018955   Rani S;Mohan D;Kishore N (NO, Guru Jambheshwar University of Science and Technology, Hisar-125 001, Email: sgarhwal48@gmail.com) : Effect of swift heavy ions irradiation on third order nonlinear optical properties of As₂S₃ chalcogenide films. Invertis J Sci Technol 2012, 5(2), 79-84.

Third order nonlinear optical response and optical switching in Ge irradiated As₂S₃ thin film at room temperature [As₂S₃/Ge(RT)], Ge and Ni irradiated As2S3 thin films at liquid nitrogen temperature [As₂S₃/Ge(LNT)], [As₂S₃/ Ni(LNT)] have been observed using single beam z-scan technique at second harmonic of Nd: YAG laser (532nm). Nonlinear refractive index (n₂), nonlinear absorption coefficient and third order nonlinear susceptibility (<157>3) As₂S₃/Ge(LNT) and As₂S₃/Ni(LNT) thin films have been estimated. Self defocusing (n₂<60>0) in As₂S₃/Ge(LNT), self focusing (n₂<62>0) in As₂S₃/Ge(RT) and As₂S₃/Ni(LNT) have been observed. The results have been interpreted in terms of electrostriction effect and variation in band gap with heavy ion effect. Further optical switching behavior has been assessed as a function of input intensity. Higher nonlinearity has been observed in As₂S₃/Ge(LNT) and it has been found that the swift heavy ion irradiated films are much more promising materials for nonlinear optics, functional optical fibers and ultrafast optical switching.

018954   Purnima;Devendra Mohan;Jyoti D (Laser Lab, Applied Physics Dep, Guru Jambheshwar University of Science and Technology, Hisar-125 001, Email: arya.manu14@gmail.com) : Optical limiting behavior in nickel complex dye doped polymeric and silica matrix under nanosecond laser source excitation. Invertis J Sci Technol 2012, 5(2), 98-102.

During the present course of investigations, nickel-complex bis (4-dimethylaminodithiobenzyl)-nickel)(BDN) dye is encapsulated in poly-methylmethacrylate (PMMA) and tetra-ethylorthosilicate (TEOS) matrix to obtain solid-state transparent samples. Nanosecond pulses of Nd: YAG laser at 532nm wavelength with 5ns pulses and 200mJ maximum energy per pulse is employed as source for experimental characterization of optical limiting behavior. Limiter performance parameters viz. limiting threshold and dynamic range are reported. Comparative analysis of limiting character of the dye in polymeric and silica matrices is made. Self-defocusing and nonlinear absorption attributes to limiting behavior in polymer matrix whereas in silica environment, limiting is governed by nonlinear scattering due to nanoscale pore-size.

018953   Patel K;Negi P S;Banerjee P (NO, CSIR-National Physical Laboratory, New Delhi-110 012, Email: kpatel@nplindia.org) : Analysis and development of Ka- and Q-band waveguide impedance standards. MAPAN 2012, 27(2), 97-103.

Reports the salient design features and performance analysis of a precision waveguide, standard mismatches of voltage standing wave ratios (VSWRs) 1.10, 1.20 and 1.30 at Ka-band frequencies. Also standard waveguide sections and flush shorts are developed at Ka-band and Q-band and these are analyzed based on their physical dimensions, respectively. The performances of precision waveguide and standard mismatches are observed based on their dimensions and compared with measured values using slotted line technique at Ka-band. The calibration results of mismatch set are found with good agreement for their designated VSWRs with expanded uncertainties <60>0.03 and their traceability is established through the precision waveguide. These standards will serve as transfer standards of impedance at Ka-band and Q-band ranges and to assign the accuracy of impedance measuring instruments.

7 illus, 4 tables, 23 ref

018952   Parsai N;Mishra A;Shrivastav B D (Sanghvi Innovative Academy, Institute of Technology and Management, Pragati Vihar II, Indore-452 010, Email: parsai.neetu@gmail.com) : X-ray K-absorption spectral studies of cobalt (II) hydroxamic mixed ligand complexes. Indian J pure appl Phys 2013, 51(3), 185-90.

X-ray absorption fine structure (XAFS) at the K-edge of cobalt has been studied in some cobalt (II) mixed ligand complexes having hydroxamic acid as one of the ligands. The study can be used to yield useful and important information about the molecular structure of the complexes. The X-ray absorption measurements have been performed at the recently developed BL-8 dispersive EXAFS beamline at 2.5 GeV Indus-2 Synchrotron Source at RRCAT, Indore, India. The data obtained has been processed using EXAFS data analysis program Athena. From the experimental measurements, the energies of the K absorption edge, chemical shifts, edge-widths, shifts of the principal absorption maximum in the complexes have been estimated. The data obtained from these studies have been utilized to estimate effective nuclear charge.

3 illus, 3 tables, 14 ref

018951   Mekawy M;El Din Mahmoud E;Mohy E (Thermometry Dep, National Institute for Standards (NIS), Tersa Street, P.O. Box 136, El-Haram, Giza 12211, Egypt, Email: essam70@yahoo.com ) : Re-realization of the NIS national viscosity scale and its range extension up to 250,142 mm<. MAPAN 2012, 27(2), 129-32.

Wide-range viscosity standard system has generally been realized with capillary viscometers, which are calibrated by the stepping-up method on the basis of viscosity value of distilled water at 20 °C. As per recommendation of Bureau International des Poids et Mesures (BIPM), the national primary viscosity scale must be realized every 10 years. The present work is an attempt to re-realize the existing scale and extend it to from 70,000 to 250,142 mm²/s. This would enable NIS to calibrate different types of viscometers with the highest constant. The NIS viscosity scale was first realized in 2001 [1] using glass capillary viscometers in the range from 1 to 70,000 mm²/s. From the present calibration results of the NTS viscometers, the present scale is realized with an uncertainty of about 0.07% at low viscosities (0.9 mm²/s) rising to about 0.25% at higher viscosities (250,142 mm²/s).

4 tables, 7 ref

018950   Kwon J Y;Kang J S;Lee D J;Kim J H (Center for Electromagnetic Wave, Physical Metrology Div, Korea Research Institute of Standards and Science (KRISS), 267 Gajeong-Ro, Yuseong-Gu, Daejeon-305 340, Republic of Korea, Email: jykwon@kriss.re.kr) : Analysis of a steppes air line using an air line simulator. MAPAN 2012, 27(2), 105-11.

