012819   Durrani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Investigation of time in relativity. Bull pure appl Sci-Sect D 2011, 30(1), 5-6.

Added an imaginary term by hand to the proper time, AT, of special theory of relativity and wanted to see what would happen to it if I tried to get the time dilation relationship between ΔT' and ΔT'. It was found that this added imaginary term of time does not have to be zero.

012818   Durani I R (NO, Faculty of Basic Sciences, Gujrat Univ, Pakistan) : Relativistic mass increase and classical physics. Bull pure appl Sci-Sect D 2011, 30(1), 21-4.

In the past century it was believed that both the main theories (quantum mechanics and special relativity) predicted the existence of physical processes that could not be explained in the framework of classical physics. However, it has been shown recently that the solutions of Schrbdinger's equations have described the physical situation practically in full agreement with classical equations. The given equation represents the combination of classical equations with the statistical distribution of corresponding parameters, and the properties of microscopic objects may be interpreted on the ontological basis as it corresponds to our sensual knowledge. It will be shown now that also the main experimentally relevant relativistic phenomenon (i.e. the mass increase with velocity) may be interpreted in the framework of classical physics. A different prediction for this increase will be then derived, which gives the possibility to decide on an experimental basis which alternative is preferable (relativistic or classical).

012817   Datta T;Bajaj M M;Deepak Kumar;Jain M C (Physics Dep, Ramjas College, Delhi Univ, Delhi, Email: tuhindutta38@gmail.com) : Power series solutions of higher order differential equations for the hypertensive congenial BIS processes and shock waves in the neuronal nanosystem. Invertis J renewable Energy 2013, 3(4), 192-7.

BIS signifies the breakdown of integrated system. In order to discuss the perturbation in the neuronal system of it is necessary to superimpose a small BIS disturbance on these solutions and analyze the evolution of the small disturbance. This is equivalent to those solutions of nonlinear evolution equations which are expanded as a power series in terms of a small parameter ε. In this paper, on the basis of the Jacobi elliptic function expansion method, the multi-order exact solutions of some nonlinear evolution equations for the congenial and hypersensitive BIS processes are obtained. In this paper, based on Jacobi elliptic function expansion method, the Lame equation, and the Lame functions, the stationary periodic solutions to some non linear evolution equations for the neuronal nano systems and shock waves have been derived. At the same time the perturbation method is applied to obtain their asymptotic power series solutions. We have tried our best here to find out all the possible solutions of the equations evolved due to perturbation in the neuronal networks giving forth the chaos in the mind.

10 ref

012816   Das M;Sarkar D (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: sarkardeepali@gmail.com) : Structural and optical properties of n-type porous silicon fabricated in dark. Indian J pure appl Phys 2013, 51(10), 724-7.

The n-type porous silicon has been fabricated under dark condition. SEM picture shows appreciable porosity with even distribution of pores with pore size ranging from 280 to 570 nm. XRD and FTIR confirm porous silicon (PSi) formation. Photoluminescence gives characteristic yellow orange emission of PSi with peak at 607.5 nm. Raman spectra show red shift of peak at some spots and Raman enhancement of intensity at some other spots along with the characteristic crystalline Si peak.

6 illus, 19 ref

012815   Chopra K N (Applied Physics Dep, Maharaja Agrasen Institute of Technology, GGSIP Univ, Rohini, New Delhi-110 086) : Short note on the wave power and tidal power as the renewable sources of energy. Invertis J renewable Energy 2013, 3(4), 236-42.

Wave Power and Tidal Power are the important topics in the latest research efforts on the renewable sources of energy. The advantages and the utility of these renewable sources of energy have been technically analysed in detail. The computations of the wave power, tidal power, and the voltage - current characteristics, along with the output -frequency characteristics for the waves have been discussed by giving the equations, which are useful for the designers in modeling the systems. The turbine and generator arrangement and the schematic for the generation of the tidal power have been described. Tlie paper is expected to be useful for the researchers and the technologists in this fast evolving field of immense global importance.

5 illus, 14 ref

012814   Chopra K N (Applied Physics Dep, Maharaja Agrasen Institute of Technology, GGSIP Univ, Rohini, New Delhi-110 086) : Ocean energy thermal conversion (OTEC) and its mathematical modeling-a short technical note. Invertis J renewable Energy 2013, 3(4), 222-9.

Ocean energy thermal conversion (OTEC) has recently been the subject of much interest and research activity, as though it offers a good source of renewable energy, yet a lot of work is still to be done to improve the efficiency of the systems based on this technique, so as to make it really viable for the practical purposes. The present communication brings out the mathematical evaluation of the Ocean energy thermal conversion (OTEC), and its characterization in the form of a short technical review. As OTEC is one of the technologies in the use of the sources of renewable energy, a brief account of the recent efforts in the direction of using the general sources of renewable energy has been included. Some of the recent important projects undertaken by the industrial companies showing their increasing focus and product range towards OTEC have also been outlined.

3 illus, 1 table, 18 ref

012813   Chandra S;Chang C;Kegel W H;Patzer A B C; Bolick U;Sedlmayr E (Physics Dep, Lovely Professional Univ, Phagwara-144 411, Email: suresh492000@yahoo.co.in) : Study of possible new ring molecules in cosmic objects. Indian J Phys 2012, 86(7), 555-61.

Theoretically investigated a number of cyclic molecules of four kinds: XC₂H₂, XC₂H₄, XC₂, and HXC₂, where X can be C, N, O, Na, Mg, Al, Si, P, S, and Ca, respectively, which might be present in interstellar and/or circumstellar space, and calculated their structural and physical data within the rigid rotor harmonic oscillator approximation with the help of a density functional theoretic approach employing the gradient corrected exchange correlation hybrid functional B^{3at the experimentally observable quantities D₀, harmonic vibrational frequencies, infrared absorption coefficients, molecular rotational constants, and electric dipole moments. Finally, the radiative transition probabilities (Einstein A-coefficients) for pure rotational transitions are obtained.}

7 tables, 26 ref

012812   Chand K;Singh K D;Sharma S (Mathematics & Statistics Dep, H P Univ, Shimla-171 005, Email: khemthakur99@gmail.com) : Effect of hall current and rotation on heat transfer in MHD flow of oscillating dusty fluid in a porous channel. Indian J pure appl Phys 2013, 51(10), 669-82.

