015280   Rama Rao M V;Ramesh Reddy R (NO, Vasavi College of Engineering, Ibrahimbagh, Hyderabad-31) : Fuzzy finite element analysis of strucutres with uncertainty in load and material properties. J Struct Engng 2006, 33(2), 129-37.

The paper, the cumulative effect of load uncertainity and material uncertainties is explored using fuzzy-finite element analysis. Example problems are taken up, calculations are performed and results are discussed. The need for introducing uncertainty in load and material property (Young's modulus) in the analysis of solid mechanics problems is underlined. Uncertainty is introduced in load and material properties by choosing triangular membership functions with equal spread about the crisp value. Uncertain response of the structures to the fuzzy interval values of load and Young's modulus is obtained in terms of fuzzy interval displacements and the results are post-processed to obtain fuzzy interval values of bending moment, shear force and axial forces. Sensitivity analysis is performed to evaluate the relative sensitivity of displacements and forces to multiple uncertainties. The result demonstrates the need for introducing simultaneous uncertainties in the analysis of solid mechanics problems.

20 illus, 11 tables, 11 ref

015279   Rajni V;Udaya Kumar K (Electrical Engineering Dep, S.S.N. College of Engineering, Kalavakkam-603 110, Email: harirajini2yahoo.com) : Discrimination of surface of tracking patterns of gamma irradiated polymers using fractals. Bull Mater Sci 2006, 29(3), 265-70.

Radiation resistance of gamma irradiated ethylene propylene diene mononmer (EPDM) was evaluated and the pattern discriminating abilities of the surface tracking patterns were also identified. Simple objects can be described by the ideal shape primitives such as cubes, cones and cylinders. But most of the natural objects are so complex that cannot be described in terms of simple primitives. Fractals have been very successfully used to address the problem of modeling and to provide a description of naturally occurring phenomena and shapes, wherein conventional and existing mathematical models were found to be inadequate. The geometrical patterns of dielectric breakdown like electrical trees, surface discharges, and lightning are known to be of fractal in nature. These fractal patterns can be analysed numerically using fractal dimensions and lacunarity. Surface tracking occurring in HV insulation systems is a very complex phenomenon and more so are the shapes of tracking patterns. It has been fairly well established that the shapes and the underlying parameters causing tracking have a 1 : 1 correspondence and therefore, methods to describe and quantify these patterns must be explored. Reports preliminary results of such a study wherein 2-d tracking patterns of gamma irradiated ethylene propylene diene monomer were analysed and found to possess fairly reasonable pattern discriminating abilities. This approach appears promising and further research is essential before any long-term predictions can be made.

9 illus, 10 ref

015278   Panwar S;Goel D B;Pandey O P;Satya Prasad K (School of Physics & Material Science, Thapar Institute of Engineering & Technology, Patiala-147 004, Email: dbgmtfmt@iitr.ernet.in) : Effect of microalloying on aging of a cu-bearing HSLA-100(GPT) steel. Bull Mater Sci 2006, 29(3), 281-92.

Investigations were carried out on aging of a HSLA-100 steel containing Cu as the major alloying element and Nb, Ti and V as microalloying elements. The aging process after varying amounts of cold deformation was followed by hardness measurements and microstructural changes were studied using light and electron microscopy. Presence of Ti activates the formation of (Nb, Ti)C precipitates and completely suppresses the precipitation of Cu. Even a solution treatment at 1100°C is not sufficient to completely dissolve Nb and Ti in the matrix and undissolved (Nb, Ti)C precipitates were observed in oil quenched state. Strain induced aging at 400°C causes simultaneous coarsening of existing precipitates and nucleation of fresh carbides, which results in multi-stage hardening in this steel. Strong precipitate-dislocation interactions cause retardation in recrystallization of deformation structure leading to retention of high hardness levels even on prolonged aging.

11 illus, 26 ref

015277   Nageswara Rao G V S;Hanumantha Rao H; Chandrasekhar S B;Sundaresan R (Metallurgical and Materials Engineering Dep, National Institue of Technology, Warangal-506 004, Email: gvsnr@nitw.ernet.in) : Influence of hot dip galvanizing on corrosion protection of sintered ferrous components. Trans Indian Inst Metals 2006, 59(3), 423-9.

The most important drawback that hinders the applicability of P/M parts is their poor corrosion resistance due to presence of open porosity on the surface. Conventional methods of corrosion protection are not effective for these sintered components. The study deals with "Hot Dip Galvanizing". A systematic comparative study has been made on corrosion protection of P/M components subjected to conventional electroplating and hot dip galvanizing using immersion test. Metallographic analysis using optical and scanning electron microscopes, coating thickness and its uniformity using eddy current method have been evaluated. Statistical methods are employed to arrive at fruitful conclusions. The superiority of hot dip galvanizing over electroplating is established by the results obtained.

5 illus, 1 table, 9 ref

015276   Nag A K;Praveen K V U;Singh V (Metallurgical Engineering Dep, Banaras Hindu University, Varanasi-221 005, Email: vakil2bhu.ac.in) : Low cycle fatigue behaviour of Ti-6Al-5Zr-0.5Mo-0.25Si alloy at room temperature. Bull Mater Sci 2006, 29(3), 271-5.

Low cycle fatigue (LCF) behaviour of the near α titanium alloy, Ti-6Al-5Zr-0.5Mo-0.25Si (LT26A), was investigated in the (α + β) as well as β treated conditions at room temperature. LCF tests were carried out under total strain controlled mode in the range of Δε_t/2: from ±0.60% to ±1.40%. The alloy shows cyclic softening in both the conditions. Also it exhibits dual slope Coffin-Manson (C-M) relationship in both the treated conditions.

6 illus, 3 table, 9 ref

015275   Mukhopadhyay A;Venkateswaran T;Verma R;Basu B (Laboratory for Advanced Ceramics, Materials and Metallurgical Engineer, Indian Institute of Technology, Kanpur, Email: bikram@iitk.ac.in) : Processing-microstructure-property correlation of ceramic nanomaterials. Trans Indian Inst Metals 2006, 59(3), 303-19.

