012125   Andrade R;Dos Reis A;Grassi F;Hama Y;Kodama T;Ollitrault J Y;Qian W L (NO, Instiuto de Fisica-Universidade de SAo Paulo, Brazil, Email: grassi@if.usp.br) : NeXSPheRIO results on elliptic flow and directed flow for Au+Au and Cu+Cu collisions at RHIC. Indian J Phys 2010, 84(12), 1657-61.

Hydrodynamics has been rather successful at describing results obtained in reiativistic nuclear collisions at RHIC. Here we show results obtained with NeXSPheRIO on Au+Au collisions and the less studied Cu+Cu collisions. We study elliptic flow and its connection with eccentricity suggested by PHOBOS, as well as present elliptic flow fluctuations. We also show results for directed flow and compare with PHOBOS and STAR data.

5 illus, 17 ref

012124   Amirthaganesan G;Dhanabal T;Dhandapani M (Chemistry Dep, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore-641 020, Email: profga@yahoo.co.in) : Thermal and FTIR spectral characterisation of diammonium tetrachlorocobaltate (II) monohydrate crystals. Indian J Phys 2010, 84(11), 1541-48.

Single crystals of a novel compound, diammonium tetrachlorocobaltate(ll) monohydrate, were grown by slow evaporation method at room temperature. The crystals belong to a class of compounds that show interesting properties like ferroelectricity at low temperatures. The grown crystals were characterised through powder XRD, thermogravimetric (TG-DTA), low temperature differential scanning calorimetric (DSC) analyses and FTIR spectroscopy. While the powder XRD pattern of the compound confirms its crystallinity, the TG-DTA studies confirm the stoichiometry of the compound. The thermal anomalies observed in DSC curve at -4°C and -39.1 °C in the cooling cycle indicate a first order phase transition. The FTIR spectrum of the compound characterizes the various chemical bonding and water of crystallization. Further investigation of the low temperature properties of the compound is under progress.

5 illus, 2 tables, 18 ref

012123   Altaf M;Singh K K;Sheikh S A;Singh A K; Lalmani (Physics Dep, National Institue of Technology, Srinagar-190 006, Email: altafnig@rediffmail.com) : Characteristics of nighttime VLF/ELF emissions with frequency drift estimation of the large-scale electric field from the frequency drift observed at a low latitude Indian ground station, Jammu. Indian J Phys 2010, 84(11), 1481-95.

Characteristics of nighttime VLF/ELF emissions are examined on the basis of the data obtained at our low latitude ground station Jammu (geomagnetic latitude, 22°26' N; L = 1.17), India during our VLF/ELF campaign. From the detailed analysis of a huge amount of acquired VLF/ELF data at Jammu we have found three remarkable events which clearly exhibit a rise in their frequency in pre and past midnight sectors during magnetically quiet and substorm periods. Our analysis shows that the frequency drift in VLF/ELF emissions seems to be a rare phenomenon at low latitudes during magnetically quiet and substorm periods in pre and post midnight sectors. This property of temporal frequency drift (regular frequency increases with time) in VLF/ELF emissions observed at our station Jammu are interpreted in terms of a quasi-linear electron cyclotron instability model for wave excitation. The initial frequency increase is believed to be due to a combind effect of L-shell drift of energetic electrons. Further, the frequency drifts in VLF/ELF emissions observed at Jammu have been used to estimate the large scale electric field during quiet and substorm periods in pre and post midnight sectors. This investigation would be most useful for the study of the wave-particle interaction processes, magnetospheric plasma structure and particle dynamics, especially during quiet periods in pre-midnight sector at low latitudes.

10 illus, 21 ref

012122   Akindinov A;et al. (NO, Institute for Theoretical and Experimental Physics, Mascow, Russia) : Two-particle correlations form RHIC to LHC with a new method based on the fourier transform. Indian J Phys 2010, 84(12), 1651-5.

An extension of the study of two particle correlations used at RHIC to LHC energies (Pb + Pb at √S_NN = 5.5 TeV) is presented. The method is based on the two-dimensional Fourier Transform used to calculate the angular autocorrelation function in space. It does not require the identification of a leading particle and is, hence, optimized to the low-pt and medium-pt region at LHC where many minijets are overlapping. We discuss the feasibility of the analysis in heavy ion collisions at the LHC using HIJING and Pythia simulations.

4 illus, 9 ref

012121   Ahmad N;Khan M M;Kamal A;Azmi M D;Khan A R; Zafar M;Irfan M (Physics Dep, Aligarh Muslim Univ, Aligarh-202 002, Email: nazeer_ahmad_na@rediffmail.com) : Rapidity density fluctuations in 14.5A Gev/c <. Indian J Phys 2010, 84(12), 1641-5.

Results on correlation and clusterization amongst relativistic charged particles produced in 14.5A GeV/c ²⁸Si-nucleus collisions are presented by studying rapidity density distribution of relativistic charged particles in various pseudorapidity windows. These results are observed to agree reasonably well with the predictions of Lund Monte Carlo model FRITIOF.

3 illus, 1 table, 8 ref

012120   Agocs A;et al. (NO, MTA KFKI RMKI Research Institute of Particle and Nuclear Physics, Budapest, Hungary) : Very high momentum particle identification at the LHC. Indian J Phys 2010, 84(12), 1635-9.