The effect of Hall current and rotation on heat transfer in MHD flow of a dusty, viscous, incompressible and electrically conducting fluid under the influence of an oscillating pressure gradient has been studied. The parallel plates of the channel are assumed to be porous and subjected to a uniform suction from above and injection from the below. A uniform magnetic field is applied in the direction normal to the planes of the plates. The plates of the channel are kept at different temperature and the temperature of one of the plate is varied periodically. The entire system rotates about an axis normal to the planes of the plates with uniform angular velocity. The governing equations are solved to yield the velocity and temperature distributions for both the fluid and dust particles phase. The effects of various parameters on the velocity and temperature profiles for both fluid and particles are shown graphically and discussed.

19 illus, 17 ref

012811   Biswas N;Dey A;Mukhopadhyay A K (Mechanical Property Evaluation Science Dep, CSIR-Central Glass and Ceramic Research Institute, Kolkata-700 032, Email: anoopmukherjee@cgcri.res.in) : Loading rate effect on nanohardness of human enamel. Indian J Phys 2012, 86(7), 569-74.

In the present work, nanoindentation technique has been utilised to study the physics of deformation at the scale of micro/nano-structure of tooth enamel which is basically the hardest natural biomaterial in the human body comprising of a hybrid combination of hydroxypatite ceramic nano-crystal and organic-protein matrix and observed about 8% increase in the nanohardness of human enamel with the increase in loading rate from <126>1 x 10³ μN s^-1 to 3 x 10⁵ μN s^-1. The results have been explained in terms of the maximum shear stress generated underneath the nanoindenter.

5 illus, 61 ref

012810   Barui S;De S S;Haldar D K;Paul S;Guha G;Hazra P;Ghosh A (NO, Centre for Advanced Study in Radio Physics and Electronics, Calcutta U, Kolkata-700 009, Email: de_syam_sundar@yahoo.co.in) : Characteristic feature studies of integrated field intensity of sferics at Northeast India. Indian J Radio Space Phys 2013, 42(6), 397-403.

Some studies on the variations of integrated field intensity of sferics (IFIS) at 9 kHz are carried out at Mirik (lat 26.9°N, long 88.2°E), a hilly place of North-East India, under different seasonal conditions during January - December 2011. The recorded data are analyzed and interpreted. During locally clear days and nights, IFIS provides a regular behaviour, i.e. field strength remains constant but decreases gradually after the onset of rain. During short period showers, IFIS exhibits a sudden rise and gradual fall. An irregular variation in IFIS is observed with the coverage of roof height cloud mass.

7 illus, 33 ref

012809   Barooah D;Barman S;Phukan S (Physics Dep, Cotton College, Guwahati-781 001, Email: deb_bh@rediffmail.com) : Study of environmental radon exhalation, radium and effective dose in Delli-Jeypore coalfiled, India uisng LR-115 (II) nuclear track detectors. Indian J pure appl Phys 2013, 51(10), 690-5.

The radium contents, radon exhalation rates and corresponding annual effective doses due to inhalation of radon from coal and soil of Dilli-Jeypore coalfield of Assam, India have been measured using LR-115 (II) nuclear track detectors in the context of health risks. In the present paper, the results of the study with their corresponding geometric means (GM), geometric standard deviations (GSD) and error estimates for both coal and soil samples are presented. The estimated values for coal samples are in the range 1274.2-1658.8 Bq/m³, 16.0-20.8 mBq/kg/h, 532.5-693.2 mBq/m²/h, 16.4-21.4 Bq/kg and 38.7-50.3 μSv/y for radon activity, mass exhalation rate, surface exhalation rate, radium content and annual effective dose, respectively. In the case of soil, the values for radon activity, mass exhalation rate, surface exhalation rate, radium content and annual effective dose were estimated to be in the range 1308.8-2105.6 Bq/m³, 16.4-26.4 mBq/kg/h, 547.0-880.0 mBq/m²/h, 16.9-27.1 Bq/kg and 39.7-63.9 μSv/y, respectively. The lifetime fatality risk estimates have also been assessed.

3 illus, 2 tables, 37 ref

012808   Ambare R C;Mane R S;Bharadwaj S R;Lokhande B J (NO, School of Physical Sciences, Solapur Univ, Solapur-413 255) : Impact of % H₂O₂ incorporation on crystallinity, morphology and electrochemical measurements of sprayed Co₃O₄ films. Invertis J renewable Energy 2013, 3(4), 198-205.

Sprayed thin films of Co₃O₄, synthesized at 423 K by adding different % of H₂ O₂, are explored for structural, morphological and electrochemical measurements. Structural elucidation confirms the change of phase from amorphous to crystalline with an addition of H₂O₂. Surface evolution study shows the formation of micro porous surface with spikes-type architecture. Electrochemical studies reveal the pseudocapacitive origin with optimum 775 F/g specific capacitance value at the scan rate 2 mV/s in 1M KOH electrolyte. Specific energy, specific power and columbic efficiency are calculated chronopotentiometrically. Impact of H₂O₂% on electrochemical impedance spectroscopy measurements is investigated in the frequency range 1 mHz to 1 MHz. Change in equivalent circuit parameters, associated with the cell and caused by H₂O₂, %, is discussed and tabulated.

7 illus, 22 ref

012807   Ambare R C;Bharadwaj S R;Lokhande B J (NO, School of Physical Sciences, Solapur Univ, Solapur-413 255) : Concentration and volume of the spraying solution affects on the capacitive behaviour of the Co₃O₄ thin films. Invertis J renewable Energy 2013, 3(4), 212-21.

This work reports the preparation of Co₃O₄ thin film electrodes on stainless steel plates through aqueous route by spray pyrolytic decomposition. Samples were prepared by varying the concentration and volume of the spraying solution.XRD and SEM studies of the prepared Co3O4 thin films reveals nanocrystalline face centered cubic crystal structure with micro porous adherent morphology. Prepared Co₃O₄ thin film electrodes shows ideal rectangular behaviour exhibit maximum value of the specific capacitance 107 F/g at the scan rate 2 mV/sec in 1M KOH electrolyte. From chronopotentiometry the calculated values of specific energy and specific power were 2.104 Wh/kg and 1.77 kW/kg at the current density 16 mA/cm2. Impedance variation was studied in the frequency range 1 mHz to 1 MHz to determine internal resistance and different circuitry parameters.

