020010   Sridevi D;Rajendran K V (Physics Dep, Presidency College, Chennai-600 005, Email: mspr1972@yahoo.com) : Preparation of ZnO nanoparticles and nanorods by using CTAB assisted hydrothermal method. Int J Nanotechnol Applic 2008, 3(3), 43-8.

ZnO nanoparticles and nanorods have been successfully synthesized by hydrothermal method. In the hydrothermal method, Cetyltrimethyl ammonium bromide (CTAB) surfactant plays an important role in morphological changes. The nanostructures have been characterized by X-ray diffraction (XRD), Energy Dispersive X-ray Analysis (EDX), and Scanning Electron Microscope (SEM). Effect of pH on morphology and photoluminescence properties is discussed.

3 ills, 1 table, 15 ref

020009   Siddheswaran R;Shiv Shankar V;Jayavel R; Murugakoothan P (Physics Dep, Pachaiyappa's College, Chennai-600 030, Email: rsiddhes@yahoo.com) : Studies on growth and properties of L-tyrosine hydrochloride (LTHCL) crystal. Int J Mater Sci 2009, 4(3), 205-13.

Single crystals of L-tyrosine hydrochloride, a semi-organic nonlinear optical material have been synthesized and grown by solution using solvent evaporation technique. The solubility of the synthesized material was carried out in the temperature range of 30-50 °C. The crystal structure and unit cell parameters have been confirmed by powder XRD technique. Optical absorption spectrum recorded in the wavelength range of 200 -- 1500 nm revealed that this crystal has good optical transparency in the range 290-1100 nm. The FTIR spectrum was taken to analyze various functional groups present in LTHC1. The DTA-TGA analysis result suggests that the material is thermally stable in the working temperature upto 240 °C. Second harmonic generation efficiency of the crystal was confirmed by Kurtz's powder method using Nd : YAG laser.

8 illus, 1 table, 6 ref

020008   Nath S;Chakdar D;Gope G;Avasthi D K (Physics Dep, National Institute of Technology Silchar, Silchar-10, Email: nathss@rediffmail.com) : Luminescence spectroscopy of silica coated ZnS quantum dots embedded in PVA matrix. Int J Nanotechnol Applic 2008, 2(1), 47-53.

Reports room temperature luminescence spectra originating from ZnS quantum dots over coated with SiO₂, embedded on polyvinyl alcohol (PVA) matrix. The samples have been prepared by chemical route. Different techniques e.g. UV/VIS absorption spectroscopy; X-Ray diffraction study, high resolution transmission electron microscopy and luminescence study have been adopted for sample characterization. Optical absorption spectra show strong blue shift, which is an indication of strong quantum confinement. X-ray diffraction study and High resolution transmission electron microscopy show the existence of particles within 10 nm. Prepared samples exhibit luminescence such as Zn²⁺ related photoluminescence and efficient low voltage electroluminescence. This result has been utilized to test their applications in electronics as nano light emitting device.

6 illus, 1 table, 13 ref

020007   Jothe M K;Singh M;Shrivastava P K (Physics Dep, Govt. M.G.M.P.G. College, Itarsi, Madhya Pradesh, Email: jothemkj@gmail.com) : Interplanetary coronal mass ejections and cosmic ray intensity variation. Indian J scient Res 2010, 1(1), 55-8.

Interplanetary Coronal Mass Ejections (ICMEs) are the interplanetary manifestation of Coronal Mass Ejections observed by Coronagraphs near the sun. Based on the ICMEs observations for the descending phase of the solar cycle 23, we have proposed that the short-term modulation of cosmic rays is influenced by CMEs activity. In this study, 93 events of ICMEs have been used to derive their effects on cosmic ray intensity for the period of 2002 to 2007. Daily values of Kiel neutron monitor have been taken in chree analysis. Results of present analysis suggest that ICMEs can produce short-term transient decreases in cosmic ray intensity.

2 illus, 7 ref

020006   Indrajit Sharma B;Brojen Singh R K;Thapa R K; Paul R S;Maibam J (Physics Dep, Assam Univ, Silchar-788 011) : Density functional investigation of NbC and NbN compounds. Int J Mater Sci 2009, 4(3), 197-204.

Investigates the energy band structures of NbC and NbN within density functional theory using generalized gradient approximation. We present the results of variation of total energy of NbC and NbN at different volume ranging from 10 percent smaller to 10 percent greater than the experimental volume respectively. Energy band structures of NbC and NbN including five high symmetry points W, L, A, X and K show the shifting of Fermi energy from the earlier value reported. The decomposing points of t₂g states (T₂₅), e_g states (F₁₂) and C or N 2p states (T₁₅) show interesting behavior different from earlier reports.

4 illus, 20 ref

020005   Ganesh E N;Kishore L;Rangachar M J S (Research Scholar, JNTU, Hyderabad, Email: enganesh50@yahoo.co.in) : Analysis of energy dissipation and point charge effects in quantum cellular automata circuits. Int J Nanotechnol Applic 2008, 2(1), 25-46.

Quantum cellular automata technology is one of the promising nanotechnology in future due to the prospects of extremely low power operation and reduction of interconnections. This paper discuss about energy flow analysis in a QCA circuit. We have reviewed the energy flow equation in a QCA cell for the calculation of energy dissipation in simple QCA circuits. We found higher energy power dissipation of a QCA cell in a QCA circuit for unequal inputs due to availability of different polarization at the input and by majority logic method. We have also analysed the QCA circuit in terms of Fan-in and Fan-out terminology and calculated total energy supplied by clock in a circuit. We also investigated how the polarization of a cell affects near by QCA cell with respect to distance. We have discussed the point charge effect on a QCA cell in a diagonal and X-axis alignment. This analyses used to find the error due to polarization in a QCA circuit and to detect charge of near by QCA cell.

21 illus, 1 tables, 15 ref

020004   Bahari A;Roodbari M;Atyabi M;Morgen P (Physics Dep, Faculty of Basic Science, Mazandaran Univ, P.O. Box 47416-1467, Babolsar, Iran, Email: alibahari@ymail.com) : Distinctive feature of thermally grown ultra thin silicon nitride film. Asian J Chem 2009, 21(3), 2405-11.

