023155   Murthy M R N (Molecular Physics Unit, Indian Institute of Science, Bangalore-560 012) : Personal account of virus structure determination at the Indian Institute of Science, Bangalore. J Indian Inst Sci 2007, 87(2), 279-99.

Virus particles are excellent models for understanding the specificity of protein-protein and protein-nucleic acid interactions and mechanisms of biological assembly. At the Indian Institute of Science, detailed investigations were done on the structure, stability and assembly of two isometric plant viruses, Sesbania mosaic virus (SeMV) and Physalis mottle virus (PhMV). The protein coat of SeMV consists of 180 protein subunits of molecular mass 29 kDa. It encapsidates a ss-RNA genome of 4149 bases. The genome of PhMV is a ss-RNA of size 6.67 kb encapsidated in an icosahedral shell of 180 identical coat protein (CP) subunits of molecular mass 20 kDa. The spatial arrangements of protein subunits in both the virus particles confirms to a T = 3 icosahedral lattice. The three dimensional X-ray structures of these viruses and a large number of their recombinant capsids have been determined. It was necessary to develop new algorithms and write a large number of programs for the determination of these structures. The stability of SeMV and PhMV particles are based on very different interactions. The capsid stability of SeMV depends on protein-protein, protein-nucleic acid and calcium mediated protein-protein interactions. In contrast, PhMV particles are stabilized predominantly by hydrophobic interactions between coat protein subunits. An analysis of the structural, biochemical and biophysical properties of the native SeMV, its recombinant capsid and several of its mutants has led to the understanding of the detailed pathway for the assembly of SeMV. Comparative structural analysis of the native and recombinant capsids of PhMV and studies on the assembly and stability properties of a large number of site specific and deletion mutants have suggested that the subunit folding and particle assembly are concerted events in this virus.

^iia14 illus, 28 ref

023154   Mukherjee A K (Physics Dep, Jadavpur University, Kolkata-700 032, Email: akm@juphys.ernet.in) : Ab-initio crystal structure determination from X-ray powder diffraction data. J Indian Inst Sci 2007, 87(2), 221-35.

Wide range of crystalline solids cannot be preapred as single crystals of suitable size and/or quality for structure analysis using conventional single-crystal X-ray diffraction techniques. In such circumstances, it is essential that structural information can be obtained from powder diffraction. Highlights some recent developments in the field of ab-initio crystal structure determination from X-ray powder diffracation dta. Relevant fundamental aspects of different steps of structure determination procedure from powder data are described with particualr emphasis to the challenging structure solution stage. Examples from the recent work are given to illustrate the potential of X-ray powder diffraction methodologies in determining crystal structures of several metal-organic complexes, organic compounds and pharmaceutical materials using diffraction data collected on a laboratory powder diffractometer.

^iia12 illus, 81 ref

023153   Khaneja M;Mittal U (Solid State Physics Laboratory, , Delhi-110 054) : Design and modelling of a two-part surface acoustic wave resonator using coupling-of-modes theory. Def Sci J 2008, 58(3), 372-6.

The coupling-of-modes theory has been used to design and simulate the characteristics of a two-port SAW resonator with shorted reflection gratings to define the resonance cavity. A resonator device at 150 MHz has been designed and fabricated on ST-Quartz. It is found that the simulated and experimental characteristics of the device are in close agreement. The results show that the SAW designs based on coupling-of-modes formulation are adequate for most applications.

3 illus, 9 tables

023152   Ghoshal S K;Sharma S;Gill K S;Gebrehiwet H (Dep of Physics, addis Ababa University, Addis Ababa, Arat Kilo, P.O. Box-1176, Ethiopia, Email: lordshib@phys. aau.edu.et) : Optical properties of silicon nanocluster and the influence of surface passivation. Asian J Spectrosc 2008, 12(1), 29-38.

The mechanism of the photoluminescence from small silicon nanoclusters is studied through computer simulation using empirical pseudo-potential Hamiltonian and the moment's method. The electronic and iptical properties of silicon quantum dots are examined in detail. The variation of the band gap, density of states, oscillator strength and absorption coefficient as a function of sizes of silicon nanoclusters with hydrogen and oxygen passivation at the surface is investigated. It is found that the gap decreases for increasing dot size for pure clusters. Furthermore, the bank gap as well as oscillator strength increases dot size for pure clusters. Furthermore, the band gap as well as oscillator strength increases on passivating the surface of the dot with hydrogen and oxygen respectively. So both quantum confinement and surface passivation determine the optical and electronic properties of silicon nanoclusters. The widening of the gap is more in case of oxygenated surface as compared to hydrogenated one. Visible luminescence is due to radiative recombination of electrons and holes in the quantum confined nanostructures. Investigates the entire energy spectrum starting from the very low lying ground state to the very high lying excited states for silicon dots having 3 to 44 atoms per dot. The role of surface states on the gap energy, HOMO-LUMO states as well as the effect of passivation on the confinement has also been examined. The results are in conformity with other the oretical and experimental observations.