Bulk nanoceramic materials, containing nano-phase dispersion (characteristic length scales less than 100 nm) in ceramic matrix composites, have been the subject of considerable research activities in recent years. One of the major challenges in the processing of ceramic nanomaterials lies in the restriction of the grain growth during sintering. Among advanced sintering technique, spark plasma sintering (SPS) has been widely used to process a variety of nanoceramics and nanoceramic composites. The present contribution presents an overview of our recent research results, obtained while developing bulk ceramic nanomaterials. In particular, the processing-microstructure-property relationship of ZrO₂ nanoceramics, ZrO₂-ZrB₂ nanoceramic composite and WC-ZrO₂ nanocomposites is discussed. A comparison has been made with the conventionally sintered materials. The optimization of SPS parameters to obtain the dense ceramic nanomaterials is also reported. Some transmission electron microscopy (TEM) observations, revealing the nanoscaled (<60.100 nm) ceramic grains/reinforcements are also reported. An important observation has been that high hardness as well as improved wear resistance can be achieved with the investigated ceramic nanomaterials. The enhancement in mechanical as well as tribological property has been explained from the point of view of microstructural refinement.

12 illus, 4 tables, 35 ref

015274   Mukherjee P S;Samal S;Mukherjee T K (Regional Research Laboratory, , Bhubaneswar-751 013) : In-flight thermal plasma processing of pre-reduced ilmenite. Trans Indian Inst Metals 2006, 59(3), 353-8.

An inflight thermal plasma processing route for processing metallized ilmenite has been demonstrated for the production of TiO₂ rich slag & iron metal. The thermal plasma reactor uses a suitably designed powder feeder for carrying the charge. A systematic study has been reported here by varying the various experimental parameters viz. feed rate, degree of metallization of feed, time, to find the effects on slag quality and energy consumption. The results show that by optimizing the experimental parameters it would be possible to minimize energy consumption of the process to make it commercially viable.

2 illus, 3 tables, 14 ref

015273   Mishra A;Lakshmana Rao C;Suresh Reddy G V, (Applied Mechanics Dep, IIT Madras, Chennai-600 036) : Semi-singular BEM in axisymmetric elastostatics. J Struct Engng 2006, 33(2), 149-56.

The fundamental solutions in axisymmetric elastostatic boundary element method (BEM) are more complicated compared to those in general three dimensional elastostatic BEM from which they are derived. Evaluating the integrals of these fundamental solutions over singular elements is a tedious process. Both the standard Gaussian quadrature as well as a specialized quadrature technique, capable of integrating logarithmically singular functions, need to be used in the computation. When plotted over singular elements however, the integrals corresponding to the off-diagonal components of the axisymmetric displacement fundamental solution are found to be non-singular. Exploiting this new finding, much of the extra computational effort in integrating them over singular elements is avoided by simply using the standard Gaussian quadrature technique. This modification does not cause any loss of accuracy; it yields results identical to those obtained conventionally. In addition, it also results in dramatic savings in the time spent in evaluating the boundary integrals over singular elements. The modified implementation is termed semi-singular BEM for axisymmetric elasticity," since exactly two out of the four components of the fundamental solution arc found to be non-singular. Results obtained by solving numerical problems using the semi-singular and conventional BEM are presented and compared, which validate these clamis.

19 illus, 2 tables, 10 ref

015272   Madhavi N C;Sekar M;Paramasivam V (Civil Engineering Dep, Hindustan College of Engineering, Old Mahabalipuram Road, Padur-603 103) : Experimental investigations on the structural behaviour of prestressed concrete box griders using innovative construction technology. J Struct Engng 2006, 33(2), 171-5.

17 illus, 2 tables, 6 ref

015271   Kurian B;Menon D (Civil Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036) : Simplified method for transverse bending analysis of concrete box-girder bridges. J Struct Engng 2006, 33(2), 121-7.

Of the various methods available for the analysis of box-girder bridges subject to vehicular loading, three-Dimensional finite element analysis (3DFEA) gives accurate results, compared to the other methods. However, 3DFEA is not commonly adopted in practice, and simplified methods of frame analysis are preferred. A new simplified method (Modified Fixed Beam Method) is presented for the transverse bending analysis of box-girder bridges without overhangs. The results of extensive three-dimensional finite element analysis have been quantitatively assessed to provide a logical basis for the proposed 'Modified Fixed Beam Method' suitable for design practice. In the proposed method, the top flange of the box-girder bridge is modeled as a beam with fixity at the web-top flange junctions (fixed beam model), and the transverse bending moments so generated are suitably modified to yield the actual distribution of transverse moments. Modification factors are proposed based on extensive numerical studies, to account for the influence of type and location of loads, wheel contact dimensions, spacing of webs and the relative thickness of flange and web. Finally, the application of this proposed simplified method is demonstrated by means of two illustrative examples.

11 illus, 2 tables, 11 ref

015270   Krishnan J;Sriramula S;Kalyanaraman V (Civil Engineering Dep, Indian Institue of Technology Madras, Chennai-600 036) : Properties of Indian hot-rolled strucutral steel sections for LRFD. J Struct Engng 2006, 33(2), 167-70.

As codes of practice move towards a reliability-based approach, uncertainty modelling of the variables in design becomes essential. The most common code formats in design are Load and Resistance factor Design (LRFD) and Limit States Design (LSD) in which factors are assigned to account for variation of load effects and strength properties. This paper presents the results of statistical analyses of the strength properties - yield and ultimate strength - of hot-rolled steels. Certain standard statistical distributions are evaluated to model the variability, and results presented. Comment is also made on the partial safety factor recommendations given for steel properties in various standards, in relation to the variability observed.

14 tables, 13 ref

015269   Korda A A;Miyashita Y;Mutoh Y;Rao K B S (Mechanical Engineering Dep, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata, 940-2188 Japan, Email: mutoh@mech.nagaokaut.ac.jp) : Exploratory load controlled multiple step fatigue tests for determination of cyclic stress-strain curves. Trans Indian Inst Metals 2006, 59(3), 389-97.

Exploratory load controlled multiple step fatigue testis for determination of cyclic stress-strain curves were carried out on 1.5 mm thick specimens. The tests were performed on low carbon, ferritic-pearlitic steel. Saturation and ratcheting of total strain during cyclic load controlled tests was observed. Cyclic stress-strain curves obtained from the test are discussed and compared with their monotonic stress-strain curves.

10 illus, 2 tables, 11 ref

015268   Khanra A K;Patra S;Godkhindi M M (Metallurgical and materials Engineering Dep, Indian Institute of Technology, Kharagpur-721 302, Email: asit_iitkgp@yahoo.com.) : Electrical discharge machining studies on reactive sintered FeAl. Bull Mater Sci 2006, 29(3), 277-80.

Electrical discharge machining (EDM) studies on reactive sintered FeAl were carried out with different process parameters. The metal removal rate and tool removal rate were found to increase with the applied pulse on-time. The surface roughness of machined surface also changed with the applied pulse on-time. XRD analysis of machined surface of sintered FeAl showed the formation of Fe₃C phase during the EDM process. The debris analysis was used to identify the material removal mechanism occurring during the EDM of sintered FeAl.

