001706   Dinesh Kumar;Gupta P P (Thermal Systems Grp, ISRO Satellite Cent, Bangalore-560 07) : Indigenous development and productionisation of the state of art of ammonia heat pipes for spacecraft applications. J Spacecraft Technol 2005, 15(1), 1-14.

Details on the development of ammonia heat pipe technology for spacecraft applications at ISRO Satellite Center (ISAC), Bangalore have been presented. It includes design features for heat pipes without and with built-in heat pipe redundancy, manufacturing and testing requirements and on-orbit performance. Various aspects of heat pipe productionisation through technology transfer are also included.

19 illus, 3 tables, 14 ref

001705   Das N K;Ghosh M;Sen N (R D Cent for Iron & Steel, SAIL, Ranchi-834 002) : Studies on reduction of bof slag by aluminium and graphite for recovery of metals and evaluation of its desulphurisation capacity. Steel India 2005, 27(3), 73-7.

BOF slag generated in integrated steel plants is dumped as a waste material. This causes environment degradation. This slag has basicity of around 3 and is rich in lime and oxides of iron and manganese. There is an endeavour worldwide to use this slag efficiently. In order to recover Fe and Mn from the slag, a laboratory study was conducted to reduce the BOF slag by graphite and aluminium in a 2-kg air induction furnace using a graphite crucible. On reduction of the slag, 80 - 90 % metal could be recovered. In view of the fact that the reduced slag contained about 60% lime and is prefused,its capacity to flux was also evaluated. The amount of reduced slag used in desulphurisation experiments was about 10% of the metal weight. Results of desulphurisation of pig iron using the reduced BOF slag were encouraging. The reduction in metal sulphur was between 33 to 80%.

5 illus, 3 tables, 7 ref

001704   Blawert C;Hort N;Kainer K U (NO, , , Email: blawert@davxp3.gkss.de) : Automotive applications of magnesium and its alloys. Trans Indian Inst Metals 2004, 57(4), 397-408.

Today's interest in magnesium alloys for automotive applications is based on the combination of high strength properties and low density. For this reason magnesium alloys are very attractive as structural materials in all applications where weight savings are of great concern. In automotive applications weight reduction will improve the performance of a vehicle by reducing the rolling resistance and energy of acceleration, thus reducing the fuel consumption and moreover a reduction of the greenhouse gas CO₂ can be achieved. Gives an overview on the actual status of the development of magnesium alloys and technologies for application in the automotive industries. The development of new cast or wrought alloys and the optimisation of existing or new processes, for the production of magnesium parts are discussed. Magnesium has a long history in automotive applications. The decrease of magnesium use in automotive applications in the seventies was greatly related to its prize volatility and also to lack of knowledge. Stricter legislative rules (CAFE) and voluntary commitments to reduce the average fuel consumption have nowadays revived the interest in magnesium.

8 tables, 44 ref

001703   Aloysius R P;Sobha A;guruswamy P;Syamaprasad U (Regional Res Lab (CSIR), , Trivandrum-695 019) : Studies on the thermomechanical processing in the preparation of multifilamentary tapes of (Bi,Pb)-2223/Ag for HTS current leads. Metals Mater Process 2005, 17(2), 77-86.

The effects of heat treatment schedule and the uniaxial pressure applied prior to the last stage sintering for the preparation of (Bi, Pb) -2223/Ag multifilamentary tapes for use as HTS current leads were studied. The phase assemblage of the tapes prior to the last stage sintering is found to play a crucial role in governing the microstructure, phase purity and J_c of the finished tapes. It is observed that tapes with higher amount of Bi-2223 prior to the last stage sintering and deformation produced better sintered density, Jc and microstructure in the finished tapes. A pressure of 500 MPa applied prior to the last stage sintering was found to be optimum for obtaining better microstructure, higher sintered density and J_c. The level of J_c and J_c homogeneity along the length of the tape as well as J_c-B characteristics of the pressed tapes are much superior compared to the rolled tape. The observed scattering in J_c along the length of the pressed tape is only 0.3% of the maximum measured, while that of a rolled tape is <126>4% of the maximum. Eventhough uniaxial pressing is not suitable for the preparation of long length tapes, laboratory scale samples of length <126>20 cm can be successfully prepared by uniaxial pressing applied prior to the last stage sintering.

14 illus, 27 ref

000678   Yaragal S C;Ram H S G (Dep of Civ Engng, Natn Inst of Technol Karnataka, Surathkal, P.O., Srinivasnagar-575 025) : Wake pressure flow field characteristics associated with two dimensional triangular prisms. ISH J Hydraul Engng 2005, 11(1), 96-105.

The wind tunnel experiments were conducted on a series of two-dimensional isosceles triangular cylinders of 28 mm base height and different vertex angles (2 θ = 30°, 60° and 90°), to study the distribution of unsteady static pressures in the wake regio and to ascertain if they could be correlated. The velocity ranged from 5 to 15 m/s in the present study. The study reveals that the maximum coefficient of fluctuating pressures in the wake bears a constant ratio with base pressure coefficients for the models studied and it is found to be 0.40.

6 illus, 7 ref

000677   Yaniv A;Zilberman M;Pratzovnik A (Engng Div, Commercial Aircraft Grp Israel Aircraft Industries, 701 100, Ben-Gurion Airport, Israel, Email: ayaniv@iai.co.il) : Conceptual definition of a new very-light-jet aircraft configuration. J Aerospace Sci Technol 2005, 57(1), 148-65.

Israel Aircraft Industries (IAI) is a world leader in the design and manufacturing of business aircraft. IAI has developed and introduced to the market several biz-jets (Westwind I and II, Astra AKA Gulfstream G-100 and Galaxy- AKA Gulfstream G-200). All these aircraft have been in the midsize and recently "super-midsize" category. During the last two years, IAI has been evaluating a new aircraft design, the ProJet that belongs to the new, emerging category of "very-light jets" (VLJ). This lightweight twin turbofan aircraft is characterized by its small size and low target price, compared to existing IAI designs. The ProJet will be certificated to FAR23 normal category requirements, including single pilot operation. The ProJet exploits newly developed technologies and capabilities, such as: new, small and efficient turbofan engines; advanced low cost and sophisticated avionic systems; advanced low cost mechanical and electrical systems; rapid and efficient development and production methods. All these attributes will provide the capability of introducing a very low cost aircraft into the emerging new VLJ market sector. The ProJet is a twin turbofan, low wing, T-tail airplane utilizing an all-metal airframe; designed in accordance with damage tolerance requirements. It features a comfortable pressurized cabin with optimized seating for 6 occupants, including 2 pilots, and excellent performance. The ProJet will have a VFR range of 1200 nm, a cruise ceiling of 41,000 ft, and a cruise speed of 365 kt. It will take-off and land on runways shorter than 3000ft. Generous allowance for baggage stowage is provided in the pressurized internal baggage compartment, and in the external rear baggage compartment. The ProJet flight deck features an all-glass cockpit with an integrated avionics package, designed for ease of operation and reduced workload. Composite materials are utilized inflight control surfaces and secondary structures. Two FADEC controlled turbofan engines mounted on the upper aft fuselage supply the ProJet power. Each engine generates about 1300 pounds static installed thrust at ISA + 10°C.

