011718   Shirdeli A;Naderkhanloo V;Rahim A S (Water Engineering Dep, Zanjan Univ, Iran, Email: azimshirdeli@yahoo.com) : Experimental and numerical investigations of three-dimensional dam-break flows. Ecol Envir Conserv 2015, 21(Suppl-June), 45-53.

The numerical model can be used to predict flood wave propagation and provide the information about the flood properties. The purpose of this paper is to presents simulation of dam-break problem by three dimensional model of Mike3 Flow Model FM. The model is verified with laboratory experimental test case on a frictionless horizontal bottom for water surface elevation in five benchmark points. A good agreement between experimental data and simulation results is observed. The computed arrival time of the flood wave front and the maximum flow depths at various observation points matched well with the measurements on physical model. Also, turbulence modeling does not affect the velocity profile in the upstream reservoir, but has significant influence on the prediction of downstream velocity; the velocity magnitude at a specific location changes with time, but the shape of the velocity profiles remains similar. Therefore, the Mike3 model can correctly account for complex dam-break flows and giving a satisfactory prediction of the major characteristics such as water depth, flood extent, flood wave arrival time and velocity profiles. The results indicate that this model can be applied for simulation of dam-break problem in real life cases.

7 illus, 1 tables, 15 ref

011717   Sen S (NO, , Power Grid Corporation of India Ltd.) : Concentrating solar power system (CSP). Wat Energy int 2015, 58(5), 21-4.

16 illus

011716   Sekaran A S T;Plani Kumar K;Pitchandi K (NO, Anna Univ, Chennai, India-600 025, Email: palanikumar_k@yahoo.com) : Evaluation on mechanical properties of woven aloevera and sisal fibre hybrid reinforced epoxy composites. Bull Mater Sci 2015, 38(5), 1183-93.

Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher's main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforced polymer composites for various engineering applications. In this research, the experiments of tensile, flexural and impact tests were carried out for woven aloevera and sisal fibre hybrid-reinforced epoxy composites. The hand layup method of fabrication was employed in preparing the composites. The surface morphology of the composites was examined through scanning electron microscope. Due to the low-density and high-specific properties of sisal fibre composites, it offer cost savings when compared with synthetic fibres. Hence it has very good implications in the automotive and transportation industry.

17 illus, 1 table, 28 ref

011715   Sathya P;Anantharaja M;Elavarasu N; Gopalakrishnan R (Crystal Research Lab, Physics Dep, Anna Univ, Chennai-600 025, Email: drgkrishnan@annauniv.edu) : Growth and characterization of nonlinear optical single crystals: bis (cyclohexylammonium) terephthalate and cyclohexylammonium para methoxy benzoate. Bull Mater Sci 2015, 38(5), 1291-9.

Bis(cyclohexylammonium) terephthalate (BCT) and cyclohexylammonium 4-methoxy benzoate (C4MB) single crystals were successfully grown by the slow evaporation solution growth technique. The harvested crystals were subjected to single-crystal X-ray diffraction, spectral, optical, thermal and mechanical studies in order to evaluate physiochemical properties. The Kurtz and Perry technique for second harmonic generation (SHG) study revealed that the powdered materials of BCT and C4MB exhibit SHG efficiency 0.2 times less and 1.3 times greater than that of standard reference material potassium dihydrogen phosphate. C4MB crystal exhibits high efficiency than BCT, because of methoxy group substituted in the para position of phenyl ring. With high SHG efficiency and thermal stability para substituted C4MB crystal will be a potential candidate for optical device fabrication.

9 illus, 4 tables, 27 ref

011714   Sarkar C;Hirani H (Mechanical Engineering Dep, Dellhi Technical Univ, Delhi, Email: Chiranjit.ju@gmail.com) : Synthesis and characterisation of Nano silver particle based magnetorheological fluids for brakes. Def Sci J 2015, 65(3), 252-8.

Magnetorheological (MR) fluids can be used as brake friction materials subject to heat transfer properties of the fluids to dissipate the heat generated during braking action. The aim of this manuscript is to synthesise MR fluids having higher heat transfer properties than that of the conventional MR fluid. The coating of nano-silver-particles, having thermal conductivity more than five-times than that of iron particles used in the MR fluids, has been tried to enhance the heat dissipation rate of MR fluids. To perform feasibility study on usage of silver particles, three composition of MR fluids (without any silver particles, with 0.25 per cent weight and 0.50 per cent weight silver particles) were synthesised. The scanning electron microscopic photographs and EDX analysis of the iron particles have been presented. Shear strengths of all three different compositions of MR fluids were measured using magnetorheometer and the results have been plotted. The effect of silver particles on shear stress of MR fluids has been described. A flywheel-based MR brake experimental setup was developed to analyse the performance of synthesised MR fluids. 'T' type thermocouples were used to avail the temperature distribution of the fabricated MR brake. The results of temperature distribution of brakes containing three different compositions of MR fluids have been presented and compared.

13 illus, 30 ref

011713   Salehian S;Yosefvand F;Shabanlou S;Bejestan M s (Water Engineering Dep, College of Agriculture, Mahabad Branch, Islamic Azad Univ, Mahabad, Iran, Email: fariborz774@gmail.com) : Effects of natural roughness on hydraulic jump energy dissipation. Ecol Envir Conserv 2015, 21(Suppl-June), 41-4.

This study presents the experimental results of the effects of two types of natural bed roughness with crushed sedimentation materials on hydraulic jump relative energy loss. Tests conducted on hydraulic laboratory of Shahid Chamran University. The crushed sedimentation materials were 20 and 27 millimeters in size which were densely installed on the bottom of a laboratory flume. These roughness's were tested in different flow conditions with Froude numbers ranges from 5 to 12.7. Results show that the roughnesses can increase the amount of relative energy loss.

3 illus, 2 tables, 10 ref

011712   Saidi R;Fathi M H;Salimijazi H (Biomaterials Research Group, Materials Engineering Dep, Isfahan Univ of Technology, Isfahan-8415683111, Iran, Email: r.saidighahe@ma.iut.ac.ir) : Fabrication and characterization of hydroxyapatite-coated forsterite scaffold for tissue regeneraiton applications. Bull Mater Sci 2015, 38(5), 1367-74.

In this study, a novel hydroxyapatite (HA)-coated forsterite scaffold with a desired porous structure, high mechanical properties and good bioactivity was successfully fabricated via gel-casting and sol-gel in low pressure methods. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray map techniques were utilized in order to evaluate the phase composition, dimension, morphology, interconnectivity of the pores and state of the coating on the porosities of the synthesized scaffold. The porosity and compressive strength of the scaffolds were measured and the bioactivity was investigated by soaking the scaffolds in simulated body fluid (SBF). The results show that the prepared scaffolds had highly interconnected spherical pores with size in the range of 65-245 μm. Additionally, compressive strength and elastic modulus were 7.5 ± 0.2 and 291 ± 10 MPa, respectively. The crystallite size of the scaffolds was less than 60 nm. True (total) and apparent (interconnected) porosity of the scaffolds were in the range of 75-80 and 65-70%, respectively. In vitro tests in the SBF also confirmed good bioactivity of the prepared scaffolds. While bone-like apatite formation started from the first day of soaking and apatite covered the entire surface and inner wall of the scaffolds pores at long immersion time. Conclusion suggested that HA coating on forsterite scaffolds could significantly improve the mechanical properties and bioactivity, which might be promising for tissue engineering applications.

