An International Research Journal

Asian Journal of Physics                                                                                                                Vol. 18, No.1(2009) 1-6

 

Special Section dedicated to Prof S P Ojha


Photonic gaps in one-dimensional PBG materials containing dispersive single or double negative metamaterials

 

Munazza Zulfiqar Ali

Department of Physics
Quaid-i-Azam Campus, Punjab University, Lahore, 54590, Pakistan

 ___________________________________________________________________________________________________________________________________

The conventional photonic band gap (PBG) materials are characterized by the Bragg gaps. With the experimental realization of double negative (also known as left handed) and single negative metamaterials, mechanisms other than Bragg reflections can produce photonic gaps in PBG materials. In this article, the origin of these new gaps i.e. the zero-n gap, the zero-feff gap and the angular gaps is briefly discussed. Some of their properties are also described. © Anita Publications. All rights reserved.

Total Refs : 30

____________________________________________________________________________________________________________________________________


Asian Journal of Physics                                                                                                              Vol. 18, No.1(2009) 7-16

 

Plasmonic superlenses: theory, practice and recent developments

 

Ciaran P Moore and Richard J Blaikie

MacDiarmid Institute for Advanced Materials and Nanotechnology

Department of Electrical and Computer Engineering, University of Canterbury

Christchurch, New Zealand

 ___________________________________________________________________________________________________________________________________

The phenomenon of plasmonic resonance has been identified in recent times as a means of breaking the diffraction limit that hinders high performance lithography systems in use today. Experimental results based on interleaved silver and dielectric layers have shown that resolution as low as l/6 can be achieved and that ‘superlenses’ are indeed realisable. However, examples of ‘perfect’ lenses, predicted to have true, diffraction-free performance, have yet to be fabricated. This paper uses numerical models of silver-dielectric superlenses to explore performance around and beyond the diffraction limit, examining different superlens designs and the reasons behind their specific performance enhancements and limitations. © Anita Publications. All rights reserved.

Total Refs : 23

____________________________________________________________________________________________________________________________________


 

Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 17-56

Negative refraction metamaterials, geometrical transformations, cloaking, and related areas – A qualitative bibliographic review for the year 2008

 

K N Chopra, Joby Joseph  and  Kehar Singh

Photonics Group, Department of Physics

Indian Institute of Technology Delhi, New Delhi-110 016, India

____________________________________________________________________________________________________________________________________

The negative refractive materials (NRMs) exhibit a number of interesting properties e.g. refraction of light entering the material, on the same side of the normal; reversal of Doppler shift, and the time-averaged Poynting vector being antiparallel to phase velocity,  implying that the wavefronts move in the direction opposite to the flow of energy. Because of the interesting properties associated with these materials, many researchers are engaged in the investigations on various related topics like superlenses, superresolution, reduced beam-squinting on printed leaky-wave antennas, wave propagation, equivalent circuit models, polaritons, solitons, plasmonic waveguides, Goos-Hanchen shift, and cloaking etc. A qualitative review of the studies made in the field of negative refraction in the year 2008 has been given in this paper. Although an attempt has been made to include as many papers as possible, no claim is made as to the completeness. Inadvertent omission in citing of the work by other researchers is very much regretted.© Anita Publications. All rights reserved.

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 57-62


Binary–aware high performance static random access memory cell

 

CMR Prabhu and Ajay Kumar Singh

Faculty of Engineering and Technology

Multimedia University, Melaka, Malaysia

 ___________________________________________________________________________________________________________________________________

Low power SRAM cell is a critical component in modern VLSI systems. The write power is usually larger than the read power due to large power dissipation in driving the cell long bit-lines to full swing. A new binary-aware SRAM cell is proposed in this paper for simultaneously minimizing the write power consumption and reducing the write access delay. The proposed BA cell contains two extra tail transistors in the respective inverter to avoid charging/discharging of the bit-lines. The simulated result shows at least 57.22% write power saving and lower write delay with additional 34.3% silicon area.© Anita Publications. All rights reserved.
Total Refs : 15

____________________________________________________________________________________________________________________________________


