028771   MITTAL R, VERMANI Y K (Physics Dep, Sri Guru Granth Sahib World Univ, Fatehgarh Sahib - 140 406, Email: yugs80@gmail.com) : Clusterisation and isospin effects in heavy-ion collisions at intermediate energies. Pramana - J Phys 2018, 91(6), 86.

We study the multifragmentation phenomenon in heavy-ion collisions by varying the spatial constraint criterion in minimum spanning tree (MST) clusterisation procedure. Within the framework of isospin-dependent quantum molecular dynamics (IQMD) model, the role of isospin-dependent spatial constraint, i.e. iso-MST version, is investigated on different fragment observables in various isobaric pair of reaction systems varying in the entrance channel isospin (N/Z) content. The fragment observables such as persistence, gain, average yield of free nucleons, light and intermediate mass fragments are slightly sensitive to the isospin-dependent spatial constraint criterion particularly in heavier reaction systems. For a given isobaric pair of reaction systems, the fragment production, however, remains indifferent to isospin content of the colliding nuclei.

6 illus, 40 ref

028783   SONG X, YAN H, WANG Y, MA Z, XU B (Dalian Technology Univ, Liaoning 116024, China, Email: yanhh@dlut.edu.cn) : Simulation of the wave-absorbing model of a carbonyl iron/silver-coated core-shell structure. Pramana - J Phys 2018, 91(6), 85.

The microwave-absorbing performances of carbonyl iron powder/silver core–shell composite particles are studied on the basis of the electromagnetic scattering theory and the energy conservation law. In addition, a calculation method for reflection loss of the carbonyl iron powder/silver core–shell composite particles with microwave is proposed. The calculated reflection loss of the carbonyl iron powder/silver core–shell composite particles is compared with the experimental results. The findings show that the trend of reflection loss of the carbonyl iron powder/silver composite particles can be predicted which can subsequently provide a relevant reference for future experiment and calculation of the absorbing mechanism of electromagnetic wave-microscopic carbonyl iron powder/silver core–shell composite particles.

4 illus, 19 ref

028782   SHI-HUA CHEN (Electrical Engineering Dep, Huzhou Vocational and Technical Coll, Huzhou 313000, China, Email: hzchenshihua@126.com) : Effect of electric field and temperature on the binding energy of bound polaron in an anisotropic quantum dot. Pramana - J Phys 2018, 91(6), 84.

The ratio between the confinement lengths in the xy-plane and the z direction plays an important role in determining the properties of anisotropic quantum dot. Within a variational approach of Pekar type, we investigated theoretically the effects of electric field and temperature on the ground-state binding energies of hydrogenic impurity polarons in KBr anisotropic quantum dot. The obtained results illustrate that the binding energies increase with the electric field strength and temperature but decrease with the position of the impurity when considering different confinement lengths in the xy-plane and the z direction and present the properties of the anisotropic quantum dot.

4 illus, 13 ref

028748   AYUB K, KHAN M Y, UL-HASSAN Q M, ASHRAF M, SHAKEEL M (Mathematics Dep, Wah Univ, Wah Cantonment, Pakistan, Email: qazimahmood@outlook.com) : Soliton formations for magnetohydrodynamic viscous flow over a nonlinear stretching sheet. Pramana - J Phys 2018, 91(6), 83.

In the present paper, the main focus is to study soliton formations of a two-dimensional magnetohydrodynamic flow over a nonlinear stretching sheet with the help of transformed rational function method. The fluid is electrically conductive, normal to the stretching sheet and there is no induced magnetic field. The flow problem is described by the continuity and momentum equation with suitable boundary conditions. For solving the model, the nonlinearity poses a great challenge. Nonlinear partial differential equation has been converted into a nonlinear ordinary differential equation by using similarity transformations, and then a trial solution is assumed. The results indicate complete consistency and effectiveness of the suggested scheme compared with the existing literature.

6 illus, 37 ref

028788   XIA X, ZENG Y, LI Z (Xiangtan Univ, Xiangtan 411105, China, Email: yichengz@xtu.edu.cn) : Coexisting multiscroll hyperchaotic attractors generated from a novel memristive jerk system. Pramana - J Phys 2018, 91(6), 82.

In this paper, two kinds of novel non-ideal voltage-controlled multi-piecewise cubic nonlinearity memristors and their mathematical models are presented. By adding the memristor to the circuit of a threedimensional jerk system, a novel memristive multiscroll hyperchaotic jerk system is established without introducing any other ordinary nonlinear functions, from which 2N + 2-scroll and 2M + 1-scroll hyperchaotic attractors are achieved. It is exciting to note that this new memristive system can produce the extreme multistability phenomenon of coexisting infinitely multiple attractors. Furthermore, the dynamical behaviours of the proposed system are analysed by phase portraits, equilibrium points, Lyapunov exponents and bifurcation diagrams. The results indicate that the system exhibits hyperchaotic, chaotic and periodic dynamics. Especially, the phenomenon of transient chaos can also be found in this memristive multiscroll system. Additionally, the MULTISIM circuit simulations and the hardware experimental results are performed to verify numerical simulations.

20 illus, 3 tables, 32 ref

028791   ZHAO C Y, LIAO J X, ZHANG L (Hangzhou Dianzi Univ, Zhejiang 310018, China, Email: zchy49@hdu.edu.cn) : Vernier effect of cascaded dual microring sensor. Pramana - J Phys 2018, 91(6), 81.

We demonstrate a Vernier microring sensor consisting of a traditional cascaded dual microring resonator and an additional measurement range unit. The sensor’s performance is simulated for different concentrations of aqueous solutions of ethylene glycol (C₂H₆O₂). The theoretical sensitivity of our system is as high as 7386 nm/RIU, an order of magnitude much larger than that of the traditional cascaded dual microring sensor (562 nm/RIU), 13.1 times more than the traditional cascaded dual microring sensor. At the same time, the measurement range can reach as high as 2.49 × 10⁻² RIU.

10 illus, 1 table, 20 ref

028778   SAFARI S, JAZI B (Laser and Photonics Dep, Kashan Univ, Kashan, Iran, Email: s.safari@grad.kashanu.ac.ir) : Time growth rate optimisation of terahertz electromagnetic wave generation by converting occupied plasma region from annular plasma to filled plasma in the core, in an elliptical Cherenkov maser with two energy sources. Pramana - J Phys 2018, 91(6), 80.

In this work, a comparison between two different cases of an elliptical Cherenkov maser with two electron beams for the generation and amplification of terahertz electromagnetic waves has been presented. The waveguide is made of a hollow dielectric layer filled with a cold collisionless unmagnetised plasma. In the abovementioned configuration, there are two electron beams with opposite velocities. The dispersion relation graph and its characteristics, such as its dependence on geometrical dimensions and characteristics of the electron beam, are presented. The growth rates of the hybrid modes are numerically calculated and their diagrams in some operating frequencies are studied. The effective factors on the time growth rate of hybrid electromagnetic waves, such as geometrical dimensions, dielectric constant of the dielectric layer, accelerating voltage, plasma frequency and applied current intensity, are analysed. It is shown that the injection of background plasma into the core region of the waveguide can enhance the output frequency and the wave growth rate of the beam–wave interaction.