10 illus, 2 tables, 13 ref

012806   Abraham K E;Mathew V;Joseph J;Jacob S (Physics Dep, S.B. College, Changanacherry, Kottayam-686 101, Email: abrahamke@gmail.com) : Crystallization and spectral studies of lead malonate. Indian J Phys 2012, 86(7), 589-94.

Paper reports the preparation and spectroscopic studies of lead malonate crystals. The sample is grown by single diffusion gel technique employing sodium metasilicate. X-ray diffraction pattern of the sample reveals the crystalline nature. From diffuse reflectance spectroscopy studies, the band gap of the material is determined. The FTIR and FT Raman spectra of the grown crystals are recorded and the vibrational assignments have been made with possible explanations. The photoluminescence property of the title compound is also investigated.

6 illus, 2 tables, 33 ref

011727   Rajasekaran G (NO, Institute of Mathematical Sciences, Chennai-600 113, Email: graj@imsc.res.in) : Standard model, higgs boson and what next?. Resonance 2012, 17(10), 956-71.

One hundred years of Fundamental Physics, starting with discoveries such as radioactivity and electron, have culminated in a theory which is called the Standard Model of High Energy Phy-sics. This theory is now known to be the basis of almost all of known physics except gravity. Gives an elementary account of this theory in the context of the recently announced discovery of the Higgs Boson. Conclude with brief remarks on possible future directions that this inward bound journey may take.

5 illus, 3 ref

011726   Mampallil D;George S D (NO, MESA+ Institute of Nanotechnology, Twente Univ, The Netherlands, Email: dileep.augustine@gmail.com) : Microfluidics-a lab in your palm. Resonance 2012, 17(7), 682-90.

Few decades ago electronics evolved from huge circuits based on vacuum tubes into small scale semiconducting integrated circuits. In simple words, a calculator that was as huge as a room, now fits into a wrist watch. Nowadays, a similar trend is observed in bio and chemical engineering. Analysis and synthesis involving fluids, which originally could be done only on large scales, are more and more integrated into small devices called microfluidic chips. Such microsacle or even nanoscale devices, in general called lab-on-a-chip devices, offer a higher accuracy and better efficiency compared to bulk devices. Describes some important aspects about microfluidics.

4 illus, 7 ref

010610   Thirupathaiah P;Singh V;Sunil Krishna M V (Physics Dep, Indian Institute of Technology Roorkee, Roorkee-247 667, Email: thiruiitr@gmail.com) : Analytical approach to estimate atomic oxygen density from greenline dayglow emission in thermosphere at 250 km. Indian J Radio Space Phys 2013, 42(4), 219-28.

It is now well established that photoelectron impact on atomic oxygen is the dominant source for the production of atomic oxygen O(¹S) state in thermosphere at 250 km. A comprehensive model featuring volume emission rate and solar flux has been developed to study greenline dayglow emission. The model is tested with the Wind Imaging Interferometer (WINDII) observations. The volume emission rates have been computed between 20°S and 20°N at several solar zenith angles under variable solar activity conditions. The ratio of the volume emission rate to atomic oxygen density has been calculated at 250 km. It has been found that the ratio does not vary linearly with F10.7 solar index. The modeled ratio has been further used to obtain an analytical expression as a function of F10.7 solar index. If the volume emission rate for the 557.7 nm emission at 250 km is given, this analytical expression can be used to estimate the atomic oxygen density in the thermosphere at 250 km for all values of F10.7 solar index in the range 70 - 250.

7 illus, 28 ref

010609   Singh A K;Sardar N;Rizvi S;Rathore S;Vijay S K (Physics Dep, Govt P G College, Sehore-466 001, Madhya Pradesh, Email: singh.anup73@gmail.com) : Nighttime enhancement of ionospheric parameters. Indian J Radio Space Phys 2013, 42(4), 240-50.

In the present work, ionospheric electron content (IEC) as well as critical frequency of F2 layer (foF2) data from three locations (low, mid and high latitudes) have been used to study the anomalous nighttime F-region during low to moderate solar activity, period, i.e. from January 2006 to December 2010. The results show that at high and mid-latitude locations, there is maximum percentage of enhancement in IEC and foF2 during winter season, whereas at low latitude location, maximum percentage of enhancement in both the parameters is during equinox. The highest total number of enhancements in IEC parameter occurred at high latitude station Chilton, whereas in foF2 parameter, highest total number of enhancements occurred at low latitude station Kwajelin. Out of 1116 enhancements in IEC, 661 enhancements occurred during pre-midnight hours and 455 during post-midnight hours. Although out of 948 enhancements for foF2, 457 enhancements occurred during pre-midnight hours and 491 during post-midnight hours.

13 illus, 36 ref

010608   Simi K G;Vineeth C;Pant T K;Alex S (Physics Dep, Kerala Univ, Trivandrum-695 004, Email: kg.simi@gmail.com) : Analysis of vertical drifts in the post sunset equatorial F-region during geomagnetically quiet and disturbed periods. Indian J Radio Space Phys 2013, 42(4), 229-39.

This paper reports the HF Doppler Radar measured post sunset F-region vertical drift (V_d) over Trivandrum (8.5°N, 77°E, 0.5°N dip latitude) during quiet and disturbed periods. In general, V_d showed significant day-to-day variability, both in the overall trend and the nature of short period oscillations present. Analysis based on the simultaneous measurements of equatorial electrojet (EEJ) induced surface magnetic field (AH) and interplanetary magnetic field (IMF) revealed that the V_d, on geomagnetically quiet days, exhibit oscillations of periodicity 15-20 minutes; whereas on disturbed days, it exhibit a dominant oscillation of <126> 45 minutes periodicity, similar to the one present in the IMF. Overall, the vertical drifts during quiet days seemed to be controlled by gravity waves of lower atmospheric origin. On the other hand, during disturbed time, the vertical drift is controlled by the interplanetary medium through the coupled electric field. It has also been observed that whenever post sunset V_d showed enhanced oscillation of 15-20 minutes periodicity, the equatorial spread-F occurred.

