Indian Journal of Pure and Applied Physics


Total visitors: 1,316  since 20-07-05

 ISSN: 0019-5596

CODEN: IJOPAU 43 (7) 475-562

Volume 43

Number 7

JULY 2005

 

 

 

CONTENTS

 

Review Article

 

The pendula in mathematical sciences

479

        R S  Kaushal­

 

 

 

Nuclear Physics

 

Assessment of the natural radioactivity and its radiological hazards in some Egyptian rock phosphates

489

       A Abbady

 

 

 

Low energy gamma - ray spectrometry—A technique for estimation of high grade uranium in geological samples

494

        G Jegannathan*, Padma Satyamurthy & L Sathyanarayanan

 

 

 

Atomic and Molecular Physics

 

Vibrational spectra and normal coordinate analysis of nalidixic acid

503

        S Gunasekaran* , R K Natarajan, R Rathikha & D Syamala

 

 

 

X-ray K-absorption fine structure studies on some copper (II) complexes

509

        R K Vyas, S K Joshi*, B D Shrivastava, M C Shah  &  J Prasad

 

 

 

Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics and Fluid Dynamics

 

Design of high power pump source of eye safe laser for geo-scientific application

517

        P K Singh, S K Mittal *, Manjeet Singh & B K Sharma

 

 

 

Bright-blue organic electroluminescent device based on bis (2-methyl 8-quinolinolato) (triphenyl siloxy) aluminium

522

        Aparna Misra, Pankaj Kumar, S K Dhawan, M N Kamalasanan* &

        Subhas Chandra

 

 

 

Condensed Matter : Structural, Mechanical and Thermal Properties

       

Thermoelectric power of mixed tungsten sulphoselenide single crystals grown by vapour phase technique

527

        J B Patel, M N Parmar, M P Deshpande*, G K Solanki & M K Agarwal

 

 

 

Hydrogen diffusion in Fe0.5Ti0.5 ¾ Quantum isotope effect

532

        M Stalin Mano Gibson* & N Lawrence

 

 

 

 

Contd.

Condensed Matter: Electronic Structure, Electrical , Magnetic and Optical Properties

 

Electrical conductivity and thermoelectric power of Ge40Te60 and Ge38Sn2Te60 alloys

535

        A M Ahmed

 

 

 

Dielectric relaxation studies of ternary liquid mixtures of aniline and substituted anilines with acetonitrile in the microwave region

542

        T  Kalaivani, S Kumar & S Krishnan*

 

 

 

Structural and magnetic properties of Mn1+xSixFe1-xCr1-xO4  system

545

        S K Vyawahare, N R Shamkuwar* & Madan C Sable

 

 

 

Dielectric and conformational studies of methanol + ketone systems

550

        V Madhurima

 

 

 

Interdisciplinary Physics and Related Areas of Science and Technology

 

High output impedance current-mode universal filter

556

        N A Shah*, M F Rather & S Z Iqbal

 

 

 


 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 479-488

 

 

 

The pendula in mathematical sciences

R S Kaushal*

Department of Physics & Astrophysics, University of Delhi, Delhi 110 007

Received 2 September 2004; revised 29 April 2005; accepted 9 May 2005

The role played by the pendulum and its variants in the development of mathematical sciences is reviewed. In particular, the case of a pendulum viz. harmonic oscillator in physics is highlighted in the context of mathematical, conceptual, conventional and engineering disciplines besides the one in mathematical physics. It is pointed out that in all these applications the concept of pendulum is used as a vehicle of knowledge mainly on the basis of structural analogy. Finally, its role is an example of the consciousness-manifesting phenomenon, will be discussed.