Stepped air line is investigated by using the mode matching method with mode expansion in the transverse direction of the line. To account for the effect of the air line loss, particularly on the propagation constant, a loss compensation is applied. Next, we develop a stepped air line simulator with a GUI-based program language. The competitiveness of the simulator is numerically verified with simulated results of a commercial FEM tool and experimentally with measured results of commercially available air lines with a vector network analyzer up to 50 GHz. Simulated S-parameters of a stepped air line with specific step diameters are presented.

9 illus, 10 ref

018949   Kumar R;Titus S S K;Jain S K (Force and Hardness Standards, National Physical Laboratory, New Delhi-110 012, Email: titus@nplindia.org) : Establishment of Brinell hardness standard at NPL India for providing traceability in Brinell scale. MAPAN 2012, 27(2), 123-7.

Hardness evaluation is one of the most important and commonly used methods for material or product testing. However, the hardness measurements done in the industry are of limited accuracy due to the non-availability of standard hardness blocks having very precise and accurately assigned hardness values traceable to national primary standard. National Physical Laboratory, India has recently established a primary standard for Brinell hardness scale (HBW), besides the existing Vickers (HV) and Rockwell hardness (HR) primary standards. The uncertainty associated with the Brinell hardness standard is found to be within ±1.5% for HBW1/1 to HBW1/30 and is determined to be within ±1.0% for other HBW scales, which is also validated through comparison with precision hardness standard blocks. Some of the salient features of the machine are described and the measurement results obtained on standard hardness blocks are reported.

4 illus, 5 tables, 9 ref

018948   Kavitha B;Siva Kumar K;Narsimlu N (Physics Dep, Osmania Univ, Hyderabad-500 007, Email: bkavithaou@gmail.com) : Synthesis and characterization of polyaniline nano-fibres. Indian J pure appl Phys 2013, 51(3), 207-9.

Polyaniline (PANI) nanofibers were synthesized by polymerization of aniline in the presence of hydrochloric acid as a catalyst and ammoniumperoxidisulphate as an oxidant by the chemical oxidative polymerization method. The product powder was pelletized with the help of hydraulic machine to study the XRD, SEM and SANS. The XRD pattern indicates semi -crystalline nature of PANI with interplanar distance 4.210 Angustrum and 3.774 Angustrum, respectively. The SEM pictures show fiber like nature of particles. SANS experiment is used to find different parameters of these crystalline polymer nano-fiber particles. Dynamic light scattering (DLS) studies are performed to find the sizes of nano structured polyaniline.

5 illus, 9 ref

018947   Kalpana P;Jayakumar K;Nithiananthi P (Physics Dep, Gandhigram Rural University, Gandhigram-624 302, Email: nithiadhi@yahoo.com) : Effect of - X mixing on the donor states in a quantum dot. Invertis J Sci Technol 2012, 5(2), 106-8.

Effect of Γ- X mixing on the donor states due to the application of hydrostatic pressure in a GaAs/AlxGa1-xAs Quantum Dot has been investigated for various Al compositions. The Schrodinger equation is solved by variational method in the effective mass approximation. The results are presented and discussed.

018946   Gupta S V;Kumar A (NO, CSIR-National Physical Laboratory (CSIR-NPLI), New Delhi, Email: satyavirji@yahoo.co.in ) : Propagation of uncertainty in establisung the viscosity scale. MAPAN 2012, 27(2), 83-6.

Viscosity scale is established by step up method, in which several master viscometers and standard liquids are used. Starting point is the distilled water. The basic measurand is the efflux time. Uncertainty in the determination of viscometer constant of a viscometer or the kinematic viscosity of standard liquid at a particular step is carried forward for subsequent steps. The expressions for uncertainty for viscometer constant of the viscometer and kinematic viscosity of the liquid in nth step have been derived. Various applicable corrections and their contribution to uncertainty have been discussed.

1 illus, 5 ref

018945   Ghosh D;Deb A;Biswas S;Sarkar R (Nuclear and Particle Physics Research Centre, Physics Dep, Jadavpur Univ, Kolkata-700 032, Email: dipakghosh_in@yahoo.com) : Multiplicity dependent pion azimuthal fluctuation study with factorial correlator. Indian J pure appl Phys 2013, 51(3), 156-63.

The multiplicity dependence of fluctuation of pions produced in ³²S-AgBr interactions at 200 AGeV in azimuthal angle (φ) space in terms of a very rigorous technique (factorial correlator), has been studied in the present paper. The analysis shows that the strength of non-statistical fluctuations increases with the increase of multiplicity.

6 illus, 4 tables, 36 ref

018944   Balachandran V;Karthick T;Perumal S;Nataraj A (P G & Research Physics Dep, Arignar Anna Government Arts College, Musiri, Tiruchirapalli-621 211, Email: brsbala@rediffmail.com) : Comparative theoretical studies on natural atomic orbotals, natural bond orbitals and simulated UV-visible spectra of N-(methyl)phthalimide and N-(2 bromoethyl)phthalimide. Indian J pure appl Phys 2013, 51(3), 178-84.

The charge delocalization patterns of phthalimide derivatives such as N-(methyl)phthalimide and N-(2-bromoethyl)-phthalimide have been performed with the help of natural bond orbital (NBO) analyses and simulated UV-visible spectra. The second order perturbation energies of the most interacting NBOs and the population of electrons in core, valance and Rydberg sub-shells have been predicted by density functional theory (DFT) computations in GAUSSIAN 03W software package. In the present study, the natural atomic orbital occupancies showed the presence of charge delocalization within the molecule. The natural hybrid atomic orbital studies enhance us to know about the type of orbitals and its percentage of s-type and p-type character. In addition, the excited electronic transitions along with their absorption wavelengths, oscillator strengths and excitation energies for the gaseous phase of the title molecules have been computed at TD-DFT/B3LYP/6-311 ++G(d,p) method. The energetic behaviour of the compound in different solvent medium (water, ethanol, and methanol) has been examined by applying polarizable continuum model (PCM). The complete molecular orbital simulations and theoretical UV-visible spectra have been carried out in this study which yield better understanding of charge delocalization pattern and stability of the title molecules to a greater extent.