12 illus, 25 ref

028758   ETTEHADI-ABARI M, MOHAMMAD-TAGHI H (Islamic Azad Univ, Tehran, Iran, Email: ettehadimehdii@gmail.com) : The effect of static external magnetic field on the nonlinear absorption of the S-polarised short laser pulse in collisional underdense plasma. Pramana - J Phys 2018, 91(6), 79.

Inverse Bremsstrahlung absorption is a mechanism for generating heat in the inertial confinement fusion (ICF) process. To maximise the heat produced, it is desirable to investigate the possibilities for increasing the absorption rate through the inverse Bremsstrahlung process. It should be noted that some absorption mechanisms found for nanosecond long laser pulses also appear for ultrashort laser pulses. In this paper, the physics of absorption for S-polarised laser pulse and magnetised underdense plasma interaction in the presence of electrons ohmic heating and ponderomotive nonlinearities is analysed for both collisional isothermal and collisional non-isothermal magnetised plasmas. Here, we show that, in the presence of a static magnetic field, the absorption rate of the S-polarised laser pulse through interaction with underdense plasma can be increased intensively. In other words, by applying an external magnetic field, the laser pulse radiation will penetrate a region of greater plasma density compared to the case of non-magnetised plasma for the S-polarised absorption. It is remarkable that due to the heat of the plasma at the expanse of the wave energy in the case of the non-thermal, magnetised and collisional plasma, the absorption coefficient is increased intensively in comparison with the collisional plasma.

9 illus, 39 ref

028750   BHOI J, LAHA U (Physics Dep, National Institute of Technology, Jamshedpur - 831 014, Email: ujjwal.laha@gmail.com) : Potentials and phase shifts for nucleon-light nuclei systems. Pramana - J Phys 2018, 91(6), 77.

Two simple models based on the Coulomb-distorted phase function and supersymmetry-inspired factorisation methods are adapted to deal with the nucleon–light nuclei elastic scattering at low energies. The first one is associated with the derivation of a closed-form expression of the scattering phase shift for motion in Coulomb-distorted separable non-local potentials. The second one deals with the development of an energydependent phase equivalent local potential to the non-local one for s-wave and its subsequent generation of higher partial wave interactions through the formalism of supersymmetric quantum mechanics. The usefulness of our models is demonstrated through the computation of α–nucleon scattering phase shifts at low energies up to partial waves = 2. Certain energy-dependent correction factors are also incorporated into energy-dependent higher partial wave potentials to achieve an excellent agreement with the standard data.

14 illus, 1 table, 46 ref

028747   ATIKI M E, BENDAHANE M, KASSOU-OU-ALI A (Mohammed V Univ, Morocco, Email: atiki_888@hotmail.com) : Aharonov-Bohm effect in the ghost interference. Pramana - J Phys 2018, 91(6), 76.

In the ghost interference experiment, a pair of entangled particles is sent in the opposite directions; one of the particles passes through a Young double-slit while the other continues its way freely. It turns out that the particles passing through the slits do not show any first-order interference while those propagating freely constitute an interference pattern when they are detected in coincidence with those which pass through the slits and detected at a fixed position. In this work, we consider that the particles are charged and the effect of a confined magnetic field is analysed between the slits in an Aharonov–Bohm configuration.

3 illus, 14 ref

028785   SUNZU J M, THOMAS M (Dodoma Univ, Tanzania, Email: jefta@aims.ac.za) : New stellar models generated using a quadratic equation of state. Pramana - J Phys 2018, 91(6), 75.

We obtain new regular exact solutions to the field equations for uncharged relativistic stellar objects with vanishing pressure anisotropy. We assume a quadratic equation of state and a choice of measure of anisotropy and a metric function defining one of the gravitational potentials. In our exact models, we regain anisotropic and isotropic results generated by other researchers as a special case. It is interesting that our results are in agreement with Minkowski space–time and earlier Einstein models. The physical analysis of the plots reveals that the gravitational potentials and matter variables are well behaved in the stellar interior. Using our model, we generate finite relativistic stellar masses which are consistent with the astronomical objects previously found by other researchers.

7 illus, 1 table, 57 ref

028745   AL-NASHY B, ABDULLAH M, AL-SHATRAVI A G, AL-KHURSAN A H (Misan Univ, Iraq, Email: baq_o@yahoo.com) : Lasing without population inversion in a four-level Y-type configuration in double quantum dot system. Pramana - J Phys 2018, 91(6), 74.

This work discusses lasing without inversion in Y-scheme in a double quantum dot nanostructure. This new type of lasing, which results from the quantum interference of spontaneous emission components, was not discussed earlier in quantum dot nanostructures. It is found that both pumping and cycling fields control the laser emission. The decrease of the cycling detuning increases the possibility of lasing. Probe detuning controls the width of the absorption bath (electromagnetic-induced transparency window) of this structure. This phenomenon can have an interesting application for developing sources of coherent radiation in a region of electromagnetic spectrum where the implementation of traditional laser schemes is difficult.

9 illus, 22 ref

028775   QU Z, ZHANG Z, PENG M, BI Q (Jiangsu Univ, Zhenjiang 212013, China, Email: dyzhang@ujs.edu.cn) : Non-smooth bursting analysis of a Filippov-type system with multiple-frequency excitations. Pramana - J Phys 2018, 91(5), 72.

The main purpose of this paper is to explore the patterns of the bursting oscillations and the non-smooth dynamical behaviours in a Filippov-type system which possesses parametric and external periodic excitations. We take a coupled system consisting of Duffing and Van der Pol oscillators as an example. Owing to the existence of an order gap between the exciting frequency and the natural one, we can regard a single periodic excitation as a slow-varying parameter, and the other periodic excitations can be transformed as functions of the slow-varying parameter when the exciting frequency is far less than the natural one. By analysing the subsystems, we derive equilibrium branches and related bifurcations with the variation of the slow-varying parameter. Even though the equilibrium branches with two different frequencies of the parametric excitation have a similar structure, the tortuousness of the equilibrium branches is diverse, and the number of extreme points is changed from 6 to 10. Overlying the equilibrium branches with the transformed phase portrait and employing the evolutionary process of the limit cycle induced by the Hopf bifurcation, the critical conditions of the homoclinic bifurcation and multisliding bifurcation are derived. Numerical simulation verifies the results well.

22 illus, 25 ref

028769   KARDAY M, MITTAL H M, MEHRA R (Physics Dep, Dr B R Ambedkar National Institute of Technology, Jalandhar -144 011, Email: mittal.hm@lycos.com) : Systematic study of rigid triaxiality in Ba-Pt nuclei and role of Z = 64 subshell effect. Pramana - J Phys 2018, 91(5), 70.

A systematic variation of shape variables β and γ with N and N_pN_n is studied in the framework of an asymmetric rotor model of Davydov and Filippov for the Z = 50–82, N = 82–126 major shell space. The role of the Z = 64 subshell in producing smooth systematics has been discussed. The quadrupole moments are extracted after considering both axially symmetric and axially asymmetric nuclei. The correlation of β with γ together with the measured quadrupole moments indicates that γ -rigidity is better observed in nuclei with modest deformation.

8 illus, 3 tables, 38 ref

028757   DING XIAO-SHUAI, CAO JIN-DE, ALSAADI F E (Southeast Univ, Nanjing 210096, People’s Republic of China, Email: jdcao@seu.edu.cn) : Passivity analysis of coupled inertial neural networks with time-varying delays and impulsive effects. Pramana - J Phys 2018, 91(5), 69.