31 illus, 1 table

000676   Vengadesan S;Yokojima S;Nakayama A (Dep of Appl Mechanics, Indian Inst of Technol Madras, Chennai-600 036, Email: vengades@iitm.ac.in) : Collocated finite difference method in general coordinates for simulation of flow over arbitrary geometry. J Aerospace Sci Technol 2005, 57(2), 250-8.

A finite difference method to be used in simulations of turbulent flows such as Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) has been developed and verified for basic benchmark flows. The method is constructed using the general curvilinear coordinate system with the collocated grid arrangement of the variables so that it can be easily applied to various engineering flows including hydraulic applications involving complex geometry and moving boundary. The computer code is verified by test calculation of steady laminar internal flow in a curved cavity and an external flow above a curved hill. Further more the same code is used to conduct a DNS of fully-developed turbulent flow in a two-dimensional open channel and a LES of flow over curved hill. All results indicate that the method is sound with sufficient accuracy for the intended applications.

13 illus, 20 ref

000675   Umesh S B;Kulkarni S R;Sandhya R;Joshi G R; Damle R;Ravindra M (Components Div, ICG, ISRO Satellite Cent, Airport Road, Bangalore-560 017, Email: grjoshi@isac.ernet.in) : High-energy heavy ion testing of VLSI devices for single event upsets and latch up. Bull Mater Sci 2005, 28(5), 473-6.

Several very large scale integrated (VLSI) devices which are not available in radiation hardened version are still required to the be used in spacecraft systems. Thus these components need to be tested for high-energy heavy ion irradiation to find out their tolerance and suitability in specific space applications. The paper describes the high-energy heavey ion radiation testing of VLSI devices for single event upset (SEU) and single event latch up (SEL). The experimental set up employed to produce low flux of heavy ions viz. silicon (Si), and silver (Ag), for studying single event effects (SEE) is briefly described. The heavy ion testing of a few VLSI devices is performed in the general purpose scattering chamber of the Pelletron facility, available at Nuclear Science Centre, New Delhi. The test results with respect to SEU and SEL are discussed.

2 tables, 9 ref

000674   Swamee P K (Dep of Civ Engng, Indian Inst of Technol Roorkee, Roorkee-247 667, Email: swamifce@iitr.ernet.in) : Interrelations between alternate depths. ISH J Hydraul Engng 2005, 11(1), 22-7.

Jain (2001) has cited a corollary regarding alternate depths that fell into oblivion. This study mentions some additional corollaries of alternate depths that never saw the light of publication. Their comparison with the corresponding sequent depth equations reveals similarities and dissimilarities.

9 ref

000673   Sundararajan N;Prakash T;Singha M K;Ganapathi M (Dep of Mechanical Engng, The Univ of Akron, Akron - Ohio) : Free vibration of functionally graded skew plates subjected to thermal environment. J Aerospace Sci Technol 2005, 57(2), 270-81.

The free vibration behavior of functionally graded skew plates is investigated using finite element procedure. Temperature field is assumed to be a uniform distribution over the plate surface and varied in thickness direction only. Material properties are assumed to be temperature dependent and graded in the thickness direction according to simple power law distribution. For the numerical illustrations, silicon nitride/stainless steel is considered as functionally graded material. The variation in frequencies is highlighted considering gradient index, temperature, thickness and aspect ratios, and skew angle of the plate.

2 illus, 6 tables, 20 ref

000672   Singh R (Sch of Engng, Cranfield Univ, Bedfordshire, MK43 0AL, United Kingdom, Email: R.Singh@cranfield.ac.uk) : The role of gas path diagnostics in the changing gas turbine after-market. J Aerospace Sci Technol 2005, 57(1), 58-72.

Aero gas turbine maintenance strategies are likely to see profound changes in the future. The remarkable size of the after market for both military and civil aero gas turbines has already changed the nature of the business case. The aftermarket is large, more lucrative and not subject to the cyclical downturns of the original equipment sales. The competition which this considerably profitable after market creates will spur advances in diagnostic techniques. Of particular importance is advanced gas path diagnostics where, in recent years, engineering science research has opened pathways using somewhat surprising technologies. The work covering linear and non-linear gas path analysis, genetic algorithms, neural networks, fuzzy logic and hybrid systems. Much of the costs associated with the gas turbine after market relates to the gas path and these techniques are seen to play an important role.

13 illus, 60 ref

000671   Singh K P (NO, Aeronaut Dev Ag, Vimanapura Post, Bangalore-560 017) : CFD tools as applied to indian combat aircraft configuration-an experience. J Aerospace Sci Technol 2005, 57(1), 33-40.

Computational Fluid Dynamics (CFD) tools are extensively used by aircraft industries all over the world in design and development of airplanes, with emphasis on reducing both the cost and design cycle time. The paper deals with the use of CFD tools at Aeronautical Development Agency (ADA) in design and development of Indian combat aircraft. The applications include: (1) evaluation of incremental changes in aerodynamic configuration, (2) wave drag evaluation, (3) aerodynamic loads, (4) flow field around air data sensor locations, (5) Euler calculation for coupled internal and external flow field, and (6) viscous computation of high angles of attack flows. In the initial design phase, codes based on the potential theory were used for wing design and fuselage shape optimization. Later indigenously developed Euler and Navier-Stokes codes were employed for the various applications. The paper brings out the strength and weakness of CFD as experienced at ADA and its comparison with the Wind Tunnel and Flight Data.

14 illus, 1 table, 15 ref

000670   Shivapur A V;Prakash M N S (Dep of Civ Engng, S D M Coll of Engng and Technol, Dharwad-580 002, Email: av_shivapur@rediffmail.com) : Inclined sluice gate for flow measurement. ISH J Hydraul Engng 2005, 11(1), 46-56.

Generally, sluice gates are used to regulate flow in open channels. Discharge coefficient of a sluice gate is a function of geometric and hydraulic properties of the gate. For free flow conditions; the discharge coefficient is related to upstream flow depth and gate opening, whereas for submerged flow, it also depends on tail water depth. Flow through the gate opening has been the subject of investigation for many academicians and researchers. The main objective of this paper is to report an investigation done on flow through inclined sluice gate and to establish relationships independently for the discharge through the gate for free-flow and submerged-flow conditions. For free-flow condition, the discharge is expressed as a function of head causing flow, inclination of the gate and gate opening. For submerged-flow condition, the discharge is expressed as a function of head causing flow, inclination of the gate, gate opening and tail water depth. Experiments are carried out on different gate-inclinations such as 0° (normal to flow), 15°, 30°, and 45° with respect to the vertical plane on upstream side for different gate openings.

