001748   Wiegand S;Flege S;Baake O;Ensinger W (Materials and Geosciences Dep, Materials Analysis Group, Technisxhe Darmstadt Univ, Petersenstrasse 23, 64287 Darmstadt, Germany, Email: wiegand@ca.tu-darmstadt.de) : Influence of different heat treatment programs on properties of sol-gel synthesized (Na_0.5K_0.5)NbO₃ (KNN) thin films. Bull Mater Sci 2012, 35(5), 745-50.

Thin films of (Na_0.55K_0.5)NbO₃ (KNN) were synthesized on Pt/Ti/SiO₂/Si substrates with repeated spin-coating after fabrication of the precursor solution by a sol-gel process. The KNN precursor solution was prepared from K- and Na-acetate, Nb-pentaethoxide and 1,3-propanediol. Based on three characteristic temperatures derived from thermal analysis (TG-DTA) experiments, five heat treatment programs were developed. AH programs lead to single phase perovskite KNN films with random crystal orientation, but only the programs that included a treatment after each single spin-coating step provided pore free surfaces with grains of about 100 nm size. The lowest leakage current at 150 kV cm^-1 was obtained for the temperature program that included pyrolysis and calcination steps after each deposited layer.

6 illus, 1 table, 24 ref

001747   Venkatarathnam G;Srinivasa Murthy S (Refrigeration and Airconditioning Laboratory, Mechanical Engineering, Indian Institute of Technology, Madras, Chennai-600 036) : Refrigerants for vapour compression refrigeration systems. Resonance 2012, 17(2), 139-62.

With the mandate of Montreal Protocol banning ozone depleting substances, and Kyoto Protocol later on curtailing the use of substances which contribute to global warming, conventional refrigerants are to be replaced by environment-friendly working fluids. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are being substituted by hydrofluorocarbons (HFCs), hydrofluorooelifins (HFOs), and a variety of mixtures. In view of the global warming potential of these newly synthesized refrigerants, the recent trend is to go back to the originally used natural fluids such as ammonia, carbon dioxide, hydrocarbons, water vapour, etc. In this article, various issues related to this changeover of refrigerants being used in vapour compression refrigeration systems are discussed.

9 illus, 14 ref

001746   Varshaney M K (Civil Engg., D.N. Polytechnic, Meerut, Uttar Pradesh-250 103, Email: manojvarshaney17@gmail.com) : Re-assessment of duty in irrigation channel- a suggestive approach for valuation. Indian Surveyor 2012, 66(1), 44-5.

001745   Tan H;Ding Y;Zhang H;Yang J;Qiao G (State Key Laboratory for Mechanical Behaviour of Materials Xi'an Jiaot, Xi'an-710 049, P.R. China, Email: hb-t@163.com) : Activation energy for mullitization of gel fibres obtained from aluminum isopropoxide. Bull Mater Sci 2012, 35(5), 833-7.

Gel fibres of mullite precursor were prepared from an aqueous solution of aluminum nitrate (AN), aluminum isopropoxide (AIP) and tetraethylorthosilicate (TEOS). A 4:1 molar ratio of aluminum isopropoxide and aluminum nitrate was optimized to obtain spinnable precursor sol for synthesis of fibres. Thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) analyses were used to characterize properties of the gel and ceramic fibres. The precursor gel completely transformed to mullite at 1200 °C. The activation energy of mullite crystallization was 993.5 kJ/mol by the Kissinger equation.

6 illus, 2 tables, 19 ref

001744   Subramanian B;Prabakaran K;Jayachandran M (Electrochemical Materials Science Div, CSIR- Central Electrochemical Research Institute, Karaikudi-630 006, Email: bsmanian@cecri.res.in) : Influence of nitrogen flow rates on materials properties of CrN_x films grown by reactive magnetron sputtering. Bull Mater Sci 2012, 35(4), 505-11.

Chromium nitride (CrN) hard thin films were deposited on different substrates by reactive direct current (d.c.) magnetron sputtering with different nitrogen flow rates. The X-ray diffraction patterns showed mixed Cr2N and Cr₂N phases. The variations in structural parameters are discussed. The grain size increased with increasing nitrogen flow rates. Scanning electron microscopy image showed columnar and dense microstructure with varying nitrogen flow rates. An elemental analysis of the samples was realized by means of energy dispersive spectroscopy. The electrical studies indicated the semiconducting behaviour of the films at the nitrogen flow rate of 15 seem.

5 illus, 3 tables, 31 ref

001743   Singh P S;Parashuram K;Maurya S;Ray P;Reddy A V R (RO Membrane Div, Central Salt and Marine Chemicals Research Institute (Council of Scien, Bhavnagar-364 002, Email: puyam@csmcri.org) : Structure-performance-fouling studies of polysulfone microfiltration hollow fibre membranes. Bull Mater Sci 2012, 35(5), 817-22.

Hollow flbre microfiltration membranes were prepared by solution spinning process using polymer dope containing different amounts of polysulfone (PS), polyvinylpyrollidone (PVP) and N,N-dimethylformamide (DMF). Spinning dope having PS: PVP: DMF (w/w) of 15: 5: 80,15: 7: 78 and 17: 8: 75 were used for spinning to obtain hollow fibres having different dimensions (outer and inner diameters) and pore characteristics. Relatively high water permeability was observed for hollow fibre membrane spun from 15 wt. % solution than 17 wt. % PS solution having the same PVP/PS ratio of 0.47. Decrease of the PVP/PS ratio to 0.33 in the dope solution of 15 wt. % PS solution produced hollow fibre membrane with lower flux. By changing the spinning parameters, fibre with different dimensions were obtained without a significant change in microstructural morphology. The flux decline due to fouling for the permeation of PEO/BSA solution was maximum for the hollow fibre membrane obtained from 15 wt. % PS solution while a steady flux with slight fouling was observed for the hollow fibre membrane obtained from 17 wt. % PS solution, when the PVP/PS ratio was 0 47.

6 illus, 4 tables, 19 ref

001742   Simha R V (NO, Airtron Consulting Engineers Pvt Ltd., No. 502/A, Ist Main Jayanagar 8th Block, Bangalore-560 070, Email: simha@airtron.in) : Willis H carrier father of air conditioning. Resonance 2012, 17(2), 117-38.

Willis H Carrier, the Father of Air Conditioning, placed the science of air conditioning on a firm scientific basis in the year 1911, in his paper 'Rational Psychrometric Formulae' -widely known also as the 'Magna Carta of Psychrometrics'. This paper was presented at the annual meeting of American Society of Mechanical Engineers (ASME). The centenary of this historic event happens to be the past year 2011. Amongst his many achievements are his contributions to development of the Psychrometric Chart (which remains essentially the same as the chart presented more than a century ago), the Law of Constant Dew-Point Depression, Dew-Point Control and the invention of the Centrifugal Refrigeration Machine. His contributions to the industry, the way he tackled the technical and engineering aspects of his work, his business acumen and his leadership qualities are fairly well known. Also, recalled here are several episodes and anecdotes of his career and life, which present the pictures of 'Carrier, the Man', 'the Genius', 'the Leader' and other facets of his rich personality.

