AJP	ISSN : 0971 – 3093 Vol 24, No. 1, January, 2015

 

Editorial

     The year 2014  has ended and the dawn of 2015 has given knock at all doors. I take this opportunity to send you and your family members my best wishes for happiness, pleasure, peace, joys and success for your works in the new year.
    It is a matter of great pleasure that the year 2015 has been declared as The International year of Light. In this regard it is apt to quote Dr. Ahmed Zewail, Linus Pauling Chair, Professor of Chemistry and Professor of Physics; Director, Physical Biology Center for Ultrafast Science & Technology, California Institute of Technology, USA
    “Civilization would not exist without light—light from our sun and light from the focused and coherent lasers that have now become an important part of our daily lives; from scanning packages at supermarkets, to eye surgery, and to IT communications across oceans. The International Year of Light will surely raise awareness of these powerful discoveries and their present wide-ranging, light-based technologies, which are significant contributors to the world market. As importantly, the International Year of Light will inspire future discoveries and applications for one of the most important elements of our existence: light.”
    Asian Journal of Physics (AJP) has completed 23 volumes of its existence from the time since the first issue was launched with the opening paper by famous Raman Spectroscopist Prof Wolfgang Kiefer, University of Wurzburg, Germany. It has been possible because of enthusiastic response from the scientists of different parts of the globe. AJP is serving with its humble efforts along with its purpose of publishing and spreading new results of physics and applied topics. A very large number of reputed workers of international fame have supported this journal of scientific research by their regular contributions. This is apparent from many special issues on specific topics being published from time to time.
    We began with publishing four issues per volume in 1992, however, since  Vol 23 (2014)  we have been publishing  6 issues per volume. Vol 23, Nos 1 & 2  was  guest edited by Prof Virginia Trimble (USA) on History of Physics & Astronomy. The third issue  edited jointly by Prof Joseph Shamir (Israel) and Prof    V K Rastogi (India) was dedicated  to Prof  Kehar Singh, one of the founding members of Editorial board and a regular contributor of AJP. The fourth issue of  the year 2014 was released in honour and recognition of  a distinguished  scientist Dr A. K. Gupta, IRDE Dehradun. India. The fifth issue of this volume was edited by Prof Ekaterina Michonova-Alexova on New Horizons for Physics: Bridging the Gap between Physics and Biomedical Sciences. The last issue of this volume  was in honour and    recognition of a very old friend of mine Prof S Mohan  and guest edited by his student Arjunan.

    In order to expedite the publications and to extend coverage of several important areas, we have included a few more names in the editorial board of AJP. On behalf of the Editorial Board, I wish them all a warm welcome.

V K Rastogi
Editor
March 3, 2015, Wednesday

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A Letter written by Sir C V Raman to G D Baruah

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Few words about G D Baruah

   

The International year of Light

Vol. 24, No 1 (2015) 01-16

Double phase-image encryption using gyrator-, and fractional Fourier transforms withstructured phase mask in the frequency plane followed by a gyrator transform

 

Hukum Singh*, A K Yadav, SunandaVashisth and Kehar Singh

Department of Applied Science

ITM University, Sector 23-A, Gurgaon-122 017, (Haryana) INDIA

Fully-phase image encryption is considered more secure as compared to an amplitude image encryption. In the present paper, an encryption scheme has been proposed for double phase-images. One of the phase-images is fractional Fourier transformed (FrFT) whereas the other one is gyrator transformed, after bonding them with random phase masks. The two resulting images are then added and subtracted to give intermediate images which are bonded with a structured phase mask (SPM) in the frequency plane. Thereafter, the images are once again transformed using a gyrator transform (GT) to give the corresponding encrypted images. The use of an SPM enhances the key space for encryption and also overcomes the problem of axis alignment associated with an optical set-up.  The decryption process is the reverse of encryption. The validity of the proposed scheme has been established from the computer simulation results using MATLAB 7.1 platform. The performance of the scheme has been evaluated in terms of mean-squared-error (MSE) between the input-, and the decrypted image. In addition, the sensitivity to encryption keys such as SPM parameters, transform angles of GT and the FrFT orders has been investigated. The technique is likely to provide enhanced security in view of the increased number of encryption parameters. Robustnessof the system for partial occlusion of the encrypted image has also been investigated. © Anita Publications. All rights reserved.