The anomalies observed at RHIC for the baryon - meson ratios have prompted a number of theoretical works on the nature of the hadrochemistry in the hadronisation stage of the pp collisions and in the evolution of the dense system formed in heavy ion collisions. Although the predictions differ in the theoretical approach, generally a substantial increase in the baryon production is predicted in the range 10-30 GeV/c. We will present the possibilities of a gas ring imaging Cherenkov detector of limited acceptance which would be able to identify track-by-track protons until 24 GeV/c for the ALICE experiment.

5 illus, 1 table, 4 ref

012119   Aggarwal M M;Viyogi Y P (NO, Punjab Univ, Chandigarh-160 014, Email: aggarwal@pu.ac.in) : Event-by-event investigation of charged neutral fluctuations in heavy ion collisions using DWT technique. Indian J Phys 2010, 84(12), 1629-33.

Presents results on filtering events having nonstatistical charged neutral fluctuations using Discrete Wavelet Transforms (DWT). Pb-Pb 10⁵ events at 158 AGeV were generated using VENUS event generator and charged neutral fluctuations were injected event-by-event using simple DCC modeling. We also filtered events using DWT along with Sliding Window Method. The efficiencies and purities of samples extracted having nonstatistical charged neutral fluctuations using DWT and sliding DWT are presented.

2 illus, 1 tables, 5 ref

011163   Yadav R P;Sharma A (Physics Dep, Govt. P.G. College, Bisalpur (Pilibhit)-262 201, Email: rpyadav93pphysics@yahoo.co.in ) : Cylindrical shock waves in a mixture of gas and dusty particles. Indian J Theor Phys 2008, 56(2), 135-42.

Neglecting the effect of overtaking disturbances, the cylindrical shock waves in a dusty has been studied by Chester-Chisnell-Whitham (CCW) method. The variation of flow variables with distance in perturbed medium are obtained. Dusty gas i.e. mixture of small solid particles and gas, is assumed to be uniform. The "results obtained here are compared with earlier results.

7 tables, 12 ref

011162   Yadav M;Chauhan D S (Physics Dep, Govt. P.G. College, Kotdwara-246 149) : Freely propagating strong hydromagenetic cylindrical shock waves through rotating gas. Indian J Theor Phys 2008, 56(1), 7-16.

In this paper, using CCW method, an attempt has been made to study the propagation of freely propagating strong hydromagnetic cylindrical shock waves taking into account only constant axial magnetic field through an ideal and rotating gas at permissible shock front locations for an arbitary varying initial density distribution of the form, say, ρ ₀ = ρ ' log (1 + λr), where θ ' is the density at the axis of symmetry and λ is non-dimensionalyzing constant. The numerical estimate of the flow variables have been computed at only on those values of propagation distance r which are permitted by the initial entropy distribution condition. The result obtained has been presented through graphs and compared with earlier work.

2 illus, 1 table, 20 ref

011161   Werth G;Blaum K;Schabinger B;Sturm S;Wagner A (Physics Dep, Johannes-Gutenberg Univ, D 550 99 Mainz, Germany, Email: werth@uni-mainz.de) : Precision spectroscopy with individual ions. Indian J Phys 2010, 84(8), 939-46.

Individual charged atomic or molecular particles can be confined by electromagnetic fields for nearly unlimited times under well controlled conditions in a small volume in space. This allows performing spectroscopic experiments with unprecedented accuracy. We discuss a project to determine the magnetic moment of the electron bound in hydrogen-like ions with different nuclear charges. This serves for testing bound-state quantum-electrodynamics calculations with high precision. Previous results on C⁵⁺ and O⁷⁺ as well as the present status of the project with Si¹³⁺ and Ca¹⁹⁺ are presented in this contribution and future possibilities are discussed.

5 illus, 18 ref

011160   Varshney N K;Singh S P (Mathematics Dep, S.V. College, Aligarh, Uttar Pradesh) : Effect of porosity of medium on oscillatory flow through horizontal channel under uniform transverse magnetic field. Indian J Theor Phys 2008, 56(1), 73-9.

The problem of porosity of medium on unsteady oscillatory flow through a horizontal channel under uniform transverse magnetic field is discussed by series solution method. Numerical and graphical analysis are made for shearing stress of the unsteady hydrodynamic flow in a horizontal channel for various values of Hartmann number and porosity parameter.

2 illus, 2 tables, 10 ref

011159   Tiru B;Boruah P K;Medhi H (Physics Dep, Gauhati Univ, Gauhati-781 014, Email: btiru@gauhati.ac.in) : DSP based channel selection algorithm for adaptive trasmission in indoor power line. Indian J Phys 2010, 84(6), 745-9.

Unpredictable noise and transfer function in power line channel make it a hostile environment for communication. The paper presents an algorithm which is implemented on a TMS320C6713 Digital Signal Processor (DSP) to select the best channel suitable for transmission. A design of a suitable hardware where the system can be used is also presented.

6 illus, 1 table, 8 ref

011158   Talukdar R;Sengupta S;Debnath B;Bhattacharjee B (Physics Dep, Gauhati Univ, Guwahti-781 014, Email: bb_22@rediffmail.com) : Variation of multiplicities of the secondary charged particles on the geometry of collision. Indian J Phys 2010, 84(6), 757-61.