5 illus, 5 tables, 19 ref

018943   Arivazhagan M;Arunagiri C;Subashini A (P G & Research Physics Dep, A A Government Arts College, Musiri-621 211, Email: jimarivu@yahoo.co.in) : Quantum chemical determination of molecular geometries and interpretation of FT-IR and FT-Raman spectra for 3,4-dinitrotoluene. Indian J pure appl Phys 2013, 51(3), 191-201.

The FT-IR and FT-Raman vibrational spectra of 3,4-dinitrotoluene (3,4-DNT) have been recorded in the region 400-4000 cm^-1 and 50-3500 cm^-1, respectively. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on DFT (Density Functional Theory)-B3LYP using 6-31+G(d,p) and6-31 l++G(d,p) basis sets. A complete vibrational assignment aided by the theoretical harmonic frequency analysis has been compared with experimental FT-IR and FT-Raman spectra. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) energies confirms the occurrence of ICT (Intramolecular Charge Transfer) within the molecule. The calculated HOMO and LUMO energy gaps also confirm that charge transfer occurs within the molecule. A sufficient general agreement between the theoretical and the experimental spectra has been achieved.

5 illus, 5 tables, 44 ref

017999   Sharma N;Kumar S (Physics Dep, Christ Church College, Kanpur-208 001, Email: dr_santosh_kr@yahoo.com) : High field conduction in thin films of Se_100-xPb_x glassy alloys. Indian J pure appl Phys 2013, 51(2), 125-30.

The dc conductivity of amorphous thin films of Se_100-xPb_x (x = 0, 2, 4, 6 and 10) glassy alloys in vacuum evaporated and at high electric fields, has been measured. Current-Voltage (I-V) characteristics have been measured at various fixed temperatures. In these samples, at low electric fields, ohmic behaviour is observed. However, at high electric fields (E-10⁴ V/cm), non-ohmic behaviour is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the glassy materials studied in the present case. From the fitting of the data to the theory of SCLC, the density of defect states (DOS) near Fermi level is calculated. Increase in DOS with increase in Pb concentration has been observed which could be correlated with the electro-negativity difference between the constituent elements used in making the above glassy alloys.

8 illus, 1 table, 27 ref

017998   Rajakumar T M;Uma V;Chandramani R (Research and Development Centre, Bharathiar Univ, Coimbatore-641 046, Email: rajtm01@gmail.com) : Magneto-transport and mechanical properties of thermally evaporated Cd chalcogenide films. Indian J pure appl Phys 2013, 51(2), 131-7.

Cadmium (Cd) chalcogenide films containing tellurium (Te) and selenium (Se) in different proportions have been deposited by thermal evaporation and electron beam evaporation on different substrates. Hall effect and magneto resistance (MR) of the deposited films have been studied. From the Hall effect study, carrier concentration and the sign of the carriers have been obtained. Magneto resistance and ratio of the longitudinal and transverse magneto resistance have also been determined for all the compositions to know the shape of the Fermi surface. Mechanical characterization of all the grown films has been carried out employing Vicker's micro hardness tester to know the suitability of the films for the device application. Various hardness parameters like Vicker's hardness number (H_v, Meyer's Index (n), yield strength (σ_v), elastic stiffness constant (C₁₁) have been evaluated for all the deposited films. Studies confirm that the deposited films have good hardness and magneto transport properties making them suitable for the device application.

5 illus, 5 tables, 22 ref

017997   Prajapati A N;Rana V A;Vyas A D (Applied Physics Dep, Faculty of Technology and Engineering, M S Baroda Univ, Vadodara, Email: ranava2001@yahoo.com) : Study of molecular interaction between some primary alcohols and anilines using concentration dependent dielectric properties. Indian J pure appl Phys 2013, 51(2), 104-11.

The static dielectric constant (ε₀) and optical dielectric constant (ε_∞ = n²) of binary mixtures of some lower order primary alcohols with aniline, 2-fluoroanirme and 4-fluoroaniline over the concentration range (0.0, 0.1, .... 1.0) by volume fractions are measured at fix frequency 2 MHz using precision LCR meter and Abbe's refractometer, respectively. The excess dielectric constant, Kirkwood correlation parameter and Bruggeman parameter have been evaluated. The variations of these parameters with composition indicate the presence of molecular interaction between the participating components in these mixtures.

5 illus, 4 tables, 25 ref

017996   Kumar R;Munish Kumar (Physics Dep, G B Pant agriculture and Technology Dep, Pantnagar-263 145, Email: munish_dixit@yahoo.com) : Equation of state for nanomaterials from thermal expansion. Indian J pure appl Phys 2013, 51(2), 87-93.

Simple thermodynamic analysis of equation of state (EOS) is discussed from the knowledge of thermal expansion of nanomaterials based on molecular dynamics simulation. The formulation is used to study the isothermal compression and pressure dependence of bulk modulus of ten nanomaterials viz. CdSe, γ-Fe_{2O3, Fe, γ-Al2O3, 3C-SiC, Ni, Fe filled multi-walled carbon nanotube, Ni filled multi-walled carbon nanotube and ZnO nanorod. The results obtained are found to be in good agreement with the available experimental data, which demonstrate the validity of the formulation used in the present study.}

20 illus, 2 tables, 23 ref

017995   Kholiya K (Applied Science Dep, B T Kumaon Institute of Technology, Dwarahat-263 653, Email: kuldeep_phy1@rediffmail.com) : High pressure equation of state for nano materials. Indian J pure appl Phys 2013, 51(2), 94-7.

The modified Shanker formulation by Kumar and Kumar, Indian J Pure & Appl Phys, 46 (2008) 378) to study the compression behaviour of carbon nanotubes (bundle and individual tube) has been shown to be mathematically inconsistent. It is mentioned that one should modify the Suzuki EOS rather than the Shanker EOS, as Suzuki EOS is also not mathematically consistent while the Shanker EOS is thermodynamically and mathematically consistent. The results obtained using the thermodynamically consistent formulation (modified Suzuki EOS) are found to be in better agreement with the experimental data than the Shanker and Suzuki EOS for compression behaviour. Pressure dependence of bulk modulus and its first order pressure derivative for carbon nanotubes using the present formulation are also given and discussed.

6 illus, 14 ref

017994   Ido T (NO, National Institute of Information and Communications Technology, Koganei, Tokyo 184-8795, Japan, Email: ido@nict.go.jp) : Optical lattice clock. MAPAN 2012, 27(1), 9-12.

