001148   Narula A K;Chauhan R P;Chakarvarti S K (Physics Dep, RKSD College, Kaithal-136 027, Email: anilnarulaktl@gmail.com) : Testing permeability of building materials for radon diffusion. Indian J pure appl Phys 2010, 48(7), 505-7.

The diffusion coefficient and length for some building construction materials like limestone powder, sandstone, granite, crasher, soil, sand, cement, fly ash, gypsum, wall putty have been calculated. The diffusion of radon gas through these materials has been carried out under a control study. Uranium ore has been used as radon source and LR-115 solid-state nuclear track detectors are used to record alpha tracks due to diffusion of radon at different heights from the source. The results indicate that the diffusion coefficient and length of radon gas in building materials are the measure of its permeability through that medium

2 illus,1 table, 9 ref

001147   Nandy M;Lahiri C;Sarkar P K (NO, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata-700 064, Email: maitreyee.nandv@saha.ac.in) : Radation environment in low energy accelerator for astrophysical studies. Indian J pure appl Phys 2010, 48(7), 478-81.

Transmitted dose through different thicknesses of ordinary concrete placed at different distances from the target has been evaluated using simple Moyer model. It has been observed that though the projectile energy is low, significant neutron and gamma doses are produced at beam currents as high as 500 |lA for protons. Some radioisotopes with half-lives of the order of a few months are produced with activities of the order 10^{10-1011 Bq.}

4 illus, 1 table, 4 ref

001146   Melnitchouk W (NO, Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, VA 236 06, USA, Email: wmelnitc@jlab.org) : Pion cloud and the sea of the nucleon. Indian J Phys 2009, 83(5), 617-28.

Reviews recent progress in understanding the structure of the nucleon sea and the role of the nucleon's pion cloud. In particular, I discuss the consequences of the pion cloud for the d - U asymmetry in the proton, the neutron's electric form factor, and the proton's electric to magnetic form factor ratio.

3 illus, 37 ref

001145   Mehrez Z;Bouterra M;Cafsi A E;Belghith A; Quere P L (NO, Faculte des Sciences, de Tunis-Campus Univ, Tunis, Tunisie-10 60, Email: mehrez zouhaier@yahoo.fr) : Numerical study of the effect of a periodic disturbance on the local heat transfer in turbulent separated and rattached flow over a backward-facing step. J Energy Heat Mass Transfer 2009, 31(3), 157-68.

Large Eddy Simulation (LES) is used to investigate the effects of a periodic disturbance on the local heat transfer in the separated and reattached flow behind a backward-facing step. The disturbance is provoked by a sinusoidally blowing /suction of the fluid into a separated shear layer. The Reynolds number is fixed at 33000 and Richardson number at 0.5. The disturbance frequency is varied in the range 0 ≤St ≤ 2, where St is the Strouhal number of disturbance. The obtained results revealed the existence of an optimum perturbation frequency value, St = 0.25, in terms of the reduced reattachment length. At this frequency the heat transfer is significantly enhanced in the recirculation zone. The influence of the frequency and the amplitude of disturbance, in the maximum heat transfer positions and the maximum Nusselt number, is analysed.

8 illus, 13 ref

001144   Mathur A K;Rajesh Kumar;Mishra M;Ali S A; Sonkawade R G;Singh B P;Bhardwaj V N;Rajendra Prasad (Applied Physics Dep, Faculty of Engineering & Technology, Aligarh Muslim Univ, Aligarh-202 002) : Radon exhalation rate and natural radioactivity in soil samples collected from east Sighbhum shear zone in Jaduguda U-mines area, Jharkhand, India and its radiological implications. Indian J pure appl Phys 2010, 48(7), 486-92.

Sealed can technique was adopted for radon exhalation measurements in soil samples collected from some areas around the East Singhbhum shear zone in U-mining area of Jharkhand state of India. Radon activity varies from 3794.3 to 4891.4 Bqm^{-3 with an average value of 4368.6 Bqm-3 while radon exhalation rate varies from 1364.1 to 1758.6 mBqm-2 h-1 with an average value of 1573.8 mBqm-2h-1 Activity concentrations of naturally occurring radionuclides (238U, 232Th and 40K) were also measured in these soil samples using high resolution γ-ray spectroscopic system. Activity concentrations were found to vary from 6.1 ± 0.2 to 826.3 ± 8.5 Bq kg-1 for 238U, 8.7 ± 0.3 to 236.7 ± 3.2 Bq kg-1 for 232Th and 291.5 ±4.4 to 1391 ± 14.3 Bq kg-1 for40K. From the activity concentration of 238U, 232Th and 40K in these soil samples, the radium equivalent activity (Ra_eq) due to the presence of radionuclides is calculated and it varies from 34.0 to 924.5 Bq kg-1 with an average value of 260.4 Bq kg-1. Total absorbed gamma dose rates in the surrounding air are found to vary from 15.1 to 402.0 nGyh-1 with an average value of 120.8 nGyrT-1. The indoor and outdoor annual effective dose rates from these soil samples are determined from 0.1 to 1.9 mSv y-1 and 0.03 to 0.8 mSv y-1, respectively. External hazard index, H_ex for the soil samples studied in this work ranges from 0.14 to 2.46 with a mean value of 0.70. The internal exposure to 222Rn and its radioactive progeny are controlled by the internal hazard index Hin Computed values of Hvary from 0.2 to 4.8 with an average value of 1.02. V.}

2 illus, 4 tables, 19 ref

001143   Mallik S;Sarkar S (Theory Div, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064, Email: mallik@theory.saha.emet.in) : Spectral representation and QCD sum rules in hot nuclear matter. Indian J Phys 2009, 83(5), 629-43.

Authors construct the spectral representation of spinor two-point functions in medium, that is, at finite temperature and chemical potential. We first deal with the free spinor two-point function. Then we construct the same for interacting fields leading to the Kdllen-Lehmann representation. It is emphasised that although these two point functions have the structure of 2 x 2 matrices in the real time formulation of field theory, any one component actually suffices to describe the dynamics of the system. Our construction is then applied to write the QCD sum rules for two-point function of nucleon currents in medium. We discuss a subtracted version to increase the sensitivity of such a sum rule and point out how it differs from a conventional one.

