019746   Jena P K;Siva Kumar K;Balakrishna Bhat T (NO, Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad-500 058, Email: pradipta_rrib@rediffmail.com) : Effect of heat treatment on mechanical and ballistic properties of ultrahigh strength DMR-1700 steel. Metals Mater Process 2007, 19(1-4), 339-46.

Effect of heat treatment on the mechanical and ballistic properties of DMR-1700 steel is presented. The steel was austenatised at 875°C, 900°C and 925°C followed by oil quenching. It was then tempered at various temperatures ranging from 150-600°C. Tensile strength, impact strength, hardness and microstructure were evaluated. The 900°C austenatisation followed by tempering gives a better combination of strength and toughness properties than the other two-austenatisation temperatures. The ballistic behavior was evaluated using non-deformable projectiles at 840 m/s at normal angle of attack. Ballistic performance measured in terms of the depth of penetration indicates that 900°C austenatisation followed by 250°C tempering shows the best results.

12 illus, 4 ref

019745   Ish Rishabh;Rakshit S (NO, Centre for Artificial Intelligence & Robotics, Bangalore-560 093) : Object hierarchy-based supervised characterisation of synthetic aperture radar sensor images. Def Sci J 2008, 58(1), 159- 67.

A method of supervised characterisation of synthetic aperture radar (SAR) satellite images has been discussed in which simple object shape features of satellite images have been used to classify and describe the terrain types. This scheme is based on a multilevel approach in which objects of interest are first segmented out from the image and subsequently characterised based on their shape features. Once all objects have been characterised, the entire image can be characterised. Emphasis has been laid on the hierarchical information extraction from the image which enables greater flexibility in characterising the image and is not restricted to mere classification. The paper also describes a method for giving relative importance among features, i.e., to give more weights to those features that are better than others in distinguishing between competing classes. A method of comparing two SAR sensor images based on terrain elements present in the images has also been described here.

13 illus, 4 tables, 5 ref

019744   Gupta S K;Saxena S;Singhal A;Ghosh A K (NO, Indian Institute of Technology, Kanpur-208 016) : Trajectory correction flight control system using pulsejet on an artillery rocket. Def Sci J 2008, 58(1), 15-33.

A trajectory correction flight control system is small and durable, and consists of a lateral pulsejet ring mounted on the rocket body. The pulsejet ring consists of a finite number of individual pulsejets. Each pulsejet on the ring imparts a single, short-duration, large force to the rocket in the plane normal to the rocket axis of symmetry. Lateral pulsejets are used by flight control system to assist the rocket to follow a pre-specified (command) trajectory. The trajectory-tracking flight control system computes the position error by comparing the measured position of the rocket with the pre-specified trajectory. In actual application, the position of the rocket could be measured using in-house inertial measurement unit (IMU) or by ground-based-tracking radar system located at the firing site. A study has been undertaken to explore the feasibility of reducing the impact point dispersion of a routinely-used artillery rocket using lateral pulsejets coupled to a trajectory correction flight control system. Simulation studies have been conducted to arrive at tuning parameters, namely the tracking error window size, the required elapsed time between the pulsejet firings and the angle of tolerance between the tracking error and the individual pulsejet force. Further, the robustness of the methodology wrt measurement noise has also been evaluated.

12 illus, 15 ref

019743   Gupta P K;Gupta N K;Sekhon G S (India, Institute of Technology, Rookee-247 667) : Finite element analysis of collapse of metallic tubes. Def Sci J 2008, 58(1), 34-45.

Quasi-static axial and lateral compression tests were conducted on aluminium tubes of circular, rectangular, and square cross sections on a universal testing machine (Instron model 1197). During the compression process, different tubes were collapsed in different modes of collapse. These compression processes were also modelled using FORGE2 finite element code. The code has the capabilities of automatic mesh generation, modelling of die, creation of material data file, carrying out the finite element computations, and post-processing of results. The deforming tube material was modelled as rigid-visco-plastic. Development of different modes of collapse was investigated experimentally and computationally. The experimental load-compression curves and deformed shapes are compared with the computed results and found in good agreement. It is found that the proposed finite element models of the different compression processes are capable of predicting the modes of collapse.

7 illus, 1 tables, 30 ref

019742   Gokhale A A;Sahu S N;Kulkarni V K W R; Sudhakar B;Anand Rao A;Ramachandra Rao N;Ramamurty U (NO, Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad-500 058, Email: amol@dmrl.ernet.in) : Aluminium foam through liquid metallurgy: processing and properties. Metals Mater Process 2007, 19(1-4), 181-8.

Closed cell aluminium foams were made by liquid metallurgy route for light structural and energy management applications. Foam soundness, cell structure and mechanical properties were characterised. Localised large cavities, imperfections in cell walls and missing cell walls were some of the morphological defects found in the developmental lots, but could be reduced with improved process control. The cell wall thickness and foam density increased gradually towards the bottom of the foam ingots, both being related to liquid drainage. At a given height in the foam ingot, cell size increased towards the centre, possibly because of coarsening in the slow cooled central region. Mechanical properties such as plastic strength, energy absorption and elastic modulus were evaluated in compression tests. Preliminary results indicate that plastic strength and energy absorption increased with increasing density and strain rate. Foams were found amenable to cutting by most conventional methods. Among band saw cutting, Electric Discharge Sawing (EDS) and Wire Cut Electric Discharge Machining (EDM), the latter gave the smoothest surface finish.

9 illus, 1 table, 15 Ref

019741   Deshmukh S K;Anekar S V;Rao C R (Chemical Engineering Dep, Jawaharlal Darda Institute of Engineering and Technology, M.I.D.C., Lohara Yavatmal-445 001) : Application of artificial neutral network (ANN) for modeling of adsorption system-dyes removal from aqueous solution by using coconut shell as adsorbent. Pollut Res 2007, 26(3), 369-76.

Artificial Neutral Networks are applied to the experimental data pertaining to adsorption batch studies to develop and validate a model that can predict the Pollutant Removal Efficiency (PRE). The functional relation between the PRE as an output and the factors such as material of adsorbent, pollutant (adsorbate), pH, equilibrium and contact times, initial concentration of adsorbate, and adsorbent dosage as input are studied. These six factors are identified as input parameters and the network is systematically trained. Multi Layer Error Back-Propagation Network (BPN) is used with two hidden layers. The BPN model is systematically trained with 70 data points and is validated with 10 data points from the database. Three different combinations of learning parameters for number of neurons in hidden layer, learning rate, and error tolerance are attempted. Average root mean square error based on the test data is calculated to validate the accuracy of the output.

8 illus, 10 tables, 19 ref

019740   Dattaguru B;Muthukumar R (NO, Indian Institute of Science, Bangalore-560 012) : Behaviour of Bi-material interface cracks in the presence of material nonlinearity of adherends. Def Sci J 2008, 58(2), 295-303.