Latest progress in optical atomic clocks is so rapid that serious discussions toward the redefinition of the second is initiated. Besides single ion clocks developed since early 1980s, optical lattice clocks just invented a decade ago are one of strong candidates as a method to realize the revised definition. The current situation of this emerging method of optical clocks is briefly described.

2 illus, 15 ref

017993   Hayasaka K (NO, National Institute of Information and Communications Technology, 588-2 Iwaoka-cho, Nishi-ku, Kobe 651-2492, Japan, Email: hayasaka@nict.go.jp) : Recent progress of single-ion optical frequency standards. MAPAN 2012, 27(1), 3-7.

Recent progress of single-ion optical frequency standards is reported. Based on clock transitions in single ions trapped and laser-cooled in ion traps, measurements with fractional uncertainties down to the 10^-18 level have been achieved. Overview of the measurements reported so far is described. New attempts to overcome the limitations of the measurements are also reviewed.

3 illus, 1 table, 24 ref

017992   Devendra Mohan;Divya Jyoti;Dhar R;Singh A (Laser Laboratory, Applied Physics Dep, Guru Jambheshwar Science and Technology Univ, Hisar-125 001, Email: divyabathla17@gmail.com) : Swift heavy ion tailoring of anatase TiO₂ film for its use in dye-sensitized solar cells. Invertis J renewable Energy 2013, 3(1), 1-5.

Track radii of swift heavy ions against electronic stopping power have been estimated using thermal spike model. The time evolution of lattice temperatures at several different values of track radii in anatase TiO₂ film irradiated with 100MeV O(16), 100MeV Si(28), 100MeV Ni(58) ions have been predicted. Study of track radii can help to optimize the porosity of the film which is a major efficiency governing factor in dye-sensitized solar cells. It has been observed that radius of lattice temperature over the melting point of anatase TiO₂ He very dose to the radius of the stressed region.

2 illus, 18 ref

017991   Chopra K N (Applied Physics Dep, Maharaja Agrasen Institute of Technology, Rohini, GGSIP Univ, New Delhi-110 086, Email: kchopra2003@gmail.com) : Technological note on some novel concepts connected with spintronics. Invertis J Sci Technol 2013, 6(2), 115-28.

Spintronics, or spin electronics, is based on the controlling and manipulating the spin degrees of freedom in solid-state systems. The basic principles of the generation of carrier spin polarization, spin dynamics, and spin-polarized transport have been discussed. It is important to note that the spin transport is basically different from the charge transport, as the spin in solids is dependent on the spin-orbit and hyperfine coupling, and thus is a nonconserved quantity. A short technological note on some novel concepts connected with Spintronics from the applications point of view has been presented for the benefit of the new researchers and designers in this fast growing field.

9 illus, 1 table, 24 ref

017990   Chopra K N (Applied Physics Dep, Maharaja Agrasen Institute of Technology, Rohini, GGSIP Univ, New Delhi-110 086, Email: kchopra2003@gmail.com) : Technical note on the types of the renewable energy sources, and their comparison in checking global warming. Invertis J renewable Energy 2013, 3(1), 58-65.

Renewable Energy is a rapidly evolving field, which is based on the energy coming from the natural resources like sunlight, wind, rain, tides, and waves. Various forms of renewable energy like - Hydro Energy, Wind Energy, Biomass Energy, Geothermal Energy, and Radiant Solar Energy have been briefly described. Fuel Cells, Organic Solar Cells, and Types of Fuel Cells, and also the advantages and disadvantages of various forms of energy have been discussed. Types of Solar efficiency and their calculation have been briefly listed. The importance of the Fiber Optics in Solar Energy has been discussed. The rapid growth of nanotechnology research and their potential impact on the growing energy crisis have been brought out. The recent efforts to finalise the use of the most efficient energy sources for checking the global warming have also been presented in this note.

4 illus, 24 ref

017989   Chattopadhyay P;Guha Roy S (Electronic Science Dep, Calcutta Univ, Kolkata-700 009, Email: pcelc@cal.univ.ac.in ) : Simple method of controlling the resistivity of silver sulphide thin film prepared by chemical conversion technique. Indian J pure appl Phys 2013, 51(2), 98-103.

Simple way of controlling the resistivity of silver sulphide thin film prepared by chemical conversion of cadmium sulphide thin film, used as a source material, has been studied. It is found that the resistivity of the silver sulphide film prepared in this way depends largely upon the heat treatment of the source material. The resistivity is found to decrease from a value of 30.18 to 4.79 Ω-cm when the source cadmium sulphide film is given a prior heat treatment at about 200°C for the preparation of Ag₂S films. The SEM measurements on the Ag₂S films obtained converting heat treated source material, have revealed the grain size to vary in the range 15.38-38.45 nm. The EDS results confirm the presence of silver, sulphur and cadmium predominantly in the converted samples. An examination of XRD data of Ag₂S thin films reveals the crystalline nature of the material. The dc current-voltage characteristics of the samples are interpreted by considering the polycrystalline nature of the film and thermionic emission to be the dominant transport mechanism across the grain boundaries.

4 illus, 1 table, 32 ref

017988   Bhoopal R S;Sharma P K;Sajjan Kumar;Singh R; Beniwal R S (Thermal Physics Laboratory, Physics Dep, Rajasthan Univ, Jaipur-302 055, Email: singhrvs@rediffmail.com) : Neural network-based prediction of effective thermal conductivity of loose multi-phase systems. Indian J pure appl Phys 2013, 51(2), 118-24.

The use of an artificial neural network (ANN) approach has increased in many areas of engineering problems in the past few years. The objective of this study is to develop an artificial neural network (ANN) model to predict the effective thermal conductivity (ETC) of loose multi-phase systems that is based on experimentally measured variables. A three-layer feedforward ANN structure is constructed and a backpropagation algorithm is used for the training of ANNs. ANN models are based on feedforward backpropagation network with training functions such as: Levenberg-Marquardt (LM), one-step secant (OSS), resilient backpropagation (RP), and scaled conjugate gradient backpropagation (SCG). The training algorithm for neurons and the hidden layers for different feedforward backpropagation networks at the uniform threshold function TANSIG-PURELIN is used and run for 100 epochs. The predicted effective thermal conductivities of loose multi-phase systems are in good agreement with the available experimental data. The study demonstrates the utility and efficiency of the ANN model for estimating the ETC of loose multi-phase systems.

