013777   Goswami S K;Datta K (Dep STOPWORD Electl Engng, Jadavpur Univ, Kolkata-700 032) : On estimation errors in linear observer systems due to parameter variations. J Instn Engrs-Pt EL 2005, 86(Dec), 192-7.

An attempt has been made to evaluate the estimation errors due to small changes in important observer parameters from their nominal values which an usually fixed in the design stage. A set of appropriate sensitivity functions have been developed which could serve as a basis for formulating a design procedure for observer systems with minimum errors in estimations in case of changes in operating conditions due to small parameter variations. An illustrative example has been presented, where the developed procedure has been applied to evaluate the estimation errors and the sensitivity functions of a linear observer system.

3 illus, 2 tables, 9 ref

013776   Gnanadass R;Padhy N P (Dep STOPWORD Electl Engng, Pondicherry Engng Coll, Pondicherry-605 014) : Determination of SRMC for practical power systems with non-smooth fuel cost functions. J Instn Engrs-Pt EL 2005, 86(Dec), 180-4.

New algorithm for determination of short run marginal cost (SRMC) for feasible bilateral transactions using optimal power flow (OPF) solutions has been presented. Determination of SRMC using conventional methods suffer due to the presence of non-smooth fuel cost generators in the modern deregulated utilities. Hence in this paper, Evolutionary Programming (EP) based OPF solution has been developed for obtaining optimal generator settings with four non-smooth fuel functions. System transmission loss and penalty factor at each and every bus are computed using the OPF solution. Further bus incremental cost at all the buses is computed using penalty factors. Generalized loss coefficients are also obtained from OPF solution and they are the functions of the system operating state with non-smooth fuel functions. The performance of the proposed algorithm has been validated with IEEE 30 bus practical test system.

3 tables, 18 ref

013775   Fodor D (Dr. Eng. Fodor, Univ of Petrosani, Romania) : Modernization of operational equipment and technologies-major requirement for the contemporary mining operations. J Mines Metals Fuels 2005, 53(10), 209-14.

6 ref

013774   Fettweis G B L (Min Engng Dep STOPWORD Min STOPWORD Tunnelling, Univ Leoben, Austria) : Plea for geo-mining conditions including mining rock mechanics as a main part of the science of mining engineering. J Mines Metals Fuels 2005, 53(10), 196-200.

3 illus, 23 ref

013773   Eskikaya S (Dr. Sinasi Eskikaya, Istanbul Tech Univ, Mining Faculty) : Future of mining engineering education and the role of World mining Congress. J Mines Metals Fuels 2005, 53(10), 215-18.

22 ref

013772   Dubinski J;Kidybinski A (Int Organising Comm STOPWORD Wld Min Congr STOPWORD Head, Cent Min Inst (GIG) Katowice, Poland) : Geo-mechanical problems of deep coal and metal mines in Poland and associated research works. J Mines Metals Fuels 2005, 53(10), 189-95.

Underground coal as well as metal ore mines in Poland are confronted with growing frequency and energy of seismic tremors due to increasing depth of mining and high strength of rocks. The other problem comes from economic and environmental impact of mines closing which offers an opportunity of post-mining underground infrastructure utilization but requires research works. Research program has been initiated to solve these problems using - among others - passive seismic tomography which enables utilizing existing seismologic records from a mine to develop seismic velocity maps closely related to stress level in roof strata. This lends to precise evaluation of time trend in stress change and prediction of seismic activity expected for nearin future. Another aspect of seismic investigations is related to strong effects of copper mine caused tremors on surface structures, especially multi-floor compartment houses. Here, measurements of ground and wall vibration at various horizons made it possible to come with recommendations to the mines how to modify their mining system to reduce effects on surface structures. Test blasting in the nether roof of a roadway at Jankowice mine was arranged to check seismic resistance of new yielding roof bolts and shock resistant steel mesh - as new elements of mine supports to safely maintain openings subjected to strong seismic tremors. Closing of several coal mines in Poland in recent years leaves idle a number of openings which may be practically utilized, as underground gas storage facilities or compressed air energy storage reservoirs for example. Geo-mechanical tests were carried out to select the best locations for both potential applications mentioned.

8 illus, 2 tables, 13 ref

013771   Dash R R;Pradeep Kumar;Mehrotra I;Uniyal H P (Dep STOPWORD Civ Engng, Indian Inst of Technol Roorkee, Roorkee-247 667) : Bed filtration: water quality evaluation at Kalsi. J Indian Wat Resour Soc 2005, 25(2), 31-8.