The total charge of the projectile spectator fragments, Q is taken as a measure of the degree of centrality of collision thus defining the collision geometry. In this paper the mean multiplicities of the different charged secondaries emitted in the interaction of ²⁴Mg-Em at'4.5A GeV have been investigated as a function of the total charge Q_pf of the projectile spectator fragments. It has been observed that the average number of the produced particles, <60>N^s<62> and the heavily ionizing particles, <60>N_h<62> decreases exponentially with the increase of Q_pf showing strong correlation with the geometry of the collision. An attempt has also been made to compare these results with ⁸⁴Kr-Em interaction at 0.95A GeV.

4 illus, 16 ref

011157   Svilainis L (Signal Processing Dep, Kaunas Univ of Technology, Studentu Str 50, LT-51368 Kaunas, Lithuania, Email: linas.svilainis@ktu.1t) : Signals of ultrasonic systems. J pure appl Ultrasonics 2009, 31(3), 94-104.

The signal path in ultrasonic system was analyzed for the quality of the ultrasonic signal acquisition: excitation, reception and digitization. Transmitted signal properties and influence on time-of-flight (ToF) random errors is presented. The excitation hardware issues are discussed: electrical matching and operation performance were analyzed. Several evaluation criteria considered: power delivery efficiency, power delivered at operation frequency, bandwidth, effective bandwidth, power factor and total efficiency. Results obtained for particular transducer are presented. Reception performance analysis was based on the preamplifier - transducer noise model. Investigation of few amplifier topologies in combination with specific transducer is given. The acquisition parameters selection is suggested to be based on achievable accuracy of ToF estimation. Numerical simulation investigated the influence of noise power spectral density, signal bandwidth, carrier frequency, the sampling frequency and resolution of the analog-to-digit converter. Interpolation techniques influences are discussed.

18 illus, 51 ref

011156   Slavov D G;Cartaleva S S;Sarkisyan D;Ghosh P N;Ray B;Mitra S (Institute of Electronics, BAS, 72, Tazarigradsko Chaussee Blvd. 1784 Sofia, Bulgaria, Email: slavov_d_g@yahoo.com) : Rubidium vapor cell miniaturization-influece on the optical pumping process. Indian J Phys 2010, 84(8), 1083-93.

Presents a comparative study of the optical pumping process in four natural mixture Rb cells with different level of miniaturization. The influence of 2 Torr Ne gas added as buffer on the optical pumping is estimated using the fluorescence spectra on the Rb D₂-line obtained by tunable single-mode circularly-polarized diode laser. The obtained results provide basic information for optimization of alkali-cell dimensions and buffer gas pressure for further coherent spectroscopy based applications.

4 illus, 3 tables, 15 ref

011155   Singh N;Kale Y B;Ray A;Jagatap B N (Laser and Plasma Technology Div, Homi Bhabha National Institute, Bhabha Atomic Research Centre, Mumbai-400 085, Email: bnj@barc.gov.in) : Resonances in the pump-probe spectroscopy of a system in alkali atoms. Indian J Phys 2010, 84(8), 1119-26.

Investigates resonances in the pump-probe spectroscopy of 1 configuration of levels in the hyperfine manifold of D₂ transition of ¹³³Cs and ⁸⁷Rb with specific reference to Autler-Townes splitting, dressed state resonances in double A system and electromagnetically induced transparency. As an application, a dark resonance based magnetometer is briefly discussed.

5 illus, 8 ref

011154   Singh K P;Agarwal H;Shukla V K;Yasmin M;Gupta M;Shukla J P (Physics Dep, Univ of Lucknow, Lucknow-226 007, Email: guptagm@rediffmail.com) : Thermoacoustical properties of PEG with alkoxy ethanols. J pure appl Ultrasonics 2009, 31(3), 124-130.

The ultrasonic velocity, density and viscosity of binary mixtures of 2-butoxyethanol with PEG200 and PEG 400 were measured at 293, 303 and 313 K over the entire range of composition. Using these experimental data, various thermo-acoustic parameters such as deviation in isentropic compressibility (Δ <75> _s), excess molar isentropic compressibility (K^E_s), excess molar volume (V^E_m), and molar refractive deviation (Δ R_m) have been calculated and fitted to Redlich-Kister polynomial equation. The deviation/excess parameter were plotted against the mole fraction of 2-butoxyethanol over the whole composition range. The values of (Δ <75> _s), (V^E_m) and (Δ R_m) are found to be negative and constantly become more negative for mixtures with PEG 400 independently of the solvents. The partial molar isentropic compressibility and excess partial molar isentropic compressibility at infinite dilution have been evaluated. The results of partial molar isentropic compressibility at infinite dilution supports the presence of strong intermolecular interactions between unlike molecules and more pronounced interaction in the mixture of 2-butoxyethanol with PEG 400. The results of density, ultrasonic velocity and refractive index measurement were also fitted to a second order polynomial equation with respect to mole fraction of 2- butoxyethanol.

3 illus, 3 table, 17 ref

011153   Sharma V (Agril Engineering Dep, School of Agricultural Sciences and Rural Development, Nagaland Univ, Madziphema-797 106) : Propagation of solar flare in a non-ideal solar atmosphere. Indian J Theor Phys 2008, 56(1), 59-71.

Deals a self-similar model of the spherical shock wave propagation generated by solar flare in non-ideal atmosphere. The radius of the spherical shock wave varies as some power of time. The one-dimensional time dependent spherical dissipationless equations of motion have been discussed taking magnetic field into consideration. The numerical integration of the equations of motion have been done for the cases of self-gravitation and non-gravitation. It is seen that the non-ideal factor affects the flow variables significantly.