7 illus, 24 ref

017987   Arora P;Purnapatra S B;Acharya A;Kumar R;Sen Gupta A (Time and Frequency Div, National Physical Laboratory (CSIR-NPL), New Delhi, Email: arorap@mail.nplindia.ernet.in) : Measurement of temperature of atomic cloud using time-of-flight technique. MAPAN 2012, 27(1), 31-9.

Presents a discussion on the time-of-flight (TOF) technique for measuring temperature of cold atom clouds, with specific focus on fountain experiments. In these experiments, there exists a possibility of losing substantial number of atoms owing to the interaction of the cloud with the wall of the cavity, in case the dimension of the former exceeds the latter. Hence, we propose to include the contribution of the location and geometry of the cavity in the TOF method which otherwise, generally relies on the cloud shape and the geometry of the probe beams only. A theoretical analysis is presented and it is substantiated with experimental results for cloud temperatures of <60>10 μK and toss heights of up to 72 cm.

9 illus, 13 ref

017986   Abdullah E T;Hasan S M;Naje A N (Physics Dep, College of Science, Baghdad Univ, Iraq, Email: estabrak_talib@yahoo.com ) : Optical properties of PVC-MWCNT nano composites. Indian J pure appl Phys 2013, 51(2), 77-80.

The fabrication of multi wall carbon nanotube (MWCNT)/polyvinyl chloride (PVC) composites and a study of their optical properties are reported. The nano composites have been fabricated by casting method. The optical properties of (PVC-MWCNT) nano composites have been investigated with different concentration (0, 0.05, 0.005, and 0.0005) wt%. Results showed that the absorbance in near UV regions is high. Absorption coefficient, extinction coefficient, refractive index and real and imaginary parts of dielectric constants are increasing with increase in the MWCNT content.

7 illus, 1 table, 16 ref

017042   Zomorrodian M E;Khorramabadi F;Sepehri A; Eslami P (Physics Dep, Ferdowsi Mashhad Univ, School of Sciences, 91775-1436, Mashhad, Iran) : Two-particle momentum correlations in jets produced in e<. Pramana J Phys 2012, 78(5), 729-36.

The goal of this analysis is to measure the two-particle momentum correlation in jets, in the reaction e⁺e → hadrons, to study its dependence on jet energy, and compare the results with analytical predictions of the next-to-leading log approximation (NLLA), using data collected by the AMY detector at a centre of mass energy of 60 GeV. Results are obtained for charged particles and for events with E_c.m. == 60 GeV.

6 illus, 13 ref

017041   Zhou Z J;Wang H Y;Zhang K B (Physics Dep, Sichuan Science and Engineering Univ, Ziging-643 000, China, Email: zhjzhouzhijian@sina.com) : Dust-acoustic solitary waves in a dusty plasma with two-temperature nonthermal ions. Pramana J Phys 2012, 78(1), 127-33.

By using reductive perturbation method, the nonlinear propagation of dust-acoustic waves in a dusty plasma (containing a negatively charged dust fluid, Boltzmann distributed electrons and two-temperature nonthermal ions) is investigated. The effects of two-temperature nonthermal ions on the basic properties of small but finite amplitude nonlinear dust-acoustic waves are examined. It is found that two-temperature nonthermal ions affect the basic properties of the dust-acoustic solitary waves. It is also observed that only compressive solitary waves exist in this system.

3 illus, 20 ref

017040   Wu Y F (Electronic Engineering Dep, Ming Chi Technology Univ, New Taipei City 24301, Taiwan, Email: yfwu@mail.mcut.edu.tw) : Investigation of strain effect in InGaN/GaN multi-quantum wells. Indian J pure appl Phys 2013, 51(1), 39-43.

Strain effect of InGaN/GaN multi-quantum wells with different indium contents has been studied in the present paper. The high-resolution X-ray diffraction (HRXRD) curves of the samples have been measured and analyzed by a theoretical model. Based on the model, it is found that sample with higher indium content exhibits a stronger internal strain. To further investigate the calculated results, the injection-current dependent electroluminescence (EL) spectra have been carried out for the samples. An evident blueshift of EL peak energy with increasing current is observed for the sample with higher indium content, implying a stronger quantum-confined-Stark effect and internal strain of it. The inference obtained from the HRXRD line profile analysis is confirmed by the experimental results. The HRXRD can be used as an effective tool to investigate the internal strain of InGaN/GaN MQW heterosystems.

6 illus, 18 ref

017039   Thomas S;Varghese G;Lagzi I (Physics Dep, Calicut Univ, Malappuram-673 635, Email: gvphysics@gmail.com) : Width of Liesegang bands: a study using moving boundary model and simulation. Pramana J Phys 2012, 78(1), 135-45.

The pattern formation in reaction-diffusion systems was studied by invoking the provisions contained in the moving boundary model. The model claims that the phase separation mechanism is responsible for separating the colloidal phase of precipitants into band and non-band regions. The relation between the band separation and its width are invariably related to the concentration of the reacting components. It was observed that this model provides critical condition for the band formation in semi-idealized diffusion systems. An algorithm for generating the band structure was designed, and the simulated pattern shows a close resemblance with the experimentally observed ones.

3 illus, 39 ref

017038   Thirukkanesh S;Ragel F C (Mathematics Dep, Eastern Univ, Chenkalady, Sri Lanka, Email: thirukkanesh@yahoo.co.uk) : Exact anisotropic sphere with polytropic equation of state. Pramana J Phys 2012, 78(5), 687-96.

Study static spherically symmetric spacetime to describe compact objects with anisotropic matter distribution. We express the system of Einstein field equations as a new system of differential equations using a coordinate transformation, and then write the system in another form with polytropic equation of state and obtain two classes of exact models. The models satisfy all major physical features expected in a realistic star. For polytropic index n = 2, we obtain expressions for mass and density which are comparable with the reported experimental observations.

39 ref

017037   Tejeiro J M;Larranaga A (National Astronomical Observatory, National Colombia Univ, Bogota, Colombia, Email: ealarranaga@unal.edu.co) : Noncommutative geometry-inspired rotating black hole in three dimensions. Pramana J Phys 2012, 78(1), 155-64.