1 illus, 2 tables, 7 ref

000669   Shepshelovic M (NO, Engng Cent Israel Aircraft Industries, Ben-Gurion International Airport, Israel-701 100) : Uav wing design - a new challenge. J Aerospace Sci Technol 2005, 57(1), 93-113.

Advanced airfoil design concepts and modern wing design methodology allow development of mission-tailored, customized wing for any new aerodynamic configuration. This is especially relevant for UAV wing design, where variety of mission specifications, multi-point design requirements and imposed non-aerodynamic constraints make it unpractical the use of existing wings in configuration evaluation process. The development efforts on UAV wing design should concentrate on the radical improvement of aircraft performance, provide improved payload carriage capabilities, ensure flight safety of air vehicles, their maneuverability, capability to perform in unfavorable weather conditions and comply with structural and internal volume constraints. IAI initiated development of in-house capabilities on UAV wing design in mid 80's, recognizing the principal differences between requirements for UAV operation and known types of air vehicles such as sailplanes and general aviation aircrafts. It was acknowledged, that for most cases, design of a new UAV wing is a practically unavoidable choice, that should be supported by the adequate engineering capabilities. The build-up of technological infrastructures at 1A1 included adoption of CFD tools, promotion of advanced design concepts and WT testing of airfoils and complete configurations. The first designs targeted subsonic, long endurance UAV. concentrating on development of thick, high-lift NLF sections. This was followed by variety of subsonic and transonic designs, including wings development for high altitude flight, application of swept NLF wing technology to design of subsonic/transonic wings, promotion of the concept of hybrid transonic/subsonic airfoils, design of transonic unswept NLF wings, development in the field of low Reynolds number aerodynamics and evaluation of Mini/Micro UAV wings. IAI experience on UAV wing design is outlined in this paper by presenting a number of specialized designs and discussing the rationale of their development. This is followed by definition of future development directions that might be considered for continuation efforts on development of UAV wings.

40 illus, 19 ref

000668   Sampath S;Moustapha H;Girard G;Cooper C (Combust, Pratt and Whitney Canada, 1801, Courtney Park Drive, Mississauga, Ontario, L5T 1J3, Canada, Email: sam.sampath@pwc.ca) : Green engine technologies for small gas turbines. J Aerospace Sci Technol 2005, 57(1), 193-210.

The small gas turbines industry has witnessed a big leap in technology over the past two decades. This period was mainly characterized by a rapid development of advanced three-dimensional tools assisted by a yearly doubling of computer capacity. Validated design tools were integrated into the design system throughout the whole engine. Concurrent engineering combined with integrated product teams and a substantial reduction in testing has resulted in a reduction, of an engine design and development time, from five to three years. Further reduction to two years is possible with emphasis on technology readiness both in engineering and manufacturing. Technology strategy for the next millennium will focus on cost reduction breakthroughs, and rapid technology deployment into engines. Environmental issues such as noise and emissions reduction and elimination of hazardous waste will take more importance, particularly with more stringent regulations. The paper addresses Green engine technology developments in modern gas turbine engines.

23 illus, 2 tables, 13 ref

000667   Sai Ram K S (Dep of Civ Engng, RVR & JC Coll of Engng, Chowdavaram, Guntur-522 019, Email: sairamks@yahoo.com) : Buckling of laminated composite spherical shell cap. J Aerospace Sci Technol 2005, 57(2), 259-69.

The buckling of laminated composite spherical shell cap with and without a cutout subjected to transverse load is investigated. The geometrical non-linear analysis is carried out using the finite element method based on the first-order shear deformation theory. An eight noded degenerated isoparametric shell element with five degrees of freedom at each node is considered. The geometric non-linear behaviour and the collapse pressures with the associated mode shapes are presented for simply supported and clamped symmetrically and anti-symmetrically laminated cross-ply spherical shell cap without a cutout subjected to uniform normal pressure. The dependence of collapse pressure on the size of a central circular cutout is also studied.

6 illus, 4 tables, 19 ref

000666   Rosen A (Fac of Aerospace Engng, Technion - Israel Inst of Technol, Haifa-320 000, Israel, Email: rosen@aerodyne.technion.ac.il) : The cross coupling problem of helicopter rotor. J Aerospace Sci Technol 2005, 57(1), 114-41.

Until recently it was beyond the capability of helicopter rotor models to predict correctly the cross-coupling response. During the mid-nineties it became clear that wake distortion effects are the main contributors to the cross-coupling response. Wake distortion effects can be modeled by using detailed free or prescribed wake models. However, these models require large computer resources and long computing times, thus they are not suitable for various applications. In such cases dynamic-inflow models can be corrected to account for the missing effect by using the wake distortion coefficient or an aerodynamic phase lag. Recently, a new actuator disk model was developed where the wake distortion effect is obtained as an integral part of the derivation. In the paper all the methods of considering the wake distortion effects are reviewed and compared. The results of the various models are also compared to flight test results. Conclusions are drawn and further necessary research is identified.

^iia14 illus, 1 table, 71 ref

000665   Rao S V N;Kumar S V V;Ramasastri K S;Rao P R S (NO, Natn Inst of Hydrology, Deltaic regional centre, Kakinada) : Optimal inter basin transfer in space and time: a case study of interlinking of river systems in south India. ISH J Hydraul Engng 2005, 11(1), 85-95.

The study discusses inter basin transfer of water from designated surplus basins to deficit basins in space and time with reference to monsoon rainfall runoff conditions prevalent in south India. A linear network of multi-basins is connected for integrated operation. The network problem is solved using linear programming. The utility of the study is demonstrated with the help of a trade-off curve between two conflicting objectives i.e. minimizing cost of transferring water though the links while maximising the storage in deficit reservoirs.

4 illus, 2 tables, 4 ref

000664   Quraishi M A;Saxena N;Jamal D (Dep of Appl Chem Corros Res Laboratory, Fac of Engng & Technol Aligarh Muslim Univ, Aligarh-202 002, Email: maquraishi@rediffmail.com) : Inhibition of mild steel corrosion by oleochemical based hydrazides. Indian J chem Technol 2005, 12(2), 220-4.