9 illus, 5 ref

001741   Shirale R L;Muralidharan R;Shinde R (Civi Engineering Dep, Marathwada Institute of Technology, Maharashtra) : Experimental investigation of mechanical properties of hybrid fiber (basalt and steel) reinforced concrete. J Constr Engng Technol Mgmt 2013, 3(2), 5-10.

Paper reports experimental investigations on hybrid-reinforced concrete. The proportion of basalt fiber and steel fiber was 50% respectively of the total fiber taken as sample. Effect of fiber on various strengths of concrete is studied. Fiber content varied from 0 to 4% at an interval of 1% by weight of cement. Various considerations for investigation are compressive strength, flexural strength, split tensile and bond strength. Cube of size 150 x 150 x 150 mm for compressive strength, beams of size 500 x 100 x 100mm for flexural strength, cube of size 100 x 100 x 100mm, cylinder of 100 mm (Diameter) x 300mm (height) were casted. All the specimens were cured for 7 and 28 days and tested subsequently. The workability is measured with the slump-cone test. The wet and dry density at 7 and 28 days is calculated. Relation between compressive strength and all other strengths is developed. A comparison of results of hybrid fiber-reinforced concrete with that of normal concrete showed significant improvements in the results of various strengths.

4 illus, 7 tables, 14 ref

001740   Semsarzadeh M A;Amiri S;Azadeh M (Tarbiat Modares Univ, Jalal Al-e-Ahmad Highway, Tehran, PO Box 14115-11, Iran, Email: semsarzadeh@modares.ac.ir) : Controlled radical polymerization of vinyl acetate in presence of mesoporous silica supported TiCl₄ heterogeneous catalyst. Bull Mater Sci 2012, 35(5), 867-74.

The heterogeneous TiCl₄ catalysts supported on mesoporous mobile composition of matter (MCM-41) and mesoporous silicone particles synthesized from block copolymer of PPG-PEG-PPG (SPB) complexed with dimethyl formamide (DMF) ligand were used in a controlled free radical reaction with benzoyl peroxide (BPO) initiator in bulk polymerization of vinyl acetate (VAc). In this polymerization process, mesoporous particle of SPB increased the reactivity of TiCl₄ catalyst with DMF ligand. The active site formed on the surface and the pores of the catalyst produced specific sequences of VAc on the chain with different thermal and microstructural properties and crystallinity.

7 illus, 4 tables, 24 ref

001739   Sajani S;Moorthy K K;Rajendran K;Nanjundiah R S (NO, CSIR-Centre for Mathematical Modeling and Computer Simulation, Bangalore-560 037, Email: sajanirajendran@gmail.com) : Monsoon sensitivity to aerosol direct radiative forcing in the community atmosphere model. J Earth Syst Sci 2012, 121(4), 867-89.

Aerosol forcing remains a dominant uncertainty in climate studies. The impact of aerosol direct radiative forcing on Indian monsoon is extremely complex and is strongly dependent on the model, aerosol distribution and characteristics specified in the model, modelling strategy employed as well as on spatial and temporal scales. The present study investigates (i) the aerosol direct radiative forcing impact on mean Indian summer monsoon when a combination of quasi-realistic mean annual cycles of scattering and absorbing aerosols derived from an aerosol transport model constrained with satellite observed Aerosol Optical Depth (AOD) is prescribed, (ii) the dominant feedback mechanism behind the simulated impact of all-aerosol direct radiative forcing on monsoon and (iii) the relative impacts of absorbing and scattering aerosols on mean Indian summer monsoon. We have used CAM3, an atmospheric GCM (AGCM) that has a comprehensive treatment of the aerosol-radiation interaction. This AGCM has been used to perform climate simulations with three different representations of aerosol direct radiative forcing due to the total, scattering aerosols and black carbon aerosols. We have also conducted experiments without any aerosol forcing. Aerosol direct impact due to scattering aerosols causes significant reduction in summer monsoon precipitation over India with a tendency for southward shift of Tropical Convergence Zones (TCZs) over the Indian region. Aerosol forcing reduces surface solar absorption over the primary rain-belt region of India and reduces the surface and lower tropospheric temperatures. Concurrent warming of the lower atmosphere over the warm oceanic region in the south reduces the land-ocean temperature contrast and weakens the monsoon overturning circulation and the advection of moisture into the land-mass. This increases atmospheric convective stability, and decreases convection, clouds, precipitation and associated latent heat release. Our analysis reveals a defining negative moisture-advection feedback that acts as an internal damping mechanism spinning down the regional hydrological cycle and leading to significant circulation changes in response to external radiative forcing perturbations. When total aerosol loading (both absorbing and scattering aerosols) is prescribed, dust and black carbon aerosols are found to cause significant atmospheric heating over the monsoon region but the aerosol-induced weakening of meridional lower tropospheric temperature gradient (leading to weaker summer monsoon rainfall) more than offsets the increase in summer-time rainfall resulting from the atmospheric heating effect of absorbing aerosols, leading to a net decrease of summer monsoon rainfall. Further, we have carried out climate simulations with globally constant AODs and also with the constant AODs over the extended Indian region replaced by realistic AODs. Regional aerosol radiative forcing perturbations over the Indian region is found to have impact not only over the region of loading but over remote tropical regions as well. This warrants the need to prescribe realistic aerosol properties in strategic regions such as India in order to accurately assess the aerosol impact.

18 illus, 1 table, 41 ref

001738   Reza M A;Gheidari M H N (Civil Engineering Dep, Zanjan Branch Islamic Azad Univ, Zanjan, Iran, Email: alireza.moazzami63@gmail.com) : Investigations on hydraulic conditions effect on gypsum's solvability process in water structures foundation. Ecol Envir Conserv 2011, 17(3), 625-30.

Gypsum and Anhydrite's existence in the selected substratum and bases makes its construction face some problems. Gypsum behavior beside water flow, because of its high dissolvable potential is threatening and causes anxiety. Previous researches show that gypsum materials solvability potential has always been a threat, beside water flow with high speed. In the recent project by performing laboratorial tests, the process and amount of gypsum's solvability in dam water and distilled water has been investigated and solvability coefficient for Marash dam water and distilled water and also response degree coefficient has been carefully estimated.

13 illus, 6 ref

001737   Ravishankar N C;Srihari P V (Mech. Eng. Dep, R.V. College of Engineering, Bangalore, Email: ravishankar.nc@gmail.com ) : Development and simulation of non-linear gear dynamics model. J Aerospace Engng Technol 2013, 3(2), 11-6.