2 illus, 13 ref

001142   Kerm A (Physics Dep, College of Science, Al Jouf Univ, P.O. Box 2014m Skaka, Kingdom of Saudi Arabia) : Some properties of aluminum oxide Al₂O₃ irradiated with heavy ions. Int J pure appl Phys 2009, 5(3), 231-7.

The Optical, Mechanical and Thermoluminescence properties of Single Aluminum Oxide crystal A₂O₃ irradiated with heavy ions with energy about 1 MeV ion/amu are considered. The results will show that the optical absorption of the irradiated sample exhibits two peaks; a well resolved one at around 200 nm and another unresolved one around 260 nm. They will also show that the relative hardness increases with increasing ion doses and reaches a nearly constant value. The results will show that the Thermoluminescence exhibits different peaks at different temperatures for different ion doses.

5 illus, 10 ref

001141   Kaushik C P;Shah J G (Waste Management Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085) : Challenges in development of matrices for vitrification of high level radioactive waste. BARC Newsl 2010, (May-Jun), 20-7.

Majority of radioactivity in entire nuclear fuel cycle is concentrated in HLW. A three step strategy for management of HLW has been adopted in India. This involves: i) immobilization of waste oxides in stable and inert solid matrices, ii) interim retrievable storage of the conditioned waste under continuous cooling and iii) disposal in deep geological formations. Glass has been accepted as most suitable matrix world-wide for immobilization of HLW because of its attractive features like ability to accommodate wide range of waste constituents, modest processing temperatures, adequate chemical, thermal and radiation stability. Borosilicate matrix developed by BARC in collaboration with CGCRI has been adopted in India for immobilization of HLW. In view of compositional variation of HLW from site to site, tailor make changes in the glass formulations are often necessary to incorporate all the waste constituents and having the product of desirable characteristics. The vitrified waste products made with different glass formulations and simulated waste need to be characterized for chemical durability, thermal stability, homogeneity etc. before finalizing a suitable glass formulation. The paper summaries the studies carried out for development of glass formulations for vitrification of HLW having wide variation in their compositions.

11 illus, 3 tables, 4 ref

001140   Kant K;Rashmi;Kuriakose S;Sonkawade R G; Chauhan R P;Chakarvarti S K;Sharma G S (NO, Aggarwal College, Ballabgarh-121 004, Email: kkant_67@rediffmail.com) : Radon activity and exhalation rates in India fly ash samples. Indian J pure appl Phys 2010, 48(7), 457-62.

Fly ash is the by-product of burnt coal which is naturally occurring radioactive material (NORM). Because of human activity and its use in manufacturing of bricks, sheets, cement, land filling etc may present a radiation hazard to people and the environment Thus, it is very important to carry out radioactivity measurements in fly ash from the health and hygiene point of view In the present study, the activity concentrations of ^{238U, 232Th and 40K have been varied from 99 ± 2 to 203 ± 4 Bq/kg, 145 ± 2 to 288 ± 4 Bq/kg, and 355 ± 5 to 516 ± 6 Bq/kg, respectively in various fly ash samples The radium equivalent activity was varied from 317 to 614 Bq/kg, radon activity varied from 214 to 590 Bq/m3, radon exhalation rate varied from 7.8 to 21.6 mBqkg-1 h-1 for mass exhalation rate and from 138 to 381 mBqm-2h-1 for surface exhalation rate in the fly ash samples used in the present investigation The absorbed dose varied from 143 to 277 nGyh-1, the indoor annual effective dose varied from 0.70 to 1,36 mSv and the outdoor annual effective dose varied from 0.17 to 0.34 mSv In all the samples, the activity concentration of 238U, 232Th and 40K was found to be below the permissible levels A strong positive correlation has been observed between uranium concentration, radon activity and radon exhalation rate.}

2 illus, 1 table,33 ref

001139   Kant K;Kuriakose S;Rashmi;Sharma G S (NO, Aggarwal College, Ballabgarh-121 004) : Radon activity and radiation level in the slate mines in Arvali range in India. Indian J pure appl Phys 2010, 48(7), 463-5.

Radon activity in slate mines in the aravali range in Haryana was measured to protect the occupational workers and general public from radiation. The alpha sensitive LR-115 type II plastic track detectors (solid state nuclear track detectors) were used for the measurements. Results of various measurements of the radon activity and inhalation dose received by the workers have been reported. The radon activity and the annual inhalation dose in the environment of various slate stone mines in Haryana varied from 21 to 113 Bq m^{-3 with an average of 38.5 ± 5.8 Bq m-3 and 0.37 to 1.94 mSv with an average of 0.66 ± 0.10 mSv, respectively. Seasonal variation of radon activity has also been studied and reported.}

2 tables, 18 ref

001138   Kansal S;Mehra R;Singh N P;Badhan K;Sonkawade R G (Physics Dep, Giani Zail Singh College of Engineering and Technology, Bathinda, Email: skansal2k1@yahoo.com) : Analysis and assessment of radiological risk in soil samples of Hisar district Haryana, India. Indian J pure appl Phys 2010, 48(7), 512-5.

The activity concentrations and the gamma absorbed dose rates of radio nuclides in soil samples collected from different locations of Hisar district of Haryana have been determined for the first time using HPGe detector based on high-resolution gamma spectrometry system. The range of activity concentrations of ^{226Ra, 232Th and 40K in the soil from the studied areas varies from 13.37 (Ganguwa) to 21.43 Bq kg-1 (Khefi), 34.67 (Nehla) to 54.43 Bq kg-1 (Ganguwa) and 298.78 (Dhansu) to 398.78 Bq kg-1 (Nehla) with overall mean values of 17.79, 45.45 and 359.96 Bq kg-1, respectively. The absorbed dose rate calculated from activity concentration of 236Ra, 234>Th and 40K ranges between 6.16 and 9.88, 21.6 and h-1 with an average value of 51.42 nGy h-1. The calculated values of external hazard index (H_ex) for the soil samples of the 33.91, and 12.37 and 16.51 nGy h-1, respectively. The total absorbed dose in the study area ranges from 45.83 to 57.15 nGy h-1 with an average value of 51.42 nGy h-1. The calculated study area range from 0.26 to 0.33, which is less than unity.}

2 illus, 2 tables, 13 ref

001137   Kalugasalam P;Ganesan S (Physics Dep, Tamil Nadu College of Engineering, Coimbatore) : Thermally induced phase transition in crystalline lead phthalocyanine thin films. Int J pure appl Phys 2009, 5(3), 243-51.

