002053   Siva Sankar J;Geeta Lakshmi M;Naidu P S; Ravindra Prasad K (Physics Dep, S.V.U.P.G. Centre, Kavali-524 201) : Excess parameters of the binary mixtures of benzyl benzoate in dichloromethane and iso-butanol. J pure appl Ultrasonics 2007, 29(2-3), 82-8.

Ultrasonic velocity, density and viscosity have been measured experimentally in the two binary mixtures of benzyl benzoate in dichloromethane and iso-butanol at three temperatures 30, 35 and 40°C over the entire composition range. The thermodynamic and other allied parameters like adiabatic compressibility, free length, internal pressure, enthalpy etc. have been computed and the variation of the excess parameters like excess compressibility, excess internal pressure, excess enthalpy, excess activation energy etc. is analyzed in the light of inter molecular interactions in the mixtures. In both the mixtures, strong intermolecular interactions between the constituent molecules are suggested.

6 illus, 3 tables, 17 ref

002052   Singh C;Ganguly P;Das S;Kal S;Lahiri S K (Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur-721 302, Email: pranabendu.gangopadhyay@rediffmail.com) : Measurement of membrane thickness of MEMS structures by optical transmission. J Optics 2008, 37(4), 153-90.

Presents a simple, fast, and nondestructive technique for measurement of membrane thickness of MEMS structures using optical transmission of 1.31 μm wavelength IR light. The method involves the exposer of membrane from one side using IR source and detection of intensity oftransmitted light from other side. Optical transmitivity vs membrane thickness obtained from SEM was plotted for a set of micromachined structures to generate the calibration graph. This can be used to find the thickness of an unknown membrane structure by measuring its optical transmitivity. A theoretical estimation has also been performed and compared with the experimental data.

4 illus, 9 ref

002051   Ramasamy V;Ponnusamy V;Gomathi S S;Jose M T (Physics Dep, Aannamalai University, Annamalainagar-608 002) : Effect of thermal teatment of impurity ion (Mn<. Bull pure appl Sci-Sect F 2008, 27(1-2), 13-17.

Electron spin resonance (ESR) spectroscopic analysis of ten dolomitic crystals of Salem and Namakkal districts of Tamilnadu are put to analysis. The ESR measurement were carried out for all the samples at room temperature and shows an impurity ion Mn^{2+. The samples were subjected to the thermal treatment in the range of 200° to 900°C in steps of 50°C and observed that the six doublet line form of Mn2+ ESR signal changes into six singlet line forms at 800°C. This indicates the formation of CaO and the lattice disturbance (Mn<2+> ions are dislocated or disorder.}

2 illus, 8 ref

002050   Rajamannan B;Balachandramohan M;Viruthagiri G (Physics Dep, Annamalai University, Annamalainagar-608 002) : Porosity measurments of some brick samples collected in Villupuram district of Tamil Nadu. Bull pure appl Sci-Sect F 2008, 27(1-2), 49-51.

Measurement of the porosity values by the method of water absorption reveals the quality of the brick used in building construction. The percentage of porosity values is used to identify the class of brick samples. An attempt is made to correlate the percentage of porosity with the strength of the brick.

1 table, 5 ref

002049   Rajagopalan S;Sharma S J;Pandsey V M;Dubey P K;Vyaghra V R (Electronics Dep, S.K. Porwal College, Kamptee, Nagpur-441 002) : PC based ultrasonic attenuation recorder. J pure appl Ultrasonics 2007, 29(1), 42-5.

Ultrasonics is the study and application of sound waves having frequencies higher than those to which human ear can respond The main parameters measured in this technique are the velocity and attenuation. The study of attenuation constant can yield information about issues like elastic constants, relaxation phenomena, sub-surface anomalies etc. Ultrasonic vibrations are produced using piezoelectric transducer, generally quartz crystal. Of the many methods prevalent, the pulse-echo technique is most popular due to requirement of single transducer, low equivalent power deliverance and yield of attenuation and velocity simultaneously. In the present work, we have evolved an add-on instrumentation to record the decaying echo train, interfaced to a PC, in a pulse echo experiment set up in our lab. The technique involves obtaining samples of the data sliced in time domain, triggered by the transmitted pulse. The sampled analog data is digitized and acquired by the PC through in-house developed electronics and control software. The acquired raw data is stored on the PC for further offline analysis. The instrumentation can be used for solid as well as liquid samples. Moreover it can be used with any existing pulse-echo setup wherever the detected echo output is available, making the instrumentation very flexible and adaptable. Screen shots of the data acquisition and acquired data are given along with some typical data collected.

5 illus, 1 table, 12 ref

002048   Rajagopalan S;Sharma S J;Ghodki V M (Electronics Dep, Nagpur Univ Campus, Nagpur-440 010, Email: rajag_ngp@sancharnet.in) : PC based design of single pulse sender/receiver technique for ultrasonic velocity measurements. J pure appl Ultrasonics 2007, 29(4), 143-5.

