029985   MOHANDASS P, KHANNA D, KUMAR T M, THIYAGARAJ T, SARAVANAN C, BHALLA N K, PURI A (Physics Dep, Karunya Institute of Technology and Sciences, Coimbatore - 641 114, Email: davidkhanna@karunya.edu) : Study to compare the effect of different registration methods on patient setup uncertainties in cone beam computed tomography during volumetric modulated arc therapy for breast cancer patients. J Med Phys 2018, 43(4), 207-13.

This study compared three different methods used in registering cone‑beam computed tomography (CBCT) image set with planning CT image set for determining patient setup uncertainties during volumetric modulated arc therapy (VMAT) for breast cancer patients. Seven breast cancer patients treated with 50 Gy in 25 fractions using VMAT technique were chosen for this study. Atotal of 105 CBCT scans were acquired by image guidance protocol for patient setup verification. Approved plans’ CT images were used as the reference image sets for registration with their corresponding CBCT image sets. Setup errors in mediolateral, craniocaudal, and anteroposterior direction were determined using gray‑scale matching between the reference CT images and onboard CBCT images. Patient setup verification was performed using clip‑box registration (CBR) method during online imaging. Considering the CBR method as the reference, two more registrations were performed using mask registration (MR) method and dual registration (DR) (CBR + MR) method in the offline mode. For comparison, systematic error (∑), random error (σ), mean displacement vector (R), mean setup error (M), and registration time (Rt ) were analyzed. Post hoc Tukey’s honest significant difference test was performed for multiple comparisons. Systematic and random errors were less in CBR as compared to MR and DR (P > 0.05). The mean displacement error and mean setup errors were less in CBR as compared to MR and DR (P > 0.05). Increased Rt was observed in DR as compared to CBR and MR (P < 0.05). In addition, multiple comparisons did not show any significant difference in patient setup error (P > 0.05). For breast VMAT plan delivery, all three registration methods show insignificant variation in patient setup error. One can use any of the three registration methods for patient setup verification.

5 illus, 2 tables, 30 ref

029982   MEKKY ABDEL-BASET H (Qassim Univ, El-Mozneb 51931, Saudi Arabia, Email: univ.physics@yahoo.com) : Investigation of the influence of Br- and As-doped silica single-wall nanotubes: Hartree-Fock method. Bull Mater Sci 2018, 41(6), 164.

Synthesis of silica single-wall nanotubes was reported based on single-membered ring (single unit cell) with the element As. These results are supported by performing the Hartree–Fock/6-311G method. The electronic structure, optical band gaps, hardness (η) and softness (S) are discussed. No difference in the computed bond length and angle of doped silica was found. Doping of As and Br atoms leads to a decrease in the energy gap of pure silica. This will make the silica doped with Br and As molecules not require more energy to be excited.

4 illus, 2 tables, 55 ref

029970   HAZARIKA S J, MOHANTA D (Physics Dep, Tezpur Univ, Assam 784028, Email: best@tezu.ernet.in) : Exfoliated WS₂ nanosheets: Optical, photocatalytic and nitrogen-adsorption/desorption characteristics. Bull Mater Sci 2018, 41(6), 163.

In this work, we report on structural, optical, photocatalytic and nitrogen adsorption–desorption characteristics of WS₂ nanosheets developed via a hydrothermal route. X-ray diffraction (XRD) studies have revealed a hexagonal crystal structure, whereas nanodimensional sheets are apparently observed in scanning and transmission electron microscopy (SEM and TEM) micrographs. As compared to the bulk counterpart, the WS₂ nanosheets exhibited a clear blue shift. Through Brunauer–Emmett–Teller (BET) surface area analysis, average surface area, pore volume and pore size of the NSs were calculated as 211.5 m² g⁻¹, 0.433 cc g⁻¹ and 3.8 nm, respectively. The photocatalytic activity of the WS₂ nanosheets was also examined with malachite green (MG) as the target dye under both UV and day light (visible) illumination conditions. Accordingly, a degradation efficiency as high as 67.4 and 86.6 % were witnessed for an irradiation time duration of 60 min. The nano-WS₂ systems have immense potential in optoelectronics, solid-lubrication and other next generation elements.

8 illus, 30 ref

029977   KUNDU S, NASKAR M K (CSIR-Central Glass and Ceramic Research Institute, Kolkata 700 032, Email: milan@cgcri.res.in) : Microwave-hydrothermal synthesis of mesoporous γ-Al₂O₃ and its impregnation with AgNPs for excellent catalytic oxidation of CO. Bull Mater Sci 2018, 41(6), 161.

Mesoporous γ-alumina was synthesized by the microwave-hydrothermal process with a shorter duration time at 150 $°$C/2 h followed by calcination at 550 $°$C/1 h. Ag nanoparticles (AgNPs) were impregnated into γ-alumina under a reducing atmosphere at 450 $°$C. The synthesized product was characterized by X-ray diffraction (XRD), thermogravimetric (TG)/differential thermal analysis (DTA), X-ray photoelectron spectroscopy (XPS), N₂ adsorption–desorption study, fieldemission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The BET surface area values of γ-alumina and Ag-impregnated γ-alumina were found to be 258 and 230 m² g⁻¹, respectively. FESEM images showed the formation of grain-like particles of 50–70 nm in size with a flake-like microstructure. The XRD, XPS and TEM studies confirmed the presence of Ag in the synthesized product. Catalytic properties of the product for CO oxidation was studied with the T₅₀ (50 % conversion) and T₁₀₀ (100 % conversion) values of 118 and 135 $°$C, respectively; the enhanced values were compared with the literature reported values.

7 illus, 1 table, 35 ref

029967   GUPTA A K, BAFNA M, VIJAY Y K (Physics Dep, Agrawal P. G. Coll, Jaipur, Email: drminalphysics@rediffmail.com) : Study of optical properties of potassium permanganate (KMnO₄) doped poly(methylmethacrylate) (PMMA) composite films. Bull Mater Sci 2018, 41(6), 160.

We have developed films of pure polymethylmethacrylate (PMMA) (0.5, 1, 2 and 5 %) and potassium permanganate (KMnO₄)-doped PMMA composite films of thickness ($~$100 µm) using the solution-cast technique. To identify the possible change that happen to the PMMA films due to doping, the optical properties were investigated for different concentrations of KMnO₄ by recording the absorbance (A) and transmittance (T %) spectra of these films using UV–Vis spectrophotometer in the wavelength range of 300–1100 nm. From the data obtained from the optical parameters viz. absorption coefficient (α), extinction coefficient (κ), finesse coefficient (F), refractive index (η), real and imaginary parts of dielectric constant (ε_r and ε_i) and optical conductivity (σ) were calculated for the prepared films. The indirect optical band gap for the pure and the doped-PMMA films were also estimated.

10 illus, 1 table, 14 ref

030002   SINGHAL S, CHAWLA A K, GUPTA H O, CHANDRA R (Electrical Engineering Dep, Shiv Nadar Univ, Noida 201308, Email: sonalanilsinghal@gmail.com) : Effect of annealing temperature and CdCl₂ treatment on the photo-conversion efficiency of CdTe/Zn_0.1Cd_0.9S thin film solar cells. Bull Mater Sci 2018, 41(6), 159.

We report the effects of annealing in conjunction with CdCl₂ treatment on the photovoltaic properties of CdTe/Zn_0.1Cd_0.9S thin film solar cells. CdTe layer is subjected to dry CdCl₂ treatment by thermal evaporation method and subsequently, heat treated in air using a tube furnace from 400 to 500 $°$C. AFM and XRD results show improved grain size and crystallographic properties of the CdTe film with dry CdCl₂ treatment. This recrystallization and grain growth of the CdTe layer upon CdCl₂ treatment translates into improved photo-conversion efficiencies of CdTe/Zn_0.1Cd_0.9S cell. The results of dry CdCl₂ treatment were compared with conventional wet CdCl₂ treatment. Photo-conversion efficiency of 5.2 % is achieved for dry CdCl₂-treated cells in comparison with 2.4 % of wet-treated cell at heat treatment temperature of 425 $°$C.

