004052   Sharma M et al (NO, Joint Institute for Nuclear Research (JINR), Dubna,Russia) : Measurement of neutron-induced activation cross-sections using spallation source at JINR and neutronic validation of the dubna code. Pramana J Phys 2007, 68(2), 307-13.

Beam of 1 GeV proton coming from Dubna Nuclotron colliding with a lead target surrounded by 6 cm paraffin produces spallation neutrons. A Th-foil was kept on lead target (neutron spallation source) in a direct stream of neutrons for activation and other samples of ¹⁹⁷Au, ²⁰⁹Bi, ⁵⁹Co, ¹¹⁵In and ¹⁸¹Ta were irradiated by moderated beam of neutrons passing through 6 cm paraffin moderator. The gamma spectra of irradiated samples were analyzed using gamma spectrometry and DEIMOS software to measure the neutron cross-section. For this purpose neutron fluence at the positions of samples is also estimated using PREPRO software. The results of cross-sections for reactions ²³²Th(n, γ), ²³²Th(n,2n), ¹⁹⁷Au(n,γ), ¹⁹⁷Au(n,α), ¹⁹⁷Au(n, xn), ⁵⁹Co(n,α), ⁵⁹Co(n,xn), ¹⁹¹Ta(n, γ) and ¹⁸¹Ta(n, xn) are given. Neutronics validation of the Dubna Cascade Code is also done using cross-section data by other experiments.

3 illus, 3 tables, 10 ref

004051   Shah A M;Patel I B;George R (NO, Arts Science and Commerce College, Kamrej Char Rasta, Surat-394 185) : Barium tartrate crystals growth by gel method. Acta Cienc Indica-Phys 2007, 33(2), 197-200.

Barium tartrate has a well known property of Ferro electricity and broad applications. The authors have successfully grown them by gel method at ambient temperature in normal test tube. The effect of gel density on crystallization has been studied. On average 60% of the crystals obtained were found to be fairly transparent. The crystals size ranged about 2 mm x 2 mm x / mm. The results are reported.

3 illus, 5 ref

004050   Seliverstov V V (NO, Institute of Theoretical and Experimental Physics, 25, B. Cheremushikinskaya-117 218, Email: vladimir.seliverstov@itep.ru) : Some parameters and conditions defining the efficiency of burners in the destruction of long-lived nuclear wastes. Pramana J Phys 2007, 68(2), 173-9.

Number of new wordings and statements regarding the targeted problem of destruction of long-lived wastes (transmutation) is considered. Some new criteria concerning the efficiency of a particular burner type are proposed. It is shown that the destruction efficiency of a specific burner is greatly influenced by the prospective time period of the whole destruction process.

3 ref

004049   Satyamurthy P;Gantayet L M;Ray A K (Beam Technology Development Group, Bhabha Atomic Research Centre, Mumbai-400 085, Email: lmmhd@apsara.barc.ernet.in) : Heavy density liquid metal spallation target studies for Indian ADS programme. Pramana J Phys 2007, 68(2), 343-53.

Department of Atomic Energy, India has taken up the development of ADS in view of many attractive features like inherent safety, capability to transmute large quantities of nuclear waste, better utilization of thorium etc. A roadmap has been finalized for the development of ADS. One of the key components of the ADS is the spallation target. Considering the neutron yield, thermal-hydraulics and radiation damage issues, It is proposed to develop spallation target based on heavy density liquid metals like lead and lead-bismuth-eutectic (LBE). Both window and windowless target configurations are presently being studied. In view of the various advantages authors are also studying liquid metal flow circulation based on gas lift mechanism. An R&D programme has been initiated to address various physics and technology issues of ADS target. Under this programme, mercury and LBE experimental facilities are presently being set up. Along with these facilities, computational tools related to spallation physics (FLUKA) and CFD are being developed, and the existing ones are utilized to design the entire target loop as well as sub-systems. The details of these activities are presented.

11 illus, 12 ref

004048   Sarkar P K;Nandy M (Health Physics Unit, Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata-700 064, Email: pks@veccal.ernet.in) : Accelerator driven systems from the radiological safety point of view. Pramana J Phys 2007, 68(2), 225-33.

In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead-bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community. Spallation reaction products like high energy gammas, neutrons, muons. pions and several radiotoxic nuclides including Po-210 complicate the situation. Discusses radiation safety measures like bulk shielding, containment of radiation leakage through ducts and penetration and induced activity in the structure to protect radiation workers as well as estimation of sky-shine, soil and ground water activation, release of toxic gases to the environment to protect public as per the stipulations of the regulatory authorities. Recommends the application of the probabilistic safety analysis technique by assessing the probability and criticality of different hazard-initiating events using HAZOP and FMECA.

3 illus, 5 ref

004047   Saha A;Bag B C;Sarkar P (Chemistry Dep, Visva-Bharati Univ, Santiniketan-731 235, Email: pranab-69@yahoo.co.in) : Effects of barrier fluctuation on the tunneling dynamics in the presence of classical chaos in a mixed quantum-classical system. Pramana J Phys 2007, 68(3), 377-87.

Presents a numerical investigation of the tunneling dynamics of a particle moving in a bistable potential with fluctuating barrier which is coupled to a non-integrable classical system and study the interplay between classical chaos and barrier fluctuation in the tunneling dynamics. Fungus that the coupling of the quantum system with the classical subsystem decreases the tunneling rate irrespective of whether the classical subsystem is regular or chaotic and also irrespective of the fact that whether the barrier fluctuates or not. Presence of classical chaos always enhances the tunneling rate constant. The effect of barrier fluctuation on the tunneling rate in a mixed quantum-classical system is to suppress the tunneling rate. In contrast to the case of regular subsystem, the suppression arising due to barrier fluctuation is more visible when the subsystem is chaotic.

7 illus, 39 ref

004046   Ravi Kiran S;Sita Devi P;Janardhan Reddy K (Botany Dep, Osmania Univ, Hyderabad-500 007, Email: sitadevi@iictnet.org ) : Bioactivity of essential oils and sesquiterpenes of Chloroxylon swietenia DC against Helicoverpa armigera. Curr Sci 2007, 93(4), 544-8.