8 illus, 7 ref

015267   Harikishore S;Koria S C (Mechanical Engineering Dep, Amrita School of Engineering, Kollam-690 525) : Two dimensional modelling of thermal and solidification behaviour of droplets moving in gas field. Trans Indian Inst Metals 2006, 59(3), 359-72.

A two dimensional mathematical model has been developed to study the thermal and solidification behaviour of droplets moving in the atomizing gas field. The influence of droplet size, initial gas velocity, initial radial location, axial distance and superheat are discussed on the trajectory and solid fraction in the droplet. The numerical results show that the fine droplets are acceleraled to the periphery whereas coarse ones constitute the core of the gas field. The solid fraction in the droplet is found to increase with the increase in the radial displacement and axial distance but decrease with the increase in superheat, gas velocity and droplet size. It is asserted that droplets in the metal spray could be either fully solid or fully liquid or partially solid state depending on the size. From the proportion of different physical states of the droplets, the solid and liquid fraction in the spray is calculated and the results are discussed as a function of the process technological parameters of the spray deposition technology.

11 illus, 1 table, 26 ref

015266   Guler E;Aktas H (Physics Dep, Faculty of Arts & Science, University of Kirikkale, 71450, Kirikkale, Turkey, Email: emre71@email.com) : Mossbauer studied on an AISI 1137 type steel. Bull Mater Sci 2006, 29(3), 303-6.

An AISI 1137 type medium carbon steel was studied by means of scanning electron microscopy and Mossbauer spectroscopy. This steel in as received state at room temperature was ferritic. Different heat treatments on related steel exhibited different microstructures such as pearlite and bainite. Also magnetism of these product phases was determined as 32.7 T and 32.6 T relatively where ferromagnetism of ferritic phase in as received state was 33.05 T. Mossbauer parameters such as isomer shifts and% volumes were also determined before and after transformations.

6 illus, 2 tables, 14 ref

015265   Govindaraj V;Ramasamy J V (Civil Engineering Dep, Kumaraguru College of Technology, Coimbatore-641 006) : Optimum design of reinforced concrete rectangular columns using genetic algorithms. J Struct Engng 2006, 33(2), 139-47.

Design optimization of any reinforced concrete (RC) rectangular columns using Genetic Algorithm based methodology has been presented. The optimal design conforms to the limit state design approach as per Indian Standard Specifications I.S-456:2000. The reinforcement design includes the specification of many details beyond the determination of area of steel reinforcement such as the selection of bar diameter, the number of bars and its distribution. Most of the approaches reported in the literature consider the design variables to be continuous and the optimal solution obtained requires further modification to make it practically acceptable. Hence, author considers three different bar groups with respect to its diameter and number along with cross-sectional dimensions as discrete design variables. The objective function considered is the total cost of materials and labour for the column and the constraints are to satisfy strength requirements in addition to the accepted rules of good design practice as defined by the user. Genetic Algorithm (GA) based methodologies provide ideal techniques for handling optimization problems with discrete design variables and hence GA is used in this study. A computer program is developed to formulate the optimization problem and to evaluate the strength properties of the column. The optimal results obtained compare better than the solution given in the available literature. It is concluded that the formulation presented in this paper leads to minimum cost design of RC rectangular columns.

5 illus, 4 tables, 21 ref

015264   Ghosh U K;Prdhan N C;Adhikari B (Chemical Engineering Dep, Materials Science Centre, Indian Institute of Technology, Kharagpur-721 302, Email: ncp@che.iitkgp.ernet.in) : Synthesis and characterization of porous polyurethaneurea membranes for pervaporative separation of 4-nitrophenol from aqueous solution. Bull Mater Sci 2006, 29(3), 225-31.

Hydroxyterminated polybutadiene (HTPB) based porous polyurethaneurea (PUU) membranes were prepared. The porosity was developed by incorporation of lithium chloride into polymer matrix with subsequent leaching of the same in hot water. Scanning electron microscopic analysis of the prepared membrane surfaces was performed. The pervaporation performance of the synthesized membrane was studied with aqueous 4-nitrophenol solution as feed. The effects of various parameters on 4-nitrophenol separation factor and total as well as 4-nitrophenol flux were studied. Polyurethaneurea membrane was found to permeate 4-nitrophenol selectively with high separation factors for the organic component. Pore size and number of pores on the surface of the membrane were calculated from SEM image of the membranes. Effects of pore size and porosity on pervaporation flux were also investigated.

9 i, 1 t, 2 s, 14 r

015263   Ghosh A;Chatterjee S;Mishra S (Metallurgy & Materials Engineering Dep, Bengal Engineering and Science University, Shibpur, Howrah-711 103, Email: schatterjee46@yahoo.com) : Structure and properties of a thermo-mechanically processed low carbon ultra high strength steel. Trans Indian Inst Metals 2006, 59(3), 337-51.

A low carbon steel alloyed with Ni, Mn, Mo, Cu and micro-alloyed with Nb and Ti was prepared and the continuous cooling transformation behaviour of the steel was evaluated. It is observed that the "C" curve for high temperature decomposition product of austenite i.e. polygonal ferrite or Widmanstatten fertile has been shifted to an extreme right. A flat top "C "curve with a mixed structure of bainite and martensite has been obtained at lower temperatures and the transformation temperatures do not vary much with a wide range of cooling rates. The steel was thermo-mechanically processed followed by water quenching. Ultra high strength values obtained in die present steel are due to austenite grain refinement, highly dislocated fine lath martensitic structure along with tiny precipitates of microalloying carbide and carbomtride at all finish rolling temperatures. The formation of stable and large TiN/TiCN particles during casting have impaired the impact toughness values of the steels at ambient and at -40°C temperatures.

14 illus, 1 table, 76 ref

015262   Eswara Prasad N;Ram Mohan R;Malakondaiah G (Defence Metallurgical Research Laboratory, , PO Kanchanbagh, Hyderabad-500 058, Email: nep@dmrl.ernet.in) : Mode-I and mixed-mode I/III fracture behaviour of quaternary Al-Li-Cu-Mg alloy AA8090-T6 plate in through-thickness orientations. Trans Indian Inst Metals 2006, 59(3), 321-36.

