012185   Rameshbabu N;Sampath Kumar T S;Prasad Rao K (Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai-600 036, Email: kpr@iitm.ac.in) : Synthesis of nanocrystalline fluorinated hydroxyapatite by microwave processing and its in vitro dissolution study. Bull Mater Sci 2006, 29(6), 611-5.

Synthetic hydroxyapatite, (Ca₁₀(PO₄)₆(OH)₂, HA), is an important material used for orthopedic and dental implant applications. The biological hydroxyapatite in the human bone and tooth is of nanosize and differs in composition from the stoichiometric HA by the presence of other ions such as carbonate, magnesium, fluoride, etc. Osseointegration is enhanced by using nanocrystalline HA. This stimulates the interest in synthesizing nanocrystalline HA by different routes and among the methods, microwave processing seems to form the fine grain size and uniform characteristic nanocrystalline materials. Fluorinated hydroxyapatite, (FHA, Ca₁₀(PO₄)₆(OH)_2-xF_x, possesses higher corrosion resistance in biofluids than pure HA and reduces the risk of dental caries. Deals with the synthesis of nanocrystalline FIIAs by microwave processing. The crystal size and morphology of the nanopowders were examined by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) methods. The functional groups present in FIIA powders were ascertained by Fourier transform infrared spectroscopy (FT-IR) and laser Raman spectroscopy. Since the physiological stability is an important parameter while selecting the material for implantation, the in vitro dissolution studies of FHAs with different fluorine contents were carried out.

6 illus, 1 table, 17 ref

012184   Raina K K;Pankaj Kumar;Malik P (School of Physics and Materials Science, Thapar Institute of Engineering and Technology, Patiala-147 004, Email: rainatietp@yahoo.com) : Morphological control and polarization switching in polymer dispersed liquid crystal materials and devices. Bull Mater Sci 2006, 29(6), 599-603.

Liquid crystals dispersed in polymer systems constitute novel class of optical materials. The precise control of the liquid crystal droplet morphology in the polymer matrix is essentially required to meet the prerequisites of display device. Experiments have been carried out to investigate and identify the material properties and processing conditions required for the precise control of the droplet morphology of the dispersed liquid crystal systems. Polarization switching has been studied. Aligned liquid crystal dispersed systems showed higher polarization over unaligned ones.

6 illus, 1 table, 16 ref

012183   Pradhan M;Verma G R;Ashplya B M (Mining Engineering Dep, National Institute of Technology, Raipur) : Evaluation of explosive performance by continuous in hole VOD measurement in full scale blast environment. Indian Min Engng J 2006, 45(9), 14-17.

Explosive has to perform under different blast environment that affects its performance. Continuous in-hole VOD measurement is used for performance evaluation of explosive in full-scale blast environment. It provides a detailed picture of the detonation of explosive that took place inside the hole. The information so provided can be used for selection of explosives, site-specific custom blast designing, for diagnosing the blast failure problems and for evaluating the performance of an explosive in a particular set of blast environment conditions.

10 illus, 8 ref

012182   Pradhan G K;Pradhan M (NO, IBP Co. Ltd, Kusmunda, Chhattisgarh) : Mineral resources & development scenario of Chhattisgarh. Indian Min Engng J 2006, 45(11), 37-44.

1 illus, 8 tables, 7 ref

012181   Patel V V;Deodhare G;Chetty S (IFCS, Aeronautical Development Agency, Vimanapura Post, Bangalore-560 017) : Accelerated flight envelope expansion using near real time stability margin estimation. J Aerospace Sci Technol 2006, 58(4), 274-86.

Novel technique for estimating the stability margins in near real time has been developed by the authors [1]. This paper shares the invaluable flight test experience gained in using it for flight envelope expansion of India's first digital fly-by-wire Light Combat Aircraft (LCA). Use of this technique has resulted in reducing the overall flight test effort and cost without compromising safety. Using the technique, it was possible to estimate the stability margins on a desktop computer using real time telemetry data within approximately 60 seconds of completing the test. The flight test results for 'Fixed' (restricted flight envelope) and 'Scheduled' (full flight envelope) gain control laws, for manually generated pilot 3-2-1-1 inputs and pre-programmed 3-2-1-1 inputs generated using the onboard Flight Test Panel (FTP) are presented. During the LCA flights, the stability margins were found to be satisfactory throughout the flight envelope. In order to establish that the same technique would work equally well when the stability margins are marginal, typical results were also generated using simulation data and are included in the paper. By artificially increasing the plant gain / delay in the simulation model it is shown that even if the stability margins are low, the same technique correctly estimates the relative stability.

15 illus, 4 tables, 10 ref

012180   Orchard B (NO, , ) : Performance factors for progressing cavity pumps. Indian Pumps 2006, 38(2), 13-15.

Progressing cavity pumps have a strong representation in a wide range of industries, their popularity being attributable to the ability to handle viscous liquids and fluids with high solids content. Bryan Orchard looks at factors influencing performance and recent developments.

4 illus

012179   Necker N (NO, Burgmann Industries, ) : Mechanical sealing technology used in multiphase pumping- the benefits. Indian Pumps 2006, 38(2), 23-5,27-9.

4 illus

012178   Murthy K E S;Rao K R;Laxmaiah M V (Department of ECE, G. Pulla Reddy Engineering College, Kurnool) : Implementation of finite impulse response (FIR) filters using field programmable gate arrays (FPGA). J Instrum Soc India 2006, 36(2), 118-24.