Essential oils from the leaves and stems of Chloroxylon swietenia DC were obtained by hydrodistillatiori and the chemical composition was determined by GC and GC-MS. The major identified components in leaf oil were limonene, geijerene, pregeijerene, germacrene D and trans-β-ocimene, while stem oil essentially contained methyl eugenol, limonene and geijerene. Laboratory bioassays of the essential oils and isolated compounds were evaluated for insecticidal and antifeedant activities on Helicoverpa armigera. Toxicity was determined by topical application of the total extracts and the isolates at varying concentrations, where leaf oil, stem oil, geijerene and pregeijerene were found to be more toxic than germacrene D and limonene, with LD₅₀ values of 22.3, 26.9, 39.4 and 45.8 μg/larva respectively. Further, geijerene and pregeijerene displayed maximum feeding deterrence as well with DC₅₀ of 89.8 and 99.6 μg/sq. cm. The results indicate that these natural products may find potential application as useful biodegradable environmentally safe insect control and crop protectant agents.

3 illus, 2 tables, 19 ref

004045   Rashmi;Kapoor A K;Upendra Kumar;Balakrishnan V R;Basu P K (Solid State Physics Laboratory, , Timarpur, Delhi-110 054, Email: rashmi.sg@gmail.com) : Degradation process in organic thin film devices fabricated using P3HT. Pramana J Phys 2007, 68(3), 489-98.

The stability of regioregular poly(3-hexylthiophene 2,5-diyl) (P3HT) thin films sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes have been investigated under normal environmental conditions (25°C and R,H<126>45-50%). Electrical and optical properties of ITO/P3HT/A1 devices have been studied over a period of 30 days. Mobility μ, of the order of 10^-4 cm² /V-s has been obtained from the V² law in the as- deposited P3HT films. Scanning electron microscopy (SEM) investigations show blistering of Al contacts in devices with a poly(3,4-ethylenedioxythiophene) (PEDOT) interlayer on application of voltage whereas no blistering is seen in devices without PEDOT. The results have been explained in terms of trap generation and propagation and the moisture-absorbing nature of PEDOT.

6 illus, 25 ref

004044   Ramesh K;Arumugam V;Kannappan A N (Physics Dep, Dr. Pauls Engineering College, Tamilnadu) : Theoretical evaluation of sound velocity in binary liquid system. Acta Cienc Indica-Phys 2007, 33(2), 241-3.

Ultrasonic velocity and density have been measured in one binary system of Acetophenone + Diethylamine; for different proportions. The evaluation of sound velocity has been done using Nomoto's relation, Ideal mixture relation, Free length theory and Impedance dependence relation and an attempt has been made to compare the calculated values with the experimental values. The chi-square test for goodness of fit is also applied to test the validity of the four theories.

1 illus, 12 ref

004043   Ramesh K;Arumugam V;Kannappan A N (Physics Dep,, Dr. Pauls Engineering College, Tamilnadu) : Study of excess parameters in binary liquid mixture. Acta Cienc Indica-Phys 2007, 33(2), 153-4.

Excess sound velocity (V^E), excess viscosity (η^E), Gibb's free energy (AG^E) and excess adiabatic compressibility (β^E) have been evaluated in the binary mixtures: Acetophenone + Triethylamine at 303 k. The studies are useful in understanding the solute-solvent interactions in binary liquid mixtures.

1 table, 6 ref

004042   Rama Mohana Rao K;Hemagiri Rao P;Chaitanya B S K (Applied Mathematics Dep, Andhra Univ, Visakapatnam-530 003, Email: hemagiriraop@yahoo.co.in) : Piezoelectricity in quasicrystals: a group-theoretical study. Pramana J Phys 2007, 68(3), 481-7.

Group-theoretical methods have been accepted as exact and reliable tools in studying the physical properties of crystals and quasicrystalline materials. By group representation theory, the maximum number of non-vanishing and independent second- order piezoelectric coefficients required by the seven pentagonal and two icosahedral point groups - that describe the quasicrystal symmetry groups in two and three dimensions -is determined. The schemes of non-vanishing and independent second-order piezoelectric tensor components needed by the nine point groups with five-fold rotations are identified and tabulated employing a compact notation. The results of this group-theoretical study are briefly discussed.

2 tables, 22 ref

004041   Rajeev Kumar;Srivenkatesan R (Reactor Physics Design Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: rsriven@apsara.barc.ernet.in) : Utilization of the BARC critical facility for ADS related experiments. Pramana J Phys 2007, 68(2), 325-9.

Discusses the basic design of the critical facility, whose main purpose is the physics validation of AHWR. Apart from moderator level control, the facility will have shutdown systems based on shutoff rods and multiple ranges of neutron detection systems. In addition, it will have a flux mapping system based on 25 fission chambers, distributed in the core. Authors are planning to use this reactor for experiments with a suitable source to simulate an ADS system. Any desired sub-criticality can be achieved by adjusting the moderator level. Apart from perfecting our experimental techniques, in simple configurations, authors intend to study the one-way coupled core in this facility. Preliminary calculations, employing a Monte Carlo code TRIPOLI, are presented.

2 illus, 3 tables, 4 ref

004040   Raj Kumar;Mohan D;Aggarwal A K (Coherent Optics Div, Central Scientific Instruments Organisation, Sector 30, Chandigarh-160 030, Email: aka1945@rediffmail.com) : Interferometric key readable security holograms with secrete-codes. Pramana J Phys 2007, 68(3), 443-50.

A new method is described to create secrete-codes in the security holograms for enhancing their anti-counterfeiting characteristics. To imitate these codes is difficult as pure phase objects having complex phase distribution function are used to modulate the object beam that is recorded in conjunction with an encoded interferometric reference beam derived from a key hologram. Lloyd's folding mirror interferometer is used to convert phase variations of the reconstructed wave-front into an intensity pattern for hologram authenticity verification. Creating the secrete-codes through an interferometric reference beam from the key hologram facilitates a multi-stage authenticity verification as well as easy repositioning of the security hologram through a specific Moire pattern generated during the verification process.

