Indian Journal of Pure and Applied Physics

      Total visitors: 1,287  since 20-07-06

 ISSN: 0019-5596

CODEN: IJOPAU 44 (6) 491-562

VOLUME  44

NUMBER 7

JULY 2006

CONTENTS












Atomic and Molecular Physics

 

Vibrational spectra and thermodynamic analysis of metformin

495

S Gunasekaran*, R K Natarajan, V Renganayaki & S Natarajan

 

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

 

Holographic optics based two-channel interferometer

501

Amit K Sharma, Sushil K Kaura, D P Chhachhia, C G Mahajan & A K Aggarwal*

 

Interaction of dye laser beam  of wavelength 5750 Å with nitrogen lines

509

A Gohain  Barua*,  A K Borah  &  S S Jois

 

Physics of Gases, Plasmas and Electric Discharges

 

Determining the relation between effective coupling constant and quark mass in the parton model using massive nucleonic quarks in hyper central potential

512

A A Rajabi

 

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

 

Temperature effect on lyoluminescence of potassium halide microcrystals in luminol solution

519

R S Chandok*, R Kaur, G K Chandok & B P Chandra

 

Temperature dependent optical property studies of nematic mixtures

524

T N Soorya, Surabhi Gupta, Anant Kumar, Sachin Jain, VP Arora*  & B Bahadur

 

Thermally stimulated processes: I- Mechanisms involved in the appearance of a thermoluminescence glow curve

532

Jai Prakash, P K Singh & D K Dwivedi*

 

 

 

Synthesis and characterization of certain nanomagnetic particles coated with citrate and dextran molecules

537

R V Mehta*, Rucha Desai, Prashant Bhatt & R V Upadhyay

 

Effective heating in heavily doped semiconductor devices

543

S S De*, A K Ghosh, T K Ghosh & D Jana

 

Microwave dielectric relaxation study of poly (methyl methacrylate) and polysulphone in dilute solutions

548

A Tanwar, K K Gupta, P J Singh* & Y K Vijay

 

Structural analysis and second-order non-linear optical activity of urea hydrogen peroxide adduct

554

Malyaj Das, R Prasad & P Sen*

 

__________

*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, July 2006, pp. 495-500

 

Vibrational spectra and thermodynamic analysis of metformin

S Gunasekaran, R K Natarajan*, V Renganayaki* & S Natarajan+

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

+ Post Graduate and Research Department of Physics, Kongunadu College, Coimbatore

Received 22 December 2005; accepted 10 May 2006

Metformin is one of the important anti-diabetic drugs to treat non-insulin dependent diabetes mellitus (NIDDM). Fourier transform infrared (FTIR) and Fourier transform Raman (FTR) spectra of metformin have been used for the molecular study. A satisfactory band assignment has been made on the fundamental modes of vibration. Employing the molecular mechanics method using MM3 force field, the theoretical vibrational frequencies and geometry parameters like bond lengths, bond angles etc are calculated and compared with the experimental frequencies. The observed frequencies are used to compute the thermodynamic functions, namely, the enthalpy, entropy, heats of formation, heat capacity using standard expressions at temperature 298 K and one atmospheric pressure.

Keywords: Vibrational spectra, Metformin, Vibrational band assignment, Molecular mechanics, Thermodynamic functions

IPC Code: G01J3/28

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp 501-508

 

Holographic optics based two-channel interferometer

Amit K Sharma, Sushil K Kaura, D P Chhachhia, C G Mahajan# & A K Aggarwal*

Coherent Optics Division, Central Scientific Instruments Organisation, Sector 30, Chandigarh 160 030

#Department of Physics, Panjab University, Chandigarh 160 014

Received 6 March 2006; accepted 12 May 2006

The paper describes a simple and cost effective method for making a two-channel interferometer based on holographic optics, which is suitable for performing optical test studies on two different phase objects simultaneously and independently. The optical arrangement in the proposed method involves a simple alignment procedure and inexpensive recording material is used in the formation of holographic optical elements. Recording schemes for the formation of holographic optical elements and the related techniques for the realization of the proposed interferometer along with the effect of misalignment of holographic optical elements and typical experimental results are presented.

Keywords: Optical interferometry, Two-channel interferometer, Holography, Optical testing instruments,
                       Phase visualization

IPC Code: G03H

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 509-511

Interaction of dye laser beam of wavelength 5750 Å with absorption lines of nitrogen

A Gohain Barua, A K Borah & S S Jois

Department of Physics, Gauhati University, Guwahati 781 014

Received 27 September 2005; revised 30 November 2005; accepted 28 February 2006

The quasi-random model of molecular band absorption is used to study the interaction of dye laser beam of wavelength 5750 Å with the absorption lines of nitrogen. The values of transmittance, averaged over intervals of 0.2 cm-1, are obtained for two different path lengths in the frequency range 17386 – 17397 cm-1. From these values, the intensities of the absorption lines in the first positive system of N2 have been simulated.