8 illus, 14 Ref

011152   Sen B;Mandal S (Physics Dep, Visva-Bharati, Santiniketan-7361 235, Email: swapanvb@rediffmail.com) : Amplitude-squared squeezing in spontaneous degenerate hyper Raman process. Indian J Phys 2010, 84(8), 1111-17.

The approximate analytical solutions of various field modes for spontaneous hyper Raman process are used to obtain the amplitude squared squeezing for pump field mode. We observe that the percentage of squeezing increases with the increase of the order.

1 illus, 8 ref

011151   Sarkar T (University Science Instrumentation Centre, P.O.-North Bengal Univ, Siliguri-734 013, Email: usic@nbu.ac.in) : Study on quantum gates. Indian J Theor Phys 2008, 56(4), 251-75.

A brief study of quantum unitary gates that can be implemented to construct quantum circuits is given in this paper. The mathematical and geometrical representation of various well known gates has been explained in detail. Then, using the concept of unitary transformation, we have developed new gates in C4 space as well as shown the relation among various well known gates. We have given the essential mathematical identity and their uses in construction of higher order gates such as Toffoli gate.

1 illus, 9 ref

011150   Samanta S C;Maishal R K (Physics Dep, Midnapore College, Midnapore-721101) : Magneto-thermo-elastic disturbance in a rotating visco-elastic semi-infinite medium with finite electrical conductivity. Indian J Theor Phys 2008, 56(4), 277-93.

The propagation of magneto-thermo-elastic waves induced by a ramp-type mechanical load in a finitely conducting visco-elastic rotating half-space in contact with a vacuum is investigated. Green and Lindsay model is used as a generalized thermo-elastic model, which predicts the finite velocity of propagation.

1 illus, 9 ref

011149   Samanta S C;Maishal R K (Physics Dep, Midnapore College, Midnapore-721 101) : Magneto-thermo-elastic waves generated by a heat pulse. Indian J Theor Phys 2008, 56(3), 187-202.

Of concern in this paper, is a generalized thermo-elastic analysis of the problem of wave propagation in an infinite, isotropic, elastic and electrically perfectly conducting continuum with a cylindrical hole. The medium is permeated by a constant ambient magnetic field and the curved surface of the hole is subjected to a heat pulse of finite width. The analysis is based of Lord and Shulman model for heat conduction, Maxwell's electromagnetic field theory and the themo-elastic equations. The equations are reduced to non-dimensional forms using suitable units. The Laplace transformation technique is used to solve these coupled differential equations. The Laplace inversion is effected with small time approximation to obtain solutions in time domain. A numerical analysis is also carried out to compute the values of the field variable for different space and time co-ordinates. The results are graphically displayed.

4 illus, 14 ref

011148   Saikia B;Borthakur P R (Science and Technology University Dep, Institute of Chartered Financial Analysts of India, Tripura-799 210, Email: banashreemoni@rediffmail.com) : Lattice thermal conductivity of skutterudite compounds. Indian J Phys 2010, 84(6), 675-9.

A generalized expression is used on the basis of relaxation time approximation to facilitate calculation of lattice thermal conductivity of dielectric materials as well as skutterudite family consists of compounds of the form AB₃.it is assumed that phonon scattering processes are independent and is represented by frequency dependent relaxation times. The contributions of normal three phonon scattering processes are included explicitly as redistribution of phonon momentum between two oscillation branches is considered. Magnitudes of relaxation times are estimated from the experimental data. The result for CoSb₃ is in reasonably good agreement with the experimental result in the temperature range 1-1000°K. It is observed that redistribution of phonon momentum between two oscillation branches leads to a significant suppression of thermal conductivity maximum and it is observed that for unfilled skutterudite the main dominant mechanism at the thermal conductivity maximum is three phonon normal scattering process.

1 illus, 1 table, 11 ref

011147   Saha B;Thapa R;Das N S;Chattopadhyay K K (Physics Dep, Thin Film and Nanoscience Laboratory, Jadavpur Univ, Kolkata-700 032, Email: kalyan_chattopadhyay@yahoo.com) : Intentionally incorporated defect and its consequences in oxide thin film through radio frequency magnetron sputtering techique. Indian J Phys 2010, 84(6), 681-5.

Radio Frequency Magnetron Sputtering Technique has been employed to prepare metal oxide thin film of ZnO and CdO. The films were deposited in such condition that some point defects like oxygen vacancies have been intentionally incorporated. The defects appeared with significant modification in the properties of the thin films. The prepared films were characterized by studying with X-ray diffraction study, X-ray photo-electron spectroscopic measurement, optical transmittance measurement, and electrical study. The electrical properties are found to change profoundly with the defect concentration. Consequently the optical properties also have been changed.

4 illus, 6 ref

011146   Roy S;Boro M;Mohanta D;Choudhury A;Ahmed G A (Physics Dep, Tezpur Univ, Tezpur-784 028, Email: rsanchita1@gmail.com ) : Size quantification of sub-micron ZnSe semiconductor particles by loboratory scattering methods. Indian J Phys 2010, 84(6), 705-9.