9 illus, 38 ref

011711   Saha S;Chakaraborty D (NO, , Defence Research and Development Laboratory, Hyderabad, India-500 058, Email: Debasis_cfd@drdl.drdo.in) : Numerical simulation of a Hypersonic air intake. Def Sci J 2015, 65(3), 189-95.

Numerical simulations were carried out to study the unsteady flow in an intake of hypersonic air-breathing vehicle. Unsteady RANS simulations were performed to examine started flow of the intake when cowl surface is parallel to the ramp surface. Though started, the flow was unsteady due to flow separation bubbles inside intake. Intake with larger cowl opening at which intake unstarted was also simulated. Simulations indicated unstarted flow, with large pressure oscillations. The numerically simulation results match reasonably well with experimental data. Calculated unstarting Mach number was found to be 3.0-3.2 in comparison of wind tunnel data of 3.6 for the same cowl opening angle.

12 illus, 20 ref

011710   Rivera U S S;Pineda J M S;Susarrey-Huerta O; Herrera L A F;Meza P A T (NO, Instituto Politecnico Nacional, ESIME-SEPI, U. Zacatenco, 07738, Mexico, Email: Jsandovalp@ipn.mx) : Numerical modelling of caseless ammunition with coreless bullet in internal ballistics. Def Sci J 2015, 65(3), 203-7.

In the search of a new weapon for combat in short range, it is proposed the use of a new experimentally designed 7.62 mm calibre ammunition with a lighter weight (caseless-coreless). This can be used in carbine assault rifles with short barrel or pistols. In this work, the compressible gases flowing through the gun barrel caused by the proposed ammunition were experimentally and numerically analysed. The Large Eddy Simulation was used for the numerical simulation, considering a compressible and turbulent flow, with the chemical species transport model and a complete conversion of the propellant reaction. Variations in pressure and temperature were compared with the results obtained from a conventional 7.62 mm full metal jacket (FMJ) ammunition. Results of ballistic experimental tests and numerical simulations were similar than those of the 9 mm x 19 mm FMJ ammunitions, showing feasibility for the development of new weapons intended for operations of short range shots.

7 illus, 2 table, 22 ref

011709   Rinawa K;Maiti S N;Sonnier R;Lopez Cuesta J M (Centre for Polymer Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110 016, Email: maitisn49@yahoo.co.in) : Non isothermal crystallization kinetics and thermal behaviour of PA12SEBS-g-MA blends. Bull Mater Sci 2015, 38(5), 1315-27.

The thermal behaviour and crystallization kinetics of PA12/SEBS-g-MA blends were investigated under non-isothermal and isothermal conditions using thermogravimetric analysis and differential scanning calorimetry, respectively. The macrokinetic model given by Avrami was used to analyse both the nonisothermal and isothermal crystallization kinetics of the blends. The value of the Avrami exponent during non-isothermal crystallization predicted that pure PA12 and PA12/SEBS-g-MA blends show spherulitic growth with random nucleation of crystal structures as the n-values lie between 3 and 4. The slight nucleating effect of SEBS-g-MA was showed by nucleating activity calculated by the Dobreva and Gutzowa method.

7 illus, 8 tables, 31 ref

011708   Ramu I;Mohanty S C (Mechanical Engineering Dep, National Institute of Technology, Rourkela-769 008, Email: ramuinala@gmail.com) : Free vibration and dynamic stability of functionally graded material plates on elastic foundation. Def Sci J 2015, 65(3), 245-51.

Study of parametric resonance characteristics of functionally-graded material (FGM) plates on elastic foundation is proposed under biaxial in plane periodic load. Finite element method in conjunction with Hamilton's principle is utilised to establish the governing equations in a discrete form, Floquet's theory was applied to determine the instability regions of FGM plate resting on elastic foundation. The effects of power law index, temperature rise, and foundation coefficients on the natural frequencies and dynamic stability of the plate have been examined in detail through parametric studies. The first two natural frequencies decrease with increase in temperature and power law index values, on the contrary, these two frequencies increase with increase in the foundation constants. Increase in power law index enhances the instability of the FGM plate. Increased foundation stiffness enhances the stability of the plate. Influence of shear layer constant is more dominant compared to the Winkler foundation constant.

8 illus, 24 ref

011707   Rambabu A;Raju K C J (Hyderbad Univ, P. O Central Univ, Hyderabad-500 046, Email: rambabuhcu@gmail.com) : Effect of increasing lanthanum substitution and the sintering procedures on the properties of SrBiD4O ceramics. Bull Mater Sci 2015, 38(5), 1375-80.

Lanthanum-substituted SrBi₄Ti₄O₁₅ (SBTi) ceramic, that is SrBi_4-xLa_xTi₄O₁₅ (SBLTi), samples were calcined by solid-state reaction and densified using the microwave sintering and conventional sintering techniques. Their structural, morphological and mechanical properties were investigated. The microwave sintered samples showed high densities like 95% of the theoretical density with short duration exposures. Compared with SBTi ceramics and other lanthanide-substituted compositions, the incorporation of La^{3+ results in clear improvement in properties for SBLT (x <126> 0.75) with respect to the values of hardness and Young's modulus of the microwave sintered samples (8.8-12.5 and 160-180 GPa) are higher than that for conventional sintered (8-10 and 135-155 GPa) samples.}

6 illus, 1 table, 10 ref

011706   Raji R A;Chekuri R S;Karri R K;Kumar A P R (NO, , Defense Avionics Research Establishment, Bengalure, India, Email: Anandraji@dare.drdo.in) : Analgorithmic framework for automatic detection and tracking moving point targets in IR image sequences. Def Sci J 2015, 65(3), 208-13.

Imaging sensors operating in infrared (IR) region of electromagnetic spectrum are gaining importance in airborne automatic target recognition (ATR) applications due to their passive nature of operation. IR imaging sensors exploit the unintended IR radiation emitted by the targets of interest for detection. The ATR systems based on the passive IR imaging sensors employ a set of signal processing algorithms for processing the image information in real-time. The real-time execution of signal processing algorithms provides the sufficient reaction time to the platform carrying ATR system to react upon the target of interest. These set of algorithms include detection, tracking, and classification of low-contrast, small sized-targets. Paper explained a signal processing framework developed to detect and track moving point targets from the acquired IR image sequences in real-time.

