023193   Tiwari A K;Pandey A N (Physics Dep, K N Govt P G College, Gyanpur, S R N Bhadohi, Uttar Pradesh, Email: asholtiwari2780@gmail.com) : Radiation induced changes in PVDF polymer. Indian J scient Res 2012, 3(1), 167-70.

Optical and chemical response of poly vinylidene fluoride (PVDF) polymer has been studied after one year of indiation to avoid the short-lived activity and reactivity of the irradiated polymer with oxidation and reduction mechanism, the polymer samples were irradiated with 50 MeV lithium ion beam in the fluence range of 1.27xl0¹¹ 2.15xl0¹³ ions/cm². The post irradiation effect has been analysed using UV- visible and FTIR spectroscopic techniques. The results of UV- visible spectroscopic study shows a decrease in the optical absorption and a shift in absorption edge towards higher wavelength with increasing fluence indication a decrease in band gap. The FTIR analysis shows a dramatic increase in absorbance in the wavelength regions from 3600-2800 cm^-1 which may be ascribed to the oxidative degradation of the polymer and the increase in the absorption in the range of 2000-1500 cm^-1 indicating about the possibility of double bond formation.

4 illus, 1 table, 5 ref

023192   Thirugnanam A;Rajesh K;Madhavan J;Selvaraj R S;Praveen Kumar P (Physics Dep, Presidency College, Chennai, Tamil Nadu) : Growth and characterization of nonlinear optical L- bis valine selenate single crystals. Archiv appl Sci Res 2013, 5(3), 167-72.

Single crystals of L-Bis Vallne selenate (L-BVS) were grown by slow evaporation method. The grown crystals are characterized by single X - ray diffraction analysis. The vibrational frequencies of various functional groups of the crystal are analyzed from FTIR spectrum. The optical transmission of the material is ascertained by recording VV -VIS - NIR spectrum. Micro hardness and dielectric studies were also carried out on the grown crystals. Thermal behavior of the crystals has been investigated by DTA and TGA analysis. The NLO property of the grown crystals has been confirmed by Kurtz-powder SHG test.

9 ref

023191   Thakur C S;Verma P K (Physics Dep, B.R.A. Bihar Univ, Muzaffarpur-842 001, Email: vermapk.1@gmail.com) : Scattering of positrons by magnesium atom. Bull pure appl Sci 2012, 31D(1), 17-23.

Differential cross sections for elastic scattering of positrons by magnesium atom in the intermediate energy region from 300 to 500 eV have been calculated by employing distorted wave approach. A suitable form of polarization has been used. To observe the impact of polarization effect, differential cross sections have been calculated with and without polarization potential. The first -Born results have been reported. The aqreement between present set of results with corresponding theoretical predictions in literature is fair.

2 illus, 3 ref

023190   Srivastava U C (Physics Dep, Amity Institute of Applied Sciences, Amity Univ, Noida, Uttar Pradesh) : Debye temperature variation in thallium fluoride (TIF). Archiv appl Sci Res 2013, 5(3), 16-20.

Thallium halides have CsCl structure except TlF which has an orthorhombically distorted variant NaCl-type structure. At the normal room temperature it has a distorted rock salt structure. The nature and the physical properties of the thallous halides have attracted an increased interest in the study of their lattice dynamics. The dynamical behavior of thallium fluoride (TIP) have been studied by using van der Waals three-body force shell model (VTBFSM), which incorporates the effects of the van der Waals interaction with long-range Coulomb interactions, three-body interactions and short-range second neighbour interactions in the framework of rigid shell model (RSM). ln present paper the variations of Debye temperature with absolute temperature have been theoretically calculated for thallium fluoride using (VTBFSM).

33 ref

023189   Sonawane S S;Nandre S J;Shitole S J;Ahire R R (Physics Dep, J.J.T. Univ, Jhunjhunu, Rajasthan) : Nucleation and growth of calcium tartrate crystals in sodium meta silicate gel. Archiv appl Sci Res 2013, 5(3), 237-40.

Calcium tartrate crystals were grown by single diffusion gel technique in a sodium meta silicate gel media at ambient temperature. The effect of various parameters like pH of the gel, gel density, Concentration of reactants, gel aging on the growth of these crystals was studied. The optimum conditions required for the growth of these crystals are worked out. Opaque, whitish, crystals were obtained. An attempt has been made to explain growth mechanism.

18 ref

023188   Smarandache F (NO, New Mexico Univ, Gallup, NM 87301, USA, Email: smarand@unm.edu) : Absolute theory of relativity (ATR). Bull pure appl Sci 2012, 31D(1), 1-10.

While Einstein considered a relative space and relative time but the ultimate speed of light, we did the opposite: we considered an absolute time and absolute space but no ultimate speed, and we called it the Absolute Theory of Relativity (ATR). ATR has no time dilation, no length contraction, no relativistic simultaneities, and no relativistic paradoxes. After the 2011 CERN's muon neutrino experiments with speed greater than the light speed, we recall our hypothesis and theories of superluminality.

7 illus, 4 ref

023187   Singh S G;Saxena A K;Singh R P;Jaisawa K (Physics Dep, A.P.S. Univ, Rewa, M.P., Email: sgs81physics@gmail.com) : Time lag in long-term cosmic ray intensity variation with sunspot number. Ultra Scient phys Sci-Sect B 2012, 24(3), 452-6.

Relationship between the long-term variations of the cosmic ray intensity & Sunspot number (Solar activity) considering the different time lags has been investigated for the period 1986 to 2009. Several aspects of the long-term variations of cosmic ray intensity have been studied, adopting the K-series analysis during the ascending & descending phase of two successive sunspot solar cycles (22, 23). Correlative analysis is the basis & has been applied for several time intervals. On the overall, from the correlative analysis it has been observed that the second parts of ascending phase for sunspot cycles are more effective in cosmic ray variation. The cumulative results of these effects produce long-term trends in cosmic ray intensity.

