001088   Phatak S C (NO, Inst of Phys, Sachivalaya Marg, Bhubaneswar 751 005, Email: phatak@iopb.res.in) : Pentaquarks in chiral color dielectric model. Pramana J Phys 2006, 66(4), 647-55.

Recent experiments indicate that a narrow baryonic state having strangeness + 1 and mass of about 1540 MeV may be existing. Such a state was predicted in chiral model by Diakonov et al.the mass and width of this state.in chiral color dielectric model is compluted. It is shown that the computed width is about 30 MeV. It has been found that the mass of the state can be fitted to the experimentally observed mass by invoking a color neutral vector field and its interaction with the quarks.

2 illus, 1 table, 20 ref

001087   Paulose P I;Warrier M K R;Unnikrishnan N V (Res Cent, Maharajas Coll, Ernakulam-682 011) : Thermoluminescence analysis of gamma - irragiated Mn: Ce phosphate glass. Sci Soc 2004, 2(1), 35-44.

Thermoluminescence (TL) studies of rare earth ion and transition metal ion doped in different types of glasses were reported recently. Irradiation of glasses leads to the formation of structural defects. Studies on radiation induced glass centers provide a unique probe for elucidating not only the nature of the defect but also the glass structure as well. In the work investigated. TL emission characteristics of gamma irradiated phosphate glass doped with transition metal ion Mn²⁺ and rare earth ion Ce³⁺ and the results are incorporated. Single and well-shaped glow curves obtained for the samples at high temperatures leads the materials to use in radiation dosimetry.

3 illus, 1 table, 26 ref

001086   Oset E;Cabrera D;Magas V K;Roca L;Sarkar S; Vacas M J V;Ramos A (Departmento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia -CSIC, Instituto de Investigacion de Paterna, Apdo. Correos 22085, 46071, Valencia, Spain) : Chiral dynamics of baryon resonances and hadrons in a nuclear medium. Pramana J Phys 2006, 66(4), 731-52.

An introduction has been madde to chiral unitary theory applied to the meson-baryon interaction and it has been shown how several well-known resonances are dynamically generated, and others are predicted. Two very recent experiments are analyzed, one of them showing the existence of two Λ(1405) states and the other one providing support for the Λ(1520) resonance as a quasi-bound state of Σ(1385)π. The use of chiral Lagrangians to account for the hadronic interaction at the elementary level introduces a new approach to deal with the modification of meson and baryon properties in a nuclear medium. Examples of it for K bon, η and φ modification in the nuclear medium are presented.

14 illus, 2 tables, 49 ref

001085   Ohnishi A;Isse M;Otuka N;Sahu P K;Nara Y (Div of Physics. Grad Sch of Sci, Hokkaido Univ, Sapporo, Hokkaido 060-0810, Japan, Email: ohnishi@nucl.sci.hokudai.ac.jp) : Collective flows in high-energy heavy-ion collisions at AGS and SPS energies. Pramana J Phys 2006, 66(4), 797-807.

Proton collective flows in heavy-ion collisions from AGS ((2-11) A GeV) to SPS ((40,158) A GeV) energies are investigated in a nonequilibriuin transport model with nuclear mean-field (MF). Sideward (p_x), directed v₁, and elliptic v₂ flows are systematically studied with different assumptions on the nuclear equation of state (EoS). It has been found that momentum dependence in the nuclear MF is important for understanding the proton collective flows at AGS and SPS energies. Calculated results with momentum-dependent MF qualitatively reproduce the experimental data of proton sideward, directed, and elliptic flows in an incident energy range of (2-158) A GeV.

5 illus, 32 ref

001084   Mustafa M G (Theory Grp, Saha Inst of Nuclear Phys, 1/AF Bidhan Nagar, Kolkata-700 064, Email: munshigolam.mustafa@saha.ac.in) : Some applications of thermal field theory to quark-gluon plasma. Pramana J Phys 2006, 66(4), 669-87.

The thermal field theory briefy introducted has been within imaginary time formalism, the hard thermal loop perturbation theory and some of its applications to the physics of the quark-gluon plasma, possibly created in relativistic heavy-ion collisions.

12 illus, 33 ref

001083   Mosel U (Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen, Germany, Email: Ulrich.Mosel@theo.physik.uni-giessen.de) : Hadrons in medium. Pramana J Phys 2006, 66(4), 709-29.

Gives the motivation for investigations of in-medium properties of hadrons. Relevant symmetries of QCD and how they might affect the observed hadron properties have been discussed. Observable consequences of in-medium changes of hadronic properties in reactions with elementary probes, in particular photons, on nuclei have been discussed at length. Emphasis have been put on new experiments on changes of the σ- and ω-mesons in medium.

6 illus, 62 ref

001082   Khemchandani K P;Kelkar N G;Nowakowski M;Jain B K (Dep of Phys, Univ of Mumbai, Mumbai-400 098, Email: kanchanp@magnum.barc.ernet.in) : Resonances in eta-n light nucleus systems. Pramana J Phys 2006, 66(4), 791-6.

Resonances in η-light nucleus elastic scattering using the time delay method have been located few-body equations within the finite rank approximation have been solved in order to calculate the t-matrices and hence the time delay for the η-³He and η-⁴He systems. A resonance very close to the threshold in η-³ He elastic scattering, at about 0.5 MeV above threshold with a width of <126> 2 MeV has been found. The calculations also hint at the presence of sub-threshold states in both the cases.

