018378   Nand Kishore;Rathi S K;Singh N (Physics Dep, B.S.A. College, Mathura, Uttar Pradesh) : Effect of external field on the nucleation of ice particles. Acta Cienc Indica-Phys 2008, 34(4), 657-61.

The electric field existing in clouds affects nucleation in water vapour condensation and ice glaciation. The effect of an electric field on the relaxation time via the calculation of critical size of nucleus in homogeneous nucleation is discussed. The rate of nucleation is found to increase by more than 100 times at the breakdown electric field.

2 tables, 11 ref

018377   Mishra A K;Dadhwal V K;Dutt C B S (NO, Indian Institute of Remote Sensing (NORSA), P.B. 135, 4 Kalidas Road, Dehradun, Uttarakhand) : Analysis of marine aerosol optical depth retrived from IRS-P4 OCM sensor and compariosn with the aerosol derived from sea WiFS and MODIS sensor. J Earth Syst Sci 2008, 117(S1), 361-73.

Aerosol optical depth is regularly derived from SeaWiFS and MODIS sensor and used by the sci-entific community in various climatic studies. An attempt has been made to retrieve the aerosol optical depth using the IRS-P4 OCM sensor data and a comparison has been carried out using few representative datasets. The results show that the IRS-P4 OCM retrieved aerosol optical depth is in good agreement with the aerosols retrieved from SeaWiFS as well as MODIS. The RMSE are found to be ±0.0522 between OCM and SeaWiFS and ±0.0638 between OCM and MODIS respectively. However, IRS-P4 OCM sensor retrieved aerosol optical depth is closer to SeaWiFS (correlation = 0.88. slope = 0.96 and intercept = -0.013) compared to MODIS (correlation = 0.75, slope = 0.91 and intercept = 0.0198). The mean percentage difference radicates that OCM retrieved AOD is ± 12% higher compared to SeaWiFS and ±8% higher compared to MODIS. The mean absolute percentage between OCM derived AOD and SeaWiFS is found to be less (16%) compared to OCM and MODIS (20%).

5 illus, 5 tables, 62 ref

018376   Kazemzadeh A;Valizadeh M;Raisian H (NO, Materials & Energy Research Centre, P.O. Box 14155-4777, Tehran, Iran, Email: asg642001@yahoo.com) : Transport phenomena on singl walled carbon nanotubes. Asian J Chem 2008, 20(5), 3401-7.

One of the most fascinating properties of carbon nanotubes is the predicted interplay between geometrical and electronic structure. The topics include a giant Aharonov-Bohm effect on the band gap and landau-level formation and Hall effect in magnetic fields. Individual large diameter (8 to 15 nm) semi conducting single-walled carbon nanotube is found to exhibit are bipolar field-effect transistor behaviour. The effect of temperature and ultraviolet radiationpn their electrical properties is elucidated. Recent development in contacting nanotubes, which should soon allow study of their intrinsic transport properties. In this research electrical properties and transport phenomena on single-walled carbon nanotubes have studied with measurement of Raman spectro-scopy, XRD, ESR, I -V curve, C-V hardness and band gap methods in the UV-Vis area and suitable results obtain from analyses device in the field of electron transport phenomena in carbon nanotubes.

7 illus, 5 ref

018375   Karunakaran V;Ramanathan R (Physics Dep, Govt. Arts College, Ariyalur-621 713) : Ultrasonic attenuation and relaxation time of l-glutamic acid in water. Acta Cienc Indica-Phys 2008, 34(4), 611-14.

L-Glutamic acid was dissolved in water for ultrasonic study and its attenuation and relaxation time for various concentrations were studied at 303K, 313K and 323K. It was found that L-Glutamic acid which has two polymorphic forms, alpha and beta co-exists at room temperature, which was 303K. When the concentration was increased there was a phenomenal change in ultrasonic attenuation and relaxation time which points that there is a transformation from a mixture of alpha and beta forms to beta form. Further, there is aggregation of these forms in water, which is chaotic.

2 illus, 5 ref

018374   John L K;Abna K A;Mathew Kurian P;Paulose P I (Physics Dep, Research Centre, Maharajas College, Ernakulam 682011, Email: pipaul2006@yahoo.co.in) : Characterization and optical studies of erbium doped lithium borate glass. Asian J Spectrosc 2008, 12(4), 145-50.

Optical properties of lithium borate glass doped with Er³⁺ ions, prepared by the melt-quenching technique are investigated. The amorphous nature of prepared samples was confirmed by XRD. The analysis of optical absorption spectra shows that the fundamental absorption edge is around 380 nm. It is not sharply defined which characterizes the glassy nature of the samples. Absorption, excitation and emission spectra of all the samples were studied. The absorption peaks shows an increasing trend in intensity with the rare earth ion concentration which also confirms the incorporation of Er³⁺ in borate matrix. The direct and indirect band gap energies of all the samples were calculated and found that they are decreasing with increase in concentration of the dopant. FWHM of the emission spectra in the visible region is found to be 10 nm and the sharp peak indicates that this material can be used for laser studies.

6 illus, 3 tables, 11 ref

018373   Jadhav G H (NO, S.C.S. College, Omerga-413 606) : Field-field interaction: classical theory of photoelectric effect. Acta Cienc Indica-Phys 2008, 34(4), 577-83.