10 illus, 1 table, 18 ref

011705   Rajabi A (Water Engineering Dep, College of Agriculture, Kermanshah Branch, Islamic Azad Univ, Kermanshah, Iran, Email: ahmadrjb@yahoo.com) : Monthly and annual trend of potential evapotranspiration in west of Iran. Ecol Envir Conserv 2015, 21(Suppl-June), 19-23.

Evapotranspiration is one of the main factors of hydrological cycles. Studying potential evapotranspiration changes to know the climate change effects on hydrological cycle and to estimate the irrigation networks water requirement are significant. The present study has estimated potential evapotranspiration by Penman- Monteith method according to synoptic stations climate data of west of Iran from 1961 to 2009. Evapotranspiration trend in these stations have been studied by Mann-Kendall and Spearman's Rho tests. Potential evapotranspiration has an increasing trend in all stations in the observed record period which is much more significant from 1990 on. Among all the stations, Khoramabad station has the highest increase and Sanandaj station has the lowest one. Monthly evapotranspiration changes in these stations don't follow any specific rules which mean increase in some months and decrease in other months. In almost all the stations the trend was increasing in warm months of the year that will be so significant in estimating and providing water requirement of agriculture products.

1 illus, 3 tables, 20 ref

011704   Pratap Prabal;Bhatia R S;Binod Kumar;Nazir M; Pratap S (Electrical Engineering Dep, National Institute of Technology, Kurushetra, Email: prabalpr@gmail.com) : Design and analysis of slit cut stacked equilateral triangular microtrip patch antenna. Def Sci J 2015, 65(3), 240-4.

In this paper, a novel structure of slit-cut stacked equilateral triangular microstrip antenna (ETMA) has been theoretically studied using cavity model and found in agreement with the stimulated result calculated by high frequency simulator structure (HFSS). The analysis of stacked ETMA and slit-cut ETMA is done. The theoretical and simulated results of stacked ETMA and slit-cut ETMA are presented and compared. The main concentration is to find the different results, i.e. input impedance and return loss of the slit-cut ETMA and slit-cut stacked ETMA.

8 illus, 11 ref

011703   Prasanna K M L;Somlal J;Ranjithkumar R J;Jain A (NO, K L Univ, Vaddeswaram, Andhra Pradesh) : Load flow studies for distribution system with and without distributed generation. Wat Energy int 2015, 57(12), 34-8.

Distribution system load flow studies are different from those of transmission system, because of its high R/X ratio and radial nature. Several methods have been proposed earlier for doing this distribution load flow studies, but fast load flow algorithms with better results are always needed. This paper presents load flow algorithms for radial as well as weakly meshed distribution systems with and without inclusion of distributed generations and these are based on backward forward sweep method and matrix based method (BIBC/BCBV). Attention is given to number of iterations being taken for convergence, applicability for weakly meshed systems and applicability for distribution systems having distributed generation where distributed generations are modeled as either PQ model or PV model.

2 table, 11 ref

011702   Patil S;Goyal S;Karkare B (Civil Engineering Dep, Vishwakarma Institute of Information Technology, Pune-411 048, Email: shweta@thapar.edu) : Acoustic emission based mathematical procedure for quantification of rebar corrosion in reinforced concrete. Curr Sci 2015, 109(5), 943-8.

One of the most important causes for deterioration of reinforced concrete structures is corrosion of steel rebar in concrete. Acoustic emission (AE) technique is reported as an effective non-destructive tool for qualitatively identifying the onset of rebar corrosion. The applicability of AE for quantitative assessment of rebar corrosion in concrete is studied here. Statistical analysis of experimental results under accelerated corrosion confirmed a promising relationship between gravimetrical rebar mass loss and AE measurement. The efficacy of the developed mathematical model was further confirmed under realistic prolonged corrosion exposure. Thus, a new procedure has been developed for quantification of rebar corrosion through experimental verification.

5 illus, 2 table, 23 ref

011701   Olaniyan O S;Omokanye D J;Akolade A S (Civil Engineering Dep, Ladoke Akintola Univ of Technology, Ogbomoso, Nigeria, Email: zayd0109@yahoo.com) : Modification of existing culverts on river OMI using HEC-RAS. Int J civ struct Engng 2014, 5(2), 125-9.

HEC-RAS (Hydrologic Engineering Center's River Analysis software) is a one-dimensional computer program that models the hydraulics of water flow through natural rivers and other channels. It was used to modify the existing culverts on River Omi which in the past years and of recent has inundated its surroundings. The hydrological data was also measured and used as an input to the model. The model was used over MIKE11, flovial and other hydraulic mathematical model because of its high visual capability and complete output with detailed. The results showed and confirmed that the existing culverts at the considered cross-sections could no longer accommodate the river's discharge. A box-culvert spanning 7.2 m with a rise of 1.8 m will be adequate and economical to replace the existing ones. The existing wing wall was sufficient for the modified cross-section.

4 illus, 2 table, 5 ref

011700   Okonkwo V O;Aginam C H;Chidolue C A (Civil Engineering Dep, Nnamdi Azikiwe Univ Awka, P M B 5025 Awka, Anambra State, Nigeria, Email: odinakao@gmail.com) : Efficient sizing of rigidly fixed portal frames under different static loads. Int J civ struct Engng 2014, 5(2), 188-98.

Work considered the height to span ratio (h/L) ratios that would give the most economical design for portal frames under different static loads. The equations for minimum depth for each section of the portal frame were first developed. These were used to formulate the equation for the volume of the frame. The volume of the frame was taken to be proportional to the cost of the portal frame. The usefulness or benefit of the frame was computed as the ratio of the frame's cross-sectional area to its perimeter. The economical height to span ratio (h/L) for any kind of load were the ratios that gave the least cost/benefit value. These values were found to depend on the ratio of the load to the grade of portal frame material w/σ and the thickness b of the portal frame.

7 illus, 2 table, 9 ref

011699   Okakpu A;Ozay G (Building Technology Dep, Massey Univ, Albany Campus, Auckland, New Zealand, Email: a.i.okakpu@massey.ac.nz) : Comparative study of building strengthening methods to have an efficient and economical solution Case study in Famagusta, Cyprus. Int J civ struct Engng 2014, 5(2), 165-76.

Chamber of Civil Engineers in Northern Cyprus began to approve building projects in 1981. Until that time, such projects were designed according to the rules of the Streets and Buildings Regulations (Cap 96). By the new revisions of these building rules and regulations of 1981, buildings which are higher than four storeys were asked to make an earthquake analysis to ascertain if they are able to resist earthquake force. In 1993, new revisions were made and some practical precautions were taken for better solutions and quality of the projects then. If shear walls are placed in two different directions at 1% of the total floor area of a building, then earthquake analysis will not be required. Since there is a building stock that was constructed without this earthquake analysis, and their performances are not well known, earthquake performances of these buildings are analysed. The buildings found to be earthquake prone are strengthened by application of suitable strengthening method. Presently, there are needs to improve the economy of strengthening method application to ensure that the cost of strengthening does not exceed the cost of raising a new building. Therefore, in this study, a real life building apartment is selected from the building stock constructed in 1970 in Famagusta, Cyprus. It is modeled using structural software. The performance assessment is obtained. According to these results, most available strengthening methods in this region are compared. A direct real cost of the strengthening materials are considered. The economy of the materials required for the strengthening application is obtained. Such methods will serve its purpose on the building bearing load capacity, with respect to the economy of the applied strengthening methods. The best method is recommended considering the economy and problems found during the performance check for the building investigated.