The well known features of crack face interpenetration/contact at the tip of an interface crack is re-examined using finite element analysis and assuming material nonlinear properties for the adherends. It was assumed in literature that the crack tips are fully open at all load levels in the presence of material nonlinearity of the adherends. Analysis for the case of remote tension shows that even in the presence of material nonlinearity, crack tip closes at small load levels and opens above a certain load level. Mixed-mode fracture parameters are evaluated for the situation when the crack tips are fully open. Due to the presence of nonlinearity, the mixed-mode fracture parameters are measured with the symmetric and anti-symmetric components of J-integral. The present analysis explains the sequence of events at the interface crack tip with progressively increasing remote tension load for the case of adherends with material nonlinear behaviour.

17 illus, 11 ref

019739   Das N;Singh S;Hazari N;Chaterjee D;Praveen V V N S C (NO, Defence Metallurgical Research Laboratory, Hyderabad-500 058, Email: ndasdmrlh@yahoo.com) : Indigenous cast superalloys and investment casting technology fro gas turbine components. Metals Mater Process 2007, 19(1-4), 189-202.

Performance of turbojet engines depends largely on high temperature capability of turbine blades, and the nozzle guide vanes, which direct the hot gas at optimum angle towards the rotating blades. The most reliable and affordable blade and vane materials so far have been the Ni-based super alloys offering the highest turbine entry temperature (TET). This paper describes the progress made in the area of gas turbine aerofoil castings and advanced cast Ni-based super alloys development at Defence Metallurgical Research Laboratory, Hyderabad. DMRL has developed the expertise of invest molding and vacuum casting for a variety of thin walled aerofoil castings designed for advanced aero-engines having intricate cooling channels and favorable <001> growth texture in single crystal or columnar-grain form. Significant improvement in shell mold quality could be realized to avoid mold cracking, hot tear, upper-cast porosity and aerofoil distortion. Several engine sets of such castings have been supplied to GTRE, Bangalore after qualifying through rigorous airworthiness type certification exercise. A novel technique has been developed to realize integral rotor castings with columnar-grained blades and fine-grained hub in a single casting step. This combination of better creep resistant columnar-grained blades with fatigue resistant fine grains in hub promises enhanced engine performance and life. DMRL has developed its own third generation polycrystalline super alloy DMD4 and the single crystal alloy DMS4, which offer more than 100°C metal temperature advantages over the current turbine aerofoil material being imported for the GTRE aero-engine under development. The alloy DMD4 designed for columnar-grained turbine blades and vanes has properties and performance comparable to those of second-generation single crystal alloys at a much lower component production cost than that of single crystal castings.

10 illus, 1 table, 27 ref

019738   Damse R S;Singh A (NO, High Energy Materials Research Laboratory, Pune-411 021) : Evaluation of energetic plasticisers for solid gun propellant. Def Sci J 2008, 58(1), 86-93.

This paper reports the evaluation of four different energetic plasticisers, viz., glycidyl azide polymer (GAP, MW = 390), l,5-diazido-3-nitrazapentane (DANPE), ethylene-glycol-bis-azido-acetate (EGBAA) and N-n-buty-N-(2 nitroxyethyl) nitramine (n-Bu-NENA) separately into high energy gun propellant containing 28 per cent NC (13.1 N %), 65 percent RDX, 6 per cent di-octyl-phthahate (DOP) and 1 per cent carbamite. Four different propellant compositions based on the energetic plasticiser have been formulated separately with the replacement of non-energetic plasticiser, DOP. The propellants were processed by standard solvent method and evaluated experimentally along with the control composition to determine the ballistic parameters, cal-val, sensitivity, thermal characterisation, thermal stability and mechanical properties. The performance of the propellants containing the energetic plasticiser has been compared with that of the control composition containing the non-energetic plasticiser, DOP so as to assess the suitability of the energetic plasticiser for the futuristic gun propellant formulations. It has been found out that n-Bu-NENA is the superior plasticiser among the four energetic plasticisers evaluated in this study.

8 tables, 24 ref

019737   Chen T C;Liu C C (Chung Cheng Institute of Technology, National Defense Univ, Tao Yuan, Taiwan-335 09, R.O.C.) : Inverse estimation of time varied heat flux and temperature on 2-D gun barrel using input estimation method with finite-element scheme. Def Sci J 2008, 58(1), 57-76.

When a gun fires, a large amount of heat flux is triggered by the propellant gas acting on the gun barrel inner wall, leading to the rise of temperature, which will cause serious destruction. In this paper, an inverse method based on the input-estimation method including the finite inverse heat conduction problem (IHCP) element scheme to inverse estimate the unknown heat flux on the 2-D gun barrel has been presented. The use of the online accuracy to inversely estimate the unknown heat flux on the chamber has been made using 7.62 mm gun barrel outer wall temperature measurement data. Using simulation uniform and non-uniform heat flux q(z,t) cases involves a gun barrel inner wall that varies with time t and the axial z-location with convection situation in the outer surface. Computational results show that the proposed method exhibits a good estimation performance and highly facilitates practical implementation.

14 illus, 1 table, 22 ref

019736   Bhuvaneswari C M;Kakade S D;Deuskar V D;Dange A B;Gupta M (NO, High Energy Materials Research Laboratory, Pune-411 021) : Filled ethylene-propylene diene terpolymer elastomer as thermal insulator for case-bonded soild rocket motors. Def Sci J 2008, 58(1), 94-102.

Ethylene-propylenc diene terpolymer (EPDM)-based insulation system is being globally used for case-bonded solid rocket motors. A study was undertaken using EPDM as base polymer, blended with hypalon and liquid EPDM and filled with fibrous and non-fibrous fillers. These formulations were evaluated as rocket motor insulation system. The basic objective of the study was to develop an insulation system based on EPDM for case-bonded applications. A series of rocket motor insulator compositions based on EPDM, filled with particulate and fibrous fillers like precipitated silica, fumed silica, aramid, and carbon fibres have been studied for mechanical, rheological, thermal, and interface properties. Compositions based on particulate fillers were optimised for the filler content. Comparatively, fumed silica was found to be superior as filler in terms of mechanical and interface properties. Addition of fibrous filler (5 parts) improved the peel strength, and reduced the thermal conductivity and erosion rate. All the compositions were evaluated for sulphur and peroxide curing. Superior mechanical properties were achieved for sulphur-cured products, whereas peroxide-cured products exhibited an excellent ageing resistance. Rocket motors were insulated with optimised composition and propellant cast, and the motors were evaluated by conducting static test in end-burning mode.

2 illus, 6 tables, 18 ref

019735   Bharathi Y H;Rekha B R;Bhaskar P;Parvathi C S;Kulkarni A B (NO, Gulbarga Univ, Gulbarga-585 106) : Multi-input fuzzy logic controller for brushless DC motor drives. Def Sci J 2008, 58(1), 147-58.