4 illus, 18 ref

023151   Chopra D;Guru Row T N (Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560 012, Email: ssctng@sscu.iisc.ernet.in) : In situ cryocrystallization: pathways to study intermolecular interactions. J Indian Inst Sci 2007, 87(2), 167-211.

In situ crystallization of a liquid, the subsequent determination of its molecular and crystal structure and consequent study of intermolecular interactions is an area of contemporary interest. This technique has been successfully applied for the structure determination of compouunds, which are liquids at room temperature, solvents, low-melting solids, gas hydrates and ionic liquids. Particularly in solvents, the importance of how the molecules pack in the crystal lattice is of relevance in the context of polymorphyic modifications and their possible implicatiosn in directing other molecules to crystallize. In situ cryocrystallization, i.e. crystallization of compoudns in capillaries on the diffractometer, has offered meaningful outputs to understand both intra- and inter-molecular interactions. These offer will defined targets for molecular design, which can be exploited for the design of futuristic materials including areas like drugs, pharmaceuticals and technologically important materials.

85 illus, 1 table, 26 ref

023150   Bhowmick A;Krishnan L;Salunke D (Structural Biology Unit, National Institute of Immunology, New Delhi-110 067, Email: dinakar@nii.res.in) : Structural immunology: mechanisms of antigen recognition. J Indian Inst Sci 2007, 87(2), 301-7.

Mechanisms of antigen recognition by the immune system have been extensively addressed during past two decades. Ingeniously designed X-ray crystallographic experiments have provided great insights with regard to antigenic specificity and self/non-self discrimination, the hallmark of the adaptive immune system. These studies have also helped shed light on the mechanistic aspects of the immune recognition potential and the molecular events necessary for a successful immune response. The laboratory has made important contributions in understanding the physiological processes associated with self-nonself discrimination in terms of physico-chemical principles of molecular interactions. Crystallographic approaches were employed in analyzing how immune system reacts when encountered with the antigens that keep changing shape. Addresses the breakdown in specificity of immune recognition by providing molecular insights into the functional mimicry. The conundrum of a limited antibody repertoire faced with an infinite range of antigens was also addressed demonstrating that while the pluripotency of germline antibodies can be expressed through an ensemble of conformational states, each one of these states was itself capable of recognizing a wide range of antigens through varied juxtapositions.

^iia3 illus, 29 ref

023149   Ariponnammal S;Vanitha Rani R (Dep of Physics, Gandhigram Rural University, Gandhigram-624 302, Email: arikumar67@yahoo.co.in) : FTIR spectroscopic analysis on cosmetic powders. Asian J Spectrosc 2008, 12(1), 67-8.

The fourier Transform Infra-red Spectroscopic (FTIR) analysis have been made on some commercially available cosmetic powders. The active matters in the cosmetic powders have been determined and the quality control analysis have been made based on FTIR spectra.

1 illus, 1 table, 5 ref

023148   Ariponnammal S;Rathiha S K (Dep of Physics, Gandhigram Rural University, Ganghigram-624 302, Email: arikumar67@yahoo.co.in) : Study of intermediate alence fluctuation in europium telluride (EuTe). Asian J Spectrosc 2008, 12(1), 61-5.

The presence of intermediate valence fluctuation in EuTe is analysed by deducing the charge transfer from experimental and theoretical X-ray diffraction data. The direction and amount of charge transfer are obtained by plotting and comparing the structure factor of the components. The amount of charge transfer from europium (Eu) to tellurium (Te) is 0.15. The presence of intermediate valence flucutuation is inferred from the present study.

2 illus, 2 tables, 13 ref

022422   Zhang Z (Laboratoire de l'Accelerateur Lineaire, IN2P3-CNRS et Universite Paris-Sud 11, BP 34, 91898 Orsay Cedex, France, Email: zhangzq@lal.in2p3.fr) : Detector and trigger challenge for supersymmetrical dark matter scenarios at the international linear collider. Pramana J Phys 2007, 69(6), 1195-8.

Two supersymmetrical (SUSY) dark matter scenarios are discussed to illustrate how challenging it is to detect and trigger these events out of standard model background events at a future international linear collider (ILC).

5 ref

022421   Yoshioka T (ICEPP, Tokyo Univ, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Email: tyosioka@icepp.s.u-tokyo.ac.jp) : Performance of GLD detector. Pramana J Phys 2007, 69(6), 1115-8.

Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC experiment have been proposed so far in the world; the GLD detector that has a large inner calorimeter radius, which is considered to have an advantage for a PFA, is one of them. General scheme and performance of the GLD-PFA are presented.

2 illus, 1 table, 7 ref

022420   Yogendra Kumar (Physics Dep, Gyan Bharti Residential Complex, Bodh-Gaya-824 231) : Background study of the combined 2πγ and 2π2γ decay mode of the ω meson. Acta Cienc Indica-Phys 2008, 52(2), 101-3.

Reports some results on the analysis of the background tor a combined decay modes of 2irf and 2n2y of the ® meson. These results are very interesting.