The structural properties of thin film of Lead Phthalocyanine (PbPc) on a glass substrate is prepared by vacuum deposition method. The thickness of the films were 150nm, 300nm and 450nm. The effect of film thickness, structural and annealing of the Lead Phthalocyanine thin films are investigated by X-ray diffraction and Scanning Electron Microscopy (SEM). The results obtained from X-ray diffraction measurement indicate the monoclinic structure with a (001), (320), (111) and (420) orientation and triclinic structure with (400) orientation. Thickness of 450 nm is annealed at 323 K and 373 K. The film consist of triclinic (200), (300) and (400) phases for 323 K annealed sample and (100) reflection of triclinic phase for 373 K annealed sample. SEM is one of the best tools to investigate the surface smoothness and to find the grain size of the particles. From the image it is evident that the surface of the films is smooth and grain size is less than a micrometer.

4 illus, 22 ref

001136   Islam M T;Saha S;Ali M;Islam M Q;Saha G (Mechanical Engineering Dep, Bangladesh Engineering and Technology Univ, Dhaka, Bangladesh-1000) : Mixed convection heat transfer characteristics in a channel with an open cavity. J Energy Heat Mass Transfer 2009, 31(2), 73-89.

Mixed convection heat transfer in an open cavity, subjected to a flush mounted discrete heat source of constant heat flux partially embedded on the bottom wall while other remaining walls are kept adiabatic, has been investigated numerically. External airflow enters the enclosure through the horizontal channel at a uniform velocity and temperature. Numerical simulation is conducted by using Galerkin residual finite element discretization method. In the present study, the influence of the Richardson number (0 ≤ Ri ≤ 10), the discrete heat source size (0.2 ≤ ε ≤ 0.8), the inclination angle (0 ° γ 45 °) and the aspect ratio of the cavity (AR = 0.5, 1, 2) on the thermo-fluid fields has been reported. Disquisitions are presented through the streamlines, isotherms and heat transfer parameters.

7 illus, 22 ref

001135   Himanshu A K;Bandyopadhyay S K;Sen P;Gupta D C;Chakraborty R;Mukhopadhyay A K;Choudary B K;Sinha T P (NO, Advanced Materials Laborattory, VECC, 1/AF, Bidhan Nagar, Kolkata-700 064, Email: himanshu_ak@yahoo.co.in) : Dielectric and micromechanical studies of barium titanate substituted (1-y)Pb (Zn_1/3Nb_2/3) O_3-y PT ferroelectric ceramics. Indian J pure appl Phys 2010, 48(5), 349-56.

Dielectric studies have been carried out on barium titanate substituted lead zinc niobate ferroelectrics ceramics, (Pb_0.88Ba_0.12)[(Zn_1/3Nb_2/3/3)_0.88Ti_{0. 12})]O₃ and (Pb_0.8Ba_0.2)[(Zn_1/3Nb_2/3)_0.8Ti_0.2) ]O₃. The dielectric dispersion of the solid solutions has been studied as a function of temperature in the frequency range 100 Hz-lMHz. The temperature variation of the real components of dielectric permittivity (e') at different frequencies shows a diffuse phase transition. Micromechanical studies have been carried on (Pb_0.88Ba_0.12)[(Zn_1/3Nb_2/3/3)_0.88Ti_{0. 12})]O₃and (Pb_0.8Ba_0.2)[(Zn_1/3Nb_2/3)_0.8Ti_0.2) ]O₃ by nanoindentation at different loads. Hardness, Young's modulus, elastic energy and total energy have been extracted. It is seen that in case of (Pb_0.8Ba_0.2)[(Zn_1/3Nb_2/3)_0.8Ti_0.2) ]O₃, the plastic deformation energy is lower than the other sample, which is due to extra Ti content in B-site. This is also reflected in polarization studies, which confirms that the presence of Ti⁴⁺ in B-site brings forth rigidity in Ti-O bond.

10 illus, 2 tables, 12 ref

001134   Hasanov E R;Hosseyn P N;Panahov A Z;Demirel A I (NO, Baku State Univ, 23 Z, Khalilov Str., AZ 1148, Baku City) : Impurity semiconductor as an energy radiator in presence of constant external electric field. Int J pure appl Phys 2009, 5(3), 239-42.

It is shown that an impurity semiconductor in the presence of an external electric field can become an energy radiator with the certain frequency. Values of the frequency and external electric field, at which excited waves inside the semiconductor become instable, have been determined.

3 ref

001133   Gupta M;Mehur A K;Sonkawade R G;Verma K D; Rajendra Prasad (Physics Dep, S V (P G) College, Aligarh-202 001, Email: guptaapd1@yahoo.co.in) : Measurement of radon activity, exhalation rate and radiation doses in fly ash samples from NTPC Dadri, India. Indian J pure appl Phys 2010, 48(7), 520-3.

Radon activities and radon exhalation rates have been measured in fly ash samples from NTPC (National Thermal Power Corporation), Dadri situated in Uttar Pradesh, using "Can technique". This technique employs LR-115 type II solid state nuclear track detectors fixed at the top of the "Can" filled with fly ash samples. Radon activity has been found to vary from (222.56 ± 25.8) to (673.68 ±45.1) Bqm^{-3 with an average value of (431.71 ± 35.5) Bqm-3. Surface exhalation rate has been found to vary from (80 ± 9) to (243 ± 16) mBqm-2 h-1 with an average value (155 + 13) mBqm-2 h-1, whereas mass exhalation rate has been found to vary from (3.1 ± 0.4) to (9.34 ± 0.6) mBq kg-1 h-1 with an average value of (5.98 ± 0.5) mBqkg-1 h-1. Indoor inhalation exposure (radon) effective dose has also been estimated which is found to vary from (5.8 ±0.7) to (17.6 ± 1.2)μSvy-1 with an average value of (11.3 ± 0.9) μSvy-1.}

2 tables, 13 ref

001132   Gupta M;Chauhan R P;Garg A;Sushil Kumar; Sonkawade R G (Physics Dep, National Institute of Technology, Kurukshetra, Haryana, Email: monika.kkr@gmail.com) : Estimation of radioactivity in some snad and soil samples. Indian J pure appl Phys 2010, 48(7), 482-5.