With the policy of Government of India to provide at least one safe source of water to each village, number of piped water supply schemes were constructed in Uttaranchal hills (Longitude 77° 34' 27" to 81° 02' 22" E and Latitude 28° 53' 24" to 31° 27' 50" N). The spring sources were not sufficient to cater the demand, so sources like rivers and streams (gadheras) were also tapped using boulder filled galleries (BFGs). However, many problems were experienced by Uttaranchal Jal Sansthan (UJS) in maintenance of BFGs. Moreover, as there was no arrangement for the removal of turbidity in BFGs, the water supplied during rainy season used to be generally muddy. To overcome this perpetual problem, UJS has tried a number of alternatives. The use of Uttaranchal Koops appears to be an appropriate, cost effective and reliable system. It is being used successfully for <62>300 rural water supply schemes in different districts of Uttaranchal. Koop is placed below the bed to collect the continuous sub-surface flow in direct connectivity with the surface water above it. A case study of water collection for Kalsi (District Dehradun, Uttaranchal, India) using such wells has been discussed. Physical, chemical and bacteriological water quality characteristics of well water conformed to Indian and World health Organization (WHO) standards for drinking water. These improvised-innovation adapted by UJS are operative, almost maintenance free, economical, and sustainable. Koops are able to provide reliable, safe and uninterrupted supply of water without purification.

7 illus, 2 ref

013770   Das P K;Chanda R S ;Bhattacharjee P K (Dep STOPWORD Electl Engng, Govt Engng Coll, Jalpaiguri) : Fuzzy set based reliability approach to transmission expansion planning. J Instn Engrs-Pt EL 2005, 86(Dec), 155-9.

The paper presents a reliability analysis of an optimally planned transmission system using fuzzy fault tree technique. Fault trees are constructed after finding system minimal cuts upto third order containing line components. Minimal cuts an determined based on the criteria that the system fails if a load bus fails. This paper considers the trapezoidal nature fuzziness of the components or primary event and accordingly fuzzy top event probabilities are calculated. In this paper reliability improvement index (RII) and sensitivity index (SI) calculation is proposed to establish the rank of component and cut sets and the degree of sensitivity of component respectively. Finally a method has been proposed to design a maximum reliable network when the failure probabilities are fuzzy in nature based on the criterion that the system fails if an overload occurs in a line or bus voltage variation more than ±11 % and the system fails if overload in a line and bus voltage variation more than ±11% occurs simultaneously. The 400 kV transmission system of West Bengal State Electricity Board is used as an example system.

6 illus, 4 tables, 12 ref

013769   Chowdhury R (Corporate Office, SAIL, Kolkata) : Environmental monitoring for consent compliance at (a) Kuteshwari limestone mines, (b) Bhawanathpur limestone mines and (c) Tulsidamar dolomite quarry. J Mines Metals Fuels 2005, 53(9), 177.

7 ref

013768   Chellappa R G;Saraswati S K (NO, Airports Auth of India Sourthern Region, Chennai Airport (ATS Complex) Chennai-600 027) : Required navigation performance (RNP)-a navigation update. J Aerospace Sci Technol 2005, 57(4), 383-91.

4 illus, 9 ref

013767   Chandekar S M (Dep STOPWORD Electl Engng, Rungta Coll of Engng and Technol, Bhilai) : Re-scheduling of active power transfers in a multi-terminal DC network during sub-normal frequency period in an AC/DC system. J Instn Engrs-Pt EL 2005, 86(Dec), 198-203.

Paper shows that a multi-terminal dc network helps in improving the sub-normal frequency performance of load buses in an ac/dc system, thus minimising the need of applying and load shedding measures during the period of under-frequency. It is also demonstrated that the controllers' action of HVDC converters compensate for deficit in active powers experienced at remotely located load buses during the period of under-frequency by suitably modulating their power transfers quickly to save from economical loss to the power utility. A multi-terminal 'HVDC network is also found to be useful in maintaining power factor of load buses by utilising the fast electronic reactive power absorbing capacity in inverter terminals.

2 illus, 6 tables, 10 ref

013766   Budan D A (Dep STOPWORD Mechanical Engng, Univ BDT Coll of Engng, Davangere-577 004, Email: abdul_budan@rediffmail.com) : Influence of fibre proportion and position on the machinability of GFRP composites- an FEA model. Indian J Engng Mater Sci 2005, 12(5), 443-50.

More commonly considered criteria for judging the machinibility are the cutting forces on the tool and power consumption. A classical Merchant's model is widely used to predict the cutting forces while machining isotropic material. However, no such model exists to predict the cutting forces while machining orthotropic materials. An effort is made to modify the Merchant's formula by incorporating the K-factor to evaluate the shear strength, the fibre orientation as shear angle and a constant coefficient of friction. The cutting forces evaluated by modified Merchant's model on unidirectional GFRP composite material has been compared with the results predicted by two-dimensional FEA model. In FEA model both maximum stress and Tsai-Hill failure criteria were used to simulate the chip separation. The influence of composite design, in particular the fibre proportion and orientation on cutting forces has been investigated. The higher fibre proportion in the composite caused an increase in cutting force values. Fibre orientations 45° and 60° have shown favorable results. The FEA predicted results have shown good agreement with the results evaluated by modified Merchant's model.

8 illus, 12 ref

013765   Boonmarlert P;Phongthanapanich S;Dechaumphai P (Mechanical Engng Dep, Chulalongkorn Univ, Bangkok 10330, Thailand, Email: fmepdc@eng.chula.ac.th) : Combined characteristic-based split algorithm and mesh adaptation technique for high-speed compressible flow analysis. Indian J Engng Mater Sci 2005, 12(5), 376-88.

