013581   Binu S;Mahadevan Pillai V P;Chandrasekaran N (Optoelectronic Dep, Kerala univ, Triruvananthpuram-695 581) : OPTDR based fiber optic microbend sensor for distributed sensing applications in structural pressure minotoring. J Optics 2006, 35(1), 36-44.

The ability to understand and monitor the distributed behaviour of extended, critical structures is recognized as a matter of increasing importance. Optical fibres offer unique advantages for spatially distributed measurement. An especially important feature is the one dimensional nature of the medium, since this offers unique advantages for spatially distributed measurement. Describes the principle of operation, the design and performance of a novel single mode fiber based multipoint microbend pressure sensor architecture, which may be utilized in distributed measurement. The actual sensor element is a single mode fiber coupled to the measurand field through the usual microbend inducing structures. The sensor uses optical time domain reflectometry (OTDR) to detect pressure induced charges of backscatter power at many separate locations in the fiber as a function of length along a single fiber with no taps or branches. The sensitivity of this structure to microbend induced losses has been thoroughly characterized. This feature greatly increases the information from a single instrument and hence decreases the cost-benefit ratio.

4 illus, 10 ref

013580   Bhatti H S;Gupta A;Verma N K;Sunil Kumar (Physics Dep, Panjab Univ, Patiala-147 002, Email: drhsbhatti03@yahoo.co.in) : Optical Properties of ZnO phosphors activated with Mn and Se impurity. J Optics 2006, 35(1), 45-50.

Various optical parameters of interest have been obtained from the synthesized singly and doubly doped ZnO semiconductor phosphors with variable concentrations of manganese and selenium. Time resolved photoluminescence (PL) spectra have been observed in doped phospors when these are excited by the UV laser radiation, giving rise to emission in the visible region. The phosphors under investigations were exited by UV pulsed N₂ laser (having high peak output power) at room temperature. In present context transition probability, oscillator strength, integrated cross-section and dipole-moment values have been calculated from the laser induced photoluminescence decay curves of the singly and doubly doped ZnO phosphors. In case of doubly doped ZnO phosphors the increasing trend of all the parameters is attributed to the fact that the emission from shallow trapping states plays the dominant role or it may be due to energy transfer mechanism.

4 tables, 14 ref

013579   Baluja S;Kachhadia N;Kasundra P K;Vaishnani K P (Chemistry Dep, Saurashtra Univ, Rajkot-360 005) : Dissociation constants of some schiff bases. Ultra Scient phys Sci 2006, 18(3), 339-42.

The proton ligand dissociation constants of some Schiff bases and the stability constants have been determined in dioxane-water (60:40 v/v) medium at 308. 15 K. using Bjerrum-Calvin pH titration as extended by Irving and Rossotti. The stability constants are related to dissociation constants of these ligands, which depends on the substituents attached to the organic moiety.

1 table, 14 ref

013578   Baldev Raj;Philip J;Rajkumar K V; Kalyanasundaram P (Indira Gandhi Centre for Atomic Research, , Kalpakkam, Tamil Nadu-603 102) : Effect of magnetic field on ultrasonic velocity in a magnetic nanofluid. Proc Indian Natn Sci Acad 2006, 72(3), 145-51.

Ordering and agglomeration behavior of a magnetic nanofluid under the influence of an external magnetic field was investigated by measuring ultrasonic velocities. The magnetic nanofluid used in our investigations consist of magnetite particles, with an average diameter of 8 nm, coated with an organic layer of surfactant and dispersed in a carrier fluid. A dramatic increase in the ultrasound velocity is observed along the direction of applied magnetic field, when the particle concentration was above 25 wt%. A saturation in the longitudinal velocity is observed at a magnetic field of 300 Gauss. The ultrasound velocity changes in the perpendicular direction of the magnetic field were not significant as compared to parallel direction. The change in velocity Ac, in presence of magnetic field clearly indicates the structural changes due to one dimensional ordering of the magnetic particles. It has been found that Ac depend on the magnetic field strength,'magnetic fluid concentration and direction of the field. The decrease in ultrasonic velocity with increase in magnetic nano-particle concentrations, in the absence of external magnetic field, can be understood in terms of increased average density and changes in adiabatic compressibility of the nanofluid.

9 illus, 20 ref

013577   Azimaraghi M E (Advanced Materials and Photonics Group, Applied Physics Div, Physics D, Teacher Training Univ, 49 Shahid Mofateh Avenue, Tehran, Iran) : Electrical properties of chloroaluminium phthalocyanine thin film sandwich devices. Indian J pure appl Phys 2007, 45(1), 40-3.

Spectroscopic measurements in the range 10 kHz - 6-MHz at different temperatures are reported for Au/ClAlPc/Au thin film sandwich devices. The ac conductivity was found to vary with the angular frequency ω. In the high frequency region, the ac conductivity is proportional to ωⁿ. The capacitance and loss tangent decrease with increasing frequency and the capacitance increases with increasing temperature. The results show that the relative importance of the hopping model and band theory in describing the film conduction with regard to the operating conditions. The band theory is dominant at high temperatures and low frequencies, whereas hopping model is dominant at high frequencies and low temperatures.

5 illus, 12 ref

013576   Ataullah Ansari M;Singh N P;Indu B D (Physics Dep, Gurukul Kangri Vishvavidyalaya, Haridwar-249 404) : Role of scattering processes in lattice thermal conductivity of Ge. Indian J pure appl Phys 2007, 45(1), 27-30.

