014699   Poonia S;Soni S N (Division of Natural Resources and Environment, Central Arid Zone Research Institute, Jodhpur-342 003, Email: surendra_1975@yahoo.com) : Lβ₁ satellites in X-ray emission spectra of 4d transition elements. Indian J pure appl Phys 2006, 45(2), 119-26.

The X-ray satellite spectra arising due to 2p_1/2^-13x^-13d^-1 (x = s, p, d) transition array, in elements with Z = 40 to 50, have been calculated. The energies of various transitions of the array have been determined by using available Hartree-Fock-Slater (HFS) data on 1s^-1-2p^-13x^-1, 3x^-1 Auger transition energies and their relative intensities of all the possible transitions have been estimated by considering cross - sections for the Auger transitions simultaneous to a hole creation and then distributing statistically the total cross-sections for initial two hole states 2p_1/2^-13x^-1 amongst various allowed transitions from these initial states to 3x^-1 3d^-1 final states by Coster-Kronig (CK) and shake off processes. In both these processes, initial single hole creation is the prime phenomenon and electron bombardment has been the primary source of energy. Each transition has been assumed to give rise to a Gaussian line and the overall spectrum has been computed as the sum of these Gaussian curves. The calculated spectra have been compared with the measured satellite energies in Lβ₁ spectra. Their intense peaks have been identified as the observed satellite lines. The peaks in the computed satellite spectra have been compared with the experimentally reported satellites β1^I, β1^II, β1^III and β1^IV, which lie on the high-energy side of the Lβ1 dipole line.

4 illus, 5 tables, 20 ref

014698   Pawan Kumar;Aravind Kumar;Dixit P N;Sharma T P (Physics Dep S C R I E T, C C S Univ, Meerut-250 004) : Optical, structural and electrical properties of zinc sulphide vacuum evaporated thin film. Indian J pure appl Phys 2006, 44(9), 690-3.

The II-VI group semiconductors are of great importance due to their applications in various opto-electronic devices. Among these semiconductors, zinc sulphide film is the most suitable for its utility in opto-electronic devices. ZnS film has been prepared on glass substrates by using vacuum evaporation method. The optical properties, especially refractive index by transmission spectra of these films have been studied in the wavelength range 400-850 run using Manifaciers envelope method. The ZnS film has a direct band gap of 3.50 eV. The wurtzite structure of ZnS film has been confirmed by X-ray diffraction analysis. The electrical properties of ZnS especially dark conductivity and photoconductivity at different temperatures have also been studied.

4 illus, 2 tables, 15 ref

014697   Patra S (Physics Dep, G B Pant Agriculture & Technology Univ, Pantnagar- 263 145) : Surface phenomenon of chemisorption and its effect on density of states with reference to correlation on the metal surface. Indian J pure appl Phys 2006, 44(8), 616-19.

A change in density of states is obtained by inclusion of intra-atomic interaction term to the mixing Hamiltonian constructed due to chemisorbed adatoms with the clean metal surface. The double-time Green function technique was employed in the Zubarev's equation of motion formalism and in order to decouple the hierarchy of higher order Green functions Hartee-Fock decoupling approximation was assumed. From the corresponding surface Green function, the modified density of states was obtained through which chemisorption energy and energy of localization were estimated and it was found that they were of the same order as per the prediction.

2 illus, 10 ref

014696   Pant B D;Mahesh Kumar;Subha Lakshmi;Arora A; Prasad M;Sharma A;Patel M;Radhakrishnan S;Dwivedi V K (MEMS Laboratory, Central Electronics Engineering Research Institute, Pilani-333 031) : Fabrication of MEMS composite-polymer gas sensor arrays for electronic nose. Indian J pure appl Phys 2007, 45(4), 321-5.

Sensor arrays capable of sensing different gases combined with a sampling system and a means of pattern classification and recognition comprise a basic system for an 'Electronic Nose' A complete process for the fabrication of micro-cavities with sensing electrodes and volumes ranging from 2.5 to 12 nano-liters for the development of polymer gas sensors has been reported. An array of eight sensing cells in four sizes have been fabricated using SU-8 negative tone resist through UV-LIGA process developed at CEERI, Pilani. The length and width of the SU-8 cavities are: 250 x 250, 300 x 300, 500 x 500 and 500 x 600 micron and the depth of each of them was optimized to be 40 micron. These cavities filled with different polymer composites comprise the basic sensing cells for a variety of gases. The current paper presents the salient features of the fabrication process in detail and the results obtained in ethanol and methanol ambient using a polymer composite developed through dissolution of styrene and polyaniline in PMMA. A number of other composites such as Pc-Ppy, Pr-Ppy, Fc+-PPy have also been synthesized and tested for a high sensitivity in carbon monoxide.

8 illus, 9 ref

014695   Narasimha Reddy P;Ashok Kumar A;Jagadeswara Reddy K;Venkataramana Reddy S (Microelectronics Division, Department of Physics, Sri Venkateswara University, Tirupati-517 502) : Data acquisition system using matlab for deep level transient spectroscopy studies. Indian J pure appl Phys 2007, 45(3), 204-9.

A microcontroller (AT89S8252) based data acquisition system has been developed for acquiring and processing the data from a home built deep level transient spectroscopy (DLTS)system. User friendly menu driven software has been developed in Matlab for selection of different DLTS measurement modes, data acquisition modes, channels (four channels) selection and number of data points on a single transient. It can be operated in two data acquisition modes namely scan mode and continuous mode. The scan mode is used to perform online analysis and continuous mode for offline data analysis. The developed software is also useful to operate the DLTS system in any one of the two operating modes namely boxcar mode or high resolution mode. The versatility of the data acquisition system is that the software developed can be used to obtain I-V characteristics using commercially available source meters. Also deals with the different wavelet decomposition methods for DLTS data acquisition and processing.