Selected hydrazides of fatty acids with C₉-C¹⁷ carbon atoms have been synthesized and evaluated as corrosion inhibitors of mild steel (MS) in hydrochloric acid (HCl) solutions by weight loss and potentiodynamic polarization methods. The adsorption of all the hydrazides on mild steel surface in the acid solution has been found to obey Langmuir's adsorption isotherm. The potentiodynamic polarization studies revealed that all compounds block the corrosion reactions. Inhibition efficiency (IE) of these compounds has been found to vary with the concentration of the compound, solution temperature, immersion time and concentration of the acid solution. The values of activation energy (E_a) and free energy of adsorption (∪G_ads) have been calculated to investigate the mechanism of the corrosion inhibition.

6 illus, 4 tables, 24 ref

000663   Pienaar E;Ksel T;Goosen P;Cloete C;Botha L (Radar and Electronic Warfare Systems, CSIR Defencetek, South Africa) : Role of radar cross section facilities in a radar and electronic warfare defence research and evaluation capability. J Aerospace Sci Technol 2005, 57(1), 211-24.

The paper demonstrates the role of Radar Cross Section (RCS) facilities, consisting of modelling and simulation (M&S), Hardware in the Loop- (HWIL) and field Test and Evaluation (T&E) environments, in a Radar and Electronic Warfare (EW) Defence Research and Evaluation capability. The link between the development and utilisation of radar and EW facilities and the scientific process is illustrated by examples.

13 illus, 1 table, 8 ref

000662   Pethe P C;Kulkarni M R;Bhosekar V V; Deolalikar P B (Cent Wat and Power Res Stn, , Pune-411 024) : Hydraulic model studies for Tala dam spillway, Bhutan. ISH J Hydraul Engng 2005, 11(1), 106-19.

000661   Pani B S (NO, I.I.T., Bombay) : Trajectory of a round buoyant jet in cross-flows. ISH J Hydraul Engng 2005, 11(1), 11-21.

A semi-empirical relationship was developed to predict the trajectory of buoyant and non-buoyant jets in uniform cross-flows. The momentum conservation principle, with a suitable modification, formed the basis of analysis. Empirical coefficients were estimated based on the available data. In this approach, the use of a drag coefficient to find the force acting on the jet can be avoided. The predicted trajectory agrees fairly well with the observations of other researchers.

5 illus, 10 ref

000660   Majumdar J (Aerial Image Exploitation Div Aeronaut Dev Establishment, Def Res and Dev Organisation, C. V. Raman Nagar, Bangalore-560 093, Email: Jharna@ade.ernet.in) : Advances in aerial image exploitation. J Aerospace Sci Technol 2005, 57(1), 166-92.

The availability of low cost sensors, high bandwidth communication links and the growing popularity of Unmanned Aerial Reconnaissance Platforms like UAVs have resulted in dramatic new opportunities to conduct remote battlefield surveillance and reconnaissance missions from relatively safe Ground Control Stations. The sensors used in UAV explore the visible, infrared and microwave regions the spectrum and the images are produced optically, electronically or by film. Aerial Image Exploitation is an innovative image utilization program that uses multi sensor, multi resolution and multi spectral imagery obtained from Aerial Reconnaissance Platform for the purpose of Extraction, Exploitation, Dissemination and Interpretation of Imagery Intelligence. Research in aerial image exploitation is focused to provide a total solution of the problem by combining both hardware and software at the system and subsystem level. Major operational goal of image exploitation technology is to extract the vital intelligence from a large storehouse of available imagery by filtering those which are most likely to produce valuable findings, to combine classical image/signal processing techniques with technologies available in other fields and to use specialized hardware wherever required. The first part of the paper describes the Ground Image Exploitation System and Imagery Intelligence Exploitation System being developed in ADE. The second part of the paper describes some of the basic and advanced research work being carried out in ADE, which is the backbone that lead to the development of these systems. Some of the areas discussed in this paper are adaptive preprocessing of imageiy, image mosaicing, terrain classification and high-resolution reconstruction of target region.

10 illus, 29 ref

000659   Maillard T;Letty R L;Barillot F;Rajeev G (CEDRAT Technologies, 15 ch. de Malacher ZIRST, F-38246 Meylan Cedex France, Email: actuator@cedrat.com) : Piezo mechanisms for optical and space applications in Europe. J Aerospace Sci Technol 2005, 57(1), 142-7.

Piezoelectric actuators find their first applications in active space optics. The purpose of the paper is to describe the state of the art and some applications. Piezo actuators display attractive features for space applications, such as precise positioning, unlubricated, non-magnetic and compact features, and low power consumption. However, piezo mechanisms cannot be considered separately from their driving and control electronic. Piezo actuators, such as Amplified Piezo Actuators or Parallel Pre-stressed Actuators, initially designed under the French Space Agency contracts, shall find their first space flight applications in optics on the first European LIDAR, to be on board on AEOLUS in 2007.

10 illus, 1 table, 9 ref

000658   Kuzmenko M L;Egorov I N;Shmotin Yu N (NO, NPO Saturn, Kasatkin 13, Moscow-129 301, Russia) : Increasing of air engine efficiency basing on optimization technology. J Aerospace Sci Technol 2005, 57(1), 41-8.

NPO Saturn possesses the complex of technologies, which allow obtaining the most efficient technical solutions when creating up-to-date gas-turbine engines and their components. In the paper there are presented the examples researches aimed at axial compressors perfection basing on up-to-date analysis and optimization tools. As the analysis tools there are used the well-known commercial software packages (CFX-TASC flow, ANSYS etc.), as well as the models developed by NPO Saturn: the adequateness of latter had been proved by experimental data. To rise the efficiency and margins of gas dynamic stability for multistage axial compressors NPO Saturn is using widely the methods of CFD and optimization based on IOSO technology. In the paper there are presented some examples of real-life problems solutions.

12 illus, 3 ref

000657   Kale S;Biswas K (NO, Nasik Def Res and Dev Organisation (DRDO), Ojhar, Nasik-422 207, Email: kaleshirsh@rediffmail.com) : Evolution of airframe materials for russian fighters. J Aerospace Sci Technol 2005, 57(2), 282-8.

Fighter aircraft make extensive use of materials such as Steels, Aluminum alloys, Magnesium alloys, Titanium alloys and composites for construction of airframe. It has been seen that many of the airframe materials used in Russian fighters are common. But attempt has been made to introduce progressively superior quality alloy grades in the later version of aircraft. A comprehensive study (1) is thus made to identify the important structural member of the airframe and its materials in different generations of the Russian fighters to highlight the ways lighter and superior alloys replaced steels. The paper describes the application of various aerospace materials used from the evolution of old generation Russian combat fighters to latest Russian fighters. Effort have been made to analyse and explain the change of some of the grades within the domain of these Russian fighters and use of superior structural materials (western and Russian origin) to old age aircraft to enhance the performance. It also discusses the percentage weight change of various types of materials used in the construction of Russian fighter aircrafts under operation in India. Main objective of the study which is discussed here, to keep aware the operators as well as manufacturer's of Russian aircrafts within India to exchange these Russian materials during rationalization, substitution, indigenization and at a times of short supply or non-availability of these grades based on their merits.