Advantages of implementing Digital Signal Processing (DSP) systems using Field Programmable Gate Arrays (FPGAs) has been described. As an important application, Finite Impulse Response (FIR) filters are implemented using Hardware Description Language (HDL). The FIR filters are targeted with Xilinx and Altera FPGAs. The advantages of FPGAs are exploited. The direct and transposed forms of FIR filters are implemented, and the developed HDL codes are used to study the effect of pipelining and the critical path. Results obtained using the timing analyzer are discussed. Also covered is the comparison of different techniques in implementing FIR filters.

5 illus, 2 tables, 10 ref

012177   Menin J A;Meuter P (Sulzer pumps, , ) : Getting the oil to the shore. Indian Pumps 2006, 38(1), 15-18.

Off the southeastern coast of Brazil lies the Campos offshore field, the main source of Brazilian oil. The Brazilian oil company, Petrobras, is implementing a master plan designed to transport and to deliver part of the Campos output onward to the on-shore refineries. The plan comprises a combination of subsea pipelines, ships, and one fixed repumping platform. Sulzer Pumps delivers pumps for high-viscosity fluids crucial to the project, as well as long-term maintenance services, which will keep the oil flowing with almost 100% availability.

5 illus

012176   Madhusudhan Reddy G;Meshram S D (Defence Metallurgical Research Laboratory, , Hyderabad-58) : Grain refinement in ferritic stainless steel welds through magnetic arc oscillation and its effect on tensile property. Indian Weld J 2006, 39(3), 35-41.

Grain size reduction in weld fusion zone confers the advantage of increased resistance to solidification cracking and improved mechanical properties. In an effort to refine the fusion zone grain structure in AISI 430 ferritic stainless steel, Gas tungsten arc welding (GTAW) was performed during which transverse oscillations of the arc were induced through the use of an alternating external magnetic field. Oscillation variable, which resulted in maximum grain refinement in the fusion zone, was employed to evaluate longitudinal all-weld tensile properties, and residual stresses across weldments. The tensile properties of arc oscillation welds were found to be superior to those of conventional welds. Arc oscillated welds exhibited low tensile residual stresses in the fusion zone compared to conventional gas tungsten arc welds.

9 illus, 3 tables, 19 ref

012175   Kumar D G;Mustafa P V;Kumar Reddy K V (Engine and Test Bed Research and Design Centre (ETBR & DC), Engine Di, Hindustan Aeronautics Limited, Bangalore-560 093, Email: giridhar1975@rediffmail.com) : Off design performance analysis of a turbo shaft engine. J Aerospace Sci Technol 2006, 58(4), 313-21.

Off-design performance of a gas turbine engine is strongly influenced by the characteristics of individual components. It involves the interplay of a large number of variables and would require a detailed computer code. In the paper, an effort is made to predict the influence of performance characteristics of individual components on the off-design performance of the engine. For this purpose, a computer code is developed with necessary iterations and convergence criteria. Parameters are estimated with respect to speeds ranging from 39500 rpm to 50500 rpm for a typical turbo-shaft engine with free power turbine. The effect of altitude on these parameters up to 6 km is also studied. Variation of specific heat and enthalpy with respect to temperature and fuel to air ratio is considered to estimate the performance calculations more accurately and to simulate a real engine behavior as close as possible.

17 illus, 1 table, 9 ref

012174   Kannan T;Murugan N (NO, Kumaraguru College of Technology, Coimbatore-641 006) : Effect of welding parameters on pitting resistance quivalent number of duplex stainless steel clad metals. Indian Weld J 2006, 39(3), 18-23.

Resistance to pitting corrosion is commonly expressed by Pitting Resistance Equivalent Number (PREN). During duplex stainless steel weld cladding, pitting resistance balance is disturbed by the formation of intermetallic precipitates, or by excessive precipitation of secondary austenite in surface regions. This paper highlights an experimental study and analysis of various welding parameters influencing PREN in duplex stainless steel cladding deposit by Flux Gored Arc Welding (FCAW). The effects of welding parameters on PREN have been presented in graphical form, which helps in selecting appropriate welding parameters to obtain the desired PREN quickly.

5 illus, 5 tables, 11 ref

012173   Kadam P A;Raut B J;Kadam P A;Sawant S R (Department of Electronics, Shivaji University, Kolhapur-416 004) : Mouse signal interpreter using microcontroller 89C2051. J Instrum Soc India 2006, 36(2), 101-12.

Mouse, a pointing device, is generally connected to the standard serial (COM1, COM2, etc.) port of PC. It is used to move the cursor around a CRT screen to make drawings or execute commands by selecting commands from menu. During the mouse manufacture process the last and important stage is mouse testing. For this purpose a low cost embedded system has been designed around ATMEL 89c2051 micro controller and tested. This system can be used to test all the functions of standard serial 3-button mouse. The system is found to be very useful in testing serial mouse.

5 illus, 2 tables, 8 ref

012172   Deepu M;Gokhale S S;Jayaraj S (Department of Mechanical Engineering, NSS College of Engineering, Palakkad-678 008, Email: ssg1@vnitnagpur.ac.in) : Numerical modelling of supersonic combustion of hydrogen in the wake region of a strut. J Aerospace Sci Technol 2006, 58(4), 338-46.

Numerical modeling of combustion of a sonic hydrogen stream injected into a supersonic stream of air using a strut is presented. Results are obtained by numerically solving unsteady, compressible, turbulent Navier-Stokes equations, using Unstructured Finite Volume Method (UFVM) incorporating RNG based K-ε two equation model and time integration using three stage Runge Kutta method. Reaction is modeled using an eight step H2-air chemistry. The developed numerical procedure is based on the implicit treatment of chemical source terms by preconditioning and solved along with unsteady turbulent Navier Stokes equations explicitly. Code is validated against a standard wall jet experimental data and is successfully used to model the reacting flow field resulting due to combustion of hydrogen in the wake region of strut placed in heated supersonic air stream.