Presents a classical solution to the photoelectric effect with introducing a force through field-field interaction. The equation deduced is similar to Einstein's photoelectric equation in few respects. Classically it allows kinetic energy of the photoelectrons to depend on frequency of the incident electromagnetic (EM) wave. It also shows the dependence of kinetic energy on amplitude of the incident electric field wave. Experimental observations are in support of the theory.

6 illus, 4 ref

018372   Chandrash A P K;Singh M N (P.G. Dep of Physics, Samastipur College, Samastipur, Bihar) : Gemotrical optics solutions for dielectric wedge antennas. Acta Cienc Indica-Phys 2008, 34(4), 573-5.

The development is presented here, derived from a physical optics version of the gemotrical theory of diffraction of a simple edge coefficient for external and internal diffraction at planar dielectric edges. Two classes of dielectric wedges with a common edge are considered. For a certain direction of incidence and polarization of the primary plane wave, conditions are given under which total transmission occurs at all interfaces, i.e., the edge does not scatter and geometrical optics is the exact solution to the boundary value problem.

2 illus, 6 ref

018371   Celik G;Ates S (Physics Dep, Faculty of Arts and Science, Selcuk Univ, Campus 42075 Konya, Turkiye, Email: gultekin@selcuk.edu.tr) : Investigation of the effect of expectation values for radii on the determination of transition probabilities using WBEPM theory. J Astrophys Astr 2008, 29(3-4), 367-78.

Transition probabilities for some excited s-p and p-s transition arrays of neutral nitrogen have been calculated using the weakest bound electron potential model theory (WBEPMT) for the investigation of effects of expectation values of radii. We have used both numerical non-relativistic Hartree-Fock (NRHF) wave functions and numerical Coulomb approximation (NCA) wave functions to calculate expectation values of radii. The transition probability results obtained using the parameters determined with two different wave functions agree well with each other and accepted values taken from NIST for low values of transition probability. However, the NRHF wave functions present better results for p-s transitions, while NCA wave functions are better in s-p transitions for large values of transition probability.

1 illus, 2 tables, 26 ref

018370   Bayrakceken F (Optical Spectroscopy Div, Biomedical Engineeringy Dep, Yeditepe Univ, Istanbul 34755, Turkey, Email: fubay@yeditepe.edu.tr) : Photochemical rearrangement and optical energy transfer studies for rubrene-rubreneperoxide system. Asian J Spectrosc 2008, 12(4), 121-30.

Sensitized fluorescence of rubrene is very interesting, if the sensitizer is rubreneperoxide, not only as a probe for the unknown characteristics of rubrene singlets, triplets and twisted excited states, but also the triplet-triplet absorption and emission of rubrene in different phases. Unfortunately unstable rubreneperoxide adduct formed in the dark, therefore, when one irradiates rubrene, unstable adduct, rubreneperoxide, becomes stable. Rubrene is sensitized by rubreneperoxide by using an excimer laser and emissions from rubrene were observed at 560 nm. Measured sensitized fluorescence decay time was found to be in between 16-23 nseconds depending on the phases, and the solyents. Two-photon absorption is also observed for rubrene at 1064 nm. Twisted "unrelaxed" singlet and triplet states lifetimes were in the microsecond time domain.

10 illus, 3 tables, 26 ref

018369   Baris B;Bayrakceken F;Bastas S A;Sarhancy E; Karaaslan I S (Physics Dep, Giresun Univ, Giresun, 28200, Turkey, Email: fubay@yeditepe.edu.tr) : Determination of nanostructured porous silicon in rock samples by energy dispersive fluorescence spectroscopy. Asian J Spectrosc 2008, 12(4), 131-5.

Silicon atomic fluorescence was excited within a carbon atomiser by high voltage (12 kV) discharge technique. Silicon atoms in different rock samples were excited to the upper electronic energy levels, then excited silicon atoms returned to the ground state by emitting characteristic fluorescence lines. Ail fluorescence transitions observed were resonance lines. Fluorescence lines of silicon were observed at 250.69, 251.43, 251.61, 252.41 and 252.81 nm, as intense discrete emission lines. These emission lines were calibrated by iron arc and mercury arc emission spectra.

2 illus, 1 table, 25 ref

018368   Bagade S M;Zatale D A;Rathod S T;Ghosh S A (Physics Dep, Govt. Institute of Science, Mumbai, Maharashtra) : Molecular interaction studies in binary liquid mixtures, comparison based on free length theory & revised free length theory. Acta Cienc Indica-Phys 2008, 34(4), 591-7.

The sound velocity (U) and density (ρ) of binary liquid mixtures of 1-butanol -pyridine and toluene-pyridine have been measured over the entire range of compositions at temperatures 303K, 313K and 323K. These data have been utilized to estimate free length (L_f), excess parameters i.e., excess volume (V^E), excess adiabatic compressibility (β_a^E), and excess free length (L_f^E). These excess values have been found to be useful in estimating the strength of the molecular interaction in the mixtures. The values of sound velocities and free length are also calculated theoretically by using Jacobson free length theory (FLT) and Kalidoss revised free length theory (RFLT). The comparison between theoretical and experimental values shows that in these mixtures RFLT is preferable to FLT.

3 illus, 2 tables, 12 ref

018367   Aloysius M;Mohan M;Suresh Babu S;Nair V S; Parameswaran K;Ksirhna Moorthy K (Sace Physics Laboratory, Vikram Sarabhai Space Center, Thiruvananthapuram-695 022, Email: mannil_mohan@ussc.gov.in) : Influence of circulation parameters on the AOD variations over the Bay of Bengal during ICARB. J Earth Syst Sci 2008, 117(S1), 353-60.

