015033   Dube G P;Kapuria S;Dumir P C;Pramod J P (NO, Indian Inst of Technol Delhi, New Delhi-110 016) : Effect of shear correction factor on response of cross-ply laminated plate using FSDT. Def Sci J 2005, 55(4), (NULL).

Results of the first order shear deformiation theory (FSDT) depend on the choice of the shear correction factor. In a companion paper, the authors presented a unified general formulation of all higher-order theories for geometrically nonlinear response of cross-ply plates, based on a single polynomial expansion of displacements in the thickness coordinate, z. It includes 10 models available in the literature as special cases. In the paper, numerical results for the static, vibration, and buckling of the FSDT has been compared with the elasticity solution and /or a higher-order theory solution, to investigate the effect of choice of the shear correction factor on the response of composite and simply supported rectangular plates.

10 tables, 12 ref

015032   Dhabadgaonkar S M (NO, , "Laxmi", 58, PMG Layout, Narendra Nagar, Nagpur-440 015) : An 'ecosan' approach for household sanitation in rural & semi-urban areas in developing countries. J Indian Wat Wks Ass 2005, 37(4), 259-66.

Describes new approach (an 'Ecosan' approach) for effective collection, treatment disposal of domestic wastes in rural and semi-urban areas. The approach combines the best features of Water Seal Type Pour Flush Double Pit Privy, Fixed Film Anaerobic Reactor and Fluidized Bed Anaerobic Reactor, in sequence. The small quantity of treated wastes is envisaged to be lifted up daily and utilized for gardening, preferably in the courtyards. Where this is not possible, the effluent may mixed with other waste waters and carried through open drains. The mixture BOD will still be below permissible limits for discharge in natural drainage courses. Alternately, a Small Bore Sewer System (SBSS), with appropriate modifications, may be provided to transport the effluents to a suitable site for disposal on land. The system has few limitations, but offers several advantages such as (i) avoiding pollution of surface and ground water resources, (ii) Protecting public health, (iii) utilization of irrigative and nutritive values in human wastes for gardening, (iv) not causing any structural damage to the buildings in the vicinity, (v) suitable for impermeable sub-soil (vi) cheaper and better than septic tanks, (vii) conservation of water. The design and operation of this eco-friendly system is discussed in details. Having many advantages and a few limitations, it is expected that the system offers an eco-friendly and appropriate approach to the problem.

2 illus, 9 ref

015031   Deergha Rao K;Plotkin E I;Swamy M N S (Res and Training Unit for Navigational Electron, Osmania Univ, Hyderabad 500 007, Email: korraidrao@yahoo.com) : Adaptive blind equalization of nonlinear channels and chaotic systems using coupled EKF and RLS estimator. IETE J Res 2005, 51(3), 181-92.

Novel approach, which employs coupled extended Kalman filter (EKF) and recursive least squares (RLS) estimator has been proposed for adaptive blind equalization of nonlinear channels and chaotic systems. The conventional models of nonlinear FIR Volterra channels, nonlinear IIR channels, and chaotic communication systems are cast into regression models to formulate RLS algorithm to estimate the unknown channel parameters. The state-space representation of the channels have been formulated to develop the EKF to estimate the state from which the input sequence can be recovered. Then, the EKF and RLS estimator are coupled to estimate jointly the channel parameters and the state. The stability problem of the estimator has also been addressed. The proposed estimator was corroborated with simulation examples on adaptive blind equalization of nonlinear FIR Volterra channels, nonlinear IIR channels, and chaotic communication systems. Simulation results shows that the proposed estimator is effective in recovering the input sequence as well as the channel parameters blindly from the channel output measurement.

14 illus, 16 ref

015030   Datta R;Sengupta I (Dep of Computer Sci and Engng, North East Regional Inst of Sci and Technol, Nirjuli, Arunachal Pradesh-791 109, Email: raja_datta_nerist@yahoo.com) : Static and dynamic connection establishment in WDM optical networks. IETE J Res 2005, 51(3), 209-22.

Authors has given a brief review of the work done by various researchers over the years in the area of Wavelength Division Multiplexed (WDM) optical network and more specifically in the area of connection establishment. Optical WDM is the most promising solution for setting up of the next generation networks. Static and dynamic lightpath establishments are the two types of lightpath establishments in WDM networks. In static environment the lightpath establishment is permanent, whereas in dynamic environment the lightpaths are established in real time and taken down as per requirement. Review the important algorithms under static and dynamic connection establishment. Author has also discuss the use of evolutionary algorithms in optical networks and review distributed optical network control algorithms, as these topics are generating lot of interest now-a-days. To make the review concise, it has been confined to the cases where connections are established in WDM networks without wavelength converters.

^iia8 illus, 74 ref

015029   Dash S K;Pal U S;Sudheer K P (NO, Coll of Agric Engng and Technol, OUAT, Bhubaneswar, Email: sk_dash1006@rediffmail.com) : Comparison of energy requirements of some alternate parboiling methods for paddy. J rur Technol 2004, 1(5), 227-30.

An analysis was carried out for the energy consumption in some alternate parboiling methods than the popular CFTRI method of parboiling to study their feasibility of adoption under Indian rural conditions. The methods studied were the high temperature drying-cum-parboiling process, short soaking tempering process, parboiling using thermic fluid, parboiling by simple soaking in hot water and the pneumatic pressure parboiling. It was observed that under the identical initial moisture condition, the high temperature drying-cum-parboiling method, which used essentially roasting in sand, used the maximum energy up to the gelatinisation process (1050.3 MJ/tonne) followed by the parboiling method using thermic fluid (615.2 MJ/tonne of paddy). This was mainly due to the conductive heating method, which also in turn resulted in maximum amount of heat loss to surroundings. The other methods used almost similar amount of energy as CFTRI method. The minimum energy consumption up to the completion of gelatinisation process was in case of the short soaking-tempering process at 363.6 MJ/tonne. When the energy utilization due to drying was also added, the maximum energy consumption was 1497.8 MJ/tonne for pneumatic pressure parboiling followed by 1304.8 MJ/tonne for the high temperature drying-cum-parboiling method. The minimum energy was for short soaking tempering method at 855.4 MJ/tonne. This analysis could help in designing and analysis of energy utilization pattern of rice processing operations.