1 illus, 1 table, 3 ref

022419   Wierba W (NO, , The Henryk Niewodniczanski Institute of Nuclear Physics, Email: Wojciech.Wierba@ifj.edu.pl) : Very forward calorimeters readout and machine interface. Pramana J Phys 2007, 69(6), 1191-3.

Describes the requirements for the readout electronics and DAQ for the instrumentation of the forward region of the future detector at the international linear collider. The preliminary design is discussed.

2 illus, 4 ref

022418   Wendt O;Gaede F;Kramer T (NO, DESY, 22603 Hamburg, Germany, Email: oliver.wendt@desy.de) : Event reconstruction with MarlinReco at the international linear collider. Pramana J Phys 2007, 69(6), 1109-14.

After an overview of the modular analysis and reconstruction framework Marlin an introduction on the functionality of the Marlin-based reconstruction package MarlinReco is given. This package includes a full set of modules for event reconstruction based on the particle flow approach. The status of the software is reviewed and recent results using this software package for event reconstruction are presented.

2 illus, 1 table, 17 ref

022417   Wadhwa A (Physics & Electronics Dep, SGTB Khalsa College, Delhi University, Delhi-110 007) : Simulation of the radioactive decay series. Phys Educ 2007, 24(1), 33-8.

Performed a simulation experiment on the phenomenon of radioactivity by considering a nuclear decay series. The simulation has been done using the Monte-Carlo method involving random numbers. The approach used here can be easily adopted in any undergraduate lab for better understanding of the phenomenon of radioactivity.

3 illus, 1 table, 3 ref

022416   Vijayaragavan R;Janakiraman G;Satheesh Kumar M (Physics Dep, Arasu Engineering College, Kumbakonam (Tamilnadu)) : Chemical and strength behaviour analysis of some green brick samples. Acta Cienc Indica-Phys 2008, 52(2), 23-7.

The Green brick samples were collected from different areas in Nagai district. With the aim to carryout Chemical analysis of various Oxide groups and strength behaviour (Density & Compressive Strength) analysis of these samples.

2 tables, 2 illus, 8 ref

022415   Vachhani P S;Solanki P S;Markna J H;Parmar R N;Bhalodia J A;Kuberkar D G (Physics Dep, Saurashtra Univ, Rajkot-360 005, Email: dgkuberkar@rediffmail.com) : Strain induced non-linear conduction in epitaxial La_0.7A_0.3MnO₃ manganite thin films. Indian J Engng Mater Sci 2007, 14(2), 163-6.

The current-voltage (l-V) properties of La_0.7A_0.3MnO₃ (A = Ca, Sr, Ba) manganite thin films grown on single crystalline LAO (100) substrate using chemical solution deposition (CSD) technique have been reported. Epitaxial nature of all the films has been confirmed from XRD measurements. The l-V measurements carried out on La_0.7Ba_0.3MnO₃ (LBMO) films show an unusual non-linear transport behaviour contrary to that observed for La_0.7Ca_0.3MnO₃ (LCMO) and La_0.7Sr_0.3MnO₃ (LSMO) films. This non-linearity has been explained in terms of non-uniform strain distribution resulting due to mismatch in the lattice parameters of LBMO film and substrate. The conductance data for all the films have been fitted using Simmon's model and the possible mechanism of charge conduction in the films has been discussed.

3 illus, 16 ref

022414   Topkar A;Praveenkumar S;Aggarwal B (NO, Bhabha Atomic Research Centre, Trombay, Mumbai-400 080, Email: anita@apsara.barc.ernet.in) : Silicon detector technology development in India for the participation in international experiments. Pramana J Phys 2007, 69(6), 1085-8.

mpecific research and development program has been carried out by BARC in India to develop the technology for large area silicon strip detectors for application in nuclear and high energy physics experiments. These strip detectors will be used as pre-shower detector in the CMS experiment at LHC, CERN for π°/λ rejection. The fabrication technology to produce silicon strip detectors with very good uniformity over a large area of ~40 cm², low leakage currents of the order of 10 nA/cm² per strip and high breakdown voltage of <62>500 V has been developed by BARC. The production of detectors is already under way to deliver 1000 detector modules for the CMS and 90% production is completed. In this paper, research and development work carried out to develop the detector fabrication technology is briefly described. The performance of the silicon strip tectors produced in India is presented. The present status of the detector technology is scussed.

4 illus, 4 ref

022413   Thomson M A (Cavendish Laboratory, Cambridge Univ, J J Thomson Avenue, Cambridge, CB3 0HE, UK, Email: thomson@hep.phy.cam.ac.uk) : Particle flow calorimetry at the international linear collider. Pramana J Phys 2007, 69(6), 1101-7.

One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of 0.3/√E(GeV). Describes the current performance of the PANDORAPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached. At higher energies the jet energy resolution becomes worse and can be described by the empirical expression: σE/E ≈ 0.265/√E(GeV) + 1.2 x l0^-4E(GeV).