Characteristic-based split algorithm is combined with a mesh adaptation technique to analyze high-speed inviscid compressible flow problems. The solution accuracy is improved by coupling an error estimation procedure to an adaptive remeshing technique that generates small elements in regions with large change in solution gradients, and at the same time, larger elements in the other regions. The efficiency of the combined procedure is evaluated by solving several problems for both transient and steady-state flow behaviours.

16 illus, 1 table, 18 ref

013764   Bazaras Z (Dep STOPWORD Transp Engng, Kaunas Univ of Technol, Kestucio 27, Kaunas-4, LT-44025, Lithuania, Email: zilvinas.bazaras@ktu.it) : Analysis of probabilistic low cycle fatigue design curves at strain cycling. Indian J Engng Mater Sci 2005, 12(5), 411-18.

Low cycle fatigue tests were carried out and mechanical characteristics of three materials (steel of grades 15X2MFA and 45 and aluminium alloy D16T1), representing all possible variations of cyclic properties (fatigue, quasi-static and intermediate mode of fracture) were determined experimentally. Based on the data obtained, design curves of equal fracture probability for steels 15X2MFA and 45 and aluminium alloy D16T1 at low cycle strain-controlled loading were generated and the design curves were compared with experimental data. Analysis of calculated and experimental low cycle fatigue curves constructed according to the fracture probability parameter, revealed that the use of analytical relationships for lifetime assessment of structures may lead to an error and decreasing safety margin. It is recommended to use experimental 50 fracture probabilistic curves in lifetime assessment of power equipment structures.

4 illus, 4 tables, 15 ref

013763   Barui K L;Bhattacharya B (Dep STOPWORD Appl Phys, Univ of Calcutta, Kolkata-700 009) : Failure assessment of a driven shaft of an extrusion gear pump. Indian J Engng Mater Sci 2005, 12(5), 472-74.

Investigation of failure of a driven shaft made of BS 970-1991 Series 080 M40 (BS 970-1955 Series En 8) grade steel has been made. It broke after 1100 h run while pumping out liquid polythene under normal operating condition. Metallurgical investigation reveals Widmanstatten pattern and very coarse grains enveloped with ferrite, though the chemical and physical properties of the material are satisfactory. Presence of such microstructure due to elevated finishing temperature of the forging process causes brittle fracture. The suggested remedial measure is to keep the finishing temperature just above the lower critical temperature.

3 illus, 5 tables, 3 ref

013762   Arya L D;Pande V S (Dep STOPWORD Electl Engng, SGSITS, Indore, Madhya Pradesh) : Artificial neural network based voltage stability assessment and corrective rescheduling. J Instn Engrs-Pt EL 2005, 86(Dec), 170-6.

The paper describes an algorithm for on-line assessment of voltage stability and corrective rescheduling of reactive power control variables based on a trained multi-layer feed forward neural network. The network is trained with back propagation algorithm (BPA). Trained network is utilised to evaluate the sensitivity of the proximity indicator (minimum eigen value) with respect to reactive power control variables and loads at the buses. These sensitivities are used for rescheduling the reactive power control variable and if required, amount and location of the load shed can also be determined. In fact, sensitivities can be updated using the newly derived closed form relation and this makes the methodology suitable for on-line application. The developed algorithm has been implemented on a sample test system.

3 illus, 3 tables, 19 ref

012723   Wadhwani S;Gupta S P;Kumar V (Dep of Electl Engng, IIT, Roorkee-247 667) : Wavelet based vibration monitoring for detection of faults in ball bearings of rotating machine. J Instn Engrs-Pt EL 2005, 86(September), 77-81.

Describes the application of wavelet transform (WT) for detection of bearing damage from the vibration signal of the bearing. The wavelet transform approach enables instant to instant observation of the contribution of different frequency components over the full spectrum form. Actually, wavelet transform acts as a 'mathematical microscope' in which one can observe different parts of the signal by 'adjusting the focus'. A new technique combining the WT nith neural network for detection and classification of ball bearing fault in a three phase, 3.75 kW induction motor is presented. The method is tested successfully for three faulty bearing conditions: crack in inner race, crack in outer race and defect in balls.

6 illus, 4 tables, 12 ref

012722   Sharma R;Sha O P (Dep of Ocean Engng and Nav Archit, Indian Inst of Technol, Kharagpur-721 302) : ERP model for medium scale shipyards-I. production planning. J Instn Engrs-Pt MA 2005, 86(July), 1-13.

Enterprise Resource Planning (ERP) has become something like a magic wand for large manufacturing industries because of its capability to integrate all different modules networked online and provide access to all through one window, hence making the whole process an integrated one with a reduction in inventory. However, ship production is not a manufacturing process in a strict sense because of high customisation, widely varying scales of operations and less compatibility between various production processes. Ship production is planned in activity driven network scheduling system in general and is assumed more as a construction process rather than a manufacturing process. An ERP principle is based upon information management system and hence is effective in all manufacturing processes. Discusses a methodology for, production planning, integration of different modules, and communication networks in the ERP model for a medium sized shipyard is presented. The integration driven production planning is activity based network scheduling. By combining both network scheduling and ERP, the ship production process will be better streamlined, planned and executed.

