014547   Dojcinovic I P;Tapalaga I;Puric J (NO, Univ of Belgrade, Faculty of Physics, P O Box 44, 11000 Belgrade, Serbia, Email: irine1@ff.bg.ac.rs) : Stark width regularities within homologous spectral series of alkaline earth metals. Bull Astr Soc India 2013, 41(4), 281-9.

Stark width regularities within homologous spectral series of neutral atoms of alkaline earth metals were found and discussed. The emphasis is on: (i) the Stark width dependence on the upper level ionization potential (χ); and (ii) term structure influence on the found Stark parameter dependences. The relations found for particular electron temperature and density were of the form ω = a^{-b where a, b are constants, for particular homologous spectral series. Published Stark widths data are used to demonstrate the existence of these kinds of regularities for the electron impact contributions to the Stark widths. The obtained functions were used to predict the electron impact Stark widths data for 37 lines of strontium and 29 for barium neither calculated nor measured so far.}

3 illus, 2 tables, 33 ref

014546   Dhamgaye V P;Tiwari M K;Sawhney K J S;Lodha G S (Indus Synchrotrons Utilization Div, Raja Ramanna Centre for Advanced Technology, Indore-452 013, Email: vishal@rrcat.gov.in) : Microfocussing of synchrotron X-rays using X-ray refractive lens developed at Indus-2 deep X-ray lithography beamline. Pramana J Phys 2014, 83(1), 119-29.

X-ray lenses are fabricated in polymethyl methacrylate using deep X-ray lithography beamline of Indus-2. The focussing performance of these lenses is evaluated using Indus-2 and Diamond Light Source Ltd. The process steps for the fabrication of X-ray lenses and microfocussing at 10 keV at moderate and low emittance sources are compared.

9 illus, 1 table, 16 ref

014545   Desai A J;Mohan S;Murty S V S (NO, PLANEX, Physical Research Laboratory, Ahmedabad-380 009, Email: murty@prl.res.in) : Lunar crater ejecta distribution and charactrization using Mini -RF and LROC-WAC data. Curr Sci 2014, 107(5), 824-31.

A detailed quantification of ejecta matter for small craters (<6 km) on the basis of its amount of spatial deposition has been attempted in this study. We used scattering information derived from circular polarization ratio (CPR) and displaying intensity (S₁) from Miniature Radio Frequency (Mini-RF) instrument on-board Lunar Reconnaissance Orbiter (LRO), to characterize the radar backscatter of a large number of craters from Rimae Sirsalis, a highland-mare mixed region for deriving spatial ejecta blanket coverage. The radar derived ejecta blanket extent has been further compared with the amount derived by optical sensor for understanding and assessing the relative merits. In order to accurately estimate the total ejecta deposition, its characterization into finer and coarser material has also been done. We have studied the relation between the measured ejecta extents to the crater geometrical parameters and observed a strong relation between the crater ejecta extent and crater diameter using power or polynomial function.

5 illus, 1 table, 40 ref

014544   Brahmachari K;Ray M (Applied Optics and Photonics Dep, Univ of Calcutta, Technology Campus, Acharya Prafulla Chandra Roy Shiksha Prangan, JD -2, Sector-III, Salt Lake City, Kolkata-700 098, Email: mraphy@caluniv.ac.in) : Design of nanocomposite film-based plasmonic device for gas sensing. Pramana J Phys 2014, 83(1), 107-17.

Surface plasmon resonance (SPR) is a very efficient tool for chemical and biological sensing in nanotechnology, nanobiotechnology, medicine and environmental monitoring. A theoretical simulation study incorporating the use of admittance loci design methodology in SPR-based sensing device using gold-tungsten trioxide (Au-WO_3-x) nanocomposite film is reported in this paper. A simple Kretschmann-Raether-type prism-based plasmonic device consisting of a glass prism, Au-WO_3-x nanocomposite film and various gas samples is considered. Complex permittivity for both stoichiometric and non-stoichiometric Au-WO_3-x nanocomposite films has been used for the simulation of the admittance loci plots, resonance curves and sensitivity curves by considering angular interrogation at a fixed wavelength of 632,8 nm.

6 illus, 2 tables, 14 ref

014543   Bhattacharya A B;Bhoumick A;Bhattacharya R (Physics Dep, Kalyani Univ, Kalyani-741 235, Email: bhattacharyaasitbaran@gmail.com) : Trends of total ozone as derived from satellite and ground based measurements. Sci Cult 2014, 80(9-10), 287-9.

Ozone profiles over four Indian Stations viz. New Delhi (28°40'N, 77°13'E), Kolkata (22°38'N, 88°26'E), Hyderabad (17°22'N, 78°28'E) and Kodaikanal (10°13'N, 77°28'E) have been examined. A distinct latitudinal fall of ozone is noted. In the analysis the low and high ozone days are taken as the days with ozone values lower than or greater than 10% of the station's average. From this consideration increasing frequency rates in low ozone days for all stations are observed, especially in higher latitudinal station like New Delhi and Kolkata. Different parameters which are responsible for influencing the stratospheric ozone when considered critically exhibits interesting results which we have also presented in this paper.

4 illus, 2 tables, 12 ref

014542   Balachandran V;Lalitha S;Rajeswari S (Centre for Research, Physics Dep, A A Government Arts College, Musiri-621 211, Email: brsbala@rediffmail.com) : Study of spectroscopic properties, thermodynamic, NBO, quantum chemical calculations and curie plot of 3'-(triflouromethyl) acetophenone. Indian J pure appl Phys 2014, 52(12), 799-11.

The experimental spectra 3'-(triflouromethyl) acetophenone have been assigned based on DFT calculations at B3LYP level of theory using the standard 6-31+G(d) and 6-311++G(d, p) basis sets and scaling of the calculated frequencies. In ?tting the calculated wavenumbers to the experimental ones, two different scaling procedures called "scaling wavenumbers with dual scale factors" and "uniform scaling procedure", were preceded. These procedures have yielded results in very good agreement with the experiment and thus proved the necessity for an efficient scaling procedure over the calculated harmonic wavenumbers for performing a correct vibrational spectroscopic analysis on the basis of B3LYP calculations. The HOMO-LUMO energy gap of the molecule has been calculated and used for predicting the site for electrophilic and nucleophilic attack. The presence of the flouro-methyl group has a strong effect on the physical structure of the compound. The NBO and Mulliken population analysis have been performed on the molecule for understanding the charge distribution, molecular geometry, hybridization and the strength of different bonds forming the molecule. The thermodynamic and paramagnetic susceptibility variations with temperature are recorded for different temperature ranges.