7 illus, 15 ref

014694   Manoravi P;Joseph M;Balamurugan A K; Rajagopalan S;Ramamurthy P (Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam) : Boron isotope distribution in laser deposited thin films of B₄C. Indian J pure appl Phys 2006, 45(2), 131-4.

Isotope enrichment in laser-ablated plume is an interesting phenomenon. Compares the boron isotope distribution present in thin films of B₄C that are formed by pulsed laser deposition using nanosecond (ns) and picosecond (ps) pulse Nd-YAG lasers. With the ns laser beam, in the plume we could observe an isotope ratio of ¹⁰B/¹¹B as high as 0.9, but in the film one could hardly see any enrichment. With ps pulsed laser, the maximum value obtained for the ¹⁰B/¹¹B ratio is about 0.29 in the film.

4 illus, 12 ref

014693   Manoj Kumar;Kumar M (Departement of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar-263 145, Email: munish_dixit@yahoo.com) : Melting temperatures of solids using the theory of equation of state. Indian J pure appl Phys 2007, 45(3), 256-7.

A simple method based on the theory of equation of state of solids is used to predict the melting temperatures of sixteen alkali halide solids. The results are compared with the experimental data. A good agreement between theory and experiment supports the validity of the model used. The method can also be used to determine B'₀- when the melting temperatures are known.

1 table, 13 ref

014692   Mangal R K;Singh M;Vijay Y K;Avasthi D K (NO, Jaipur Engineering College & ResearchCenter, Jaipur) : Ion and electron beam irradation effects in Al-Sb bilayer thin films. Indian J pure appl Phys 2006, 44(9), 685-9.

Thin films having uniform thicknesses of aluminium over different thicknesses of antimony were prepared by thermal evaporation (resistive heating) method at the pressure 10^-5 torr. The samples were irradiated by Ag¹²⁺ heavy ions of energy 160 Mev at the fluence 2.2x10¹³ ions/cm². The similar set of these films have also been irradiated by electron beam having energy 10 keV for two hours. The optical absorption spectra and Rutherford back scattering analysis have been carried out for these films. X-ray diffraction spectra of virgin as well as ion irradiated sample, show orthorhombic structure of the films. These results show that the inter diffusion of bilayer with irradiation effects. It is also suggested that ion beam irradiation gives the better results in comparison to electron beam. These results confirm the mixing of Al/Sb bilayer by irradiation process.

10 illus, 1 table, 20 ref

014691   Manapuram R K;Ghosn M;Larin K V (Biomedical Optics Laboratory, Univ of Houston, N207 Engineering Bldg 1, Houstan, TX 77204-4006, Email: klarin@uh.edu) : Identification of artificial fingerprints using optical coherence tomography technique. Asian J Phys 2006, 15(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 we 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. Identifies presence of the artificial materials at all times. 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

014690   Mahesh Kumar;Mahant Prasad;Goswami N;Arora A; Pant B D;Dwivedi V K (NO, Central Electronics Engineering Research Institute, Pilani) : Deposition of low stress polysilicon thin films using low-pressure chemical vapour deposition. Indian J pure appl Phys 2007, 45(4), 400-2.

The deposition of polysilicon thin films on silicon wafers using low-pressure chemical vapour deposition (LPCVD) was carried out and the process parameters were optimized to obtain normal and low stress films. The films of thickness 150 nm to 2 microns were deposited on 4" and 6" silicon wafers and the thickness uniformity was measured using Dektak 6M surface profiler. The thickness variation across the wafer was found to be in 5-10% range. Stress measurements were carried out using X-ray diffraction method. Deposits low stress films with stress -14 MPa. The quality of the films was found to be good and they were used in fabrication of MEMS based silicon devices.

1 illus, 2 tables, 4 ref

014689   Madhu U;Mukherjee N;Bandyopadhyay N R;Mondal A (School of Materials Science and Engineering, Bengal Engineering and Science University, Shibpur, Howrah-711 103) : Properites of CdS and CdTe thin films deposited by an electrochemical technique. Indian J pure appl Phys 2007, 45(3), 226-30.

CdS and CdTe films have been deposited onto transparent conducting oxide (TCO) coated glass substrates using an electrochemical technique, where a cadmium foil was used as a sacrificial anode and no external bias being used during film deposition. The films were characterized using X-ray diffraction, scanning electron microscopy and optical absorption measurements. A CdS/CdTe thin film solar cell utilizing this deposition technique has been developed.

8 illus, 17 ref

014688   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, 15(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

014687   Li Weixue;Wang Q;Dai J (Physics Dep, State Key Laboratory of New Nonferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730 050, P R China, Email: jfdai@MIT.EDU@lut.cn) : Anistrpic properties of aligned SWNT modified poly (methyl methacrylate) nanocomposites. Bull Mater Sci 2006, 29(3), 313-16.

The poly (methyl methacrylate) (PMMA)/single-walled carbon nanotube (SWNT) composites with good uniformity, dispersion and alignment of SWNT were fabricated in an improved figuration process. The semidried mixture was stretched along one direction at a drawing ratio of 50 before it was dried, and then folded along the same direction stretching repeatedly for 100 times. The transmission electron microscopic (TEM) observation demonstrated that SWNT in the PMMA/SWNT composite tends to align in the stretching direction owing to a torque exerting on it in the stretching process. The electrical and mechanical properties of PMMA/SWNT composite were studied as a function of SWNT orientation and concentration. The aligned SWNT modified PMMA/SWNT composite presented highly anisotropic properties. The experimental results showed that the electrical conductivity and mechanical properties of composite rise with the increase of SWNT concentration, and that composite films showed higher conductivity and higher mechanical draw ratios along the stretched direction than perpendicular to it. The thermogravimetric analysis (TGA) revealed that embedding the SWNTs into the PMMA matrix also improves the thermal stability of the composite.