10 illus, 34 ref

010607   Sharma N K (NO, Faculty of Technology, Chandra Shekhar Azad Agriculture & Technology U, Kanpur Campus, Etawah-206 001, Email: nks_2005@india.com) : Cosmic ray and geomagnetic response to radio-loud coronal mass ejections (CMEs). Indian J Radio Space Phys 2013, 42(4), 213-8.

Catalog of type II bursts observed by the Radio and Plasma waves (WAVES) experiments onboard the wind space craft and the associated coronal mass ejections (CMEs) observed by the Solar and Heliospheric Observatory (SOHO) mission are used to study the influence of medium and high speed coronal mass ejections on cosmic ray neutron intensity during 1997-2008, which corresponds to the solar activity cycle 23. The CMEs in the catalog are called radio-loud CMEs because of their ability to produce type II bursts. It is noteworthy that the occurrence of high speed coronal mass ejections is significantly high during 1997-2008. The results indicate that the magnitude of the depression in cosmic ray intensity is large for high speed coronal mass ejections in comparison with the low and medium speed CMEs. It is observed that in all three cases, the depression in cosmic ray intensity is maximum on +4 day after the arrival of the CMEs. Also, the geomagnetic perturbations are more pronounced on + 4 day after the arrival of CMEs for low and medium speed coronal mass ejections.

2 illus, 1 table, 24 ref

010606   Nanda J N (NO, Zaheer Science Foundation, 8052/C-8, Vasant Kunj, New Delhi-110 001, Email: drjnanda@gmail.com) : Atomic explosions in the earth. Proc Indian Natn Sci Acad 2012, 78(4), 735.

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009598   Ubeid M F;Shabat M M;Sid-Ahmed M O (Physics Dep, Faculty of Science, Islamic Gaza Univ, P.O. 108, Gaza, Gaza Strip, Palestinian Authority, Email: mubeid@mail.iugaza.edu) : Numerical study of a structure containing left-handed material waveguide. Indian J Phys 2012, 86(2), 125-8.

A waveguide structure consisting of a pair of left-handed material (LHM) and dielectric slabs inserted in vacuum is investigated theoretically. Maxwell's equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell's law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected and transmitted powers of the structure. Numerical results are illustrated to show the effects of frequency, angle of incidence and LHM thickness on the transmitted power when the refractive index of the dielectric layer changes. The same procedure is repeated to show the variation of the transmitted power with the change in the mentioned parameters under different values of dissipation factor of the lossy LHM. Consequently, two cases of the LHM are considered, loss-less case and loss case. The results obtained, are in agreement with the law of conservation of energy.

4 illus, 19 ref

009597   Singh S J;Karmakar M;Bhattacharya M;Singh S D;Singh W S;Azharuddin S (Ballistics Div, Manipur State Police Forensic Laboratory, Pangei, Yangdong-795 114, Email: mahua_apc@yahoo.com ) : On the reappraisal of the peak shape method for general order thermoluminescence. Indian J Phys 2012, 86(2), 113-6.

Critical appraisal of the work of Kitis and Pagonis on peak shape method has been made. It has been pointed out that they have not taken note of the different existing works on peak shape method and their prescription does not lead to an overall improvement of the method. Finally peak shape method has been applied to experimental thermolumines-cence peaks of albite.

1 illus, 3 tables, 15 ref

009596   Sasini N;Paikaray R;Sahoo G;Patra D C;Ghosh J;Sanyasi A (Physics Dep, G.C. College, Jajpur-755 032, Email: n_sasini@rediffmail.com) : Pulsed plasma across a spatial lengt inside curved chamber using cylindrical double probe. Indian J Phys 2012, 86(2), 151-5.

Authors report the measurement of ion density, electron density and electron temperature of the plasma blob produced by plasma gun (PG) inside a curved vacuum chamber using cylindrical double probe. The double probe is placed at different distances from the plasma gun and the profiles of ion density, electron density and electron temperature are obtained. The plasma parameters change continuously as the plasma blob propagates away from the source. As the blob moves away from the source, the dynamics of oppositely charged species are different although the resultant effect contributes towards a coherent structure. The profile of electron temperature is fluctuating in nature which may be due to some sort of perturbation phenomena occurring during the motion of the plasma blob.

6 illus, 25 ref

009595   Roy S;Chakravarti A;Sil S (Physics Dep, Visva-Bharati, Santiniketan, West Bengal-731 235, Email: subhasish.roy@visva-bharati.ac.in) : Simple phase-sensitive amplifier with automatic offset nulling. Indian J Phys 2012, 86(2), 117-24.

Described a simple and inexpensive analog phase-sensitive detector using commercial off-the-shelf components. Instead of multiplication by a square wave as found in many standard lock-in-amplifiers, we have used multiplication by a sine wave to minimize higher harmonic contributions. One of the main features of the system is the incorporation of auto-balancing circuitry to minimize distortions due to transistor mismatch in the multiplier. A pair of sample-and-hold circuits arranged in a master-slave configuration has been used to hold the final integrated value, ensuring that the integration limits are located almost exactly at the zero crossings of the reference input.

12 illus, 2 tables, 12 ref

009594   Ray S;Chakrabarti S K;Sasmal S (NO, Indian Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata-700 084, Email: chakraba@bose.res.in) : Precursory effects in the nighttime VLF signal amplitude for the 18th january, 2011 Pakistan earthquake. Indian J Phys 2012, 86(2), 85-8.

Analysis of the nighttime VLF signals transmitted from the Indian Navy station VTX (latitude 8.43°N, longitude 77.73°E) at 19.2 kHz and received at Kolkata (latitude 22.57°N, longitude 88.24°E). On 18th January, 2011 an earthquake of magnitude 7.4 occurred at Southwestern Pakistan (latitude 28.9°N, longitude 64°E). We have analyzed the nighttime VLF signals for 2 weeks around 18th of January, 2011 to see if there have been any precursory effects of this earthquake. We have found that the amplitude of the nighttime VLF signals anomalously fluctuated 4 days before the earthquake. This agrees well with our previous findings based on the analysis of 1 year of earthquake data.