This paper is devoted to the passivity analysis of an array model for coupled inertial delayed neural networks (NNs) with impulses under different network structures, namely directed and undirected topologies. Firstly, utilising the information of eigenvectors for the directed coupling matrix, a new Lyapunov functional is constructed, by which, together with the aid of some inequality techniques and network characteristics, the two sets of sufficient criteria are established to, respectively, guarantee the strictly input passivity and strictly output passivity of the impulsive network with directed coupling. Secondly, benefited from the properties of the undirected coupling matrix, some more concise conditions that are easier to be verified for the passivities of the undirected coupled network accompanied by impulsive effects are proposed. Finally, two numerical examples are designed to execute the verification of the derived theoretical results.

12 illus, 38 ref

028780   SAIKIA D, SARMA R (Physics Dep, J.B. Coll, Jorhat - 785 001, Email: dhrubajun@gmail.com) : Performance improvement of organic light emitting diode using 4,4'-N,N'-dicarbazole-biphenyl (CBP) layer over fluorine-doped tin oxide (FTO) surface with doped light emitting region. Pramana - J Phys 2018, 91(5), 65.

In this study, high performance of organic light emitting diodes (OLEDs) with a buffer layer of dicarbazole-biphenyl (CBP) film is demonstrated. With an optimal thickness of CBP (12 nm), the luminance efficiency of OLED is found to increase compared to the single-layer anode OLED. To study the performance of OLED using the buffer layer, we deposited CBP films of different thicknesses on the fluorine-doped tin oxide (FTO) surface and observed their J–V and L–V characteristics. Further analysis was carried out by making the host–guest combination within the light emitting region using iridium (III) complexes (Ir(ppy)₃) as the dopant material to enhance the efficiency of the device. We also measure the sheet resistance, optical transmittance and surface morphology of both the single and bilayer electrode surfaces using the FE-SEM images. Here the maximum value of current efficiency is found to be 12.45 cd/A under optimised doped and quantum tunnelling conditions.

5 illus, 1 table, 50 ref

028763   GUPTA V, KUMAR A, RAY N (Jawaharlal Nehru Univ, New Delhi -110 070, Email: nirat@alum.mit.edu) : Rapid communication: Permeability of hydrogen in two-dimensional graphene and hexagonal boron nitride sheets. Pramana - J Phys 2018, 91(5), 64.

We study the permeability of atomic hydrogen in monolayer hexagonal boron nitride (h-BN) and graphene using first-principles density functional theory-based simulations. For the specific cases of physisorption and chemisorption, barrier heights are calculated using the nudged elastic band approach. We find that the barrier potential for physisorption through the ring is lower for graphene than for h-BN. In the case of chemisorption, we have studied three specific cases where the H atom passes through by making bonds with the atoms at different sites in the ring. The chemisorption barrier height for graphene is found to be, in general, higher than that of h-BN. We conclude that the dominant mechanism of tunnelling through the graphene sheet and h-BN sheets would be physisorption and chemisorption, respectively.

3 illus, 1 table, 22 ref

028777   RATH B, NANAYAKKARA A, MALLICK P, SAMAL P K (Physics Dep, North Orissa Univ, Odisha - 757003, Email: brath@iopb.res.in) : SUSY quantum mechanics for pt symmetric systems. Proc Natl Acad Sci India A 2018, 88(4), 633–8.

A new way of constructing SUSY partner potentials with PT symmetry is proposed. In this construction, PT symmetric superpotentials generate PT symmetric SUSY partners and supercharges that satisfy commutator-anti-commutator relations of close superalgebra SL(1/1). Conversely, every PT symmetric Hamiltonian having zero or non zero ground state energy can be generated using PT symmetric superpotentials. Further, superpotentials having separate P and T symmetries can generate strictly isospectral SUSY partners if the wedge of integration can accommodate two asymptotically opposite quantization contours.

2 tables, 28 ref

028744   ABDULLAH B J, OMAR M S, JIANG Q (Physics Dep, Salahaddin-Erbil Univ, Iraq, Email: botan_nano@yahoo.com) : Size effects on cohesive energy, Debye temperature and lattice heat capacity from first-principles calculations of Sn nanoparticles. Proc Natl Acad Sci India A 2018, 88(4), 629–32.

The size-dependent cohesive energy, melting temperature, Debye temperature and lattice heat capacity are investigated using density functional theory within generalized gradient approximation of Sn nanoparticles. The analyses of the obtained total energies are presented by considering effect of mean bond length and the ratio number of surface atoms to that of its internal with size. The cohesive energy is calculated for Sn nanoparticles and the obtained data are used to determine melting temperature, Debye temperature and lattice heat capacity. The cohesive energy, melting point and Debye temperature drop while the lattice specific heat rise when the size is decreased due to the effects of the elevated bond length stretch. The results obtained are in excellent agreement with the available experimental results for melting point and Debye temperature of Sn nanoparticles. Also, the same trend variations of the lattice heat capacity obtained for Sn nanoparticles to that calculated theoretically in Se and Cu.

4 illus, 1 table, 26 ref

028742   ABARI F F, HOSSEINI M, FARDMANESH M (Physics Dep, Shiraz Technology Univ, Iran, Email: hosseini@sutech.ac.ir) : Optimization of a/b-axis regions of YBCO thin film for sensor applications. Proc Natl Acad Sci India A 2018, 88(4), 625–8.

The effect of substrate temperature on epitaxial growth of Y₁Ba₂Cu₃O_7-x film deposited on (100) crystalline lanthanum aluminate (LAO) substrates by RF Sputtering method has been investigated. The crystal mismatch between film and substrate is about 1.6 %. The sputtering was carried out in vacuum with base pressure better than 10^-5 Torr and 10/20 Pa oxygen/argon partial pressures. Substrate temperature at this condition is about 730 °C based on Bormann–Hammond diagram. As well known, because of the small lattice mismatch between YBCO and LAO, fabricated thin films are not perfectly c-axis and there is tendency to form a/b-axis regions in the film. Due to substantial effects of the density and size of the a/b axis regions on performance of HTS based devices like noise level of high temperature superconductor SQUIDS, optimization of a/b axis regions is crucial. YBCO thin film deposition was performed at different substrate temperatures to find the optimum temperature. The SEM results show that by decreasing deposition temperature in the range of 720–740, a/b axis regions decrease, making the films proper for fabrication of devices such as step-edge junction SQUIDs.

3 illus, 13 ref

028772   MOONA G, KAPRUWAN P, SHARMA R, OJHA V N (CSIR-National Physical Laboratory, New Delhi - 110012, Email: moonag@mail.nplindia.org) : Silicon wafer surface reflectance investigations zby using different surface texturing parameters. Proc Natl Acad Sci India A 2018, 88(4), 617–23.