4 illus, 11 ref

014686   Kumar V;Pal K;Gupta G K (Physics Dep, D B S College, Dehradun, Uttaranchal) : Novel single resistance controlled sinusoidal oscillator using FTFN and OTA. Indian J pure appl Phys 2006, 44(8), 625-7.

A novel single resistance controlled sinusoidal oscillator using one p Four terminal floating nullor (pFTFN) and one Operational transconductance amplifier (OTA) to alongside two resistors and two capacitors, all ground, is presented. It is suitable for 1C implementation due to use of grounded capacitors. The oscillation frequency is adjustable through grounded resistor R₁ which can be made voltage variable.

3 illus, 15 ref

014685   Koul S K;Kumbhat A;Basu A (Center for Applied Research in Electronics, Indian Institute of Technology Delhi, Hauz-khas, New Delhi-110 016) : Micromachined conductor backed coplanar waveguides for millimeter wave circuit application. Indian J pure appl Phys 2007, 45(4), 336-44.

Conductor Backed Coplanar Waveguide (CBCPW) lines on Si micromachined substrate are in use for more than a decade, but their detailed analysis is still not available in the open literature. Presents design data and closed form expressions on characteristic parameters of CBCPW lines on Si-micromachined structures that are valid up to 40 GHz. Effect of various physical parameters are studied. Procedure for deriving lumped equivalent circuit models for discontinuities on Si-Micromachined substrate as a function of discontinuity physical parameters is also presented. Scattering parameters obtained from equivalent circuit models agree well with those obtained from full wave FEM for all the discontinuity structures. To show the usefulness of the data generated on discontinuities, design of a Ka-band band pass filter is described. The results presented are useful in designing micromachined components at microwave and millimeter wave frequencies.

14 illus, 20 ref

014684   Konda R B;Pushpanjali G M;Mulgi S N;Satnoor S K;Hadalgi P M;Hunagund P V (Applied Electronics Dep, Gulbarga Univ, Gulbarga-585 106) : Design of wideband and multiband microstrip array antennas. Indian J Radio Space Phys 2006, 35(5), 372-5.

Method for improving the impedance bandwidth of microstrip array antenna by incorporating a slot in the radiating patches is presented. It is further described by using a common parasitic element, which is gap-coupled to the radiating edges of the rectangular patches and embedding a slot in the parasitic element. The use of gap-coupling and slot in the parasitic element makes the antenna to have wider impedance bandwidth and leads to its operation at more than one band of frequencies. The design concepts of antenna are described and experimental results discussed. These antennas may find application in mobile communication.

9 illus, 1 table, 8 ref

014683   Khanna V K;Prasad M;Dwivedi V K;Chandra Shekhar;Pankaj A C;Basu J (NO, Central Electronics Engineering Research Institute, Pilani-333 031) : Design and electro-thermal simulation of a polysilicon microheater on a suspended membrane for use in gas sensing. Indian J pure appl Phys 2007, 45(4), 332-5.

A microhotplate array comprising four 100 μm x 100 μm unit cells has been designed. It has a multi-layer structure: Si-thermal oxide-polySi-PECVD (plasma enhanced chemical vapour deposition) oxide-Sputtered Pt-Gas sensing film (SnO₂). Electro-thermal simulation of the unit cell has been carried out using ANSYS. The simulations show that for an applied bias of 4 V a mean temperature of 706°C is obtained at the centre of the heater area. The heat is assumed to flow from the hot plate to the surrounding air at an ambient temperature of 30°C by conduction. The power dissipation is less than 50 mW. Presents the design methodology of the hotplate.

6 illus, 1 table, 9 ref

014682   Khanna V K (MEMS and Microsensors, Central Electronics Engineering Research Institute, Pilani-333 031, Email: vkk@ceeri.ernet.in) : Advances in chemical sensors, biosensors and microsystems based on ion-sensitive field-effect transistor. Indian J pure appl Phys 2007, 45(4), 345-53.

Introduces as a tool for electrophysiology three and a half decades ago, the ion-sensitive field-effect transistor (ISFET) is a generic electrochemical structure offering a family of analytical devices for applications in agriculture, food processing, medical diagnostics, pharmaceuticals, paper, pulp and chemical industries, and environmental control. Besides its use as a chemical sensor, this device has also served as the electrical transduction element for many enzyme and immunological biosensors. This paper presents the current status of this microelectronic device in terms of the theoretical understanding of its operational mechanism, the techniques used for its fabrication and the measurement circuits used in instrumentation. The state of the art of ISFET as a chemical and biosensor is examined, major problems in this area are discussed, perspectives of recent interesting developments are described and future research directions are indicated. Highlights of the work done on ISFET at our institute are presented.

7 illus, 121 ref

014681   Kannappan V;Indra Gandhi N (Postgraduate and Research Department of Chemistry, Presidency College, Chennai-600 005) : Ultrasonic studies on charge transfer complexes of certain aldehydes with benzylamine and cyclohexylamine as donors in n-hexane at 303K. Indian J pure appl Phys 2007, 45(3), 221-5.

The ultrasonic velocities (U), densities (ρ), and viscosities (η) were measured for solutions containing equimolar concentrations of eight aldehydes namely, benzaldehyde, o-chlorobenzaldehyde, anisaldehyde, p-tolualdehyde, cinnamaldehyde, crotonaldehyde, propionaldehyde, and valeraldehyde as acceptors, benzylamine and cyclohexylamine as donors in n-hexane at 303K. Acoustical parameters such as adiabatic compressibility (β), free length (L_f), viscous relaxation time (r), molecular interaction parameter (χ) have been computed. These values indicate the formation of charge transfer complexes between aldehydes and amines. Formation constant (K) values of the complexes have been evaluated using a modified Bhat equation proposed by Kannappan. The constant values of free energy of activation (ΔG^<35>) and relaxation time indicate the formation of similar type of complexes in these systems. However, the variation in free energy of formation (ΔG) values suggests that their thermodynamic stability depends on the structure of donor and acceptor.