The most popular and effective technique for ultrasonic velocity measurements is the pulse technique. In the present work, a computer based single-pulse sender/receiver technique is designed in the laboratory using indigenous components and a PCL-812 ADC card. A program written in C controls the pulse generation, detection and travel time measurement. An r.f. burst of 2 MHz of 5 μs width is obtained from the ADC card. This pulse is amplified and sent to the transmitting transducer. The received pulse is detected and processed by the ADC card for determining the travel time and displays the ultrasonic velocity of propagation in the system on the computer screen. The system developed in the laboratory has been tested for the ultrasonic velocity measurements in different standard liquids. It has been found that the ultrasonic velocity measurements carried out using the above system matches well with those reported in the literature.

^ssc1 illus, 1 table, 10 ref

002047   Rajagopalan S;Sharma S J;Dubey P K;Vyaghra V R;Pandsey V M (Electronics Dep, R.T.M. Nagpur Univ Campus, Nagpur-440 033) : Remote surface mapping using ultrasonic technique. J pure appl Ultrasonics 2007, 29(1), 36-41.

Mapping of the object periphery with added intelligence yields important information in terms of shape and surface deformity in the object. Remote mapping of object is an excellent tool for surface analysis studies. In the present work, we have developed an object surface scanning implemented using a PC in conjunction with an ultrasonic pulser/receiver system by modifying an ultrasonic distance estimation setup. In this technique, an object under analysis is rotated through 360 °and its reflecting surface is graphically plotted on screen using personal computer with the help of custom software. Object rotation is carried in steps of 1.8°; thus mapping 200 scanned points, which can be increased further up to 400 points in micro rotation mode.

6 illus, 7 ref

002046   Raghuwanshi P B;Doshi A G;Tayade D T (NO, Brijlal Biyani Science College, Amravat) : Ultrasonic study of benzopyrazoline and its complexes with Cu (II), Ni (II), Cr (II) and Fe (II) in 70% dioxane - water mixture. J pure appl Ultrasonics 2007, 29(2-3), 99-103.

The study, the solvent-solute, solvent-ion, solvent-solute (L) and solute (ion) and solute (L)-solute (ion) interactions were investigated by ultrasonic velocity and density measurements at 301K at 0.01 molar concentration in 70% dioxane-water as solvent. The main goal of this study was to find the effects of nuclear charge, ionic size, ionic ratio, ionization potential, tendency of metal ions to form π bond etc. of different metal ions with ligand [L=l-H-3-(2-hydroxy-3,4-benzophenyl)-5-phenyl-2-pyrazoline in solute-solute interaction and also on solvent in solvent-solute interaction and to note the changes in the acoustic properties like β_s' φ_v, L_f, R_A, and Z. This study explores the effects of various metal ions in solute (L)-solvent (ion) interaction and solvent-solute interaction.

2 illus, 1 table, 14 ref

002045   Pohit M (Amity Institute of Applied Sciences, Amity Univ, Sector 125, Noida-201 301, Email: mpohit@ase.amity.edu) : Scale-invariant road sign recofnition by fourier plane scaling of spectrum. J Optics 2008, 37(3), 93-100.

A new method is proposed for estimation of object size from the Fourier spectrum leading to scale-invariant pattern recognition. Instead of using the standard procedure of radial harmonic functions, the scaling factor is estimated from the Fourier spectrums of reference and test images. Since Fourier Transform of a two-dimensional object and its Fraunhofer diffraction pattern are identical, it is utilized to determine the scale factor. The test image is correlated with the reference image after resealing its Fourier spectrum. Computer simulation results are presented for a reference object at several scaling versions as well as for some non-target objects.

6 illus, 15 ref

002044   Nair B M;Balasubramanian P (Naval Physical and Oceanographic Laboratory, , Thrikkakara, Kochi-682 021) : Focusing through inhomogeneous media : time reversal matched filter approach. J pure appl Ultrasonics 2007, 29(1), 1-6.

Time reversal mirror (TRM) is a novel method of self adaptive, focusing in the absence of prior knowledge about the properties and structure of the medium. Focusing via time reversal realizes the spatio-temporal matched filter to the inhomogeneous propagation transfer function between the array and the focal point. The spatial and temporal shape of the wave is distorted through refraction, diffraction and multiple scattering in an inhomogeneous medium. Numerical simulation of the reversal focusing is discussed in this paper. TRM is investigated when the loss of information breaks the time invariance. A matrix formalism of the propagation operator is introduced to compare the time reversal mirror and inverse filter technique. Each Fourier component of this spatiotemporal filter is a complex matrix H. The inverse filter is described by matrix inverse diffraction operator HH^{-1. Time reversal operator is also introduced as HH where H is the transpose conjugate. Two frequencies of 30 kHz and 750 Hz were used as sources in a shallow oceanic environment.}

4 illus, 8 ref

002043   Mitra N;Mukhopadhyay S (Physics Dep, Burdwan Univ, Golapbag-713 104, Email: Nandita_phy@rediffmail.com) : New scheme of an all-optical J-K flipflop using non-linear material. J Optics 2008, 37(3), 85-92.

The role of memory devices in any communication and data processing system is very essential. So for optical computation and information processing the memory devices play also the significant role. Many proposed phenomenon are already seen where the optical memory devices are developed with the help of nonlinear material. Here, in this communication the authors propose an implementation scheme for an All-optical J-K Flip-flop, which may serve a significant role in optical computation as well as in information processing. The advantages of this optical J-K Flip flop over its electronic counter part are also indicated. This Flip-flop may overcome the need of Master Slave Flip-flop under some special circumstances.