9 illus, 13 tables, 6 ref

011698   Ojha B K (NO, , Energy Infratech Pvt. Ltd.) : Fiber shotcrete in Teesta-III. Wat Energy int 2015, 58(5), 58-63.

The Teesta III Hydro-electric project (1200 MW) is located on Teesta River in the North district of state of Sikkim. The project is under active construction and is slated for commissioning by March 2016. It is the first mega project being constructed under PPP model in joint venture with Govt. of Sikkim. Except diversion structure, all project components are underground and therefore innovative tunneling practice with special emphasis on shotcreting has been the notable feature of the execution strategy of the project. The use of latest shotcreting equipment, Alkali free accelerator and micro silica with poly fibers for the shotcrete has benchmarked the construction practices to a new level in India. This paper highlights the different aspects of mix design, uses of modern construction material and the field performance of shotcrete in this project.

4 illus, 4 tables, 6 ref

011697   Mulani K;Momin M;Ganjave N;Chavan N (Polymer Science and Engineering Div, CSIR-National Chemical Labortary, Pune-411 008, Email: nn.chavan@ncl.res.in) : Thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybezoyloxy)-2-methyl-1, 4-benzene and aliphatic dicarboxylic acid chlorides. Bull Mater Sci 2015, 38(5), 1301-8.

A series of thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene (BHBOMB) and aliphatic dicarboxylic acid chlorides were investigated. All these polyesters were synthesized by interfacial polycondensation method and characterized by differential scanning calorimetry and wide-angle X-ray diffractometer. These polyesters consist of BHBOMB as a mesogenic diol and aliphatic diacid chlorides were used as flexible spacers. The length of oligomethylene units in polymer was varied from the trimethylene to the dodecamethylene groups. The transition temperatures and thermodynamic properties were studied for all these polymers. All these polyesters were soluble in chlorinated solvents such as chloroform, dichloromethane, dichloroethane, etc. More importantly, all these polyesters exhibited very large mesophase stability.

3 illus, 3 tables, 28 ref

011696   Massera J;Petit L;Koponen J;Glorieux B;Hupa L;Hupa M (Electronics and Commucation Engineerign Dep, Tampere Univ of Technology, Korkeakoulunkatu 3, FI-33720, Tampere, Finland, Email: benoit.glorieux@icmcb.cnrs.fr) : Er_{3+>D>B<-Al2B3 nanoparticles doping of brorosilicate glass.} Bull Mater Sci 2015, 38(5), 1407-10.

Novel borosilicate glasses were developed by adding in the glass batch Er^{3+-Al₂O₃ nanoparticles synthetized by using a soft chemical method. A similar nanoparticle doping with modified chemical vapour deposition (MCVD) process was developed to increase the efficiency of the amplifying silica fibre in comparison to using MCVD and solution doping. It was shown that with the melt quench technique, a Er3+-Al22O3 nanoparticle doping neither leads to an increase in the Er3+ luminescence properties nor allows one to control the rare-earth chemical environment in a borosilicate glass. The site of Er3+ in the Er3+-Al₂O₃ nanoparticle containing glass seems to be similar as in glasses with the same composition prepared using standard raw materials. We suspect the Er3+ ions to diffuse from the nanoparticles into the glass matrix. There was no clear evidence of the presence of Al₂O₃ nanoparticles in the glasses after melting.}

3 illus, 1 table, 11 ref

011695   Manjunath K;D'Souza V;Dupont J;Ramakrishnappa T;Nagaraju G (Chemistry Dep, Siddaganga Institute of Technology, Tumkur, India, Email: nagarajugn@rediffmail.com) : Ionic liquid intercalted V₂O₅ nanorods: synthesis and characterization. Bull Mater Sci 2015, 38(5), 1309-13.

In this work, ionic liquid (IL) intercalated V₂O₅ (IL-V₂O₅) nanorods have been synthesized through the IL-assisted hydrothermal method using imidazolium-based functionalized IL at 130°C for 3 days. The structure and morphology of the obtained product was characterized using various techniques. X-ray diffraction pattern reveals the intercalation of IL at 2θ = 7° in orthorhombic V₂O₅. The Fourier transform infrared spectrum shows a band at 1044 cm^{-1, which could be assigned to stretching vibration of terminal vanadyl (V=O), sensitive to cation intercalation between vanadium oxide layers. UV-vis absorption spectrum of IL-V₂O₅ nanorods and calcined V₂O₅ nanoparticles show a maximum absorbance at 402 and 420 nm, respectively. The morphology of the product was investigated by scanning electron microscopy and transition electron microscopy (TEM). TEM analysis reveals the nanorods with thickness of 30-50 nm.}

7 illus, 29 ref

011694   Maheswari S U;Hemanth D J (ECE Dep, Karunya Univ, Coimbatore-641 114, Email: jude_hemanth@rediffmail.com) : Image steganography using hybrid edge detector and ridgelet transform. Def Sci J 2015, 65(3), 214-19.

Steganography is the art of hiding high sensitive information in digital image, text, video, and audio. In this paper, authors have proposed a frequency domain steganography method operating in the Ridgelet transform. Authors engage the advantage of ridgelet transform, which represents the digital image with straight edges. In the embedding phase, the proposed hybrid edge detector acts as a preprocessing step to obtain the edge image from the cover image, then the edge image is partitioned into several blocks to operate with straight edges and Ridgelet transform is applied to each block. Then, the most significant gradient vectors (or significant edges) are selected to embed the secret data. The proposed method has shown the advantages of imperceptibility of the stego image is increased because the secret data is hidden in the significant gradient vector. Authors employed the hybrid edge detector to obtain the edge image, which increases the embedding capacity. Experimental results demonstrates that peak signal-to-noise (PSNR) ratio of stego image generated by this method versus the cover image is guaranteed to be above 49 dB. PSNR is much higher than that of all data hiding techniques reported in the literature.

6 illus, 2 table, 17 ref

011693   Liu X P;Song D D;Wan L;Pang X B;Li Z (College of Materials Science and Engineering, Hunan Univ, Changsha-410 082, China, Email: liuxiaopanjj@126.com) : Influence of heart treatment temperature on bonding and oxidation resistance of diamond particles coated with Tio_{2 film.} Bull Mater Sci 2015, 38(5), 1263-70.