Finds a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole. We deduce the thermodynam-ical quantities of this black hole and compare them with those of a rotating BTZ solution and give corrections to the area law to get the exact nature of the Bekenstein-Hawking entropy.

6 illus, 21 ref

017036   Talebian M;Talebian E;Abdi A (Physics Dep, Faculty of Science, Urmia Univ, Urmia, P.O. Box 165, Iran, Email: m.talebian@urmia.ac.ir) : Calculation of active Raman modes of α-quartz crystal via density functional theory based on B3LYP Hamiltonian in 6-311+G(2d) basis set. Pramana J Phys 2012, 78(5), 803-10.

Obtained an approximation of the force field of α-quartz crystal using a new idea of applying density functional theory [J Purton, R Jones, C R A Catlow and M Leslie, Phys. Chem. Minerals 19, 392 (1993)]. Calculations were based on B3LYP Hamiltonian [A N Lazarev and A P Mirgorodsky, Phys. Chem. Minerals 18, 231 (1991)] in 6-31 l+G(2d) basis set for H₁₆Si₇O₆ cluster and included a unit cell of the lattice. The advantage of our method is the increase in the speed of calculations and the better adaption of simulation results with the experimental data.

6 illus, 3 tables, 34 ref

017035   Singh D K;Pandey D K;Yadav R R;Singh D (Physics Dep, Government Inter College, Bangra, Jalaun-285 121, Email: pandeydrdk@rediffmail.com) : Study of nanosized zinc oxide and its nanofluid. Pramana J Phys 2012, 78(5), 759-66.

The synthesis and characterization of nanosized zinc oxide and its nanofluid in a polyvinyl alcohol (PVA) matrix have been done in the present investigation. Crystalline zinc oxide nanoparticles are synthesized using single-step chemical method while the nanofluids are prepared by the dispersion of nanoparticles in PVA solution using an ultrasonicator. The prepared nanoparticles are characterized using X-ray diffraction, SEM-EDX and UV-visible spectrum. The particle size distribution measurement is carried out by acoustic particle sizer. The ultrasonic velocities are measured in the synthesized nanofluid under different physical conditions using an ultrasonic interferometer. It is found that the degree of crystallinity of nanoparticles depends on the evaporation rate during its synthesis and ultrasonic velocity has non-linear relation with temperature for the present nanofluid.

6 illus, 26 ref

017034   Siddaraju G N;Ananda H T;Somashekarappa H; Somashekar R (Physics Dep, J S S Women's College, Saraswathipuram, Email: rs@physics.uni-myscore.ac.in) : Effect of electric field on mulberry (bivoltine) and tassar fibres. Indian J Fibre Text Res 2012, 37(4), 347-52.

Effect of AC electric field on mulberry (bivoltine) and tassar silk fibres has been studied using X-ray scattering technique. Microstructural parameters are computed using line profile analysis for fibres subjected to various magnitudes of AC electric fields. Crystallite shape ellipsoids obtained from these analyses have been compared. By adopting the axial stress equation for a fibre, the findings have been used to explain the behaviour of silk in the presence of an external electric field. The variations in microstructural parameters of the samples in the applied electric field gradient reveal the fact that there is deformation of samples from the varying electric field which is equivalent to a non-hydrodynamic compression. The increase in the elastic modulus parameters is due to two factors, namely (i) the presence of varying electric field and (ii) the polymer network (crystallite) strengthening.

4 illus, 2 tables, 13 ref

017033   Shchigolev V K (Theoretical Physics Dep, Ulyanovsk State Univ, 42 L Tolstoy Street, Ulyanovsk-432 000, Russia, Email: vkshch@yahoo.com) : Cosmological model of interacting phantom and Yang-mills fields. Pramana J Phys 2012, 78(5), 819-25.

Authors consider a model of interacting phantom and Yang-Mills (YM) fields by assuming dilaton-type coupling. Using the specific solution for YM equation previously found by the author, we obtain simple exact solutions for the accelerated expansion of the Friedmann-Robertson-Walker (FRW) cosmological model. Besides, authors derive induced potentials of phantom field corresponding to some given regimes of expansion. The effective equations of state (EoS) have been reconstructed for all types of models considered here.

1 illus, 34 ref

017032   Samir Z;Samia B;Abdelhafid C;Redha L M (NO, Constantine Univ, Faculty of Engineering, Institute of Electronic, Semiconductor and Ultra High Frequency Laboratory, Constantine 25000 Al, Email: spet7_sam@yahoo.fr) : Detection of the distribution of size of the desert aerosols by multispectral method LIDAR (UV to IR) by using genetic algorithms, compared with Longtin's model. Indian J pure appl Phys 2013, 51(1), 26-32.

Aerosols are an important component of urban pollution and physico-chemistry of the atmosphere. It is essential to dispose cartographies three dimensions of their concentration by LIDAR (Light Detection And Ranging) method. The interest of optic measurements of LIDAR teledetection is to give a direct access to the repartition of limited layers and to the optical extinction of atmospheric particles. The characterization of micro-physical properties of aerosols (size, concentration) is, therefore less easy, because size distribution of aerosols interferes in an integral form within a certain extent of the optical extinction by physical properties of the measurement. Therefore, this has been realized in the case of less complex atmospheres (desert particles, acids, silica, fog, cloud). The principal objective of our study is the detection of the distribution of size of the desert aerosols by multispectral method LIDAR by using the model characteristic of Longtin. Measurements of concentrations thus will be possible without any presentation of distribution contrary to other methods such as LIDAR (taking by impaction).

5 illus, 14 ref

017031   Ruwali K;Hosoyama K (NO, Raja Ramanna Centre for Advanced Technoloy, Indore-452 013, Email: kailash_ruwali@yahoo.com) : Design of self-correction coils in a superferric dipole magnet. Pramana J Phys 2012, 78(5), 811-18.

Design of self-correction coils in a superferric dipole magnet is carried out. By adopting the self-correction coil (SCC) scheme, we can do online correction of unwanted fields inside the magnet aperture during the whole operating cycle irrespective of their origin. The self-correction coils are short-circuited superconducting coils of required symmetry placed in the useful aperture of the AC dipole magnet. Design and operation mechanism of self-correction coils in a superferric dipole magnet are discussed in this paper.