In the current complementary metal oxide semiconductor (CMOS)-CPU generation the silicon gate oxide is 1.2 nm thick. A shrinking of this thickness with one atomic layer for the next generation will lead to a couple of orders of magnitude increase in tunneling current. Another critical issue for future generations is gate oxide degradation due to boron penetration into the oxide from the poly-silicon gate electrode. Ultrathin silicon nitride films have been identified as potential candidates to replace conventional silicon oxide gate dielectrics in current and future complementary metal oxide semiconductor, or as barrier layers between other high-dielectric constant materials and the silicon substrate. We have demonstrated a number of new processes to grow ultra thin silicon oxides and silicon nitrides based on the self limiting nature of the direct interaction between oxygen gas and heated silicon surfaces, or between atomic nitrogen produced in a microwave discharge and heated silicon surfaces. Theses pure ultrathin silicon oxide and nitride films have been studied on Si(100) in ultrahigh vacuum and studied by XPS and high resolution surface sensitive photoemission spectroscopy.

4 illuse, 20 ref

020003   Bahari A;Eimeri R;Rezazadeh R (Physics Dep, Faculty of Basic Science, Mazandaran Univ, P.O. Box 47416-1467, Babolsar, Iran, Email: alibahari@ymail.com) : Leakage current through the ultra thin silicon dioxide. Asian J Chem 2009, 21(3), 2399-404.

A significant issue i.e., leakage of current through the gate oxide, has been considered relevant to the use of ultra thin (< 1 -2 nm) pure oxides of silicon in the next complementary metal oxide semiconductor (CMOS) device generation based on the analytical Landauer-Buttiker method. The ratio of leakage of current through the single and double oxide was also estimated. The result shows that the double gate can reduce the leakage of current.

4 illus, 18 ref

014704   Szalai S;Szarka L (Geodetic and Geoelectric Research, Institute of the Hungarian Academy of Science, Sopron, P.B.5, Hungary, Email: szalai@ggki.hu) : Geoelectric arrays. Curr Sci 2009, 96(10), 1298.

2 illus, 5 tables

014703   Sharma S K;Shukla R;Banerjee P;Shyam A;Rana S;Shah A (Energetics & Electromagnetics Div, Institute for Plasma Research, Gandhinagar, Gujarat-382 428) : Compact 80 kv trigger generator for triggered spark gap. Prajna 2009, 17(Dec), 137-9.

A 80 kV trigger generator was designed and fabricated for triggering the field distortion type spark gap switch. The trigger generator can be operated in mode up to repetitive 10 Hz operation. The trigger generator consists of a compact power supply, transformer, bridge rectifier, capacitor, thyristor switch and a pulse transformer. The capacitor is charged with supply mains voltage stepped up to 800 V and then rectified using full bridge or by another 9 V battery operated compact power supply. The two power supplies are isolated and they charge a 2 μ F capacitor to 1 kV. The capacitor is discharged into Ihe input of 1 kV / 80 kV pulse transformer and produces 80 kV at the secondary of pulse transformer. The triggering circuit of Ihyristor consists of RC circuit and 555 timer producing 5V pulse for gate terminal of the thyristor. The 80 kV pulse is | used to trigger the spark gap of high voltage capacitor bank.

4 illus, 5 ref

014702   Rodriguez P;Lee S M (NO, Safety Research Institute of the Atomic Energy Regulatory Board, Kalpakkam-603 102, Email: sureshlee@rocketmail.com) : Is the department of atomic energy shifting the goal posts for its three stage nuclear power programme?. Curr Sci 2009, 96(3), 367-63.

In the context of India's three-stage nuclear power programme, there have been a number of recent submissions emphasizing the disadvantages of using thorium in fast breeder reactors (FBRs), and implying that thorium utilization should be through thermal reactors in the third stage. In this article, it is pointed out that the advantages of using thorium in fast reactors far outweigh the perceived disadvantages, which are anyway common for the thermal reactors also. Therefore, authors advocate a strategy that ensures both growth and sustainability in nuclear electricity generation through a symbiotic combination of Pu/^{238U FBRs and Pu/238U FBRs with thorium radial blankets early enough in the second stage, and using the 233U so produced to set up 233U/Th FBRs along with thermal reactors (breeders or advanced converters), which will then become the mainstay of the third stage. The key concept is to avoid a sequential mind-set and have proper blend and gradual merging of the stages.}

3 tables, 32 ref

014701   Ramalingam S;Prabhu T;Manimaran K;Murugan S; Nagarajan S M (NO, Physics Dep, Mannampandal-609 305, Email: ramalingam.physics@gmail.com) : Bio-EMF device (BED) using Hibiscus leaf as electrolyte. Asian J Microbiol Biotechnol envir Sci 2009, 11(4), 783-4.

An electrochemical cell is fabricated using the grinded leaves of Hibiscus rosa sinensis mixed with distilled water as the electrolyte. To obtain a close value to the available energy density, the cell is discharged at a current drain of 11 mA and initial open circuit voltage of 0.7 V. An observation is made regarding the variation of voltage and current with respect to time, which is unlike the variation observed for any other electrochemical cell. The curve features and the power production for different combination (Series and Parallel) of cells have been studied.

1 illus, 1 table, 10 ref

014700   Patel K D;Rathod J R;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Structural and optical properties of Zn Te thin films. Prajna 2009, 17(Dec), 180-4.

The investigation deals with the structural and optical properties of ZnTe thin films. Thin films of ZnTe with thicknesses around 4.kA and 6.kA have been deposited by thermal evaporation method on the ultrasonically cleaned glass substrates kept at 373K under the pressures of 5 x 10⁶ Torr. The thicknesses of the films were measured by quartz crystal thickness monitor. The structural and optical characterizations of the films were carried out by using X-ray diffraction (XRD) and UV-VIS-IR spectroscopy respectively. The lattice constant (a), grain size (D), strain (e) and dislocation density (p) have been calculated. The optical band gap (E_g) which was evaluated from the optical absorption spectra indicates direct band to band transitions. Spectral distribution of transmission coefficient T, refractive index n, extinction coefficient k of ZnTe thin films have also been investigated and discussed in light of the structure of ZnTe.

