020393   Meena S L;Bhatia B (Ceremic Lab, Physics Dep, Jai Narain Vyas Univ, Jodhpur-342 001, Email: shankardiya7@rediffmail.com) : Spectroscopic properties of Nd<. J pure appl ind Phys 2016, 6(1), 89-96.

Zinc lithium bismuth borate glasses containing Nd³⁺ in (25- x): Bi₂O₃:20Li₂O:20ZnO: 35B₂O₃:xNd₂O₃ (where x=l, 1.5,2 mol %) have been prepared by melt-quenching method. The amorphous nature of the glasses was confirmed by x-ray diffraction studies. Optical absorption spectra were recorded at room temperature for all glass samples. Slater-Condon parameters F_k(k=2, 4, 6), Lande's parameter ξ_4f and Racah parameters E^k(k=l, 2, 3) have been computed. Using these parameters energies and intensities of these bands has been calculated. Judd-Ofelt intensity parameters Ω_λ (λ=2, 4, 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. The stimulated emission cross section (σ_p) for the transition (⁴F_3/2→⁴I_11/2) is found to be in the range 2.75- 2.86 x 10^-20 cm². The σ_p values are comparatively large suggesting the possible utilization of these materials in laser applications.

3 illus, 6 tables, 22 ref

020392   Mathpal R;Prasad L;Hema;Mathpal C;Pokhariya M;Bhoj C (Physics Dep, M.B. Govt. P.G. College, Haldwani (Nainital) 263 139, Email: rajeshmthpl@gmail.com) : Relationship of high speed solar wind streams with geomagnetic field variation during 2003-2005 of solar cycle 23. J pure appl ind Phys 2016, 6(1), 25-8.

In the present analysis, events of high speed solar wind streams (HSSWS) have been taken to derive their relationship with geomagnetic activity for the period of 2003 to 2005, covering the moderate phase of solar activity period of solar cycle 23. The Ap index is taken as the measure of geomagnetic activity. Results of present analysis suggest that HSSWS can produce increase in geomagnetic activity. The geomagnetic activity varies with solar cycle. In mid period of solar cycle it goes out of phase. In mid period of solar cycle the geomagnetic activity is maximum one day before the HSSWS event. This indicates modrate phase of solar cycle.

1 illus, 11 ref

020391   Lahkar N;Kalita S;Duorah H L;Duorah K (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: nanditalanhakar1@gmail.com) : Comparative study on SN II progenitors for the synthesis of Li<. J Astrophys Astr 2015, 36(3), 375-83.

The synthesis of Li⁷ and B¹¹ confronts astrophysicists. Type II (SN II) and Type Ic (SN Ic) supernovae are supposed to be the producers of these two elements. In this study we calculate the yields of these two elements for SN II progenitors with 8, 10 and 20 solar masses. The process considered here is the neutral current interaction of heavy flavour neutrinos (V_μor V_τ) with He⁴ nuclei of the helium zone. The low mass progenitors are considered because the helium zone lies much closer to the core and hence experiences large neutrino flux. The starting point of the helium zone depends on detail stellar model. However, the shell radius at which it begins is available for these stars. 20 solar mass is considered for comparison of our production ratio Li/B with that of an earlier work. It is contrasted with the shock heating yields in the hydrogen envelope. The Li/B ratio has been found to be about 0.96. In the three model stars, the Li⁷ and B¹¹ yields are found to be in the range 6.61 x l0^-6-2.63 x 10^-6M_Sun and 6.92 x 10^-6-2.75 x 10^-6M_Sun respec- tively as we go from 8 to 20M_Sun. Some equivalence is found with shock induced nucleosynthesis model for SN II. The SN II yield is found to be compatible with that of hypernovae produced by C-O core collapse but higher than the yields obtained by neutrino processes in SNIc.

2 illus, 1 table, 21 ref

020390   Karmakar B;Mandal S (Glass Science & Technology Section, Glass Div, CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata-700 032, Email: basudebk@cgcri.res.in) : Glass development and production at CSIR-CGCRI for optical applications: Some success stories. Sci Cult 2015, 81(11-12), 327-36.

CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI) is the premier glass research institute in the country. From its inception, it is developing and producing various types of glasses for use in different types of optical applications particularly by the strategic sectors and industry. Among these developments and production, the most important glasses and glass-ceramics are classical and new generation optical glasses, radiation shielding glasses, lead-free glasses for use in plasma display devices, chalcogenide glasses and near zero expansion transparent glass-ceramics. In this article, a brief overview of these glasses and glass-ceramics with some events of set up of CSIR-CGCRI is presented.

8 illus, 6 tables, 12 ref

020389   Hossain M A;Sakib K N;Billah M M (Physics Dep, Govt. Fazilatunnesa Mahila College, Bhola, Bangladesh, Email: sakib_58@yahoo.com) : Determination of natural and artificial radionuclides in soil samples of Bhola district, Bangladesh. J pure appl ind Phys 2016, 6(1), 57-64.

Though there is no enough information about radioactivity in Bhola district of Bangladesh due to lack of measurement, geographical position and natural resources of this area are in favour of radioactivity. For this reason, concentration of radionuclides in 21 soil samples have been studied and evaluated. Soil samples were collected from 21 locations of Bhola district. Experimental results were obtained by using a High Purity Germanium (HPGe) Detector and the radioactive standard sources supplied by IAEA were used to determine the efficiency. The measuring time of all samples is 5000 seconds.

2 illus, 4 tables, 7 ref

020388   Ghosh D;Biswas K;Balaji S;Das P P;Sujatha Devi P;Annapurna K (Glass Div, CSIR-Central Glass and Ceramic Research Institute, Kolkata-700 032, Email: annaprnak@cgcri.res.in) : Revisit on solar cell: Generation of electricity by harvesting sunlight. Sci Cult 2015, 81(11-12), 337-47.

In the present day knowledge based society, Science transforms the Culture. This can be witnessed through the contemporary rationalized society that aroused with the advancement of science. Such revolutionised change leading to very fast modern-day walks of life can essentially be credited to the progression in light based technologies. However, in order to meet the continuously mounting demand for energy in this developed world, one has to look for the renewable energy resources and among all such resources most abundant one is the sunlight. In this context, an attempt has been made here to report a brief review on the development of solar cell, the simplest device that converts sunlight to electricity. Further, this article also presents the contributions of CSIR-CGCRI in this field.

7 illus, 2 tables, 45 ref

020387   Ghatak A;Bhadra S (Physics Dep, Indian Institute of Technology Delhi, New Delhi-110 016, Email: ajoykghatak@gmail.com) : Wonders of the optical fiber. Sci Cult 2015, 81(11-12), 298-308.