The various objections raised against Callaway's classic paper on the model of phonon heat conductivity such as (i) unresolved problem of additivity of inverse relaxation times (inadequate use of Mathiessen's rule), (ii) absence of dispersion relation and (iii) lack of sufficient information pertaining to phonon modes (phonon velocities), have been amicably removed in this paper. The problem is solved by the use of phonon frequency spectrum and phonon group velocity formulation via the method of double time thermodynamic Green's functions developed via an almost realistic Hamiltonian (second quantized) containing the effects of impurities, anharmonicities and their interactions. The lattice thermal conductivity of two samples of germanium has been analyzed on the basis of this modified model and a fairly good agreement between theory and experimental observations has been reported. The involvement of different scattering events has been discussed via a new approach, which is capable to explore the various temperature regimes of their effectiveness. The role of interference mode is an additive feature of this work.

5 illus, 15 ref

013575   Anil Kumar P;Mitra S;Mandal K (Magnetism Laboratory, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata-700 098, Email: anil@bose.res.in) : Structural and magnetic properties of Co nanoparticles in Cu/SiO₂ matrix. Indian J pure appl Phys 2007, 45(1), 21-6.

The magnetic properties of Co nanoparticles embedded in SiO₂ and Cu matrices separately, have been presented. The size of the cobalt nanoparticles is varied between 15-35 nm. Co forms a usual hcp structure in SiO2 matrix whereas it forms fcc structure when embedded in Cu matrix. This fact is also supported by the higher coercivity of Co nanoparticles in SiO₂ matrix. A large coercivity value (<126> 855 Oe) for Co nanoparticles embedded in SiO₂ matrix and considerably high value (<126> 465 Oe) for Co nanoparticles embedded in Cu matrix have been reported. The Law of Approach to Saturation is used in the case of Co-Cu composite to calculate the magnetocrystalline anisotropy constant and saturation magnetization.

6 illus, 1 tables, 7 ref

013574   Ananthanarayan B;Gautam C;Mavalankar A; Shivaraj K;Uma Sankar S;Upadhyay A (Centre for High Energy Physics, Indian Institute of Science, Bangalore-560 012, Email: anant@cts.iisc.ernet.in) : Progress in determination of neutrino oscillation parameters. Curr Sci 2006, 91(7), 864-7.

30 ref

013573   Al-Khattabi L A (Physics Dep, Faculty of Science, King Abdulaziz Univ, Jeddah, (Kingdom of Saudi Arabia)) : <. Ultra Scient phys Sci 2006, 18(3), 365-70.

Working within the framework of Coulomb modified Glaubar theory author calculate ¹²C - ¹²C and ¹²C - ²⁷ A1 total reaction cross sections in the energy range from 10 <126> 1000 MeV/nucleon in the rigid projectile model in terms of the phenomenological N - ¹²C amplitude parameters. A comparison of the predictions of the model with the available experimental data shows that it works quite satisfactorily at energies above about 20 MeV/nucleon.

2 illus, 1 table, 16 ref

013572   Ahmed S;Watts S J;Holmes Siedle A;Matheson J; Chowdhury M A H (Physics Dep, Shahjalal Univ of Science and Technology, Sylhet, Bangladesh) : Impurity concentration calculations in detector-grade silicon using deep level transient spectroscopy. Ultra Scient phys Sci 0000, 18(3), 349-54.

Deep Level Transient Spectroscopy (DLTS ) is one of the most important technique by which defect with deep levels are characterized. Using the data measured by DLTS technique authors have calculated the concentration of oxygen and carbon in float zone and epitaxial diodes. The calculated values were then compared with the values those measured by Infrared absorption (IR) and Secondary Ion Mass Spectroscopy (SIMS) for these materials. A reasonable good agreement is obtained in all cases except in the epitaxial diodes. The results showed that the epitaxial material is compensating. Canberra epi-MACOM diode processed by MACOM Ltd., USA, seems to be highly compensated.

3 illus, 2 tables, 5 ref

013571   Acharya B B;Tripathy S;Roy G S (Physics Dep, Christ College, Cuttack) : Study of the structure and properties of lightly crosslinked polyethylene crystallized from the melt under uniaxial compression. Ultra Scient phys Sci 2006, 18(3), 343-8.

Structure and properties of lightly crosslinked polyethylene crystallized from the melt under uniaxial compression" have been studied. The observations indicate that if a lightly crosslinked polyethylene of adequate crosslink density is uniaxially compressed from the melt and cooled to room temperature a very unique orientation of the crystal planes appears. This crystallisation of molecular chains takes place in the absence of high pressure and shear. This is due to the intrinsic crystallographical structure of polymer.

3 illus, 9 ref

013570   Acharya B B;Mohanty S;Roy G S (Physics Dep, Christ College, Cuttack) : Study of Structure of lightly crosslinked polypropylene crystallized from the melt under uniaxial compression. Ultra Scient phys Sci 2006, 18(3), 397-400.

When a cross linked sample is uniaxially compressed in the melt, the crystallization occurs and when cooled a unique orientation of crystallites takes place. These crystallites are randomly distributed about the normal to the film surface. This random distribution of crystallites are independent for all compression ratios and with the increase in compression ratio, the molecular chain axes in the crystallites orient more parallel to the film surface.

8 illus, 9 ref

012534   Zhu D;Luo Q;Zhang T;Cheng H;Zeng S;Ulyanov S (The Key Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430014, P.R. China) : Laser speckle microscopic system for monitoring of dynamic blood perfusion. Asian J Phys 2006, 25(1), 67-75.