MODIS (Moderate Resolution Imaging Spectroradiorneter) level-3 aerosol data, NCEP (National Centers for Environmental Prediction) reanalysis winds and QuikSCAT ocean surface winds were made use of to examine the role of atmospheric circulation in governing aerosol variations over the Bay of Bengal (BoB) during the first phase of the ICARB (Integrated Campaign for Aerosols, gases and Radiation Budget) campaign (March 18-April 12, 2006). An inter-comparison between MODIS level-3 aerosol optical depth (AOD) data and ship-borne MICROTOPS measurements showed good agreement with correlation 0.92 (p < 0.0001) and a mean MODIS underestimation by 0.01. During the study period, the AOD over BoB showed high values in the northern/north western regions, which reduced towards the central and southern BoB. The wind patterns in lower atmospheric layers (> 850 hPa) indicated that direct transport of aerosols from central India was inhibited by the presence of a high pressure and a divergence over BoB in the lower altitudes. On the other hand, in the upper atmospheric levels, winds from central and northern India stretched south Bgtwards and converged over BoB with a negative vorticity indicative of a downdraft. These wind patterns pointed to the possibility of aerosol transport from central India to BoB by upper level winds. This mechanism was further confirmed by the significant correlations that AOD variations over BoB showed with aerosol flux convergence and flux vorticity at upper atmospheric levels (600-500 hPa). AOD in central and southern BoB away from continental influences displayed an exponential dependence on the QuikSCAT measured ocean surface wind speed. This study shows that particles transported from central and northern India by upper atmospheric circulations as well as the marine aerosols generated by ocean surface winds contributed to the AOD over the BoB during the first phase of IC ARB.

6 illus, 1 table, 28 ref

018366   Aksoy A (Physics King Fahad Univ of Petroleum and Minerals Dep, , P.O. Box 416, Dhahran 31261, Saudi Arabia, Email: aaksoy@kfupm.edu.sa) : Energy spectrum measurement of 14 MeV neutrons from the KFUPM 350 keV accelerator using activation foils. Asian J Spectrosc 2008, 12(4), 151-5.

The energy spectrum of fast neutrons produced in the T(d,n)⁴ He reaction with 150 keV deuterons was measured at the 350 keV accelerator of King Fahd University of Petroleum and Minerals (KFUPM) using the activation foil technique. The Zr and Nb foils were sandwiched between Al foils and were mounted at 0°, 70°, 90°, 110° and 150° with respect to the incident deuteron beam axis. The foils were irradiated for several hours. The neutron energies were determined from the intensities of 909 keV and 934 keV γ-lines of ⁸⁹Zr and ^92mNb isotopes. The measured energy distribution is in agreement with the published data within 1% uncertainty.

4 illus, 8 ref

017331   Sharma H;Parashar J;Gaur N K (Applied Physics Dep, Samrat Ashok Tehnological Institute, Vidisha-464 001, Email: j.p.parashar@gmail.com) : Self-distortion of a short laser pulse in a plasma. Curr Sci 2008, 95(6), 760-3.

Self-distortion of a high-intensity laser pulse due to relativistic effects propagating in a high-density plasma is investigated. As the pulse energy increases, its front portion expands and tail portion get compressed. The effect of nonlinearity outweighs the effect of dispersion.

3 illus, 23 ref

017330   Samir O M;Manjunath A;Parameswara P; Somashekarappa H;Somashekar R (Studies in Physics Dep, University of Mysore, Manasagangotri, Mysore-570 006, Email: rs@physics.uni-mysore.ac.in) : Micro-structural parameters of polymer materials using WAXS data: bimodals crystal size distribution. J Polym Mater 2008, 25(4), 529-40.

Line Profile Analysis (LPA) of polymer samples using single order method employing various bimodal functions for crystal size distributions have been carried out for the first time. The results indicate a better fitting with reduced errors due to truncation and background of a profile. Normally observed ripples in the tail of a simulated profile are reduced considerably in the present approach.

7 illus, 1 table, 25 ref 

017329   Rajneesh Kumar;Hundal B S (Mathematics Dep, Kurukeshetra Univ, Kurukeshetra, Haryana, Email: hundal_bs@yahoo.co.in) : Wave propagation in circumferential direction of fluid saturated incompreesible porous elastic cylindrical curved plates. Int J Mech Solids 2008, 3(1), 23-42.

The propagation of waves along circumferential direction in cylindrical curved plates of a fluid saturated incompressible porous material has been analyzed. The governing equations are simplified and solutions are obtained by using Bessel functions. The frequency equations connecting the frequency with circumferential wave number and other physical parameters are derived for stress free as well as for rigidly fixed cylindrical plates. The theoretical results are numerically discussed for a particular model.

9 illus, 47 ref

017328   Pal T K (NO, Research Centre Imarat, Hyderabad-500 069) : Series resistance of silicon millimeter wave (Ka-band) IMPATT diodes. Def Sci J 2009, 59(2), 189-93.

Describes a computer-based method to calculate the series resistance R₅ of a millimeter wave Ka-band packaged IMPATT diode from small signal conductance-susceptance characteristics. The series resistance R₅ has been calculated at the threshold condition when the small signal conductance of the packaged diode just becomes negative and the device susceptance becomes positive. Again, the value of series resistance R₅ has been determined from the measurement of threshold current and threshold frequency with the silicon Ka-band IMPATT diode embedded in a resonant cap cavity which agrees well with the values obtained by the computer method.