Telecommunication networks across the globe have been revolutionized with the deployment of optical fibers. Owing to the demand of present days internet services and access networks, fiber optic networks are expanding at a faster rate. The basic optical fiber material is high purity silica glass. Most of the technologies are now perfected and research is now directed towards new highly transparent materials for getting larger bandwidth. Recent development of photonic crystal fiber has shown tremendous benefit to medical sciences. Year 2015 has been proclaimed as the International Year of Light and Light-based Technologies by The United Nations General Assembly in order to campaign for optics and photonics research around the globe. Part of this article has been published in the journal - Transactions of the Indian Ceramic Society in December, 2014. Applications of guided medium, optical fiber and photonic crystal fiber will be described.

28 illus, 23 ref

020386   Bhadra S K (Fiber Optics and Photonics Div, CSIR-Central Glass & Ceramic Research Institute, Kolkata, Email: skbhadra88@gmail.com) : Trapping of light in natural and artificial photonic crystals and in hollow core photonic crystal fiber. Sci Cult 2015, 81(11-12), 309-18.

Quest for new materials in conjunction with technological advancement is an important part of intensive research and development. Truth is that the solution is embedded in natural materials. We find structural colouration in natural materials like plants and species. Some natural species possess photonic structures that produce beautiful colours and similar properties could be mimicked in artificial photonic crystals. We describe these aspects with available references and explain trapping of light in hollow core photonic crystal fibers (HCPCF). Bandgap guidance, related properties and designing various photonic structures are explained with computational photonics, and finally fabrication of HCPCF is described. CSIR-CGCRI has created a comprehensive facility to fabricate such optical fibers including nonlinear photonic crystal fiber (NPCF) for supercontinuum generation.

20 illus, 10 ref

020385   Bandyopadhyay S;Halder R (NO, CSIR-Central Glass & Ceramic Reseaarch Institute, Kolkata-700 032, Email: sbando@cgcri.res.in) : Transparent ceramics. Sci Cult 2015, 81(11-12), 348-53.

6 illus, 1 table, 7 ref

020384   Azeezaa V;Sunitha T G;Joseph Arul Pragasam A; Suresh S (Physics Dep, SRR Engineering College, Chennai-603 103, Email: azeezaaphysics@gmail.com) : Investigations on the mechanical and electrical properties of an L-Cysteine nicotinamide monohydrate single crystal. Int J chem Sci 2015, 13(3), 1410-20.

Single crystal of L-Cysteine Nicotinamide Monohydrate (LCNM) was grown by slow evaporation method. Single crystal XRD method was used for structural identification. The microhardness study shows that the hardness steadily increases with increase in loads. Work hardening coefficient indicates that the grown crystals are moderately softer. Variation of stiffness constant with load for the given crystals was analysed. Dielectric constant and dielectric loss have been obtained as a function of frequeny between 50 Hz -5 MHz and different temperatures. The dependence of AC conductivity (σ_ac) on temperature and frequency of the applied field (50 Hz-5 MHz) was studied. The D.C. conductivity was deduced from the A. C. conductivity and activation energy is calculated. The photoconductivity studies reveal that the LCNM crystal exhibits negative photoconductivity nature of the grown single crystal.

8 illus, 33 ref

020383   Asole A W (Physics Dep, Shri Shivaji Science College, Amravati-444 602, Email: anilasole15@gmail.com) : Study of ultrasonic properties of binary liquid mixture at 313K and 1MHz frequency. J pure appl ind Phys 2016, 6(1), 50-6.

The densities (ρ), viscosities (η) and Ultrasonic velocity (U) of binary liquid mixture of Ammonium Hydroxide (NH₄OH) with the solvent Ethanol (CH₃CH₂OH) were measured over the entire composition range at the temperature 313K and the frequency 1MHz. The observed experimental data have been utilized to evaluate some of the derived thermodynamic parameters such as adiabatic compressibility (β_a), free length (L_f), acoustic impedance (Za) and molar Volume (Vm). The behavior of these parameters with composition of the mixture has been discussed in terms of molecular interaction between the components of liquids. The excess values of adiabatic compressibility (β_a^E), free Length (L_f^E), acoustic impedance (Za^E) and molar Volume (Vm^E) were evaluated and discussed in the light of molecular interactions in the mixture.

4 illus, 2 tables, 13 ref

020382   Arefieff K N;Miculis K;Bezuglov N N; Dimitrijevic M S;Klyucharev A N;Mihajlov A A;Sreckovic V A (St. Petersburg State Univ, St. Petersburg, 198 904 Russia, Email: sreckovicvladimir@gmail.com) : Dynamics resonances in atomic states of astrophysical relevance. J Astrophys Astr 2015, 36(4), 613-22.

Ionized geocosmic media parameters in a thermal and a subthermal range of energy have a number of unique features. The pho-toresonance plasma that is formed by optical excitation of the lowest excited (resonance) atomic states is one example of conversion of radiation energy into electrical one. Since spontaneous fluorescence of excited atoms is probabilistic, the description of the radiating quantized system evolution along with photon energy transfer in a cold atom medium, should include elements of stochastic dynamics. Finally, the chaotic dynamics of a weakly bound Rydberg electron over a grid of the energy level diagram of a quasi-molecular Rydberg complex provides an excitation migration of the electron forward to the ionization continuum. This work aims at discussing the specific features of the dynamic resonances formalism in the description of processes involving Rydberg states of an excited atom, including features in the fluorescence spectrum partially caused by the quantum defect control due to the presence of statistic electromagnetic fields.

^iia3 illus, 27 ref

020381   Abojassim A A;Al-Alasadi L A;Shitake A R; Al-Tememie F A;Hussein A A (Univ of Kufa, Faculty of Science, Physics Dep, Iraq) : Long lived gamma emitters in biscuit samples consumed in Iraq. Int J envir Sci 2015, 5(5), 956-63.

Biscuit is important type of food that is widely consumed by baby in Iraq and other countries. This work measurers the natural radioactivity duo to long-lived gamma emitters in Children biscuit by gamma spectroscopy, and estimates radiation hazard indices which are the radium equivalent activity, the representative of gamma level index, the internal hazard index and annual effective dose in children. Ten samples were collected from the Iraqi market for different original countries. The average of specific activities for ²²⁶Ra, ²³²Th and ⁴⁰K were (9.390, 3.1213 and 214.969) Bq/kg respectively, but the average of the radium equivalent activity and the internal hazard index were 33.101 Bq/kg and 0.107 respectively. The total average of annual effective dose from consumption of adult, child and infant is estimated to be 0.655, 1.009 and 0.875 mSv respectively. The values of specific activity, radiation hazard indices and annual effective dose in all samples in this study are found lower than worldwide median value for all groups, therefore theses values are found to be safe.