2 illus, 2 tables, 10 ref

022412   Thakur A K (Research Fellow, L.N. Mithila Univ, K. Nagar, Darbhanga (Bihar)) : Antenna miniaturization and study of their effect on the radiation characteristics. Acta Cienc Indica-Phys 2008, 52(2), 171-4.

Reports the importance of personal communication system devices. Now-a-days the demand of highly developed and small mobile communication device is very high. To design small light weight and user friendly mobile communication devices, is creating the challenge of antenna miniaturization. Finally, presentes some techniques of antenna miniaturization and its analytical study has been done on radiation characteristics.

3 illus, 2 tables, 15 ref

022411   Telnow V I (NO, Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia, Email: telnov@inp.nsk.su) : Lay-out of the photon collider at the international linear collider. Pramana J Phys 2007, 69(6), 1177-9.

One of the interaction regions at the linear colliders should be compatible both with e⁺e^- and γγ, γe modes of operation. The differences in requirements and possible design solutions are discussed.

1 illus, 5 ref

022410   Telnov V L (NO, Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia, Email: telnov@inp.nsk.su) : Ultimate parameters of the photon collider at the international linear collider. Pramana J Phys 2007, 69(6), 957-61.

At linear colliders, the e⁺e luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). In γγ collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping ring designs, nominal DR parameters correspond to those required for e⁺e- collisions. In this note, I would like to stress once again that as soon as we plan the photon collider mode of ILC operation, the damping ring emittances are dictated by the photon collider requirements - namely, they should be as small as possible. This can be achieved by adding more wigglers to the DRs; the incremental cost is easily justified by a considerable potential improvement of the γγ luminosity. No expert analysis exists as of now, but it seems realistic to obtain a factor five increase of the γγ luminosity compared to the 'nominal' DR design.

1 illus, 23 ref

022409   Tambade P S;Wagh B G (NO, Ramkrishna More ACS College, Akurdi, Pune-411 044, Email: pstam3@rediffmail.com) : Numerical solution for composition of two mutually perpendicular simple harmonic motions Lissajous figures-A case study. Phys Educ 2007, 24(3), 197-202.

The objective of this article is to graphically illustrate to the students the physical phenomenon of motion under the action of two mutually perpendicular simple harmonic motions by simulating particle motion on a computer. Differential equations of two mutually perpendicular simple harmonic motions are solved numerically and Lissajous figures are obtained. This will make the concept, which so far is left to the abstract imagination come alive for the student, and initiate a deeper understanding of particle motion.

2 illus, 4 ref

022408   Takeshita T (NO, , Asahi, 3-1-1, Mataumoto, Nagano, Japan 390-8621, Email: tohru@azusa.shinshu-u.ac.jp) : Development of MPPC. Pramana J Phys 2007, 69(6), 1079-83.

For fine segmented scintillator calorimeter, need semiconductor-based photon sensor. Progress for MPPC which is developed in Japan is presented. One of the results which is relevant to photon detection efficiency indicates promising future of MPPC. However, further development is required for the dynamic range and operating voltage value.

5 illus, 1 ref

022407   Sunil Kumar (Applied Physics Dep, T.I.T.S. College Birla Colony, Bhiwani-127 021) : Crystal and molecular structure of Vth group pyridoxal oxime. Acta Cienc Indica-Phys 2008, 52(2), 111-16.

The crystal and molecular structure of Vth group pyridoxal oxime (C₈H₁₁O₆P) has been determined by single crystal X-ray diffraction. The crystal are triclinic. The space group was found to be PI or PI with unit cell dimensions α = 10.94 A, β = 8.06 A, c = 9.44 A, a = 57.18 A, p = 107.68°, γ = 116.53° and Z = 2 Dm = 1.57 cm^-3, V = 627 Angstrum³. The crystal structure is based upon a complex network of H-Bonds involving the two water molecules and various construction of the pyridoxal phosphate oxime.

5 illus, 2 tables, 14 ref

022406   Stefanow K D (NO, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK, Email: K.D.Stefanov@rl.ac.uk) : Linear Collider Flavour Identification status report: Sensors for the International Linear Collider. Pramana J Phys 2007, 69(6), 1001-8.

The Linear Collider Flavour Identification (LCFI) collaboration is continuing I lie work to develop column-parallel CCDs (CPCCD) and CMOS readout chips to be used in the vertex detector at the international linear collider (ILC). The CPCCD achieves al orders of magnitude faster readout than conventional CCDs because every column is equipped with amplifier and ADC, enabling efficient data taking with low occupancy. Alnwly two generations of CPCCDs and readout chips have been manufactured and the first chips have been fully tested. The second generation devices are now being evaluated. A new CCD-based device, the in-situ storage image sensor (ISIS) has also been developed. The ISIS offers numerous advantages in terms of relaxed readout, increased radiation hardness and great immunity to EMI. Presents the results from the tests of the CPCCDs, readout chips and ISIS, as well as the plans for future developments.

5 illus, 6 ref

022405   Srinivasa Rao R;Ghanash Krishna M (School of physics, Hyderabad Univ, Hyderabad-500 046) : Development of the electronics interface for the direct conversion of short-circuit current to temperature for use rare earth selective emitter based temperature sensors. J Instrum Soc India 2007, 37(3), 169-75.