7 illus, 35 ref

030001   SINGH R (Physics Dep, Sri Guru Gobind Singh Coll, 160019 Chandigarh, Email: ranber14@gmail.com) : Spin-orbit coupling in graphene, silicene and germanene: Dependence on the configuration of full hydrogenation and fluorination. Bull Mater Sci 2018, 41(6), 158.

We investigate the effect of full hydrogenation and fluorination on the spin-orbit coupling (SOC) in graphene, silicene and germanene. In chair conformation, the fluorination of graphene increases the spin-orbit splitting (E_so), while the hydrogenation and fluorination of other structures reduce the E_so at the -point. In case of boat conformation, the hydrogenation and fluorination reduce the symmetry of honeycomb structure, which in turn remove the degeneracy of valence band maximum at the -point. The change in band gaps due to SOC is very small in boat conformation structures as compared to that in the corresponding chair conformation structures.

3 illus, 3 tables, 38 ref

029995   SHARMA J, HASHMI S A (Physics and Astrophysics Dep, Delhi Univ, Delhi 110007, Email: sahashmi@physics.du.ac.in) : Plastic crystal-incorporated magnesium ion conducting gel polymer electrolyte for battery application. Bull Mater Sci 2018, 41(6), 147.

Studies on a novel composition of magnesium ion conducting gel polymer electrolyte (GPE), comprising a solution of Mg-salt, magnesium trifluoromethanesulfonate (Mg-triflate or Mg(Tf)₂) in a plastic crystal succinonitrile (SN), entrapped in a host polymer poly(vinylidenefluoride–hexafluoropropylene) (PVdF–HFP) was reported. Small amount of an ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf) was added to stabilize the GPE composition. The electrolyte possesses excellent dimensional integrity in the form of free-standing thick film, which offers the ionic conductivity of 4 × 10⁻³ S cm⁻¹ at room temperature ∼26$°$C. The electrochemical potential window of the electrolyte, observed from the linear sweep voltammetry, is determined to be ∼4.1 V. The magnesium ion conduction in the GPE film is confirmed from cyclic voltammetry, electrochemical impedance spectroscopy and dc polarization techniques. Different structural, thermal and electrochemical studies demonstrate the promising characteristics of the polymer film, suitable as electrolyte in rechargeable magnesium batteries. The potential of the GPE as electrolyte/separator was ascertained by fabricating a prototype magnesium battery of the configuration Mg:graphite composite anode/GPE/MnO₂-cathode. The specific discharge capacity of 40 mAh g⁻¹ (with respect to the MnO₂ cathode material) was obtained at the first discharge. The cell shows charge–discharge performance for eight cycles with a substantial fading in capacity.

9 illus, 32 ref

029960   DAKHEL A A (Physics Dep, Bahrain Univ, Zallaq, Kingdom of Bahrain, Email: adakhil@uob.edu.bh) : Comparative study of structural, optical and magnetic properties of Fe-Pt, Fe-Cu and Fe-Pd-codoped WO₃ nanocrystalline ceramics: Effect of annealing in hydrogen atmosphere. Bull Mater Sci 2018, 41(6), 139.

Tungsten oxide (W-oxide) nanoparticles doped and codoped with different transition-metal (TM) ions (Fe, Pt, Cu and Pd) were synthesized by hydrochloric acid-assisted precipitation. The synthesized powders were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS) and magnetic characterization methods. The room temperature (RT) monoclinic (P21/n) structure founded for pristine WO₃ nanopowder was converted into orthorhombic (Pbam) structure by Fe-doping, while codoping, (Fe–Pt) and (Fe–Cu) preserved the P21/n space group (SG) structure. It was found that the hydrogenation of the synthesized doped-samples corroded the crystallites without changing the crystalline SG structure. Moreover, controllable room temperature ferromagnetic (RT-FM) properties were created by hydrogenation of the codoped W-oxide samples. The oxygen vacancies-mediated ferromagnetic (FM) interaction could be responsible for the observed FM. The relative highest RT-FM energy was created with hydrogenated Fe–Pd codoped W-oxide. Therefore, Fe–Pd-codoped W-oxide nanopowder could be considered as a potential candidate for many applications involving partial FM properties, such as catalysts and optical phosphors.

5 illus, 2 tables, 42 ref

029983   MELAVANKI R, GEETHANJALI H S, THIPPERUDRAPPA J, KUSANUR R, PATIL N R, BHAVYA P (Physics Dep, M S Ramaiah Institute of Technology, Bangalore 560 054, Email: melavanki73@gmail.com) : Effect of hydrogen bonding and solvent polarity on the fluorescence quenching and dipole moment of 2-methoxypyridin-3-yl-3-boronic acid. Indian J Pure Appl Phys 2018, 56(12), 989-96.

Two photophysical properties namely, fluorescence quenching and dipole moment (both ground state and excited state) of 2-methoxypyridin-3-yl-3-boronic acid (2MPBA) have been investigated in alcohol environment using steady state fluorescence technique at 300 K. In quenching studies, a rare but not unusual observation; negative Stern-Volmer (S-V) deviation has been noticed. It has been explained using the concept of solute’s conformational changes in the ground state due to inter-molecular and intra-molecular hydrogen bonding in alcohol environment. The spectroscopic data has been processed using Lehrer equation and thereby Stern-Volmer constant (K_SV) has been evaluated. It has been found to be above 100 for most of the solvents used. The data related to dipole moment has been examined using different solvent polarity functions. Theoretical calculation of dipole moment in the ground state has been done using Gaussian software. The general solute–solvent interactions and hydrogen bond interactions have been found to be operative. An appreciable red shift of about 25 nm in the emission spectra has been identified with the rise in solvent polarity and decrease in molar mass of alcohols. It confirms the π→π^* transition as well as the possibility of intra-molecular charge transfer (ICT) character in the emitting singlet state of 2MPBA.

11 illus, 3 tables, 30 ref

029961   DAVE G, KANCHAN D K (Physics Dep, The M S Baroda Univ, Vadodara 390 002, Email: dkkanchan.ssi@gmail.com) : Dielectric relaxation and modulus studies of PEO-PAM blend based sodium salt electrolyte system. Indian J Pure Appl Phys 2018, 56(12), 978-88.

Dielectric properties of solid polymer electrolyte having PEO-PAM blend matrix with sodium trifluoromethane sulfonate (NaCF₃SO₃) as ionic salt have been studied. The samples have been prepared by solution cast technique. X-ray diffraction analysis has been carried to understand the formation of blend, complexation and crystallinity of the polymer blend with the variation of salt amount. Complex impedance spectroscopy has been used to study ionic conductivity, dielectric relaxation and modulus formalism as a function of frequency at various temperatures. Scaling of M" spectra has been carried out and it has been found that the dynamic relaxation processes occurring in the system are dependent on temperature as well as salt concentration. Highest conductivity at room temperature has been found to be 2.81x10^-7 S/cm for sample with 17.5 wt% NaCF₃SO₃.

18 illus, 1 table, 45 ref

029968   GUPTA D K, VERMA M, GOPAL R, JASUJA N D, SHARMA K B, SAXENA N S (Vivekananda Global Univ, Jaipur 303 012, Email: deepak.nanoconverge@gmail.com) : Synthesis, characterization and electrical properties of GO/PANI/NPs (NPs = CdSe, CdSe/CdS, CdSe/ZnS) nanocomposites. Indian J Pure Appl Phys 2018, 56(12), 970-7.

