018464   Pai A (NO, Indian Institute of Science Education and Research Thiruvananthapuram, CET Campus, Sreekaryam, Thiruvananthapuram-695 016, Email: archana@iisertvm.ac.in) : Gravitational waves in an interferometric detector. Curr Sci 2017, 112(7), 1353-60.

Detection of gravitational waves by two LIGO detectors has begun a new exciting era of gravitational wave astronomy. Following the two detections, India has stepped in the global effort towards gravitational wave observation via her involvement in the LIGOIndia project. The LIGO-India project will open up new opportunities in the cutting edge and challenging field of gravitational wave detection. This article provides a background about gravitational waves and interferometric detector.

3 illus, 29 ref

018463   Nanal V (Nuclear and Atomic Physics Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, Email: nanal@tifr.res.in) : Is neutrino its own antiparticle?. Curr Sci 2017, 112(7), 1375-80.

Neutrino is a neutral spin 1/2 particle, discovered through nuclear beta decay, that interacts only through the weak interaction. It is now well established that neutrinos have mass. The mass and nature of neutrinos play an important role in theories beyond the Standard Model. Whether neutrino is its own antiparticle, as proposed by Majorana, is still an open question. At present, neutrinoless double beta decay (0 vββ) is perhaps the only experiment that can reveal the true nature of the neutrinos. Given its significance, there is a widespread interest in the quest for 0vββ employing different techniques. This article presents a brief overview of 0 vββ experiments and highlights the indigenous effort to search for 0vββ in ¹²⁴Sn using a cryogenic bolometer at the India-based Neutrino Observatory.

4 illus, 2 tables, 36 ref

018462   Makkar M;Viswanatha R (New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru-560 064, Email: rv@jncasr.ac.in) : Recent advances in magnetic ion-doped semiconductor quantum dots. Curr Sci 2017, 112(7), 1421-9.

Dilute magnetic semiconductor (DMS) quantum dots (QDs) have potential to be used as basic working components of spin-based electronic devices. Therefore it is important to study these materials from fundamental and technological viewpoints. Quantum confinement effects are known to enhance exchange interactions and induce properties that were previously not observed in bulk materials. In fact, properties are known to alter dramatically when dimensions are reduced to nanometre size regime. In this review we briefly discuss the recent advances in chemical (synthetic) and physical (properties) aspects of DMS QDs. We first discuss the various issues involved in the synthesis of DMS QDs - 31 - followed by a discussion of the solutions obtained so far. We then discuss the interesting properties of DMS QDs with emphasis on their magnetic, magneto-optical and magneto-electrical properties arising from the cooperative effects of spin-exchange interactions.

6 illus, 61 ref

018461   Maji C (Materials Science Dep, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata-700 032, Email: chhayabrita@gmail.com) : Properties of magnetic shape memory alloys in martensitic phase. Curr Sci 2017, 112(7), 1390-1401.

The Heusler alloys that exhibit reversible martensitic transition show multifunctional properties including magnetic shape memory effect. The properties of two kinds of magnetic shape memory alloys are studied, where magnetic field-induced strain is driven by two different mechanisms. The properties differ in martensitic phase with composition and thus they are studied in martensitic phase. The crystal structure (Xray diffraction), magnetic behaviour (SQUID), transport analysis (four-probe method), magneto-transport trend (up to 8 T), magnetocaloric effect (around room-temperature), electronic structure (X-ray photoelectron spectroscopy and ab initio calculation), surface characterization (ultraviolet photoelectron spectroscopy and inverse photoelectron spectroscopy) are discussed for the matensitic phase. Analysis of the properties reveals alloys with possible applicability at room temperature with low magnetic field.

25 illus, 5 tables, 57 ref

018460   Khanduri P C;Upadhyay T C (Physics Dep, HNB Garhwal Univ, Srinagar Garhwal, Uttarakhand-246 174, Email: prabhantkhanduri@yahoo.com) : Dependence of dielectric constant and loss tangent on electric field in antiferroelectric squaric acid crystal. J Metall Mater Sci 2016, 58(4), 213-20.

The double-time thermal Green function method with the symmetric and antisymmetric decoupling scheme and modified pseudospin model proposed by Li and Qin for squaric acid have been used in present study to discuss the effect of electric field on some dielectric properties. Expressions for shift, width, soft mode frequency, dielectric constant, loss and transition temperature have been evaluated. By fitting model values of physical quantities in the theoretical expressions thermal dependence of antiferroelectric mode frequency, dielectric constant and loss have been calculated in presence of electric field in the vicinity of transition temperature. Theoretical results are similar to other antiferroelectric crystals.

018459   Garg N (High Pressure and Synchrotron Radiation Physics Div, Bhabha Atomic Research Centre, Mumbai-400 094, Email: nandini@barc.gov.in) : High pressure: One of the many tools to study material properties at extreme conditions. Curr Sci 2017, 112(7), 1430-43.

High pressure is a powerful and clean variable, which when applied can bring about large changes in structure and properties of materials. It can be used to simulate the conditions found deep inside the earth or in different planetary interiors. It is widely used in chemical industry, especially when the chemical reaction products have lower volumes than the initial reactants, and also in the food preservation industry, where it ensures that aromas and flavours are not lost even after preservation. Materials under pressure can be studied both theoretically and experimentally. In this article apart from discussing how to set up a basic high pressure experiment using the DAC, some examples have been elaborated to show how both experiments - 30 - and theory complement each other and both put together can help in a deeper understanding of the changes brought about by application of high pressure.

13 illus, 130 ref

018458   Choubey S (NO, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad-211 019, Email: sandhya.choubey@gmail.com) : Neutrino oscillations. Curr Sci 2017, 112(7), 1381-4.

Neutrinos are massless as proposed in the Standard Model of particle physics. However, neutrino experiments in the last few decades have revealed that neutrinos flavour oscillate, a scenario possible only if they have mass and mixing. Existence of neutrino mass was the first conclusive evidence of physics beyond the Standard Model, and explaining the smallness of the neutrino masses and peculiar mixing angles still remains a challenge for model-builders proposing beyond Standard Model scenarios. We give a brief introduction to the phenomenon of neutrino oscillations and showcase some recent work where we look for physics beyond the three-generation neutrino oscillation paradigm and its impact on future experiments.