Regular Papers


Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 63-66


Spectroscopic characterisation of Schiff base complexes of cobalt(II), nickel(II) and

copper(II) with 1-oxo-1,2,3,4-tetrahydrocarbazole hydrazone

 

BK Rai, Anukul Prasad1, Vinayak2, Arvind Kumar3 and Shaktidhar Jha Sunit4

Department of Chemistry

LNT College (BRA Bihar University), Muzaffarpur-842 002, India

1Department of Chemistry, MM Das Mahila College, Sirsia, Muzaffarpur, India

2Kendriya Vidyalaya, Muzaffarpur-842 002, India

3Department  of Chemistry, SN Sahay College, Muzaffarpur-842 002, India

4Brajesh Bhawan, Speaker Chowk, Muzaffarpur-842 002, India

 ___________________________________________________________________________________________________________________________________

A number of new transition metal complexes of the general formula [M(OTCH)2X2] have been synthesized, where M = Co(II), Ni(II) and Cu(II), OTCH = 1-oxo-1, 2, 3, 4-tetrahydrocarbazole hydrazone and X = Cl–,  Br– and I– . The newly synthesised complexes have been characterized by elemental analyses, electronic and IR spectra, magnetic susceptibility and molar conductance measurements. OTCH acts as neutral bidentate ligand and coordination takes place through amino N and azomethine N. © Anita Publications. All rights reserved.
Total Refs : 21

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 67-72


Spectroscopic studies on some complexes of cobalt(II), nickel(II) and
copper(II) with a Schiff base

 

BK Rai, Vineeta Singh, Vinayak1, Shiv Pujan Singh21 and Shaktidhar Jha Sunit3

Department of Chemistry

LNT College (BRA Bihar University), Muzaffarpur-842 002, India

1Kendriya Vidyalaya, Muzaffarpur-842 002, India

2Department  of Physics, RSS College, Chochahan, Muzaffarpur, India

3Brajesh Bhawan, Speaker Chowk, Muzaffarpur-842 002, India

____________________________________________________________________________________________________________________________________

Stable complexes of the type [M(MQSC)2X2], where M = cobalt(II), nickel(II) and copper(II), MQSC = Methaqualone semicarbazone and X = Cl,  Br, I, NO3 and ClO4  have been prepared. The ligand and complexes have been characterized by elemental analyses, IR spectra, electronic spectral, magnetic moment and molar conductance data. MQSC acts as a neutral bidentate ligand and coordination is proposed through azomethine N and carbonyl O atoms of semicarbazone moiety. The complexes are proposed to be monomeric octahedral in geometry on the basis of electronic spectral and magnetic moment values. © Anita Publications. All rights reserved.
Total Refs : 21

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 73-78


On the conversion of phase-mixed Alfv´en wave energy into thermal energy

 

Lalan Prasad, Manish Kumar Pandey and Sandeep Kumar

 Department of Physics

M.B. Govt. (P.G.) College Haldwani, Nainital-263 141, India

 ___________________________________________________________________________________________________________________________________

Alfv´en wave propagation is considered along the magnetic field lines in inhomogeneous and resistive plasma. In the presence of dissipative factor perturbation of the physical quantity is responsible for phase-mixing of the linear plane Alfv´en wave. Sink of Alfv´en wave energy leads to the strong transverse gradients in the wave amplitude. Decay of the phase-mixed Alfv´en wave energy is cause of generation of acoustic wave, which propagates along magnetic field direction. Fast and slow magnetosonic waves emerged from the non-linear solution of considered MHD model. The fast magnetosonic waves, originated from the coronal base, can propagate upwards into the corona and dissipates its mechanical energy as heat. It is conversion of phase-mixed Alfv´en wave energy into thermal energy via magnetosonic waves. The fast magnetosonic waves prove to be a likely candidate to heat the solar corona. We studied phase mixing of a three dimensional MHD wave in the compressive, three dimensional regime. Coupling of its compressive part does not alter the behavior of the Alfv´enic part of a compressible MHD wave. The dependence upon resistivity of the Alfv´enic part of the MHD wave and decay of its amplitude is shown using 3d numerical code simulation. © Anita Publications. All rights reserved.
Total Refs : 27