In this paper, GO/PANI/NPs (NPs = CdSe, CdSe/CdS, CdSe/ZnS) nanocomposites have been prepared using chemical method. The electrical properties of CdSe quantum dots, core shell nanoparticles (CdSe@CdS and CdSe@ZnS), graphene oxide/polyaniline nanocomposite (GO/PANI) and graphene oxide/polyaniline/nanoparticles (GO/PANI/NPs) nanocomposites have been measured using electrometer/high resistance meter (Keithley 6517A) at different wt% ratio. The above obtained nanoparticles (CdSe, CdSe@CdS and CdSe@ZnS) show the electrical current in nano ampere (nA) range while GO/PANI nanocomposites show the electrical current in miliampere (mA) range in the I-V measurement. The results of this study have been expected to reveal the effect of finite particle size on the conductivity of nanoparticles. The observed electrical conductivity of GO/PANI/NPs nanocomposites has been significantly reduced after the mixing of above obtained nanoparticles in different wt% ratio with GO/PANI nanocomposites. The knowledge of electrical conductivity and the effective mechanism for the conduction in nanocomposite is important for the fabrication of an electronic device such as solar cell.

9 illus, 1 table, 45 ref

029996   SHARMA P, DHAWAN A, NAQVI S F, SHARMA S K (Physics Dep, Anand International Engineering Coll, Jaipur 303 012, Email: dr.anildhawan11@gmail.com) : Effect of Ni ion irradiation on microstructure and corrosion properties of Zr₅₉Nb₃Cu₂₀Al₁₀Ni₈ amorphous alloy. Indian J Pure Appl Phys 2018, 56(12), 965-9.

The amorphous Zr₅₉Nb₃Cu₂₀Al₁₀Ni₈ alloy has been irradiated by 100 MeV Ni⁺⁷ ion beam at the fluence rates of 1×10¹³ and 1×10¹⁴ ions/cm² at room and elevated temperature. The effect of irradiation on structure sensitive properties of Zr-based amorphous alloys has been investigated in this study using XRD and FESEM and potentiodynamic polarization study. The results reveals that there are no significant changes in the microstructure at lower fluence rate but the formation of nanocrystalline structures have been observed at the higher fluence rates and the results have been corroborated using corrosion studies.

4 illus, 1 table, 17 ref

029987   PATEL S M, KALRA Y, OJHA V N, SINHA R K (Applied Physics Dep, Delhi Technological Univ, Delhi, Email: dryogitakalra@gmail.com) : A simple method to estimate the loading effects of Al/Si on the characteristic impedance of multilayer microstrip line. Indian J Pure Appl Phys 2018, 56(12), 959-64.

The present study aims to experimentally determine the microwave transmission and reflection properties of aluminum thin film grown on silicon using sputtering. A simple microstrip line based structure has been used for the microwave characterization in the frequency range 10 MHz to 26.5 GHz. Complex S-parameter measurements reveal only small differences on silicon loading and aluminum/silicon loading in comparison to the microstrip line. The characteristic impedance (Z) of the microstrip line loaded with silicon and with aluminum/silicon have been obtained corresponding to the length of the loadings using two port microwave analysis. Comparison of loaded microstrip line with no loading shows large changes in the real part well as imaginary part of the characteristic impedance in the frequency range less than 10 GHz. Percentage changes in the real (Z) and imaginary (Z) have been found as ± 40% and ± 10% in average, respectively, for silicon loading in comparison to the no loading case, whereas these changes have been found to be below ± 5% for aluminium/silicon loading, thus these smaller changes suggest the similar responses for aluminium/silicon loading and no loading. The results reveal that the propagation can be restored with the application of aluminum with any semiconductor or dielectric as loading on the microstrip line, which shows its potential to be explored for making an individual microwave component.

7 illus, 14 ref

029965   DUDUK N, TOLA A T (Electronics and Automation Dep, Pamukkale Univ, 20160 Kinikli, Denizli, Turkey, Email: nduduk@pau.edu.tr) : Design of log domain differential class AB universal biquad filter by employing lossy integrators. Indian J Pure Appl Phys 2018, 56(12), 949-58.

A new current mode low voltage differential Class AB second order universal biquad filter has been designed in this work. In design process, inspiring from Kerwin-Huelsman-Newcomb circuit, the circuit is realized with lossy integrators. The circuit has fundamental filter outputs namely; low pass, high pass and band pass. All pass and notch filter outputs have also been obtained by using additional circuits. In circuit design process, the state space method and translinear principle have been used. Two of the circuit parameters are electronically tunable which are the quality factor Q and the pole frequency f₀. PSpice circuit simulations have been obtained to check the theoretical results’ validity. In PSpice simulations, both ideal and AT&T CBIC-R type real transistor models have been used.

18 illus, 25 ref

030000   SILOTIA P, GIRI R, PRASAD V (Physics and Astrophysics Dep, Delhi Univ, Delhi 110 007, Email: psilotia21@gmail.com) : Spectra of distorted quantum ring in external fields. Indian J Pure Appl Phys 2018, 56(12), 941-8.

The spectra and response of a single electron on a distorted quantum ring have been studied in detail. The distortion in the ring has been taken care by a geometrical factor. We take few different cases of distortion. Role of strength of the distortion along with the external static and laser field on spectrum has been studied.

9 illus, 38 ref

030005   TRIPATHY A, NATH G, PAIKARAY R (Applied Science and Humanities Dep, ABES Engineering Coll, Ghaziabad 201 009, Email: ganesh_nath99@yahoo.co.in) : Effect of ultrasonication in treatment of crude oil. Indian J Pure Appl Phys 2018, 56(11), 914-9.

The demand of petroleum oil has proven its importance in energy sector as well as in the streamlining the economic scenario of the country. In production sector of crude oil, the problem has been observed when the ambient temperature is lower than the wax appearance temperature (WAT), which results the oil become cool leading to deposition of wax. The present paper focuses effect of ultrasonic energy on crude oil sample to reduce the deposition of wax. The propagation of ultrasonic wave in waxy crude oil in presence of suitable blend makes it possible to proper analyse the reduction of wax by suitable mathematical theory. The treatment of ultrasonic energy in wax reduction process involves experimentation and computation of some basic parameter which are explaining the basic mechanism of reduction of wax deposition. The variation of acoustic parameters, their excess values have been discussed in terms of molecular interactions present in the solvent mixture, which explains the physio- chemical behaviour of the crude oil at WAT due to complex formation. The treatment of crude oil with the optimum suitable blend makes it possible to reduce the wax percentage.

8 illus, 20 ref

029994   SESHADRI S, PADMAVATHY M (Physics Dep, Urumu Dhanalakshmi Coll, Trichy 620 019, Email: ssudc@14gmail.com) : Use of vibrational spectroscopy to study 1,3-dimethyl-5-nitrobenzene: A combined theoretical and experimental approach. Indian J Pure Appl Phys 2018, 56(11), 902-13.

The FTIR and FT-Raman spectra of 1,3-dimethyl-5-nitrobenzene (DMNB) have been recorded in the range 4000‒400 cm⁻¹ and 3500‒100 cm⁻¹, respectively. The molecular structures, fundamental vibrational frequencies and intensity of the vibrational bands have been investigated and interpreted theoretically with the use of structural optimizations and normal coordinate force field calculations based on density functional theory (DFT) with 6-31G(d,p) basis set. The vibrational assignments have been made from potential energy distribution (PED). The theoretically simulated vibrational spectra of the molecule show excellent agreement with the experimental spectra. The hyper conjugative interaction energy (E⁽²⁾) and electron densities of donor (i) and acceptor (j) bonds have been calculated using NBO analysis. The electronic transition has been studied using UV-Visible analysis of the title molecule with B3LYP/6-31G(d,p) level of theory. The microscopic non-linear optical (NLO) behaviour of the title compound has also been calculated. In addition, the ¹H and ¹³C NMR chemical shifts values of DMNB in the ground state for B3LYP/6-31G(d,p) method have also been calculated using gauge independent atomic orbital (GIAO) method.

5 illus, 9 tables, 42 ref

029957   CHAUDHARY R K, KUMAR R, RANGRA V S (Physics Dep, Government Coll, Kangra 177 103, Email: raman.phy.hpu@gmail.com) : An investigation on molecular dynamics of binary mixtures of N-methylacetamide and tetramethylurea in microwave region. Indian J Pure Appl Phys 2018, 56(11), 896-901.