3 illus, 20 ref

009593   Malik A;Chand F;Kumar H;Mishra S C (Physics Dep, Kurukshetra Univ, Kurukshetra-136 119, Haryana, Email: fchand@kuk.ac.in) : Exact solutions of nonlinear diffusion-reaction equations. Indian J Phys 2012, 86(2), 129-36.

In the present work, the (G'/G)-expansion method and its generalized version have been employed for obtaining a variety of exact traveling wave solutions of the nonlinear diffusion reaction equation with quadratic and cubic nonlin-earities. We have examined the density independent nonlinear diffusion reaction equation with a convective flux term and successfully have obtained some new and more general solutions in terms of Jacobi elliptic functions. The work highlights the significant features of the employed methods and shows the variety in the obtained solutions:.

41 ref

009592   Lincy A;Mahalakshmi V;Thomas J;Saban K V (Smart Materials Analytic Research and Technology (SMART), Physics Dep, St. Berchmans College, Changanassery-686 101, Email: smartlabindia@gmail.com) : Growth, spectral and thermal properties of manganous malonate dihydrate crystals. Indian J Phys 2012, 86(2), 109-12.

Manganous malonate dihydrate crystals have been grown by ionic diffusion in hydrosilica gel. Powder XRD pattern and the FTIR spectrum have been recorded for the sample. The vibrational bands corresponding to various functional groups are identified. Thermogravimetric studies have been done to explore the nature of the material as regards thermal decomposition.

4 illus, 4 tables, 35 ref

009591   Kumari S;Nirala A K (Biomedical Optics Laboratory, Applied Physics Dep, Indian School of Mines, Dhanbad-826 004, Email: sule_baij@yahoo.co.in) : Light propagation in human and animal tissues by Monte Carlo simulation. Indian J Phys 2012, 86(2), 97-100.

Monte Carlo Simulation for light propagation in different types of human and animal tissues has been performed using programming methods. During the simulation we have recorded the photon reflectance, transmittance and absorption in lung and dermis tissues of human, pig and rabbit and compared. Average values of total diffuse reflectance, transmittance and absorption have been calculated by the 10 simulations of 100,000 photons for these tissues at 633 nm. We have found that transmittance, reflectance and absorption are strongly dependent on tissue type and diffuse reflectance increases as the scattering coefficient (μ_s), increases or anisotropy (g), decreases, while diffuse transmittance increases as absorption coefficient (μ_a) or (μ_s) decreases, or as (g) increases.

6 illus, 2 tables, 11 ref

009590   Kelkar D S;Chourasia A B (Physics Dep, Institute of Science, Civil Lines, Nagpur-440 001, Email: abchourasiansk@rediffmail.com) : Effect of dopant on thermal properties of polythiophene. Indian J Phys 2012, 86(2), 101-7.

Polythiophene (PT) was chemically synthesized, undoped using aqueous ammonia and then re-doped using FeCl₃ as well as iodine. Doping concentration was changed by changing the duration of doping process. FTIR results indicate the complex formation between PT and each of the dopants. Elemental analysis of FeCl₃ doped samples show that as the duration increases concentration of Fe⁺ ions increases. In case of iodine doped samples atom equivalent of iodine per thiophene unit increases with doping duration. XRD analysis has been used to calculate crystallinity. It is observed that for FeCl₃ and iodine (except 120 min) doped samples there is increase in crystallinity due to doping and crystallinity increases with increase in dopant concentration. TGA analysis shows that FeCl₃ doped samples are thermally stable compared to iodine doped samples. Results of DTA as well as DSC indicate that Tg values vary with dopant as well as with dopant concentrations. Reduction in Tg values for all FeCl₃ doped samples indicate that FeCl₃ acts as plasticizer in PT. In iodine doped samples for low values of dopant concentrations Tg increases indicating anti-plasticizer effect whereas for high concentration of iodine, there is decrease in Tg value indicating plasticizer effect of iodine in PT.

4 illus, 4 tables, 19 ref

009589   Goel G;Sharma P;Singh R;Setia B (Civil Engineering Dep, Sharda Univ, Greater Noida) : Optimal use of surface drains for enhancing ground water recharge. J Indian Wat Resour Soc 2013, 33(3), 43-52.

Growing demand for the fresh water has resulted in increased exploitation of its limited sources the foremost of them being the groundwater. Artificial recharge through a network of surface drains can be one of the remedy to this problem. In this paper, Khepar's model has been used to investigate the effect of drain parameter on the amount of recharge. The parameters which were kept in focus during the investigation were check dam height, number of check dams, bed slope of drain and wetted perimeter of drain. One of the key findings was that the recharge rate is found directly proportional to check dam height, bed slope of drain and wetted perimeter of drain. This formulation can lead to optimization of recharge and consequent raise in water table in addition to effective usage of surface drains.

7 illus, 10 ref

009588   Devee M;Baishya R;Sarma J K (Physics Dep, Tezpur Univ, Napaam, Tezpur-784 028, Email: deveemayuri@gmail.ocm) : Solution of singlet Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation in next-to-next-to-leading order at small-x. Indian J Phys 2012, 86(2), 141-4.

Obtained the singlet structure function by solving the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equation in next-to-next-to-leading order at the small-x limit. Here we have used a Taylor series expansion to solve the evolution equations to get the t (=ln Q²/A²) and x-evolutions of structure functions, where x is the Bjorken variable, Q² is the four momentum transfer in a deep inelastic scattering (DIS) process and A is the QCD cut off parameter. We have also calculated the t and x-evolutions of deuteron structure functions. Results are compared with recent experimental data and parametrizations.

3 illus, 28 ref

009587   Baishya R;Sarma J K (Physics Dep, Jawaharlal Nehru College, Boko-781 123, Email: rjitboko@yahoo.co.in) : Solution of snglet and non-singlet unpolarized DGLAP evolution equations in next-to-next-to-leading order (NNLO) by method of characteristics. Indian J Phys 2012, 86(2), 145-50.