6 illus, 11 ref

002042   Kshetrimayum R;Khaneja M;Tandon R P;Yadava R D S (Physics and Astrophysics Dep, Delhi Univ, Delhi-110 007) : SAW interdigital transducer designs for multiple frequency oscillators and sensors. J pure appl Ultrasonics 2007, 29(1), 46-53.

The paper proposes a new method to design surface acoustic wave interdigital transducers (SAW IDTs) to realize multi-mode SAW comb filters. The new design takes advantage of the Remez exchange algorithm for designing rung IDTs of a ladder transducer. This helps in achieving both the wide band width as well as a large number of comb modes with nearly constant insertion losses. Simulated characteristics of the new design are compared with those for the standard comb filter designs to illustrate its advantages. The usefulness of the present design in mode selection in multifrequency operations are discussed. It is suggested that the present design approach can provide an easily realizable multifrequency SAW platform for accurate vapor sensing and polymer characterization.

6 illus, 26 ref

002041   Kheraj V A;Panchal C J;Desai M S;Sharma T K (Applied Physics Dep, Faculty of Technology & Engineering, The M.S. Univ of Baroda, Vadodara-390 001, Email: cjpanchal_msu@yahoo.com) : Simple low-cost technique for in-situ reflectivity monitoring of optical thin-films and its application in laser diode facets-coatinvg. J Optics 2008, 37(3), 101-9.

Laser diodes are by far the most varied, flexible, cheapest and the most abundant lasers. For long-term, reliable operation and for maximum optical power utilization, laser diode is coated with the anti-reflection (AR) and high-reflection (HR) coatings by means of dielectric layers on the front and the back facet, respectively. For the optimum performance, accurate monitoring and control over the reflectivity of the dielectric thin film layers at specific lasing wavelength is necessary. We have demonstrated a simple and inexpensive in-situ reflectivity measurement system for the facets-coating of laser diodes. The system relies on the measurement of dynamic optical reflectance of the growing thin film by means of intensity of a laser-beam reflected from the gallium arsenide test-substrate kept in the close vicinity of the laser diode facet being coated. The in-situ reflectivity monitoring of single layer AR film and multilayer HR films have been demonstrated and verified with ex-situ reflectivity measurements.

6 illus, 16 ref

002040   Kannaujia A K;Singh K (Anaesthesia and Critical Care, S.N. Medical College, Agra-282 002) : New epidural space detection device: an innovation. J Anaesth clin Pharmac 2008, 24(1), 61-2.

7 illus, 3 ref

002039   Kalyana Raman S B;Uvarani R (Physics Wing, DDE, Annamalai Univ, Annamalainagar, Tamilnadu) : Complete C-program to evaluate the suitability of theories / relations of ultrasonic velocities in binary / ternary / quaternary liquid systems. J pure appl Ultrasonics 2007, 29(2-3), 75-81.

A complete C-program has been developed and presented for the theoretical computation of velocities of ultrasonic waves in mnary/ternary/quaternary liquid mixtures. Five of the existing theories that are commonly used are included in the program. The program also finds the 'goodness of fit' of the theories by evaluating the Average Percentage Error (APE), the worst-case error and chi-square values.

4 tables, 8 ref

002038   Jamwakl K K S;Gowhar Bashir;Kanwar A;Maqbool I;Bhat G H (NO, , ) : Temperature stabilsed led and LD drive circuits. J Optics 2008, 37(3), 110-14.

The Light emitting diode (LED) and Laser Diode (LD) drive circuits for optical fiber communication transmission systems are very sensitive to the variations in temperature as forward current increases and diode junction voltage decreases leading to the poor spectral and circuit stability of the LED and LD drive circuits can be improved by designing the circuits for the two temperature ranges and the circuits analysed in these stability conditions. The performance of such circuits is better than any other design technique.

^ssc3 illus, 6 ref

002037   Hanumantha Rao M V;Venkateswaran R;Mahale N; Ravi V C;Singh S;Sriram K V;Chakraborty P;Negendra C L (Laboratory for Electro-Optics Systems, Peenya Industrial Estate I Stage, Bangalore-560 058, Email: mvhrao@gmail.com) : Ion figurine of light-weighted aspherical mirrors. J Optics 2008, 37(4), 115-21.

High accuracy surface figuring of light-weighted aspherical optical mirrors using conventional polishingtechniques becomes increasingly difficult with size as problems such as tool footprint, edge turndown become severe. Hence, a non-contact polishing process called "ion figuring" was evolved where in material removal is done by energetic ion bombardment. In this paper the development of an ion figuring system based on ion beam sputtering process shall be described and demonstrated with a few examples.

6 illus, 3 ref

002036   Ghosh S;Khare P (School of Studies in Physics, Vikram Univ, Ujjain-456 010) : Acoustic wave amplification in magnetized piezoelectric ion-implanted inhomogeneous semiconductors. J pure appl Ultrasonics 2007, 29(1), 2-16.