Natural radioactivity is composed of the cosmogenic and primordial radionuclides. It is common in the rocks and soil that make up our planet, in water and oceans, and in our building materials and homes. Natural radioactivity in sand and soils comes from ^{238U and 232Th series and natural 40K. Radon is formed from the decay of radium which in turn is formed from uranium. The gaseous radioactive isotope of radon from natural sources has a significant share in the total quantum of natural sources exposure to human beings. Gamma radiation from 238U, 232Th and 40K represents the main external source of irradiation of the human body. In the present study, the activity for 238U, 232Th and 40K is found to vary from 45±1.2 to 97± 4.9 Bq/kg, 63 ± 2.0 to 132 ±3.2 Bq/kg and 492 ± 5.9 to 1110 ±10.5 Bq/kg, respectively in the soil samples while the variations have been observed from 63± 3.8 to 65 ± 3.7 Bq/kg, 86 ± 2.5 to 96 ± 2.6 Bq/kg and 751± 7.7 to 824± 8.2 Bq/kg, respectively in the sand samples.}

1 illus, 2 tables, 12 ref

001131   Govinda Raju S P (Aerospace Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: spg@aero.iisc.ernet.in) : Aerobasics-an introduction to aeronautics. Resonance 2010, 15(5), 400-10.

There is much current interest in small unmanned airplanes weighing about five kilograms all the way down to about 100 grams. Even such small airplanes are capable of performing useful surveillance missions in peace time and during conflicts. As these airplanes operate at very low flight speeds in the range of about 10-20 m/s, their performance is strongly affected by the low Reynolds numbers characteristic of such flight. In this article, we consider the special aerodynamic and propulsion problems associated with the flight of such small airplanes.

6 illus, 7 ref

001130   Gambhir Y K;Ghagwat A;Gupta M (NO, Manipal Univ, Manipal-576 104, Email: yogy@phy.iitb.ac.in) : Superheavy elements: overview. Indian J Phys 2009, 83(5), 661-9.

Superheavy Elements (SHE) up to Z = 118 have been produced and studied. The Relativistic Mean Field (RMF) theory provides a reasonably good description of the ground state properties (binding energies, Q-values, deformation, radii, densities etc.) of these elements. Shell closures revealed by the vanishing/ minimum pairing energy, are predicted for specific combination of neutron number N and proton number Z, specifically at N = 38, 164, 172, 184 and 198. Some of these have been confirmed experimentally. Future experiments are expected to validate the remaining predictions. Microscopic a-nucleus potential generated in the frame work of double folding model, employing the RMF densities for the daughter nucleus and the experimental densities for the a, along with the density dependent M3Y nucleon - nucleon interaction, qualitatively reproduce the experimental half lives for a - decay, calculated in the WKB approximation.

4 illus, 23 ref

001129   Dikshit B;Bhatia M S (Laser and Plasma Technology Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085) : Studies on electron beam vapour generation in PVD processes. BARC Newsl 2010, (May-Jun), 10-19.

Generation of metal vapour by electron beam heating is a complex phenomenon that involves many concurrent physical and dynamical processes in response to the impact of concentrated flux of energetic electrons on the metal target. These processes occurring at different stages need to be understood in detail for optimization of the process. Detailed investigations were carried out in our laboratory on various aspects of the e-beam evaporation process such as electron optics, stability of e-beam power, process monitoring, convective heat transfer in melt pool of the target and physical processes occurring in the metal vapour and plasma emerging from the hot zone. Our results on these aspects are presented.

6 illus, 14 ref

001128   Dhar D (Theoretical Physics Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005, Email: ddhar@theory.tifr.res.in) : States of matter. Resonance 2010, 15(6), 514-25.

5 illus, 4 ref

001127   Dattagupta S (NO, Indian Institute of Science Education and Research (IIser), Kolkata-741 252, Email: sushantad@gmail.com) : Peierls' elucidation of diamagnetism. Resonance 2010, 15(5), 428-33.

Summarizes the contribution to the phenomenon of Diamagnetism made by Rudolf Peierls, as Quantum Mechanics was triumphantly unfolding in the 1930's.

12 ref

001126   Cohen T D (Physics Dep, Maryland Univ, College Park, MD-20742 4111, USA, Email: cohen@physics.umd.edu) : Challenges facing holographic models of QCD. Indian J Phys 2009, 83(5), 681-91.

Takes a critical look at holographic models of QCD focusing on "practical" models in which the five-dimensional theory is treated classically, A number of theoretical and phenomenological challenges to the approach are discussed.

41 ref

001125   Chauhan R P (Physics Dep, National Institute of Technology, Kurukshetra-136 119, Email: chauhanrpc@gmail.com ) : Monitoring of radon, thoron and their progeny in dwellings of Haryana. Indian J pure appl Phys 2010, 48(7), 470-2.

The environmental monitoring of radon, thoron and their progeny in different dwellings of Northern Haryana has been carried out. The radon-thoron twin dosimeter cups are used for the study. The annual dose received due to radon-thoron and their progeny by the inhabitants in the dwellings under study have also been calculated. The health risk assessment in the dwellings under consideration has been done.

2 tables, 19 ref

001124   Broniowski W (H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland, Email: wojciech.broniowski@ifj.edu.pl) : Generalized vector form factors of the pion in a Chiral quark model. Indian J Phys 2009, 83(5), 649-60.

Generalized vector form factors of the pion, related to the moments of the generalized parton distribution functions, are evaluated in the Nambu-Jona-Lasinio model with the Pauli-Villars regularization. The lowest moments (the electromagnetic and the gravitational form factors) are compared to recent lattice data, with fair agreement. Predictions for higher-order moments are also made. Relevant features of the generalized form factors in the chiral quark models are highlighted and the role of the QCD evolution for the higher-order GFFs is stressed.

4 illus, 27 ref

001123   Bharathi G;Mahendranath B (Meteorology & Oceanography Dep, Andhra Univ, Visakhapatnam-530 003) : Total column ozone measurements at Visakhapatnam using microtops-II. Sun-photometer. Int J pure appl Phys 2009, 5(3), 183-94.