7 illus, 8 tables, 44 ref

014541   Avila M (NO, Centro Universitario UAEM Valle de Chalco, UAEMex, Maria Isabel, Valle de Chalco, Estado de Mexico, CP 56615, Mexico, Email: vlkmanuel@uaemex.mx) : Nanodiabatic correction to a quantum dot quantum computer working in adiabatic limit. Pramana J Phys 2014, 83(1), 161-4.

The time of operation of an adiabatic quantum computer must be less than the deeoherence time, otherwise the computer would be nonoperative. So far, the nonadiabatic corrections to an adiabatic quantum computer are merely theoretical considerations. By the above reason, we consider the particular case of a quantum-dot-confined electron spin qubit working adi-abatically in the nanoscale regime (e.g., in the MeV range of energies) and include nonadiabatic corrections in it. If the decoherence times of a quantum dot computer are <126>100 ns [J M Kikkawa and D D Awschalom, Phys. Rev. Lett. 80, 4313 (1998)] then the predicted number of one qubit gate (primitive) operations of the Loss-DiVincenzo quantum computer in such an interval of time must be <62> 10^{10. However, if the quantum-dot-confined electron spin qubit is very excited (i.e., the semiclassical limit) the number of operations of such a computer would be approximately the same as that of a classical computer. Our results suggest that for an adiabatic quantum computer to operate successfully within the decoherence times, it is necessary to take into account nonadiabatic corrections.}

1 illus, 10 ref

013523   Thomas V;Elizabeth A;Joseph C;Biju P R;Jose G;Unnikrishnan N V (Physics Dep, SB College, Changanachery, Email: vinoythoma@gmail.com) : Synthesis and optical characterization of gadolinium praseodymium oxalate, gadolinium dysprosium oxalate, and dysprosium praseodymium oxalate crystals. Asian J Adv Basic Sci 2014, 2(1), 61-9.

Preparation and optical characterization of dysprosium gadolinium oxalate (DGO), dysprosium praseodymium oxalate (DPO) and gadolinium praseodymium oxalate (GPO) single crystals are reported. The crystals were grown using silica gel technique, by the controlled reaction of rare earth nitrates with oxalic acid. Crystals were characterized using X-ray powder diffraction and optical absorption studies. Radiative transition probability, fluorescence branching ratio and radiative lifetime of Dy^{3+ and Pr3+ in the crystals are evaluated by the parameterization of the absorption spectrum using Judd-Ofelt theory.}

3 illus, 6 tables, 30 ref

013522   Singh R P (Physics Dep, Dayanand Post Graduate College, Hisar-125 001, Email: rps7762@yahoo.in) : Pressure dependence of elastic constants for intermetallic compounds. Asian J Adv Basic Sci 2014, 2(1), 125-9.

Elastic properties of solids are closely related to many fundamental properties such as EOS, thermal expansion, interatomic potentials etc. The relatively strong covalent bonding between the constituents of intermetallic compounds like LiBC, MgB₂ and TiB₂ gives high Bulk Modulus in the range 150-220 GPa at high melting point nearly 3000K. This behaviour makes these compounds very interesting for studies under high pressure and high temperature. In the present study, pressure-volume relationship at different temperatures for three intermetallic compounds is given. For the low compressions the increase in pressure is low but the rate of increase of pressure increases faster as we approach the high compression region. At higher temperature, the bulk modulus decreases and, therefore, the pressure required for producing same amount of compression becomes less and less.

4 tables, 11 ref

013521   Singh R P (Physics Dep, Dayanand Post Graduate College, Hisar-125 001, Email: rps7762@yahoo.in) : Temperature dependence of elastic constants and bulk modulus of metals. Asian J Adv Basic Sci 2014, 2(1), 116-21.

Temperature dependence of bulk modules was given by Q. Liu & Q. He^{13 using fundamental thermodynamic relations. The assumption in this theory was that volume thermal expansion coefficient is quadratic function of temperature. The new expressions and formulations were also derived by Tallon14. In the present study temperature of elastic constants is based on the combination of above mentioned formulations. A method to estimate the temperature dependence of bulk modules is developed with the approximation that coefficient of volume thermal expansion depends linearly on temperature. This approximation is valid only for small expansions in low temperature range.}

3 tables, 22 ref

013520   Shanthi J;Vijayalakshmi S R (Physics Dep, Avinashilingam University for Women, Coimbatore-43, Email: shanthinelson@gmail.com) : Microcontroller based rotary evaporator for solution growth. Asian J Adv Basic Sci 2014, 3(1), 89-93.

Crystal growth is an interdisciplinary subject. The main research work involved in this is the production of pure materials and improved equipment associated with the preparation of the materials. The main research work involved in this is the development of microcontroller based rotary evaporator for the solution growth. The PIC microcontroller PWM module is used to control the DC motor in turn it controls the operation of rotary evaporator equipment. This evaporator helps to mix up the reagents reaction and speed up the overall process. The rate of evaporation of the solvent is increased and there by seeding of the solution becomes better with the help of the DC motor. The PWM of the DC motor drive was adjusted at the different choice. The polarity of rotation is automatically selected by the toggle switch.

3 illus, 6 ref

013519   Rastogi R G;Chandra H;Janardhan P;Shah R (Physical Research Laboratory, , Ahmedabad-380 009, Email: hchandra@prl.res.in) : Equatorial and mid-latitude ionospheric currents over the Indian region based on 40 years of data at Trivandrum and Alibag. Indian J Radio Space Phys 2014, 43(4-5), 274-83.

Forty years of geomagnetic data obtained from two Indian stations, Trivandrum (TRD) located near the magnetic equator; and Alibag (ABG) located away from the magnetic equator, for the period 1958-1998 are examined to study the daily ranges in H and in the strength of the equatorial electrojet (EEJ) obtained from the differences in the ranges at the two stations. Mean diurnal and seasonal variations in H, averaged over the 40 years are described for the two stations and for EEJ. The annual mean ranges in H show linear increases with sunspot number (Rz) and vary from 65 to 140 nT at TRD, 30 to 70 nT at ABG and from 40 to 72 nT for the EEJ. The rate of increase in H is faster at TRD than at ABG. Seasonal variations show equinoctial maxima for TRD and EEJ during the months of April and October. The range of H at ABG shows a weak secondary maximum during June-July, in addition to maxima during April and October. During the months of June-July, the range of H at ABG is stronger than that of EEJ. The occurrence of the afternoon counter electrojet is highest during low sunspot years and seasonally, during the June solstices.