7 illus, 3 tables, 6 ref

017030   Ravishankar M N;Ahlam M A;Chandramani R;Gnana Prakash A P (Studies in Physics Dep, Mysore Univ, Manasagangotri, Mysore-570 006, Email: ravibhumi2004@gmail.com) : Comparative study of mechanical, dielectric and electrical properties of solution grown semi-organic NLO crystal glycine with additives-ammonium oxalate, potassium anmd barium nitrate. Indian J pure appl Phys 2013, 51(1), 55-9.

Semi-organic non-linear optical (NLO) crystals of γ-glycine (G), with additives like ammonium oxalate (AO), barium nitrate (BN) and potassium nitrate (PN) were grown by aqueous solution method. The mechanical properties like Vicker's micro hardness number (H_v), stiffness constant (C₁₁) and yield strength (σ_v) of grown crystals have been evaluated. The dielectric constant and dielectric loss of the grown crystals have been investigated in the frequency range 10 kHz-10 MHz. The dependence of ac conductivity on frequency of the applied field has been established. Studies confirm that the grown NLO crystals retain the merits of organic (SHG response and flexibility) and inorganic (good hardness) properties. Glycine ammonium oxalate (GAO) is a preferred material for device application compared to glycine barium nitrate potassium nitrate (GBNPN) crystal. Based on mechanical and electrical characterization, comparison has been made between the additives ammonium oxalate (AO), barium nitrate (BN) and potassium nitrate (PN).

8 illus, 3 tables, 21 ref

017029   Rao P M;Gupta A (Atomic and Molecular Physics Div, Bhabha Artomic Research Centre, Mumbai-400 085, Email: pushpam@barc.gov.in) : Optical probing of Eu ions confined in an RF trap. Pramana J Phys 2012, 78(1), 109-20.

The Eu ions confined in an RF quadrupole trap, has been optically detected. Using a tunable dye laser which is pumped by a Nd-YAG pulsed laser system, the resonance ⁹ S₄-6p3/2, J = 5 transition of the Eu ions have been excited and the resulting fluorescence to the metastable ⁹_4-6 state has been detected. In preparation to determine the ground-state hyperfine splitting of the odd isotopes we found the optimum trapping operating point. We have also observed a number of instabilities inside the region of the stability for an ideal trap. These non-linear resonances arise from higher-order contributions to the ideal quadrupole potential.

8 illus, 22 ref

017028   Paul A (NO, Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany, Email: amitesh.paul@frm2.tu.de) : Grazing incidence polarized neutron scattering in reflection geometry from nanolayered spintronic systems. Pramana J Phys 2012, 78(1), 1-58.

This review summarizes recent experimental investigations using neutron scattering on layered nanomagnetic systems (accentuating my contribution), which have applications in spintron-ics also. Polarized neutron investigations of such artificially structured materials are basically done to understand the interplay between structure and magnetism confined within the nanometer scale that can be additionally depth-resolved. Details of the identification of buried domains and their nature of lateral and vertical correlations within the systems are important. A particularly interesting aspect that has emerged over the years is the capability to measure polarized neutron scattering in directions parallel and perpendicular to the applied field direction (which is also the quantization axis for neutron polarizations). This was added with the capability of measuring in specular as well as in off-specular geometry. Distorted wave Born approximation (DWBA) theory for neutrons has proved to be a remarkable development in the quantitative analysis of the scattering data measured simultaneously for specular and off-specular modes within the same framework. In particular, the depth and lateral distribution of the ferromagnetic spins relative to the interface within interlayer-coupled or exchange-coupled system has been extensive. For example, twisted magnetization state at interlayer coupled interfaces or intricacies of symmetric and asymmetric magnetization reversals along with suppression of training effect in exchange coupled system was microscopically identified using neutron scattering only. The investigation on the distribution of magnetic species within dilute ferromagnetic semiconductor superlattices, with low angle neutron scattering, has played a crucial role both from practical and fundamental research points of view.

22 illus, 158 ref

017027   Panda S;Panda B K (Mathematics Dep, Ravenshaw Univ, Cuttack-752 003, Email: sudhira@iopb.res.in) : Effect of conduction band nanparabolicity on the optical properties in a single quantum well under hydrostatic pressure and electric field. Pramana J Phys 2012, 78(5), 827-33.

The effect of conduction band nonparabolicity on the linear and nonlinear optical properties such as absorption coefficients, and changes in the refractive index are calculated in the Al_0.3Ga_0.7As/GaAs heterostructure-based symmetric rectangular quantum well under applied hydrostatic pressure and electric field. The electron envelope functions and energies are calculated in the effective mass equation including the conduction band nonparabolicity. The linear and nonlinear optical properties have been calculated in the density matrix formalism with two-level approximation. The conduction band nonparabolicity shifts the positions of the optical properties and decreases their strength compared to those without this correction. Both the optical properties are enhanced with the applied hydrostatic pressure. While the absorption coefficients are bleached under the combined effect of high pressure and electric field, the bleaching effect is reduced when nonparabolicity is included.

2 illus, 1 table, 29 ref

017026   Pal I;Agarwal A;Sanghi S;Sanjay;Aggarwal M P (Applied Physics Dep, Guru Jambheshwar Science and Technology Univ, Hisar-125 001, Email: ip_gjust@yahoo.com) : Spectroscopic and radiative properties of Nd<. Indian J pure appl Phys 2013, 51(1), 18-25.

Glasses having composition 20ZnO-xBi₂O₃. (79-x)B₂O₃ (15 ≤ x ≤ 35, in mol%) doped with 1 mol% of Nd³⁺ ions were prepared. The different physical and absorption spectral properties have been investigated to understand the variation of the hypersensitive absorption band intensities. From the absorption spectra, Judd-Ofelt intensity parameters, Ω_λ (λ = 2, 4, 6) have been calculated and these parameters were used to estimate the radiative properties. The values of Judd-Ofelt parameters increase with increase in the concentration of Bi₂O₃, which may be due to the increase in neodymium-oxygen (Nd-O) covalency. The glass having high bismuth content has displayed a significant increase in the intensity of the hypersensitive transition ⁴G_5/2 + ²G_7/2 ← ⁴I_9/2 of Nd³⁺ ion which may be attributed to the asymmetry ligand field around the rare earth ion site. The shifting of the hypersensitive band shows that the covalency of the rare earth (RE-O) bond increases with Bi₂O₃ content in the glass due to increased interaction between the rare earth ion and the non-bridging oxygen. The large radiative transition probabilities in the present glasses suggest their suitability for various laser applications. The structure of the present glasses has been studied using FTIR spectroscopy.