The dielectric relaxation times (τ) and the dipole moments (µ) of the binary mixtures of different molar concentrations of tetramethylurea (TMU) in the binary mixtures of N-methylacetamide (NMA) and tetramethylurea (TMU) in benzene solutions have been calculated by using standard standing wave microwave techniques and Gopala Krishna’s single frequency (9.90 GHz) concentration variational method at different temperatures (25 °C, 30 °C, 35 °C and 40 °C). The energy parameters (H_e, F_e, S_e) for the dielectric relaxation process of binary mixtures containing 30 % mole-fraction of TMU have been calculated at the respective given temperatures and the comparison has been made with the corresponding energy parameters (H_η, F_η, S_η) for the viscous flow. On the basis of the observations, it is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process. The solute-solute and solute-solvent types of the molecular associations have been predicted.

4 illus, 3 tables, 16 ref

029981   MEENA P L, KUMAR R, SREENIVAS K (Physics Dep, Delhi Univ, New Delhi 110 078, Email: plmeena@gmail.com) : Structural, elastic and magnetic properties of spinel Co₃O₄. Indian J Pure Appl Phys 2018, 56(11), 890-5.

We have investigated the structural and magnetic properties of Co₃O₄ ceramic synthesized by solid state reaction method. Powder X-ray diffraction (XRD), Raman spectroscopic and Fourier transforms infrared (FTIR) analysis reveals single phase formation at room temperature. Analysis of XRD data indicates that the Co₃O₄ crystallizes in cubic symmetry with face-centered cubic (fcc) Bravais lattice. Force constants and elastic properties have been estimated at room temperature using XRD and FTIR spectra and interpreted in terms of bond lengths. An octahedral broadening of the FTIR band (v_o) and large force constant (k_o) has been observed and indicated the inverse proportionality relationship between the force constant and the bond length. The elastic moduli and Poisson’s ratio uncorrected and corrected to zero porosity reveals the solidification of the Co₃O₄ ceramic sample. The field cooled (FC) and zero field cooled (ZFC) magnetization measurements using superconducting quantum interface device (SQUID) magnetometer exhibit a well-defined long-range antiferromagnetic order below transition (T_N = 40 K) temperature.

6 illus, 1 table, 39 ref

030009   YADAV S, SRIVASTAVA S, KUMAR D, KUMAR A (Physics Dep, I I T, Kanpur 208 016, Email: sarishbti@gmail.com) : Study of thermal stability in Se₉₀Sb_10-xAg_x glassy alloys. Indian J Pure Appl Phys 2018, 56(11), 884-9.

Alloys of Se_100-xSb_10-xAg_x (x = 2, 4 & 8) glassy system have been obtained by quenching technique. Kinetic parameters, which represent thermal stability, have been determined from differential scanning calorimetric technique. The rate of crystallization decreases with Ag concentration and is lowest for glassy Se₉₀Sb₂Ag₈ alloy. Thermal stability (T_c-T_g), Hruby criterion H_r , Saad Poulain ‘S’ have been found to increase with Ag concentration and are maximum for Se₉₀Sb₂Ag₈. Thus, one can conclude that the rate of crystallization is related to the thermal stability. The reduced glass transition temperature for Se₉₀Sb_10-xAg_x is found to be 2/3, which shows that these glassy alloys are suitable for phase change optical memories.

7 illus, 12 tables, 41 ref

029974   JERUSHA E, KIRUPAVATHY S S (Physics Dep, Velammal Engineering Coll, Chennai 600 066, Email: shahilkirupavathy@yahoo.co.in) : Phase transitional ferroelectric like behaviour of ammonium tetroxalate dihydrate single crystal. Indian J Pure Appl Phys 2018, 56(11), 875-83.

Dielectric characterisation on ammonium tetroxalate dihydrate (ATOXAL) single crystal has been carried out. The dielectric constant and dielectric loss studied as a function of temperature and frequency have been found to have anomalous variations in the vicinity of the phase transitions at 100 °C and 140 °C which have been duly supported by thermal studies. An Arrhenius shift in the temperature variation of relaxation frequency has estimated the activation energy and the means of conduction. The ferroelectric and paraelectric phase activation energies have been determined to be 1.772 eV and 3.477 eV, respectively. The Penn band gap is 1.892 eV and the polarizability has been evaluated. The piezoelectric coefficient d₃₃ has been found to be 1.5 pCN^-1. The ferroelectric hysteresis behaviour has been investigated at room temperature. From the hysteresis loop it is found that the grown crystal exhibites a remanent polarization (P_r) ∼ 0.367 μC/cm², saturation polarisation (P_s) ∼ 1.789 μC/cm² and coercive field (E_c) ∼ 6.599 kV/cm.

12 illus, 4 tables, 31 ref

029998   SHARMA S, SHUKLAA R, TRIPATHY M R (Physics Dep, Deenbandhu Chottu Ram Univ, Sonepat 131 039, Email: suman.iitidelhi@gmail.com) : Analog/RF performance and effect of interface trap charges in dielectric engineered gate all around junctionless MOSFET with ZrTiO₄ as gate dielectric. Indian J Pure Appl Phys 2018, 56(11), 869-74.

The present study provides the comprehensive appraisal of analog/RF performance of dielectric engineered gate all around junctionless MOSFET by the assimilation of gate material engineered along with ZrTiO₄ as high-k gate dielectric. The radical reductions in impact of positive and negative interface traps have been reported, which augment the device reliability. The cylindrical geometry of the MOSFET accounts for the self heating effect in the device, which accelerates the practice of hot carrier effect and diffusion of H, conscientious for negative bias temperature instability (NBTI) effect in P-MOSFET and PBTI effect in the N-MOSFET. The proposed design has been studied by taking SiO₂, and orthorhombic ZrTiO₄ symmetric gate stack to improve the reliability of the device. The electrical characteristics like I_d-V_g, electric field, centre potential, transconductance and frequency have been measured using the ATLAS 3D simulator. Orthorhombic ZrTiO₄ with dielectric constant 45.9 shows the enhanced performance of the device. The interface trap charge concentration of 1×10¹¹ cm^-2 (positive and negative both) for ZrTiO₄ have been compared with the device devoid of gate stack which provides the knowledge about the RF and analog performance of the MOSFET.

11 illus, 1 table, 35 ref

029999   SIDDESH B M, MANJUNATH M, DAMLE R, RAMESH K P (Physics Dep, Indian Institute of Science, Bengaluru 560 012, Email: keralapuraramesh@gmail.com) : Fabrication of low cost and versatile internal field pulsed nuclear magnetic resonance spectrometer to study the magnetic materials. Indian J Pure Appl Phys 2018, 56(11), 859-68.

We have built a low cost and versatile pulsed internal field nuclear magnetic resonance (IFNMR) spectrometer and used it to study ferromagnetic materials. Initially optimization of the instrument has been tested with nuclear quadrupole resonance (NQR) active nuclei. Ferromagnetic materials like bulk iron, bulk cobalt and carbon coated cobalt nanopowder have been used as the testing materials for our spectrometer. Preliminary results obtained from the present spectrometer have been compared with the earlier reports and are in good agreement. The specifications and performance standard of the instrument match quite well with standard instruments elsewhere in the world which is testified with the observation of NMR echo signals in the above mentioned materials confirming the quality of the spectrometer. Additionally NMR signals from the grain boundaries are observed in Co@C nanomaterials which prove the sensitivity of the spectrometer.

8 illus, 1 table, 32 ref

029956   CHANDRA A, SHUKLA R, NAGARCH R K, CHANDRA A (Shri Shankaracharya Institute of Professional Management and Technolog, Raipur - 492015, Email: chandrassi@gmail.com) : Silver ion conducting nanocomposite polymer electrolytes: Ion transport and battery fabrication. Indian J Pure Appl Phys 2018, 56(11), 847-52.

