011214   Li X;Zhang D;Zhu P;Yang C (Key Laboratory of Advanced Civil Engineering Materials, Ministry of Ed, College of Materials Science and Engineering, Tongji University, 4800 CaoAn Road, Shanghai-200092, China, Email: zhangdng@tongji.edu.cn) : Influence of temperature and voltage on electrochemical reduction of graphene oxide. Bull Mater Sci 2014, 37(3), 629-34.

In this paper, the influence of temperature and voltage on direct electrochemical reduction were discussed in detail. Reduced graphene oxide is characterized with X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). It is found that the reduction degree of graphene oxide (GO) decreases gradually with the increase of applied temperature. The optimal applied temperature found in our experiment is 20°C; Meanwhile, as the applied voltage increases from 0.1 to 12.5 V, the reduction degree of graphene oxide increases gradually. However, above 2.5 V, increasing voltage has little effect on the reduction degree of graphene oxide.

6 illus, 2 tables, 17 ref

011213   Lewandowski A;Feldshtein E (Faculty of Mechanical Engineering, University of Zielona G¢ra, Zielona G¢ra Poland, Email: E.Feldsztein@ibem.uz.zgora.pl) : Technological heredity when roller burnishing of ductile cast iron. J scient ind Res 2014, 73(8), 559-65.

When processing EN GJSFP 450-10 ductile cast iron. The L18 Taguchi robust plan was used to optimize the processing conditions. The application of this method allowed determination of optimal conditions taking into account the conditions of pre-turning and burnishing. Due to optimization, the value of the S/N parameter increased by 25%. Best results were achieved when using a minimum turning and burnishing feed ratio, minimum turning speed, a large nose radius of the turning tool, maximum burnishing speed and indirect burnishing force in the presence of base oil. The phenomenon of technological heredity action was observed when roller burnishing, in other words, the influence of the pre-burnishing process conditions on the Ra surface roughness parameter after burnishing.

2 illus, 3 tables, 43 ref

011212   Joseph D;Nayak C;Venu Babu P;Jha S N; Bhattacharyya D (Nuclear Physics Div, BhabhaAomic Research Centre, Mumbai-400 085, Email: dibyendu@narc.gov.in) : Chemical shift of U L₃ edges in different uranium compounds obtained by X-ray absorption spectroscopy with synchrotron radiation. Bull Mater Sci 2014, 37(3), 643-7.

Uranium L₃ X-ray absorption edge was measured in various compounds containing uranium in U^{4+, U5+ and U6+ oxidation states. The measurements have been carried out at the Energy Dispersive EXAFS beamline (BL-08) at INDUS-2 synchrotron radiation source at RRCAT, Indore. Energy shifts of ~ 2-3 eV were observed for U L₃ edge in the U-compounds compared to their value in elemental U. The different chemical shifts observed for the compounds having the same oxidation state of the cation but different anions or ligands show the effect of different chemical environments surrounding the cations in determining their X-ray absorption edges in the above compounds. The above chemical effect has been quantitatively described by determining the effective charges on U cation in the above compounds.}

2 illus, 2 tables, 19 ref

011211   Hosseini S N;Enayati M H;Karimzadeh F (Meterials Engineering Dep, Isfahan University of Technology, Isfahan-84156-83111, Iran, Email: golenarges63@yahoo.com) : Nanoscale grain growth behaviour of CoAl intermetallic synthesized by mechanical alloying. Bull Mater Sci 2014, 37(3), 383-7.

Grain growth behaviour of the nanocrystalline CoAl intermetallic compound synthesized by mechanical alloying has been studied by isothermal annealing at different temperatures and durations. X-ray diffraction method was employed to investigate structural evolutions during mechanical alloying and annealing processes. The disordered CoAl phase with the grain size of about 6 nm was formed via a gradual reaction during mechanical alloying. The results of isothermal annealing showed that the grain growth behaviour can be explained by the parabolic grain growth law. The grains were at nanometric scale after isothermal annealing up to 0.7 T_m. The grain growth exponent remained constant above 873 K indicating that grain growth mechanism does not change at high temperatures. The calculated activation energy indicated that the grain growth mechanism in the disordered CoAl phase at high temperatures was diffusing Co and Al atoms in two separate sublattices. Furthermore, an equation has been suggested to describe the grain growth kinetics of nanocrystalline CoAl under isothermal annealing at temperatures above 873 K (T/T m ≥ 05).

5 illus, 2 tables, 17 ref

011210   He Y H;Huang J F;He Z;Lu J;Shen Q (NO, College of Materials Science and Engineering, Shaanxi University of S, China-710 021, Email: hehy@sust.edu.cn) : Microstructural and optical properties of transparent conductive ZnO : Al : Mo films deposited by template-assisted sol-gel method. Bull Mater Sci 2014, 37(3), 519-25.

Transparent conductive ZnO : Al : Mo films with a molar ratio of Zn : Al : Mo = 99 : 0.99 : 0.01 were deposited on quartz glass substrate by a template-assisted sol-gel process and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy, and UV-Vis and luminescent spectrophotometries. The four types of organic template have induced nanowire morphology with varying aspect ratio. Dip coating in one constant positive and reverse direction causes the parallel array of ZnO : Al : Mo nanowires on the quartz glass substrate. Long and parallel arrayed nanowire films show obviously blue shifts and enhanced transmittances in the UV-Vis light range. The PEG-1000 and PEG-2000 have optimal effects among four templates as constant weight content is used. The films show strong ultraviolet, violet and bluish violet emissions. The templates also lead to overall thicker film and more native defect and thereby remarkably enhancing photoluminescence of the films. Long chain organic template can be used to optimize the optical properties of the doped ZnO film.

7 illus, 1 table, 38 ref

011209   Han X Y;Wang J;Cheng H F (Science and Technology on Advanced Ceramic Fibers and Composites Labor, College of Aerospace Science and Engineering, National Univ of Defens, Hunan Changsha 410073, China, Email: hanxiaoyi@mail.nudt.edu.cn) : Investigation of thermoelectric SiC ceramics for energy harvesting applications on supersonic vehicles leading-edges. Bull Mater Sci 2014, 37(1), 127-32.

Utilizing thermoelectric technology to aerodynamic heat harvesting on the leading-edge is worth noticing in the thermal protection systems. In this paper, a nose-tip model in a supersonic flow field is developed to predict the thermoelectric performance of SiC ceramics structures. The generation performance is numerically investigated in terms of the computational fluid dynamics and the thermal conduction theory. The output power and energy efficiency of the nose-tip model are obtained with Mach number varying from 2.5-4.5. The generated power reaches 1.708 W/m^{2 at a temperature difference of 757 K at M = 4.5. With respect to the Thomson effect, the output power decreases rapidly. However, larger output power and energy efficiency would be obtained with the increase of Mach number, with or without considering the Thomson heat. Moreover, under the higher Mach numbers, larger range of output current value is available.}

9 illus, 4 tables, 25 ref

011208   Gunasekaran K;Baskar S K;Divya Sapphire Mohan;Sastry T P (Bio-Products Laboratory, Central Leather Research Institute, Adyar, Chennai-600 020, Email: sastrytp@hotmail.com) : Influence of mineral phase in mineralization of a biocomposite containing chitosan, demineralized bone matrix and bone ash-in vitro study. Bull Mater Sci 2014, 37(3), 729-33.