1 table, 37 ref

013518   Pasrija R;Srivastava S (Physics Dep, DAV College, Abohar-152 116, Email: goodluckritu@gmail.com) : Interfacial layer effect on thermal conductivity of CNT nanofluids. Curr Sci 2014, 107(6), 1001-5.

We formulate a model to predict the thermal conductivity of carbon nanotube nanorefrigerants. The interfa-cial layer has proved to be a significant factor responsible for the anomalous thermal conductivity enhancement of these nanofluids. The present model predicts the thermal conductivity in accordance with the experimental results with mean deviation only of 1.5%. A comparison with other models has also been made.

3 illus, 1 table, 22 ref

013517   Nigam R;Habeeb S;Priyadarshi A;Jaggi N (Physics Dep, National Institute of Technology, Kurukshetra-136 119, Email: ravinigam09@gmail.com) : Electrical conductivity of metal-carbon nanotube structures: effect of length and doping. Bull Mater Sci 2014, 37(5), 1047-51.

The electrical properties of asymmetric metal-carbon nanotube (CNT) structures have been studied using density functional theory and non-equilibrium Green's function method with Atomistix tool kit. The models with asymmetric metal contacts and carbon nanotube bear resemblance to experimental set-ups. The study shows the effect of varying length of carbon nanotube on electronic transmission and conductance of various structures. The effects of silicon doping on CNT-based structures have also been studied. The conductance of structure with longer CNT is more compared with shorter CNT. Silicon doping increases the conductivity of carbon nanotube-based structure.

6 illus, 29 ref

013516   Laishram K;Mann R;Sharma R;Bhardwaj D;Shakya S;Malhan N (NO, Laser Science and Technology Centre, DRDO, Delhi-110 054, Email: kiranmala@lastec.drdo.in) : Nd: GGG nanopowders by microwave gel combustion route and sinterability studies. Def Sci J 2014, 64(5), 490-4.

Synthesis of Nd_0.03 Gd_2.97, Ga₅O₁₂ (Nd:GGG) nanopowder was carried out by microwave-assisted nitrate-citrate gel combustion technique. Various nitrate-to-citrate ratios from stoichiometric-to-fuel lean were explored. Gels were combusted by microwave heating and the combusted powders were calcined at 900 °C for 2 h. Fourier Transform Infra-red Spectroscopy (FTIR) and X-ray Diffraction (XRD) of calcined nanopowders showed phase pure Nd:GGG formation, from stoichiometric-to-fuel lean nitrate-to-citrate ratio of 1 to 0.416. Particles in the size range of 150 nm - 200 nm were obtained for stoichiometric ratio. Highly uniform, spherical morphology, with size range 90 nm - 100 nm, were obtained in fuel lean ratio of 1 to 0.416. Sintering of these nanopowders at 1550 °C for 2 h in air resulted in retention of phase purity as observed by XRD. Grain growth of less than 2 μm, for fuel lean ratio of 1 to 0.416, indicated formation of highly sinterable Nd:GGG nanopowders.

4 illus, 24 ref

013515   Kumbhar A G;Bhardwaj Y K;Naik D B (Water and Steam Chemistry Div, Bhabha Atomic Research Centre, , Trombay, Mumbai-400 085, Email: agk@barc.gov.n) : Hydrogen generation by gamma radiolysis of aqueous suspension of nano zirconia. Curr Sci 2014, 107(1), 88-93.

Aqueous suspension of nano zirconia with methanol was irradiated with gamma (γ) rays. Hydrogen (H₂) generated in this process was studied as a function of pH and γ-dose. In the presence of 1M methanol and at pH 3.0, low gamma dose irradiation showed optimum H₂ generation. This is explained on the basiszeta potential and surface charge on zirconia particles. Positive surface charge at low pH could be the reason for enhanced H₂ generation. Maximum H₂ yield G(H₂) of 3.7 was observed. This is 400 times more compared to nano pure water. The method can be utilized for building a medium-scale H2generation plant.

19 illus, 14 ref

013514   Joseph D;Bhattacharya D;Jha S N;Milton K J; Ramanna M V (Nuclear Physics Div, BARC, , Trombay, Mumbai, Email: djoseph@barc.gov.in) : Investigations on megalithic pottery samples by X-ray emission spectroscopy (EDXRF and XANES). Asian J Adv Basic Sci 2014, 3(1), 60-6.

Megalithic pottery samples (Red ware-RW, Black Polished ware -BPW and Black Red ware BRW) were studied for their trace element compositions by EDXRF (Energy Dispersive X-ray Fluorescence) and later for the oxidation states by XANES (X-ray Absorption Near Edge Structure). It was found that elements Fe, Cu, Zn, Sr, Nb and Mo were predominantly present in the pottery samples using an EDXRF system consisting of radio-isotope Cd 109, a Si(Li) detector of resolution 170 eV at 5.9 keV and PCA. XANES spectra of Fe, Cu and Zn obtained from INDUS-2 Synchrotron Source showed different oxidation states. The Fe edge indicated mixed oxidation states of +2 and +3 for iron in all the samples. Zn is present in the elemental form in all the samples. In the case of Cuit was found that Cu is in 2+ oxidation state in case of RWI sample and the other two samples, oxidation states were in elemental form..The motive of the study was to obtain an insight into the cultural heritage of Megallithic pottery samples using X-ray Emission Spectroscopy.

7 illus, 6 ref

013513   Ganguly N D (Physics Dep, St. Xavier's College, Navarangpura, Ahmedabad-380 009, Email: ganguly.nandita@gmail.com ) : Case study of deep STE event of ozone at a low latitude Indian station using simultaneous balloon borne ozonesonde and surface ozone measurements. Mausam 2013, 64(4), 605-12.

Stratosphere Troposphere Exchange (STE) of ozone is an important factor influencing the budget of ozone in the troposphere. It is well established that STE is relatively uncommon at low latitudes. Therefore a case study of deep STE event of ozone at a low latitude tropical coastal site of India is presented in the paper using ozonesonde, satellite and UV photometric ozone analyzer data.

9 illus, 20 ref

013512   Essa K S M;Etman S M (Mathematics and Theoretical Physics Dep, Nuclear Research Center, Atomic Energy Authority Cairo, Egypt, Email: mohamedksm56@yahoo.com) : Crosswind integrated concentration for various dispersion parameter systems. Mausam 2013, 64(4), 645-54.