Keywords: Dye laser beam, Laser, Absorption lines, Nitrogen

IPC Code: B23K26/00

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp 512-518

 

 

Determining the relation between effective coupling constant and quark mass in the parton model using massive nucleonic quarks in hypercentral potential

A A Rajabi

Physics Department, Shahrood University of Technology, PO Box 36155-316 Shahrood, Islamic Republic of Iran

Email: A.A.rajabi@shahrood.ac.ir

Received 6 December 2004; accepted 5 April 2006

The reliable values of effective strong coupling constants (as) for hadrons from various reactions have been found by investigating experimentally. So far, it has been proved that the as is not a fixed quantity. In this paper, we show that how the value of as depends on the constituent quark masses in hadrons. The effective values of as for different quark masses can be determined by using short-range attractive hyper-Coulombic potential, which would be in agreement with .

Keywords: Hypercentral, Three-body force, Valence quark, Coupling constant, Quark mass, CQM-Jacobi coordinates,
                    H O potential

IPC Code:  G01N15/00

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 519-523

 

 

Temperature effect on lyoluminescence of potassium halide
microcrystals in luminol solution

 

R S Chandok*, R Kaur**, G K Chandok+ & B P Chandra++

*Sri Guru Tegh Bahadur Khalsa College, Mahanadda, Jabalpur

**Guru Ramdas Khalsa Institute of Science & Technology, Jabalpur

+Gyan Ganga Institute of Science and Technology, Jabalpur

++Department of Postgraudate Studies & Research in Physics & Electronics, Rani Durgavati Vishwavidyalaya, Jabalpur (M P)

Received 28 September 2005; revised 10 April 2006; accepted 24 April 2006

When g-irradiated microcrystals of potassium halides are dissolved in the luminol solution, the lyoluminescence (LL) intensity initially increases linearly with time, attains an optimum value and then decreases and finally disappears. The LL intensity was detected by PMT whose output was connected to X-Y recorder. Temperature dependence of LL intensity shows that initially the peak of LL intensity (Im) increases with temperature, attains a peak value, and then decreases with further increase in temperature. Also, the total intensity IT initially increases, attains an optimum value and then it decreases with further increase in temperature. The decay time decreases with increasing temperature of the solvent, from where the value of activation energy Ea can be calculated. A plausible explanation for the experimental results is given.

Keywords: Activation energy, Luminol (3 amino-phthalahydrazide), Lyoluminescence

IPC Code: F21K2/00, G06N7/00

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 524-531

 

Temperature dependent optical property studies of nematic mixtures

 

T N Soorya, Surabhi Gupta, Anant Kumar, Sachin Jain & V P Arora

Department of Physics, Vardhaman College, Bijnor, Uttar Pradesh

and

B Bahadur

Display Centre Technology, 400 Collins Road NE, Cedar Rapids, IA 52498-0001, USA

Received 7 December 2005; accepted 24 April 2006

The refractive indices ne and no, of two nematic mixtures: ZLI 2141-000 and ZLI 2452 have been measured in the temperature range 291-391 K using 589 nm light source. A slight modification to the four-parameter model given in Li J et al., J Appl Phys, 96 (2004) 19, is made to carry out the analysis of the data. The temperature dependence of refractive indices and the birefringence agree closely with that obtained using four-parameter model. Different parameters have been compared. The value of parameter β is larger for ZLI 2452 than for ZLI 2141-000, which may be due to the presence of BCH in place of CB component in the latter. A linear relation is observed between birefringence (Δn) and the order parameter (S). The normalized polarizabilities: αe/ < α >, αo /< α > and the order parameter S agree fairly well with those obtained using modified model.

Keywords: Birefringence, Order parameter, Polarizability, Liquid crystals, Nematic mixtures

IPC Code: G02F1/13

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 532-536

Thermally stimulated processes: I-Mechanisms involved in the appearance of a thermoluminescence glow curve

 

Jai Prakash, P K Singh & D K Dwivedi

Department of Physics, D D U Gorakhpur University, Gorakhpur 273 009

Email: dwivedidk@rediffmail.com

Received 10 November 2005; accepted 28 April 2006

Mechanisms involved in the appearance of a thermoluminescence (TL) glow curve are re-investigated with an aim to establish a suitable model. A generalized equation has been developed which is found to be able to explain the intensity of TL glow curves of different systems. Suggested equation successfully represents the TL intensities of systems involving different order of kinetics including first order. The proposed model helps in the evaluation of the values of trap depth or activation energy, the frequency factor governing the release of electrons from their traps, the initial concentration of the trap centres, order of kinetics involved and extent of rates of retrapping and recombination.