Keywords: phase-image, fractional Fourier transform, gyrator transform,structured phase mask, mean-squared-error

Total Refs : 39

Vol. 24, No 1 (2015) 17-32

On the methods of measurement of radius of curvature and focal length

Rajpal S Sirohi
 Department of Physics,Tezpur University, Napaam
Tezpur-784 028, India

Dedicated to Prof G D Baruah
Radius of curvature of spherical surfaces and the focal length of optical imaging systems are very important parameters to be measured. Large number of techniques and methods have been developed over the years. They offer varying accuracy and ranges. However, the complexities of measurement increase depending on the desired accuracy and range. The paper presents a variety of techniques and methods that include contact type and non-contact type methods.© Anita Publications. All rights reserved.

Total Refs : 22

 

Vol. 24, No 1 (2015) 33-59

Vibrational Spectroscopy:
A tool for characterization of nucleic acid constituents: Cytosine and Uracil

 

M A Palafox¹, S K Rathor², Rachna Rastogi², Daisy Bhat³, V Bena Jothy⁴ and V K Rastogi^2,3

¹Nofima AS – the Norwegian Institute of Food, Fisheries and Aquaculture Research,Osloveien 1, 1430 Ås, Norway

²Indian Spectroscopy Society, KC-68/1, Old Kavinagar, Ghaziabad-201 002, India

³R D Foundation Group of Institutions, NH-58, Kadrabad (Modinagar), Ghaziabad-201 204, India

⁴Department of Physics and Research Centre, Women’s Christian College, Nagercoil-629 001, India

Vibrational spectroscopy is one of the most powerful methods for the characterisation of nucleic acid constituents and their spectroscopic studies may help to throw light on their role in biological systems. The main advantage of vibrational spectroscopy in the characterisation of molecules is its applicability in all physical forms, i.e. solids, liquids and gaseous states. The motivation for predicting theoretically the vibrational spectra is to make vibrational spectroscopy a more practical tool. In the present work, the vibrational spectroscopy with the help of DFT calculations was used  for the characterization of the nucleic acid constituents: cytosine (Cy) and uracil (U). Here, the  molecular structure of Cy and U are analyzed from the data available in the bibliography as determined theoretically by quantum chemical methods and experimentally by x-ray diffraction, whereas their IR and Raman spectra were analyzed with the support of ab initio (HF, MP2) and DFT (B3LYP, PBE, B-P, CCSD, etc) calculations using several basis sets. In addition, the 30 ring normal modes of uracil and cytosine molecules were characterized and numbered for their use as notations in the spectra of their derivatives. © Anita Publications. All rights reserved.

Keywords: Cytosine, Uracil, Vibrational wavenumbers, DFT, IR and Raman spectra

 Vol. 24, No 1(2015) 61-70

Time-resolved fluorescence measurements of seeds of the bitter gourd (Momordica charantia L.)

 

Priyangshu Rana Borthakur¹ and Anurup Gohain Barua²

¹Faculty of Science & Technology, The ICFAI University, Tripura-799 210, India

²Department of Physics, Gauhati University, Guwahati-781 014, India

375 nm and 405 nm excitations of the seeds of the bitter gourd produce fluorescence emission bands at 410, 450 nm, and 500, 630, 670 nm, respectively, in both raw and ripe stages. Here we measure the decay times at these two stages of growth of the fruit at these emission wavelengths. At the 375 nm excitation, two decay times are displayed in the two stages at both the emitted wavelengths. At the 405 nm excitation, two decay times are revealed in the two stages at the emitted wavelengths 500 and 630 nm; at 670 nm, however, only one decay time appears at the raw and two decay times appear at the ripe stages. This result points towards existence of the involved fluorophores in free and bound forms.
© Anita Publications. All rights reserved.