16 illus, 5 tables, 7 ref

012721   Sarangi S K (Managing Director, Geomin Consulants (P) Ltd, 267, Kharvela Nagar, Bhubaneswar-751 001) : Mining opportunities in Congo. SGAT Bull 2005, 6(2), 71-7.

4 ref

012720   Sadhu S;Ghoshal T K (Dep of Electl Engng, Jadavpur Univ, Kolkata-700 032) : Proportional-integral observer based input estimation approach for seeker filtering. J Instn Engrs-Pt EL 2005, 86(September), 136-41.

Describes the concept of a special form of observer (called JPI observer) which is superficially similar to PI observers and then investigates the possibility of using the same for estimating unknown input of a target tracking seeker system. It has been demonstrated that a JPI observer, can be used far estimating unknown inputs in cases where traditionally Kalman filters have been used. For the seeker, the white noise assumption with a constant covariance for base motion is often invalid and therefore, a more general, observer oriented approach has been adopted here. Unlike conventional Kalman filter based approaches where the target kinematics is assumed as the plant description, here, the seeker dynamics with its track and stabilisation loups are considered as the plant and the platform motion is considered as a known input. The central theme of this work is about using JPI observer for eliminating base motion disturbance in a missile seeker (target tracker) from the target sight line rate (guidance) signal. The guidance signal may be considered as an unknown input. It has been demonstrated that using the JPI method, seeker filters may be made which are independent of stab loop parameters and do not require the measurement of platform motion. JPI observers require extra integrators to convert the unknown input into a state. It is shown that unless cart is taken, in modeling, introduction of integrators may render the plant unobservable. A systematic trade off mechanism for estimation of bandwidth and noise vulnerability is proposed for the JPI observer. The investigation uses structural/topological/algebraic properties of the plant as well as the knowledge of the relative values of the plant parameters.

5 illus, 15 ref

012719   Renuga P;Ramraj N;Magesh T (EEE Dep, Thiagarajar Coll of Engng, Madurai, Tamil Nadu) : Analyses of unavailability of aging failures in power system equipments. J Instn Engrs-Pt EL 2005, 86(September), 107-9.

Unavailability is an essential data and index in power system reliability assessment. The traditional definition for unavailability is only associated with repairable failures, but does not cover the aging failure mode. Presents a definition and a calculation approach for the unavailability of aging failures.

4 illus, 3 tables, 3 ref

012718   Reddy B R (Dep of Electl and Electron Engng, Pondicherry Engng Coll, Pondicherry-605 014) : Analytical solution for eddy current loss in solid cores under saturated conditions. J Instn Engrs-Pt EL 2005, 86(September), 82-5.

Double excitation field problem is solved analytically, so as to find the power loss, flux, power factor and depth of penetration in solid ferromagnetic cores under saturated conditions. An experiment is conducted on conventional single-phase induction motor after replacing the rotor by solid iron rotor with no air-gap. The capacitor is removed from the starting winding. The solid iron rotor is provided with copper end-rings. The developed analytical solution is valid for the frequency ratio of input excitations greater than 2. Therefore, to supplement the problem, a graphical method is proposed for the frequency ratio between 1 and 2.

2 illus, 9 ref

012717   Ravikiran K;Gupta T;Chaudhry S (NO, Nav Coll of Engng INS Shivaji, Lonavala) : Materials for seawater systems in new construction ships. J Instn Engrs-Pt MA 2005, 86(July), 19-22.

With the advent of large modern sophisticated high-powered ships, it becomes economicallly justifiable to incorporate sophisticated materials in salt water circulating systems in an effort to obtain increased reliability. Maximum operational availability and minimum down time of ships art the guiding factors for ship designers. In the case of new construction ships, these factors should be considered at the design stage itself. Many of the problems that have subsequently developed appear to be associated with errors in the design of minor details, material selection and the method of installing the pipes, fittings and components that comprise a system. It is of utmost importance to select the most suitable material and to take care with regard to design, fabrication and installation, to ensure that these materials perform satisfactorily. The criteria like the effect of corrosion, operating condition, type of fluid, velocity of the fluid, temperature, bio-fouling etc are required to be looked into while selecting the system pipes and valve material. Aims at carrying out a detailed study of the seawater systems and valves and selection of material as regards their reliability, failure rate and increasing the mean time between the failures and thereby the operational availability.

3 illus, 3 tables, 6 ref

012716   Rajagopal K;Veena P H;Pravin V K (Dep of Mech Engng, P D A Coll of Engng, Gulbarga-585 102) : Heat transfer in a fluid over a linearly stretching sheet with variable thermal conductivity and internal heat generation. J Energy Heat Mass Transfer 2005, 27(1), 65-81.