Unacceptably low through-thickness fracture toughness values and their large disparity with those values corresponding to the in-plane orientations has been the principal limitation for the use of thicker sections of aluminium - lithium alloys for aerostructural applications. Optimisation of fracture toughness among the three orthogonal directions is one of the primary requirements of this class of advanced alloys if they are to become realistic aerostructural materials to displace the traditionally used aluminium alloys. Reported the mode-I (tensile) and mixed-mode I/III fracture behaviour in the through-thickness orientations of S-L and S-T in quaternary Al-Li-Cu-Mg alloy in the peak aged (T6) temper condition. Results reported here include microstructural characteristics, tensile properties, mode-I and mixed-mode I/III fracture toughness properties. The alloy plate exhibited significant anisotropy in through-thickness fracture resistance with fracture toughness values that are less than half of those in in-plane orientations. A two-step aging treatment suggested in the literature involving short time, high temperature thermal exposure, was evaluated in case of the present alloy. In line with the reported observations, two-step aging treatment resulted in significant improvement in fracture resistance with a moderate decrease (2-5%) in the tensile strength properties. The alloy plate also exhibited enhanced total fracture resistance with imposed mode-III components and hence, the structural design of these alloys in the through-thickness orientations could be based on mode-I fracture toughness, K_IC.

11 illus, 11 tables, 33 ref

015261   Bekri-Abbes I;Srasra E (Unite de Recherche sur les Materiaux, Institut National de la Rechereche Scientifique et Techniaque, BP95 20, Tunisia, Email: bekrimene@gmail.com) : Synthesis of an organic-inorganic hybrid material by solid state intercalation of 2-mercaptopyridine into Na-,AI(III)- and Co(II)-montmorillonite. Bull Mater Sci 2006, 29(3), 251-9.

Preparation of an organic-inorganic hybrid material by solid state intercalation of 2-mercaptopyridine (2Mpy) into Na-, Co(II)- and Al(III)-montmorillonite has been studied using a variety of techniques. The extension of d₀₀₁ from XRD proves that the intercalation of 2-mercaptopyridine into Na-, Co(II)-and Al(III)-mont occurs at ambient temperature in 5 mn. When the intercalated samples were heated at different temperatures, It has been found that the d₀₀₁ gave different values. For instance, for intercalated Al(III)- and Co(II)-, d₀₀₁ remained unchanged for a temperature under 500°C. However, for intercalated Na-mont, it shifted to 14 Angstrom for a temperature of 300°C, the washing of different samples with a methanol solution shifted the d₀₀₁ of intercalated Na-mont to 14 Angstrom. However, for intercalated Al(III) and Co(II), it did not change. This proves that in the case of Na-mont, the molecules of 2-mercaptopyridine interact with the clay through hydrogen bindings and physical interactions. However, for Al(III) and Co(II), it forms coordination linking and physical interaction. 13C NMR and FTIR spectroscopy have been employed for the characterization of the intercalation compounds. Tautomeric equilibrium between thiol and thione species of 2-mercaptopyridine must be taken into account to explain the arrangement of molecular aggregates and their particular orientation in the interlayer space. The isotherm of adsorption-desorption of nitrogen and topographic AFM images prove that intercalation of 2Mpy is accompanied by a total blockage of clay porosity and an increase in rough-ness.

8 illus, 3 table, 37 ref

015260   Basvakumar K G;Mukunda P G;Chakraborty M (Metallurgical and Materials Engineering Dep, Indian Institute of Technology, Kharagpur-721 302, Email: ganuk@rediffmail.com) : Effect of grain refinement and modification on microstructure and impact properties of Al-12Si and Al-12Si-3Cu cast alloys. Trans Indian Inst Metals 2006, 59(3), 399-406.

The microstructures and impact properties of Al-12Si and Al-12Si-3Cu cast alloys were studied after various melt treatments like grain refinement and/or modification. Results indicate that combined grain refined and modified Al-12Si-3Cu alloys have microstructures consisting of uniformly distributed α-Al dendrites, interdendritic network of fine eulectic silicon and fine CuAl₂ blocks in the interdendritic region. These alloys exhibited improved impact properties in as cast condition when compared to those treated by individual addition of grain refiner or modifier. The improved impact properties of Al-12Si-3Cu alloys is related to breakage of the large aluminum dendrites and uniform distribution of eutectic silicon and fine CuAl₂ particles in the interdendritic region due to combined refinement and modification. Also attempts to investigate the influence of the microstrutural changes in the A1-12Si and Al-12Si-3Cu cast alloys by grain refinement, modification and combined addition of both on the impact properties.

3 illus, 2 tables, 24 ref

015259   Ashok Kumar;Rao M H;Singhal L K (NO, MECON Limited, Ranchi-834 002, Email: jslhsr@nde.vsnl.net.in) : Optimisation of process parameters during quenching and self tempering of rebars using mathematical model. Trans Indian Inst Metals 2006, 59(3), 407-21.

Mathematical model has been developed to characterize the thermal and mechanical behaviour and phase transformation kinetics of low carbon steel rebars during quenching and self-tempering process. The model solves one dimensional heat conduction equations in cylindrical co-ordinates employing explicit finite difference method. The operating process parameters such as rebar diameter, rolling speed, finishing temperature and design parameters, namely, cooling tube length and water flow rate have been accounted in the model. The phase transformation kinetics from austenite to mariensite, bainite and ferrite plus pearlite at surface, sub-surface and at the core respectively have also been incorporated in the model. The model predicted tempering temperature, volume fraction of different phases and yield strength of rebar at different water flow rates and finishing temperatures have been compared with the values which were measured at Visakhapatnam Steel Plant for 10 and 18 mm diameter rebars. Comparison between predicted and measured values shows a reasonably good agreement under industrial condition. The optimum process parameters viz. quenching time and water flow rate for different finishing temperatures have been computed to achieve the desired yield strength for 10 to 18 mm rebars. Based on the above model study, a rapid water quenching system was designed and engineered indigenously. The system has already been commissioned successfully at IISCO, Bumpur and SISCOL, Salem.

8 illus, 3 tables, 15 ref

015258   Abdalla K M (Civil Engineering Dep, Jordan University of Science and Technology, Irbid-Jordan) : Influence of lubricant on the behavior of high strength bolts. J Struct Engng 2006, 33(2), 113-20.

The thread lubricant condition of high strength bolts is important in determining the bolt-tensile characteristics. This paper presents result of tests performed upon 20 mm (3/4 in.) diameter, 76.2 mm (3 in.) and 152.4 mm (6 in.) long A325 (M164) bolts, as it varies under different thread and weathering conditions. Factors that affect the pretension of a bolt are bolt-material strength, thread conditions, the diameter of the annular groove at the splined end, and the surface conditions at the nut-washer-joint interface. The resulting relationship between pretension and nut rotation is used to explain the behavior of the nut and bolt as the lubrication is varied. Tests are performed upon 177 nut and bolt, to determine the effect of a lubricant and weather on the behavior of high-strength bolts. Lubrication is found to have an influence on the maximum clamping force of the bolts.