Designing of a temperature indicator for use in rare earth selective emitter based temperature sensors is given. A selective emitter based temperature sensor has been studied in vacuum and furnace environments. The key component of the sensor is Yb₂O₃, which is in contact with the sample being measured. The sensor does not require the knowledge of emissive properties of sample being measured for temperatures greater than 1500°C. The measured short-circuit current from the detector is used to deduce the temperature readout. At high temperatures accuracy of 2 % and linearity of 5% has been achieved. Response time in milliseconds is predicted.

4 illus, 5 ref

022404   Sopczak A;Finch A;Freitas A;Milstene C; Schmitt M (NO, Lancaster Univ, Lancaster, LA1 4YW, UK) : Small visible energy scalar top iterative discriminant analysis. Pramana J Phys 2007, 69(6), 995-9.

Light scalar top quarks with a small mass difference with respect to the neutralino mass are of particular cosmological interest. This study uses an iterative discriminant analysis method to optimize the expected selection efficiency at the international linear collider (ILC).

5 illus, 1 table, 8 ref

022403   Solanki G K;Deshpande M P;Agarwal M K (Physics Dep, Sardar Patel Univ, Vallabh, Vidyanagar-388 120, Email: solankigunvant@yahoo.co.in) : Synthesis, characterization and studies of phase transition in GeSe single crystals grown using different transporting agants. Indian J Engng Mater Sci 2007, 14(5), 373-80.

Reports growth of germanium monoselenide (GcSc) single crystals by vapour phase technique using different transporting agents. The single crystallinity and composition of the grown samples have been verified through transmission electron microscopy (TEM) and energy dispersive analysis of X-rays (EDAX) respectively. In order to look for the possibility of phase transition, resistivity measurements have been carried out in different temperature ranges starting from 10 K. The results have indeed shown discontinuities both in the low temperature range as well as in the high temperature range. Such discontinuities in the past have been associated with possible phase transitions in GeSe. A possible explanation for the discontinuities is provided and the implications have been discussed.

7 illus, 3 tables, 23 ref

022402   Sinha R;Jha V N;Praveen Kumar (P.G. Department of Physics, B.N.M.U., Madhepura) : Study of radiowave attenuation by rain drops. Acta Cienc Indica-Phys 2008, 52(2), 57-60.

An empirical formula for calculating the extinction cross section (ECS) by raindrops over a broad frequency range is derived based on extensive calculations made on a widely varying in mean radius of modified pruppacher and pitter rain drop models. This formula thus provides a simple and inexpensive method for calculating the attenuation of rain drops, which otherwise requires complicated, tedious and extensive methods of calculations. Based on the study by isotropic or an isotropic spherical wave expansion, the specific rain attenuation equation was introduced. By implementing the empirical formula of the ECS into the rain attenuation equation, a new numerically empirical formula for the calculation of specific rain attenuation is also established. The validity of the empirical formula for calculating the specific rain attenuation is also verified by comparing the obtained results of specific rain attenuation with those obtained by different researchers found in literature.

1 illus, 11 ref

022401   Singh S P;Roychoudhury M (Physics and Electronics Dep, Dr. R.M.L. Avadh Univ, Faizabad) : Evolution of patterns in an unstables thin polymer film adsorbed on solid substrate: a dynamic Monte Carlo study. Acta Cienc Indica-Phys 2008, 52(2), 61-70.

Results of Monte Carlo simulation performed for unstable thin linear polymer molecules adsorbed on solid substrates, are presented. Thin polymer films of thickness <60>100 nm show spinodal dewetting when annealed above their glass transition temperatures. A 24x18x6 size lattice has been initially taken. 24 beads have been taken along the backbone of the polymer chain in X direction. The initial average density of beads is 3.64. The film is placed between two hard boundaries in Z direction. A completely self avoiding random walk has been performed applying free boundary condition at the ends of chains. The attempted Monte Carlo update consists in a monomer displacement where the new position r' = r ± Δr with Δr = (Δx, Δy, Δz) being chosen randomly and uniformly from the intervals -0.30 Ax, Ay, Δz 0.30. Glauber kinetic function has been used for shifting beads form their respective earlier positions. The evolution patterns show creation of holes in the film. Stacking of beads is also observed. Dominant spinodal waves are observed in the XY plane. The rate of initial equilibration process of free energy is also reported. A brief account of the theory of dewetting of thin film and dynamic Monte Carlo simulation procedure is given in this paper.

4 illus, 15 ref

022400   Singh S N;Yadav S K (P.G. Department of Physics, C.M. Science College, L.N.M.U., Darbhanga) : Analytical study of composite DRA for wideband application. Acta Cienc Indica-Phys 2008, 52(2), 51-6.