8 illus, 3 tables, 11 ref

017327   De A K;Roy D;Saha B;Goswami D (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: dgoswami@iitk.ac.in) : Simple method for constructing and calibrating an optical tweezer. Curr Sci 2008, 95(6), 723-4.

^ssc4 illus, 11 ref

016168   Valantina S Rubalya;Neelameagam P (Department of Physics, SASTRA University, Thirumalaisamudram, Thanjavur-613 402, Email: rvalantina@gmail.com) : Rheological behavior and oxidative stability of rice bran and corn oil using FTIR spectra. Int J pure appl Phys 0000, 4(1), 77-86.

In the food industry, rheological behavior and thermal degradation is the important parameters required to determine the quality and stability of food system. The rheological behavior and thermal degradation of rice bran and corn oil, is investigated ****. Redwood viscometer is used to measure viscosity at various temperatures. A 16F88 microcontroller based temperature controller is designed to measure and to keep the temperature of the oil at the desired temperature. The rice bran and corn oil exhibit Newtonian behavior during heating and cooling in the temperature range 30° to 90°C. The oils also exhibit Newtonian behavior even after heating to the frying temperature. A non-Newtonian characteristic is observed in sunflower oil due to rancidity that changes the complex chemical composition of oil. To characterize the cooking oils the structural study is carried out using FTIR spectra analysis and it is observed that the antioxidant activity is stronger in rice bran oil. The performance of Microcontroller based temperature controller is studied.

7 illus, 11 ref

016167   Singh J P;Prabakaran S (Management Studies Dep, Indian Institute of Technology Roorkee, Roorkee-247 667, Email: jatinfdm@iitr.ernet.in) : Quantum computing through quaternions. Int J pure appl Phys 2008, 4(1), 87-96.

The geometry of the single and two qubit states of quantum computing has been studied by using quaternions. Through the Hopf fibrations, identify geometric manifestations of the separability and entanglement of two qubit quantum systems.

15 ref

016166   Shomar T L (Human and Social Sciences Dep, Philadelphia Univ, Jordan, Email: T.L.Shomar@lse.ac.uk) : Phenomenologism vs fundamentalism: the case of superconductivity. Curr Sci 2008, 94(10), 1256-64.

Phenomenological treatment of physical problems is more powerful than fundamental treatment. Developments in the field of superconductivity present us with a clear example of such superiority. The BCS (Bardeen, Cooper and Schrieffer) was accepted as the fundamental theory of superconductivity for a long time. Nevertheless, Landau and Ginzburg gheno-menological model has so far proven to be a more fruitful theoretical representation to understand and to predict the features of superconductivity and superconductive material.

21 ref

016165   Shirali S A (NO, Rishi Valley School, Rishi Valley-517 353, Email: shailesh.shirali@gmail.com) : Algebraic methods in plane geometry, 3. Use of mappings. Resonance 2008, 13(12), 1156-72.

Examined the role of mappings in elementary geometry. After making some comments about the Erlangen programme initiated | by Felix Klein in 1872, wherein he proposed a] way of studying geometries based on the underly- ing transformation groups. See how theorems like Von Aubel's theorem and Napoleon's theorem can be proved in an elegant manner using similarity mappings, and how some construction problems may be solved using isometrics. At the end present a recent proof by Alain Connes of "Morley's Miracle", based on affine transfer- mations.

9 illus, 1 table, 4 ref

016164   Sharma S;Rajput S S;Jamuar S S (Physics and Electronics Dep, Jammu Univ, Jammu-180 006, Email: ssrajput@iiitm.ac.in) : Floating-gate MOS structures and applications. IETE Tech Rev 2008, 25(6), 338-45.

Floating-gate MOS transistor (FGMOS) has proved to be suitable for low-voltage analog applications, owing to its threshold voltage programmability. Paper presents FGMOS based circuit structures and their applications in analog signal processing. The FGMOS based current mirror and its application as voltage controlled current source has been presented. The performance of these structures has been verified using PSpice simulations for 0.5 μm CMOS technology at ±0.75 V.

20 illus, 15 ref

016163   Paul B S;Bhattacharjee R (ECE Dep, Indian Institute of Technology, Guwahati, Assam-781 039, Email: babusena_paul@yahoo.com) : MIMO channel modeling. IETE Tech Rev 2008, 25(6), 315-19.

Channel modeling plays an important role in understanding the behavior and designing of communication systems for different environments. A brief review of the different channel modeling techniques used to model a multiple-input-multiple-output wireless channel.

^iia4 illus, 15 ref

016162   Padmanabhan T (IUCAA, Pune Univ Campus, Post Bag 4, Ganeshkhind, Pune-411 007, Email: paddy@iucaa.ernet.in) : Snippets of physics. X. Thermodynamics of self-gravitating particles. Resonance 2008, 13(10), 941-50.

Statistical mechanics of a system of particles interacting through gravity leads to several counter-intuitive features. One of them, called Antonov instability, in this installment in explored.

4 ref

016161   Padmanabhan T (IUCAA, Pune Univ Campus, Post Bag 4, Ganeshkhind, Pune-411 007, Email: paddy@iucaa.ernet.in) : Snippets of physics, 12. Paraxial optics and lenses. Resonance 2008, 13(12), 1098-1106.

Discovering unexpected connections between completely different phenomena is always a delight in physics. In this and the next installment, we will look at one such connection between two unlikely phenomena: propagation of light and path integral approach to quantum mechanics.