Excitation of modified acoustic modes and favourable properties introduced due to presence of carrier density gradient along the propagation direction in n-type piezoelectric semiconductor are investigated. Derived a linear dispersion relation for the acoustic wave in semiconductor plasma in presence of colloids by using multi-fluid analysis and Maxwell's equations. This dispersion relation is used to study wave spectrum and acoustic wave amplification characteristics analytically. We find that only when <9_oc > 9_s < 9_od gain spectrum width decreases otherwise increases. We also find that the gradient parameter (8/k) reduces the gain per radian. Hence the application of magnetic field and choice of homogeneous medium are favorable in achieving higher acoustic gain per radian in ion-implanted piezoelectric semiconductor.

8 illus, 16 ref

002035   Ghosh N;Chakraborty A K;Bhattacharya K (Optics and Photonics Dep, Calcutta Univ, 92 A.P.C. Road, Kolkata-700 009) : Single element birefringence-sensitive interferometer. J Optics 2008, 37(4), 147-52.

It is shown that a cube beam splitter can serve as a single-element birefringence-sensitive interferometer. The polarization-masked beam splitter is oriented as in Gate's Interferometer i.e., the beam splitting interface is parallel to the incident plane beam. The output consists of apair of collinearly propagating orthogonally polarized beams which intercepts the birefringent sample placed before a linear polarizer. It is interesting to note that in the proposed method, measurement of birefringence remains unaffected by any phase non-uniformity that might be present in the sample.

3 illus, 15 ref

002034   Ghandhimathi R;Lalitha V;Vijayalakshmi K (Physics Dep, Urumudhanalakshmi College, Tiruchirapalli, Tamil Nadu) : Hydration number and thermochemical analysis of aqueous solutions of cobalt acetate through ultrasonic measurements. J pure appl Ultrasonics 2007, 29(1), 23-5.

The number of water molecules that interact with the solute at one time is the measure of the hydration number and it is determined using the ultrasonic velocity measurements. Using the hydration number the apparent molal compressibility, apparent molal volume and molar solvated volume are determined for the solutions of cobalt acetate. The hydration number study provides valuable information regarding the molecular interaction in solution and also about the structure. It is evident that in solutions hydration number variations are analogous to internal pressure variations.

4 illus, 3 tables

002033   Geetha D;Rkkappan C;Ramesh P S (Physics Dep, Annamalai Univ, Anamalainagar-608 002) : Acoustical studies on cellulose acetate phthalate in alkali metal hydroxides and water mixture. J pure appl Ultrasonics 2007, 29(2-3), 71-4.

Ultrasonic velocity studies were undertaken on solutions of cellulose acetate phthalate in alkali metal hydroxides LiOH, NaOH and KOH and water mixture in the concentration range 0-2.5% by weight at frequency of 3 MHz in three different temperatures, 303 K, 313 K, 323 K. The observed non-linear increase in ultrasonic velocity with increase of cellulose acetate phthalate concentration is attributed to the polymer-ion interaction in higher electrolytes.

3 tables, 12 ref

002032   Geetha D;Rakkappan C (Physics Dep, Annamalai Univ, Anamalainagar-608 002) : Effect of alkyl amines on the growth of sodium lauryl sulphate micelles. J pure appl Ultrasonics 2007, 29(2-3), 65-70.

The studies were performed to see the.influence of alkyl amines on the growth of 0.3 molar sodium lauryl sulphate micellar solutions at 303 K, 313 K and 323 K. In the present study ethylamine and n-tributyl amine were used. The results are interpreted and reported with the help of ultrasonic velocity and absorption studies.

4 tables, 12 ref

002031   Dutta U;Hazra L N (Applied Optics & Photonics Dep, Calcutta Univ Dep, 92, A.P.C. Road, Kolkata-700 009, Email: u_dutta@rediffmail.com) : Primary aberrations of embedded diffractive lens. J Optics 2008, 37(4), 26-46.

An embedded diffractive lens can be fanned by two diffractive lenses on finite substrates with their matching diffractive profiles in contact. An analytical treatment pertinent to the study of primary aberrational characteristics of an embedded diffractive lens is presented. We take resort to the well known Sweatt Model within the framework of thin lens aberration theory for tackling the case of unequal object and image spaces. The variations of the primary aberrations with various design parameters viz. substrate curvature, optical characteristics of the substrates and the conjugate positions are illustrated.

15 illus, 15 ref

002030   Arivudai Nambi T;Philomi Nathan P; Dhanalakshmi A (P.G. and Research Dep of Physics, Rajah Serfoji Govt. College (Autonomous), Thanjavur-613 005) : Acoustical and thermodynamical studies of L-histidine solutions. J pure appl Ultrasonics 2007, 29(1), 31-5.

Amino acids play crucial role in medical application and hence their subsequent ultrasonic and thermodynamic parameters are of due importance. Thermodynamic interaction in L-Histidine in aqueous medium has been studied extensively using experimental results of density, viscosity and velocity at different temperatures ranging from 303K to 328K. Various ultrasonic measurements are made using ultrasonic interferometer (2MHz). The internal pressure, free volume, adiabatic compressibility and other related parameters of Histidine for different concentrations are presented here. In addition, acoustical parameters such as specific acoustical impedance, relaxation time, Rao's constant and Wada's constant are computed. The variations in ultrasonic velocity and internal pressure play a significant role in understanding the solute- solvent, intra and intermolecular interactions.