This paper discusses surface texturization of monocrystalline silicon wafer (100) by using a very simple and cost effective technique consisting of a combination of mechanical grinding and chemical etching, to achieve desired surface reflectance for solar cell applications. The abrasive used for mechanical grinding is aluminum oxide powder with different grain sizes. Potassium hydroxide– isopropyl alcohol solution (with different molar concentrations) is used as alkaline etchant. The change in surface reflectance may be correlated with the change in surface roughness parameters of silicon wafer after texturing. The roughness measurements are performed by using white light interferometry based three dimensional optical profiler. Reflectance measurements of texturized silicon wafer samples are carried out by ultra violet visible spectrophotometer. A comparative reflectance study of silicon wafer samples after using these methods reveals that the combination of mechanical grinding and alkaline etching is more effective for surface texture modification in terms of significantly reduced surface reflectance as compared to a single texturization technique. After reflectance data analysis of texturized samples, correlations have been established for percentage reflectance versus abrasive grain size and percentage reflectance versus molar concentration of etchant. These correlations provide a combination of abrasive grain size and etchant molar concentration to achieve desired value of percentage surface reflectance of silicon wafer from 23.97 to 11.85 % at 800 nm wavelength, which is significant for solar cell applications.

5 illus, 1 table, 25 ref

028755   DASH N, BISWAL S (Physics Dep, OUAT, Bhubaneswar, Email: dash.namita79@gmail.com) : Hall effect on MHD flow induced by torsional oscillation of a porous disc in a rotating fluid. Proc Natl Acad Sci India A 2018, 88(4), 591–601.

This paper deals with the study of Hall effects on magnetohydrodynamic viscous flow induced by torsional oscillation of a porous disc in a rotating fluid. Constitutive equations of motion and energy have been developed using both hydrodynamic and electrodynamic equations. Expressions for velocity, temperature and phases are obtained by solving the equations of momentum and energy. The expression for skin-friction has also been derived alongwith its amplitude and phase. After computerization with the permitted numerical values of the fluid parameters, the velocity, temperature and shear stress profiles are obtained. It is observed that the radial velocity of the fluid increase with distance from the porous disc. However, the increase in Hall parameter is observed to reduces the axial velocity for, 0$<$$\mathrm{\eta }$ $\le$ 2, but for $\mathrm{\eta }$$>$2, it increases. The phase / of the transverse shear stress decreases with the decrease of Hartmann number for n$>$p (frequency (n) greater than fluid pressure (p).

8 illus, 29 ref

028770   KRASNOV I N, KRASNOVA A YU , MIROSCHNIKOVA V V, TOLSTOUKHOVA T N (Don State Agrarian Univ, Rostov Region, Zernograd, ul. Lenina, 21-Russia) : Energy saving in milk pasterization process with hydrodynamic heater use. Plant Arch 2018, 18(2), 2593-9.

They determined the sources of heat loss during milk pasteurization: in the surrounding medium and with the flow of cooling water. They proposed the heat insulation of the milk heater to reduce heat and energy losses in a pasteurization pack by mounting of the holder on its surface and the use of a heat pump during the last stage of pasteurized milk cooling. They obtained the calculated dependences to determine the main parameters of the improved pasteurizer with a hydrodynamic heater.

4 illus, 1 table, 10 ref

028781   SALMAN A M, ABOJASSIM A A, KADHIM S H, KITAN A J A Z (Physics Dep, Kufa Univ, Iraq, Email: ali.alhameedawi@uokufa.edu.iq) : Evaluating some characters of vegetative growth and natural radioactivity of Papyrus and Reeds in marsh Al-chibayish, Iraq. Plant Arch 2018, 18(2), 2439-42.

This investigation was carried out during season 2017 at 30 march on plants of papyrus and reeds grown in marsh east 30 km at AL- Chibayish, Nassria Governorate in area Ishan Goba at length stem under water 100 - 150 cm. The plants were grown in silt soil. The experiment included the local cultivar plants of papyrus and reeds with three replicates and the replicate 5 plants. Therefore, it is implemented according to Randomized Complete Block Design (RCBD). Also, it is measured natural radioactivity (²³⁸U, ²³²Th and ⁴⁰K) using gamma-ray spectroscopy, statistical analyzed is carried out by Duncan test at the probability level around 5%. Results showed that , leaf area, leaf moisture, number leaves/plant, leaf thickness, number of nods, total chlorophyll and firmness of pulp on plants of stem at length 100 cm from soil more than plants of stem at length 150 cm from soil. There were a significant effect between treatment. The results of specific activity for uranium-232, thorium-232 and potassium-40 were lower than the allowed world limit, so there are no health effect for human according to radiation contents.

4 tables, 14 ref

028749   AZIZ W J, JASSIM H A (Physics Dep, Mustansiriyah-Univ, Iraq, Email: hanenali940@yahoo.com) : A new paradigm shift to prepare copper nanoparticles using biological synthesis and evaluation of antimicrobial activity. Plant Arch 2018, 18(2), 2020-4.

In the present study, a simple way, fast and environmentally friendly “hydrothermal method” for preparation Cu nanoparticles. Cu NPs were prepared from Syzygium aromaticum (clove) bud extract. The synthesized nanoparticles were subjected to structural, optical, morphological, antimicrobial and antifungal studies. The nanoparticles structural properties and surface morphology formation were studied by X-Ray diffraction, Scanning Electron Microscopy and average grain size also have been calculated. Ultraviolet-visible (UV-Vis) absorption spectrum showed the absorption peak of CuNPs at 305 nm. The high crystalline nature of CuNPs with an (FCC) phase isobvious from the X-ray diffraction (XRD) pattern. The greatest intensity peak located at (111) orientation. Crystallite size was found to be ~12 nm. The obtained formation was homogeneous and relatively spherical and cluster nanoparticles. The antimicrobial studies of CuNPs effect against Bacillus subtilis, Escherichia coli and pronounced fungicidal activity against Candida albicans of microorganisms. The diameters of the inhibition zones of CuNPs were of Bacillus subtilis (42 mm) and Escherichia coli (33 mm) at 200 µg/ml concentration. The diameter of the inhibition zones of CuNPs against the fungus strains was of Candida albicans (50 mm) at 200 µg/ml concentration. The current study clearly indicates that the Syzygium aromaticum bud extract mediated CuNPs exhibited the excellent antimicrobial activity.

5 illus, 1 table, 22 ref

028767   KADHIM I H, HUSSAIN S (Physics Dep, Babylon Univ, Iraq, Email: pure.inaam.hani@yahoo.com) : Measurement the concentration of Radon gas emitted from sample of henna consumed in Iraq using nuclear track detector Cr-39. Plant Arch 2018, 18(2), 1987-92.

In this work, investigated of radioactive content in some Henna consumed by Women and recognize the limits allowed by using CR-39 detector technology, the number of selected species under study reported 9 kind of various henna, these tests were conducted in the laboratories of the Faculty of Education for Pure Sciences / Physics Department, University of Babylon, where the duration of preparation for the samples was 60 days and the readings were somewhat different. after examination of the models are compared with indicators of radiation protection (ICRP), which was within the allowable limits of (200-800) Bq/m³.

4 illus, 1 table, 7 ref

028743   ABASS A H, MUTTALEB M K (Physics Dep, Babylon Univ, Iraq, Email: mam50_24@yahoo.com) : Study of natural radioactivity (²³⁸U, ²³²Th, ⁴⁰K) for canned rice samples in local markets in Hilla city. Plant Arch 2018, 18(2), 1847-50.