The brushless dc motors are used in various applications such as defence, industries, robotics, etc. In these applications, the motor should be precisely controlled to give the desired performance. The proposed controller systems consist of multi-input fuzzy (two-and three-input) logic controller (FLC) and multi-input integrated fuzzy logic controller (IFLC) for the speed control of brushless dc servomotor drive. The input for the controllers are error e(k), change in error [first derivative of error ce(k)] and change of change in error [second derivative of error cce(k)] with a single-output. The error cce(k) is substantial at the overshoots/undershoots and is therefore essential for accurate speed control of brushless dc motor. The error cce(k) has been introduced for the first time in the literature as one of the input in the FLC and IFLC design. The IFLC is designed using FLC and proportional derivation integral (PID) controllers. The controller systems have been studied systematically for the transient and steady-state conditions. The three-input IFLC is found to be superior, more robust, faster, flexible, and is insensitive to the parameter variations as compared with the FLC (with two-and three-input) and conventional two-input IFLC.

8 illus, 22 ref

019734   Bhanu Prasad V V;Somara K;Subrahmanyam J (NO, Defence Metallurgical Research Laboraotry, Kanchanbagh, Hyderabad-500 058, Email: bhanu@dmrl.ernet.in) : Powder metallurgy processing of Aluminium matrix composites with very high volume fraction of silicon carbide reinforcement. Metals Mater Process 2007, 19(1-4), 27-39.

Aluminium Metal Matrix Composites containing very high volume fractions of Silicon carbide have a unique set of properties that are ideally suited for the thermal management applications of electronic industry. The matching coefficient of thermal expansion (CTE) value of Al/60-70% SiC with that of the Ga As and Si devices make them potential material for these applications. Conventionally these packages are made by melt infiltration technique. In the present study, powder metallurgical route using Vacuum Hot Pressing (VHP) technique is employed to synthesize high volume fraction composites (2124 Al/70 % SiCp.). Size(36#, 220# and 600#) and proportion of the reinforcement particles were varied to make different MMCs like mono-modal, bi-modal and tri-modal composites. These composites were studied for their mechanical and physical properties like density, flexural strength etc. Structure property correlation has been drawn among these composites. Necessity of higher processing temperatures for finer reinforced composites, achievement of higher densification in multi modal composites over mono-modal composites and lowered and matching CTE are some of the salient observations of the present study.

7 illus, 6 tables, 13 ref

019733   Baligidad R G (NO, Defence Metallurgical Research Laboratory, Kanchanbagh, P.O. Hyderabad-500 058, Email: rbaligbad@yahoo.com) : Processing of iron aluminides by ingot metallurgy route. Metals Mater Process 2007, 19(1-4), 55-67.

Melting procedure for air induction melting (AIM) of Fe-AI-C based intermetallic alloys (containing 7 to 23 wt.% Al, 0.01 to 1.0 wt.% C and 0.02 to 4.0 wt.% alloying elements such as Mo, W, Cu, Cr, Si, Ni, Mn, Nb, Ti, Zr, Ce and B) is described. Air induction melting resulted in the formation of hydrogen gas porosity in cast AIM ingots. Use of flux cover and proprietary charging schedule during air induction melting resulted in elimination of hydrogen gas porosity. Refining by flux-metal reactions results in significant reduction in impurity (S, O, N) levels during air induction melting with flux cover (AIMFC). Criteria for flux selection and flux to metal ratio are discussed. Processing of AIMFC ingots through electrosiag remelting (ESR) has further improved the ductility and hot-workability. Excellent recovery of alloying elements has been achieved by both AIMFC and ESR. Proper selection and control of process parameter during electrosiag remelting of even highly porous AIM ingots resulted in clean, sound, homogenous and defect free ingots. Possible mechanisms for the elimination of hydrogen gas porosity during ESR have been discussed. The cast ESR ingots exhibit a marked susceptibility to cracking at high power inputs. The optimum power level for the alloys was found to be significantly lower than that of steels. The Fe-AI-C based intermetailic alloy ingots with low carbon content produced with combination of AIM/AIMFC and ESR exhibits microcracks. These micro cracks led to cracking of the ingots during fabrication of test samples by cutting and turning as well as during hot-forging, it is argued that the presence of carbon may be necessary to get AIM/AIMFC plus ESR castings with desirable mechanical properties. The process route and composition developed in the present work allows the use of inexpensive source of iron (such as steel scrap) and commercial aluminium for bulk production of Fe-AI-C based intermetallic alloys.

14 illus, 3 tables, 25 ref

019732   Balachandran G;Raghavendra Rao D;Bhushan Goud E;Venkateshwara Rao D;Mukhopadhyay A (NO, Defence Metallurgical Research Laboratory, P.O. Kanchanbagh, Hyderabad-500 058, Email: gbala@dmrl.ernet.in) : Development of hydrogen storage materials at DMRL. Metals Mater Process 2007, 19(1-4), 153-70.

Hydrogen storage is an emerging area of technology that is being promoted for exploitation in an era, where fossil fuel utility is becoming increasingly difficult. Presently, technologies concerned with the economic means of generation of hydrogen, efficient means of hydrogen storage and application of hydrogen based devices, are being intently pursued. Over the past few years, the focus at DMRL has been centered on development of materials for hydrogen storage. Apart from the traditional high pressure gas cylinders that stores gaseous hydrogen, there are metal and alloys that stores hydrogen as metal hydrides, complex chemical compounds such as sodium alanates [NaAlH₄], caged zeolites and isoreticular metal organic frame works that trap hydrogen gas, Carbon nano fibers and carbon nano tubes that stores H₂ by adsorption etc. Among these, metal hydride based technologies were chosen. Metal hydrides have good volumetric storage capacity but poor gravimetric storage capacity. These metal hydride alloys have potential applications such as in Ni-MH batteries, hydrogen storage containers, heat pumps, refrigeration and air conditioning systems, solar and industrial waste heat recovery units, H-isotope separation units, chemical catalysts, mechanical actuation systems etc. In India, the technologies pertaining to large scale exploitation of the metal hydride alloys were hampered by the fact that there were no large scale producers of such materials. Hence, the focus was on developing technologies to make alloys in significant batch sizes. In addition, the development was aimed at two important application of metal hydrides namely Ni-MH batteries and hydride based storage containers. Rare earth based AB₅ intermetallics were successfully developed and supplied to meet Ni-MH battery application. A metal hydride based hydrogen storage container (20L H₂ at STP) was successfully developed and 200 units have already been supplied to end user. Based on the expertise gained, several other prototype containers based on AB₅, AB₂ and AB intermetallics are being developed. The containers have designed output capacity ranging from 20L to as large as 750L H₂ gas at STP. The technical aspects concerned with the alloy and container development are presented.

9 illus, 8 tables, 21 ref

019731   Baig M A H;Pradyumna R (NO, Defence Metallurgical Research Laboratory, Hyderabad-200 058, Email: r_pradyumna@hotmail.co) : Die technology for investment casting of aerospace turbine blades and vanes. Metals Mater Process 2007, 19(1-4), 241-52.