12 illus, 3 tables, 11 ref

014334   Venkatathri N (Composite Materials Center, Korea Institute of Ceramic Engineering and Technology, Seoul, South Korea) : Novel route to synthesis silica hollow spheres having ZSM-5 structure in absence of template. Ultra Scient phys Sci 2006, 18(3), 285-90.

A novel route to synthesize silica hollow spheres with thick walls having ZSM-5 structure without using template at 140°C was presented. X-ray diffraction (XRD), Scanning electron microscopy (SEM), TG/DTA, FT-IR and nitrogen adsorption were employed to characterize the morphology and microstructures of the as-prepared silica hollow spheres. Experimental results indicated that the hollow spheres had an average diameter of nearly 40 nm with a surface area of 342 m²/g.

2 illus, 29 ref

014333   Suresh Kumar M D (NO, , Type B-204, Donimalai Township, Bellary Dt. Karnataka-583 118) : Need for working longwall under hard roof in future underground mining - an experience of negotiating main weighting in sand stone roof. Indian Min Engng J 2006, 45(10), 9-17.

Coal contributes about 67% of power generation in India. As the power requirement increases. this demand of coal could not be met with the present underground mining technology. Presently the open cast technology is the dominating method of mining. In the coming years, the reserves viable to be extracted by the above technology are depleting gradually. Therefore, it is necessary to uplift underground mining technology to cater the needs of power, steel and cement sectors. The longwall technology is the only alternative to cope up the change in the trend and the only bulk continuous coal production is guaranteed by this method. The longwall technology is the only alternative to cope up the change in the trend and the only bulk continuous coal production is guaranteed by this method. The longwall faces worked with hard roof condition shown partial success. Hence, it is preferred to work the faces under immediate coal and shale roof. But it will be needed to work under hard roof as the depth of the coal seam increases. In this juncture, success of any longwall face lies mainly on scientific strata management and the efficiency of powered supports and its condition monitoring. In PVK 5. Incline lying in Kothagudem area of S.C.Co.Ltd, long wall mining was started in 1995 with the package imported from M/s CME, china. So far, 10 lonwall panels have been completed and 11^th panel was worked in top section of top seam with sand stone as contact roof. Strata management in the stone roof longwall face during main weighting has been described.

15 illus, 2 tables, 6 ref

014332   Soni D K;Jain A;Rajbir Singh (Department of Civil Engineering, National Institute of Technology, Kurukshetra, Haryana) : Effect of speciment geometry on unconfined compressive strength of rocks. Indian Min Engng J 2006, 45(10), 23-6.

For the design and construction of Civil Engineering structures having the bed strata as rock formation, it becomes necessary to have the knowledge and idea about the compressive strength of rock formation to aoid failure due to settlement. In practice, uniaxial compression tests are used to determine compressive strength of rocks. But the strength that these purport to represent depends upon many factors. The conditions which influence the measured strength include rate of loading, the shape and relative dimensions of the specimens, the end conditions of the test piece and the amount of moisture present in the pore spaces. Rock-steel contact also influences the strength. In fact, there is no test yet devised which provides the strength of rock in uniform uniaxial compression. Uniaxial compression tests have been conducted on samples of Dholpur red sandstone having different size and shape to show the effect of specimen geometry on compressive strength.

4 illus, 4 tables, 9 ref

014331   Singh A;Sharma A K;Kamal T S;Vishal (NO, Beant College of Engineering and Technology, Gurdaspur) : Analyzing the effect of four wave mixing including first- and second-order dispersion parameters in wavelength division multiplexing (WDM) systems. Ultra Scient phys Sci 2006, 18(3), 323-32.

A modified analysis of phase matching factor for Four Wave Mixing (FWM) by incorporating the higher order dispersion parameters have been reported. Further an intensity-dependent phase-matching factor has been calculated. With the help of modified formula for FWM crosstalk under the effect of first- and second-order dispersion parameters at different transmission length, effective fiber core areas and different input channel powers have been analyzed. It is also shown that under the combined effect of first- and second-order dispersion parameters, the cross talk introduced by FWM reduces. our caIculations are more accurate and feasible than that of the results reported earlier. Also analyzes the effects of individual and combined first- and second-order dispersion parameters at linear phase matching factor and intensity-dependent phase-matching factor that has not been discussed earlier.

10 illus, 3 tables, 5 ref

014330   Shankar Ganesh P;Ramasamy E V;Gajalakshmi S; Sanjeevi R;Abbasi S A (Centre for Pollution Control and Energy Technology, Pondicherry Univ, Pondicherry-605 014, Email: prof_abbasi@vsnl.com) : Treatment of low-strenth effluents by UASB reacter and its application to dairy industry wash waters. Indian J Biotechnol 2007, 6(2), 234-8.

In the backdrop of lack of success achieved by the past workers in using upflow anaerobic sludge blanket (UASB) reactor for treating low-strength wastewaters, highlights the importance of R&D in this area. The two main reasons behind the importance of using UASB are: (1) generation of large volumes of low-strength wastewaters, which are often disposed untreated due to high costs, and (2) the potential of stabilizing the organic wastes by producing valuable energy as byproduct. Results are presented on the successful operation of UASB in treating low-strength dairy industry wash waters [Chemical oxygen demand (COD) 1200-2000 mg/L]. The reactors achieved treatment efficiency of the order of 75-85% and were able to withstand shock-loads without adversely affecting the treatment efficiency. One of the reactors which was accidentally contaminated with acid, recovered quickly.

3 illus, 4 tables, 25 ref

014329   Sen P K;Josan P S;Veeravalli S V;Carpenter P W (Dep of Applied Mechanics, Indian Institute of Technology, New Delhi-100 016) : Suppression of wall turbulence by stability and turbulence analysis using a compliant surface. Proc Indian Natn Sci Acad 2006, 72(3), 159-66.

Discusses the role of hydrodynamic stability theory in understanding wall turbulence and its possible suppression by using compliant surfaces. The work reveals that, in wall turbulent flows, there are three important 'mode classes'; namely, the Tollmien-Schlichting (TS) mode class, the Static- Divergence (SD) mode class, and the high-speed highly damped (HSHD) mode class. All these modes scale with inner wall variables (with wave speed, C_r, close to 0.3) and so do the material properties of 'the compliant surface. The general thrust should be to replace TS modes by HSHD stable modes. Outer modes (with C_r, close to 1.0) were also investigated and found to be damped. Comparative analysis of the work was established with the experimental results of Gad-el-Hak et al. (1985), Veeravalli, Sen & Joshi (2006) and theoretical analysis of Yeo (1988).

