024674   Singh S K;Sinha A (NO, Central Mining Res Inst, Dhanbad-826 001, Email: satyendraksingh@yahoo.com) : Production challenges in underground coal mining: scenario planning and extraction strategies below surface and sub-surface properties. J Mines Metals Fuels 2006, 54(8-9), 198-202.

4 illus, 9 ref

024673   Singh R K;Nayak P;Niyogi U K;Khandal R K; Singh G (NO, Shriram Institute for Industrial Research, 19, University Road, Delhi-110 007, Email: rksingh@shriraminstitute.org) : Gamma radiation process for destruction of toxic polychlorinated biphenyls (PCBs) in transformer oils. J envir Sci Engng 2006, 48(1), 45-50.

Polychlorinated biphenyls (PCBs) are synthetic organic chemicals commercially used worldwide in many applications. PCBs were used in oils because of their excellent properties such as good thermal stability, flame resistance, dielectric constant, high break down voltage, high boiling point and low volatility. However, because of their adverse affects on environment and human health, the use of PCBs has been banned now. PCBs are today considered among the widespread pollutants in the global system. PCBs sources still exist in various industrial products and in waste streams such as capacitor oils, lubricating oils , transformer oils, hydraulic oils, paints, rubbers, cables, etc. Several such materials containing PCBs emanating from various sources need to be detoxified before their reuse or before going to landfill for final disposal. Various remedial technologies have been developed in the world to destroy toxic PCBs. The radiolysis has been investigated as an environment-friendly process for waste oil treatment contaminated with PCBs, which may be a better alternative to the globally most widely accepted incineration method. A study was undertaken to detoxify PCBs in transformer oil by gamma radiation using Cobalt 60 source. Analysis of PCBs in transformer oils before and after radiation was carried out by GC -MS instrument. The effect of radiation dose and destruction of PCBs in transformer oils are discussed in details. The method used was found to be highly effective and destruction was as high as 79 %. Further, the transformer oil samples were also evaluated before and after radiation to check their quality. The properties of oils were not significantly altered by gamma radiation treatment as evident from the results given.

5 illus, 4 tables, 8 ref

024672   Singh N;Singh V (Metallurgical Dep, Engineering Centre of Advanced Study,, Institute of Technology, Varanasi-221 005, Email: vakil@bhu.ac.in) : Microstructural characterization of the near α titanium alloy IMI834. Metals Mater Process 2006, 18(3-4), 309-18.

Microstruclural characterization of near alloy IMI834 in the α+β and β solution treated and differently cooled/quenched conditions has been carried out. Solution treatment in α+β phase field at 1293 K resulted in two-phase microstructure having equiaxed primary a in the matrix of transformed p. Solution treatment in β phase field at 1353 K resulted in single-phase microstructure having transformed β. Slowly cooled microstructures resulted in precipitation of fine Ti₃AI and silicide precipitates. Both α+β and β heat treated samples were subjected to stabilization treatment at 973K for 2hrs and cooling in air. The stabilization treatment leads to spheroidization of retained β, coarsening of existing Ti₃AI and silicide precipitates along with formation of new precipitates.

8 illus, 26 ref

024671   Singh B P;Bhattacharjee B (General of Mines Safety, , Dhanbad) : Deep (long) hole blasting to induce caving in longwall panel-a strata control technique. J Mines Metals Fuels 2006, 54(8-9), 157-63.

8 illus, 6 tables, 4 ref

024670   Singh A K;Schwarzer R A (Defence Metallurgical Research Laboratory, , Kanchanbagh P.O., Hyderabad-500 058) : Development of cold rolling texture in the binary Ti-0.4M n alloy. Metals Mater Process 2006, 18(3-4), 351-60.

Development of cold rolling textures in the alloy Ti-0.4Mn has been investigated in detail using two different modes of deformation. The alloy has been unidirectionally rolled up to 75% reduction. In order to understand the effect of modes of deformation by rolling, other specimens have also been subjected to 50% reduction by multi-step cross rolling. The results are compared with those of pure titanium and other titanium alloys. Finally, an attempt has been made in this study to propose a possible mechanism of the development of texture.

4 illus, 1 table, 20 ref

024669   Shukla A K;Balasubramaniam R (Materials and Mettallurgical Engineering Dep, Indian Institute of Technology, Kanpur-208 016) : Surface film nature on titanium-aluminum-iron alloys in simulated human body fluid conditions. Metals Mater Process 2006, 18(3-4), 421-29.

Nature of surface films on the surface of TI-6AI-4V, Ti-5AI-2.5Fe and Ti-6AI-4Fe alloys was investigated as a function of immersion time using electrochemical impedance spectroscopy (EIS). The surface film that formed on immersion was characterized by scanning electron microscopy. It was . confirmed that the surface film that forms on immersion was apatite. Electrochemical impedance spectroscopy studies revealed higher passive film resistance with immersion time for the alloys containing iron when compared to Ti-6AI-4V. The Ti-6AI-4Fe alloy exhibited greater increase in surface film resistance compared to Ti-5AI-2.5Fe alloy.

10 illus, 16 ref

024668   Shivran H S;Dinesh Kumar;Singh R V (Chemistry Dep, Rajasthan Univ, Jaipur-302 004, Email: kudiwal@datainfosys.net) : Improvement of water quality through biological denitrification. J envir Sci Engng 2006, 48(1), 57-60.

Study was undertaken to observe the effect of biological denitrification process on water quality parameters. The results obtained in the investigations show that the value of pH and alkalinity was increased due to generation of alkalinity during biological denitrification process. The obtained value of the DO in the treated water was found lower than the supplied water, which indicates, DO was consumed by the bacterium. The COD of the treated water was nil, which shows that the organics have been consumed by the bacterium during the denitrification process. The biological reduction of nitrate-nitrogen (from 50.79 mg/L to 0.57 mg/L) was found to be lower than the tolerance limit prescribed by WHO without changing the water quality.

2 illus, 2 tables, 10 ref

024667   Shekhar H (NO, High Energy Materials Research Lab, ) : Peak strain in regressing finocyl port propellant grains under pressure loading. Def Sci J 2007, 57(2), 259-66.