5 tables, 17 ref

019170   Zhang J;Bai R;Zhai F;Duan Y;Zhang Q;Zhao H; Huang Q;He Y (Key Laboratory of Natural Pharmaceutical and Chemical Biology of Yunna, Honghe Univ, Mengzi 661199, P.R. China, Email: juchengzhang@163.com) : Photoactivity of Ag/TiO₂ microsphere by one-step hydrothermal method. Asian J Chem 2015, 27(7), 2482-4.

Ag/TiO₂ microsphere photocatalyst was prepared via one step hydrothermal method and prepared catalyst was used for photodegradation of rhodamine B under visible light. The Ag/TiO₂ catalyst was characterized through X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed Ag was uniformly distributed in the titanium matrix. The 6% Ag doped TiO₂ catalyst had the higher photoactivity than other proportion to degrade rhodamine B 86.6% within 60 min under visible light. The Ag doped TiO₂ also had the good activity under solar light cut off UV light.

6 illus, 14 ref

019169   Vandana Kumari;Kaswan A;Patidar D;Sharma K; Saxena N S (Physics Dep, Semi-Conductor & Polymer Science Lab, Rajasthan Univ, Room No. 14-15, Jaipur-302 004, Email: vandana.spsl@gmail.com) : Electrical conduction mechanism in GeSeSb chalcogenide glasses. Bull Mater Sci 2016, 39(1), 255-62.

Electrical conductivity of chalcogenide glassy system Ge_30-xSe₇₀Sb_x (x = 10, 15, 20 and 25) prepared by melt quenching has been determined at different temperatures in bulk through the I-V characteristic curves. It is quite evident from results that Poole-Frenkel conduction mechanisms hold good for conduction in these glasses in a given temperature range. The variation in electrical conductivity with composition was attributed to the Se-Sb bond concentration in the Se-Ge-Sb system. Results indicated that Ge₅Se₇₀Sb₂₅ showed the minimum resistance. In view of this the composition Ge₅Se₇₀Sb₂₅ may be coined as 'critical composition' in the proposed series. Also the activation energies of conduction of these glassy alloys have been calculated in higher and lower temperature range using the Arrhenius equation.

10 illus, 2 tables, 31 ref

019168   Thongprasri P (Si Racha, Kasetsart Univ Sriracha Campus, Chonburi-20230, Thailand, Email: sfengprt@src.ku.ac.th) : Capacitor voltage balancing in dc link five-level full-bridge diode-clamped multilevel inverter. Indian J pure appl Phys 2016, 54(1), 73-80.

The voltage balancing of dc capacitors is a great problem of all multilevel with several dc link. The chopper circuit in a five-level full-bridge diode-clamped multilevel inverter to overcome the unbalance charging of capacitor voltage has been studied in the present paper. The proposed chopper circuit requires additional inductors and control scheme, is very simple to implement and its different operation modes are described in the present paper. Simulation and experimental results are presented to verify the proposed chopper circuit for dc capacitor voltage balancing in the five-level full-bridge diode-clamped multilevel inverter and show that it can reduce a total harmonic distortion of output voltage and current.

21 illus, 12 ref

019167   Suganthi S;Kannapan V;Sathyanarayanamoorthi V;Karunathan R (Research and Development Centre, Bharathiar Univ, Coimbatore-641 046, Email: vkannappan48@gmail.com) : Quantum mechanical investigation of vibrational and electronic spectra of some 5-substituted isoquinolines. Indian J pure appl Phys 2016, 54(1), 15-34.

Fourier Transform infrared (FTIR) and FT-Raman spectra of 5-bromoisoquinoline (5-BIQ), 5-aminoisoquinoline (5-AIQ) and 5-nitroisoquinoline (5-NIQ) have been recorded and analyzed. The geometric bond lengths and bond angles have been optimized. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated by ab-initio and density functional theory (DFT) methods. The assignments of the vibrational spectra have been carried out. The calculated HOMO and LUMO energies indicate that charge transfer occurs within the molecule. Stability of the molecule due to conjugative interactions arising from charge delocalization has been analyzed using extensive natural bond orbital (NBO) analysis. Electronic spectral properties have been computed in benzene medium for the three compounds and compared with the experimental values. Thermodynamic parameters such as zero point vibrational energy (ZPVE), thermal energy and specific heat capacity, entropy of 5-BIQ, 5-AIQ and 5-NIQ at 298 K in ground state have been calculated by HF and DFT methods.

8 illus, 7 tables, 39 ref

019166   Sreedevi R;Amarsingh Babu K;Balu T; Murugakoothan P;Rajasekaran T R (Physics Dep, Aditanar College of Arts and Science, Tiruchendur-628 216) : Growth and characterization of N,N'-dimethylurea admixtured sulphamic acid single crystals. Asian J Chem 2015, 27(7), 2642-6.

The single crystals of N,N'-dimethylurea admixtured sulphamic acid (DMUASA) were grown by slow evaporation technique from an aqueous solution at room temperature. Good quality crystals of size 34 mm x 15 mm x 7 mm had been obtained within 30 days. To synthesise the N,N'-dimethylurea admixtured sulphamic acid salt, N,N'-dimethylurea and sulphamic acid were taken in 1:1 molar ratio. The solubility of N,N'-dimethylurea admixtured sulphamic acid salt in water had been carried out at various temperatures. The grown crystal was characterized by single crystal X-ray diffraction analysis to confirm the structure of sample. Powder X-ray diffraction studies confirm the crystalline nature of the grown crystals. Fourier transform infrared study was used to confirm the presence of various functional groups in the grown crystal. UV-visible-NIR transmittance spectrum was recorded to study the optical properties of the grown crystal. The existence of second harmonic generation signals was confirmed by performing Kurtz-Perry powder test and the output power generated by the crystal was comparable with that of potassium dihydrogen phosphate. Thermal properties of the crystal had been investigated using thermogravimetric analysis and differential thermal analysis. The mechanical strength of the crystal was estimated by Vickers hardness test.

8 illus, 1 table, 27 ref

019165   Rajeh S;Barhoumi A;Mhamdi A;Leroy G;Duponchel B;Amlouk M;Guermazi S (Unit of Physics of Insulators Materials and Semi-insulators, Sfax Univ, B.P. 1171, 3000 Sfax, Tunisia, Email: mhaammar@gmail.com) : Structural, morphological, optical and opto-thermal properties of Ni-doped ZnO thin films using spray pyrolysis chemical technique. Bull Mater Sci 2016, 39(1), 177-86.