7 illus, 12 ref

014328   Sai Srinadh K V (Mechanical Engineering Dep, National Institute of Technology, Warangal-506 004) : Knowledge based expert system for welding defect analysis. Indian Weld J 2006, 39(4), 32-5.

Knowledge based expert systems are computer programs which can store human expertise, consists of a colllection of thumb rules, facts about a particular area of specialization and have means to use the information to solve problems. Development of an expert system for the analysis of welding defects has abeen presented. The program for the welding defects was made using VC++ environment to obtain graphic user interface.

5 illus, 4 ref

014327   Ramachandra P K;Meguro K (Earthquake Engineering Research Centre, International Institute of Information Technology, Gachibowli, Hyderabad-500 019, Email: ramanchalra@iiit.ac.in) : Numerical modelling of faults for study of ground surface deformation using applied element method. Curr Sci 2006, 91(8), 1026-37.

Aims to understand the response of soil deposits underlying bedrock fault displacement in three dimensions. When an active bedrock fault ruptures, movement along the fault propagates through the overlying soil and produces zones of intense shear. It is important to study the surface behaviour based on fault characteristics. Attempted develop application of Applied Element Method by modelling the fault rupture zone.Modelled the fault rupture problem in three dimensions. First, a simple model is used to illustrate absorption of the bedrock deformation by the overlying soil in elastic case. In the later pan, nonlinear analysis is carried out to study the complex failure propagation in three dimensions. Influence of mechanical properties of the material is also discussed.

16 illus, 1 table, 18 ref

014326   Praveen Kumar (NO, IIT, Kharagpur) : Flow measurement in coal bunker using Edinburgh Cohesion tester. Indian Min Engng J 2006, 45(10), 18-22.

Described a newly developed Cohesion Tester by Edinburgh University called Edinburgh cohesion Tester which is able to make real time measurements of cohesion, with the aim of eliminating these bunker flow problems. This Edinburgh cohesion tester which is of more superior to earlier used dome or cone tester if used in our country than much of problem due to bunker jamming will be solved.

5 illus, 1 table, 5 ref

014325   Philip J;Annamala Pillai S (Experimental Mechanics Div, Vikram Sarabhai Space Centre, Thiruvananthapuram-695 022) : Assessment of the residual stress field in the HAZ of tig welded aluminium 2219 plates due to weld repairs using high speed hole drilling technique. Indian Weld J 2006, 39(4), 43-8.

Residual stresses are those stresses, which remain in the material or body in the absence of any external forces or thermal gradients. They are introduced mostly during manufacturing operations like rolling, welding, forming etc. The quantitative estimation of these stresses is important because they can modify the effective load bearing capacity of the component by getting added to the applied or service stresses and also stimulate stress corrosion failures.

3 illus, 2 tables, 10 ref

014324   Mukhopadhyay A;Basu B (Laboratory for Advanced Ceramics, Materials and Metallurgical Engineering Dep, Indian Institute of Technology, Kanpur-208 016) : Bulk nanoceramic composites for structural applications. Proc Indian Natn Sci Acad 2006, 72(2), 97-111.

With the recognition that the nanocrystalline ceramics, having grain sizes typically smaller than 100 nm, posses some appealing mechanical physical, chemical and tribological properties, they have been the subject of considerable research activities in recent years. Considering the challenges involved in the processing of bulk ceramic nanomaterials, the research on nanostructured ceramics and composites was triggered with the advent of some advanced sintering techniques like, Field Assisted Sintering Techniques (FAST). This review paper presents an overview of the classification of ceramic nanocomposites, analyses some of the major challenges involved in the processing of these materials and in particular, discusses the use of FAST technique in processing nanoceramic materials. This contribution is also designed to highlight the improvement in mechanical properties, over conventional ceramics, and to provide a discussion on the processing-microstructures-mechanical properties of some selected oxide and non-oxide nanoceramic composites. Additionally, the limited literature reports covering the tribological properties of some of the nanocomposites is discussed. At the end, the unresolved issues concerned with the properties of nanoceramics and the scopes for future work have been touched upon.

^iia9 illus, 3 tables, 70 ref

014323   Kaushik H B;Rai D C;Jain S K (Civil Engineering Dep, Indian Institute of Technology, Kanpur-208 016, Email: dcrai@iitk.ac.in) : Case for use of dynamic analysis in designing for earthqueke forces. Curr Sci 2006, 91(7), 874-7.

3 illus, 1 table, 5 ref

014322   Jebara A;Rajamuthamilselvan M; Lakshminarayanan P R (Manufacturing Engineering Dep, Annamalai University, Annamalai Nagar, Tamilnadu) : GTAW of LM 25 Al SiCp metal matrix composites. Indian Weld J 2006, 39(4), 15-19.

Aluminum based MMCs have greater strength; good wear resistance and excellent elevated temperature properties. Aluminum based MMCs are being widely used in Automotive and Aerospace industries. In spite of the advantages of MMCs as described above they are not widely used due to lack of their applicability to tertiary process like welding. However, the presence of reinforcement causes difficulties in welding of these materials. Study has been aimed at optimization of welding parametrs for weld strength and examination of difficulties/defects during welding of these materials.

3 illus, 4 tables, 4 ref

014321   Datta S;Bandyopadhyay A;Pal P K (Mechanical Engineering Dep, B.P. Poddar Institute of Management and Technology, 137, VIP Road, Poddar Vihar, Kolkata-700 052, Email: s_bppimt@yahoo.com ) : Submerged arc welding with a mixture of fresh flux and fused slag-modeling with quadratic response surface methodology. Indian Weld J 2006, 39(4), 20-31.

Reconsumption of the slag, generated during conventional submerged arc welding, has been proposed during subsequent runs by incorporating appropriate treatment and mixing it with fresh flux, with certain proportions. Experiments have been carried out by using four different levels of process parameters like welding current, flux basisity index and slag-mix percentage (percentage of slag in the mixture of fresh flux and fused slag) to obtain bead-on-plate weldment on mild steel plates. Parameters associated with bead geometry like bead height, bead width, depth of penetration have been measured for each experimental run. Heat affected zone (HAZ) geometry in terms of HAZ width has been obtained. Assuming simple geometry of the weld bead and unit length of the job, approximate bead volume has also been calculated. All these data have been efficiently utilized to develop mathematical models for prediction of geometry and quality of weld bead as well as heat affected zone. Quadratic response surface methodology (RSM) has been applied to develop the mathematical models between predictors and responses. Hardness Test has also been carried out to reflect graphically, the influence of using slag-mix in SAW process on mechanical property of the weld ment i.e. hardness of weld metal as well as HAZ. Finally it has been concludedd that effect of using slag-mix (up to 20%) do not impose any alarming adverse effect on features of bead geometry and HAZ. Therefore, the use of slag-mix, in submerged arc welding can be recommended to apply it in practical cases, which may make the process more economical.