A novel route has been developed to synthesize sub-micron Zinc Selenide semiconductor particles through elemental solvothermal process. Transparent polyvinyl alcohol matrix was chosen as host material for embedding these ZnSe particles in order to stop agglomeration of the particles as well as to facilitate optical characterization. Structural and morphological characterizations were carried out through high resolution electron microscopy and UV-vis spectroscopy. In order to understand light scattering phenomena of these particles, they were investigated by a custom made set up which uses a He-Ne laser of wavelength 632.8nm and an array of Silicon photodetectors. An attempt was made to experimentally determine the most significant element of the Mueller scattering matrix. Novel computational technique, involving single scattering for spherical particles using T-matrix theory was applied. The analysis of the experimental data was done by the method of comparison with theoretically generated data. The theoretical prediction was found to agree well qualitatively with the experimental data. Our results validitate that within an acceptable margin of error of the experimental results, the combination of experimental setup and associated computational method is an efficient and reliable in-situ system for size quantification of sub- micron semiconductor particles in the laboratory.

3 illus, 7 ref

011145   Rosangliana;Ghimire M P;Lalmuanpuia;Sandeep; Thapa R K (Physics Dep, Govt. Zirtiri Residential Science College, Aizawl-796 001) : Study of photofield emission in tungsten by using free electron model. Indian J Phys 2010, 84(6), 723-7.

Presents here the results of the calculations of photofield emission current by using the free electron model in which the appropriate wavefunctions are used. The transmission probability had been calculated by solving the Airy's equation. The model developed is used to calculate photofield emission current from tungsten.

3 illus, 5 ref

011144   Rai D P;Hashemifar J;Jamal M;Lalmuanpuia; Ghimire M P;Sandeep;Khathing D T;Patra P K;Indrajit Sharma B; Rosangliana;Thapa R K (Physics Dep, Mizoram Univ, Tanhril, Aizawl-796 009, Email: rktt@sancharet.in) : Study of Co₂ MnAl heusler alloy as half metallic ferromagnet. Indian J Phys 2010, 84(6), 717-21.

Studies of half metallacity of Co₂MnAI as half-Heusler alloy in L2₁ structure which consists of four inter-penetrating fcc sub-lattices. Density functional theory based electronic structure calculations will be performed by using the full-potential linear augmented plane wave (FP-LAPW). We will use the general gradient approximation method (GGA) and local density approximation method called LDA+U. Density of states and band structure results will be presented.

5 illus, 6 ref

011143   Raghu A;Yogesha;Ananthamurthy S (Physics Dep, Government College for Women, Mandya-571 401, Email: asharath@gmail.com ) : Optical tweezer for micro and nano scale rheology of biomaterials. Indian J Phys 2010, 84(8), 1051-691.

Since the first proposal and demonstration of an optical trap to hold micron sized particles by Ashkin in 1986, optical tweezer-based techniques for control and manipulation of particles has seen tremendous progress and enabled the exploration of the structure and dynamics of materials at the nano length scale. In biophysical applications, these techniques have enabled a range of activities from measurements of very small forces (at sub-pN levels) at operation within cells thus assisting in the elucidation of intracellular transport mechanisms, to obtaining elastic parameters of biomolecules. The techniques have helped in gaining insights on the viscoelastic properties at micro and nano length scales of a range of soft materials such as colloids, polymer melts, bio membranes etc. The paper describes some of the studies carried out by us to understand polymer structure and elasticity of these materials in solution. The domains of "passive" and "active" rheology are explained with examples of studies undertaken to address these domains. The work using video microscopy to study silk fibroin solutions is used to exemplify the domain of passive rheology. We present recent work on bacterial solutions wherein live bacteria influence the optical trap region and thereby help us study the local viscoelasticity of such a medium.

4 illus, 37 ref

011142   Podlaha M F (NO, , Marktplatz 15, D-94065, Waldkirchen) : On the photoeffect. Indian J Theor Phys 2008, 56(4), 315-17.

9 ref

011141   Podlaha M F (NO, , Marktplatz 15, D-94065, Waldkirchen) : Hypothesis about the creation of the world. Indian J Theor Phys 2008, 56(3), 237-40.

8 ref

011140   Podlaha M F (NO, , Marktplatz 15, D-94065, Waldkirchen) : On hubble's discovery. Indian J Theor Phys 2008, 56(2), 157-60.

The astronomer Edwin P. Hubble (1889-1953) observed that spectral lines of nebulae are shifted to the red part of the spectra. This shift is described by the formula c. Δ λ/λ <126> H.D, - (1), where H is the Hubble constant and D is the distance of the nebulae from the observer.

9 ref

011139   Podlaha M F (NO, , Marktplatz 15, D-94065, Waldkirchen) : Matter waves and nuclear reactions. Indian J Theor Phys 2008, 56(1), 1-6.

Two kinds of matter waves are the basis of the stability of elementary particles. Elementary particles cannot be deformed by external forces. However, elementary particles change the form with the change of the optical vacuum density of the vacuum field and with the velocity of their transport in the vacuum field.

12 ref

011138   Poddar P;Ray B;Biswas D;Ghosh P N (Physics Dep, Calcutta Univ, 92, A. P. C. Road, Kolkata-700 009, Email: brphy@caluiv.ac.in) : Overtone spectroscopy of water molecules based on room temperature diode laser emitting in the NIR range. Indian J Phys 2010, 84(8), 921-7.