Design and development of an injection molding wax pattern die is the first critical step in establishing investment casting process. Advanced CAD/CAM techniques are used for developing a process warpage/shrinkage- compensated three dimensional CAD model of the blade/vane component, which is split along parting lines keeping feature reproducibility and extraction of pattern in mind. Various CAD models of die inserts are developed based on the finalized die configuration and machining programs are generated on CAD/CAM systems and processed on 3-axis CNC milling machines. Each and every die insert thus machined is inspected using 3D Coordinate Measuring Machines (CMM ) and matched against its CAD model and re-machined/polished. Die assembly is the final critical step, wherein all the die parts are assembled to a common reference and qualified through CMM inspection. The die must also incorporate ceramic core locating and locking features in order to get a hollow casting, maintaining wall thicknesses of the order of 0.5 mm on either side of the pattern. Design and development of wax pattern dies is a well established process in DMRL, where in highly complicated dies for a variety of components have been successfully developed and proved. Based on this expertise of over a decade, DMRL has forayed into development of ceramic core dies in recent times. Ceramic core dies present an entirely different set of challenges for die technologist, which include machining of hardened blocks of 55-60 HRc, development of a series of EDM electrodes and control of spark erosion machine parameters, superior surface finish requirements, reproduction of fine features & fillets of casting internal geometry of the order of 0.25-0.50 mm, etc. DMRL has successfully developed dies for highly twisted and thin aerofoil ceramic cores and is in an advanced stage of establishing this crucial technology. The present paper deals in depth the path traversed by DMRL in establishing die technology of wax pattern as well as ceramic core components.

12 illus, 6 ref

019730   Appa Rao G;Balasubramaniam S;Satyanarayana D V V (NO, Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad-500 058) : Microstructure and mechanical behaviour of hot isostatically pressed materials for aerospace applcations. Metals Mater Process 2007, 19(1-4), 321-38.

Inert gas atomized (IGA) AISI-304 grade austenitic stainless steel and chemistry modified (by addition of 0.4% Hf and 0.3% Nb) low carbon (LC) astroloy (Ni-base superalloy) powders were consolidated by hot isostatic pressing at optimized temperature within the range of 1100-1200°C under a pressure between 100-130 MPa for an optimized sustaining time of 3 hours. The density of the as-HIPed steel and superalloy compacts was found to be nearly the same as their respective theoretical density values. Optical microscopic investigations of the HIPed steel have revealed a highly homogeneous and fine grained microstructure with annealing twin bands and is completely free from undesirable features such as prior particle boundary (PPB) networks. Yield strength (YS), ultimate tensile strength (UTS) and the ductility of the as-HIPed steel were much higher than those specified for conventionally processed wrought 304 stainless steel. Impact strength and fracture toughness (Kic) values of the HIPed steel were superior to those of the wrought material. Based on these properties, the P/M (HIPed) steel could be recommended for the development of critical components for aerospace applications. Metallographic studies of as-HIPed and HIP + heat treated L.C. astroloy have also shown a homogenous and fine grained microstructure as in the case of stainless steel but contained the PPB networks decorated with metallic oxy-carbides (MOCs). This has been attributed to the higher impurity levels, particularly the oxygen content (~ 200 ppm) in the inert gas atomized superalloy powder. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies have shown the presence of gamma prime (⊥) [Ni₃ (Al, Ti)] precipitates with cuboidal and spherical morphology in the matrix. YS and UTS values of HIP + heat treated superalloy were found to be comparable to those of the wrought heat treated material, but the ductility and stress rupture properties were much lower than their wrought counterparts, due to the high concentration of PPBs leading to grain boundary embrittlement and intergranular mode of fracture. This has become the limiting factor for the HIPed L.C. astroloy (modified) for using the near net shaped components for long term applications involving high temperature and stress levels. In order to overcome this problem, superalloy EP741NP powder produced by plasma rotating electrode process (PREP) with low oxygen content of 60 ppm was consolidated by HIPing. The PREP + HIPed alloy was found to be free from PPBs, thermally induced porosity and ceramic inclusions. As a result, the alloy has shown a good strength and consistent ductility values at room temperature and at 650°C. The stress rupture roperties of the as-HIPed material at 650°C and at stress level of 980 MPa were found to be comparable to that of the vendors data on HIPed and heat treated material. High strength combined with good dictility and stress rupture properties obtained in the as HIPed EP741NP alloy suggest that the PREP powders could be utilized for exploring the near net shape advantage of HIP technology to its maximum potential for aerospace applications.

14 illus, 10 tables, 35 ref

019729   Anoop Kumar;Gupta S K;Kale S R (Mechanical Engineering Dep, NIT, Hamirpur, Email: jas_anoop@yahoo.co.in) : Effects of drop acceleration and deceleration on particle capture in a cross-flow gravity tower at intermediate drop Reynolds numbers. J envir Sci Engng 2007, 49(2), 157-63.

Cross-flow gravity towers are particle scrubbing devices in which water is sprayed from the top into particle-laden flow moving horizontally. Models for predicting particle capture assume drops traveling at terminal velocity and potential flow (Re_D <62> 1000) around it, however, Reynolds numbers in the intermediate range of 1 to 1000 are common in gravity towers. Drops are usually injected at velocities greater than their terminal velocities (as in nozzles) or from near rest (perforated tray) and they accelerate/decelerate to their terminal velocity in the tower. Also, the effects of intermediate drop Reynolds number on capture efficiency have been simulated for (a) drops at their terminal velocity and (b) drops accelerating/decelerating to their terminal velocity. Tower efficiency based on potential flow about the drop is 40% - 50% greater than for 200 mm drops traveling at their terminal velocity. The corresponding values for 500 mm drops are about 10% - 20%. The drop injection velocity is important operating parameter. Increase in tower efficiency by about 40% for particles smaller than 5 mm is observed for increase in injection velocity from 0 to 20 m/s for 200 and 500 mm drops.

7 illus, 13 ref

018612   Venkat Reddi R;Reddy G C M;Reddy T A J (Mechanical Engg Dep, SRTIST, Nalgonda) : Recent enhances to increase the productivity in machining of welded drill pipes. Mfg Technol Today 2007, 6(9), 21-5.

Recent development for increasing the productivity in machining of φ5"- welded low-carbon low-alloy steel drill pipes. Different mechanisms have been used for machining of the welded drill pipes earlier giving moderate results. The shearing method associate with friction welding operation that has been developed and implemented in one of the local industries is presented in this paper. The newly developed method gives the high volume of production at minimum cost within the stipulated final parameters of welded pipes.