Ion transport characterization studies on a new Ag⁺ ion conducting (poly-ethylene oxide) PEO-based nanocomposite electrolytes (NCPEs): (1-x) [30PEO:70(0.75AgI:0.25AgCl)] + x SiO₂, where 0<x<20 wt.%, have ben reported. A novel hot-press/ solvent free technique has been used for the formation of the present NCPE films. Nano-size (~ 8 nm) SiO₂ particles have been dispersed as a second dispersoid in to the first phase host matrix: [30PEO:70(0.75AgI:0.25AgCl)], identified as the highest conducting polymer electrolyte composition. A conductivity enhancement of more two orders that of the pure polymer-electrolyte host could be achieved in the nano-composite polymer electrolyte composition: 95[30PEO:70(0.75AgI:0.25AgCl)] + 5SiO₂ (σ ~ 6.2 × 10^-5 S.cm^-1) and this has been referred to as optimum conducting composition (OCC). Polymer-salt/ nano-filler complexations have been explained with the help of XRD, DSC and TGA analysis. To explain the ion transport characterization various ionic transport parameters viz. conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (t_ion) etc. have been determined at room temperature and the temperature dependent conductivity measurements have also been carried out to evaluate the activation energy (E_a). A new Ag⁺ ion conducting solid state polymer battery have been fabricated and studied the cell parameters at room temperature.

7 illus, 2 tables, 37 ref

029989   RAJABALINIA-JELODAR H, SALEM M K, AGHAMIR F M, ZAKERI-KHATIR H (Islamic Azad Univ, Tehran, Iran, Email: mkssalem@gmail.com) : Dispersion characteristics and excitation of space-charge and cyclotron modes in inhomogeneous warm plasma waveguide. Indian J Phys 2018, 92(12), 1629–41.

In this paper, we are going to investigate the effects of plasma parameters on dispersion characteristics of electrostatic modes in a cylindrical inhomogeneous warm magnetized plasma waveguide. To this aim, the radial inhomogeneity for different characteristic length with strongly spatial dispersion are taken into account. Due to radial inhomogeneity of plasma, all essential equations for studying the properties of dispersion are calculated in Bessel–Fourier and differential Bessel–Fourier expansion. Moreover, two cases of strong and weak magnetic fields are considered for the analyses. We show that there was just an interval in which the space-charge and cyclotron modes are excited. We called it the Longitudinal Wavenumber Excitation Interval that is due to the thermal effect consideration. The effect of different radial inhomogeneity characteristic length on the dispersion properties is also studied in this work.

10 illus, 42 ref

029954   ASLAM S M, SULEYMANOV M K, WAZIR Z, GILANI A R (Physics Dep, Riphah International Univ, Islamabad 44000, Pakistan, Email: zafar_wazir@yahoo.com) : Study of the cumulative number distribution of charged particles produced in He¹²C interactions at 4.2 A GeV/c. Indian J Phys 2018, 92(12), 1623–7.

The behavior of the cumulative number distribution along with maximum values of cumulative number of all charged particles (i.e. protons, $\mathrm{\pi }$^±-mesons) produced in He¹²C-interactions at 4.2 A GeV/c from experimental and simulation data coming from cascade evaporation model has been analyzed in this paper. One could see four different regions in the distributions of cumulative number for protons in which the last region has cumulative number greater than one which correspond to cumulative region. Similarly one could see two different regions for negative and positive pions respectively but there is totally absence of the cumulative area for both positive and negative pions. The simulation data obtained from Cascade code could reproduced agreeably the distributions of the cumulative number for protons as well as for maximum values of cumulative number distribution.

2 illus, 27 ref

029952   ARIOGLU C, TAMER O, AVCI D, ATALAY Y (Physics Dep, Sakarya Univ, 54187 Sakarya, Turkey, Email: omertamer@sakarya.edu.tr) : Optimized geometry, spectroscopic characterization and nonlinear optical properties of carbazole picrate: A density functional theory study. Indian J Phys 2018, 92(12), 1613–21.

The molecular modeling of carbazole picrate (CP) was carried out by using B3LYP and HSEH1PBE levels of density functional theory and 6-311++G(d,p) basis set by means of Gaussian 09 revision D.01 program. These methods have been used to determine the optimized molecular geometries, vibrational frequencies, electronic transitions and bonding features of the title compound. The computed small energy gap between HOMO and LUMO energies shows that the charge transfer occurs within the investigated compound. Additionally, the intensive interactions characterized by high stabilization energies were the powerful indicators of intra- and intermolecular charge transfer interactions. The obtained molecular dipole moment ($\mathrm{\mu }$), polarizability ($\mathrm{\alpha }$) and hyperpolarizability ($\mathrm{\beta }$) indicates that CP exhibits considerable nonlinear optical characteristic. The theoretical structural parameters such as bond lengths and bond angles are in a good agreement with the experimental values of the title compound. Additionally, the hydrogen bonding interactions were visualized via molecular electrostatic potential surface.

4 illus, 6 tables, 65 ref

029990   RAMASAMY V, MOHANA V, SURESH G (Physics Dep, Annamalai Univ, Chidambaram - 608 002, Email: srsaranram@rediffmail.com) : Study of Ni:CeO₂ nanoparticles for efficient photodegradation of methylene blue by sun light irradiation. Indian J Phys 2018, 92(12), 1601–12.

Pure and different concentration of Ni-doped CeO₂ nanoparticles were synthesized using a sol–gel technique. The products were characterized by X-ray diffraction (XRD), UV–Vis absorption and photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and TG-DTA measurements. The XRD analysis dictated that the product has CeO2 crystallites with cubic structure. The average crystallite size varied from 10.98 to 35.43 nm. The SEMEDAX analysis shows the nature of morphology and the presence of elements. A suitable temperature is selected using TGDTA analysis to tune the optical band gap. The HR-TEM pictures show that the particles are spherical in shape and affirmed the XRD investigation. The optical properties of the nanoparticles are seen by UV–visible and PL spectroscopy. The structural bond vibrations of pure and Ni-doped CeO₂ nanoparticles were analyzed by FTIR spectroscopy. The photocatalytic activity of pure and Ni-doped CeO₂ nanoparticles was assessed by methylene blue degradation in an aqueous solution which directed that the 0.1 M. % of the Ni-doped CeO₂ show the best photocatalytic movement.

13 illus, 2 tables, 58 ref

029993   SANTHOSH K P, CYRIAC A, KRISHNAN S (Kannur Univ, Kerala - 670 327, Email: drkpsanthosh@gmail.com) : Cold binary fragmentation of even–even ^238-248Pu isotopes. Indian J Phys 2018, 92(12), 1589–600.

Within the framework of Coulomb and proximity potential model, we studied the cold binary fission of even– even ^238–248Pu isotopes using the two versions of nuclear proximity potential, Proximity 1977 and Proximity 2000. The most favorable binary fission path is the one that has a high Q value and a minimum driving potential with respect to the mass and charge asymmetries. A nucleus with doubly closed shell or near doubly closed shell always appears as the heaviest nucleus in the favored channel of the binary fission of all the mentioned isotopes. For ²³⁸Pu isotope, the highest yield was predicted for the isotope of Pb (Z = 82) as one fragment, whereas for ^240,242Pu isotopes, fragments with isotope of Hg (Z = 80) as one fragment possesses the highest yield. In the case of ^244,246,248Pu isotopes, the highest yield is for the fragments with Sn (Z = 50) as one fragment. It was found that asymmetric splitting is superior for Pu isotopes with mass number A $\le$ 242 and symmetric splitting is superior for Pu isotopes with A $\ge$ 244. We computed relative yields for the cold binary fission of even–even ^238–248Pu isotopes using two different proximity potentials. These results were compared with the available experimental data collected from the double energy method by Wagemans et al. (Nucl Phys A 502:287c, 1989). The two results were found to be in agreement with each other.

12 illus, 56 ref

030007   WADATKAR N S, WAGHULEY S A (Physics Dep, Government Polytechnic, Yavatmal - 445 001, Email: nswadatkar81@gmail.com) : A novel studies on electrical behaviour of chemically synthesized conducting polyindole. Indian J Phys 2018, 92(12), 1551–9.