Keywords: Pendulum, Mathematical sciences, Conscious pendulum

IPC Code: G01C 9/12

 

 

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 489-493

 

 

 

Assessment of the natural radioactivity and its radiological hazards
in some Egyptian rock phosphates

 

A Abbady

Physics Department, Faculty of Science, South Valley University Qena, Egypt

Received 30 August 2004; revised 11 January 2005; accepted 13 May 2005

Radioactivity of terrestrial radionuclides 226Ra, 232Th and 40K in phosphate rock samples has been measured using gamma ray spectrometry system with an HPGe detector. The samples showed fairly high mean concentrations, 410±39 Bq.kg-1 of 226Ra, 7.9±0.95 of 232Th and 37.6±4 of 40K. Mean absorbed gamma dose rate of 181.9±20 nGy.h-1 was measured in air. Assessment of radiological hazards was made by calculating radium equivalent activities with external and internal hazard indices. The calculations showed radium equivalent activity ranging from 317 to 520 Bq.kg-1. External and internal hazard indices ranging from 0.4 to 0.7 and 0.1 to 0.4, respectively. The results of the analysis have been found to be in a good agreement with the data obtained by others.

Keywords: Radioactivity, Radiological hazard, Phosphate, Radionuclides

IPC Code: G21F9/00

 

 

 

 

 

 

 

 

        Indian Journal of Pure & Applied Physics

        Vol. 43, July 2005, pp. 494-502

 

 

 

Low energy gamma-ray spectrometry — A technique for estimation of high grade uranium in geological samples

G Jegannathan, Padma Satyamurthy1 & L Sathyanarayanan

Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Bangalore 560 072

Received 9 March 2004; revised 21 March 2005; accepted 5 May 2005

Low Energy Gamma-Ray Spectrometry (LEGS) has been proved to be a rapid technique for analyzing high-grade uranium in geological samples. From the low energy portion between (40-400 keV) of the gamma-ray spectrum of uranium and thorium series, the contents of uranium, its daughter radium (eq), and thorium are determined. This gives significant information about the geochemical anomalies. A standard gamma ray spectrometer with a 1¾ ´ 2 well type NaI (Tl) gamma detector constitutes the instrumentation requirements of this technique. Sample weighing about a few grams in a glass vial is used for analysis. A detailed study on the contribution of uranium daughter’s energies in gamma spectrum of uranium has made the system more efficient for analyzing high grade (20%) uraniferous samples. Minimum personal exposure and an excellent correlation of uranium values with the chemical results have made this technique a versatile one in high-grade uranium exploration programme. This paper deals with problems faced by the conventional methods that is Beta-Gamma and High Energy Gamma-Ray Spectrometry used for determining the contents of uranium and thorium in high-grade uraniferous geological samples and the advantage of this technique over them.

Keywords: Low energy gamma ray spectrometry, Uraniferous geological samples, Gamma detector

IPC Code: G01J3/28

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 503-508

 

 

 

 

Vibrational spectra and normal coordinate analysis of nalidixic acid

 

S Gunasekaran*, R K Natarajan, R Rathikha & D Syamala

*Post Graduate and Research Department of Physics, Pachaiyappa’s College, Chennai 600 030

Post Graduate and Research Department of Physics, Presidency College, Chennai 600 005

E-mail: rathikhar@yahoo.com

Received 16 November 2004; accepted 17 March 2005

Nalidixic acid is one of the important anti-bacterial with molecular formula C12H12N2O3. Fourier transform infrared (FTIR) and Fourier transform Raman (FTR) spectra of nalidixic acid have been used for the molecular study. A detailed vibrational analysis has been made on the fundamental modes of vibration. A normal coordinate analysis (NCA) has been carried out for nalidixic acid following the Wilson’s F – G matrix method assuming the ethyl and the methyl group as point masses. A set of potential constants has been evaluated using the method of kinetic constants on the basis of Cs point group symmetry. The evaluated potential constants have been compared with those of related molecules and are in the expected range to confirm the correctness of the assignments made. To check whether the chosen set of vibrational frequencies contribute maximum to the potential energy associated with the normal coordinates of the molecule potential energy distribution (PED) has been evaluated.