4 illus, 8 ref

023186   Singh J P;Lata Sneh;Pandey A N (Physics Dep, R. Post Graduate College, Jamuhai, Jaunpur, U.P.) : Change of entropy for galaxies clustering. Ultra Scient phys Sci-Sect B 2012, 24(3), 535-8.

Presents the entropy change in gravitational clustering of galaxies in view of thermodynamical and statistical scheme in point mass particles system and extended mass particles (non-point mass) i.e. in an expanding universe. And obtain analytically the relations for gravitational entropy in terms of temperature T and average density n of galaxies (particles) in the given phase cell.

8 ref

023185   Singh A K;Paswean J K;Singh S K (Physics Dep, Samta College, Jandaha, Vaishali, Bihar) : Coherent quantum transport in carbon nanotube with reflectionless contacts. Bull pure appl Sci 2012, 31D(1), 37-40.

Studied theoretically coherent quantum transport in a carbon nanotube with reflectionless contacts to external reservoirs, two complementary transport formalies were used. The Kubo conductance was computed. In the presence of static disorder, the diffusivity for a given wave packet reach a time saturation regime, whose value is related to the elastic mean free path through diffusivity with the velocity of the wave packet of energy. This approach implemented using order -N computational techniques, has been successfully compared to analytical results derived from the Fermi Golden rule, but for uniform disorder. The Landauer Buttiker conductance was evaluated from transmission co-efficient. An external magnetic field applied perpendicularly to the nanotube axis was shown to induce a floating up in energy of the quasibound states.

3 illus, 5 ref

023184   Sheth P R (NO, , E-705/706 Kalp Nagari, Vaishali Nagar, Mulund (West), Mumbai-400 080, Email: parulsheth@gmail.com) : Safety aspects of Indian nuclear power plants. Curr Sci 2011, 101(6), 722-3.

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023183   Shashi Devi S;Reddy S N;Chary A S (Physics Dep, Vardhaman College of Engg., Shamshabad, R.R. Dist, Andhra Pradesh) : AC conductivity and complex impedance analysis of Ba(NO₃)₂-KNO₃ mixed crystals. Archiv appl Sci Res 2013, 5(3), 241-6.

AC conductivity studies and complex impedance spectroscopic studies were carried out on Ba(NO3)2-KNO3 mixed crystals in the temperature range from room temperature to melting points of their respective systems and the frequency range from 50 KHz to I MHz. Dielectric constant, loss tangent, capacitance and AC conductivity, in these systems are presented. Dielectric constant, loss capacitance and AC conductivity are found to increase with temperature and with mole percent of Ba(NO3)2 in KNO3. These dielectric properties are interpreted in terms of space charge polarization and increased concentration of defects in the interfacial layer formed between the host and the dispersoid.

22 ref

023182   Sharma S V (Regional Institute of Education, NCERT, Ajmer-305 004, Email: svsriea@yahoo.co.in) : Mechanism of superconductivity in YBaCuO high T_c oxide superconductors. Bull pure appl Sci 2012, 31D(1), 51-8.

Present study attempts to explain the attainment of zero resistance in all Y/RE-Ba-Cu-O (123) (RE= rare earth elements) systems of high Tc superconductors along the guide lines of proposed mechanisms for superconductivity in Y-Ba-Cu-O system. In the light of proposed mechanisms attempts have been made to explain some other experimental results of high Te superconductors.

1 illus, 34 ref

023181   Sharma A;Sanjay Kumar;Budhiraja N;Dahiya S; Singh M (Physics Dep, M.D. Univ, Rohtak, Haryana) : Effect of calcination on optical properties and morphology of NiO-CuO nanocomposites. Archiv appl Sci Res 2013, 5(3), 122-8.

Novel NiO-CuO nanocomposite has been synthesized by a sol-gel method based on polymeric network of polyvinyl alcohol (PVA). In this work mixed solvent of 50:50 ethanol water was used to dissolve cupric nitrate, nickel nitrate and PVA. The mixture was heated to 80° C to form a homogeneous gel solution. The obtained gel was slowly heated to evaporate the solvent to form a hard homogeneous gel. The hard gel was calcinated at temperature 600° C for 4 hours and 6 hours and converted into nanocomposite. The prepared nanocomposites have been characterized using X-Ray Diffraction (XRD), FTIR, VV-VIS. In the observed spectral features, the peak position, intensity and bandwidth were related to some structural properties of investigated samples. The size of NiO-CuO nanocomposites heated at 600° C for 4 hours and 6 hours using Scherrer Formula comes out to be 17.1 nm and 21.2 nm. Size of NiO-CuO nanocomposites increases with increase in temperature. Infrared spectroscopy is also used to determine presence of various functional groups. XRD revealed the polycrystalline structure of the nanocomposite. NiO-CuO nanocomposites shows increase in absorption when it goes from UV region to visible region. SEM gives the morphology of the nanocomposites.

25 ref

023180   Senthilkannan K;Gunasekaran S;Peter V J; Gopalakrishnan B (PG and Research Physics Dep, Pachaiyappa's College, Chennai, Tamil Nadu) : Spectroscopic (IR & Raman) studies of picolinium maleate (pm) single crystals. Archiv appl Sci Res 2013, 5(3), 100-3.

Picolinium Maleate is an organic NLO material, synthesized by slow evaporation technique. The studies such as IR, Raman have been taken and analysed and reported.

4 ref

023179   Sengwa R J;Choudhary S (Physics Dep, J N V Univ, Jodhpur-342 005, Email: rjsengwa@rediffmail.com) : Dielectric properties and structural dynamics of melt compounded hot-pressed poly(ethylene oxide)-organophilic montmorillonite clay nanocomposite films. Bull Mater Sci 2012, 35(1), 19-25.