Deals with the study of two dimensional boundary layer heat transfer flow in Newtonian fluid caused by a porous linearly stretching the sheet with internal heat generation in the presence of suction or blowing. The thermal conductivity is assumed to vary linearly with temperature as is found in liquid metals. The resulting non-linear energy equation is solved by analytical series method after the applications of perturbation analysis. Several closed from analytical solutions for non-dimensional temperature, heat flux, are obtained for zeroth order equations in the form of confluent hypergeometric (Kummer's functions) functions for two different cases of the boundary conditions, namely (1) wall with prescribed second order power law temperature (PST) and (ii) wall with prescribed second order power law heat flux (PHF). The effect of various physical parameters like suction or blowing parameter, heat source or sink parameter, Prandtl number on temperature profiles are analysed. The effects of all these parameters on wall temperature gradient are also discussed.

3 illus, 21 ref

012715   Prasad R;Yadav S P;Rani R (Dep of Electl Engng, IIT Roorkee, Roorkee-247 667) : New computing technique for order reduction of linear time invariant systems using stability equation method. J Instn Engrs-Pt EL 2005, 86(September), 133-5.

New method of model order reduction is introduced based on the stability equation method and time moments and/or Markov parameter matching. In the method the denominator of the reduced order model is derivedusing stability equation met hod while the numerator of the reduced order model is obtained by using the indirect approach of retaining the time moments and/or Markov parameters of original system. The reduced order model will always be stable if the original high order system is stable.

1 illus, 13 ref

012714   Prasad R;Yadav S P;Rani R (Dep of Electl Engng, IIT, Roorkee-247 667) : Determination of transfer matrix for linear time-invariant control system from its state space representation. J Instn Engrs-Pt EL 2005, 86(September), 100-2.

New direct method is proposed for evaluation of transfer matrix for a linear time invariant system from its state space description [A, B, C]. This method makes use of time moments of the system in place of Markov parameters. The method is supported by illustrative examples.

9 ref

012713   Pradhan S;Gaur S J;Manohar K G;Jagatap B N (Laser & Plasma Technol Div, Bhabha Atom Res Cent, Mumbai-400 085, Email: spradhan@apsara.barc.ernet.in) : Kinetics of collisions involving laser-cooled atoms in an ultrahigh vacuum environment. Bull Indian Vacuum Soc 2005, 8(3), 27-30.

Collision kinetics of laser-cooled cesium (Cs) atoms is investigated in an ultra high vacuum (UHV) environment of a magneto-optical trap (MOT). The process of capture and loss of atoms into and out of the MOT are studied by following the time dependent fluorescence emanating from the laser cooled atoms when the cooling laser beam is modulated to generate bright and dark periods of unequal intervals. The kinetics of the atom capture is analysed in terms of the linear and quadratic trap loss rates, which are governed respectively by the densities of the background gas and the cold atoms. The linear trap loss is related to the number of background atoms, thereby giving an independent measurement of vacuum in the MOT chamber.

3 illus, 7 ref

012712   Pande V S;Arya L D (Dep of Electl Engng, GEC, Ujjain, Madhya Pradesh) : Steady state load shedding for line overload alleviation using Hopfield model based optimization. J Instn Engrs-Pt EL 2005, 86(September), 142-8.

Describes a load shedding algorithm for alleviating lint overloads based on Hopfield model for optimisation. Newly derived sensitivity coefficients relating line flow changes with load shedding at a bus have been used for alleviating the line overloads. Then coefficients have been derived using incremental power flow equations as obtained at the end of N-R load flow solution. Minimum load shed at load buses have been obtained using a quadratic objective function and comparing it with energy function of Hopfleld model. Neurons in Hopfield model are augmented with a linear activation function. Such augmentation provides closed form relations for load sheds at various buses. Developed algorithm has been implemented on 25 bus standard IEEE test system.

3 illus, 3 tables, 11 ref

012711   Muruganandam A;Prabhaharan G;Anand S (Dep of Mech Engng, PSNA Coll of Engng and Technol, Dindigual, Tamil Nadu) : Machine cell formation using particle swarm optimization and tabu search approach. Int J Mgmt Syst 2005, 21(1), 79-90.

Shorter product life cycles, unpredictable demand, and customized products have forced manufacturing firms to operate more efficiently and effectively in order to adapt to changing requirements. Cellular manufacturing, which incorporates the flexibility of job shops and the high production rate of flow lines, has been seen as a promising alternative for such cases. Although cellular manufacturing provides greater benefits, the design of cellular manufacturing systems is complex for real-life problems. Addresses the problem of grouping machines in order to design cellular manufacturing cells, with a combined objective of minimizing Total Moves (Intercellular and Intracellular moves) and Total cell load variation. The considered parameter includes routing sequence, processing time, demand of the parts and machine capacity. A Particle Swarm Optimization Algorithm is proposed to form machine cell and the results were compared with the results obtained from Tabu Search Algorithm. Problems with up to 40 machines and 100 part types from the literature were tested and analyzed in the computational experiments. Numerical results indicate that the proposed Tabu Search algorithm minimized the combined objective value for the tested problems.