Resorbable composite which acts as a active barrier in guided bone regeneration was fabricated using chitosan, demineralized bone matrix and bone ash. Its potential to form bone like apatite in simulated body fluid was assessed in this study. The mechanical strength of these composites was correlated with bone ash ratios and composites with better tensile strength were studied for their acellular bioactivity by incubating in simulated body fluid for 21 days. Composites without bone ash did not show acellular bioactivity which was confirmed by thermogravimetric analysis. In case of biocomposites with bone ash, there was an increase in residual weight indicating the mineralization of the composite. The composite containing bone ash has shown the peaks related to phosphate vibrations in its Fourier-transform infrared spectrum. Scanning micrographs revealed formation of apatite like crystals on its surface. Ca/P ratio was found to be 17 which is nearer to that of natural bone. Thus, prepared composites can be used as resorbable biocomposite in maxillofacial and oral defects.

4 illus, 1 table, 19 ref

011207   Guedes M;Costa V;Silva T;Teles A;Yang X;Ferro A C (Mechanical Engineering Dep, Escola Superior de Tecnologia, Instituto Politecnico de Setubal, 2910-761 Setubal, Portugal, Email: mafalda.guedes@estsetubal.ips.pt) : Processing and characterization of alumina/LAS bioceramics for dental applications. Bull Mater Sci 2014, 37(3), 695-703.

Alumina allows to recreate the functionality and aesthetics of natural teeth. However, its low fracture toughness rises concern regarding use in dental restoration. Structural reliability is addressed here by formulating a material containing alumina and a glass-ceramic from LAS system. The presence of LAS in the mixtures result in formation of glass phase during sintering, promoting densification at lower temperature and enhanced surface finishing. A composite microstructure with increased toughness can thus be produced. Powder mixtures containing 0, 20, 50, 80 and 100 wt%-LAS were prepared by planetary milling and uniaxial pressing and sintered. The compositions were investigated regarding their processability, mechanical performance and biological behaviour. Aesthetics was evaluated by comparison with a commercial dental matching guide. Variations on hardness and fracture toughness with starting LAS fraction were assessed by indentation. Interaction with biological medium was evaluated by immersion in a simulated body fluid. Resulting microstructures were characterised by FEG- SEM, EDS and XRD.

13 illus, 7 tables, 22 ref

011206   Esther J;Sukla L B;Pradhan N;Panda S;Sadangi C K;Subbiah T (NO, CSIR Institute of Minerals and Materails Technology, Bhubaneswar-751 013) : Development of Bio process for nickel metal recovery from nickeliferous chromite overburden. SGAT Bull 2014, 15(2), 32-7.

Nickeliferous chromite overburden (COB) in the Sukinda Valley of Odisha containing 0.7-1% nickel awaits a suitable process methodology to extract the valuable metals ingrained in their mineral phases. The conventional pyro- and hydro- metallurgy methods consume intense energy, require high capital investments, cause environmental hazards, etc., thus becoming industrially and environmentally unfeasible. Employing microorganisms towards biotechnological means of extraction may overcome the above downsides. A group of microorganisms called 'dissimilatory iron reducing bacteria (DIRB) inherently reduce Fe^{3+ to Fe2+ coupled to oxidation of organic carbon source for their energy and growth requirement. Hence, in the first step of present study, COB of 5% pulp density was subjected to biological pre-treatment using DIRB capable of transforming the mineral phase (Goethite → Hematite, Magnetite) at 1L scale. In second step enhanced nickel recovery was achieved by reductive acid leaching of the bioreduced COB with glucose as the organic reducing agent in sulphuric acid. A total of 88.8% nickel was recovered from the nickeliferous COB subjected to bio-reduction and reductive acid leaching. Nickel was recovered from leach solution through solvent extraction using Na2DHPA as extractant in the third step. Finally, electrowinning of the nickel laden aqueous phase obtained a metallic nickel deposit with 99.6% purity. Hence, in this study, an efficient and eco-friendly process is proposed involving bioreduction, acid leaching, solvent extraction and electrowinning (BR-AL-SX-EW).}

5 illus, 5 tables

011205   Emdadifard M;Hosseini S M M M (Civil Engineering Dep, Amirkabir Univ of Technology, Tehran, Iran, Email: smmirhos@aut.ac.ir) : Study of the wave velocity in granular soils using discrete element method. Biosci Biotechnol Res Asia 2014, 11(2), 657-63.

In the present paper, discrete element method (DEM) is used to study wave propagation phenomenon in granular soils. The effect of factors such as coefficient of friction, frequency, normal stiffness and soil gradation on the wave speed is studied. Using the wall motion based on the sinusoidal function is the method of loading used in this simulation, through which the pressure wave is transferred to particles. Simulations results are well consistent with the results of experiments conducted by other researchers. In addition, the results obtained are shown as graphs to study the effectiveness of each parameter. According to the results, the coefficient of friction and normal stiffness have a greater effect on the wave speed.

8 illus, 18 ref

011204   Dalai S;Pakrashi S;Chakravarty S;Shamima H; Chandrasekaran N;Mukherjee A (Centre for Nanobiotechnology, VIT University, Vellore-632 014, Email: amit.mookerjea@gmail.com) : Studies on interfacial interactions of TiO₂ nanoparticles with bacterial cells under light and dark conditions. Bull Mater Sci 2014, 37(3), 371-81.

Probable underlying mechanism(s) of bacterial cell-TiO₂ nanoparticles (TiO₂ NPs) interaction in the absence of photo-irradiation has been less studied since most of the prior cytotoxicity studies focused on irradiated TiO₂. The present study draws attention to the possible role of cell surface-TiO₂ NP interactions under dark conditions, through an array of spectroscopic and microscopic investigations. A dominant freshwater bacterial isolate, Bacillus licheniformis, which interacted with environmentally relevant concentrations of TiO₂ NPs (1 μg/mL), was analysed and compared under both light and dark conditions. Aggregation of cells upon NP interaction and adsorption of NPs onto the cell membrane was evident from the scanning electron micrographs under both light and dark conditions. The FT-IR and FT-Raman spectra suggested stress response of bacterial cells by elevated protein and polysaccharide content in the cell-NP interaction. The Xray photoelectron spectroscopic data substantiated the reduction of titanium from Ti(IV) to Ti(III) species which might have contributed to the redox interactions on the cell surface under light as well as dark conditions. The internalization of NPs in the cytoplasm were obvious from the transmission electron micrographs. The consequent cell death/damage was confirmed through fluorescence spectroscopy and microscopy. To conclude, the current study established the substantial role of interfacial interactions in cytotoxicity of the TiO₂ NPs irrespective of the irradiation conditions.

8 illus, 44 ref

011203   Chandra Shekar K;Sai Priya M;Subramanian P K; Anil Kumar;Prasad B A;Prasad N E (Mechanical Engineering Dep, Vignan Institute of Technology and Science, Deshmukhi, Hyderabad-508 284, Email: nep@cemilac.drdo.in) : Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite. Bull Mater Sci 2014, 37(3), 597-602.

Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

7 illus, 3 tables, 7 ref

011202   Chakrabarti S;Pan K (NO, , Kolkata, West Bengal, Email: subratachakrabarti2011@gmail.com) : Sheehan' syndrome associated with pancytopenia- a rare entity. Int J med Sci pub Hlth 2014, 3(3), 382-3.