Delectric properties of melt compounded hot-pressed nanocomposite films consisting of a poly(ethylene oxide) (PEO) and organophilic montmorillonite (OMMT) clay surface modified with trimethyl stearyl ammonium as filler with increasing amount up to 20 wt. % OMMT were investigated in a frequency range of 20 Hz-1 MHz at 30 °C. The predominance of OMMT exfoliated structures in PEO-OMMT nanocomposites were recognized by a decrease of the real part of complex dielectric function. OMMT concentration dependent dielectric and electric modulus relaxation times have revealed that the interactions compatibility between PEO molecules and dispersed OMMT nano-platelets in PEO matrix governs the PEO segmental dynamics. A.C. conductivity of these nanocomposites increases by two orders of magnitude in the experimental frequency range.

6 illus, 6 ref

023178   Sahoo B K;Panda B N (Physics Dep, D A V College, Korapur-764 021, Email: basanta@iopb.res.in) : Effect of hybridizaion and dispersionof quasiparticles on the coexistent state ofsuperconductivity and antiferromagnetism in RNi₂B₂C. Pramana J Phys 2011, 77(4), 715-26.

Effect of hybridization of conduction electrons and f-level on superconductivity (SC) and antiferromagnetism (AFM) in the coexistent phase of rare-earth nickel borocarbide superconductors (RNi2B₂C) is reported. The Hamiltonian of the system is a mean field one and has been solved by writing equations of motion for the single-particle Green functions. It is assumed that superconductivity arises due to BCS pairing mechanism in the presence of antiferromagnetism in nickel lattices of Rni₂B₂ plane. The expressions for superconducting and antiferromagnetic order parameters are derived using double time electron Green functions. The quasiparticle energy bands are plotted and the nature of band dispersion of the quasi particles is studied.

16 ref

023177   Saha A;Bhattacharya K;Chakraborty AK (Plectronics & Communication Engineering Dep, B P Poddar Institute of Management & Technology, 137, VIP Road, Kolkata-700 052, Email: arijit_sh@yahoo.com) : A near-infrared zero-order achromatic retarder. Pramana J Phys 2011, 77(4), 627-31.

. Phase retarders normally show strong wavelength dependence. Achromatic retarders which exhibit nearly identical characteristics over a wide wavelength spectrum is used in polychromatic light. The present investigation deals with a technique to design and study the characteristics of an achromatic combination of birefringent plates in 800-2000 nm range. The retarder has been designed using calcite, crystalline quartz and ADP. The thicknesses of the plates are 19.38 μm, 446.14 μ and 12.57 μm respectively. The new arrangement of three birefringent plates proposed has the promise of producing a zero-order quarter wave achromatic combination with fairly good accuracy.

5 illus, 11 ref

023176   Sagar S;Anantharaman M R (Physics Dep, Cochin Science and Technology Univ, Cochin-682 002, Email: mraiyer@yahoo.com) : On conduction mechanism in paramagnetic phase of Gd based manganites. Bull Mater Sci 2012, 35(1), 41-5.

Materials belonging to the family of manganites are technologically important since they exhibit colossal magneto resistance. A proper understanding of the transport properties is very vital in tailoring the properties. A heavy rare earth doped manganite like Gd_0.7Sr_0.3MnO₃ is purported to be exhibiting unusual properties because of smaller ionic radius of Gd. Gd_0.7Sr_0.3MnO₃ is prepared by a wet solid state reaction method. The conduction mechanism in such a compound has been elucidated by subjecting the material to low temperature d.c. conductivity measurement. It has been found that the low band width material follows a variable range hopping (VRH) model followed by a small polaron hopping (SPH) model. The results are presented here.

4 illus, 37 ref

023175   Reddy N N K;Reddy V R (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: reddy_vrg@rediffmail.com) : Barrier characteristics of Pt/Ru schottky contacts on n-type GaN based on I-V-T and C-V-T measurements. Bull Mater Sci 2012, 35(1), 53-61.

Investigated the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Ru/Pt/n-GaN Schottky diodes in the temperature range 100-420 K. The calculated values of barrier height and ideality factor for the Ru/Pt/n-GaN Schottky diode are 0 73 eV and 14 at 420 K, 0 18 eV and 4.2 at 100 K, respectively. The zero-bias barrier height (Φ_b0) calculated from I-V characteristics is found to be increased and the ideality factor (n) decreased with increasing temperature. Such a behaviour of Φ_b0 and n is attributed to Schottky barrier (SB) inhomogeneities by assuming a Gaussian distribution (GD) of barrier heights (BHs) at the metal/semiconductor interface. The current-voltage-temperature (I-V-T) characteristics of the Ru/Pt/n-GaN Schottky diode have shown a double Gaussian distribution having mean barrier heights (Φ_b0) of 1-001 eV and 0-4701 eV and standard deviations (σ₀) of 0 1491 V and 0 0708 V, respectively. The modified ln(J₀/T²) - (q²σ₀²/2k²T²) vs 10³/T plot gives Φ_b0 and Richardson constant values as 0-99 eV and 0-47 eV, and 27.83 and 10.29 A/cm²K², respectively without using the temperature coefficient of the barrier height. The difference between the apparent barrier heights (BHs) evaluated from the I-V and C-V methods has been attributed to the existence of Schottky barrier height inhomogeneities.

8 illus, 1 table, 45 ref

023174   Ranjith V;Kumar N (Theoretical Physics Group, Raman Research Institute, Bangalore-560 080, Email: ranjithv@rri.res.in ) : Effect of injected noise on electromagnetically induced transparency and slow light. Curr Sci 2011, 101(5), 653-7.

Authors have examined theoretically the phenomenon of electromagnetically induced transparency (EIT) in a three-level system operating in the A-configuration in the presence of an externally injected noise coupling the ground level to the intermediate (metastable) level. The changes in the depth and width of the induced transparency and the slowing down of the probe light have been calculated as a function of the probe detuning and strength of the injected noise. The calculations are within the rotating-wave approximation. Our main results are the reduction and broadening of the EIT with increasing strength of the injected noise, and a reduction in the slowing down of group velocity of the probe-laser beam. Thus, the injected semi-classical noise, unlike the quantum-dynamical noise associated with the spontaneous emission, is not effectively cancelled by the EIT mechanism.