2 illus, 15 ref

001081   Jain P;Mitra S (Phys Dep, Indian Inst of Technol Kanpur, Kanpur-208 016, Email: pkjain@iitk.ac.in) : Proton electormagnetic form factors at large momentum transfer. Pramana J Phys 2006, 66(4), 703-8.

Current experimental and theoretical status of the proton electromagnetic form factors have been reviewed.

20 ref

001080   Jain B K;Kelkar N G;Khemchandani K P (Dep of Phys, Tilak Bhavan, Vidyanagari, Santacruz (E), Mumbai 400 098, Email: brajesh_jain@vsnl.com) : Hadron production near threshold. Pramana J Phys 2006, 66(4), 753-64.

Final state interaction effects in pp → p ΛK⁺ and pd → ³He η reactions are explored near threshold to study the sensitivity of the cross-sections to the pΛ potential and the ηN scattering matrix. The final state scattering wave functions between Λ and p and η and 3He are described rigorously. The Λ production is described by the exchange of one pion and a K-meson between two protons in the incident channel. The η production is described by a two-step model, where in the first step a pion is produced. This pion then produces an η by interacting with another nucleon.

7 illus, 1 table, 14 ref

001079   Hubbell J H (NO, Natn Inst of Stand and Technol Radiat Phys Bldg 100 Bur Drive, Gaithersburg, MD 20899-8463 USA) : Radiation physics. Sci Soc 2004, 2(1), 5-14.

The constitution of the International Radiation Physics Society (IRPS) defines Radiation Physics as the branch of science which deals with the physical aspects of interactions of ionizing radiations (both electromagnetic and particulate) with matter. It thus differs in emphasis both from atomic and nuclear physics and from radiation biology and medicine, instead of focusing on the radiations.

30 ref

001078   Hosaka A (Res Cent for Nuclear Phys, Osaka Univ, Ibaraki 567-0047, Japan, Email: hosaka@renp.osaka-u.ac.jp) : Structure and reactions of pentaquark baryons. Pramana J Phys 2006, 66(4), 625-45.

Current status of the exotic pentaquark baryons has been reviewed. After a brief look at experiment of both positive and negative results, theoretical methods to study the structure and reactions for the pentaquarks have been discussed. The quark model and the chiral soliton model are first introduced, where the relation of mass spectrum and parity with some emphasis on the role of chiral symmetry has been discussed. It is always useful to picture the structure of the pentaquarks in terms of quarks. As for other methods, the a model independent method has been discussed, and have been briefly mentioned the results from the lattice and QCD sum rule. Decay properties are then studied in some detail, which is one of the important properties of θ⁺. The relation between the decay width and the quark structure having certain spin-parity quantum numbers has been investigated. Through these analyses, as plausible quantum numbers of θ⁺, J^p = 3/2^- have been considered. Production reactions of θ⁺ which provide links between the theoretical models and experimental information have been discussed. Photoproductions and hadron-induced reactions which are useful to explore the nature of θ⁺ structure have been discussed.

7 illus, 3 tables, 69 ref

001077   Gunasekaran S;Natarajan R K;Syamala D; Rathikha R (Postgrad and Res Phys Dep, Pachaiyappa's Coll, Chennai-600 030) : Normal coordinate analysis of urea metanitrobenzoic acid crystal. Indian J pure appl Phys 2006, 44(4), 315-19.

Urea meta nitrobenzoic acid is a crystal with the molecular formula C₈H₇O₄N₃. A normal coordinate analysis (NCA) has been carried out on this molecule with a systematic set of symmetry coordinates following Wilson's F-G matrix method based on C_s point group symmetry. The frequency assignments in the FTIR and FTR spectra have been presented. A reasonable set of potential constants evaluated for this molecule has been compared with those of related molecules and are in the characteristic range. The potential energy distribution has been evaluated using the vibrational spectral data and molecular parameters. The potential energy distribution value obtained reflects the correctness of the assignment mode.

3 illus, 1 table, 12 ref

001076   Gultekin A;Kaynak G;Gurler O (Fac of Art and Sci Univ of Uludag, , 16059 Bursa, Turkey) : Determination of full energy peak efficiency of HpGe detector from 59.5 to 1332.5 keV. Indian J pure appl Phys 2006, 44(4), 281-6.

To detect very low radio activities in the environmental samples, it is sometimes necessary to know the full energy peak efficiency of the detector. This work proposes a full energy peak efficiency simulation which represents adequately the high purity germanium coaxial detector responses in the energy range 59.5-1332.5 keV and at distances of 5, 10 and 25 cm.

6 illus, 1 table, 18 ref

001075   Godbole R M;Grau A;Hegde R;Pancheri G; Srivastava Y (Cent for High Energy Phys, Indian Inst of Sci, Bangalore-560 012) : Theroretical expectations for sigma<. Pramana J Phys 2006, 66(4), 657-68.

Various model predictons for pp total cross-section, for σ^pp_tot summarized and compared giving an estimate of the range of predictions for the total cross section, σ^pp_tot tot expected at the LHC. Concentration placed on the results for σ^pp_tot obtained in a particular QCD based model of the energy dependence of the total cross-section, including the effect of soft gluon radiation. The range of predictions in this model by exploring the allowed range of model parameters. Further a handy parametrisation of these results which incidentally spans the range of various other available predictions at the LHC as well has been given.