With the development of high-speed mechanical transmission, the dynamic characteristics of gear transmission require continuous improvement and more accurate prediction of the gear system dynamics becomes more and more important. The literature revealed that the gear pair transmission system is inherently non-linear which exhibits complex behavior and it is significant to study its vibration characteristics in detail and to analyze the influencing factors. A nonlinear dynamic model of gear transmission is developed using lumped mass parameter approach. The equations of torsional motion of the mathematical model of gear pair system was developed based on the Newton's Second law of motion/D' Alembert's principle, and the gear backlash was included in the mathematical model which is a discontinuous and non-differentiable function. The numerical simulation of the non-linear second order ordinary differential equation was carried out in MATLAB using Runge-Kutta method ((6h-8h order). The aim of this paper is to compare the dynamic behaviour of lightly loaded and heavily loaded gears and to analyze the effect of force ratio, damping ratio and excitation frequency on gear dynamics which provides a theoretical basis for in-depth studying of the gear dynamics. Clearly, the study showed that if a suitable load ratio is chosen and the damping parameter is increased, the chaotic motion can be controlled and can avoid the unstable motion in order to decay the vibration and noise of the gear-pair system.

6 illus, 6 ref

001736   Ravi Kumar S N;Pawar S (NO, Carl Zeiss India, IMT Div, Application, Email: rksirige@zeiss.co.in) : Effect of environmental conditions on measurementn accuracy using shop-floor CMM'S. Mfg Technol Today 2012, 11(4), 13-8.

Expectations on today's production measuring technology are largely focused on shopfloor application and the rough environmental conditions encountered there. The trend is obvious. Measurement is being shifted from the metrology room into the manufacturing process, which considerably reduces reaction times. Shop floor machines should have ease of operation by production staff, and ability to provide metrology room precision in a manufacturing environment despite poor temperature conditions, dirt and floor vibrations.

4 ref

001735   Rao C K;Mathur P;Jain R;Pathak S;Sundaram S; Rajeev R B;Govinda K V (Systems Integration Group, ISRO Satellite Center, Bangalore, Email: pravesh@isac.gov.in) : Recent trends in spacecraft alignment using optical & digital metrology techniques. Mfg Technol Today 2012, 11(4), 5-12.

Process of finalization of configuration of a spacecraft starts with 3D CAD definition of Mechanical/Optical/RF axes of various components, subassemblies, and major assemblies. After finalization of the 3D CAD definition the same is sent for the fabrication. Once the fabrication is over, the critical geometries and parameters of each component are measured using the different contact and non-contact methods before the same is assembled to the spacecraft main assembly. The measurement of the geometries of the subsystem and their relative orientation with respect to the spacecraft main assembly is a challenging task. The alignment of the subsystems with respect to the spacecraft main assembly includes the measurement of six transformation parameters and correcting the deltas between the theoretical CAD model and the measured assembly. The evolving technology of intelligent cameras with automated photogrammetric measurements & use of computational metrology has recently begun to play a prominent role in enhancing the productivity and meet the accuracy requirements. An attempt is made to use the close range photogrammetry system with digital intelligent camera and various optical metrology techniques for spacecraft applications right from the fabrication stages of components to the final spacecraft main assembly. This paper provides the details of the work carried out to check the feasibility of implementation of photogrammetry technique for spacecraft integration. The paper further provides a brief on recent advancements in the optical and digital metrology techniques as well as their advantages/limitations over the existing conventional metrology techniques within ISRO.

18 illus, 1 table, 5 ref

001734   Ramay S M;Siddiqi S A;Sabieh Anwar M;Park C Y;Shin S C (Physics Dep, School of Science and Engineering, Lahore Management Sciences (LUMS) U, Opposite Sector U.D.H.A., Lahore 54972, Pakistan, Email: sabieh@lums.edu.pk) : Effect of annealing time on structural and magnetic properties of laser ablated oriented Fe₃O₄ thin films deposited on Si(100). Bull Mater Sci 2012, 35(4), 501-3.

Fabricated <126>143 nm Fe₃O₄ thin films on Si(100) substrates at 450°C and then annealed them at the same temperature for 30, 60 and 90 min under a vacuum of 10^-6 torr with pulsed laser deposition. Studied the effects on the structural and magnetic properties of Fe3O4 thin films. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). XRD studies showed pure single phase spinel cubic structure of Fe3O4 with a preferential [111] orientation, independent of substrate orientation at 90 min annealing. Higher magnetization was obtained up to 60 min annealing due to Fe phase but at 90 min, we obtained reduced magnetization of 335 emu/cc. This is attributed to the formation of antiphase boundaries between substrate and film.

3 illus, 1 table, 20 ref

001733   Rad H E;Aref F;Rezaei M;Amiri E;Khaledian M R (Irrigation and Drainage Dep, Islamic Azad Univ, Firouzabad Branch, Iran) : Effects of salinity at different growth stage on rice yield. Ecol Envir Conserv 2011, 17(3), 455-62.

Population growth increases fresh water consumption and decreases water availability. This situation results in increasing pressure on water resources and consequently decreasing in the water portion of agricultural sector. These new conditions led us to find new solutions for utilization of low quality water in agriculture. As other crops, rice production area of northern Iran has met these kinds of problems. A tendency to use saline water in rice production is rising in recent years, but the optimum management of saline waters is still questionable. In order to assess the possibility of brackish water use in rice production and the effects of saline water on different growth stages of rice (Hashemi variety, a popular local variety), a pot research was performed in Rice Research Institute of Iran in Rasht in the North of Iran, under a shelter during 2010 crop season. 4 levels of water salinity i.e. 2, 4, 6, and 8 dsm-1 were applied at 4 different growth stages i.e. tillering (vegetation stage), panicle forming (reproductive stage), heading stage and ripening stage of this local rice variety. Another treatment with fresh water during the whole growth stage was applied to do mean comparison. Saline water was made by using NaCl + CaSO₄ (2:1). After 7 days as a period of recovery, salinity treatments were exerted up to 5cm water standing. In order to prevent salt concentration, at the end of each growing stage, pots' soils were washed and irrigation was continued with fresh water. All agricultural practices were done based on usual farmers. After harvesting, plant height, biomass, harvest index, yield and yield components were measured and analyzed, mean comparison was done based on DMRT. Results showed a considerable sensitivity to salinity. Water salinity rate had significant effects on yield, number of filled panicle (p<60>0.01), biomass and harvest index (p<60>0.05). Effects of timing of salinity introduction in different rice growth stages on yield, number of filled panicle, biomass and harvest index (p<60>0.01) and dry weight of straw were statistically significant (p<60>0.05). The highest yield was obtained from fresh water (no salinity) with 21.5 gr per pot while salinity treatments of 2, 4, 6 and 8 dSm-1 yielded 18.71, 17.79, 14.87 and 12.59 gr per pot, respectively, represented 21, 25, 37, 47% yield losses It can be stated that the panicle formation and tillering stages with 9.40 and 11.81 gr per pot of yield were the most sensitive stages to salinity. The other growth stages including heading and ripping with 20.98 and 21.77 gr per pot, respectively, were the lowest sensitive stages to salinity. Generally, the most sensitive rice processes were reproductive and vegetation stages. The best time of using saline water during the crop season of this Iranian local rice variety seems to be after panicle initiation to the end of ripening application of saline water of any EC in early growth stage will cause a high yield loss.

1 illus, 3 tables, 40 ref

001732   Prasad K S;Vommi Krishna;Ashok Kumar B B (Mechanical Engineering Dep, Anil Neerukonda Institute of Technology & Sciences, Visakhapatnam, Email: kspanits@gmail.com) : Aerofoil profile analysis and design optimisation. J Aerospace Engng Technol 2013, 3(2), 1-10.