Food is indispensable to human life, thus an important parameter of environmental science. The presence of radionuclides in food grains poses a number of health hazards, especially when these radionuclides are deposited in the human body, through food. The main objective of this study is to determine the radioactivity concentration of gamma emitting radionuclides e.g. ²³⁸U, ²³²Th, ⁴⁰K activity in food grain sample. Nine samples of food grain were collected from the different market of Hilla city, have been measured by means of gamma ray spectroscopy with a NaI(Tl) detector. The average value of specific activities ²³⁸U, ²³²Th and ⁴⁰K were in the samples of rice (2.787±0.408) Bq.Kg^-1(6.058 ± 0.58) Bq.Kg^-1 (77.671 ± 38.54) Bq.Kg^-1, respectively. Also, it was found that, the average value of Radium Equivalent and the Internal Hazard Index were (17.380) Bq. kg^–1, ( 0.051) Bq. kg^–1, respectively. As were all the results It was found that the values of the specific radioactivity of the Uranium ²³⁸U and the ²³²Th and the ⁴⁰K Potassium were distributed in varying proportions for rice models and are within the internationally permissible range.

4 illus, 3 tables, 14 ref

027541   GOYAL S, CHAUHAN R P (Physics Dep, National Institute of Technology, Kurukshetra - 136 119, Email: chauhanrpc@gmail.com) : Effect of Ar⁺ ion implantation on the properties of electrodeposited CdTe thin films. Bull Mater Sci 2018, 41(5), 131.

Semiconducting nanomaterials of II–VI groups are the key elements of continued technological approaches made in the field of optoelectronic, magnetic and photonic devices due to their size-dependent properties. Ion beams create changes in the material along their track; this not only exhibits excellent properties but also tailors new materials. This article reports the effect of Ar⁺ ion implantation on the properties of cadmium telluride thin films of about 80 nm thickness. The implantation parameters were adjusted based on computer-aided learning using SRIM (stopping and range of ions in matter) software. The CdTe thin films were deposited by electrodeposition method on ITO substrate. Thin films of CdTe are exposed to Ar⁺ ions with different fluencies of 1 × 10¹⁵, 5 × 10¹⁵ and 1 × 10¹⁶ ions cm⁻² at Ion Beam Centre, Kurukshetra University, Kurukshetra, India. After implantation, the films were characterized using UV–visible spectroscopy, photoluminescence (PL) and a four-probe set-up with a programmable current–voltage (I–V) source metre. The scanning electron microscopy of pristine film showed smooth and uniform growth of sphere-shaped grains on substrate surface. From optical studies, the values of optical band gap for as-deposited and argon-ion-implanted thin films were calculated. It was found that values of optical band gap decreased with the increase in fluence of ion beam. From PL studies it was found that the intensity got increased with ion fluence. A considerable increase in current was noticed from I–V measurements with ion fluence after implantation. Different properties of pre- and post-implanted thin films are studied.

8 illus, 36 ref

027573   RADULOVIC M, SEKARA T B, LUTOVA C B (Montenegro Univ, Cetinjski put bb, 81000 Podgorica, Montenegro, Email: milovanr@ac.me) : Decomposition of a class of linear electrical networks for calculation of total power. Sadhana 2018, 43(9), 139.

A new method of decomposition of linear electrical networks for calculating total power is presented. By an iterative procedure, on the basis of decomposition of the electrical network, the branches containing power sources (voltage and/or current) are selected first until the remaining network becomes passive. Then, one calculates the power dissipated by the decomposed networks supplied by the corresponding power sources. Total power dissipated by impedances of the starting networks is equal to the sum of powers dissipated by impedances of the decomposed networks, under the condition that all impedances Z of the network are either resistive Im(Z) = 0 or reactive Re(Z) = 0 or mutually equal.

11 illus, 16 ref

027532   DATTA U, KALAM A, SHI J (Victoria Univ, Melbourne, Australia, 8001, Email: ujjwal.datta@live.vu.edu.au) : Electric vehicle (EV) in home energy management to reduce daily electricity costs of residential customer. J Sci Ind Res 2018, 77(10), 559-65.

Exploiting energy storage capacity of proliferating EVs in present power system may contribute to minimize adverse impact of EV charging and electricity operating costs of residential customers. This study investigates an electric vehicle (EV) charging/discharging strategy in home energy management system (HEMS) to evaluate economic benefit of different operation modes in dynamic pricing schemes. Three different operation modes i.e. grid-to-vehicle (G2V), vehicle-to-grid (V2G) and vehicle-to-home (V2H) and their relative financial advantage using single and dual EVs are investigated without affecting customer comfort of EV for driving. The proposed economic analysis is carried out for a single residential customer for one day. Numerical studies show that reducing electricity consumption from grid in peak pricing periods using V2H is more beneficial than V2G or G2V in term of economy as selling energy to the grid is technically inflexible and financially competitive.

3 illus, 3 tables, 16 ref

027522   AMAECHI I C, BALOGUN B B, NWACHUKWU M I, SOUSA C T, KAKAZEI G N, ARAUJO J P, OSUJI R U (Physics and Astronomy Dep, Nigeria Nsukka Univ, Enugu State, Nigeria, Email: ifeanyichukwu.amaechi@emt.inrs.ca) : Activation parameters of conjugated polyaniline electrolyte via dielectric relaxation technique. Indian J Pure Appl Phys 2018, 56(10), 830-6.

The synthesis and relaxation mechanism of polyaniline electrolyte in form of thin film by oxidative polymerization in the presence of inorganic acid have been reported. The films have been characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, 2-point probe and UV-Vis absorption spectroscopy. The mechanism of electrical conductivity for the disordered system has been explained in terms of Mott’s variable-range hopping for the intrinsic conduction of the protonated long chain. The dielectric parameters including real part, imaginary part and loss tangent have been measured between the wavelength range 400 – 1100 nm. These have been employed in the determination of dielectric relaxation time τ which exhibits Arrhenius-like behaviour. Finally, the temperature dependent relaxation time which is a function of activation energy of dipole orientation otherwise known as Gibbs free energy ∆G^#, has been utilized in estimation of some thermodynamic parameters such as enthalpy ∆H^# and entropy ∆S^#. The SEM shows an aggregation of randomly oriented fibrous network of polyaniline on the surface of substrate. Fourier transform infrared confirms the acoustic vibrational modes of the long chain polymer.

7 illus, 1 table, 62 ref

027562   NATARAJ A, BEENA T, SUDHA L, NARAYANA B, BALACHANDRAN V (Physics Dep, S R M Institute of Science and Technology, Chennai - 600 089, Email: sakuraj86@yahoo.co.in) : Spectroscopic characterization and quantum chemical investigation of molecular structure and vibrational spectra of phthalazine-1(2H)-one. Indian J Pure Appl Phys 2018, 56(10), 802-13.

In this study, vibrational and electronic transition analysis of phthalazine-1(2H)-one have been presented using experimental techniques FT-IR, FT-Raman and density functional theory (DFT) calculation. The structural properties of the molecule in the ground state have been calculated using DFT employing B3LYP/6-311++G(d,p) basis set. Optimized geometrical parameters have been interpreted and compared with the experimental values. The complete assignments have been performed on the basis of the experimental data and potential energy distribution (PED) of the vibrational modes. The calculated HOMO and LUMO energies and energy difference (ΔE_HOMO‒LUMO = − 4.876 eV), confirm that charge transfers occur within the molecule. The stability of the molecule arising from hyperconjugative interactions and the charge delocalization has been analyzed using natural bond orbital’s analysis (NBO). The specific heat, Gibb’s free energy, and entropy of molecule have been calculated as a function of temperature by using statistical mechanics coupled with quantum chemical calculation. Observed vibrational wave numbers have been compared with calculated values, and found to be in agreement with experimental results. The study of dielectric properties like dielectric constant at microwave frequency, static dielectric constant and dielectric constant at optical frequency of Phthalazine-1(2H)-one have been determined. The dielectric relaxation studies provide information about the molecular structure and intermolecular interaction between phthalazine-1(2H)-one and alcohol mixture.