6 illus, 2 tables, 27 ref

001074   El-Arabi A M;Abbady A;Ahmed N K;Michel R; El-Kamel A H;Abbady A G E (Phys Dep, Fac of Sci Qena South Valley Univ, Egypt) : Assessment of radon-222 concentrations and exhalation rates of rocks and building materials. Indian J pure appl Phys 2006, 44(4), 287-91.

One hundred samples were collected from two regions (Bir El-Sid and Wady El-Gemal) in the Nile Valley. It contains various types of igneous and metamorphic rock samples (acidic dyke, intermediate dykes, basic dykes, serpentinite, metagabbro, menalge). Another set of samples were collected from different regions of Germany. Samples were analyzed and the concentrations in Bq/kg dry weight of radium were determined by gamma-ray spectrometry using hyper-pure germanium (HPGe) detector. A direct method is used to measure ²²²Rn emanated from the samples, which was analyzed in laboratory using the portable radon monitor Prassi. ²²²Rn activity concentrations (Bq/m³) were in the range from 36.1±2 to 96.4 ± 6, 17.8 ± 3 to 73.6 ± 4 and 18.0 ± 2 to 188.1 ± 15 Bq/m<6>3 for samples collected from Bir Elsid. Wadi El-Gemal and samples from Germany respectively. The corresponding values of exhalation rates were from 0.0012 to 0.004, 0.005 to 0.015 and 0.007 to 0.0069 Bq/gs for these areas respectively.

2 illus, 5 tables, 13 ref

001073   Barathan S;Govindarajan D;Sivakumar G;Raghu K (NO, , ) : Microwave study of hydration of cement with different waters. Indian J pure appl Phys 2006, 44(4), 334-8.

The dielectric constant and electrical conductivity of laboratory prepared cement paste, using X-band microwave technique in the frequency range 8.5-11.5 GHz have been studied. The cement was mixed with different waters, in a water to cement ratio (w/c) of 0.3, 0.4 and 0.5. With the help of dielectric constant and electrical conductivity, the hydration reactions of the cement pastes have been studied.

5 illus, 1 table, 17 ref

001072   Ajay Kumar;Garg M L;Nirmal Singh;Vijayan V (Phys Dep, Panjab Univ, Chandigarh-160 014) : Elemental analysis of potteries using energy dispersive X-ray fluorescence technique. Indian J pure appl Phys 2006, 44(4), 300-7.

Archaeological pottery samples belonging to four different civilization from Sanghol, India, were analyzed by Energy Dispersive X-ray Fluorescence (EDXRF) technique using the fundamental parameter approach. The samples for elemental analysis were excited by 17.8 keV X-ray photons of Mo secondary exciter in conjunction with X-ray tube. Ten elements namely, K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr and Y have been quantified. The experimental procedure adopted for elemental analysis was established by comparing the certified reference materials, obtained from National Institute of Standards and Technology (NIST), Chandigarh. It is concluded that the concentrations of the observed elements in pottery samples do not vary significantly for four different periods. The result indicates that the pottery of different periods was made from the same type of soil of the Sanghol region and pottery making was probably well developed art/technology at Sanghol.

4 illus, 6 tables, 12 ref

000129   Xie Y;Tang J (Dep of Engng Mechanics, Hum Univ, Changsha-410 082, Email: xieyuanxi88@163.com) : Superposition method in seeking the solitary wave solutions to the KDV-Burgers equation. Pramana J Phys 2006, 66(3), 479-83.

Starting from the careful analysis on the characteristics of the Burgers equation and the KdV equation as well as the KdV-Burgers equation, the superposition method is put forward for constructing the solitary wave solutions of the KdV-Burgers equation from those of the Burgers equation and the KdV equation. The solitary wave solutions for the KdV-Burgers equation are presented successfully by means of this method.

25 ref

000128   Udomsamuthirun P;Kumvongsa G;Burakorn A (Dep of Physics. Fac of Sci, Srinakharinwirot Univ, Bangkok, 10110, Thailand) : Effect of interband interaction on isotope effect exponent of M gB₂superconductors. Pramana J Phys 2006, 66(3), 589-96.

The exact formula of Tc's equation and the isotope effect exponent of two-band s-wave superconductors in the weak-coupling limit are derived by considering the influence of interband interaction. In each band, the model consists of two pairing interactions: the electron-phonon interaction and non-electron-phonon interaction. Finds that the isotope effect exponent of MgB₂, α - 0.3 with T_c ≈ 40 K can be found in the weak coupling regime and interband interaction of electron-phonon shows more effect on the isotope effect exponent than on the interband interaction of non-phonon.

2 illus, 53 ref

000127   Srivastan C S;Murthy M V N;Bhaduri R K (Dep of Phys, Indian Inst of Technol, Kanpur-208 016) : Gentile statistics and restricted partitions. Pramana J Phys 2006, 66(3), 485-94.

In a recent paper (Tran et al, Ann. Phys. 311, 204 (2004)), some asymptotic number theoretical results on the partitioning of an integer were derived exploiting its connection to the quantum density of states of a many-particle system. Generalises these results to obtain an asymptotic formula for the restricted or coloured partitions P^s_k(n). which is the number of partitions of an integer n into the summand of sth powers of integers such that each power of a given integer may occur utmost k times. While the method is not rigorous, it reproduces the well-known asymptotic results for s = I apart from yielding more general results for arbitrary values of s.

3 illus, 12 ref

000126   Singh S (Univ Dep of Phys, Ranchi Univ, Ranchi-834 008, Jharkhand, Email: vasudha_rncl@rediffmail.com) : Unitary transformation method for solving generalzed Jayanes-Cummings models. Pramana J Phys 2006, 66(3), 615-20.

