Indian Journal of Pure and Applied Physics

      Total visitors: 1,369  since 15-05-06

 ISSN: 0019-5596

CODEN: IJOPAU 44 (5) 349-418

VOLUME  44

NUMBER 5

MAY 2006

CONTENTS

Nuclear Physics

 

Inhalation dose due to radon and its progeny at Pune

353

K Nagaraja*, B S N Prasad, M S Chandrashekara, L Paramesh & M S Madhava

 

Atomic and Molecular Physics

 

FTIR, FT Raman spectra  and normal coordinate analysis of hydralazine

360

S Gunasekaran*, S Seshadri & S Muthu

 

Effect of divalent metal oxides on absorption spectra of some sodium borate
glasses containing mixed nickel and iron oxides

367

F H El-Batal*, A M Fayad, S A El-Rahman* & F A Moustaffa

 

Photoluminescence of Cu+ in some double sulphates

375

R R Patil*, S V Moharil, S M Dhopte, P L Muthal & V K Kondawar

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Non-equilibrium ensemble method: A quantum-statistical-mechanical approach

378

Behzad Haghighi*, Hamed Maaleki & S J Shakhs Emampour

 

Lattice dynamical calculations of spinel structure compounds

385

A K Kushwaha*, Girija Shankar & S S Kushwaha

 

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

 

Dielectric study of Ba(Zn1/3Nb2/3)O3 at low temperature

391

A K Himanshu, D C Gupta & T P Sinha*

 

 

 

Interdisciplinary Physics and Related Areas of Science and Technology

 

High input impedance all-pass and notch filter configuration

398

P Kumar, K Pal & G K Gupta*

 

Voltage-mode OTA-based active-C universal filter and its transformation
into CFA-based RC-filter

402

N A Shah* & M F Rather

 

Optimization of polymer coated silicon microcantilever for chemical
sensing applications

407

M Ganesan, N K Sharma* & V K Jain

 

 

__________

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

  

Indian Journal of Pure & Applied Physics

Vol. 44, May 2006, pp. 353-359

   

Inhalation dose due to radon and its progeny at Pune

K Nagaraja, B S N Prasad, M S Chandrashekara, L Paramesh & M S Madhava

Department of Studies in Physics, University of Mysore, Mysore 570 006

Received 4 February 2005; revised 21 April 2005; accepted 6 February 2006

The radon and its progeny concentrations are measured near the surface of the earth at the Indian Institute of Tropical Meteorology, Pune, India. In-situ measurements of the meteorological parameters such as temperature and relative humidity are also made simultaneously. The concentrations show maxima in the early morning hours when the turbulence mixing is the minimum; whereas in the afternoon the turbulence mixing is the maximum and concentrations exhibit minima. The diurnal and seasonal variations in the concentrations of radon and its progeny are found to exhibit correlation with the relative humidity, and anti-correlation with the temperature. The annual effective dose for Pune environment is found to be 0.55 mSv which is within the permissible limit.

Keywords: Radon, Progeny, Dose, Diurnal/Seasonal variations

IPC Code: C01B 23/00, G01T

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, May 2006, pp. 360-366

 

FTIR, FT Raman spectra and normal coordinate analysis of hydralazine

 

S Gunasekaran1, S Seshadri2 & S Muthu3

1PG & Research Department of Physics, Pachaiyappa’s College, Chennai 600 030

2 Department of Physics, Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya, Enathur, Kanchipuram 631 561

3 Department of Applied Physics, Sri Venkateswara College of Engineering, Sriperumbudur 602 105

E-mail: sri_sesha@yahoo.com

Received 22 September 2005; accepted 31 January 2006

Hydralazine (C8H8N4.HCl) is chemically known as 1-hydrazinophthalazine mono hydrochloride. It is used as an anti- hypertensive agent. In the present investigation, normal coordinate analysis has been carried out for the molecule of the title compound using fundamental modes of vibration observed in infrared and Raman spectroscopy. The vibrational modes are classified into A′ and A″ irreducible representations and are distributed as Γvib=35 A′+19 A″ based on Cs point group symmetry associated with the structures. In the present work, only 18 A′ and 12 A″ normal modes are considered due to complexity of the molecule. A systematic set of orthonormal symmetry co-ordinates has been constructed. Wilson’s F–G matrix method has been adopted for the normal coordinate analysis. A satisfactory vibrational band assignment has been made by using the FTIR and FT Raman spectra of the compounds.