5 illus, 16 ref

004039   Puzhakkal S M;Bannur V M (Physics Dep, Calicut Univ, Malappuram-673 635) : Qq pair production in non Abelian gauge fields-a resonance phenomenon. Acta Cienc Indica-Phys 2007, 33(2), 177-82.

Calculate the qq^- pair production probability in the colour flux tube model by taking the effect of non-Abelian interactions in the theory. By solving SU(2) Yang Mill's equation obtained an exact expression for electric field which is found to be time dependent and oscillating with a characteristic frequency (ω_o which depends on the amplitude of the field strength. By using WKB approximation in complex time calculated the pair creation probability and it is seen that when ever the strength of the field (gE) is comparable to the quark-antiquark energy (p²+m²) the corresponding pair creation probability is maximum, and for the static field w₀ - <62> 0, recovered the famous Schwinger result.

13 ref

004038   Petwal V C;Senecha V K;Subbaiah K V;Soni H C; Kotaiah S (Industrial and Medical Accelerator Section, Centre for Advanced Technology, Indore-452 013, Email: senecha@cat.ernet.in) : Optimization studies of photo-neutron production in high-z metallic targets using high energy electron beam for ADS and transmutation. Pramana J Phys 2007, 68(2), 235-41.

Monte Carlo calculations have been performed using MCNP code to study the optimization of photo-neutron yield for different electron beam energies impinging on Pb, W and Ta cylindrical targets of varying thickness. It is noticed that photo-neutron yield can be increased for electron beam energies ≥100 MeV for appropriate thickness of the target. It is also noticed that it can be maximized by further increasing the thickness of the target. Further, at higher electron beam energy heat gradient in the target decreases, which facilitates easier heat removal from the target. This can help in developing a photo-neutron source based on electron LINAC by choosing appropriate electron beam energy and target thickness to optimize the neutron flux for ADS, transmutation studies and as high energy neutron source etc. Photo-neutron yield for different targets, optimum target thickness and photo-neutron energy spectrum and heat deposition by electron beam for different incident energy is presented.

5 illus, 6 ref

004037   Pavan Kumar G V;Narayana C (Light Scattering Laboratory, Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore-560 064, Email: cbhas@jncasr.ac.in) : Adapting a fluorescence microscope to perform surface enhanced Raman spectroscopy. Curr Sci 2007, 93(6), 778-81.

Methodology to modify a simple fluorescence microscope to perform sophisticated Surface Enhanced Raman Scattering (SERS) experiments, retaining the primary function of the microscope is discussed. Recent advancement in the use of SERS for the study of biologically important molecules for structural information, sensors and diagnostic applications, makes this an important development. The method not only reduces the cost of acquiring a Raman spectrometer, but also facilitates an ability to perform experiments without major modifications to the sample preparation and mounting techniques that exist in the laboratory.

5 illus, 29 ref

004036   Pal U;Jagannathan V (Reactor Physics Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, Email: v_jagan1952@rediffmail.com) : A conceptual high flux design with scope for use in ADS applications. Pramana J Phys 2007, 68(2), 151-9.

A 100 MWt reactor design has been conceived to support flux level of the order of 10¹⁵ n/cm²/s in selected flux trap zones. The physics design considers high enriched metallic alloy fuel in the form of annular plates placed in a D²O moderator tank in a hexagonal lattice arrangement. By choosing a tight lattice pitch in the central region and double the lattice pitch in the outer region, it is possible to have both high fast flux and thermal flux trap zones. By design the flux level in the seed fuel has been kept lower than in the high flux trap zones so that the burning rate of the seed is reduced. Another important objective of the design is to maximize the time interval of refueling. As against a typical refueling interval of a few weeks in such high flux reactor cores, it is desired to maximize this period to as much as six months or even one year. This is possible to achieve by eliminating the conventional control absorbers and replacing them with a suitable amount of fertile material loading in the reactor. Requisite number of seedless thorium-aluminum alloy plates are placed at regular lattice locations vacated by seed fuel in alternate fuel layers. It is seen that these thorium plates are capable of acquiring asymptotic fissile content of 14 g/kg in about 100 days of irradiation at a flux level of 8 x 10¹⁴ n/cm₂/s. In summary, the core has a, relatively higher fast flux in the central region and high thermal flux in the outer region. The present physics design envisages a flat core excess reactivity for the longest possible cycle length of 6 months to one year. It is also possible to modify the design for constant subcriticality for about the same period or longer duration by considering neutron spallation source at the centre and curtailing the power density in the inner core region by shielding it with a layer of thoria fuel loading.

12 illus, 1 table, 2 ref

004035   Mukherjee S N (Physics Dep, Banaras Hindu Univ, Varanasi-221 005, Email: snthmukherjee@rediffmail.com) : Neutrino physics - an expanding realm. Curr Sci 2007, 93(4), 464-70.

Authour describe how the ethereal neutrino gradually assumed a tangible form and played a pivotal role in the quest to understand intrinsic particle properties. In the road map for the exploration of neutrino mass, new experiments and new facilities are planned to find the nature of the neutrino mass, the possible cosmological relevance of neutrino as hot dark matter and the origin of all matter in the universe.

5 illus, 18 ref

004034   Moinul Haque Meaze A K M;Devan K;Lee Y S;Oh Y D;Kim G N;Son D (Physics Dep, Chittagong Univ, Chittagong 4331, Bangladesh, Email: mhqmeaze@yahoo.com) : Neutron total cross-sections and resonance parameters of Mo and Ta. Pramana J Phys 2007, 68(2), 279-87.