Two fully quantized generalized Jaynes-Cummings models for the interaction of a two-level atom with radiation field are treated, one involving intensity dependent coupling and the other involving multiphoton interaction between the field and the atom. The unitary transformation method presented here not only solves the time dependent problem but also allows a determination of the eigensolutions of the interacting Hamilto-nian at the same time.

17 ref

000125   Singh M;Deka P N (Dep of Math, Dibrugarh Univ, Dibrugarh, Assam-786 004, Email: mahindersingh29@rediffmail.com) : Plasma-maser instability of the ion acoustics wave in the presence of lower hybrid wave turbulence in inhomogenous plasma. Pramana J Phys 2006, 66(3), 547-61.

A theoretical study is made on the generation mechanism of ion acoustics wave in the presence of lower hybrid wave turbulence field in inhomogeneous plasma on the basis of plasma-maser interaction. The lower hybrid wave turbulence field is taken as the low-frequency turbulence field. The growth rate of test high frequency ion acoustics wave is obtained with the involvement of spatial density gradient parameter. A comparative study of the role of density gradient for the generation of ion acoustics wave on the basis of plasma-maser effect is presented. It is found that the density gradient influences the growth rate of ion acoustics wave.

24 ref

000124   Singh M;Arora J S;Vijay Y K;Sudharshan M (Dep of Phys, Univ of Raj, Jaipur-302 004, Email: mangej_singh@yahoo.com) : Optical, electrical and thermoelectric power studies of Al-Sb thin film bilayer structure. Bull Mater Sci 2006, 29(1), 17-20.

The III-V semiconductors are of great importance due to their applications in various electro-optic devices. The Al-Sb thin film was deposited on glass substrate by thermal evaporation method at a pressure of 10^-5 torr. The samples were annealed for 3 h at different constant temperatures in a vacuum chamber at a pressure of 10^-5 torr. The electrical resistance vs temperature studies show phase transformation from metallic to semiconducting. The observed positive thermoelectric power indicates that Al-Sb thin films are p-type in nature. The Rutherford back scattering analysis and optical band gap measurements also indicate that the inter-diffusion concentration varies with temperature.

4 illus, 23 ref

000123   Setlur G S (Dep of Phys, Indian Inst of Technol, Guwahati, North Guwahati Assam-781 039, Email: girish_setlur@yahoo.com) : Bosonization and quantum hydrodynamics. Pramana J Phys 2006, 66(3), 575-88.

It is shown that it is possible to bosonize fermions in any number of dimensions using the hydrodynamic variables, namely the velocity potential and density. The slow part of the Fermi field is defined irrespective of dimensionality and the commutators of this field with currents and densities are exponentiated using the velocity potential as conjugate to the density. An action in terms of these canonical bosonic variables is proposed that reproduces the correct current and density correlations. This formalism in one dimension is shown to be equivalent to the Tomonaga-Luttinger approach as it leads to the same propagator and exponents. Computes the one-particle properties of a spinless homogeneous Fermi system in two spatial dimensions with long-range gauge interactions and highlight the metal-insulator transition in the system. A general formula for the generating function of density correlations is derived that is valid beyond the random phase approximation. Finally, writed down a formula for the annihilation operator in momentum space directly in terms of number conserving products of Fermi fields.

16 ref

000122   Senturk S;Harigaya K;Ozsoy O (Dep of Phys, Fac of Arts and Sci, Dumlupmar University, Kutahya 43100, Turkey, Email: ozxoyo@gop.edu.tr) : Polarizability effect in metallic clusters. Pramana J Phys 2006, 66(3), 507-12.

Langevin approach implemented in the inelastic cross-sections measured for the low-energy electrons colliding with metallic clusters points out that statical form of the polarizability dominate at energies less than 1.25 eV. The dynamical form comes into play at energies around 1.3 eV. The form of the polarizabilities indicates that polarizability of the metallic clusters is energy-dependent.

2 illus, 34 ref

000121   Sarma R;Mazumdar N;Das H L (Dep of Phys, Gauhati Univ, Guwahati-781 014, Email: hld_guphys@rediffmail.com) : Some spectral response characteristics of ZnTe thin films. Bull Mater Sci 2006, 29(1), 15-16.

Zinc telluride thin films have been grown at room temperature and higher temperature substrates by thermal evaporation technique in a vacuum of 10^-6 torr. A main peak in the photocurrent is observed at 781 nm (1.58 eV) with two lower amplitude peaks on the lower wavelength side and one on higher wavelength side. the evaluated thermal activation energy is found to correspond well with the main spectral peak. From these studies it can be inferred that temperatures up to 453 K is still in the extrinsic conductivity region of the studied ZuTe thin films.

2 illus, 7 ref

000120   Rajagopalan S;Sharma S J (Phys Dep, Nagpur Univ, Nagpur University Campus, Nagpur-440 003) : Mulberry silk-polyacryl amide blend using ultrasonic technique. J pure appl Ultrasonics 2005, 27(4), 105-9.

Ultrasonic velocity measurements in mulberry silk and polyacryl amide by Sing-around technique were made at 20°C, 25°C, 30°C and 35°C. The ultrasonic velocity was observed to vary linearly with concentration of polyacrylamide (PAA) in the solution. This indicates the formation of a single-phase system and the compatibility of a natural mulberry silk polymer with the synthetic polymer, polyacryl amide. The compatibility is due to the linear chain structure and prsence of the similar end group of amide in both the polymers.

