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Indian Journal of Pure & Applied Physics

 

ISSN : 0019-5596

 CODEN : IJOPAU 42(4) 235-308

Volume 42

 Number 4

 April 2004

 

Contents
Nuclear Physics

 

Compton profiles of praseodymium and gadolinium

Thomas Varghese*, K M Balakrishna & K Siddappa

239

 

 

Multi-element determination of sandstone rock by instrumental neutron activation analysis

A El-Taher , H M Mahmoud & Adel G E Abbady*

243

                                     

 

Atomic and Molecular Physics

 

Spectroscopic analysis of the structure of repeat unit of polyethylene terepthalate(PET)

S Gunasekaran* & Hemamalini R

246 

 

 

RHF and DFT based study  of the structure, thermodynamic properties and electronic spectra of methacryloyl halides

Archna Sharma, V P Gupta* & Ajit Virdi

251

Dual phase wide band lock-in amplifier for linear and non-linear photo-thermal  signal processing

K Sreekumar & V K Vaidyan*

258

Physics of  Gases, Plasmas and Electric Discharges

 

Dynamics and the characteristics behaviour of soliton propagation in dusty plasmas

G C Das*, Karabi Devi, Jnanjyoti Sarma & Nirupama Devi

265

 

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Superconducting transition edge bolometer based on single phase BPSCCO 2223 thick film

A T Nimal, Vijay Kumar, A K Gupta* & G L Bhalla

275

 

 

Microscopic structure of CuSn compound forming binary molten alloys

S K Chatterjee* & L C Prasad

279

 

 

Effective heat storage coefficient of two phase isotropic systems

Jagjiwanram & Ramvir Singh*

283

 

 

Electronic heat capacity of crystalline solids

C P Painuli, R M Bhatt, Y P Raiwani, Sanjiv Srivastava, S C Gairola, R P Gairola, B D Indu* & M D Tiwari

 

288

Fluorescence quenching of aniline and p- toluidine by picric acid in methanol

S Bakkialakshmi*, B Shanthi & A Priyadharsini

294

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

 

 

 

Minimum component current-mode universal filter

N A Shah*, S Z Iqbal & Basharat Parveen

296

Synthesis of CaB4O7:Dy phosphor

S J Dhoble*,D I Shahare & S V Moharil

299

High energy plasmon satellites in Auger spectra of 4d transition metals

K S Srivastava*, M Husain & Sharad Srivastava

302

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

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 239-242

 

Compton profiles of praseodymium and gadolinium

Thomas Varghese and K M Balakrishna & K Siddappa

 

The Compton profiles of rare earth elements Pr and Gd were measured using IGC HPGe detector. The target atoms were excited by means of 59.54 keV gamma rays from Am-241 radioactive source of strength 300 mCi. Elemental foils of uniform aerial density, and purity better than 99.9% were used as targets. The data were recorded and analyzed using a 4K multichannel analyzer. The present experimental Compton profiles of Pr and Gd constitute the first measurement. The results are compared with theoretical Hartree-Fock free-atom profiles.

 

[Keywords: Compton scattering; Compton profile; electron momentum density]

IPC Code: G 01 J 3/00

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 243-245

 

Multi-element determination of sandstone rock by instrumental neutron activation analysis

A El-Taher and H M Mahmoud & Adel G E Abbady

 

The instrumental neutron activation analysis technique (INAA) was used in the qualitative and quantitative analysis of sandstone samples from Aswan area in South Egypt. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of 71011 n/cm2.s in the TRIGA Mainz research reactor facilities. Gamma spectra from hyperpure germanium HPGe detector were analysed. The present study provides the basic data of elemental concentrations of sandstone rock. The following elements constituents have been determined: Na, K, Fe, Sc, Cr, Co, Zr, Ce, La, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The X-ray fluorescence (XRF) was used for comparison and to detect elements which can be detected only by XRF.

 

[Keywords: Instrumental Neutron Activation Analysis, Sandstone,TRIGA Mainz.]

IPC Code: G 01T 3/02

 

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 246-250

 

Spectroscopic analysis of the structure of repeat unit of polyethylene terepthalate (PET)

S Gunasekaran* & Hemamalini R

 

The proper use of FTIR and laser Raman to study the structure of repeat unit of polyethylene terephthalate (PET) has been presented. A normal co-ordinate analysis of crystalline poly ethylene terephthalate (PET) (trans form) has been carried out. A systematic set of potential constants has been computed using the method of kinetic constants on the basis of C2h symmetry. The potential energy distribution confirms the correctness of the assigmnents made.