8 illus, 7 tables, 40 ref

027559   MISHRA R M, RAI J S P (Central Institute of Plastics Engineering & Technology, Lucknow - 226 008, Email: rmmcipet@gmail.com) : Preparation and properties of nanocomposites based on polyetherimide (PEI)/silicone rubber reinforced with halloysite nanotubes. Indian J Pure Appl Phys 2018, 56(10), 787-91.

This paper presents the results of investigating the effect of halloysite on the thermal, mechanical and morphological properties of PEI/silicone rubber blend based nanocomposites. Novel PEI/silicone rubber filled with halloysite nanotubes nanocomposites have been prepared for various HNTs loadings with the aid of co-rotating twin screw extruder. The results obtained depict that the tensile strength, tensile modulus, elongation at break, hardness and impact strength have significantly increased with increase of HNTs loading. The thermal stability of nanocomposites has been enhanced and found to be maximum at 3 phr HNTs loading. Morphology of the tensile fractured surfaces of nanocomposites has been studied by Scanning electron microscope (SEM). The morphological studies have demonstrated an appreciable reduction in domain size of silicone rubber at 3 phr loading of HNTs and it clearly indicates the reinforcing ability of the HNTs. The interfacial and inter-tubular interactions between HNTs and polymer matrices, and formation of HNTs zig-zag structures are the main reasons for the improvement of various properties.

2 illus, 4 tables, 29 ref

027563   NAYAK M K, SHAW S, MAKINDE O D (Physics Dep, Biju Patnaik Technology Univ, Khurda - 752 057, Email: mkn2122@gmail.com) : Chemically reacting and radiating nanofluid flow past an exponentially stretching sheet in a porous medium. Indian J Pure Appl Phys 2018, 56(10), 773-86.

The influence of non-uniform permeability, thermal radiation and variable chemical reaction on three-dimensional flow of an incompressible nanofluid over an exponentially-stretching sheet in association with a convective boundary condition has been investgated. In the present study, a new micro-convection model known as Patel model has been employed to enhance the thermal conductivity and hence the heat transfer capability of nanofluids. In the present analysis, base fluids such as water, 30 % ethylene glycol, 50 % ethylene glycol and nanoparticles such as Cu, Ag and Fe₃O₄ have been considered. With the help of some suitable transformations the governing partial differential equationsare converted into a set of ordinary differential equations which have beeen then solved numerically by using fourth-order Runge-Kutta method along with shooting technique. The influence of various embedded physical parameters have been explored through graphs for velocity, temperature, concentration, skin friction, local Nusselt and Sherwood numbers. The resistive force offered by the porous matrix belittles the momentum boundary layer and helps in growing the temperature and concentration boundary layers. Fluid temperature is an increasing function of radiation parameter Rd and Biot’s number Bi whereas concentration field is a decreasing function of Schmidt number Sc and chemical reaction parameter γ.

27 illus, 3 tables, 45 ref

027587   SARKAR S, DAS R (Physics Dep, Tripura Univ, Suryamaninagar - 799 022, Email: dasratantuphy@tripurauniv.in) : Determination of structural elements of synthesized silver nano-hexagon from X-ray diffraction analysis. Indian J Pure Appl Phys 2018, 56(10), 765-72.

Silver nano-hexagons (AgNHs) have been prepared by a chemical reduction method using poly-vinyl pyrrolidone (PVP) as a stabilizing agent. The XRD results exhibit the crystalline nature of the prepared sample, with a face centred cubic (fcc) phase. Transmission electron microscopic (TEM) results reveal that the silver nanoparticles are nearly hexagon in shape with an average size of 50 nm. Here, crystallite size has been calculated using Williamson-Hall (W-H) method, which is nearly matching with average size obtained from TEM analysis. Again, using W-H method, micro strain has been calculated, which is produced in the nano-hexagon due to dislocation of silver atoms. Further, the lattice constant of the nano-hexagons has also been estimated from the Nelson–Riley plot. Moreover, the appropriate structural parameters such as Lorentz factor, Lorentz polarization factor, dislocation density, number of atoms in a unit cell and morphological index have also been studied from the X-ray diffraction profile.

7 illus, 1 table, 52 ref

027544   HOROZ S (Electrical and Electronics Engineering Dep, Siirt Univ, Siirt - 56100, Turkey, Email: sabithoroz@siirt.edu.tr) : Structural, optical and photovoltaic properties of Co (3 %): CdZnS nanoparticles. Indian J Pure Appl Phys 2018, 56(10), 759-64.

In the present study, CdZnS and Co (3 %): CdZnS nanoparticles (NPs) have been synthesized via wet chemical method at room temperature using 1-thioglycerol as a capping agent. The incident photon-to-current conversion efficiency (IPCE) measurement has been carried out for Co (5 %): CdZnS for the first time in this study. The results show that Co (3 %): CdZnS can be utilized as sensitizers to improve the performance of solar cells. In addition to the photovoltaic properties; structural, optical and morphological properties of Co (3 %): CdZnS NPs have been investigated. The results indicate that Co (3 %): CdZnS NPs can be suitable material for photovoltaic applications.

7 illus, 1 table, 25 ref

027530   BOGLE K A, MORE K D, BEGUM S, DADGE J W, MAHABOLE M P, KHAIRNAR R S (Swami Ramanand Teerth Marathwada Univ, Nanded - 431 606, Email: kashinath.bogle@gmail.com) : Optical and electrical properties of F doped SnO₂ thin films. Indian J Pure Appl Phys 2018, 56(10), 755-8.

A wide variety of commercial devices needs conducting/semiconducting metal oxide materials due to their unique combination of high optical transparency and high electrical conductivity. Moreover, induced defects within the host atomic arrangement are fairly responsible for their desirable optical and electrical properties. Therefore, studying the effect of doped ion is essential for better understanding of the behaviour of conducting/semiconducting metal oxides. In this context, influence of fluorine doping on optical and electrical properties of polycrystalline SnO₂ thin films synthesized using sol-gel assisted spin coating method have been investigated in this work. The structural, optical and electronic analysis of pure and F doped SnO₂ thin film indicates major effect of F doping concentration. Based on the electrical measurement these films show semiconducting nature with optical band gap in the range from 2.88 to 3.11 eV with increasing F concentration. These results suggest that F doped SnO₂ thin films are suitable in field of advance electronic or nano-electronic device technology.

3 illus, 18 ref

027558   MELAVANKI R M, MUTTANAVAR V T, VAIJAYANTHIMALA S, PATIL N R, NAIK L R, KADADEVARMATH J S (Physics Dep, B V B Coll of Engineering and Technology, Hubli - 580 031, Email: patilnr23@gmail.com) : Solvent effects on the dipole moments and photo physical properties of laser dye. Indian J Pure Appl Phys 2018, 56(10), 749-54.