1 illus, 1 ref

016160   Ommai F;Nekofar K (Faculty of Engineering, Department of Mechanic, Tarbiat Modares University, Tehran, Iran, Email: fommi@modares.ac.ir) : New approaches to equilibrium thermodynamics. Int J pure appl Phys 2008, 4(1), 53-63.

The problem of quantum gravitation is transferred in the field macro-quantum gravitation and there is resolved within the framework of the nonlocal version of classic thermodynamics. Last one makes provision for elimination the "model" traces of continuous medium from mermodynamic phenomenology and transition to the discrete space- time metric. Such routine together with usage of physical initial principles is equivalent to macro -quantization of gravitational fields for classic, homogeneous and isotropic thermodynamically equilibrium material medium. It is established that a state, which one the classic thermodynamics accepts for equilibrium. Actually is only very good approximation of description the spontaneous process of temperature fall and entropy. In a usual term it is the strongly braked process, so the realization of "perpetuum mobile" on this basis is possible only in space - time scale of Universe. The opening opportunities of a new methodological fundamental are illustrated on the examples from a cosmology. (The nature of Big Bang, the arrow of time, black holes, etc.) The data of experiments and observations for the benefit of the viewed version are presented.

18 ref

016159   Manjunath M S;Sannappa J (Department of Physics and Electronics, Yuvaraja's College, University of Mysore, Mysore-570 001, Email: manjumsphy@yahoo.com) : Molecular association of amides with 1-propanol in non-polar solvent: dielectric study. Int J pure appl Phys 2008, 4(1), 71-6.

Experimental results of dielectric investigations of X-band microwave bench at 9.86 Ghz for amides (Foramide, N-methylforamide and N, N-dimethylformaide) with 1-propanol have been studied in carbon tetrachloride at 303 K. The relaxation time has been determined using the measured dielectric data. The results show that carbonyl group of amide and alkyl chain-length of both the alcohols and amides plays an important role in the determination of the strength of hydrogen bond (O-H:O=C) formed. The most likely association between alcohol and amides is 1:1 complex through the free hydroxyl group of the alcohol and the carbonyl group of amide and the results show a linear dependence of relaxation time on alkyl chain length of alcohols and alkyl amides and also on the nature of the solvent.

2 illus, 3 tables, 11 ref

016158   M Mousavi-baygi (NO, Ferdowsi University of Mashhad, Iran, Email: mousavi500@yahoo.com) : Implementation of fog water collection systems in northeast of Iran. Int J pure appl Phys 2008, 4(1), 13-21.

The study is the evaluation of the possibility of obtaining water for different uses of the local population (domestic, agricultural, cattle rising and forestry), by means of fog collectors. The instruments used during this study were fog collectors of different sizes and shapes, meteorological instruments and visual measurements of the fog. The experiments indicated fog water collection holds considerable potential as an alternative water source in the mountainous area. It is feasible to obtain an average water production of 0.53 1 m^-2 day^-1. The maximum amount of water collected in a day was 3.3 1m^-2 day^-1. The numbers and size of the modules chosen will depend on local topography and the quality of the materials used in the panels. According to the research of that multiple nylon mesh system can absorb and collect more water than a comparable plain system, we may build a complex structures machine that can collect more water. Alternatively, the collectors may be more complex structures, made up of a series of such collection panels joined together. The complete system can be easily built or assembled on site. Installation and connection of panels is quick and simple.

6 illus, 1 table, 10 ref

016157   Kuryan S;Abrahan R;Isac J (St. Stephen's College, Kollam, Kerala, Email: renykuryan@rediffmail.com) : Microwave studies on gadoliniium barium coppr oxalate crystals. Int J pure appl Phys 2008, 4(1), 45-51.

Rare earth compounds are recognized for outstanding physical, magnetic, electrical and optical properties. Using cavity perturbation technique dielectric parameters of the sample such as complex permittivity and conductivity at microwave frequency were determined. Using X-ray diffraction study the crystalline nature of the sample was established. Photoconductivity studies of the Gadolinium Barium Copper Oxalate (GdBaCuOx) crystals revealed the negative photo conducting nature.

5 illus, 12 ref

016156   Kishan Kumar V S;Gupta S;Sharma C M (Forest Products Div, Forest Research Institute, Dehra Dun) : Vacuum press drying of Populus deltoides. Indian For 2008, 134(6), 835-42.

Studies were taken up on one-inch thick samples of Populus deltoides to understand its drying behaviour under vacuum press drying. The experiment was conducted under eight different vacuum levels and temperature combinations. The results were analysed to understand which combination gives maximum drying rates in terms of moisture content reduction in various MC ranges. It was found that the samples could be dried to less than 15% MC levels from 90% MC levels effectively in two steps. No serious drying degrades were observed in the samples in spite of taking them through different drying cycles.

12 tables, 9 ref

016155   Joardar S;Bose S K;Sarkar S;Bhattacharya A B (Physics Dep, Kalyani Univ, Kalyani-741 235, Email: somareplyme@rediffmail.com) : Low-frequency radio spectrograph for capturing Jovian radio bursts in tropical and equatorial regions. IETE J Res 2008, 54(6), 391-5.