This research article is intended for the novel study of thermal, electrical and dielectric properties of conducting polyindole (PIn) as-synthesized through chemical oxidative route. The characterization techniques such as Fourier transform infrared spectroscopy; X-ray diffraction and Thermo gravimetric-differential thermal analysis ensured the structural and thermal properties of the as-synthesized materials. The dielectric measurements of the samples were performed through AC impedance analyser in the frequency and temperature ranges from 20 Hz – 1 MHz to 308–393 K respectively. The variation of AC conductivity with frequency obeys Jonscher’s universal power law. The modulus spectra depicted the non-Debye nature of the material. The dielectric studies of as-synthesized PIn samples validate their potential utilization for energy storage application. The thermal study ensures that, the synthesized samples have fairly good thermal stability.

11 illus, 2 tables, 40 ref

029963   DEVI J, DAS B, SARMA S, DATTA P (Electronics and Communication Technology Dep, Gauhati Univ, Assam - 781 014, Email: jutika.electronics@gmail.com) : Non-linear model of nanoscale devices for memory application. Indian J Phys 2018, 92(12), 1541–50.

COMSOL multiphysics software based model has been developed for the mem-devices comprising of undoped and doped CdSe/starch quantum dots and CdS/PVA nanocomposites as active layer. The assembly of quantum dots/nanocomposites can be represented by an equivalent structure comprising of almost infinitely alternating repetition of building blocks, each block having conducting and non-conducting regions. The time-dependent inductance (L) along with time-dependent resistance (R) and capacitance (C) are used as model input and the solutions are obtained using semiconductor, electric circuit and ordinary differential equation module. From this study it is clear that the mem-behaviour of the as-fabricated nanodevices having ROFF RON $>$10 can be well explained by the time-dependent R, C and L features of the nanoparticle assembly adopting COMSOL Multiphysics software. However, for devices with ROFF RON $<$10, hysteresis behavior is governed by only time-dependent R and C features. As higher ($>$ 10) ROFF RON values enhance efficiency of memory units, the present model incorporating time-dependent L in addition to time-dependent R and C will be useful for optimization in the device design for application as memory units.

11 illus, 2 tables, 28 ref

030008   WU C-L, LIN Y-J (National Changhua Education Univ, Changhua 500, Taiwan, Email: rzr2390@yahoo.com.tw) : Incorporation of MoS₂ nanoflakes into poly(3-hexylthiophene)/n-type Si devices to improve the rectification behavior and optoelectronic performance. Indian J Phys 2018, 92(12), 1533–9.

This study determines the effect of incorporating MoS₂ nanoflakes into poly(3-hexylthiophene) (P3HT) on the electrical conduction mechanisms using the rectification current–voltage characteristics of P3HT/n-type Si devices. It is shown that the forward-voltage current for P3HT/n-type Si devices is limited by the combined effect of thermionic emission and space-charge-limited current conduction. However, carrier transport for P3HT:MoS₂/n-type Si devices in the forward-voltage region is almost dominated by thermionic emission. Incorporation of MoS₂ nanoflakes into P3HT modifies the P3HT-Si interface and the values for the carrier mobility in the P3HT layer and the external quantum efficiency of the P3HT/n-type Si devices are significantly increased, which improves the rectification and optoelectronic performance of P3HT:MoS₂/n-type Si devices.

6 illus, 51 ref

029979   MADHURI S R, NAMITHA N S, URS M B K, GOWTHAM G K, URS T G, SOMASHEKAR R (Physics Dep, Regional Institute of Education, Mysuru - 570 006, Email: rs@physics.uni-mysore.ac.in) : Modelling of X-ray patterns using Fourier transforms: Application to nanomaterials. Indian J Phys 2018, 92(12), 1525–32.

Stucture of crystalline materials is obtained by studying the diffraction patterns using electromagnetic radiations like X-rays, electron and neutron beams. These patterns are essentially Fourier transforms of the sample space. As the diffraction pattern corresponds to reciprocal lattice of the atomic arrangement, Fourier transform can be used to convert the data from real space to reciprocal space. Thus, an image of real space when transformed to Fourier space should resemble the X-ray diffraction profile. For this, we have developed an algorithm for image processing using Fourier transform employing GNU Octave. In essence we would like to investigate the Fourier transform of several two-dimensional ordered systems which mimic two dimensional nanostructures in general. For this, we have built several two-dimensional models to study the ordered patterns with various shapes of the repeating entity like circular, rectangle, squares, benzene shape along irregular patterns. We study the variation in diffraction patterns that are in transformed space and compare them inorder to simulate with two dimensional images.

2 illus, 3 tables, 15 ref

029988   RADY K E, DONYA H (Engineering Basic Sciences Dep, Menoufia Univ, Shebin El-Koom, Egypt, Email: k_rady_2001@hotmail.com) : Influence of gamma irradiation and Er³⁺ substitution on the structure, magnetic and electrical properties of Mn²⁺ substituted Ni–Zn ferrite. Indian J Phys 2018, 92(12), 1515–23.

The effect of gamma irradiation and the substitution by Er³⁺ ions on the microstructure, magnetic and electrical properties was studied for some ferrite samples of the general formula Ni_0.1Mn_0.5Zn_0.4Er_xFe_2-xO₄, (0 $\le$ x $\le$ 0.1, step 0.025). The samples are prepared using the standard ceramic technique. The structure of the prepared samples is confirmed using x-ray diffraction patterns. The samples are irradiated at a certain dose of 100 kGy using gamma rays of ⁶⁰Co source. The obtained results show high stability of the crystalline structure where no new phases were found as a result of the high dose of gamma irradiation. The lattice parameter of the prepared samples is found to increase with increasing Er³⁺ content. The surface morphology of the samples and the percentage of the ions are studied using scanning electron microscope and EDAX analysis respectively. The effect of temperature and substitution by Er³⁺ ions on the saturation magnetization and initial permeability are also studied. The experimental results indicate that, the substitution by Er³⁺ ions led to improve the magnetic properties of the studied samples. Also, the obtained results show a decrease in the saturation magnetization and improvement in the coercivity of the samples as a result of gamma irradiation. On the other hand, the present study shows an increase in the DC conductivity due to the substitution by Er³⁺ ions and gamma irradiation. The final results show that, the sample of x = 0.025 has high magnetic properties and low porosity which can be exploited in a certain technical applications.

14 illus, 3 tables, 25 ref

030004   THAKUR V, PAGARE G (Physics Dep, Sarojini Naidu Government Girls P. G. Autonomous Coll, Bhopal - 462 002, Email: gita_pagare@yahoo.co.in) : Theoretical calculations of elastic, mechanical and thermal properties of REPt₃ (RE = Sc, Y and Lu) intermetallic compounds based on DFT. Indian J Phys 2018, 92(12), 1503–13.

The elastic, mechanical and thermal properties of isostructural and isoelectronic nonmagnetic REPt₃ (RE = Sc, Y and Lu) intermetallic compounds, which crystallize in AuCu₃-type structure, are studied using first principles density functional theory based on full potential linearized augmented plane wave method. The calculations are carried out within PBE-GGA, WC-GGA and PBE-sol GGA for the exchange correlation potential. Our calculated ground state properties such as lattice constant (a_o), bulk modulus (B) and its pressure derivative (B$\text{'}$) are in good agreement with the available experimental and other theoretical results. We first time predict the elastic constants for these compounds using GGA approximations. All the compounds are found to be ductile in nature in accordance with Pugh’s criteria. The computed electronic band structures show metallic character of these compounds. The charge density plot and density of states of these compounds reveals that the chemical bond between RE and Pt is mainly ionic. The elastic properties including Poisson’s ratio ($\mathrm{\sigma }$), Young’s modulus (E), shear modulus (G_H) and anisotropy factor (A) are also determined using the Voigt–Reuss–Hill averaging scheme. The average sound velocities (v_m), density (p) and Debye temperature ($\mathrm{\theta }$_D) of these REPt₃ compounds are also estimated from the elastic constants. We first time report the variation of elastic constants, elastic moduli, sound velocities and Debye temperatures of these compounds as a function of pressure.