Aerofoil section is the incarnation of a wing or a lifting surface which is very important in an airplane wing design. While the shape of the aerofoil changes, their aerodynamic characteristics also change. This paper deals with a standard symmetrical aerofoil as reference and the effect of changes in shape due to minor variations in the coordinates. Eight new aerofoil shapes have been produced in this optimisation process. The aerodynamic characteristic results such as the coefficients of lift and drag (Cd, Cl), pressure coefficient (Cp), moment coefficient (Cm) are noted for all eight different profiles, produced from the standard NACA 0012 aerofoil with changes in the chord thickness distance but no change in the maximum thickness in percentage of chord. The modus-operandi used in this optimisation process is the Computational Fluid Dynamics (CFD). Flow changes have been recorded for these aerofoil shapes and the results are arrived for finding the best aerofoil that can be advisable to be used in compressors, turbines, etc. with reduced flutter and maximum life.

9 illus, 3 tables, 7 ref

001731   Pilpayeh A;Jahromi H M;Raoof M;Hosseini M M; Enollahi G (NO, Islamic Azad Univ (IAU), Parsabad Moghan Branch, Iran, Email: a.pilpayeh@iaupmogan.ac.ir) : Optimization of consecutive multipurpose reservoir dam operation (case study of Aras river basin, Iran). Ecol Envir Conserv 2011, 17(3), 447-54.

The genetic algorithm (GA), is widely used in different branch of sciences. The application of a number of these methods has been reported in the case of optimal operation of reservoirs. The aim of this paper is presenting programs for the optimal release of water from consecutive multi-purpose reservoir dams with non polar parameters of inflow and water in demand. In this study, the genetic algorithm technique has been used for optimizing reservoir dams in the Aras River Basin in northwestern Iran. The objective function is minimizing the water shortages necessary in required regions and minimizing the water-electrical energy production shortage at the power stations in reservoir dams. In the present article three scenarios of moderate time terms data are entered in the model and the findings are analyzed. The selected scenarios are called S₁₁ S₁₂ S₁₃ which have been applied for Aras and Khodaafarin reservoir dams, Iran. The dam precept curves have been derived by the genetic algorithm method (GA) and probable shortage rate for each period has been specified.

7 illus, 13 ref

001730   Nouri A Z;Sedghi H;Telvari A R;Babazadeh H; Manshori M;Bavani A R M (Irrigation Dep, Science and Research Branch Islamic Azad Univ, Tehran, Iran, Email: alireza.zamani58@yahoo.com ) : Using L-moments method for estimating flood quantiles uncertainty in regional flood frequency analysis. Ecol Envir Conserv 2011, 17(3), 479-88.

Major consideration in designing dams and hydraulic structures on rivers is prediction of catastrophic events. Lack of sufficient data and the uncertainty involved in these cases are the main challenges in estimating the catastrophic events. Generalizing the results of frequency analyses conducted in the gauged regions to those of the ungauged rivers in the same hydrological region is a possible way out of the problem. L-moments method is a suitable regional analysis method as it is not sensitive to distant workstation and values and also short annual flood series. In this study, in order to analyze the uncertainty in flood quantiles, L-moments method was applied to the data collected from flood-gauging stations at Karkheh basin in Western Iran. The study shows that the flood quantiles obtained by L-moments method has a three parameter log normal distribution. The study also suggests that with an decrease in the probability of quantiles, the uncertainty will also increase.

2 illus, 4 tables, 36 ref

001729   Neeraj Kumar;Sharma A;Rajiv Kumar (NO, Faculty of Mechanical Engineering GEC, Panipat, Haryana) : Review on BPR and RSCM in an auto ancillary industry: a combined thought. Int J Sci Engng Comput Technol 2013, 3(1-2), 17-20.

Ecological and fiscal issues have significant impacts on Reverse Supply Chain Management (RSCM) and are consideration to shape one of the developmental keystones of sustainable supply chain. Business Process Reengineering is a subterfuge- determined organizational inventiveness, basically reexamine and redesign business practice with the intention of accomplishing competitive step forward in quality, receptiveness, expenditure, customer fulfillment and other critical process performance measures. In this research paper we offer an appraisal of BPR vision focusing upon the use of informational techniques to facilitate a shift way from linear sequential work organization towards parallel work and multidisciplinary team work.

2 illus, 2 tables, 15 ref

001728   Morouzian S;Larijani M M;Afzalzadeh R (Physics Dep, Iran Science and Technology Univ, P.O. Box 16765-163, Tehran, Iran, Email: sh.norouzian@yahoo.com) : Effect of nitrogen flow ratio on structure and properties of zirconium nitride films on Si(100) prepared by ion beam sputtering. Bull Mater Sci 2012, 35(5), 885-7.

In this study, zirconium nitride thin films were deposited on Si substrates by ion beam sputtering (IBS). Influence of N₂/(N₂+Ar) on the structural and physical properties of the films has been investigated with respect to the atomic ratio between nitrogen and zirconium. It was found that the thickness of layers decreased by increasing the F(N₂). Moreover, crystalline plane peaks such as (111), (200) and (220) with (111) preferred orientation were observed due to strain energy which associate with (111) orientation in ZrN. Also, the fluctuation in nitrogen flow ratio results in colour and electrical resistivity of films.

3 illus, 1 table, 15 ref

001727   Mondal S;Bardhan R;Mondal B;Dey A; Mukhopadhyay S S;Roy S;Guha R;Roy K (Centre for Advanced Materials Processing, CSIR-Central Mechanical Engineering Research Institute, Durgapur-713 209, Email: bnmondal@rediffmail.com) : Synthesis, characterization and in vitro cytotoxicity assessment of hydroxyapatite from different bioresources for tissue engineering application. Bull Mater Sci 2012, 35(4), 683-91.

In the present study, hydroxyapatite (HAp) is synthesized from different biosources like eggshell, fish scale and bovine bone in a cost effective and ecofriendly way. HAp materials were synthesized from eggshell by wet precipitation method whereas thermal decomposition method was applied in case of fish scale and bovine bone. The phase purity and crystallinity of different calcined HAp powder were determined by XRD and FTIR analyses. The thermogravimetric analysis was carried out to show thermal stability of HAp powder. Average grain sizes of sintered samples were in submicron range. The morphology of the powders were observed under scanning electron microscopy (SEM). The dried powders were wet ball milled for several hours and surfactants like Triton-X small fillers (2/4 mm long rod-shaped) were made for in vitro testing. In order to verify the biocompatibility of HAp powders, cytotoxicity evaluation was carried out in RAW macrophage like cell line media for an incubation period of 72 h. The cell attachment studies on HAp compacts show an excellent affinity between cells and compact surface. These results proved high biocompatibility of HAp powders obtained from different biosources for tissue engineering applications.

17 illus, 2 tables, 21 ref

001726   Masjedi A;Abyar H;Akbari I (Agriculture Dep, Islamic Azad Univ, Ahvaz Branch, Ahvaz, Iran) : Effect of wing length of L-shape spur dike on the local scour in a 180 degree flume bend. Ecol Envir Conserv 2011, 17(3), 463-8.