Experimental results of transmissions for the samples of natural molybdenum with thickness 0.0192 atoms/barn and for the four samples of natural tantalum with thickness 0.0222, 0.0111, 0.0055 and 0.0025 atoms/barn are presented in this work. Measurements were carried out at the Pohang Neutron Facility which consists of a 100 MeV Linac, water-cooled tantalum target, and 12 m flight path length. Effective total cross-sections were extracted from the transmission data, and resonance parameters were obtained by using the code SAMMY. The present measurements were compared with other measurements and with the evaluated nuclear data file ENDF/B-VI.8.

ref

004033   Mohrir M N (Botany Dep, Mahavidyalaya, Paithan. Dist. Aurangabad) : Genetic variability and heritability in cotton (Gossypium hirsutum L.) under irrigated condition. Bioinfolet 2007, 4(2), 168-70.

1 table, 8 ref

004032   Mohanty J N;Baral K C;Nath G (NO, Centre of Astrophysics, 438 Nuasahi, Nayapalli, Bhubaneswar-751 012, Email: ganesh_nath99@yahoo.co.in) : Diffusion and transport phenomena in a collisional magnetoplasma having both streaming and temperature anisotropy: collisional kinetics. Pramana J Phys 2007, 68(3), 457-66.

Boltzmann-transport equation is analytically solved for two-component mag-netoplasma using Chapman-Enskog analysis to include collisional diffusion transport having anisotropies in both streaming velocity and temperature components. The modified collisional integrals are analytically solved with flux integrals and perturbed kinetic equa-tion to arrive at drift diffusion velocity and resulting transport coefficients which are markedly affected by both streaming and temperature anisotropy. The early isotropic results are recovered in the limit V₀ = 0 and T⊥ = T⊥ which reduce to eqs (11.30) and (11.31) of [1] and eqs (2.7) and (2.13) of [2j. The electrical resistivity (η⊥ diminishes sharply in fusion temperature limit kT⊥ = 1 keV. The shape of the curves for both electrical resistivity and thermal conductivity is rectangular hyperbolic. However, for low thermal ratio (T⊥/T⊥ <60> 1), the curves are raised up and for high thermal ratio (T⊥/T⊥ <60> 1), they are lowered down the isotropic case (T⊥/T⊥ <60> 1), showing comparatively diminished magnitudes of the quantities.

2 illus, 9 ref

004031   Mishra R K;Agarwal Mishra R (Computer and I.T. Section, Tropical Forest Research Institute, P.O. RFRC, Mandla Road, Jabalpur-482 021, Email: rkm_30@yahoo.com) : Daily variation in cosmic ray intensity during high / low amplitude days. Pramana J Phys 2007, 68(3), 407-22.

A detailed study has been conducted on the long-term changes in the diurnal, semi-diurnal and tri-diurnal anisotropies of cosmic rays in terms of the high/low amplitude anisotropic wave train events (HAE/LAE) during the period 1981-94 using the neutron monitor data from Deep River Neutron Monitoring Station. In all, 38 HAE and 28 LAE cases have been studied. An inter-cornparison of the first three harmonics during these events has been made so as to understand the basic reason for the occurrence of these types of events. It has been observed that the phase of diurnal anisotropy shifts towards earlier hours for HAEs and it shifts towards earlier hour as compared to 18-h direction for LAEs. For semi-diurnal anisotropy, phase remains statistically the same for both HAE and LAE. In the case of tri-diurnal anisotropy, phase is evenly distributed for both types of events. The interplanetary magnetic field (IMF) and solar wind plasma (SWP) parameters during these events are also investigated. It has also been observed that HAE/LAEs are weakly dependent on high-speed solar wind velocity. The two types of solar wind streams (corotating streams and flare-generated streams) produce significant deviations in cosmic ray intensity during HAE/LAE.

10 illus, 58 ref

004030   Mantha V;Mohanty A K;Satyamurthy P (Laser and Plasma Technology Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: lmmhd@apsara.barc.ernet.in) : Thermal hydraulic studies of spallation target for one-way coupled Indian accelerator driven systems with low energy proton beam. Pramana J Phys 2007, 68(2), 355-63.

BARC has recently proposed a one-way coupled ADS reactor. This reactor requires typically <126>1 GeV proton beam with 2 mA of current. Approximately 8 kW of heat is deposited in the window of the target. Circulating liquid metal target (lead/lead-bismuth-eutectic) has to extract this heat and this is a critical R&D problem to be solved. At present there are very few accelerators, which can give few mA and high-energy proton beam. However, accelerators with low energy and hundreds of micro-ampere current are commercially available. In view of this, it is proposed to simulate beam window heating of <126>8 kW in the target with low-energy proton beam. Detailed thermal analysis in the spallation and window region has been carried out to study the capability of heat extraction by circulating LBE for a typical target loop with a proton beam of 30 MeV energy and current of 0.267 mA. The heat deposition study is carried out using FLUKA code and flow analysis by CFD code. The detailed analysis of this work is presented.

5 illus, 1 table, 14 ref

004029   Manoharan C;Dhanapandian S;Veeramuthu K (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002) : Characterization of South Indian archaeological potteries using FT-IR spectroscopy. Acta Cienc Indica-Phys 2007, 33(2), 229-34.

Fourier Transform Infrared (FT-IR) Spectroscopy is a versatile technique in the characterization of clays and clay products like potteries, bricks, tiles etc. Analyses the archaeological potteries collected from Thiruchitrambalam (TCM) (Lat 8° 56 'N; Long 77° 16 'E) and Cheramanperambhu (CPU) (Lat 10° 53 'N; Long 76° 27'E), South India. The type of clay minerals associated, their firing temperature and firing conditions prevailed during manufacturing the potteries are well established from the FT-IR analysis. Potteries TCM-1, TCM-2, CPU-1 and CPU-2 were made up of red clay type and fired around 650°C. The samples were fired under oxidizing conditions except TCM-2, which was fired under reduced atmospheric conditions.

4 illus, 18 ref

004028   Majumdar D;Kar K (NO, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700 064, Email: debasish.majumdar@saha.ac.in) : Beta decay rates of nuclei with 65 <60> A <60> 75 for pre-supernova and supernova evolution. Pramana J Phys 2007, 68(3), 423-33.

