012225   Sahoo S;Sit S K (Electronics & Instrumentation Enggineering Dep, Dr. Meghnad Saha Institute of Technology, Haldia-721 657, Email: swapansit@yahoo.co.in) : Relaxation phenomena of binary polar liquid mixture in C₆H₆ form conductivity of solution measured at 10 GHZ electric field. Indian J Phys 2010, 84(11), 1549-59.

The dielectric relaxation times τ_jk's and dipole moments μ_jk's of the binary (jk) polar mixtures of N,N-dimethyl formamide (DMF) and pyridine dissolved in benzene (i) are estimated using linear slope of σ_ijk" - σ_ijk' curves as well as ratio of slopes of σ_ijk" - W_jk and σ_ijk' -w_jk curves at w_jk → 0 for different mole fractions xj's of pyridine and experimental temperatures under 9.875 GHz electric field. The measured μ_jk's and τ_jk's agree well with the reported values validating the proposed methods. The solute-solute (dimer) molecular associations are inferred from the plot of τ_jk - x_j and μ_jk - x_j curves for x_j = 0.0 to 0.5 of pyridine and thereafter solute-solvent (monomer) molecular association occurs. The theoretical μ_theo's are calculated to predict solute-solute and solute-solvent molecular association. The μ_jk- Tcurves are drawn to show elongation of bond angles and bond moments with temperatures. The thermodynamic energy parameters are calculated from Eyring's rate theory equations to know the molecular dynamics as well as to ascertain Debye-Smyth relaxation mechanism of the systems.

2 illus, 5 tables, 15 ref

012224   Sahoo M;Jayannavar A M (NO, Institute of Physics, Sachivalaya Marg, Bhabaneswar-751 005, Email: jayan@iopb.res.in) : Classical and thermodynamic work fluctuations. Indian J Phys 2010, 84(10), 1421-34.

Studies the nature of classical work (W_c) and thermodynamic work (W) fluctuations in systems driven out of equilibrium both in transient and time periodic steady state. As the observation time of a large number of trajectories increases, the fraction of trajectories which exhibit excursions away from the typical behaviour, namely, W_c <60> 0, W <60> ΔF and dissipated heat Q <60> 0 decreases as anticipated for macroscopic time scales. An analytical expression for such trajectories is obtained. Trajectory for which W_c <60> 0 may not correspond to W <60> ΔF or Q <60> 0. The applicability of steady state fluctuation theorems is discussed in our linear as well as nonlinear models.

8 illus, 35 ref

012223   Saha B;Thapa R;Jana S;Chattopadhyay K K (Physics Dep, Jadavpur Univ, Kolkata-700 032, Email: kalyan_chattopadhyay@yahoo.com) : Optical and electrical properties of p-type transparent conduction CuAlO₂ thin film synthesized by reactive radio frequency magnetron sputtering technique. Indian J Phys 2010, 84(10), 1341-6.

Thin films of p-type transparent conducting CuAlO₂ have been synthesized through reactive radio frequency magnetron sputtering on silicon and glass substrates at substrate temperature 300 °C. Reactive sputtering of a target fabricated from Cu and Al powder (1:1.5) was performed in Ar+O₂ atmosphere. The deposition parameters were optimized to obtain phase pure, good quality CuAlO₂ thin films. The films were characterized by studying their structural, morphological, optical and electrical properties.

5 illus, 29 ref

012222   Rukmangad A;Aynyas M;Sanyal S P (Physics Dep, Sadhu Vaswani College, Bhopal462 030, Email: aditil.rukmangad@yahoo.co.in) : Structural phase transition and elastic properties of rare earth nitrides. Indian J Phys 2010, 84(9), 1183-92.

The structural phase transition, elastic and thermal properties of nitrides of lanthanum and ytterbium (REN, RE = La and Yb) under high pressure have been investigated by using two-body interionic potential theory with modified ionic charge (Z_me) to include Coulomb screening effect by the delocalized f electrons of rare earth ion. The present theoretical approach predicted that LaN and YbN exhibit a NaCI (B₁) type structure at an ambient pressure, undergo a structural phase transition from NaCI (B₁) into CsCI (B₂) phase at 100 GPa and 133 GPa, respectively. We have reported the second order elastic constants (SOECs), third order elastic constants (TOECs) and pressure derivatives of second order elastic constant for these compounds. The variation of elastic constants (C₁₁ C₄₄) with pressure is also presented. The thermal properties and its variation with pressure have been reported for these compounds for the first time.

3 illus, 5 tables, 23 ref

012221   Rudresha M S;Kumar R J;Rao K V S G (Physics Dep, Sri Siddhartha Institute of Technology, Tumkur-5) : Centre of concentration-introduction of novel concept and its study. Ultra Scient phys Sci 2009, 21(1), 153-6.

This work introduces a novel concept entitled "Center of concentration" which is similar to concepts in physics such as 'Center of gravity', and 'Center of mass'. It helps in a better understanding of the concentration of emissions from an assortment of stacks of varying heights and different pollutant emissions. Gaussian plume Dispersion Model is used in the study comprising of various Atmospheric stability Classes each of which representing a measure of turbulence in the ambient atmosphere. The effect of wind velocity is also studied. The proposed model helps in protecting and managing ambient air quality.

2 tables, 5 ref

012220   Rudresha M S;Jeevan Kumar;Rao K V S G (Physics Dep, Sri Siddhartha Institute of Technology, Tumkur-5) : Briggs's plumerise equation-a study. Ultra Scient phys Sci 2009, 21(1), 73-8.

The Briggs plume rise equations arise in the study of 'Atmospheric dispersion modeling'. The widely used equations studied in the model suggest that the Briggs' equations proposed for bent-over, hot buoyant plumes are the only relevant ones in general. Such models are important to governmental agencies tasked with protecting and managing the ambient air quality the models are typically employed to determine whether existing or proposed new industrial facilities are or will be in compliance with national ambient air quality standards. The models also serve to assist in the design of effective control strategies to reduce emissions of harmful air pollutants.

1 illus, 2 tables, 9 ref

012219   Roy S;Gogoi A;Ahmed G A (Physics Dep, Tezpur Univ, Tezpur-784 028, Email: rsanchita1@gmail.com) : Size dependent optical characteization of semiconductor praticle: CdS embedded in polymer matrix. Indian J Phys 2010, 84(10), 1405-11.