12 illus, 5 tables, 8 ref

018611   Usha Rani M;Subramanian K (Civil Engineering Dep, V.L.B. Janakiammal College of Engineering and Technology, Kovaipudur, Coimbatore-641 642) : Utilization of fly ash and bagasse ash as the ecofriendly building materials. Nat Envir Pollut Technol 2007, 6(4), 557-64.

Greatest challenge for construction industry in the present times is realization of projects aimed at infrastructure development in harmony with the sustainable development concept. Sustainable development means, judicious use of natural resources for various construction activities. The construction industry, due to its huge size to meet the growing needs of construction activities, is the largest consumer of natural resources such as aggregates, cement (made from lime available naturally) and water etc. To achieve sustainable development in construction sector, it is necessary to replace some of these materials with the alternative materials, which are basically by-products/or waste materials from industries, such as fly ash, granulated slag, silica fume, and their disposal is an environmental threat. These alternative materials not only benefit the environment but also add value to, in the form of enhancement of performance characteristics by judicious selection and proportioning and use. In the study fly ash (FA) and bagasse ash (BA), obtained from fired at controlled conditions, are admixed with Portland cement at different replacement levels. The properties of concrete investigated include compressive strength, splitting tensile strength, modulus of elasticity, modulus of rupture and resistance to chloride ion penetration. Optimum percentage of FA and BA for strength development along with other results are discussed in detail.

9 illus, 5 tables, 8 ref

018610   Tiwari R K;Sethi P K (Donimalai Iron Ore Mine, National mineral Development Corporation Ltd., Post: Donimalia Township-583 118, Email: dr_pksethi@rediffmail.com) : Donimalai iron ore mine - a model mine in the Bellary-hospet sector. J Mines Metals Fuels 2007, 55(8), 227-30.

3 ref

018609   Telsang M T;Patil S K;Brahmankar P K (Mechanical Engg, Rajarambapu Inst of Technol, Post-Sakharale, City-Islampur, Email: telsang1@rediffmail.com) : Humanware - a critical dimension for achieving competitive advantage in JIT environment. Mfg Technol Today 2007, 6(9), 10-14.

Implementation of Just-in- Time challenges traditional manufacturing practices and involves not only technical changes but also administrative and cultural changes. Implementation of JIT system requires complete support and understanding from every operational division, especially the human resource. The humanware technology of JIT consists of four components such as Education and Training programme, Development of co-operative environment, Rewards and incentive programme, Open communication and worker involvement. This paper aims to study how the humanware influence the competitive advantage of the firm, JIT contributes to the achievement of competitive advantage to the firm as a result of planned management actions in terms of discipline, understanding, dedication, confidence and continuous striving in every employee.

4 illus, 4 tables, 13 ref

018608   Tayade N H;Kuttappan R;Kamble A K;Mahalle D M;Khambalkar V P (Unconventional Energy Sources and Electrical Engng Dep, Dr. PDKV, Akola, Maharashtra) : Use of solar photovoltaic system with tracking arrangement to battery charging and sprayign operation. Biomed 2007, 18(1-2), 81-3.

The electronic controlled sun tracking system for a photovoltaic module using stepper motor was designed, constructed and used for battery charging and spraying operation. Experimental set up was installed in the college of Agricultural Engineering and Technology, Dr.P.D.K.V., Akola, (latitude 20.42° N and longitude 70.02°E). The testing was carried out and it was observed that the charging period for two batteries (in series) was 5 hrs. The tracking system ensures a constant 12 V d.c. supply due to battery (12V). The system consumed a very low power of about 6 W only. It was observed that the panel tilted through an angle of 150 for every hour.

2 table, 4 ref

018607   Srinivasa Pai P;Nagabhushana T N (Dep of Mechanical Engg., NMAM Institute of Technology, Nitte-574 110, Email: srinivasapai@rediffmail.com) : (NULL). Mfg Technol Today 2007, 6(7), 4-10.

Attempts to monitor the surface roughness caused by the increse of tool wear (flank wear), through the variations of acoustic emission in face milling operations under different cutting conditions and for one workpiece material. the analysis revealed that there is a good correlation between two important parameters of the acoustic emission signal namely ring down count and RMS voltage with the surface roughnessparameter namely R_a. The results show that acoustic emission can be used as an effective signal for monitoring surface roughness in face milling and thereby can be useful for establishing the end of tool life in face milling operations. Artificial Neural Network (ANN) is a powerful tool that can be applied to many scientific and engineering problems. In this paper a simple feed forward ANN has been applied to predict surface roughness using acoustic emission parameters, flank wear and cutting conditions.

10 illus, 15 ref

018606   Sreeramulu M;Arumaikkannu G;Gowri S (Dep of Manufacturing Engineering, College of Engineering, Anna University, Chennai-25, Email: sreeram49@yahoo.co.in) : Finite element analysis of parts fabricated by FDM. Mfg Technol Today 2007, 6(6), 27-31.

High degree of automation of layered manufacturing process and its ability to create geometrically complex parts to precise dimensions provide it with a unique potential for low volume production of rapid tooling and functional components. As the rapid prototyping going towards rapid manufacturing in recent days, strength becomes the main factor which affected by many process parameters. In this study, stress analysis has been done on FDM (Fused Deposition Modeling) parts mesostructure by finite element method. In this Finite Element Analysis (FEA) models were designed with different mesostructural process parameters like road, width, air gap and slice thickness, on this a linear orthotropic analysis was done to know the effect of each parameter on stress distribution. FEA results were compared with experimental yield strength results and they have better agreement with experimental results in knowing the effect of each parameter on strength.

11 illus, 2 tables, 10 ref

018605   Singh S P;Xavier P (Mining Engng, Laurentian Univ, Sudbury, Canada) : Role of rock mass quality in blast damage control. J Mines Metals Fuels 2007, 55(12), 576-80.

The quality of a rock mass has a direct influence on the level of dynamic forces to which an excavation can be subjected and sustain damage. Although each rock mass is a unique occurrence, yet there are common features in rock masses which can influence the outcome of perimeter control in a similar way. A field study was conducted which involved assessment of blast damage at several operating mines and the blasting of small scale models. The effects of joint parameters, block size and strength, rock quality designation, hydrology, foliation and rock mass rating on the blast damage have been investigated and discussed in this study.

5 illus, 9 tables, 15 ref

018604   Singh A K;Sinha A (NO, Central Inst of Mining & Fuel Res, Barwa Road, Dhanbad-826 001) : (NULL). J Mines Metals Fuels 2007, 55(10-11), 502-6.

Bord and pillar method of mining is predominantly practiced for production of coal from underground Indian mines. In this system of mining problem of self-heating and fire are commonly noticed, particularly in coal pillars lying between main intake and return of the ventilation circuit. The problems of fire in coal pillars were noticed after 1960 in Nimcha, Jambad-Kajora and Pandaveshwar area of Raniganj coalfield. The problem is gradually increasing with increasing ventilation pressure of the mine. In order to avoid such problems the authors are carrying out a study funded by Ministry of Coal, Government of India to work out proper actions in advance to prevent the heating in coal pillars. For this purpose one pillar at I and 2L in between 2D and 3D, nearby the pit bottom of Satgram project of Raniganj coalfield has been selected. This pillar is selected due to its typical geomining condition. There is persistence of a fault in this pillar and high ventilation pressure difference exists across it. An attempt has been made to discuss about heating pattern in coal pillar on the basis of variation of CO₂, O₂ and blackdamp concentration with time.