The absorption and emission spectra of fluorescent laser dye namely, 4,4”’-bis-2-butyyloctyl-oxy)-P-quaterphenyl have been recorded at room temperature in solvents of different polarities. The exited state dipole moments (µ_e) have been estimated from Lippert’s, Bakhshiev’s and Kawski-Chamma-Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The geometry of the molecule has been fully optimized and the µ_g has also been calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The µ_g and µ_e have been calculated by means of solvatochromic shift method. It has been observed that µ_e is higher than µ_g, indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected laser dye. Further, the changes in the dipole moment (µ) has been calculated both from solvatochromic shift method and microscopic empirical solvent polarity parameter (E) and values are compared.  

6 illus, 3 tables, 28 ref

027545   KALE S K (Pimpri Chinchwad Engineering Coll, Pune - 411 044, Email: sonalikale6@gmail.com) : Functionalization of Fe₃O₄ nanoparticles. Indian J Pure Appl Phys 2018, 56(9), 728-31.

Magnetic iron oxide (Fe₃O₄) nanoparticles are used as ferrofluids and in biomedical field as diagnostic and therapeutic tools, contrast agents in magnetic resonance imaging, drug delivery to tumor cells, cancer treatment by hyperthermia. These applications usually require uniform, chemically stable and monodispersed particles in liquid media. As a result of anisotropic dipolar attraction, nanoparticles of iron oxide aggregate into large clusters which may lead to the failure of their properties. Surface modification is often required to prevent such aggregation of nanoparticles. It has been already proved that aggregation can be avoided by surface modification of Fe₃O₄ nanoparticles using silica. The present work seeks the preparation and characterizations of monodispersed magnetic nanoparticles (Fe₃O₄) as well as silica coating. Fe₃O₄ nanoparticles have been synthesized using thermal decomposition route. The reaction involves high temperature (230 °C) heating of iron acetylacetonate Fe(acac)₃ in the presence of reducing agent and surfactant. Structural characterizations and surface chemistry of nanoparticles have been analyzed using X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. Further work has been extended by coating as prepared Fe₃O₄ nanoparticles with silica. It reveals from microscopic analysis that each silica sphere contains several monodisperse Fe₃O₄ NP.

5 illus, 18 ref

027592   SINGH A P, GHOSHAL S K, KUMAR H (Mechanical Engineering Dep, National Institute of Technology Delhi, Delhi - 110 040, Email: harishkumar@nitdelhi.ac.in) : A contemporary investigation of force transducers: Past and present scenario. Indian J Pure Appl Phys 2018, 56(9), 717-27.

In this paper, retrospective investigation of different types of force transducers, used in different applications (metrological, industrial, scientific etc.) for force measurement, has been done. The paper discusses the complete classification of force transducers based on shape, display and applications. Various types of force transducer have been discussed in the paper including symmetrical, unsymmetrical and alteration types. An attempt has been made to provide a comprehensive investigation related to metrological aspects of force transducer.

7 illus, 1 table, 54 ref

027542   GULDALI O E, OKUR I (Physics Dep, Sakarya Univ, Sakarya - 54187 , Turkey, Email: iokur@sakarya.edu.tr) : Microstructural and optical properties of La-doped ZnO thin films deposited by spin coating on quartz glass. Indian J Pure Appl Phys 2018, 56(9), 708-16.

The potassium titanate fibers have been synthesized using TiO₂ and KOH as startup materials in one step hydrothermal method. The thickness of synthesized fibres ranges from 20 to 100 nm whereas the length varies from 200 nm to 200 microns. The effect of annealing at various temperatures on the synthesized nanofibers has also been investigated by characterization using XRD, SEM, TEM, Raman and FT Raman. The annealing at 800 °C has been found to yield a pure K₂Ti₆O₁₃ phase when its XRD peaks have been compared with the standard XRD data. The growth of nanowires is along  the (010) direction. However, when annealed at 400 °C, 600 °C, 800 °C and 1000 °C the samples show the transformation into several other structural phases. However, annealing above 800 °C causes all the structures of nanowires to transform into K₂Ti₆O₁₃. The TEM image shows that the product formed contains a large quantity of fibres with almost uniform thicknesses but with varied lengths.

8 illus, 25 ref

027579   RAWAT S, SHARMA J, SHARMA S (Jawaharlal Nehru Univ, New Delhi - 110 067, Email: shatendra@gmail.com) : Study of effect of annealing on morphology of hydrothermally synthesized potassium titanate fibers. Indian J Pure Appl Phys 2018, 56(9), 703-7.

The potassium titanate fibers have been synthesized using TiO₂ and KOH as startup materials in one step hydrothermal method. The thickness of synthesized fibres ranges from 20 to 100 nm whereas the length varies from 200 nm to 200 microns. The effect of annealing at various temperatures on the synthesized nanofibers has also been investigated by characterization using XRD, SEM, TEM, Raman and FT Raman. The annealing at 800 °C has been found to yield a pure K₂Ti₆O₁₃ phase when its XRD peaks have been compared with the standard XRD data. The growth of nanowires is along the (010) direction. However, when annealed at 400 °C, 600 °C, 800 °C and 1000 °C the samples show the transformation into several other structural phases. However, annealing above 800 °C causes all the structures of nanowires to transform into K₂Ti₆O₁₃. The TEM image shows that the product formed contains a large quantity of fibres with almost uniform thicknesses but with varied lengths.

15 illus, 31 ref

027528   BHAVSAR V, TRIPATHI D (Physics Dep, Gujarat Univ, Ahmedabad - 380 009, Email: vaishali.b.bhavsar@gmail.com) : Surface and dielectric studies of PVC-PVP blend films for green electronics. Indian J Pure Appl Phys 2018, 56(9), 696-702.

In the present communication, an attempt has been made to prepare and study surface and dielectric properties of polyvinylchloride-polyvinylpyrrolidone blend films. Surface properties such as water absorption, contact angle, surface free energy of the films have been measured to investigate the interaction of blend films with water. These measurements reveal that on increasing the weight percentage concentration of polyvinylpyrrolidone in polyvinylchloride, hydrophilicity of the films increases. The surface free energy increases with increasing concentration of polyvinylpyrrolidone in polyvinylchloride, which indicates that these films tend to adsorb more moisture and dust particles from atmosphere thereby affecting its ageing and rendering it degradability. Further the dielectric properties in the low frequency range (1 kHz – 2 MHz) have been studied. The results show that the dielectric constant, loss tangent and ac conductivity of blend films increase as the weight percentage concentration of polyvinylpyrrolidone is raised. Amongst various compositions of polyvinylchloride-polyvinylpyrrolidone films studied, it is the blend film having 50 % weight concentration of polyvinylchloride and polyvinylpyrrolidone each which exhibits improved mechanical flexibility, better degradability and modulated dielectric properties. This biodegradable low-cost composition can find application in field of green electronics.

11 illus, 1 table, 29 ref

027589   SHAH D P, RANA V A, TRIVEDI C M (Physics Dep, Gujarat Univ, Ahmedabad - 380 009, Email: varana@gujaratuniversity.ac.in) : Orientational and dielectric behaviour of N, N-dimethylformamide in different non-polar solvents. Indian J Pure Appl Phys 2018, 56(9), 677-83.