Experimental investigation on scoring and determination of depth of scoring are among the most important issues in L-shape spur dike designation with model L-shape spur dike was measured in a laboratory flume with 180 degree bend under clear-water. Experiments were conducted for different locations, wings length of L-shape spur dikes at the bend with various Froude number. In this study, the time development of the local scour around the L-shape spur dike plates was studied. The results of the model study indicated that the maximum depth of scour is highly dependent on the experimental duration. It was observed that, the greatest depth of the scour hole was associated with 9/180 =0.41 spur dike. By increasing the wing length of the spur dike, the maximum depth of scour decreases and decreases depth of scour occurs at 1/L=0.50. With increasing Froude number the maximum scour depth increases. Measuring depth of scouring based on experimental observation, an empirical relation is developed with high regression coefficient 91%.

7 illus, 8 ref

001725   Manna O;Singh S K;Paul G (Mechanical Engineering Dep, Haldia Institute of Technology, Haldia-721 657, Email: gayatri.paul@gmail.com) : Enhanced thermal conductivity of nano-SiC dispersed water based nanofluid. Bull Mater Sci 2012, 35(5), 707-12.

Silicon carbide (SiC) nanoparticle dispersed water based nanofluids were prepared using up to 0.1 vol% of nanoparticles. Use of suitable stirring routine ensured uniformity and stability of dispersion. Thermal conductivity ratio of nanofluid measured using transient hot wire device shows a significant increase of up to 12% with only 0.1 vol% nanoparticles and inverse dependence of conductivity on particle size. Use of ceramic nanoparticles appears more appropriate to ensure stability of dispersion in nanofluid in closed loop single-phase heat transfer applications.

5 illus, 21 ref

001724   Manes G S;Dixit A;Poonamjeet Kaur;Arshdeep Singh;Simarjeet Singh (Farm Machinery and Power Engineering Dep, Punjab Agricultural Univ, Ludhiana-141 004) : Variations in dimensions of three point hitch and PTO of available tractors. Indian J agric Res 2012, 46(3), 208-16.

Study was under taken to find the variations in dimensions related to three point linkage and PTO of available tractors of different horse power range, so as to find out a range for standardization of dimensions of three point hitch system and PTO for available tractors. A total of 45 tractors of different makes were divided into five categories depending on their horse power viz. below or equal to 35 hp, 36-45 hp, 46-55 hp, 56-65 hp and above 65 hp. All tractors of all hp categories had the PTO diameter in the range of 34 to 35 mm. Exposed length of PTO spline for 67% tractors was in the range of 100-140 mm. Horizontal distance of PTO end from centre line passing through lower links for 62% tractors was in the range of 450-550 mm. Distance of lower hitch point from centre line of rear tire for 53% tractors was in the range of 250-400 mm. Horizontal distance between the free ends of lower hitch points for 69% tractors was in the range of 700-950 mm.

2 illus, 4 tables, 2 ref

001723   Maiti T K;Maiti C K (Electronics and Electrical Communication Engineering Dep, Indian Institute of Technology, Kharagpur-721 302, Email: ckm@ece.iitkgp.ernet.in) : Hybrid orientation technology and strain engineering for ultra-high speed MOSFETs. Bull Mater Sci 2012, 35(5), 859-65.

Reports RF MOSFET performance in sub-45-nm hybrid orientation CMOS technology. Based on the combination of hybrid orientation technology (HOT) and process-induced local strain engineering, MOSFET RF performance is investigated using CAD (TCAD) technology. Transistor optimization on (100) substrate via silicon nitride (Si₃N₄) cap layer thickness for n-MOSFETs, Ge mole fraction optimization for p-MOSFETs on (110) substrates and channel length scaling have resulted in record RF performance, viz. the cut-off frequency, ↵_T.

9 illus, 2 tables, 29 ref

001722   Mahalakshmi P V;Vanithakumari S C;Gopal J; Mudali U K;Baldev Raj (Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Email: kamachi@igcar.gov.in) : Enhancing corrosion and biofouling resistance through superhydrophobic surface modification. Curr Sci 2011, 101(10), 1328-36.

Simple approach was developed for generating superhydrophobic surface modification of titanium and 9Cr-lMo steel. Motivated by the lotus effect in which water droplets falling on the leaves bead up and roll off, anodization as well as etching followed by dip coating in myristic acid was attempted to create super-hydrophobic surfaces. However, the water contact angle on titanium was found to be 148° ± 4°, whereas in the case of 9Cr-lMo steel, it was 107° ± 2°. A detailed description of the surface-modified superhydrophobic titanium and hydrophobic 9Cr-lMo steel is presented in this article. The corrosion performance and anti-bio-fouling properties are ascertained using electrochemical impedance spectroscopy and epifluorescence microscopy. The present study revealed enhanced corrosion resistance and antibiofouling of the materials after superhydrophobic surface modification.

10 illus, 29 ref

001721   Ma Z;Zhao N;Xiong C (School of Chemical and Material Engineering, Huangshi Institute of Technology, Huangshi-435 003, P.R. China, Email: zhaona014112034@163.com) : Degradation and miscibility of poly(DL-lactic acid)/poly(glycolic acid) composite films: effect of poly(DL-lactic-co-glycolic acid). Bull Mater Sci 2012, 35(4), 575-8.

The in vitro degradation behaviour of poly(glycolic acid) (PGA) and its composite films containing poly(DL-lactic acid) (PDLLA) and poly(DL-Iactic-co-glycolic acid) (PDLGA) were investigated via mass loss, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). All the films were prepared by solution casting, using l,l,l,3,3,3-hexafluoro-2-propanoI (HFIP) as the solvent. Since the degradation rate of PDLLA is lower than that of PGA, those of the PDLLA/PGA composite films decreased. As a compatibilizer, PDLGA improved the compatibility and hydrolytic stability of PDLLA/PGA composite films. Changes in the composite films indicate that this kind of PGA-based composite biomaterial may be applicable to device design for clinical application in the future.

5 illus, 1 table, 6 ref

001720   Kumar B S;Vijayakumar S R (NO, Electronics Test and Development Centre, Bangalore) : Measurement capability assurance through identification and compensation of 'hidden error'. Mfg Technol Today 2012, 11(4), 27-9.

With the advent of technologies, the equipment manufacturers are offering precision multifunction calibrators, precision multi meters, High accuracy DC Resistance Bridge, precision LCR meters etc at competitive prices. Accordingly most of the Electro technical calibration laboratories are increasingly acquiring such higher end calibrators/standards to add business value with enhanced measurement capability. The measurement capability of such laboratories range from sub ppm level to single digit ppm level. Though it is possible to achieve the enhanced measurement capability as per the claimed specification and the methods specified by the equipment manufacturer, it often raises doubt whether in reality and practice the best measurement capability is achieved without adopting good measurement practices. This paper details good measurement practices to be established and implemented by calibration laboratories as part of measurement capability assurance to demonstrate its competence and capability to calibrate at low ppm level using precision calibrators and standards. An attempt is also made to highlight the possible errors known as hidden errors which get observed into measurement results and in certain cases errors introduced could be more than the best measurement uncertainty claimed by the laboratories.