2 tables, 9 ref

015028   Choudhury J P;Sarkar B (Inf Technol Dep, Kalyani Govt. Engng Coll, Kalyani) : Forecasting of engineering manpower on the basis of ANOVA analysis. J Instn Engrs-Pt ID 2005, 86(Nov), 43-8.

Effort is made to assess the engineering manpower requirement (personnel belonging to mechanical engineering) in certain industry group (steel manufacturing) in the state of West Bengal in India. The models of fuzzy time series, Markov modelling and artificial neural network (feed forward backpropagation neural network) are tested and based on ANOVA analysis (analysis of variance) that model with maximum ANOVA coefficient is selected and used for assessment of futuristic engineering manpower. Certain statistical functions, ie, least square technique based on linear, exponential, curvilinear (parabolic) equations and the tables of orthogonal polynomial are applied on the estimated data value calculated earlier. The particular statistical model is chosen based on the average error of estimated date generated using statistical models with the actual data over span of years. Under fuzzy time series method, a first order time invariant model has been developed and a max-min composition operator has been used for calculating forecasted output. Under Markov modelling, the vector of state probabilities are calculated based on transition matrix. With Markov model, there is a requirement that all the state probabilities must sum to one for each observation. Membership functions in fuzzy time series do not have this restriction. Artificial neural network (ANN) is a network which is trained for certain specific purpose. In case of supervised neural network, supervision exists over training. Feedforward back propagation neural network belongs to supervised neural network.

3 illus, 7 tables, 23 ref

015027   Chauhan B S;David E;Datta P K (NO, Instruments Res & Dev Establ, Dehradun-248 008) : Sensors for desert surveillance. Def Sci J 2005, 55(4), 493-503.

Various types of sensors-visible, passive night vision, infrared, synthetic aperture radar, etc. can be used for desert surveillance. The surveillance capability of these sensors depends to a large extent, on various atmospheric effects, viz., absorption, scattering, aerosol, turbulence, and optical mirage. In the paper, effects of various atmospheric phenomena on the transmission of signals, merits and demerits of different means of surveillance under desert environmental conditions have been discussed. Advanced surveillance techniques, i.e. multisensor fusion, multi and hyperspectral imaging, having special significance for desert surveillance, have also been discussed.

^iia2 illus, 2 tables, 21 ref

015026   Chachadi A G;Choudri B S (Dep of Earth Sci, Goa Univ, Goa-403 206) : Well hydrographs as tools for impact assessment of open cast mining on groundwater regime in Goa. J appl Hydrol 2004, 17(2-3), 20-6.

5 illus, 1 ref

015025   Bose N;Senthilbalamurugan S (Mech Engng Dep, Mepco Schlenk Engng Coll, Mepco, Virudhnagar-626 005) : Experimental and numerical analysis of temperature distribution and NO_x conversion in a diesel particulate filter. J Instn Engrs-Pt MC 2005, 86(October), 134-9.

Forced by strict emission standards, interest in the reduction of exhaust emissions from automobiles has been increasing. In a diesel engine, a modelling approach for the combined catalyst and diesel paniculate filter (DPF), system has been attempted. DPFs are probably the most effective means for trapping the exhaust emitted paniculate from diesel engines. Foam type filter becomes a promising alternative to common wall flow filters, since they are effective in filtering small size panicles and provide a large specific area for catalytic coatings. A two-dimensional model taking into account the significant phenomenon during the filtration of foam filters has been developed, which can predict the temperature distribution and NO_x conversion. The predicted results from the model for NO_x conversion show an encouraging agreement with experimental results and the error lies within ± 4%.

6 illus, 8 ref

015024   Bhattacharya S;Sarkar B;Mukherjee R N (Dep of Mech Engng, Jadavpur Univ, Kolkata-700 032) : Selection of a conveyor belt material under multi-criteria decision making environment. J Instn Engrs-Pt MC 2005, 86(October), 140-4.

Conveyor belts are required to transport different types of materials in industries under varying operating conditions. A number of materials for such belts are available in the market. However, it is impossible to identify one such material which will perfectly respond to all such requirements in a given environment. Hence, arises the question of optimisation. The present ankle is based on one such optimisation technique known as analytical hierarchy process (AHP). The algorithm used is obtained by integrating Brown and Gibson model and AHP. It considers a number of alternative materials as well as design criteria (respectively 4 and 5 in the present paper) and arrives at the most suitable material. The algorithm calculates the priority vector (PV) values by eigen-vector method of pair-wise comparison. These PV values are calculated through an iterative process, and are accepted if the concerned matrices yield consistency ratios (CR) below a specific limit. Then the composite priority (CP) values are calculated, and the alternatives are ranked according to their CP values. Next, the sensitivity analysis is taken up where the CP values are used as subjective factor measures (SFM) in determining belt material measure (BMM). The algorithm is coded in FORTRAN language. The program is general, and can be used to handle smaller or larger number of criteria and alternatives as well.

8 illus, 10 tables, 9 ref

015023   Bhat S K;Balkrishna K M (NO, Mangalore Univ, Mangalagangotri-574 199) : Review on natural ventilation of residential building. J Instn Engrs-Pt AR 2005, 86(Oct), 25-7.

Supply of outdoor fresh air into the indoor space to displace vitiated air; to dilute indoor contaminants and concentration of carbon dioxide; to remove body odours; to maintain a balance of air pressure between indoor and outdoor; to remove positive ions and to provide acceptable thermal environment is called as ventilation. Ventilation is one of the basic parameters required to create an acceptable indoor environment. Ventilation may be either natural ventilation or mechanical ventilation.

9 ref

015022   Ahuja B M;Bhandari R K;Ahuja V (NO, Ahuja Consultants Pvt Ltd, New Delhi) : New sports facilities by Delhi Devlopment Authority - structural challenges. J Instn Engrs-Pt AR 2005, 86(Oct), 32-4.

Delhi Development Authority (DDA) in the recent past had been developing various sports facilities in Delhi. Presents some of the structural challenges faced by DDA and how they had been tackled. Among the interesting structures was the tackling of a substitution of simple trusses for large spans with sheeting by ferro-cement on doubly curved space frames in a different manner. Also dealt with was the situation of 3-D folded plates used for roofs. Another example is of preventing expensive heavy floors for swimming pools against floatation when constructed at sites with high water table. Some of the structures built are described.

6 illus

015021   Ahmed M;Sekhon G S;Singh D (NO, Indian Inst of Technol Delhi, New Delhi-110 016) : Finite element simulation of sheet metal forming processes. Def Sci J 2005, 55(4), 389-401.