6 illus, 4 tables, 13 ref

014680   Kannappan V;Chidambara Vinayagam S, (Postgraduate Chemistry Dep, Presidency College, Chennai-600 005) : Ultrasonic study ion-solvent interactions in aqueous and non aqueous solutions of transition and inner transition meatal ions. Indian J pure appl Phys 2006, 44(9), 670-6.

Ultrasonic velocities(u) and densities(ρ) of aqueous and dimethyl sulphoxide (DMSO) solutions of manganous(II) sulphate cobalt(II) chloride, nickel(II) sulphate, ferrous sulphate, copper(II) sulphate, zinc(II) sulphate, lanthanum(III) nitrate, cerium(IV) nitrate, uranyl nitrate and thorium(IV) nitrate in a wide range of concentrations at a temperature 303K have been measured. Acoustical parameters, such as, adiabatic compressibility (β), free length (L_f) and solvation number(S_n) are computed to assess the ion-solvent interaction in these solutions. It is found that the ion-solvent interactions depend on concentration, ionic size and nature of metal ion. The transition and inner transition metal ions behave as structure breaker for the associated clusters of water molecules, especially in dilute solution, as evidenced from the trend in the solvation number with molarity. It is also found that the strength of ion-dipole interaction in aqueous solution of the metal ion is also dependent on concentration.

4 illus, 7 tables, 14 ref

014679   Kannappan V;Chidambara Vinayagam S, (Post Graduate Dep of Chemistry, Presidency College, Chennai-600 005) : Ultrasonic investigation of ion-solvent interactions in aqueous and non-aqueous solutions of transition and inner transition metal ions. Indian J pure appl Phys 2006, 45(2), 143-50.

Ultrasonic velocities (u) and densities (p) have been measured for aqueous and dimethyl sulphoxide (DMSO) solutions of manganous(II) sulphate, cobalt(II) chloride, nickel(II) sulphate, ferrous sulphate, copper(II) sulphate, zinc(II) sulphate, lanthanum(III) nitrate, cerium(IV) nitrate, uranyl nitrate and thorium(IV) nitrate in a wide range of concentrations at 303 K. Acoustical parameters, such as, adiabatic compressibility (β), free length (Lf) and solvation number (S_n) have been computed to assess the ion-solvent interaction in these solutions. It is found that the ion-solvent interactions depend on concentration, ionic size and nature of metal ion. The transition and inner transition metal ions behave as structure breaker for the associated clusters of water molecules, especially in dilute solution, as evidenced from the trend in the solvation number with molarity. The strength of ion-dipole interaction in aqueous solution of the metal ion is also concentration dependent, which is also investigated in the present work.

2 illus, 7 tables, 14 ref

014678   Kal S;Das S (Department of Electronics & ECE, Advanced Technology Centre, Indian Institute of Technology, Kharagpur-721 302) : Development of silicon and quartz based MEMS high precision accelerometers. Indian J pure appl Phys 2007, 45(4), 299-303.

Conventional electro-mechanical inertial sensors are being replaced by MEMS versions which are miniature in size, light weight, cost effective, more reliable and sensitive, low power consuming and VLSI compatible. Although silicon is the most widely used material for MEMS, quartz has some advantage for realizing, inertial sensors due to its piezoelectric property. The R&D activities undertaken in the authors' laboratory in the area of MEMS based silicon and quartz acceleration sensors have been described. While the silicon accelerometer is based on the piezoresistive technique, the quartz double ended tuning fork (DETF) accelerometer works on the stress dependence of vibration frequency.

5 illus, 9 ref

014677   Joshi S J;Parekh B B;Vohra K D;Joshi M J (Physics Dep, Saurasthra University, Rajkot-360 005, Email: mshilp24@rediffmail.com.) : Growth and characterization of gel grown pure and mixed iron-manganese levo-tartrate crystals. Bull Mater Sci 2006, 29(3), 307-12.

Several applications of iron tartrate and manganese tartrate compounds are reported in the literature. Grown pure and mixed iron (II)-manganese levo-tartrate crystals by single, diffusion gel growth technique. Crystals with spherulitic morphology were harvested. The colouration of the crystals changed from black to pinkish brown upon increasing the content of manganese in the crystals. The crystals were characterized by FTIR spectroscopy, powder XRD, TGA, VSM and dielectric study. Crystal structures of different mixed crystals were studied. From TGA it was observed that on heating the hydrated crystals became anhydrous and then converted into oxides. Paramagnetic nature of the crystals was revealed from VSM study. The variation of the dielectric constant with frequency was studied. The results are disscussed.

5 illus, 1 table, 23 ref

014676   Joshi M;Kale N;Mukherjee S;Lal R;Ramgopal Rao V (Micro-fabrication Laboratory, Indian Institute of Technology Bombay, Mumbai-400 076, Email: rrao@ee.iitb.ac.in) : Affinity cantilever sensors for cardiac diagnostics. Indian J pure appl Phys 2007, 45(4), 287-93.

Cardiac problems are on the rise in the Indian sub-continent due to the changing life styles and food habits. Acute Myocardial Infraction (AMI) is becoming a major concern. Reports the development of affinity cantilever based sensors for the detection of AMI with optical and electrical readouts. We designed, simulated and fabricated these cantilevers with various micro fabricated materials such as silicon dioxide, silicon nitride and SU-8. Thin films such as silicon nitride and p-type polysilicon are deposited using hot wire CVD technique. For electrical detection, p-type polysilicon was used as a piezoresistive layer. The mechanical and electrical performance parameters of these cantilevers were investigated using Atomic Force Microscope (AFM) set-up. The top surface of these cantilevers was selectively immobilized with the antibodies. Following this, antibody specific antigens were allowed to react with the cantilever surface in the liquid cell of AFM set-up for the optical detection. For electrical signal detection, microcontroller based signal conditioning and digital readout circuit was developed.