Keywords: Fourier transform infrared spectrum, Fourier transform Raman spectrum, Nalidixic acid, Normal coordinate analysis, Potential energy distribution

IPC Code: G01J3/00

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 509-516

 

 

 

X-ray K-absorption fine structure studies on some copper(II) complexes

R K Vyas1, S K Joshi1*, B D Shrivastava2, M C Shah3 & J Prasad4

1Physics Department, Government Post Graduate Arts and Science College, Ratlam 457 001

2School of Studies in Physics, Vikram University, Ujjain 456 010

3Physics Department, Barkatullah University, Bhopal 462 026

4Department of Chemistry, University of Allahabad, Allahabad 211 002

Received 21 February 2005; accepted 1 April 2005

The X-ray K-absorption spectra of copper and arsenic in complexes [Cu(f3AsO)2X2] and [Cu(f3PO)2X2], where X = Cl or Br and f = C6H5, have been studied using a 40 cm bent crystal spectrograph. Various X-ray absorption parameters such as edge shift, phase parameters and bond-distances have been estimated. Our studies reveal that triphenylarsine oxide is a better s-donor than triphenylphosphine oxide. The splitting of the main edge K into K1 and K2 components have been explained. The existence of the white line have been attributed to the transition of K-electrons into a high density of normally unoccupied states with p symmetry in the neighbourhood of the copper or arsenic atom. Further, our studies on phase shift determination indicate that variation in the first or second coordination environment around the central absorbing atom has a dominant effect on the values of backscattering phase shifts.

Keywords: X-ray K-absorption spectra, Copper (II) complexes, Backscattering shift

IPC Code: G01J3/28

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 517-521

 

 

 

 

Design of high power pump source of eye safe laser for geo-scientific application

P K Singh, S K  Mittal, Manjeet Singh & B K Sharma

Geo Scientific Instrument Division, Central Scientific Instruments Organisation, Sector- 30C, Chandigarh 160 030

(E-mail: skmskm1@rediffmail.com)

Received 17 May 2004; revised 19 April 2005; accepted 16 May 2005

The design consideration of high power diode laser at wavelength of 980 nm as pump source for erbium doped glass eye safe laser at wavelength 1.54 mm is presented here. The design of high power laser requires precise control of waveguide dimensions, material and doping profile of layers. The maximum optical power is proportional to transverse optical spot size. The transverse optical spot size and threshold current density have been calculated with transverse waveguide thickness. The effect of current spreading on threshold current density is calculated. The geo-scientific application of eye safe laser is also presented.

Keywords: Diode laser, High power pump source, Eye safe laser

IPC Code: H01S 5/00

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 522-526

 

 

 

 

Bright-blue organic electroluminescent device based on bis (2-methyl
8-quinolinolato) (triphenyl siloxy) aluminium

 

Aparna Misra, Pankaj Kumar, S K Dhawan, M N Kamalasanan* & Subhas Chandra

Polymeric & Soft Material Section, National Physical Laboratory, Dr K S Krishnan Road, New Delhi 110 012

*Email: mnkamal@mail.nplindia.ernet.in

Received 8 February 2005; revised 6 April 2005; accepted 20 May 2005

An organic-luminescent material bis (2-methyl 8-quinolinolato) (triphenyl siloxy) aluminium (III) (SAlq) was synthesized and its electrical and optical properties were studied. The material exhibited high photoluminescence (PL) and electroluminescence (EL). Photoluminescence (PL) spectra recorded at room temperature revealed a broad blue emission peak at 490 nm along with a shoulder at 448 nm. The material was characterized by UV-visible, photoluminescence, electroluminescence and IR spectroscopic methods. The thermal stability of the material was determined using Thermo Gravimetric Analysis (TGA), which suggests that the material is thermally stable up to 300 oC. Using the Tauc relation and the absorbance cut-off wavelength at 410 nm, the optical band gap of the material was evaluated to be 3.1 eV. OLEDs were fabricated in the configuration ITO/TPD/SAlq/LiF/Al. The CIE chromaticity was also studied and the coordinates were found to be independent of operating voltage. The devices show typical non-linear diode I-V characteristics under forward bias with the threshold voltage of 5 V.

Keywords: OLEDs, SAlq, Electroluminescence, Photoluminescence, Blue emission

IPC Code: G01J3/00

 

 

 

 

 

 

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 527-531

 

 

 

Thermoelectric power of mixed tungsten sulphoselenide single crystals grown by vapour phase technique

J B Patel, M N Parmar, M P Deshpande, G K Solanki & M K Agarwal

Department of Physics, Sardar Patel University, Vallabh Vidyanagar 388 120 Gujarat.