Classification of formulations dealing with geometry and material nonlinearity in the context of finite element simulation of forming operations has been recapitulated. The procedures based upon shell and continuum approaches and methods of dealing with frictional contact has been described.

^iia119 ref

013814   Ziliukas A (Dep STOPWORD Mechanics STOPWORD Solids, Kaunas Univ of Technol, Kestucio str. 27, Kaunas LT-44025, Lithuania, Email: antanas.ziliukas@ktu.lt ) : Fracture criterion developed for elastic-plastic Russian materials. Indian J Engng Mater Sci 2005, 12(5), 451-5.

One of the ways to maximize the safety of metal structures and components is to use elastic-plastic materials instead of brittle ones. The use of such materials reduces the probability of catastrophic failure occurring from crack like flaws that may have resulted from the manufacturing process or during the operational life. However, within the field of fracture mechanics, the criterion of brittle fracture is more developed than brittle-plastic fracture criteria. Paper deals with the analysis of universal fracture criteria, which are suitable not only for elastic materials with the brittle fracture, but also for elastic-plastic materials with the elastic-plastic fracture. An analytical two-parametrical fracture criterion has been proposed for static loading, which is validated experimentally and compared with the behaviour of perfectly plastic and elastic specific Russian materials. It allows the fracture resistance of structural components made of elastic-plastic materials to be evaluated more precisely.

2 illus, 1 tables, 9 ref

013813   Vijaya Vittala C B;Bhaumik S;Gupta S C; Agarwal V K (Dep STOPWORD Mechanical Engng, North East Regional Inst of Sci & Technol, Nirjuli-791 109) : Nucleate pool boiling of methanol on PTFE coated heating tube. Indian chem Engr 2005, 47(3), 152-5.

An attempt has been made to study nucleate pool boiling of methanol from polytetrafluoroethylene (PTFE) coated brass heating tubes at atmospheric and subatmospheric pressures. The value of heat flux ranges from 15.288 to 43.680 kW/m² and pressure from 26.33 kN/m² to 97.60 kN/m². Three heating tubes covered with PTFE coating thicknesses of 21, 39 and 51 microns are used for the investigation. Boiling characteristics on such surfaces are compared with those on uncoated one. Enhancement of boiling heat transfer coefficient due to PTFE coating is a function of heat flux, pressure and thickness of coating. It also provides a criterion for the enhancement of heat transfer coefficient for saturated boiling of methanol on a PTFE coated tube.

5 illus, 1 table, 9 ref

013812   Turkel V;Ogur A;Anik S (NO, IGDAS, Umraniye, Istanbul, Turkey) : Computer aided investigation of spherical LPG vessel design and manufacturing. Bull pure appl Sci-Sect D 2004, 23(2), 103-9.

Spherical pressure vessels are the main elements, hearts of chemical plants and refineries. There are several circumstances, which have to be covered in design of spherical vessels. Several standards have adapted for these circumstances. In the study, a computer program, which is prepared according to conditions defined by three different standard institutions has been presented. Calculation and comparison based on several engineering and design parameters can be realised easily and quickly. Besides short operation time, the software provides possibility of the selection of the best design by comparing the results. In the concept of the paper, possible analysis options were discussed by describing software and its functions.

4 illus, 8 ref

013811   Thakkar D;Ganguli R (Dep STOPWORD Aerospace Engng, Indian Inst of Sci, Bangalore-560 012) : Active twist control of smart helicopter rotor. J Aerospace Sci Technol 2005, 57(4), 429-48.

Helicopter vibration and blade-vortex interaction noise are major problems restricting the wider use of helicopters in civil and military applications. Traditional methods based on vibration isolators and absorbers and passive designs of the rotor blade to reduce BVI noise have reached the point of diminishing returns and are increasingly unable to meet the stringent requirements of next generation helicopters. The advent of smart materials such as piezo-ceramics, has opened the possibility of actively twisting the rotor blade using control algorithms in a manner such that new higher harmonic forcing is developed which cancels the existing unsteady higher harmonic aerodynamic forces that are the main sources of vibration and noise on the rotor. Since the main rotor of a helicopter is the principal source of vehicle vibration, active twist control offers possibility of a low vibration helicopter. The paper reviews the literature in active twist rotor control using smart material.

11 illus, 92 ref

013810   Sudarsana Rao H;Ramana N V (Dep STOPWORD Civ Engng, JNTU Coll of Engng, Anantapur-515 002) : Behaviour of slurry infiltrated fibrous concrete (SIFCON) simply supported two-way slabs in flexure. Indian J Engng Mater Sci 2005, 12(5), 427-33.

Slurry infiltrated fibre concrete (SIFCON) is one of the recently developed construction material. SIFCON could be considered as a special type of fibre concrete with high fibre content. The matrix consists of cement slurry or flowing cement mortar. This composite material has already been used for structures subjected to blast loading, repair of pre-stressed concrete beams and safe vaults. Information on behaviour of two-way slabs in flexure has been presented. Flexure and cyclic load tests have been conducted and compared with fibre reinforced concrete (FRC) and plain concrete slabs. Both strength and deflection characteristics have been studied. The results of the experimental investigation indicate that with 12% fibre by volume of matrix, slabs possess excellent performance among other slabs in all respects.

7 illus, 2 tables, 11 ref

013809   Sharma P D (Mktg Dep, Sol Explosive Ltd, Nagpur) : Tunnel blasting-emulsion explosives and proper blast design are the prerequisite for better efficiency. J Mines Metals Fuels 2005, 53(9), 157-65.

In the article the author tries to discuss the best possible explosives available for undertaking such a important job (i.e., emulsion Explosives and its superiority over other form of explosives available) and various blast designs, sequence of excavation, types of strata encountered and steps required for its control, sequence of delays to be used in blasting etc. Regarding controlled blasting for carrying out ideal blast in tunnel, i.e., to blast in such a way that minimum of damage to the rock that remains and a minimum of over break is made. This has many advantages like, less rock damage to achieve greater stability and requirement of less ground support, safer tunneling operation as less scaling is required, less over break makes a smoother hydraulic surface for an unlined tunnel and less concrete required to fill excess void created by over break. At the same time, the author discusses the theory of blast induced ground vibration during tunneling and to control such adverse effect.