10 illus, 16 ref

014675   Jianbin L (State Key Laboratory of Tribiology, Tsinghua University, Beijing 100084, China) : Variation of surface layer during chemical mechanical polish. Indian J pure appl Phys 2007, 45(4), 403-5.

Nanoparticles have been widely used in oils and polish slurry such as chemical mechanical polish (CMP) process. The movement of nanoparticles in liquid and the interaction between nano-particles and solid surface are very important to obtain an atomic smooth surface in CMP process. Presents both experimental and theoretical studies on the movement of nanoparticles in fluid and the collision between nanoparticles as well as that between the particles and solid surfaces in two phases flowing process.

6 illus, 6 ref

014674   Jia-tian Z;Ying-le L (School of Electronic Engineering, Xi'an Shiyou University, Xi'an-710 065) : A new research apporach of electromagnetic theroy and its applications. Indian J Radio Space Phys 2006, 35(4), 249-52.

A new research approach of electromagnetic theory is presented. The relations of electromagnetic parameters in the scale-transformation coordinate system and in the original coordinate system are presented. The applied fields of the scale-transformation theory are introduced. The result obtained with the scale-transformation theory is in agreement with that in the literature. The method presented has the characteristics of briefness and is of convenience in engineering.

2 illus, 8 ref

014673   Jain V K (CSIO (Delhi Centre), CSIR Complex, Pusa Campus, New Delhi-110 012) : Uncooled infrared detectors based on MEMS technologies. Indian J pure appl Phys 2007, 45(4), 304-10.

Uncooled infrared (IR) detectors are gaining importance over the HgCdTe based IR photon detectors because of their room temperature operation, low power consumption and smaller in size. Silicon micromachining has made it possible to make micro bolometer base IR detector. In a focal plane array (FPA), there is a two dimensional assembly of bolometers and each bolometer acts as a thermally sensitive pixel. The detector element consists of thermal sensitive material suspended above the readout electronics having an air gap of 2 micron and supported by thermally isolated hinges. The most important task is to design the structure of the sensor having the lowest possible thermal conductance. The characterization gives that thermal conductance and thermal mass are the deciding factors for the higher responsivity and detectivity. This paper presents a modified design based on thermal characterization of the membranes of micro bolometer. Based on our theoretical analysis, the required thermal conductance can be achieved even with short hinges. This can be done by reducing the thermal conductivity of the material of hinges. Our experimental investigations are in good agreement with this concept. This will also enhance the fill factor of the two dimensional IR array.

5 illus, 8 ref

014672   Issac Samuel E;Seshu Bai V (Mechanical Mettalugry Division, Indira Gandhi Centre for Research, Kalpakkam-603 102, Email: issac @igcar.gov.in) : ac MH loop measurements on Mn doped YBa₂Cu₃O₇-δ superconductors. Bull Mater Sci 2006, 29(3), 201-5.

Isothermal ac MH (magnetization-field) loops for varying field amplitudes were recorded at 77 K on YBa₂(Cu_1-xMn_x)₃O_7-γ with x = 0, 0.010, 0.015, 0.020, 0.025, 0.035 and 0.050, YBa₂(Cu_0.075Fe_0.025)₃O_{7-δ, YBa2(Cu0.075Ni0.025)3O7-δ and YBa2(Cu0.075Zn0.025)3O7-δ samples up to a maximum field amplitude of 80 Oe. Flat band susceptibility, ac losses and flux profiles were deduced from the ac MH loops. The undoped sample exhibited a minimum weak link ac loss and the 5.0% doped sample showed maximum weak link ac loss. Ni and Fe doped samples showed higher granular losses. Jcg estimated from the flux profiles decreases monotonically with increasing concentrations of Mn up to 2.5%.}

5 illus, 1 table, 20 ref

014671   Harish Bahadur, et al (National Physical Laboratory, , Dr K S Krishnan Road, New Delhi-110 012) : Nano-structured ZnO films by sol-gel process. Indian J pure appl Phys 2007, 45(4), 395-9.

Thin films of ZnO grown by sol-gel spin method using two different precursors viz. zinc nitrate and zinc acetate have been characterized for their crystalline nature and associated nanostructures. In some cases, the films consist of nanostructures in the form of nanocrystals and nanoneedles of dimensions in the range 15-60 nm. A comparison between the physical characterization and the nanostructures of the films grown by two different precursor materials has been presented and the results are discussed in terms of the fundamental considerations governing the growth kinetics of the ZnO films.

10 illus, 6 ref

014670   Hao Y (National key Lab of Micro/Nano Fabrication Technology, Institute of Microelectronics, Peking University, Beijing, 100 871, Email: ylhao@ime.pku.edu.cn) : Silicon-based MEMS fabrication technique and standardization. Indian J pure appl Phys 2007, 45(4), 317-20.

The silicon-based MEMS fabrication technology, including bulk micromachining and sacrificial layers technology have been developed and studied. The 3-D fabrication and integration of silicon-based MEMS and standard process fabrication have been studied in the present paper.

5 illus, 7 ref

014669   Gunasekaran S;Seshadri S;Muthu S (PG & Research Physics Dep, Pachaiyappa's College, Chennai-600 030) : Vibrational spectra and normal coordinate analysis of flucytosine. Indian J pure appl Phys 2006, 44(8), 581-6.

A normal coordinate analysis on flucytosine has teen carried out with a systematic set of symmetry coordinates following Wilson's F-G matrix method. The potential constants evaluated for the molecule are found to be in good agreement with literature values thereby confirming the vibrational assignments. To check whether the chosen set of vibrational frequencies contributes maximum to the potential energy associated with the normal coordinates of the molecule, the potential energy distribution has been evaluated.