The Gaussian plume model is the most widely used model for local scale dispersion. The Gaussian formula has been integrated to obtain the crosswind-integrated concentration. Different systems of dispersion parameters are used to calculate the crosswind integrated concentration. A logarithmic wind profile is used to describe the variation of wind speed with height in the surface layer. The effective release height was taken into consideration. Statistical measures are utilized in the comparison between the predicted concentrations for different dispersion parameter systems and the observed concentrations data obtained from Copenhagen diffusion experiment.

2 illus, 9 tables, 27 ref

013511   Dhiman C;Khan M S;Reddy M N (NO, , Jamia Millia Islamia, New Delhi-110 025, Email: mskhan@jmi.ac.in) : Phase-shift cavity ring-down technique for detection of NO₂ in PPM concentration. Def Sci J 2014, 64(5), 426-30.

Phase-shift cavity ring-down spectroscopy (PS-CRDS) experimental set-up has been established using a broadband diode laser for the measurement of phase shift due to absorption of NO₂ in a sealed off cavity ring-down cell. The PS-CRDS technique is verified by optimising various parameters of CRDS cavity and excitation laser. The PS-CRDS signals were measured on the first harmonics using a lock-in-amplifier. The square modulated laser pulses were used in the experiment to obtain the decay time. Measurements of the signal strengths at different CRDS cavity lengths were also carried out to verify the detection sensitivity for ppm level concentration measurement of trace gases.

5 illus, 2 tables, 19 ref

013510   Das M;Das D;Mukherjee A;Nandy M (NO, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064, Email: mala.das@saha.ac.in) : Exploring radiation in many splendors. Curr Sci 2014, 107(1), 15-16.

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013509   Choudhary K K;Gupta N;Kaurav N;Katiyal S; Ghosh S K (Physics Dep, National Defence Academy, Khadakwasla, Pune-411 023, Email: kkchoudharyl@yahoo.com) : Spin fluctuation and small polaron conduction dominated electrical resistivity in La_0.875Sr_0.125MnO₃ manganite nanostructures. Bull Mater Sci 2014, 37(5), 1095-1100.

The anomalous temperature-dependent electrical resistivity p(T) of La_0.875Sr_0.125MnO₃ manganite nanoparticles (particle size 18 nm) is theoretically analysed. p(T) exhibits semiconducting phase in low-temperature regime (20 K <60> T <60> 53 K), shows a minima near 53 K and increases with T at high temperatures (53 K<60> T<60> 170 K). The resistivity in metallic phase (T<62> 53 K) is theoretically analysed by considering the strong spin-fluctuation effect, which is modelled using Drude-Lorentz type function. In addition to the spin fluctuation-induced contribution, the electron-phonon and electron-electron p_e-e(T) = BT^{2 contributions are also incorporated for complete understanding of experimental data. The contributions to the resistivity by inherent acoustic phonons (p_ac) as well as high-frequency optical phonons (p_op) were estimated using Bloch-Gruneisen (BG) model of resistivity. It is observed that the resistivity contribution due to electron-electron interaction shows typical quadratic temperature dependence. Spin fluctuation-induced resistivity is dominant over electron-electron and electron-phonon contributions in overall temperature range in the manganite nanoparticles. Resistivity in the semiconducting phase is discussed with small polaron conduction (SPC) model. SPC model consistently retraces the low-temperature resistivity behaviour (T<60>53K). Finally, the theoretically calculated resistivity compared with experimental data is found to be consistent in wide range of temperature.}

3 illus, 22 ref

013508   Bhargava H;Sudheesh V D;Nehra J;Sebastian V; Lakshmi N (Physics Dep, Vijaya College, Bangalore-560 004, Email: nambakkat@yahoo.com) : Size-dependent magnetic properties in Cu_0.25Co_0.25Zn_0.5Fe₂O₄. Bull Mater Sci 2014, 37(5), 953-61.

Cu_0.25Co_0.25Zn_0.5Fe₂O₄ nanoparticles were prepared by a co-precipitation method and the size was varied by varying annealing temperatures. The cation distribution, estimated using Mossbauer spectroscopy, shows that it is the same for all samples, irrespective of the size. The variation of Curie temperature and saturation magnetization as a function of particle size, studied using d.c. magnetization, clearly indicates that these are a result of finite size scaling effects. The superparamagnetic size limit is estimated to be 8 nm.

9 illus, 5 tables, 37 ref

013507   Akkurt I;Gunoglu K;Calik A;Karakas M S (Faculty of Arts and Sciences, Physics Dep, Suleyman Demirel Univ, Isparta, Turkey, Email: iskenderakkurt@sdu.edu.tr) : Determination of gamma ray attenuation coefficients of Al-4% Cu/B₄C metal matrix composites at 662, 1173 and 1332 keV. Bull Mater Sci 2014, 37(5), 1175-9.

Gamma ray attenuation coefficients of metal matrix composites have been investigated. For this purpose, the linear attenuation coefficients of composites containing boron carbide (B₄C) at different rates have been measured using a gamma spectrometer that contains a Nal(Tl) detector and MCA at 662, 1173 and 1332 keV, which are obtained from ^{137Cs and 60Co sources. The measured results were compared with the calculation obtained using computer code of XCOM for 1 keV-1 GeV gamma energies.}

6 illus, 2 tables, 17 ref

013506   Ahmadi E;Ramazani A;Mashhadi-Malekzadeh A; Hamdi Z;Mohamadnia Z (Chemistry Dep, Zanjan Univ, P.O. Box 45195-313, Zanjan, Iran, Email: ahmadi@znu.ac.ir) : Preparation and characterization of monosubstituted porphyrins immobilized on nanosilica. Bull Mater Sci 2014, 37(5), 1101-12.

Three kinds of heteroaldehydes, N-(3-triethoxysilylpropyl)-4-formyl benzamide (TPHA/SiO₂), were prepared by the reaction of terephthalaldehydic acid with different silica supports such as hexagonal SBA-15, spherical SBA-15 and amorphous SiO₂ for comparison purposes. Anchoring of this aldehyde to different supports allows the synthesis of mono-substituted porphyrins without the production of di-, tri- and tetra-substituted porphyrin side products. The exclusion of the aforementioned side products during the synthesis of monosubstituted porphyrins greatly reduced the complexity during purification of the product. Absorption spectrophotometry was performed on silica gel immobilizing porphyrin (CPTTP), free base tetraphenylporphyrin (H₂TPP) and heteroaldehydes (TPHA/SiO₂) using UV-Visible instrument and confirmed the presence of porphyrin on the structure of CPTTP.

11 illus, 2 tables, 35 ref

012590   Zhang L (Mathematics Dep, Huzhou Univ, Huzhou, Zhejiang-313 000, Email: zsdzln@126.com) : The bifurcation and peakons for the special C(3, 2, 2) equation. Pramana J Phys 2014, 83(3), 331-40.