8 illus, 1 table, 46 ref

000119   Rajagopalan M;Kalpana G;Priyamvadha V (Dep of Phys, Anna Univ, Chennai-600 025, Email: mraja1948@yahoo.co.in) : Pressure induced structural phase transition in SnS-An ab initio study. Bull Mater Sci 2006, 29(1), 25-8.

Structural behaviour of SnS under pressure has been investigated by first principle density functional calculations of the total energy by the TB-LMTO approach. It was found that SnS undergoes a structural phase transition from orthorhombic type to monoclinic type structure around 17 GPa which is in good agreement with the recent experimental study. In addition, the ground state properties are computed and compared with the available results.

6 illus, 2 tables, 20 ref

000118   Patidar D;Sharma R;Jain N;Sharma T P;Saxena N S (Dep of Physics, , Jaipur-302 004, Email: n_s_saxena@rediffmail.com) : Optical properties of CdS sintered film. Bull Mater Sci 2006, 29(1), 21-4.

Chemical method has been used to prepare cadmium sulphide by using cadmium, hydrochloric acid and H₂S. The reflection spectra of covered and uncovered sintered films of CdS have been recorded by `Hitachi spectrophotometer' over the wavelength range 300-700 nm. The energy band gaps of these films have been calculated from reflection spectra. It is found that the energy band gap of both films is same as 2.41 eV. It is indicated that energy band gap of these films does not change. This value of band gap is in good agreement with the value reported by other workers. The measurement of photocurrent has also been carried out using Keithley High Resistance meter/Electrometer. This film shows the high photosensitivity and high photocurrent decay. Thus so obtained films are suitable for fabrication of photo detectors and solar cells.

4 illus, 20 ref

000117   Naik V;Naik R;Somashekarappa H;Mahesh S S; Somashekar R (Dep of Phys, Wayne St Univ, Detroit, MI, USA) : Variation of crystallite size of Al_1-xIn_xN for different values of x and band gap. Bull Mater Sci 2006, 29(1), 29-34.

By using wide angle X-ray scattering (WAXS) technique, author has characterized the epitaxial al_1-xIn_xN films (thickness, 150 nm) with 0<60>x<60>1 grown by plasma source molecular beam epitaxy on sapphire (0001) at the low substrate temperature of 375°C, by computing the crystallite size in these samples. Observe that the crystallite size decreases with increase in the concentration of indium and that the band gap in these samples has a direct correlation with the crystallite size.

5 illus, 1 table, 23 ref

000116   Nadgaran H;Elahi P (Dep of Phys Coll of Sci, Shiraz Univ, Shiraz, 71454, Iran, Email: nadgaran@susc.ac.ir) : Overall phase shift and lens effect calcuation using Gaussian boundary conditions and paraxial ray approximation for an end-pumped solid-state laser. Pramana J Phys 2006, 66(3), 513-19.

The inhomogeneous equation of heat conduction was exactly solved by applying inhomogeneous boundary conditions for laser crystals of aspect ra-tio=l (aspect ratio=radius of the laser rod/length of the laser rod). Shows that the paraxial ray approximation leads the solution to be a function of r², that is, the approximation is equivalent to a situation in which a homogeneous pump source is used. The solution was then used to derive expressions for the overall phase shift, focal length of the thermal lens and the end effect induced curvature of the end face. The expressions were then applied to Nd:YAG laser medium. The result shows a meaningful correction of the order of 0.001 cm to the focal length of Nd:YAG rod for 3 W source power and beam waist of 100 μm.

1 illus, 9 ref

000115   Muthuselvi L;Dhathathreyan A (Chem Lab., Cent Leath Res institute, Adyar, Chennai-600 020, Email: adhatha@md5.vsnl.net.in) : Contact angle hysteresis of liquid drops as means to measure adhesive energy of zein on solid substrates. Pramana J Phys 2006, 66(3), 563-74.

Adhesion of zein to solid substrates has been studied using surface energy profiles as indices and by adhesion mapping using atomic force microscopy (AFM). Different plasticizers like glycerol and sorbitol have been used to form mixed films with zein and properties of these films are studied using surface energy profiles. Comparison of the results from the different mixed samples with those from the pure zein films showed that force mapping could identify areas rich in protein. The adhesion maps produced were de-convoluted from sample topography and contrasted with the data obtained from contact angle measurements. A comparison of the two methods shows that the extent of contact angle hysteresis is indicative of both hydrophobicity of the surface as well as the force of adhesion. Mechanical properties and microstructure of zein films prepared by casting from solutions and using Langrnuir-Blodgett film technique have been investigated. Pure zein seemed brittle and exhibited an essentially linear relationship between stress and strain. Films with plasticizer were tougher than these films. In general, mixed films showed better mechanical properties than pure films and had higher ultimate tensile strength and increased per cent elongation. Further, the mixed films of zein showed a higher force of adhesion compared to the pure films.

4 illus, 1 table, 29 ref

000114   Murali Mohan Y;Keshava Murthy P S;Mohana Raju K (Polym Sci and Technol Dep, Synth Polym Lab Sri Krishnadevaraya Univiersity, Anantapur-515 003) : Miscibility studies of hydroxyl-terminated poly (butadiene) (HTPB) and glycidyl azide polymer (GAP). J pure appl Ultrasonics 2005, 27(4), 119-24.