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

IPC Code:   G01J3/00

 

 

 

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp 367-374

  

Effect of divalent metal oxides on absorption spectra of some sodium borate glasses containing mixed nickel and iron oxides

FH El-Batal, AM Fayad, SA El-Rahman* & FA Moustaffa

Glass Research Department, National Research Centre, Dokki, Cairo, Egypt

*Chemistry Department,Faculty of Science, Cairo University, Egypt

Received 27 May 2005; accepted 23 November 2005

Absorption spectra of nickel and iron ions in some sodium borate glasses containing magnesia, cadmium oxide, zinc oxide, lime, strontium oxide or barium oxide were carried out to study the structure of these glasses and the effect of divalent metal oxides on the glass structure. Nickel usually exists in glass as divalent nickel ions in two different forms, octahedral (NiO6) and tetrahedral (NiO4), while iron usually exists in glass as ferrous and ferric states in two different forms, octahedral and tetrahedral according to the glass composition. The states of the transition metal ions in the glasses depend on several factors such as: (i) the polarizability of the oxygen ligands surrounding the transition metal ion; (ii) the mobility of the alkali ions and their field strengths and (iii) the opportunity of forming network units such as MO4 for some of the divalent metal oxides.

Keywords: Absorption spectra, Sodium borate glasses, Divalent metal oxides

IPC Code: C03C4/12

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp. 375-377

 

 

Photoluminescence of Cu+ in some double sulphates

 

R R Patil*, S V Moharil, S M Dhopte, P L Muthal & V K Kondawar

*Department of Physics, Institute of Science, Nagpur 440 001

Department of Physics, Nagpur University, Nagpur 440 010

National Environmental Engineering Research Institute, Nehru Marg, Nagpur

Received 28 June 2005; accepted 12 September 2005

Using the reactive atmosphere processing, Cu+ has been doped in double sulphates for the first time. Photolumine­scence of Cu+ in double sulphates is reported. The results establish that it is now possible to incorporate Cu+ in double sulphates. This opens up new, exciting possibilities of studying photoluminescence vis-a-vis sequence of phase transitions.

Keywords: Photoluminescence, Double sulphates, Phase transitions

IPC Code: F21V9/16

 

 

 

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp. 378-384

  

 

Non-equilibrium ensemble method: A quantum-statistical-mechanical approach

 

1Behzad Haghighi, 2Hamed Maaleki & 3S J Shakhs Emampour

1Thermodynamic & Transport Properties Research Laboratory (T&TPRL), Department of Chemistry
Faculty of Science, Birjand University, 97175-615, Birjand, Southern Khorasan Province, Iran

2Solid State and Condensed Matter Physics Laboratory (SS&CMPL), Department of Physics, Faculty of Science
Birjand University, 97175-615, Birjand, Southern Khorasan Province, Iran

3Department of Chemistry, Faculty of Science, Ferdowsi University, 91779-1436, Mashhad
Razavi Khorasan Province, Iran

Received 11 February 2005; revised 27 June 2005;accepted 28 June 2005

The non-equilibrium ensembles method has been applied to Boltzmann quantum-kinetic equation. We used the quantum-kinetic equation governing the density matrix, which has been proposed by Ogul and Eren, J Chem Phys, 105 (1996) 7664. The non-equilibrium quantum-mechanical ensemble can be constructed in terms of non-equilibrium entropy, Boltzmann entropy, constrained by the quantum Boltzmann equation as a dynamical equation of motion, which has governed the time evolution of non-equilibrium density matrix. The quantum-mechanically non-equilibrium partition function has been obtained. The conjuncture with the traditional irreversible thermodynamics has been shown.

Keywords: Non-equilibrium ensemble, Non-equilibrium statistical mechanics, Non-equilibrium partition function, Non-equilibrium entropy, Time-integrated entropy, Quantum-kinetic equation

IPC Code: G06

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp. 385-390

 

Lattice dynamical calculations of spinel structure compounds

 

A K Kushwaha, Girija Shankar & S S Kushwaha

Department of Physics, Bundelkhand University, Jhansi 284 128

E-mail: akkphys_bu@yahoo.com

Received 10 August 2005; revised 15 February 2006; accepted 28 February 2006

Lattice dynamical calculations have been performed for normal spinel structure compounds using the proposed theoretical model. In this model, the dynamical matrix is split into two parts: (i) the short range part is evaluated by using Taylor’s expansion of the crystal potential energy in the harmonic approximation and (ii) the long range part is evaluated on the basis of screened Coulomb potential. This model is applied to study the zone centre (G=0) phonon frequencies of sulphide spinels MCr2S4 (M= Mn, Fe, Cd). The significant outcome of the present work is that (i) the tetrahedral M-S force constants are smaller than the respective octahedral (Cr-S) ones, (ii) the bending force constants are negligible, and (iii) the effective dynamical charges of the bivalent metal ions are nearly zero. The zone-center phonon frequencies, thus calculated using these parameters are found to be in very good agreement with the observed results.