The half-lives are calculated for the β^- decay process for nuclei in the mass range <126>65-75 relevant for the core of a massive star at the late burning stage of stellar evolution and the collapse that leads to supernova explosion. These half-lives and rates are calculated by expressing the β^- Gamow-Teller decay strengths in terms of smoothed bivariate strength densities. These strength densities are constructed in the framework of spectral averaging theory for two-body nuclear Hamiltonian in a large nuclear shell model space. The method has a natural extension to electron captures as well as weak interaction rates for r and rp-processes.

2 tables, 25 ref

004027   Kumar V;Kumawat H;Sharma M (High Energy Nuclear Physics Laboratory, Physics Dep, Rajasthan Univ, Jaipur-302 004, Email: vkumarv1sancharnet.in) : Role of (n, xn) reactions in ADS, IAEA-benchmark and the Dubna cascade code. Pramana J Phys 2007, 68(2), 315-24.

Dubna Cascade Code (version-2004) has been used for the Monte Carlo simulation of the 1500 MW_t accelerator driven sub-critical system (ADS) with ²³³U + ²³²Th fuel using the IAEA benchmark. Neutron spectrum, cross-section of (n, xn) reactions, isotopic yield, heat spectra etc. are simulated. Many of these results that help in understanding the IAEA benchmark are presented. It is revealed that the code predicts the proton beam current required for the 1500 MW_t ADS for K_eff = 0.98 to be 11.6 mA. Radial distribution of heat is fairly in agreement with other codes like the EA-MC and it needs nearly 1% less enrichment than given by other codes. This may be because the code takes care of the role of larger order of the (n, xn) reactions. It is emphasized that there is a strong need to study (n, xn) reactions both theoretically and experimentally for better design.

7 illus, 3 tables, 17 ref

004026   Kozodaev A M;Gavrilin N D;Igumnov M M;Konev V N;Lazarev N V;Raskopin A M;Seliverstov V V;Shvedov O V;Volkov E B (NO, Institute of Theoretical and Experimental Physics, 25, B.Cheremushkinskaya-117 218, Email: a.kozodaev@itep.ru) : Electro-nuclear neutron generator - XADS at ITEP. Pramana J Phys 2007, 68(2), 243-55.

The purpose and status of the currently constructed ITEP experimental accelerator driven system (XADS) are discussed. This hybrid electro-nuclear facility of moderate power integrates the pulse proton linac (36 MeV, 0.5 mA) and heavy water sub-critical blanket assembly (heat power of 100 kW). Most parts of the equipment units are ordered for industrial manufacturing and some are under development. The facility is supposed to be used for investigations of a wide range of problems concerning both the target-blanket assembly and the accelerator-driver and at the same time explore the dynamical processes arising during their combined operation. Some other applications of the proton beam and neutron source are also discussed. It is possible in future to increase the current and energy of proton or heavy ion beam.

13 illus, 1 table, 15 ref

004025   Korovin Y A;Artisyuk V V;Ignatyuk A V;Pilnov G B;Stankovsky A Y;Titarenko Y E;Yavshits S G (NO, Obninsk State Technical Univ Nuclear Power Engineering, 1, Studgorodok-249 030, Email: korovin@iate.obninsk.ru) : Transmutation of radioactive nuclear waste - present status and requirement for the problem-oriented nuclear data base. Pramana J Phys 2007, 68(2), 181-91.

Transmutation of long-lived actinides and fission products becomes an important issue of the overall nuclear fuel cycle assessment, both for existing and future reactor systems. Reliable nuclear data are required for analysis of associated neutronics. Gives a review of the status of nuclear data analysis focusing on the waste transmutation problem.

1 illus, 5 tables, 22 ref

004024   Kochurov B P;Konev V N;Kwaretzkheli A Y (NO, Institute of Theoretical and Experimental Physics, Moscow-117 218, Email: boris.kochurov@itep.ru) : On the transmutation of am in a fast lead-cooled system. Pramana J Phys 2007, 68(2), 193-9.

Characteristics of the equilibrium fuel cycle for the core or a blanket of ADS having the structure of the core of a fast lead-cooled reactor of type BREST (Russian abbreviation for 'Bystryy Reaktor so Svintsovym Teplonositelem') in a mode of americium transmutation are calculated. Americium loading was taken 5% of heavy atoms. Keeping the average multiplication factor the same as in a standard equilibrium cycle, reactivity swing over 1 year's microcycle is about 1%, that demands partial fuel reloading with a periodicity of about one month. For one year of operation, 61 kg of americium is destroyed, and due to increased ²³⁸Pu content, americium is mainly converted to fission products. Thus in a system of i GWt (thermal), 87 kg of americium can be transmuted yearly. The estimate of the reactivity void effect has shown that it increases to 0.6% almost linearly with the void fraction increasing up to 25% and reaches its maximum of 0.7% at a void fraction of about 50%. Application of similar strategy for ADS with a sub-criticality level ≈0.96-0.98 can essentially relax safety problems related to positive void effects.

2 illus, 4 tables, 2 ref

004023   Kochurov B P;Knyazev A P;Kwaretzkheli A Y (NO, Institute of Theoretical and Experimental Physics, Moscow-117 218 Russia, Email: boris.kochurov@itep.ru) : Methods and computer codes for nuclear systems calculations. Pramana J Phys 2007, 68(2), 213-23.

Some numerical methods for reactor cell, sub-critical systems and 3D models of nuclear reactors are presented. The methods are developed for steady states and space-time calculations. Computer code TRIFON solves space-energy problem in (X, Y) systems of finite height and calculates heterogeneous few-group matrix parameters of reactor cells. These parameters are used as input data in the computer code SHERHAN solving the 3D heterogeneous reactor equation for steady states and 3D space-time neutron processes simulation. Modification of TRIFON was developed for the simulation of space-time processes in sub-critical systems with external sources. An option of SHERHAN code for the system with external sources is under development.

3 illus, 8 ref

004022   Kaushik S;Raina R K;Bhatia G;Verma G L; Khandal R K (Shriram Institute of Industrial Research, 19 Univ Road, Delhi-110 007, Email: rkhandal@shriraminstitute.org) : Modification of coal tar pitch by chemical method of reduce benzo(a) pyrene. Curr Sci 2007, 93(4), 540-4.