In this paper, TiO₂ films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, composition, chemical bonds, oxidation resistance and compressive strength of diamond particles coated with TiO₂ films were characterized through scanning electron microscopy, Fourier transform infrared, Raman spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, thermogravimetric-differential scanning calorimetry and compressive strength test. The results showed that when the temperature reached 600°C, the amorphous TiO₂ on the diamond particles surface exhibited as a dense anatase film and the Ti-O-C bond formed between TiO₂ and the diamond substrates. When temperature reached 800°C, TiO₂ films were still in anatase phase and part of the diamond carbon began to graphitize. The graphitizated carbon can also form the Ti-O-C bond with TiO₂ film, although TiO₂ film would tend to crack in this condition. Meanwhile, the temperature had a serious influence on the oxidation resistance of diamond particles coated with TiO₂ films in air. When the heat treatment temperature reached 600°C, the initial oxidation temperature of the coated diamond particles reached the maximum value of 754°C. When the diamond particles were oxidized at 800°C for 0.5 h in air, the weight loss rate reached the minimum value of 6.7 wt% and the compressive strength reached the maximum value of 15.7 N.

9 illus, 2 table, 14 ref

011692   Liu F;Yuan C;Liu X;Qu J J (College of Materials Science and Engineering, Central South Univ, Changsha-410 083, PR China, Email: yclguet@yahoo.com) : Effect of LiF on microwave dielectric properties of 0.25Ca_0.8Sr_0.2,TiO₃0.75Li_0.5,Nd _0.5TiO₃ ceramics. Bull Mater Sci 2015, 38(5), 1223-9.

The effects of LiF addition on sinterability, microstructure and microwave dielectric properties of 0.25Ca_0.8Sr_0.2TiO₃-0.75Li_0.5Nd_0.5TiO₃ ceramics were investigated. The LiF addition enhanced the sintering temperature of 0.25Ca_0.8Sr_0.2TiO₃-0.75Li_0.5Nd_0.5TiO₃ ceramics from 1200 to 1300°C, because the LiF addition could compensate the evaporation of Li during the sintering process. It was found that the bulk density and dielectric constant (ε_r) gradually decreased, the quality factor (Q_f) greatly increased and the temperature coefficient of resonant frequency (τ_f) shifted to a near-zero value with the increase in LiF addition. Obviously, excess Li addition could efficiently improve the microwave dielectric properties. In addition, 0.25Ca0.8Sr0.2 TiO3-0.75Li0.5Nd0.5TiO3 + 4.0 wt% LiF ceramics sintered at 1350°C for 4 h exhibited good microwave dielectric properties of ε_r <126> 123.4, Q_f <126> 2209 GHz (at 2.43 GHz) and τ_f <126> 12.3 ppm °C^-1.

8 illus, 20 ref

011691   Lashbrook M;Martin R;Satija N (NO, M&I Materias Ltd, UK) : Ester-based dielectric fluids for enhanced transformer reliability and asset life extension. Wat Energy int 2015, 57(12), 28-33.

011690   Korulla M;Roshan R S V;Rudra B;Meenu P S (NO, , Maccaferri Environment Solutions Pvt. Ltd.) : Monitoring systems applicable to landslide disaster management. Wat Energy int 2015, 58(5), 63-8.

18 illus

011689   Khanduja V;Chakraverty S;Verma O P (Computer Engineering Dep, Netaji Subhas Institute of Technology, Delhi-110 078, Email: vidhikhanduja9@gmail.com) : Water marking categorical data: algorithm and robustness analysis. Def Sci J 2015, 65(3), 226-32.

Importance of watermarking digital databases has increased by leaps and bounds due to the high vulnerability of digital assets to piracy attempts when they traverse through the internet. To deter piracy, we propose a robust watermarking scheme for relational databases containing categorical data that resolves ownership issues. We propose a three-level security strategy. Firstly, the watermark is itself made secure using playfair cryptographic algorithm. Secondly, the database is securely partitioned using a primary key independent hash partitioning technique. This step virtually reorders the tuples before embedding. Thirdly, we entail a secret key based embedding process to ensure security. Linear feedback shift registers are implemented to generate pseudorandom numbers which selects different watermark bit index for each partition. The process of embedding does not produce any distortion in the database. Hence it is suitable for databases with categorical attributes containing sensitive information that cannot tolerate perturbations. Each watermark bit is embedded multiple times into different partitions. This makes the scheme highly robust against various attacks. The technique is proved by experimentally, and by theoretical analysis to be extremely robust. Experimental results show that it is 400 per cent resilient to subset addition attack, 100 per cent resilient to subset alteration attack, and 96 per cent resilient to tuple deletion attack. We prove analytically the resilience of the proposed technique against invertibility and additive attacks.

5 illus, 4 tables, 20 ref

011688   Khaki A M;Pour P J H (Civil Engineering Dep, Univ of Science and Technology, Tehran, Iran, Email: st_p_jafari@azad.ac.ir) : Impacts of traffic signal timings optimization on reducing vehicle emissions and fuel consumption by Aimsun and Synchro software's (Case study; Tehran Intersections). Int J civ struct Engng 2014, 5(2), 144-54.

Considering the fact that in recent years the transport sector allocated considerable fuel consumption and emissions, evaluating issues related to fuel consumption and air pollution is one of the most important issues of transport sector. Estimate of fuel consumption models and emissions are new issues that discussions of various models have been published in Iran and different countries. But assessing the impact of traffic signal timing optimization on fuel consumption and emissions is one of the new and important subjects that have significant effect on emissions and economics. Therefore, 5 Intersections of Tehran in 5 different areas selected for the case study and studied period in traffic simulation and optimization to address problems related to emissions were in 2013 in this thesis. Traffic data and parameters that related to emissions and fuel consumption is obtained as ADT in days of October in studied year. After optimization, the validity and accuracy of project have been used by Aimsun software and it was observed that traffic signal timing optimization have significant reduction in emissions and fuel consumption. The considerable results of this research can be cited to Synchro software application in traffic signal timing optimization. For example, after optimization fuel consumption has been decreased about 0.25%, 0.17% in AM peak time and, 3.63%, 2.46%, in PM peak time at Mahalati-10 farvardin, Shariati-Dolat intersections respectively.

15 illus, 3 tables, 6 ref

011687   Joseph N;Kumar P N (ECE Dep, Anna Univ, Chennai, Email: Neenuj@gmail.com) : Fpga-based realisation of SDR with OFDM tranceiver. Def Sci J 2015, 65(3), 233-9.

Software-defined radio architecture is the key point of next generation communication systems in which some of the functional units are designed as software on a reconfigurable processor. This paper proposes the physical layer architecture of SDR with modified orthogonal frequency division multiplexing (OFDM). One of the main drawbacks of OFDM is that its high peak-to-average reduction (PAPR) ratio. The PAPR can be reduced using filtering and adaptive peak windowing method with Kaiser window. The adaptive window method finds the positions of maximum peak values using a peak detector in the signal and applies the window function with variable parameter. The radix 2 scalable N point FFT algorithm is used in the system. The mapping of the information signal is done with BPSK, PSK, and 16 QAM modulation. According to the signal-to- noise ratio (SNR) value, the type of modulation can be selected. Decoding of the OFDM signal in the receiver is done with Viterbi decoding algorithm. The communication system simulation is done in MATLAB and the baseband operations are implemented on Xilinx FPGA.

