivity of rock samples collected from three towns, one from each district, of northern region of Karnataka, India. The measured mean activity concentrations of ²³²Th, ²³⁸U and ⁴⁰K are found to be 73.54, 47.32 and 114.76 for Gadag, 7.2, 4.9 and 121.8 from Gulbarga and 20.96, 42.2 and 875 Kottur samples, respectively. The measured values of dose rate due to natural radioactivity in the rock samples varied from 11 to 170 (μSv). This study shows that a basalt rock contains lesser radioactivity concentration compared to the green schist belt rocks.

1 illus, 1 table, 9 ref

007792   Karmakar S;Roy N K;Kumbhakar P (Electrical Engineering Dep, National Institute of Technology, Durgapur-713 209, Email: nitdgpkumbhakar@yahoo.com) : Monitoring of high voltage power transformer using direct optical partial discherge detection technique. J Optics 2009, 38(4), 207-15.

In electrical power systems, high voltage power transformers are used to transfer the power from one substation to another. The insulation of the high voltage power transformers are gradually deteriorated due to electrical, chemical and mechanical stresses caused by the partial discharges (PDs). It is well established from several studies that PDs are the major source of insulation failure in HV power transformers. Thus the monitoring of PDs is essential for an early prediction of its life and advanced maintenance. In this paper, direct optical partial discharge detection (DOPDD) technique is used to monitor the PDs in a dielectric test cell, which is considered to be a laboratory model of a high voltage power transformer. The presented method has several advantages, as it is immune to electromagnetic interference, compact in size, and low cost etc.

8 illus, 11 ref

007791   Karhale G A;Kawale R S;Tumberphale U B;Pawar N P;Kalamse G M (P.G. Physics Dep, Microwave Research Lab, N E S Science College, Nanded-431 605, Email: karhalega@gmail.com) : Dielectric study amla (Emblica officinalis Gaertn) at microwave frequency. Bionano Front 2011, 4(1), 173-7.

The effect of packing density and temperature on dielectric parameters, relaxation time, conductivity, moisture content of amla (Emblica officinalis Gaertn) was assessed. The results showed that there was a systematic increase in dielectric crimonstant and loss factor with increasing values of relative packing fraction and decrease in dielectric constant and loss factor with increasing temperature. Moisture content is measured using Thermo-gravimetric method, Expeental results of different relative packing fractions (8r) were further used to obtain transformation to 100% solid bulk using correlation equations of Landau-Lifshitz-Looyeng and Bottcher. There is a good agreement between experimental values and theoretical values of different dielectric parameters. The shows eohesion in the particles of amla powder under investigatton.

8 illus, 2 tables, 17 ref

007790   Kamalaker V;Upender G;Prasad M;Chandra Mouli V (Physics Dep, Osmania Univ, Hyderabad-500 007, Email: vorucm90@yahoo.com) : Infrared, ESR and optical absorption studies of Cu<. Indian J pure appl Phys 2010, 48(10), 709-15.

Glasses of composition 80 TeO_-2(20-x)ZnO-xNaF mol % were prepared by melt quenching technique and characterized by ESR, optical absorption and infrared spectroscopy. The IR spectra reveal that the glass consists of TeO₃, TeO₄, Te(O,F)₃ and Te(O,F)₄ units as local structure of the glass network. The hydroxyl group concentration decreases with the increase of NaF content. From ESR spectra, it is found that the Cu²⁺ ions are in octahedral sites with tetragonal distortion with d_x²-y² as ground state. From the ESR and optical absorption studies, molecular orbital coefficients were calculated and correlated with the structural variation of the glass system. From the optical absorption data, the optical band gap (E_opt) and Urbatch energy (AΔE) values were calculated. It is found that E_opt values increase with NaF content. The low AE values showed that the present glasses were highly homogenous and stable.