Nickel-doped zinc oxide thin films (ZnO : Ni) at different percentages were deposited on glass substrates using a chemical spray technique. The effect of Ni concentration on the structural, morphological, optical and photoluminescence (PL) properties of the ZnO : Ni thin films were investigated. X-ray diffraction analysis revealed that all films consist of single phase ZnO and was well crystallized in wurtzite phase with the crystallites preferentially oriented towards the (002) direction parallel to the c-axis. The optical transmittance measurement was found to be higher than 90%, the optical band gap values of ZnO thin films decreased after doping from 3.29 to 3.21 eV. A noticeable change in optical constants was observed between undoped and Ni-doped ZnO. Room-temperature PL is observed for ZnO, and Ni-doped ZnO thin films.

10 illus, 5 tables, 54 ref

019164   Pai B H V;Shanbhag A A;Prabhath R K;Thakare S V;Jagadeesan K C;Krishnamoorthy A;Sarkar P K;Nandy M (NO, Manipal Institute of Technology, Manipal-576 104, Email: maitreyee.nandy@saha.ac.in) : Estimation of trace element concentration and neutron induced radioactivity in rock samples of different geological compositions for neutron shielding. Indian J pure appl Phys 2016, 54(1), 7-14.

Rock samples of different geological compositions intended for use as coarse aggregates (CA) in self-compacting concrete (SCC) have been analysed for concentrations of the elements Sc, Co, Fe, Cs, Ta Eu. These elements give rise to long-lived radioactivity in concrete used as neutron shields, consequent to long-term neutron irradiation. This study has been performed on all the eleven samples of different geological compositions to compare their low-activation characteristics and determine their suitability for developing SCC based neutron shielding. The collected samples quartzite rock exhibits lowest induced activity on neutron irradiation. But it failed the fresh property tests for SCC as observed in an earlier study (Pai B H V, et al.,) [communicated to Journal of The Institution of Engineers (India): Series A]. Among the CA samples suitable for SCC composition), dolomite rock produces lowest activity for all the isotopes studied. Concretes having low radioactivation properties will facilitate mitigating the prevailing radiological waste management problems during decommissioning of nuclear facilities.

3 illus, 6 tables, 11 ref

019163   Mehdizadeh F;Soroosh M (Engineering Faculty, Shahid Chamran Univ of Ahvaz, Iran) : Designing of all optical NOR gate based photonic crystal. Indian J pure appl Phys 2016, 54(1), 35-9.

In the present paper, an all-optical 3-Input NOR gate based on photonic crystals is proposed. In designing this gate, three resonant rings have been used. By employing high intensity optical power into the device based on Kerr effect, the refractive index of the rods has been varied and the coupling of light into output has been controlled. The consistency of simulation results with the logical table of NOR gate confirms the suitable functionality of the device.

3 illus, 1 table, 23 ref

019162   Megha U;Varghese G;Shijina K (Physics Dep, Calicut Univ, Kerala-673 635, Email: meghaunikoth@gmail.com) : Effect of Bi and Sr doping on morphological and magnetic properties of LaCo_0.6Fe_0.4O₃ nanosized perovskites. Bull Mater Sci 2016, 39(1), 125-31.

Nanopowders of La_1-xBi_xCo_0.6Fe_0.4O₃ (x = 0, 0.1, 0.2) and La_1-2xBi_xSr_xCo_0.6Fe_0.4O₃ (x = 0.1) multinary perovskites were synthesized by citrate sol-gel autocombustion method. Crystalline phase and the lattice parameters were obtained from X-ray diffraction pattern. The XRD result shows that all compounds have rhombhohedral crystal structure with R3_R3_ c space group and Bi (x = 0.2) have the presence of secondary peaks. Crystallite size, dislocation density, specific area and strain were calculated from XRD. The elemental composition and micrographs of grain were obtained from EDAX (energy dispersive X-ray analysis) and SEM (scanning electron microscopy), with an average grain size below 400 nm. Surface morphological studies using XPS (X-ray photoelectron spectroscopy) were used to find out the chemical states and surface proportion of oxygen present in samples. Finally, using the vibrating sample magnetometer the room temperature magnetic behaviour of compounds was studied and it was observed that the ferromagnetic behaviour of LaCo_0.6Fe_0.4O₃ was reduced by Bi and Sr doping.

9 illus, 3 tables, 27 ref

019161   Lekhal A;Benkhalifa F Z;Mecabih S;Abbar B; Bouhafs B (Physique Dep, Faculte des Sciences, Univ Djilaili Liabes, Bp 89, Sidi Bel Abbes 22000, Algeria, Email: mecabihsa@yahoo.com) : Structural and electronic properties of non-magnetic intermetallic YAuX (X=Ge and Si) in hexagonal and cubic phases. Bull Mater Sci 2016, 39(1), 195-200.

The structural and electronic properties of non-magnetic intermetallic YAuX (X = Ge and Si) crystallized in hexagonal phase have been investigated using the full potential linearized augmented-plane wave (FP-LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation (GGA). The calculated lattice parameters were in good agreement with experiment. Also, the structural and electronic properties of the non-magnetic half-Heusler YAuPb compound including the artificial YAuX (X = Ge and Si) calculated in cubic phase were determined. It was found that the half-Heusler YAuPb compound presented metallic character. The results showed that YAuGe in cubic phase is a semiconductor whereas the cubic YAuSi is an isolator.

8 illus, 1 table, 35 ref

019160   Kumar V;Tundwal A;Vijay Y K;Palsania H S (Univ School of Basic and Applied Sciences, G G S Indraprastha Univ, New Delhi-110 078, Email: vkverma274@gmail.com) : Investigation of defect production in iron on gamma irradiation using the positron doppler broadening technique. Indian J pure appl Phys 2016, 54(1), 51-5.

The parameters S and W corresponding to the positron Doppler broadening technique have been used to study displacement type defects produced in iron samples irradiated by various imparted doses of gamma ranging from 20 Gy to 2kGy. For the logistic support of the experimental observations, Monte Carlo simulation of displacements has also been performed. Of the increase of S parameter with dose up to a limit, it is revealed that vacancy type defects dominate. From both the experimental observations and the Monte Carlo study, it is inferred that on irradiation monovacancies are produced and under the given irradiation conditions there is negligible chance of the atom+atom collision cascade which may give rise to multiple type vacancies.

6 illus, 1 table, 12 ref

019159   Fan J;Li T;Heng H (School of Materials Science and Engineering, Anhui Univ of Technology, Maanshan-243 002, China, Email: fanjincheng2009@163.com) : Hydrothermal growth of ZnO nanoflowers and their photocatalyst application. Bull Mater Sci 2016, 39(1), 19-26.