5 illus, 15 ref

014699   Patel K D;Patel H S;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Structural and optical characterization of CdTe thin films prepared by thermal evaporation process. Prajna 2009, 17(Dec), 176-9.

Cadmium Telluride (CdTe), a member of group II-VI semiconductors is one of the promising materials from its applications point of view. The present investigations are about the preparation and optical characterization of CdTe thin films. Thin films of CdTe with thickness around 4.2kA have been deposited by thermal evaporation method. CdTe charge was used as starting material for preparation of the films. The structural characterization of this charge was carried out using XRD. The structure of CdTe before and after the deposition was found to be hexagonal. Also, the lattice parameters were evaluated from the XRD data. The chemical composition of the deposited CdTe thin films has been confirmed using EDAX technique. From TEM of CdTe thin films, the polycrystalline nature was confirmed. Optical characterization of CdTe thin films has been carried out using UV-VIS-IR spectroscopy and the results have been discussed here.

5 illus, 13 tables, 10ref

014698   Parmar A;Patel B;Vinodkumar P C (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Two-photon decay widths of n_c, χ_C0 and χ_C2 charmonium states using coulumb plus power potential (CPPv). Prajna 2009, 17(Dec), 157-61.

Deals with the two-photon decay widths of the different charmonium states based on coulomb plus power km of the inter-quark potential (CPPV). The masses of the cc states and their radial wave functions obtained from the study If the charmonium spectroscopy are employed for the present calculations. The Schrodinger equation is solved numerically for different choices of the power index v. The decay widths are found to be in accordance with the experimental values for the choices of the inter-quark potential index in the range 0.7 < v < 1.1.

3 illus, 3 tables, 35 ref

014697   Mullainathan S;Nithiyanantham S;Rajeeskaran M (Physics Dep, SRM Univ, Kattankulathur-603-203, Email: s_nithu59@rediffmail.com) : Molecular interaction study on binary mixture of phenol in dioxane, methanol and acetonitrile at 303 K. Asian J Chem 2009, 21(6), 4789-92.

The ultrasonic velocity (U), density (p) and viscosity (η) at 303 K have been measured in the binary system of phenol in dioxane, methanol and acetonitrile. The acoustical parameters such as adiabatic compressibility ((β), free length (L_f), free volume (V_f), internal pressure (π), Wada's constant (W), Rao's constant (R) and acoustical impedance (Z) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.

1 table, 15 ref

014696   Misra K;Sagar R (Inter Univ Centre for Astronomy and Astrophysics, , Post Bag 4, Ganeshkhind, Pune-411 007, Email: kunta@iucaa.ernet.in) : Insight into the progenitors of gamma ray bursts from the optical afterglow observations. Curr Sci 2009, 96(3), 347-56.

Authors have probed more than 50 gamma ray bursts (GRBs) fields since January 1999 and obtained successful optical afterglow observations for 27 of them. Upper limits were reported for the rest of the cases. Optical observations of GRB afterglows provide information about GRB distances, nature of emission, surroundings, their environments and progenitors. The presence of supernova signature in long-duration GRB afterglows has further strengthened the fact that the collapse of a massive star gives rise to a long-duration GRBs. However, the observed properties of short-duration GRBs arc in agreement with the NS-NS or NS-BH coalescence model.

8 illus, 1 table, 71 ref

014695   Kothari H N;Joshipura K N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Ionization cross sections of helium and neon by positron impact-theoretical investingations. Prajna 2009, 17(Dec), 185-90.

Authors have calculated various total cross sections of positron interactions and scattering with helium and neon atoms. We have calculated total elastic cross sections (Q_et) and inelastic cross sections (Q_inel) from partial wave analysis of complex spherical e⁺ - atom potentials. In positron atom scattering it is difficult to separate out ionization and excitation cross sections from inelastic cross sections because the positronium formation is another inelastic channel taking off prior to excitation threshold in noble gas atoms. Our goal in this paper is to find out the contribution of ionization cross sections in the inelastic cross sections (Q_inel) along the lines of 'complex scattering potential-ionization contribution' (CSP-ic) method of electron - atom scattering.

2 illus, 21 ref

014694   Kiran Kumar A S (Space Applications Centre, Jodhpur Tekra, Ahmedabad-380 015, Email: kiran@sac.isro.gov.in) : Terrain mapping camera: a stereoscopic high-resolution instrument on Chandrayaan-1. Curr Sci 2009, 96(4), 492-5.

Chandrayaan-1, India's first lunar mission, has the prime objective of simultaneous chemical, mineralogi-cal and photo-selenological mapping of the lunar surface. In keeping with the mission objectives, Chandrayaan-1 carries the Terrain Mapping Camera (TMC) designed to map the entire lunar surface during the planned two-year mission. TMC data will enable preparation of a three-dimensional lunar atlas with 5 m sampled spatial and altitude data of 12 bit digitization. The TMC will image in the panchromatic spectral band of 0.5-0.75 μm with a stereo view in the fore, nadir and aft directions of the spacecraft movement and have a base to height ratio of one.

7 illus, 3 ref

014693   Karthick Kumar S K;Goswami T;Bhattacharyya I; Goswami D (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: dgoswami@iitk.ac.in) : Visible 20-femtosecond pulse generation by double-pass non-collinear optical parametric amplifier. Curr Sci 2009, 96(11), 1496-1500.

Reports a new design and construction of a high-power, white light seeded double-pass non-collinear optical parametric amplifier (NOPA) in the visible wavelength using a single amplifier crystal. For its successful implementation, many important practical considerations are discussed in detail. Tunable femtosecond pulses were obtained with pulse widths less than 20 fs and characterized using frequency-resolved optical gating technique. The generated visible pulse, tunable from 490 to 740 nm from the NOPA, was further optimized by second harmonic and four-wave mixing signals.

11 ref

014692   Kambale J B;Sarangi A;Singh D K;Singh A K (Agricultural Engineering Div, Water Technology Centre, Indian Agricultural Research Institute, New Delhi-110 012, Email: asarangi@iari.res.in) : Performance evaluation of filtration unit of groundwater recharge shaft: laboratory study. Curr Sci 2009, 96(4), 471-4.