9 illus, 4 ref

018603   Sharan K K (Projects & Planning, Western Coalfields Ltd, , Nagpur) : Environment protection measures for eco-friendly coal mining in western coalfields limited - with special reference to Maharashtra. J Mines Metals Fuels 2007, 55(9), 449-53.

8 illus, 3 tables

018602   Shanmugasundaram B (Faculty of mechanical Engg., V.L.B.Janakiammal College of Engg. and Technology, Kovaipudur, Coimbatore-641 042, Email: bshan_india@rediffmail.com) : Analysis of cutting tool-workpiece system with PID controller. Mfg Technol Today 2007, 6(7), 18-22.

Objective is to develop a two degree of freedom model with PID controller for turning process to reduce regenerative chatter with the aim of improving productivity, quality of surface finish, tool life and reducin environmental noise caused by chatter. A system model consisting of a workpiece subsystem (workpiece with end supports represented by mass, stiffness, damping coefficient) and a cutting tool subsystem (tool with its supports represented by mass, stiffness and the damping coefficient). A Mechatronic system has been proposed and developed for reducing ool vibration in lathe tool during machining. It consists of electrical and mechanical components; the controller is designed to control the chatter that occurs between the tool and the workpiece. A Piezo actuator and sensor was embedded into the tool holder. The controller is used to send a feedback to the actuator. The Controller is to be designed so that it suppresses the settling time and dampens the tool. The effective cutting stiffness and effective cutting damping are modelled as a spring and damper during machining. the original response of the system is modelled using transfer function method. their output responses were obtained using Mat lab software.

14 illus, 3 tables, 19 ref

018601   Sengar S H;Kohari S (Renewable Energy Sources Dep, Coll of Technol and Engng, Maharana Pratap Univ of Agric and Technol, Udaipur-313 001) : Arch shape greenhouse for ornamental plant. Biomed 2007, 18(1-2), 131-3.

Hi-tech cultivation of horticultural crops inside the greenhouse was took during the month of November to May at instructional farm, CTAE, MPUAT. Udaipur (Raj.). Parameter like inside outside air temperature, relative humidity and solar radiation were selected for study. It was found that considerably higher temperature than outside condition could be obtained by using green house, in winter season. Also the thermal environment inside the greenhouse could modify to a desire extent, by use of suitable temperature controlling measures. The air temperature inside the green house was 8.5°C to 15°C more than the open condition in winter season. The relative humidity was 60%-70% during peak hours. The germination and survival percentage for croton and ornamental plant were 100% respectively. The maximum plant height of croton, Acalypha and Hibiscus rosa-sinensis were 32 cm, 92 cm and 69 cm respectively. For horticultural crops, NPW, benefit cost ratio and pay back period for the green house were Rs 5,11,693, 3.24 and 3.08 years respectively.

1 illus, 2 tables, 3 ref

018600   Sekhon J S (NO, Assam and Assam-Arakan Basin, Oil and Natural Gas Corporation Ltd, Jorhat) : Schuppen belt in north east India: a case of exploration challenges in frontier domains. J Mines Metals Fuels 2007, 55(3), 68-70.

018599   Seemikeri C Y;Brahmankar P K;Mahagaonkar S B (NO, Dr. Babasaheb Ambedkar Technological University, [Dr B.A.T.U.], Lonere-402 103, Email: rtg_chandra@yahoo.com) : Some investigations into low plasticity burnishing of AISI 316L. Mfg Technol Today 2007, 6(5), 17-21.

Results of the latest research indicate that the life and the reliability of machine components are affected greatly by the varieties of surface enhancement technologies applied and also by the sequence and conditions of their application. low Plasticity Burnishing (LPG) is a new method of surface enhancement, which can provide deep stable surface compression for improved surface integrity characteristics. The present study focuses only on the surface roughness and surface micro-hardness aspects using full factorial design of experiments. After studying the effects of various parameters of the LPB process on AISI 316, favourable and optimum conditions could be predicted and tailored for different requirements. The parameters that have greater influence on the surface roughness in the decreasing order of importance are number of passes, ball diameter, pressure, and speed, whereas ball diameter, speed, pressure, and number of passes is the order for the surface hardness.In order to minimize the roughness of the surface it is advisable to set the speed pressure, number of passes at high level and ball diameter at low level looking into the strong interaction that pressure is involved with speed and number of passes. After analysing the interaction effects of parameters on the surface hardness, it is advisable to set the speed, number of passes at lower level and ball diameter, burnishing pressure at higher level to maximize the surface hardness.

7 illus, 13 ref

018598   Sayadi A R;Monjezi M;Vahidi M (Tarbiat Modarres Univ, , Iran) : Sensitivity and risk analysis of critical technoeconomical variables of sungun copper mine. J Mines Metals Fuels 2007, 55(1-2), 11-18.

Sungun copper mine is one the most important mines in Iran. It is in the final stage of development. The rate of productions of this mine is 7 and 14 Mt in the first and second phase, respectively. Average grade of the deposit is 0.6% and the grade of mill concentrate would be 30%. Feasibility study and mine design are carried out on the basis of several technoªeconomical and financial variables. Estimation of these variables is made under uncertainty conditions and therefore, sensitivity of economical indexes should be evaluated. In this research work, firstly, with the help of Excel and Comfar softwares, a model was developed and run considering scenarios for a certain variation of expected value of variables. It was observed that internal rate of return (IRR) is affected more by concentrate price comparing to other relevant factors. In this regard, mill recovery plant, exchange rate, capital costs, mine overall slope angle and operating costs can be ranked in the next degrees of importance. Secondly, for economic and financial risk analysis, Mont Carlo technique was applied for estimation of most probable' economical indexes of the project. It was concluded that with a 90% level of confidence, range of IRR is more than 9.32% and less than 19.56%.

23 illus, 5 tables, 11 ref

018597   Satyabrata Mohanta (Chem Esngng Dep, Indira Gandhi Inst of Technol, Sarang-759 146, Email: satyabrata.mohanta@rediffmial.com) : Washability studies of talcher coal. J Mines Metals Fuels 2007, 55(5), 153-5,164.

The float-and-sink analysis result for six different coal samples collected from six different coal mines of Talcher coalfield is presented and near gravity material index is clculated to know the washability characteristic of each coal sample and compared.