1 illus, 2 tables, 5 ref

000656   Jategaonkar R V (Inst of Flight Systems, DLR-German Aerospace Cent, 38108 Braunschweig, Germany, Email: Jategaonkar@dlr.de) : Aerodynamic modeling and system identification from flight data. J Aerospace Sci Technol 2005, 57(1), 1-16.

System identification is fundamental to modeling of any observed dynamic process. The overview presentation brings out why and what system identification is as applied to flight vehicles. A historical background is briefly provided, tracing the developments to the 18th Century and early flight experiments in 1920s. Transition from classical to modern methods is brought out, highlighting the unified Quad-M approach to flight vehicle system identification that has evolved over the last three decades. Various aspects of kinematic consistency checking of recorded flight data and typical problems encountered are covered in detail. This is followed by several advanced examples pertaining to aerodynamic databases, covering (1) modeling at extreme flight conditions of large sideslip angles and stall hysteresis, (2) proof-of-match for critical flight phases, and (3) Phoenix RLV demonstrator. At the end, re-emerging aspects of recursive parameter estimation are briefly presented. The paper is concluded by indicating the possible future directions of work.

27 illus, 1 table, 27 ref

000655   Gupta U P;Sharma N;Ojha C S P (NO, Cent Wat Commn, New Delhi) : Modelling of local scour around rectangular submerged vane. ISH J Hydraul Engng 2005, 11(1), 57-66.

At optimal angle of attack, occurrence of destabilizing local scour phenomenon especially around the leading edge of the vane is formed and at this angle vane induced secondary circulation is also maximum. The maximum scour depth around the vane mainly depends on flow depth and flow Froude number. Flow Froude number is more important than Densimetric Froude number. This will presuppose checking the magnitude of local scour around the submerged vanes by a suitable local scour retarder method.

7 illus, 1 table, 14 ref

000654   Gopalaswami R (Bharat Dynamics Ltd, , Hyderabad, Email: gopalavatar@123india.com) : Advanced hypersonic transportation perspectives. J Aerospace Sci Technol 2005, 57(2), 225-49.

High-speed transportation design concepts are examined for advanced civil aviation and space transportation applications. The design concept of transatmospheric vehicles, flying directly from earth to orbit, will enable launching and recovery of small telecommunication and remote sensing satellites, harvesting solar energy from space, and space tourism. Commonality of flight regimes in atmospheric flight, the similarity of fuels, propulsion technology, aerodynamic configuration design, and airframe structure materials used in these high-speed flight regimes for air and space transportation are discussed in detail. A single, Integrated Hypersonic Transport Programme, is recommended, based on small size, low risk, and low cost vehicles. A dual fuel, kerosene-hydrogen system meets the needs of such an Integrated Hypersonic Transportation Programme, with kerosene for take-off, powered landing and low speed ascent/descent flight. Hydrogen is used for high-speed cruise flight. India would greatly benefit by an Integrated Hypersonics Transportation Programme, with leading institutions like ISRO, NAL and ADA working together to jointly study, design and build a strong technology base for small, unmanned hypersonic flight demonstrators. This project could then lead on, safely and economically, to hypersonic Executive Jet aircraft, and small fully Reusable Trans-Atmospheric Vehicles for direct ascent of the hypersonic aero spacecraft to earth orbit.

19 illus, 9 tables, 40 ref

000653   Ghose M K (Cent of Min Environment, Indian Sch of Mines, Dhanbad-826 004, Email: ghosemrinal@hotmail.com) : Biotechnological approach for the treatment of coke plant effluent: a suitable option in Indian context. Indian chem Engr 2005, 47(1), 56-60.

Coke plants are producing gas and coke for metallurgical purposes and also supply the raw materials for manufacture of dyes, drugs and high explosives. Naturally-found coal is converted into coke in coke ovens and a large quantity of water is used for quenching hot coke and for washing gas. Effluent generated contains high-suspended solids, high BOD, COD, phenols, ammonia and other toxic substances, which cause serious water pollution problem. There are a large number of coke plants in operation in the vicinity of Jharia Coal Field (JCF). The effluent treatment system was found to be inadequate. One large coke plant has been chosen to evaluate the characteristics of the effluent and to suggest a proper treatment method. Working principle of the coke plant and the effluent produced have been described. Effluent samples collected have been analyzed and the results have been discussed. Biological treatment has been considered as a suitable option for the treatment of coke plant effluent. With proper environmental control, coke plants effluent can be treated biologically. A scheme has been proposed for the biological treatment, which can be suitably adopted for the recycling, reuse and safe disposal of the treated effluent. Various processes and operations involved in the treatment system and disposal of sludge have been discussed.

6 illus, 1 table, 22 ref

000652   Dhamejani C L (NO, Vehicles Res and Dev Establishment, Vahannagar Post, Ahmednagar-414 006, Email: vrde@sancharnet.in) : Light weight propulsion system development for UAVs. J Aerospace Sci Technol 2005, 57(1), 49-57.

UAV has established itself as one of the major force multipliers for many applications of various armies throughout the world. These UAVs employ different kinds of machines as propulsion systems. Both the Reciprocating and Rotary engines are the leading contenders amongst these machines. Performance parameters like power to weight ratio, specific fuel consumption and the limited number of requirement of UAV engines call for a development methodology very specific to these engines. Related aspects of development methodology and proving of a modular series of single, twin and four cylinder two-stroke engines indigenously developed for UAV are reported in the paper. Technologies so developed for said series of UAV engines are presented in the paper. Endurance tests as well as limited trials conducted with airframe are also included. Grey areas as foreseen in the indigenous development technologies of rotary engines have been brought out.

34 illus, 1 table, 3 ref

000651   Desai V R;Ghosh S N;ISH M;Patro J (Civ Engng Dep, Indian Inst of Technol, Kharagpur-721 302) : National water grid - its objective and challenge. ISH J Hydraul Engng 2005, 11(1), 1-10.

In countries like India, having a large variation of water resources with space and time, inter-basin water transfer projects seem to be the ultimate solution to ease the water crisis and achieve a stable economic growth of the nation. But the projects of such huge magnitudes are always prone to large controversies, due to their numerous advantages and disadvantages. The water crisis in India may be stated as due to its vast expanse, huge population and a large variation of annual precipitation, both spatially and temporally. The substitute to the interlinking of rivers can be considered as adopting some techniques like extensive water harvesting, massive dredging operations to improve upon the water carrying capacity of the river systems, extensive soil conservation, tank rehabilitation schemes in the south and linking up all the existing coastal navigational canals for economical transport. Presents the scenario of inter-basin water transfers in India, its objectives, scope and the challenges to be met in the investigation, planning, design, execution and maintenance of the project.