Reports the optical investigation and analysis of both nano-sized and micrometer size Cadmium Sulphide particles which is embedded in a transparent polyvinyl alcohol (PVOH) dielectric host material. A designed and fabricated laser based light scattering system using a He-Ne laser of wavelength 632.8nm was used for the measurement and study of the scattering properties of the particles as a function of the scattering angle at this wavelength. An attempt was made to experimentally determine the most significant elements of the Mueller scattering matrix using combinations of randomly and linearly polarized incident laser beam and subsequent analyzers in corresponding orientations. The analysis of the experimental data was done by the method of comparison with theoretically generated data. Novel computational technique, involving single scattering for spherical particles using Mie-theory, was developed and applied. The theoretical data was found to be in good agreement with the experimental data within an acceptable margin of error. The results have proved that the combination of the experimental setup and associated computational method is a highly efficient and reliable in-situ system for monitoring size growth of semiconductor particles in the laboratory.

5 illus, 1 table, 15 ref

012218   Robert M C;Saravanan R (Physics Dep, H K R H College, Uthamapalayam-625 533, Email: saragow@dataone.in) : Single crystal X-ray analysis of the electronic structure of the thermoelectric material Sn-GeTe. Indian J Phys 2010, 84(9), 1203-10.

The precise bonding and the electronic structure of the thermoelectric material Sn_1-xGe_xTe with two different doping levels viz., x= 0.12 and x= 0.25 have been determined using single crystal X-ray data and maximum entropy method (MEM). The thermal vibration parameters of the individual atoms in these two systems have also been studied and reported. The electron densities at the middle of the bond along [1 0 0] direction are found to be 0.346 e/A³and 0.359 e/A³ for x= 0.12 and 0.25, respectively, showing different strengths of the bonding.

4 illus, 5 tables, 15 ref

012217   Ray Chaudhuri B (Physics Dep, Presidency College, 86/1, College Street, Kolkata-700 073, Email: barun.raychaudhuri@gmail.com) : Prototype neural network hardware with analog electonic circuit. Indian J Phys 2010, 84(10), 1435-40.

The work realizes a model for hardware of neural network with four synaptic input links and corresponding weights constructed with operational amplifier. It can generate, in terms of dc voltage transfer characteristic, sigmoid functions of varied steepness and outputs for random variations of inputs, weights and threshold. The limitation in threshold variation is also estimated. Neural network hardware realization like the present one is unsuitable for VLSI implementation, but useful to discrete-component systems and has flexibility in power supply and output levels.

3 illus, 2 table, 8 ref

012216   Rathod P I;Dodia K;Patel V;Oza A T (Physics Dep, Sardar Patel univ, Vallabh Vidyanagr-388 120) : Infrared spectroscopy of charge transfer complexes of elastin. Prajna 2010, 18(1-4), 136-9.

Elastin, a well-known stretchable two dimensional protein, is well-known among biomolecules. In the present study, elastin and its charge transfer complexes with organic acceptors such as TCNQ, TCNE, DDQ, chloranil and iodine have been studied using FTIR spectroscopy. Elastin is a weak donor. In the infrared spectra, it is observed that there is low frequency hopping process revealed by square-power beta density. In CT complexes, gaussians are observed in mid-IR range. Elastin-iodine, elastin-DDQ and elastin-chloranil show range of nature of transition for the transition across a band gap.

14 illus, 2 tables, 5 ref

012215   Rasheed T;Ahmad S (Physics Dep, Aligarh Muslim Univ, Aligarh-202 002, Email: ahmad.shabbir@rediffmail.com) : Computational studies of vibrational spectra and molecular properties of 6-methyluricil using HF, DFT and MP2 methods. Indian J Phys 2011, 85(2), 239-60.

Theoretical investigations of atomic charges, conformers, frontier molecular orbitals, molecular geometries, thermodynamic properties, hyperpolarizabilities and harmonic vibrational frequencies of 6-methyluracil (6MU) have been carried out using ab initio Hartree-Fock (HF), density functional theory (DFT) and second order Maller-Plesset (MP2) methods. All calculations were performed using the GAMESS-US program package with the basis sets 6-31G(d,p) and 6-311G(d,p). FT-IR and Raman spectra of 6MU were recorded in the regions 50-4000 cm^-1 and 60-4000 cm^-1 respectively. Optimized geometries were obtained using the global optimization procedure. The calculated structural parameters for two conformers of 6MU have been compared with experimentally observed values. The energy barrier (ΔE=ELUIV1O-EHOMO) between the HOMO and LUMO is predicted on the basis of theoretical calculations. The simulated TD-DFT spectrum has been compared with experimental electronic spectrum for 6MU. The calculated potential energy distribution (PED) values have been utilized to perform vibrational assignment of the infrared and Raman spectra.

7 illus, 8 tables, 53 ref

012214   Ramanamurthy C V;Kavitha K R (NO, , 54-14/8-16, Plot No. 4, Road No. 9, Bharathi Nagar, Vijayawasda 8, Andhra Pradesh-520 008, Email: kavithasrikanth73@gmail.com) : Flow of a second order fluid over an inclined porous plate. Ultra Scient phys Sci 2009, 21(3), 585-94.

The unsteady state flow of a visco elastic fluid of second order type over an inclined porous plate is examined, taking into account of a uniform tangential force in terms of Heaviside's unit step function which acts on the free surface for a finite interval of time with different angles of inclination of the plate and gravitational pull into consideration. The decrease in the fluid velocity during the initial length of the plate is in accordance with the natural law of absorption. When the void space is fully saturated, due to the presence of the gravitational force and partly due to the inclination of the plate the fluid velocity increases at a rapid rate only in the later part of the plate.

5 illlus, 22 ref

012213   Prince P R;Renuka G (School of Technology and Applied Sciences, Mahatma Gandhi Univ, Regional Centre, Pathanamthitta, Kerala-689 645, Email: drprprince@yahoo.com) : Plasma sheet electrical conductivity and energy transactions during a magnetospheric substorm-a case study. Ultra Scient phys Sci 2009, 21(3), 559-64.

Magnetospheric substorms play an important role in determining the physical state of the geomagnetotail plasma sheet. Degree of energy transactions from the magnetosphere to the ionosphere during substorms is anlaysed against changes in the conducting properties of the sheet. The diversion of cross-tail current through the auroral ionosphere is addressed in the context of conductivity variations.