Keywords: Spinel structure, Lattice dynamics, Octahedral, Zone center, Phonons

IPC Code: C30B

  

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp. 391-397

 

 

Dielectric study of Ba(Zn1/3Nb2/3)O3 at low temperature

A K Himanshu, D C Gupta & T P Sinha+

School of Studies in Physics, Jiwaji University, Gwalior 474 011

Department of Physics, Bose Institute, 93/1, APC Road, Kolkata 700 009

Received 18 October 2005; revised 23 January 2006; accepted 6 February 2006

The dielectric study of Ba(Zn1/3Nb2/3)O3 has been studied at low temperature in a frequency range 100 Hz-1 MHz and a temperature range from 145K to room temperature. An analysis of real and imaginary part of dielectric permittivity, impedance (Z), conductivity and electric modulus with frequency and temperature is performed, showing the polydispersive nature of the relaxation time in the sample as confirmed by the Cole-Cole plot of the dielectric permittivity and impedance. All these results suggest that the relaxation phenomenon seen in the configuration has been attributable to the damping of dipole oscillators due to the application of the external fields.

Keywords : Perovskite, Cole-Cole, Polydispersive, Impedance spectroscopy

IPC Code: G01R27/26

Indian Journal of Pure & Applied Physics
Vol. 44, May 2006, pp. 398-401

 

High input impedance all-pass and notch filter configuration

P Kumar, K Pal* & G K Gupta

Department of Physics, D.B.S. College, Dehradun 248 001, Uttranchal

*Department of Earthquake Engineering, Indian Institute of Technology  Roorkee, Roorkee 247 667

E-mail: ranapkumar@yahoo.co.in, kiratfeq@iitr.ernet.in

Received 8 June 2005; revised 2 January 2006; accepted 28 February 2006

A circuit realizing second order all-pass and notch filter, employing current conveyors and operational amplifier/CFA as the active circuit elements is proposed. The circuit uses only two current conveyors, one operational amplifier/current feedback amplifier, four resistors and two grounded capacitors. The current conveyors used in the circuit are replaceable by translinear current conveyors and thus quality factors Q and center frequency become controllable through the bias currents of the translinear current conveyors. The filter also displays low incremental parameter sensitivities. The simulation results on the filter support theory.

Keywords: Active filters, Current conveyor, Translinear current conveyor, All-pass filter, Notch filter

IPC Code: H01P1/20

Indian Journal of Pure & Applied Physics

Vol. 44, May 2006, pp. 402-406

 

Voltage-mode OTA-based active-C universal filter and its transformation into CFA-based RC-filter

N A Shah & M F Rather

Department of Electronics & Instrumentation Technology, University of Kashmir, Srinagar 190 006

E-mail: farsgr@yahoo.co.in

Received 28 June 2005; revised 22 December 2005; accepted 1 February 2006

An absolute minimum component voltage-mode (VM) universal filter, employing two each of operational transconductance amplifiers (OTAs) and capacitors with three inputs and one output, is presented. The circuit can be transformed into CFA-based RC-filter involving two each of current feedback amplifiers (CFAs), capacitors and resistors. OTA-C circuit enjoys electronic tunability of filtering parameters while its CFA-based RC version offers low output impedance which suits cascadability. PSPICE simulation and the experimental results of both the circuits are included.

Keywords: Voltage-mode filters, Operational transconductance amplifiers, Current feedback amplifiers

IPC Code: H01S

 

Indian Journal of Pure & Applied Physics

Vol. 44, May 2006, pp. 407-413

Optimization of polymer coated silicon microcantilever for
chemical sensing applications

 

M Ganesan, N K Sharma & V K Jain

Central Scientific Instruments Organisation (Delhi Centre), CSIR Complex, Pusa Campus, New Delhi

Received 4 October 2004; revised 5 December 2005; accepted 25 January 2006

The mechanical design and optimization of polymer coated silicon microcantilever (MC) for chemical sensing application have been studied through simple mass sensitivity factor. For this theoretical modeling, silicon is the base layer (substrate) and the functional layer can be selected according to the chemical detection. The mass sensitivity factor and spring constant change before and after chemical reactions have been analyzed theoretically by taking minimum of four hundred samples in each case study. Finally, the specific dimensions and guidelines for designing high sensitivity polymer coated microcantilever for chemical sensing application based on the case study have been suggested. The optimized microcantilever is theoretically analyzed with detection of water vapour and primary alcohols.

Keywords: Microcantilever, Resonance frequency, Mass sensitivity factor, Spring constant

IPC Code: B81B7/02