The groundwater resource of our country is now under serious threat due to over-exploitation, pollution, industrialization and improper management. The recharge shaft is an efficient and economic method for recharging groundwater. In this study, the effect of variable thickness of coarse sand (CS), gravel (G) and pebble (P) layers of the filtration unit of the recharge shaft on the recharge rate and the sediment concentration of effluent water was evaluated. An experiment was carried out with laboratory-scale models having varying depths of CS, G and P layers in five different thickness combinations, viz. 1: 1.5: 3, 7.5: 1:3, 3:1:1.5, 3:1.5:1, 1:1:1 (CS: G: P). These models were operated with six different treatments having varying concentrations of turbid water, similar to the sedimentation level of the surface run-off ranging from 6 to 16 g/l. It was observed that higher thickness of CS resulted in reduction of the recharge rate, but improved the filtration of the effluent. Overall, considering both the recharge rate and sediment concentration of the effluent, the filtration layer thickness ratio of 1.5:1: 3 (CS: G: P) would be the optimal design of the filtration unit to facilitate higher recharge and perform better filtration of the turbid water.

5 illus, 1 table, 6 ref

014691   Charles J;Ramkumar G R (Physics Dep, S.S.N. College of Engineering, Old Mahabalipuram Road, S.S.N. Nagar, Kalavakkam-603 110, Email: juliecharles2005@gmail.com) : Qualitative analysis of high density polyethylene using FTIR spectroscopy. Asian J Chem 2009, 21(6), 4477-84.

FTIR spectroscopic technique is projected in the present work to make complete qualitative analysis on high density polyethylene (HOPE) and commercial HOPE polymers. Infrared spectra have been used for the molecular structure study of the repeating unit of polyethylene. The qualitative analysis of the commercial HDPE samples has been made by evaluating the internal standards with the standard source sample as the reference. The internal standards are ratios indicative of the quality of the sample. The internal standards are computed for certain specific modes of vibration and are compared to identify the quality and purity of the samples. Thus, FTIR spectral measurements have been made to differentiate the commercial HDPE samples with the source HDPE. The growth of polyethylene products has acquired enormous heights owing to its application as insulating material. The dielectric constants have been determined for all polymer samples in the GHz range using the microwave benches. The magnitude of dielectric constants for all samples observed in X band is of the same trend as that in K band, i.e. a decrease in dielectric constant with increase in microwave frequency has been observed. Materials with lower dielectric constant would be preferred for insulation application due to their high dielectric strength.

3 illus, 3 tables, 20 ref

014690   Charles J;Ramkumar G R (Physics Dep, S.S.N. College of Engineeirng, Old Mahabalipuram Road, S.S.N. Nagar, Kalavakkam-603 110, Email: juliecharles2005@gmail.com) : FTIR and thermal studies on polyethylene terephthalate and acrylonitrile butadiene strene. Asian J Chem 2009, 21(6), 4389-98.

Deals with the characterization of the polymeric materials viz., polyethylene terephthalate (PET) and acrylonitrile butadiene styrene (ABS) by employing FTIR and thermal measurements. The complete vibrational band assignment made available for PET and ABS using FTIR spectra confirms their chemical structure. FTIR spectro-scopy provides detailed information on polymer structure through the characteristic vibrational energies of the various groups present in the molecule. The thermal behaviour of PET and ABS essential for proper processing and fabrication was studied through TGA and DTA thermo-grams. The thermal stability of the polymers was studied from TGA and the activation energy for the degradation of the polymeric materials was calculated using Murray-White plot and Coats-Redfern plot. The polymer with high activation energy is more thermally stable. Polyethylene terephthalate is found to be more thermally stable than ABS. The major thermal transitions such as crystalline melting temperature (T_m) and degradation temperature (T_a) of the polymers were detected from DTA curves. The melting behaviour of the polymer depends upon the specimen history and in particular upon the temperature of crystallization. The melting behaviour also depends upon the rate at which the specimen is heated. The various factors such as molar mass and degree of chain branching govern the value of T_m in different polymers.

5 illus, 7 tables, 23 ref

014689   Chaki S;Deshpande M P;Sakaria P N;Pandya N N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Single crystal growth, surface microstructure and thermal studies of MoS2. Prajna 2009, 17(Dec), 170-5.

Direct vapour transport (DVT) technique was employed to grow large size single crystals of molybdenum disulphide (MoS₂). The Energy Dispersive Analysis of X-ray (EDAX) and X-ray diffraction (XRD) techniques were used to determine the stoicViionietric composition and the lattice parameters of the as-grown DVT MoS₂ single crystals respectively. The detailed surface microstructure study reveals that the crystal growth is by spiral and lateral layer spreading mechanisms. The thermal stability of the as-grown DVT MoS₂ single crystals was studied using thermogravimetric analysis (TGA) technique. The thermal activation energy of the MoS₂ single crystal was determined using non-mechanistic equations for thermal decompositions.

8 illus, 1 table, 14 ref

014704   Szalai S;Szarka L (Geodetic and Geoelectric Research, Institute of the Hungarian Academy of Science, Sopron, P.B.5, Hungary, Email: szalai@ggki.hu) : Geoelectric arrays. Curr Sci 2009, 96(10), 1298.

2 illus, 5 tables

014703   Sharma S K;Shukla R;Banerjee P;Shyam A;Rana S;Shah A (Energetics & Electromagnetics Div, Institute for Plasma Research, Gandhinagar, Gujarat-382 428) : Compact 80 kv trigger generator for triggered spark gap. Prajna 2009, 17(Dec), 137-9.

A 80 kV trigger generator was designed and fabricated for triggering the field distortion type spark gap switch. The trigger generator can be operated in mode up to repetitive 10 Hz operation. The trigger generator consists of a compact power supply, transformer, bridge rectifier, capacitor, thyristor switch and a pulse transformer. The capacitor is charged with supply mains voltage stepped up to 800 V and then rectified using full bridge or by another 9 V battery operated compact power supply. The two power supplies are isolated and they charge a 2 μ F capacitor to 1 kV. The capacitor is discharged into Ihe input of 1 kV / 80 kV pulse transformer and produces 80 kV at the secondary of pulse transformer. The triggering circuit of Ihyristor consists of RC circuit and 555 timer producing 5V pulse for gate terminal of the thyristor. The 80 kV pulse is | used to trigger the spark gap of high voltage capacitor bank.