20 ref

018457   Chorwadwala A M H (NO, Indian Institute of Science Education and Research Pune, Pune-411 008, Email: anisa@iiserpune.ac.in) : Glimpse of shape optimization problems. Curr Sci 2017, 112(7), 1474-7.

In this mini review, we give a glimpse of a branch of geometric analysis known as shape optimization problems. We introduce isoperimetric problems as a special class of shape optimization problems. We include a brief history of the isoperimetric problems and give a brief survey of the kind of shape optimization problems that we (with our collaborators) have worked on. We discuss the key ideas used in proving these results in the Euclidean case. Without getting into the technicalities, we mention how we generalized the results which were known in the Euclidean case to other geometric spaces. We also describe how we extended these results from the linear setting to a non-linear one. We describe briefly the difficulties faced in proving these generalized versions and how we overcame these difficulties.

21 ref

018456   Chakrabarti S (Applied Nuclear Physics Div, Saha Institute of Nuclear Physics, 1/AF Bidhanager, Kolkata-700 064, Email: shrabana.chakrabarti@saha.ac.in) : Manipulating cold atoms with optical fibres. Curr Sci 2017, 112(7), 1369-74.

In this article we present some demonstrations of atom-photon interactions at low photon level using optical fibres. We - 29 - report an experiment on the interaction between cold atoms produced in a magneto optical trap and tapered optical nanofibre and discuss some applications of the same. We then expound our experimental plan to study nonlinear processes such as electromagnetically induced transparency in laser cooled atomic medium confined within a hollow core photonic crystal fibre. Possible applications of this system are also discussed.

6 illus, 45 ref

018455   Bhobe P A (Discipline of Physics, Indian Institute of Technology Indore, Simrol, Indore-453 552, Email: pbhobe@iiti.ac.in) : Peek into the world of materials using thermopower and XAFS as investigative probes. Curr Sci 2017, 112(7), 1402-12.

Over the last few decades, there has been growing interest for developing technologies aimed at providing cleaner and more sustainable energy sources. Great efforts are directed towards synthesis of newer functional materials and tailoring the existing ones with an aim to optimize their usability. As materials are being developed with various complexities in their physical properties and forms like single crystals, thin-films, nanostructure and composites, measurement of their basic physical properties is also getting equally challenging. This review deals with a brief summary of our efforts in developing the basic understanding of some functional materials, using experimental tools that are best known to us, viz. measurement of Seebeck coefficient and X-ray absorption fine structure spectroscopy (XAFS). In particular, we discuss the results of our investigation of magnetic shape memory alloy Ni₂MnGa and multiferroic CdCr₂Se₄.

17 illus, 1 table, 34 ref

018454   Banerjee N;Bhatkar S A (NO, Indian Institute of Science Education and Research, Dr Homi Bhabha Road, Road, Pashan, Pune-411 008, Email: nabamita@iiserpune.ac.in) : Non-relativistic fluids. Curr Sci 2017, 112(7), 1385-9.

We present the dynamics of a most generic uncharged dissipative parity, even Galilean fluid, to the first derivative order. The construction is embedded in a symmetry broken phase of one higher dimensional relativistic system, namely the null fluid. Both the null fluid and the Galilean fluid have identical symmetries, thermodynamics and constitutive relations to all order in derivative expansion. Finally, we present the number of transport coefficients for most generic charged Galilean fluid and Galilean Superfluid.

1 table, 11 ref

017493   Sharma S;Khan S;Ranjan R;Choudhary R N P (Physics Dep, Jamshedpur Co-operative College, Kolhan Univ, Jharkhand, Email: rajivranjan.jcc@gmail.com) : Analysis of impedance and electric modulus properties of sensing and transducing material lead zirconate titanate (PZT) ceramics doped with gadolinium. J Metall Mater Sci 2017, 59(2), 49-58.

The sensing and transducing electroceramic material lead zirconate titanate (PZT) doped with the rare earth gadolinium (Gd³⁺) has been synthesized through solid-state reaction technique with chemical composition Pb_1-xGd_x(Zr_0.65Ti_0.35)_1-x/4O₃ where x = 0.00, 0.06 and 0.09. Electrical behaviour of the sintered samples has been analyzed using complex impedance spectroscopy (CIS). The real and imaginary parts of impedance have been investigated within wide range of temperatures and frequencies. The complex Z'<126>Z" Nyquist plots exhibit single semicircle or its tendency. It suggests about the presence of mostly bulk resistive (grain) contributions in the materials with a decreasing tendency as temperature increases. It shows negative temperature coefficient of resistance (NTCR) type behaviour of the materials. Complex modulus M'<126>M" plots indicate the presence of grain (bulk) as well as grain boundary contributions in the materials. It also supports the NTCR behaviour of the materials. Both the complex impedance and modulus plots indicate the presence of non-Debye type of relaxation in the materials.

017492   Manivel P (NO, Thanthai Periyar Government Institute of Technology, Vellor-632 002, Email: asokroy@nmlindia.org) : Comparative study on the inhibitive effect of para-substituted anilines on corrosion of iron in 1M HCI solutions. J Metall Mater Sci 2017, 59(1), .

Corrosion inhibition of Iron in 1M Hcl by some p-substituted anilines of various concentrations was studied using electrochemical measurements such as Impedance and Polarization methods. The inhibition efficiencies of the inhibitors have been found to be dependant on the nature of substituent group present at para position. It has been observed that anilines with electron donating groups increase inhibition efficiency.

017491   Jassim A K;Alias M F A;Abbas M M (Physics Dep, College of Science, Baghdad Univ, Baghdad, Iraq, Email: amelalmalki1974@yahoo.com) : Effect of BI substitution on the superconducting properties of Tl_2-xBi_xBa₂Ca₂Cu₃O_{10+< F128><100>} system. Int J Sci Nat 2017, 8(2), 343-6.

This study was to investigate the effect of Bi doping in the Tl-2223 superconductor by preparing a series of samples (at 860°C for 3h) with complete stoichiomerty Tl_2-xBi_xBa₂Ca₂Cu₃O_10+<100> with x ranging from 0 to 1. The superconducting properties of the samples have been examined by electrical measurements and DC magnetization measurements. It is found that a partial substitution for Tl by Bi decreases the formation of high -T_c phase and decreases its T_c. XRD pattern analyses have shown a tetragonal structure, and there are at least two superconducting phases.