The measurement of very weak overtone spectroscopic line shape of water molecule is performed using wavelength modulation spectroscopy (WMS). In this work a high resolution near infrared diode laser spectrometer is used to record first derivative (1f) signal of buffer gas Helium and Carbon dioxide broadened water vapour transitions around 820 nm wavelength region. The effect of collision due to perturber pressure on signal to noise ratio (SNR) is discussed. The Lorentzian HWHM of observed 1f signal is calculated. The comparison is made between collisional broadening of water vapour transition broadened by inert gas Helium and high quadrupole moment active gas Carbon dioxide.

4 illus, 5 ref

011137   Paul D;Das S R;Sen A K (Physics Dep, Assam Univ, Silchar-788 011, Email: hsdas@iucaa.ernet.in) : Polarisation properties of comet NEAT C/2001 Q4. Indian J Phys 2010, 84(6), 623-27.

Comets exhibit high (up to 25 %) amount of optical polarization when they are observed through ground based or space telescopes. These polarizations are caused due to the scattering of cometary dust. The observed linear polarisation of comets is generally a function of the wavelength of incident light (λ), the scattering angte (θ), the geometrical shape and size of the particle and the composition of dust particles in terms of the complex values of the refractive index. The scattering properties of cometary dust will help to know the nature of cometary dust. In the present work, the observed linear polarization data of Comet NEAT are studied through simulations using Ballistic Particle-Cluster Aggregate (BPCA) and Ballistic Cluster-Cluster Aggregate (BCCA). Using Superposition T-matrix code, the best-fitting values of complex refractive indices are calculated which can well fit the observed polarization data of Comet NEAT C/2001 Q4. The best fitting values of complex refractive indices coming out from the present analysis correspond to mixture of both silicates and organics.

2 illus, 29 ref

011136   Pathak A;Verma A (Physics and Material Science and Engineering Dep, Jaypee institute of Information Technology Univ, Noida-201 307, Email: amit.verma@jiit.ac.in) : Recent developments in the study of higher order nonclassical states. Indian J Phys 2010, 84(8), 1005-19.

The observations on higher order nonclassicality are described. Recently we have shown that a generalized npjion of higher order nonclassicality (in terms of higher order moments) can be introduced. Under this generalized framework of higher order nonclassicality, conditions of higher order squeezing and higher order subpoissonian photon statistics are derived. Further, with the help of simple density matrices, it is shown that the higher order antibunching (HOA) and higher order subpoissonian photon statistics (HOSPS) are not the manifestation of the same phenomenon and consequently it is incorrect to use the condition of HOA as a test of HOSPS. It is established that the HOA and HOSPS may exist even in absence of the corresponding lower order phenomenon. It is also shown that the potential sources of single photon must satisfy the condition of HOA. Most of the intermediate states are shown to satisfy the criteria of HOA. A protocol for comparison of potential single photon sources (SPS) is reported here and the protocol is used to compare some of the existing proposals of SPS. Further, it is shown that it is possible to derive an arbitrarily large number of criterion for higher order nonclassicality but all of them does not yield new and interesting information.

2 illus, 2 tables, 30 ref

011135   Pal P;Bhowmik A;Roy R;Ali R;Choudhury A;Guha A;De B K (Physics Dep, M B B College, Agartala, Tripura-799 004, Email: pinakipal@hotmail.com) : Correlation study of solar activity index and amplitude of VLF trans-equatorial propagation. Indian J Phys 2010, 84(6), 641-5.

Diurnal and seasonal behavior of amplitude of NWC 22.3 kHz signal transmitted from Australia (22°49'S, 114°23'E), and received atKolkata (22°34'N, 88°24'E), India have been investigated The signal amplitude is remarkably low in October. The variations of daily maximum and daily minimum of signal amplitude have been analyzed. The signal on the present propagation path showed non-correlation with A index, but showed a moderate but negative correlation with 10.7 cm solar flux.

3 illus, 7 ref

011134   Pal C;Kshirsagar R J (Physics Dep, Ramakrishna Mission Vidyamandira, Belurmath, Howrah-711 202, Email: cmpmagra@gmail.com) : DFT molecular structure and initial asignment for the FTIR spectrum of V₇ band of nitromethane-D₃. Indian J Phys 2010, 84(8), 929-37.

The-preliminary analysis of the DFT calculations and the high-resolution Fourier transform spectrum of the v₇ band of CD₃NO₂ have been carried out for the first time. The rotational structure up to J = 10 have been fitted using Watson's A-reduction in l^r representation with a standard deviation of 0.0048cm^-1. The rotational constants A, B, C have been obtained for the v₇ state of CD₃NO₂ with good statistical significance.

2 illus, 2 tables, 15 ref

011133   Omolo J A (Physics Dep, Maseno Univ, P.O. Private Bag, Maseno, Kenya, Email: ojakeyo@maseno.acke) : Revisiting Yuen's two-photon coherent state therory. Indian J Theor Phys 2008, 56(4), 241-9.

Yuen's model of two-photon coherent states of light is recast in a spin equation form, yielding simpler exact solutions under resonance. The approach leads to further physical interpretations and practical applications.

12 ref

011132   Nirmal Singh N;Zeen Devi H;Sharma A K;Patgiri M (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: nimai03@yahoo.com ) : Discrimination of neutrino mass models. Indian J Phys 2010, 84(6), 751-5.