Finite element analysis (FEM) has been conducted for case-bonded finocyl port propellant cross section under pressure loading conditions during burning. Peak strain is found to decrease in course of burning, hence, analysis of any intermediate configuration in course of burning is not required for assessing margin of safety in finocyl port propellant grains. The Power Law proposed has also been used to predict peak strain. Variation in strains obtained by FEM and using the Power Law is found to be matching closely with findings reported in CPIA (Chemical Propulsion Information Agency) publications. Extension in domain of power law to regressing pressurised finocyl port propellant grain eliminates dependence on time-consuming computer- intensive FEM computations without compromising the accuracy of of results.

8 illus, 1 table, 7 ref

024666   Sharma R;Sha O P (Ocean Engineering and Naval Architecture Dep, Design Laboratory, Indian Institute of Technology, Kharagpur-721 302, Email: rajivatri@yahoo.com) : An investigation into design of fair surfaces over irregular domains using data-dependent triangulation. Sadhana 2006, 31(pt5), 645-59.

Design of fair surfaces over irregular domains is a fundamental problem in computer-aided geometric design (CAGD), and has applications in engineering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over irregular domains defined over scattered data, it was widely accepted till recently that the classical Delaunay triangulation be used because of its global optimum property. However, in recent times it has been shown that for continuous piecewise linear surfaces, improvements in the quality of fit can be achieved if the triangulation pattern is made dependent upon some topological or geometric property of the data set or is simply data dependent. The fair surface is desired because it ensures smooth and continuous surface planar cuts, and these in turn ensure smooth and easy production of the surface in CAD/CAM, and favourable resistance properties. In this paper, Authorsdiscuss a method for construction of C¹ piecewise polynomial parametric fair surfaces which interpolate prescribed ℜ³ scattered data using spaces of parametric splines defined on ℜ³ triangulation. Shows that the method is more specific to the cases when the projection on a 2-D plane may consist of triangles of zero area, numerically stable and robust, and computationally inexpensive and fast. Numerical examples dealing with surfaces approximated on plates, and on ships have been presented.

4 illus, 15 ref

024665   Shankaranarayan Y S;Paramjeet Singh; Arunachalam R;Rama Rao H S (Systems Reliabililty Group, ISRO Satellite Centre, Bangalore-560 017) : Reliability prediction of spacecraft mechanisms. J Spacecraft Technol 2007, 17(1), 60-7.

Presents a case study of reliability prediction of a spacecraft mechanism using a combination of strength-stress interference appraoch and Monte Carlo simulation.

10 illus, 3 tables, 4 ref

024664   Shankar M;Ganesan V;Sole R (NO, Anna Univ, Chennai, Email: vaidehi@igcar.gov.in) : Laser cladding on Ti-6AI-4V alloy to improve wear and corrosi on resistance. Metals Mater Process 2006, 18(3-4), 387-95.

TI-6AI-4V alloy is a gateway material (Liquid Oxygen Propellant Tank) used in aerospace applications. Titanium alloys are used for construction of space vehicle systems because of their high strength to weight ratio. This alloy is impact sensitive and susceptible to pitting and stress corrosion in liquid oxygen environment. Nickel is impact insensitive and hence nickel coating (electroless and electro-plating) was made on these specimens and laser irradiated (different power: 100 to 200 W) to improve the wear and corrosion resistance of Ti-6 AI-4 V alloy. Multi beam continuous wave CO₂ laser was used to modify the surface in order to improve corrosion resistance, microhardness, wear resistance etc. The microstructures were analysed in detail. In as received condition this alloy exhibits mixture of alpha (Al alpha stabilizer-hep crystal structure) and beta phase (V-beta phase stabilizer-bcc). This alloy is an alpha-beta alloy. After laser treatment (fast cooling from high temperature of 1200°C) acicular alpha prime martensites (needle shape) are formed on the surface and penetrate to a depth of <62> 60 μm. Alpha prime (martensite) is a non-equilibrium super-saturated alpha structure produced by diffusionless (martensitic) transformation of beta. Ti-Ni intermetallic phases are also formed. These microstructures have sufficiently improved the corrosion resistance, wear resistance, micro-hardness etc., of the laser cladded TI-6AI-4V alloy. The results are discussed in detail.

3 illus, 8 tables, 16 ref

024663   Sethu S;Manivasagam G;Kannappan J G (Kannappans Orthodontic Center, , 68 Radhakrishnan Salai, Chennai-600 004) : Titanium in dental applications. Metals Mater Process 2006, 18(3-4), 451-61.

Biomaterials play a pivotal role in the restoration and rehabilitation of lost biological structures and functions. Titanium and its alloys are well known and widely used materials right from outer space to deep into biological systems and tissues. It is certainly a biomaterial of choice in a variety of fields like orthopedics, dentistry, cardiovascular, otolaryngology and also in the manufacture of surgical instruments. Its application in dentistry is vast. It is a more advantageous material in the manufacture of oral implants, crowns, fixed prostheses, removable prostheses, orthodontic wires & appliances, endondontic instruments, fracture fixation devices and maxillofacial reconstructive materials. Its use is clinically successful due to its unique properties like, excellent biocompatibility, greater strength, low elastic modulus, better corrosion resistance, low density and availability. Newer Titanium based alloys and techniques in the fabrication process will further improve its quality and versatility in varied applications.

4 illus, 1 table, 43 ref

024662   Savyanavar R C;Reddy G R;Parulekar Y M;Kumar P;Rama Rao A;Chavan S P;Vaze K K;Ghosh A K;Kushwaha H S (NO, Walchand College of Engineering, Sangli-416 415) : Experimental evaluation and retrofitting of structure subjected to earthquake loading with circular tuned liquid damper (TLD). J Struct Engng 2007, 33(6), 79-86.

Tuned Liquid Damper (TLD) has been effectively utilized in suppressing narrow-band wind induced response of the structures. However some numerical studies suggest that, due to inherent property of sloshing to occur in any direction, a properly designed TLD is suitable for controlling seismic response of the structure. In this paper, an effort is made to explore the suitability of circular TLD in controlling the seismic response of a flexible structure. An experimental approach is adopted to evaluate the effectiveness of circular TLD under varying level of harmonic excitations. Design parameters which are needed for proper designing of the TLD are discussed. Finite Element analysis is performed on an existing structure to show the effectiveness of TLD to control its seismic response of the structure.