Coal tar pitch (CTP) comprises mainly polycyclic aromatic hydrocarbons, some of which are carcinogenic in nature. Among these, benzo(a)pyrene (B(a)P) is one of the most prominently reported carcinogens and its presence in CTP is a cause of concern for environmentalists. B(a)P gets released into the atmosphere during processing of CTP for various applications and is the cause of adverse effects on human health and the environment. CTP has been modified using different modifiers to reduce the content of B(a)P. This involves not only the analysis for content of B(a)P in CTP by HPLC, but also deals with the several physico-chemical properties before and after modification of CTP. It has been observed that the B(a)P content can be reduced almost to the extent of 80% by chemical modification. On comparing the physico-chemical properties of CTP before and after modification, it has been observed that there is no noticeable change. Thus, modified CTP can be effectively used for various applications, without the potential hazards of B(a)P.

3 illus, 5 tables, 28 ref

004021   Hari Kishore M;Mukherjee G K (Physics Dep, Andhra Univ, Visakhapatnam-500 003, Email: gkm@iigs.iigm.res.in) : Equatorial F-region plasma drifts: a study using OI 630 mm emission all-sky images. Curr Sci 2007, 93(4), 488-97.

Equatorial ionospheric plasma bubbles that occur at the low-latitude F-region of the ionosphere and the irregularities associated with them are responsible for severe interference and sudden disruption of trans-ionospheric radio propagation up to Giga Hertz frequency range, interfering with the communication systems, including the GPS. A CCD-based all-sky imager with 180° field-of-view has been operating at a low-latitude station, Kolhapur (16.8°N, 74.2°E, dip lat. 10.6øN) in India on clear, moonless nights, to study the F-region dynamics through the imaging of OI 630.0 nm oxygen emission line. The imager has the capability of permitting observations over regions covering several million square kilometres from a single observing station. The ionospheric plasma bubbles manifest in all-sky imaging observations as nearly north-south aligned intensity-depleted regions. The all-sky images permitted the determination of the eastward plasma drift velocities, depth and width of the plasma bubbles. Also, the observed zonal plasma bubble drift velocities are compared with the thermospheric zonal neutral wind velocities obtained from the HWM-93 model. It reveals good agreement during some nights. The rate of change of zonal wind velocities has been modelled and is found to be consistent in terms of pressure variation computed from the MSIS-E 90 model.

12 illus, 2 tables, 34 ref

004020   Gunasekaran S;Thilak Kumar R (Phys Dep, St. Joseph's College of Arts and Science, Cuddalore-607 001, Email: manojthilak@yahoo.com) : Pharmacokinetic studies on diazepam using UV-visible spectroscopy. Asian J Chem 2007, 19(1), 472-80.

Bound blood-drug interaction of diazepam using UV-Vis spectroscopic method has been studied. Diazepam is an anti-epileptic drug which can be useful in the treatment of epilepsy. Bound blood-drug interaction is a method of analysis to understand the pharmacokinetic parameters with regard to the plasma drug concentration in the blood. The pharmacokinetic properties of a particular drug are basically related to its absorption, distribution, metabolism and excretion. When a drug is given, it reaches its peak level in the blood pretty quickly and the drug level then decreases as the drug is broken down and removed from the blood. UV-Vis spectra] measurements have been used to study the pharmacokinetic interaction of the drug with the living system (dog as a model); the results of clinical significance have been discussed.

6 illus, 1 table, 15 ref

004019   Gunasekaran S;Seshadri S;Muthu S (Phys Dep, Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya Enathur, Kanchipuram-631 561, Email: sri_sesha@yahoo.com) : Vibrational spectra and normal coordinate analysis of P-anisaldehyde. Asian J Chem 2007, 19(1), 465-71.

A normal coordinate analysis on p-anisaldehyde has been carried out with a systematic set of symmetry coordinates following Wilson's F-G matrix method. The potential constants evaluated for the molecule are found to be in good agreement with literature values thereby confirming the vibrational assignments. To check whether the chosen set of vibrational frequencies contribute maximum to the potential energy associated with the normal coordinates of the molecule, the potential energy distribution has been evaluated.

1 illus, 2 tables, 19 ref

004018   Ganesan S (Reactor Physics Design Div, Central Complex, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, Email: ganesan@barc.gov.in) : Nuclear data requirements for accelerator driven sub-critical systems - a roadmap in the Indian context. Pramana J Phys 2007, 68(2), 257-68.

Development of accelerator driven sub-critical systems (ADSS) require significant amount of new nuclear data in extended energy regions as well as for a variety of new materials. This paper reviews these perspectives in the Indian context.

1 table, 41 ref

004017   Fu Q;Wu S Y;Lin J Z;Yao J S (Applied Physics Dep, Electronic Science and Technology Univ, China, Chengdu-610 054, Email: shaoyi_wu@163.com) : Theoretical evaluation of the electron paramagnetic resonance spin hamiltonian parameters for the impurity displacements for Fe<. Pramana J Phys 2007, 68(3), 499-506.

The impurity displacements for Fe³⁺ and Ru³⁺ in corundum (Al₂O3) are theoretically studied using the perturbation formulas of the spin Hamiltonian parameters (zero-field splitting and anisotropic g factors) for a 3d⁵ (with high spin S = 5/2) and . a 4d⁵ (with low spin 5 = 1/2) ion in trigonal symmetry, respectively. According to the investigations, the nd⁵ (n = 3 and 4) impurity ions may not locate at the ideal A1³⁺ site but undergo axial displacements by about 0.132 A and 0.170 A for Fe³⁺ and Ru³⁺, respectively, away from the center of the ligand octahedron along the C₃ axis. The calculated spin Hamiltonian parameters based on the above axial displacements show good agreement with the observed values. The validity of the results is discussed.

1 table, 29 ref

004016   Elahi P;Nadgaran H;Kalantarifard F (Physics Dep, Payame Noor Univ, Shiraz, Iran, Email: pelahi@spnu.ac.ir) : Core temperature in super-Gaussian pumped air-clad photonic crystal fiber lasers compared with double-clad fiber lasers. Pramana J Phys 2007, 68(3), 529-34.