7 illus, 1 table, 7 ref

002029   Arivudai Nambi T;Philomi Nathan P; Dhanalakshmi A (P.G. and Research Dep of Physics, Rajah Serfoji Govt. College (Autonomous), Thanjavur-613 005) : Molecular interactions in N-acetyl D-glucosamine through ultrasonic measurements. J pure appl Ultrasonics 2007, 29(1), 26-30.

Ultrasonic parameters provide information about various intra and inter molecular interactions in solutions. The physical and chemical behaviours of solutions and their molecular interactions are studied by measuring the density, viscosity and velocity of N-Acetyl-D-glucosamine in aqueous medium at different temperatures from 303K to 328K, The velocity measurements are carried out in a ultrasonic interferometer of fixed frequency 2 MHz. The acoustical parameters such as adiabatic compressibility, acoustical impedance, relaxation time, ultrasonic attenuation, Rao's constant and Wada's constant are computed on the measurements. Hydrogen bonding and molecular interations in the solutions are analysed on the basis of acoustical studies.

7 illus, 1 table, 7 ref

001101   Patel M;Dave M;Patel K R;Patel S G;Oza A T (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Infrared spectroscopy of the iodine inclusion compounds of three (α, β and γ)-cyclodextrins. Prajna 2006, 14, 117-28.

Study of infrared spectra of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin with KI-I₂ (i.e. I₃^- ions) reveals changes in the spectra of three cyclodextrins in the range 400-1800 cm^-. New bands in the C-O-C stretching range are caused by charge transfer interaction of iodine with oxygen atoms. Other changes in the spectra are ascribed to hydrogen bonding between water molecules and cyclodextrins, water of crystallization, structural effects and the interaction of iodine atoms with the hydrocarbon linings of cyclodextrin molecules.

001100   Patel K R;Vaidya R D;Dave M S;Patel A J;Patel S G (physics Dep, Sardar Patel Univ, Vallabh Vidyanagar) : Microstructural analysis of zirconium triselenide single crystals. Prajna 2007, 15, 91-7.

The zirconium triselenide (ZrSe₃) single crystal has been grown by chemical vapour transport technique using iodine as a transporting agent. The optimum conditions for the growth of this crystal are given. The stoichiometry of the grown crystals was confirmed on the basis of energy dispersive analysis by X-ray (EDAX) and structural characterization was accomplished by X- ray diffraction (XRD) studies. The lattice parameters obtained from the XRD analysis were a = 5.45 Angustrum, b = 3.74 Angustrum and c = 9.44 Angustrum. These crystals were found to possess monoclinic, layered structure. The X-ray density was found to be 5.63 gm/cc and volume was calculated about 193.50 Angustrum³. The optical band gap of as grown crystals have been calculated with the help of optical absorption spectra in the range of 700 -1400 nm.

001099   Patel D;Bhavin G;Patel S;Neetha J;Job K A; Chandra A (Plastic Technology, Institute of Science & Technology for Advanced Studies & Research (IST, Vallabh Vidyanagar, Gujarat-388 120, Email: neethajob@yahoo.co.in) : Effect of stretching on physical properties and consequently on crystallinity on nylon-6 cord. Prajna 2006, 14, 146-53.

The influence of the different dipping parameters has great importance on the properties of the cord and also on the final performance of the tyres in service, The performance of the tyres in service is also influenced by the crystallinity of the nylon tire cord. An attempt to study the above variations and the variations between the different suppliers of fabric was conducted.

001098   Patel B;Vinodkumar P C (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Interaction of electromagnetic wave with human head at different telecommunication freouencies. Prajna 2006, 14, 129-39.

Interaction of the electromagnetic plane wayes of cpmmonly used telecommunication frequencies with the multilayer model of human head is investigated. Exact analytical expressions are derived for the plane wave complex reflection and transmission coefficients as a function of frequency at the interfaces of the stratified structure of human head. The induced electric field, power dissipation and SAR (Specific Absorption Rate) at different layers of human head are computed at frequencies 900, 1800 and 3000 MHz. The results are represented graphically.

001097   Patel A J;Patel K R;Vaidya R;Jani A R;Patel S G (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar) : Growth and characterizatipon of TaSe₂ single crystals grown by chemical vapour transport technique. Prajna 2007, 15, 98-104.

The need for advanced materials has stimulated a large area of researches in which TaSe₂ (Tantalum diselenide) occupy a growing place due to its distinct atomic and electronic features. The present investigation focuses on the growth and characterization of TaSe₂ single crystals, which has Important applications due to semiconducting nature. An attempt has been made to yield TaSe₂ single crystals py chemical vapour transport (CVT) using iodine as a transporting agent. Optimum conditions for growing these crystals are given. These crystals belong to transition metal dichalcogenides (TMDC) group, exhibiting very interesting physical properties. The energy dispersive analysis by X-rays (EDAX) gives the confirmation about stoichiometry of these crystals. The X-ray diffraction (XRP) studies were also carried out for the structural characterization. Hall-Effect and optical absorption measurements at room temperature have been made for the grown crystals. The resistance of layered crystal TaSe₂ is determined as a function of pressure up to 8 GPa using Bridgman anvils.

001096   Padmanabhan T (IUCAA, Post Bag 4, Pune Univ Campus, Ganeshkhind, Pune-411 007, Email: paddy@iucaa.ernet.in) : Lagrang has (more than) a point!. Resonance 2009, 14(4), 318-27.