6 illus, 4 tables, 31 ref

017025   Ouis M A;ElBatal H A;Azooz M A;Abdelghany A M (Glass Research Dep, National Research Centre, Dokki, Cairo, Egypt, Email: h_elbatal@yahoo.com) : Characterization of WO₃-doped borophosphate glasses by optical, IR and ESR spectroscopic techniques before and after subjecting to gamma irradiation. Indian J pure appl Phys 2013, 51(1), 11-17.

Borophosphate glasses containing increasing WO₃ within the doping level (0.16-1.33%) have been prepared and investigated by UV-visible, infrared spectral measurements. These glasses have been exposed to gamma rays with a dose of 8 Mrad for studying the effect of gamma radiation on the combined studied spectra of such glasses. The optical spectrum of undoped borophosphate glass reveals strong UV absorption but with no visible bands. This strong UV absorption is related to the presence of unavoidable trace iron impurities within the chemicals used for the preparation of this borophosphate glass. The WO₃-doped samples show two additional UV and visible bands at about 380 and 740 nm due to the presence of both W⁶⁺ and W⁵⁺ ions in noticeable content. The calculated induced spectra reveal the appearance of an ultraviolet band at 320 nm and two visible bands centered at 390 and 540 nm which are related to the combined presence of W⁶⁺ and W⁵⁺ ions. The FTIR spectra show vibrational bands due to characteristic constitutional phosphate and borate groups but the phosphate groups are predominant due to the high P₂O₅ content (50%). The effect of the addition of WO₃ with the dopant level reveals limited changes in the IR spectra. Electron spin resonance (ESR) spectra show specified signals in the high WO₃ content glass but on gamma irradiation the signals are disappeared. This result confirms the decrease of the W⁵⁺ ions by photochemical oxidation to paired W⁶⁺ ions. This result is also observed in optical absorption of WO₃ doped glasses after gamma irradiation through the disappearance of the visible band at 740 nm.

7 illus, 1 table, 20 ref

017024   Muthulakshmi S;Chithralekha P;Ganesh Sanjeev; Pathinettam Padiyan D (Physics Dep, Manomaniam Sundaranar Univ, Tirunelveli-627 012, Email: dppadiyan@msuniv.ac.in) : Effect of exposure to electron beam irradiation in biopolymer papain and their electrical behaviour. Indian J pure appl Phys 2013, 51(1), 33-8.

Obtention of biopolymer papain irradiated with 8 MeV energy of electron beam to different doses from 1 kGy to 10 kGy and the effect of the radiation on the electrical behaviour of the biopolymer have been investigated in the temperature range 29°-135°C. The ac impedance plots indicate a single relaxation process in biopolymer papain in different temperatures. An increase in bulk electrical conductivity was noted for biopolymer papain with temperature after irradiation which is related to the hopping of charge carriers between the sites. The electrical conductivity of fresh and irradiated papain follows the universal power law and from which it is observed that the ac conductivity is frequency dependent and it obeys the electron tunneling model of conduction mechanism. The SEM images reveal the larger particle size with non-uniform structure upon irradiation of papain.

5 illus, 2 tables, 20 ref

017023   Mustafa M;Beigh M R (Electronics & Instrumentation Dep, Kashmir Univ, Kashmir, Email: mrbku@yahoo.com) : Design and implementation of quantum cellular automata based novel parity generator and checker circuits with minimum complexity and cell count. Indian J pure appl Phys 2013, 51(1), 60-6.

Quantum-dot Cellular Automata (QCA) is a possible future nanoelectronic computing technology, based on cells of coupled quantum dots. The QCA cells have features on the very low nanometer scale, much smaller than the present state of art size of the smallest transistor. This paper presents design and layout of novel XOR gate implementations with minimum complexity and cell count in comparison with the already proposed designs. Authors present here QCA implementation of combinational circuits like parity generator and checker based on the proposed XOR gate designs. The proposed designs were verified using simulation from QCA designer tool. These algorithms and simulations are useful for building more complex circuits based on QCA.

16 illus, 19 ref

017022   Mohammadi M (Physics Dep, Shahreza Branch, Islamic Azad Univ, Shahreza, Isfahan, Iran, Email: mohammadi@iaush.ac.ir) : Gravitational Jaynes-Cummings model beyond the rotating wave approximation. Pramana J Phys 2012, 78(5), 767-78.

The quantum properties of a two-level atom and the cavity-field in the Jaynes-Cummings model with the gravity beyond the rotating wave approximation are investigated. For this purpose, by solving the Schrodinger equation in the interaction picture, the evolving state of the system is found by which the influence of the counter-rotating terms on the dynamical behaviour of atomic population inversion and the probability distribution of the cavity-field as quantum properties is explored. The results in the atom-field system beyond the rotating wave approximation with the gravity show that the quantum properties are not completely suppressed under certain conditions.

2 illus, 34 ref

017021   Manes J;Stora R;Zumino B (Lawrence Berkeley Laboratory, Berkeley, CA 94720, USA, Email: bzumino@Ibl.gov) : Algebric study of chiral anomalies. Pramana J Phys 2012, 78(6), 907-25.

The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles by the introduction of a fixed background connection. Some of the techniques used in the study of the anomaly are improved or generalized, including a systematic way of generating towers of 'descent equations'.

35 ref

017020   Labidi M;Ebadi G;Zerrad E;Biswas A (Laboratory of Engineering Mathematics, Tunisia Polytechnic School, Carthage Univ, BP 743, La Marsa 2070, Tunisia, Email: biswas.anjan@gmail.com) : Analytical and numerical solutions of the Schrodinger-KdV equation. Pramana J Phys 2012, 78(1), 59-90.

The Schrodinger-KdV equation with power-law nonlinearity is studied. The solitary wave ansatz method is used to carry out the integration of the equation and obtain one-soliton solution. The G'/G method is also used to integrate this equation. Subsequently, the variational iteration method and homotopy perturbation method are also applied to solve this equation. The numerical simulations are also given.

6 illus, 6 tables, 31 ref