In this paper, author investigate a special C(3, 2, 2) equation u_t+ ku_x - u_xxt + 3(u^{3)_x = u_x(u2)_xx + u(u2)_xxx. The bifurcation and some new exact representations of peakons, bell-shaped solitary wave solutions and periodic cusp wave solutions for the equation are obtained using the qualitative theory of dynamical systems. It is shown that the peakons are actually the limit of bell-shaped solitary waves and periodic cusp waves. Moreover, a new characteristic of non-smooth solutions, two peakons coexisting for the same wave speed, is found. Some previous results are extended.}

2 illus, 14 ref

012589   Yaghobi M;Larijani F A (NO, Ayatollah Amoli Branch, Islamic Azad Univ, Amol, Iran, Email: m.yaghoubi@iauamol.ac.ir) : Effect of doping of N and B atoms on thermoelectric properties of C₆₀ molecule. Pramana J Phys 2015, 84(1), 155-65.

In this work, the doping effect on the thermoelectric properties of the C₆₀ molecule (fullerene) was studied by considering inelastic electron-phonon interactions. It is seen that the maximum value of thermal conductance (k_max) with respect to the molecules are k_maxC₅₉N) <60> fcmaxCCeo) <60> kmaxC₅₉B). Also, the oscillatory behaviour of thermal conductance is dramatically dependent on the type of molecules. The values of figure of merit (ZT) against energy and with respect to the type of molecules are between 0.25 x 10^{-5 and 0.194 x 10-3 and effect of the type of molecules is small on the minimum value of ZT.}

6 illus, 39 ref

012588   Wang H Y;Zhang K B (NO, School of Science, Sichuan Science and Engineering Univ, Zigong-643 000, Email: wanghyswallow@126.com) : Planar dust acoustic waves in electron-positron-ion-dust plasmas with dust-size distribution under higher-order transverse perturbations. Pramana J Phys 2015, 84(1), 145-53.

Propagation of small but finite nonlinear dust-acoustic solitary waves are investigated in a planar unmagnetized dusty plasma, which consists of electrons, positrons, ions and negatively charged dust particles with different sizes and masses. A Kadomtsev-Petviashvili (KP) equation is obtained by using reductive perturbation method. The effect of positron density and positron-electron temperature ratio on dust-acoustic solitary structures are studied. Numerical results show that the increase in positron number density increases the amplitude of hump-like solitons but decreases the dip-like solitary waves. Furthermore, increase in the positron-electron temperature ratio results in the decrease of the amplitude of dip-like solitary waves. It seems that both the dip and hump-like solitary waves can exist in this system. Our results also suggest that the dust-size distribution has a significant role on the amplitude of the solitary waves.

4 illus, 20 ref

012587   Verma V;Sharma P;Singh A (Physics Dep, Hindu College, Delhi Univ, Delhi-110 007, Email: vermavivek.neel@gmail.com ) : Effect of iron content on permeability and power loss characteristics of Li_0.35Cd_0.3Fe_2.35O₄ and Li_0.35Zn_0.3Fe_2.35O₄. Bull Mater Sci 2014, 37(4), 855-9.

Substituted lithium ferrites having the chemical formula, Li_0.35Cd_0.3Fe_2.35O₄ and Li_0.35Zn_0.3Fe_2.3O₄, with different iron (metal) contents (2, 4, 6, 8 and 10) in wt% have been prepared by solid-state technique. Complex permeability and power loss of all samples have been measured by network analyser in the frequency range of 50-5000 kHz. Magnetic properties like saturation magnetization, coercivity, retentivity have been measured by vibrating sample magnetometer (VSM). The permeability of cadmium doped lithium ferrites exhibited higher values than zinc doped lithium ferrites. The power loss of cadmium doped lithium ferrites is lesser as compared to zinc doped lithium ferrites in the frequency range of 50-5000 kHz and at flux density of 10 mT. The behaviour of power loss with flux density has been found near about same for both series. Magnetic and power loss behaviour of the samples suggest that a small amount of Fe content can improve the properties of ferrite samples for microwave devices.

5 illus, 13 ref

012586   Udupa D V;Sanjiva Kumar;Narayanan O;Patil P B;Ajaykumar S;Sampathkumar R;Thankarajan K;Sahoo N K (Atomic and Molecular Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: dudupa@barc.gov.in) : Indigenous echelle grating spectrograph for simultaneous trace elemental analysis by atomic emission spectroscopy. Curr Sci 2014, 106(11), 1475-80.

Detailed optical design and construction of an indigenously developed echelle grating spectrograph for simultaneous spectrochemical analysis of up to 51 elements by optical emission spectroscopy are presented here. The spectrograph consists of two concave spherical mirrors for collimation and focusing, an echelle grating with groove frequency of 79 lines/mm, and a two-dimensional CCD detector for recording the spectral lines. Fused silica Littrow prism is used for sorting the different spectral orders of 60-120 in the spectrum. The instrument has a wavelength range 200-400 nm with a resolving power of 15,000. The reciprocal linear dispersion of the instrument is 0.353 nm/mm at a wavelength of 300 nm. Results of simultaneous spectrochemical analysis using the inductively coupled plasma source of excitation are also presented.

8 illus, 1 table, 19 ref

012585   Singh V;Deshmukh M M (Condensed Matter Physics and Materials Science Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005, Email: v.singh@tude1ft.nl) : Nanoelectromechanics using graphene. Curr Sci 2014, 107(3), 437-46.

The large in-plane modulus of rigidity and low mass density of one-atom-thick graphene makes it an exciting material for studying mechanics at nanoscale. Further, the remarkable electronic properties of graphene give an additional edge to explore the small coupling between electronic and mechanical degrees of freedom. Ballistic transport can be reached in very clean suspended graphene samples, allowing to probe coupling between nanoscale electromechanics and quantum Hall effect. Such devices can also be used to measure intrinsic properties of graphene like coefficient of thermal expansion. In this article, we present summary of results from our group integrating these aspects of graphene. Towards the end, we briefly speculate roadmap for future experiments harnessing unique properties of graphene. Nanomechanical devices can then be used for applications as well as to explore aspects of mesoscopic physics with unprecedented detail.

9 illus, 53 ref

012584   Singh M K;Soma A K;Singh V;Pathak R (Physics Dep, Banaras Hindu Univ, Varanasi-221 005, Email: venkaz@yahoo.com) : Target dependence of clan model parameter in <. Pramana J Phys 2014, 83(3), 377-86.