7 illus, 10 ref

023173   Rajan G;Ramaswamy S;Gopalakrishnan C; Thiruvadigal D J (Nanotechnology Research Centre, SRM Univ, Kancheepuram District-603 203, Email: shivi.masti@gmail.com) : Effects of nitrogen annealing on surface structure, silicide formation and magnetic properties of ultrathin films of Co on Si(100). Bull Mater Sci 2012, 35(1), 13-18.

Effects of nitrogen annealing on structural and magnetic properties of Co/Si (100) up to 700° C has been studied in this paper. Ultrathin Co films having a constant thickness of 50 A were grown on Si (100) substrates using electron-beam evaporation under very high vacuum conditions at room temperature. Subsequently, the samples were annealed at temperatures ranging from 100-700°C in a nitrogen environment at atmospheric pressure. Sample quality and surface morphology were examined using atomic force microscopy. Silicide formation and the resultant variation in crystallographic arrangement were studied using X-ray diffractometer. The magnetization measurements done using a vibrating sample magnetometer indicate a decrease in coercivity and retentivity values with increase in annealing temperature. Resistivity of the samples measured using a four-point probe set up shows a decrease in resistivity with increase in annealing temperature. Formation of various silicide phases at different annealing temperatures and the resultant variation in the magnetic susceptibility has been thoroughly studied and quantified in this work.

4 illus, 15 ref

023172   Prasad D;Thakur A N;Jai Prakash (Basic Science Dep, U.P. Textile Technology Institute, Kanpur (U.P.), 208001, Email: dev07.2007@rediffmail.com) : T L glow curve analysis technique for evaluation of decay parameters and order of kinetics. Ultra Scient phys Sci-Sect B 2012, 24(3), 489-96.

In the present paper a new method has been developed to evaluate decay parameters and order of kinetics by analyzing thermolu-minescence (TL) glow curve. It has been observed that the decay parameters are characteristic feature of the system under investigation whereas order of kinetics does not. Extents of recombination and simultaneous retrapping decides the order of kinetics involved in the T L process. Order of kinetics increases with extent of retrapping within the system. TL decay parameters, order of kinetics and initial concentration of trapped electrons per unit volume are evaluated easily and conveniently following the proposed method of analysis.

3 illus, 1 table, 16 ref

023171   Pandey S;Pandey K L (Physics Dep, Nehru Gram Bharti Univ, Kotwa, Dubawal, Allahabad) : Polytropes and their property. Ultra Scient phys Sci-Sect B 2012, 24(3), 539-45.

Polytropes has been analytical studied under the concept of a sphere of uniform density by the polytrophic indices n tending to zero and n tending one. In this paper we have demonstrated that the temperature of the stars keeps on decreasing from its centre to surface. Approximate analytic solutions to the equilibrium equations have been presented in phase planes such as (U_p, V_p), Transformations connecting solutions in this phase plane have been obtained and discussed.

3 illus, 22 ref

023170   Pakarzadeh H;zakery A (NO, College of Sciences, Shiraz University, hysics Dep) : Numerical modelling of the pump-to-signal relative intensity noise transfer in two-pump fibre opticalparametric amplifier. Pramana J Phys 2011, 77(4), 655-67.

An accurate numerical model to investigate the pump-to-signal relative intensity noise (RIN) transfer in two-pump fibre optical parametric amplifiers (2-P FOPAs) for low modulation frequencies is presented. Compared to other models in the field, this model takes into account the fibre pump depletion as well as the gain saturation. As a result, the model allows to include a wide e of practical circumstances, both in and beyond the undepleted pump regime, related to different applications of FOPAs. In the small-signal or undepleted pump regime, the model predicts the ripples of the RIN spectrum very well and yields better results than those of other models. It is shown that beyond the small-signal regime, pump power variations do not remain unchanged over the length of amplifier and for high signal powers, when the FOPA saturates, minimum pump-to-signal RIN transfer occurs. The results of the model are also compared with the available experimental data in the field and a very good agreement can be seen.

7 illus, 27 ref

023169   Negi A;Hariwal R V;Semwal A;Sonkawede R G; Kanjilal D;Rana J M S;Ramola R C (Physics Dep, H N B Garhwal University, Badshahi Thaul Campus, Tehri Garhwal-249 199, Email: rcramola@gmail.com) : Opto-chemical response of Makrofol-KG to swift heavy ion irradiation. Pramana J Phys 2011, 77(4), 707-14.

In the present study, the effects of swift heavy ion beam irradiation on the structural, chemical and optical properties of Makrofol solid-state nuclear track detector (SSNTD) were investigated. Makrofol-KG films of 40 109>m thickness were irradiated with oxygen beam (O⁸⁺) with fluences ranging between 10¹⁰ ion/cm² and 10¹² ion/cm². Structural, chemical and optical properties were investigated using X-ray diffraction, FTIR spectroscopy and UV-visible spectroscopy methods. It is observed that the direct and indirect band gaps of Makrofol-KG decrease after the irradiation. The XRD study shows that the crystalline size in the films decreases at higher fluences. The intensity plots of FTIR measurements indicate the degradation of Makrofol at higher fluences. Roughness of the surface increases at higher fluence.

18 ref, 4 illus

023168   Nagendran R;Thirumurugan N;Chinnasamy N; Janawadkar M P (Matter Physics Div, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Email: nags@igcar.gov.in) : Development of advanced measuring instruments based on SQUID sensors for laboratory and industrial applications. Curr Sci 2011, 101(5), 607-16.