9 illus, 4 ref

013808   Shan G (NO, Inst of Electron Chin Acad of Sci, LongZeYuan 24-3-501, ChangPing District, Beijing 102208, P.R.China, Email: rg@mail.ie.ac.cn) : Space-time transformation for superluminal signaling. Bull pure appl Sci-Sect D 2004, 23(2), 75-80.

Author has analyzed the implication of the possible existence of superluminal signaling for space-time structure. A new space-time transformation for superluminal signaling is presented based on the superluminal synchrony method. Argued that Lorentz transformation should be replaced by the new transformation in case of the existence of superluminal signaling. Author has also discussed the possible existence of absolute frame, and propose a possible method to probe it.

24 ref

013807   Schaecter N;Jakob K F (Mgmt Bd, RAG Coal Int, VDMA, Germany) : The German mining industry-recent developments. J Mines Metals Fuels 2005, 53(10), 201-8.

27 illus

013806   Satija P K (NO, Tata Steel, Noamundi, Email: pk.satija@tatasteel.com) : Application of artificial neural networks at Noamundi-a case study of water pipeline leak detection. J Mines Metals Fuels 2005, 53(9), 172-5.

Artificial neural networks are used for predictive analysis of systems using pattern recognition and various other techniques. In this study it is proposed to predict the location of a leak in the water pipeline supplying water to Noamundi plant operations. This 17 km long pipeline exists between Noamundi plant and the water supply source. This area in between has mostly hilly and uninhabitable terrain. Whenever a pipeline leak or break occurs it takes several hours to locate and repair the break/leak during which time the production gets adversely affected. In this study statistical techniques such as Wald's Sequential probability test ratio and pressure point analysis are being evaluated to be used in conjunction and within a artificial neural network framework to predict the breakage/leak and reduce the location and repair time of the same in a significantly reduced time compared to the present.

8 illus, 8 ref

013805   Sastry M K S;Ramana Rao P V;Bala Subrahmanyam P V (Dep STOPWORD Electl Engng, Kamla Inst of Technol and Sci, Huzurabad-505 468) : Interactive approach for distribution supply restoration based on relational database. J Instn Engrs-Pt EL 2005, 86(Dec), 166-9.

User friendly and highly interactive scheme for distribution supply restoration is suggested using a relational database support. This scheme is capable of dealing with realistic, large-scale outages caused by faults of any type in HV and MV distribution networks. Data is methodically arranged and hierarchy within all the devices with proper hierarchy. The proposed scheme exploits the relational feature and hierarchy of the data and determines the viable and best restoration strategy while taking all the necessary restoration constraints into account. A typical 11 kV urban distribution network is considered for testing the scheme and results are presented.

1 illus, 8 tables, 9 ref

013804   Santhi Seela R;Janarthanan S (NO, Aeronaut Devolopment Establ, CV Raman Nagar, Bangalore-560 093) : Generic components based expert system shell for avionics applications. J Aerospace Sci Technol 2005, 57(4), 449-58.

The paper focuses on the construction of a Generic Components Based Expert System Shell for various avionics applications. Traditional Expert Systems have been constructed using a single monolithic software program for a specific application. In traditional/commercial Expert System, either the Knowledge base is hard-coded into the program or the linking of the Expert System modules with the knowledge bases takes place during compilation time. These commercial Expert Systems can't be used for complex applications where multiple knowledge bases have to be handled at run time, because the coupling of any particular knowledge base needs either the alteration of program code and/or recompilalion. Secondly, all these commercial Expert Systems are working in interactive mode during the inference process. To overcome these problems, ADE (Aeronautical Development Establishment) is currently involved in the design and development of a complex competent shell i. e. A Generic Components Based Expert System Shell for Avionics applications. This shell works in automatic mode and the system engineer can easily configure these generic components into a domain-oriented solution for any complex application including applications where multiple knowledge bases are handled. In this paper, the role and generic nature of this shell along with its components and how they are configured as a domain-oriented solution for different kinds of applications at ADE have been discussed.

7 illus, 1 table, 6 ref

013803   Sankaran R;Avirajamanjula P (NO, SASTRA (Deemed University), Thanjavur-613 402) : Closed loop real-time speed control of single phase induction motor using a PC. J Instn Engrs-Pt EL 2005, 86(Dec), 177-9.

The paper deals with real-time closed loop speed control of a single phase 0.75 kW induction motor using a PC. The motor is fed from a variable-frequency, variable-voltage IGBT power inverter and the driver circuits are interfaced with a PC. The latter executes the control program and serves also as a data acquisition system through an ADC IDAC add-on card. The program and time overhead on the PC are minimised by external hardware which digitally generates the PWM signals required by the inverter. The multitasking software in C language using foreground and background programs enables the PC to function interactively with an operator in real time.

4 illus, 4 ref

013802   Sadhu S;Ghoshal T K (Electl Engng Dep, Jadavpur Univ, Kolkata-700 032) : Input estimation and seeker filtering with special reduced order observers. J Instn Engrs-Pt EL 2005, 86(Dec), 185-91.

The property of zero sensitivity of the JHG and JPI filters for stabilizing loop parameters has been utilised for constructing observes of substantially reduced order. The order reduction has been brought about by a method, which is quite different from standard reduced order observers. It has been shown that the order reduction is possible not only from the insensitivity of the JHG and JPI filters to parameters and signals in the inner stabilising loop, which accrued through the algebra of pole placement technique, but may also be deduced more simply from block diagram manipulations. With the block diagram manipulation, it is not necessary to assume a linear model for the inner stabilising loop. Elimination of the inner stabilising loop, which is usually non-linear and uncertain, makes the proposed reduced order observer type filter structurally much simpler for on-line implementation. It has been demonstrated that the reduced order RJHG and RJPI observers, may, like their predecessors, be used for estimating the unknown input as well as states. Some interesting properties including sensitivity of the proposed observers to outer loop parameters have been exemplified with a case study.

7 illus, 13 ref

013801   Routray P K;Chakraborty A (NO, Natn Alumin Col. Ltd., Damanjodi-763 008) : Mining and electronics-an overview with reference to a NALCO mine, India. J Mines Metals Fuels 2005, 53(10), 219-22.