ZnO nanoflowers were prepared by the hydrothermal method and studied by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and photoluminescence. ZnO nanoflowers with star-like morphology were of pure wurtzite phase. The edges of the petals were composed of assemblies of smaller nanocrystallites. Green and orange emissions in photoluminescence were attributed to O vacancies and O interstitials, respectively. Furthermore, ZnO nanoflowers demonstrated the effective photocatalytic activities, and O vacancies and O interstitials were considered to be the active sites of the ZnO photocatalyst.

10 illus, 49 ref

019158   Elangovan S;Mullainathan S (Physics Dep, Easwari Engineering College, Chennai-600 089, Email: elangovan.physics@rediffmail.com) : Ultrasonic studies in binary mixtures of N-propyl formate with 1-alcohols at 303 K. Asian J Chem 2015, 27(7), 2508-12.

Density (ρ), viscosity (η) and ultrasonic velocity (U) have been measured for binary mixtures composed of n-propyl formate with 1-butanol, 1-pentanol and 1-hexanol at 303 K. From the experimental data, various parameters such as adiabatic compressibility (β), free length (L_f), free volume (V_f), Internal pressure (pπ_i), viscous relaxation time (τ) and Gibbs free energy (ΔG) have been deduced. Excess values of the above parameters (β^E, L_f^E, V_f^E, π_i^E, τ^E and ΔG^E) from their ideal values have also been calculated and fitted in Redlich-Kister polynomial equation. The results have been interpreted in terms of molecular interactions. The deviations in sign and excess values from the ideal mixing reveal that strength of intermolecular interactions between n-propyl formate with selected 1-butanol, 1-pentanol and 1-hexanol have been observed in the order of 1-butanol <60> 1-pentanol <60> 1-hexanol.

4 illus, 4 tables, 19 ref

019157   Datta P K (Kalpana Chawla Center for Space and Nano Science, Physics Dep, Presidency College, Kolkata-700 073, Email: dattapradip@gmail.com) : Development of white light sources. Sci Cult 2015, 81(7-8), 192-5.

The Nobel Prize in Physics for 2014 has been awarded for the invention of efficient blue light emitting diodes (LED) which has which has enabled bright and energy-saving white light sources. In this paper the history of the development of white light sources, starting from incandescent lamps, and the physics behind the sources have been discussed. A comparison among the sources has also been made.

5 ref

019156   Chandran D;Nair L S;Balachandran S;Rajendra Babu K;Deepa M (Physics Dep, Mahatma Gandhi College, Kerala Univ, Pattom Palace P.O., Thiruvananthapuram-695 004, Email: sbcnair@gmail.com) : Band gap narrowing and photcatalytic studies of Nd<. Bull Mater Sci 2016, 39(1), 27-33.

Pure and Nd³⁺-doped tin oxide (SnO₂) nanoparticles have been prepared by the sol-gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM, energy-dispersive spectroscopy and UV-visible spectroscopy. The XRD patterns of all the samples are identified as tetragonal rutile-type SnO₂ phase which is further confirmed by TEM analysis. Neodymium doping introduces band gap narrowing in the prepared samples and enhances their absorption towards the visible-light region. The photocatalytic activity of all the samples was evaluated by monitoring the degradation of methylene blue solution under day light illumination and it was found that the photocatalytic activity significantly increases for the samples calcined at 600 than 400°C, which is due to the effective charge separation of photogenerated electron-hole pairs. The efficiency of photocatalysts was found to be related to neodymium doping percentage and calcination temperature.

7 illus, 2 tables, 43 ref

019155   Cai C Y;Zhao C L;Xiao J L (Institute of Condensed Matter Physics, Inner Mongolia Univ for the Nationalities, Tongliao-028 043, China, Email: xiaojlin@126.com) : Effects of temperature on ground state binding energy of the strong coupling magnetopolaron in RbCl parabolic quantum dots. Indian J pure appl Phys 2016, 54(1), 56-9.

The external fields which are introduced during the formation of nanostructures, can trap particles and manipulate their quantum states. The effects of temperature on the strong coupling magnetopolaron's ground state binding energy (MGSBE), have been investigated by employing Lee-Low-Pines unitary transformation (LLPUT) and linear combination operation (LCO) methods. Numerical results, performed in the RbCl parabolic quantum dot (QD), show that the MGSBE increases with the increase of effective confinement strength (ECS), cyclotron frequency (CF) of the magnetic field and temperature.

2 illus, 35 ref

019154   Bhalla V;Singh D (Amity Institute of Applied Sciences, Amity Univ Uttar Pradesh, Noida-201 313, Email: vyoma.bhalla@student.amity.edu) : Anisotropic assessment of ultrasonic wave velocity and thermal conductivity in ErX (X:N, As). Indian J pure appl Phys 2016, 54(1), 40-5.

The elastic and ultrasonic properties of erbium nitride (ErN) and erbium arsenide (ErAs) have been investigated in the temperature range 0-300K. The second order elastic constants (SOECs) have been obtained using Coulomb and Born-Mayer potentials up to second nearest neighbours. SOECs have been used to evaluate various mechanical and thermal parameters which provide knowledge about the future performance of ErX. Mechanical properties such as Young's modulus, bulk modulus, shear modulus, Zener anisotropy factor, Poisson's ratio and toughness to fracture ratio (G/B) have also been calculated. The chosen materials are found to be brittle and anisotropic in nature. The ultrasonic wave velocities for longitudinal and shear modes of propagation along <60>100<62>, <60>110<62> and <60>111<62> crystallographic directions have also been computed at room temperature using evaluated values of SOECs and density of the chosen materials. These properties have been visualized using MTEX 4.0.22 software for ErAs. The ultrasonic wave velocity computed along different orientations is an important physical quantity in studying the thermal properties such as Debye temperature and anisotropic thermal conductivity. These properties play a significant role in quality control in material producing industries. The obtained results are discussed in correlation with mechanical and thermophysical properties of the materials.

2 illus, 3 tables, 34 ref

019153   Bagheri Khatibani A;Rozati S M (Nano Research Lab, Lahijan Branch, Islamic Azad Univ, P.O. Box 1616, Lahijan, Iran, Email: bagherikhatibani@gmail.com) : Spray pyrolytically grown NiAlOx cermets for solar thermal selective absorbers: spectral properties and thermal stability. Bull Mater Sci 2016, 39(1), 97-107.