Postpartum pituitary necrosis, or Sheehan's syndrome, is the infarction of the pituitary gland during the peripartum period. Although hyponatremia and normocytic, normochromic anaemia are documented features of this condition, pancytopenia is an extremely rare manifestation of this condition. We report a case where a patient presented with severe hyponatremia along with pancytopenia in the background of Sheehan's syndrome.

^ccr1 illus, 7 ref

011201   Bhuyan S K;Samal S;Pattanaik A;Panda S K; Padhi B;Mishra S C (Metallurgical & Materials Engineering Dep, National Institute of Technology, Rourkela, Email: purisubash@gmail.com) : High valued utilization of an industrial waste. SGAT Bull 2014, 15(2), 26-31.

Present day world suffers from power crises for social maintenance of living beings. Most of the electric power crises are met by thermal power generation plants; which generates a lot of wastes i.e. fly-ash which creates environmental hazards, needs disposal/utilization. Present work has been undertaken to reveal the possibility of high valued utilization of fly ash. Thermal plasma spray coating of fly ash mixed with graphite is deposited on metal substrate. It is found that coating-substrate interface bond strength is dependent on input power of plasma torch. Maximum adhesion strength of 35MPa is obtained at 16kW power level.

4 illus, 3 tables, 15 ref

011200   Beyaz S;Kockar H;Tanrisever T (Chemistry Dep, Science and Literature Faculty, Balikesir University, 10145 Balikesir, Turkey) : Parametric characterizations in superparamagnetic latex. Bull Mater Sci 2014, 37(3), 389-90.

Effect of synthesis parameters on the production of superparamagnetic latex, which are magnetite nanoparticles covered with a poly(methyl methacrylate) layer, were studied. The synthesis method was based on the developed route of emulsifier-free emulsion polymerization. Under this study, effects of the monomer and initiator concentrations, the amount of magnetic sol, the stirring rate and the adding rate of the magnetic sol on the properties of synthesized latexes were investigated. The characterizations were performed by a high resolution transmission electron microscopy, a dynamic light scattering, a vibrating sample magnetometer and a gel permeation chromatography. The results showed that the monomer concentration was found to be the most effective parameter on latex stability. As the initiator amount and the stirring rate increased, saturation magnetization and average molecular weight decreased due to the reactions occurring between surfaces of magnetite nanoparticles and initiator fragments. On increasing amount of magnetic sol, the saturation magnetization and polymer molecular weight increased but the size of nanospheres was unchanged because of the ions in magnetic sol. It was seen that the desired size and magnetic properties of the latex could be obtained since the parameters were found to have substantial impact on their properties.

5 illus, 1 table, 33 ref

011199   Bauri R (Metallurgical and Materials Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: rbauri@iitm.ac.in) : Optimization of process parameters for friction stir processing (FSP) of Al-TiC in situ composite. Bull Mater Sci 2014, 37(3), 571-8.

Segregation of in situ formed particles at the grain boundaries is a major drawback of in situ composites. In this study, it has been demonstrated that friction stir processing (FSP) can be used as an effective tool to homogenize the particle distribution in Al based in situ composites and FSP processing parameters were optimized for this purpose. An Al-5 wt% TiC composite was processed in situ using K₂TiF₆ and graphite in Al melt and subjected to FSP. Processing parameters for FSP were optimized to get a defect free stir zone and homogenize the particle distribution. It was found that a rotation speed <62> 800 rpm is needed. A rotation speed of 1000 rpm and a traverse speed of 60 mm/min were found to be an optimum combination. The grain size was also refined in addition to homogenization of the as-cast microstructure. This resulted in significant improvement in the mechanical properties of the processed composite.

9 illus, 2 tables, 37 ref

011198   Banerjee S;Duckers L;Blanchard R E (Business Dep, Environment and Society, Coventry University, Priory Street, CV1 5FB, UK, Email: wave.banerjee@gmail.com) : An overview on green house gas emission characteristics and energy evaluation of ocean energy systems from life cycle assessment and energy accounting studies. J appl nat Sci 2013, 5(2), 535-40.

Analysis has been made as regards emission characteristics of ocean energy systems from life cycle assessment and scope of energy availability from energy accounting studies. Assessment tools developed and standardized were the indices like scope of Green house gases (GHG) emission per kWh power generation, percentage of CO2 saved compared to coal fired power station and the energy payback period. Emission characteristics of ocean energy systems were also compared with that from solar power, bio-fuels and wind energy systems. Four case studies were made comprising of wave energy converters, Ocean Thermal Energy Conversion (OTEC) system and tidal energy. It could be observed that CO2 emission percentage saved from ocean energy schemes were more than 95 per cent; and energy payback period varied between one year and a little higher than two years, depending on the type of the device.

011197   Aminmoghaddam E (Mathematics and Cryptography Dep, Imam Hossein Univ, Tehran, Iran, Email: emadam@gmail.com) : Providing a forward secure authentication and key agreement protocol for UMTS. Biosci Biotechnol Res Asia 2014, 11(2), 649-56.

Access to the wireless and radio connections is different from wired networks regarding to the vulnerability of wireless networks. Universal Mobile Telecommunication System (UMTS) as one of the third-generation cellular telecommunication systems is capable of adjustment to the Global system for Mobile Communications (GSM) and has resolved some of its drawbacks too. Furthermore, UMTS has provided an authentication and key agreement protocol (AKA) namely UMTS AKA that has some disadvantages like as bandwidth usage, huge memory to store data, lack of User Identification security, and synchronization problem. In this paper we investigate an authentication and key agreement protocol named IAP AKA that has resolved a number of problems associated with the security shortcomings of the UMTS AKA protocol. Then, we will represent a new protocol that has applied new procedures for the secrecy of User Identification by preventing general access to user identity. In addition, Elliptic Curve Cryptography is used to strength our protocol security. Finally, the most interesting property of our proposed protocol is Forward Secrecy which is necessary for user conversations confidentiality.

1 illus, 1 table, 15 ref

011196   Amiandamhen S O;Izekor D N (Forestry and Wildlife Dep, University of Benin, P.M.B.1154, Benin City, NIGERIA, Email: soamiandamhen@yahoo.com) : Effect of wood particle geometry and pre-treatments on the strength and sorption properties of cement-bonded particle boards. J appl nat Sci 2013, 5(2), 318-22.

Effect of particle geometry and pretreatments on the strength and sorption properties of wood particle cement composite boards was investigated. Wood particles (flakes and sawdust) of Gmelina arborea were mixed with cement and water in the production of composite boards. The wood particles were pretreated with hot water, calcium chloride and a combination of both treatments to enhance bonding with cement. The slurry was poured into rectangular moulds for board formation. After demoulding, the boards formed were tested for modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The results revealed that the mean MOR for flakes boards was 3.23N mm-2 while the mean MOR for sawdust boards was 3.01N mm-2. Hot water and calcium chloride treatment produced the best effect in flake composite boards with MOR and MOE values of 6.90 N/mm2 and 1897.36 N mm-2 while sawdust composite boards had mean MOR and MOE values of 5.69N mm-2 and 1664.31N mm-2 respectively. The WA rate after 24 hours of flakes and sawdust boards treated with hot water and calcium chloride was 3.63% and 4.28% while the TS rate was 0.69% and 1.44% respectively. Particle geometry and pretreatments significantly improved strength and sorption properties of wood particle cement composite boards (p<60>0.05).