Mineral demand explosion has led to the needs for higher production, improved productivity and O.M.S. Reliable communication system has become essentially required to support business. In this post industrial age, technology (technique + structure) has been rapidly changing aiming at safe production i.e. accident free mining to get result in quality ore production at least cost in environment-friendly way so as to survive in competition. After the onset of the industrial revolution, the modes of our industrial production processes and social behaviour etc. had been following a certain pattern. However, over the last few decades. Internet revolution and the information technology have provided a new dimension to many spheres of human activity. At the dawn of this new millennium, we are on the threshold of IT revolution. Mining being the mother industry, provides base for all successes. Therefore, smart mining needs support of advanced technologies. Electronics is the prime mover for development Mining industry has incorporated technologies like GPS based truck dispatch system (TDS) in opencast mines, micro processor in blast hole drills, thyrester controlled A.C. synchronous motor in long distance cable belt conveyor with programmable logic control (PLC), computerized mine planning, IT and computers for MIS, mine survey by EDM, OFC for telecommunication. Also, walkie-talkies for field co-ordination etc. are the specific use of electronics in mining. Thus, this paper deals with the use of electronics in mining, accrued benefits and with some suggestions for the future.

3 ref

013800   Ravi G;Chakrabarti R;Choudhuri S (Dep EEE, Pondicherry Engng Coll, Pondicherry, Kerala) : ANN approach for economic dispatch by considering load patterns. J Instn Engrs-Pt EL 2005, 86(Dec), 149-54.

At attempt to explore the feasibility of artificial neural networks (ANN) approach to solve the economic load dispatch (ELD) problem in accordance with variations of consumer load patterns. The proposed approach is tested on the IEEE 6-bus system with several heuristic load patterns. It has been observed that the trained network successfully classifies the unknown load patterns and yields much faster results with sufficient accuracy. This powerful and versatile feature of the proposed method is quite suitable for real time implementation of power system operation, especially in security assessment problems.

3 illus, 2 tables, 15 ref

013799   Raju S;Rajendra Kumar;Nim S P;Bodas M S (Geol Surv STOPWORD India, Nth Region, Lucknow) : An evaluation of multicoloured granitic rocks from Bundelkhand granitic complex, Uttar Pradesh as dimension stone. J Mines Metals Fuels 2005, 53(9), 166-171,175.

The Bundelkhand granitic complex (BGC) exposes a variety of granitic rocks and associated basic intrusives, covering an area of about 11,000 km² in southern parts of Uttar Pradesh. In the last decade, the northern region of Geological Survey of India did a resource survey of these granitic rocks and basic intrusive (commercially known as multicoloured and black granite respectively) to understand their viability as dimension stone. Evaluation of these multicoloured granites as dimension stone has been attempted on the basis of the field and laboratory studies.

10 illus, 3 tables, 10 ref

013798   Ozarpa C;Ogur A;Gure Cam;Vural M (Mechanical Engng Dept, Sakarya Univ, Sakarya, Turkey) : Friction stir welding of aluminium alloys EN AW 2024-0 and EN AW 5754-H22. Bull pure appl Sci-Sect D 2005, 24(1), 23-31.

Friction stir welding (FSW) is a new solid phase technique invented and patented for the butt and lap welding of ferrous and non ferrous metals. Structure and mechanical properties of friction welded joints of aluminium alloys EN AW 2024 and EN AW 5754 is studied. By using of different aluminium alloys EN AW 2024 and EN AW 5754 friction stir welding performed that is called dissimilar welding.

7 illus, 6 tables, 10 ref

013797   Naik S D;Apte S K;Sonawane R S;Mulik U P;Kale B B (NO, Cent for Mater for Electron Technol, Panchawati, Off Pashan Road, Pune-411 008, Email: kbbb1@yahoo.com) : Nanostructured CdS/CdSSe glass composite for photonic application. Pramana J Phys 2005, 65(4), 707-12.

The work describes the synthesis of CdS/CdSSe glass nanocomposites and its characterization. A few glass compositions were optimized and the optimized host glass was remelted along with different semiconductors like CdS and CdSSe at high temperature. The CdS/CdSSe is present in amorphous state in the glass matrix. The thermal treatments have been carefully optimized to obtain well-defined uniform crystal growth of CdS and CdSSe. The glasses with optimized conditions were fabricated and characterized thoroughly using UV, TG/DTA and TEM. The shift in absorption edge to the longer wavelength with heat treatment implies the increase in the crystal size. The band gap has been increased with decrease in the particle size. Crystal size of semiconductors obtained by TEM was 2.5-5 nm for the glass showing absorption edge cut-off at 475 nm (CM-475).

5 illus, 2 tables, 9 ref

013796   Moroglu B;Uzuner B A;Sadoglu E (Civ Engng Dep, Cumhuriyet Univ, 58050 Sivas, Turkey, Email: uzuner@.edu.tr) : Behaviour of the model surface strip footing on reinforced sand. Indian J Engng Mater Sci 2005, 12(5), 419-26.

Series of tests were carried out with an eccentrically loaded model surface strip footing on un-reinforced and reinforced dense sand to investigate the behaviour of the footing (decrease in ultimate load with increasing eccentricity, failure surfaces and load displacement relations). The experimental set-up used to run the tests consists of tank, model footing, sand and loading mechanism. A single woven geotextile strip sheet was placed horizontally below the footing's base at a depth half of the footing's width. The primary failure surfaces occurred at the eccentricity side for this laterally unrestricted footing. The use of this reinforcement increased the ultimate load by about 50% for centrally loaded strip footing in comparison with un-reinforced case and its contribution to ultimate load decreased as eccentricity increased in these conditions. Geotextile not only increased ultimate load, but also increased necessary amount of vertical displacement of footing to reach failure compared with un-reinforced case. The experimental results are in good agreement with Meyerhof' s effective width concept than the customary analysis and the customary analysis is unsafe outside the core.

11 illus, 3 tables, 22 ref

013795   Mohanty K B (Electl Engng Dep, Natn Inst of Technol, Rourkela-769 008) : Fuzzy sliding mode controller for a field-oriented induction motor drive. J Instn Engrs-Pt EL 2005, 86(Dec), 160-5.

The paper presents a robust contral technique for a field oriented induction motor drive. Sliding Mode Controller (SMC) and Fuzzy Sliding Mode Controller (FSMC) are designed for the speed loop of the drive. The design steps for both the controllers are laid down clearly. The FSMC uses three-level input membership sets and five-level output membership set of symmetrical triangular shape, nine fuzzy rules, and the centre of gravity defuzzification technique. The performance of the FSMC has been evaluated, through simulation studies, with respect to the conventional sliding mode controller. The chattering free improved performance of the FSMC makes it superior to conventional SMC, and establishes its suitability for the induction motor drive.