Received 17 September 2004; revised 25 January 2005; accepted 15 February 2005

The growth of mixed tungsten sulphoselenide single crystals i.e. WSxSe2-x  (0 £ x £ 2) grown by vapour phase technique and their characterization by Hall effect and thermoelectric power measurements have been reported. The Hall effect measurement indicates that these crystals are p-type in nature, which is very well supported by thermoelectric power measurements. From the temperature dependence of thermoelectric power, the Fermi energy (EF) and the constant (A) indicating the nature of scattering process have been obtained for all the samples. The density of states (NA) and effective mass of holes (), have also been calculated for WSxSe2-x samples.

Keywords: Vapour phase technique, Single crystals, Thermoelectric power, Tungsten sulphoselenide

IPC Code: G01R 21/08

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 532-534

 

 

 

 

Hydrogen diffusion in Fe0.5Ti0.5—Quantum isotope effect

 

M Stalin Mano Gibson* & N Lawrence

*Department of Physics, MEPCO Schlenk Engineering College, Sivakasi, Virudhunagar 626 005

Department of Physics, St. Joseph’s College, Tiruchirappalli 620 002

Received 20 September 2004; accepted 10 March 2005

A quantum mechanical theory has been used to workout the Quantum Isotope Effect (QIE) on activation energy of the intermetallic compound Fe0.5Ti0.5. The QIE has been calculated with the assumption that the hydrogen isotopes move as ions which diffuse interstitially in the crystal potential computed with the screened Coulomb interaction between proton and host ions. The QIE arises from the quantum mechanical zero point energy associated with the confining potential at the saddle point in the interstitial channel. In Fe0.5Ti0.5 system, the inequality  in activation energy is reversed. QIE values have been calculated for various pressures ranging from normal to 2.5 GPa. A remarkable agreement between theory and experiment is observed. The value of QIE slightly increases with pressure. In this compound, hydrogen prefers the octahedral position and diffuses by O – O jump mechanism.

Keywords: Hydrogen diffusion, Activation energy, Quantum isotope effect, Barrier energy, Intermetallic compound

IPC Code: C01B 4/00

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 535-541

 

 

 

Electrical conductivity and thermoelectric power of Ge40Te60 and Ge38Sn2Te60 alloys

A M Ahmed

Physics Department, Faculty of Science, South Valley University, 82524 Sohag, Egypt

Received  25 February 2004; revised 19 April 2004; accepted 16 May 2005

The dc conductivity (s) and thermoelectric power (TEP) have been measured for the bulk binary alloy Ge40Te60 and ternary alloy Ge38Sn2Te60. X-ray diffraction confirms that the samples are polycrystalline. The measurments were carried out in the temperature range 133 < T< 400 K. Variation of electrical conductivity with ambient temperature (T) proved the  semiconductor behaviour for all range of T for both materials. With annealing time (tan), the electrical conduction activation energy (Es) has been found to be with range from 0.11´10-3 eV-63.3´10-3 eV for Ge40Te60 and from 0.95´10-3 to 52.93´10-3 eV while the thermo-electric power activation energy (Es) has been found to be in the range 2.28´10-3-39.3´10-3 eV and 1.58´10-3-34.2´10-3 eV for two alloys, respectively.

Keywords: Elecrical conductivity, Thermo-electric power, Activation energy

IPC Code: G01R 21/08

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 542-544

 

 

 

Dielectric relaxation studies of ternary liquid mixtures of aniline and substituted anilines with acetonitrile in the microwave region

 