5 illus, 1 table, 14 ref

017490   Alias M F;Jassim A K;Hermiz G Y (Physics Dep, Baghdad Univ, College of Science, Iraq, Email: amelalmalki1974@yahoo.com) : Effect of sintering time on the superconducting propertie of Tl_1.6Hg_0.4Sr₂Ca₂Cu₃O_{10 +δ} and Tl_1.8Bi_0.2Sr₂Sr₂Ca₂Cu₃ O_10+δ compounds. Int J Sci Nat 2017, 8(2), 240-4.

The solid state reaction technique has been used to prepare homogeneous superconducting samples for Tl_1.6Hg_0.4Sr₂Ca₂Cu₃O_10+<100> and Tl_1.8Bi_0.2Sr₂Ca₂Cu₃O_10+<100>. The effect of sintering time on the transition temperature (T_c) has been studied. The structural properties and electrical resistivity of these systems have been investigated using x-ray diffraction (XRD) and four probe method respectively. The XRD pattern showed a tetragonal structure, with at least two superconducting phases. It is found for Tl-2223 system, the T_c decreased with increasing sintering time.

6 illus, 1 table, 11 ref

016546   Visnu Prasad A K;Monica S;Jojo P J (Center for Advanced Research in Physical Sciences. Physics Dep, Fatima Mata National College (Autonomous), Kollam, Kerala, Email: jojo@fatimacollege.net) : Attached progeny profile in a high level radon-thoron coastal environment. Ultra Scient phys Sci-Sect B 2016, 28(5-7), 168-73.

Wide inconsistency in indoor radon and thoron levels has been reported in the Monazite bearing densely populated regions in the coastal belt of Kerala, India. Inhalation doses are predominantly due to these gas progenies and the unattached fraction is significant in determining radiation dose to the human lungs. The attached and unattached radon and thoron concentrations have been determined using direct radon (²²²Rn) and thoron (²²⁰Rn) progeny sensors (DRPS/ DTPS) in the Neendakara and Chavara hamlets of Kollam district, Kerala. The equilibrium equivalent concentration of the unattached fraction of ²²²Rn and ²²⁰Rn (EERC_U and EETC_U) was found to vary from 0.5 to 2.4 Bqm^-3 and 0.1 to 0.2 Bqm^-3, respectively. The concentrations of the attached fraction of ²²²Rn were found to be greater than the unattached fraction. The attached fraction of ²²⁰Rn progeny was in the range 1.01 to 3.8 Bqm^-3. The total (attached + unattached) equilibrium equivalent ²²²Rn concentration (EERC_A+U) and total (attached + unattached) equilibrium equivalent ²²⁰Rn concentration (EETC_A+U) were found to vary from 8.8 to 22.5 Bqm^-3 and 1.1 to 4 Bqm^-3, respectively. Annual effective dose rates were also determined.

6 illus, 1 table, 19 ref

016545   Vishwam T;Sarma N K S P S;Murthy V R K;Sastry S (NO, Gitam Univ-Hyderabad campus, Rudraram village, Hyderabad-502 329, Email: sreeharisastry@yahoo.com) : Dielectric relaxation studies of acetonitrile/propylene glycol and their binary mixtures. Indian J pure appl Phys 2017, 55(6), 403-12.

Dielectric relaxation spectra in the frequency range 0.02 <60> v/GHz <60> 20 have been collected for propylene glycol (PG), acetonitrile (AN) and their binary mixtures between 303 K-323 K. The average relaxation times have been calculated by the Cole-Davidson and Cole-Cole relaxation models. The experimental determined values of static dielectric permittivity (ε₀), relaxation time (τ), excess permittivity (ε^E) and excess inverse relaxation time (1/τ)^E show smooth temperature dependence. The larger relaxation time values of propylene glycol when compared to acetonitrile are due to the co-operative process of multimers with O-H-O linkage and also the steric hindrance behavior phenomena. The activation entropy (ΔS*), activation enthalpy (ΔH*), Kirkwood correlation factor (g_f), Helmholtz energy (ΔF^E) parameters have also been determined for propylene glycol and acetonitrile and the results have been correlated.

12 illus, 6 tables, 51 ref

016544   Vasantha Kumar V;Nagabhushanam M;Rao J L (Physics Dep, Vignan Institute of Technology of Science, Hyderabad-500 007, Email: lkjoshiji@yahoo.com) : Ab initio and DFT studies on structure, vibrational spectra of 4-tert-butyl-1,3-thiazol-2-amine (BTA). Indian J pure appl Phys 2017, 55(6), 420-30.

Theoretical studies have been carried out on 4-tert-butyl-1, 3-thiazol-2-amine (BTA) using both the B3LYP/6-311+G and HF/6-311+G methods. The geometrical parameters and vibrational spectra of BTA have been calculated and analyzed. The calculated IR wavenumbers have been compared with the observed FTIR wavenumbers. The complete assignments have been performed based on the potential energy distribution (PED) of the vibrational modes. The wavenumbers obtained from B3LYP method are in good agreement with the observed wavenumbers when compared to HF method. It has been found that there - 51 - is an excellent correlation with 0.999 regression coefficient between the experiment and calculated vibrations. Thermal properties like rotational constants, zero point vibrational energies and nonlinear optical properties like dipole moment, hyperpolarizabilities, NBO analysis and the effect of temperature on various thermodynamic properties have been calculated and orted.

5 illus, 6 tables, 40 ref

016543   Subba Reddy G;Veera Krishna M (Mathematics Dep, Rayalaseema Univ, Kurnool, Andhra Pradesh-518 007, Email: gsreddy.lucky@gmail.com) : Heat transfer on MHD flow of heat generating/absorbing fluid through porous medium in a rotating parallel plate channel. Ultra Scient phys Sci-Sect B 2017, 29(1-4), 71-81.

In this paper, Authors have considered the heat transfer on the unsteady hydromagnetic convective flow of an incompressible viscous electrically conducting heat generating/absorbing fluid through porous medium in a rotating parallel plate channel under the influence of uniform transfer magnetic field normal to the channel. The momentum equation for the flow is governed by the Brinkman's model. The analytical solutions for the velocity and temperature distributions are obtained by making use of regular perturbation technique and computationally discussed with reference to flow parameters through the graphs. The skin friction and Nusselt number are also evaluated analytically and computationally discussed with reference to pertinent parameters in detail.