3 illus, 10 ref

012212   Prasad K;Jha A K;Prasad K;Kulkarni A R (Univ Dep of Physics, Tilkamajhi Bhagalpur Univ, Bhagalpur-812 007, Email: k.prasad65@gmail.com) : Can microbes mediate nano-transformation?. Indian J Phys 2010, 84(10), 1355-60.

A green low-cost and reproducible microbe (Lactobacillus) and baker's yeast (Saccharomyces cerevisiae) mediated biosynthesis of metallic and oxide nanoparticles are reported. Silver and copper oxide nanoparticles are synthesized using Lactobacillus sp. and Saccharomyces cerevisiae. The synthesis is performed akin to room temperature in the laboratory ambience. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of metallic and oxide nanoparticles. Individual nanoparticles having the dimensions of 2-6 nm (metallic) and 10-20 nm (oxide) are found. A possible mechanism involved for the synthesis of metallic and oxide nanoparticles has also been proposed in which pH as well as the partial pressure of gaseous hydrogen (r-H₂) or redox potential of the culture solution seem to play an important role in the process.

5 illus, 1 table, 11 ref

012211   Phadke S;Shrivastava B D;Mishra A (Physics Dep, Govt. Girls College, Devi Ahilya Univ, Indore, Madya Pradesh) : Thermodynamic, acoustical, volumetric and viscometric study of borassus flabellifier at 313.15 K. Ultra Scient phys Sci 2009, 21(3), 499-504.

Ultrasonic velocity has proved to be useful in understanding the physicochemical behaviour of the particular system. Study of Borassus flabellifier (toddy) and different type of wine is important due to its wide range of applications in medicine and industries. Toddy (natural liquid of palm tree Borassus flabellifier) is chemically alcoholic behaviour on fermentation. Borassus flabellifier (Toddy) is used medicinally as a detersive astringent in intestinal troubles. Measured ultrasonic velocity, Viscosity Density, Surface tension of Borassus flabellifier first time then calculated adiabatic compressibility (3, acoustical impendence Z, intermolecular free length Lf, viscous relaxation time τ, Gibb's free energy ΔG. Reported Ultrasonic velocity, of absolute alcohol, different type of wine (i.e. Rum, Dry Gin, and Whiskey), Toddy with compare to distil water at temperature 313.15K and 2 M.Hz.

3 tables, 16 ref

012210   Pathak V K;Dewangan B L (NO, Govt. P.G. College, Dhamtari) : Performance evaluation of a shaping mill system. Ultra Scient phys Sci 2009, 21(1), 185-92.

Deals with the performance evaluation of a Shaping mill system involving four essential components viz. one main unit, two associate units and one independent unit. Only one repairman is used for repairing the failed components of all the units. Taking failure rates as exponential and arbitrary repair rates, various system effectiveness measures such as transition probabilities, mean time to system failure, availability, busy period of repairman are calculated. At last profit analysis is done on the basis of above measures.

15 ref

012209   Patel M;Patel K D;Patel C A;Patel K K;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: physics.mayur@gmail.com) : Temperature dependent transport and barrier properties of DVT gorwn WSe₂ crystals and schottky devices. Prajna 2010, 18(1-4), 119-22.

Single crystals of Tungsten diselenide (WSe₂) have been grown using direct vapour transport technique (DVT). Measurements of thermoelectric power in temperature range 300 - 673 K confirms that WSe₂ possess a p-type conductivity. The Ohmic cotacts were developed using Ag-paste and the Hall effect measurements have been carried out in the temperature range 10 - 300 K to determine some essential parameters such as the hole mobility (μ_h), carrier concentration (n), Hall coefficient (R_H). The DVT grown crystals were also used to fabricate Schottky junction with thermally evaporated Indium contacts and the diode behavior was characterized over temperature in range 200 - 310 K. The thermoelectric and electrical properties variation with temperature and temperature variation of diode parameters are discussed.

7 illus, 2 tables, 18 ref

012208   Patel K D;Rathod J R;Patel H S;Pathak V M; Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: jrrathod84@gmail.com) : Characterization of thermally evaporated ZnTe Thin films. Prajna 2010, 18(1-4), 126-8.

Thin films of ZnTe with thicknesses around 8k Angstrum and 10 k Angstrum have been deposited by thermal evaporation technique on the ultrasonically cleaned glass substrates kept at 373 K. The thicknesses of the films were measured using quartz crystal thickness monitor. The structure of ZnTe thin films was investigated by Transmission Electron Microscopy (TEM). This reveals that films have polycrystalline nature with cubic phase. The band tail energy was estimated from optical absorption curves. The electrical resistivity of the films has been investigated as a function of temperature using Lakeshore-7504 Hall measurement set-up. The results of all these studied parameters are presented and discussed in this paper.

3 illus, 1 table, 9 ref

012207   Patel K D;Hingarajiya K S;Patel H S;Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: hingarajiyakeyur@gmail.com) : Barrier characteristics of thinfilm AI/Cds schottky junctions by I-V-T measurements over a wide temperature range. Prajna 2010, 18(1-4), 123-5.

Cadmium sulphide (CdS), a member of group II-VI semiconductors is one of the promising materials from its applications point of view. The present investigations are about the preparation and electrical characterization of CdS thin films. CdS thin films with thickness around 700nm have been deposited by vacuum evaporation technique keeping substrates at 400 K. Characteristic parameters of Schottky junctions formed by a thermal-vapor-deposition of 500 nm Al films on pre-coated CdS glass substrates were obtained experimentally from the I-V characteristics in the temperature range of 40-300 K. Diode parameters, such as the zero bias barrier height φ_b0, the flat band barrier height φ_bf and the ideality factor η, calculated using thermionic emission theory were found to be strongly temperature dependent. It is found that as the temperature decreases the rectification properties of Al/CdS deteriorates, may be due to increasingly dominant role played by interfacial states and inhomogenities.

3 illus, 1 table, 11 ref

012206   Parida B;Sahoo J;Shadangi N;Nayak P (PG Dep of Physics, Sambalpur Univ, Sambalpur-768 019, Email: jitendrasahoo2008@gmail.com) : Effect of electron-phonon interaction and temperature depedence of resistivity in some heavy fermion systems. Indian J Phys 2010, 84(10), 1333-9.