This article focusses on the study of clan model parameters and their target dependence in light of void probability scaling for heavy (Ag and Br) and light (C, N and O) groups of target present in nuclear emulsion detector using ^{84Kr₃₆ at <126> 1 A GeV. The variation of scaled rapidity-gap (rap-gap) probability with single moment combination has been studied. We found that experimental points lie approximately on the negative binomial distribution (NBD) curve, indicating a scaling behaviour. The increase in average clan multiplicities (N) for interactions with the pseudorapidity interval (Δη) was also observed. The values of N for AgBr targets are larger than those for C/N/O target and also average number of particles per clan (n_c) increases with increase in pseudorapidity interval. We further observed that for a particular target, the average number of particles per clan (n_c) increases with an increase in the size of projectile nucleus.}

3 illus, 23 ref

012583   Shrivastava R;Jagjeet Kaur;Dubey V;Jaykumar B (NO, Govt. VYT PG Autonomous College, Durg-491 001, Email: ravishrivastava95@gmail.com) : Photoluminescence, trap states and thermoluminescence decay process study of Ca₂MgSi₂O₇: Eu<. Bull Mater Sci 2014, 37(4), 925-9.

Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of dysprosium were synthesized using solid-state reaction. The Fourier transform infrared (FT-IR) spectra confirmed the proper preparation of the sample. The prepared phosphors were characterized using photoluminescence excitation and emission spectra. Prominent green colour emission was obtained under ultraviolet excitation. The thermoluminescence glow curves of the samples were measured at various delay times. With increased delay time, the intensity of the thermoluminescence peak decays and the position of the thermoluminescence peak shifts towards higher temperature, indicating the considerable retrapping associated with general order kinetics.

5 illus, 2 tables, 26 ref

012582   Sahu M (Physics of Sound Dep, Indira Kala Sangit Vishwavidyalaya Khairagarh, Chhattisgarh) : Stock shift and thermal characteristics of semiconductor nanoparticles. Nano Vision 2014, 4(1), 13-16.

This paper review recent advances in luminescence of semiconductor nanoparticles. With reducing size of the semiconductor nanoparticles the onset of absorption takes place at longer wavelength. Such blueshift with reducing size of the nanocrystals is the reflection of bandgap increase owind to the quantum confinement effect. In most case blueshift in the peak of the photoluminescence (PL) spectra is observed with reducing size of the nanocrystals, but the luminescence from certain surfsce state may give rise to the redshift with reducing size of the nanocrystals. Whereas the decay time of luminescence decreases, the quantum efficiency of luminescence and Stock shift increase with reducing size of nanoparticles. The PL intensity of nanoparticles decreases with the increasing temperature. It is optimum for a particular concentration of the dopants in the nanoparticles. The luminescence of semiconductor nanoparticles is exciting to the researchers and it has several important potentials.

2 illus, 4 ref

012581   Saha R K;Roy M;Datta A (Surface Physics and Material Science Div, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064@ratank.saha@saha.ac.in) : Simulation study on the photoacoustic of cells with endocytosed gold nanoparticles. Curr Sci 2014, 106(11), 1554-58.

Effect of endocytosis of gold nanoparticles (AuNPs) on photoacoustic (PA) signal is examined using computer simulations. It assumes that the endocytosed AuNPs significantly enhance cellular optical absorption but do not alter thermophysical parameters. The PA signals were computed employing a theoretical model at various cell and intracellular NP concentrations for 532 nm illumination. It was found that the PA amplitude increased linearly in both the cases. The simulation results, when the contributions from both coherent and incoherent components are included, demonstrate good agreement with published experimental results.

5 illus, 1 table, 22 ref

012580   Sadeghe H;Khalili H;Nahidinejad S (Physics Dep, Faculty of Science Arak Univ, Arak 38156-8-8349, Iran, Email: H-Sadeghi@Araku.ac.ir) : Three body calculation of Be double A hypernuclei. Pramana J Phys 2014, 83(3), 365-75.

Energy levels and ∧ ∧ bond energy of the double-A hypernucleus are calculated by considering two- and three-cluster interactions. Interactions between constituent particles are contact interactions for reproducing the low binding energy of nuclei. The effective action is constructed to involve three-body forces. In this paper, we also compare the obtained binding energy result with experimental and other cluster and shell models. The results of all schemes agree very well showing the high accuracy of our method to calculate the other many-body hyperonic nuclei using three-cluster interactions. The experimental values of B_∧∧(^{10>_∧<185> Be) = (11.90 ± 0.13) MeV, B_∧∧(11>_∧<185>Be) = (20.49 ± 1.15) MeV and B_∧∧(_∧12 _∧Be) = (22.23 ± 1.15) MeV seem to be more compatible with our calculated value of B_∧∧(_∧10 _∧Be) = 14.04 MeV, B_∧∧(_∧11 _∧Be) = 19.31 MeV and B_∧∧(_{∧12>∧Be) = 21.45 MeV in comparison with the other calculated results by Hiyama et al, Gal et al and Guleria et al.}}

4 illus, 2 tables, 22 ref

012579   Reddy A N K;Sagar D K (Physics Dep, College of Science Osmania Univ, Hyderabad-500 007, Email: naarereddy@gmail.com) : Half-width at half maximum, full-width at half maximum analysis for resolution of asymmetrically apodized optical systems with slit apertures. Pramana J Phys 2015, 84(1), 117-26.

Resolution for the modified point spread function (PSF) of asymmetrically apodized optical systems has been analysed by a new parameter half-width at half-maximum (HWHM) in addition to the well-defined parameter full-width at half-maximum (FWHM). The distribution of half-maximum energy in the centroid of modified PSF has been investigated in terms of HWHM on good side and HWHM on bad side. We observed that as the asymmetry in PSF increases, FWHM of the main peak increases and then decreases and is being aided by the degree of amplitude apodization in the central region of slit functions. In the present study, HWHM (half-width at half-maximum) of the resultant PSF has been defined to characterize the resolution of the detection system. It is essentially a line of projection, which measures the width of the main lobe at its half-maximum position from the diffraction centre and has been computed for various amplitudes and antiphase apodizations of the slit aperture. We have noticed that HWHM on the good side decreases at the cost of the increased HWHM on the bad side in the presence of asymmetric apodization.

7 illus, 4 tables, 13 ref

012578   Rathod K D;Singh P K;Natarajan V (Physics Dep, Indian Institute of Science, Bangalore-560 012, Email: physics.iisc.ernet.in) : Cold beam of isotopically pure Yb atoms by deflection using 1D optical molasses. Pramana J Phys 2014, 83(3), 387-93.