4 illus, 5 ref

014702   Rodriguez P;Lee S M (NO, Safety Research Institute of the Atomic Energy Regulatory Board, Kalpakkam-603 102, Email: sureshlee@rocketmail.com) : Is the department of atomic energy shifting the goal posts for its three stage nuclear power programme?. Curr Sci 2009, 96(3), 367-63.

In the context of India's three-stage nuclear power programme, there have been a number of recent submissions emphasizing the disadvantages of using thorium in fast breeder reactors (FBRs), and implying that thorium utilization should be through thermal reactors in the third stage. In this article, it is pointed out that the advantages of using thorium in fast reactors far outweigh the perceived disadvantages, which are anyway common for the thermal reactors also. Therefore, authors advocate a strategy that ensures both growth and sustainability in nuclear electricity generation through a symbiotic combination of Pu/^{238U FBRs and Pu/238U FBRs with thorium radial blankets early enough in the second stage, and using the 233U so produced to set up 233U/Th FBRs along with thermal reactors (breeders or advanced converters), which will then become the mainstay of the third stage. The key concept is to avoid a sequential mind-set and have proper blend and gradual merging of the stages.}

3 tables, 32 ref

014701   Ramalingam S;Prabhu T;Manimaran K;Murugan S; Nagarajan S M (NO, Physics Dep, Mannampandal-609 305, Email: ramalingam.physics@gmail.com) : Bio-EMF device (BED) using Hibiscus leaf as electrolyte. Asian J Microbiol Biotechnol envir Sci 2009, 11(4), 783-4.

An electrochemical cell is fabricated using the grinded leaves of Hibiscus rosa sinensis mixed with distilled water as the electrolyte. To obtain a close value to the available energy density, the cell is discharged at a current drain of 11 mA and initial open circuit voltage of 0.7 V. An observation is made regarding the variation of voltage and current with respect to time, which is unlike the variation observed for any other electrochemical cell. The curve features and the power production for different combination (Series and Parallel) of cells have been studied.

1 illus, 1 table, 10 ref

014700   Patel K D;Rathod J R;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Structural and optical properties of Zn Te thin films. Prajna 2009, 17(Dec), 180-4.

The investigation deals with the structural and optical properties of ZnTe thin films. Thin films of ZnTe with thicknesses around 4.kA and 6.kA have been deposited by thermal evaporation method on the ultrasonically cleaned glass substrates kept at 373K under the pressures of 5 x 10⁶ Torr. The thicknesses of the films were measured by quartz crystal thickness monitor. The structural and optical characterizations of the films were carried out by using X-ray diffraction (XRD) and UV-VIS-IR spectroscopy respectively. The lattice constant (a), grain size (D), strain (e) and dislocation density (p) have been calculated. The optical band gap (E_g) which was evaluated from the optical absorption spectra indicates direct band to band transitions. Spectral distribution of transmission coefficient T, refractive index n, extinction coefficient k of ZnTe thin films have also been investigated and discussed in light of the structure of ZnTe.

5 illus, 15 ref

014699   Patel K D;Patel H S;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Structural and optical characterization of CdTe thin films prepared by thermal evaporation process. Prajna 2009, 17(Dec), 176-9.

Cadmium Telluride (CdTe), a member of group II-VI semiconductors is one of the promising materials from its applications point of view. The present investigations are about the preparation and optical characterization of CdTe thin films. Thin films of CdTe with thickness around 4.2kA have been deposited by thermal evaporation method. CdTe charge was used as starting material for preparation of the films. The structural characterization of this charge was carried out using XRD. The structure of CdTe before and after the deposition was found to be hexagonal. Also, the lattice parameters were evaluated from the XRD data. The chemical composition of the deposited CdTe thin films has been confirmed using EDAX technique. From TEM of CdTe thin films, the polycrystalline nature was confirmed. Optical characterization of CdTe thin films has been carried out using UV-VIS-IR spectroscopy and the results have been discussed here.

5 illus, 13 tables, 10ref

014698   Parmar A;Patel B;Vinodkumar P C (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Two-photon decay widths of n_c, χ_C0 and χ_C2 charmonium states using coulumb plus power potential (CPPv). Prajna 2009, 17(Dec), 157-61.

Deals with the two-photon decay widths of the different charmonium states based on coulomb plus power km of the inter-quark potential (CPPV). The masses of the cc states and their radial wave functions obtained from the study If the charmonium spectroscopy are employed for the present calculations. The Schrodinger equation is solved numerically for different choices of the power index v. The decay widths are found to be in accordance with the experimental values for the choices of the inter-quark potential index in the range 0.7 < v < 1.1.

3 illus, 3 tables, 35 ref

014697   Mullainathan S;Nithiyanantham S;Rajeeskaran M (Physics Dep, SRM Univ, Kattankulathur-603-203, Email: s_nithu59@rediffmail.com) : Molecular interaction study on binary mixture of phenol in dioxane, methanol and acetonitrile at 303 K. Asian J Chem 2009, 21(6), 4789-92.

The ultrasonic velocity (U), density (p) and viscosity (η) at 303 K have been measured in the binary system of phenol in dioxane, methanol and acetonitrile. The acoustical parameters such as adiabatic compressibility ((β), free length (L_f), free volume (V_f), internal pressure (π), Wada's constant (W), Rao's constant (R) and acoustical impedance (Z) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.

1 table, 15 ref

014696   Misra K;Sagar R (Inter Univ Centre for Astronomy and Astrophysics, , Post Bag 4, Ganeshkhind, Pune-411 007, Email: kunta@iucaa.ernet.in) : Insight into the progenitors of gamma ray bursts from the optical afterglow observations. Curr Sci 2009, 96(3), 347-56.