The results of the continuing systematic measurements of the total column ozone over Visakhapatnam are given. It has been shown that the total column ozone varies within a wide range during a day, a season, and from year to year. It is found that the total column ozone is minimum in winter and maximum in summer. Measurements of atmospheric total column ozone over Visakhapatnam (17.43N, 83.14E) are being carried out first time using Microtops - II (sun photometer) for the period from February 2005 to till date, but the results are presented for three years (i.e.) from February 2005 to December 2007, to study the systematic behavior of the total column ozone. The data obtained during the study period, have been analyzed to study diurnal and seasonal variations of the total column ozone over Visakhapatnam. The results show that the total column ozone is maximum at noon time and minimum in the evening time in almost all the cloud free days. The daily and seasonal variations of total column ozone over Visakhapatnam indicate that total ozone values are low in winter season and high in summer season. It is observed that the monthly averaged column ozone over Visakhapatnam is maximum (336.ODu (Dobson Units)) in May and minimum (273.8 Du) in December. The monthly variations in the column ozone mostly depend on temperature which controls the chemical and dynamical processes related to the photochemical reactions in the atmosphere.

4 illus, 1 table, 15 ref

001122   Bale R;Govindarajan R (Mechanical Engineering Dep, Northwestern Univ, Illinois, USA, Email: bale.rahul@gmail.com) : Transient growth and why we should care about it. Resonance 2010, 15(5), 441-57.

The phrases 'transient growth' and 'non-normality' have become common parlance in fluid mechanics nowadays. Presents these ideas with a simple two-dimensional system, to enable the reader to look for transient growth, as a trigger for nonlinear behaviour to set in a variety of situations probably having nothing to do with fluid mechanics. The article is aimed at undergraduate students of science, engineering, fi-"nance, etc., and the material is based completely on the excellent books of Trefethen and Embree, and Schmid and Henningson.

6 illus, 8 ref

001121   Bahl S;Lochab S P;Aleynikov V E;Molokanov A G;Rupasov A A;Pandey A;Pratik Kumar (Medical Physics Unit, All India Institute of Medical Science, New Delhi-110 029) : Thermoluminescent response of nanocrystalline Ba_0.97Ca_0.03SO₄: Eu for proton beam. Indian J pure appl Phys 2010, 48(7), 500-4.

Nanocrystalline Ba_0.97Ca_0.03SO⁴ doped with Eu, was prepared by the chemical co-precipitation method. The formation of the compounds was confirmed by XKD. The particle size was calculated by the broadening of the XRD peaks using Scherrer's formula. The particle size was found to be around 45 nm. Samples in the form of pellets were irradiated by 150 MeV proton beam. Thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. It has been found that there is a prominent TL glow peak at 498 K with a small shoulder at around 465 K. The TL response is linear in the range 0.1-150 Gy and then saturates for higher doses. The wider linear TL response of nanocrystalline Ba_0.97Ca_0.03SO₄: Eu and low fading makes it a good candidate as a dosimeter to be used for detecting the doses of protons which are commonly being used in proton therapy for the treatment of cancer.

3 illus, 17 ref

001120   Aly A E (Physics Dep, Faculty of Science at Damieta, Mansoura Univ, New Damieta, Egypt, Email: abeerresmat78200@yahoo.com) : Density of states of rare-earth permanent magnet Nd₂Fe₁₄B using spin-orbit coupling. Int J pure appl Phys 2009, 5(3), 215-29.

The electronic structures of Nd₂Fe₁₄B are calculated using first-principles full-potential linearized augmented plane wave (FPLAPW) method. We study the effect of considering the spin-orbit coupling and Coulomb correlations in the Nd₂Fe₁₄B on the magnetic properties and the electronic structure. Results are presented for total density of states (DOS) as well as the site-projected partial density of states (PDOS), the spin magnetic moment of Fe at each of the six in-equivalent transition-metal sites and charge-spin density maps. The total spin-magnetic moments and the average Fe moment are in a good agreement with the values deduced from the neutron scattering experiment and the LDA + U + SO scheme is used. The spin-polarized calculations, excluding the Hubbard and SO interaction, resulted in the total spin magnetic moment is 46.6 UB compared to the experimental values 34.63 μB to the value of 39.6 μB we obtained using LDA+U scheme without Spin-Orbit coupling(SO). But using LDA+U +SO the total spin magnetic moment is 37.6. Including the spin-orbit coupling are necessary for getting a better agreement with experimental data. The charge density map and the spin density maps are calculated on the basal and (110) plane of the tetragonal cell.

8 illus, 3 tables, 22 ref

001119   Ahmed S (Mathematics Dep, Goalpara College, Goalpara, Assam-783 101, Email: sahin_glp@yahoo.co.in) : Heat and mass transfer on free convective three dimensional unsteady flows over a porous vertical plate. J Energy Heat Mass Transfer 2009, 31(2), 89-110.

The unsteady free convective heat and mass transfer flow of a viscous incompressible fluid along an infinite vertical porous plate with uniform free stream velocity has been analysed. The plate is subjected to a transverse sinusoidal suction velocity fluctuating with time and thus generating a three-dimensional flow of the fluid. By series expansion method, the expressions for transient velocity, transverse velocity components, temperature, Spices Concentration, Skin-friction and the rate of heal and mass transfer have been obtained. During the course of discussion, it is found that the frequency of fluctuation, ω, has no effect on the tangent of the phase angle, tan Φ₁, in case of large Reynolds number i.e. for small viscosity due to cooling of the plate. However, for small Reynolds number i.e. for large viscosity the behaviour of amplitude M of the rate of mass transfer is more significant than the small viscosity.

8 illus, 13 ref

001118   Ahirwar G;Verma P;Tiwari M S (School of Studies in Physics, Vikram Univ, Ujjain-456 010, Email: ahirwarg.ssp70@yahoo.co.in) : Electromagnetic ion-cyclotron waves with general loss-cone distribution and multi-ions plasma-particle aspect approach. Indian J pure appl Phys 2010, 48(5), 334-42.