The singlet and non-singlet structure functions have been obtained by solving Dokshitzer, Gribov, Lipatov, Altarelli, Parisi evolution equations in next-to- next-to-leading order at the small x limit. Here we have used Taylor Series expansion and then the method of characteristics to solve the evolution equation. We have also calculated t and x-evolutions of deuteron structure function as well as non singlet structure function and the results have been compared with the New Muon Collaboration, E665 experimental data, CLAS Collaboration and NNPDF Collaboration data.

7 illus, 31 ref

008534   Zhang S;Jie Q;Wang Q (Mathematics and Physics Dep, North China Electric Power Univ, Baoding 071003, People's Republic of China, Email: shihuizhang@yahoo.cn) : Revival and decay of entanglement in a two-qubit system coupled to a kicked top. Indian J Phys 2012, 86(5), 387-93.

Investigates the entanglement dynamics of a two-qubit system coupling to a spin environment, described by a quantum kicked top (KT). The entanglement of the two-qubit system is sensitive to the classical orbit of the KT and displays rich dynamic behaviors. It quickly vanishes for chaotic orbit, but has significant revivals after the death when the KT is classically regular. As the tori of the KT shrink, the concurrence decay of the system is weakened and the concurrence revival of the system is strengthened. Such phenomena are analyzed in the literature of the interaction picture and the dynamics of wavepacket. It is found that the decay and revival of the concurrence of the system is closely related to the periodic motion of the wavepacket.

6 illus, 52 ref

008533   Upadhyay T C;Joshi M (NO, H N B Garhwal University, Physics Dep, Email: mayankphysics@gmail.com) : Dielectric properties of quasi-one dimensional PbHPO₄ crystal in presence of external electric field. J Metall Mater Sci 2012, 54(3), 209-18.

The third and fourth order phonon anharmonic interactions external electric field terms are added in the two-sublattice pseudospin model for PbHPO₄ crystal. By using double time thermal Green's function method modified model, theoretical expressions for soft mode frequency, dielectric constant, shift, width and tangent loss are evaluated for PbHPO₄ crystal. Temperature and field variations of soft mode frequency, dielectric constant and loss tangent are calculated numerically. Present theoretical results agree with experimental result of Smutney and Fousek for dielectric constant of PbHPO₄.

11 illus, 2 tables, 22 ref

008532   Talukdar M P (Physics Dep, Tezpur University, P O, Napaam, Tezpur-784 028, Email: madhurrya@gonitsora.com) : Melting point behavior of low dimensional systems. J Metall Mater Sci 2012, 54(3), 203-7.

An attempt has been made to give a detailed review of the melting point characteristics of materials and their variatio from bulk to nano regime. A proper understanding of this property is important both from science and engineering aspects. Main focus has been given on the superheating phenomena which means rise in melting temperature of a material and how this can be achieved. Both the theoretical developments done so far supported by enough experimental evidence have been presented in this work in a chronological manner. Important models such as Surface Area Difference model (SAD), Liquid Drop Model (LDM) have been discussed in detail and the role of cohesive energy and surface energy in determining the melting behavior of nano-systems has been emphasized.

1 illus, 9 ref

008531   Singh J;Mohanty G C;Acharya S (Physics Dep, Synergy Institute of Engineering & Technology, Dhenkanal-759 001, Email: snehaljayashree@gmail.com) : Evaluation on ultrasonic parameters in binary mixture of ethyl methyl ketone and alcohols vis-a-vis molecular interaction. Indian J pure appl Phys 2013, 51(8), 542-5.

In view of utility of ethyl methyl ketone (EMK) as a nuclear extractant used in atomic energy industry, several ultrasonic parameters namely ultrasonic velocity, isentropic compressibility, acoustic impedance and intermolecular free length have been determined in binary mixture of EMK and alcohols at temperature 303.16 K and frequency 2 MHz by using ultrasonic interferometer. The excess parameters β^E, Z^E are also computed for different mole fraction of EMK, the results indicate that there is formation of micro heterogeneous clusters of unlike molecules in both the systems.

4 illus, 1 table, 20 ref

008530   Singh B P;Rakesh Kumar;Ashwani Kumar;Gaur J; Singh S P;Tyagi R C (Physics Dep, C C S Univ, Meerut-250 004, Email: drbeerpal@gmail.com) : Effect of annealing on properties of transparent conducting tin oxide films deposited by thermal evaporation. Indian J pure appl Phys 2013, 51(8), 558-62.

The surface morphology, structural characteristics and optical properties of the transparent conducting SnO₂ films deposited by vapour deposition of SnCl₂.2H2O on heated glass substrate have been evaluated by X-ray diffraction, scanning electron microscopy, ED AX analysis and spectro-photometric examination. The 'as deposited' films of tin oxide were found to be polycrystalline, adhesive and pin hole free. After annealing at a higher temperature, these films exhibited an improved crystalline surface morphology and also displayed random perforations having a dendrite structure. It is found that heat treatment of the 'as deposited' tin oxide films results in conversion of the SnO component into SnO2 phase which resulted in a better transparency, larger crystallite size and reduced film thickness due to diffusion of tin into the matrix of the glass substrate thereby making the film more suitable for device applications. The increased porosity of 'annealed' films provides more surface area for use as sensors and also makes them less likely to fracture when used as high temperature electrodes.

6 illus, 25 ref

008529   Shugani M;Aynyas M;Sanyal S P;Rajagopalan M (Physics Dep, Sadhu Vaswani College, Bairagarh, Bhopal, Madhya Pradesh-462 030, Email: shugani.mani@gmail.com) : Electronic properties of MoSi₂. Indian J pure appl Phys 2013, 51(9), 634-7.

The electronic structure and ground state properties of MoSi₂ have been studied using first principles density functional theory (DFT). The full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA) and local spin density approximation (LSDA) for exchange correlation have been used for calculation of total energy. The ground state properties such as equilibrium lattice constants (a₀, c₀), bulk modulus (B), its pressure derivative (B') are computed. Apart from the density of states N(E_F), specific heat coefficient (γ) are also estimated and compared with the experimental data. The density of states at the Fermi level N(E_F) is 0.25 states/eV for MoSi₂. The band structure and density of states around the Fermi level suggest that this compound is semi-metal in nature. The calculated parameters are found to be in overall good agreement with the experimental data.