16 illus, 5 tables, 6 ref

014320   Agrawal S K (NO, M.S. University of Baroda, Vadodara-390 001) : Welding of aluminium-selection of filler metals. Indian Weld J 2006, 39(4), 36-42.

3 illus, 4 tables, 5 ref

012197   Thyagarajan K;Annadurai M (Department of Space, ISRO Satellite Centre, Airport Road, Bangalore-560 017) : Chandrayaan-1: the first Indian mission to the moon. J Aerospace Sci Technol 2006, 58(4), 259-65.

The primary objectives of the Chandrayaan-1 mission are simultaneous chemical, mineralogical and topographic mapping of the lunar surface. These data should enable us to understand compositional variation of major elements. The major element distribution will be determined using an X-ray fluorescence spectrometer (LEX), sensitive in the energy range of 1-10 keV where Mg, Al, Si, Ca and Fe give their Ka lines. A solar X-ray monitor (SXM) to measure the energy spectrum of solar X-rays, which are responsible for the fluorescent X-rays, is included. Radioactive elements like Th will be measured by its 238.6 KeV line using a low energy gamma ray spectrometer (HEX) operating in 20-250 keV regions. The mineral composition will be determined by a Hyperspectral imaging spectrometer (HySI) sensitive in 400-930 nm range. The wavelength range is further extended to 3000 nm where some spectral features of the abundant lunar minerals and water occur, by using a near infra-red spectrometer (SIR-2) and Moon Mineralogy Mapper (M3). A terrain mapping camera (TMC) in the panchromatic band will provide three dimensional map of the lunar surface with a spatial resolution of about 5 m. Aided by a laser altimeter (LLRI) to determine the altitude of the lunar craft, to correct for spatial coverage by various instruments, TMC should enable us to prepare an elevation map with an accuracy of about 10m. Five struments under international cooperation have been accommodated that will complement and supplement the scienfific objectives of Chandrayaan-1. These are: a miniature Imaging Radar instrument (mini-SAR), Sub keV Atom Reflecting Analyser (SARA), The moon Mineralogy Mapper (M³), Infra Red Spectrometer (SIR-2) and a Radiation Dose Monitor (RADOM). Apart from these scientific payloads, a Moon Impact Probe (MIP) which will be released to impact on the Moon during the mission is also accommodated as a technology fore runner for future Lunar Landing mission.

4 illus, 1 table

012196   Thimmaiah P;Rao K R;Gopal E R (Department of Electronics, Sri Krishnadevaraya University, Anantapur) : Design and development of an embedded system for web camera control. J Instrum Soc India 2006, 36(2), 125-32.

Microcontrollers are becoming an integral part of Engineering design process known as Embeded system, the design includes major portion of the Hardware and entire Software incorporated on a single chip. Design of an Embedded system for the control of web camera has been described. Software is developed in Assembly language. The software in the form of Hex file is dumped on the microcontroller AT89C51 using the PC. Also describes the development of hardware for the above work and the results are discussed at the end.

6 illus, 4 ref

012195   Sitaram N;Issac J M;Govardhan M (Thermal Turbomachines Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600 036, Email: nsitaram@iitm.ac.in) : Effect of diffuser vane height and position on diffuser wall static pressures in a centrifugal compressor. J Aerospace Sci Technol 2006, 58(4), 322-7.

Experimental investigations on the effect of diffuser vane height and its position on diffuser wall static pressures of a low speed centrifugal compressor has been reported in this paper. Apart from the standard types of diffusers, namely, vaneless, vane and low solidity vane diffusers, a partial vane diffuser, whose height is less than the diffuser width is also tested. The vane height of the partial vane diffuser is varied from 0.3, 0.4 and 0.5 times the diffuser width in vane and low solidity vane diffuser configurations. In addition, the effect of vane position is examined by fixing the partial vanes to the hub, shroud or hub and shroud. It is found that there is an optimum height for the diffuser vane height, which is found to be 0.3 times the diffuser width. The effect of position of the partial vanes on the hub or shroud on the diffuser wall static pressures is found to be negligible. However when partial vanes are fixed on the hub and shroud staggered at half spacing the diffuser performance based on wall static pressures is improved substantially.

10 illus, 3 tables, 6 ref

012194   Singh N L;Qureshi A;Rakshit A K;Avasthi D K (Physics Department, M.S. University of Baroda, Vadodara-390 002, Email: singhnl_msu@yahoo.com) : Analysis of organometallics dispersed polymer composite irradiated with oxygen ions. Bull Mater Sci 2006, 29(6), 605-9.

Thin films of polymethyl methacrylate (PMMA) were synthesized. Ferric oxalate was dispersed in PMMA films. These films were irradiated with 80 MeV O⁶⁺ ions at a fluence of 1 x 10¹¹ ions/cm². The radiation induced changes in electrical conductivity. Mossbauer parameter, microhardness and surface roughness were investigated. It is observed that hardness and electrical conductivity of the film increases with the concentration of dispersed ferric oxalate and also with the fluence. It indicates that ion beam irradiation promotes (i) the metal to polymer bonding and (ii) convert the polymeric structure into hydrogen depleted carbon network. Thus irradiation makes the polymer harder and more conductive. Before irradiation, no Mossbauer absorption was observed. The irradiated sample showed Mossbauer absorption, which seems to indicate that there is significant interaction between the metal ion and polymer matrix. Atomic force microscopy shows that the average roughness (R_a) of the irradiated film is lower than the unirradiated one.

5 illus, 1 table, 15 ref

012193   Sharma B C (NO, G.B. Pant Engineering College, Pauri (Garhwal), Uttaranchal-246 001, Email: bc_sharma@yahoo.com ) : Analysis of some basic coated MMAW electrodes based on statistical analysis, mechanical weld properties and hydrogen content. Indian Weld J 2006, 39(3), 24-34.

Experimental investigations have been carried out to study the behaviour of basic type of coated electrodes (IS:E614514 HJ), AWS: E7018,DIN: E5144B 1026) of different sizes produced by different manufacturers for evaluation of process stability, weldment mechanical properties and diffusible hydrogen content. Time analysis, voltage analysis and current analysis have been carried out using an Analyser Hannover. This is a digital measuring and analyzing system. Better arc stability is associated with the electrodes of particular manufacturer depending upon the size of electrode, the melting rate (gm/J) increases with the increase in the electrode diameter. Higher impact strengths are associated with the electrode which yield low diffusible hydrogen contents.