11 illus, 2 tables, 34 ref

016542   Singh A K (Physics Dep, Bareilly College, Bareilly-243 005, Email: aksnmr@gmail.com) : Study of dielectric relaxation time and thermodynamic parameters in some polar molecules in dilute - 50 - solution of benzene. Ultra Scient phys Sci-Sect B 2017, 29(1-4), 24-8.

Present communication reports the experimental values of the dielectric relaxation time (τ) of 4 Methoxyaniline, 4 Ethoxyaniline, 2 Nitroaniline, 2 Chloro, 4 Nitroaniline, 2,6 Dichloroaniline and 2 Methoxy, 3 Nitroanilinein dilute solution of benzene at wavelength 3.13 cm in the microwave region. The measurements have been made at 293, 303 and 313°K, in order to calculate the free energy of activation for dipole orientation process (ΔF_σ). The experimental values of τ have been correlated with the calculated value of τ obtained using different theories of dielectric relaxation time (τ ). It is concluded from this comparative study that the Murty equation is a better representation of the dielectric relaxationphenomenon. Thermo dynamical parameters like molar free energy of activation (ΔF_τ), molar enthalpy of activation (ΔH_τ) and molar entropy of activation (ΔS_τ) have been evaluated by considering the relaxation as the rate process. From the values of ΔF_τ for the various compounds investigated conclusion has been made that energy of activation increases with the size of molecule.

2 tables, 19 ref

016541   Saji S K;Jeyasingh T;Vinodkumar R; SobhanaWariar P R;Radhakrishnan R (Physics Dep, Univ College, Thiruvananthapuram-695 034, Email: prswariar53@gmail.com) : Dielectric relaxation in combustion synthesized perovskite SmAlO₃. Ultra Scient phys Sci-Sect B 2017, 29(1-4), 54-7.

SmAlO₃ perovskite material was prepared by solution combustion technique. The ac conductivity and dielectric properties of the sintered pellet of the sample have been investigated in the frequency range 1Hz to 1MHz and temperature range 303K-783K. The experimental results indicate that the ac conductivity (σ_acω), dielectric constant (ε') and loss tangent (ε") depends on depends on the temperature and frequency. The ac conductivity was found to obey the power law ωⁿ with and the behavior of exponent n with temperature suggested that the conduction mechanism in the ceramic follows OLPT model. The obtained results are compared to the principal theories that describe the universal dielectric response behavior. The value ε' and tan δ were found to be temperature and frequency dependent.

3 illus, 17 ref

016540   Ratnesh Kumar (Physics Dep, SVBPIC, Amritakhas, Pilibhit-262 201, Email: ratnesh.svbp@gmail.com) : Weak isothermal shock wave in heat radiating atmosphere. Ultra Scient phys Sci-Sect B 2016, 28(5-7), 163-7.

The motion of strong spherical shock in non-uniform atmosphere has been investigated by Chester-Chesnell- Whitham method. This method is often used to study the freely propagation of shock waves in uniform and non-uniform medium. Though the effect of overtaking disturbances plays a significant role but for the sake of simplicity, its effect on the shock has neglected. The expressions for shock velocity, shock strength, particle velocity, and pressure are obtained using Bhowmick conditions.

5 tables, 27 ref

016539   Raghwendra Kumar;Ramakrishna S A (Physics Dep, Indian Institute of Technology, Kanpur-208 016, Email: raghawk@iitk.ac.in) : Microstructuring by two-photon polymerization using a sub-nanosecond laser. Curr Sci 2017, 112(8), 1668-74.

A multi-photon absorption-based laser writing system with sub-micrometer resolution has been developed using an inexpensive sub-nanosecond laser for two- and three-dimensional structuring in photosensitive resist materials. New combinations of commercially available photoresists such as SU-8 and AR-N 4340, and a photo-initiator (2, 4, diethyl-9H-thioxanten-9-one) with large two-photon absorption at 532nm are shown to be effec-tive in obtaining sub-micrometer line or dot resolu-tion. Systematic studies of the resolution on the system and fabrication parameters such as laser power, writ-ing speed, focusing arrangement, etc. have been car-ried out. The sub-nanosecond-based laser micro writer is an in expensive alternative with similar capabilities as a femtosecond-based laser writer. This system is compara-bly effective and has much higher capabilities for 2D structuring in terms of the aspect ratio of the fabricated structures than conventional 2D laser micro writers.

6 illus, 19 ref

016538   Pathak S K (Physics Dep, Chintamani College of Science-Pombhurna District-Chandrapur, Maharashtra, Email: sushilkumarpathak01@gmail.com) : Equations of state for metals under high compression. Ultra Scient phys Sci-Sect B 2016, 28(5-7), 142-8.

The extreme compression value of the pressure derivative of bulk modulus i.e. K_∞ has been treated as an adjustable parameter in recent studies on high pressure equations of state (EOS) for solids. The present study presents the elastic behaviour of metals i.e. Iron, Aluminium and Copper under high compression with the help of Birch-Murnaghan, Bre-Stacey, Shanker, Born, Vinet, Bardeen, Ullaman and Tait Equations of state. Further these EOS have been critically examined by evaluating the values of pressure derivative of bulk modulus at infinite pressure. The value of this parameter is found out to be grater than 5/3 by some EOS in case of Fe, Al and Cu such results is in good agreement with the Seismic Study of these metals.

3 illus, 1 table, 32 ref

016537   Mukhopadhyay S (NO, , ) : Experiments to determine the effect on magnetic field on floating potential in glow discharge plasma system. J nucl Engng Technol 2017, 7(1), 9-11.

In this experimental work, the variations in floating potential are discussed by the experimental research on plasma physics. The variations in floating potential with respect to the discharge voltage in the glow discharge plasma system are discussed. The variations in floating potential with respect to the distance of bar magnet from cathode are experimentally studied and discussed. The variations in floating potential with respect to the chamber pressure are experimentally studied. These experimental results may be useful for the applications in basic sciences and in technology.

016536   Mehrotra M;Mehrotra I (NO, , ) : QUARK degree of freedom in the binding energy difference of. J nucl Engng Technol 2017, 7(1), 17-19.

Invoking quark degrees of freedom in the nuclei, the six-quark bag formation effect contributes significantly to the binding energy difference of the mirror pair of p-shell hypernuclei, in the hybrid quark model. The six-quark cluster formation effect increases the binding of -hyperon in neutron rich partner compared to that of its proton rich partner.