The objective of the study is to enhance the band width of DRA by using stacked configuration above an infinite ground plane. The DRA is axi-symmetric, and coaxial probe is placed off the antenna axils to excite HEM mode. The radiation is resulted in broad side pattern. The effect of different parameters on antenna performance has been studied. The optimum condition for a band width of 36% has been produced for stacked DRA configuration. An equivalent electric circuit model has been postulated to explain dual resonant behavior of stacked DRA system.

1 table, 5 illus, 6 ref

022399   Singh R S (Physics Dep, Faculty of Science, J.N.V. Univ, Jodhpur-342 005) : Lattice dynamics of B.C.C. transition metals. Acta Cienc Indica-Phys 2008, 52(2), 127-30.

The Pseudopotential Technique has been used as a tool for the evaluation of the lattice dynamics of tungsten. The normal modes of vibrations of this crystal depend strongly on their electronic structure and anamolous features are related to the electronic properties. Taking into account, the hybridization effect in terms of d-state radius dependent effective mass, most of the anomalies of the phonon spectrum of tungsten are evaluated and found to be in good agreement with experiment.

1 illus, 12 ref

022398   Singh R K;Sinha A K;Singh A;Mishra L K (Physics Dep, Town Inter College, Aurangabad) : Study of two-fluid superfluid hydrodynamics in trapped bose-gases. Acta Cienc Indica-Phys 2008, 52(2), 89-94.

Superfluid dynamics of trapped Bose-gases at finite temperature has been studied. Using the Gross-Pitaevskii (G - P) equation for the condensate macroscopic wave functions and a kinetic equation for the non-condensate, the Landau-Khalatnikov (L-K) two fluid hydrodynamic equations for the trapped Bose gas was derived. The main feature of these super-fluid hydrodynamic equations is that it is a microscopic model, which allows one to compute all the thermodynamical quantities of trapped Bose gases.

21 ref

022397   Singh R K;Sinha A K;Singh A;Mishra L K (Physics Dep, Town Inter college, Aurangabad) : Study of two fluid hydrodynamics in trapped bose gases and evaluation of speed of sound (C) as a function of condensate peak density <. Acta Cienc Indica-Phys 2008, 52(2), 83-8.

Two fluid hydrodynamics of pure condensate at T = 0 has been studied and speed of sound C as a function of condensate peak density ⁿC₀ has been determined. Our theoretical results are not in good match with experimental data for low ⁿC₀ but agreement is quite good for high ⁿC₀. The evaluation is done by G - P equation rewritten in the form of two coupled equation for the density and and velocity field. These equations have the typical structure of the dynamic eqution of superlluid to T = 0.

18 ref

022396   Shukla S;Singh L K;Singh P K;Tiwari R C (Physics and Electronics Dep, Dr. Ram Manohar Lohia Avadh Univ, Faizabad-224 001) : Electroluminescence in Cu and Mn activated ZnO electroluminophors. Acta Cienc Indica-Phys 2008, 52(2), 77-81.

Study of electroluminescence in ZnO phosphor activated with Cu and Mn and co-activated with hydrogen is made under different excitation field conditions. The doubly activated system provides simultaneous appearance of green and yellow emission bands. The effect of excitation field on the temperature dependence of EL emission is also studied in detail for isolated green and yellow emission bands.

4 illus, 11 ref

022395   Shrama A K;Verma K K (Physics & Electronics Dep, Dr. R.M.L. Avadh Univ, Faizabad-224 001) : Preparation and characterization of monolayer TI:HTSC film by spray pyrolysis technique. Acta Cienc Indica-Phys 2008, 52(2), 121-6.

Reports the preparation of TI-1201 (calcium less) HTSC film by spray pyrolysis technique using an aqueous nitrate solution of 0.3 M concentration on MgO (100) single crystal substrate. The film exhibited lower Tc phase with Tc (on set) at 18.8 K and Tc (R = 0) - 7.6 K. The XRD analysis of the film exhibited the full width at half maximum (FWHM) 0.13 for φ peak which is indicative of the good texturing and crystaliinity of the film. The presence of very few <60> 0 0 ≥ peaks indicates the unoriented nature of the film. The film shows tetragonal structure with lattice parameter, as calculated by POWD program, of a = 4.2669 Angstrum and c = 10.2800 Angstrum respectively.

5 illus, 7 ref

022394   Sharma S (NO, Tata Institute of Fundamental Research, Mumbai-400 005, Email: Seema.Sharma@cern.ch) : Understanding the performance of CMS calorimeter. Pramana J Phys 2007, 69(6), 1069-74.

The performance of the CMS hadron calorimeter is studied using test beam facilities at CERN. Two wedges of brass-scintillator calorimeter are exposed to negative and positive beams with momenta between 3 and 300 GeV/c. Light produced in the scintillators are collected using wavelength shifting fibres and read out using hybrid photo-diodes. Each of the wedges has 17 layers of scintillators. In one of these wedges signal from all 17 layers are grouped together while in the other each layer is read out separately. The response, energy resolution, longitudinal and lateral shower profiles are measured.

5 illus, 5 ref

022393   Sharma K C (R.I.E. Ajmer-305 004, , , Email: kcsharma149@yahoo.com) : Maxwell's displacement current (Alternative strategy towards functional understanding). Phys Educ 2007, 24(2), 105-12.