14 illus, 14 ref

024661   Sasi Kumar C;Rao D S;Srikanth S;Narashimhan B R V;Ravikumar B;Mukhopadhyay N K (National Mettallurgical Laboratory - Madras Centre, , CSI R Madras Complex, Post TTTI, Taramani, Chennai-600 113, Email: s_srikanth_99@yahoo.com) : Effect of natural weathering and mechanical activation on the acid dissolution kinetics of Indian beach sand ilmenites. Metals Mater Process 2006, 18(3-4), 211-24.

Four naturally weathered ilmenites with varying degree of alteration were collected from beach placer deposits at Chatrapur, Navaladi, Manavalakurichi and Chavara, India and characterized for their physico-chemical properties and dissolution behavior in sulfuric acid. The extent of alteration can be characterized by their ferric to ferrous ratio. With increased alteration/weathering it has been observed that the physical properties like specific gravity and crystallite size decrease and surface area as well as average pore size increase. It has also been found that the solubilities of iron and titania in sulfuric acid decrease significantly and the activation energies of dissolution increase with alteration/weathering of the samples because of the oxidation of Fe⁺² to Fe⁺³. Mechanical activation of these natural ilmenites has been carried out to compare with the weathering process and study their dissolution kinetics vis a vis those of the naturally altered samples. Although the mechanical activation process also resulted in increased ferric to ferrous ratio, higher surface areas and lower crystallite sizes, the dissolution kinetics was substantially enhanced by the activation process. The enhanced dissolution kinetics in the mechanical activation process is attributed to the increase in strain and defect concentration introduced during the activation process. The activation energies for leaching of both titanium and iron decreased monotonically with time of activation.

15 illus, 1 table, 34 ref

024660   Sarkar P;Agrawal R;Menon D (Civil Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036) : Design of RC beam-column joints undr seismic loading - a review. J Struct Engng 2007, 33(6), 449-57.

Beam-column joint is a very critical element in reinforced concrete (RC) framed structure where the elements intersect in all three directions. Joints ensure continuity of a structure and transfer forces that are present at the ends of the members. The present provisions in IS 13920:1993 are inadequate, in terms of (i) minimum column width, (ii) column/beam flexure strength ratio, (iii) estimation of shear demand, (iv) assessment of shear strength, design and detailing of shear reinforcement, and needs to be upgraded regarding the beam-column joint under seismic loading. Reviews the design procedures for the RC beam-column joints under seismic loading reported in literature, with a special emphasis on three international codes of practice viz. ACI 318M-02, NZS 3101:1995 and prEN 1998-1:2003. It is pointed out that although there is a need for continuing research to resolve various disparities, there is an urgent need to revise IS 13920 suitably, in the interest of structural safety.

5illus, 6 tables, 18 ref

024659   Sahu A;Vaishnav M M (Chemistry Dep, G.B.V. Post-Graduate College, Hardibazar, Korba) : Fluoride in ground water around the balco, Korba area (India). J envir Sci Engng 2006, 48(1), 65-8.

Study was undertaken for the determination of fluoride ions in drinking water at the BALCO, Korba region by the ion selective electrode method. The ground water samples of thirty four villages of this region were collected. The fluoride concentration values varied from 1.07 ppm to 3.10 ppm. In this area, villagers were found suffering with dental and skeletal fluorosis. The villagers were suggested to use alum, lime and Nalgonda technique to avoid all type of fluorosis. It was found that fluoride was present within the permissible limit (1.5 ppm) in most of the villages studied but the fluoride level was unacceptable in drinkig water samples taken from some villages of BALCO, Korba area.

2 illus, 1 table, 13 ref

024658   Sahoo N;Saravanan S;Jagadeesh G;Reddy K P J (Mechanical Engineering Dep, Indian Institute of Technology, Guwahati-781 039, Email: shock@iitg.ernet.in) : Simultaneous measurement of aerodynamic and heat transfer data for large angle blunt cones in hypersonic shock tunnel. Sadhana 2006, 31(pt5), 557-81.

Aerodynamic forces and fore-body convective surface heat transfer rates over a 60° apex-angle blunt cone have been simultaneously measured at a nominal Mach number of 5.75 in the hypersonic shock tunnel HST2. An aluminum model incorporating a three-component accelerometer-based balance system for measuring the aerodynamic forces and an array of platinum thin-film gauges deposited on thermally insulating backing material Hush mounted on the model surface is used for convective surface heat transfer measurement in the investigations. The measured value of the drag coefficient varies by about ±6% from the theoretically estimated value based on the modified Newtonian theory, while the axi-symmetric Navier-Stokes computations overpredict the drag coefficient by about 9%. The normalized values of measured heat transfer rates at 0° angle of attack are about 11% higher than the theoretically estimated values. The aerodynamic and the heat transfer data presented here are very valuable for the validation of CFD codes used for the numerical computation of flow fields around hypersonic vehicles.

20 illus, 3 tables, 31 ref

024657   Ruppel U;Angosch U (Ulrich Ruppel and Ulrich Langosch, DMT, , Essen, Germany) : New method for dimensioning of shield support to improve longwall roof control. J Mines Metals Fuels 2006, 54(8-9), 179-84.

Uses practical examples to demonstrate the R & D results and present the various methods now available for calculation and prediction in longwall roof control.

15 illus, 3 ref

024656   Ramasamy A;Padmanabhan;Gurudath C S;Gupta P P;Bhandari D R;Narayanamurthy H (Thermal Systems Group, ISRO Satellilte Centre, Bangalore) : Performance of single stage split stirling cryocooler development model. J Spacecraft Technol 2007, 17(1), 49-54.

Development of split Stirling cycle cryocooler for spacecraft application has been carried out at Indian Space Research Organization (ISRO) and its thermal performance demonstrated. The efficiency of the cooler at 80K with 1W load is 11% at ambient heat rejection temperature of 300K, which is higher than that reported in literature. This development model meets the specified performance and provides 1W of cooling power at 80. 70 and .60K for the compressor input power of 25, 32 and 43W respectively.

4 illus, 2 tables, 5 ref

024655   Ramanujan R V (School of Materials Science and Engineering, Nanyang Technological Univ, Singapore-639 798, Email: ramanujan@ntu.edu.sg) : Artificial hip joints based on titanium alloys. Metals Mater Process 2006, 18(3-4), 463-72.