Electromagnetic ion-cyclotron (EMIC) waves with multi-component plasma have been studied by single particle approach with general loss-cone distribution function at different plasma densities. The dispersion relation and growth rate of the electromagnetic ion-cyclotron waves with multi-component plasma have been investigated. The effect of the steepness of the general distribution function in a low p (ratio of plasma pressure to magnetic pressure) homogeneous plasma with different densities has been studied with multi-ions plasma. The wave is assumed to propagate parallel to the static magnetic field. The whole plasma is considered to consist of resonant and non-resonant particles. It is assumed that resonant particles participate in energy exchange with the wave, whereas non-resonant particles participate in the oscillatory motion of the wave. The effect of general loss-cone distribution function with varying plasma density is to enhance the wave growth of EMIC waves with multi-ions plasma (H^{+, He+ and O+). The loss-cone distribution acts as the source of free energy. The results are interpreted for the space plasma parameters appropriate to the auroral acceleration region of the earth's magneto-plasma.}

9 illus, 18 ref

000179   Verma K K;Sinha R K;Tiwari R S;Srivastava O N (Physics and Electronics Dep, Dr R M L Avadh University, Faizabad-224 001, Email: kkverma23@gmail.com) : Optimisation of annealing condition for the prepration of (Bi, Pb)-Sr-Ca-Cu-O HTSC film by spray pyrolysis technique. Indian J pure appl Phys 2010, 48(6), 410-4.

High temperature superconducting (HTSC) films (Bi,Pb)-Sr-Ca-Cu-O have been prepared by spray pyrolysis technique on MgO (100) single crystal substrate. Annealing steps in regard to oriented nature of the films have been studied in detail which have been confirmed by XRD and SEM results. The optimized film has shown maximum T_c (R=Q) of ~ 82 K and J_c is ~ 6 x 10³ Acirf^-2 at 77 K.

5 illus, 1 table, 21 ref

000178   Singh P K (Physics Dep, Institute of Basic Sciences, Khandari, Agra-282 022, Email: pramod0002ooo@yahoo.com) : Thermoelastic properties of NaCl crystal using Holzapfel AP2 equation of state. Indian J pure appl Phys 2010, 48(6), 403-9.

Pressure P, bulk modulus K and its first and second pressure derivatives K' and K", and the Gruneisen parameter 7 and its volume derivative q for NaCl crystal down to a compression, V/V₀ = 0.65 have been studied. These properties have been calculated along different isotherms at selected temperatures in the range 300-1050 K using Holzapfel AP2 equation of state. The results obtained have been found to be in good agreement with the data reported in the literature. A reciprocal K-primed equation, quadratic in P/K, has been found to satisfy the relationship between P, K and K' along with different isotherms, and is also consistent with the values of K" at different compressions and temperatures. Volume dependence of the Griineisen parameter has been discussed in terms of the existing recent formulations.

4 illus, 8 tables, 134 ref

000177   Sharma S;Rana S;Pal K (Physics and Electronics Dep, University of Jammu, Jammu-180 006, Email: susheelksharma@gmail.com) : Realisation of high Q notch/allpass filter using low-voltage current conveyor. Indian J pure appl Phys 2010, 48(6), 435-7.

A high quality factor (Q) biquad is realized using low-voltage (±0.75 V) second-generation current conveyors (CCII), which can realize dual filter functions (notch/allpass) depending on the resistance ratio. The circuit uses mostly grounded components, thus, enables its easy implementation in standard CMOS technologies. The circuit offers high input resistance (10^{20 Ω) making it suitable for cascading and dissipates 3.8 mW power. The workability of this circuit has been verified by PSpice simulations using 0.5 μm technology parameters.}

4 illus, 1 table, 16 ref

000176   Sharma S;Banerjee P (National Physical Laboratory, Council of Scientific and Industrial Research, New Delhi-110 012, Email: sumanshano@yahoo.com) : Effect of error in position coordinates of the receiving antenna on single satellite GPS timing. Indian J pure appl Phys 2010, 48(6), 429-34.

It is well established that the position co-ordinates of the receiving antenna should be determined precisely in advance for getting time of the GPS receiver through a single GPS satellite technique. So it is desirable to know the extent of accuracy of the position coordinates required for a particular timing accuracy. In this paper, an analytical expression relating to the position error and the corresponding error in the time of the GPS receiver has been derived. Time of the GPS receiver error caused by the error in position coordinates largely depends on the position of the satellite indicated by the respective elevation and azimuth of the satellite. To validate the derived formulation, it is important to configure the experimental plan judiciously. A special experiment has accordingly been conducted at National Physical Laboratory, New Delhi, India (NPLI). The observed data have been found to tally well with the derived relation.

8 illlus, 7 ref

000175   Sharma H K;Kaanodiya K K (Mathematics Dep, B.S.A. College, Mathura, Email: harish_k_ sharma@sify.com) : Effect of thermal diffusivity on unsteady mhd free convection and mass transfer flow through porous medium with constant suction and constant heat flux in rotating system. Int J mathl Sci 2009, 8(3-4), 159-69.

An analysis of unsteady two-dimensional free convection and mass transfer (low of a viscous incompressible electrically conducting fluid through a porous medium bounded by a vertical infinite surface with constant suction velocity and constant heat flux in rotating system in the presence of mass diffusion and thermal diffusivity is presented. The effect of Hartman number (M) and Rotation velocity parameter (E) with time on the primary and secondary velocities and skin-friction in x and y-directions are discussed with the help of graphs.

4 illus, 4 tables, 12 ref

000174   Reddy M H P;Raddy P N;Uthanna S (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: Uthanna@rediffmail.com ) : Structural, electrical and optical behaviour of rf magnetron sputtered cuprous oxide films. Indian J pure appl Phys 2010, 48(6), 420-4.

Thin films of cuprous oxide have been deposited on glass substrates by sputtering of copper target at different substrate temperatures in the range 303-523 K and at oxygen partial pressure of 2 x 10^{-2 Pa using rf magnetron sputtering method. The deposited films are characterised by studying crystallographic structure with X-ray diffraction, surface morphology by atomic force microscopy, and electrical and optical properties. The effect of substrate temperature on the physical properties of the deposited films has been systematically studied. The films deposited at 303 K are found amorphous while those formed at higher temperatures are polycrystalline with improved crystallinity. The electrical resistivity of the films decreases from 29 to 8Ω cm and optical band gap increases from 2.15 to 2.32 eV with the increase of substrate temperature from 303 to 523 K.}

5 illus, 1 table, 28 ref

000173   Raman Kumar;Sharma V;Rangra V S (Physics Dep, Electronics Researcy Laboratory, Himachal Pradesh University, Shimla-171 005, Email: vs_rangra@yahoo.co.in) : Dielectric relaxation studies of binary mixrures of tetrahydrofuran and N-Methylacetamide in benzene solutions using microwave absorption data. Indian J pure appl Phys 2010, 48(6), 415-19.