5 illus, 2 tables, 9 ref

013794   Mishra A K;Mohan A (Tech Services Manager, Indian Explosive Ltd., Kolkata) : Can we handle misfires in surfece mines...?. J Mines Metals Fuels 2005, 53(9), 155-6.

Today blasting is an integral pan of any mining activity, which comes with its own inherent potential threats, if proper care is not taken in handling, transportation, and usage of explosives. Misfire is one of them. Many accidents have occurred in the past due to misfires in the mineral industry. However, misfires rarely occur but it necessitates a very careful handling and understanding of the problem. This paper deals with causes of misfires and provides an approach of handling it in opencast mines.

4 ref

013793   Maruthamuthu S;Rajasekar A;Sathiyanarayanan S;Muthukumar N;Palaniswamy N (Corros Sci STOPWORD Engng Div, Cent Electrochem Res Inst, Karaikudi-630 006, Email: biocorr@cecri.res.in) : Electrochemical behaviour of microbes on orthodontic wires. Curr Sci 2005, 89(6), 988-96.

Aim of the study was to investigate the electrochemical behaviour of orthodontic wires in artificial saliva with and without bacteria. Four factors were considered to characterize the bacteria present in the saliva, viz. urban and rural groups of vegetarians and non-vegetarians. The results showed that among the heterotrophic bacterial isolates, Gram-positive species dominated over the Gram negative species in the ratio of 4:1. The samples also confirmed the presence of sulphate reducing bacteria. Moreover, chemolithotrophs like manganese and iron oxidizing bacteria and acid producing bacteria were isolated and identified in the saliva. The bacterial strains were isolated and identified based on their morphological, physiological and biochemical characterstics. Nesseria sicca, Eikenella corrodens, Pseudomonas sp., Wolinella sp., Campylobacter sp., Kurthia sp., Corynebacterium maturochotii, Brocothrix sp., Listeria sp., Staphylococcus sp., Gallionella sp., Legionella sp., and Thiobacillus sp. were noticed in the saliva. Polarization and impedance studies were carried out for orthodontic wires, investigating the electrochemical behaviour of stainless steel in the presence of microbes. On the basis of electrochemical investigattions, it was concluded that NiTi-0.016 and SS-26 Gauge were better candidate material for dental applications.

7 illus, 8 tables, 31 ref

013792   Maiti J (Dep STOPWORD Industrial Engng STOPWORD Mgmt STOPWORD Reliability Engng, IIT, Kharagpur-721 302) : Injury epidemiology - the concept and its application in mining. J Mines Metals Fuels 2005, 53(9), 147-54.

Injury epidemiology is the study of distribution and causes of injuries in population. The concept although applied in mines since 1912, however, the initial focus was on disaster mitigation and prevention. In toady's mining scenario, the major killer in mines is not the disaster but the day-to-day accidents/injuries. Application of injury epidemiology to day-to-day injuries in mines will enable to identify the root of the occurrences of such undesired events. Epidemiologic efforts to study injuries follow the framework of accident triad, which considers injury events as an interaction of three factors; the host (victim/individual), the agent (equipment/ system), and the environment. An example is the DGMS classification, which is not focused on the true accident triad; rather it describes only the agents (equipment/system) causing such accidents in mines. Identification of accident triad for mines is utmost required. Further, mine accident is a very complex phenomenon and can be attributed to many factors in a multivariate situation. The multifaceted causes of accident in mines are needed to be identified, analyzed and disseminated for development of adequate and effective safety programmes including training to reduce accidents/injuries in mines. In this paper, the above issues were addressed with application to mining.

7 illus, 2 tables, 7 ref

013791   Lakshminarasimhan J;Gowda B H Lakshmana; Sivannarayana C (Dep STOPWORD Appl Mechanics, Indian Inst of Technol, Chennai-600 036, Email: jln_apm@iitm.ac.in) : Interference effects on wind pressure on low-rise and high-rise square structures in side-by-side arrangement. Indian J Engng Mater Sci 2005, 12(5), 398-410.

The effects of interference on three-dimensional bluff bodies with square cross-section placed in side-by-side arrangement for a low-rise body and a high-rise body have been investigated experimentally. The extent of interference effects are brought out by varying the spacing between the bodies. The pressure distributions on the surfaces of the bodies are measured to bring out the severity of interference due to another body adjacent to it. The bodies are exposed to an air stream with a velocity profile satisfying the l/7th power law. It is seen that the pressure distribution on rear side and interference side is greatly affected for low-rise body when interfered by a high-rise body in close proximity.

11 illus, 1 table, 12 ref

013790   Kisi O ;Uncuoglu E (Hydraulics Div Civ Engng Dep Engng Fac, Erciyes Univ, Kayseri, Turkey) : Comparison of three back-propagation training algorithms for two case studies. Indian J Engng Mater Sci 2005, 12(5), 434-42.

The use of three back-propagation training algorithms, Levenberg-Marquardt, conjugate gradient and resilient back-propagation for the two case studies, stream-flow forecasting and determination of lateral stress in cohesionless soils. Several neural network (NN) algorithms have been reported in the literature. They include various representations and architectures and therefore are suitable for different applications. In the study, three NN algorithms are compared according to their convergence velocities in training and performances in testing. Based on the study and test results, although the Levenberg-Marquardt algorithm has been found being faster and having better performance than the other algorithms in training, the resilient back-propagation algorithm has the best accuracy in testing period.

3 illus, 9 tables, 36 ref

013789   Keshari A K (Dep STOPWORD Civ Engng, I.I.T. Delhi, New Delhi-110 016) : Environmental management plan for riverbank filtration. J Indian Wat Resour Soc 2005, 25(2), 1-7.