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 79-88


Power law and hydrodynamical approach of nanoflare heating

 

Lalan Prasad and VK Joshi

Department of Physics

MB Govt. PG College, Haldwani

Nainital-263141, India

 ___________________________________________________________________________________________________________________________________

The concept of coronal heating by nanoflare is shown to be the characteristic of active regions which results presumably from a large number of more or less random heating agents. The flare associated with small impulsive events of magnetic energy dissipation from 5 ´ 1023 to 1026 ergs are called nanoflares and are treated as heating agents. The analysis of these agents is represented by a power law distribution as a function of their energies with a negative slope of 1.5 and  more. We discussed the physical characteristics and features of nanoflare heating process in respect of power law distribution and formulated  the coronal luminosity. We estimated the radiation energy and generation rate of nanoflares and discussed the hydrodynamical simulation results of nanoflare with the variation of power law index α . © Anita Publications. All rights reserved.
Total Refs : 36

____________________________________________________________________________________________________________________________________


Asian Journal of Physics                                                                                                            Vol. 18, No.1(2009) 89-94


Investigation of electronic transport in the novel charge
transfer complex p-cresol(TCNQ)2

 

Neelu Chouhana* , M L Kalrab and Suresh C Ametac

a*Department of Chemistry, Government P G College, Bundi-323 001, India

bDepartment of Physics, Mohan Lal Sukhadia University, Udiapur-313 001, India

cDepartment of Chemistry, Mohan Lal Sukhadia University, Udiapur-313 001, India

 ___________________________________________________________________________________________________________________________________

The charge transfer complex p-cresol(TCNQ)2, prepared by solution growth method, belongs to the monoclinic crystal system with space group P21/m and cell parameters a = 6.892 Å, b = 17.379 Å, c = 17.888 Å, b = 93.737 o, Z = 8, d = 2. 41 g cm–3, V = 2138 Å3. It was characterized by elemental analysis, UV-Vis, NMR, XRD and SEM. DC conductivity measurements showed that this quasi one dimensional complex was semiconducting till 433 K with s RT =1.4103 × 10–11 Ω1 cm1 and Ea = 0.0921 eV, while it exhibited constant resistivity (38.40 × 103 Ω cm) in the temperature range 433-543 K. © Anita Publications. All rights reserved.
Total Refs : 18

____________________________________________________________________________________________________________________________________

 

 Asian Journal of Physics                                                                                                          Vol. 18, No.1(2009) 95-100


Hybrid fusion and energy parks as keys to sustainable development

 

Wallace Manheimer

Retired from the US Naval Research Laboratory

 Washington DC, USA 

____________________________________________________________________________________________________________________________________

Because of the long development time for fusion power, it is rarely mentioned when renewable and sustainable energy is discussed. However another option for fusion is the fusion hybrid, namely using fusion neutrons to breed nuclear fuel. This paper briefly explores this option and cites other references where more information can be found. The author asserts that with a focused development effort, fusion hybrid based power can supply large scale energy to the world by mid century. © Anita Publications. All rights reserved.
Total Refs : 16

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 101-106


Fiber optic temperature sensor based on surface plasmon excitation

 

V Kumar a , S Kumbhaj b , P Sen b and P K Sen b

aDepartment of Electronics and Instrumentation, Indian School of Mines, Dhanbad-826 004, India
bDepartment of Applied Physics S G S Institute of Technology and Science, Indore-452 003, India.