T Kalaivani, S Kumar & S Krishnan

Department of Physics, Annamalai University, Annamalainagar 608 002

E-mail: prof_krishnan@yahoo.com

Received 6 January 2005;accepted 10 May 2005

The molecular structure and molecular forces in liquids and solution in particular have been investigated by dielectric relaxation studies. The nature and strength of molecular interactions have been established as the main cause for the chemical behaviour of compounds. The dielectric behaviour of three amines and their mixtures (i) N-methyl aniline + acetonitrile (ii) aniline + acetonitrile (iii) N,N-dimethyl aniline + acetonitrile has been studied at microwave frequency 9.36 GHz at 303 K. Different dielectric quantities like dielectric constant (e¢), dielectric loss (e¢¢), static dielectric constant (eo) and dielectric constant at optical frequency (e¥) have been determined. The relaxation time (t) has been calculated by both Higasi’s method and Cole-Cole method. The molar free energy of activation (DFt) and (DFh) has also been reported. The complex systems investigated show the maximum relaxation time values at 1:1 complex ratio by both Higasi’s method and Cole-Cole plot method.

Keywords: H-bonding, Proton donor, Proton acceptor, Dielectric relaxation, X-band microwave Aniline, Acetonitrile

IPC Code: G01R27/26

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 545-549

 

 

 

Structural and magnetic properties of Mn1+xSixFe1-xCr1-xO4 system

S K Vyawaharea, N R Shamkuwarb& Madan C Sablec

aDepartment of Physics, Deogiri College, Aurangabad 431 005

bDepartment of Physics, Dr Babasaheb Ambedkar Marathawada University, Aurangabad

cDepartment of Physics, Jijamata Mahavidyalaya, Buldhana 443 001

Received 17 August 2004; revised 2 December 2004; accepted 31 March 2005

The structural and magnetic properties of mixed spinel system Mn1+xSixFe1-xCr1-xO4 (x = 0.0, 0.1,0.2,0.3,0.4,0.5) have been investigated by X-ray diffraction and magnetization studies. X-ray intensity calculations indicate that Si4+ ions occupy only tetrahedral (A) sites replacing Fe3+ ions and Mn3+ ions replace Fe3+ ions from (B) site. The variation of saturation magnetic moment per formula unit measured at 300 K with the Si4+ content is explained on the basis of Neel’s collinear spin ordering model.

Keywords: Cation, Intensity, Magnetization, X-ray diffraction, Mixed spinel system

        IPC Code: G01N25/20

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 550-555

 

 

 

 

 

Dielectric and conformational studies of methanol + ketone systems

V Madhurima

School of Physics, University of Hyderabad, Hyderabad 500 046 

Received 1 November 2004; revised 22 March 2005; accepted 12 May 2005

Semi-empirical conformational analysis of five methanol + ketone systems with a systematic study with the variation of the hydrogen bond angle have been studied. The results of the conformational analysis are compared with experimentally determined dipole moments of the five systems. The ketones chosen for the present study are acetone, 2-butanone, 3-pentanone, cyclohexanone and acetophenone. Conformational analysis is done using the PM3 semi-empirical Hamiltonian and the dipole moments are determined using dielectric relaxation studies at microwave X-band frequency (9.97 GHz). Further confirmation with previous 13C NMR chemical shift data is also sought.

Keywords: Dielectric studies, Conformational analysis, Dipole moment

IPC Code: G01R31/12

 

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, July 2005, pp. 556-558

 

 

 

High output impedance current-mode universal filter

N A Shah, M F Rather & S Z Iqbal

Department of Electronics and Instrumentation Technology

The University of Kashmir, Srinagar 190 006

E-mail: farsgr@yahoo.co.in

Received 29 September 2004; accepted 6 April 2005

A new current-mode universal filter with single input and three outputs employing two second-generation current conveyors (CCIIs), one current follower (CF) and four grounded/virtually grounded passive elements is presented. The proposed circuit enjoys the following features: simultaneous realization of lowpass(LP), bandpass(BP), and highpass(HP) filtering responses, no need of matching conditions, employment of grounded resistors which are ideal for IC implementation, employment of grounded/virtually grounded capacitors, orthogonal control of ω0 and ω0 / Q, high output impedance suiting cascadibility for higher order filters, and low passive sensitivity. PSPICE simulation results are included, confirming the workability of the proposed circuit.

Keywords:   Current-mode universal filter, Second generation current conveyors, Current follower

IPC Code: H03K 3/00

 

 

 

 

 

*The corresponding author has been indicated by (*) mark in case of papers with more than one author.