Polymer blending manifests superior properties than the individual components of the blending system. But these properties are dependent on the miscibility of the components. Thus miscibility probing for the polymer blends is very important whcih can be analyzed by physico-chemical techniques. The miscibility of hydroxyl-terminated poly (butadiene) (HTPB)/glycidyl azide polymer (GAP) blends were carried out in toluene by viscosity, ultrasonic velocity, refractive index, and density measurement at 30°C. By utilizing the viscosity data, the Chee and Sun interaction parameters are computed to have less than zero value indicating that the HTPB/GAP blends are immiscible. In addition to this, the ultrasonic, refractive index and density data also showed the immiscible nature of HTPB/GAP blends. Finally, two glasstransition temperatures are noted in the DSC analysis of the blend confirming the immiscible nature of the blend.

5 illus, 1 table, 23 ref

000113   Mishra S C;Chand F (Dep of Phys, Kurukshetra Univ, Kurukshetra-136 119, Email: subash_kuk@rediffmail.com) : Construction of exact dynamical invariants of two-dimensional classical system. Pramana J Phys 2006, 66(3), 601-7.

A general method is used for the construction of second constant, of motion of fourth order in momenta using the complex coordinates (z, z). A fourth-order potential equation is obtained whose solutions directly provide a large class of integrable systems. The potential equation is tested with an interesting example which admits second constants of motion.

14 ref

000112   Mazumdar N;Sarma R;Sarma B K;Das H L (Dep of Phys, Gauhati Univ, Guwahati-781 014, Email: hld_guphys@rediffmail.com) : Photoconductivity of ZnTe thin films at elevated temperatures. Bull Mater Sci 2006, 29(1), 11-14.

Photoconductivity of thermally evaporated ZnTe thin films was studied at different elevated temperatures. A gap type cell configuration with Al electrodes on glass substrates was used. The conductivity was found to obey two distinct conduction mechanisms within the region of applied fields. At low fields the photoconduction is ohmic and at high fields it is of Poole-Frenkel type. With increase of ambient temperatures, the Poole-Frenkel conductivity regions were found to extend to lower fields. The temperature dependence of dark conductivity also was found to be of similar nature.

4 illus, 8 ref

000111   Mahboob S;Prasad G;Kumar G S (Dep of Phys, Osmania Univ, Hyderabad-500 007, Email: gskumar1948@sify.com) : Electrical conduction in (Na_0.125Bi_0.125Ba_0.65Ca_0.1)(Na_{0 .065}Ti_0.87Nd_0.065)O₃ ceramic. Bull Mater Sci 2006, 29(1), 35-41.

Polycrystalline ceramic samples of sodium bismuth titanate with simultaneous doping at A and B sites have been studied for the influence of these dopants on the electrical conduction mechanism. A.C. conductivity measurements were done on the prepared sample in a wide range of frequency and temperature. Study revealed that the conduction in the sample arises due to hopping of bound charges. Four-term power law is used to characterize the frequency dependence of a.c. conductivity. From the temperature dependence of the exponents,the a.c. conduction in the samples is explained.

4 illus, 2 tables, 29 ref

000110   Kor S K;Srivastava A K (Phys Dep, Univ of Allahabad, Allahabad-211 002) : Ultrasonic studies in mexed solvents of water and heavy water in cetyl trimehtyl ammonium bromide. J pure appl Ultrasonics 2005, 27(4), 125-7.

Ultrasonic velocity and absorption measurement in C.T.A.B. in water and heavy water separately show a minimum in velocity and maximum in absorption at 6.5 gm/100 ml. It is expected that in mixed solvents of water and heavy water minimum in velocity and maximum in absorption will be enhanced. As such, in the study ultrasonic velocity and absorption measurements have been made as a function of concentration at fixed temperature and a fixed frequency. No minimum in velocity and maximum in absorption has been observed.

2 tables, 10 ref

000109   Harun S W;Samsuri N M;Ahmad H (Fac of Engng, Multimedia Univ, Jalan Multimedia, 63100, Cyberjaya, Selangor, Malaysia, Email: wadi72@yahoo.com) : Gain-clamping teachniques in two-stage double-pass L-band EDFA. Pramana J Phys 2006, 66(3), 539-45.

Two designs of long-wavelength band erbium-doped fiber amplifier (L-band EDFA) for gain clamping in double-pass systems are demonstrated and compared. The first design is based on ring laser technique where a backward amplified spontaneous emission (ASE) from the second stage is routed into the feedback loop to create an oscillating laser for gain clamping. The gain is clamped at 18.6 dB from -40 to -8 dBm with a gain variation of less than ñ0.1 dB and a noise figure of less than 6 dB. Another scheme is based on partial reflection of ASE into the EDFA, which is demonstrated using a narrowband fiber Bragg grating. This scheme achieves a good gain clamping characteristic up to -12 dBm of input signal power with a gain variation of less than ñ0.3 dB from a clamped gain of 22 dB. The noise figure of a 1580 nm signal is maintained below 5 dB in this amplifier since this scheme is not based on lasing mechanism. The latter scheme is also expected to be free from the relaxation oscillation problem.

6 illus, 8 ref

000108   Chaudhari M M;Londhe C T;Behere S H (Maharashtra Mahavidyalaya, Nilanga, Latur-413 521, Email: subhashbehere@yahoo.com) : Determination of rotational temperature of AlO from the B<. Pramana J Phys 2006, 66(3), 597-600.