It is well known that the planet Jupiter produces strong radio bursts in very high frequency band (decametric wavelengths) from regions of temporary radio emission in its magnetosphere. These are of interest to scientists and engineers for studying the effects of the emission on the Earth's environment. Till now, most of the Jovian burst detectors were more or less complicated to build. Here a simple but effective instrument built by us for capturing these bursts and recording them for further analysis. It uses a moderately wide band antenna, a spectrum analyzer and a data recording system. The data recording is done on a printed circuit (PC), interfaced to the spectrum analyzer using a general purpose interface bus (GPIB) setup. The antenna primarily focuses on a bandwidth between 18 to 25 MHz, which is the best possible interference-free frequency band, and which contains major information from the planet Jupiter, at decametric wavelengths. The mathematical analysis has been included. Some Jovian radio bursts, captured using this instrument, is presented with possible scientific outcomes.

4 illus, 2 tables, 12 ref

016154   Hasanov E R;Novruzov M F;Panahov A Z;I Demirel A (Baku State University, 23 Z. Khalilov str., Az 1148, Baku city Physical Institute of the Azerbaijan National Academy of Sciences, 33 H. Javid ave., Az 1143, Baku ci) : Instability of thermomagnetic waves in the GeAu semiconductors with impurities. Int J pure appl Phys 2008, 4(1), 23-8.

The thermomagnetic waves theory in the semiconductors with impurities is constructed. It is shown that the thermomagnetic waves' frequency depends on a frequency of the current carriers recombination and in the concrete conditions the recombination wave suppresses the thermomagnetic waves.

8 ref

016153   Gour A;Singh S;Singh M;Singh R K (Physics Dep, Barkatullah Univ, Bhopal-462 016, Email: atul_gour@rediffmail.com) : Theoretical analysis of high pressure phase transition and stability of LaTe and SmTe with NaCl-structure. Int J pure appl Phys 2008, 4(1), 29-38.

Predictes the phase transition pressures and corresponding relative volume change of LaTe and SmTe having NaCl- type structure under high pressure using three body interaction potential (TBIP) approach and found better results with TBIP. In addition we have checked the conditions for relative stability in terms of modified Born certerion and also found that LaTe and SmTe follow the universal equation of state described by Vinet et al.

4 illus, 3 tables, 23 ref

016152   Giri A K (Physics Dep, Punjabi Univ, Patiala-147 002, Email: aanjan98@yahoo.co.in) : Unparticle - the unconventional stuff: not a typo. Curr Sci 2008, 94(10), 1241-3.

A new high energy machine is going into operation right away, named as the Large Hadron Collider, with a truly international collaboration, where sophisticated particle physics experiments will be taken up. Hope-fully, will discover many expected particles and verify many phenomena in particle physics and as a byproduct may be we will find some new particles or see something un-expected. In 2007 unparticle was added to the wish list and we in this paper present the path leading to the inception of the idea, discuss the basic features and the prospects of it being detected at the upcoming experiments.

10 ref

016151   Dey D;Islam M N;Hussain S A;Bhattacharjee D (Physics Dep, Tripura University, Suryamaninagar-799 130, Email: dh_dey@rediffmail.com) : Layer by layer (LbL) technique for fabrication of electrostatic self assembled ultrathin films. Int J pure appl Phys 2008, 4(1), 39-44.

Layer by Layer (LbL) technique is a unique way for fabricating ultrathin nanostructured electrostatic self assembled films of water soluble material with controlled layer structure and lattice parameters etc. LbL films have many technical applications in the field of molecular electronics and biotechnology. Reports the early development, technology and application of LbL films along with national and international status of this newly booming technique for the fabrication electrostatic Self Assembled ultrathin films.

1 illus, 12 ref

016150   Bhan R K;Dhar V (Solid State Physics Laboratory, , Lucknow Road, Delhi-110 054, Email: bhan/sspl@ssplnet.org) : Transition from CCD to CMOS cameras. Indian Sci Cruiser 2008, 22(3), 27-34.

Modern digital photography is nowadays connected with a variety of applications from simple photography to recent pictures captured from Mars. With advancing technology in cameras, CMOS is taking over from CCD. Nevertheless, CCDs will survive in high-end niches. Reviews the differences between the two and compare many aspects to guide the user in deciding the CCD vs. CMOS option.

10 illus, 2 tables

016149   Alvi M A (Department of Physics, Science Faculty, King Abdulaziz University, Jeddah-21589, Saudi Arabia, Email: alveema@hotmail.com) : Analytical expression for p-<. Int J pure appl Phys 2008, 4(1), 65-70.

Applying Coulomb correction factor to the Glauber multiple scattering model an analytical expression has been derived for microscopic study of pmton-³He total reaction cross section. Using independent single particle model for the density of ³He, reasonably good account of the data has been achieved.

1 ilus, 16 ref

016148   Ahmed S A;Diab A K;Abdel Hakeem A M (Girls College of Education, P.O. Box 3137, Unaizah 51911, Qassim-Kingdom of Saudi Arabia, Email: Saadzf2003@yahoo.com) : Density of states effective mass of SnBi₄Se₇ deduced from the temperature dependence of electrical conductivity in the activation regime. Int J pure appl Phys 2008, 4(1), 1-12.

Current-voltage (I-V) measurements on polycrystalline samples of Bi₂Se₃ and stoichiometric ternary compound in the quasi-binary system SnSe-Bi₂Se₃ at different temperatures in the vicinity of room temperature have been performed. Also, temperature dependence of electrical conductivity has been measured. From the analysis of the temperature dependence of electron concentration in the activation regime above room temperature, the density of states effective mass m* has been determined. Some intrinsic and contact properties such as barrier heights, ideality factors and carriers concentrations have been investigated using I-V characteristics. It has been found that all samples exhibit ohmic and space charge limited conduction at low and high fields, respectively.