Total Refs : 18

 Vol. 24, No 1(2015) 71-76

Ion momentum mapping spectrometer (IMMS): a novel facility developed
at BHU to study the fragmentation dynamics of molecules

 

R Shanker

(UGC-Emeritus Professor and DST-Ramanna Fellow)

Atomic Physics Laboratory, Physics Department, Faculty of Science,

Banaras Hindu University, Varanasi-221 005, India

A unique facility in the Atomic Physics Laboratory, Physics department, BHU has been developed in the recent years to study the fragmentation dynamics of molecules of atmospheric interest under impact of energetic electrons. This apparatus is recognized as the only functional facility available in the university system of the country; however, there exist a few similar facilities in the national laboratories, for instance, in Physical Research Laboratory (PRL), Ahmedabad, Inter University Accelerator Centre (IUAC), New Delhi and in Tata Institute of Fundamental Research (TIFR), Mumbai. This article highlights some of the many research contributions to the fundamentals of science on fragmentation dynamics of molecules from our laboratory. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 77-83

 

Dielectric relaxation study of o-chlorotoluene and p-chlorotoluene in benzene mixtures using time domain reflectometry technique

 

K P Rajappan Nair¹, A C Kumbharkhane², Pravin G Hudge² and S C Mehrotra³

²School of Physical Sciences, S R T M University, Nanded-431 606, MS, India

 ³Department of Computer Science, Dr B A M. University, Aurangabad, Maharashtra, India

The complex dielectric spectra of binary mixture of o-chlorotoluene and p-chlorotoluene with benzene were obtained in the frequency range 10 MHz to 30 GHz over entire concentration range at 25°C using a Time Domain Reflectometry (TDR) technique. The static dielectric constant (ε₀) and relaxation time τ(ps) have been obtained. The excess dielectric properties and the Bruggeman factor are also determined. © Anita Publications. All rights reserved.

Keywords: Time domain reflectometry; Complex dielectric spectra; Dielectric properties

Total Refs : 22

Vol. 24, No 1(2015) 85-93

Energy- and angular distributions of bremsstrahlung photons produced from energetic electrons incident on free atoms and molecules

 

R Shanker, Namita Yadav, Pragya Bhatt, Raj Singh, and B K Singh

Atomic Physics Laboratory, Department of Physics, Banaras Hindu University, Varanasi-221005, India

An apparatus has been developed to measure the energy- and the angular distributions of bremsstrahlung (BS) photons generated from collisions of energetic electrons with isolated atoms and molecules. With this setup, a considerable reduction of prevalent thick target bremsstrahlung (TTB) background caused due to the scattered electrons from the wall of collision chamber has been achieved. A brief description of the experimental set up is presented and discussed. The reliability and performance of the apparatus are demonstrated by obtaining test results on angular- and energy distributions of BS photons produced from collisions of 4.0 keV electrons with free argon atoms. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 95-99

Electric dipole oscillator strengths for the

3p⁶ 3d ²D^e → 3p⁵ 3d^2 2P^o, ²D^o, ²F^o transitions in V⁴⁺ ion

 

S N Tiwary

UGC-Academic Staff College

University Department of Physics,BRA Bihar University, Muzaffarpur,

Electric dipole oscillator strengths (OOS), of both length (f_L) and velocity (f_V) forms, have been calculated for the 1s² 2s² 2p⁶ 3s² 3p⁶ 3d ²D^e → 1s² 2s² 2p⁶ 3s² 3p⁵ 3d^2 2P^o, ²D^o, ²F^o transitions in V⁴⁺ ion of the potassium isoelectronic sequence by employing  multiconfiguration Hartree-Fock (MCHF) method exactly in the same way as we did in our earlier work (Tiwary et al, Pramana-J. Phys. 46(1996) 381). Comparison has been made with available relevant experimental data and our earlier theoretical results obtained by employing the configuration interaction (CI) method (Tiwary et al, J. Phys. B: At. Mol. Phys, 16(1983)2457). Our present investigation clearly demonstrates that the MCHF method is more accurate than the CI method. © Anita Publications. All rights reserved.