5 illus, 5 tables, 43 ref

007789   Kalashasti S;Sanjeeva Rao B;Venkatappa Rao T; Saptagiri Prasad J;Madhukar K;Raju A (Physics Dep, Kakatiya Univ, Warangal-506 009, Email: tvraokmm@yahoo.co.in) : Temperature dependent ESR spectra of irradiated nylon homopolymer. Int J chem Sci 2010, 8(1), 261-8.

Temperature dependent free radical decay behavior in irradiated nylon homopolymer has been investigated by electron spin resonance (ESR) and Fourier transform infrared (FTIR) techniques. The ESR spectrum observed for nylon irradiated to 1 M rad radiation dose has shown a complex shape and eight hyperfine lines. The spectrum is analysed by computer simulations and resolved to be superposition of component spectra arising due to macroradicals of the -CH₂-CH-CH₂ <126>(I) and radicals of the type <126>CHi-C=O (II). The magnetic parameters corresponding to the free radicals were evaluated by theoretical methods. ESR spectra of irradiated nylon were also recorded in the temperature range 300-400 K. The hyperfine structure observed at room temperature (RT) gradually diminished and the ESR signal completely vanished around 405 K. Reasons for this temperature dependent free radical decay has been explained. Fourier Transform Infrared (FTIR) spectra of unirradiated and irradiated nylons were recorded to ascertain chemical changes induced by radiation.

4 illus, 3 tables, 15 ref

007788   Joshi N;Janyani V (Electronics and Communication Engineering Dep, Malaviya National Institute of Technology (MNIT Jaipur), J.L.N. Road, Jaipur-302 017, Email: vijay.janyani@ieee.org) : Efficient coupling of light into photonic crystal waveguides using chirped photonic crystal tapers. J Optics 2009, 38(4), 216-31.

Photonic crystal waveguides are a common application of photonic crystals that are used for realizing integrated optics. Chirping in photonic crystal waveguides is studied for controlled dispersion and optimization of coupling. Study the chirped photonic crystal tapers and observe their transmission characteristics. This would result in low-loss coupling between fiber and photonic crystal waveguide and compactness of photonic integrated circuits. The numerical results obtained by FDTD and PWE methods validate the application of chirped photonic crystal tapers for optimized coupling. The coupling efficiency is increased for frequencies that arise in the band gap as predicted using 2D FDTD simulations.

20 illus, 35 ref

007787   Joshi D S;Sarkar P K (Health Physics Div, Bhabha atomic research center, Mumbai-400 085, Email: dsjoshi@barc.gov.in ) : Estimation of radiation source term and concrete shield thickness for low energy particle accelerators. Indian J pure appl Phys 2010, 48(11), 771-3.

Electron beams with varying energy (0.5-15 MeV) have been extensively used for processing of various materials. Main source of radiation is bremsstrahlung radiations (X-rays) generated when electron beam strikes high Z materials. The emergent spectra have angular distribution and with increasing electron energy X-ray emission rate peaks in the forward direction. Photo neutron generation in such electron accelerator is less significant as it generates after certain threshold energy. The accelerated protons interact with matter and lead to the primary radiological hazards, which consist of prompt radiation (neutrons and gamma). Another source is delayed radiation which is due to induced radioactivity in accelerator component. Thus, in electron accelerator bremsstrahlung radiation and in proton accelerator, neutrons are the main sources of radiation that decide the shield thickness. The emergent radiation has angular distribution and accordingly shield thickness also varies. Radiation source terms are evaluated for 3, 7, 10 and 15 MeV electron beam and 10/20 MeV proton beam accelerator. Required concrete shield thickness for housing these accelerators is also evaluated and presented in this paper. Emergent radiation yield values are verified by Monte Carlo stimulations and are found to be in good agreements.

4 illus, 1 table, 6 ref

007786   Janarthanan S;Rajan Y C;Umarani P R;Jayaraman D;Premanand D;Pandi S (Physics Dep, Presidency College, Chennai-600 005, Email: drspandi2gmail.com) : Synthesis, growth, optical and thermal properties of a new organic crystal semicarbazone of p-anisaldehyde (SPAS). Indian J Sci Technol 2010, 3(8), 885-9.