3 illus, 3 tables, 8 ref

018596   Sarkar B C;Saikia K;Sarma M;Pandey S;Paul P R (Appl Geol Dep, Indian School of Mines, , Dhanbad-826 004, Email: bhabesh_sarkar2003@yahoo.co.in) : Geostatistical approach to estimation of coal bed methane potentiality in a selected part of Jharia coalfield, Jharkhand. J Mines Metals Fuels 2007, 55(12), 596-94.

Jharia coalfield, being one of the largest coalfields of India with vast reserves of coal, makes it a lucrative prospect for coal bed methane (CBM) in the country. CBM exploration activities in the coalfield primarily focus the deeper part of the Jharia basin where coal seams occur within Barakar formation at great depth. Parbatpur block under Bharat Coking Coal Limited (BCCL) command area is one of the most promising blocks among others in Jharia coalfield (JCF). In the present study, an integrated geological, statistical and geostatistical approach to evaluation of CBM potentiality has been attempted in a small part of the Parbatpur block in the coalfield. The geological study includes preparation of lithologs, their correlation and an understanding of the relationship of various analytical constituents of coal with depth. Statistical and geostatistical modelling of ash, volatile matter and thickness in respect of seam xv reveal the population parameters and spatial characteristics of individual variables. Block-wise CBM potentiality has been assessed by estimating gas-in-place (GIP) for each block. The overall approach to evaluation of the CBM potentiality in the selected part of Jharia coalfield provides an improved means to accurate and reliable technique for CBM assessment. The block-by-block CBM estimates thus obtained can be utilized for follow-up decisions in respect of CBM exploitation in the coalfield.

9 illus, 4 tables, 13 ref

018595   Sarangi A K;Bhowmik S C;Jha V N (Uranium Corporation of India Ltd., , Jaduguda) : Radiological impact assessment in Bagjata uranium deposit. J Mines Metals Fuels 2007, 55(5), 127-33.

Describes the philosophy of such studies and the findings that helped in formulating a separate environmental management plan.

1 table, 10 ref

018594   Saraf R R;Thipse S S;Saxena P K (Mechanical Engineering Dep, MNIT, Jaipur-302 017) : Homogeneous charge compression ignition (HCCI) - a new technology to reduce pollutants in gasoline injected engines. Nat Envir Pollut Technol 2007, 6(4), 703-8.

Homogeneous charge compression ignition (HCCI), also called as controlled auto ignition combustion (CAI), is recent combustion technology which has caught attention of automotive manufacturers all over world because of its ability to eliminate NOx and particulate emissions. HCCI combines advantages of both spark ignition and compression ignition engines. Focuses on current research work on HCCI direct and port fuel injected gasoline engines. It contains basic comparison between performance of gasoline injected engines and carburetted engines. This comparison is related to parameters like power output, fuel consumption, brake thermal efficiency and emissions. Also contains information about HCCI combustion and its merits.

1 illus, 2 tables, 1 ref

018593   Sahay N;Varma N K;Ahmad I;Sinha V K (NO, Central inst of Mining and Fuel Res, Dhanbad) : Critical temperature - an approach to define proneness of coal towards spontaneous heating. J Mines Metals Fuels 2007, 55(10-11), 510-16.

Realistic knowledge of liability index/proneness of coal V towards spontaneous heating is extremely useful in working out strategies for prevention and control of fire due to spontaneous in coal mines. In India, crossing point temperature is generally adopted for the above purpose. The method, though effective, but defines only advanced stage of oxidation. The authors based on a set of experience in the laboratory have defined a new index 'critical temperature' which can categorized the coal in respect of their susceptibility towards spontaneous heating much in advance compared to the existing method/indices. The results when compared with crossing point temperature show good correlation. The paper discusses review of the subject, the details of the experimental procedure adopted for determination of critical temperature and its correlation with crossing point temperatures.

4 illus, 6 tables, 16 ref

018592   Roy I (Central mine planning and design Inst, , Ranchi, Email: indraroy@rediffmail.com) : Engineering significance of geological discontinuities in rockmass. J Mines Metals Fuels 2007, 55(6-7), 172-7.

Laboratory and field investigations were carried out in order to collect the required input data for slope stability analysis. Recommendation of this investigation is being implemented by the mine officials in predicting future slope failure in the highwall benches.

5 illus, 5 tables, 5 ref

018591   Reddy Babu G;Sudarsana Rao H;Ramana Reddy I V (Civil Engineering Dep, SKIT, Srikalahasti-517 640) : Use of treated indstrial wastewater as mixing water in cement works. Nat Envir Pollut Technol 2007, 6(4), 595-600.

Feasibility of treated industrial wastewater as mixing water and effect of its constituents on cement mortar was experimentally evaluated. Cement mortar specimens were cast using deionised water (DW), tap water (TW), treated paint industry wastewater (TPIWW), and presence of zinc (Zn), lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), iron (Fe) and chromium (Cr). The results, when compared with the results of reference specimen made with DW, showed that TPIWW significantly and TW insignificantly increased the setting times and were made indistinguishable strength variations. Compressive and flexural strength increased as the concentration of metals increased, when compared with reference specimens. Therefore, TPIWW is found to be suitable for mixing water in cement mortar with no adverse effects and metal ions are positively interacted with cement mortar.

3 tables, 15 ref

018590   Ray S K;Krishna Ghosh A (NO, Central Mining Res Inst, Barwa Road, Dhanbad-826 001) : Coal mine fires - hazards and modern control techniques. J Mines Metals Fuels 2007, 55(1-2), 30-4.

Fires have long been recognized as hazards associated with coal mining. Coal mine fire causes economic losses by virtue of loss of coal and coal winning machinery. Environmental problems at surface and underground due to coal mine fire are discussed in terms of production of noxious, toxic gases, global warming and fire damp explosion. Social and health problems due to mine fire are dealt with. An account of modern techniques like water mist technology, remote sensing and infusion of carbon dioxide are also given.

19 ref

018589   Ramachandiran R (Central Zione, Directorate General of Mines Safety, , Dhanbad) : Earth fault protection with unearthed neutral system of power supply in Indian mines. J Mines Metals Fuels 2007, 55(10-11), 490-8.

8 illus, 15 ref

018588   Rajendran R;Venkataswamy S;Jaikrishna U; Gowrishankar N;Rajadurai (Dep of Mechanical Engineering, B.S.A. Crescent Engineering College, Chennai-600 048) : Effect of Dip time variaton on the coating characteristics of duplex coated steel. Mfg Technol Today 2007, 6(6), 20-6.