016535   Mandlik N;Bhoraskar V N;Patil B J;Dahiwale S S;Sahare P D;Dhole S D (Physics Dep, Fergusson College, S P Pune Univ, Pune-411 004, Email: sanjay@physics.unipune.ac.in) : Thermoluminescence studies of CaSO₄: Eu nanophosphor for electron dosimetry. Indian J pure appl Phys 2017, 55(6), 413-19.

Sample of CaSO₄: Eu nanophosphor has been synthesized by chemical co-precipitation method and irradiated with 6.5 MeV electrons over the fluence range from 5 x - 48 - 10¹⁴ to 4 x 10¹⁵ e/cm². The as-synthesized sample has been characterized by the XRD and TEM. The TEM image reveals that the nanocrystallites are in the form of nanorods of length 75 to 125 nm, with varying diameter of 10 to 20 nm. The XRD yields an average grain size <126>15 nm, with hexagonal structure. The electron irradiated samples exhibit the thermoluminescence glow curve with a single peak at 162 °C. Moreover, the TL peak intensity increases with the increase in electron fluence and saturates beyond 3x10¹⁵ e/cm². Moreover, TL glow curves have been theoretically fitted using computerized glow curve deconvolution (CGCD) method to determine trapping parameters. The results indicate that CaSO₄: Eu can be used as a dosimeter for 6.5 MeV electrons over dose range from 15-80 kGy.

6 illus, 2 tables, 27 ref

016534   Kien D T;Thanh P V (Faculty of Physics, V N U Univ of Science, Vietnam National Univ, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam, Email: phamvanthanh@hus.edu.vn) : Influence of temperature on mechanical characteristics of 1018 low carbon steel estimated by ultrasonic non-destructive testing method. Indian J pure appl Phys 2017, 55(6), 431-5.

The temperature dependence of ultrasonic velocities propagated in low carbon steel 1018 has been investigated by the A-scan mode of the ultrasonic non-destructive testing method. Experimental results show that these velocities are linearly dependent on temperature of the carbon steel sample in the range of 0 to 50 °. Based on the experimental velocities of the longitudinal wave and the shear one, mechanical characteristics of this carbon steel including Poisson's ratio (u), Young's modulus (E), shear modulus (G), and bulk modulus (K) have been calculated. These mechanical characteristics have also been linear response with respect to the increase of sample's temperature. By using linear fitting approach, the temperature dependence coefficients of these mechanical characteristics have been analyzed and estimated to be 9.76x10^-6/°, -0.057 GPa/°, -0.023 GPa/°, and -0.038 GPa/° for v, E, G, and K, respectively. It is concluded that the influence of the temperature on the mechanical properties of the carbon steels is necessary determined due to the improved accuracy of the ultrasonic testing method.

4 illus, 24 ref

016533   Karda R;Guhe S;Das D (NO, , ) : Estimation of airborne concentration of radionuclides using fundamental approach. J nucl Engng Technol 2017, 7(1), 4-8.

Most of the literature exists on the simulation of accidental release from chemical or nuclear plant. In this work we have carried out fundamental modelling of radioactive release under normal operating conditions. An attempt is made to estimate the airborne radionuclide concentration in the atmosphere from probable release from slack. The effect of release stack height and the radionuclide source strength on the airborne radionuclide concentration are studied. The location of maxima of airborne radionuclide concentration is investigated in this work. The released source strength was varied to study the impact on the radionuclide concentration profile. Study reveals with increase in source strength of radionuclide airborne concentration of radionuclide increases. It is observed from the study that for similar weather condition even though source strength was varied the concentration profiles remain same and only absolute value of maxima increases with source strength. The maximum airborne concentration of radionuclide was estimated 1.031E-01 Bq/m³ for 50 m high stack release considering radioactive release source strength of 1.807E-03 Bq/s.

016532   Kalita S;Mukhopadhyay S (NO, , ) : Effect of aluminium nitride nucleation-layer on the drain characteristics on nanoelectronic algan/gan single-heterojunction HEMTS. J nucl Engng Technol 2017, 7(1), 1-3.

The simulation studies on the effect of aluminium nitride (AIN) nuclcation layer in nanoelectronic single-heterojunction AlGaN/GaN high electron mobility transistors (HEMTs) is the novelty of this work. The variations in drain current with drain voltage are studied corresponding to different gate voltages. Also, the variations in drain current with gate voltage are studied corresponding to any considered drain voltage. This simulation work may be an useful prediction for the fabrication of AlGaN/GuN HEMTs to achieve the maximum drain current.

016531   Jain P;Singh S;Siddiqui A M;Srivastava A K (Electron and Ion Microscopy Group, CSIR-National Physical Laboratory, New Delhi-110 012, Email: sukhvirster@gmail.com) : Microstructural characteristics and optical performance of nano-structured thin films of tin oxide. Indian J pure appl Phys 2017, 55(6), 385-93.

Transparent conducting tin oxide thin films (thickness <126>140 nm) have been synthesized by using vacuum evaporation technique under the vacuum of the order of 10^-6 mbar at room temperature. These films have been deposited onto glass and single crystals of KCl substrates and subsequently annealed at different temperatures for varying time periods in high purity oxygen (99.999%) atmosphere to obtain single phase of tin oxide. X-ray diffraction measurements have been carried out on the films deposited onto glass substrates to reveal the phase formation of tin oxide. Secondary ion mass spectrometer (SIMS) and selected area electron diffraction pattern (SAEDP) measurements identify the presence of Sn, SnO and SnO₂ phases in the films. Detailed XRD measurements and microstructural features recorded employing SEM, HRTEM, AFM and SIMS have been interpreted in the light of emission bands of these films occurred at 442 nm and 452 nm. The effect of vacuum conditions and annealing on nucleation and growth mechanism of tin oxide thin films has been presented and discussed in detail.

12 illus, 3 tables, 15 ref

016530   Harish Kumar;Moona G;Arora P K;Haleem A;Singh J;Rajesh Kumar;Anil Kumar (NO, CSIR-National Physical Laboratory, Dr K S Krishnan Marg, New Delhi-110 012, Email: kumarh@nplindia.org) : Monte carlo method for evaluation of uncertainty of measurement in brinell hardness scale. Indian J pure appl Phys 2017, 55(6), 445-53.