The design and development of Superconducting Quantum Interference Devices (SQUID)-based measuring systems using the indigenously developed SQUID sensors and the associated readout electronics is described in detail. The high-field SQUID magnetometer has a sensitivity of 1.2 x 10^-7 emu of magnetic moment. It incorporates several novel features such as a variable temperature regulator based on impedance capillary for achieving excellent temperature control, and the use of a novel input circuit that utilizes two SQUID sensors with different strengths of input signal coupling in order to allow a user-selectable trade-off between high-resolution measurements with a lower dynamic range and low-resolution measurements with a higher dynamic range to permit measurement of magnetization of samples with low as well as high values of magnetic moment. SQUID-based system for nondestructive evaluation of materials harnesses the low-frequency sensitivity of the SQUID sensors for the detection of deep subsurface defects not detectable by the conventional eddy current techniques owing to skin depth limitations. The system is based on a precision X-Y-9 scanner with a position resolution of 50 μMn, custom designed indigenously for this application and has been extensively used for studies on the frequency and depth dependence of the magnetic anomalies associated with the perturbation of the flow of eddy currents in the vicinity of the defects.

18 illus, 2 tables, 27 ref

023167   Mudry S;Yakymovych A;Shtablavyi I;Sidorov V; Shunyaev K (Metal Physics Dep, Ivan Franko National Univ, 8 Kyrylo and Mephodiy Str. 79005 Lviv, Ukraine, Email: yakymovych@online.ua) : Correlation between diffraction and viscosity data for Bi-Ga molten alloys. Bull Mater Sci 2012, 35(1), 83-7.

Structure of Bi_100-xGa_x molten alloys containing 38.5, 50, 70 and 91.5 at. % Ga has been studied by means of X-ray diffraction method and compared with viscosity measurements data. Significant changes in the structure factor profile were observed in vicinity of the concentration 70 at. % Ga. The dynamic viscosity coefficient was calculated by use of a statistical atomic distribution model and a Born-Green kinetic theory. The concentration dependence of viscosity is in agreement with change of structure parameters obtained from diffraction data.

3 illus, 1 table, 14 ref

023166   Manju Kumari;Prasad J N (Physics Dep, Ranchi University, Ranchi, Jharkhand, Email: smanju123@yahoo.co.in) : Phenomenological description of spin coulomb drag considering spin-flip possibility. Indian J scient Res 2012, 3(1), 157-9.

Phenomenological equations for spin coulomb drag using the spin-drag co-efficient γY is discussed in this paper. Expression for transresistivity ρ is also given and it is shown that θ is directly proportional to ρ. In brief electron-electron collision and electron-impurity collision with spin-flip process are discussed. Finally, the collision-integral equation is given which .terprets spin coulomb drag as damping mechanism for spin-current and a source for power loss in spintronic devices or circuits.

7 ref

023165   Mahammad D V;Ratna Raju M;Goud B V S (Electronics & Instrumentation Tech. Dep, Acharya Nagarjuna Univ, Nagarjuna Nagar-522 510, Email: profbvsgoud@gmail.com) : Design of simple monochromator and its microcontroller based wavelength drive system. Bull pure appl Sci 2012, 31D(1), 25-36.

Design of a reflection grating monochromator and its wavelength drive mechanism for the measurement of spectroscopic properties of a sample in near-ultraviolet to visible range spectra of light is presented. The discussion includes practical guidelines accessible to non-specialists who wish to design their own instrument. The basic characteristics and the design principles of such device are discussed, with emphasis on the key components. The system consists of a 32mm x 32mm in size, 1200 lines per mm reflection type grating, blazed at 250 nm and two 200mm focal length concave mirrors. Using a 10 μm wide entrance slit, a resolving power of 0.5nm has been demonstrated. A microcontroller based wavelength drive system is also discussed. Sensing of initial position, Scanning of wavelength spectra, stepping to desired wavelength and sensing of extreme positions are performed by the wavelength drive system. An effort is made to recall the fundamental laws and concepts of related optics.

5 illus, 2 tables, 8 ref

023164   Khan S;Singh P;Mazher J;Behera N (Physics Dep, Govt. Motilal Vigyan Mahavidyalaya, Barkatullah Univ, Bhopal-462 001, Email: shabinakhank@gmail.com) : Investigations of the alloy hardening among the Zinc-Beryllium-Selenide ternary solid solutions by using extended x-ray absorption fine structure (EXAFS) technique. Ultra Scient phys Sci-Sect B 2012, 24(3), 445-51.

A detailed ab initio analysis is carried out for the cationic substitution doped mixed alloy's theoretical EXAFS simulations. Suitable data processing codes are used for the subsequent experimental EXAFS spectral fittings. Authors simulated various x-ray scattering single and multiple paths around the core atomic environ and subsequently they are compared with the spectroscopic results. As-obtained parametric values are used to find the hardening and crystalline disorders among these heavily Be doped ZnSe ternaries. The hardening phenomenon amongst the alloys are explained by using the doping related variations of the Zn-Se and Be-Se bond lengths and the presence of structural stabilities during the initial stages of alloying.

4 illus, 18 ref

023163   Khan S;Mazher J;Behera N (Physics Dep, Govt. Motilal Vigyan Mahavidyalaya, Barkatullah Univ, Bhopal-462 001, Email: shabinakhank@gmail.com) : Extended x-ray absorption fine structures of the Zinc-Beryllium-Selenide ternary solid solutions. Ultra Scient phys Sci-Sect B 2012, 24(3), 405-10.

Hardening in the Zinc-Beryllium-Selenide ternaries has been achieved by cationic substitution alloying. Six samples of these ternaries are prepared by varying the concentration of Be dopant 'x'. EXAFS experiments for Zn core excitations are performed on the x-ray absorption spectroscopy (XAS) beamline at SOLEIL synchrotron radiation facility located at Gif sur Yvette, France. Extraction of useful EXAFS oscillations and various computational procedures require for the ZnBeSe spectral data analysis are discussed. Our analyses indicate that the hardening increases with Be-doping. Prospects of semiconductor alloy hardening through Be doping are also discussed in detail.

3 illus, 34 ref

023162   Khabaz R;Hakimabad H M (Physics Dep, School of Sciences, Fedowsi University of Mashhad, Mashhad, Postal code: 91775-1436, Iran, Email: rahimkhabaz@yahoo.com) : Evaluation of response matrix of a multisphere neutron spectrometer with water moderator. Pramana J Phys 2011, 77(4), 599-609.