2 illus, 12 ref

000650   Chandrasekar P;Ayyappan S (Dr Mahalingam Coll of Engng and Technol, , Pollachi, Tamil Nadu) : Effect of kerosene - ethanol blending on the performance of petrol engine. Pollut Res 2005, 24(1), 123-6.

In order to reduce the cost of fuel, improving the engine performance and reducing the noxious emissions, authors are carrying out the research work on adding 5% kerosone with ethanol blended petrol to be used as fuel in IC engines and study the engine performance and exhaust emissions. The study is being carried out on the four-stroke petrol engine under various loading conditions. The engine performance parameters like Brake power, Brake thermal efficiency, specific fuel consumption are being recorded for various loading conditions. Similarly the composition of the exhaust gases is being analysed for studying the polluting effect produced by this fuel on the atmosphere. The performance of the IC engine running on ethanol-blended petrol, petrol-ethanol-kerosone mixture under various loading conditions is recorded and is thoroughly analyzed.

2 illus, 4 tables

000649   Chakrabartty S K (Computational and Theoretical Fluid Dynamics Div, Natn Aerospace Laboratories, Post Box No. 1779, Bangalore-560 017, Email: drskc@ctfd.cmmacs.ernet.in) : Role of computational fluid dynamics in the design of aerospace configurations. J Aerospace Sci Technol 2005, 57(1), 24-32.

Computational Fluid Dynamics (CFD), a mature discipline now, can contribute considerably to the design, analysis and development of engineering systems involving fluid flows. Visualization of flow-field, surface load distribution and various aerodynamic forces and moments are the criteria for basic design of aerospace configurations. GFD complements experimental and theoretical fluid dynamics by providing an alternative and cost effective means to simulate real flow phenomena. The main advantage lies in its ability to cut down the number of wind-tunnel tests leading to reduction in the design cycle time and design cost. After a brief introduction to CFD, the role played by the modern CFD tools developed at the Computational and Theoretical Fluid Dynamics Division of National Aerospace Laboratories, Bangalore in the design and analysis of Aerospace configurations will be discussed here.

16 illus, 24 ref

000648   Bimalkhedkar S;Durga Prasad C H (NO, Def Avionics Res Establishment, New Thippasandra Post, Bangalore-560 075, Email: sbimalkhedkar@vsnl.com) : Defensive avionics for fighter aircraft - design considerations with emphasis on system installation. J Aerospace Sci Technol 2005, 57(1), 73-8.

A fighter aircraft is vulnerable to precision radar guided weapons of the adversary Air Defences. The aircraft survivability can be enhanced only by equipping it with modern Defensive Avionics. The Defensive A vionics typically comprises wide band sensitive receivers, powerful Signal Processors and high ERP transmitters. The sensitive receivers get affected by on board transmitters and the transmitters of the Defensive Avionics may interfere with satisfactory operation of other onboard avionics. Mutual compatibility is usually ensured by suitable temporal, spectral and spatial management techniques. The restricted spaces and limited ECS for cooling the Defensive gear call for careful tradeoffs to be made. The paper addresses these considerations and tradeoffs and suggests practical solutions to ensure that Defensive Avionics suite performs its role without degrading other avionics operation.

5 illus, 2 tables, 1 ref

000647   Athar Md (Dep of Civ Engng, Z H Coll of Engng & Tech.,A M U, Aligarh) : Energy loss due to sharp edged elliptical orifice plates. ISH J Hydraul Engng 2005, 11(1), 28-45.

The results of an experimental investigation concerning the loss coefficient for concentric, sharp edged elliptical orifice plates in a pipe line have been presented. Data were collected on five elliptical orifice plates with orifice area to pipe area ratio as 0.2, 0.33, 0.5, 0.66 and 0.84, keeping the major axis of the plates horizontal (displacement angle θ = 0°) as well as vertical (θ = 90°) . Five concentric circular orifice plates with same area ratios have also been tested for comparative study. The range of pipe Reynolds number was 1.0 x 10³ to 4.0 x 10⁴ while loss coefficient C_L varies from 0.09 to 80.0. It was found that for low pipe Reynolds number, loss coefficient is a function of area ratio and pipe Reynolds number but for high pipe Reynolds number (R_p ≥2.0 x 10⁴), loss coefficient is in variant of Reynolds number and only depends on area ratio. It is also found that there is little effects of displacement angle and elliptically on the loss coefficient.

12 illus, 2 tables, 8 ref

000646   Ahmad Z (Dep of Civ Engng, Indian Inst of Technol Roorkee, Roorkee-247-667, Email: zulfifce@iitr.ernet.in) : Finite volume scheme for river pollutant transport. ISH J Hydraul Engng 2005, 11(1), 67-84.

Accurate prediction of behaviour of pollutants discharged into rivers is crucial to the effective management of water quality of riverine systems. A finite volume (FV) scheme for the solution of the equation describing unsteady transport of non-conservative pollutant/BOD with first order decay rate is developed. The well-tested QUICK scheme is used for the computation of gradients of diffusion term and control volume face values of the advective term. The proposed FV scheme is tested with two examples: one for continuous plane injection of non-conservative pollutants for finite duration of time and the other with time-dependent periodic injection of pollutant into the riverine systems. The FV scheme leads to a solution that compares well with the analytical solution. The scheme is inherently conservative, transportive and produces oscillation free solution at the discontinuity in the concentration field.

4 illus, 25 ref

000645   Adimurthy V;Balu R;Priyadarshi P;Ramanan R V; Ravikumar C (NO, Vikram Sarahai Space Cent, Thiruvananthapuram-695 022, Email: v_adimurthy@vssc.org) : Multidisciplinary optimization in aerospace design: the emerging technology for complex systems. J Aerospace Sci Technol 2005, 57(1), 79-92.

The design, development and launching of a space vehicle is a highly interdisciplinary activity, with strong interaction between aerodynamics, structures, thermodynamics, flight mechanics, navigatian-guidance-control propulsion, telemetry, range safety etc. Performance, weight and finally cost optimality are most important in these systems. The desired goals are best achieved through formal disciplinary and multi-disciplinary optimization. In the context of the Indian space vehicle design, optimization of trajectories is routinely carried out for all missions. In recent times a number of aerodynamic shape optimization problems are taken up, many of them using high fidelity CFD codes. The need to limit the launch cost drives the increasing use of multi-level and multidisciplinary design optimization. The paper discusses the class of optimization algorithms used and developed along with a few case studies on disciplinary and multi-level optimization in the trajectory design of orbital and interplanetary missions, and emphasizes the emerging trends in the multidisciplinary design optimization of aerospace systems.