1 table, 24 ref

012710   Murugan V;Kamalakannan C R;Gunaraj V (Dep of Mech Engng, Kumaraguru Coll of Technol, Coimbatore-641 006) : Finite element analysis of heat flow in multi-pass MIG-CO₂ welding of structural steel plates. J Energy Heat Mass Transfer 2005, 27(2), 153-69.

In welding, portion of the metal adjacent to weld pool is exposed to servere thermal events. As a result, complex changes in metallurgical structure occur in this region. These changes in structure depend upon the material of the work piece and on the temperature history experienced. The objective of this study is to predict the temperature history using general purpose finite element software ANSYS. A new three dimensional finite element model of the heat flow during multi-pass welding of structural steel plate with filler metal deposition temperature as thermal load was considered for analysis. The heat transfer and parametrice design capabilities of ANSYS were employed for this purpose. Temperature dependent thermal properties and the convective and radiative boundary conditions were included in the model. This model consist of one in which the finite element mesh grows continuously in order to accommodate metal transfer in welding. Contour plots and time history plots were obtained and are presented. Numerical results thus obtained were compared with experimental values showing good agreement. It is therefore demonstrated that this new finite element model can be applied to understand multi-pass welding process and hence be a useful tool for future process analysis and control with the view of optimising product properties and microstructure.

12 illus, 17 ref

012709   Mittal V;Baig M F;Khan B K (Dep of Mech Engng, BRCM Coll of Engng and Technol, Bahal-127 028) : Buoyancy-driven convection in liquid metals subjected to transverse magnetic fields. J Indian Inst Sci 2005, 85(3), 119-29.

Presents the numerical simulation Navier-Stokes, energy and hydromagnetic equations to analyse two-dimensional natural convection of liquid metals subjected to transverse magnetic field. The spatio-temporal study shows that the oscillatory flow changes to steady fluid flow pattern with increase in intensity of applied magnetic field for a range of Rayleigh number (Ra) between 10⁵ and 10⁸. The strength of magnetic field governs the pattern formation as well as the amplitude of the velocities for any particular Rayleigh number in the above range. The amplitude of aperiodic oscillations of any dynamical variable at higher Ra gets significantly damped out, especially removal of low-power harmonics with increase in the strength of magnetic field through variation of Chandrasekhar number.

10 illus, 2 tables, 14 ref

012708   Mehrotra S P;Ranganathan S (Natn Metall Lab, , Jamshedpur-831 007, Email: spm@nmlindia.org) : Vacuum metallurgy - science and technology. Bull Indian Vacuum Soc 2005, 8(3), 13-21.

Subject of vacuum metallurgy encompasses various diverse areas such as the extraction of metals, refining, degassing, remelting, sintering, heat treatment, brazing and other techniques for joining under vacuum. These processes are carried out under vacuum either because the process can not be carried out under normal atmospheric conditions or the rate of process is enhanced under vacuum. Vacuum also protect the metal from the environment during processing. Removal of the volatile phases formed during chemical reactions from the reaction interface shifts the equilibrium and enhances the rate of reaction. Sometimes, the vapour pressure of the metal produced by such a reaction is so low that unless a vacuum applied, the reaction will not take place. Chemical transport reactions are employed in the refining of highly refractory metals such as titanium, zirconium, vanadium etc. The metal is converted into a volatile compound under vacuum. The volatile material is subsequently decomposed to recover a high purity metal. Another type of refining exploiting vaccum is degassing or deoxidation of melts. The principles of thermodynamics and kinetics play a crucial role in the vacuum metallurgy operations. Application of vacuum metallurgy for extraction and refining processes is illustrated with appropriate examples.

^iia2 illus, 4 tables, 13 ref

012707   Massoudi M;Phuoc T X (U S Dep of Energy, Natn Energy Technol Lab, P O Box 10940, Pittsburgh, PA 15232, U S A, Email: massoudi@netl.doe.gov) : Conduction heat transfer and dissipation in the flow of granular materials due to shear. J Energy Heat Mass Transfer 2005, 27(1), 1-21.

Looks at the dense flow of an assembly of spherical particles situated between two horizontal flat plates where the lower plate is fixed and heated, and the upper plate is set into motion with a constant velocity and is at a lower temperature than the lower plate. Derives the steady fully developed flow due to shear and study the heat transfer to particles, which are modelled using continuum mechanics. The equations are made dimensionless and the effects of different dimensionless numbers and viscous dissipation are discussed.

9 illus, 37 ref

012706   Kohler B;Petters W (NO, , ) : Integral drives - Drive technology trends. Indian Pumps 2005, 37(3), 17-20.

Progress in power electronics and microelectronics is having a strong impact on automation Technology. That in turn, is altering the role played by centrifugal pums. Modern automation technology is increasingly supplanting conventional systems in which pumps keep working constantly at their design point with no dependence on the surrounding situation. In reality, a pump and its gearing, asynchronous motor and frequency inverter all form a unified whole that amounts to an integrated, mechanical-electronic system (mechatronic system).

4 ref

012705   Khanduri G M;Panwar B S (NO, Cent for Appl Res in Electron Indian Inst of Technol Delhi, Hauz Khas, New Delhi-110 016, Email: gagan1_1@yahoo.com) : Improved current gain at high collector current densities for SiGe heterostructure transistors. J Indian Inst Sci 2005, 85(3), 131-9.