Considers the Majorana CP violating phases derived from right-handed Majorana mass matrices to estimate the baryon asymmetry of the universe, for different neutrino mass models, namely degenerate, inverted hierarchical and normal hierarchical models, with tri-bimaximal mixings. Considering three possible diagonal forms of Dirac neutrino mass matrix as charged-lepton, up-quark or down-quark mass matrix within the framework of left-right symmetric GUT models, the right-handed Majorana mass matrices are constructed from the light Majorana neutrino mass matrix through the inverse seesaw formula. These light neutrino mass matrices have already been tested to provide good predictions on neutrino mass parameters and mixing angles. They are again applied to predict baryon asymmetry of the universe in the present work. The normal hierarchical model gives the best prediction for baryon asymmetry, consistent with observation. The analysis may serve as additional information in the discrimination of the presently available neutrino mass models.

1 table, 10 ref

011131   Nayak N;Ghosh B;Majumdar A S (Applied Physics Dep, Birla Institute of Technology, Mesra-835 215, Email: archan@bose.res.in) : Environment induced entanglement in cavity-QED. Indian J Phys 2010, 84(8), 1039-50.

The effects of dissipative dynamics on the magnitude of entanglement generated in atom-photon interactions inside-cavities is studied. We present some concrete examples of environment induced entanglement in atom-photon interactions. Consider various dissipative atom-cavity systems and show that their collective dynamics can be used to maximize entanglement for intermediate values of the cavity leakage parameter K. We first consider the interaction of a single two-level atom with one of two coupled microwave cavities and show analytically that the atom-cavity entanglement increases with cavity leakage. We next consider a system of two atoms passing successively through a cavity and derive the expression for the maximum value of in terms of the Rabi angle gt, for which the two-atom entanglement can be increased. Finally, numerical investigation of micromaser dynamics also reveals the increase of two-atom entanglement with stronger cavity-environment coupling for experimentally attainable values of the micromaser parameters.

4 illus, 1 table, 24 ref

011130   Mukhopadhyay S (Physics Dep, Burdwan Univ, Burdwan-713 104, Email: sourangshu2004@yahoo.com) : Role of optics in super-fast information processing. Indian J Phys 2010, 84(8), 1069-74.

From the decade of seventy a motivation inspired the people of optical and computing community for using optics in place of electronics as information carrying signal in digital data and image processing. Here in this communication the author extends a brief report on the role of optics in super fast computation and its advantages.

4 illus, 15 ref

011129   Mohanty S;Ravi S (Physics Dep, Indian Institute of Technology, Guwahati, Guwahati-781 039, Email: sravi@iitg.ac.in) : Magnetic properties of co-doped SnO₂ diluted magnetic semiconductors. Indian J Phys 2010, 84(6), 735-9.

Polycrystalline samples of SnCo_xO₂ are prepared for x=0.02, 0.05 and 0.10. They all exhibit room temperature ferromagnetism with decrease in saturation magnetization with increase in doping. The magnetization data recorded at 85 K, 295 K and 400 K for x ≥ 0.05 could be analyzed in terms of bound magnetic polaron model and the typical polaron concentration at room temperature is found to be in the order of 10²¹.

3 illus, 1 tables, 23 ref

011128   Mitra S;Hossain M M;Ray B;Ghosh P N (Physics Dep, Calcutta Univ, 92, A. P. C. Road, Kolkata-700 009, Email: speclab_cu@yahoo.com) : EIT locking of a semiconductor diode laser: significant improvement over doppler locking. Indian J Phys 2010, 84(8), 969-75.

Reports a precise frequency locking technique using electromagnetically induced transparency in an atomic vapour cell for a semiconductor diode laser. The sub natural line-width of EIT (Electromagnetically induced transparency) allows improvement in the stability of the laser diode under the locked condition. D₂ transition of ⁸⁵Rb atom is used for this experiment. Frequency stability of the laser under the locked condition is of the order of 426 kHz which provides nearly 80 times better stability than the Doppler locked condition.

6 illus, 16 ref

011127   Mazumder N;Gogoi A;Kalita R D;Ahmed G A; Buragohain A K;Choudhury A (Physics Dep, Optoelectroic and Photonics Research Laboratory, Tezpur Univ, Tezpur-784 028, Email: ankurgogoi@gmail.com) : Luminescence studies of fresh water diatom frustules. Indian J Phys 2010, 84(6), 665-9.

Siliceous frustules were extracted from fresh water diatoms by treating with concentrated HCI. The diatom frustules consist of nano-porous silica structures that exhibit unique optoelectronic and photonic properties. Photoluminescence (PL) properties of diatom frustules at various excitation wavelengths were done. A visible PL band centered at 440 nm was observed when excited at 300 nm, 370 nm and 380 nm wavelengths. The observed PL activity of the diatom frustules has the potential for use in optoelectronic and photonic devices.

2 illus, 11 ref

011126   Luy B (Chemie Dep, LS OC II, Technische, Munchen Univ, Lichtenbergstr. 4,85747 Garching, Germany, Email: burkhard.luy@ch.tum.de) : Disinction of enantiomers by NMR spectroscopy using chiral orienting media. J Indian Inst Sci 2010, 90(1), 119-32.