10 illus, 3 tables, 16 ref

024686   Waghmare S S;Pathak K K;Morchhale R K;Nandan M J (Regional Res Lab, , Bhopal-462 026, Email: waghmaress@rrlbpl.org) : Ferrocement water tank : an economical water storage facility for rural areas. J rur Technol 2006, 2(4), 156-60.

Ferrocement water tank exhibits high degree of impermeability, cheaper to built and require less skilled labour at site. They can withstand shock due to their flexibility, can be speedily erected and found economical and durable. A study has been carried out to observe the performance of a cylindrical ferrocement water tank of 3000 liters capacity made up of cement, sand and smaller size coarse aggregate (<60> 10 mm) in the mix proportion of 1 :2:2. Reinforcement are laid into two layers consisting of skeletal steel of 6mm diameter M.S. bars and chicken mesh to resist earthquake and wind effect and it's economy is compared with conventional ferrocement water tank having cement mortar 1 : 1 , reinforced cement concrete water tank with mix 1: 1.5:3 as well other available tanks in the market.

4 illus, 1 table, 10 ref

024685   Verma R;Shyam A;Shah K G (NO, Institute for Plasma Research, Gandhinagar-382 428, Email: rverma@ipr.res.in) : Design and performance analysis of transmission line-based nanosecond pulse multiplier. Sadhana 2006, 31(pt5), 597-611.

Conventionally, Marx generators are used for the production of short duration, high voltage pulses but since many discharge gap switches are utilized for stepping up the voltage, there are many disadvantages. An alternative and much simpler technique for the multiplication of nanosecond high voltage pulses has been presented in which multiplication takes place by switching single spark gap providing voltage gain of 'nxV' where n is the subsequent number of stages. Stepped up high voltage pulse with fixed voltage gain of defined shape with fast rise time and good flat top is produced without using additional pulse-forming network. Its operation has been made repetitive by switching single spark gap. Multipurpose use, low cost, small size, light weight (weighing less than 50 kg) and portability are the additional benefits of the system. The reported nanosecond pulser has been made by cascading three stages of Blumlein. To cross check its performance the parasitic impedance of the system has been evaluated to realize its adverse effect on the voltage gain and pulse shape. Also its operation has been simulated by PSPICE circuit simulator program and good agreement has been obtained between simulated and experimental results. Applications of this pulse generator include X-ray generation, breakdown tests, ion implantation, streamer discharge studies and ultra wideband generation, among others.

17 illus, 10 ref

024684   Verma H N (Water Technology Centre for Eastern Region, , Bhubaneswar-751 023) : Challenging issues related to watershed development and management. J rur Technol 2006, 2(4), 180-4.

Watershed is a hydrological entity refers to the entire area having a common outlet of water. It is most appropriate land unit for development and management of natural resources on the basis of its hydrological behaviours. The main principle of watershed development and management is to start planning, design and execution of works from the outer boundary near ridge line coming down from first order to second order and higher order streams covering upper parts of watersheds first and then coming to lower parts. There are many watershed development/management projects going on in our country but none of the projects has made satisfactory progress to fully serve the intended purpose. Watershed development and management is a dynamic process and a fully developed watershed becomes traditional after 2-3 decades needing further development. For sustainable development and management of natural resources on the basis of land and water, watershed should be considered as a bigger unit including irrigation water resources and it's catchment areas as well as command areas. Micro-level development and management of land and water following watershed principle, saturating the whole watershed, is ultimately going to control river flow. Conjunctive use of rain water, surface water and ground water at all the points in all the fields and multiple use of irrigation water for fish and crop production are going to increase productivity of water available in a watershed. Adequate manpower and budget should be provided in the projects to develop a region. There is an urgent need to develop replicable watershed model in different agro-climatic regions based on manpower and budget availability for the whole region.

3 ref

024683   Venkata Ramaiah K;Saikrishna C N;Bhaumik S K; Bhattacharya A;Nandy T K;Sagar P K (Materials Science Div, National Aerospace Laboratories, Bangalore-560 017) : Melting and processing of Ni-Ti shape memory alloys. Metals Mater Process 2006, 18(3-4), 411-19.

Nicke-titanium is a unique class of material known as Shape Memory Alloy (SMA). A thermoelastic martensitic phase transformation in the material is responsible for its extraordinary properties such as shape memory effect, superelasticity, and high damping capability. The near-equiatomic Ni-Ti alloys are the most commercially exploited SMAs because of the unique combination of these properties and superior ductility, strength, fatigue and corrosion resistance. The properties of Ni-Ti SMAs are very sensitive to composition and the processing parameters. The properties of Ni-Ti SMAs can be modified to a great extent by judicious choice of composition, mechanical working, and heat treatment. Desirable memory properties, in general, are obtained with 49.3 to 51 at.% Ni. Most of the metal fabrication techniques employed on normal metals and alloys are applicable to Ni-Ti SMAs, but many needs to be modified to accommodate the unique challenges that are encountered during processing of this class of materials. The various factors, which affect the processing of Ni-Ti SMA wires, are discussed. The areas covered are melting, hot working, cold working, wire drawing and heat treatment.

1 illus, 1 table, 33 ref

024682   Vasudeva Rao P;Sudhakar L (NO, The Singareni Colleries Co. Ltd., Kothagudem, Dist Khammam-507 101, ) : Futue of underground coal mining in India - mechanized bord and pillar or longwall. J Mines Metals Fuels 2006, 54(8-9), 169-74.

5 tables, 10 ref

024681   Upadhyay J;Chakera J A;Navathe C P;Naik P A; Joshi A S;Gupta P D (Laser Plasma Div, Centre for Advanced Technology, , P O CAT, Indore-452 013, Email: janky@cat.ernet.in) : Development of single frame X-ray framing camera for pulsed plasma experiments. Sadhana 2006, 31(pt5), 613-20.

Single-frame X-ray framing camera has been set up for fast imaging of X-ray emissions from pulsed plasma sources. It consists of two parts, viz. an X-ray pin-hole camera using an open-ended microchannel plate (MCP) detector coupled to a CCD camera, and a high voltage short duration gate pulse for the MCP. The camera uses a 10-μm pin-hole aperture for imaging on the MCP detector with a magnification of 6 X. The high voltage pulser circuit generates a pulse of variable duration from 5 to 30 ns (at 70% of peak amplitude) with variable amplitude from 800 V to 1.25 kV, and is triggered through a laser pulse synchronized with the event to be recorded. The performance of the system has been checked by recording X-ray emission from a laser-produced copper plasma. A reduction factor of ~6.5 is seen in the dark current contribution as the MCP gate pulse is decreased from 250μs to 5 ns duration.