Keywords: Thermoluminescence, Glow curves, Electron traps, Thermally stimulated process, Order of kinetics

IPC Code: F21K2/04

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 537-542

 

Synthesis and characterization of certain nanomagnetic particles coated with citrate and dextran molecules

R V Mehta*, Rucha Desai, Prashant Bhatt+ & R V Upadhyay

Department of Physics, Bhavnagar University, Bhavnagar 364 002

+Department of Chemistry, Bhavnagar University, Bhavnagar 364 002

Received 9 November 2005; revised 10 April 2006; accepted 4 May 2006

Nanomagnetic particles of magnetite and Mn-Zn ferrites are synthesized and coated with dextran and citrate molecules. Particles are characterized by XRD, FTIR , TGA and magnetometry. FTIR as well as TGA shows that binding of citrate molecules on magnetite is stronger then in case of dextran on magnetite. In the case of Mn-Zn ferrite particles citrate ions are bound by physi- as well as- chemi-absorption. The calculated value of binding from TGA analysis agrees with that obtained from magnetometry analysis.

Keywords: Nanomagnetic particles, Magnetic iron dextran, FTIR

IPC Code: B82B

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp 543-547

 

Effective heating in heavily doped semiconductor devices

S S De, A K Ghosh, T K Ghosh & D Jana

Centre for Advanced Study in Radiophysics and Electronics, University of Calcutta, Kolkata 700 009

Received 11 May 2005; revised 16 December 2005; accepted 2 May 2006

A model has been developed to investigate the heat generation processes in semiconductor devices under heavily doped condition. The equilibrium between heat generation and heat dissipation by various mechanisms has been studied. The variations of heat dissipation with the change of carrier concentrations and the heat along the distance from the junction to the bulk have been estimated by numerical analyses. These are shown graphically with the results of an earlier work.

Keywords: Thermal properties, Semiconductor devices, Energy conversion

IPC Code: H01L21/00

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 548-553

 

Microwave dielectric relaxation study of poly (methyl methacrylate) and polysulphone in dilute solutions

A Tanwar, K K Gupta, P J Singh & Y K Vijay

Department of Physics, M S J College, Bharatpur 321 001

Department of Physics, University of Rajasthan, Jaipur 302 004

E-mail: tanwar17msj@yahoo.com

Received 23 January 2006; revised 3 April 2006; accepted 17 April 2006

Dielectric relaxation studies of poly (methyl methacrylate) in dilute solutions of benzene and 1,4-dioxane and polysulphone in dilute solutions of 1,4-dioxane have been carried out at 8.92 GHz and temperatures 30, 40, 50, 60ºC, respectively. Average relaxation time t0, and relaxation times corresponding to group rotation t (1) , segmental motion t (2) and dipole moment m  have been determined. The results have been interpreted by the internal and hindered rotation of ester group and sulphone unit for PMMA and polysulphone, respectively. The study reveals the existence of both, the intramolecular and overall orientations in PMMA and polysulphone. Thermodynamic parameters, viz. free energy, enthalpy and entropy of activation have been calculated using the dielectric data. Thermodynamic parameters indicate existence of cooperative orientation in the molecule resulting from the dipole-dipole interaction.

Keywords: Dielectric relaxation, Poly (methyl methacrylate), Polysulphone, Dipole-dipole interaction

IPC Code: G01R27/26

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, July 2006, pp. 554-558

 

 

Structural analysis and second-order non-linear optical activity of urea hydrogen peroxide adduct

Malyaj Das, R Prasad* & P Sen

 Department of Applied Physics, S G S Institute of Technology & Science, Indore 452 003

*School of Chemical Sciences, D A University, Takshila Campus, Indore 452 017

E-mail: pratima_sen@hotmail.com

Received 8 August 2005; revised 27 December 2005; accepted 3 April 2006

Urea hydrogen peroxide adduct is synthesized and characterized using UV and IR spectra. Second harmonic generation (SHG) efficiency has been determined experimentally in this adduct using pulsed Nd: YAG laser at 1064 nm wavelength. The efficiency is higher in the adduct as compared to urea. Geometry of the molecule was optimized using Austin Model 1 (AM1) semi-empirical technique. Our computations suggest two conformers of the adduct, both having no center of symmetry. Complete geometry of the molecule and the dipole moment calculations have been reported. It is concluded that increased dipole moment of one of the conformers of the adduct is responsible for the enhanced SHG efficiency of the adduct.

Keywords: Urea hydrogen peroxide adduct, Hydrogen bonding, Dipole moment, Second harmonic generation

IPC Code:B05D5/06