NMR spectroscopy is a very important analytical tool in modern organic and inorganic chemistry. Next to the identification of molecules and their structure determination, it is also used for the distinction of enantiomers and the measurement of enantiomeric purity. This article gives a brief review of the techniques being developed for enantiomeric differentiation by virtue of chiral alignment media and their induction of enantiomerically dependent anisotropic NMR parameters like residual dipolar couplings. An overview of existing chiral alignment media, a brief introduction into the basic theory and measurement of the various anisotropic parameters, and several example applications are given.

^iia11 illus, 104 ref

011125   Karumuri S R;Choudhury J;Sarkar N K;Gogoi B; Bhattacharjee R (Physics Dep, Assam (A Central) Univ, Silchar-788 011, Email: srinivasakarumuri@gmail.com) : Vibrational spectroscopy of bio-molecules: an algebraic approach. Indian J Phys 2010, 84(6), 647-52.

Porphyrins have received numerous considerable attentions during recent years because of their great biologicaf importance. The most interesting areas of current research in molecular spectroscopy are the study of the vibrational ground and excited states of polyatomic molecules especially for the Metalloporphyrins. In this paper, we have calculated the fundamental and extrapolated vibrational energy levels of Magnesium, Nickel, Copper, Zinc, Metalloporphyrin molecules using U (2) algebraic model Hamiltonian. The results obtained by this method are in good agreement with the experimental data. This study gives a general approach for solving the vibrational spectra of Metalloporphyrin molecules.

1 illus, 2 table, 7 ref

011124   Kalita S;Duorah H L;Duorah K (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: sanjeevkalita 1@ymail.com) : Late time cosmic acceleration of a flat matter dominated universe with constant vacuum energy. Indian J Phys 2010, 84(6), 629-33.

Matter and radiation densities are compared with a constant vacuum energy density of positive cosmological constant, from a few seconds of the universe till the present epoch. Epoch of acceleration is calculated by estimating Baryonic density from consideration of finite thickness of last scattering surface and dark matter density from inflationary flatness condition. The calculated epoch of acceleration is found to be in good agreement with recent supernova observations.

2 tables, 9 ref

011123   Kalita G;Bhuyan P K;Bhuya N K (Physics Dep, Dibrugarh Univ, Dibrugarh-786 004, Email: gayatry.kalita@gmail.com) : Variation of total columnar ozone characteristics over Dibrugarh, India and comparison with satellite observations over the Indian subcontinent. Indian J Phys 2010, 84(6), 635-9.

Investigates the characteristics of the total columnar ozone (TCO) over Dibrugarh (27.3° N and 94.6° E), India for the period September 2007 to February 2009 using Microtops II Ozonometer. These measurements are compared with TCO data available from Total Ozone Mapping Spectrometer (TOMS) on board Nimbus-7 satellite for the same period. It has been observed that the TCO increases from morning till noon and then decreases rapidly in the afternoon. A distinct seasonal variation of TCO is observed with low value in the months of September-December and high values in the month of April, May and June as seen from both Microtops II and TOMS measurements. Satellite observations reveal that the TCO at all latitudes is nearly equal in the months of September-November and May to August. The seasonal variation of TCO between December to May is nearly a mirror image between low and mid latitudes along the three longitudes sectors.

3 illus, 7 ref

011122   Kaliambos L A (NO, Institute of Larissa Komninon 15, Larissa-41223, Greece) : Spin-spin iteractions of electrons and also of nucleons create atomic molecular and nuclear structures. Indian J Theor Phys 2008, 56(2), 81-92.

Fundamental interactions of spinning electrons at an interelectron separation less than 578.8 fin yield attractive electromagnetic forces with 5 = 0 creating vibrations under a motional emf. They explain the indistinguishability of electrons and give a vibration energy able for calculating the ground-state energies of many-electron atoms without using any perturbative approximation. Such forces create two-electron orbitals able to account for the exclusion principal and the mechanism of covalent bonds. In the outer subshells of atoms the penetrating orbitals interact also as pair-pair systems and deform drastically the probability densities of the quantum mechanical electron clouds. Such a dynamics of deformation removes the degeneracy and leads to the deviation from the shell scheme. However in the interior of atoms the large nuclear charge leads to a spherically symmetric potential with non-interacting pairs for creating shells of degenerate states giving an accurate explanation of the X-ray lines. On the other hand, considerable charge distributions in nucleons as multiples of 2e/3 and - e/3 determined by the magnetic moments, interact for creating the nuclear structure with p-n bonds. Such spin-spin interactions show that the dominant concept of the untisymmetric wave function for fermions is inapplicable not only in the simple p-n, p-p, and n-n systems but also in the LS coupling of atoms in which the electrons interact from different quantum states giving either 5=0 or 5=1.

17 ref

011121   Indrajit Sharma B;Maibam J;Paul R S;Thapa R K;Brojen Singh R K (Physics Dep, Assam Univ, Silchar, Assam-788 011, Email: indraofficial@rediffmail.com) : Studies on energy band structure of NbC and NbN using DFT. Indian J Phys 2010, 84(6), 671-4.

Energy band structure of NbC and NbN are calculated using generalized gradient approximation (GGA) within density functional theory (DFT) including five high symmetry points W, L, r, X and K. The lowest band correspondTto 2s band of non metal (C and N) atoms and the next lowest band is formed by 2p nonmetal. The decomposing points of t2g states (T₂₅), e_g states (r₁₂) and C or N 2p states (r₁₅) show interesting behavior different from earlier reports.

1 illus, 15 ref