3 illus, 1 table, 20 ref

014668   Goswami N;Krishan Lal;Miao J;Hartnagel H L (National Physics Laboratory, , New Delhi-110 012, Email: ngoswami@mail.nplindia.ernet.in) : Microfabrication and characterization of gallium arsenide membranes for force sensor applications. Indian J pure appl Phys 2007, 45(4), 382-6.

High-precision force sensors based on membranes of semi-insulating gallium arsenide with stable structures had been fabricated by micromachining. Their structural quality had been evaluated by high-resolution X-ray diffraction techniques. Free hanging membranes with thicknesses of <62> 2μm have been synthesized by utilizing photolithography, implantation and selective etching. Starting wafers were (100) n-type GaAs crystals with n = 3.5 x 10¹⁷ cm^-3. Implantation by 4 MeV N²+ (dose ≈ 10¹⁵cm^-2) produced N compensated semi-insulating GaAs with a resistivity of 10⁹Ω cm and breakdown voltage of <126>60 V. An <126> 100 μm deep cavity below the membrane was produced by selective etching. A typical sensor was coiled shaped with five segments. The five-crystal X-ray diffractometer developed at NPL was employed in (+, -, +) configuration for structural characterization of the final device structures. A highly monochromated and well-collimated Mo Kα1, X-ray beam of very narrow lateral width (<126> 10 μm) was employed as the exploring beam. Specimens were studied in symmetric as well as in highly asymmetric Bragg geometries with (400) and (511) diffracting lattice planes, respectively. Crystalline quality, tilt between adjoining sensor segments and the level of stress in the specimens were determined.

3 illus, 9 ref

014667   Ganguly P;Biswas J C;Lahiri S K (Integrated Optics Laboratory, Advanced Technology Centre, Indian Institute of Technology, Kharagpur-721 302, Email: pran@ece.iitkgp.ernet.in) : Design of single mode annealed proton exchange LiNbO₃ waveguides by effective-index based matrix method. J Optics 2006, 35(1), 51-62.

Effective-index based matrix method is used to analyse annealed proton exchanged (APE) LiNbO₃ waveguides. The variation of refractive index with the fabrication parameters, such as, exchange time, annealing time, waveguide width, and transmitting wavelength has been studied. The computed surface refractive index changes of the waveguides are compared with the published experimental results. The 2D transverse refractive index profile of the APE lithium niobate waveguide is transformed to the laterial ID effective index profile by WKB method, which is then discretised using a partitioning scheme. The matrix method is then applied to obtain the propagation constants of the guided modes. Variation of propagation constant with the fabrication parameters of APE waveguide is studied and the single mode APE lithim niobate channel waveguides has been designed.

5 illus, 1 table, 22 ref

014666   Gaikwad S A;Samuel E P;Patil D S;Gautam D K (Department of Electronics, North Maharashtra University, Jalgaon-425 001, Email: israiel_jal@sancharnet.in) : Temperature dependent analysis of refractive index band gap and recombination coefficient in nitride semiconductor lasers. Indian J pure appl Phys 2007, 45(3), 238-42.

Temperature dependent analysis of recombination coefficient, band gap and refractive index has been carried out to explore applicability of nitride lasers at higher temperatures. To estimate recombination coefficient at various temperatures Shockley-van Roosbroeck model has been used. Our results reveal that refractive index increases in linear manner with temperature and indium mole fraction in InGaN. However, refractive index was found to be decreasing with Al mole fraction and temperature in non-linear manner. The band gap deduced from our analysis was found to be increasing with Al mole fraction and decreasing with In mole fraction and therefore, these alloys provide better opportunity to form effective heterostructures with GaN. The recombination coefficient analysed, was observed to be decreasing non-linearly with band gap and temperature for AlGaN. However, in case of InGaN, the recombination coefficient shows linear increase with band gap and non-linear decrease with temperature.

5 illus, 20 ref

014665   Dua P;Panwar S;Singh I (Physics Dep, Indian Institute of Technology, Roorkee-247 667) : Role of inter-site hybrid interactions itinerant ferromagnetism. Indian J pure appl Phys 2006, 44(9), 677-84.

The role of inter-site hybrid interactions in deciding ferromagnetic state in the itinerant electron (narrow band) systems like some of the transition metals has been studied: Considered Hubbard like tight binding model alongwith exchange and hybrid interactions. All interactions have been treated within mean-field approximation. It is found that hybrid interactions play significant role at zero as well as finite temperatures in deciding on-set of ferromagnetic state. The variation of effective mass of up and down spin electrons in ferromagnetic state as a function of temperature has been studied. The magnetic susceptibility, optical conductivity and magnetoresistance as a function of temperature have also been studied.

10 illus, 20 ref

014664   Dharmaraj T;Murthy B S;Sivaramakrishnan S (NO, Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pune-411 008) : Vertical structure of the lower atmosphere over the Arabian Sea and West Coast station during weak phase of the Indian summer monsoon. Indian J Radio Space Phys 2006, 35(6), 418-23.

The height of the day time mixed layer, vertical structure of the atmospheric boundary layer (ABL) and its variation over the Arabian Sea (hereafter Sea) and the West Coast Station (Goa: 15°21' N, 73°51' E) during the weak phase of south-west monsoon (20-24 July 2002) have been calculated using Radiosonde, the surface meteorological data collected at 12 m above mean sea level onboard ORV Sagarkanya and at Goa during ARMEX-fr, It is observed that the depth of mixed layer over Goa and offshore was about 1 km during the period, while the first 200 m was showing super adiabiitic lapse rate over Goa but not over the Sea. The marine atmospheric boundary layer is found to be well-mixed with its height, progressively increasing from 750 m to 1000 m during 21-24 July 2002. The vertical profiles of virtual potential temperature show an inversion above 1 km, which was very steep over both the Sea and Goa. The relative humidity (RH) in the mixed layer (0-1 km AGL) was varying from 70 to 100% over the sea, whereas over Goa it was from 70 to 90% during 20-24 July 2002. Above 2-3 km, RH decreases from 70% to 30% over the Arabian Sea and Goa on 24 July, indicating the presence of subsiding warm and relativley dry layer.