^ssc5 illus, 3 tables, 14 ref

012171   Das S;Dey T K (Crylogy Engineering Centre, Indian Institute of Technology, Kharagpur-721 302, Email: tapasdey@hijli.iitkgp.ernet.in) : Role of spin polarized tunneling in magnetoresistance and low temperature minimum of polycrystalline La1-xKxMnO3 (x=0.05, 0.1, 0.15) prepared by pyrophoric method. Bull Mater Sci 2006, 29(6), 633-6.

Low temperature resistivity and magnetoresistance of bulk samples of La_1-xK_xMnO₃ has been investigated between 10 K and 300 K with and without the magnetic field (H = 0.8 T). All the samples show metal-insulator transitions with Curie temperature (Tc) ranging between 260 K and 309 K, At temperature below 60 K, the K-doped manganites exhibit a shallow minimum, which disappears under an applied field of 0.8 T. This field dependent minimum in resistivity, observed in K-doped lanthanum manganites is explained in the light of intergrain tunneling of the charge carriers between anti-ferromagnetically coupled grains of the polycrystalline samples. The field variation of magnetoresistance below T_c follows a phenomenological model which considers spin polarized tunneling at the grain boundaries. The intergranular contribution to the magneto-resistance is separated out from that due to spin polarized tunneling part at the grain boundaries. The temperature dependence of intrinsic contribution to the magnetoresistance follows the prediction of the double exchange model for all values of field at T <60> Tc.

7 illus, 3 tables, 11 ref

012170   Das D;Das H (Department of Physics, North Gauhati College, Guwahati-781 031) : PC based temperature recording and monitoring system. J Instrum Soc India 2006, 36(2), 75-81.

Very simple arrangement based of transducer and PC for temperature recording and monitoring has been designed, fabricated and tested. A software programme for the PC has been written for recording and monitoring the temperature. This technique can be easily applied in continuous recording and monitoring of temperature.

8 illus, 3 ref

012169   Cropper M;Dupont P;Parker J (Sulzer pumps, , ) : Low flow - High head. Indian Pumps 2006, 38(1), 11-4.

Many processes in the hydrocarbon processing industry require pumps delivering high heads at low flows. To reach high heads, either the pump has to operate above synchronous speed, or the impellers need to have large diameters and very small flow passages. The former solution usually requires gear-driven pumps with inducer-type hydraulics to manage the suction requirements. The latter solution leads to large impellers with narrow passages, which require special casting techniques to reliably reach the performance goals. Sulzer Pumps has developed an innovative pump with a novel impeller geometry, which avoids these disadvantages.

5 illus

012168   Biswas K;Sharma J K (Centre for Military Airworthiness and Certification (CEMILAC), Defence Research and Development Organisation (DRDO) Marathahalli Post, Bangalore-560 037) : System safety approach in accident prevention. J Aerospace Sci Technol 2006, 58(4), 266-73.

4 illus, 4 ref

012167   Bhardwaj N;Singh N P;Mittal R;Gupta S C; Mittal V K (Department of Physics, Punjabi University, Patiala-147 002) : A new method for developing of ultra thin self-supporting polymer films. J Instrum Soc India 2006, 36(2), 133-7.

Simple method for developing self-supporting thin polymer film (of thickness less than 1 μm) has been presented. The basic part of the system is a high-speed motor of 15000 & 20000 revolutions per minute (rpm). The measurement of the thickness is done by α - energy loss method. These measurements show that self-supporting polymer film with thickness in the sub micron range can be prepared. Results are reported on a number of such films.

2 illus, 3 ref

012166   Barick K C;Bahadur D (Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai-400 076, Email: dhirenb@iitb.ac.in) : Assembly of Fe₃O₄ nanoparticles on SiO₂ monodisperse spheres. Bull Mater Sci 2006, 29(6), 595-8.

Assembly of superparamagnetic Fe₃O₄ nanoparticles on submicroscopic SiO₂ spheres have been prepared by an in situ reaction using different molar ratios of Fe³⁺/Fe²⁺ (50-200%). It has been observed that morphology of the assembly and properties of these hybrid materials composed of SiO₂ as core and Fe₃O₄ nanoparticles as shell depend on the molar ratio of Fe³⁺/Fe²⁺.

4 illus, 1 table, 20 ref

012165   Abhyankar S L (NO, , ) : Selecting materials of construction (MOC) for pumps. Indian Pumps 2006, 38(2), 17-22.

013311   Vishwakarma J P;Pandey S N (NO, D.D.U Gorakhpur Univ, Gorakhpur-273 009) : Converging cylindrical shock waves in a nonideal gas with an axial magnetic field. Def Sci J 2006, 56(5), 721-31.

Propagation of converging cylindrical shock waves in a nonideal gas, in the presence of an axial magnetic field has been analysed. Chester-Chisnell-Whitham's method has been employed to determine the shock velocity and the other flow-variables just behind the shock in the cases, when (i) the gas is weakly ionised before and behind the shock front, (ii) the gas is strongly ionised before and behind the shock front, and (iii) nonionised gas undergoes intense ionisation as a result of the passage of the shock. The effects of the nonidealness of the gas, the conductivity of the gas, and the axial magnetic field have been investigated. It is found that in the case (i), an increase in the value of parameter characterising the nonidealness of the gas accelerates the convergence of the shock. In the case (ii), the shock speed and pressure behind the shock increase very fast as the axis is approached; and this increase occurs earlier if the strength of the initial magnetic field is increased. In the case (iii), for smaller values of the initial magnetic field, the shock speed, and pressure behind the shock decrease very fast after attaining a maximum; and for higher values of the initial magnetic field, the tendency of decrease appears from the beginning. This shows that the magnetic field has damping effect on the shock propagation. In the case (iii), it was also found that the growth of the shock in the initial phase and decay in the last phase were faster when it was converging in a nonideal gas in comparison with that in a perfect gas. Further, it has been shown that the gas-ionising nature of the shock has damping effect on its convergence.