Though method based on law of propagation of uncertainty (LPU), described in GUM, is widely used as an international method for estimation of the uncertainty associated with measurements, JCGM through supplement JCGM 101:2008, which deals with the propagation of distributions, recommends the application of Monte Carlo method (MCM) to evaluate the uncertainty of measurement as an alternative method to LPU. In MCM approach, probability distribution function of measurand has been determined by assigning appropriate probability distribution of the input quantities. In the present paper, effort has been made to discuss the procedure for the application of MCM for computing the uncertainty of measurement of hardness blocks, which have been calibrated by Brinell hardness machine and observations have been recorded. A comparison of the findings of the LPU and MCM has been made, which shows good agreement between the two methodologies adopted. The paper attempts to highlights the MCM for uncertainty of measurement evalution and its implications in this regard. The paper thrusts upon the practical viability of MCM in similar applications and reliability of method have been discussed and presented.

6 - 46 - illus,

016529   Giri R;Nath G (Physics Dep, Veer Surendra Sai Univ of Technology, Sambalpur-768 018, Email: ganesh_nath99@yahoo.co.in) : Study of acoustic properties of nuclear extractants and its application. Indian J pure appl Phys 2017, 55(6), 436-44.

In nuclear industries and different reprocessing centre, for radionuclide production, reprocessing of the nuclear reactor material and extraction of rare earth materials, solvent extraction is a significant technique. Easily available and cost effective liquid like tri butyl phosphate (TBP) (extractant) and toluene (diluent) have been used in this study for extraction cerium from rare earth material like cerium oxide (CeO₂). The application sound theory derived from the propagation of ultrasonic wave in the treatment medium has been applied to investigate the different physico-chemical properties of mixture of extractant and diluent. Different sound wave parameters have been demonstrated using the experimentally calculated value of ultrasonic velocity, density and viscosity. Molecular interactions present inside the binary mixture are the main basis to study the variations of physical and acoustical parameters. After investigating all the parameters in terms of molecular interaction an optimum value for extraction has been established. Cerium has been separated from CeO₂ by phase separation using the biphasic system and maximum extraction efficiency has been examined using Nernst equation.

10 illus, 5 tables, 29 ref

016528   Ghosh S;Dubey P (School of Studies in Physics, Vikram Univ, Ujjain-456 010, Email: priyadubey1009@gmail.com) : Electron-electron two stream instability in n-GaAs plasma embeded with a nanoparticle. Indian J pure appl Phys 2017, 55(6), 394-402.

Electron-electron two stream instability in many valley semiconductors like n-GaAs embedded with a nanoparticle has been studied in hydrodynamic regime. The ingredients of this study are the consideration of polar optical phonon as the dominant intravalley scattering mechanism and a drifted Maxwellian distribution for the carriers in each valley of the medium. A dispersion relation has been developed by the self consistent solution of the momentum transfer, continuity and Maxwell's equations. Typical values of the parameters of n-GaAs at room temperature are considered for analyzing the dispersion relation of the electrostatic wave. Detail qualitative analysis of the convective instability of possible four modes of propagation reveals that the dispersion, propagation and gain profiles of all the four modes have been affected profoundly by the presence of a nanoparticle in the medium via electron plasma frequency of electron cloud present in the nanoparticle.

6 illus, 1 table, 32 ref

016527   George A;Khadar M A (Physics Dep, Mar Ivanios College, Thiruvananthapuram-695 015, Email: aneeshndlphy@gmail.com ) : Photo response studies of electrophoretically deposited nanostructured cadmium sulfide thin film. Ultra Scient phys Sci-Sect B 2017, 29(1-4), 82-6.

Cd²⁺ rich Cadmium Sulfide (CdS) nanoperticles caped with Triethanolamine (TEA) as an organic ligand were synthesized by chemical precipitation. These nanostructured CdS nanoparticles were deposited on aluminum foil by electrophoretic deposition technique. Both nanoparticles and thin film are studied by x-ray diffraction, glancing incidence x-ray diffraction and atomic force microscopy measurements to understand the growth, stability and surface morphology. The highest photocurrent obtained as 6.5 μA at incident - 45 - wavelength λ = 400 nm with an applied bias voltage of 10 V in the CdS thin films. Also time response of the photocurrent reveals the corrosion at the surface of CdS particles i.e get decompose into Cd²⁺ and S^2- ions.

7 illus, 12 ref

016526   Gangadhar Reddy M;Veera Krishna M (Mathematics Dep, Rayalaseema Univ, Kurnool, Andhra Pradesh-518 007, Email: veerakrishna_maths@yahoo.com) : Variable heat and mass transfer on MHD flow of visco-elastic fluid past an impulsively started vertical porous plate. Ultra Scient phys Sci-Sect B 2017, 29(1-4), 58-70.

In this paper, Authors have discussed the MHD flow of visco-elastic fluid through a loosely packed porous medium in an impulsively started vertical plate with variable heat and mass transfer. The temperature of plate is made to rise linearly with time. The fluid considered is gray, absorbing-emitting radiation but a non-scattering medium. The equations for the governing flow are solved by making use Laplace-transform technique. The velocity, temperature and concentration are obtained analytically and computationally discussed with reference to governing parameters and are illustrated graphically, and physical aspects of the problem are discussed. Also skin friction, Nusselt number and Sherwood number are obtained analytically and are tabulated.

13 illus, 3 tables, 45 ref

016525   Efimov A;Potapov G;Nisan A;Urazov M;Ivanov V (NO, Moscow Institute of Physics and Technology, Dolgoprudny, Russia, Email: efimov.aa@mipt.ru) : Application of the spark discharge generator for solvent-free aerosol jet printing. Oriental J Chem 2017, 33(2), 1047-50.

A new solvent-free method of aerosol printing for fabrication conductive structures in the form of lines with a minimum width of 60 μm and an average thickness of up to 6 μm has been proposed and investigated. This method is based on dry deposition of focused beam of silver nanoparticles synthesized by the multi-spark discharge generator. Printed and sintered microstructures showed low electrical resistivity equal to 7.5 μΩ*cm, which is five times greater than the resistivity of bulk silver. The described method of dry aerosol printing without solvents could be a promising alternative to conventional "wet" aerosol jet printing.

4 illus, 18 ref

016524   Chilom C;Nistorescu A (Electricity and Solid State and Biophysics Dep, Faculty of Physics, Bucharest Univ, Romania, Email: claudiafir@gmail.com) : Spectroscopic study of the - 44 - interaction of HSA with tetracaine. Indian J Biochem Biophys 2016, 53(5-6), 206-11.