7 illus, 1 table, 5 ref

014663   Dash U N;Roy G S;Mohanty S;Ray M (Chemistry Dep, Utkal University, Bhubaneswar-751 004) : Thermo-acoustic study of cobalt (III) complexes in aqueous and binary aqueous media. Indian J pure appl Phys 2006, 45(2), 151-6.

The acoustic response of the solutions of trans-bis (1,2-diaminoethane) (amino-carboxylato) halogeno cobalt-III complexes containing the carboxylato-bonded aminoacids e.g glycine, alanine and alanine in aqueous and aquo-organic solvent systems has been investigated at 303.15, 308.15 and 313.15K. From the measured ultrasonic velocities, acoustic parameters like intermolecular free length, free volume, internal pressure etc. have been determined and interpreted to study the intramolecular and intermolecular interactions and various structural effects of the solvent in the solution.

4 illus, 4 tables, 15 ref

014662   Chernova S P;Pravdin A B (NO, Saratov State Univ, 83 Asrakhanskaya, 410012 Saratov, Russia) : Development of the multiplayer phantoms for spectrofluorimetric studies. Asian J Phys 2006, 15(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, A = 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 (A_cm = 510 nm) observed in the fluorescence spectra of real tissue is put forward.

5 illus, 15 ref

014661   Chandra S;Bhatt V;Ravindra Singh;Sharma P;Pal P (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, Hauz-khas, New Delhi-110 016, Email: schandra@care.iitd.ernet.in) : MEMS prototyping using RF sputtered films. Indian J pure appl Phys 2007, 45(4), 326-31.

The deposition and characterization of dielectric, piezoelectric, semiconductor and conductor films by RF diode / RF magnetron sputtering process for applications in MEMS fabrication have been reported. Thin films of silicon dioxide, silicon nitride, amorphous silicon, zinc oxide and lanthanum doped lead zirconate titanate (PLZT) were prepared by RF sputtering process and extensively characterized for their structural, optical, and electrical properties. Thin films of conducting materials which are commonly used in MEMS fabrication (Cr, Au, Ti, and Pt) were also prepared by the same process. A few applications of these films in MEMS are demonstrated. It has been concluded that RF sputtering can be advantageously used for rapid prototyping of MEMS and demonstrating new ideas especially by researchers who do not have access to a well-established MEMS foundry.

11 illus, 13 ref

014660   Brahma R;Ghanshyam Krishna M;Bhatnagar A K (School of Physics, University of Hyderabad, Hyderabad-500 046, Email: mgksp@uohyd.ernet.in) : Optical, structural and electrical properties of Mn doped tin oxide thin film. Bull Mater Sci 2006, 29(3), 317-22.

Mn doped SnO_x thin films have been fabricated by extended annealing of Mn/SnO₂ bilayers at 200°C in air for 110 h. The dopant concentration was varied by controlling the thickness of the metal layer. The overall thickness of the film was 115 nm with dopant concentration between 0 and 30 wt% of Mn. The films exhibit nanocrystalline size (10-20 nm) and presence of both SnO and SnO₂. The highest transmission observed in the films was 75% and the band gap varied between 2.7 and 3.4 eV. Significantly, it was observed that at a dopant concentration of -4 wt% the transmission in the films reached a minimum accompanied by a decrease in the optical band gap. At the same value of dopant concentration the resistivity also reached a peak. This behaviour appears to be a consequence of valence fluctuation in Sn between the 2+ and 4+ states. The transparent conductivity behaviour fits into a model that attributes it to the presence of Sn interstitials rather than oxygen vacancies alone in the presence of Sn₂₊.

5 illus, 25 ref

014659   Biswas P K;Del A;Dua L K;Chkoda L (Sol-Gel Div, Central Glass and Ceramic Researeh Institute, Kolkata-700 032, Email: pkbiswas@cgcri.res.in) : Surface charecterization of sol-gel derived indium tin oxide films on glass. Bull Mater Sci 2006, 29(3), 323-30.

Indium tin oxide (ITO) films containing different In : Sn atomic ratios, viz. 90 :10, 70 : 30, 50 : 50, 30 : 70, were deposited on two types of glass substrates by sol-gel spinning technique. XPS analysis of the films was done under as-received and after-sputtering conditions. The narrow spectra obtained for the Nals, In3d, Sn3d and Ols have been discussed. Oxygen was found to exist in three chemical environments in as-received samples due to the existence of (i) environmental hydroxyl (-OH) group, (ii) crystalline ITO and (iii) amorphous ITO; but it was in two chemical environments, (ii) and (iii), after surface cleaning by sputtering. The presence of both tin metal and tin oxides was confirmed by the peak analysis of Sn3d. The In : Sn atomic ratio taken in the precursor sols did not change considerably in the case of developed films of low Sn content, but considerable change was observed in the films having high Sn content.

4 illus, 3 tables, 33 ref

014658   Binu S;Mahadevan Pillai V P;Chandrasekaran N (Optoelectronics Dep, University of Kerala, Thiruvananthapuram-695 581) : OTDR based fiber optic microbend sensor for distributed sensing applications in structural pressure monitoring. 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. This article 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

014657   Bhatti H S;Gupta A;Verma N K;Sunil Kumar (Physics Dep, Punjabi University, 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

014656   Bhattacharya P P;Banerjee P K (Electronics and Communication Engineering Dep, Netaji Subhash Engineering College, Techno City, Police Para, Garia, Email: partha_p_b@yahoo.com) : New velocity dependent variable hysteresis-margin-based call handover scheme. Indian J Radio Space Phys 2006, 35(5), 368-71.