____________________________________________________________________________________________________________________________________

Metal clad fiber optic temperature sensor, which is one of the intensity modulated intrinsic sensors, has been designed and developed in the laboratory. This type of sensor is based on surface plasmon excitation. Basic principle of surface plasmon excitation has been described briefly. Design technique and experimental results have also been discussed. The present sensor has been tested in temperature range 33 – 80°C and found to be working well. Optical fiber, being dielectric, non-metallic and non-sparking, is an intrinsically safe media and hence such temperature sensors are best suited to the hazardous industries and process control applications. © Anita Publications. All rights reserved.
Total Refs : 19

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 107-112


Study of finite element method for antenna simulation


Manish Kumar, Upendra Prasad and Lalan Jha

University Department of Physics

LN Mithila University, Darbhanga – 846 004, India

____________________________________________________________________________________________________________________________________

In this review paper Finite Element Method (FEM) for antenna simulations has been analysed and studied. Analysis of the two most commonly used approaches in practice for the development of finite element approximation of differential equation based on boundary value problem of interest has been made. FEM is based on high frequency structure simulation which has been defined and discussed briefly. This discussion presents methodologies and algorithms. © Anita Publications. All rights reserved.
Total Refs : 7

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 113-120


Suppression of Rayleigh-Taylor instability in plasma by the
transverse magnetic field


S Basavaraja, T Sankarappa, RD Mathad and BS Krishnamurthy

Department of Physics, Gulbarga University, Gulbarga-585 106, India

and

N Rudraiah

Former Vice-Chancellor, Gulbarga University, Gulbarga-585 106, India

____________________________________________________________________________________________________________________________________

The effect of transverse magnetic field on the Rayleigh-Taylor instability in a thin layer of viscous and electrically conducting plasma has been examined using the linear theory in the creeping flow limit. The growth rate of the instability was found to be controlled by the thickness of the plasma layer, ratio of surface tension to the stress gradient and the Chandrashekhar number which  was a function of an applied transverse field. It also revealed that the transverse field prevent the growth of finger instabilities which exist for thick films. The growth rate of the instability is found to be exponentially decaying with the transverse magnetic field. © Anita Publications. All rights reserved.
Total Refs : 12

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 121-126


Thermodynamical quantities of germanium and silicon diatomic molecules

(GeO, GeS, GeSe, GeTe, SiC, SiN, SiO and SiS) from spectroscopic data


Shipra Tiwari, Shuchi Srivastava, Pavitra Tandon, Renu Singh and KN Uttam

Saha’s Spectroscopy Laboratory, Department of Physics

University of Allahabad, Allahabad-211 002, India

____________________________________________________________________________________________________________________________________

Thermodynamical quantities of germanium and silicon  diatomic molecules (GeO, GeS, GeSe, GeTe, SiC, SiN, SiO & SiS) in the temperature range 100-2200 K have been calculated from spectroscopic data using partition function theory. The results have been discussed in terms of molecular motion.© Anita Publications. All rights reserved.
Total Refs : 18

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 127-130


Laser induced fluorescence of Namsai Meteorite

 

N Dehingia, M Konwar* and GD Baruah

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

*Department of Physics, Moran College, Moran-785 670, India

____________________________________________________________________________________________________________________________________

Laser induced fluorescence spectrum of Namsai meteorite has been excited with the help of a 25 mW Green (532 nm) solid state laser and photographed on a glass spectrograph in the range of wavelength 5400-6500 Å. The spectrum is diffused. The band system is attributed to silicate (olivine), a major component of the meteorite. A comparison of the emission system with that of Dergaon meteorite has been made. © Anita Publications. All rights reserved.
Total Refs : 11

____________________________________________________________________________________________________________________________________

 

Asian Journal of Physics                                                                                                         Vol. 18, No.1(2009) 131-142


Pulse width performance of a CW pumped passively Q-switched laser taking account of the

Q-switch recovery time

 

M Lu, CR Chatwin, P M Birch, RCD Young, and W Wang

Department of Engineering and Design, School of Science and Technology,

 University of Sussex, Brighton BN1 9QT, UK

____________________________________________________________________________________________________________________________________

A model is presented to show the effect of the absorber’s recovery time on selecting an output coupler and absorber pair to generate a shorter pulse width. The pump power pumping the laser system is kept constant as is the output energy.  Results are presented which compare the model predictions with and without considering the Q-switch recovery time. Simulation results are presented by considering a CW pumped Cr: YAG passively Q-switched Nd:YAG laser. © Anita Publications. All rights reserved.
Total Refs : 27

____________________________________________________________________________________________________________________________________

Back            Top