Steady state fluorescence followed thermal denaturation of human serum albumin (HSA) and its interaction with the tetracaine (TTC) ligand. Thermal denaturation of HSA is a slightly reversible one step process. The binding of TTC to HSA is characterised by a moderate strength, as the moderate affinity constant showed and this interaction is entropically driven.

5 illus, 2 tables, 21 ref

015652   Zaki M F;Tabay M M El;Radwan R M (Experimental Nuclear Physics Dep, Nuclear Research Center (NRC), Atomic Energy Authority (AEA), P.O. 13759, Abu Zaabal, Cairo, Egypt) : Effect of Ar bombardment on the electrical and optical properties of low-density polyethylene films. Pramana J Phys 2016, 87(5), 1-8.

The influence of low-energy Ar ion beam irradiation on both electrical and optical properties of low-density polyethylene (LDPE) films is presented. The polymer films were bombarded with 320 keV Ar ions with fuences up to 1 x 10¹⁵ cm^-2. Electrical properties of LDPE films were measured and the effect of ion bombardment on the DC conductivity, dielectric constant and loss was studied. Optically, the energy gap, the Urbach's energy and the number of carbon atoms in a cluster were estimated for all polymer samples using theUV-Vis spectrophotometry technique. The obtained results showed slight enhancement in the conductivity and dielectric parameters due to the increase in ion fluence. Meanwhile, the energy gap and the Urbach's energyvalues showed significant decrease by increasing the Ar ion fluence. It was found that the ion bombardment induced chain scission in the polymer chain causing some carbonization. An increase in the number of carbonatoms per cluster was also observed.

7 illus, 27 ref

015651   Wazwaz A M (Mathematics Dep, Saint Xavier Univ, Chicago, IL 60655, USA, Email: wazwaz@sxu.edu) : Breaking soliton equations and negative-order breaking soliton equations of typical and higher orders. Pramana J Phys 2016, 87(5), 1-6.

Authors develop breaking soliton equations and negative-order breaking soliton equations of typical and higher orders. The recursion operator of the KdV equation is used to derive these models.We establish the distinctdispersion relation for each equation. We use the simplified Hirota's method to obtain multiple soliton solutions for each developed breaking soliton equation. We also develop generalized dispersion relations for the typical breaking soliton equations and the generalized negative-order breaking soliton equations. The results provide useful information on the dynamics of the relevant nonlinear negative-order equations.

015650   Wang H;Zheng S;Chen L;Hong X (College of Global Change and Earth System Science, Beijing Normal Univ, Beijing, 100875, People's Republic of China, Email: 1187411801@qq.com) : Bifurcations and new exact travelling wave solutions for the bidirectional wave equations. Pramana J Phys 2016, 87(5), 1-8.

By using the method of dynamical system, the bidirectional wave equations are considered. Based on this method, all kinds of phase portraits of the reduced travelling wave system in the parametric space are given. All possible bounded travelling wave solutions such as dark soliton solutions, bright soliton solutions and periodic travelling wave solutions are obtained. With the aid of Maple software, numerical simulations are conducted for dark soliton solutions, bright soliton solutions and periodic travelling wave solutions to the bidirectional waveequations. The results presented in this paper improve the related previous studies.

10 illus, 11 ref

015649   Wang H;Zhang K (School of Science, Sichuan Univ of Science and Engineering, Zigong-643 000, China, Email: wanghyswalow@136.com) : Effect of dust size distribution and dust charge fluctuation on dust ion-acoustic shock waves in a multi-ion dusty plasma. Pramana J Phys 2016, 87(1), 1-6.

The effects of dust size distribution and dust charge fluctuation of dust grains on the small but finite amplitude nonlinear dust ion-acoustic shock waves, in an unmagnetized multi-ion dusty plasma which contains negative ions, positive ions and electrons, are studied in this paper. A Burgers equation and its stationary solutions are obtained by using the reductive perturbation method. The analytical and numerical results show that the height with polynomial dust size distribution is larger than that of the monosized dusty plasmas with the same dustgrains, but the thickness in the case of different dust grains is smaller than that of the monosized dusty plasmas. Furthermore, the moving speed of the shock waves also depend on different dust size distributions.

5 illus, 31 ref

015648   Wang D;Cheng S (School of Physics and Optoelectronic Engineering, Ludong Univ, Yantai 264025, China, Email: lduwdh@163.com) : Photodetachment of H<. Pramana J Phys 2016, 87(5), 1-8.

We study the photodetachment of H^- ion in crossed gradient electric and magnetic fields and put forward an analytical formula for calculating the photodetachment cross-section. Compared to the photodetachment of H^- ion in a gradient electric field, the Hamiltonian of the detached electron has three degrees of freedom, which makes the dynamical behaviour of the detached electron complex. Photodetachment cross-section for variousexternal fields and the laser polarization are calculated and displayed. A comparison with the photodetachment cross-section in crossed uniform electric and magnetic fields or in a single gradient electric field has been made.The agreement of our results with the above two special cases suggests the correctness of our calculation. Our study may have some potential applications in the photodetachment microscopy experiment or in ion detection.

8 illus, 23 ref

015647   VisakhKumar U L;Varghese B S;Kurian P J (Physics Research Centre, St. Berchmans College, Changanacherry-686 101, Email: pjkplasma@yahoo.ca) : Nanoflare heating model for collisonless solar corona. Pramana J Phys 2017, 88(2), 143-147.

The problem of coronal heating remains one of the greatest unresolved problems in space science. Magnetic reconnection plays a significant role in heating the solar corona. When two oppositely directed magnetic fields come closer to form a current sheet, the current density of the plasma increases due to which magnetic reconnection and conversion of magnetic energy into thermal energy takes place. The present paper deals with a model for reconnection occurring in the solar corona under steady state in collisionless regime. The model predicts that reconnection time in the solar corona varies inversely with the cube of magnetic field and varies directly with the Lindquist number. Our analysis shows that reconnections are occurring within a time interval of600 s in the solar corona, producing nanoflares in the energy range 1021-10231021-1023 erg/s which matches with Yohkoh X-ray observations.

1 illus, 18 ref

015646   Venkatesh P R;Venkatesan A (Physics PG & Research Dep, Nehru Memorial College, Puthanampatti, Tiruchirapalli-621 007, Email: venkatesh.sprv@gmail.com) : Significance of power average of sinusoidal periodic excitations in nonlinear non-autonomous system. Pramana J Phys 2016, 87(1), 1-11.