011195   Afshoon Y;Fakhar A (Mechanical Engineering Dep, Kashan Branch, Islamic Azad Univ, Kashan, Iran) : Numerical study of improvement and heat transfer coefficient of Cu-O water nanofluid in the shell and tube heat exchangers. Biosci Biotechnol Res Asia 2014, 11(2), 739-47.

This research evaluated improved rate of heat transfer coefficient and friction factor of Cu-O water nanofluid compared to water-based fluids by Cu-O water nanofluid as a incompressible, homogeneous and turbulent flow in the shell and tube heat exchangers by numerical methods in FLUENT, given the constant thermophysic properties of nanofluids in the size of nanoparticles at nanofluid volume concentrations of 0.015, 0.031, 0.078, 0.157 and 0.236% of nanofluids, in the range of 6000 to 31000 Reynolds as a fully developed turbulent flow compared to the base fluid, water, and setting initial conditions and boundary conditions based on temperature and inlet velocity of nanofluids. Increase in the volume concentration and Reynolds of nanofluid increase the local heat transfer coefficient, overall heat transfer coefficient and pressure drop of nanofluids. Improved heat transfer coefficient compared to water-based fluids is concluded as 32 percent.

17 illus, 13 ref

010150   Zhang G;Nianu Liu (Materials Engineering Dep, Wuhan Univ, Wuhan 430072, P.R. China, Email: yznian@163.com) : Novel method for massive synthesis of SnO₂ nanowires. Bull Mater Sci 2013, 36(6), 953-60.

This paper reports a simple, inexpensive and fast method to prepare SnO₂ nanowires. A large amount of ultra-long high purity single-crystalline SnO₂ nanowires with rutile structure, that is over hundreds of micrometers in length and 20-100 nm in diameter, have been synthesized through a one-step typical thermite reaction at 200 °C in 02 atmosphere, with a gas pressure of 0.9 atm. These SnO₂ nanowires do not grow in one direction as those synthesized by other methods do, and are perfect single crystals without any dislocation or point defects detected in TEM images. The optoelectronic properties of these smooth and uniform nanowires have been characterized by means of X-ray photoelectron spectra, laser Raman spectrum and Fourier transform infrared spectrum. The result of X-ray photoelectron spectra analysis shows that some oxygen vacancies exist in these SnO₂ nanowires. In addition, possible growth mechanism of the SnO₂ nanowires has been described in detail by the studies of comparative experiments, which is quite different from that of SnO₂ nanowires synthesized by some other methods.

15 illus, 1 table, 37 ref

010149   Titus S S K;Jain S K (Force and Hardness Standards, CSIR-National Physical Laboratory (CSIR-NPL), Dr. K.S. Krishnan Marg, New Delhi-110 012, Email: titus@nplindia.org) : Establishment and development of torque metrology in CSIR-NPL for providing the traceability in torque measurements to user industries. MAPAN 2013, 28(1), 11-16.

Torque primary standard machines are established at CSIR-NPL, India to realize the torque scale and to disseminate the same for user industries for providing the traceability in torque measurement. Two torque machines, a primary standard machine comprising of elastic hinge supported load lever with scale pan having an uncertainty of ±0.01% and a secondary standard machine comprising of an unsupported lever arm with a scale pan suspended by a knife edge having an uncertainty of ±0.05%, are established. The uncertainty of these machines are estimated theoretically by considering the uncertainty contributions of various input quantities which is also reaffirmed through the inter-comparison carried out on these machines.

5 illus, 2 tables, 13 ref

010148   Sup Lee D;Kim S J;Kwon E B;Park C W;Jun S M; Choi B;Kim S W (Urology Dep, The Catholic Univ of Korea, Seoul, Korea, Email: ksw1227@catholic.ac.kr) : Comparison of In vivo biocompatibilities between parylene-C and polydimethylsiloxane from implantable microelectronic devices. Bull Mater Sci 2013, 36(6), 1127-32.

Implantable devices are often composed of or coated with different biologically compatible materials based on their requirements. Selecting a surface material for an implantable device is not an easy task, and it is necessary to compare the biocompatibilities of the available surface materials. In this study, we perform a comparison of the in vivo biocompatibilities of polydimethylsiloxane (PDMS) and para-xylyene polymer (parylene-C) as they are considered to be candidates for a coating material for implantable microelectronic devices. For in vivo biocompa-tibility testing, fifty four male Sprague-Dawley rats were used for testing, and they were divided into three groups (PDMS, parylene-C and a positive control). At one, four and twelve weeks after implantation of the test object, the density of inflammatory cells and the granulation layer thickness were recorded for each group and compared with other groups using visible light and fluorescence microscopy. The thickness of the granulation layer tended to decrease over time for all of the experimental groups, whereas the granulation layer thickness remained constant in the positive control group. The thinnest capsular layer was observed for the parylene-C group and fewest inflammatory cells were observed in this group during the entire experimental period. Macrophage infiltration was minimal, even at one week, and was not observed thereafter. The parylene-C group showed better biocompatibility than the PDMS groups, both for acute and chronic implantation. Thus, parylene-C is the best candidate of the tested materials for applications involving permanent implantable micro-devices.

4 illus, 27 ref

010147   Sundaram B A;Ravisankar K;Senthil R; Parivallal S (Structural Health Monitoring Laboratory, CSIR-Structural Engineering Research Centre, Chennai-600 113, Email: arunsundaram@serc.res.in) : Wireless sensors for structural health monitoring and damage detection techniques. Curr Sci 2013, 104(11), 1496-1505.

Structural health monitoring (SHM) is an emerging field in civil engineering, offering the potential for continuous and periodic assessment of the safety and integrity of civil infrastructure. Based on the knowledge of the condition of the structure, certain preventive measures can be taken to prolong the service life of the structure and prevent catastrophic failure. Damage detection strategies can ultimately reduce life-cycle cost. Using traditionally wired sensors to implement such a SHM system with a dense array of sensors is quite challenging because of the difficulties in deploying and maintaining the associated wiring. Recent development of smart sensors has created the possibility of dense array of sensors in SHM. Damage detection algorithms which can take advantage of the distributed computing environment offered by smart sensor technology are highly desired but currently limited. Dense arrays of low-cost smart wireless sensor networks (WSNs) have the potential to improve the quality of the SHM dramatically using their on-board computational and wireless communication capabilities. These WSNs provide rich information which SHM algorithms can utilize to detect, locate and assess structural damage caused by severe loading events and by progressive environmental deterioration as well as economical realization of the SHM system. Information from densely instrumented structures is expected to result in deeper insight into the physical state of the structural system. In this article, recent research and development activities in the field of smart wireless sensors and application of smart sensing, monitoring and damage detection techniques for civil infrastructures are presented.

4 illus, 40 ref

010146   Sugumar S J;Jayaparvathy R (NO, Coimbatore Institute of Technology, Coimbatore-641 014, Email: sjs_cit@yahoo.co.in) : An early warning system for elephant intrusion along the forest border areas. Curr Sci 2013, 104(11), 1515-26.