12 illus, 23 ref

011686   Hareena C B V;Prakash A;Rajasankar J;Rao B P (NO, V R Siddhartha Engineering College, Vijayawada, Email: hareencherukuru@gmail.com) : Numerical study on underground structures subjected to shock loading. Int J civ struct Engng 2014, 5(2), 177-87.

This paper presents a numerical investigation on shock response of underground structures made of fibre reinforced composite material. A finite element model is developed for determining the shock response of the structure including soil-structure interactions. Commercially available software ABAQUS is used for the finite element model and computations. Circular, horseshoe and square cross-sections of the underground structures are considered for the analysis and design against the air blast of 500 kT TNT at a distance of 1 mile. Equivalent of TNT yield value the pressures and time histories are generated and accordingly blast parameters are obtained. The mechanical properties of steel fibre composite material used in the study are determined based on laboratory tests. The soil-structure interaction effects are implemented through spring and dashpot systems at the boundary regions. Various responses like displacements, von Mises stresses and strain energies obtained from the numerical analysis are reported.

12 illus, 6 table, 17 ref

011685   Haghighi R D (Materials Science and Engineering Dep, Shiraz Branch, Islamic Azad Univ, Shiraz, Iran, Email: derakhshande@shirazu.ac.ir) : Effect of ECAP and extrusion on particle distribution in Al-nano-Al₂O₃ composite. Bull Mater Sci 2015, 38(5), 1205-12.

In this study equal channel angular pressing (ECAP) and conventional extrusion were used as two different techniques for consolidation of attritioned aluminium powder (45 μm) with varying concentrations of nanoalumina powders (35 nm). The evolution of the homogeneity of the particle distribution in the material during ECAP and conventional extrusion was investigated by the quadrat method with image analysis software. The frequency histograms of the number of alumina particles per quadrat, N_q, for each investigated condition were plotted and the effect of particle distribution on fracture surface and wear resistance of the composite was investigated.

11 illus, 1 table, 18 ref

011684   Gupta S (Materials Science Dep, Indian Association for the Cultivation of Science, Calcutta-700 032, Email: guptasnigha646@gmail.com) : Synthesis and characterization of silicon doped polycrystalline GaN films by r. f. sputtering. Bull Mater Sci 2015, 38(5), 1163-70.

Silicon-doped polycrystalline GaN films were successfully deposited at temperatures ranging from 300 to 623 K on fused silica and silicon substrates by radio frequency (r.f.) magnetron sputtering at a system pressure of <126> 5 Pa. The films were characterized by optical as well as microstructural measurements. The optical properties were studied by UV-vis-NIR spectrometer and photoluminicence (PL) measurements. The microstructural information was obtained from scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and X-ray diffraction (XRD) studies. PL measurement at 80 K exhibited two strong transitions located at <126> 2.1 and <126> 2.7 eV along with lower intensity peaks for luminescence at the higher energy side at <126> 3.45 and <126> 3.3 eV for all the films deposited here, and the peaks at <126> 3.45 and <126> 3.3 eV could be ascribed to transitions related to excitons bound to a neutral donor for h-GaN and c-GaN, respectively. A broad peak at <126> 2.1 eV indicated the presence of yellow luminescence in all the films. The SEM and AFM images revealed that the films are compact with well-dispersed polycrystalline constituting the films. The XRD traces contained the signature of both the hexagonal and cubic phases of GaN.

7 illus, 1 table, 32 ref

011683   Ghannam M;Mahmoud N S;Badr A;Salem F A (Structural Eng. Dep, Faculty of Eng., Mansoura University, Email: ghannam83@yahoo.com) : Strengthening and repairing of an existing steel bridge using posttenioning. Int J civ struct Engng 2014, 5(2), 91-100.

Deals with strengthening and repairing of an existing steel box girder bridge by using post tensioned cables. The bridge crosses the river Nile in Sherbeen city near Mansoura, Dakahlia province, Egypt. The bridge has been closed years ago for cars and vehicles as well as for navigation in the river Nile. It is required to reopen the bridge for light weight vehicles and for its movable part to reopen for navigation again. The study for the bridge includes site investigation and finite element (FE) analysis to calculate the failure load capacity for all the bridge elements and the effect of post tensioning in increasing this capacity. The FE model where verified against previous test results. ANSYS finite element program is used to build the models of different parts of the bridge.

14 illus, 13 ref

011682   Geng T;Zhang L;Wang H;Zhang K;Zhou X (Anhui Key Laboratory of Spin Electron and Nanomaterials, School of Chemistry and Chemical Engineering, Suzhou Univ, Suzhou, Anhui-234 000, China, Email: szxygt@163.com) : Facile synthesis of porous Co₃O₄ nanoplates for supercapacitor applications. Bull Mater Sci 2015, 38(5), 1171-5.

Porous tricobalt tetraoxide (Co₃O₄) nanoplates with large aspect ratio have been obtained by annealing Co(OH)₂ precursor nanoplates synthesized by a facile reflux method without the need for any template or surfactant. After the heat treatment, the as-obtained phase-pure Co₃O₄ nanoplates with a wellretained structure were applied as the electrode material for supercapacitors, and the sample exhibits excellent performance with a high specific capacitance of 225 F g^{-1 after 2000 charge-discharge cycles at 2 A g-1, corresponding to a retention of 97% of the initial capacitance.}

4 illus, 16 ref

011681   Gawshinde S;Naidu B S K (NO, Great Lakes Institute of Management, GLIM, Gurgaon) : Solar rooftops in India: awaiting a new sunshine of awareness, promotion, financing and manufacturing thrust. Wat Energy int 2015, 58(5), 42-8.

India has been a land of revolution witnessing the life changing revolutions like the Green Revolution and the White Revolution. Now it's on the verge of next big revolution hidden behind the clouds of non-acceptance, unawareness & expensive financing. The newly set target of 40 GW Solar Rooftop PV (SRPV) deployments by 2022 will change the position of India on the map of solar powered nations across the world. The country has around 337 million houses as per the census 2011. A 1 kW system per house could add up to 337 GW of installed capacity; commercial and industrial rooftop space being additional avenue for generation which signifies that the 40 GW target is very much achievable and not over ambitious. The commencements of "Make in India" and "Housing for all by 2022" missions are other elements which can accelerate the transition. China already has plans to set up a manufacturing unit in India; Sun Edison has signed a MoU to build the largest solar manufacturing capacity in India and many others are following suit. The advent of new target has opened many business opportunities along the Solar Value Chain both in Manufacturing and Services sectors. The market research firm expects the nation's solar photovoltaic (PV) market to grow at a CAGR of 43.2% over the period 2013-2018 due to its huge technical potential of around 5000 trillion kWh per year and minimum operating costs. Before venturing into the market, an analysis of various segments of the SRPV Chain is required with an assessment of competition, ROI and the risks involved. Value chain analysis is therefore proposed to be presented for the benefit of all the stakeholders including foreign investors. The paper also attempts to bring out awareness among the citizens resolving apprehensions in their mind for solar deployment in India sequel to an on-line survey conducted. SRPV is a decentralised technology, which is being encouraged due to its low land footprint and ability to reduce T&D losses. After analysing the Policy & Regulatory Mechanism of Solar Rooftop PV in India and the markets in other solar matured Nations of the world, paper attempts to outline the Financial Scheme which can make SRPV projects viable for the potential investors and owners in India.