3 ref

001719   Koo M;Bae J S;Kim H C;Nam D G;Ko C H;Yeum J H;Oh W (Materials & Components Engineering Dep, Electronic Ceramics Centre, Dong-Eui Univ, Busan-614 714, Korea, Email: wtoh2005@deu.ac.kr) : Electrochemical oxidation of some basic alcohols on multiwalled carbon nanotube-platinum composites. Bull Mater Sci 2012, 35(4), 545-50.

Some composites of multiwalled carbon nanotubes, which were chemically treated in acidic and/or hydrogen peroxide solution, and platinum nanoparticles were prepared by the simple reduction in glycerol solution. Carboxylated and/or hydroxyl MWNTs were structurally analysed using X-ray photoelectron spectroscopy. In addition, the MWNT-Pt composites were characterized by XRD and TEM in detail. The electrochemical oxidation of some basic alcohols, which was catalyzed by the MWNT-Pt composites, was analysed by cyclic voltammetry. Their catalytic activities were studied with cyclic voltammograms of alcohols.

5 illus, 36 ref

001718   Kole M;Tripathi D;Dey T K (Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur-721 302, Email: tapasdey@hijli.iitkgp.ernet.in) : Percolation based enhancement in effective thermal conductivity of HDPE/LBSMO composites. Bull Mater Sci 2012, 35(4), 601-9.

Thermal conductivity of composites with electrically conducting La_0.7Ba_0.15 Sr_0.15MnO<>3 (LBSMO) filler of nanometric grain size in HDPE matrix is investigated. Volume fraction of LBSMO fillers was varied between 0 and 0.30. SEM photographs of the composites show the presence of clusters and percolative paths, particularly for composites prepared with higher filler volume fractions. The effective thermal conductivity of the composites displays significant enhancement with increasing filler content in HDPE. A maximum enhancement of <126>65% compared to that for pure HDPE has been observed for composite with 0.30 volume fraction of LBSMO filler. Most of the models those are generally used to predict the properties of two phase mixtures, has been found either to under/overestimate the measured effective thermal conductivity of the composites. It was confirmed that the observed rapid increase in the effective thermal conductivity of HDPE/LBSMO composite over the studied range of filler volume fraction (viz. 0-0-30), is predicted very well, considering the effect of percolation as proposed by Zhang et al (2009).

5 illus, 2 tables, 56 ref

001717   Kim Y C;Park J O;Jang W K (Optometry Dep, Eulji Univ, Seongnam-si, Gyeonggi-do-463 713, South Korea, Email: jwk@hanseo.ac.kr) : Laser inspection for visualizing vibration in a fine structured device. Asian J Chem 2011, 23(5), 2292-4.

Real time optical metrology to detect nano-scale vibration on the surface of solid materials is presented. Comparing to the electric method checkable only whether the vibration occurred or not on the surface of device to be investigated. The real time optical metrology provides visual information how and where the vibration occurred in nano-scale. We propose a laser inspection method for real time visualizing any vibration on the surface of device or materials. The measuring limit and conditions to detect a small surface vibration are given with a function of speed and sensitivity of detector. The observed signals of interference and diffraction are analyzed by theoretical interpretation.

3 illus, 4 ref

001716   Kim Y C;Kim H S;Park J O;Jang W K (Optometry Dep, Eulji Univ, Seongnam-si, Gyeonggi-do-461 713, South Korea, Email: jwk@hanseo.ac.kr) : Fabrication and characterization of a low voltage micro-electron column for scan field size and magnification. Asian J Chem 2011, 23(5), 2302-5.

Fabrication and characterization of a low voltage micro-electron column are reviewed. Many optical technologies in fabrication of a micro-electron-column such as laser aid optical alignment and in situ laser bonding are introduced in assembling basic components of micro-electron column. The maximum field of view and scan field size were investigated as a function of biased voltage of deflectors and electron emission tip voltage. The magnification and the linearity of zooming current image dependant on the electron emission tip voltage are also discussed.

4 illus, 3 ref

001715   Kalpana P (Chemical Engineering Dep, GMR IT, Rajam-535 127, Email: kalpanamtech@yahoo.com) : Augmentation of mass transfer coefficient in decaying swirl flow. Asian J Chem 2011, 23(5), 2128-30.

Enhancements in mass transfer coefficients due to the presence of helical tape promoter is presented in this paper. The variables studied are the flow rate of the electrolyte, rotational speed, Reynolds number, rotational Reynolds number and Scmidt number. It is found that the mass transfer coefficient increased with increased flow rate and also increased with increase in the rotational speed. Rotation improved the mass transfer coefficient from 5-107%. Mass transfer coefficient in the rotation of helical tape swirl generator is enhanced from 0.5 fold to 13 fold over the mass transfer coefficient in forced convection flow.

5 illus, 20 ref

001714   Jayabal S;Sathiya Murthy S;Loganathan K T; Kalyanasundaram S (Mechanical Engineering Dep, A.C. College of Engineering and Technology, Karaikudi-630 004, Email: jayabalsubbaian@ediffmail.com) : Effect of soaking time and concentration of NaOH solution on mechanical properties of coir-polyester composites. Bull Mater Sci 2012, 35(4), 567-74.

The green husk coir fibres were treated with different levels of soaking time and concentration of alkali solution. As a result of alkali treatment, the surface modifications were done on the fibre surface and were studied using scanning electron micrographs. The coir-polyester composites were fabricated using hand lay up process and the mechanical properties (tensile, flexural and impact strength) were evaluated as per ASTM standards. The effect of soaking time and concentration of NaOH solution were studied based on evaluated values of mechanical properties to find out optimum fibre treatment parameters.

18 illus, 6 tables, 12 ref

001713   Jangra S K;Mustakeem;Devender Kumar;Atal D K (Biomedical Engineering Dep, Deenbanchu Chhotu Ram Science & Technology Univ, Murthal, Haryana) : Microcontroller based low cost FES device for foot drop. Int J Sci Engng Comput Technol 2013, 3(1-2), 14-6.

Foot drop occurs when there is damage to nerve pathways that are responsible for the dorsiflexion movement of the foot. Foot drop is a common problem of neurological dysfunction in the spinal cord nerve. Functional Electrical Stimulator (FES) plays an important role in stimulating the nerves and muscles of the human body and tends to recover the dysfunction. Neuromuscular stimulators have offered new possibilities for the treatment of foot drop. In this paper a novel technique for developing a low cost microcontroller based FES system for Foot Drop patients is discussed.

3 illus, 24 ref

001712   Inda G S (NO, , ) : Inland water transport (IWT) for sustainable development and growth of north east region (NER). Indian Surveyor 2012, 66(1), 46-7.