15 illus, 9 tables, 14 ref

012192   Shanmugasundaram M;Lakshmi P;Vincent J; Rajasundaram P;Chandra T;Rajan K K;Rajan M;Purniah B (Sodium Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Power supply systems for in sodium testing facility. J Instrum Soc India 2006, 36(2), 82-90.

In sodium testing facility (INSOT) for testing the creep and fatigue behaviour of Fast Breeder Reactors (FBR) at elevated temperatures is developed. Used Class I, Class II, Class III and Class IV power supply systems analysed. An advanced PLC based monitoring and communicating Class - I power supply system (Lead Acid Battery Bank) for in-sodium testing facility has been developed in IGGAR. INSOT has one set of 300AH, 24V battery bank having 12 cells in series and the battery charger which has the rating of 24V - 100A. A unique feature of this system is the availability of this backup for the control panel operations as well as minimal lighting in case of failure of class III and IV power supplies. Describes the advance PLC based communication & monitoring class-I lead acid battery system, Class II, class III and class IV which has been implemented.

2 illus, 6 ref

012191   Shanmugasundaram M;Lakshmi P;Sundari C; Vincent J;Purnaiah B (Metallaurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Advanced neural & fuzzy temperature and flow control systems for in sodium test facility. J Instrum Soc India 2006, 36(2), 91-100.

In-sodium testing facility (INSOT) for evaluating of creep and fatigue behaviour of fast breeder reactor structural materials under flowing sodium at elevated temperature is developed. Existing architecture for instrumentation and control of creep and fatigue loops of INSOT facility contains programmable logic controllers (PLCs), Field access units (FAUs) and personal computers based software of INSOT facility. Temperature controlling various methods are studied and, improved. This paper examines the advancement features of the system architecture. The advancement covers the replacement of microcontroller (8749) chip, which resulted in an increase in speed and reduction in the programming time. The new microcontroller (89C51) architecture enable us electrically erase several times thus reducing the cost. The assembler and disassembler software are easily available. The internal memory 4K flash PRAM. The number of ports are more, so interrupts can be externally added. Upgrade possibility of neutral networks and fuzzy control in the insot was analysed, results obtained.

7 illus, 8 ref

012190   Sathyamoorthy S;Raja S;Stanley A J (Department of Aerospace Engineering, Madras Institute of Technology, Anna University, Chromepet, Chennai-600 004) : Piezoelectric based adaptive wing for flow control. J Aerospace Sci Technol 2006, 58(4), 305-12.

Attempt is made to develop a piezoelectric based adaptive wing concept that can be used in Micro Air Vehicle (MAV) and Unmanned Air Vehicle (UAV) applications. Laminar bouridary layer separation is considered to be a significant problem in low Reynolds number vehicles like MAV. Recently, periodic excitation has gained much interest in the control of flow separation through energizing the boundary layer. In the study, a piezoelectric bimorph actuator has been used to develop a mechanism that will deflect or vibrate a segment of the wing to produce the required thickness variation and achieve flow control. A Finite Element model of the adaptive wing is developed in ANSYS and numerical results are compared with experiments. A five percent increase in the camber has resulted in 4.39 percent additional lift at higher angles of attack.

21 illus, 8 ref

012189   Sasikumar K;Suresh G;Thomas K A;John R; Natarajan V;Mukundan T;Vishnubhatla R M R (NO, Naval Physical and Oceanographic Laboratory, Thrikkakara, Cochin-628 021, Email: tsonpol@vsnl.com) : Magnetoactive elastomeric composites: cure, tensile, electrical and magnetic properties. Bull Mater Sci 2006, 29(6), 637-40.

Magnetically active elastomer materials were prepared by incorporating nickel powder in synthetic elastomeric matrices, polychloroprene and nitrile rubber. Cure characteristics, mechanical, electrical and magnetic properties were experimentally determined for different volume fractions of magnetoactive filler. The cure time decreases sharply for initial filler loading and the decrease is marginal for additional loading of Tiller. The tensile strength and modulus at 100% strain was found to increase with increase in the volume fraction of nickel due to reinforcement action. The magnetic impedance and a.c. conductivity are found to increase with increase in volume fraction of nickel as well as frequency.

7 illus, 2 tables, 10 ref

012188   Roy S B;Chattopadhyay M K;Manekar M A;Sokhey K J S;Chaddah P (Magnetic and Superconducting Materials Section, Raja Ramanna Centre for Advanced Technology, Indore-542 013, Email: sbroy@cat.ernet.in) : First order magneto-structural transition in functional magnetic materiasl: phase-coexistence and metastability. Bull Mater Sci 2006, 29(6), 623-31.

First order magneto-structural transition plays an important role in the functionality of various magnetic materials of current interest like manganese oxide systems showing colossal magnetoresistance, Gd₅(Ge, Si)₄ alloys showing giant magnetocaloric effects and magnetic shape memory alloys. The key features of this magneto-structural transition are phase-coexistence and metastability. This generality is highlighted with experimental results obtained in a particular class of materials. A generalized framework of disorder influenced first order phase transition is introduced to understand the interesting experimental results which have some bearing on the functionality of the concerned materials.

6 illus, 33 ref

012187   Rivas M A;Paley R (Sulzer pumps, , ) : Dringking water from the sea. Indian Pumps 2006, 38(1), 19-22.

Changing climatic conditions, population growth, and the resulting development of existing limited natural supplies all build up pressure on the supply of clean drinking water. Reverse osmosis is an established method of turning seawater into drinking water. A new approach to this technology has led to a marked reduction in supply costs. Sulzer Pumps has played a key role in the successful development and commissioning of the ground-breaking Ashkelon (IL) desalination plant, the world's largest reverse osmosis installation.

5 illus

012186   Reddy K V S;Reddy P S;Uthanna S (Department of Physics, Sri Venkateswara University, Tirupati-517 502) : DC reactive magnetron sputter deposition of copper nitride films. J Instrum Soc India 2006, 36(2), 113-7.

Thin Films of Cu₃N were deposited on glass substrates by sputtering of pure copper target under different nitrogen partial pressures in the range 1x10^-4 -5x10^-3 mbar employing dc magnetron sputtering technique. The variation of cathode potential with the nitrogen partial pressure was explained in terms of nitridation of copper target and secondary electron emission. The deposition rate of the films was correlated with the nitrogen partialpressure. The influence of nitrogen partial pressure on the electrical and optical properties of Cu₃N films was systematically studied. The Cu₃N films with electrical resistivity of 2.2x10¹ Ωcm and optical band gap of 1.85 eV were obtained at an optimized nitrogen partial pressure of 1x10^-3 mbar.

4 illus, 13 ref