Man-animal conflict has been on the rise in the forest border areas with herds of wild pachyderms straying into human habitation. The surveillance and tracking of elephant herds are difficult due to their size and nature of movement. In this article, we present an analytical procedure to study the behaviour of elephants along forest border areas by taking migration data into consideration using a three-state Markov chain. The migration data over the whole year is divided into four different periods for the study. We also develop an intrusion detection system to detect the intrusion of herds of wild elephants from the forests into the human habitation and to send an early warning through SMS to the forest officials to take necessary action. We validate the analytical results in comparison with the data obtained from the Forest Department. We also present a multi-class classification algorithm for providing zero false alarm rate. Species classification accuracy percentage is found to be 91.25.

14 illus, 8 tables, 27 ref

010145   Singh M;Yadav R K;Kumar R (Precision Metrology Laboratory, Mechanical Engineering Dep, Sant Longowal Institute of Engineering and Technology, Longowal-148 106, Email: rajesh_krs@rediffmail.com) : Discrete wavelet transform based measurement of inner race defect width in taper roller bearing. MAPAN 2013, 28(1), 17-23.

Local bearing detect monitoring and measurement has been a challenging area of research for profitable use of motion. A technique based on decomposition using Symlet wavelet is implemented for measuring inner race defect width in a taper roller bearing. It is difficult to estimate the defect width in inner race because defect moves continuously with respect to accelerometer. The bursts are selected from the signal for measuring the defect width on the basis of their amplitude. The degree of ambiguity in detecting the entry point in the groove gets reduced by using Symlet5 wavelet based decomposition which is almost linear phase nature and hence, sharpness in the signal gets maintained even in case of sudden change induced in raw signal. The technique has been successfully implemented for measuring defect width ranging from 0.4714 to 1.8145 mm. The measurement of defect width has also been verified by image analysis. Maximum difference in measurements has been found to be 6.68% for the defect width of 0.4714 mm at no load condition and this gets reduced to 1.21% with increase in load. This method has also potential in dimension measurement of surfaces having dissimilar and uneven surface characteristics.

5 illus, 1 table, 14 ref

010144   Singh D;Singh P K;Jadhav N A;Bhattacharya B (Material Research Laboratory, School of Engineering and Technology, Sharda Univ, Greater Noida-201 306, Email: b.bhattacharya@sharda.ac.in) : Electrostatic model of semiconductor nanoparticles trapped in polymer electrolytes. Bull Mater Sci 2013, 36(6), 977-80.

Simple electrostatic model is applied to study the solvation energy and localization energy to inorganic semiconductor nanocrystallites trapped in polymer and ion conducting polymer electrolytes. The effective mass approximation has been applied to the system. In the single charge configuration, the dielectric constant of the medium has been identified as the selection criteria for hosting the nanoparticles. Solvation energy has been shown to depend on the host medium and the size of the crystallite.

3 illus, 18 ref

010143   Sevim I;Hayat F;Kulekci M K (Mechanical Engineering Dep, Engineering Faculty, Mersin Univ, 33343 Ciftlikkoy, Mersin, Turkey, Email: ibrahimsevim33@gmail.com) : Nucleus geometry and mechanical properties of resistance spot welded coated-uncoated DP automotive steels. Bull Mater Sci 2013, 36(6), 1049-55.

In this study, mechanical properties of resistance spot welding of DP450 and DP600, galvanized and ungalvamzed automotive sheets have been investigated. The specimens have been joined by resistance spot welding at different weld currents and times. Welded specimens have been examined for their mechanical, macrostructure and microstructure properties. Depending on the weld current and time, effects of zinc coating on tensile properties, microhardness values as well as microstructure nugget geometry and nucleus size ratio have been investigated. X-ray diffraction analysis has been used to investigate the phase that formed at the joint interface. Result of the experiment show that nugget diameter, indentation depth and tensile load-bearing capacity are affected by weld parameters. Coating prevents full joining at low parameters. Microhardness increased in heat-affected zone and weld metal.

9 illus, 1 table, 18 ref

010142   Sanjeev Kumar;Chugh R (Amity Institute of Nuclear Science and Technology, Amity Univ, Noida, Uttar Pradesh-201 303, Email: sanjeev1283@gmail.com) : Probing the nucleons cross section and nuclear equation of state with elliptical flow at intermediate energies. Asian J Adv Basic Sci 2015, 3(2), 10-8.

The detailed analysis of excitation function of elliptical flow by taking into account the nature of equation of state, nucleon-nucleon (NN) cross sections as well as momentum dependent interactions is performed within Quantum Molecular Dynamics (QMD) model. All the physical parameters are found to sensitive towards the elliptical flow. The interesting observation from the study is that the transition energy is found to be decrease with increase in the size of the fragment in the presence of static equations of state and different NN cross sections, while trend gets opposite when momentum dependent interactions are included. Finally, experimental data of INDRA collaboration around the transition energy of ₇₉Au^{197 +₇₉ Au197 is verified with static hard equation of state in the presence of large cross section.}

5 illus, 38 ref

010141   Rusu S;Buzaianu A;Galusca D G;Ionel L;Ursescu D (Faculty of Materials Science and Engineering, Technical Univ, "Gheorghe Asachi" of Iasi, No. 61A Dimitrie Mangeron Blvd., Iasi, Romania, Email: rusu.st@gmail.com) : Aluminum alloy nanosecond vs femtosecond laser marking. Bull Mater Sci 2013, 36(6), 1037-42.

Based on the lack of consistent literature publications that analyse the effects of laser marking for trace-ability on various materials, the present paper proposes a study of the influence of such radiation processing on an aluminum alloy, a vastly used material base within several industry fields. For the novelty impact, femtolaser marking has been carried out, besides the standard commercial nanosecond engraving. All the marks have been analysed using profilometry, overhead and cross-section SEM microscopy, respectively and EDAX measurements.

6 illus, 9 ref

010140   Ruanbing Hu;Jiang G;Wang X;Xi X;Wang R (Key Laboratory of Advanced TExtile Materials and Manufacturing Technol, Ministry of Education, Zhejiang Sci-Tech Univ, Hangzhou 310018, People's Republic of China, Email: polymer_jiang@hotmail.com) : Facile preparation of superhydrophobic surface with high adhesive forces based carbon/silica composite films. Bull Mater Sci 2013, 36(6), 1091-5.

Glass substrates modified by carbon/silica composites are fabricated through a two-step process for the preparation of a superhydrophobic surface (water contact angle ≥ 150°). Carbon nanoparticles were first prepared through a deposition process on glass using a hydrothermal synthesis route, then the glass was modified by SiO₂ using the hydrolysis reaction of tetraethylorthosilicate at room temperature. It is not only a facile method to create a superhydrophobic surface, but also helps to form a multi-functional surface with high adhesive forces.

4 illus, 31 ref

010139   Romanowska J;Zagula-Yavorska M;Sieniawski J (Materials Science Dep, Rzeszow Univ of Technology, 2, W. Pola st, 35-958 Rzeszow, Poland, Email: jroman@prz.edu.pl) : Zirconium influence on microstructure of aluminide coatings deposited on nickel substrate by CVD method. Bull Mater Sci 2013, 36(6), 1043-8.

Influence of Zr on the microstructure and phase characteristics of aluminide diffusion coatings deposited on the nickel substrate has been investigated in this study. The coatings with and without zirconium were deposited by CVD method. The cross-section chemical composition investigations revealed that during the coatings formation, there is an inward aluminum diffusion and outward nickel diffusion in both types of coatings (with and without zirconium), whereas zirconium is located far below the coating surface, at a depth of <126>17 μm, between β-NiAl phase and γ'-Ni₃sAl phase. XRD examinations showed that β-NiAl, γ-NiAl and γ'-Ni₃Al were the main components of the deposited coatings. β-NiAl phase is on the surface of the coatings, whereas γ-NiAl and γ'-Ni₃Al form deeper parts of the coatings. Zirconium is dissolved in NiAl on the border between β-NiAl and γ'-Ni₃Al.