5 illus, 1 table, 38 ref

013310   Vishnu Prasad;Shukla S N;Joshi S G (NO, Maulana Azad National Institute of Technology, Bhopal) : Performance characteristic of pump as turbine. Indian Pumps 2006, 38(4), 5-9.

In view of the development of small and mini hydropower it is essential to standardise the turbines for these plants to make the projects economically viable. This requires the equipment, which is easily available, to be reliable, easy to maintain and durable with low running cost. The design of new turbine for each small power plant and its manufacturing is costly and time-consuming. The practical solution for remote areas is to use the pump as turbine and driving the induction generators. Looking to this aspect, two pumps manufactured by Kirloskar Brothers Limited (KBL), Pune were tested in turbine mode at Maulana Azad National Institute of Technology (MANIT), Bhopal under the industry-institute collaborative effort, to assess their efficiency and cavitation performance under varying operating conditions. The test results of both the pumps as turbine are provided in this paper. The results are compared with the prediction from the Manual on Pumps used as Turbine.

5 illus, 1 table, 3 ref

013309   Varna P (Systems Reliability Group, ISRO Satellite Centre, Bangalore-560 017) : Failure mode effects and criticality analysis of interface circuit. J Spacecraft Technol 2006, 16(2), 29-34.

Failure mode effects and criticality analysis (FMECA) is one of the tools used to assess the reliability of a system. All failure modes down to the individual part level are addressed, as part of FMECA analysis as there is a great deal of concern not only with the probability of failure of parts but also with the potential consequences of different modes of failure. FMECA has to be carried out in totality for a system by; considering its redundancy and interfaces with other systems. Otherwise, there is a possibility of missing the single point failure which could be catastrophic to a mission when FMECA is carried out on a system as a stand-alone unit. Hence, FMECA of an interface circuit has be carried out as minimum requirement for all interface circuitry, as part of FMECA. A case study of a typical interface circuit is presented here to explain the significance of FMECA of an interface circuit and the consequences of different modes of failure of parts on the system performance.

3 illus, 3 tables, 3 ref

013308   Varaprasad R;Seshagiri Rao V (Satish, Dhawan Space Centre SHAR, Sriharikota-524 124) : Range safety real-time system for satellite launch vehicle missions-testing methodologies. Def Sci J 2006, 56(5), 693-700.

Real-time system plays a critical role in the range safety decision-making in a satellite launch mission. Real-time software the heart of such systems, is becoming an issue of criticality. Emphasis is being laid on the development of reliable, robust, and operational system. This paper purports to delineate prudent testing methodologies implemented to test the real-time system.

2 illus, 8 ref

013307   Tripathi V (VISI Design Dep, Semiconductor Complex Ltd., S.A.S. Nagar-160 071) : Design of 12-bit Σ-Δ ADC with PGA and programmable comb filter. J Spacecraft Technol 2006, 16(2), 47-51.

Implementation of 2nd order Σ-Δ ADC with PGA and programmable comb filter has been presented in this paper. The PGA has a digitally programmable range of 1 to 128 in binary steps to accommodate a wide range of signal inputs. The PGA implementation is done within the modulator by changing the sampling frequency and ref. capacitor. The three-stage comb filter notch frequency is programmable from 24Hz to 976Hz, which allows various input bandwidths. The design details are presented. The circuit operates on ±5V supply. With an over sampling ratio of 128 and a clock rate of 62.5kHz, the ADC achieves 12 bits [min] resolution. This work has been done for VSSC under a project Software Programmable Data Acquisition System (SOFTDAS). The chip is functional and measured device results are given.

7 illus, 4 ref

013306   Subramanian N;Chandra Shekar N V;Sanjay Kumar N R;Sahu P C (Advanced Materials Section, Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Development of laser-heated diamond anvil cell facility for synthesis of novel materials. Curr Sci 2006, 91(2), 175-82.

Investigation of material behaviour under extremely high pressures and temperatures using IR laser-heated diamond anvil cells (DACs) has emerged in the recent years as an important area of research, both basic and applied. Presents details of a laser-heated DAC facility that authors have recently set up at the laboratory. The facility consists of a suitable arrangement of a CO₂ laser, motorized translation stages, a Mao-Bell-type DAC, IR and visible optical assembly, CCD-based monochromator, etc. Also, the facility has the capability of pressure measurement using Ruby fluorescence method and temperature measurement using spectroradiometric technique. With this facility, materials can be subjected simultaneously to high pressures and temperatures (P_max <126> 100 GPa; T_max≥ 5000 K). Results on successful synthesis of InSb by direct elemental reaction and on a preliminary experiment wherein direct conversion of graphite to a transparent phase has been attempted with this facility are also presented.

7 illus, 28 ref

013305   Sridhar S;Sekar N S (NO, Combat Vehicles Research & Development Establishment, Chennai-600 054) : Optimisation of kinematics for tracked vehicle hydro gas suspension system. Def Sci J 2006, 56(5), 743-52.

Modern-day armoured fighting vehicles (AFVs) are basically tracked vehicles equipped with hydro gas suspensions, in lieu of conventional mechanical suspensions like torsion bar and coil spring bogie suspensions. The uniqueness of hydro gas suspension is that it offers a nonlinear spring rate, which is very much required for the cross-country moveability of a tracked vehicle. The AFVs have to negotiate different cross-country terrains like sandy, rocky, riverbed, etc. and the road irregularities provide enumerable problems during dynamic loadings to the design of hydro gas suspension system. Optimising various design parameters demands innovative design methodologies to achieve better ride performance. Hence, a comprehensive kinematic analysis is needed. In this study, a methodology has been derived to optimise the kinematics of the suspension by reorienting the cylinder axis and optimising the load-transferring leverage factor so that the side thrust on the cylinder is minimised to a greater extent. The optimisation ultimately increases the life of the high-pressure and high-temperature piston seals, resulting in enhanced system life for better dependability.