Authors have probed more than 50 gamma ray bursts (GRBs) fields since January 1999 and obtained successful optical afterglow observations for 27 of them. Upper limits were reported for the rest of the cases. Optical observations of GRB afterglows provide information about GRB distances, nature of emission, surroundings, their environments and progenitors. The presence of supernova signature in long-duration GRB afterglows has further strengthened the fact that the collapse of a massive star gives rise to a long-duration GRBs. However, the observed properties of short-duration GRBs arc in agreement with the NS-NS or NS-BH coalescence model.

8 illus, 1 table, 71 ref

014695   Kothari H N;Joshipura K N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Ionization cross sections of helium and neon by positron impact-theoretical investingations. Prajna 2009, 17(Dec), 185-90.

Authors have calculated various total cross sections of positron interactions and scattering with helium and neon atoms. We have calculated total elastic cross sections (Q_et) and inelastic cross sections (Q_inel) from partial wave analysis of complex spherical e⁺ - atom potentials. In positron atom scattering it is difficult to separate out ionization and excitation cross sections from inelastic cross sections because the positronium formation is another inelastic channel taking off prior to excitation threshold in noble gas atoms. Our goal in this paper is to find out the contribution of ionization cross sections in the inelastic cross sections (Q_inel) along the lines of 'complex scattering potential-ionization contribution' (CSP-ic) method of electron - atom scattering.

2 illus, 21 ref

014694   Kiran Kumar A S (Space Applications Centre, Jodhpur Tekra, Ahmedabad-380 015, Email: kiran@sac.isro.gov.in) : Terrain mapping camera: a stereoscopic high-resolution instrument on Chandrayaan-1. Curr Sci 2009, 96(4), 492-5.

Chandrayaan-1, India's first lunar mission, has the prime objective of simultaneous chemical, mineralogi-cal and photo-selenological mapping of the lunar surface. In keeping with the mission objectives, Chandrayaan-1 carries the Terrain Mapping Camera (TMC) designed to map the entire lunar surface during the planned two-year mission. TMC data will enable preparation of a three-dimensional lunar atlas with 5 m sampled spatial and altitude data of 12 bit digitization. The TMC will image in the panchromatic spectral band of 0.5-0.75 μm with a stereo view in the fore, nadir and aft directions of the spacecraft movement and have a base to height ratio of one.

7 illus, 3 ref

014693   Karthick Kumar S K;Goswami T;Bhattacharyya I; Goswami D (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: dgoswami@iitk.ac.in) : Visible 20-femtosecond pulse generation by double-pass non-collinear optical parametric amplifier. Curr Sci 2009, 96(11), 1496-1500.

Reports a new design and construction of a high-power, white light seeded double-pass non-collinear optical parametric amplifier (NOPA) in the visible wavelength using a single amplifier crystal. For its successful implementation, many important practical considerations are discussed in detail. Tunable femtosecond pulses were obtained with pulse widths less than 20 fs and characterized using frequency-resolved optical gating technique. The generated visible pulse, tunable from 490 to 740 nm from the NOPA, was further optimized by second harmonic and four-wave mixing signals.

11 ref

014692   Kambale J B;Sarangi A;Singh D K;Singh A K (Agricultural Engineering Div, Water Technology Centre, Indian Agricultural Research Institute, New Delhi-110 012, Email: asarangi@iari.res.in) : Performance evaluation of filtration unit of groundwater recharge shaft: laboratory study. Curr Sci 2009, 96(4), 471-4.

The groundwater resource of our country is now under serious threat due to over-exploitation, pollution, industrialization and improper management. The recharge shaft is an efficient and economic method for recharging groundwater. In this study, the effect of variable thickness of coarse sand (CS), gravel (G) and pebble (P) layers of the filtration unit of the recharge shaft on the recharge rate and the sediment concentration of effluent water was evaluated. An experiment was carried out with laboratory-scale models having varying depths of CS, G and P layers in five different thickness combinations, viz. 1: 1.5: 3, 7.5: 1:3, 3:1:1.5, 3:1.5:1, 1:1:1 (CS: G: P). These models were operated with six different treatments having varying concentrations of turbid water, similar to the sedimentation level of the surface run-off ranging from 6 to 16 g/l. It was observed that higher thickness of CS resulted in reduction of the recharge rate, but improved the filtration of the effluent. Overall, considering both the recharge rate and sediment concentration of the effluent, the filtration layer thickness ratio of 1.5:1: 3 (CS: G: P) would be the optimal design of the filtration unit to facilitate higher recharge and perform better filtration of the turbid water.

5 illus, 1 table, 6 ref

014691   Charles J;Ramkumar G R (Physics Dep, S.S.N. College of Engineering, Old Mahabalipuram Road, S.S.N. Nagar, Kalavakkam-603 110, Email: juliecharles2005@gmail.com) : Qualitative analysis of high density polyethylene using FTIR spectroscopy. Asian J Chem 2009, 21(6), 4477-84.

FTIR spectroscopic technique is projected in the present work to make complete qualitative analysis on high density polyethylene (HOPE) and commercial HOPE polymers. Infrared spectra have been used for the molecular structure study of the repeating unit of polyethylene. The qualitative analysis of the commercial HDPE samples has been made by evaluating the internal standards with the standard source sample as the reference. The internal standards are ratios indicative of the quality of the sample. The internal standards are computed for certain specific modes of vibration and are compared to identify the quality and purity of the samples. Thus, FTIR spectral measurements have been made to differentiate the commercial HDPE samples with the source HDPE. The growth of polyethylene products has acquired enormous heights owing to its application as insulating material. The dielectric constants have been determined for all polymer samples in the GHz range using the microwave benches. The magnitude of dielectric constants for all samples observed in X band is of the same trend as that in K band, i.e. a decrease in dielectric constant with increase in microwave frequency has been observed. Materials with lower dielectric constant would be preferred for insulation application due to their high dielectric strength.

3 illus, 3 tables, 20 ref

014690   Charles J;Ramkumar G R (Physics Dep, S.S.N. College of Engineeirng, Old Mahabalipuram Road, S.S.N. Nagar, Kalavakkam-603 110, Email: juliecharles2005@gmail.com) : FTIR and thermal studies on polyethylene terephthalate and acrylonitrile butadiene strene. Asian J Chem 2009, 21(6), 4389-98.