Studies the design of an artificial hip joint using materials assessment principles to determine which materials will increase its durability and lifespan. This was done by evaluating the properties and processing techniques of the materials used. The materials selected for the ball and cup, screw, femoral stem were alumina-titanium, titanium and aluminum with s-glass composite respectively.

1 illus, 7 tables, 4 ref

024654   Ramana Murthy V;Kulkarni S B;Singh B B (NO, Finolex Academy of Management and Technology, Ratnagiri-415 639) : Exact solutions of an incompressible fluid flow of second order by forced oscillations on the porous boundary. Def Sci J 2007, 57(2), 197-209.

Exact solution of an incompressible fluid of second-order type by causing forced oscillations in the liquid of finite depth bounded by a porous bottom has been obtained. The results presented are in terms of nondimensional elastico-viscosity parameter (β) which depends on the non-Newtonian coefficient and the frequency of excitation (σ) of the external disturbance while considering the porosity (K) of the medium. The flow parameters are found to be identical with that of Newtonian case as β → 0 and K → ∞. It is seen that the effect of β and the porosity of the bounding surface has significant effect on the velocity parameter. Further, the nature of the paths of the fluid particles have also been studied with reference to β and the porosity of the bounding surface.

9 illus, 13 ref

024653   Rama Rao M V;Ramesh Reddy R (Civil Engineering Dep, Vasavi College of Engineering, Hyderabad-31) : Analysis of a cable-stayed bridge with multiple uncertainties - A fuzzy finite element approach. J Struct Engng 2007, 33(6), 523-5.

6 illus, 4 tables, 7 ref

024652   Rajpal P S;Shishodia K S;Sekhon G S (NO, Indian Institute of Technology Delhi, New Delhi-110 016) : Reliability, availability, and maintainability of intermittently-used repairable systems. Def Sci J 2007, 57(2), 211-22.

Composite measure comprising linear combination of reliability, availability, and maintamability (CMRAM) is proposed for an intermittently-used complex repairable system, namely a transport helicopter. The failure data are fitted in Weibull distribution for overlapping intervals of operating time to capture the effect of recent maintenance and other actions. Evaluation of CMRAM is helpful in formulating future operational and maintenance strategies.

8 illus, 4 tables, 10 ref

024651   Pathak K K;Sehgal D K;Akhtar S;Bhadauria S S (NO, Regional Research Laboratory, Bhopal (M.P)-462 026) : A review of structural shape optimization techniques. J Struct Engng 2007, 33(6), 505-14.

5 illus, 106 ref

024650   Parate B A;Kulkarni C M (NO, Armament Research and Development Establishment, Pune-411 021) : Esitmation of heat loss in a closed vessel. Def Sci J 2007, 57(2), 223-8.

Power cartridges are designed and developed for use in military aircraft in association with High Energy Materials Research Laboratory, Pune. During development, the cartridge is fired in a closed vessel to generate basic design parameters. When the cartridge is fired, the heat is lost to the walls of the vessel due to conduction, convection, radiation, and to some extent, by expansion of the vessel. An attempt has been made to estimate the heat loss from the vessel and the surrounding. The aim of the study was to lay down the technical results theoretically and their validation through experiments.

^ssc1 illus, 1 table, 10 ref

024649   Pant B;Singh S K;Mittal M C (Materials and Metallurgy Group, Polymers, Propellants, Chemicals and M, , Trivandrum-695 022, Email: bhanupant2000@gmail.com) : Titanium alloys for Indian space programme. Metals Mater Process 2006, 18(3-4), 249-60.

Space programs require high specific strength materials compatible to various working fluids. Titanium alloys possess these characteristics and hence are materials of choice for various space applications like high-pressure gas bottles and upper stage propellant tanks. For the Indian Space program, main contribution is from the two-phase Ti6AI4V alloy, the workhorse Titanium alloy that is used in annealed as well as in STA (solution treated and aged) conditions. Applications at 20K have necessitated indigenous development of a special α-Ti alloy namely Ti5Ai2.5Sn-ELI. For these two alloys, technology has been established to realize various components through closed-die forging/plate forming, machining and EB welding route. However, the highest strength Ti-alloys are based on heat-treatable β-type alloys, which offer added advantage of amenability to extensive cold forming. For this class of heat-treatable alloys, cold forming of components is possible leading to very high specific strength coupled with overall low costs. Development of such beta-Ti15V3Cr3AI alloy has been taken up for space applications such as strips and pressure vessels. Another challenging area is of development of lightweight temperature resistant material for future space missions based on reusability concept (for RLV or reusable launch vehicle). In this class of high temperature titanium alloys, some of near α-Ti alloys like Ti1100, Timetal 834, and Ti 6242 can serve upto a temperature of about 873K. A new class of Intermetallic alloys based on titanium aluminide of γ- type, which has density half of superalloys, is perspective material of choice for applications at temperatures upto 1273K. The development work carried out in the areas of titanium alloys and aluminides have been presented covering various technology aspects and involved qualification tests leading to eventual space application of these materials.

14 illus, 9 tables, 15 ref

024648   Nikhil B K;Kapadia J S;Alexander C P;Vinaya M M (NO, Bangalore Institute of Technology, K.K. Road, Bangalore-560 004) : Rigid body motion using FEM - a case study of pan camera release system. J Spacecraft Technol 2007, 17(1), 45-8.

Presents the details of the transient dynamic analysis carried out on the pan-camera using a standard finite element analysis package. The process of solving a rigid-body motion problem involves deriving the equations of motion for the body and solving them. Generally, Newton's method or Lagrange's approach is used for deriving the differential equations of motion. These are solved numerically to get the time-displacement and other characteristics of motion of an object. Commercially available special purpose packages like ADAMS, DADS etc., are used extensively for rigid body motion analysis. It is also customary To use finite element methods (FEM) for activities like stress analysis, frequency analysis, response analysis etc. However, a successful and novel attempt has been made to solve a rigid body motion problem using a standard FEM package. The release dynamics of the pan-camera has been studied using the software package NISA. The results of the study have been observed to be agreeing well with the corresponding test data and also with the results of conventional analyst.