Consideres the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence of resistivity in some heavy fermion (HF) systems. Since the resistivity is related to the imaginary part of the electron self energy, the expression of the same is evaluated from electron Green function by the double time temperature dependant Green function technique of the Zubarev type. In order to understand the effect of electron-phonon interaction in these systems, we couple the phonons to both the f-electrons as well as to the electrons of the hybridization band of both conduction and f-electrons. The influence of various model parameters, namely, the position of 4f level E₀, the electron-phonon coupling strengths f₁(q) and f₂(q), the effecting coupling strength g = N(0)γ²₀/ω₀ have been studied on the temperature dependence of resistivity in HF systems. The numerical analysis is performed for q = 0 and for finite temperature in the static limit. The analysis of the results gives satisfactorily in comparison to the experimental observations.

2 illus, 10 ref

012205   Parhi N;Rout G S;Behera S N (Physics Dep, Maharaja Purna Chandra College, Baripada-757 001, Email: nilima@iopb.res.in) : J-T effect on the self-energy of electrons in manganite systems. Indian J Phys 2010, 84(10), 1369-77.

Presents a theoretical study of the effect of Jahn-Teller(J-T) distortion on the self-energy of electrons in the CMR manganites. The model consists of the itinerant e_g electrons distorted by J-T effect and the localized t_2g core electrons carrying strong ferromagnetism due to Hund's rule. The phonon interacts with the e_g electrons as well as the J-T distorted e_g band. The electron Green's functions are calculated by Zubarev's technique. The electron self-energy which carries all the information of the model is calculated from the Green's function. The effect of J-T distortion, magnetism on the frequency and temperature dependent dynamic self-energy is presented in this paper. The results are discussed.

3 illus, 12 ref

012204   Pandya M;Bhatt K (Statistics Dep, Bhavnagar Univ, Bhavnagar-364 002, Email: maywe.dave@rediffmail.com) : Statistical study on spatial autoregressive models with regional rural poverty difference in India. Prajna 2010, 18(1-4), 163-6.

The purposes of this paper are to study the literature concerning the spatial autoregressive models and then to examine the influences of different variables, in particular, spatial effects on the population under poverty line of different regions in India by employing 14 states data. Spatial econometrics is a subfield of econometrics that deals with spatial effects in regression models for spatial data. The subject of regional difference primarily focuses on inequality causes by factors of geography matters. This paper uses data of 1994 for 14 major states in India to explore whether spatial effects play a crucial role in Indian rural regional poverty difference in 1994. The basis findings are that the spatial error model reveals a strong positive relationship between measures of difference in population under poverty line and spatial heterogeneity.

4 tables, 5 ref

012203   Pandit S R;Yadav S K;Mandal K K (Physics Dep, S. K. M. Univ, Dhumka, Jharkhand) : Brief study on convensional method for the determination of thermopowers of metals from thermo E.M.F.. Ultra Scient phys Sci 2009, 21(1), 223-8.

In common practice thermopowers of metals or conductors are determined from thermo e.m.f. of the thermocouples. In the conventional method, reported in the literature [I.C.T, Barnard], thermopower of the thermocouple Js obtained from the temperature derivative of thermo e.m.f Thermopowers of individual metals are obtained by using thermopowers of the reference metals3. Previous method as well as thermopowers of reference metals have the vital role8 in the determination of thermopowers of the test metals. Some points in favour of the need of test of these factors are essential. Moveover, there is a poor agreement between theory and experiment of thermopowers of metals. Either values of thermopowers of a metal reported by two authors or valves obtained with respect to two reference metals or valves of thermopowers of two sample of a metal, hardly agree with each other [I.C.T.⁹, Seitz¹³, Wilson¹⁵, Barnard¹, MacDonai¹¹]. In the present communication we are going to discuss the complicated anomalies, we also test the conventional method for determination of thermopowers of metals form thermo e.m.f. and accuracy of thermopowers of some reference metals reported in the literature³ and determine the thermopowers of lead. Thermopower of the most popular reference metal⁷ has also been suggested.

3 tables, 15 ref

012202   Pandit S R;Yadav S K (Physics Dep, S. K. M. Univ, Dumka, Jharkhand) : Quantum estimation of conjectures of Bohr and von Neumann probability distributors on operator theory. Ultra Scient phys Sci 2009, 21(1), 211-4.

The probabilistic interpretation was developed by Bohr³ and others^12-15 by using operator formation. Von Neumann's¹⁶ logical structure of quantum mechanics is extended to statistical theory of quantum mechanics. In quantum mechanics, the elementary of the observed object is the property which does not allow to neglect the influence of the measuring devices. The fruitfulness of the deterministic point of view in the classical mechanics give rise to the illusion of its universally observed facts¹². However with the penetration of experimental physics into the atomic domain the inapplicability of the classical approach and the relevance of the statistical concepts in this domain became more evident. The behavior of the atomic and subatomic objects is essentially probabilistic. A quantum version of entropy has been developed by Von Neumann<6>16. In the present study, we have examined the conjectures of Bohr³ and Von Neumann¹⁶ using the theory of harilially ordered vector spaces. Mackey¹² and Lolmogorov¹¹ developed axiomatic approach related to probability distributions and operator theory in Hilbert⁷ spaces. Von-Neumann¹⁶ derived some significant results on quantum logic approach to the foundations of quantum theory.

15 ref

012201   Pandit S R;Mandal K K;Singh S S (Physics Dep, S. K. M. Univ, Dumka, Jharkhand) : Emphasis on the validity of free electron approximation in thermopowers in metals. Ultra Scient phys Sci 2009, 21(1), 207-10.

The study of thermopowers in metal has been the field of interest for the scientists since long. Mostly the convensional method for investigating the problem for thermopowers in metals are used. The presence of electric field alone the conductor results the electric current and the ratio of the current density to the electric field applied, in the absence of temperature gradient, defines the electrical conductivity of the metals considered. The presence of temperature gradient alone gives rise to the flow of heat. Further the discovery of electromagnetic induction by Faraday suppressed the phenomena of thermoelectricity. The observed features of thermoelectric properties, reported in literature are very much complicated and anomalous. The standard theory generally fails to interpret them. These interpretations are also anomalous because they have no correlation among themselves. Moreover, they are unable to co-ordinate anomalous behaviors of other transport properties. In the present communication, an emphasis on the validity of free electron approximation in thermopowers in metals has been focused. The study also gives the qualitative picture of the various phenomenological behavior of free electron approximation in thermopowers in metal from thermo e.m.f.