An alternative strategy toward the functional understanding of the vacuum displacement current in the nature of a field current, necessary to account for the energy balance in the region of the changing fields, may provide a better appreciation of the concept. Displacement current is introduced in senior secondary class. It is further discussed in undergraduate classes along with Maxwell's equations of electromagnetism. Students and teachers alike find it difficult to appreciate a current different from electronic current. Its significance is understood no better than a term ε₀ ∂E/∂t in Maxwell's equations. It is easily confused with some peculiar kind of passage of charges from one point to other. Efforts have been made in this article to touch upon the functional understanding of the vacuum displacement current usually not dealt with in the texts and teaching.

1 illus, 16 ref

022392   Sharma K C (NO, Regional Institute of Education (NCERT), Ajmer-305 004) : Science process study of cause-effect relationship (Discovering significance of Ohm's law beyond electricity). Phys Educ 2007, 24(1), 17-21.

Learning of science involves following a set of logical processes. Cause effect relationship is one such important component of the process. A large number of phenomena exhibit simple proportional cause-effect relationship over a range of interest in a vast variety of science and nonªscience disciplines. There is often a need to define characterization parameters based on this relationship for many phenomena. Proportionality phenomena like Ohm's law of electricity may be observed in many science and non-science processes in a variety of ways. Ohm's law has been taken as an exemplar. The study emphasizes on process approach which has universal validity in any phenomenon.

3 illus, 10 ref

022391   Sethumadhavan P;Anila A K;Udaynandan K M (Physics Dep, Nehru Arts and Science College, Kanghangad (Kerala)) : Gauge symmetry of work-energy theorem. Acta Cienc Indica-Phys 2008, 52(2), 1-5.

Work-energy theorem, which is a direct consequence of Newton's second law remains invariant, if the coordinate axes are rotated through fixed angles. It is proposed as a global symmetry transformation. But the theorem is not invariant under corresponding local transformation i.e. a transformation to a rotating frame of reference, but can be put in a form which possesses local symmetry. The additional work done, in rotating frame, such as work done by the centrifugal force, the Coriolis force etc. emerge as the manifestation of this local symmetry.

3 ref

022390   Schalicke A;Alexander G;Dollan R;Laihem K; Lohse T;Riemann S;Starovoitoc P;Ushakov A (DESY, Platanenallee 6, 15738 Zeuthen, Germany, Email: andreas.schaelicke@desy.de) : Study on low-energy positron polarimetry. Pramana J Phys 2007, 69(6), 1171-5.

A polarised positron source has been proposed for the design of the international linear collider (ILC). In order to optimise the positron beam, a measurement of its degree of polarisation close to the positron creation point is desired. In this contribution, methods for determining the positron polarisation at low energies are reviewed. A newly developed polarisation extension to GEANT4 will provide the basis for further polarimeter investigations.

1 illus, 11 ref

022389   Savoy-Navarro A (NO, LPNHE Universites Paris 6 et 7, and CNRS-IN2P3, 4 Place Jussieu, 75252 Paris Cedex 05, France, Email: aurore@lpnhep.in2p3.fr) : New developments of the R&D silicon tracking for linear collider on silicon trackers. Pramana J Phys 2007, 69(6), 1199-1206.

The status of the R&D activity achieved so far within the SiLC (silicon tracking for the linear collider) collaboration is reported here. It includes the following items: present status of the collaboration, new developments on sensors, on mechanics (new directions for module construction, large support structure, cooling, and alignment and integration issues), new lab test bench results on electronics and sensors. The perspectives over a period of four years are presented with a detailed test beam schedule and the roadmap including the construction of new mechanical prototypes equipped with front end and readout chips in deep sub-micron CMOS technology are discussed. Combined tests with other sub-detectors are finally addressed. This test beam program is inserted in the framework of the EUDET European project.

4 illus, 10 ref

022388   Sahoo S;Agrawalla R K;Goswami M (Physics Dep, National Institute of Technology, Durgapur-713 209, Email: sukadevsahoo@yahoo.com) : Dark energy in the universe. Phys Educ 2007, 24(1), 53-8.

One of the most evasive and fascinating enigmas in physics is the problem of the dark energy in the Universe. It represents the most mysterious phenomenon of our Universe which still did not find a satisfactory explanation in modern physics. Observations of distant supernovae and fluctuations in the Cosmic Microwave Background (CMS) indicate that the expansion of the Universe is accelerating under the action of 'dark energy. Roughly 70 % or more of the Universe consists of dark energy, whose origin and nature is completely unknown so far. Evidence for the existence of dark energy in the Universe is overwhelming. But it has not been directly observed in the laboratory.

30 ref

022387   Rakesh Kumar;Sharma B S (Physics Dep, Narain (PG) College, Shikohabad, Firozabad) : Analysis of high pressure-high temperature behaviour of geophysical minerals. Acta Cienc Indica-Phys 2008, 52(2), 7-22.