The semicarbazone of p-anisaldehyde (SPAS) is a novel organic nonlinear optical material. The SPAS has been synthesized and the solubility studies were carried out in the temperature range 30-60 C. Single crystals of SPAS have been grown following the slow evaporation technique and the unit cell parameters have been evaluated by single crystal X-ray diffraction technique. The UV-Visible, FT-IR and ¹HNMR spectra have been recorded to characterize the grown crystal. The thermogravimetric and differential thermal analysis of the grown crystal revealed that there is no phase transformation in SPAS, and its thermal stability was found to be good. The dielectric measurement was made as a function of frequency (50 Hz - 5 MHz). The second harmonic generation in the sample was confirmed by the Kurtz powder technique.

9 illus, 14 ref

007785   Horng J W (Electronic Engineering Dep, Chung Yuan Christian Univ, Chung-Li, 32023, Taiwan, Email: jwhorng@cycu.edu.tw) : Voltage/current-mode universal biquadratic filter using single CCII+. Indian J pure appl Phys 2010, 48(10), 749-56.

Voltage/current-mode universal biquadratic filter using single plus-type second-generation current conveyor (CCII), two capacitors and two resistors has been presented. The proposed voltage-mode circuit has three inputs and two outputs and can realize all the standard filter functions, which are, lowpass, bandpass, highpass, notch and allpass filters, without changing the circuit topology. One more simultaneous output filter response can be obtained from some derived filter types. The proposed current-mode circuit has two inputs and three outputs and can realize all the standard filter functions without changing the circuit topology. Each of the proposed circuits employs only one plus-type CCII (CCII+) that simplifies the configuration.

12 illus, 20 ref

007784   Gupta D;Srivastava N K (Radiotherapy Dep, Dr. S.N. Medical College, Jodhpur-342 003) : Photo conductive response in vacuum-deposited unalloyed and alloyed thin films of some metal oxides. J Optics 2009, 38(4), 199-206.

Thin films of tin oxide, alloyed with antimony have been grown on glass substrate with varying thicknesses and substrate temperature using electron beam evaporation method. In similar manner, a few thin films using indium oxide alloyed with antimony have also been prepared. These films were annealed to improve their electrical conductivity and optical transmission. XRD spectra of a few samples revealed mixed phases of the oxides with different orientation of lattice planes. The transmittance and reflectance data of these films were used to first compute absorption coefficient (a) and then to estimate the optical band gap. The optical band gaps are found to lie in the range of 3 eV corresponding to extreme lower wavelength of VIS range and the films had good optical transmission (<126> 80 %) over VIS range. Based on this knowledge, a suitable violet lamp (λ: 185-320 nm) was used to radiate the prepared thin films and the photo current generated was measured with sensitive electrometer. The variation of current with time has been measured both on application and withdrawal of incident radiation. The fast and slow carrier life time have been calculated to obtain photo current gain and maximum 3dB band width. The results have been discussed in term of deposition parameters and alloying.

2 illus, 1 table, 6 ref

007783   Ghosh N;Bhattacharya K (Applied Optics and Photonics, Calcutta Univ, 92, Acharya Prafulla Chandra Road, Kolkata-700 009, Email: nandinighosh1@yahoo.com) : Cube beam-splitter interferometer for phase shifing interferometry. J Optics 2009, 38(4), 191-98.

A cube beam splitter (CBS), which is more often used in two beam interferometers to generate orthogonally directed light beams, can interestingly be used to construct a two beam interferometer by aligning its beam splitting surface parallel to the direction of propagation of light. It is shown that in such a configuration, an optical sample placed so as to intercept one half of the expanded incident beam may be tested for phase or surface distortions. The proposed set-up can be used as well to construct a phase shifting interferometer by properly incorporating a quarter-wave plate and a polarizer for phase shifting, which can then be used to analyze phase or surface irregularities in optical samples. The monolithic design of the proposed interferometer makes it relatively immune to ambient vibrations.

7 illus, 12 ref