The increase of mobile users compels the uses of picocells in cellular mobile communication and the task of handover becomes critical. Handover response should be faster and also should depend on mobile velocity to avoid unwanted call termination for high velocity mobiles and unnecessary handover for low velocity mobiles. In this paper, a path loss exponent and user-velocity-dependent variable hysteresis-margin-based call handover algorithm is proposed and studied. The handover algorithm is tested and found to give desired response.

6 illus, 13 ref

014655   Bhatt V;Chandra S;Sushil Kumar;Rauthan C M S; Dixit P N (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, New Delhi-110 016, Email: schandra@care.iitd.ernet.in) : Stress evaluation of RF sputtered silicon dioxide films for MEMS. Indian J pure appl Phys 2007, 45(4), 377-81.

The stress evaluation of RF sputtered silicon dioxide films for MEMS applications has been reported. The films were deposited in argon atmosphere in the pressure range 5-20 mtorr at 300 W RF power using a 3 inch diameter silicon dioxide target. The stress measurements were carried out using wafer curvature technique. All the deposited films show compressive stress except the film having thickness less than 5000 angstrum. It is observed that sputtering pressure, film thickness and annealing temperature affect the stress in SiO₂ films. The dependence of deposition rate and etch rate on the deposition parameters were also investigated. To obtain the minimum stress in the film, the deposition parameters are optimized. An array of cantilever beams of sputtered silicon dioxide film was fabricated. It was observed that beams up to 500 micron length show no upward or downward bending indicating low stress in the films deposited under optimized conditions.

6 illus, 1 table, 10 ref

014654   Bhat K N (ECE Department, Indian Institute of Science, Bangalore-560 012) : Wafer bonding - a powerful tool for MEMS. Indian J pure appl Phys 2007, 45(4), 311-16.

Wafer bonding techniques play a key role in the present day silicon bulk micromachining for MEMS based sensors and actuators. Various silicon wafer bonding techniques and their role on MEMS devices such as pressure sensors, accelerometers and micropump have been discussed. The results on the piezoresistive pressure sensors monolithically integrated with a MOSFET differential amplifier circuit have been presented to demonstrate the important role played by the Silicon Fusion Bonding technique for integration of sensors with electronics on a single chip.

11 illus, 8 ref

014653   Bhat J S;Maddani K I;Karguppikar A M (Physics Dep, Karnatka University, Dharwad-580 003, Email: js_bhat@hotmail.com) : Infulunce of Zn doping on electrical and optical properties of multialyered tin oxide thin films. Bull Mater Sci 2006, 29(3), 331-7.

Electrical and optical properties of Zn doped tin oxide films prepared using sol-gel spin coating process have been investigated. The SnO₂: Zn multi-coating films were deposited at optimum deposition conditions using a hydroalcoholic solution consisting of stannous chloride and zinc chloride. Films with Zn doping levels from 0-10 wt% in solution are developed. The results of electrical measurements indicate that the sheet resistance of the deposited films increases with increasing Zn doping concentration and several superimposed coatings are necessary to reach expected low sheet resistance. Films with three coatings show minimum sheet resistance of 1.479 kΩ in the case of undoped SnO₂ and 77 kΩ for 5 wt% Zn doped SnO₂ when coated on glass substrate. In the case of single layer SnO₂ film, absorption edge is 3-57 eV and when doped with Zn absorption edge shifts towards lower energies (longer wavelengths). The absorption edge lies in the range of 3.489-3.557 eV depending upon the Zn doping concentration. The direct and indirect transitions and their dependence on dopant concentration and number of coatings are presented.

10 illus, 2 table, 28 ref

014652   Bedrrov A A;Oraevsky A A (Microbiology & Immunology Dep, Univ of Texas Medical Branch, 301 University 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, 15(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, A = 355 nm. In the 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 2x10^-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 analyzed.

4 illus, 52 ref

014651   Baskaran R;Subramanian V;Selvakumaran T S (Radiology Safety Div, Safety Group, Indira Gandhi Center for Atomic Research, Kalpakkam-603 102) : Real time measurement of aerosol size distribution using mastersizer. Indian J pure appl Phys 2006, 44(8), 576-80.

An Aerosol Test Facility (ATF) has been set-up at Radiological Safety Division (RSD), Indira Gandhi Center for Atomic Research (IGCAR), Kalpakkam, for the aerosol studies on fast reactor safety. In order to measure the Mass Median Diameter (MMD) of the aerosols in real time, a laser based instrument MASTERSIZER (M/s MALVERN, UK) is used. Mastersizer is provided with a liquid flow cell and a ponder spray unit which are useful for the off-line measurement. For the real time measurement, an aerosol flow cell is designed and fabricated. It is integrated with the MASTERSIZER and the aerosol chamber of ATF. Aerosols are drawn through the aerosol flow cell whose optical windows are aligned with the laser path of MASTERSIZER. In this paper, the details and the performance test results of the aerosol flow cell are presented. Performance test of the aerosol flow cell is carried out with polystyrene latex particles of diameter 2.799 <109>m and methylene blue aerosols. Sodium oxide aerosols are generated and injected into the aerosol chamber, and the time evolution of MMD of sodium oxide aerosols has been studied.

6 illus, 1 table, 13 ref

014650   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 (Dep of Optics and Biomedical Physics of Saratov State Univ, Institute of Optics and Biophysics, Saratov, Russia) : In vivo investigation of human skin optical clearing and blood microcirculation under the action of glucose solution. Asian J Phys 2006, 15(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