Measurement of blood perfusion has been playing an important role in the field of clinical medicine, but it has been a problem for monitoring blood perfusion in the'clinical practices like disease diagnostics, drug delivery, and tumor hyperthermia. A new apparatus for non-contacting and non-disturbance, which combined laser speckle microscopic technique with video camera, was developed. Dynamic blood flow rate was measured with laser speckle microscopy by using the techniques of zero-crossings, and corresponding blood vessel diameter was recorded with video camera. Based on the measurements of blood flow rate and vessel diameter, the blood perfusion could be deduced. This apparatus was applicable for monitoring relative change in blood perfusion of rat mesentery during cooling or heating at different constant temperature. When the temperature was lower or higher than core temperature, the blood perfusion decreased or increased at initial 20 minutes, and tended to be in equilibrium, whereas the blood perfusion was almost steady. Moreover, the increment of blood perfusion in equilibrium is linear with temperature, which is consistent with the conclusion from thermal physics method. The results showed that blood flow rate could not provide reliable information for dynamics of blood perfusion unless the dynamics of vessel diameter is considered. The comparative research proved that it is valid to investigate kinetics of blood perfusion with laser speckle microscopic monitoring technique, which could provide a new method for measuring real time dynamic blood perfusion under exterior factors.

6 illus, 25 ref

012533   Vladimirov A P;Kilunova N V;Michurov A V; Yakovleva S V (NO, Institute of Engineering Science of Ural dpt of RAS, Yekaterinburg, Russia-620 219) : Speckle dynamics produced by lecithin-water sol-gel transition. Asian J Phys 2006, 25(1), 93-100.

The goal of this work is designing the measuring equipment and developing the procedure of parameters registration, characterizing the speckle dynamics. At the base of the experiments the following conclusions can be made: (a) an optical setting was created, allowing to visualize and register the speckle dynamics in the image area of transparent cuvette, filled with lecithin- water emulsion; (b) a strategy of parameters registration was developed, characterizing the speckle dynamics, including the film recording, forming space- temporal pictures, carrying out a correlation analysis, spectral analysis, calculating the frequency of speckle winking, deducing a mean and root-mean- square deviation of the optical signal for the researching system. With a help of the technique it was discovered, that the local maximum of the frequency speckle winking takes place at the solution- gel border, the maximum of the temporal bandwidth is reached before, and the maximum of the standard signal deviation- after the lipid solution is transferred into gel.

8 illus, 2 ref

012532   Verma K D;Singh S P;Prakash D (Physics Dep, S.V. College, Aligarh-202 001, U.P) : Analysis of bulk modulus for geophysical menerals at high temperature. Acta Cienc Indica-Phys 2006, 32(4), 457-64.

Simple theoretical model has been developed to investigate the temperature dependence of bulk modulus for a number of geophysical minerals viz., MgO, CaO, Al₂O₃, Mg₂SiO₄, Grossular Garnet and Pyrope Garnet. The concept of the modified Gruneisen parameter has been adopted to obtain an equation of state. The results obtained in the study for all the six minerals are found to present an excellent agreement with the available experimental data.

6 illus, 2 tables, 17 ref

012531   Ulianova O V;Ulyanov S S;Sazanova E V;Zhihong Z;Sibo Z;Luo Q;Zudina I;Bednov A (NO, Saratov State Agrarian Univ, Saratov State Univ 410012, Moskovskaya 155, Saratov, Russia) : Photoinactivation of bacteria of Francisella tularensis by dynamic low-coherent speckles. Asian J Phys 2006, 25(1), 101-17.

Biochemical, biophysical and optical aspects of interaction of low-coherent light with bacterial cells have been discussed. Influence of low-coherent speckles on the colonies grows is investigated. It has been demonstrated that effects of light on the inhibition or re-activation of cells are connected with speckle dynamics. The regimes of illumination of cell suspension with purpose of devitalization of hazard bacteria, caused very dangerous infections, are found. Mathematical model of interaction of low-coherent laser radiation with bacteria suspension has been proposed. Computer simulations of the processes of laser-cells interaction have been carried out.

10 illus, 22 ref

012530   Singh S K;Tiwari D;Sulaiman M (Physics Dep, College of Commerce, Patna-800 020) : Effect of collision of electrons on lower hybrid instabilities. Acta Cienc Indica-Phys 2006, 32(4), 451-5.

Collisional effect of electrons as well as ions have significant effect on the stability analysis of lower hybrid drift modes in the ionosphere. Electron collisions stabilize the mode and cause a density gradient threshold for the instability. This threshold results in restriction on the inter-retation of 155 and 415 MHz backscatter results as being due to lower hybrid drift instabilities and suggests measurement to determine whether the instability can account for the backscatter.

3 ref

012529   Sangawar V S;Chikhalikar P S;Dhokne R J;Ubale A U;Meshram S D (Physics Dep, Govt Vidarbha Institute of Science & Humanities, Amravati) : Bandgap determination of PVC-charcoal composite thin film form uv measurements. Acta Cienc Indica-Phys 2006, 32(4), 477-82.

Spectroscopic techniques are very useful for characterizing semiconducting and conducting materials. The optical properties of charcoal doped with PVC with different composition were studied. UV spectra of charcoal doped PVC films has been obtained on Hitachi - 330 in the wavelength region 200 - 700 μm. The thickness of the film is of the order of 61.52 μm optical energy gap Eg(opt) values are determined from the graph [hv vs (αhv)^1/2]. It is observed that there is remarkable change in Eg(opt) values of charcoal doped PVC thin films due to change in concentration of charcoal in PVC.