For ages, it has been known that Inland Waters have been widely used by the ancient civilisation, as sustainable mode of transport for movement and trade. During the Indus civilisation, there are historical records to prove that people from India had mastered ship building techniques. There are further evidences to prove existence of ship building yards and docks at Lothal, Gujarat, Mohenjodero and Harappa in Sind (Now in Pakistan), which proves that Indus civilisation had known art of navigation and sailed on voyages, as far as South Africa, Gulfs and South East Asia (Java, Cambodia etc.) in their local made wooden sail ships and have established trade links. In the modern days, Inland Water Transport (IWT) mode is very widely used and developed for promotion of trade and economy in India and abroad; However, pace of development and modernisation in IWT has not been commensurate with advancement of modern technology, as it has developed in USA, China and Europe. There are certain region especially North eastern Region (NER) of India, where water resources are in abundance, need to be developed and used for sustainable growth and development of the region. Further, IWT need to be integrated with other modes of transport like Rail, Road etc. under multimodal mix of transport system to ensure door to door delivery of goods.

ref

001711   Hernandez-Torres J;Garcia-Gonzalez L; Zamora-Peredo L;Hernandez-Quiroz T;Sauceda-Carvajal A;Garcia-Ramirez P J;Flores-Ramirez N (Centro de Investigacion en Micro y Nanotecnologia, Veracruzana Univ, 94292, Boca del Rio, Veracruz, Mexico, Email: julihernandez@uv.mx) : Analysis of hardness of nanocrystalline coatings of aluminum-rich Ti_1-xB>Al_xN. Bull Mater Sci 2012, 35(5), 733-8.

Titanium aluminum nitride coatings were fabricated by a d.c. magnetron sputtering system from a Ti-Al (60/40wt%) target. Coatings were deposited on steel substrates, at a substrate temperature of 250 °C and a bias voltage of-80 V. The nitrogen flow was varied from 1.5-6 seem and the Ar flow was kept constant at 20 seem. The morphology and microstructure of the coatings were analysed by X-ray diffraction and scanning electron microscopy. The results of X-ray diffraction showed the presence of two cubic crystalline phases, TiN and A1N, which were confirmed by X-ray photoelectron spectroscopy. The Vicker hardness was obtained by the effective model of indentation. It was observed that the hardness of the coatings decreases from 22.8-9.5 GPa with an increased nitrogen content from 1.5-4.5 seem. Subsequently, the hardness increased to 22.1 GPa by increasing nitrogen to 6 seem. The behavior of hardness with grain size variation is consistent with the Hall-Peth relationship. The high value in the hardness of the coatings is mainly attributed to small grain sizes and the compressive stress present.

7 illus, 1 table, 24 ref

001710   Gunda J B;Rao G V (NO, Advanced Systems Laboratory, Kanchanbagh, Hyderabad, Email: jagadishasl@gmail.com) : Thermal post-buckling and large amplitude vibration analysis of composite beams vis-a-vis isotropic beams. J Aerospace Engng Technol 2013, 3(2), 17-24.

Thermal post-buckling and large amplitude free vibration analysis of composite beams is directly investigated based on an analogous relationship derived from the behavior of isotropic beams. The applicability of simple analogous relationship derived for the use of composite beams is demonstrated for various layup schemes of symmetrically laminated beam with wide variety of boundary conditions. Numerical accuracy of the proposed approach show an excellent agreement with available finite element solution which demonstrates the robustness of the analogous relationship derived here.

7 illus, 2 tables, 17 ref

001709   Goud G;Rao R N (Mechanical Engineering Dep, National Institute of Technology, Warangal-506 004, Email: pgovardhan0@yahoo.com) : Mechanical and electrical performance of Roystonea regia/glass fibre reinforced epoxy hybrid composites. Bull Mater Sci 2012, 35(4), 595-9.

The present paper investigates mechanical and electrical properties of Roystonea regia/glass fibre reinforced epoxy hybrid composites. Five varieties of hybrid composites have been prepared by varying the glass fibre loading. Roystonea regia (royal palm), a natural fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. Roystonea regia, E-glass short fibres were used together as reinforcement in epoxy matrix to form hybrid composites. It has been observed that tensile, flexural, impact and hardness properties of hybrid composites considerably increased with increase in glass fibre loading. But electrical conductivity and dielectric constant values decreased with increase in glass fibre content in the hybrid composites at all frequencies. Scanning electron microscopy of fractured hybrid composites has been carried out to study the fibre matrix adhesion.

4 illus, 3 tables, 11 ref

001708   Goswami S;Kiran K (Polymer Engineering Dep, Birla Institute of Technology, Ranchi-835 215, Email: sdptgoswami@yahoo.com) : Application of kissinger analysis to glass transition and study of thermal degradation kinetics of phenolic-acrylic IPNs. Bull Mater Sci 2012, 35(4), 657-64.

Degradation kinetics of sequential IPNs, based on novolac resin and poly (2-ethyl hexyl acrylate), are studied at linear heating rates of 2°C/min, 5°C/min, 10°C/min and 20°C/min by thermogravimetric analyser (TGA). Activation energy (E_a) and order (n) of thermal decomposition reaction for IPNs and pure phenolic resin are evaluated from TGA curves using differential method of Freeman and Carroll. Decrease in T_g with an increase of acrylate content in IPNs are seen. Lower activation energy (E_a), as calculated by applying Kissinger equation, for the concerned transition of IPNs, compared to that of pure phenolic resin is quite evident from DSC study.

10 illus, 3 tables, 18 ref

001707   Ghosh S K;Mahata D;Roychaudhuri R;Mondal R (Metallurgy and Materials Engineering Dep, Bengal Engineering and Science Univ, Shibpur, Howrah-711 103, Email: skghosh@metal.becs.ac.in) : Effect of rolling deformation and solution treatment on microstructure and mechanical properties of a cast duplex stainless steel. Bull Mater Sci 2012, 35(5), 839-46.

The present study deals with the effect of rolling deformation and solution treatment on the microstruc-ture and mechanical properties of a cast duplex stainless steel. Cast steel reveals acicular/Widmanstatten morphology as well as island of austenite within the δ-ferrite matrix. Hot rolled samples exhibit the presence of lower volume percent of elongated band of δ-ferrite (<126>40%) and austenite phase which convert into finer and fragmented microstructural constituents after 30% cold deformation. By the solution treatment, the elongated and broken crystalline grains recrystallize which leads to the formation of finer grains (<60>10 μm) of austenite. X-ray diffraction analysis has corroborated well with the above-mentioned microstructural investigation. Enhancement in hardness, yield strength and tensile strength values as well as drop in percent elongation with cold deformation increases its suitability for use in thinner sections. 30% cold rolled and solution treated sample reveals attractive combination of strength and ductility (25.22 GPa%). The examination of fracture surface also substantiates the tensile results. The sub-surface micrographs provide the potential sites for initiation of microvoids.

10 illus, 2 tables, 14 ref

001706   Ghasemzadeh M;Nemati A (Materials Engineering Dep, Karaj Branch Islamic Azad Univ, Karaj, Iran, Email: ghasemzadeh@kiau.ac.ir) : Role of MgF2 on properties of glass-ceramics. Bull Mater Sci 2012, 35(5), 853-8.