Keywords: Multiconfiguration Hartree-Fock; Configuration interaction; Excitation energies; Oscillator strengths.

 Vol. 24, No 1 (2015) 101-111

Thermodynamic and ¹H NMR spectroscopy study of binary mixtures of polymer solutions with 2-(Methylamino) ethanol (MAE) and 1-butanol

 

Sudir Kumar, Sangeeta Sagar and Manisha Gupta

Department of Physics, University of Lucknow, Lucknow-226 007, India.

Molecular interaction studies on binary liquid mixtures have been one of the most important field of research. The thermodynamic behaviour of poly (propylene glycol) monobutyl ether 1000(PPGMBE) with 2-(methylamino) ethanol (MAE) and 1-butanol have been investigated over the whole composition range at temperatures 293.15, 303.15 and 313.15K to probe the interaction in binary mixtures. For the purpose, viscometric excess parameters like deviation in viscosity (∆η) and excess Gibb’s free energy of activation of viscous flow (∆G^*E) have been calculated from the experimental values. The molecular interactions in binary mixtures have been also investigated through the ¹H spectroscopy. The NMR spectral parameters for various protons of PPGMBE, MAE and butanol show the interaction of varying strengths between PPGMBE with MAE and butanol binary mixtures. © Anita Publications. All rights reserved.

Keywords: chemical shift, ¹H NMR, molecular interaction, viscometry.

 Vol. 24, No 1 (2015) 113-124

Structural and Spectroscopic studies of Eu³⁺/ZnO: Bi₂O₃-SiO₂ matrices

 

Sajna M S, Viji Vidyadharan, Ann Mary K A, P R Biju and N V Unnikrishnan

School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam- 686 560, India.

The present work reports luminescence characterization of europium ions doped bismuth-silica matrices prepared by the sol-gel process. Structural and optical characterization of these samples were carried out using EDX, X-ray diffraction (XRD), FTIR, TGA, UV–Vis and photoluminescence spectroscopy. We have studied the effect of doping of ZnO in the emission characteristics of the prepared glass samples. Incorporation of ZnO with rare earth cations, which acts as multicolor luminescent centers in bismuth-silica matrix resulted in the enhancement of emission centered at 593 nm. The effect of annealing of the samples on fluorescence is also been studied. The samples containing Eu³⁺ and Eu³⁺ + ZnO emit remarkably intense orange- red emission at 593 nm with near line spectrum along with the broad emission of base host material around 446nm. The photoluminescence of Eu³⁺ in Bi₂O₃-SiO₂: Eu³⁺ + ZnO matrix has the strongest emission intensity at 3wt% of Eu³⁺concentration. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 125-133

Dielectric relaxation studies of aqueous KCl with N,N dimethyl formamide
through a time domain reflectometry (TDR)

A E Jadhav^a, G V Mashalkar^b and A C Kumbharkhane^b

^aDepartment of Physics, DSM’s College, Parbhani-431401, India

^bSchool of Physical Sciences, S R T Marathwada University, Nanded-431 606, India

The dielectric relaxation is studied for electrolytic interaction of aqueous KCl with N,N Dimethylformamide (DMF) using Time Domain Reflectometry technique (TDR) in the frequency range of 10 MHz -30GHz. The dielectric parameters for the system of biological importance are obtained for different concentrations of aqueous KCl electrolytic solution and DMF; at four different temperatures. The obtained parameters, static permittivity and relaxation time are compared with earlier reported values. The data suggests irrotational bonding of water molecules and DMF molecules with K⁺ and Cl^– ions. The kinetic depolarization results into decreased values of static permittivity for all ionic concentrations and increased values of relaxation time at specific range of ionic concentration. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 135-150