3 illus, 8 ref

012528   Salvi S V;Pimpale S S (Institute, of Science, Mumbai-400 032) : Charge transfer in light effect under visible radiation in an ozoniser discharge. Def Sci J 2006, 56(5), 715-20.

Two fresh discharge vessels (1 and 2) of Siemen's ozoniser type having the same height but different surface-to-volume ratios have been fabricated by enclosing argon at 10 mm mercury. By immersing these in electrolytic solution and by subjecting these to a definite high 50 Hz ac voltage, the discharge count rates in dark (C_f)_D and under light (C_f)_L have been determined using a scaler held at different bias-voltages. The plot of the ratio (C_1f/C_2f)_D and (C_1f/C_2f)_L of discharge counts versus pulse height (bias-voltage) shows that this ratio for a constant potential of 3.5 kV (rms) is initially large in value, then rapidly decreases to a minimum. It is also observed that more is the surface-to-volume ratio, more is the magnitude of net effect of irradiation. Further, the pulse height analysis shows that the charge carried by the pulses to the electrodes (charge transfer) decreases under illumination. A possible mechanism to explain the net effect of the discharge current ratio in the light of pulse height measurements is discussed.

2 illus, 1 table, 14 ref

012527   Sagar N V;Anand K S;Mithun A C;Srinivasan K (Metallurgical and Materials Engineering Dep, National Institute of Technology Surathkal, Srinivasnagar P.O-575 025, Email: ksrini@nitk.ac.in ) : Friction factor of CP aluminium-zinc alloys. Bull Mater Sci 2006, 29(7), 685-8.

Friction factor has been determined for CP aluminium and aluminium-zinc alloys using ring compression test at different temperatures from 303 K to 773 K. It is found that CP aluminium exhibits sticking whereas Al-Zn alloys do not exhibit sticking at elevated temperatures. Hot working of Al-Zn alloy is easier than that of CP aluminium at 773 K. As zinc content increases up to 10 wt% the friction factor decreases up to 0.02.

5 illus, 7 ref

012526   Roy K;Mishra R K;Sahana B C;Karmakar K (Applied Electronics and Instrumentation Engineering Dep, Asansol Engineering College, Asanol-713 304) : Application of conducting polymers in advanced electronic devices. Acta Cienc Indica-Phys 2006, 32(4), 487-95.

Until about 30 year's ago all carbon based polymers were rigidly regarded as insulators. The idea that plastics could be made to conduct electricity would have been considered to be absurd. Indeed, plastics have been extensively used by the electronics industry because of this very property. They were utilized as inactive packaging and insulating material. This very narrow perspective is rapidly changing as a new class of polymer known as intrinsically conductive polymer or electroactive polymers are being discovered. Although this class is in its infancy, much like the plastic industry was in the 30's and 50's, the potential uses of these are quite significant.

10 illus, 10 ref

012525   Reddy M C S;Rama Murty G (NO, Osmania Univ, Hyderabad-500 007) : Analysis of titanium-matrix orthotropic cylindrical shell subjected to thermomechanical loading. Def Sci J 2006, 56(5), 701-13.

Titanium-matrix orthotropic cylindrical shell with the principal direction of orthotropy following a parallel constant angle helix, has been studied when it is subjected to uniform loading conditions of internal pressure, axial load and pure twisting moment. Nondimensional parameters pertaining to loading and deformations have been calculated and results plotted. The results obtained can be usefully applied in robotic actuators where lightweight considerations with high strength are of prime importance. The study is further extended to investigate the effect of temperature on the deformations. Through parametric studies, deformation patterns are calculated and plotted that are unique to orthotropy. In most of the cases, it is observed that deformation patterns are same, but deformation is increasing with temperatures.

12 illus, 2 tables, 14 ref

012524   Ramana Murthy Ch V;Kulkarni S B (NO, Finolex Academy of Management & Technology, Ratnagiri-415 639) : On the class of exact solutions of an imcompressible second-order fluid flow by creating sinusoidal disturbances. Def Sci J 2006, 56(5), 733-41.

Exact solution of an incompressible fluid of second-order by causing disturbances in the liquid, which is initially at rest due to bottom oscillating sinusoidally, has been obtained. The results presented are in terms of nondimensional elasticoviscosity parameter (β) which depends on the non-Newtonian coefficient and the frequency of excitation of the external disturbance while considering the porosity (K) of the medium. The flow parameters are found to be identical with that of Newtonian case as β → 0 and K → ∞.

7 illus, 12 ref

012523   Premachandran M N (Crop Improvement Div, Sugarcane Breeding Institute, Coimbatore-641 007, Email: premsbi@rediffmail.com) : Cauliflower gene in sugarcane. Curr Sci 2006, 91(6), 750-1.

1 illus, 16 ref

012522   Prasad U;Jha G K (Physics Dep, M.G. College, Darbhanga) : Radiation from filamentary current distributions. Acta Cienc Indica-Phys 2006, 32(4), 397-400.

The radiatin from two simple filamentary current distributions were examined as travelling wave and uniform. The radiated or far-zone electric field was computed for an excitation. That was a Gaussian pulse in time. The explanation of the radiation shows that the radiation occurs along the entire length of filament. Destructive interference of the radiation from different points on the filament then causes the radiation to be insignificant except at the times corresponding to radiation from the ends of the filament.