Deals with the characterization of the polymeric materials viz., polyethylene terephthalate (PET) and acrylonitrile butadiene styrene (ABS) by employing FTIR and thermal measurements. The complete vibrational band assignment made available for PET and ABS using FTIR spectra confirms their chemical structure. FTIR spectro-scopy provides detailed information on polymer structure through the characteristic vibrational energies of the various groups present in the molecule. The thermal behaviour of PET and ABS essential for proper processing and fabrication was studied through TGA and DTA thermo-grams. The thermal stability of the polymers was studied from TGA and the activation energy for the degradation of the polymeric materials was calculated using Murray-White plot and Coats-Redfern plot. The polymer with high activation energy is more thermally stable. Polyethylene terephthalate is found to be more thermally stable than ABS. The major thermal transitions such as crystalline melting temperature (T_m) and degradation temperature (T_a) of the polymers were detected from DTA curves. The melting behaviour of the polymer depends upon the specimen history and in particular upon the temperature of crystallization. The melting behaviour also depends upon the rate at which the specimen is heated. The various factors such as molar mass and degree of chain branching govern the value of T_m in different polymers.

5 illus, 7 tables, 23 ref

014689   Chaki S;Deshpande M P;Sakaria P N;Pandya N N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar, Gujarat-388 120) : Single crystal growth, surface microstructure and thermal studies of MoS2. Prajna 2009, 17(Dec), 170-5.

Direct vapour transport (DVT) technique was employed to grow large size single crystals of molybdenum disulphide (MoS₂). The Energy Dispersive Analysis of X-ray (EDAX) and X-ray diffraction (XRD) techniques were used to determine the stoicViionietric composition and the lattice parameters of the as-grown DVT MoS₂ single crystals respectively. The detailed surface microstructure study reveals that the crystal growth is by spiral and lateral layer spreading mechanisms. The thermal stability of the as-grown DVT MoS₂ single crystals was studied using thermogravimetric analysis (TGA) technique. The thermal activation energy of the MoS₂ single crystal was determined using non-mechanistic equations for thermal decompositions.

8 illus, 1 table, 14 ref

024216   Solanki G K;Goyal S;Arora S K;Patel D B; Agarwal M K (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: solankigunvant@yahoo.co.in) : Effect of enhancement of selenium content in zirconium sulphoselenide on its photoelectrochemical behaviour. Indian J Phys 2009, 83(3), 275-84.

An attempted to fabricate PEC solar cells with mixed crystals of Zirconium sulphoselenide. Energy band location and redox analysis of the material have been made using Mott-Schottky plots. These studies justify the selection of an appropriate electrolyte for PEC work. Various solar cells fabricated with single crystals of selenium rich and selenium deficient zirconium sulphoselenide have been prepared. The solar cell parameters e.g. the fill factor (FF), open circuit voltage (V_oc), short circuit current (1_sc) and efficiency (η) for all the different cells have been determined. In order to see the effect of enhancement of selenium in ZrS_xSe_2-x on photoresponse, the electrolyte and intensity of illumination were kept constant and all the electrodes were prepared from crystals showing absolutely plane faces obtained through the act of cleavage with the help of an adhesive tape. The results have been thoroughly analysed and the implications have been discussed.

4 illus, 3 tables, 15 ref

024215   Soibam I;Phanjoubam S;Sharma H B;Sarma H N K; Prakash C (Physics Dep, Manipur Univ, Canchipur, Imphal-795 003, Email: ibetombi_phys@rediffmail.com) : Preparation and studies of electrical properties of cobalt substituted Li-Zn ferrites by sol-gel auto combustion method. Indian J Phys 2009, 83(3), 285-90.

A series of co substituted lithium zinc ferrite powders with different content of Co (0.00 to 0.1 in steps of 0.02) were prepared by a novel sol-gel auto combustion process using citric acid. Their spinel structure was confirmed by XRD. The variation in lattice parameter and density with cobalt concentration was studied which showed an increasing trend. A decreasing pattern was observed in variation of porosity with increasing Co. Room temperature dielectric constant and resistivity were studied as a function of composition at 10 KHz. The room temperature dielectric constant decreases with successive addition of Co^{2+ in the series. The observed variation in dielectric constant has been explained on the basis of space charge polarization and Koops two layer model. Resistivity is observed to increase with increasing concentration and the observed variation in resistivity has been explained by Verwey hopping mechanism.}

3 illus, 1 table, 11 ref

024214   Singh S V;Thakur A N;Singh O P;Kumar S C; Ahmad A (Physics Dep, TD Post Graduate College, Jaunpur-222 002, Email: ant_tdc@yahoo.com) : Dielectric properties of PbSrWO₄ and PbBaWO₄ compounds. Indian J Phys 2009, 83(3), 375-81.

PbSrWO₄ and PbBaWO₄ have been synthesised by the solid state reaction technique XRD patterns show them to be tetragonal. Dielectric constant (K' ) and Dielectric loss (K" of PbSrWO₄ and PbBaWO₄ have been measured at 1 kHz in the temperature range of 300 to 1050 K. The log K' vs T as well as log K" vs T plot of PbSrWO₄ and PbBaWO₄ shows rapid increase of dielectric constant above 590 K and 640 K, respectively.

4 illus, 4 tables, 9 ref

024213   Rudramadevi B H;Buddhudu S (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: drs99@hotmail.com) : Emission analysis of RE<. Indian J Phys 2009, 83(3), 313-23.