A solution to the 3-body problem in gravity, due to Lagrange, has several remarkable features. It describes a situation in which a particle, located at the maxima of a potential, can remain stable against small perturbations.

2 illus, 2 ref

001095   Neeraj Kumar;Jain J S;Sinha R;Garg V K;Bansal S K (NO, , ) : Evaluation of some novel chalcone derivatives for antimicrobial and anti-inflammatory activity. Der Pharmac Lett 2009, 1(1), 169-76.

A series of chalcones of substituted acetophenone and substituted aryl aldehydes were synthesized and evaluated for antimicrobial and anti-inflammatory activity The structures of synthesized compounds were confirmed by IR and 1H NMR spectroscopy. The antimicrobial activity was evaluated against S. aureus. B. subtilis. E. coli and P. putida strains whereas anti-inflammatory activity was performed by Carrageenan induced hind paw oedema method. Results obtained showed that 40% of the synthesized compounds exhibited significant antimicrobial activity against all the tested micro organisms. Compound N1 i.e. 3-(4-nitrophenyl)-1-phenyl prop-2-en-1-one emerged as the most active compound with MIC50 value of 471ug/m! against S. aureus. In anti-inflammatory screening compound N3, 3-(3,5-dimethoxy phenyl)-1-phenyl prop-2-en-1-one and compound N6, 3-(4-hydroxy phenyl)-1-phenyl prop-2-en-1-one emerged as the most potent molecules with inhibition of 38.46% and 50.0% as compared to 42.30% of Diclofenac Sodium at 1.0 hr interval of the carrageenan induced oedema.

001094   Misra N;Ahmad Siddiqui S;Pandey A K;Trivedi S (Physics Dep, Lucknow Univ, Lucknow-226 007) : Comparative vibrational spectroscopic investigation of benzonitrile derivatives using density functional theory. Der Pharma Chem 2009, 1(1), 196-209.

Comparative studies of the vibrational spectra of 4-methyl 3-nitrobenzonitrile and 2-formyl benzonitrile have been made. The spectra are interpreted with the aid of normal mode analysis following full structure optimization based on the density functional theory and different basis set combination. While making complete assignment of vibrational wavenumbers, some interesting facts were noticed for example, how modes of vibrations, bond angles and bond lengths are affected by different groups attached to the benzene ring. The main aim of the present study is to investigate in detail the vibrational spectra and thermo dynamical properties of 4-methyl 3-nitrobenzonitrile and 2-formyl benzonitrile by B3LYP/6-31 l+G(2df,2p) method and basis set combination, which can presumably help in understanding its behavicr i.e. effect on reactivity, stability, nature of state due to the different groups attached to the benzene ring. These effects are also correlated with the chemistry of attached groups.

001093   Makhija D;Maniar T S;Pathak R J;Patel K D; Pathak V M;Srivastava R (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar) : Temperature sensitivity of characteristic parameters of MoSe₂ solar cells. Prajna 2007, 15, 122-6.

MoSe₂ belongs to a class of group II-VI chalcogenides having C7 type crystal structure, which possesses a layered structure. These MX₂(M=W or Mo, X= S, Se or Te) compounds form a structurally and chemically well defined family. The basic structure of loosely coupled X-M-X sheets makes these materials extremely interesting. This compound has attracted considerable attention due to its use in the construction of regenerative electrochemical solar cells. In present investigations, MoSe₂ crystals grown by direct vapour transport method have been used. The photoconversion characteristics of n-MoSe₂/I₂/I^-/Pt PEC solar cells have been investigated under polychromatic illumination from an incandescent lamp at various intensities, which show that the photoconversion efficiency is low. The series resistance is one of the major parameters that control the photoconversion behaviour of these solar cells. Efforts have been made to estimate its value. In addition, the effect of temperature on the series resistance and various other parameters of PEC solar cells have also been investigated. It has been observed that the series resistance decreases and it improves the behaviour of PEC solar cells.

001092   Jotania R B;Chauhan C C (Physics Dep, School of Sciences, Gujarat Univ, Ahmedabad) : Synthesis, thermal and structural properties of zinc substituted barium hexaferrite powders prepared by a gel route. Prajna 2007, 15, 105-10.

Deals with the study of thermal and structural prosperities of Zinc substituted Barium hexaferrite (BaZn₂Fe₁₆O₂₇) powders prepared by a Sol-Gel route, The BaZn₂Fe₁₆Q₂₇ hexaferrite precursors were prepared using a Stearic acid gel technique and calcinated at 950°C for 4 hours in a. Static air atmosphere. The gel and calcinated samples were characterized using various experimental techniques like DTA, TGA, FTIR and XRD and the results are compared.

001091   James M E;Rastogi R G;Chandra H (Physics Dep, Gujarat Univ, Ahmedabad, Email: hchandra@prl.res.in) : Day-to-day variation of geomagnetic H field and equatorial ring current. J Indian Geophys Union 2008, 12(2), 69-78.

Describes the day-to-day fluctuations of the horizontal component of the geomagnetic field along Indo-Russian chain of stations during midday and midnight hours in relations to the corresponding variations of Dst index. The correlation between AH and Dst index is around 0.8 for all latitudes. The slope of the regression line is about 1.0 during daytime but during the nighttime hours the slope is only around 0.5. This suggests that the nighttime tail currents have almost equal contribution towards fluctuations of AH as due to the disturbance ring current. The equatorial electrojet current, designated by ΔH(TRD) - ΔH(ABG) has no correlation with Dst index because any variation of Dst are removed from ΔH at both stations and electrojet currents represents only the ionospheric current component.