5 illus, 4 ref

012521   Ojha J K;Venkatram Reddy B;Ramana Rao G (Physics Dep, Kakatiya Univ, Vidyaranyapuri, Warangal-506 001) : Normal coordinate analysis of some fluorotoluenes. Acta Cienc Indica-Phys 2006, 32(4), 509-13.

Zero-order normal coordinate analysis of in-plane vibrations was made for o-, m- and p- fluorotoluenes by transferring the force constants from earlier work. The observed and calculated frequencies agree reasonably well demonstrating the transferability of the force field. On the basis of calculated potential energy distributions and eigen vectors, several assignments suggested by earlier worker have been revised.

6 ref

012520   Nayak M;Lodha G S;Nandedkar R V (Synchrotron Utilization Div, Centre for Advanced Technology, Indore-452 013) : X-ray reflectivity investigation of interlayer at interfaces of multilayer structures: application to Mo/Si multilayers. Bull Mater Sci 2006, 29(7), 693-700.

Effect of interlayer on multilayer X-ray reflectivity (XRR) profile using simulations at 8.047 keV (CuK_α) energy. Effect of interfacial roughness and in-jdepth interlayer on reflectivity profile has been distinguished. The interfacial roughness reduces the intensity of individual peak while the in depth interlayer redistributed the reflectivity profile. Authors are able to discern the asymmetry in interlayer thickness at two interfaces if the interfacial roughness is small compared to in-depth interlayer thickness is possible. The limitation is that, the sensitivity decreases with increasing interfacial roughness. This interlayer moderi applied for electron beam evaporated Mo/Si multilayers. The Mo-on-Si interlayer thickness is 10 ± 0.5 Angstrum and Si-on-Mo interlayer thickness is 8 ± 0.5 Angstrum. The nature of interfacial compound is identified using. X-ray photoelectron spectroscopy (XPS). The mechanism of interlayer asymmetry is explained on the basis of different heats of sublimation of Mo and Si.

8 illus, 1 table, 32 ref

012519   Nandan S;Upadhyay P N (Physics Dep, V.K.S. Univ, Ara (Bihar)) : Theoretical aspects on the charmed D± (1870) mesons. Acta Cienc Indica-Phys 2006, 32(4), 465-76.

Author present an account of theoretical aspects of the charmed D^± (1870) mesons in context of quark model, parton model, bag model, dual model and standard model etc. Also presented, briefly some interesting features of its production in the e⁺e^- annihilations.

9 illus, 18 ref

012518   Mishra R K (Electronics and Communication Engineering Dep, Asansol Engineering College, Kanyapur, Asansol-713 304) : Broadband microstrip patch antennas. Acta Cienc Indica-Phys 2006, 32(4), 439-43.

Presents a theoretical and experimental investigation of a class of broadband jrinted antennas. The fundamental element of the proposed antennas the aperture stacked patch and cavity backed patch of which variations are developed for radio Communications.

5 illus, 9 ref

012517   Manikandan E;Rajamannan B;Ravisankar R (Physics Dep, Annamalai Univ, Annamalainagar, Tamilnadu, India-608 102) : FT-IR spectroscopic studies of beach sediment samples collected from Pondicherry to Porto-novo (Tamil Nadu) - East coast of India. Acta Cienc Indica-Phys 2006, 32(4), 515-20.

The vast Indian coastal zone has been playing a vital role in economic development. The distribution and abundance of minerals and heavy mineral have been used to map mineral assemblages to demarcate mineralogical province. In this sense, the coastal sediment samples were collected from Pondicherry to Porto-Novo of East Coast of Tamilnadu and subjected to mineral studies by FT-IR technique. Qualitative analyses are carried out to determine the major and minor constituent minerals present in the samples from the band position or location of the peaks. Form the prominent i. r absorption peaks; the minerals are identified with the available literature. The quartz, orthoclase, albite, kaolinite, montmorllinite, illite, calcite, aragonite, garnet and magnetite are identified. The results are discussed and the conclusions are drawn.

2 illus, 1 table, 22 ref

012516   Mangal R K;Singh M;Vijay Y K;Avasthi D K (Physics Dep, Rajasthan Univ, Jaipur-302 004, Email: yk_vijay@sancharnet.in) : Preparation of A1-Sb semiconductor by swift heavy ion irradiation. Bull Mater Sci 2006, 29(7), 653-7.

Al-Sb bilayer thin films having various thicknesses were deposited by thermal evaporation on ITO-coated conducting glass substrates at a pressure of 10^-5 torr. These films were irradiated by Ag 12⁺ heavy ions of energy, 160 MeV, with a fluence of 2.2 x 10¹³ ions/cm², to get aluminum antimonide semiconductor. Rutherford back scattering and optical band gap data confirmed mixing of bilayer to form the semi-conducting system.

10 illus, 6 ref

012515   Manapuram R K;Ghosn M;Larin K V (Biomedical Optics Laboratory, IIouston Univ, N207 Engineering Bldg 1, Houston, TX 77204-4006, Email: klarin@uh.edu) : Identification of artificial fingerprints using optical coherence tomography technique. Asian J Phys 2006, 25(1), 15-27.

Spoofing of biometric fingerprint devices is a common problem nowadays. Fingerprint gummies are frequently used to fake those machines. In this paper author present results of a pilot study on using Optical Coherence Tomography (OCT) technique to identify artificial material commonly used for spoofing fingerprint devices. Gelatin, silicone, wax, and agar-based gummies were placed on a finger and analyzed using OCT technique. The results of these studies suggest that OCT could be a powerful tool for accurate and sensitive identification of the fingerprint gummies made from different materials.