Neutron energy responses of water sphere spectrometers (WSS) to 30 MeV have been calculated by means of Monte Carlo calculations, using the computer code MCNP4C with ENDF/B-VI.O neutron cross-section. The calculations have been performed for ³He detector (typical SP9) placed inside 2, 3, 5, 8, 12 and 18-inch diameter moderating spheres composed of water in aluminum shell. These simulations included a detailed description of the geometry of the system. The newly calculated responses have been compared to polyethylene sphere responses.

10 illus, 3 tables

023161   Ketabi S A;Kazemi A S;Bagheri Mohagheghi M M (School of Physics and Center for Solid State Physics Research, Damghan University, Damghan, Iran, Email: saketabi@du.ac.ir) : The effect of complexing aget on the crystallization of ZnO nanoparticles. Pramana J Phys 2011, 77(4), 679-88.

In this work, some structural and optical properties of the zinc oxide (ZnO) nanoparticles were studied. The highly crystalline ZnO nanoparticles were produced by the hydrothermal and solgel methods. The analyses of the XRD patterns, STEM images and UV spectroscopy showed that the size of the nanoparticles prepared by oxalic acid was smaller than the ones by urea. The properties of oxalic acid and urea were also investigated to detennine the most effective crystallization process nanoparticles. It has been shown that pH, decomposition temperature and activity coefficient complexing agent have certain effects on crystallization process .

34 ref, 6 illus, 1 table

023160   Karun K K;Chandra G;Singh B K (Physics Dep, S.G.S.M. College, Sheikhpura, Bihar) : Electronic spectra and structure of some nitro-molecules by rindo-ci method. Bull pure appl Sci 2012, 31D(1), 41-50.

The electronic spectra and structure of cis-and trans-nitrous acid, nitro methane and nitro ethylene have been studied by RINDO-CI method. First the equilibrium geometries of the molecules have been calculated and these equilibrium geometries are used to predict the other properties. The calculated ground and excited state properties along with So-OT splitting and Rydberg transitions are compared with experimental and theoretical values. The results are in a good agreement with experimental values.

1 illus, 4 tables, 34 ref

023159   Jain Y S;Chhangte L;Chutia S;Dey S (Physics Dep, North-Eastern Hill Univ, Shillong-793 022, Email: profysjain@gmail.com) : On the origin of stark effect of rotons in He-II and the existence of p=0 condensate. Curr Sci 2011, 101(6), 769-75.

Linear Stark effect of roton transition, experimentally observed through microwave absorption in He-II (superfluid ⁴He) in the presence of varying external electric field, is critically analysed. We find that: (i) The effect cannot be explained in terms of conventional microscopic theory (CMT) of He-II which presumes the existence of p = 0 condensate and concludes that ⁴He atoms even at T=0 have random motions and mutual collisions which do not support the basic factor (viz. an ordered arrangement of atomic electric dipoles) needed for its occurrence. (ii) The desired order is concluded, rather, by a non-conventional microscopic theory (NCMT) as an intrinsic property of He-II. Accordingly, all atoms in He-II define a close packed arrangement of their wave packets (CPA-WP) with identically equal nearest neighbour distance (d), per particle zero-point energy (ε₀ = h²/8md²) and equivalent momentum, h/2nd. (iii) The CPA-WP prevent atoms from having relative motions and mutual collisions capable of disturbing any order of atomic dipoles. As such the NCMT and the observed Stark effect have strong mutual support; whereas the former concludes CPA-WP necessary for the occurrence of the effect, the latter strengthens the experimental support for the former, which means that the observation -does not support the presence of p = 0 condensate in He-II.

1 illus, 34 ref

023158   Israel S;Saravana Kumar S;Renuretson R;Sheeba R A J R;Saravanan R (Physics Dep, The American College, Madurai-625 002, Email: israel.samuel@gmail.com) : Analysis on insulator-metal transition in Yttrium doped LSMO from electron density distribution. Bull Mater Sci 2012, 35(1), 107-18.

Yttrium doped LSMO (La_1-xSr_xMnO₃) was prepared using sol-gel technique and analysed for the insulator-metal transition from charge density variation in the unit cell with respect to different stoichiometric inclusion of yttrium. X-ray powder diffraction profiles of the samples were obtained and the well known Rietveld method and a versatile tool called maximum entropy method (MEM) were used for structural and profile refinement. The charge density in the unit cell was constructed using refined structure factors and was analysed. The charge ordering taking place in the insulator-metal transition was investigated and quantified. The insulator-metal transition was found to occur when 20% of La/Sr atoms were replaced by yttrium. The changes in the charge environment have also been analysed.

9 illus, 7 tables, 39 ref

023157   Idrish Miah M (Physics Dep, Chittagong Univ, Chittagong-4331, Bangladesh, Email: m.miah@griffith.edu.au) : Voltage probe of the optically oriented electron spin relaxation. Curr Sci 2011, 101(6), 765-8.

Reported here a study of the voltage probe of the electron spin relaxation in zinc-blende semiconductors. Electron spins oriented by a circularly polarized light are dragged by an electric field in transparent devices formed on gallium arsenide. The observed spin polarization-dependent voltage signal (which is a measure of the spin relaxation) is found to decrease about exponentially with the applied electric field. When the spin-oriented electrons are dragged with a high field, a significant decrease in the spin polarization is observed due to an increase in the spin precession frequency of the hot electrons. It is also found that the signal rationally decreases with increasing crystal temperature. The results are discussed based on the Dyakonov-Perel spin relaxation mechanism.

3 illus, 26 ref

023156   Hussain M M (Physics Dep, R.D.S. College, Muzaffarpur, Bihar) : Study of microstrip for high gain. Bull pure appl Sci 2012, 31D(1), 11-15.