10 illus, 3 tables, 13 ref

010138   Raju G (School of Engineering and Technology, Jain Univ, Jain Global Campus, Jakkasandra Post, Kanakapura-562 112, Email: raju_garuda@yahoo.co.in) : Engineering challenges in the Megha-Tropiques satellite. Curr Sci 2013, 104(12), 1662-70.

Megha-Tropiques is an Indo-French satellite mission for climate research and applications in tropical regions. It is built using ISRO's IRS platform and four high technology payloads: MADRAS, SAPHIR, SCARAB and ROSA. MADRAS is a joint development; CNES provided SAPHIR and SCARAB; ROSA is procured by ISRO. Realization of the satellite was a challenging task for inclined orbit operations, with complex features such as: three mechanically scanning payloads; two payload deployments; large rotating mass (MADRAS); mission-critical power and signal-transfer device. Megha-Tropiques was launched on 12 October 2011 by ISRO's PSLV into a 20° inclined orbit for high observation frequency. It is controlled by ISRO's ISTRAC ground station. Science data is received at ISTRAC and CNES-stations at Kourou and Hartebeeshoek.

4 illus, 3 tables

010137   Perumal S B;Palanichamy M S;Thamarai P; SubashRaja S (Civil Engineering Dep, R.M.K. Engineering College, Kavaraipettai, Gummidipoondi, Chennai-601 206) : Water quality analysis of water sources near travancore titanium industry. Indian J envir Prot 2013, 33(9), 767-85.

5 illus, 4 ref

010136   Pal B;Ahmad S;Govil A K (NO, CSIR-National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi-110 012, Email: saood1974@yahoo.co.in) : Automation and evaluation of two different techniques to calibrate precision calibrators for low frequency voltage using thermal devices. MAPAN 2013, 28(1), 31-6.

Low frequency (LF) voltage and current are important parameters in electrical metrology. The standards for LF voltage and current are established by assigning AC-DC transfer difference to thermal devices, i.e. thermal converters or thermal transfer standard along with current shunts. Automated calibration systems have been developed based on Null method and measurement technique developed by Budovsky for calibration of precision calibrator in LF voltage and current against thermal devices. The technique based on the Algorithm developed by Dr. Ilya Budovsky (National Metrology Institute (NMI), Australia) has been compared with the conventional null technique. Indigenously developed software has been used to calibrate the precision calibrator in the entire LF voltage and current range using Holt thermal converters and current shunts. Calibration results at 1 V, 10 V in the frequency range from 10 Hz to 1 MHz as well as calibration results of 1 A in the frequency range from 40 Hz to 10 kHz are presented in this paper. These result shows that the measurement technique developed by Budovsky has reduced the complexity of AC-DC transfer measurements, measurement time and the uncertainty in measurement.

10 illus, 4 tables, 9 ref

010135   Lotfabadi A F;Idris M H;Ourdjini A;Kadir M R A;Farahany S;Bakhsheshi-Rad H R (Manufacturing and Industrial Engineering Dep, Faculty of Mechanical Engineering, Univ Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia, Email: fereidouni.a@gmail.com ) : Thermal characteristics and corrosion behaviour of Mg-x zn alloys for biomedical applications. Bull Mater Sci 2013, 36(6), 1103-13.

Thermal parameters of Mg-xZn cast alloys with 0.5-9 wt% Zn were evaluated by using computer aided cooling curve thermal analysis (CA-CCTA), whereas the corrosion behaviour was investigated by potentiody-namic polarization and immersion tests. Thermal analysis results revealed that the dendrite coherency temperature (TDCP) decreased from 642.2 to 600 °C with the addition of Zn from 0.5 to 9 wt%. The liquid fraction at coherency point (FL^{DCP) increased by 72% when Zn was increased up to 9 wt%. MgZn intermetallic phase was observed in samples with <60>3 wt% Zn. At higher percentages of Zn, the Mg₅₁Zn₂₀ intermetallic phase was also detected in addition to α-Mg and MgZn by first derivative cooling curves under non-equilibrium solidification. All these phases were observed along the grain boundary when Zn was rejected from the solid/liquid interface and enriched in the triple conjunction of grain boundary. The grain size decreased from 185.2 to 71.5 μm when Zn content was increased. The addition of Zn content had a significant effect on the corrosion rate and the corresponding mechanisms. The corrosion rate decreased from 2.1 to 1.81 mmpy as Zn content increased from 0.5 to 3 wt%; afterwards, however, this value increased with further increase of Zn. Mg-3Zn also had the lowest degradation rate and highest corrosion resistance which can be fully utilized for biodegradable orthopedic applications.}

11 illus, 1 table, 42 ref

010134   Kustikov Y A;Popov B I (Scientific Research Laboratory of the State Standards in the Field of, D.I. Mendeleyev Institute for Metrology, Moskovsky pr. 19, 190005 St. Petersburg, Russia, Email: y.a.kustikov@vniim.ru) : Progress in development of Russian National Measurement Standards in the field of mass concentration measurement of suspended particles. MAPAN 2013, 28(3), 181-91.

Aerodisperse system (ambient aerosol) is a dynamic system, thus its physical and chemical properties change continuously in the atmosphere. In addition to the changing characteristic of atmospheric aerosols, their accurate and precise measurements are a challenging task because these measurements depend on several parameters for which the traceable standards/calibration are essentially required. In Russia, the traceability for these measurements is provided in accordance with the recommendations of the Russian national regulatory standard "State hierarchy scheme for the instruments deployed for the measurements of the disperse parameters of aerosols, suspensions and powdered materials." The State primary standard for the units of disperse parameters of aerosols, suspensions and powdered materials (GET-163) and the State primary special standard for the unit of mass concentration of particles in aerodispersed media (GET-164) are placed at the top of the hierarchy scheme. This paper describes the State primary special standard GET-164 and the specificity of ensuring the traceability in disseminating the unit realized by this primary special standard to working measurement instruments. Methods used to generate aerodispersed media with desired properties are validated and the problem for achieving the highest accuracy in the measurements related to the primary special standard GET-164 is discussed. The SI unit of mass concentration of particulate matter is disseminated from the State primary special standard GET-164 to the working instruments through a set of working standards. The methods, which are used to generate aerodispersed media in disseminating the unit of mass concentration, provided for carrying out investigations and calibration of measurement instruments over a wide range of the mass concentration of suspended particles of different disperse composition. The main ways of improving the standard facilities in the field of measurements of the mass concentration of suspended particles are (i) related to the improvement of the method used to measure concentrations by means of a beta-ray analyzer-comparator (included in the composition of the State primary special standard GET-164) by reducing the uncertainty of the approximation of the conversion characteristics and (ii) due to implementation of methods providing for accurately controlled dilution of aerosols to extend the ranges in which the mass concentration values of suspended particles are reproduced. In order to develop a procedure for international comparisons of such standards, the corresponding investigations of the State primary special standard GET-164 were carried out.