AlO molecule was excited in a DC arc in air running between two aluminium electrodes. Rotational structure of the (0,0) band of the B2Σ⁺ - X²Σ⁺ system of A1O molecule was photographed in the first order of a 10.6 m concave grating spectrograph. Intensity distribution amongst the well-resolved rotational lines of R₁ and R₂ branches was recorded and the average rotational temperature calculated from these has been determined as 2880 ± 100 k.

2 illus, 11 ref

000107   Chaisi M;Maharaj S D (Astrophys and Cosmology Res Unit, Sch of Math Sci, University of KwaZulu-Natal, Durban, 4041, South Africa, Email: maharaj@ukzn.ac.za) : Anisotropic static solution in modelling highly compact bodies. Pramana J Phys 2006, 66(3), 609-14.

Einstein field equations for static anisotropic spheres are solved and exact interior solutions obtained. extends earlier treatment to include anisotropic models which accommodate a wider variety of physically viable energy densities. Two classes of solutions are possible. The first class contains the limiting case μ ∞ r^-2 for the energy density which arises in many astrophysical applications. In the second class the singularity at the centre of the star is not present in the energy density.

1 illus, 5 tables, 16 ref

000106   Chachadi A G;Ferreira J P L (Dep of Earth Sci, Goa Univ, Goa-403 206) : Assessing aquifer vulnerability to seawater intrusion using method-application to the Portuguese aquifer of Monte Gordo. J appl Hydrol 2005, 18(4), 47-56.

Presents the first application in Europe of an index developed in the framework of the EU-India INCO-DEV COASTIN project aiming the assessment of aquifer vulnerability to sea-water intrusion in coastal aquifers. The most important factors controlling seawater intrusion were found to be the following: Ground water occurrence (aquifer type; unconfined, confined and leaky confined); Aquifer hydraulic conductivity; Depth to groundwater Level above the sea; Distance from the shore (distance inland perpendicular from shoreline); Impact of existing status of seawater intrusion in the area; and Thickness of the aquifer, which is being mapped. The acronym GALDIT is formed from the highlighted letters of the parameters for ease of reference. These factors, in combination, are determined to include the basic requirements needed to assess the general seawater intrusion potential of each hydrogeologic setting. GALDIT factors represent measurable parameters for which data are generally available from a variety of sources without detailed surveys. A numerical ranking system to assess seawater intrusion potential in hydrogeologic settings has been devised using GALDIT factors. The application of the method is exemplified for the assessment of aquifer vulnerability to seawater intrusion in Portugal (Monte Gordo aquifer in the Portuguese Southern Algarve region). The system contains three significant parts: weights, ranges, and ratings. Each GALDIT factor has been evaluated with respect to the other to determine the relative importance of each factor.

13 illus, 1 table, 7 ref

000105   Anand A;Narayanamurthy C S (NO, Inst for Plasma Res, Bhatt, Near Indira Bridge, Gandhi Nagar-382 428, Email: csnaamu@yahoo.co.in) : Photorefractive dynamic holography using self-pumped phase conjugate beam. Pramana J Phys 2006, 66(3), 521-37.

Dynamic holography in photorefractive materials using self-pumped phase conjugate beam of the object beam itself as the other writing beam is proposed. The detailed theoretical analysis shows four-fold increase in the diffraction efficiency of dynamic holograms if recorded using this geometry even in photorefractive crystal like BTO (having low optical activity) without applying external field. Detailed theoretical analysis is given.

13 illus, 5 tables, 40 ref

000104   Ahmad I;Arafah M R (Dep of Phys Fac of Sci, King Abdulaziz Univ, P.O.Box, 80203, Jeddah, Saudi Arabia, Email: iahmad@kau.edu.sa) : Diffraction model analysis of pion-<. Pramana J Phys 2006, 66(3), 495-505.

Elastic scattering of 800 MeV/c pions by 12C has been studied in the diffraction model with a view to determine pion optical potential by the method of inversion. Finding an earlier diffraction model analysis to be deficient in some respects, proposes a Glauber model based parametrization for the elastic 5-matrix and show that it provides an exceedingly good fit to the pion-carbon data. The proposed elastic S-matrix gives a closed expression for the pion-¹²C optical potential by the method of inversion in the high energy approximation.

5 illus, 1 table, 16 ref

007839   Yohannan Panicker C;Varghese H T;Eapen P E; Raju K;Ganguli S;Fathima Beegum;Sheena Mary Y (Physics Dep, TKM College of Arts and Science, Kollam, Kerala, Email: cyphyp@rediffmail.com ) : Spectroscopic investigations and computationa study of aniline acetate. Int J chem Sci 2010, 8(1), 515-24.

Fourier transform infrared (FT-IR) and Fourier transform (FT) Raman spectra of aniline acetate were recorded and analyzed. The vibrational frequencies of aniline acetate were calculated using Gaussian 03 software package and the fundamental modes are assigned. The calculated frequencies are in agreement with the experimental values. The calculated geometrical parameters are compared with the geometrical parameters of similar derivatives. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non linear optics.

1 table, 28 ref

007838   Yohannan Panicker C;Varghese H T;Eapen P E; Raju K;Ganguli S;Beegum F;Mary Y S (Physics Dep, TKM College of Arts and Science, Kollam, Kerala, Email: cyphyp@rediffmail.com) : Spectroscoic investigations of anilinium nitrate. Int J chem Sci 2010, 8(1), 176-82.