5 illus, 1 table, 29 ref

001090   Jain S;Verma A;Ragini Singh (Physics & Electronics Dep, Dr. Harisingh Gour Univ, Sagar, Email: jainsujeet_78@rediffmail.com) : Spectroscopic properties of Er(III) doped in borax glass. Ind Res Commun 2009, 3(1), 93-4.

Spectroscopic properties of Er(III) ions in borax glass has been studied. Spectral intensities for various absorption bands of Er(III) doped borax glass are calculated. Various spectral parameters used like Judd-Ofelt intensity parameters (Ω₂, α₄, Ω₆), radiative transition probabilities (A), branching ratios (β) and total absorption cross section (2) are calculated for certain transitions. The radiative lifetimes (τ_R) for different excited states are estimated.

1 illus, 1 able, 8 ref

001089   Gupta D K;Jinendra Singh (NO, , ) : Corrosion inhibitive properties of different plant extract. Archiv appl Sci Res 2009, 1(1), 51-6.

The natural products in acidic media were tested for corrosion inhibition of Cu, Al and Mild-Steel in 0.5N HCI acid solution at 30 to 40 0C temperature range by Weight Loss technique, it reveals that Natural Products works as a corrosion inhibitor in halide media and protect the metals from the corrosion with great efficiency.

001088   Gangopadhyay S;Vinodkumar P C;Joshipura K N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120, Email: knjoshipura@yahoo.com) : Variable phase calculations on e-H₂ and e-CO scattering processes. Prajna 2006, 14, 108-16.

Various scattering cross sections have been calculated for the impact of electrons on H₂ and CO molecules in the energy range 20-2000 eV. We have considered two theoretical approaches viz., the asymptotic phase shift method and the variable phase method and both the results are found to be consistent. The well-known complex potential formalism is employed to these systems to determine total elastic (Q_el) and total cumulative electronically inelastic (Q_inel) cross sections. From the total inelastic cross section, the ionization cross section has been extracted using the complex scattering potential - ionization contribution (CSP-ic) method. Adequate comparisons have been made with other experimental and theoretical data.

001087   Gangopadhyay S;Joshipura K N (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar) : Electron-molecule interactions in complex potential formulation: e-H₂O example. Prajna 2007, 15, 111-21.

Makes a critical study of different model potentials of polarization and absorption interactions and their effects on various total cross sections (TCS) viz., total elastic cross sections (Q_el), total inelastic cross sections (Q_inel), total ionization cross sections (Q_ion), summed total excitation sections (<82>Q_exc), total (complete) cross sections (Q_T) and grand total cross sections (Q_TOT) of H₂O molecule on electron impact. The calculations are based on the spherical complex optical potential formalism outlined in in earlier studies. Non-spherical interactions are treated separately. The incident electron energy range is from threshold of ionization (~15 eV) to 2 KeV. Results are compared with available theoretical and experimental data. Comparisons of model potentials are examined and cross section results are discussed.

001086   Gandhi V H (Physics Dep, Gujarat Univ, Ahmedabad-9) : Electric and magnetic field due to given current in a conductor. Prajna 2006, 14, 140-5.

For a linearly time dependent current flowing in a conductor, electric and magnetic field at any point has been derived.

001085   Gandhi J R;Solanki G K;Patel K D;patel S G (Physics Dep, Sardar Patel Univ, Vallabh Vidyanagar) : Growth and X-ray diffraction studies of ZnSe crystals. Prajna 2007, 15, 127-31.

ZnSe is a wide band gap compound and has attracted many researchers due to its interesting luminescence properties. In this paper authors present their investigations on growth of ZnSe crystals by Physical Vapor Transport Technique. The structural characterization was accomplished by X-Jlay diffraction (XRD) studies and Jt was found to be cubic. Lattice parameters, volume and X-ray density have been measured for the gjown crystals. The particle size for a number of reflectipns has been calculated by using Scherrer's formula.

001084   Dixit R C (Physics Dep, Govt. Holkar Science College, Indore-452 001) : Review: lasers, free electron laser working and applications. Ind Res Commun 2009, 3(1), 95-9.

Laser (light amplification by stimulated emmission of radiation) is an important tool of todays. Initialy lasers are designed on the basis of stimulated emission like ruby laser, gas lasers, Nd YAG laser and semiconductor laser. In these lasers the basic needs were population inversion, stimulated emmission, formation of cavity etc. The main drawback of these lasers is that a particular laser can produce a laser beam of some particular range of wavelength with some particular power. The generation of coherent synchrotron radiation using beams of relativistic electrons passed through magnetic undulators opens up tremendous scope for material science, chemical technology, biophysical science, medical applications, surface studies and solid state physics. A free electron laser consists of an electron beam propagating through a periodic magnetic field. Free electron lasers of higher powers and shorter wavelengths have been designed and still the work is going on.