5 illus, 12 ref

011680   Gautam U;Ramanathan M (Instrumentation and Control Engg. Dep, JSS Academy of Technical Education, Noida, Email: ugautam_91@yahoo.com) : Simulation for path planning of SLOCUM glider in near bottom ocean current using heuristic algorithms and Q-learning. Def Sci J 2015, 65(3), 220-5.

Addressing the need for exploration of benthic zones utilising autonomous underwater vehicles, this paper presents a simulation for an optimised path planning from the source node to the destination node of the autonomous underwater vehicle SLOCUM Glider in near-bottom ocean environment. Near-bottom ocean current data from the Bedford Institute of Oceanography, Canada, have been used for this simulation. A cost function is formulated to describe the dynamics of the autonomous underwater vehicle in near-bottom ocean currents. This cost function is then optimised using various biologically-inspired algorithms such as genetic algorithm, Ant Colony optimisation algorithm and particle swarm optimisation algorithm. The simulation of path planning is also performed using Q-learning technique and the results are compared with the biologically-inspired algorithms. The results clearly show that the Q-learning algorithm is better in computational complexity than the biologically-inspired algorithms. The ease of simulating the environment is also more in the case of Q-learning techniques. Hence this paper presents an effective path planning technique, which has been tested for the SLOCUM glider and it may be extended for use in any standard autonomous underwater vehicle.

7 illus, 13 ref

011679   Fatoorehchi H;Abolghasemi H;Magesh N (School of Chemical Engineering, Center for Separation Processes Modeling and Nano-Computations, Colleg, 11365-4563, Tehran, Iran) : Differential transform method as a new computational tool for laplace transforms. Natn Acad Sci Lett 2015, 38(2), 157-60.

In this short communication, the recent differential transform method is proposed to compute Laplace transforms in an innovative manner. Unlike the common method of finding Laplace transforms, the method is free of integration and hence is of computational interest. A number of illustrative examples are given to show the efficiency and simplicity of the new technique.

^ssc9 ref

011678   Eshaghi A;Aghaei A A (Faculty of Materials Science and Engineering, Maleke Ashtar Univ of Technology, P O Box-83145-115, Shahinshahr, Iran, Email: Eshaghi.akbar@gmail.com) : Effect of TiO₂-graphene nanocomposite photoanode on dye-sensitized solar cell performance. Bull Mater Sci 2015, 38(5), 1177-1182.

In this research work, graphene-TiO₂ photoanodes with various graphene concentrations (0, 0.5, 1, 1.5 and 2 wt%) were deposited on fluorine tin oxide glass substrates as working electrodes for dyesensitized solar cells. The structure, morphology, surface composition and dye adsorption of the photoanodes were investigated by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and UV-VIS-NIR spectroscopy, respectively. The photocurrent-voltage characteristics of the dye-sensitized solar cells were examined using a solar simulator. The results indicated that the dye adsorption on photoanode surfaces increases with the increase in the graphene content. In addition, dye-sensitized solar cells efficiency increases with the increase in the graphene content to 1.5 wt% and then decreased. The efficiency of the dyesensitized solar cell, based on the TiO₂-1.5 wt% graphene nanocomposite, increased by 42% with respect to the pristine sample.

10 illus, 1 table, 17 ref

011677   Eisa A S (Structural Engineering Dep, Faculty of Engineering, Zagazig Univ, Zagazig, 4519, Egypt, Email: ahmedeisa@zu.edu.eg) : Finite element analysis of reinforced concrete columns under different range of blast loads. Int J civ struct Engng 2014, 5(2), 155-64.

Columns are the significant load-bearing elements in any structure and exterior columns are probably the most vulnerable structural elements to accidental explosions. Blast load close to or nearby a building might cause sudden failure on the building's external and internal structural skeleton. Abaqus version 6.19 is used in this study to perform numerical simulations of the dynamic responses and residual strength of reinforced concrete columns subjected to different blast charge weights. The finite element model is verified through correlated experimental studies listed on the literature. A parametric study was chosen to cover wide range of factors on the global columns response; the effects of transverse and longitudinal reinforcement ratios, the charge weight, and the column aspect ratio. The model is validated to be used in the analysis of structures, and can closely predict the exact response behaviour of reinforced concrete columns under different detonation Scenarios. The study concluded that after a certain charge weight, the residual displacement became more significant. Providing more lateral reinforcement improved the blast resistant design by decreasing the residual displacement.

8 illus, 1 table, 12 ref

011676   Ehi-Eromosele C O;Ita B I;Iweala E E;Adalikwu S A;Anawe P A L (Chemistry Dep, Covenant Univ, PMB 1023, Ota, Nigeria, Email: cyril.ehi-eromosele@covenantuniversity.edu.ng) : Magneto-structural properties of Ni-Zn nanoferrites synthesized by the low temperature auto combustion method. Bull Mater Sci 2015, 38(5), 1465-72.

Using nickel, zinc and ferric nitrates, and glycine in a fuel-rich composition, Ni_1-xZn_xFe₂O₄ nanoparticles were prepared by a simple low-temperature auto-combustion method without further sintering at high temperatures. The auto-combusted powders obtained were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDAX) analysis and vibrating scanning magnetometer measurements. XRD confirms the formation of pure nanocrystalline spinel phases with an average diameter of about 55 nm. Raman spectra show tetrahedral and octahedral sites in the structure of Ni_1-xZn_xFe₂O₄ and also imply the doping of Zn^{2+ and displacement of Fe3+ ions from the tetrahedral site. EDAX showed that the samples were close to the nominal compositions. The magnetic measurement shows that the saturation magnetization and remanence magnetization decreases with the increase in the zinc content.}

6 illus, 3 tables, 38 ref

011675   Dlugon E;Simka W;Fraczek Szczypta A;Niemiec W;Markowski J;Szymanska M;Blazewicz M (NO, AGH Univ of Science and Technology, Faulty of Materials Science and Ceramics, Mickiewicza Avenue 30, 30-059 Krakow, Poland, Email: wniemiec@agh.edu.pl) : Carbon nanotube based coatings on titanium. Bull Mater Sci 2015, 38(5), 1339-44.