Demonstrate the generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman slower. They are then subjected to a pair of molasses beams inclined at 45° with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate the selective deflection of the bosonic isotope ^{174Yb and the fermionic isotope 171Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.}

4 illus, 1 table, 16 ref

012577   Rao U R (Space Dep, Antariksh Bhawan, New BEL Road, Bangalore-560 231, Email: urrao.isro@hotmail.com) : Uniquenes of magnetic field in promoting life on Earth. Curr Sci 2014, 106(11), 1474.

7 ref

012576   Purushotham E;Gopi Krishna N (Physics Dep, SR Engineering College (Autonomous), Warangal-506 371, Email: psm45456@gmail.com) : Effect of particle size and lattice strain on Debye-Waller factors of Fe₃C nanoparticles. Bull Mater Sci 2014, 37(4), 773-8.

Fe₃C nanoparticle powders have been prepared by a high energized ball mill. The resulting nano-particle powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The high-energy ball milling of Fe₃C after 10 h resulted in crystalline size of about 5 nm. The Debye temperature, mean-square amplitudes of vibration, Debye-Waller factor, lattice parameters, particle size, lattice strain and vacancy formation of energies of Fe₃C nanoparticles prepared by ball mill have been obtained from X-ray integrated intensities. The integrated intensities have been measured with a Philips CWU 3710 X-ray powder diffractometer fitted with a scintillation counter using filtered CuKα radiation at room temperature and have been corrected for thermal diffuse scattering. The X-ray Debye temperatures obtained in the present investigation has been used to estimate the vacancy formation energies for Fe₃C nanoparticles.

8 illus, 1 table, 33 ref

012575   Pinar Z;Dutta A;Beny G;Ozis T (Mathematics Dep, Faculty Arts and Science, Namik Kemal Univ, 59030 Merkez-Tekirdag Turkey, Email: turgut.ozis@ege.edu.tr) : Analytical solution of population balance equation involving aggregation and breaking in terms of auxiliary equation method. Pramana J Phys 2015, 84(1), 9-21.

This paper presents an effective analytical simulation to solve population balance equation (PBE), involving particulate aggregation and breakage, by making use of appropriate solu-tion(s) of associated complementary equation via auxiliary equation method (AEM). Travelling wave solutions of the complementary equation of a nonlinear PBE with appropriately chosen parameters is taken to be analogous to the description of the dynamic behaviour of the particulate processes. For an initial proof-of-concept, a general case when the number of particles varies with respect to time is chosen. Three cases, i.e. (1) balanced aggregation and breakage, (2) when aggregation can dominate and (3) breakage can dominate, are selected and solved for their corresponding analytical solutions. The results are then compared with the available analytical solution, based on Laplace transform obtained from literature. In this communication, it is shown that the solution approach proposed via AEM is flexible and therefore more efficient than the analytical approach used in the literature.

3 illus, 26 ref

012574   Pandey B P;Kumar V;Proupin E M (Electronics & Communication Engineering Dep, GLA Univ, Mathura 281 406, Email: pandey.bramha@gmail.com) : Elastic constants and debye temperature of wz-AIN and wz-GaN semiconductors under high pressure from first-principles. Pramana J Phys 2014, 83(3), 413-25.

First-principles calculations were performed to study the elastic stiffness constants (C_ij) and Debye temperature (θ_D) of wurzite (wz) A1N and GaN binary semiconductors at high pressure. The lattice constants were calculated from the optimized structure of these materials. The band gaps were calculated at Γ point using local density approximation (LDA) approach. The unit cell volume, lattice parameters, c/a, internal parameter (u), elastic constant (C_ij), Debye temperature (Γ_D), Hubbard parameter (U) and band gap (E_g) were studied under different pressures. The bulk modulus (Bo), reduced bulk modulus (B₀) and Poisson ratio (v) were also calculated. The calculated values of these parameters are in fair agreement with the available experimental and reported values.

8 illus, 2 tables, 43 ref

012573   Ojo K S;Ogunjo S T;Njah A N;Fuware I A (Physics Dep, The Federal Technology Univ, Akure, P M B 704 Akure, Ondo State, Nigeria, Email: kaystephe@yahoo.com) : Increased order generalized synchronization of chaotic and hyperchaotic systems. Pramana J Phys 2015, 84(1), 33-45.

This paper presents increased-order generalized synchronization (GS) of chaotic and hyperchaotic systems with different order based on active control technique. By this technique, we design suitable control functions to achieve GS between (i) a new three-dimensional (3D) chaotic system and four-dimensional (4D) hyperchaotic Lorenz system and (ii) four-dimensional hyper-chaotic Lorenz system and five-dimensional (5D) hyperchaotic Lorenz system. The corresponding numerical simulation results are presented to verify the effectiveness of this technique.

8 illus, 24 ref

012572   Mondal A;Islam M;Islam N (Mathematics Dep, Jafarpur Kashinath High School, P O Champahati, P.S Sonarpur, South 24 Parganas-743 330, Email: amitmondal26@gmail.com) : Robust antisynchronization of chaos using sliding mode control strategy. Pramana J Phys 2015, 84(1), 47-67.

The paper proposes a sliding mode control strategy-based scheme for achieving anti-synchronization between two coupled non-linear chaotic systems. The method works irrespective of whether the systems under consideration possess or lack inverse symmetry. Using a linear sliding surface, a sliding mode control input and a non-linear coupling function are designed that synchronizes the systems antiphase. Finite-time convergence of the method is established. The controller is also robust to all forms of bounded perturbations and this robustness can be easily achieved by tuning of a single controller parameter and introduction of a control vector. The controller is also made chattering-free by producing a continuous analogue of the discontinuous control input. The effectiveness of the method is established by implementing it to antisynchronize chaotic Sprott systems and Rossler systems. The results are also verified through numerical simulation work.

18 illus, 16 ref

012571   Mishra A (Instrumentation and Applied Physics Dep, Indian Institute of Science, Bangalore-560 012, Email: abha@isu.iisc.ernet.in) : Carbon nanotubes and graphene based chemical sensors. Curr Sci 2014, 107(3), 419-29.

The chemical sensing behaviour of the carbon nano-tube and graphene-based sensors for detecting various chemical analytes is presented in this article. A focus on detection mechanisms has been provided to assess their relative potential under different environmental conditions. The performance of these two carbon allo-tropes is compared based on their sensitivity towards various types of electron donating and accepting molecules. Although these carbon materials still have to meet crucial challenges in fabrication and optimization, continued progress in this field may lead to a sensor with superior sensitivity for a wide range of applications.