Riverbank filtration is coming up as a new facet in water treatment technology and in turn is becoming a new dimension in drinking water supply schemes. With the growing complexity in managing water quality of rivers and groundwater systems, this novel approach of improving the quality of influent (raw) water through natural filtration process throws a number of questions that will be required to address to avoid or minimize long-term adverse implications to groundwater regime on local or regional scale. There has been an increasing concern regarding degradation of river water quality due to industrial and human activities, which in turn draws attention to quality of adjoining groundwater too. A number of geochemical processes may culminate because of the facilitation of riverbank filtration depending upon the prevailing hydrogeological set up and hydraulic gradient. The fate and transport of various chemical species varying in physico-chemical and biological characteristics and the attenuation processes during the groundwater residence time is poorly understood. This necessitates to chalk out meticulously designed environmental management plans through detailed groundwater modelling study to prevent or eliminate any adverse impacts on the groundwater regime. Otherwise the groundwater resources at a larger scale may be at the stake of hydrogeological risk. Modelling the fate and transport of contaminants within groundwater systems become complicated because of complex hydrogeochemical processes, its sensitivity to changes in hydrogeologic and thermodynamic conditions in aquifers due to unplanned and inappropriate exploitation of groundwater resources, seasonal variation in hydrological events and associated uncertainties. The occurrence, origin and mobility of chemical species in groundwater systems are significantly influenced by local geology, geochemistry and geohydrological settings of aquifers. Since there is no physical barrier within the groundwater regime, hydraulic control and channelization of groundwater movement are warranted. A number of issues that need to be given appropriate and adequate attention during various phases of riverbank filtration project are elucidated, and the research gaps have been identified that need to be addressed in prevailing hydrogeological set up of aquifer systems.

3 illus, 16 ref

013788   Karthik B;Kowsik B V R;Venkateswarlu N;Sujith R I;Chakravarthy S R (Dep STOPWORD Aerospace Engng, Indian Inst Technol Madras, Chennai-600 036, Email: sujith@iitm.ac.in) : Acoustic field in a duct resulting from vortex shedding from multiple restrictors. J Aerospace Sci Technol 2005, 57(4), 421-8.

An experimental investigation of the acoustic field in a duct due to vortex shedding from multiple restrictors has been reported. The spacing between two restrictors was varied very closely in these experiments. It was observed that high amplitude acoustic field was established in the duct when the restrictors were closely spaced and that the highest amplitude of acoustic oscillations occurred for a certain specific spacing of the restrictors depending upon other conditions. It was also observed that the dominant frequencies locked on to the different possible natural acoustic modes that could be established in the duct.

7 illus, 1 table, 10 ref

013787   Joshi A;Sivan K (Aerospace Engng, Indian Inst of Technol Bombay, Powai, Mumbai-400 076, Email: ashokj@aero.iitb.ac.in) : Development of mathematical model of a generic RLV for reentry mission simulation. J Aerospace Sci Technol 2005, 57(4), 401-7.

Nonlinear models for simulating the atmospheric reentry dynamics of a generic Reusable Launch Vehicle (RLV) have been presented. The six degrees-of-freedom flight dynamics is modeled with the overall objective of minimum number of constraints without increasing the complexity of equations. This requirement leads to the definition and use of a number of frames of reference for describing different aspects of the dynamics of the RLV. In this context, the inertia/ reference frame is used for translation motion, while body frame and wind frame are used to describe the forces acting on the RLV. Further, quaternion representation is used for vehicle attitude motion in order to avoid computational singularities in respective kinematic model equations. The vehicle complex aerodynamic characteristics are modeled using the coefficient approach in order to simplify interpretation of available data while the propulsion system model takes into account the atmospheric conditions. The vehicle subsystem models of sensors, navigation system and actuators are also included. The operating environment models viz., Earth's atmosphere, Earth's shape and gravitational acceleration are also modeled appropriately. The model presented is for a generic RLV and has the potential for application to RLVs of widely different configurations.

6 illus, 7 ref

013786   Jha R;Ojha C S P;Sharma C D (NO, Natn Inst of Hydrology, Roorkee) : Evaluation of river bank filtration potential for selected cities in the Ganges plains. J Indian Wat Resour Soc 2005, 25(2), 39-54.

Induced infiltration or bank filtration describes pumping of groundwater from aquifers that are hydraulically connected to rivers or lakes. Pumping induces seepage from the surface water into the aquifer and provides filtration of the water en-route to the water supply well. This is commonly used in alluvial aquifers in Europe for purifying water supplies. An attempt has been made to explore the possibilities of bank filtration for the cities along the alluvial banks of river Ganga in India. It is found that there are significant periodical variations in water quality and flow at various locations of River Ganga and it would be appropriate to apply bank filtration criteria for pumping improved quality of water, which may be supplied for drinking purposes to the township.

17 illus, 1 table, 14 ref

013785   Jain A;Choudhary S;Singh S N;Rai L (Dep STOPWORD Mechanical Engng, Indian Inst of Technol, New Delhi-110 016, Email: sidhnathsingh@hotmail.com) : Flow analysis in a model can-type gas turbine combustor. Indian J Engng Mater Sci 2005, 12(5), 389-97.

Flow analysis has been carried out in a model can-type gas turbine combustor using a commercial computational fluid dynamics (CFD) code. The code has been validated against the experimental results quoted in the literature and part of the study. The comparison has shown that CFD code can be effectively used to carry out parametric investigations on the complete combustor model for the combustor design.

10 illus, 2 tables, 18 ref

013784   Iyer N R;Murthy A. R C;Rajasankar J;Palani G S (NO, Structural Engng Res Cent, Taramani, Chennai-600 113, Email: nriyer@sercm.csir.res.in) : Damage tolerance evaluation of wing bottom skin panel of an aircraft. J Aerospace Sci Technol 2005, 57(4), 408-20.

Details of damage tolerance evaluation of a Wing Bottom Skin Panel (WBSP) of an aircraft have been presented. Finite element analysis (FEA) of an integrally stiffened WBSP has been conducted to identify the probable location for crack initiation and the same has been confirmed by conducting experiments. Linear elastic fracture mechanics (LEFM) principles have been used for computation of stress intensity factor (SIF). Static results obtained from FEA and experiments are found to compare well. SIF has been computed for different crack lengths in mode I under intact-stiffener condition by using displacement extrapolation and strain energy release rate (SERR) techniques. SIF has also been computed for the same crack lengths under broken stiffener and unstiffened conditions. A comparison between the residual strength predicted under intact-stiffener, broken stiffener and unstiffened conditions clearly indicates the efficacy of the stiffener in arresting the crack propagation.

18 illus, 4 tables, 18 ref

013783   Ismail S;Singh J (Flight Mechanics STOPWORD Control Div, Natn Aerospace Laboratories, Post Box No.1779, Bangalore-560 017, Email: shaik@css.nal.res.in) : Nonlinear aerodynamic global model identification using gram-Schmidt orthogonalization. J Aerospace Sci Technol 2005, 57(4), 392-400.