Formation of machinable glass-ceramic in the system MgO-SiO2-Al2O3-K2O-B2O3-F with and without addition of MgF2 has been investigated. Crystallization of glass sample was done by controlled thermal heat treatment at nucleation and crystallization temperatures. The results showed that MgF2 in high concentration had a synergistic effect and enhanced the formation of interlocked mica crystals. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses were changed in the range of 235-405 kJ/mol, while the crystallization activation energies of samples with addition of MgF₂ were changed in the range of 548-752 kJ/mol.

9 illus, 3 tables, 13 ref

001705   Gao S Y;Le Q C;Zhang Z Q;Cui J Z (Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern Univ, Shenyang-110 819, China, Email: jzcui@mail.neu.edu.cn) : Grain refinement of AZ31 magnesium alloy by electromagnetic stirring under effect of grain-refiner. Bull Mater Sci 2012, 35(4), 651-5.

The effects of electromagnetic stirring and Al₄C₃ grain refiner on the grain refinement of semi-continuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an effective refining effect on the grain size of AZ31 magnesium alloy under the effect of Al₄C₃ grain refiner. Electromagnetic stirring can 'activate' the Al₄C₃ particles, resulting in more heterogeneous nucleation sites for the primary α-Mg grains. But, longer holding time can 'deactivate' the Al₄C₃ particles and poison the grain refining effect.

4 illus, 19 ref

001704   Elkhattabi E H;Badreddine M;Berraho M; Legrouri A (Laboratorie de Chimie Biomoleculaire, Substances Naturrelles et Reactivites, Unite de Materiaux, Faculte des, BP 2390, Marrakech 40000, Morocco, Email: legrouri@aui.ma) : Incorporation of fluorophosphate into zinc-aluminium-nitrate layered double hydroxide by ion exchange. Bull Mater Sci 2012, 35(4), 693-700.

The intercalation of fluorophosphate (PO₃F^2-, FP) in the [Zn-Al] layered double hydroxides (LDHs) was investigated. A nitrate precursor was prepared by coprecipitaion at pH 9. An attempt to intercalate FP by direct coprecipitation reaction led to a poorly crystalline LDH phase. The effects of pH, aging time and anion concentration were studied and allowed to confirm that the best crystalline material, with high exchange extent, was obtained by carrying out the exchange at 25 °C in 0.1M FP solution at pH 9 with at least 20 h of aging time.

9 illus 1 table, 16 ref

001703   Dutta S;Chatterjee S;Sen R (Metrology Group, CMERI, Durgapur, Email: rsen@cmeri.res.in) : Accuracy of a long-travel-range, utra-high-resolution, hybrid-drive translational stage using laser interferometer. Mfg Technol Today 2012, 11(4), 19-22.

Performance of micro-meso machine tools is profoundly affected by its position accuracy and built-in motion error of the machine tool. Further, errors in position and orientation in a multi-axis machine are the results of errors in the individual links of the machine and the interactions between them. Therefore it is very important to study the individual stage movements before it is assembled in the machine tools. In this study, the linear and angular errors of a hybrid-drive translational stage has been examined with a laser interferometer.

6 illus, 3 tables, 8 ref

001702   Das J (NO, , Mine Surveying Asansol Polytechnic) : Trilateration survey network adjustment- an alternative approach. Indian Surveyor 2012, 66(1), 34-8.

In high school, one learns how to compute distances from coordinates using the Pythagorean theorem. The inverse problem-determining coordinates from distances is not taught, but it is just what is needed here. There are n(n-l)/2 possible (symmetric) distances between n points. As long as there are six or more points, this quantity grows quadrati-cally with a linear increase in the number of points, so that the configuration is overdetermined; and should really need only 2n distances in two dimensions- one pertaining to each pair of points. That is because the two points are fixed when one has the two coordinates.

3 illus, 15 ref

001701   Colaco R M;Nagaraj M K;Pakkala T P M (NO, NITK, Surathkal) : Risks in construction industry of Mangalore. J Constr Engng Technol Mgmt 2013, 3(2), 11-20.

Study of risks in construction industry is an open-ended experiment as not many references are available for comparison. The geographical divide of India poses a challenge to the construction fraternity due to varied factors of risks involved in construction activities and it is not possible to give a common risk matrix for construction projects in India. It invariably has to be divided into smaller segments and the geographical area has to be selected based on similarities in conditions. Nevertheless, when the study of a particular region is completed the model can be replicated in other regions to get the risks associated with construction activities in that particular region. Also the construction activity varies with type of projects, viz., public, private and public-private partnership projects. In the present study, the construction activity in Mangalore city is taken as the pilot sample. The private residential projects, viz., apartments, houses and commercial complexes are taken as the group under study. The risk associated with the above construction activity is obtained through a questionnaire survey and the outcome is studied.

3 tables, 5 ref

001700   Choudhary S;Qureshi S (Electrical Engineering Dep, Indian Institute of Technology, Kanpur-208 016, Email: suds@itk.ac.in) : Theoretical study on effect of radial and axial deformation on electron transport properties in a semiconducting Si-C nanotube. Bull Mater Sci 2012, 35(5), 713-8.

Investigate electron transport properties in a deformed (8, 0) silicon carbide nanotube by applying self consistent non-equilibrium Green's function formalism in combination with the density-functional theory to a two-probe molecular junction constructed from deformed nanotube. The results suggest significant reduction in threshold voltage in the case of both radially compressed and axially elongated (8, 0) SiCNTs, a large difference in current-voltage characteristics was observed. Analysis of frontier molecular orbitals (FMO) and transmission spectrum show bandgap reduction in deformed nanotubes. Deformation introduces electronic states near the Fermi level, enhancing the conduction properties of (8, 0) SiCNT. The FMOs and the orbitals corresponding to peaks in T(E) around Fermi level obviously has some major contributions from the deformed site. However, localization of the electronic state near the Fermi level is weak in (8, 0) SiCNT, possibly because of its large bandgap.

6 illus, 31 ref

001699   Bhattacharyya S;Patra A (Materials Science Dep, Indian Association for the Cultivation of Science, Kolkata-700 032, Email: msap@iacs.res.in) : Photoluminescence quenching of semiconducting polymer nanoparticles in presence of Au nanoparticles. Bull Mater Sci 2012, 35(5), 719-25.

In this report, we have demonstrated the photoluminescence quenching and energy transfer properties of semiconducting polymer nanoparticles, poly (N-vinylcarbazole) (PVK) in presence of different sized Au nanopar-ticles by steady state and time-resolved spectroscopy. We have described the quenching phenomena by sphere of action static quenching mechanism and both dynamic and static quenching processes are found in these systems. PL quenching values are 24.22% and 57.3% for 14 nm and 18 nm Au nanoparticles, respectively. It is found that the radiative and nonradiative decay have been modified with the size of Au nanoparticles. PL quenching and shortening of decay time regarding polymer nanoparticles in presence of Au nanoparticles suggest the nonradiative energy transfer process. The values of energy transfer are 6.7%, 49.5% and 53.38% from PVK polymer nanoparticles to 3 nm, 14 nm and 18 nm Au nanoparticles, respectively. Using FRET and SET equations we have calculated the average distance of donor PVK polymer nanoparticles and acceptor Au nanoparticles.

6 illus, 3 tables, 22 ref