10 illus, 3 ref

013304   Soni D K;Jain A (Civil Engg Dep, National Inst Technol, Kurukshetra-136 119) : In-situ rock strength determination for tunnel blasting. Indian Min Engng J 2006, 45(6-8), 29-32.

Compressive strength of rocks is often required by mining engineers and quarrying authorities for blasting operations. Uniaxial compressive strength of rocks can be predicted with reasonable accuracy with the help of point load strength tests which can be easily conducted at site by field staff, simultaneously as the cores are recovered from drilling operations. A number of diametral point load tests and uniaxial compressive study the effect of ground water saturation on strength. It has been observed that due to saturation uniaxial compressive strength and point load strength get reduced to a maximum of 32 and 29 per cent respectively. It has also been observed that uniaxial strength is sixteen times the point load strength in air dried as well as saturated conditions. However, this factor used for calculating uniaxial compressive strength may be reduced to a lower value for the safety of miners in field blasting operations.

2 illus, 4 tables, 10 ref

013303   Singh S;Singh R K (Nucleic Acids Research Lab, Chemistry Dep, Allahabad Univ, Allahabad-211 002) : Synthesis and fluorescence studies of fluorescently labelled phosphoramidites: synthons for multiple labelled oligonucleotides. Curr Sci 2006, 91(6), 836-9.

Two highly fluorescent compounds, viz. 6-[6-isobutyryl-amino-1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl]-hexan oic acid and 6-(6-dimethylamino-1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl)-hexanoic acid have been synthesized and attached to uridine and 2'-de-oxyuridine at the C-5 position using a suitable linker, 5-aminopentanol-1, and to 2'-deoxycytidine at the C-4 position using spermine as a linker molecule. These /nucleosides have been converted to their respective phosphoramidites and thus used to synthesize labelled oligonucleotides, showing appreciable fluorescence, on solid support.

3 illus, 21 ref

013302   Singh A K;Apte D (NO, Defence Institute of Advanced Technology, Pune-411 025) : Modelling and analysis of hysteresis in Piezoelectric actuator. Def Sci J 2006, 56(5), 825-33.

Piezoelectric actuators are the potential actuators having a wide range of applications in smart structures and systems. However, the presence of hysteresis nonlinearity leads to degradation in their performance. This paper discusses a mathematical model for hysteresis in piezoelectric actuators based on domain wall bending and translation. The validity of the model has been illustrated through comparison with the experimental observations of piezoelectric stack actuator developed using PZT5H material.

3 illus, 1 table, 17 ref

013301   Shyamala B;Dodagoudar G R (Civil Engineering Dep, I.I.T. Madras, Chennai-600 036) : Settlement reliability analysis of strip footing embedded in the poroelastic media. Indian Geotech J 2006, 36(2), 144-59.

12 illus, 3 tables, 11 ref

013300   Sharma B;Bose P (Department of Civil Engineering, Environmental Engineering and Management Programme, Indian Institute o, Kanpur-208 016) : Arsenic sequestration by metallic iron under strongly reducing conditions. Curr Sci 2006, 91(2), 204-8.

Objective of this study was to elucidate the mechanism of arsenic sequestration by metallic iron in strongly reducing conditions. Contacting arsenic with metallic iron in anaerobic batch systems showed considerable reduction in dissolved arsenic concentration. Scanning electron micrographs of the metallic iron surface after contact with arsenic showed evidence of surface depositions. X-ray diffraction patterns of such surfaces showed evidence for the presence of iron arsenide (FeAs and FeAs₂) phases, and arsenopyrite (FeAsS) and oripment (As₂S₃) phases respectively, in the absence and presence of dissolved sulphate. Theoretical chemical speciation studies supported the above experimental results. It was thus concluded that strong reducing conditions produced in the vicinity of the anaerobically corroding metallic iron surface result in arsenic sequestration.

^ssc6 illus, 12 ref

013299   Saravanan M;Pillai R M;Pai B C;Brahmakumar M; Ravi K R (Materials and Minerals Div, Regional Research Laboratory, Thiruvananthapuram-659 0196, Email: rmpillai@rediffmail.com) : Equal channel angular pressing of pure aluminium. Bull Mater Sci 2006, 29(7), 679-84.

Equal channel angular pressing (EcAP) is a novel tecnique for producing ultra line grain structures in submicron level by introducing a large amount of shear strain into the materials without changing the billet shape or dimensions. This process is well suited for aluminium alloys and is capable of. producing ultra fine grain structures with grain sizes falling between 200 and 500 nm. Attempts to apply ECAP technique to 99-5% pure aluminium and characterize the resulting aluminium by optical metallography, atomic force microscopy (AFM) and hardness measurement. ECAP of 99-5% pure aluminium produces ultrafine grain structure of about 620 run after 8 passes. Despite an increase in the hardness from 23 to 47 BHN up to 6 passes, it decreases slightly for seventh and eighth passes. The results are compared with the already existing results available on pure aluminium. Analysis of the results of this investigation with those available in the literature has revealed that the number of passes essential to achieve a homogeneous micro-structure in pure Al increases, while the ultimate equilibrium grain size obtained becomes finer with decreasing purity.

7 illus, 2 tables, 19 ref

013298   Salve P R;Krupadam R J;Wate S R (NO, National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur-440 020) : Assessment of atmospheric particulate mercury HG(P) in the vicinity of coal based power plant. J Indian Ass Envir Mgmt 2006, 33(1), 39-41.