Additional sinusoidal and different non-sinusoidal periodic perturbations applied to the periodically forced nonlinear oscillators decide the maintainance or inhibitance of chaos. It is observed that the weak amplitude of the sinusoidal force without phase is sufficient to inhibit chaos rather than the other non-sinusoidal forces and sinusoidal force with phase. Apart from sinusoidal force without phase, i.e., from various non-sinusoidal forces and sinusoidal force with phase, square force seems to be an effective weak perturbation to suppress chaos. The effectiveness of weak perturbation for suppressing chaos is understood with the total power average of the external forces applied to the system. In any chaotic system, the total power average of the external forces is constant and is different for different nonlinear systems. This total power average decides the nature of the force to suppress chaos in the sense of weak perturbation. This has been a universal phenomenon for all the chaotic non-autonomous systems. The results are confirmed by Melnikov method and numerical analysis. With the help of the total power average technique, one can say whether the chaos in that nonlinear system is to be supppressed or not.

5 illus, 1 table, 72 ref

015645   Vega A;Flores J (Instituto de Fisica y Astronomia, Universidad de Valparaiso, Avenida Gran Bretana 1111, Valparaiso, Chile, Email: alfredo.vega.uv.ck) : Heavy quarkonium properties from cornell potential using variational method and supersymmetric quantum mechanics. Pramana J Phys 2016, 87(5), 1-7.

Using the variational method and supersymmetric quantum mechanics we calculated, in an approximate way, the eigenvalues, eigenfunctions and wave functions at the origin of the Cornell potential. We compared results with numerical solutions for heavy quarkonia cc_, bb_ and bc_.

2 illus, 4 tables, 36 ref

015644   Varehnay N K;Singh A;Benerji N S (Excimer Laser Section, Laser Material Processing Div, Raja Ramanna Centre for Advanced Technology, Indore-452 013, Email: nsb@rrcat.gov.in) : Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression. Pramana J Phys 2017, 88(2), 111-116.

Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for repetitive operation. A magnetically coupled tangential blower is used for gas circulation inside the laser chamber for repetitive operation. The exciter consists of C-C energy transfer circuit and thyratron is used as a high-voltage main switch with singlestage magnetic pulse compression (MPC) between thyratron and the laser electrodes. Low inductance of the laser head and uniform and intense pre-ionization are the main features of the electric circuit used in the laser. A 250 ns rise time voltage pulse was compressed to 100 ns duration with a single-stage magnetic pulse compressor using Ni-Zn ferrite cores. The laser can generate about 150 mJ at <126>100 Hz rep-rate reliably from a discharge volumeof 100 cm³. 2D spatial laser beam profile generated is presented here. The profile shows that the laser beam is completely filled with flat-top which is suitable for material processing applications. The SEM image of the microhole generated on copper target is presented here.

11 illus, 18 ref

015643   Tilbi A;Boudjedaa T;Merad M (Laboratoire de Physique Theorique, Departement de Physique, Universite de Jijel, BP 98, Quled Aissa, 18000 Jijel Algeria, Email: tilbinacer@yahoo.fr) : Space-time transformation for the propagator in de broglie-bohm theory. Pramana J Phys 2016, 87(5), 1-8.

A linear space-time transformation proposed to calculate the propagator in the de Broglie-Bohm theory, is viewed as an expansion of the guiding wave function over the velocity space. It is shown that the quantum evolution is preserved in its semiclassical scheme through this change. The case of variable-frequencyharmonic oscillator is presented as an example.

32 ref

015642   Tholkappiyan R;Vishista K;Hamed F (Physics Dep, College of Engineering, Guindy, Anna Univ, Chennai-600 025, Email: thols2006@gmail.com) : Factors controlling phase formation of nocel Sr-based Y-type hexagonal ferrite nanoparticles. Pramana J Phys 2017, 88(2), 53-62.

New Sr-based Y-type nanocrystalline hexagonal ferrites with a nominal chemical composition of Sr₂Mg₂Fe₁₂O₂₂ (Sr₂Y) were prepared by autocombustion from mixtures of - 75 - Sr(NO₃)₂, Mg(NO₃)₂.6H₂O and Fe(NO₃)3.9H₂O. The newly prepared Sr₂Y nanocrystalline particles were characterized by powder X-ray diffraction (XRD). A well crystalline phase of Sr₂Y with hexagonal crystal structure was observed. Fourier transform infrared spectroscopy (FTIR) studies revealed the information about the positions of the ions and their bonds within the lattice structure of the Sr₂Y. The chemical elements and their oxidation states in the Sr₂Y hexaferriteswere determined using X-ray photoelectron spectroscopy (XPS). The XRD, FTIR and XPS studies confirmed the formation of Sr₂Mg₂Fe₁₂O₂₂ hexaferrites. The morphology and porosity of the prepared Sr₂Y nanocrystalline Sr₂Y hexaferrite particles were studied by field emission scanning electron microscopy. The magnetic properties of Sr22Y hexaferrites showed dependence on the methods of preparation conditions and calcination treatments. The values of coercivity, saturation magnetization and retentivity were in the range of 21.33-19.66 kA m^-1, 42.44-38.72 emu g^-1 and 10.05-13.19 emu g^-1 respectively.

7 illus, 1 table, 33 ref

015641   Thingujam K;Bhattacharjee A;Choudhary B; Alapati P R (Physics Dep, National Institute of Technology, Agartala-799 046, Email: kiranmala.thingujam@gmail.com) : Optical parameter measurement of a nO.m liquid crystalline compound. Indian J pure appl Phys 2017, 55(4), 269-74.

Differential scanning calorimetry (DSC) and density studies for a Schiff's base liquid crystalline nO.m compound N (4 - n - hexyloxybenzylidine) 4'- m - hexylaniline (6O.6) have been carried out. Using the previously reported refractive index data and present density data, the molecular polarizability values for the sample have been obtained. Vuks' method and Neugebauer's method have been used to calculate the parallel and perpendicular components of molecular polarizabilities. The calculation of order parameters have been previously done using direct extrapolation method and modified Vuks' method from the measured refractive indices. The order parameters of the sample have been calculated using the refractive indices and density values following Vuks' method and Neugebauer's method. The results obtained have been compared and analysed in detail.

7 illus, 2 table, 22 ref