5 illus, 1 table, 36 ref

016147   Acharya D P;Panda G (Electronics and Communication Engineering Dep, National Institute of Technology, Rourkela-769 008, Email: ganapati.panda@gmail.com) : Independent component analysis techniques and their applications. IETE Tech Rev 2008, 25(6), 320-32.

Independent Component Analysis, a computationally efficient blind statistical signal processing technique, has been an area of interest for researchers for many practical applications in various fields of science and engineering. The present paper attempts to treat the fundamental concepts involved in the independent component analysis (ICA) technique and reviews different ICA algorithms. A thorough discussion of the algorithms with their merits and weaknesses has been carried out. Applications of the ICA algorithms in different fields of science and technology have been reviewed. The limitations and ambiguities of the ICA techniques developed so far have also been outlined. Present different ICA algorithms from their basics to their potential applications to serve as a comprehensive single source for an inquisitive researcher to carry out his work in this field.

^iia3 illus, 57 ref

015111   Sudhakar Reddy B;Buddhudu S (Physics Dep, Sri Venkateswara University, Tirupati-517 502, Email: sudhakar_b9@rediffmail.com) : Optical characterization of Nd<. Indian J Phys 2008, 82(7), 871-83.

Highly transparent, moisture resistant and brightly pale violet coloured Nd3+ ions dope luorophospho-borate glasses. By applying the Judd-Otelt intensity parameters ot Nd ions doped fluoro-phospho-borate glasses, radiative properties ot the emission transitions (⁴F_3/2 → ⁴/_{j=9/2, 1/2 and 13/2}) at 906, 1079 and 1349 nm have been evaluated. Series-A and series-B glasses, that contain TeO₂ have revealed encouraging emission and absorption results. Suggests that 69.8 B₂O₃ -10P₂O₅ -10TeO₂ -10AIF₃ from Series-A and 69.8 B₂O₃ -10P₂O₅ -10T_eO₂ - 10 Lif from Series-B, as two novel and potential Nd³⁺ glasses to produce strong and intense emission performance at 1079 nm.

5 illus, 4 tables, 38 ref

015110   Sinha S;Santra S B (Physics Dep, Indian Institute of Technology Guwahati, Guwahati-781 039, Email: ssinha@iitg.ernet.in) : Finite-size scaling theory for anisotropic percolation models. Indian J Phys 2008, 82(7), 919-27.

Finite-size scaling (FSS) theory for anisotropic percolation models is rarely studied. A simple FSS theory is developed here for anisotropic percolation models considering the cluster size distribution function as a generalized homogeneous function of the system size L and two connectivity lengths ξ|| and ξ⊥. The scaling theory predicts a new FSS function form for the cluster related quantities in terms of the anisotropic exponent θ = v||/v ⊥ where v || and v⊥ are the connectivity exponents in the longitudinal and transverse directions respectively and a set of new scaling relations are obtained. In the directed percolation (DP) and directed spiral percolation (DSP) models, the clusters generated are anisotropic and they are called anisotropic percolation models. The FSS theory developed here is verified applying to the DP and DSP models.

4 illus, 10 ref

015109   Singh A K;Philip A T;Mohan Lal (Electronics and Instrumentation Dep, BITS-Pilani, Goa Campus, NH17B Bypass Road, Zuarinagar, Goa-403 726, Email: 2005135@bits-goa.ac.in) : Development of automatic electronic load circuit for I-V curve measurement of solar cells. J Coop Univ Res Ind Enterpr 2009, 2(1), 49-56.

Aims at the automated I-V characterization of solar cells using a power MOSFET based electronic load and a PIC microcontroller based interfacing circuit. The load circuit used is a dynamic electronic load that uses a power MOSFET biased in its linear region. A unity gain Op-amp is used to provide the appropriate voltage to the gate of the MOSFET so that it acts as a varying resistance, driving the current in the circuit. A microcontroller (PIC16F873) based circuit was used to measure the current and voltage levels, digitize it, and transmit them over RS232 cable using the USART protocol. An open-source cross-platform software for plotting the I-V curve was also developed. The program uses the OpenGL API to display primitives.

4 illus, 11 ref

015108   Sahu D K;Khare P K;Yadav V S (Physics Dep, Institute of Basic Sciences, Bundelkhand University, Jhansi-284 128, Email: dkpolymer_2003@yahoo.co.in) : Steady state conduction current of polyvinylidene fluoride film electrets. Indian J Phys 2008, 82(7), 843-53.

Steady state conduction current in solution grown polyvinylidene fluoride (PVDF) films (about 20 μm thick) was investigated with different poling fields (10-100 kV cm^-1) as a function of temperature in the range 40-80°C. The steady state current showed a strong dependence on temperature. To identify the possible mechanism of conduction, current versus square root of field characteristics were drawn with aluminium and silver electrodes. The current-electric field characteristics show two regions of conduction with a slope of curve 1.2-1.5 at lower and with a slope 1.97-2.00 at higher fields. The current-electric field characteristics are analyzed and quantitative information about the transport parameters is derived. The result of current-electric field measurements on PVDF film electrets have been interpreted to show that the Richardson mechanism alongwith space-charge limited conduction is the controlling mechanism. The other mechanism for the non linear behaviour e.g. field assisted injection or Poole-Frenkel (PF) mechanism is excluded.

8 illus, 3 tables, 27 ref

015107   Sachs M (NO, University at Buffalo, State University of New York, USA, Email: msachs@buffalo.edu) : Entropy and objective reality. Indian J Phys 2008, 82(7), 907-11.