3 illus, 1 table, 18 ref

008528   Sahu B;Roychoudhury R (Mathematics Dep, West Bengal State Univ, Barasat, Kolkata-700 126, Email: biswajit_sahu@yahoo.co.in) : Effect of finite ion temperature on arbitrary amplitude dust ion acoustic solitary waves in quantum plasma. Indian J Phys 2012, 86(5), 401-5.

Effect of finite ion temperature on the formation of arbitrary amplitude dust ion acoustic solitary waves in unmagnetized quantum plasma is investigated using the Sagdeev's potential approach. It is found that the ion temperature significantly affects the region of existence and formation of dust ion acoustic solitary waves in quantum plasma. The investigation shows that the solitary structure ceases to exist when the different parameters, viz., temperature, dust density and the soliton velocity cross certain critical values. It is also found that the presence of ion temperature increases the range of wave Mach number from subsonic to supersonic regime both in presence or absence of dust particle density in unmagnetized quantum plasma.

7 illus, 29 ref

008527   Rujanapich P;Poyai A;Srithanachai I; Ueamanapong S;Titiroongruang W (Electrical Engineering Dep, Faculty of Engineering, King Mongkut's Institute of Technology Ladkrab, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand, Email: poopolr@yahoo.com) : X-ray soft annealing process study for p-n junction diode. Indian J pure appl Phys 2013, 51(8), 587-92.

The effect of X-ray soft annealing on the electrical properties of p-n junction diodes has been investigated. Under a forward bias of 1.0 V at 303 K, the forward current is approximately two orders of magnitude higher for X-ray annealed than for non-X-ray annealed samples. This effect is further investigated by evaluating the following properties under forward-bias conditions: ideality factor, saturation current, activation energy, series resistance, under reverse-bias conditions, carrier-generation lifetime, and activation energy. Results suggest that X-ray soft annealing improves the electrical properties of p-n junction diodes under forward-bias conditions.

13 illus, 20 ref

008526   Purnapatra S B;Arora P;Yadav S;Agarwal A;Sen Gupta A (Time & Frequency Div, National Physical Laboratory (CSIR-NPL), Dr K S Krishnan Road, New Delhi-110 012, Email: arorap@mail.nplindia.ernet.in) : Characterization of laser beams for cesium atomic fountain experiment. Indian J pure appl Phys 2013, 51(9), 615-20.

The design and characterization of the laser beams used in NPLI's Cesium Fountain experiment is described in the present paper. A 1-D photodiode array based instrument was indigenously developed for this dedicated purpose. Major advantages over the conventional 2-D array based instruments include stand alone operation, reduced cost and computational requirements. This instrument specifically finds applications for direct measurement and analysis of broad laser beams (FWHM<126>20 mm).

10 illus, 9 ref

008525   Prameela C;Anjaiah M;Krishna Murthy K; Srinivasarao K (Science and Humanities Dep, Vignan Univ, Vadlamudi-522 213, Email: kotarisrinu@yahoo.co.in) : Structural, optical and electrical properties of (V₂O₅)_1-x-(MoO₃)_x thin films. Indian J pure appl Phys 2013, 51(8), 563-8.

Thin films of V₂O₅, MoO₃ and (V₂O₅)_1-x-(MoO₃)_x were deposited on to glass and p-Si (1 0 0) substrates by flash evaporation technique at the substrate temperatures of 300 K and 500 K at a fixed oxygen partial pressure of 5x10^-4 mbar. These deposited films were characterized by XRD, IR, UV VIS spectra. The structure of (V₂O₅)_1-x-(MoO₃)_x films is found to be amorphous or X= 0.5. The IR spectra confirm the formation of (V₂O₅)_1-x-(MoO₃)_x mixed oxide films for O<60>x<60>l. The energy gaps of the mixed oxide films are in between 2.1 to 2.56 eV. The width of localized states is 0.92 eV (for x=0). The electrical conductivity of the V₂O₅ films is 2x10^-3 ohm^-1 cm^-1 and decreases with increasing the MoO₃ concentration in (V₂O₅)_1-x-(MoO₃)_xthin films.

6 illus, 1 table, 19 ref

008524   Paul I;Pakira G;Chattopadhyay S K;Paul S N; Ghosh B (Physics Dep, Jadavpur Univ, Kolkata-700 032, Email: bsdvghosh@gmail.com) : Analytical study on the existence of ion-acoustic solitary waves in a plasma consisting of warm streaming ions and nonthermal electrons. Indian J Phys 2012, 86(5), 395-400.

Theoretical investigations have been made for the formation of ion-acoustic solitary wave structure in a plasma consisting of warm streaming positive ions and nonthermal electrons. Analytical solutions have been obtained with some sufficient and necessary conditions for the existence of ion-acoustic solitary waves. Some critical values of the ion temperature and the nonthermal parameter of electrons have been obtained and presented graphically. It is shown that drift of the ions and the nonthermal electrons have significant effects on the formation of ion-acoustic solitary waves. In presence of the streaming motion of the ions, two distinct modes (fast and slow) of propagation have been obtained. Limiting values of the soliton speed for these modes have been calculated. It is found that the drift motion and ion temperature change significantly the conditions for the existence and properties of ion-acoustic solitons.

5 tables, 31 ref

008523   Nath S;Ghosh N K (Physics Dep, Kalyani Univ, Kalyani-741 235, Email: nanda.ku@rediffmail.com) : Finite temperature properties of the 2D Hubbard model extended by next-nearest-neighbor hopping interaction. Indian J Phys 2012, 86(5), 351-6.

Presents an exact diagonalization study on a two dimensional Hubbard model extended by next-nearest-neighbor (NNN) hopping for a small cluster. The thermodynamic properties of spin-spin correlation, local moment, double occupancy, entropy, specific heat are studied for different U and NNN hopping interactions (t¹). The increase of NNN hopping interaction favors the formation of doublans and hence decreases local moment in the low temperature region. Transition temperature (T_c) region is identified from entropy curves. Characteristic double peak structure is observed in the specific heat curves with the inclusion of NNN hopping interaction.

8 illus, 41 ref

008522   Moghaddam B G;Vahabi-Moghaddam M;Sadremomtaz A (Physics Dep, Faculty of Science, Guilan Univ, P.O. Box 3489, Rasht, Iran, Email: behanz.moghaddam@gmail.com) : Evaluation of target dose based on water-equivalent thickness in external beam radiotherapy. J med Phys 2013, 38(1), 44-51.