8 illus, 4 tables, 48 ref

029958   CHIRDE V R, SHEKH S H (Mathematics Dep, J.D.I.E.T, Yavatmal - 445 001, Email: da_salim@rediff.com) : Dynamic minimally interacting holographic dark energy cosmological model in f(T) gravity. Indian J Phys 2018, 92(11), 1485–94.

We have investigated the dynamics of Spatially Homogeneous Bianchi type-I (LRS) space–time filled with two minimally interacting fields, Matter and Holographic dark energy components with volumetric power and exponential expansion laws towards the gravitational field equations for the linear form of f(T) gravity. The aspects of space–time discussed with the help of solution and made out both models are at late times turn out to be flat Universe. The power law model has initially singular and stable but with expansion it is unstable while exponential model is free from any types of singularities and stable throughout the expansion. In the same way the models showing an accelerated expansion with inflationary era in the early and the very late time of the Universe. For sufficiently large time derived model predicts that the anisotropy of the Universe will damp out and the Universe will become isotropic.

7 illus, 45 ref

029966   GREGOR M H M (Park Coll, MD, USA, Email: mhmacgreg@aol.com) : The α-quantization of lepton, quark and particle lifetimes. Indian J Phys 2018, 92(11), 1473–83.

There are 196 elementary particles with well-measured lifetimes. Plotted logarithmically, they group into four Zones: (1)$>$10^-7 s; (2) 10^-7 –10^-14 s; (3) 10^-14–10^-21 s; (4) 10^-21–10^-25 s, as follows: (1) neutron and muon; (2) quark ground-state particles with flavor-breaking electroweak decays: (3) quark ground-state particles with flavor-conserving and radiative decays; (4) short-lived excited states and high-energy W, Z, Higgs boson and t-quark states. Ground states have α-quantized lifetimes, while excited states occur with a continuum of values. An α-quantized lifetime grid is anchored on the $\mathrm{\pi }$^± lifetime, and extends over 12 powers of α, where α^-1 ~137 is the fine structure constant. Ground-state lifetimes separate into (u,d), s, c, b flavor groups, each dominated by a single quark, in accordance with the rule (u,d) $>$s $>$b $>$c. Flavor-breaking lifetimes are longer than flavor-conserving lifetimes by a factor of ~α^-4. Each Zone (2) flavor group has a central lifetime, and deviations occur as integer factors of ~2, 3, or 4. This observed lifetime α-dependence is conjugate to an observed mass/energy α-dependence.

11 illus, 3 tables, 9 ref

029953   ARTUN O (Physics Dep, Bulent Ecevit Univ, Zonguldak, Turkey, Email: ozanartun@yahoo.com) : A study of some nuclear structure properties of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵²Mn, ⁵²Fe, ⁶⁰Cu, ⁶²Zn, ⁶³Zn, ⁶⁶Ga, ⁶⁸Ga, ⁷⁶Br, ⁸¹Rb, ⁸²Rb, ⁸²Sr, ⁸³Sr, ⁸⁶Y, ⁸⁹Zr and ⁹²Rb nuclei used for PET in the axial deformation. Indian J Phys 2018, 92(11), 1449–60.

In this paper, we mainly investigated important nuclear structure properties of nuclide used in positron-emission tomography for 13 different Skyrme force parameters in the axial deformation such as the binding energy, root mean square charge, proton and density radii, neutron skin thicknesses, quadrupole deformation parameter ($\mathrm{\beta }$₂), proton and neutron quadrupole moments (Q_m). To analyze accuracy of the obtained results, the calculated data also were compared with available experimental and the theoretical results in the literature, such as relativistic mean-field theory and the finiterange liquid-drop model. According to Hartree–Fock–Bogolyibov approach with the axial deformation, we discussed Skyrme force parameters on the basis of the obtained result. Further, when taking into account the enormous number of the existing Skyrme-force parameterizations, it has been noticed the obtained results reveal appropriate Skyrme force parameters for each nucleus.

9 tables, 25 ref

029971   HOANG N L H, LUU M Q, PHAM V T, NGUYEN M H, NGUYEN T L, PHAM T H, HOANG C H, NGUYEN H L (VNU Science Univ, Hanoi, Vietnam, Email: huonghnl@hus.edu.vn) : Influence of Ag on the properties of Ag combined Nb-doped TiO₂ (TNO) thin films deposited by a co-sputtering process. Indian J Phys 2018, 92(11), 1413–8.

Nb-doped TiO₂ (TNO) is known as a multifunctional thin film. In this study, Ag was added to TNO thin films via a co-sputtering methodology to improve the properties of the films. X-ray diffraction, scanning electron microscopy and Raman spectroscopy were used to characterize the samples. The UV–Vis spectra indicated that the transparency of the samples decreased as the Ag content increased. The photocatalytic properties of the co-sputtered films were evaluated by photodegrading a methylene blue (MB) solution under ultraviolet (UV) radiation using back-side illumination; i.e., the UV light reaches the thin film through the Corning glass instead of the MB solution. By adding Ag into TNO films, their photocatalytic property significantly improved. The 2-min Ag-TNO film showed a maximum photocatalytic efficiency (k = 0.034 min^-1) and good transparency of 70 % in the visible range. Nevertheless, adding too much Ag led to a negative photocatalytic performance. The results suggested that the co-sputtering process is an efficient method to combine Ag with TNO thin films to improve their photocatalytic performance.

7 illus, 36 ref

029959   DAHMANE F, DOUMI B, KHENATA R, WANG X T, OMRAN S B, RAI D P, TADJER A (de SM Dep, Institue des Sciences et des Technologies, 38000 Tissemsilt, Algeria, Email: fethallah05@gmail.com) : The effect of Sn substitution on the Al sites in full Heusler compound Fe₂VAl. Indian J Phys 2018, 92(11), 1403–11.

A first-principles method has been employed to determine the electronic, magnetic and structural characteristics of the full-Heusler alloys Fe₂VAl with Sn doping. All the calculations were performed by using a computational code based on full-potential linearized augmented plane wave method called WIEN2k. The electron exchange–correlation is treated by the generalized gradient approximation within a scheme developed by Perdew, Burke and Ernzerhof (PBEGGA). The electronic band structures of Fe₂VAl_1-xSn_x (x = 0, 0.25, 0.50, 0.75) compounds show that the majority-spin (spin-up) exhibits a metallic characteristic, whereas the minority-spin (spin-dn) have an energy band gap. Our calculations predict that Fe₂VAl_1-xSn_x compounds are half-metallic ferromagnets with an integer value of magnetic moment, 0, 1, 2, and 3 $\mathrm{\mu }$_B, respectively. Our findings suggest that these materials are potential candidates for manufacturing spintronic devices.

4 illus, 2 tables, 36 ref

030006   ULUSAN A B, TATAROGLU A (Physics Dep, Gazi Univ, Ankara, Turkey, Email: aysel.buyukbas@gmail.com) : Analysis of barrier inhomogeneities in AuGe/n-Ge Schottky diode. Indian J Phys 2018, 92(11), 1397–402.

The barrier inhomogeneities in AuGe/n-Ge Schottky diode have been analyzed by using current–voltage (I–V) measurements over a wide temperature range of 200 to 400 K. The electrical parameters such as ideality factor (n), zerobias barrier height ($\mathrm{\varphi }$_Bo), and series resistance (R_s) of the diode were found to be strongly temperature dependent. The abnormal increase of the barrier height with temperature was attributed to the existence of barrier height inhomogeneities at the metal/semiconductor interface. Therefore, the conventional and modified Richardson plots were drawn to explain Gaussian distribution (GD) of barrier heights. The modified Richardson plot shows a good linearity over the temperature range. The modified Richardson constant (A^*) was found to be 141.49 A cm^-2 K^-2, which is close to the theoretical value of 140 A cm^-2 K^-2 for n-Ge. Moreover, the barrier height values obtained from I–V and Norde methods are found to be in good agreement with each other.