14 illus, 1 table, 5 ref

010133   Kuntumalla M K;Ojha H;Srikanth V V S S (School of Engineering Sciences and Technology (Sest), Hyderabad Univ, Hyderabad-500 046, Email: vvssse@uohyd.ernet.in) : Identification of β-SiC surrounded by relatable surrounding diamond medium using weak raman surface phonons. Bull Mater Sci 2013, 36(6), 1087-90.

It is difficult to detect β-SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, β-SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/β-SiC nanocomposite thin film system is considered in which nanosized β-SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm^{-1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of β-SiC phase as seen in the present case of diamond/β-SiC nanocomposite thin films.}

5 illus, 20 ref

010132   Khalifa M;Hajji M;Ezzaouia H (Laboratoire de Photovoltaique, CRTEn, Technopole de Borj-Cedria, BP 95 CP 2050, Hammam-Lif, Tunisia, Email: mhajji2001@yahoo.fr) : Efficient method combining thermal annealing and acid leaching for impurities removal from silica intended for photovoltaic application. Bull Mater Sci 2013, 36(6), 1097-1101.

This work investigates the photothermal treatment of silica sand to reduce impurities to a low level suitable for the production of acceptable solar grade silicon for photovoltaic application. It describes experiment carried out by using a tungsten lamp furnace to purify silica under controlled atmosphere. This process enables to attract impurities to the surface of silica grains where they can be easily extracted by partial dissolution in an acid mixture. Thus obtained silica was investigated by inductively coupled plasma atomic emission spectrometry (ICP-AES) method. Major impurities present in silica sand were Al, K, Fe, Na, Ca, Mg and B. Among the new products, almost major impurities were removed effectively. Indeed purity degree, given by characterization of ICP-AES, passes from 99.76 to 99.96% and the average impurity removal efficiency is 83.33%.

6 illus, 3 tables, 9 ref

010131   Jing H;He S;Ou Q;Hsiao T C;Chen D R (Energy Dep, Environmental and Chemical Engineeering, Washington Univ in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA, Email: dchen3@vcu.edu) : Development of a compact electrostatic nanoparticle sampler for offline aerosol characterization. MAPAN 2013, 28(3), 217-26.

Compact electrostatic nanoparticle sampler has been developed to support the offline analysis of nano-particles via electron microscopy. The basic operational principle of the sampler is to electrically charge particles by mixing nanoparticles and unipolar ions produced by DC corona discharge, and electrostatically collecting charged particles. A parametric study was first performed to identify the optimal operating condition of the sampler: a total flow rate (i.e., the sum of the particle and ion carrier flow rates) of 1.0 1pm, an aerosol/ion carrier flow rate ratio of 1.0, and a collection voltage of 4.5 kV. Under the above condition, the sampler achieved a collection efficiency of more than 90% for particles ranging from 50 to 500 nm. The effect of particle material on the sampler's performance was also studied. The prototype had lower collection efficiencies for oleic acid particles than for sodium chloride particles in the size range from 50 to 150 nm, while achieving a comparable efficiency in the size range large than 150 nm. Effects of particle diameter, particle material, and total flow rate on the sampler's collection efficiency are explained by the particle charging data, i.e., charging efficiencies and average charges per particle.

11 illus, 30 ref

010130   Ghosh A;Joshi P K (NO, TERI Univ, 10, Institutional Area, Vasant Kunj, New Delhi-110 070, Email: pkjoshi27@hotmail.com) : Remote sensing of moving objects. Curr Sci 2013, 104(12), 1013-15.

3 illus, 1 table, 13 ref

010129   Chang-Ling F;Hari Om;Ke-He Z;Shao-Chang H (College of Materials Science and Engineering, Hunan Univ, Changsha 410082, P.R. China, Email: clfanhd@yahoo.com.cn) : Influence of conductive electroactive polymer polyaniline on electrochemical performance of LiMn_1.95Al_0.05O₄ cathode for lithium ion batteries. Bull Mater Sci 2013, 36(6), 1005-11.

Conductive electroactive polymer polyaniline is utilized to substitute conductive additive acetylene black in the LiMn_1.95Al_0.05O₄ cathode for lithium ion batteries. Results show that LiMn_1.95Al_0.05O₄ possesses stable structure and good performance. Percolation theory is used to optimize the content of conductive additive in cathode. It shows that the conductivity of cathode reaches its maximum value when the content of conductive additives is 15 wt%. This is in agreement with the results of charge and discharge experiments. The application of polyaniline can evidently enhance the electrochemical performance of cathode. The discharge capacity of cathode using 15 wt% polyaniline is 95.9 mAh g^{-1 at the current density of 170 mA g-1. The charge transfer resistance under different depths of discharge of cathode is much lower compared with the use of acetylene black. It can be concluded that the application of polyaniline in cathode can greatly improve the electrochemical performances of LiMn_1.95Al_0.05O₄ cathode.}

9 illus, 1 table

010128   Biswas S;Agrawal A (Mechanical Engineering Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: amit.agrawal@iitb.ac.in) : Noise reduction in a large enclosure using single, dual and ensconced helmholtz resonators. Curr Sci 2013, 104(12), 1681-91.

Helmholtz resonators reduce the noise level especially at the low frequency end of the sound spectrum. This study explores the amount of reduction for different configurations of Helmholtz resonators coupled to a relatively large-sized enclosure through detailed experiments. The experiments were performed in a <126>1.2 m^{3 enclosure. The eigenfrequencies of the enclosure were calculated theoretically and verified experimentally. Thereafter, a tunable piston-cylinder-type Helmholtz resonator was designed to target a particular frequency, which was coupled to the enclosure volume. The location of the resonator was chosen to lie close to the anti-nodal plane. The results obtained showed a substantial decrease in sound pressure level. A study was also made with two Helmholtz resonators with identical resonance frequency and mounted at separate anti-nodal planes; this configuration showed a still larger reduction in the sound pressure level. Resonator placed inside the cavity volume was further explored to increase the applicability of the Helmholtz resonator; encouraging results were obtained for two cases considered here.}

11 illus, 1 table, 22 ref

010127   Balaji C;Ramanujam K S (Mechanical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: balaji@iitm.ac.in) : Retrieval of the vertical rainfall structure from the MADRAS imager data of the Megha-Tropiques satellite. Curr Sci 2013, 104(12), 1627-34.

Physically based algorithm for the retrieval of vertical cloud and rain structure from the MADRAS imager data of Megha-Tropiques is developed. A community-developed meso-scale numerical weather simulation software, WRF, has been used for simulation of ther-modynamic, cloud and rain profiles for a cyclone case. The WRF simulated profiles in conjunction with two of the rain-measuring instruments on-board the TRMM satellite, the TMI and the TRMM PR, are used as a priori cloud and rain profiles database. These profiles were input to an in-house radiative transfer code. Brightness temperatures at MADRAS imager frequencies were simulated to complete the generation of a priori database. Brightness temperatures were also simulated for TMI channels for comparison, wherever possible. Sample MADRAS data were downloaded and retrievals were performed for the MADRAS channels. The retrieved wind speed, column-integrated liquid water and surface rain rate were compared against the Level 2 data of Megha-Tropiques mission. A comparison of daily averaged rain rate with TMI retrievals was also made. The results show that the retrieval algorithm is robust and able to retrieve the vertical cloud and rain structure even in the absence of a radar on-board the Megha-Tropiques.