7 illus, 1 table, 25 ref

012514   Lukyanov V F (NO, Saratov State Medical Univ, Saratov, ul. B. Kazachya 112, Russia) : Flowmetry as method for diagnostics of microvascular resistance at essential hypertension. Asian J Phys 2006, 25(1), 85-91.

New Doppler-Laser flowmetry diagnostic test of functional condition of microcirculation was worked out of find precapillar and postcapillar resistance. Flowmetry was used to measure vasomotion and blood flow after arterial compression, decompression and venous hyperemia were held. Patients of essential hypertension were examined with the help of Doppler-Laser Flowmetry, optical photometry (540 nm). Precapillar resistance included next basis parameters: vasomotion with high frequency (10-16 per/min) and low amplitude, latent time after decompression, large postocclusive reactive hyperemia, absent venous hyperemia. Postcapillar resistance included next basis parameters: vasomotion with low frequency (4-8 per/min) and high amplitude, "paradoxical hyperemia" in arterial compression, little or absent postocclusive reactive hyperemia, large venous hyperemia. This test-method was applied to select patogenetic treatment of essential hypertension.

3 illus, 26 ref

012513   Kavei G;Karami M A (Material, and Energy Research Centre, P.O. Box 14155-4777, Tehran, Iran, Email: g-kavei@merc.ac.ir) : Fabrication and characterization of the p-type (Bi₂Te₃)_x(Sb₂Te₃)_1-x. Bull Mater Sci 2006, 29(7), 659-63.

In the present study, p-type; (Bi₂Te₃)_x (Sb₂Te₃)_1-x crystals with various chemical compositions (x = 0.2, 0.22, 0.235, 0.25, 0.265, 0.28 arid 0.3) were fabricated through the zone melting method. Thermoelectric properties, including Seebeck coefficient (a), electrical conductivity (σ), thermal conductivity (ϕ) and Hall constants, were measured at room temperature, 300 K. The influence of the variations of Bi₂Te₃ content (x) on the thermoelectric properties was studied. The increase of Bi₂Te₃ content (x) caused a decrease in (carrier) hole concentration and thus a decrease of σ and an increase of α. The maximum figure of merit (Z = α²σ/K) of 2-7 x 10^-3 K^-1 was obtained at about 300 K for the composition of 25% Bi₂Te₃-75% Sb₂Te₃ with 3wt% excess of Te.

18 illus, 25 ref

012512   Karmakar K;Mishra R K;Sahana B C;Roy K (Electronics & Communication/Instrumentation Engineering Dep, Asansol Engineering College, Kanyapur, Asansol-713 304) : CPLD based generation of different spreading codes & study of its correlation properties in DS-CDMA. Acta Cienc Indica-Phys 2006, 32(4), 497-504.

Modern era of mobile communication symbolizes an era of Direct Sequence (DS) Code Division Multiple access(CDMA). And Spreading Code generation has been an instrumental part in DS-CDMA or WCDMA realization. This paper contains two contributions. The first major contribution of this paper is to present the method of generation of two different spreading codes using VHDL m-sequence and Gold sequences of length 25-l have been coded with VHDL, simulated and implemented on Xilinx XC9500CPLD series XC95108 - TQ100' device. The second major contribution is to study the correlation properties of the generated spreading codes & to present the results in tabular form which will be helpful in selecting the CDMA codes.

6 ref

012511   Jha G K;Mishra P K;Jha S C (Univ Physics Dep, L.N. Mithila Univ, Darbhanga-846 004) : Interaction studies in binary liquid mixtures of non-polar solvents from viscosity. Acta Cienc Indica-Phys 2006, 32(4), 401-4.

Intermolecular interaction in terms of excess free energy of mixing of binary mixtures of acetone with non-polar solvent at 307.35 K has been evaluated from the viscosity data. The nature of interaction has been discussed in detail. The results are shown in tabular form.

1 table, 2 ref

012510   Herndon J M (11044 Red Rock Drive, San Diego, CA 92131, USA) : Enhanced prognosis for abiotic natural gas and petroleum resources. Curr Sci 2006, 91(5), 596-8.

Prognosis for vast potential resources of abiotic natural gas and petroleum depends critically upon the nature and circumstances of earth's formation. Until recently, that prognosis has been considered solely within the framework of the so-called standard model of solar system formation, which is incorrect and leads to the contradiction of terrestrial planets having insufficiently massive cores. By contrast, that prognosis is considerably enhanced (i) by the new vision that I have disclosed of earth's formation as a Jupiter-like gas giant; (ii) by core formation contemporaneous with raining-out from within a giant gaseous protoplanet, rather than through subsequent whole-earth re-melting after loss of gases; (Hi) by the consequences of whole-earth decompression dynamics, which obviates the unfounded assumption of mantle convection, and (iv) by the process of mantle decompression thermal-tsunami. The latter, in addition to accounting for much of the heat leaving the earth's surface, for the geothermal gradient observed in the crust, for substantial volca-nism, and possibly for earthquake generation as well, might also enhance the prognosis for future abiotic energy supplies by pressurizing and heating the base of the crust, a potential collection point for abiotic mantle methane or other mantle-derived carbon-containing matter.

22 ref

012509   Gupta R S;Sharma S K;Chandok R S (Physics Dep, Govt P.G. College, Satna) : Lyoluminescence of gamma irradiated saccharides. Acta Cienc Indica-Phys 2006, 32(4), 417-22.