1 table, 18 ref

012200   Pandey S H;Jsohipura K N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagr-388 120, Email: siddharth033@gmail.com) : Dissociation of atomospheric molecules H₂ and N₂ by electron impact - neutral atom production. Prajna 2010, 18(1-4), 151-6.

This paper aimed at the estimation of neutral atom pair generation from abundant atmospheric molecules like H₂ and N₂ upon electron impact. Atmospheres of Jupiter and Titan (one of Saturn's moons) are largely comprised of H₂ and N₂ gases respectively. The relative atmospheric chemistry induced by neutral dissociation of H₂ and N₂ via energetic electrons or via photoelectrons plays an important role in these atmospheres. An attempt is made here to calculate this quantity using total dissociation cross sections for these molecules. The relevant cross sections are employed to estimate the rates for production of neutral atom pairs. While estimating productions of neutrals, cascading from higher states is considered duly, along with dissociative ionization generating a single atom per event.

5 illus, 1 tables, 34 ref

012199   Palani R;Pachikkannu A;Kabila K (Physics Dep, D.D.E. Annamalai Univ, Annamalainagar-608 002, Email: plani_physics06@yahoo.co.in) : Acustical study of some amino acids in binary aqueous solutions of MgCl₂.6H₂O at 298.15 K. Ultra Scient phys Sci 2009, 21(3), 485-92.

Ultrasonic velocity (U), density (ρ) and viscosity (η.) have been measured for three amino acids viz., L-serine, L-leucine and L-histidine in aqueous magnesium chloride solution at 298.15 K. Using the experimental values, the adiabatic compressibility (β), hydration number (n_H), apparent molal compressibility (ϕK), apparent molal volume (ϕ_v), limiting apparent molal compressibility (ϕ°_K), limiting apparent molal volume (ϕ°_v), and their constant (S_K,S_V), transfer volume (Δϕ°_v) and viscosity A and B coefficients of Jones-Dole equation were calculated for all the ternary systems. All these results have been interpreted in terms of solute-co-solute and ion-solvent interactions in the given solution.

3 tables, 26 ref

012198   Palani R;Pachaikkannu A;Bernadeth A A S (Physics Dep, D.D.E. Annamalai Univ, Annamalainagar-608 002) : Excess thermodynamical properties of ternary organic liquid mixtures at 303, 308 and 313K. Ultra Scient phys Sci 2009, 21(3), 515-24.

Ultrasonic velocity (U), density (ρ) and viscosity (η|) measurement have been carried out in three ternary liquid mixtures of chlorobenzene, nitrobenzene, bromobenzene with N,N, Dimethyl formamide (DMF) and aniline at 303,308,313K. The experimental data have been used to calculate adiabatic compressibility (β), free volume (V_f), and Gibb's free energy (ΔG). The excess values of the above parameters and Grunberg-Nissan interaction parameter 'd' have been calculated and discussed in the light of intermolecular interaction in the mixtures.

3 illus, 3 tables, 24 ref

012197   Oza A T;Solanki G K;Ray A;Amin A (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Mechanism of conduction in TTF and TMTSF organic conductors from a study of their vibrational spectra. Indian J Phys 2010, 84(11), 1527-40.

The charge transfer complexes of organic donors TTF and TMTSF have been prepared and studied with infrared spectroscopy. The nature of transition has been studied by analyzing features of absorption. TTF-TCNQ was found to be a Peierls semiconductor and not metallic. This shows that the mean field transition temperature is operative in TTF-TCNQ. TMTSF-TCNQ and TMTSF-DDQ showed lesser band gap than that of TTF-TCNQ. TTF-DDQ and TTF-I₂ also showed very small band gap and were more conducting than TTF-TCNQ. The band gaps could be assigned to either the Peierls gap or the pinning gap of charge density waves.

8 illus, 5 tables, 31 ref

012196   Oommen R;Anuradha A (Physics Dep, Avinashilingam Univ for Women, Coimbatore-43) : Comparative study on the thermal performance of wick type and step type solar stills. Ultra Scient phys Sci 2009, 21(3), 467-72.

The need of the hour in places where portable water is scarce is solar distillation. In the present work, a comparative study on the thermal performance of the step type solar still and wick type solar still is carried out. Numerical analysis has been carried out by making use of temperatures of water, glass, basin and ambient and the performances of both the stills are compared. Efficiency of the still is found to be in the range of 10-25% (wick type) and 20-40% (step type). Physical and chemical analysis of the water samples have been done. Cost-benefit analysis has been carried out and found that the amount spent on the system could be recovered in three years. The distilled output is found to vary from 47-817ml (wick type) and 82-1258ml (step type). Step type still is found to be better in performance than the wick type still.

6 illus, 1 table, 3 ref

012195   Nimje N;Dubey S;Ghosh S (School of Studies in Physics, Vikeram Univ, Ujjain-456 010, Email: nileshnimje.ssp@gmail.com) : Effect of carrier heating on diffusion induced modulational instability in semiconductor plasmas. Indian J Phys 2010, 84(11), 1567-85.

The purpose of the present paper is to report the study on modulational amplification in diffusive semiconductors including hot carrier effects. Considering that the origin of modulational interaction lies in the third-order optical susceptibility x⁽³⁾' arising from the nonlinear diffusion current density and using coupled mode theory, an analytical investigation of frequency modulational interaction between co-propagating laser beams and internally generated acoustic mode is presented. We have studied the steady state and transient amplification characteristics of modulated waves arising in diffusive semiconductor plasmas. The effect of carrier heating adds new dimensions to the present study. The heating effect reduces the required threshold amplitude of wave and enhances steady-state as well as transient gain of the generated acoustic mode.

6 illus, 35 ref

012194   Nath A K;Deka M;Kumar A (Physics Dep, Tezpur Univ, Napaam, Tezpur-784 028, Email: ask@tezu.ernet.in) : Ionic conduction and phase sparation studies in PEO-P(VdF-HFP)-LiCIO₄-dedoped polyaniline nanofiber composite polmer electrolytes-II: Effect of incorporation of PC and DEC. Indian J Phys 2010, 84(10), 1307-13.