After deposition of NiAlOx thin films on stainless-steel substrates by the spray pyrolysis technique, various properties of the films were investigated using Fourier transform infrared spectroscopy, UV-visible reflectance spectrophotometry, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical quantities were determined using reflectance spectra in the relevant spectrum region. At first the optimal substrate temperature was selected and then different nickel to aluminium ratios were examined to find the efficient solar absorber. The SEM revealed changes in morphology due to different molar ratios. The XRD of the selected sample showed a mixture of nickel and nickel oxide phases with the strong presence of substrate peaks and without the presence of alumina phase while in the EDX test the peaks corresponding to O, Al and Ni appeared. Long-term thermal stability study was performed by means of performance criterion concept.

14 illus, 8 tables, 55 ref

019152   Ahmad S;Shah J;Katiyar A K;Chaujar R;Puri N K;Negi P S;Kotnala R K (NO, CSIR-National Physics Laboratory, New Delhi, Email: ahmads@mail.nplindia.org) : Microwave device jig characterization for ferromagnetic resonance induced spin Hall effect measurement in bilayer thin films. Indian J pure appl Phys 2016, 54(1), 60-5.

Microwave device jig for evaluating magnetic thin films consists of two symmetrical radial copper pad sections each having panel mounted RF connector. A non resonant measurement method for obtaining spin Hall voltage across magnetic thin films using ferromagnetic resonance was developed, based on electrical impedance of thin film and copper pads of the microwave device jig both in contact with each other. A geometry is introduced, which provides good impedance match characteristics and is optimised for maximum power transmission. It also gives the flexibility in measurements for any orientation of thin film with respect to applied magnetic field. In this geometry, a quantitative study of the microwave device jig has been done by measuring spin Hall voltages in the frequency range 0.1-10 GHz for bilayer thin films. The experimentally recorded voltages can be fully ascribed to SHE detection due to microwave induced FMR.

7 illus, 27 ref

018163   Singh K;Singh G (Physics Dep, Punjabi University, Patiala-147 002, Email: kanwal345@gmail.com) : Intensive study of gamma ray interactions with flyash concretes. Asian J Adv Basic Sci 2015, 4(1), 68-72.

Six concrete mixtures were casted with 0%, 20%, 30%, 40%, 50% and 60% of flyash replacing the cement content and having constant water to cement ratio. The different radiation parameters were computed theoretically in the energy region of 10 keV to 100 GeV. The mechanical properties show improvement with specimen age and results of radiation parameters show no significant effect of flyash substitution on mass attenuation coefficient while there is some variation in results of some parameters.

3 illus, 2 tables, 41 ref

017137   Wang Z;Wang X;Bu Y;Chen L;Cai G (Electronic Engineering Dep, Xiamen Univ, Xiamen, China, Email: Wangxz@xmu.edu.cn) : A 1073.8 nm Nd:YAG laser using a Fabry-Perot band-pass filter as output mirror. J Optics 2015, 44(2), 195-9.

We designed and fabricated a dielectric Fabry-Perot filter (FPF) with pass band of 24 nm as the output coupler of a [111]-cut Nd:YAG laser to restrain the strong emission near 1064 nm and obtain a 1073.8 nm lasing output with a plano-plane resonator cavity. The threshold pump power is about 2.9 W. The maximum output power is 261.7 mW at pump power of 5.3 W and the slope efficiency is 12.1%. Passively Q-switched 1073.8 nm laser is realized using a [100]-cut Cr:YAG crystal as the saturable absorber. The full width at half maximum (FWHM) pulse duration of 75.7 ns and pulse repetition rate of 4.23 kHz is achieved at pump power of 5.3 W. The design principle of the Fabry-Perot filter used as output mirror is discussed and the advantages of the method are summarized.

7 illus, 1 table, 11 ref

017136   Vanaei H;Sedaghat Z;Heidari E (Sciences Dep, Bushehr Branch, Islamic Azad Univ, Bushehr, Iran, Email: vanaie.physics@iaubushehr.ac.ir) : Non-equilibrium transport through quantum dots. Indian J pure appl Phys 2016, 54(2), 130-6.

Electron transport through Ca@C₆₀ or Ca^{2+@C₆₀ molecules is considered by using the non-equilibrium Green's function formalism and GW method. The effects of gate and bias voltages, encapsulation, position and displacement of ion into the cage are important factors in endohedral molecular junction that are considered in our calculations. The current value against the bias voltage, independent of the contacts strength, decreases when the calcium atom lies far from the cage center. Also, NDR behaviour is observed when it is in center of fullerene.}

6 illus, 36 ref

017135   Singha M;Singh L (Physics Dep, Khalsa College, Amritsar-143 005, Email: mohansinghphysics@gmail.com) : Vibrational spectroscopic study of muscovite and biotite layered phyllosilicates. Indian J pure appl Phys 2016, 54(2), 116-22.

In the present paper, the muscovite and biotite phyllosilicates minerals from the Nilore mica belt, India, have been studied using a combination of different techniques. Vibrational spectroscopy enables an assessment of the molecular structure of muscovite and biotite silicates and helps to understand their complex structures which will be useful for various scientific and industrial applications. The present results have been well compared with the published data for the correspondent minerals of different origins.

6 illus, 6 tables, 29 ref

017134   Siliu X;Petrovic N;Belic M R (The School of Electronic and Information Engineering, Hubei Univ of Science and Technology, Xianning-437 100, China, Email: xusiliu1968@163.com) : Two-dimensional dark solitons in diffusive nonlocal nonlinear media. J Optics 2015, 44(2), 172-7.

Using the balance principle and the F-expansion method, we find dark soliton solutions in a general nonlocal nonlinear optical model with a diffusive type of nonlinearity. These solutions are modeled by numerical simulation, in order to study how they propagate and interact with each other. Our results show that the multidimensional nonlocal solitary waves can be manipulated and controlled by changing the degree of nonlocality and the diffraction coefficient.

4 illus, 1 table, 26 ref

017133   Shi Y;Wang L;Chen H (College of Optical and Electronic Technology, China Jiliang Univ, Xueyuan Street No.258, Xiasha Higher Education District, 310 018 Hangzhou City, China) : Light extraction design of white LEDs with high luminous efficiency and uniformity. J Optics 2015, 44(2), 136-45.