Duplex coating is used in surface engineering to provide improved wear and corrosion resistance. The present study aims at hot dip aluminizing of a steel base followed by diffusion and nitriding treatments. The base material chosen for study is BS₉₇₀ grade EN 8 steel (or 080M₄₀). The specimens were dipped in molten aluminium-silicon alloy bath (11-13% Si) for various dip times (5-25 minutes) at ₉88K and diffused at ₁₁₇₃K for 8 hours. The diffused specimens were gas nitrided for 10 hours 50 minutes. the effect of dip time on coating thickness, diffusion layer thickness, microhardness and microstructure of aluminized, diffused and nitrided steel specimens were studied. The aluminium coating thickness does not significantly increase with the dip time beyond certain duration. The experimental studies indicate that the diffused layer thickness varies from 54^-69 μm. The prolonged dipping time does not provide any significant advantage in increasing the diffused layer thickness. The surface hardness of EN 8 steel could be increased to about 800 HV when aluminized diffused and to about 1200 HV on subsequent nitriding. The increase in the hardness is attributed to the formation of hard nitride layer (Al-N). This methodologycould be adopted for automotive and other engineering application.

7 illus, 2 tables, 15 ref

018587   Pratap R;Mohit S;Pnadey A K (CranesSci MEMS Lab, Dep of Mechanical Engineering, Indian Institute of Science, Bangalore-560 012, Email: pratap@mecheng.iisc.ernet.in) : Squeeze film effect in MEMS devices. J Indian Inst Sci 2007, 87(1), 75-94.

Squeeze film effects naturally occur in dyanmic MEMS structures because most of these structures employ parallel plates or beams that trap a very thin film of air or some other gas between the structure and the fixed substrate. An accurate estimate of the effect of squeeze film is important for predicting the dynamic performance of such devices. In design, availability of very good models for squeeze film flow modelling, tracking its routes to the air damped vibrating system studies in the ealy twentieth century. Try to capture the early developments in gas lubrication theory and then discuss the current developments motivated by the complexities in squeeze film flow analysis brought out by the geometries and flow conditions prevalent in dynamic MEMS devices.

^iia13 illus, 86 ref

018586   Prabhulingaiah G;Jakhar S R;Shekhawat M S; Ranawat P S;Sekhar D M R (Rahasthan State Mines and Minerals Ltd, , Bikaner-334 001, Email: dmrsekhar@rsmm.com) : Resistance of limestone to size reduction. Indian chem Engr 2007, 49(2), 143-50.

High-grade limestone (+ 53% CaO) from gotan and Jaisalmer in India differs in the resistance offered to size reduction during loading (railway siding of the mine), transportation and unloading (railway siding of the steel plants). Compressive strength and Bond's Work Index (BWI) of limestone samples from these mines are studied. BWI better represents resistance of limestone to size reduction during loading, transportation and unloading. Jaisalmer limestone is mechanically isotropic and, hence, shows reasonable correlation between BWI and compressive strength.

4 illus, 4 tables, 8 ref

018585   Pophare A M;Shami S K (Geol Dep, R.T.M. Nagpur univ, Law Coll Square, Nagpur-440 001) : UnFC system and (RE) assessment of chromite resources of India. J Mines Metals Fuels 2007, 55(1-2), 35-41.

Classification of reserves/resources of chromite presently prevailing in India and the revised classification in accordance with the United Nation's Framework Classification system (UNFC) are discussed. The Indian Bureau of Mines adopted UNFC system for preparation of national mineral inventory on chromite.

5 tables, 5 ref

018584   Nierobisz A (Lab of Rock Mass Bolting of Central Mining Inst in Katowice, , Poland) : Characteristic of yielding bolt work in the light of laboratory and underground tests. J Mines Metals Fuels 2007, 55(12), 581-5.

The predominant system of extraction in Polish hard coal mines is a longwall system. One main gate constructed with the use of steel arch support is commonly applied for one longwall. Such a system is extremely expensive due to the prices of steel. Beginning from 1991, when a government started to diminish subventions to mining from the State budget, an implementation of bolt support as a factor causing reduction of costs of coal production has begun. After 15 years, a range of bolt support applying in relation to a capability is low. This is caused by restrictions of psychological nature, because fear occurs of inefficacy of bolt support in excavations liable to tremors and rockbursts. Lack of practical solutions and examples as well as materials (bolts, lagging) caused that development of bolt support observed in last years did not include regions of coal mines liable to rockbursts (70% of working mines). Therefore, works were begun on new constructions of bolt, which would contain destructive impact of tremors and rockbursts more effectively. Results of this works were presented. The following parameters characterize developed construction of bolt.

10 illus, 2 tables, 3 ref

018583   Nanda N K (Donimalai Iron One Mine, NMDC Ltd., , Karnataka) : Blastiong improvement in iron ore mine for cost optimisation - experience at deposit No.5. J Mines Metals Fuels 2007, 55(8), 221-3,230.

Deep within India S heartland in the Chhattisgarh State lies Bailadila - 'the hump of an ox' in the dialect of the native adivasi remote, replete with wild life, roaring dense forest guarding the secret treasures of the earth. The territory rising to a height of 1260 m above sea level, is about 32 km in length and 4 km in width. Copious rainfall averaging 350 cm in a year is the high point of the region. The Bailadila range with 14 iron ore deposits is a name to recon, within the world of mineral deposits. The initiation of activity started way back 1968 at Deposit-14 and in the year 1977, the Deposit No.5 was brought into production. From that day, about three decades have passed and the project has gone through many ups and downs, but proved its mettle to be one of the largest high grade iron ore mine in the world.

2 tables, 3 ref

018582   Moorthy T V;Vinoth Babu N (Manufacturing Engg Dep, CEG, Anna Univ, Chennai, Email: tv-moorthy@yahoo.com) : Effect of process parameters of friction welding process by ANN. Mfg Technol Today 2007, 6(9), 26-8.

Direct Friction welding of low weldability Aluminium 6063 alloy and type 304 Stainless steel was conducted and suitable welding conditions for producing a sound weld was investigated. In particular the effect on feature of weldment, its mechanical properties and microstructure were studied by varying the parameters and results were produced. Then the obtained experimental results were compared with that of the mathematical model developed by the Artificial Neural Network (ANN).

13 illus, 7 tables, 14 ref

018581   Monjezi M;Goshtasbi K;Moghadam S G;Singh P K (Blasting Dep, Central Mining Res inst, Dhanbad, Email: monjezi2001@yahoo.com) : Evolution of a mathematical model for determination of burden in blasting operations. J Mines Metals Fuels 2007, 55(1-2), 19-23.

One of the main objectives of blasting operation is to obtain proper fragmentation. The overall cost of mine is reduced significantly having a good fragmentation. There are several factors affecting the result of blasting amongst which burden is the most important parameters. Physicoªmechanical properties of the rocks are very critical in determining the size of burden. The main objective of this research work is to develop a mathematical model for determination of burden. To fulfill the objectives of the model, geo-mechanical properties of the rocks and blasting pattern of few blasting muck in Muteh gold mine were recorded and analyzed. The criteria of selecting the rock blocks, for this purpose, are the result of having good fragmentation. With the help of dimensional analysis method, burden was found to be a function of blast hole diameter and physico-mechanical properties of the rocks. It was also found that powder factor has not any relationship in determining burden.

2 tables, 17 ref