In the work, ionic transport and interfacial stability of dedoped (insulating) polyaniline (PAni) nanofibers dispersed P(VdF-HFP) based nanocomposite gel polymer electrolytes have been investigated. Samples of P(VdF-HFP)-(PC+DEC)-LiCIO₄-x wt.% dedoped PAni nanofibers (x = 0, 2,4, 6, 8,10) are prepared by conventional solution casting technique. By analysis of SEM, XRD and impedance spectrosoopy results it has been demonstrated that the incorporation of up to 6 wt.% of dedoped PAni nanofibers to P(VdF-HFP)-(PC+DEC)-LiCIO₄ polymer electrolyte system significantly enhances the ionic conductivity and interfacial stability of the electrolyte system. Above that concentration phase separation of PAni nanofibers is observed leading to decrease in ionic conductivity. The aggregated phase decreases the porosity, which results in lower ionic conductivity as confirmed by SEM. Experiments on the interfacial stability reveals that the stability of polymer electrolytes containing nanofibers is better than that of nanofiber free polymer electrolytes.

5 table, 20 ref

012193   Mondal P;Ghosh S (Physics Dep, Nizam College (A), Osmania Univ, Hyderabad-500 001, Email: saisum@hotmail.com) : Modulations in the images of periodic saw-tooth wave targets by a human eye in the presence of stiles-crawford effect-I. Natn Acad Sci Lett 2009, 32(1-2), 41-4.

The directional sensitivity of human photoreceptors is a result of their structure that makes them act as optical fibers. The images formed on the retina of a human eye in the presence of Stiles-Crawford Effect-I by extended periodic saw - tooth wave targets have been studied in this paper. The modulations in these images have also been evaluated. The dependence of the modulations on the slope of these targets has been ascertained.

5 illus, 6 ref

012192   Moinul Haque Meaze A K M;Kim G N (Physics Dep, Chittagong Univ, Dhittagong 4331, Bangladesh, Email: mhqmeaze@yahoo.com) : Determinations of niobium and palladium resonance cross-sections by time-of flight transmission experiment. Indian J Phys 2011, 85(2), 329-38.

The neutron total cross-sections and resonance parameters of Niobium (Nb) and Palladium (Pd) were measured in the neutron energy regions from 0.1 eV to 100 eV by using the time-of-flight method at the Pohang Neutron Facility, Korea, which consists of an electron linear accelerator, a water-cooled Tantalum (Ta) target with a water moderator, and a 12.06 m long time-of-flight path. A ⁶Li-ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of 1.6 cm was used as a neutron detector, and high purity natural Nb and Pd metallic sheets with thickness of 15 mm (0.0833 atoms/barn) and 1 mm (0.0068 atoms/barn) respectively, were used for the neutron transmission measurements. The notch filters composed of Cobalt (Co), Indium (In), and Cadmium (Cd) were used to estimate the background level and also to calibrate energy. In order to reduce the gamma-ray background from Bremsstrahlung and from neutron capture, we employed a neutron- gamma separation system based on their different pulse shapes. The resonance parameters of natNb and natPd were obtained from the transmission ratio by using the SAMMY code, which utilizes both Doppler and resolution broadening effects and Bayes' generalized least squares technique. The present measurements were compared with the existing experimental and the evaluated reactions data files.

3 illus, 2 tables, 22 ref

012191   Misra N;Panda H S;Kapusetti G;Jaiswal S; Bhattacharya S (NO, School of Biomedical Engineering, Institue of Technology, Banarsh Hind, Varanasi-221 005, Email: nira1953@yahoo.com) : Physical and conductivity properties of poly (Vinyl chloride) ionomers. Indian J Phys 2011, 85(2), 271-9.

Poly (vinyl chloride)(PVC) is a cheapest plastic. Importance of PVC based ionomer has been gradually being popularizing due to compatibility of PVC with a number of salts to replace polyethylene oxide based ionomer. Under present investigation few of chloride group of PVC chain have been replaced by basic thiouronium group and these thiouronium groups are further oxidized to sulfonate group. Introduction of thiouronium group in PVC is confirmed through FTIR and further its oxidation to sulfonate group is also confirmed by FTIR. Conductivity in different stoichiometric ratio of PVCTU and PVCSO₃H was studied and found that PVCTU : PVCSO₃H in 1:1 ratio has conductivity near to pure PVC (10^-9 Ohm^-1 cm^-1 ) and increases with proportion of PVCSO₃ Na in the mixture (10^-6 Ohm^-1 cm^-1) for pure PVC, PVCTU has less conductivity not much significant.

5 illus, 1 table, 13 ref

012190   Mishra G R;Tiwari R K (Physics and Electronics Dep, Dr. R.M.L. Avadh Univ, Faizabad, Uttar Pradesh) : High performance low voltage level shifted cascode current mirror. Ultra Scient phys Sci 2009, 21(1), 167-72.

The current mirror is one of the basic building block in analog and mixed signal processing circuits. For high performance analog circuit applications the accuracy and output impedance are the most important parameters to determine the performance of the current mirror. This paper presents a new topology for a simple high performance current mirror for low voltage applications with high output impedance and large dynamic range. This topology is simulated in SPICE simulator for 0.13 micron CMOS technology.

8 illus, 22 ref

012189   Manocha L M;Basak A;Manocha S (Materials Science Dep, Sardar Patel Univ, Vallabh Vidyanagar, Email: manocha52@rediffmail.com) : Synthesis and raman characterization of multwalled carbon nanotubes by Catalytic chemical vapour deposition. Prajna 2010, 18(1-4), 102-5.

Catalytic chemical vapour deposition (CCVD) was used to synthesize CNTs, on silica substrate using xylene as carbon precursor and ferrocene as catalyst source. The carbon nanotubes are multiwall nanotubes which have been found to grow in bundles with CNTs within the bundles growing in one direction in a zig zag manner. The inner diameter of the tubes is found to decrease with total (outer) diameter of the CNTs. These CNTs have been characterized using SEM, XRD, TEM and Raman spectroscopy. The results obtained from these techniques have been interrelated.