^ssc4 ref

015106   Rezaei Ochbelagh D (Physics Dep, University of Mohaghegh Ardabili, P.O. Box 179, Andabil, Iran, Email: ddrezaey@yahoo.com) : Investigation of collimator effect of full-width at half-maximum of NaI(TI) detector. Asian J expl Sci 2009, 23(1), 357-62.

The interaction process of gamma rays in various media results in complete absorption, elastic scattering and inelastic scattering of incident photons. Photon interactions are due to photoelectric effect, Compton scattering and pair production processes. There are higher-orders processes occur due to large number of secondary radiation produced in the first encounter and are known as multiply Compton scattered radiations. Collimator dimension and interaction probability of radiation play important role on Compton scattered radiation counts. In this study the Monte Carlo simulation used for generation of theoretical data. Therefore, at the first the system geometry has been defined by Monte Carlo simulation. Two 137CS gamma apart sources and a NaI(Tl) detector with 2" diameter used to study collimator effect on FWHM (full-width at half-Maximum). Theoretical results show, the FWHM is function of geometrical arrangement radioactive sources and detector, collimator dimension. The present study depicted optimum thickness for lead collimator with a 3mm diameter bore radius (circular section parallel holed) is 2cm. These results have been obtained by 2" NaI(Tl) detector. There are different approaches to account for the multiply scattering of gamma rays in a material. It is difficult to determine collimator dimensions due to complicated nature of the scattering process and differing geometrical constraints. Monte Carlo methods can be used to determine different parameters such as bore radius of collimator and distance of detector from source. In order to obtain optimize FWHM on a detector type the proper bore radius must be defined for each collimator thickness.

6 illus, 11 ref

015105   Rai S B;Singh S K (Laser and Spectroscopy Lab, Physics Dep, Banaras Hindu University, Varanasi-221 005, Email: sbrai49@yahoo.co.in) : Optogalvanic detection of NaNe and Na₂ in a hollow cathode lamp. Indian J Phys 2008, 82(7), 885-90.

NaNe and Na₂ molecules have been detected in a hollow cathode lamp containing Na and Ne by using the optogalvanic technique. A broad band continuum ascribed to NaNe molecule is seen superposed with atomic lines of Ne at an applied voltage <150 volts. Increasing the voltage beyond 150 volts showed the appearance of discrete bands ascribed to Na₂. If the voltage exceeds 170 volts, atomic lines due to Ne and Na predominate.

3 illus, 1 table, 16 ref

015104   Nath P P;Joarder R N (Engineering Physics Dep, Bengal Institute of Technology, Kolkata-700 150, Email: rnjoarder@yahoo.co.in) : Dynamical structure of liquid LiNa alloy. Indian J Phys 2008, 82(7), 913-17.

Dynamical structure factors of liquid LiNa alloy are calculated in the visco-elastic approximation using static properties like effective pair potential and static structure factors. The results are compared with inelastic neutron scattering (INS) and molecular dynamics (MD) simulation results. The specific features are discussed. It is clearly shown that the effect of the concentration variation on the dynamical structure is small though the corresponding effect on the static structure is quite large.

^ssc4 illus, 12 ref

015103   Melagiriyappa E;Jayanna H S;Chougule B K (Physics Dep, Kuvempu University, Shankaraghatta-577 451, Email: jayanna60@yahoo.co.in) : Structure and DC conductivity studies of Sm<. Indian J Phys 2008, 82(7), 863-9.

Polycrystalline ferrites having the general formula Mg_1-xZn_xFe_2-ySM_yO₄ (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y= 0.0, 0.05, 0.1) were prepared by standard ceramic method. The samples were characterized by XRD, IR, SEM, and EDAX techniques. The single-phase spinel formation of ferrites was confirmed by X-ray diffraction technique. The DC electrical conductivity of the pelletized samples was measured by two-probe method in the temperature range 300 K to 800 K. The experimental results reveal that the DC conductivity increases as temperature increases and as the Zn²⁺ and Sm³⁺ ion content decreases. The electrical conduction mechanism in these ferrites is due to electron hopping between Fe²⁺ and Fe³⁺ ions on octahedral sites. The activation energy for ferrimagnetic region is lower than that in paramagnetic region. The addition of Sm³⁺ impedes conduction in samples. Thus, the activation energy is higher for Sm³⁺ substituted samples than those for the corresponding undoped samples in both the regions.

3 illus, 2 tables, 31 ref

015102   Kaushal R S (Physics Dep, Ramjas College (University Enclave), Delhi-110 007, Email: rkaushal@physics.du.ac.in) : Model for quark-gluon plasma with pentaquark baryons and tetraquark mesons. Indian J Phys 2008, 82(7), 891-906.

With a view to exploring a new kind of phase transition in the process of hadronization of quark gluon plasma (QGP) investigates the occurrence of pentaquark baryons and tetraquark mesons in the system. For this purpose, an analogue of Saha's ionization formula for the colored ions in the system is used. The study of color-ionic-fraction (CIF) of multiple (color) ionized to unionized quark clusters (termed as "quarkons") as a function of temperature is carried out. It is pointed out that not only the temperature of the fire-ball in the relativistic heavy ion collisions evolves with respect to space and time but also the CIF associated with a particular stage of ionization. Further, for the case of single color-ionization a correspondence of the present results with those available for the bubble nucleation mechanism in QGP is demonstrated.

4 illus, 1 table, 25 ref