3 illus, 9 ref

000162   Yadav R P;Singh H;Rawat P S (Physics Dep, Govt. P.G. College, Bisalpur, Philibhit-426 621, Email: rpyadav93pphysics@yahoo.co.in) : Effect of magnetic field on the composition of blood: an experimental study. Ultra Scient phys Sci 2008, 20(1), 143-8.

Magnetic field affects the physical and physiological activities of our body, hence the composition of the blood. In this paper experimental investigation are presented and analysis the composition of human blood in the presence of magnetic field. The experimental results are obtained in the presence of different magnetic field. Strength (5.46 gauss, 10.90 gauss and 21.84 gauss). It is observed that the effect of magnetic field is to change the data of blood significantly.

4 illus, 6 ref

000161   Yadav R P;Ratnesh Kumar;Gangwar M K (Physics Dep, Govt. P.G. College, Bisalpur, Pilibhit-262 201, Email: rpyadav93pphysics@yahoo.co.in) : Spherical shock in heat radiating atmosphere. Ultra Scient phys Sci 2008, 20(1), 47-50.

Chester - Chesnell- Whitham method has been applied to study the propagation of strong spherical shock in the heat radiating atmosphere having uniform density distribution. Neglecting the effect of overtaking disturbances the analytical expressions for shock velocity, shock strength, particle velocity and pressure have been obtained using Bhowmick conditions. The results obtained here are compared with those for non-radiating heat atmosphere.

3 tables, 18 ref

000160   Yadav R P;Pal V;Arvind Kumar;Kumar K;Rawat P S (Physics Dep, Govt. P.G. College, Bisalpur, Pilibit, Uttar Pradesh, Email: rpyadav93pphysics@yahoo.co.in) : Motion of strong shock waves in highly viscous medium. Ultra Scient phys Sci 2008, 20(1), 135-42.

Neglecting the effect of overtaking disturbances, the propagation of strong shock waves in highly viscous uniform medium has been investigated by Chester-Chisnell-Whitham method. It is found that the shock velocity and shock strength both decreases as shock advances for low viscous region of a medium to the high viscous region. A very large change in viscocity coefficient leads to very small perturbation in flow variables. This is due to the large dessipation of energy in the highly viscous medium.

7 tables, 25 ref

000159   Yadav D C;Satyendra Singh;Gaur K (Physics Dep, K.N. Govt. P.G. College, Gyanpur, Bhadohi) : Ionic and electronic conductivity in the system Li₃BO₃ " xLi₃PO₄. Ultra Scient phys Sci 2008, 20(1), 157-64.

The electrical conductivity (σ) and Seebeck Coefficient (S) of the solidified melt of lithium based superionic system Li₃BO₃ : xLiPO₄ (with x = 0,0.33, 0.50, 0.67, 1.0, 1.5 and 2.0) are presented in the temperature range 450 to the melting point of each solid. The ionic (σ_i) and electronic (σ_e) contribution towards the electrical conductivity (a) have been separated over the entire temperature range with the time dependence study of d.c. electrical conductivity (σ_dc). In all the studied solids superionic phase have been observed below their melting points and conductivity is purely ionic in that phase. The phase transition temperature (T_p) at which solid undergoes from normal to superionic phase has been obtained. It has been shown that these solids are mixed conductor in normal phase. The variation of both the σ_i and σ_e with the temperature are presented and conduction mechanism have also been discussed.

11 illus, 3 tables, 28 ref

000158   Victorbabu B R (Statistics Dep, Acharya Nagarjuna Univ, Guntur-522 510) : Modified second order slope rotatable designs with equi-spaced levels using pairwise balanced designs. Ultra Scient phys Sci 2008, 20(2), 257-62.

A new method of construction of modified second order slope rotatable designs with equi-spaced levels using pairwise balanced designs is suggested. The proposed method may sometimes lead to designs with less number of design points than those available in the literature. A table is provided where for a range of different values of v (v-stands for number of factors) the design points needed by different methods are compared for 3 ≤ V ≤ 15.

2 tables, 16 ref

000157   Uttam K N;Kumar S;Singh R;Tandon P (Saha's Spectroscopy Laboratory, Physics Dep, Allahabad Univ, Allahabad-211 002, Email: kailash.uttam@rediffmail.com) : Thermodynamical quantities of potassium monohalides from spectroscopic data. Proc Natn Acad Sci India-Sect A 2008, 78(Pt 3), 249-54.

Thermodynamical quantities like free energy, enthalpy, entropy and specific heat of potassium monohalides have been calculated from spectroscopic data using partition function theory. The results have been calculated in the temperature range 100-2200 K. The calculated values of KC1 have been compared with the available data and discussed in the light of molecular motions.

4 tables, 16 ref

000156   Tyagi R K;Tyagi B D;Pathak P (Physics Dep, Govt. (P.G.) College, Khatima-262 308) : Porous density dependent photoluminescence from porous silicon. Ultra Scient phys Sci 2008, 20(1), 1-4.

Porous silicon is obtained by electrochemical etching of single crystalline silicon with 48% hydrofluoric acid. In this work we calculate energy gap AE for different visible wavelengths in the white light spectrum by treating energy levels in the bands of porous silicon as Bohr levels. This emission of monochromatic visible wavelengths is related to porous density of porous silicon (p-si) material. These visible wavelengths are expected to be emitted from degenerate energy levels above band gap.

3 illus, 1 table, 20 ref