In this paper a new planar optical system with patterned phosphor-layer structures is demonstrated. The phosphor film herein acts as a wavelength converter and a light diffuser simultaneously. The patterned structures can increase the depth of blue ray intrude into phosphor film. The absorption rate of blue ray and the utilization efficiency of phosphors are increased. So the luminous efficiency is improved. Given different patterns on the phosphor layer surface, the optical properties of the proposed optical system, light-emitting efficiency and uniformity, are studied. Eventually, an average irradiance of 58.372 W/m^{2 and a more appropriate color temperature of the lighting source for high quality optical system were achieved. Phosphor layer of flat and part-etched pattern were compared in irradiance. The result validates part-etched phosphor-layer produce 2.57 % higher average irradiance than flat phosphor-layer. The patterned area on phosphor-layer can increase the extraction efficiency of blue rays at periphery part, the uniformity of correlated color temperature (CCT) at periphery area is significantly improved, the light candela distribution of output light are adjusted by the patterns, so the illumination uniformity of planar optical system is adjusted. Finally, the yellow circle phenomenon of planar optical system is effectively improved by the given patterns. Then it will be utilized in high quality planar optical system.}

11 illus, 23 ref

017132   Shahbazian J H (ECE Dep, Tufts Univ, Medford, MA-02155, USA) : Manipulation and trapping of particles in the ray optics regime using DPS-DNG layered structures: toward calibration and precision of optical tweezers. J Optics 2015, 44(2), 93-8.

Optical traps or tweezers use the forces exerted by structured beams of light to confine and manipulate non-intrusively and non-destructively microscopic objects including living cells and bacteria, with high accuracy. This technique provides unique means to control the dynamics of small particles and played a revolutionary role in areas of the physical and biological sciences. This manuscript aims at absolute force calibration of optical beams, using new technique and structure of DPS-DNG layered structure to manipulate targets in the far field with high resolution trapping scheme. Using this layered structure which acts as a tunable optical band-pass filter would help to calibrate and control the forces on the target(s). The band-pass effect varies with the periodic parameters of the DPS-DNG structure, applied electric and magnetic field, incident angle and frequency.

6 illus, 30 ref

017131   Saravani M;Raghunath K;Rao S V B (Physics Dep, SV Univ, Tirupati-517 502, Email: kraghunath@narl.gov.in) : Lidar signal denoising methods- application to NARL rayleigh lidar. J Optics 2015, 44(2), 164-71.

Lidar (Light Detection And Ranging) is a remote sensing tool of great practical importance in environmental monitoring sciences. As an active remote sensing instrument, lidar provides vertical profiles of aerosol layers and atmospheric temperatures. The effective range and data reliability of lidar is often limited by various noises. Signal processing for lidar applications involves highly nonlinear models and consequently nonlinear filtering as the backscattered signal follows log-linear form. Denoising of the signal is essential for reducing random unwanted variations of the signal, in order to get the significance of the signal as much as possible. In this work, various denoising methods are applied to the signal from Rayleigh receiver of lidar at National Atmospheric Research Laboratory (NARL), Gadanki (13.8°N, 79.2°E) near Tirupati, India. Denoising methods such as Moving Average method, Wavelet and Empirical Mode Decomposition (EMD) method are considered and compared in this work. The Signal to Noise Ratio (SNR), temperature profiles and statistical standard temperature errors are obtained using denoised signals. It is found that EMD gives better SNRs than other denoising methods. The statistical standard temperature error obtained using EMD denoised signal and the original signal are compared and the EMD method is found to reduce temperature errors at higher ranges better than conventional method.

8 illus, 3 tables, 12 ref

017130   Renugadevi R;Venkatachalam T;Narayanasamy R; Prabahar S;Krishnamurthi P (Physics Dep, Coimbatore Institute of Technology, Coimbatore, Email: renuga.1304@gmail.com) : Structural, optical and photocatalytic activity studies of cobalt doped TiO₂ nano thin films. Rasayan J Chem 2016, 9(2), 125-32.

The structural, morphological, optical and photocatalytic properties of the cobalt doped TiO₂ films were studied using different techniques. Device quality coated TiO₂ thin films were prepared using by simple sol-gel technique by the various amount of dopants (0 to 15% of Co). The coated films have been characterized by different techniques such as XRD and EDAX and optical absorption studies for further investigation which is essential to make full use of their active properties. TiO₂ thin films of different thickness were prepared by using the sol-gel technique. XRD shows that the as deposited films are exhibit anatase crystalline structure. The optical transmittance of the film prepared in this work studied n the range of 190 to 2500 nm with direct band transition and band gap energy value equals to 3.4 ev. The photocatalytic of the film were studied by TiO₂ and Co doped TiO₂. The films were dipped in tannery effluent with different time interval. The carbonate, chloride and sulphate present in different concentrations the remaining effluent were analyzed by conventional methods. It is found that increases the catalytic activity while increases dopant concentration.

6 illus, 1 table, 31 ref

017129   Ramanan N;Ashwani Kumar;Rajput P;Thankarajan K;Bhattarcharyya D;Jha S N;Lahiri D (High Pressure & Synchrotron Radiation Physics Div, Bhabha Atomic Research Centre, Mumbai, India-400 085, Email: Debdutta.lahiri@gmail.com) : First phase commissioning of high pressure XAFS setup at ED-XAFS beamline, indus-2 synchrotron radiation source, India. J Optics 2015, 44(2), 182-94.

In this work, we report the first-phase commissioning of High Pressure setup at XAFS beamline (Bl-08) of Indus-2. This involved installation of vertically focusing bendable elliptical mirror to obtain <126> 50 μm spot size, as required for Diamond Anvil Cell-based High Pressure XAFS experiment. We present details of the mirror alignment procedure, observed deviations from design goals and suggestions for improvement. We provide realistic estimate of the kind of experiments that can be performed in the current setup.

14 illus, 7 tables, 50 ref

017128   Rakhmatullaev I;Gorelik V;Kurbonov A (NO, Institute of Applied Physics of National Univ of Uzbekistan, Russia, Email: rakhmatullaev@uzscience.uz) : Isochronous secondary radiation in aromatic compounds. Res Envir Life Sci 2015, 8(3), 403-6.

Authors propose an improved method of recording of the spectra of micro- and nanopowders under repetitively pulsed laser excitation. The newly developed laser source is capable nondestructive heating of substances providing the possibility of multiple measurements without damage of the sample. Isochronous secondary radiation spectra of a number of aromatic powders are studied and relaxation times of the corresponding electron terms are calculated. Using pulse-periodic excitation and the time delay settings in the registration system allowed us to study the conditions of the emergence and separation of "fast" and "slow" components of the secondary radiation of the structures under study. The developed method provides information even with small amounts of the sample.

4 illus, 1 table, 14 ref

017127   Pundir D;Yadav V (Physics & Computer Sciences Dep, Dayalbagh Educational Institute, Agra-282 110) : Determination of nonlinear refractive index of zirconium and CNTs doped iron oxide thin films. J Optics 2015, 44(2), 99-102.

In this present work, we have determined the nonlinear refractive index of zirconium (1 %) and CNTs (2 %, SW) doped iron oxide thin films by the single beam Z- scan technique with He-Ne laser at wavelength 532 nm. The findings of our study were that zirconium and CNTs doped iron oxide thin films show better nonlinearity comparison to reported results. The effect of dopant CNTs (2 %, SW) was negligible on the nonlinearity of zirconium doped iron oxide thin film. The order of nonlinear refractive index was 10^-8.