7 illus, 1 table, 44 ref

029972   HU M, WANG H L, GONG Q, WANG S M (Physics Dep, Qufu Normal Univ, Qufu - 273 165, China, Email: phyhlwang71@126.com) : The impacts of electric and magnetic field on the binding energy of hydrogenic donor impurity in a InGaAsP/InP ring-shaped quantum well wire. Indian J Phys 2018, 92(11), 1389–95.

The ground state binding energy of a hydrogenic donor impurity in a InGaAsP/InP ring-shaped quantum well wire is calculated via the plane wave basis method. It is shown that the donor binding energy is strongly dependent on the geometry, impurity position, axial electric field and transverse magnetic field. In particular, the impacts on the binding energy due to axial electric field and transverse magnetic field can mutually compensate.

7 illus, 33 ref

029992   SANGALA B R, GUDA K (Physics Dep, Palamuru Univ, Telangana - 509 103, Email: bagvanthreddy.physicist@gmail.com) : Thermal expansion of α-nitrogen ice in terahertz spectroscopy. Indian J Phys 2018, 92(11), 1385–8.

The volumetric thermal expansion coefficient of α-nitrogen (N₂) ice is calculated for temperatures between 10 and 25 K using its terahertz transmission data and a phonon model. The observed dip in terahertz transmission around 1.45 THz is modeled as phonon absorption based on an intermolecular potential which is sum of the Lennard-Jones potential and quadrupole–quadrupole interaction term. Using this model and our experimental data, the lattice parameters of α-N₂ ice were obtained.

3 illus, 1 table, 14 ref

029950   ACHOURI M M, ZIANI N, BOUAMRANE R, ABDERRAHMANE A (de Ge´nie physique Dep, (USTO-MB), Oran, Algeria, Email: achouri.mohamed.malik@gmail.com) : Molecular dynamics investigation of structures and the potentials of para tellurite (α-TeO₂) and europium oxide (Eu₂O₃) materials by aiming the effect of Eu³⁺ low doping in α-TeO₂ on the mechanical and structural properties. Indian J Phys 2018, 92(11), 1373–84.

In this work, the interatomic potentials of para tellurite (α-TeO₂) and cubic europium oxide (Eu₂O₃) based on molecular dynamics method were studied. We reported the structural properties of α-TeO₂ and Eu₂O₃ in their crystalline and glass phases and we calculated for the first time their mechanical properties, where our results showed good agreement with the experimental data from previous reports. Finally, we investigated the effect of potential combination of α-TeO₂ and Eu₂O₃, and we used the results to discuss the effect of Europium doping on α-TeO₂ matrix. As conclusion, any composition of the three elements (tellurium, oxygen and europium) can be modelled using our interatomic potentials.

9 illus, 6 tables, 74 ref

029975   KADAM S S, KANSE K S, JOSHI Y S, RANDER D N, KUMBHARKHANE A C (Physics and Electronics Dep, Lal Bahadur Shastri Mahavidyalaya, Maharashtra - 431 809, Email: kskanse@gmail.com) : Dielectric relaxation studies of 1,3 and 1,4-butanediol-water mixtures using time domain technique. Indian J Phys 2018, 92(11), 1367–72.

The Complex dielectric permittivity measurements in the frequency range 10 MHz–30 GHz have been carried out for 1,3 and 1,4 -Butanediol in Water mixtures over the entire concentration range using time domain reflectometry method at 25 $°$C. The dielectric parameters such as static dielectric constant and relaxation time are obtained from the complex permittivity spectra using nonlinear least square fit method. Molecular interactions among the butanediol–water mixtures have been studied using Kirkwood correlation factor, Excess dielectric constant and Bruggeman factor.

4 illus, 2 tables, 28 ref

029964   DEY R K, DAM S, RAY S, BASAK A, CHATTOPADHYAY P (Physics Dep, North Bengal Univ, West Bengal - 734 013, Email: rkdey2007phy@rediffmail.com) : Determination of the mass and energy of primary cosmic rays above 100 TeV. Indian J Phys 2018, 92(11), 1357–65.

This analysis aims to determine the mass composition and energy of cosmic rays at energies above 100 TeV based on the lateral distribution of extensive air showers. Here, we propose quite a few air shower observables for reconstructing the mass and energy of the primary particles. The present reconstruction uses a detailed Monte Carlo simulation for cosmic ray induced air showers in KASCADE and NBU types surface arrays of particle detectors. Some of the observables obtained from this analysis of simulated data are used to infer the nature of the primary particles from a comparison with KASCADE and/or NBU data. It is expected that the determination of primary energy of a cosmic-ray shower may deliver a better accuracy compared to standalone analysis using shower size or S600 or S500 or N_pe etc, owing to strong fluctuations in the EAS development. Moreover, the present study might be useful to discriminate between hadronic cosmic rays and primary gamma rays, and to measure the cosmic ray all-particle energy spectrum.

6 illus, 28 ref

029969   HANJAGI P S, AWAJI S M (ICAR-National Rice Research Institute, Odisha) : High-throughput imaging tools to phenotype traits in plants for stress environments. J Pharmacogn Phytochem 2018, 7(6), 97-102.

Despite the rapid development of plant genomic technologies, a lack of advancement in high-throughput image based plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput image based phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (drought, disease, insects, and salinity). These imaging techniques include visible (RGB) imaging, spectroscopy imaging (multispectral and hyperspectral remote sensing), thermal infrared imaging, fluorescence imaging. This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping for abiotic stresses are described and discussed in this review.

3 illus, 45 ref

029991   SAHOO H, MONDAL K K, GHOSH B (Physics Dep, Jadavpur Univ, Kolkata - 700 032, Email: himangshusahoo@gmail.com) : Nonlinear propagation of ion plasma waves in dust-ion plasma including quantum-relativistic effect. Pramana - J Phys 2018, 91(6), 88.

In this paper we have theoretically investigated the quantum and relativistic effects on ion plasma wave in an unmagnetised dust-ion plasma. By using the method of normal mode analysis, we have obtained a linear dispersion relation. It has been analysed numerically for quantum and relativistic effects on the propagation of ion plasma wave. By using the standard reductive perturbation technique, we have derived a Korteweg–de Vries (KdV) equation which describes the nonlinear propagation of the wave. Numerically, it is shown that only compressive type of soliton can exist in the plasma under consideration. It is found that the solitary wave profile depends significantly on the quantum and relativistic parameters. The dust size, dust charge and the dust number density are also shown to have significant influences on these solitary waves. The results of this present investigation have some relevance to the nonlinear propagation of ion plasma wave in some astrophysical, space and laboratory plasma environments.

5 illus, 41 ref

028761   GOYAL M (Physics Dep, GLA Univ, Mathura - 281 406, Email: monika.goyal@gla.ac.in) : Shape, size and phonon scattering effect on the thermal conductivity of nanostructures. Pramana - J Phys 2018, 91(6), 87.

A phenomological model is described here to study the effect of size, shape and phonon scattering on the thermal conductivity of nanostructures. Using the classical model proposed by Guisbiers et al (Phys. Chem. Chem. Phys. 12, 7203 (2010), J. Phys. Chem. C 112, 4097 (2008)) in terms of the melting temperature of nanostructures, the expression for variation of thermal conductivity is obtained in terms of shape and size parameter. An additional term is included in the expression of thermal conductivity to consider the impact of phonon scattering due to the surface roughness with a decrease in size. The expression of thermal conductivity is obtained for spherical nanosolids, nanowires and nanofilms. The thermal conductivity is found to decrease in nanostructures in comparison with the counterpart bulk material. The values of thermal conductivity obtained from the present model are found to be close to the available experimental data for different values of roughness parameter which verifies the suitability of the model.

2 illus, 1 table, 31 ref