5 illus, 21 ref

012188   Mallick P;Rath C;Dash J K;Biswal R;Agarwal D C;Behera D;Avasthi D K;Kanjilal D;Satyam P V;Mishra N C (Physics Dep, North Orissa Univ, Baripada-757 003, Email: pravanjan_phy@yahoo.co.in) : Observation of grain growth in swift heavy ion irradiated NiO thin films. Indian J Phys 2010, 84(10), 1399-1404.

NiO thin films grown on Si(100) substrates by electron beam evaporation, were sintered at 500 °C and 700 °C. The films were irradiated with 120 MeVAu⁹⁺ ions. Irradiation had different effects depending upon the initial microstructure of the films. Irradiation of the films at a fluence of 3 *** 10¹¹ ions cm^-2 leads to grain growth for the films sintered at 500 °C and grain fragmentation for the films sintered at 700 °C. At still higher fluences of irradiation, grain size in 500 °C sintered film decreased, but the same improved in 700 °C sintered film. Associated with the grain size, texturing of the films was also shown to undergo significant modifications under irradiation.

3 illus, 10 ref

012187   Liao S;Zhou H;Zhou Z;Xie H;Ouyang Y;Zhang B (Physics Dep, Hunan Normal Univ, Changsha-410 081 China, Email: liaosz@hunnu.edu.cn) : Atomic parameter model for the solid solubilities in binary transition metal based alloys. Indian J Phys 2011, 85(2), 261-70.

Based on the same method by us which describes the solid solubilities of the binary nontransition metal based alloys, the solid solubilities at room temperature in 1380 binary alloys which are based on the 23 transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Ru, Rh, Pd, La, Hf, Ta, W, Re, Os, Ir and Pt) of the fourth, fifth and sixth long periods have been studied in this paper. It has been found that the soluble elements can be separated from the insoluble elements by an ellipse equation (x-m)²/c²+(y-n)²/d² = 1, by using a criterion of 0.5at% solubility at room temperature for every host element. The results show that the overall reliability for the ellipse equation is up to 90% for the 1380 alloys, which indicates the theoretical results are very good in agreement with the experimental data. The parameters m, n, c and d in the ellipse equation can be explained by the appropriate parameters for every host metal.

5 illus, 5 tables, 20 ref

012186   Kumar S;Rana M K;Gautam A K (Physics Dep, Agra College, Agara-282 002) : Modified CCW description for the motion of cylindrical shock in self-gravitating rotating gas. Ultra Scient phys Sci 2009, 21(3), 651-66.

Effects of overtaking disturbances behind the flow have been included in CCW^1-3 approach for the motion of diverging cylindrical shock in a self-gravitating rotating gas, simultaneously for weak and strong cases. Taking initial density distribution (i) ρ ₀= ρ¹e±λ^r and ρ₀ = ρr±^w (where ρ is the density at the axis of symmetry, 'K' is a non-dimensionalising constant and w is a constant), the analytical expressions fof flow variables have been derived representing Free Propagation(CCW Description) and eod on CCW^1-3 results. Permissible shock front locations have been obtained ensuring the validity of this study for density increasing and decreasing regions, as well.

1 table, 10 ref

012185   Kuang X;Wang X;Liu G (NO, Mathematics and Physics College, Chongqing Univ, Chongqing, 400044, China, Email: xkdkxj@yahoo.com.cn) : Structural stabillty and electronic properties of Au₅H_n (n=1-10) clusters. Indian J Phys 2011, 85(2), 281-92.

A systematic study on the geometrical structures, electronic and magnetic properties of Au₅H_n (n=1-10) clusters has been performed by using the all-electron scalar relativistic density functional theory with generalized gradient approximation at the PW91 level. It is found that all Au₅H_n clusters prefer to keep the planar structures like pure Au₅ cluster, the Au₅ structures in Au₅H₄, Au₅H₆ and Au₅H₆ clusters are distorted obviously. The adsorption of a number of hydrogen atoms enhances the stability of Au5 cluster and all Au₅H_n clusters are more stable than pure Au₅ cluster energetically. The odd-even alteration of magnetic moment is observed in Au₅H_n clusters and may be served as the material with tunable code capacity of "0" and "1" by adsorbing odd or even number of H atoms. It seems that the most favorable, adsorption between Au₅ cluster and a number of hydrogen atoms takes place in the case that the odd number of hydrogen atoms is adsorbed onto Au₅ cluster and becomes Au.H cluster with even number of valence electrons.

5 illus, 3 tables, 39 ref

012184   Krishnan S S;Thiruvadigal D J (Applied Physics Dep, Sri Venkateswara College of Engineering, Sriperumbudur-602 203) : Vibrational analysis of 2-halopropenes. Ultra Scient phys Sci 2009, 21(3), 473-6.

The vibrational analyses of 2-halopropenes are carried out by Redington's method The vibrational analysis comprises the solving of 14x14 and an 7x 7 inverse vibrational problems to determine the force field. The force field thus obtained is utilized to evaluate the other molecular constants such as the mean square amplitudes of vibration. The results are compared with those obtained by the earlier workers.

4 illus, 1 table, 2 ref

012183   Krishnan S S;Kumutha R;Sheela N R;Muthu S (Applied Physics Dep, Sri Venkateswara College of Engineering, Sriperumbudur-602 105, Email: sambathk@svce.ac.in) : Vibrational analysis of N-acetylthiourea. Ultra Scient phys Sci 2009, 21(3), 691-8.

Theoretical force field for the molecular vibration of N-acetylthiourea (C₃H⁶N²OS) has been determined from ab initio calculation at the Density Functional Theory, using the B3LYP basic sets (6.31G). The reliability offeree field is analyzed by calculating the Vibrational frequencies. The frequency calculated from the force field are utilized critically examine the experimental assignments in acetylthiourea compounds. Theoretical geometry, the calculated 1R intensities are analyzed.

2 illus, 3 tables, 9 ref

012182   Kocak H;Dahong Z;Yildirim A (Mathematics Dep, Ege Univ, Bornova-351 00-Izmir, Turkey, Email: hkocak.ege@gmail.cim) : Analytical expression to temperature-dependent kirkwood-frohlich dipole orientation parameter using the boubaker polynomials expansion scheme (BPES). Indian J Phys 2011, 85(2), 311-7.