A two-dimensional simulation study is presented to analyze the current gain performance of an NPNSi/SiGe/SiGe graded heterojunction bipolar transistor (SiGe GHBT) having a uniform 20 atomic per cent (at%) Ge profile in its base and a linear tapering of Ge at% in collector with zero at% Ge at collector ohmic contact. A contemporary NPN Si/SiGe/Si double heterojunction bipolar transistor (SiGe DHBT) having a uniform 20 at% Ge profile in the base region and zero Ge at% in collector is also simulated for comparison. The analysis predicts that a valence band offset for holes at base-collector junction gives rise to the formation of dynamic retarding potential barrier for minority carrier electrons at the base-collector heterojunction of the DHBT structure, which increases with the collector current density. However, the formation of such a potential barrier is smoothed out in an SiGe GHBT structure with base-collector homojunction. The GHBT structure shows an improved current gain and a better current-gain fall-off at high collector current density in comparison with the conventional SiGe DHBT, thus providing the option of operation at higher current densities.

6 illus, 8 ref

012704   Jayavel P;Nakamura S;Koyama T;Kumagawa M; Hayakawa Y (Res Inst of Electron, Shizuoka Univ, 3-5-1 Johoku, Hamamatsu, Shizuoka-432-8011, Japan) : Systematic study on the evaluation of structural and electrical properties of InAsSb ternary layers grown on GaAs (001) substrates. Bull Indian Vacuum Soc 2005, 8(3), 3-11.

Author has investigated the structural and electrical properties of InAsxSb1-x ternary layers grown on GaAs (001) substrates at arsenic (As) temperature ranging from 220 to 290°C. The epilayers have been evaluated using x-ray diffraction (XRD), scanning electron microscopy (SEM) and Hall effect measurements. The arsenic composition (x) of the alloy is found to increase of 0.02 to 0.90 with increasing the As temperature. SEM reveals growth transition from plateau-like 2D crystals to high density of coalesced 3D islands with increasing x. The structural changes are attributed to the strain relaxation at the initial stage of the growth of the alloy resultin from lattice mismatch between the layer and substrate. Hall effect results indicate that a decrease in the electron mobility of the layer with increasing x. Further, the alloys have been grown on Sb-rich InAsSb buffer layer with three different As temperatures of 250, 270 and 280°C. The results are compared with the alloys directly grown on GaAs. An enhancement in the crystalline quality, homogeneity and mobility of the InAsxSb1-x alloys has been observed by inserting the buffer layer.

9 illus, 1 table, 20 ref

012703   Gnanadass R;Venkatesh P;Palanivelu T G; Manivannan K (Dep of Electl and Electron Engng, Pondicherry Engng Coll, Pondicherry-605 014) : Evolutionary programming based economic dispatch of generators with multiple fuel options, ramp rate limits and prohibited operating zones. J Instn Engrs-Pt EL 2005, 86(September), 123-8.

Presents the solution of economic load dispatch (ELD) problem of generator units with multiple fuel options, ramp rate limits and prohibited operating zones. Recently evolutionary computation algorithms are devoted to solve non-smooth fuel cost functions of dynamic economic dispatch problems. The proposed EP algorithm is demonstrated to solve ELD problem for IEEE 30 bus system with line flow constraints. The line flows in MVA. are computed directly from Newton Raphson method. In the proposed EP algorithm, mutation is changing non-linearly with respect to the number of generations to avoid premature condition. The test results prove that the EP method is simpler and more efficient for solving ELD problem with multiple cost functions with many constraints.

3 illus, 5 tables, 14 ref

012702   Ganesan S;Kishore Kumar S;Ganesan V (Dep of Mech Engng, Indian Inst of Technol Madras, Chennai-600 036) : Numerical calculations of non-reacting flows in a gas turbine afterburner model. J Energy Heat Mass Transfer 2005, 27(1), 23-38.

A three-dimensional non-reacting flow analysis has been carried out in a gas turbine afterburner model. The model consists of a conical diffuser and flame stabilizer. The flame stabilizer is a single ring V-gutter with twelve outer and six inner radial v-gutters with included angle of 40° and creating a blockage of 32.5%. Both standard k-ε models have been employed or turbulence to study their capabilities in predicting such complex flows. The analysis is performed using SIMPLE algorithm in a body-fitted multi-block grid using STAR-CD software. The axial, radial and circumferential velocity components are compared with experimental data. A reasonably good agreement is obtained for the all three velocity components. The flow field predictions have been extended to a turbo jet afterburner system. Three V-gutter configurations with blockage ratio of 26.5%, 32.5% and 38.5% have been analysed under non-reacting conditions.

15 illus, 16 ref

012701   Das S;Sha O P;Misra C S (Dep of Ocean Engng and Nav Archit, Indian Inst of Technol, Kharagpur-721 302) : Investigation into resistance characteristics of rectangular barges. J Instn Engrs-Pt MA 2005, 86(July), 14-8.