 

[Keywords: Polyethylene terephthalate (PET), FTIR, and Laser Raman spectra, Normal coordinate analysis

IPC Code: G 01 J 3/44

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 251-257

 

RHF and DFT based study of the structure, thermodynamic properties and electronic spectra of methacryloyl halides

Archna Sharma, V P Gupta & Ajit Virdi

 

Advanced level theoretical studies using Density Functionals Thoery (DFT) and Hartree-Fock (HF) methods involving extended basis sets with the inclusion of polarization and correlational effects have been attempted for understanding the conformational peculiarities of methacryloyl halides (F, Cl, Br), in their electronic ground (S0) and first excited (S1) states and to determine their thermodynamic and physico-chemical parameters. Potential energy curves for the S0 and S1 states of the molecules have been plotted for studying rotational isomerism. Two stable conformers s-trans and s-cis have been identified, with the former being more stable than the latter, thus excluding the possibility of the higher energy gauche conformer reported in some experimental measurements. A complete interpretation of the electronic spectra in terms of the energy levels, frequency, intensity and nature of transition has been made for the stable conformers on the basis of CI level calculations involving singly excited states.

 

[Keywords: Density functional theory, Hartree-Fock (HF) method, Methacryloyl halides, Rotational isomerism]

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 258-264

 

Dual phase wide band lock-in amplifier for linear and
non-linear photo-thermal signal processing

K Sreekumar & V K Vaidyan

 

A dual phase lock-in amplifier has been designed and developed for the processing of photo-thermal signals in 1 Hz to 110 kHz frequency range, with automatic frequency tracking over the entire bandwidth. The low power consumption of about 3.5 W of the unit ensures an efficient support in experiments of long duration like photothermal microscopy and subsurface imaging. The system accepts reference signals of any wave shape and synthesizes corresponding sine wave for fundamental-only-response. Second harmonic detection scheme has been incorporated for applications in non-linear photothermal experiments up to 55 kHz. At 1 kHz, the measured common mode rejection ratio of the differential front end is about 70 dB, input voltage noise is about 25 nV/ and current noise is about. 1 pA/The sensitivity is 200 nV and the maximum possible dynamic reserve is 54 dB. The full-scale sensitivity is adjustable from 2 V to 200 mV and time constant from 1 ms to 50s. Optional notch filters are included for line frequency and its second harmonic. The phase stability, output offset drift and the total output error have been analyzed. The unit has been employed in laser-photoacoustic imaging for detecting a subsurface hole in an aluminium block and photothermal radiometry of a silicon wafer and the results have been presented. Though developed for photothermal applications, care has been taken to make it a low cost general-purpose instrument.

 

[Keywords: Photo-thermal signal processing; lock-in amplifier]

IPC Code: H 04 L 12/12

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 265-274

 

Dynamics and the characteristics behaviour
of soliton propagation in dusty plasmas

G C Das, Karabi Devi, Jnanjyoti Sarma* & Nirupama Devi**

 

Formation of various solitary waves in a plasma contaminated with dust charged grain have been investigated. Based on pseudopotential analysis, nonlinear Sagdeev potential equation has been derived, from where acoustic modes describing the soliton propagation in dusty plasma have been highlighted. Moreover, for showing the formation of different features of solitons, Sagdeev potential has been expanded due to which different nonlinear wave equations have been formed. It has been shown that the controlling of dust charge composition expects the coexistence of solitons, double layer or shock-like wave along with other nonlinear waves. The catchy of the present investigation has been emphasized to a modified formalism, called tanh-method, in finding the soliton solution from nonlinear wave equations. The success of using tanh-method derives soliton propagation from the Sagdeev potential equation in dusty plasma. Further, other nonlinear modes have been shown which enable to predict the collapse along with the conditions required for its existence.

 

[Keywords: Dusty plasmas, Soliton propagation, Pseudopotential analysts]

IPC Code: H 05BH 1/04

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 275-278

 

Superconducting transition edge bolometer based on single phase BPSCCO 2223 thick film

A T Nimal, Vijay Kumar & A K Gupta and G L Bhalla

 

Single-phase Bi(Pb)-Sr-Ca-Cu-O (BPSCCO) polycrystalline thick films on MgO substrates were used to realize superconductor bolometer, to detect infrared radiation. BPSCCO 2223 single-phase thick films were prepared by screen-printing technique with TC(R=0) = 107K. The film is patterned as a meander line to increase the length and the resistance of the detector. The patterned thick film mounted on a thermal insulator and maintained at mid point temperature of superconducting transition constitutes the bolometer. The bolometer is current biased and exposed to chopped IR radiation of wavelength 915 nm, and the output is measured as voltage. The bolometer response is studied for chopping frequencies in the range of 1 Hz to 1 kHz. Responsivity of 15 V/W has been achieved at chopping frequency of 2 Hz.

 

[Keywords: High-TC Superconductor, BPSCCO 2223, Thick film, Screen-printing, Superconducting bolometer]

IPC Code: C 04B 35/01

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 279-82

 

Microscopic structure of CuSn compound
forming binary molten alloys

S K Chatterjee & +L C Prasad

 

A simple statistical mechanical theory based on compound formation model (compound Abv formed by the preferential arrangement of A and B constituent atoms of the alloy AB, A + vB = ABv) has been used to investigate the phenomenon of compound formation in CuSn liquid alloys through the study of microscopic function in CuSn liquid alloys, i.e. concentration fluctuation in long wavelength region [Scc(o)] and chemical short range order parameter (1). The study explains the observed asymmetry successfully and suggests the existence of Cu3Sn complex in the melt. The tendency of compound formation has been found to be weak. The system exhibits an ideal behaviour at Sn-rich end. The existence of inter-metallic compound Cu3Sn in the solid phase, which is manifested in the phase diagram, may be one of the factors for the anomalous behaviour of properties of mixing.