Dielectric behaviour of concentrated solutions of different mole fractions of N, N-dimethylformamide in various non-polar solvents has been studied using precision LCR meter with four terminal liquid dielectric test fixture over a frequency range 20 Hz to 2 MHz at 303.15 K temperature. The dielectric parameters namely dielectric constant (ε′), dielectric loss (ε″) and static dielectric constant (ε₀) have been determined by capacitive measurement method. The limiting dielectric constant (ε_∞) has been determined by Abbe’s refractometer for the same solutions at 303.15 K temperature. Kirkwood correlation factor g^eff has also been calculated using determined values of ε₀ and ε_∞,to gain information about the orientational behaviour of N, N-dimethylformamide in different non-polar solvent environments.

4 illus, 3 tables, 30 ref

027555   MAHAJAN G R, KUMBHARKHANE A C (Swami Ramanand Teerth Marathwada Univ, Nanded-431 606, Email: akumbharkhane@yahoo.co.in) : Dielectric relaxation study of N-methylformamide in 1, 4-dioxane solvent using time domain reflectometry technique up to 30 GHz. Indian J Pure Appl Phys 2018, 56(9), 669-76.

Complex dielectric permittivity has been determined for the mixture of N– methylformamide (NMF) – 1, 4 –dioxane (DX) with various concentrations in the frequency range from 10 MHz to 30 GHz by time domain reflectometry (TDR) at different temperatures. The Luzar theory has been applied to compute Kirkwood correlation factors for the mixtures. It adequately reproduces the experimental values of static dielectric constants. The Bruggeman model for the non linear case has been fitted to the dielectric data of the binary mixture.

7 illus, 3 tables, 35 ref

027594   SRIVASTAVA S, MISRA S K, CHOPRA D, SHARMA P (Prosthodontics Dep, Saraswati Dental College, Lucknow - 227 105, Email: dr.Sudhanshu101@gmail.com) : Enlightening the path of dentistry: Lasers - A brief review. Indian J Dent Sci 2018, 10(3), 184-9.

Lasers were brought into the field of clinical dentistry with the expectation of conquering a portion of the downsides postured by the customary strategies for dental practice. One of the primary objectives in dentistry is to give the treatment as agreeable as conceivable. The laser is being utilized as a part of various dental procedures including soft tissue surgeries, cavity preparation, caries removal, and caries detection. The utilization of current normal lasers in dentistry brought about less pressure and dread in patients amid dental techniques, likewise prompting more moderate nonobtrusive strategies for delicate and hard tissues with insignificant discomfort and bleeding. This article will briefly elaborate uses of laser in dentistry.

1 illus, 72 ref

027520   AGHAEI-AMIRKHIZI N, SADJADI S, MOGHADDAM-BANAEM L, ATHARI-ALLAF M, JOHARI-DEHA F (Production and Separation of Isotopes Dep, Nuclear Science and Technology Research Institute, Iran, Email: lmoghaddam@aut.ac.ir) : Dosimetry of ¹⁷⁵ytterbium poly (amidoamine) therapy for humans' organs. J Med Phys 2018, 43(3), 173-8.

This investigation focuses on biodistribution of irradiated dendrimer encapsulated Ytterbium-175 (¹⁷⁵Yb) and to estimate the absorbed dose from intravenous injection of PAMAM encapsulated ¹⁷⁵Yb to human organs. A dendrimer compound containing an average of 55 Yb⁺³ ions per dendrimer was prepared and irradiated with neutrons for 2 h at 3×10¹¹ n.cm-² s-¹ neutron flux. The resulting mixture was injected into a group of tumor bearing mice and the mice were excised, weighed and counted at certain times to study the biodistribution. The human organs absorbed dose was assessed by MIRD schema and MCNP simulation. The specific activity and radiochemical purity of the irradiated nano-composite were 7MBq/mg and >99 % respectively. The rapid up take of dendrimer was in liver, lung, and, spleen. MIRD and MCNPX were applied for dose estimation. The human absorbed dose in liver, lung, spleen, kidney and bone that simulated by MCNP are 1.266, 0.8081, 0.8347, 0.03979 and 0.01706 mGy/MBq respectively and these values for MIRD schema are 1.351, 0.73, 1.03, 0.039, and 0.0097 mGy/MBq respectively. The results showed that ¹⁷⁵Yb-PAMAM nano-radiopharmaceutical has potential of application for liver and lung tumors.

6 illus, 4 tables, 32 ref

027547   KAVITHA Y B, UDAGANI C, KAVITHA K H, KAVYA G (Studies and Research in Physics Dep, Tumkur Univ, Tumkur-572 103, Email: drchikkappa19@gmail.com) : Study of β- radiation penetration depth in low density organic liquids. Indian J Pure Appl Phys 2018, 56(8), 656-9.

This paper presents a precise method of determining the penetration depth of β- radiation in low density organic liquids. The radiation sources used are Thallium- 204(Tl-204) and Ceasium-137(Cs-137). The measurements have been carried out using Gamma- Scout (GmbH & Co. Germany). The Gamma-Scout is a general purpose Geiger counter that measures alpha, beta and gamma radiations. It has proven to be useful in the medical, nuclear, mining and foundry industries. Acetic acid, paraffin and ethanol of densities 1.049 g/cm³, 0.85 g/cm³ and 0.789 g/cm³, respectively, have been used for the studies. The penetration depth of beta particles depends mainly on density of sample material and energy of the incident beta radiation. Determination of penetration depth of β- particles in the low density organic liquids is helpful in understanding the interaction of β- particles with low density materials such as flesh and blood.

5 illus, 5 tables, 5 ref

027585   SANKARSHANA B M, KUMAR S P, UMESH T K (Studies in Physics Dep, Mysore Univ, Mysuru-570 006, Email: tku@physics.uni-mysore.ac.in) : Effective atomic number of polymer blended granite stones for Compton scattering. Indian J Pure Appl Phys 2018, 56(8), 653-5.

Polymer blended granite stones which are a combination of polymers with their flexibility on the one hand and granite stones with their strength on the other, are useful in many applications of human enterprise. It is very important to understand the interaction of these materials with gamma radiation especially in the widely used energy region 50 keV to 1500 keV. In this energy region, Compton scattering is a dominant process. Hence in the present work we have made an attempt to determine the effective atomic number (Z_eff) of some polymer blended granite stones using the single differential scattering cross section for gamma rays of energy 59.54 keV at 105°. Compositions of these samples have been determined using energy dispersive X-ray spectroscopy (EDS), which is further used to determine theempirical values of Z_eff of these samples based on Auto-Z_eff programme. On comparison these values are found to match with Z_eff obtained from experiment within the range of experimental errors.

3 illus, 1 table, 6 ref

027557   MANDAL R, DEV B N, BHORASKAR V N, SENGUPTA D (Geology and Geophysics Dep, Indian Institute of Technology, Kharagpur-721 302, Email: ranjita169@gmail.com) : Depth profiling of sodium and lithium doped samples using Rutherford backscattering spectrometry. Indian J Pure Appl Phys 2018, 56(8), 650-2.

Various samples of Teflon chemically doped with lithium and sodium have been irradiated with hydrogen ions in order to study the depth profile using Rutherford backscattering (RBS) spectrometry which can detect even microgram of sample. Studies have also been done to see the effects of irradiation on the samples after and before doping them with sodium or lithium. Co-60 gamma-rays (1.17 and 1.33 MeV) and 1 MeV electrons have been used for irradiation.

3 illus, 12 ref