5 illus, 2 tables, 4 ref

024647   Nandy T K;Bhattacharjee A;Singh A K;Gogia A K (Defence Mettallurgical Research Lab., , P.O. Kanchanbagh, Hyderabad-500 058, Email: tapashnandy@rediffmail.com) : Phase transformation and microstructure evolution in titanium alloys. Metals Mater Process 2006, 18(3-4), 289-307.

Variety of phase transformations is encountered in titanium alloys. The allotropic transformation, β (bcc) to α (cph) phase forms the basis for most of the transformations. Since the transformation of β to equilibrium a is kinetically unfavorable, it goes through a number of intermediate phases such as omega (ω), martensite (α'/α") and β+β. Presence of intermetallics such as Ti₃Al, TiAl, Ti₂Cu, Ti₅Si₃ and so on adds to a whole new range of phase transformations that have been studied in considerable detail. The present article briefly describes these transformations. Additionally, the effects of processing and heat treatment in conjunction with phase transformation on the evolution of microstructure are also discussed.

25 illus, 1 table, 41 ref

024646   Nagesh R V S;Alla Bhakshu S;Dora Swamy B V; Kirtania M;Ram Narayana V;Brahmendra Kumar G V S;Sridhar D;Sitaraman T S;Ramachandran C S (Defence Metallurgical Research Laboratory, , Kanchanbagh, Hyderabad, Andhra Pradesh, Email: nagesh@dmrl.ernet.in) : Development of indigineous technology for commercial production of titanium sponge. Metals Mater Process 2006, 18(3-4), 239-48.

Titanium metal assumes strategic importance to our country in view of its applications in high performance aerospace components. Processing of minerals, ingot melting and production of mill products have been practiced on industrial scale with only a technology gap of sponge production in the Indian titanium metallurgy. Over the last two decades, DMRL has been vigorously pursuing technology ' development activity for large scale production of titanium sponge by Kroll process of magnesium reduction of TiCl4. Technology demonstration at DMRL for the production of aerospace grade titanium sponge has been successfully completed recently. This has come about at a critical moment, when the Departments of Space and Defence were finding it extremely difficult to import sponge meeting their stringent quality specifications. A 500 TPY capacity Titanium Sponge Project by the Kerala Minerals and Metals Limited based entirely on DMRL Technology and funded by the department of Space is currently under implementation.

4 illus, 3 tables, 11 ref

024645   Nagesh M;Pandit D (School of Construction Management NICMAR, , Pune) : Construction safety and labour conditions in and around Ahmedabad. NICMAR J Constr Mgmt 2006, 21(3), 15-37.

Construction is the second largest economic activity in India next to agriculture. The construction industry has recorded enormous growth world-wide and particularly in India during the last decade. Constructing safe structures and providing safe working environment to the personnel is a vital factor in successful construction business. Thus safety is an important function in the management of construction projects. The concern for safety has to start from the design stage and continues till the facilities are delivered to the owner. Construction is also a high accident-prone industry employing major work force, most of them being labourers and skilled workers. Besides, construction sector is a highly unorganized sector and is a high risk industry for clients, contractors and workers. The term "Safety" is difficult to define due to the inter-relationship of several factors. Safety in general can be defined as "the freedom from danger of risks of personal injuries or damage to the health, over a period of time, arising from both immediate and long term effects of the exposure to unhealthy working environment". Very often, safety is adjudged in terms of an inverse relationship with the accident rate. High rate means low safety and vice versa. Theoretically, safety would mean the absence of danger at work which is made possible by eliminating hazards that create the danger. A more practical definition used in a document states "A thing is provisionally categorized as safe if its risks are deemed known and, in the light of that knowledge, judged to be acceptable".

19 illus, 5 tables

024644   Nagaraja K (Aeronautical Development Agency, , Bangalore-560 017) : Indigenous development of the aircraft standard "dual temperature sensor" (thermistor) for the radar cooling system (RCS) of typical fighter aircraft. J Instrum Soc India 2006, 36(4), 284-8.

Dual temperature sensor is mounted in the Pump-Motor unit of Radar Cooling System. The Sensor is used to sense the inlet temperature of the coolant for the Radar. It consists of two thermistors elements in a single housing. These thermistors have a negative temperature coefficient characteristic. The design requirement of thermistors is of 30Kohm ± 5% at 25°C. Working temperature range is -40 to 80°C, working line pressure is 10 bar g. Insulation resistance is greater than 20Mohms, Weight is less than 200gms. The design is according to the requirements of MIL-STD-810E, Environmental Standard. In this standard, temperature range is -55°C (storage) to 80°C, the acceleration is of-3.5g to 9g, and the altitude level is 18Km above sea level. The acceptance tests such as the measurement of Insulation resistance, Calibration check, Cyclic test etc and Qualification tests such as the high temperature, low temperature, thermal shocks, humidity, acceleration, vibration, shock, fungus, salt fog, transit drop, endurance tests of 1000 cycles at 0°C and 80°C, are successfully done according to the Military standards, which demonstrate the functionality within performance specification limits and under simulated environmental conditions. In every stage of development there is an involvement of Quality Assurance Department (QA), Chief Resident Inspector (CRI), Regional Center for Military Airworthiness (RCMA), and all the necessary approvals of Drawings, process sheets, test Documents etc. have been taken and all test reports have been prepared, which authenticates that the unit is functioning satisfactorily as per the Airworthiness requirement.

2 illus, 1 table, 6 ref

024643   Muraleedharan C V;Bhuvaneshwar G S (Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences & Tchnology, Thiruvananthapuram-695 012, Email: muralicv@sctimst.ac.in) : Titanium alloys in implant applications. Metals Mater Process 2006, 18(3-4), 441-50.

Use of natural and artificial materials for replacing and/or augmenting body functions is known for centuries. But it has become a regular practice during the last century to the extend that most of the structural elements, and many of the of the signalling/controlling elements of human body could be replaced with artificial ones now. This state could be achieved by the advancements in the knowledge of materials and their interaction with the biological systems, and the emergence of the field of biomaterials. Though many engineering materials can be found with physical properties matching the requirements of biological applications, owing to the stringent biocompatibility requirements, only very few material groups have been found successful in the area of implants. Titanium and some of its alloys is one such group, which is becoming increasingly popular owing to its excellent structural, tribological and biological properties.