In high performance aircraft, spacecraft, satellite and missile application, where size, weight, cost, performance ease of installation, presently there are many other commercial applications, such as mobile radio and wireless communication. In this paper, a novel design technique for enhancing gain that improves the performance of a conventional microstrip patch antenna is proposed. This paper presents a novel wideband probe fed inverted multiple slot microstrip patch antenna. The design adopts contemporary techniques; probe feeding, inverted patch structure and stacked multiple slotted patch. The composite effect of integrating these techniques and by introducing the novel multiple shape patch, offer a low profile, broadband, high gain, and compact antenna gain of about 12.35 dBi and a fractional impedance bandwidth of 21.48%. The design is suitable for array applications especially for base station.

2 illus, 7 ref

023155   Hemalatha B;Vasantharani P (Physics Dep, Annamalai Univ, Annamalai Nagar, Tamil Nadu) : Ultrasonic studies on ternary liquid systems at different temperatures. Archiv appl Sci Res 2013, 5(3), 31-7.

The measurement of ultrasonic velocity, density and viscosity has been made for the ternary liquid mixtures of 1-pentanol and 1-hexanol with decane in cyclohexane at different temperatures (303 K, 308 K and 313 K). Acoustic parameters such as adiabatic compressibility, intermolecular free length, free volume and internal pressure have been evaluated. Weak molecular interaction taking part between the unlike molecules of solute in each mixture have been studied through these acoustical parameters and their excess values.

24 ref

023154   Gupta V K;Sharma N;Jangid R A (Microwave Research Lab Physics Dep, Raj Rishi Autonomous Govt PG College, Alwar-301 001) : Emission and scattering behaviour of bare and vegetative soil surfaces of different moist states by microwave remote sensing. Indian J Radio Space Phys 2013, 42(1), 42-51.

Dielectric constant (ε) and dielectric loss (ε) of artificially moistened soil of Alwar have been determined at microwave frequency 9.78 GHz and at temperature 32.5°C using wave guide cell method. In view of the active and passive microwave remote sensing, the horizontal-horizontal radar backscattering coefficient (σ⁰_hh) for bare and vegetative soil surface have been estimated by Integral Equation Model (IEM) and Water Cloud Model (WCM), respectively using ε and ε of soil and view angle as input parameters. The horizontal component of microwave emissivity (e_h) for bare soil surfaces have been determined by emissivity model. The e_h for vegetative soil surfaces determined by radiative transfer equation using suitable vegetation dependent parameters, like single way vegetation transmissivity (γ) and single scattering albedo (ω) for agricultural vegetation, respectively. The present study reveals that the σ⁰_hh for bare and vegetative soil surface exhibit a positive correlation with soil moisture content (SMC). Vegetative soil surface σ⁰_hh is lower than that of bare soil surface for the same values of SMC and view angle. Further, e_h for bare and vegetative soil surfaces decreases with an increase in SMC. Vegetative soil surface emissivity is higher than that of bare surface for the same values of SMC and observation angle. Further, backscattering coefficient and emissivity for bare and vegetative soil surfaces decrease as the angle of observation increases due to contribution of diminished coherent component.

6 illus, 27 ref

023153   Gogebakan M;Avar B (Physics Dep, Faculty of Arts and Sciences, Kahramanmaras Sutcu Imam University, Kahrmanmaras-46100, Email: barisavar@ksu.edu.tr) : Structural evolutions of the mechanically alloyed Al₇₀Cu₂₀Fe₁₀ powders. Pramana J Phys 2011, 77(4), 735-47.

Elemental mixtures of AI, Cu, Fe powders with the nominal composition of Al₇₀Cu₂₀Fe₁₀ were mechanically alloyed in a planetary ball mill for 80 h. Subsequent annealing of the as-milled powders were performed at 600-800°C temperature range for 4 h. Structural characteristics of the mechanically alloyed Al₇₀Cu₂₀Fe₁₀ powders with the milling time and the heat treatment were investigated by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and differential thermal analysis (DTA). Mechanical alloying of the Al₇₀Cu₂₀Fe₁₀ did not result in the formation of icosahedral quasicrystalline phase (i-phase) and a long time milling resulted in the formation of β-Al(Cu,Fe) solid solution phase (β-phase). The i-phase was observed only for short-time milled powders after heat treatment above 600°C. The fJ-phase was one of the major phases in the Al₇₀Cu₂₀Fe₁₀ alloy. The w-Al₇Cu₂Fe₁ phase (w-phase) was obtained only after heat treatment of the short-time milled and unmilled samples. The present investigation indicated that a suitable technique to obtain a large amount of quasicrystalline powders is to use a combination of short-time milling and subsequent annealing.

8 illus, 30 ref

023152   Girigisu S;Ibeanu I G E;Adeyemo D J;Onoja R A;Bappah I A;Okoh S (Physics Dep, Federal College of Education (Technical) Gusau, Zamfara State, Nigeria) : Assessment of radiological levels in soils from Bagega artisanal gold mining exercises at Bagega Zamfara State, Nigeria. Archiv appl Sci Res 2013, 5(3), 204-10.

The research consists of assessments of radiological levels from Bagega artisanal gold mining exercises in Zamfara State of Nigeria. Results show mean values of activities in the order ⁴⁰K <62>²²⁶Ra <62> ²³² Th gives 370.79±7.98 Bq kg^-1, 18.3 ± 1. 77 Bq kg^-1, 16.86 ± 0.94 Bq kg^-1. The mean value of outdoor gamma dose rate is 27.25 nGy h^-1 which is well below the global average values. The mean annual effective dose rate is 33.44 μSv y^-1 (= 0.033mSv y^-1), which is correspondingly much lower compare to 0.07 mSv y^-1 UNSCEAR base line. This valve are low radiological speaking and should not cause health concerns, however the unprofessional practices of the miners which included non-usage of gas mask puts them at risk of exposure to respiratory crystalline silica as well as exposure to radon gas inhalation.