Using standard standing wave microwave X-band technique and by following Gopala Krishna's single frequency (9.90 GHz) concentration variational method, the dielectric relaxation times (τ) and the dipole moments (μ) of dilute solution of tetrahydrofuran(THF), N-methylacetamide(NMA) and THF+NMA binary mixtures in benzene solutions have been calculated at different temperatures 25°, 30°, 35° and 40°C. The energy parameters (ΔH_ε,ΔF_{<1 01>},ΔS_ε) for the dielectric relaxation process for THF+NMA binary mixture containing 30 mol% THF have been calculated at 25°, 30°, 35° and 40°C and compared with the corresponding viscosity parameters. A good agreement between the free energy of activation from these two sets of values shows that the dielectric relaxation process like the viscous flow process can be treated as the rate process. From relaxation time behaviour of THF and NMA binary mixture in benzene solution, solute-solute types of the molecular association have been proposed.

2 illus, 3 tables, 13 ref

000172   Pradeep D;Ashok Kumar;Naithani U C (Physics Dep, H.N.B Garhwal Central University, Campus Pauri, (Garhwal), Uttarakhand-246 001, Email: dushyant_pradeep@yahoo.co.in) : Sound attenuation in Ba_1-xCa_xTiO₃ ferroelectric perovskites. Indian J pure appl Phys 2010, 48(6), 398-402.

Theoretical expression of attenuation constant of anharmonic Ba_1-xCa_xTiO₃ ferroelectric crystal in paraelectric phase using double times temperature dependent Green's function technique, is derived. The variation of attenuation constant with frequency and temperature has been studied by considering third- and fourth-order anharmonic interactions, taking electric field as an important parameter. The mass and force constant change due to the presence of impurity atoms in Silverman-Joseph Hamiltonian augmented with higher order anharmonic terms. The effect of electric field, defect and anharmonicity on stabilization of the soft mode frequency has also been studied. The attenuation constant increases with increasing temperature and frequency in the presence of an electric field. In the vicinity of the Curie temperature, attenuation constant increases anomalously.

3 illus, 31 ref

000171   Nautiyal R C (Mathematics Dep, Deenbandhu Chhotu Ram Science and Technology Univ, Murthal-131 039, Email: ravendranautiyal@yahoo.co.in) : Some theorems on conformally flat almost hermitian manifolds with pointwise constant holomorphic sectional curvature. Int Rev pure appl Math 2008, 4(1), 51-7.

In this paper some conformally flat almost Hertmitian manifold of dimensions 2n equipped with J-invariant or J-anti invariant Ricci-tensor and with point wise constant holomorphic sectional bisectional curvature are studied and some theorems been established.

7 ref

000170   Muthucumaraswamy R;Sathappan K E;Natarajan R (Applied Mathematics Dep, Sri Venkateswara College of Engineering, Sriperumbudur, Email: msamy@svce.ac.in) : Unsteady flow past and exponentially accelerated infinite isothermal vertical plate with uniform mass flux. Int J mathl Sci 2009, 8(1-2), 67-73.

An analysis is perform to study the flow of an incompressible viscous fluid past an exponentially accelerated infinite isothermal vertical plate with uniform mass flux. The plate temperature is raised to T_w and the concentration level near the plate is also made to at an constant rate. The dimensionless governing equations are solved using Laplace-transform technique. The velocity, temperature and concentration fields are studied for different physical parameters like thermal Grash of number, mass Grash of number, Schmidt number, a and time. It is observed that the velocity increases with increasing values of a or t.

5 illus, 5 ref

000169   Muthucumaraswamy R;Manivannan K;Thangaraj V (Applied Mathematics Dep, Sri Venkateswara College of Engineering, Pennalur, Sriperumbudur, Email: msamy@svce.ac.in) : Effects of chemical reaction on isothermal vertical oscillating plate in the presence of thermal radiation. Int J mathl Sci 2009, 8(1-2), 55-65.

Thermal radiation effects on unsteady free convective flow of a viscous incompressible flow past an infinite isothermal vertical oscillating plate, in the presence of homogeneous chemical reaction of first order has been studied. The fluid considered here is a gray, absorbing-emitting radiation but a non-scattering medium. The plate temperature is raised to T_w and the concentration level near the plate is also raised to C'_w. An exact solution to the dimensionless governing equations has been obtained by the Laplace transform method, when the plate is oscillating harmonically in its own plane. The effects of velocity, temperature and concentration are studied for different physical parameters like phase angle, radiation parameter, chemical reaction parameter, Schmidt number, thermal Grashof number, mass Grash of number and time are studied. It is observed that the velocity increases with decreasing phase angle ω.

8 illus, 10 ref

000168   Muthucumaraswamy R;Maheswari J;Pandurangan J (Applied Mathematics Dep, Sri Venkateswara College of Engineering, Sriperumbudur-602 105, Email: masamy@svce.ac.in) : Unsteady MHD flow past an impulsively started semi-infinite vertical plate in the presence of chemical reaction. Int Rev pure appl Math 2008, 4(1), 119-33.

Finite difference solution of the homogeneous first order chemical reaction on unsteady flow past an impulsively started semi-infinite vertical plate in the presence of magnetic field have been studied. The wall temperature T'_w and species concentration on the wall C'_w vary as the power of the axial coordinate in the form T'₄w (x) = T'_∞ + ax" and C'_w (x) = C'∞ + bx^m' is analyzed. The dimensionless governing equations are solved by an efficient, more accurate, unconditionally stable and fast converging implicit scheme. The effect of velocity, temperature and concentration for different physical parameters are studied graphically. The concentration profiles are compared with the exact solution and are found to be in good agreement. It is observed that the velocity increases with decreasing magnetic field parameter. It is also observed that due to the presence of first order chemical reaction, the velocity increases with decreasing values of the chemical reaction parameter or magnetic field parameter.