Reports here the luminescence spectra of certain rare earth ions (Eu^{3+3+, Tb3+ & Ho3+) doped B₂O₃-B₂O₃-LiF/AiF₃ based on the measurements of emission and decay curves of prominent emission transitions. For both the reference host glasses, FTIR, XRD, DTA-TG profiles have been recorded to understand their structural and thermal properties. Eu3+ doped glasses have shown five emission transitions of 5D₀→77F_{01,2,3and 4} located at 580nm, 593nm, 615nm, 655nm and 704nm respectively with an excitation at λ_exci = 392 nm (7F₀→5L₆). Also under an UV source, these europium glasses have displayed a bright red emission from their surfaces. Tb3+ glasses have exhibited four emission bands of 5D₄→7F_6,5,4,3 at 491 nm, 547nm, 588nm and 625nm respectively with an excitation at λ_exci = 376 nm (7F₆→5G₆). Intense green emission from the glass surfaces has been noticed upon exposure to the UV source. Prominently bluish-green emission has been noticed from the surfaces of the holmium glasses under an UV source and same emission transition (5F₄→5I₈) at 519 nm with an excitation at λ_exci = 389 nm (5l5 G₂) has also been obtained from their measured emission spectra. For all the prominent emissions of the rare earth glasses, decay curves have been measured to compute their lifetimes.}

9 illus, 1 table, 27 ref

024212   Ramasamy V;Ponnusamy V (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002, Email: srsaranram@rediffmail.com ) : Analysis on air suspended particles of Coimbatore a FTIR study. Indian J Phys 2009, 83(3), 301-12.

An infrared absorption method has been used to identify the minerals in dust collected from some parts of Coimbatore, Coimbatore district, Tamil Nadu without grinding. The KBr pellet technique was employed. The results obtained from the IR spectra show the presence of quartz, asbestos, kaolinite, calcite, haematite, montmorllonite, nacrite and coal. The hazardous effect of inhalation of these minerals are explained. The results show Pollachi main road is more contaminated with hazardous minerals.

6 illus, 1 table, 29 ref

024211   Poonia S;Soni S N (Natural Resources and Environment Div, Central Arid Zone Research Institute, Jodhpur-342 003, Email: poonia.surendra@gmail.com) : 2P_3/2 <. Indian J Phys 2009, 83(3), 325-37.

The X-ray satellite spectra arising due to 2p_3/2^{-13x-1-3x-13d-1 (x = s, p, d) transition array, in elements with Z = 40 to 48, have been calculated, using available Hartree-Fock-Slater (HFS) data on 1s-1-2p-1 3x- and 2p_3/2-1-3x-1,3x-1 Auger transition energies. The relative intensities of all the possible transitions have been estimated by considering cross - sections for the Auger transitions simultaneous to a hole creation and then distributing statistically the total cross sections for initial two hole states 2p-1_3/2 - 3x-1 amongst various allowed transitions from these initial states to 3x-1 3d-1 final states by Coster-Kronig (CK) and shake off processes. In both these processes initial single hole creation is the prime phenomenon. Each transition has been assumed to give rise to a Gaussian line and the overall spectrum has been computed as the sum of these Gaussian curves. The calculated spectra have been compared with the measured satellite energies in Lα₁ spectra. Their intense peaks have been identified as the observed satellite lines. The peaks in the theoretical satellite spectra were identified as the experimentally reported satellites α₃, α₄ and α₃, which lie on the high-energy side of the La, dipole line.}

4 illus, 5 tables, 36 ref

024210   Pakzad H R;Javidan K (Physics Dep, Azad Univ of Bojnourd, Bojnourd, Iran, Email: pakzad@bojnourdiau.ac.ir) : Solitons of the KP equation in dusty plasma with variable dust charge and two temperature ions : energy and stability. Indian J Phys 2009, 83(3), 349-63.

The propagation of nonlinear waves in dusty plasmas with variable dust charge and two temperature ions is analyzed. By using the reductive perturbation theory, the Kadomtsev-Petviashivili (KP) equation is derived. A Sagdeev potential has been investigated. This potential is used to study the stability conditions for existence of solitonic solutions. Also, it is shown that a rarefactive soliton can exist in most of the cases. The energy of the soliton has been calculated and by using the standard normal-mode analysis a linear dispersion relation has been obtained. The effects of variable dust charge on the amplitude, width and energy of soliton and its effects on the angular frequency of linear wave are also discussed.

10 illus, 23 ref

024209   Mandal G;Roy K;Chatterjee P (APCE Dep, East West Univ, Mohakhali, Dhaka, Bangladesh, Email: prasantachatterjee1@rediffmail.com) : Large amplitude double layers in a four component dusty plasma with non-thermal ions. Indian J Phys 2009, 83(3), 365-74.

Dust acoustic double layers are studied in a four component dusty plasma. Positively and negatively charged mobile dust and Boltzmann distributed electrons are considered. The ion distribution is taken as nonthermal. The existence of compressive and rarefractive double layers is studied by pseudopotential approach. The effect of non-thermal ions on small amplitude and arbitrary amplitude double layers are also studied.

4 illus, 40 ref

024208   Mahato D N;Mathur B K;Bhattacharjee S (PG Dep of Physics, Tata College, Chaibasa-833 202, Email: dn.mahato08@yahoo.com) : Layer disorders defect in coir fiber under thermal and chemical treatment. Indian J Phys 2009, 83(3), 267-73.

Natural coir fibers, subjectd to thermal treatments in the range of 0°C to 200°C and alkali treatment with 5% to 30% concentration w/w, have been used in the present investigation to determine the interlayer variability of the cellulose planes (020), (110) and (110<96>). Among the equatorial reflections (110), (110<96>)and (020), the extent of variability is found to be more with the proportion of such affected planes less for (020) reflection in the native cellulose at lower temperature while at higher temperature (110) and (110<96>) become more affected by variability defect. (110) and (110<96>) planes are more affected also with alkali treatment.

2 illus, 16 ref

024207   Hothi N;Bisht S (Physics Dep, Kumaun Univ, Nainital-263 002, Email: shbisht@gmail.com) : Comparative analysis of mesonic, baryonic and glueball regge trejectories. Indian J Phys 2009, 83(3), 339-48.

Presents a comparative analysis of mesonic, baryonic and Glueball Regge trajectories based on different parameters. The different inbuilt compositions of the three seem to serve as a basis for their individual identities. Discusses features such as crossed channel forces, signature, string models and also the dependence of the slope of the mesons and baryons on the fine structure constant. We infer that inspite of various inherent similarities, these three Regge trajectories have some distinctive features which serve as a basis for their identification.

37 ref