3 illus, 2 tables, 13 ref

024642   Mukartihal G B;Radhakrishnan S;Ramasubba Reddy M;Ayyar S S K (Biomedical Engineering Div, Applied Mechanics Dep, IIT Madras, Chennai-600 036) : Design and development of visual evoked potentials recording system for diagnosis of optic nerve diseases. J Instrum Soc India 2006, 36(4), 227-34.

Deals with the design and development of a Visual Evoked Potentials (VEPs) recording system for the diagnosis of optic nerve diseases. In this system visual stimulator, electrodes, surge protection circuit, pre-amplifier, filter network, post amplifier, isolation circuit and A/D converter have been used as building blocks to acquire VEPs. After proper signal processing, the amplitude between the first positive peak P100 and the preceding negative trough N75 and the peak latency of the P100 components of the VEP signals are quantified for prognostic and therapeutic reasons. This aesthetically designed system has got many salient features such as low power consumption, compactness, low cost and ease of operation. The designed system is tested to validate its performance by recording VEP signals for the same group of adult subjects and results are in good agreement with that of the high cost clinical standard electrodiagnostic equipment. Therefore, this cost effectively designed compact system could be used for the diagnosis of optic nerve diseases without the loss of any accuracy.

4 illus, 1 table, 11 ref

024641   More N;Paul S N;Roy M (Mechanical Engineering Dep, Anjuman College of Engineering & Technology, Nagpur-440 001) : Erosive wear of Ti, Ti-6AI-4V, Ti-6AI-6V-2Sn and VT-9. Metals Mater Process 2006, 18(3-4), 397-410.

Tianium and its alloys find wide spread application in aircraft engine where solid particle erosion is an important material degradation mechanism. In view of this, the study is undertaken to evaluate and compare the erosion behaviour of Ti and its alloys at ambient temperature. Towards that purpose, commercially pure Ti and three of its alloys are investigated for two different impact velocities and two different impact angles. The results show that though the mechanical properties of all these alloys are quite different, the erosion rates of these alloys are nearly comparable. All these alloys exhibit ductile erosion signature in terms of dependence of erosion rate on impact angle and impact velocity and material removal mechanism.

14 illus, 8 tables, 31 ref

024640   Mohanty M K;Sorayan V P S (Center for Rural Develop Technol, Indian Inst of Technol, New Delhi-110 016, Email: mohanty_m@hotmail.com) : Biogas production and utilisation in rural India. J rur Technol 2006, 2(4), 150-5.

Biogas is one of the alternate technologies for development of rural India. The major considerations that are likely to weigh in favour of biogas in rural areas include availability of raw material/ feed (ie. cow dung, agriculture waste and kitchen waste) for generation of biogas which in term can used as cooking fuel, for operation of dual fuel engines for mechanical and electrical power and can provide manorial inputs to the soil through the use of digested slurry. The viability of gas production depends upon the environment in which the system operates. Therefore operational improvement must be conducted for optimum out put to be determined at beneficiary sites. Psychological and practical problems associate with handling of various inputs, lack of capital, using space for installing family size units may lead to non-adoption by villagers. To be effective operations and utilization, extension programs along with technical services are the solutions.

1 illus, 2 tables, 12 ref

024639   Mohandas T (Defence Mettallurgical Research Laboratory, , Kanchanbagh, Hyderabad-500 058) : Microstructure and mechanical property of titanium alloy welds. Metals Mater Process 2006, 18(3-4), 319-40.

Mechanical properties of titanium alloy welds are dictated by the microstructure. The microstructure of the welds is derived from solidification of the welds coupled with post solidification solid state phase transformations. Solidification related microstructure features are fusion zone grain size, micro porosity, elemental segregation, solidification cracking and the scale of solidification structure. The fusion zone grain size in welds without filler metal addition is controlled by the grain size in the parent metal due to epitaxial solidification. Elemental segregation that is common in heavily alloyed materials leads to inhomogeneous post solidification phase transformation. Alloy chemistry and welding process influence the microstructure development and in-turn the mechanical properties. Micro porosity leads to scatter in fatigue properties due to reduced crack initiation life. Alloys with intermediate beta stabilizer exhibit fine martensite microstructure that has low toughness due to its inability to plastically blunt the crack tip of an advancing crack. Low heat input welding processes like electron beam welding results in fine scale martensite due to high cooling rates and therefore exhibit low ductility and toughness. Post weld heat treatments that coarsen the intragranular microstructure lead to improved ductility and toughness. Solid state welding processes like friction welding result in fine beta grain size due to thermo-mechanical working during welding and coarser intragranular microstructure that is tough.

36 illus, 7 tables, 54 ref

024638   Manmadha Reddy M;Nikhil K;Sairam M;Sagar P K (NO, Sathyabama Institute of Science & Technology, Chennai-600 019) : Tensile properties of a β-titanium alloy for implant application. Metals Mater Process 2006, 18(3-4), 431-40.

There has been a spurt in use of titanium alloys for biomedical implant application since they are biocompatible and possess lower modulus of elasticity (MoE) with higher specific strength. Among the titanium alloys, focus has completely shifted to β titanium alloys, which possess lower MoE and are composed of non-toxic elements like Nb, Ta, Zr, and Mo compared to higher MoE α+β alloys which also posses toxic elements like V and Al. The alloy with a nominal composition of Ti-35Nb-7Zr-5Ta is among the latest β titanium alloys being pursued for implant applications. The tensile properties were studied for various heat treatment conditions and the heat treatment for bulk production has also been suggested. Higher values of tensile strengths were realized with lower MoE (55GPa) as reported in the literature. Work hardening studies show that this alloy possesses favorable characteristics for cold processing.

11 illus, 7 tables, 20 ref

024637   Mamta Kumari (NO, R.V.S. College of Engineering & Technology, Jamshedpur-831 012) : Numerical analysis of electromagnetic scattering from dielectric material. J Metall Mater Sci 2006, 48(2), 75-91.