9 illus, 1 table, 15 ref

010126   Balachandran V (NO, , Kalyan Flats, Viswanathan Street, West Mambalam, Chennai-600 033, Email: balachandran.viswanathan@gmail.com) : Mountain tunnelling, aquifer and tectonics - a case study of gran sasso and its implications for the India-based neutrino observatory by V.T. padmanabhan and Joseph makkolil-a critique. Curr Sci 2013, 104(11), 1479-81.

3 ref

009159   Youping Ma;Li X;Liu Y;Zhou S;Dang X (School of Metallurgical Engineering, Xi'an Univ of Architecture and Technology, Xi'an 710055, China) : Microstructure and properties of Ti-Nb-V-Mo-alloyed high chromium cast iron. Bull Mater Sci 2013, 36(5), 839-44.

Correlations of microstructure, hardness and fracture toughness of high chromium cast iron with the addition of alloys (titanium, vanadium, niobium and molybdenum) were investigated. The results indicated that the as-cast microstructure changed from hypereutectic, eutectic to hypoeutectic with the increase of alloy contents. Mo dissolved in austenite and increased the hardness by solid solution strengthening. TiC and NbC mainly existed in austenite and impeded the austenite dendrite development. V existed in multicomponent systems in forms of V alloy compounds (VCrFe₈ and VCr₂C₂). With the increase of alloy additions, carbides size changed gradually from refinement to coarseness, hardness and impact toughness were increased and then decreased. Compared with the fracture toughness (6 J/cm^{2) and hardness (50.8HRC) without any alloy addition, the toughness and hardness at 0.60 V-0.60Ti-0-60Nb-0-35Mo (wt%) additions were improved and achieved to 11 J/cm2 and 58.9HRC, respectively. The synergistic roles of Ti, Nb, V and Mo influenced the solidification behaviour of alloy. The refinement of microstructure and improvement of carbides morphologies, size and distribution improved the impact toughness.}

9 illus, 2 tables, 23 ref

009158   Wang P;Wu L L;Zhang D;Zhang H Q (State Key Laboratory of Metastable Materials Science and Technology, Yanshan Univ, Qinhuangdao 066004, China) : Effect of chain conformation on micro-mechanical behaviour of MEH-PPV thin film. Bull Mater Sci 2013, 36(5), 833-7.

Morphology, photoluminescent properties and micro-mechanical character of poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) thin films prepared from toluene (T film) and chloroform (C film) were studied by transmission electron microscopy (TEM), absorption, photoluminescence spectrophoto-metry and nanoindentation test. The morphological feature of worm-like entities which appeared in T film was <126>10-20 nm in length and 3-5 nm in width. The C film displayed the continuous cotton fibre-shaped morphology. In contrast with C film, the band-edge absorption and maximum emission for T film shifted to the longer wavelength. An analysis from TEM photograph, absorption and photoluminescence spectra indicated that different chain conformation presented in these two kinds of films. The nanoindentation test showed that the elastic modulus and indentation hardness of T film under the same experimental parameter (load: 50-200 μN, loading rate: 20 μN/s and holding time: 20 s) decreased by 33.3 ± 0.3 and 8.9 ± 0.5%, respectively comparing with C film. In addition, critical bending radius of these two films based on the flexible base was also evaluated from the obtained experimental results.

4 illus, 27 ref

009157   Van N P;Ngan P H (NO, VNU Univ of Science, 334 Nguyen Trai, Hanoi, Vietnam, Email: nhopv@vnu.edu.vn) : Use of co-spray pyrolysis for synthesizing nitrogen-doped TiO₂ films. Bull Mater Sci 2013, 36(5), 827-31.

Nitrogen-doped nanocrystalline TiO₂ is well known as the most promising photocatalyst. Despite many years after discovery, seeking of efficient method to prepare TiO₂ doped with nitrogen still attracts a lot of attention. In this paper, we present the result of using co-spray pyrolysis to synthesize nitrogen-doped TiO2 films from TiCl₄ and NH₄NO₃. The grown films were subjected to XRD, SEM, photocatalysis, absorption spectra and visible-light photovoltaic investigations. All the deposited films were of nanosized polycrystal, high crystallinity, pure anatase and porosity. Specific characteristics involved nitrogen doping such as enhanced photocatalytic activity, bandgap narrowing, visible light responsibility and typical correlation of the photoactivity with nitrogen concentration were all exhibited. Obtained results proved that high photoactive nitrogen-doped TiO₂ films can be synthesized by co-spray pyrolysis.

7 illus, ref

009156   Thangaraj R;Thenmozhi R (Civil Engineering Dep, CMS College of Engineering and Technology, Coimbatore-641 032) : Industrial and environental application of high volume fly ash in concrete production. Nat Envir Pollut Technol 2013, 12(2), 315-20.

A large number of structural properties of plain concrete are improved with addition of admixtures to concrete. It is well known that the addition of fly ash to plain concrete improves workability, strength, durability, less permeable and more stable. In conventional concrete the flexural strength reaches a maximum value between 14 and 28 days. In high volume fly ash (HVFA) concrete the strength keeps on increasing with age because of pozzolanic reaction of fly ash and strengthening of the interfacial bond between cement paste and aggregate. The use of fly ash as a partial replacement for Portland cement will usually reduce water demand and bleeding of HVFA concrete ranges from negligible to very low. Only few research works have been carried out earlier on flexural study on R C conventional beams without fly ash. Therefore in this investigation an attempt has been made to study any likely improvement on the effect of fly ash on the properties of HVFA concrete in R C beam elements with confinement of stirrups in compression zone. It has been suggested that the effective use of fly ash minimizes the disposal of fly ash, which also solves an environmental problem. This HVFA concrete is easy to pump, consolidate and finish the surface, free from cracks, reduces carbon-dioxide emissions, superior environmental friendliness, reduction in stone mining since it consumes less volume of Portland cement. The methodology adopted above improves ductility and improves the rotation capacity of the joints of framed structure, thus, improving the ultimate load carrying capacity. An attempt is also made to compare the load versus deflection of the HVFA concrete beams with conventional RCC beams and evaluated the performances of the proposed method of confinement. The results indicated that the confinement in the form of stirrups improves the ultimate strength and ductile behaviour of the concrete (IS 3812-1981). An attempt has been made in the present paper to highlight the utilization of fly ash in construction.

8 illus, 3 tables, 14 ref

009155   Sridhar J;Malathy R (Civil Engineering Dep, K S Rangasamy College of Technology, Tiruchengode-637 215, Email: sridharjayaprakash@gmail.com) : Effective utiliazation of industrial waste-steel slag for enhancement of flexural behaviour of ferrocement laminates. Pollut Res 2013, 32(1), 45-54.

In today's world there is a need for conserving resources, environment and proper utilisation of energy. Hence, there is an emphasis on the use of waste and industrial by-products in construction industry. Recently the growing trends towards the use of supplementary materials are emphasised, for cement mortar because of scarcity of materials. The main objective of this investigation is to study the flexural behaviour of ferrocement laminates with partial replacement of fine aggregate by steel slag (by-product of steel industry) in mortar matrix. The variables considered in this study are type of mesh, volume fraction, and steel slag content of 0% to 50% by weight of fine aggregate. From the study maximum first crack load, maximum ultimate load was obtained for ferrocement laminates with 30% steel slag, volume fraction 2.348% in case of galvanised square weld mesh and 3.770% in case of chicken mesh.

30 illus, 7 table, 12 ref