Investigates the core temperature of air-clad photonic crystal fiber (PCF) lasers pumped by a super-Gaussian (SG) source of order four. The results are compared with conventional double-clad fiber (DCF) lasers pumped by the same super-Gaussian and by top-hat pump profiles.

4 illus, 10 ref

004015   Drezet A (Institute of Physics and Erwin Schrodinger Institute for Nanoscale Res, Karl-Franzens-Univ, Universitatsplatz 5, 8010 Graz, Austria, Email: aurelien.drezet@uni-graz.at ) : Single photon and nonlocality. Pramana J Phys 2007, 68(3), 389-96.

In a paper by Home and Agarwal it is claimed that quantum nonlocality can be revealed in a simple interferometry experiment using only single particles. A critical analysis of the concept of hidden variable used by the authors of shows that the reasoning is not correct.

2 illus, 28 ref

004014   Dhanapandian S;Manoharan C;Resmi Nair P S; Gnanavel B;Veeramuthu K;Sathiyaseelan S (Physics Dep, Annamalai Univ, Annamali Nagar-608 002) : Spectroscopic and mechanical analysis of roofing tiles collected from Amaravila, Kerala. Acta Cienc Indica-Phys 2007, 33(2), 189-96.

Work is the results of a study concerning the processing of roofing tiles composed of clay, non-calcareous and quartz by establishing the type of clay, presence of major and minor minerals, firing temperature, firing atmosphere, colouring mechanisms and strength with increasing temperature of roofing tile during its manufacturing. The characterization of roofing tiles were carried out with the determination of chemical composition, water absorption, porosity, compressive strength, flexural strength, Fourier transform infrared (FTIR) and x-ray diffraction (XRD).

4 illus, 1 table, 15 ref

004013   Degweker S B;Ghosh B;Bajpai A;Paranjape S D (Theoretical Physics Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, Email: degweker@apsara.barc.gov.in) : The physics of accelerator driven sub-critical reactors. Pramana J Phys 2007, 68(2), 161-71.

In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future nuclear energy generation. The physics of ADS is quite different from that of critical reactors. As such, physics studies on ADS reactors are necessary for gaining an understanding of these systems. Development of theoretical tools and experimental facilities for studying the physics of ADS reactors constitute important aspect of the ADS development program at BARC. This includes computer codes for burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods. Discusses the physics issues specific to ADS reactors and presents the status of the reactor physics program and some of the ADS concepts under study.

3 illus, 1 table, 35 ref

004012   Dahiya R (Physics Dep, National Institute of Technology, Kurukshetra, Haryana) : Simulation of unified power flow controller. Acta Cienc Indica-Phys 2007, 33(2), 245-58.

Mathematical model of a unified power flow controller (UPFC) in a Single machine Infinite Bus system (SMIB) is proposed. The model consists of a simple voltage source whose magnitude and angle depend on the UPFC control parameters. The voltage-source model of UPFC can easily be incorporated into the generator output power equation and that simplifies the dynamic analysis of the system. With some appropriate assumptions, the proposed UPFC model can also be used to represent other FACTS devices, such as, static synchronous compensators, static synchronous series compensators (SSSC), etc. The proposed model is then used to determine and compare the dynamic behavior of a simple system equipped with various FACTS devices.

20 illus, 12 ref

004011   Dahiya R (Elect. Engineering Dep, National Institute of Technology, Kurushetra, Haryana) : Mathematical modelling of power system with facts, using D-decomposition techniques. Acta Cienc Indica-Phys 2007, 33(2), 165-70.

D-decomposition technique is suggested for small signal stability studies along with FACTS controllers. Brief description of D-decomposition technique is introduced. SNUB system is considered along with FACT device. The super conducting magnetic energy storage (SMES) and thyristor control series controller (TCSC) arc the FACTs devices for stability studies.

8 illus, 7 ref

004010   Cheng X S;Harun S W;Ahmad H (Photonics Laboratory, Physics Dep, Malaya Univ, 50603 Kuala Lumpur, Malaysia, Email: wadi72@yahoo.com) : Effects of output coupler reflectivity on the performance of a linear cavity Brillouin / erbium fiber laser. Pramana J Phys 2007, 68(3), 451-6.

The effect of output coupler reflectivity (or output coupling ratio) on the performance of a linear cavity Brillouin/erbium fiber laser (BEFL) is demonstrated. The  operating wavelength, output laser power and number of channels vary with changes in the" coupling ratio in the linear cavity system. The optimum BEFL operation is obtained with an output coupling of 40%, i.e.. 60% of the laser power is allowed to oscillate in the cavity. A stable laser comb consisting of up to 40 channels with line spacings of approximately 0.09 nm are obtained at the Brillouin pump and 980 nm pump with powers of 2.5 mW and 100 mW, respectively. The linear cavity BEFL has the potential to be used in inexpensive wavelength division multiplexing system.

4 illus, 5 ref

004009   Blomgren J (Neutron Research Dep, Uppsala Univ, Box 525, S-751 20 Uppsala, Sweden, Email: jan.blomgren@tsl.uu.se) : Neutron cross-sections above 20 MeV for design and modeling of accelerator driven systems. Pramana J Phys 2007, 68(2), 269-78.

One of the outstanding new developments in the field of partitioning and transmutation (P&T) concerns accelerator-driven systems (ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies, nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program on neutron-induced data related to ADS for P&T is running at the 20-180 MeV neutron beam facility at 'The Svedberg Laboratory' (TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (n, xn') reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program of development is outlined.

10 illus, 14 ref

004008   Biswal S;Mahalik S (Physics Dep, Nayagarh College Utkal Univ, Nayagarh-752 069) : Unsteady free convection flow and heat transfer of a visco-elastic fluid past in impulsively started porous flat plate with heat sources/sinks. Acta Cienc Indica-Phys 2007, 33(2), 259-71.