In vivo dosimetry was carried out for 152 patients receiving external beam radiotherapy and the treatment sites were divided into two main groups: Thorax, Abdomen, and Pelvic (120 fields) and Head and Neck (52 fields). Combined entrance and exit dose measurements were performed using LiF: Mg, Cu, P thermoluminescent dosimeters (TLDs). Water-equivalent (effective) thicknesses and target dose were evaluated using dose transmission data. The ratio of measured to expected value for each quantity was considered as an indicator for the accuracy of the parameter. The average ratio of the entrance dose was evaluated as 1.01 ± 0.07. In the diameter measurement, the mean ratio of effective depth divided by the contour depth is 1.00 ± 0.13 that shows a wide distribution which reflects the influence of contour inaccuracies as well as tissue inhomogeneities. At the target level, the mean ratio of measured to the prescribed dose is 1.00 ± 0.07. According to our findings, the difference between effective depth and patient depth has a direct relation to target dose discrepancies. There are some inevitable sources which may cause the difference. Evaluation and application of effective diameter in treatment calculations would lead to a more reliable target dose, especially for fields which involve Thorax, Abdomen, and Pelvic.

10 illus, 23 ref

008521   Makha M;Cattin L;Dabos-Seignon S;Arca E;Velez J;Stephant N;Morsli M;Addou M;Bernede J C (NO, Nantes Univ, MOLTECH-Anjou, CNRS, UMR 6200, 2 rue de la Houssiniere, BP 92208, Nantes, F-44322 France, Email: jean-christain.bernede@univ-nantes.fr) : Study of CuI thin films properties for application as anode buffer layer in organic solar cells. Indian J pure appl Phys 2013, 51(8), 569-82.

After chemico-physical characterization of Cul thin films, the structures indium tin oxide (ITO) /Cul are systematically studied and show that the morphology of the 3 nm thick Cul film depends on its deposition rate. To obtain smooth homogeneous Cul film, it is necessary to depose it at 0.005 nm/s. After optimization of the deposition conditions of Cul, it is shown that it behaves like a template for the organic layer. For instance, when the organic film is copper-phthalocyanine, the molecules which are usually perpendicular to the plane of the substrate lie parallel to it when deposited onto Cul. In a same way, when the electron donor is a prophyrin derivative, Cul allows to double the power conversion efficiency of the cells based on the heterojunction porphyrin/C₆₀. When Cul is used as anode buffer layer, it increases systematically the short circuit current, the open circuit voltage, thus the efficiency of the organic solar cell. These effects are related, not only to the improvement of the band matching between the ITO and the electron donor, but also to the templating effect of the Cul. Moreover, we show that the beneficial effect of Cul is effective, not only with ITO, but also with fluorine doped tin oxide.

16 illus, 2 tables, 59 ref

008520   Khaneja M;Bisen L;Gautam S;Prashant Kumar; Rawat J S B S;Ghosh S;Chaudhury P K;Vikram Kumar (NO, Solid State Physics Laboratory, Lucknow Road, Timarpur, Delhi, Email: mamta.khaneja@gmail.com) : Optimization of screening and emitter density for an array of carbon nanotube field emitters. Indian J pure appl Phys 2013, 51(8), 583-6.

In order to exploit the high current carrying capacity of Carbon Nanotubes (CNTs), it is important to maximize current density J by controlling screening as well as the emitter density. A model is developed in MATLAB to calculate the current density from an array of nanotube bundlestaking into account both the effect of screening and the emitter density in the framework of standard Fowler-Nordheim (F-N) theory. The results obtained indicate that field emission can be optimized when the inter bundle distance is comparable with the nanotube height. Field emission measurements carried out on vertically aligned CNT bundles grown on patterned substrates give a strong support to the results obtained by simulation.

4 illus, 15 ref

008519   Joshi D P;Sharma K;Gill F S (Physics Dep, DBS (PG) College, Dehradun, Uttarakhand, Email: kkiransharma@rediffmail.com) : Effect of inversion layer and oxide layer thickness on the performance of PX-Si TFT devices. Indian J pure appl Phys 2013, 51(9), 638-41.

In the present paper, the dependence of transfer characteristics of PX-Si TFT devices on gate oxide thickness (t_ox) and inversion layer thickness (t_si) has been investigated theoretically by considering a new Gaussian energy distribution of GB trapping states. The dependence of drain current (I_D) and GB space charge potential barrier height (qV_g) of PX-Si TIT on gate voltage (V_GS) at different inversion layer thickness qV_g, and oxide layer thickness has also been studied. It is observed that the drain current increases on decreasing the thickness of oxide layer and inversion layer.

6 illus, 12 ref

008518   Janaki A;Balachandran V;Lakshmi A (Physics Dep, Govt Arts College for Women, Pudukkottai-622 001, Email: brsbala@rediffmail.com) : First order molecular hyperpolarizabilities and intramolecular charge transfer from vibrational spectra of NLO material: 2,6-dichloro-4-nitroaniline. Indian J pure appl Phys 2013, 51(9), 601-14.

Vibrational spectral analysis of the non-linear optical (NLO) material, 2,6-dichloro-4-nitroaniline (DCNA) has been carried out by using FT-IR and FT-Raman spectroscopic techniques. The Hartree-Fock(HF) and Density Functional Theoretical (DFT) computations have been performed at 6-311++G** level to derive equilibrium geometry, vibrational wavenumbers, intensities and first order hyperpolarizability. The optimized geometry, various bonding features and harmonic vibrational frequencies of DCNA have been investigated. Vibrational bands to the various structural groups and their significance were investigated by analyzing the vibrational spectra. Vibrational analysis reveals that simultaneous IR and Raman activation to the phenyl ring modes also provide evidence for the charge transfer interaction between the donors and acceptor can make the molecule polarized and the intramolecular charge transfer interaction must be responsible for the NLO properties of DCNA. The Mulliken atomic charge analysis was also made in the present study. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the investigated molecule have been computed using HF and B3LYP methods.

4 illus, 6 tables, 47 ref