Distribution of particulate mercury in the vicinity of coal-based power plant was studied during winter season (November-December, 2002), Samples were collected twice a week from each location using calibrated high-volume samplers at the flow rate of 1.1-1.2 m³in for 24 hours. A portion of the sampled filters and blank was cut and Hg was extracted by means of reflux digestion for further determination using mercury vapor analyzer. The average concentration values of paniculate mercury Hg(p) and total suspended paniculate matter (TSPM) at different locations were found to be in the range of 0.100-0.395 ηg/m³ and 158-392 μg/m³ respectively. Based on the monitoring data, the distribution of paniculate Hg and total suspended paniculate (TSPM) in the vicinity of coal-based power plant was represented spatially. Major contributor of paniculate Hg is from coal combustion followed by wind-blown soil material.

2 illus, 1 table, 9 ref

013297   Roy S K;Singh R R;Kumar R;Amritv A K;Rao V V R (Explosive & Explosion Lab, Central Mining Res Inst, Barwa Road, Dhanbad-826 001) : Explosive-cord system for blasting gallery method. Indian Min Engng J 2006, 45(6-8), 37-40.

Blasting Gallery (BG) method of mining thick seams has been proved advantageous over other methods vis-a-vis production, productivity, investment, conservation etc. since 1987 when it was introduced with collaboration and technical assistance from CdF, France. As pattern of drilling and conditions of usage of explosives in Blasting Gallery method differs from the conventional blasting in cut face or solid blasting, specially designed explosive-cord system is required for use in ringhole blasting in BG panels. Ban of NG-based explosives by Govt. of India caused impasse in execution of BG panels practised in five mines in Singareni Collieries Company Limited (SCCL) and one mine in Coal India Limited (CIL) as there was no alternative non-NG based explosive-cord system approved for use in BG panels. Development of Powering-Powercord system, the first and only emulsion based explosive with suitable cord system, for used in BG method was accomplished under joint efforts put by Central Mining Research Institute (CMRI) and Indian Explosives Limited (IEL). Laboratory trials under simulated conditions at CMRI and field trial of powerring - Powercord system in SCCL mines have demonstrated its safety and efficacy. Describes the development of explosive-cord systems including powering - powercord system.

1 table, 7 ref

013296   Rodriguez P;Armstrong R W (Metallurgical and Materials Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: cidrod@iitm.ac.in) : Strength and strain rate sensitivity for hcp and fcc nanopolycrystal metals. Bull Mater Sci 2006, 29(7), 717-20.

While there is overwhelming evidence that strengthening from grain size refinement persists into the nanocrystalline grain size regime consistent with extrapolation of classical Hall-Petch (H-P) behaviour, there are indications of a transition to an inverse H-P dependence, i.e. grain boundary weakening behaviour, occurring below a grain size of <126> 10-20 nm. When Hall-Petch strengthening predominates, and the stress intensity, i.e. H-P slope value is thermally-activated (as is the case for pure fcc and the easy basal slip hcp metals), the strain rate sensitivity, defined as [∂σ/∂ in (dγ/dt]_T, also is predicted to follow an H-P type dependence, thus, increasing with decrease in grain size. As a consequence, the activation volume that is inversely proportional to the strain rate sensitivity, is, found to decrease by an order of magnitude, from around 1000 b³ in conventional grain size fcc Cu and Ni materials to 10-100 b³, for nanomaterials. At the smallest grain sizes, the transition to an inverse H-P dependence has been proposed to occur because of onset of effective high temperature grain boundary weakening behaviour that is well known in limiting creep property descriptions. If the inverse H-P effect (grain boundary weakening) is genuine, author predicts that the strain rate sensitivity and corresponding inverse activation volume dependence on grain size should also have to show a reversal.

2 illus, 21 ref

013295   Rathore S S;Jain S C (Mining Engng Dep, College of Engng and Technol, Maharana Pratap Univ of Agric and Techn, Udaipur-313 001) : Impact study of ground vibration due to blasting in bauxite mining area near Kutch. Indian Min Engng J 2006, 45(6-8), 33-6.

Large scale application of explosives for breaking rock at the quarries have become a serious threat to the environment. When explosive energy is treansmitted to the rock only 5 to 20% energy is utilized in breaking the rock and remaining energy creates ill effects like ground vibrations, air-overpressure, flyrock, noise, dust etc. Amongst these ground vibration is a burning problem for the mining industry. In this regards a case study in being conducted with the aim to ascertain effect of ground vibration to the temples of Goddesses Aashapura Mataji situated near the lease boundary of bauxite mining near village Ratadia. Also to ascertain effect on railway track and high tension line passing near Naredi mining area in district Kutch of Gujarat. Blast vibrations were monitored at various places including temple site, high-tension electric power line etc. with the help of Blastmate series III instrument. On the basis of monitoring study and using blastware software analysis was done. Conclusions have been drawn for safe blasting operation. Equation has been established for safe charge at various distances from the blast site.

1 illus, 4 tables, 6 ref

013294   Ramjibhai H D K (NO, Gujarat Water Supply and Sewerage Board, Dipak-Jyoti Building, Opp. Satyanarayan Mandir, Porbandar-360 575) : Desalination economics in water supply projects of south-west coastal belt of Saurashtra region in Gujarat state. J Indian Ass Envir Mgmt 2006, 33(1), 1-6.

Today in domestic water supply sector many technological options are available, with different investments for single problem. All alternatives shall be evaluated under, functional approach to identify the real requirement of the project. It is endeavored to seek out the best functional balance between the cost and reliable performance between two alternatives for providing domestic water supply in South - West Coastal Belt Of Saurashtra Region In Gujarat State. The alternatives are, treating and conveying water from long distant source or treating the existing saline ground water of well with reverse osmosis technique. The evaluation for these alternatives is discussed.