A simple technique to identify global models for nonlinear aerodynamic force and moment coefficients of aircraft using multivariate orthogonal functions has been discussed. Classical Gram-Schmidt procedure and Predicted Squared Error metric are used to generate the orthogonal functions. Global models for the F-16 aircraft are identified from a simplified subsonic (Mach<60>0.6) wind tunnel database available in open literature. The identified models arec compared with those found in literature for the same wind tunnel database and conclusions are drawn.

9 illus, 3 tables, 16 ref

013782   Irmscher R (NO, Stadtwerke Dusseldorf Ag, Germany) : Background and experiences of riverbank filtration in Germany. J Indian Wat Resour Soc 2005, 25(2), 55-7.

Drinking water supply depends on numerous critical parameters. A good raw water is the best presupposition for a successful water purification process. The Rhine basin characterises the landscape of large parts of Germany. The river Rhine is with a length of 1,320 km and a catchment area of 185,000 km², the third biggest river and the largest source of drinking water in Europe. More than 50 million people are living in this region, 30 millions of them get their tap water from the rivers. The dusseldorf water works situtated at the river Rhine have been using riverbank filtration as basic step in the purification process since 1870. Three necessary preconditions for bank filtration are: Hydraulic contacted between the river bed and the aquifer, self purification mechanisms in the infiltration areas, for example by natural gravel and sand transportation in the river, sufficient river water quality. If these three requirements are complied, riverbank filatration could be the right path for drinking water abstraction. This article provides some background information about riverbank filtration in the lower Rhine valley in dusseldorf, Germany.

^ssc2 illus, 4 ref

013781   Hinislioglu S;Aras H N;Bayrak O U (Dep STOPWORD Civ Engng, Engng Fac Ataturk Univ, 25240 Erzurum, Turkey, Email: shinis@atauni.edu.tr) : Effects of high density polyethylene on the permanent deformation of asphalt concrete. Indian J Engng Mater Sci 2005, 12(5), 456-60.

An investigation about the effect of high density polyethylene (HDPE) in powder form as a bitumen modifier on the permanent deformation of asphalt concrete using Marshall design parameters and creep behaviour have been investigated. The parameters assessed are the compacted mix density, the percentage of air voids in the mixture, the percentage of void in the mineral aggregate, the percentage of voids filled with bitumen, Marshall stability and flow and also Marshall quotient (MQ), axial strain and stiffness modulus. It is also investigated the effect of HDPE on some physical properties such as penetration, softening point and ductility. Bitumen is mixed with the HDPE at 1-4% by weight of bitumen at 185°C for 60 min. duration using a high shear mixer. Marshall samples prepared with the HDPE modified binder provide the specification limits. The addition of 3% HDPE, results in an increase of 57% in Marshall quotient. In addition, it has been observed that the use of 2% HDPE decreased the permanent strain by 34% and increased the creep stiffness by 52%. The creep recovery values of the asphalt concrete with HDPE after 15 min have been found to be higher than control mixtures. It can be concluded that HDPE modified asphaltic binders provide better resistance against permanent deformation, because of their higher stability and stiffness, relatively lower flow. As a result, HDPE modified asphaltic binders are considered to be very useful in mitigating permanent deformation in hot climate regions.

2 illus, 7 tables, 21 ref

013780   Gupta S P;Karim M Z A (Dep STOPWORD Electl Engng, IIT Roorkee, Roorkee) : Supply current distortion in cycloconverter fed induction motor drive. J Instn Engrs-Pt EL 2005, 86(Dec), 204-8.

The paper presents digital simulation of a cycloconverter fed induction motor drive. Effects of magnetic saturation and core loss have been incorporated in the mathematical model of the induction motor. The cycloconverter has been considered operating in a non-circulating current mode. The drive model is used to obtain the supply current waveforms. Harmonic contents of these currents have also been investigated and presented for typical operating conditions. Comparison between simulated waveforms and the corresponding experimental waveforms has also presented.

7 illus, 13 ref

013779   Grischek T;Schoenheinz D;Sandhu C;Hiscock K M (Deptt. STOPWORD Civ Engng STOPWORD Architecture, Univ of Appl Sci Dresden, Friedrich-List-Platz 1, Q1069 Dresden, Germany) : River bank filtration-its worth in Europe and India. J Indian Wat Resour Soc 2005, 25(2), 25-30.

Bank filtration, induced through the river bed by pumping from a system of connected lateral or vertical wells, provides a means of obtaining public water supplies. The success of such schemes is dependent on the microbial activity and chemical transformations that are commonly enhanced in the colmation layer within the river bed compared to those that take place in surface or ground waters. The actual biogeochemical interactions that sustain the quality of the pumped bank filtrate depend on numerous factors including aquifer mineralogy, shape of the aquifer, oxygen and nitrate concentrations in the surface water, types of organic matter in the surface and ground water environments, land use in the local catchment area, and temperature of surface water. To evaluate the potential of using bank filtration for water supply in India, an EU-India Riverbank Filtration Network will be established, supported by the EU Commissions.

1 illus, 11 ref

013778   Goswami T (Mechanical Engng Dep, T J Smull Coll of Engng Ohio Nth Univ, Ada, OH 45810, USA) : Long crack growth mechanisms in T1-6A1-4V alloy. Indian J Engng Mater Sci 2005, 12(5), 367-75.

Transition mechanism of long crack growth from structure sensitive (Regime I) to insensitive region (Regime II) was investigated at (i) room temperature under high humidity conditions, and (ii) elevated temperatures for Ti-6Al-4V alloy and other materials. Constant amplitude tests were conducted using several stress ratios (R = 0.05, 0.1, 0.4 and 0.7) for the high humidity tests and 0.1 for room and elevated temperature tests. Conventionally forged Ti-6A1-4V alloy disks, processed to the solution treated and over-aged condition, were studied for both programs. An increase in stress ratio and temperature lowered the transitional stress intensity factor range where Regime I transitioned to Regime II. Higher stress ratios (R = 0.7) accelerated the fatigue crack growth rates many times the crack growth rates obtained at lower stress ratios (R = 0.05). However, higher temperatures (345°C) influenced the crack growth rates only marginally. The mechanisms controlling elevated temperature fatigue crack growth in Ti-6A1-4V were by the secondary crack formation, striations and some cavity features on the fracture surface. The damage was localized on the a platelets, where a type dislocations found with the Burgers vectors.

13 illus, 2 tables, 22 ref