Analytical expression is proposed to the Kirkwood-Frohlich dipole orientation correlation parameter g. This parameter, which has been considered as a relevant guide to understanding the structuredness of supercritical fluids, had been always determined numerically. The advantage of the used protocol: the BPES, is to yield continuous and integrable expressions which can be easily incorporated in analytical models. The results have been compared to several precedent studies.

2 illus, 2 tables, 33 ref

012181   Khandka S;Chauhan S (Physics Dep, Allahabad Agricultural Institute, Deemed Univ, Allahabad-211 007, Email: saritakh@rediffmail.com) : Electronic specific heat of cuprates with interlayer interaction. Natn Acad Sci Lett 2009, 32(1-2), 35-40.

Electronic specific heat of high Tc layered Cuprates is studied taking interlayer interactions along with intralayer interactions. Expression for electronic specific heat is obtained and numerically solved. Its implications are studied for parameters compatible with experimental values. A jump at Tc, which is a signature of superconducting transition is obtained. Energy gap and ΔC/γTc are calculated for YBaCuO superconductor. The results are in good agreement with experiments and role of interlayer interaction is emphasized.

2 illus, 1 table, 16 ref

012180   Kerur B R;Rajeshwari T;Nagabhushna N M;Anil Kumar;Narayani S;Rekha A K (Physics Dep, Gulbarga Univ, Gulbarga-585 106, Email: kerurbrk@yahoo.com) : Radioactivity measurement in the granites of north Karnataka, India and radiological implications. Indian J Phys 2010, 84(11), 1467-80.

The natural radioactivities due to uranium, thorium and potassium in granite samples contribute to the radiation dose received by human beings significantly. It is essential to evaluate the activity levels of these nuclides for the assessment of natural radiation dose. The natural radioactivity levels of some granite samples collected from different quarries of North Karnataka, India are estimated using high-resolution gamma ray spectrometry technique and the results are reported in this paper.

5 illus, 5 tables, 27 ref

012179   Jotani M M;Baldaniya B B (Physics Dep, Bhavan's Sheth R A College of Science, Khanapur, Ahmedabad-380 001, Email: mmjotani@rediffmail.com) : Crystal structure of ethyl (2Z)-2-(3-methoxy-4-acetyloxy benzylidene) -7 methyl-3-oxo-5-phenyl-2,3-dihydro-5H-[1,3] thiazolo[3,2-a]pyrimidine -6- carboxylate. Indian J Phys 2010, 84(9), 1177-82.

The title compound, C₂₆H₂₄N₂O₆S₁ (I), crystallizes in the monoclinic space group, P2₁/c₁, with cell parameters a = 16.248(1), to = 7.927(1), c= 19.371(4) A, β = 105.295(2)°, Z = 4. The central pyrimidine ring in the compound (I) is significantly puckered, assuming a screw-boat conformation. The C11-C16 benzene ring stands vertical while thiazole and C18-C23 benzene rings are coplanar to the mean plane of pyrimidine ring having dihedral angles of 87.48(12), 3.63(11) and 0.94(12)°, respectively. In the absence of potential hydrogen bonding interaction, the crystal packing is influenced by intramolecular C-H---S interaction and intermolecular C-H---π interactions.

3 illus, 3 tables, 19 ref

012178   Joseph G;Santhosh Kumar A;Rajesh R;Louis G (Physics Dep, Sacred Heart College, Thevara, Cochin-682 013, Email: godfrey@cusat.ac.in) : Growth and dc conductivity studies of tripotassium sodium dichromate single crystal. Indian J Phys 2010, 84(9), 1223-8.

DC electrical conductivity studies were carried out along the three crystallographic axes for tripotassium sodium dichromate (K₃Na(CrO₄)₂ or KNCr). Earlier studies of phase transition in this crystal show successive phase transitions at 239 K and 853 K. In this paper we report the dc electrical conductivity measurements in the temperature region 303-430 K along the crystallographic axes. An anomaly in conductivity was obtained around 326 K along both the axes. This may be attributed as due to a newly observed phase transition in the crystal. DSC taken for the sample also shows exothermic peak supporting the occurrence of newly observed phase transition.

7 illus, 13 ref

012177   Jamwal K K S;Vakil G B (Physics Dep, Kashmir Univ, Srinagar-190 006) : Dielectric and polymer material propertiess & characteristics for microwave antenna applications. Ultra Scient phys Sci 2009, 21(3), 717-19.

Dielectric materials like Alumina (Al₂O₃) have been used for design of microwave antennas. However, due to material properties and difficulty in fabrication, it is not suitable for L, C, X and Ku-Band frequencies applications between 1-15 GHz. Polymer materials like Nylon, Teflon, polyacetal, polypropylene etc., however, have shown good gain and radiation characteristics at these frequencies and are easily fabricated with different design profiles. The polymer materials considered suitable for microwave antennas should have fairly large dielectric constant ε_r (between 1.5-10) and relatively small tan 8 loss factor (<60> 0.001) at these frequencies. The paper presents material characteristics, antenna profiles and gain-radiation characteristics of some important polymer microwave antennas that have found wide acceptance in the industry.

1 table, 4 ref

012176   Jain S;Verma A;Singh R (NO, Synergy Institute of Technology, Dewas, Madhya Pradesh, Email: jainsujeet_78@rediffmail.com) : Spectral analysis of spectroscopic properties of ND (III) doped borax glasses. Ind Res Commun 2010, 4(2), 203-5.

Spectral and radiative parameters of Nd (III) doped borax glasses have been observed in solid phase. Judd-Ofelt analysis is performed from Na₂B₄O₇.10H₂O+Nd₂NO₃ +CaCl₂ based glass system to evaluate the symmetry parameter (T), Transition probability (Ωλ,) and relaxation timing (A_{T and TR) for intermediate fluorescent levels. Some radiative properties for the intermediate transition levels individual and total transition probabilities along with their branching ratios and the relaxation timings for the ⁴F5/2, ⁴F7/2, ⁴G5/2, ⁴G7/2,⁴G7/2,⁴G7/2,²P3/2,⁴D3/2 levels evaluated. The above results are also compared with those of other host glass materials with the similar Nd(III) dopant concentration, which suggests that present new glass is shows the possibility to occurrence of conduction band in the doped matrix environment. M-O, C-O and O-H bonds by FTIR spectra represent the presence of water of hydratioty.}

2 illus, 3 tables, 13 ref