2 illus, 1 table, 6 ref

013293   Punit Singh;Kshirsagar J T;Caglar S;Nestmann F;Natanasabapathi (Institut fur Wasserwirtschaft und Kulturtechnik (IWK), Karlsruhe Univ, Kaiser Str. 12, D 76128, Karlsruhe, Germany) : Experimental and computational studies of the effect of 'casing eye rib' on the swirl flow at the exit of a pump as turbine. Indian Pumps 2006, 38(4), 11-20.

Detailed hydraulic analysis of the effects of the casing eye rib on a pump operating as a turbine has been presented. It describes a flow-zone "approach within a pump as turbine and lays out the build-up for the experimental and numerical techniques applied. The pump as turbine exhibits very good characteristics with a maximum operating efficiency over 82%. The similitude between experimental numerical results has been satisfactory. The Two stages, namely, the 'casing rib present' and the 'casing rib absent' are compared at six different load points encompassing the entire characteristics. Both methods reveal that the performance of the PAT has enhanced without the presence of the rib. However, the two methods show different causes for this behaviour. A comparison of the swirl profiles reveals that the fluid in the casing rib absent' stage has greater rotational momentum in the part-load and overload region compared to the 'casing rib present' stage. However, the casing rib absent' stage displays more symrmetric swirl profiles. At the end of the paper, an uncertainty analysis for the experimental efficiency is carried out.

19 illus, 4 ref

013292   Patki A V;Krishnamurthy T S (Integrated Engineering Services, Satyam Computer Services Ltd, Hyderabad) : On relevance of extreme value distribution. J Spacecraft Technol 2006, 16(2), 1-4.

Many aero-space systems are designed for specified life or for specified number of operatios. Reliability of such a system depends on how well the operating loads are modelled. For achieving higher reliability, it is necessary that even the extreme or the rare' events are accounted properly and risk assessed appropriately.

7 llus, 15 ref

013291   Nabiullah;Pingua B M P;Jagdish (NO, Central Mining Research Institute, Dhanbad-826 001) : Study on optimum powder factor and quality of explosives in surface mines. Indian Min Engng J 2006, 45(6-8), 19-28.

Bulk explosives, booster and blast design play an important role in rock blasting. Bulk explosives are booster sensitive explosives. The firing density is in range of 1.05 to 1.20 g/cm³. The velocity of detonation and absolute weight strength (AWS) is in range of 3500 to 4500 m/s and 800 to 850 kcal/kg. Powder factor is an important economic index for assessment of blastability of rock. The optimum powder factor for any surface mines is depends upon various factors such as geology of rock, blast design, explosive energy output and its utilization. The optimum powder factor in most of mines in CIL was recorded. The powder factor in NCL, BCCL, SECL, ECL, WCL and West Bokaroo Collieries was in range of the optimum powder factor and quality of explosives was measured. The rating index of bulk explosives is varied in between 70 and 100. The powder factor in hard rock was 1.5 to 2.5m³/kg and in soft rock it was in range of 2.0 to 3. m³/kg.

14 tables, 11 ref

013290   Murali Krishna P;Mohana Krishna G;Agarwal V K (Control System Group, ISRO Satellite Centre, Bangalore-560 017) : Indigenous development of high torque, true ripple free, brush less DC (BLDC) motor for DGA applications. J Spacecraft Technol 2006, 16(2), 21-7.

Brush less dc (BLDC) motors are best suited for space applications where smooth control of speed and torque is the prime requirement. Despite this fact CARTOSAT-2, dual gimba antenna (DGA) with import BLDC motor is experiencing a disturbance torque which affects the smooth rotation of DGA and also the control system of the spacecraft. These disturbances in the inherent characteristics of present motor design are due to cogging and magnetic hysterisis. A compensation scheme is being planned which however may not be perfect. Alternate solution is the core-less moter with zero cogging and zero hysterisis, but the major penalty is very low torque capability (<60>25% of core motor) and the critical fabrication & assembly process. That is the reason why these motors are not popular and commercially not available. The response of core-less motor is faster (<62>5 times) and its power consumption is lesser (<60>50%) than the core motor. In spite of its advantages, only few people used this design for low torque applications due to the criticalities in realization. A high torque, 1.0 Nm (0.5 Nm prime + 0.5 Nm redundant) core-less BLDC motor to improve the performance of DGA replacing import motor is designed and developed. Describes the design and development of core-less brushless dc motor. The realization of proto model motor and its test results are also discussed. It is proposed to use this motor for CARTOSAT-2B and CHANDRAYAN-1 DGAs replacing the import motor.

8 illus, 3 tables, 5 ref

013289   Mehta S;Bera K;Patel V D;Roy Chowdhury A; Samudraiah D R M (Space Applications Centre, ISRO, Ahmedabad-380 015) : Low noise high speed camera electronics for cartosat - 1 imaging system. J Spacecraft Technol 2006, 16(2), 35-44.

India's Space programme for cartography is aimed at up-gradation of topographic maps and utilization of natural resources for planned development of country. The Canosat satellite, launched in early May 2005, has unique features compared to previous Indian cartographic missions in providing higher resolution and along track stereoscopic imaging. The camera sensor is a linear CCD. The camera electronics is a high-speed low noise system generating stimulus for the detector operation, for processing the detector signal and for digitization in a W-bit format. The design takes into consideration the high speed design requirements while meeting the low noise performance requirement with a goal of SNR<62>1024 in mixed signal environment. The noise contributions are apportioned, controlled and optimized. A low noise configuration has been evolved and accordingly camera electronics system has been developed. Detailed simulation, testing and analysis have been carried out on the designs. Consistent performance has been achieved during all the tests and the designed performance at the camera level has been validated through excellent imageries obtained from the satellite after launch.