Reports the lyoluminescence (LL) of Gamma Irradiated Saccharides namely Maltose, Sucrose, Fructose & Dextrose. The effect of particle size, mass of solute. pH of solvent and effect of temperature of solvent on the lyoluminescence yield in saccharides hasyen studied using LL reader. It is observed that the peak LL intensity (Im), time corresponding the peak intensity (t_m) and total intensity, area below the LL intensity versus time curve (I_t) increases upto a certain particle size (180 μm - 212 μm) and subsequently it decreases nth further increase in particle size. Studies on effect of mass of solute on LL shows that initially the LL intensity increases with increasing mass of the solute and attain a peak intensity (I_m) at 1 mg. of solute. After increasing this particulars mass of the solute the intensity decreases. In the study of pH dependence it was found that there is gradually increase in LL intensity with increasing pH up to a certain value of the pH. It is observed that the LL yield decreases with increase in temperature of the solvent (distilled water) in irradiated saccha-Zrides. An attempt has been made to explain the results on the basis of free radical recombination, rate of dissolution and molecular structure. Conclusively it can be said that the LL emission comes from the radiation induced free radical reactions.

5 illus, 10 ref

012508   Gupta R N;Yadav S;Jaiswal N;Gupta G K (Physics Dep, D.D.U. Gorakhpur Univ, Gorakhpur-273 009) : Mercuric chloride as ferroelectric material. Acta Cienc Indica-Phys 2006, 32(4), 405-8.

The variation of dielectric constant versus temperature of Mercuric Chloride has been studied from room temperature upto near melting point using capacitance bridge. It has been found that the compound has high dielectric constant which goes on increasing and attains a high value at 45øC (ε = 5440) and thereafter it decreases and becomes almost constant (ε = 130) about the temperature of 120øC or more. The high value of ε is mainly contributed by polarization. The results have been explained on the basis of temperature dependent activated polarization. At low temperatures electric field poles the non polar region, causing a breathing motion besides the flip-flopping motion.

2 illus, 9 ref

012507   Gulalkari R S;Bakale Y G;Deshmukh S H; Burghate D K;Deogaonkar V S (P.G. Physics Dep, Shri Shivaji Science College, Amravati-444 603) : Thermally stimulated discharge current (TSDC) of thermoelectret of polyvinyl chloride (PVC)-ploymethyl methacrylate (PMMA) blend film doped with polyaniline. Acta Cienc Indica-Phys 2006, 32(4), 429-32.

TDSC technique has peen used for the study of polymer blend of polyvinylchloride and 'Polymethylmethacrylate doped with conducting polymer polyaniline. The sample is in the form of a thin film 0.01 mm thick poled at different poling fields, thereby forming a thermoelectret. Thermally stimulated discharge current of this thermoelectret reveals that appreciable dis-rge current appears at higher values of poling fields Ep = 300 kv/m to 1500 kv/m. This has ascribed to be due to greater alignment of dipoled at higher fields which subsequently, on heating produce greater current during polarisation. These discharge current peaks for Ep 1500 kv/m are observed at temperatures, at regular intervals, of approximately 10øC steps, may probably be due to the release of charge carriers front equally spaced depths in the polyblends. The order of discharge current is slightly higher which may be due to the presence the conducting polymer poly aniline used as dopant.

2 illus, 13 ref

012506   Geetha D;Rajeshwari M K;Ramesh P S (Physics Dep, Annamalai Univ, Annamalainagar-608 002, Tamil Nadu) : Ultrasonic investigations on aqueous solutions of polymer blends. Acta Cienc Indica-Phys 2006, 32(4), 409-11.

Ultrasonic velocity at a frequency of 3 MHz was measured as a function of concentration ratio in ternary solutions of MC + PEG + water and NaCMC + PEG + water. From the measured experimental data and the values of acoustical parameters, the molecular interaction between the two different molecules in the mixture was discussed.

1 table, 7 ref

012505   Dhana Lakshmi Y;Srinivas V (Computer Science and Engineering Dep, Acharya Nagarjuna Univ, Nagarjuna Nagar-522 001) : Studies on the efficiency of single server queue model. Acta Cienc Indica-Phys 2006, 32(4), 505-7.

The paramount importance of Internet gateway has been realized in the recent past in the light of server based queue model Deals with M/G/l/N queue model and the efficiency of the system has been estimated qualitatively and quantitatively with three fold and four fold analyses.

2 illus, 15 ref

012504   Chernova S P;Pravdin A B (Saratov, State Univ, 83 Asrakhanskaya, 410012 Saratov, Russia, Email: chernova@optics.sgu.ru) : Development of the multiplayer phantoms for spectrofluorimetric studies. Asian J Phys 2006, 25(1), 119-29.

Development (the selection of structure and composition) and the procedure of preparation of multilayer phantoms of biological tissue, intended for spectrofluorimetric studies, are described. Under UV excitation, λ_ex = 360 ± 20nm, the phantoms obtained reproduce within the range 400 - 650 nm the fluorescence spectrum of normal tissue and the alterations in the spectrum caused by the disappearance of squamous epithelium. The adequacy of reproduction of fluorescent properties is ensured by the use of natural fluorophors and hemoglobin in phantoms and by the simulation of the structure and optical properties (coefficients of scattering and absorption) of the biological object. Based on measurements on the phantoms of different composition the assumption about the nature of the weakly expressed maximum (λ_ex ≈ 510 nm) observed in the fluorescence spectra of real tissue is put forward.