Unsteady free convection flow and heat transfer of a visco-elastic fluid past an impulsively started porous flat plate with heat sources/sinks has been theoretically analysed. The constitutive equations of continuity, motion and energy have been framed and then non-dimensionalised with the help of non-dimensional parameters like R_c, G, P, S and K etc. Small parameter regular perturbation technique has been employed to solve the momentum and energy equations for velocity and temperature of the fluid, and then the expression for the shear stresses, the rates of heal transfer are deduced. Velocity and temperature profiles are shown by graphs and the values of the shear stresses and the rates of heat transfer are entered in the tables after obtaining the results by computation. It is observed that the permeability factor K reduces both the mean and transient velocity of non-Newtonian (Rivlin-Ericksen) flow under investigation.

6 illus, 1 table, 23 ref

004007   Biswal S;Mahalik S (Physics Dep, Nayagarh Autonomous College, Nayagarh-752 069) : Heat transfer in the free convection flow of a viscoelastic fluid inside a porous vertical channel with constant suction and heat sources. Acta Cienc Indica-Phys 2007, 33(2), 155-64.

Free Convection currents are set up in all types of fluids due to difference in temperature between hot and cool layers. In some cases, the process is rapid with slight variation of temperatures of the layers and in some other cases, the process is slow depending upon the properties of the fluids. Heat transfer problems of free convection flow of both Newtonian and non-Newtonian fluids have attracted the attention of many researchers to investigate the velocity and temperature of the fluid, the shear stresses and the rates of heat transfer of such flows owing to various practical application in industry and technology.The aim is to study the problem of thermal energy transmission in the free convection flow of a visco-elastic fluid inside a porous vertical channel with constant suction and heat sources including the effect of porosity.

5 illus, 3 tables, 11 ref

004006   Bergelson B R;Gerasimov A S;Tikhomirov G V (NO, Institute of Theoretical and Experimental Physics, 25, B. Cheremushkinskaya-117 218 Moscow, Russia, Email: geras@itep.ru) : Operation of Candu power reactor in thorium self-sufficient fuel cycle. Pramana J Phys 2007, 68(2), 143-50.

Presents the results of calculations for CANDU reactor operation in thorium cycle. Calculations are performed to estimate the feasibility of operation of heavy-water thermal neutron power reactor in self-sufficient thorium cycle. Parameters of active core and scheme of fuel reloading were considered to be the same as for standard operation in uranium cycle. Two modes of operations are discussed mode of preliminary accumulation of ²³³U and mode of operation in self-sufficient cycle. For the mode of accumulation of ²³³U it was assumed for calculations that plutonium can be vised as additional fissile material to provide neutrons for ²³³U production. Plutonium was placed in fuel channels, while ²³²Th was located in target channels. Maximum content of ²³³U in target channels was estimated to be <126>13 kg/t of ThO₂. This was achieved by irradiation for six years. The start of the reactor operation in the self-sufficient mode requires ²³³U content to be not less than 12 kg/t. For the mode of operation in self-sufficient cycle, it was assumed that all channels were loaded with identical fuel assemblies containing ThO₂ and certain amount of ²³³U. It is shown that nonuniform distribution of ²³³U in fuel assembly is preferable.

6 illus, 3 tables, 4 ref

004005   Banyal R K;Raghavendra Prasad B (NO, Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore-560 034, Email: brp@iiap.res.in) : Measurements of photoinduced refractive index changes in bacteriorhodopsin films. Pramana J Phys 2007, 68(3), 435-41.

Reports the pump-probe measurements of nonlinear refractive index changes in photochromic bacteriorhodopsin films. The photoinduced absorption is caused by pump beam at 532 urn and the accompanying refractive index changes are studied using a probe beam at 633 nm. The proposed technique is based on a convenient and accurate determination of optical path difference using digital interferometry-based local fringe shift. The results are presented for the wild-type as well as genetically modified D96N variant of the bacteriorhodopsin.

5 illus, 14 ref

004004   Ashraf I M;Elshaikh H A;Badr A M (Physics Dep, South Valley Univ, Egypt, Email: badr_egsc@yahoo.com) : Characteristics of photoconductivity in thallium monosulfide single crystals. Pramana J Phys 2007, 68(3), 467-79.

This work elucidates the photoconductivity (PC) of thallium monosulfide single crystals. Results are obtained in the 77-300 K temperature range, 1500-4500 V lx excitation intensity, 6-18 V applied voltage, and in the 640-1500 nm wavelength range Both the ac-photoconductivity (ac- PC) and the spectral distribution of the photocurrent are studied in different values of light intensity, applied voltage and temperature. Dependencies of carrier lifetime on light intensity, applied voltage and temperature are also investigated as a result of the ac-PC measurements. The temperature dependence of the energy gap width was described by studying the de-photoconductivity (de-PC).

6 illus, 29 ref

004003   Arul Prakash K;Rathish Kumar B V;Biswas G (Mechanical Engineering Dep, Indian Institute of Technology, Kanpur-208 016, Email: arulk@iitk.ac.in) : A numerical study of the target system of an ADSS with different flow guides. Pramana J Phys 2007, 68(2), 365-76.

Mechanical design of the target module of an accelerator driven sub-critical nuclear reactor system (ADSS) calls for an analysis of the related thermal-hydraulic issues because of large amount of heat deposition in the spallation region during the course of nuclear interactions with the molten lead bismuth eutectic (LBE) target. The LBE also should carry the entire heat generated as a consequence of the spallation reaction. The problem of heat removal by the LBE is a challenging thermal-hydraulic issue. For this, one has to examine the flows of low Prandtl number fluids (LBE) in a complex ADSS geometry. In this study, the equations governing the laminar flow and thermal energy are solved numerically using the streamline upwind Petrov-Galerkin (SUPG) finite element (FE) method. The target systems with a straight and a nozzle guide have been considered. The principal purpose of the analysis is to trace the flow and temperature distribution and thereby to check the suitability of the flow guide in avoiding the recirculation or stagnation zones in the flow space that may lead to hot spots.

10 illus, 12 ref