 

[Keywords: Chemical short range order parameter, Concentration fluctuation in long wavelength region binary molten alloys]

IPC Code: C 01 G 3/00

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 283-287

 

Effective heat storage coefficient of
two-phase isotropic systems

Jagjiwanram & Ramvir Singh

 

A theoretical expression for predicting effective heat storage coefficient of two-phase isotropic systems has been developed. The porous system has been assumed to contain particles of irregular shape, being dispersed randomly within the continuous medium. The concept of averaging the temperature field within different phases has been used. The theoretical expression so obtained predicts values of effective heat storage coefficient quite close to the experimental results.

 

[Keywords: Heat storage coefficient (HSC), two-phase isotropic systems, adjustable parameter, continuous medium]

IPC Code: C 09 K 5/00

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 288-293

 

Electronic heat capacity of crystalline solids

C P Painuli1, R M Bhatt2, Y P Raiwani2, Sanjiv Srivastava2, S C Gairola3,

R P Gairola4, B D Indu5* & M D Tiwari6

 

The expressions for the electron density of states (EDOS) and electronic heat capacity (EHC) have been obtained for an isotopically disordered anharmonic crystal. The quantum dynamics of the crystal has been discussed in the light of an almost complete Hamiltonian consisting of (i) harmonic and anharmonic phonon fields, (ii) electrons, (iii) electron-phonon interaction and (iv) localized fields. It is observed that the electron-phonon coupling plays a crucial role in determining EDOS and EHC. The temperature dependence of EDOS is the remarkable feature of the present formulation

 

[Keywords: Electron density of states, Anharmonicity, electron-phonon coupling, localized fields, electronic heat capacity]

IPC Code: C 09 K 5/02

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 294-295

 
Fluorescence quenching of aniline and
p-toluidine by picric acid in methanol

S Bakkialakshmi, B Shanthi* & A Priyadharsini

 

The fluorescence quenching spectra of aniline and p-toluidine using picric acid as a quencher in methanol have been studied. The stern-volmer constants for all the quenching processes have been plotted. Regression analysis for stern-volmer plot has been carried out. Regression coefficient (r) and the stern-volmer constant (Ksv) have been calculated. Stokes shift, ionization potential, electron affinity and the solvent parameter (z) have also been calculated.

 

[Keywords: Fluorescence quenching, picric acid, aniline, p-toluidine, stern-volmer plot, stokes shift, ionization potential, electron affinity and solvent parameter.]

IPC Code: C 09 K 11/06

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 296-298

 

Minimum component current-mode universal filter

N A Shah, S Z Iqbal & Basharat Parveen

 

A novel current-mode (CM) universal filter based on and employing only one second generation current conveyor (CCII+), two operational transconductance amplifiers (OTAs), and three grounded capacitors is presented. The grounded capacitor configuration of the proposed circuit is beneficial to an integrated circuit (IC) implementation. Three types of current-transfers lowpass (LP), highpass (HP), and bandpass (BP) can be achieved simultaneously while other filtering responses allpass (AP) and notch can be obtained by summing the appropriate node currents without any change to be induced in the filter structure and/or employment of additional components. The transconductance gains of OTAs are used to tune the filter characteristics electronically in an orthogonal manner. The structure is devoid of resistors and enjoys low sensitivity performance. The experimental results are included.

 

[Keywords: Current-mode universal filter; trensconductance amplifiers]

IPC Code: H 03 H 7/075

 

 

Indian Journal of Pure & Applied Physics

Vol. 42, April 2004, pp. 299-301

 

Synthesis of CaB4O7:Dy phosphor

S J Dhoble1, D I Shahare2, S V Moharil3

 

Synthesis of CaB4O7:Dy phosphors prepared by solid state diffusion technique has been reported. These are shown to be four times sensitive than the commercially used LiF:TLD100 phosphor. The phosphor has a linear response, negligible fading and excellent reusability. This property makes them a suitable replacement for LiF:TLD100 which is currently used for the dosimetry of ionizing radiation using thermo-luminescence.

 

[Keywords: CaB4O7 , Radiation dosimetry, Phosphor]

IPC Code: C 01B 25/32

 

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, April 2004, pp. 302-303

 

High energy plasmon satellites in Auger spectra
of 4d transition metals

K S Srivastava, M Husain & Sharad Srivastava*

 

Theory of plasma oscillations in solids has been used to calculate the energy separation and relative intensity of plasmon satellites of Ag, Pd, Rh, Ru, Mo and Nb. The calculated values of energy separation and relative intensity agree well with the estimated values of energy separation and relative intensity of second satellites on the high energy side of the main line in the L3M4,5 M4,5 Auger spectra observed by Landers et al. J. Electron Spect & Related Phenom, 72 (1995) 211.

 

[Keywords: Auger spectra; plasmon satellites; transition metals]

IPC Code: H 05 H