5 illus, 5 ref

012503   Cheng T;Fang Z;Zou C;Hu Q;Hu B;Yang X;Zhang Y (Chemistry Dep, Research Centre of Tobacco and Health, Univ Science and Technology of China, Hefei 230026, P.R. China, Email: zyj@ustc.edu.cn) : One-step single source route to carbon nanotubes. Bull Mater Sci 2006, 29(7), 701-4.

Carbon nanotubes (CNTs) have been synthesized via directly pyrolyzing ferrocene in the autoclave. The nanotubies with several micrometers' in length have outer and inner diameters in the range of 40-100 nm and 20-40 nm, respectively. An yield of <126>70 % of CNTs can be obtained without any accessorial solvents and catalysts. Experimental results showed that a temperature higher than 600°C in conjunction with piroper pressure was favourable for achievement of the nanotubes. The growth mechanism of CNTs was also discussed.

4 illus, 28 ref

012502   Chauhan R S;Pal M L;Dubey G S (Physics Dep, R.P.G. College, Jamuhai, Jaunpur (U.P)) : Some exact solutions in string cosmology. Acta Cienc Indica-Phys 2006, 32(4), 433-8.

Study the Letelier model in the context of Bianchi types II, VI VIII and IX. Author reproduced Einstein equations coupled to a cloud of strings, derived the solutions and conclude with a brief discussion of the solutions.

1 table, 15 ref

012501   Bednov A A;Oraevsky A A (Microbiology & Immunology Dep, Univ of Texas, Medical Branch 301 Univ Blvd, Galveston, Texas 77555, USA) : Comparison of glucose effect in model media and biological tissue measured using time-resolved optoacoustic method. Asian J Phys 2006, 25(1), 55-66.

Time-resolved optoacoustic (OA) method of monitoring the absorbed laser energy distribution in tissues was employed to measure changes in glucose concentration in phantoms and tissue in vitro. Increase in glucose concentration in aqueous media containing scattering particles/fibers causes reduction in optical scattering. The values of optical attenuation coefficient, μ_eff also decrease and can be found by measuring the time-resolved OA profiles. Glucose effect has been studied in phantoms and then in rabbit sclera in vitro at the wavelength, λ = 355 nm. In the present study, the forward and backward modes of OA detection were employed. Experimental results demonstrated that a one-millimolar (mM) increase in glucose level resulted in a decrease of μ_eff (5 x 10^-4 in phantoms and 2 x 10^-3 in sclera in vitro). It was found that both the amplitude and profile of OA signal were influenced by the experimental conditions. Physiological factors capable of affecting the accuracy of measurements have been analayzed.

4 illus, 52 ref

012500   Bashkatov A N;Korolevich A N;Tuchin V V; Sinichkin Y P;Genina E A;Stolnitz M M;Dubina N S;Vecherinski S I; Belsley M S (Institute of Optics and Biophotonics, Optics and Biomedical Physics De, State Univ Saratov, Russia) : In vivo investigation of human skin optical clearing and blood microcirculation under the action of glucose solution. Asian J Phys 2006, 25(1), 1-14.

Presents experimental results on optical properties of the human skin controlled by administration of the 40%-glucose solution. In vivo reflectance spectra of the human skin were measured. Results of the experimental study of influence of the 40%-glucose solution on reflectance spectra of the human skin are presented. A significant decrease of reflectance of the human skin under action of the osmotic agent is demonstrated. The experiments show that administration of the glucose solution allows for effective control of tissue optical characteristics, that makes skin more transparent, thereby increasing the ability of light penetration through the tissue. Laser Doppler flowmetry has been used for study of skin blood microcirculation under the action of the glucose solution. Results of the experiments demonstrated that at the action of the glucose solution blood perfusion and blood concentration increase, however the mean blood velocity does not change. The presented results can be used in developing functional imaging techniques, including OCT and reflectance spectroscopy. A potential benefit of the optical clearing technique is the improvement of laser therapeutic techniques that rely on sufficient light penetration to a target embedded in tissue.

9 illus, 81 ref

012499   Bakklalakshmi S;Shanthi B;Premalatha M (Physics Dep, Annamalai Univ, Annamalai Nagar-608 002) : Impact of citric acid and malic acid on N, N-dimethylaniline. Acta Cienc Indica-Phys 2006, 32(4), 483-6.

Quenching of fluorescence of N,N-dimethylaniline by citric acid and malic acid has been studied in 1,4-dioxane solvent at room temperature to understand the quenching mechanism. Stern-Volmer plot has been found to be linear for both the, quenchers. Regression sufficient (r), the Stern-Volmer constant (K_sv), Stokes shift, ionization potential, electron *** and the solvent parameter have also been, calculated. The results suggest that the quenching here is not static but dynamic in nature.

3 illus, 2 tables, 3 ref

012498   Bains B S (Physics Dep, Punjabi Univ, Patiala-147 002) : Mirror symmetry of π<. Acta Cienc Indica-Phys 2006, 32(4), 393-6.

3 illus, 7 ref

012497   Bagade S;Zatale D;Ghosh S (Physics Dep, Govt. Ismail Yusuf College, Mumbai) : Ultrasonic analysis in the binary mixtures of aniline + pyridine. Acta Cienc Indica-Phys 2006, 32(4), 413-16.

The values of sound velocity density have been measured at 308 K to 318 K in the system of aniline + pyridine. From these data, acoustical parameters such as free length, acoustical impedance Z, ultrasonic velocity using free length theory and excess parameters V^E and βa^E were estimated using the standard relation. The results are interpreted in terms of molecular Interaction.

3 illus, 8 ref