Developments in spectroscopy since the advent of tunable lasers

 

S N Thakur

Ex-Professor of Physics

Banaras Hindu University, Varanasi-221 005, India

The advent of tunable lasers revolutionized the field of experimental spectroscopy. It became possible to get rid of the Doppler broadening of spectral lines and finer details of the spectral features could be reveled by adopting techniques of saturation absorption and polarization labeling. The so called ‘dark states’ of atoms and molecules which did not emit fluorescence could be explored by the technique of photoacoustic spectroscopy. Atomic and molecular species in hostile environments like flames and discharges could be probed by the technique of optogalvanic spectroscopy. In the present article the basic principles and a few examples of some diverse applications of spectroscopy with tunable lasers are given that would help a beginner in the area of laser spectroscopy to exploit these techniques in his experimental investigations.© Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 151-154

Excitation of Auger transition in sodium atomic system*

 

S N Tiwary

UGC-Academic Staff College

University Department of Physics, BRA Bihar University, Muzaffarpur, India

Electron impact integral cross sections for the excitation of the Auger transition generated due to the inner-shell excitation 1s² 2s² 2p⁶ 3s ²S^e → 1s² 2s² 2p⁵ 3s² 2P^o complex transition in sodium (Na) atomic system have been calculated employing single configuration Hartree-Fock (HF) wave functions for both initial and final states involved in the transition matrix element within the asymptotic Green function approximation (AGFA) proposed by Tiwary (1981) exactly in the same way as we did in our earlier work in the case of the lightest alkali-metal atom lithium (Li) (Tiwary;1985, Tiwary, Macek and Madison; 1985) and the heaviest alkali-metal atom cesium (Cs) (Tiwary, 1983) in the bombarding energy range from threshold to 1500 eV. For the first time, Tiwary (1983) predicted the resonance behaviour in the near vicinity of excitation threshold in Cs using AGFA. Feuerstein et al (1998) performed experiment and observed resonance behaviour in the neighbourhood of excitation threshold in Na. Comparison has been made with available relevant experimental observations and other theoretical predictions. Our present AGFA theoretical result is qualitatively in accord with experimental result. © Anita Publications. All rights reserved.

 Vol. 21, No 1 (2014) 155-163

The influence of the force of gravitation  behind a disturbance produced by solar flare

 

S N Ojha

Department of Mathematics, Department of Physics

S.C. College, Ballia, India

A mathematical model of inhomogeneous expanding gas driven by solar flare in the equatorial plane of the Sun is considered and the effects due to Roache model of gravitation and the gravitation due to self-expanding gas are discussed separately. In course of discussion the method of similarity solutions is used. It has been observed that in both the cases of gravitation, the ambient distribution of matter is more significant than the details of discontinuity itself. In particular, the time of transit of the disturbance to the earth surface is calculated.© Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 165-172

Spontaneous emission, vacuum fluctuation and some phenomena in classical world showing analogous pattern

 

R Bora Bordolo1i¹, R Bordoloi² and G D Baruah³

¹Department of Physics, Dibrugarh University, Dibrugarh ,Assam-786 004, India

²Women’s College, Tinsukia, Assam-786 125, India

³Centre for Laser and Optical Science, New Uchamati, Doomdooma, Assam – 786 151, India

The present work is connected with the universal phenomenon, zero point fluctuation, which has been worked out on the basis of quantization of electromagnetic field. Though it is a well established notion that there is no classical analogue of zero point fluctuation, we have shown that in the macroscopic world, particularly in the biological domain there are innumerable cases of spontaneous growth from some initial fluctuations stages of unknown origin. In the present work, we have explored two such cases of spontaneous growth in non physics context. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2014) 173-179

Quantum zeno effect, three level maser and some non physics contexts

 