13 illus, 7 ref

000167   Mukherjee M N (NO, , ) : Foucault's penduylum. Indian Sci Cruiser 2009, 23(1), 21-2.

The Foucault pendulum is named after its inventor Leon Foucault, who demonstrated with it the earth's diurnal rotation at the Paris Exhibition in 1851. Visitors can see this device in the Pantheon Paris.

1 illus, ref

000166   Gayan R N;Bhar R;Pal A K (Instrumentation Science Dep, USIC Building, Jadavpur University, Calcutta-700 032, Email: mskp2002@yahoo.com.in) : Synthesis and characterization of vertically aligned ZnO nanorods with controlled aspect ratio. Indian J pure appl Phys 2010, 48(6), 385-93.

Vertically aligned zinc oxide (ZnO) nanorods with controlled aspect ratio have been deposited by hybrid wet chemical route onto glass substrates with pre-deposited ZnO seeds produced by sputtering a ZnO target in argon plasma. Films have been characterized by measuring microstructural and optical properties. The photoluminescence (PL) spectra have been found to be dominated by the presence of peaks at ~ 394 nm (~ 3.15 eV) due to the free exciton emission and at ~470 nm (~2.64 eV) due to transitions from deep donor states arising out of oxygen vacancy (V₀) located ~0.06 eV below the conduction band to the valance band. Bonding environment has been obtained from Raman and Fourier transformed infrared (FTIR) studies.

8 illus, 1 table, 39 ref

000165   Celikel O;Sametoglu F;Sozeri H (NO, Tubitak Ume Optics Laboratory PO Box: 544 470 Gebze - Kocaeli, Turkey, Email: oguz.celikel@ume.tubitak.gov.tr) : Optoelectronic design parameters of interferometric fiber optic gyroscope with LiNbO₃ having north finder capability and earth rotation rate measurement. Indian J pure appl Phys 2010, 48(6), 375-84.

North finder capability gyroscopes supply the reference north azimuth information to the relevant base system. This paper covers the design details of both optical and electronic components of an open-loop Interferometric Fiber Optic Gyroscope (IFOG) with integrated-optic phase modulator LiNbO₃ and the measurement results of earth rotation rate carried out by means of the designed north finder IFOG with LiNbO modulator in laboratory plane together. Scale factor model function is derived for the open-loop IFOG with LiNbO₃. Additionally, bias stability and the temperature dependence of the bias stability for the north finder IFOG have been studied in the temperature range 23°-42°C.

8 illus, 1 table, 12 ref

000164   Bhadra J;Sarkar D (Physics Dep, Gauhati Univ, Guwahati-781 014) : Electrical and optical properties of polyaniline polyvinyl alcohol composite films. Indian J pure appl Phys 2010, 48(6), 425-8.

Polyaniline polyviny) alcohol (PANI-PVA) composite films have been prepared chemically in inorganic acid medium at different ratios of their monomer units. A homogeneous blend can be obtained even using inorganic acid medium by terminating the reaction soon after the mixture attains homogeneous colour change. The SEM pictures show that the films have well formed grains with approximate sizes ranging from 0.3 to 1.2 μm. The results show definite dependence of various parameters on the PANI-PVA ratio in the blend. The XRD spectra show increase in crystallinity in the films with increase of PVA concentration. The FTIR spectra show some peaks, which ascertain chemical interlinking of PANI and PVA in these blends. The studies of electrical conductivity of these films through measurement of current-voltage (I-V) characteristics show non-ohmic power law behaviour (I α V^{n) with power (n) lying in the range 0.22 to 0.88. The conductivity value of these films is found to be between 1.80 to 0.9 S cm.}

4 illus, 1 table, 15 ref

000163   Bal S;Bose M (Physics Dep, Jadapru Univ, Jadavpur, Kolkata) : Solar activity and precipitation in India: possible connection. Indian Sci Cruiser 2009, 23(1), 44-50.

To realize the effect of a continuous and natural energy source into our country's most needed phenomenon for the agricultural purpose have been studied. 100 years' data (1901-2000), were used for studying effects due to solar activity, temperature and cloud cover on the occurrence of precipitation over India. We examine the correlation coefficients for the seasonal months of March-May (MAM), June-August (JJA), Septemeber-November (SON), December-February (DJF) and annual mean data. Our findings shows that solar activity shows positive (low to moderate) correlations to annual, MAM, JJA precipitation and negative correlation during SON, DJF seasonal months. Wavelet analysis is also employed to study the effect of solar activity on precipitation.

3 illus, 3 tables, 20 ref

020012   Vinothini C;Malathi M (Condensed Matter Research Laboratory, VIT Univ, Vellore, Tamil Nadu, Email: emailvino@gmail.com) : Application of nanotechnology in textile materials. Int J Nanotechnol Applic 2008, 3(3), 83-7.

Nanotechnology has proven its importance in almost all areas, and textile industry is not an expection. The aim of the research was to explore the effect of methyl red dye, bulk/nano TiO₂ and methyl red dye with bulk/nano TiO² on antistatic and antiflammable property of commercially available textile samples. Nano TiO₂ was synthesized by polyol method and characterized by X-Ray diffraction (XRD) and Atomic Force Microscopy (AFM). From our results, it's clear that materials coated by methyl red with nano TiO₂ prove to have better antistatic and antiflammable property.

2 illus, 14 ref

020011   Srivastava A;Vishwakarma H L (Applied Physics Dep, Rungta College of Egg & Tech, Kohka Road, Kurud, Bhilai, Durg (C G)-491 024, Email: archana2176@rediffmail.com) : Synthesis and optical properties of bulk and doped zinc sulfide nanocrystals. Int J Nanotechnol Applic 2008, 3(3), 77-81.

The II- VI group semiconductors are of great importance due to their applications in various opto-electronic devices. Among these semiconductors, zinc sulfide is the most suitable for its utility in opto- electronic devices. Manganese doped ZnS nanoparticles (ZnS:Mn) with varying concentration of capping agent as well as of Mn^{2+ were synthesized by chemical precipitation method at room temperature. The optical properties get modified dramatically due to confinement of charge carriers with in the nanoparticles. The optical absorption studies show that the absorption edge shifts towards blue region as the capping agent concentration is increased indicating that the effective band gap energy increase with decreasing particle size while with the change in doping concentration no variation was observed in the absorption spectra.}

2 illus, 17 ref