3 illus, 2 tables, 15 ref

017126   Prasad K R Y;Srinivas T;Ramana D V (ECE Dep, IISc, Bangalore, Email: yogeshprasad1976@gmail.com) : Design and demostration of hardware efficient OPLL for generation of stable microwave signals by optical heterodyning. J Optics 2015, 44(2), 103-18.

Generation of microwave signals by optical heterodyning has been an active area of research in the field of Microwave Photonics. Though this approach offers great flexibility in choosing the microwave frequency, issues related to frequency stability and phase noise performance are inherent to it. The effect of laser phase noise on heterodyned output is mathematically analyzed, simulated and practically demonstrated. Design of hardware-efficient Optical Phase Locked Loop (OPLL) that overcomes the issues of phase noise and frequency instability is proposed. Frequency stability and phase noise tracking achieved by the proposed OPLL is demonstrated experimentally. Highly stable microwave signals, exhibiting phase noise as low as -105 dBc/Hz at 10 KHz offset (limited by the phase noise of the reference source used in the experiment), are successfully generated by the proposed approach. The generated microwave signals have been shown to be devoid of spurious components and harmonics.

35 illus, 13 ref

017125   Panda M;Srinivas V;Thakur A K (Physics and Meteorology Dep, Indian Institute of Technology, Kharagpur-721 302, Email: panda.maheswar@gmail.com) : Multiferroic properties of polyvinyledene fluoride/nickel nano-composites. Indian J pure appl Phys 2016, 54(2), 144-8.

Electrical and magnetic properties of ferroelectric polymer (polyvinyledene fluoride) and ferromagnetic metal [nanocrystalline nickel (nc-Ni)] composites have been investigated as a function of volume fractions of nc-Ni (f_Ni). A significant enhancement in saturation magnetization of 24 emu/g, measure of permeability (μ') of 1.11 and dielectric constant of 2050 at 100 Hz has been observed at the electrical percolation threshold (f_c) of the composite. The critical exponents (x and y) obtained are within the universal regime. The decrease of magnetization of the composite with decrease in fNi is attributed to the dilution effect and magnetic dipolar exchange interaction. The constancy of coercive field (H_c) has been explained on the basis of Stoner-Wohlfarth model. The value of μ?' increases linearly with increase of f_Ni as the magnetic flux concentrates over individual nc-Ni clusters/particles even beyond f_c. On the other hand, the value of μ' decreases for pure nc-Ni probably due to the increased connectivity among the nc-Ni clusters/particles and hence being a conductor results in eddy current generation in alternating magnetic field. The enhancement of dielectric constant near f_c is explained with the help of boundary layer capacitor effect.

7 illus, 1 table, 32 ref

017124   Pallavi P;Lakshmi M;Srivastava R (Computer Science & Engineering Dep, Sathyabama Univ, Chennai, Email: pallavi.das12@gmail.com) : Physical layer analysis of AWG based optical packet switch architecture. J Optics 2015, 44(2), 119-27.

Optical packet switching is the next generation switching technique in conjunction with mature electronic switching. In optical packet switching, the core router plays an important role in the routing and buffering of packets. In recent past, AWG based optical router are proposed and heavily investigated due to its very low insertion loss and very simple wavelength dependent routing pattern. In this paper, a further modification in an AWG based optical packet switch is proposed. These modifications improve the signal reception quality at the output. Power budget analysis is presented to evaluate the buffer capacity. As a physical layer parameters, the minimum switch power is evaluated using the mathematical model and at the BER level of 10^{-9 the maximum buffering capacity is evaluated. Finally, simulation results are presented in terms of network layer parameters, packet loss probability and average delay. The packet loss probability is as low as 10-7 well under acceptable limits.}

9 illus, 6 tables, 12 ref

017123   Niazian M R;Yaghobi M (Physics Dep, Ayatollah Amoli Branch, Islamic Azad Univ, Iran, Email: m.r.niaziangmaiil.com) : Inelastic electron transport in C₇₀ fullerene. Indian J pure appl Phys 2016, 54(2), 123-9.

The effect of inelastic electron-phonon interactions on thermoelectric and electron transport properties of the C₇₀ molecule has been studied. The results show that thermopower sign is positive for negative energies; while for positive energies it reverses its sign. A linear graph via energy with staircase structure is seen for thermopower of the C₇₀ molecule by considering inelastic electron-phonon interactions. In addition, rate of entropy production and the figure of merit of C₇₀ cages have been studied to get more insight of the thermoelectric properties of C₇₀ molecules. The values of ZTs are in the range 0 - 2 x 10-4 and the effect of single contacts is small on the values of ZT.

8 illus, 38 ref

017122   Murugavel S;Malathi M (Condensed Matter Research Laboratory, Materials Physics Div, School of Advanced Sciences, VIT Univ, Vellore, Tamil Nadu, Email: mmalathi@vit.ac.in) : Synthesis and characterization of polythiophene nanofibers. Int J chem Sci 2016, 14(1), 363-71.

Polythiophene nanofibers have been prepared by in situ chemical oxidative polymerization method. X-ray diffraction method (XRD) and Fourier transform infrared analysis (FTIR) were used to confirm the formation of polythiophene. The synthesised polythiophene nanofibers were also characterized by energy dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM) and atomic force nicroscopy (AFM). Zeta potential measurement was employed to determine the surface charge of the polymer.

5 illus, 2 tables, 25 ref

017121   Medhat M E;Singh V P (Experimental Nuclear Physics Dep, Nuclear Research Center, P.O.13759, Cairo, Egypt, Email: kudphyvps@rediffmail.com) : Geant4 Monte Carlo code application in photon interaction parameter of composite materials and comparison with XCOM and experimental data. Indian J pure appl Phys 2016, 54(2), 137-43.

In the present work, the applicability of Geant4 Monte Carlo code for mass attenuations of different types of composite materials such as building materials, glasses, plastics and water matrix at photon energies 59.5, 80, 356, 661.6, 1173.2 and 1332.5 keV has been tested. The Geant4 simulated results of mass attenuation coefficients of composite materials have been compared with the experimental and theoretical XCOM data and a good agreement has been observed. The results indicate that this simulation process can be followed to determine the data on the gamma rays interaction parameters with the several energies in different types of materials. The modeling for photon interaction has been standardarised for any type of composite samples. The Geant4 code can be utilized for gamma ray mass attenuation coefficients for each sample at different energies, which may sometimes be impractical by experiment investigation.

5 illus, 5 tables, 13 ref