10 illus, 64 ref

012570   Masud M M;Tasnim I;Mamun A A (Physics Dep, Bangladesh Engineering & Technology Univ, Dhaka, Bangladesh, Email: ismita.tasnim@yahoo.com) : Dust ion acoustic gardner double layers in a dusty plasma with two temperature electorns. Pramana J Phys 2015, 84(1), 137-44.

The properties of dust-ion-acoustic Gardner double layers (DIA GDLs) in an unmag-netized dusty plasma, whose constituents are negatively-charged stationary dust, inertial ions, and Boltzmann electrons of two distinct temperatures, are rigorously investigated by employing the reductive perturbation method: Gardner approach. The standard Gardner equation is derived, and its double layer (DL) solution is obtained. It has been shown that the properties of the DIA GDLs are significantly modified by some plasma parameters (viz. σ = T_e1/T_e2, μ_el = n_e10/n_i0O and μ_e2 = μ_e2 = n_e20/n_i0, where T_e1 (T_e2) is the cold (hot) electron temperature, n_e10 (n_e20) is the cold (hot) electron number density at equilibrium, and n_i0 is the ion number density at equilibrium). The implications of our investigation in understanding the basic features of nonlinear electrostatic perturbations observed in many space plasma systems and laboratory devices are briefly discussed.

5 illus, 42 ref

012569   Mandeep Kaur;Suneel Kumar (NO, School of Physics and Materials Sciences, Thapar Univ, Patiala-147 004, Email: suneel.kumar@thapar.edu) : On the momentum distribution of particles participating in nuclear stopping. Pramana J Phys 2015, 84(1), 101-11.

Nuclear stopping is studied as a function of incident energy and charge of the fragment produced in central heavy-ion collisions (HIC) of ₇₉^{197Au+₇₉197Au and ₂₈58Ni+₂₈58Ni using stopping parameter VARXZ. Various momentum constraints were imposed to get better insight into the stopping. The comparison of measured and calculated values of stopping for protons reveals the significance of these constraints. Maximum stopping is obtained for the particles lying in the lowest range of the momentum distribution at all incident energies.}

5 illus, 1 tables, 23 ref

012568   Khanbabaei B;Ghasemizad A;Khoshbinfar S (Physics Dep, Faculty of Science, Guilan Univ, Rasht, Iran, Email: ghasemi@guilan.ac.ir) : Deuterium tritium catalytic reaction in fast ignition optimum parameters approach. Pramana J Phys 2014, 83(3), 395-411.

One of the main concerns about the current working on nuclear power reactors is the potential hazard of their radioactive waste. There is hope that this issue will be reduced in next generation nuclear fusion power reactors. Reactors will release nuclear energy through microexplosions that occur in a mixture of hydrogen isotopes of deuterium and tritium. However, there exist radiological hazards due to the accumulation of tritium in the blanket layer. A catalytic fusion reaction of DT_x mixture may stand between DD and an equimolar DT approach in which the fusion process continues with a small amount of tritium seed. In this paper, we investigate the possibility of DT_x reaction in the fast ignition (FI) scheme. The kinematic study of the main mechanism of the energy gain-loss term, which may disturb the ignition and burn process, was performed in FI and the optimum values of precompressed fuel and proton beam driver were derived. The recommended values of fuel parameters are: areal density ρR ≥ 5 g cm^{-2 and initial tritium fraction x ≤ 0.025. For the proton beam, the corresponding optimum interval values are proton average energy 3 ≤ E_p ≤ 10MeV, pulse duration 5 ≤ t_p ≤ 15 ps and power 5 ≤ W_p ≤ 12 x 1022 (keV.cm3.ps-1). It was proved that under the above conditions, a fast ignition DT_x reaction stays in the catalytic regime.}

8 illus, 1 table, 31 ref

012567   Khan S;Arya S;Lehana P;Suresh Kumar (Physics & Electronics Dep, Jammu Univ, Jammu-180 006, Email: sawan2k2@yahoo.co.in ) : Synthesis of copper-ferrous (CuFe) nanowires via electrochemical method and its investigations as a fluid sensor. Bull Mater Sci 2014, 37(4), 889-93.

The special behaviour of nanowires with respect to electrical conductivity makes them suitable for sensing application. In this paper, we present a copper-ferrous (CuFe) nanowires based sensor for detection of chemicals. CuFe nanowires were synthesized by template-assisted electrochemical method. By optimizing the deposition parameters, continuous nanowires on a copper substrate were synthesized. The morphological and structural studies of the synthesized CuFe nanowires were carried out using scanning electron microscope (SEM) and X-ray diffraction (XRD). Substrates containing CuFe nanowires were moulded to form a capacitor. Different chemicals were used as dielectric in the capacitor which showed that the capacitance was a nonlinear function of the dielectric constant of fluid unlike the linear relation shown by conventional capacitors. This unique property of the nanowires based capacitors may be utilized for developing fluid sensors with improved sensitivity.

7 illus, 23 ref

012566   Kausar A (Nanosciences and Catalysis Div, National Centre for Physics, Quaid-i-Azam Univ Campus 44000, Islamabad, Pakistan, Email: asheesgreat@yahoo.com) : Design, synthesis and physical properties of poly(styrene-butadiene-styrene)/poly(thiourea-azo-sulfone) blends. Bull Mater Sci 2014, 37(4), 917-23.

A new aromatic azo-polymer, poly(thiourea-azo-sulfone), has been synthesized using l-(4-thiocarbamoylaminophenylsulfonylphenyl)thiourea and diazonium salt solution. Conducting and thermally stable rubbery blends of poly(styrene-block-butadiene-block-styrene) (SBS) triblock copolymer and poly(thiourea-azo-sulfone) (PTAS) were produced by solution blending technique. PTAS possessed fine solubility in polar solvents and high molar mass 63 x 10^{3 g moL-1. Microscopic analysis on SBS/PTAS blends revealed good adhesion between the two polymers without macro phase separation. Electrical conductivity measurement recommended that blending of SBS with 60% PTAS was sufficiently conducting 1.43 S cm-1. A relationship between PTAS loading and thermal stability of blends was observed. With the increasing PTAS content, 10% gravimetric loss was increased from 481 to 497 °C, while glass transition improved from 123 to 136 °C (better than neat SBS but lower than PTAS). The blends also established higher tensile strength (52.40-59-96 MPa) relative to SBS. Fine balance of properties renders new SBS/PTAS, potential engineering plastics for a number of aerospace relevance.}

6 illus, 3 tables, 39 ref