Review of a hybrid finite-element method with the method of moment for two and three-dimensional electromagnetic scattering from inhomogeneous. arbitrarily shaped objects has been presented. The basic technique is to apply the equivalence principle and transform the original problem into interior and exterior problems, which are coupled on the exterior dielectric body surface through the continuities of the tangential electric field and magnetic field. The interior problem involving inhomogeneous medium is solved by the finite element method and exterior problem is solved by the method of moment. The coupling of the interior and exterior problems on their common surface result in a matrix equation for the equivalent current source. The surface of the object is approximated by triangles and the volume of the object is approximated by tetrahedron. The electrical parameters are assumed constant in each tetrahedron. The paper begins with a general description of the method. A number of two and three-dimensional applications are then given, including numerical computations which demonstrate the methods accuracy, efficiency and capability.

17 illus, 4 tables, 20 ref

024636   Mallela U K;Upadhyay A (Civil Engineering Dep, Indian Institute of Technology Roorkee, Roorkee-247 667) : Artificial neural network based prediction of buckling load of laminated composite panels. J Struct Engng 2007, 33(6), 515-21.

6 illus, 2 tables, 30 ref

024635   Madhavasarma P;Radhakrishnan T K;Sundaram S (Process Control Lab, Electronics & Instrumentation Engineering Dep, SASTRA Deemed Univ, Thanjavur-613 402) : Model based evaluation of a controller using pole placement technique for conductivity process. J Instrum Soc India 2006, 36(4), 246-56.

Developing a model for a conductivity based process has a recent importance. It has found extensive application in-chemical industry more so in effluent treatment plant and power plants. A system with varying transportation lag has been chosen for model generation and hence to select control parameters. Two percent sodium chloride solution has been sinusoidally injected in to the system and the response is observed using online Forbes Marshall conductivity analyzer. A first order plus dead time model is best suited for this process. The model parameters were found. The simulated frequency response for the identified model is been compared with experimental value controller performance were monitored using Mat lab simulation.

8 illus, 1 table, 10 ref

024634   Lolov D S;Lilkova Markova S V (Technical Mechanics Dep, Architecture Univ, 1046, Bulgaria, Sofia, Email: dlolov@yahoo.com) : Dynamic stability of a curved pipe bent in the arc of a circle on hinge supports at the ends. Sadhana 2006, 31(pt5), 537-41.

Curved pipes conveying fluids are investigated in the paper. Methods of numerical solution of the dynamic stability of a pipe in its plane are developed. An example of a curved pipe is solved by these methods. A non-dimensional parameter of flow velocity and a non-dimensional circular frequency are obtained.

3 ref

024633   Lohar K A;Sridevi T V;Viswanatha N;Kamalakar J A;Jain Y K (Laboratory for Electro-Optics Systems (LEOS), ISRO, Bangalore-560 058) : Opto mechanical design of fine analog sun sensor for space capsule recovery experiment project. J Spacecraft Technol 2007, 17(1), 26-33.

High accuracy sun sensor with an accuracy of ± 0.1 ° for a linear range of ± 10° is designed for spacecraft. This is realised by making suitable design changes in the mechanical housing and optics of the existing coarse analog sun sensor (CASS) which has an accuracy of ± 0.5° for linear range of ± 25°. The reliability of this sensor is the same as that of CASS, since the qualified processing electronics of CASS is used without any change.

12 illus, 2 tables, 3 ref

024632   Kurien S M;Thampuran A (Civil Engineering Dep, TKM College of Engineering, Kollam) : Quality certification for the housing industry-the Indian context. NICMAR J Constr Mgmt 2006, 21(3), 38-49.

Quality' has gained acceptance as a key factor that helps organizations to achieve success and competitive edge in the global market. Following the path set by manufacturing and service industries, Indian construction organizations also have started adopting different quality management philosophies and quality standards. Quality standards such as ISO 9001 are believed to be the milestones in the journey to TQM. This study attempts to offer an intensive and yet simple instrument for scientifically examining how concepts and practices involved in quality management can be structured into a systematic framework for understanding the critical factors of quality management in housing construction industry, and to understand the inter-relationships among its constructs. Relationship between TQM practices and operational performance in housing industry has also been studied. This research work attempts to add to the 'not-so-rich' literature available on quality management issues in housing development in general, and with respect to the emerging housing development countries (mostly belonging to developing economies in Asia) in particular. Such studies in different cultural and economic background could help the researchers to further understand the intricacies and relevance of the various aspects of quality management in housing industry. The findings can be treated as an indication of the suitability of TQM philosophy as a strategic measure to achieve success and competitive advantage in construction industry.

3 tables, ref

024631   Kumar R;Sivashanmugam P;Palani S;Konnur M S (Instrumentation and Control Engineering Dep, , Tiruchirappali-620 015) : Recurrent neuro computing approach for the flow sensorless measurement and control. J Instrum Soc India 2006, 36(4), 267-75.

Flow measurement and control through a pipe requires three devices namely a meter, control valve and a controller. This conventional flow control loop causes pressure drop in the flow measurement which in turn leads to usage of more energy for pumping the fluid. To overcome this difficulty the valve itself is used as a flow meter apart from acting as a control valve. A relationship developed between the differential pressure produced by the control valve and flow through it helps to measure and control the flow rate. For this approach, it is necessary to use a computer or a processor based-system . The results obtained in this method is less accurate as the mathematical expression used for computing the flow rate is non -linear in nature. An alternative approach for determining the flow rate without flow meters is suggested to capture the characteristics of the flow control valve using Neural Network model (NNM). In this paper a novel method is suggested to measure flow rate in which the restriction characteristics of the control valve and Recurrent Neural Network (RNN) Model is embedded in ARM 9 processor. The viability of the methodology proposed is illustrated by the real flow measurements.

6 illus, 2 tables, 10 ref

024630   Kasthuri P K;Arulanantham A;Natesan M (Chemistry Dep, Govt. College of Technology, Coimbatore) : Effect of Acalypha indica extract as corrosion inhibitor on the mild steel in 1m sulphuric acid. J Metall Mater Sci 2006, 48(2), 109-16.

Influence of acid extract of Acalypha indica on the corrosion of mild steel in 1M H₂SO₄ has been studied by weight loss method. It is found that the plant extract shows better inhibition action in 1M H₂SO₄. The Inhibition efficiency increases with the inhibitor concentration and immersion time. The effect of temperature on the corrosion behaviour of mild steel inlM H₂S0₄ with and without inhibitor was studied in the temperature range from 298K to 343K. Thermodynamic parameters like activation energy (Ea), free energy of adsorption (ΔGads) Enthalpy of adsorption (AH) and Entropy of Adsorption (AS) were calculated. The adsorption of the inhibitor on the metal surface obeys the Langmuir adsorption isotherm. The inhibition action of the plant extract may be due to the presence of phytochemical constituents like Aclyphine and Aclyphamide.