Studies the high pressure-high temperature behaviour of geophysical minerals such as Al₂O₃, Mg₂SiO₄, MgAl₂O₄, Mg₃Al₂Si₃O₁₂. Makes use of the Vinet-Rydberg equation of state (EOS) and the Shanker EOS. The results have been obtained for pressure P, isothermal bulk modulus K_T and its pressure derivative K'_T = dK_T/dP for the minerals under study at different compressions down to V/V₀ = 0.60. The results obtained from the two EOS are found to present close agreement with each other for all the minerals. It is founds that the bulk modulus increases with the increase in pressure, but decreases with the increase in temperature. Thus the minerals are found to become less compressible at high pressures and more compressible at high temperatures.

4 tables, 11 ref

022386   Penzo A (INFN-Sezione di Trieste, Area di Ricerca, Padriciano, Trieste, Italy, Email: aldo.penzo@ts.infn.it) : Evolution of the dual-readout calorimeter. Pramana J Phys 2007, 69(6), 1075-8.

Measuring the energy of.hadronic jets with high precision is essential at present and future colliders, in particular at ILC. The 4th concept design is built upon calorimetry criteria that result in the DREAM prototype, read-out via two different types of longitudinal fibers, scintillator and quartz respectively, and therefore capable of determining for each shower the corresponding electromagnetic fraction, thus eliminating the strong effect of fluctuations in this fraction on the overall energy resolution. In this respect, 4th is orthogonal to the other three concepts, which rely on particle flow analysis (PFA). The DREAM test-beam results hold promises for excellent performances, coupled with relatively simple construction and moderate costs, making such a solution an interesting alternative to the PFA paradigm. The next foreseen steps are to extend the dual-readout principle to homogeneous calorimeters (with the potential of achieving even better performances) and to tackle another source of fluctuation in hadronic showers, originating from binding energy losses in nuclear break-up (measuring neutrons of few MeV energy).

9 ref

022385   Pawan Kumar;Aravind Kumar;Dixit P N;Sharma T P (Physics Dep, G K V, Hardwar-249 404, Email: kumarpawangkv@indiatimes.com) : Study of optical constants in Cd_xZn_1-x vacuum eveporated thin films. Indian J Engng Mater Sci 2007, 14(4), 313-16.

Thin films of II-VI group semiconductors have been deposited by the vacuum evaporation technique onto highly cleaned glass substrates under the vacuum of the order of 10^-5 torr. The optical properties of these thin films have been determined from transmission spectra by using Manifcier's envelope method. These films posed, in genera] good transparency (T <62> 50%), exhibiting an interference pattern. The wavelength dependence of optical constant (refractive index and extinction coefficient) of these films have been reported.

1 illus, 3 tables, 26 ref

022384   Narayanpethkar A B;Vasanthi A;Mallick K (Solapur Univ, , Solapur, Email: mallik_ku@yahoo.com) : Demarcation of liquefaction zones by bouguer gravity and electrical resistivity method. J Indian Geophys Union 2007, 11(4), 175-80.

Of all the disasters the mankind faces, perhaps those due to the earthquakes are most severe. The danger to life and other damages are enormous due to soil liquefaction triggered by earthquakes. Prediction and demarcation of liquefaction zones in high seismicity regions will be a great help to mitigate hazards. In the present communication, it has been demonstrated for 1934 Bihar-Nepal and 1 993 Killari earthquakes that Bouguer and electrical resistivity methods (only for Killari) can be of help to delineate the liquefaction zones. With this backdrop, we believe that in conjunction with soil and sediment characteristics indicating high susceptibility to liquefaction, gravity and resistivity anomalies will provide vital information to predict and identify the liquefaction zones.

5 illus, 10 ref

022383   Morguno V L (DESY, FLC, Notkestrasse 85, Germany and ITEP, Moscow, Email: vasiliy.morgunow@desy.de) : Calorimeter energy calibration using the energy conservation law. Pramana J Phys 2007, 69(6), 1097-1100.

New calorimeter energy calibration method was developed for the proposed ILC detectors. The method uses the center-of-mass energy of the accelerator as the reference. It has been shown that using the energy conservation law it is possible to make ECAL and HCAL cross calibration to reach a good energy resolution for the simple calorimeter energy sum.

5 illus, 1 table, 6 ref

022382   Monig K (DESY, Platanenallee 6, D-15738 Zeuthen, Germany, Email: klaus.moenig@desy.de) : Physics issues on triggering. Pramana J Phys 2007, 69(6), 1207-8.

The detectors at the ILC are planned to run without hardware trigger. The physics constraints for a pure software trigger are discussed.

2 ref

022381   Monig K (DESY, Platanenallee 6, D-15738 Zeuthen, Germany, Email: klaus.moenig@desy.de) : Detector issues for a photon collider. Pramana J Phys 2007, 69(6), 1181-4.

The photon collider is an option at the ILC. In this note detector issues are discussed that are relevant for the change from the e⁺e^- mode of the ILC to the γγ mode.

2 illus, 9 ref