5 illus, 4 ref

024680   Undale M;Shamrao;Abdul Hameed H;Yadav S; Nagaraj B P;Viswanatha N;Murali N S;Nataraju B S (Spacecraft Mechanism Group, ISRO Satellite Centre, Airport Raod, Bangalore-560 017) : Large unfurlable antenna reflector. J Spacecraft Technol 2007, 17(1), 34-44.

Describes the design and fabrication of Large Unfurlable antenna (LUFA), which is currently under development and qualification for an Indian geo-synchronous communication satellite. The design features of Deployable Rim Truss (DRT), Cable Network, Hold-down Release and Primary Deployment Mechanism are described with different option studies. A parametric study with different nested rings has been carried out to arrive at statically determinate cable net configurations. Software has been developed using cable element to arrive at pre-defined cable-net configuration with positive tension in all cables. Hold-down release mechanism has been designed to withstand the separation and launch loads, and to prevent the unfurling before the arm locks to the required orientation. Primary deployment mechanism is designed to deploy the antenna reflector through a predefined angle and lock to the desired orientation. Issues related to surface profile measurement and corrections are also discussed. A brief summary of tests to be conducted for qualification of the LUFA reflector is also resented. A 5.5 m aperture reflector model, has been fabricated and assembled, and the functioning successfully demonstrated.

12 illus, 2 tables, 6 ref

024679   Thamarai Selvi S;Malmathanraj R (NO, Madras Institute of Technology, Anna University, Chennai-600 044) : Missile defence and interceptor allocation by LVQ-RBF multi-agent hybrid architecture. Def Sci J 2007, 57(2), 173-83.

Authors proposes a solution methodology for a missile defence problem using theatre missile defence (TMD) concept. In the missile defence scenario, the concept of TMD is generally used for the optimal allocation of interceptors to counter the attack missiles. The problem is computationally complex due to the presence of enormous state space. The Learning vector quantiser-Radial basis function (LVQ-RBF) multi-agent hybrid neural architecture is used as the learning structure, and Q-learning as the learning method. The LVQ-RBF multi-agent hybrid neural architecture overcomes the complex state space issue using the partitioning and weighted learning approach. The proposed LVQ-RBF multi- agent hybrid architecture improvises the learning performance by the local and global error criterion. The state space is explored with initial coarse partitioning by LVQ neural network. The fine partitioning of the state space is performed using the multi-agent RBF neural network. The discrete reward scheme is used for LVQ-RBF multi-agent hybrid neural architecture. It has a hierarchical architecture which enables quicker convergence without the loss of accuracy. The simulation of the TMD is performed with 500 assets and six priority of asset.

^ssc9 illus, 18 ref

024678   Surender G D;Mukherjee T K (Regional Research Laboratory, (CSIR), Trivandrum-695 019, Email: tkm@barc.gov.in) : Can India emerge as a manufacturing hub for global TiO₂ feedstock and pigment industry by the year 2025. Metals Mater Process 2006, 18(3-4), 201-9.

Global TiO₂ industry is witnessing a paradigm shift towards Asia in the last few years with China dominating the growth in the pigment industry. It is widely predicted that India will follow the. Chinese example in the years to come but with an additional advantage namely, the possession of an-excellent ilmenite mineral resource base. Both the commercially proven processes and the yet to be proven but promising TiO₂ feedstock technologies have been compared and their dependence on energy resources is highlighted. Aims to analyse the emerging scenario and identifies metallised ilmenite as an intermediate marketable product, along with an integrated process involving IGCC and slag technologies as a strategy to achieve global competitiveness under Indian conditions.

5 illus, 3 tables, 9 ref

024677   Sujata M;Bhargava S;Suwas S;Sangal S (Materials Science Div, National Aerospace Laboratories, Bangalore-560 017, Email: s_mathukumilli@yahoo.com) : Mechanism of formation of Ti9Al₂₃ phase during interaction between solid Ti and liquid Al. Metals Mater Process 2006, 18(3-4), 283-8.

Technique of reaction synthesis widely used for the production of TiAl₃ base intermetallics. Studies show that various other Al-rich compounds also form during synthesis of this compound. The reaction temperature plays a dominant role in controlling the microstructure and the composition of the various intermetallics that form during synthesis. The study was conducted to identify the conditions under which the Ti₉Al₂₃ phase forms during synthesis between soild Ti and liquid Al. X-ray diffraction studies suggest that formation of Ti₉Al₂₃ phase occurs in addition to TiAl₃ at the temperatures of 1373K. The mechanism of formation of this phase was explained in terms of the incipient melting of freshly formed TiAl₃ as a result of adiabatic rise of temperature at the reaction interface.

4 illus, 2 tables, 20 ref

024676   Srinivasan C;Sivakumar C;Gupta R N (NO, National Institute of Rock Mechanics, P.O. Champion Reefs, Kolar Gold Fields, Karnataka-563 117) : Application of rock mechanics and microseismic investigation in coal mining in India. J Mines Metals Fuels 2006, 54(8-9), 192-7.

Presents results from studies carried out in Indian coal mines with respect to bord and pillar ining and Longwall mining operation. The objective of the study was to know strata-support interaction, assess stability of coal mine workings, identify highe stress zone and predict the occurrence of roof falls. The field investigation and analysis of difficult-to-cave roof using powered supports under a massive dolerite sill in central India using a state-of-the-art dtat logger system are described. A sophisticated PC based data acquistion and analysis system developed at NIRM and installed at Churcha west coal mine to monitor the goaf falls. The system has recorded many roof falls and given clear indication before the occurrence of loal and main falls. Multi channnel 24 bit digital microseismic monitoring system was installed on the longwall panel P-2 at Rajendra colliery to study the strata behaviour in real time. The result obtained indicated good correlation between microseismic activity rate, roof falls, periodic weighting and propagation of fractures. Among serveal seismic parameters, microseismic event rate showed a clear indication for short range predictionof impending roof falls in real time. The experience and results from these studies are explained in thisp paper which could pay the way for successrul underground mining in India.

8 illus, 1 table, 8 ref

024675   Sita Manohar Reddy K;Ranganath R;Sridhara C D (Spacecraft Mechanisms Group, ISRO Satellite Center, Airport Road, Bangalore-560 017) : Automated test facility for characterisation of hinge assemblies for solar panel deployment mechanism. J Spacecraft Technol 2007, 17(1), 68-77.

Describes the development of an automated hinge characterization test facility, which is extremely useful in ascertaining the performance characteristics of hinge assembly pairs in the entire range of its operation with higher accuracy and repeatability than the conventional method hitherto adopted. Hinge assemblies characterized using this facility have been successfully flown on GSA T-3 (EDUSAT) and INSAT-4A satellites.

10 illus, 4 tables, 4 ref