This paper reports results of the modification of titanium surface with multiwalled carbon nanotubes (CNTs). The Ti samples were covered with CNTs via electrophoretic deposition (EPD) process. Prior to EPD process, CNTs were functionalized by chemical treatment. Mechanical, electrochemical and biological properties of CNT-covered Ti samples were studied and compared to those obtained for unmodified titanium surface. Atomic force microscopy was used to investigate the surface topography. To determine micromechanical characteristics of CNT-covered metallic samples indentation tests were conducted. Throughout electrochemical studies were performed in order to characterize the impact of the coating on the corrosion of titanium substrate. In vitro experiments were conducted using the human osteoblast NHOst cell line. CNT layers shielded titanium from corrosion gave the surface-enhanced biointegrative properties. Cells proliferated better on the modified surface in comparison to unmodified titanium. The deposited layer enhanced cell adhesion and spreading as compared to titanium sample.

7 illus, 2 table, 26 ref

011674   Dixit P N;Tyagi R K;Agrawal G;Ray S S H (NO, , ) : Continual improvement of power transformers reliability based on operational experience in powergrid network. Wat Energy int 2015, 57(12), 24-7.

Large power transformers are expensive and critical elements of a utility transmission system. Some transformers are so important that consequences of their failure are tremendous e.g. 765 kV Transformers and Converter Transformers of HVDC System which are transmitting bulk power from remote generating stations to load centers. POWERGRID is operating and maintaining 648 power transformers, 94 converter transformers and 976 shunt reactors installed in 190 substations across the country as on Jan' 2015. Present task in front of POWERGRID is to maintain serviceability of such a large fleet of transformers/reactors which are critical considering the ageing fleet and significant effect on the grid due to any outage. During Operation and Maintenance of Transformers & Reactors in POWERGRID, various problems/failures are observed. These failures were analyzed in detail and various measures are taken to improve the serviceability of Transformers & Reactors. In this paper, experience of POWERGRID in operation of Transformers & Reactors and corresponding modification carried out in various areas are presented.

6 illus

011673   Dehaghani M T;Ahmadian M (Materials Engineering Dep, Isfahan Univ of Technology, Isfahan-84156-83111, Iran, Email: ma.taghian@ma.iut.ac.ir) : Effect of sintering temperature and time on the mechanical properties of Co-Cr-Mo58S bioglass porous nano composite. Bull Mater Sci 2015, 38(5), 1239-46.

In the present study, Co-Cr-Mo/58S bioglass porous nano-composite samples were successfully produced using 30 wt% carbonate hydrogen ammonium and polyvinyl alcohol solution as space holder and binder, respectively. The cold compacted samples were heated at 175°C for 2 h and then were heated to sinter at 1100, 1150, 1200 and 1250°C for 3, 6, 9 and 12 h. True porosity of samples was measured and the samples were characterized using the X-ray diffraction (XRD) technique, scanning electron microscopy (SEM) and compressive test. Although the results of compression test for samples sintered at 1200 and 1250°C showed that the shape of stress-strain curves were similar to each other, compacted powders sintered at 1100 and 1150°C exhibited some fluctuations. Moreover, the compressive strength increased by decreasing the true porosity, indicating the role of high temperature on the sintering process. In addition, volume diffusion was predominant mechanism for these samples at sintering temperature of 1250°C. SEM images of the porous sample sintered at 1250°C for 3 h showed an appropriate range of pore sizes and interconnectivity. The XRD results showed that there are no contaminations and new phase is detectable in the sintered porous samples.

12 illus, 32 ref

011672   Chen H;Jiang G;Li L;Liu Y;Huang Q;Jiang T;Du X (Materials Engineering Dep, Zhejing Sci-Tech Univ, Hangzhou-310 018, PR China, Email: ghjiang_cn@zstu.edu.cn) : Facile fabrication of highly flexible graphene paper for photocatalytic reduction of 4-nitrophenol. Bull Mater Sci 2015, 38(5), 1457-63.

Freestanding paper-like materials prepared from chemically derived graphene have considerable potential as a carbon-based catalyst in high-performance flexible catalytic reaction. Herein, a highly flexible graphene paper (GP) assembled from graphene oxides (GOs) with the aid of polyacrylamide (PAA) and electroless deposition of gold nanoparticles (AuNPs) was prepared. In contrast to previous reports on GOs based on a flow-directed assembly of graphene sheets, this GOs/PAA/Au composite paper exhibited a highly wrinkled and disordered morphology. The resultant GOs/PAA/Au composite paper was applied as a catalytic material for the reduction of 4-nitrophenol and showed the favour separation, recovery and cyclic utilization properties.

5 illus, 32 ref

011671   Chandra A (NO, Central Electricity Authority, New Delhi) : Solar power potential, present status, govt. schemes, policy, regulations and financing. Wat Energy int 2015, 58(5), 15-20.

011670   Caliskan M;Yesilakaya S S;Canlica M (Physics Dep, Yildiz Technical Univ, Davutpasa Campus, 34220 Esenler, Istanbul, Turkey, Email: sserkis@gmail.com) : Characteristics of CoPcCdS hybrid diode device. Bull Mater Sci 2015, 38(5), 1439-42.

CdS/CoPc hybrid heterojunctions were fabricated and characterized. CdS films were deposited by the spray pyrolysis technique on indium tin oxide (ITO)-coated glass substrates and CoPc films coated on CdS by chemical precipitation. Ag contact metal deposited on CoPc by e-beam evaporation and glass/ITO/CdS/ CoPc/Ag structures were fabricated. Rectification ratio, ideality factor, barrier height and junction parameters of the devices were determined. It is shown that device has diode characteristics with the ideality factor (n) of 4.8, rectification ratio of 4.5 and the built-in voltage (V_b) of 0.48 V. Absorption energy for CoPc was found as 1.57 eV. The results encourage utilizing CoPc as absorber organic material for solar cells.

7 illus, 18 ref

011669   Beneberu E;Goode J;Yazdani N (Civil Engineering Dep, P E Univ of Texas at Arlington, P O Box 19308 Arlington, Tx 76019 0308, USA, Email: eyosias.beneberu@mavs.uta.edu) : Computational fluid dynamics application for design of highway sign support structures. Int J civ struct Engng 2014, 5(2), 101-11.

Computational Fluid Dynamics (CFD) has applications in many areas of science including civil engineering. The study reported herein had two main objectives: to compare wind fatigue design load of cantilever sign support structures for natural wind gust using CFD and the American Association of State Highway and Transportation Officials (AASHTO) provisions and to show the application potential of CFD in typical civil engineering problems. A typical highway steel sign support structure was analyzed herein. The bending moment at critical locations, such as at the base and the connection between the horizontal and vertical members, were determined for comparison purposes. The results showed that the bending moments from the AASHTO provisions are much greater than those from the CFD analysis. This is because AASHTO considers a yearly mean wind speed in the sign structure design, while the CFD analysis is based on a one time natural wind gust.

6 illus, 1 table, 13 ref