The vibrational frequencies of anilinium nitrate were calculated using Gaussian03 software package and the fundamental modes are assigned. The calculated frequencies are in agreement with the reported experimental values. The calculated geometrical parameters are compared with the geometrical parameters of similar derivatives. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non linear optics.

1 table, 15 ref

007837   Yohannan Panicker C;Hassan R;Varghese H T; Eapen P E;Raju K;Ganguli S;Beegum F;Sheena Mary Y (Physics Dep, TKM College of Arts and Science, Kollam, Kerala, Email: cyphyp@rediffmail.com ) : Vibrational spectroscopic studies and Ab initio calculations of 3-methylsulfanilic acid. Int J chem Sci 2010, 8(1), 29-40.

The Fourier transform-infrared spectrum of 3-methylsulfanilic acid was recorded and analyzed. The vibrationaf wavenumbers of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar structures and is an attractive object for future studies of non linear optics. Optimized geometrical parameters of the title compound are in agreement with similar reported structures.

1 illus, 1 tables, 48 ref

007836   Yogesh Kumar;Tiwari N;Manoj Kumar;Tomar S (NO, DAV College, Muzzaffarnagar-251 001, Email: neelutiwari5@gmail.com) : Total ionization cross-sections of atmospheric molecules due to electron impact. Indian J pure appl Phys 2010, 48(9), 621-5.

The total ionization cross-sections of atmospheric molecule due to electron impact for threshold ionization energy to 10 MeV have been studied. Many researchers like Khare and Wadhera [Phys Lett A, 198 (1995) 212] have successfully employed the Plane Wave Born Approximation (PWBA), corrected for the exchange, the Coulomb and the relativistic effects to calculate the outer shell ionization of molecules including transverse interaction for the inner shell ionization of atoms and molecules The present results have been compared with experimental data and other theoretical data wherever available.

6 illus, 2 tables, 20 ref

007835   Vitisha Suman;Datta D;Sarkar P K;Kushwaha H S (Health Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: vitisha@barc.gov.in) : Symbolic math for computation of radiation shielding. Indian J pure appl Phys 2010, 48(11), 787-9.

Radiation transport calculations for shielding studies in the field of accelerator technology often involve intensive numerical computations. Traditionally, radiation transport equation is solved using finite difference scheme or advanced finite element method with respect to specific initial and boundary conditions suitable for the geometry of the problem. All these computations need CPU intensive computer codes for accurate calculation of scalar and angular fluxes. Computation using symbols of the analytical expression representing the transport equation as objects is an enhanced numerical technique in which the computation is completely algorithm and data oriented. Algorithm on the basis of symbolic math architecture is developed using Symbolic math toolbox of MATLAB software. Present paper describes the symbolic math algorithm and its application as a case study in which shielding calculation of rectangular slab geometry is studied for a line source of specific activity. Study of application of symbolic math in this domain evolves a new paradigm compared to the existing computer code such as DORT.

2 illus, 5 ref

007834   Verma K C;Mast Ram;Kotnala R K;Bhatt S S;Negi N S (Physics Dep, Himachal Pradesh Univ, Shimla-171 005, Email: kuldeep0309@yahoo.co.in) : Multiferroic Pb_1-xSr_1-x(Fe_0.012Ti_0.988)O₃ nanoparticles: room temperature dielectric relaxation, ferroelectricity and ferromagnetism. Indian J pure appl Phys 2010, 48(8), 593-9.

The effect of particles size and lattice parameters on dielectric constant, ferroelectricity, ferromagnetism and dc resistivity of Pb_1-xSr_x(FeTi_0..988)O₃ (PSFT) nanoparticles has been studied at room temperature. The PSFT nanoparticles were prepared by a chemical synthesis route. The X-ray diffraction patterns confirm the phase structure of PSFT nanoparticles. The tetragonal distortion (c/d) and particles size have been reduced with increasing Sr²⁺ ion substitution. The microstructural behaviour shows the average particle's size of PSFT specimens which lie in the ra, ge of 4-13 nm. The Sr-doped PSFT specimens show higher value of dielectric constant than undoped PFT. At 30 mol% of Sr concentration, the PSFT specimen shows dielectric relaxation up to 18 MHz with ε = 101 and tan8 = 0.075. Also, the maximum value of saturation magnetization, M_s = 64.4x10^-3 emu/g with low magnetic coercive field, H_c = 35.9 Oe, and spontaneous polarization, P_s = 20.7 μC/cm², remanent polarization, P_x = 13.3 μC/cm² and electric coercive field, E_c = 5.7 kV/cm have been observed. Compositional plots between average particle's size and dc resistivity, and dielectric constant and saturation magnetization have been given.

6 illus, 1 table, 29 ref

007833   Vajapurkar S G;Bera A (NO, Defence Laboratory, Jodhpur-342 011, Email: vaijapurkar@yahoo.com) : Present status of radiochromic techniques for nuclear radiation measurements. Indian J pure appl Phys 2010, 48(11), 830-6.

Various developmental stages of radiochromic dosimetry in kGy to mGy range depending on its applications in radiation processing industries, radiological safety, medical sciences, nuclear or dirty bomb exposition and radiation accident have been described. Leuco dyes, pH sensitive dye with halogen containing compound and radiation induced solid state polymerization arc the basic chemical methods presently in use for radiochromic techniques. The present status including achievements, limitations and R&D required for further improvements of accurate and precision measurements has also been highlighted. The reader system for mapping of radiation distributions in patient dosimetry and accurate measurements of personal doses in any nuclear or radiological accident scenario are also elaborated.

9 illus, 17 ref