4 illus, 3 tables, 2 ref

024629   Karthikeyan T;Mythili R;Saroja S; Vijayalakshmi M (Physical Metallurgy Section, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Email: saroja@igcar.gov.in) : Development of Ti-5T a-1.8Nb - a new alloy for structural applications in highly oxidizing media. Metals Mater Process 2006, 18(3-4), 269-82.

Overview of the extensive research activities at IGCAR to develop a Ti-5Ta-1.8Nb alloy as candidate material for structural applications, in view of its excellent resistance to three phase corrosion in highly oxidizing media has been presented. The experimental program consisted of four main components with an objective to generate a complete data base for this alloy with respect to its fabrication and process flowchart, design of optimum microstructure, weldability, structure property correlations and basic studies on the nature of phase transformation and texture developed in the alloy. The R & D efforts towards developing this alloy as an alternative to the presently used commercial grades of Ti and steel are briefly described. The alloy was classified as α+β; β transus and Ms temperature were determined using a combination of physical metallurgy, experimental and computational tools; the safe operating window for Thermo-mechanical processing was identified. Corrosion control through microstructure design has been successfully achieved. The weldability of this developmental alloy has been demonstrated for the first time and the Procedure Qualification Record (PQR) and Welding Procedure Specification (WPS) established. The microstructural variations in the weldment have been understood based on differences in phase transformation mechanisms as dictated by thermal cycles. The Temperature-Time profile, cooling rate and thermal gradients as a function of position and temperature have been simulated by applying the Rosenthal steady state solution to the weldment. This alloy exhibited interesting texturing behavior during deformation and subsequent β →α+β transformation, which has been studied using XRD and Electron Back Scatter Diffraction techniques. The dependence of transformation texture on the mode of deformation was elucidated for this alloy. The extensive R & D efforts resulted in a complete understanding of the metallurgy of the alloy and attempts are in progress to scale up its fabrication into various geometrical shapes as a future structural material.

12 illus, 1 table, 24 ref

024628   Kahraman S;Saatci A;Misir S (Civil Engineering Dep, Faculty of Engineering, Dokuz Eylul Univ, Izmir, Turkiye, Email: serap.kahraman@deu.edu.tr) : Effects of adding illegal storeys to structural systems. Sadhana 2006, 31(pt5), 515-26.

Earthquake in Turkey are frequently occurring disasters, causing much loss of life and property. It is tragic indeed that earthquakes should share the agenda with amnesty laws for illegal buildings. Illegal buildings are those constructed without authorization, legal bureaucratic sanction and, in most cases, without normal engineering control and checks. Buildings may become illegal for a variety of reasons. The very prospect of a waiver bill for illegal buildings spurs further illegal construction. The status of illegal buildings may legally change in time. What is an illegal building today may well be legal tomorrow under these circumstances. Deals with two different kinds of building: one is the framed building and the other has shear-wall frame. The capacity ratios, storey drifts and natural periods for the legally approved buildings and the effects of illegal or legal additional floors on these values are compared. It is determined that these buildings with illegal storeys should be strengtnened and retrofitted by providing cast in-situ reinforced concrete shear walls.

7 illus, 12 tables, 11 ref

024627   Johnson D (NO, , ) : The need to fully mechanise the underground coal industry in India. J Mines Metals Fuels 2006, 54(8-9), 164-8.

Looks at the current production and productivity levels of the major global underground coal producing countries and trends in mining methods for the future. The present position of the Indian underground cool industry is considered and benchmarked against other major global producers. Actions are suggested, that need to be taken by the Indian industry, if it is to be successful the Indian coal industry is in stepping up to the challenge.

3 illus, 6 ref

024626   Jeyanthi J;Saseetharan M K;Priya V S (Civil Engineering, Govt. College of Technology, Coimbatore-13) : Modelling of secondary clarifier using regression analysis and artificial neural networks. J envir Sci Engng 2006, 48(1), 1-8.

Mathematical models for the surface area of secondary clarifier were developed for wastewater generated from a dairy industry and from domestic sources, by correlating the parameters namely, surface area per unit flow rate (A/Q), influent concentration (C_o), underflow concentration (C_U), recycling ratio (r) and Mean Cell Residence Time (θ_C) using multiple regression analysis. There was found a good correlation between the measured data and the model results with regression coefficients of 0.9. Thickener area requirement of combined wastewater was comparehat obtained for dairy wastewater. Thickener area was found to decrease with increase in Mean Cell Residence Time and the area required for treating the combined wastewater was less, when compared with the requirement for dairy wastewater treatment. Neural network was trained with experimental data to 'acquire' knowledge about it. The Back Propagation Network technique was used in which the error was back propagated through the network. The results evolved from the neural network training were compared with the results of regression model and experimental data. Greater deviation was observed between the observed and predicted values of A/Q at high underflow concentrations, indicating that the limiting solids flux was reached. The output from Neural Network approach had greater consistency with the experimental data than the output from conventional regression analysis. Hence, Artificial Neural Network technique is highly adaptive and efficient in investigating input - output relationships.

3 illus, 5 tables, 8 ref

024625   Jaiswal S;Suresh Kumar H N;Viswanatha N; Nataraju B S (Spacecraft Mechanisms Group, ISRO Satellite Centre, Bangalore-560 017) : Latch-up shock analysis of reflector deployment considering flexibility of mechanism. J Spacecraft Technol 2007, 17(1), 55-9.

Considers the flexibility of the brackets of the deployment mechanism. Transient dynamic analysis has been carried out to determine the latch-up shock moments, modeling the system as an initial velocity problem. The latch up velocity obtained from the deployment dynamics is taken as the initial condition. The addition of brackets makes the system more flexible and thus a reduction in values of root moment has been observed in comparison with the earlier model where the brackets were assumed to be rigid. The values have been observed to be well within the corresponding specifications thus providing a useful design feedback with regard to the margins available for root shock moment. Provides details of these activities along with the results of analysis.

9 illus, 2 tables, 4 ref