16 ref

023151   Giri M;Jaggi N;Singh N;Jaiswal R M P (Physics Dep, Haryana College of Technology & Management, Kaithal-136 027, Email: manojgiri1@rediffmail.com) : Absorption, excitation and fluorescence spectra of acid yellow 99 in aqueous solutions. Asian J Spectrosc 2012, 16(1-4), 39-44.

The absorption, excitation and fluorescence spectra of acid yellow 99 [C₁₆H₁₃N₄O₈S].Cr, a fluorescent azo dye have been recorded in aqueous solutions at concentrations between 10³ M and 10^-6 M. This has led to the determination of optimum concentrations and suitable excitation wavelengths to record the fluorescence spectra of the molecule. The absorption spectrum shows two absorption peaks at - 311 and 460 nm, recorded in the spectral region 260-600 nm, which have been assigned to ¹W≥A (π ≥n) and 'B ≥A (π≥π) transitions respectively. Fluorescence spectra of the compound have shown two fluorescence peaks at - 375 nm and 545 nm respectively at different concentrations.

8 illus, 19 ref

023150   Ghosh J;Ghosh R;Deepak Kumar (School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, Email: rghosh.jnu@gmail.com) : Analysis of adiabatic transfe in caity quantum electrodynamics. Pramana J Phys 2011, 77(4), 633-53.

A three-level atom in a A configuration trapped in an optical cavity forms a basic unit in number of proposed protocols for quantum information processing. This system allows for efficient storage of cavity photons into long-lived atomic excitations, and their retrieval with high fidelity, in an abatic transfer process through the 'dark state' by a slow variation of the control laser intensity. Authors study the full quantum mechanics of this transfer process with a view to examine the non-adiabatic effect arising from inevitable excitations of the system to states involving the upper level of A, which radiative. Also find that the fidelity of storage is better, the stronger the control field and the slower die rate of its switching off. On the contrary, unlike the adiabatic notion, retrieval is better with faster rates of switching on of an optimal control field. Also, for retrieval, the behaviour with dissipation is non-monotonic. These results lend themselves to experimental tests. Our exact computations, when applied to slow variations of the control intensity for strong atom-photon couplings, are in very good agreement with Berry's superadiabatic transfer results without dissipation.

9 illus, 1 table, 36 ref

023149   Ganesh I (Laboratory for Photoelectrochemical Cells and Advanced Ceramics, International Advanced Research Centre for Powder Metallurgy and New M, Hyderabad-500 005, Email: ibram_ganesh@yahoo.com) : Conversion of carbondioxide to methanol using solar energy. Curr Sci 2011, 101(6), 731-3.

Conversion of carbon dioxide into methanol or to any other value-added chemical using solar light (known as artificial photosynthesis) is of great importance from the point of view of energy crisis and global warming problem. This note discusses the methods and challenges that need to be addressed for realizing processes for converting carbon dioxide to value-added chemicals.

^ssc10 ref

023148   El-Taher A;Madkour H A (Physics Dep, Al-Azher Univ, Assuit Branch, 75142 Assuit, Egypt, Email: Atef_Eltaher@hotmail.com) : Texture and environmental radioactivity measurements of safaga sand dunes. Indian J Geomar Sci 2013, 42(1), 35-41.

The contents of natural radionuclides were measured in sand dunes samples collected from Safaga region in the Red Sea, Egypt by using low level gamma spectrometry. Based on the characteristic spectral peaks, the radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K concentrations were determined. Average activity levels for these elements are 28.82, 14.03 and 558.39 Bq kg^-1. These values are lower than the global values reported in UNSCEAR publications. Results are discussed and compared with the levels in sand samples from different countries. Averages of radiation hazard parameters for the Safaga sand dunes samples are lower than the acceptable level 370 Bq kg^-1 for radium equivalent Raeq, 1 for level index I γr, the external hazard index Hex ≤ 1 and 59 (nGy.h^-1) for absorbed dose rate. These data records the radioactivity background levels in Safaga sand dunes samples.

1 illus, 4 tables, 47 ref

023147   Durrani I R (Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Exact solitonic solutions of the gross pitaevskii equation with linear potential. Bull pure appl Sci 2012, 31D(1), 161-6.

Exact solitonic solutions of the time dependent Gross Pitaevskii (GP) equation are derived. The solutions correspond to a string of bright solutions with phase difference between adjacent solitons equal to π.

2 ref

023146   Durrani I R (Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Exact solitonic solutions of the one dimensional gross-pitaevskii equation with a time-dependent harmonic potential and interatomic interaction. Bull pure appl Sci 2012, 31D(1), 149-59.

Derived exact solitonic solutions of the one-dimensional time-dependent Gross-Pitaevskii equation with time-dependent strengths of the harmonic external potential and the interatomic interaction. The time-dependence of the external potential and interatomic interaction are given in terms of a general function of time. For an oscillating strength of the external potential, the solutions correspond to breathing single and multiple solutions. The amplitude and frequency of the oscillating potential can be used to control the dynamics of the centre of mass of the solitons. For certain values of these parameters, the solitons can be trapped at the centre of the harmonic potential.

6 illus, 25 ref

023145   Durrani I R (Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Non quasilinear evolution of particle velocity in incoherent waves with random amplitudes. Bull pure appl Sci 2012, 31D(1), 141-7.

One-dimensional motion of N particles in the field of many incoherent waves is revisited numerically. When the wave complex amplitudes are independent, with a gaussian distribution, the quasilinear approximation is found to always overestimate transport and to become accurate in the limit of infinite resonance overlap.

3 illus, 18 ref

023144   Durrani I R (Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Electric fields in a Tokamak. Bull pure appl Sci 2012, 31D(1), 135-40.

With the establishment of vanishing net electrostatic fluids in a toroidally symmetric tokamak at equilibrium one is left needing an explanation for the measurement of an apparent radial electric field in experiments. Two scenarios are proposed depending on the type of measurement being considered. Indirect measurement via the radial equation of motion for an impurity species possibly measures that species net radial viscous force, and direct measurement via the motional Stark effect might reveal electric fields generated by the shifting of the toroidal magnetic flux density.

4 illus, 4 ref