12 illus, 2 tables, 9 ref

013288   Laxmana Chary M;Nagabushanam S;Venkateswarlu A (Control System Group, ISRO Satellite Centre, Bangalore-560 017) : Optimization of bracket configuration for a reaction wheel/ momentum wheel. J Spacecraft Technol 2006, 16(2), 13-19.

Technique of optimizing a bracket configuration that results in the minimum mass for a giver stiffness/frequency. Salient features associated with the selection of proper configuration, mechanical design procedure and manufacturing processes (electro discharge machining and CNC machining) required for the realization of the bracket are also presented.

7 illus, 2 tables, 2 ref

013287   Kshirsagar J T;Gunaseelan S;Joshi S G; Srivastava R K (NO, Kirloskar Brothers Limited, Udyog Bhavan, Tilak Road, Pune, Email: jtkshirsagar@pnr.kbl.co.in) : Investigation of siphon action in a discharge duct. Indian Pumps 2006, 38(4), 21-7.

Siphon action in a discharge duct of a pumping scheme is a common feature used to lower down the total head requirement in the absence of flow-control devices. The advantage of lowering down the losses due to absence of controlling devices, such as NRV or Butterfly Valve in discharge duct is also associated with some of the features that could hamper proper operation of the pumping station. Unscheduled power failure could establish reverse flow owing to differential head in suction and delivery reservoirs. These aspects become very important when the quantum of water to be pumped is relatively large. During the pump start/stop, the removal/inclusion of air respectively involves two-phase flow in the system. Model study was carried out to observe the quantity of trapped air, based on which the siphon creation/breaking devices were sized.

6 illus, 3 ref

013286   Khadse G K;Nanoti M V (Environmental Management Div, National Environmental Engineering Research Institute, Nagpur-440 020) : Characterization of sewage irrigated soils near Nagpur for their management and resporation. J Indian Ass Envir Mgmt 2006, 33(1), 30-1.

Sewage and sewage irrigated soils vis-a-vis well water and control soils (soils not irrigated with sewage) were characterized for their physical, chemical, metal contents and bacteriological properties. The sewage irrigated soils show higher concentrations of nitrate, phosphate, potassium, calcium, magnesium, sodium, bicarbonate, sulphate and chloride along with metals Fe, Mn, Cu, Zn, Cd, Co, Ni and Pb as compared to soils irrigated with well water. These parameters were within respective permissible limits, and some of these act as essential plant nutrients. Sewage showed high load of Total coliforms and Faecal coliforms. If sewage irrigation continues for longer period, soil will be accumulating these constituents and may lead to adverse impact on soil qualities and risk of infiltration in groundwater. The crops grown exert potential adverse impact on the human and animal health.

4 tables, 11 ref

013285   Kaushik H B;Dasgupta K;Sahoo D R;Kharel G (Civil Engineering Dep, Indian Institute of Technology Kanpur, Kanpur-208 016, Email: hemantbk@gmail.com) : Performance of structures during the Sikkim earthquake of 14 February 2006. Curr Sci 2006, 91(4), 449-55.

Performance of structures in different areas of Sikkim, during the earthquake of 14 February 2006, is reviewed. The earthquake caused damage to heritage structures as well as modern buildings. Both masonry and reinforced concrete buildings showed poor performance. On the other hand, traditionally constructed wooden houses performed extremely well. The damage seen in and around Gangtok was clearly disproportionate to the size of the earthquake, which was a moderate 5.7 on the Richter scale. This very clearly establishes the high level of seismic vulnerability of the region. The damage is primarily attributed to poor design and construction practices, and lack of quality control. Urgent need for trained human resources and for creation of a system of checks and balances, to ensure safe constructions in Sikkim is highlighted.

8 illus, 12 ref

013284   Kashyap S K;Girija G;Raol J R (National, Aerospace Laboratories, Bangalore-560 017) : Error model-converted measurement and error model-modified extended Kalman filters for target tracking. Def Sci J 2006, 56(5), 679-92.

Two-filter schemes have been evaluated to handle the polar measurements using error model (for bias correction and measurement noise covariance computation) for target-tracking application. It is assumed that a good reference source of target information is available. Schemes based on error model converted measurement Kalman filter (ECMKF) and error model modified extended-Kalman filter (EMEKF) algorithms are presented. Also some comparison with CMKF (debiased) is given. It is inferred that EMEKF gives better performance compared to other filters. Features of CMKF (debiased), ECMKF, and EMEKF are highlighted. Also the sensitivity study on the performance of EMEKF is carried out wrt to processing order of radar measurement channels.

8 illus, 6 tables, 6 ref

013283   Kamble B M;Chougule B A;Rathod S D;Rathod P K (NO, Agrticultural Research Station, K Digraj, Dist-Sangli-416 305) : Improvement of salt affected-water logged soil in Western Maharashtra through subsurface drainage (ssd) system. Asian J Bio Sci 2006, 1(2), 64-7.

Subsurface drainage system was installed on farm with corrugated perforated PVC pipes on 8.81 ha of salt affected soils at Agril. Research station K. Digraj Dist-Sangli (M.S.) in December, 2002 to study the effect of subsurface drainage system for improvement of salt affected - waterlogged soils. The results revealed that the pH, ECe, SAR and ESP of soil in SSD with synthetic envelope, coarse sand filter and synthetic envelope + coarse sand filter were decreased in monsoon and winter season but slightly increased during the summer season. This indicates that the improvement in salt affected soils due to subsurface drainage and gypsum application within a period of one year.

5 tables, 9 ref