R Gogoi¹, J Saikia², R K Dubey³ and G D Baruah⁴

¹Department of Physics, Doomdooma College, Doomdooma -786 153, India

²Department of Physics, J B College, Jorhat – 785 001, India

³SAS, Haldia Institute of Technology, Haldia (West Bengal) – 721 857, India

⁴2Centre for Laser & Optical Science, New Uchamati, Doomdooma -786 151, India

Quantum Zeno Effect (QZE) is an important phenomenon in quantum optics and it is associated with quantum theory of laser and measurements. The term quantum Zeno effect was first introduced by Misra and Sudarshan in 1977. It describes the situation in which an unstable particle, if observed continuously will never decay. Thus the effect is concerned with the inhibition of transition by frequent measurements. The phenomenon may be applied to various transitions and has also been experimentally observed. In the present work, we specifically consider a three level laser where QZE may be realized. We also discuss some non-physics situations to illustrate QZE. © Anita Publications. All rights reserved.

 Vol. 24, No 1 (2015) 181-187

Self consistency of universal laws appearing in different contexts

 

R B Bordoloi¹, R Bordoloi², R Konwer³, M Konwer⁴, R K Dubey⁵, J Saikia⁶, D Baruah⁷, H Konwar⁷ and G D Baruah⁷

¹Department of Physics, Namrup College, P.O .Parbatpur, Namrup -786 623, Assam, India

²Women’s College, Tinsukia, P. O .Tinsukia -786 125, Assam, India

³Tinsukia College, P. O. Tinsukia -786 125, Assam, India

⁴Digboi Mahila Mahavidyalaya, Digboi – 786 171, Assam, India

⁵SAS Haldia Institute of Technology, Haldia -721 657, West Bengal, India

 ⁶J. B. College, Jorhat -785001, Assam, India

Self consistency is one of the central tenets of the natural laws appearing in different contexts ranging from quantum optics to biological science. It also appears in non physics situations like economics and business managements. This paper reviews various schemes of natural laws appearing in various domains. We consider few topics for our discussion and conclude that it is a universal phenomenon. It is reasonable to believe that our work will be useful in working out an acceptable model for physical laws in different contexts. © Anita Publications. All rights reserved.

Keywords: Self Consistency

Vol. 24, No 1 (2015) 189-194

Qualitative estimate of the non classical (Squeezed) light in the photobacterial biophoton emission

 

J Saikia¹ and G D Baruah²

¹Department of Physics, J B College, Jorhat-785 001, India

The ultraweak emission from a species of photobacteria has been investigated using photographic techniques. Qualitative estimate of the non classical light has been made and the possibility of biophoton emission from squeezed light has been suggested.© Anita Publications. All rights reserved.

Keyword: Photobacteria, Squeezed light

 Vol. 24, No 1 (2015) 195-202

Analysis of optical absorption and EPR spectra of Mn²⁺: PEO+PVP blended polymer films

 

K Naveen Kumar* and S Buddhudu

Department of Physics, Sri Venkateswara University, Tirupati-517502, India

Magneto-polymer composites of a reference PEO+PVP and also Mn²⁺: PEO+PVP blended polymer films have been synthesized by a solution casting method. Their structures properties have been investigated based on XRD features, and SEM images. Raman spectral measurements have confirmed the complexes formation of the polymer films because of the presence of Mn²⁺ ions in those blended polymer films. Absorption spectrum of Mn²⁺: PEO+PVP polymer film has enabled to evaluate its energy-level characteristic (B, C) and crystal field (Dq) parameters. The ESR spectra of PEO+PVP & Mn²⁺: PEO+PVP films have exhibited resonance signals and hence number of spins has been computed. The Zero-field splitting parameter (D) at the room temperature has been evaluated based on the intensities of the allowed hyperfine-lines. Mn²⁺: PEO+PVP blended polymer film has shown a super-paramagnetic nature and it has been validated based on the VSM profile. These magneto-polymer composites could significantly possess several applications. © Anita Publications. All rights reserved.

Keywords: Mn²⁺ doped blended polymer films; EPR; VSM analysis

Total : 31