The components of a blunt ended barge have been studied. The frictional resistance is primarily two-dimensional since the sides and bottom are straight without any curvature. 1TTC 1957 friction line can be used to predict this value. A large portion of the drag is due to separation at the forward end which is a function of the area of the forward end and B/T. The wave making drag is primarily due to fore body since the shoulders do not exist and aft wave is subdued due to boundary layer and aft separation. A resistance formulation has been made based on these principles. A large number of barge models have been made including sloped fore end and aft end. All the models have been tested in the Ship Hydrodynamics Laboratory of ITT Kharagpur, Regression analysis has been done an all the resistance data to obtain the coefficients of various drag components. Based on these values Resistance has been predicted and compared with measured values. The comparison is satisfatory.

10 illus, 1 table, 10 ref

012700   Das P K;Chanda R S;Bhattacharjee P K (Dep of Electl Engng, Jalpaiguri Govt Engng Coll, Jalpaiguri) : Combined generation and transmission system expansion planning using implicit enumeration and linear programming technique. J Instn Engrs-Pt EL 2005, 86(September), 110-16.

Presents a long-term optimal combined generation and transmission expansion planning problem solution technique. First the generation expansion problem (GEP) is formulated as an optimisation problem and solved by using implicit enumeration technique to select the plants from the proposed units and the output level of each generating unit is found by using linear programming (LP) technique. Here the objective function reflects the capital and operating cost. The constraints are the physical limitations of the plants and power balance. After obtaining the new plants and output level of all the plants the transmission expansion planning (TEP) is formulated as an optimisation problem and solved by using LP to find the optimum routes. The objective function reflects the cost of proposed routes. The considered constraints are the power balance at buses and line loading limits. The proposed method has been applied to a six-bus representative power system and results are discussed.

3 illus, 5 tables, 13 ref

012699   Das J K;Chowdhury S P;Chowdhury S;Choudhur S (NO, , 53/1, K K Mazumdar Road, Santoshpur, Kokata-700 075) : Use of tie line power support during restoration of a real utility from complete grid collapse-an improved approach. J Instn Engrs-Pt EL 2005, 86(September), 86-94.

During a total grid collapse of an electric utility, the mode of arranging black start power had been explored earlier from within the utility itself where gas based or battery supported black start units were.available. Model and systematic bottom-up approaches were described by the authors to avoid secondary collapse during restoration of a real utility from a total collapse scenario. KL Lion et al attempted to formulate a mathematical model to maximize generation capability involving both import and export through tie-lines with an idea to minimise outage area. Attempts to consider the availability of tie line power as cranking source from the neighbouring survived utilities and to study the improving effect it can render in restoration performance of the utility under outage. Simulation study suggests the overall improvement in the robustness of restoration planning for a real utility. Comparative analysis with the conventional bottom up approach with this build down strategy shows the restoration performance, restored generation against restoration time margin is greatly improved with minimisation of chance of secondary collapse. Further more the restoration performance through this top down methodology adopted here by utilising tie-line assistance from neighbouring utilities has also been compared with the actual restoration case of a real utility.

4 illus, 4 tables, 15 ref

012698   Danaraj R M S;Gajendran F (Res and Dev, Sri Krishna Coll of Engng and Technol, Coimbatore-641 008) : Quadratic programmig solution to emission and economic dispatch problems. J Instn Engrs-Pt EL 2005, 86(September), 129-32.

Presents a new and efficient way of implementing quadratic programming to solve the economic and emission dispatch problems. Economic load dispatch (ELD), minimum emission dispatch (MED), combined economic emission dispatch (CEED) and emission controlled economic dispatch (ECED) are solved using the proposed method. Transformation of variables technique along with quadratic programming is applied recursively to solve both problems. The advantage of this method is its robustness to find the global minimum for all the problems. The algorithm is tested on a test system and compared with genetic algorithm and hybrid genetic algorithm. The results clearly demonstrate the effectiveness of the proposed method.

8 tables, 12 ref

012697   Chiu-On Ng;Rudraiah N;Nagaraj C;Nagaraj H N (Natn Res Inst for Appl Math, , Bangalore-560 082) : Electrohydrodynamic dispersion of macromolecular components in nanostructured biological bearing. J Energy Heat Mass Transfer 2005, 27(1), 39-64.

The effects of fixed charges, osmotic pressure, and nonuniform electric field on the electrohydrodynamic dispersion of hyaluronic acid (HA), glycoprotein adn other macromolecular components from synovial fluid (SF) to artificial or natural synovial joints is studied using Taylor's dispersion model. This model explicitly takes into account the charges of the cartilage tissues and poorly conduction SF flow. The synovial fluid in an artificial joint is known to obey Newtonian character and that in the natural joint is regarded as couple stress poorly conducting fluid and the cartilage is modeled as nanostructured smart material. The velocity and concentration distributions are analytically obtained using slip and couple stress boundry conditions. The volumetric rate and Taylor dispersion coefficient are obtained analytically in the case of artifical joints and numerically in the case of natural joints. Finds that the Electrohydrodynamic dispersion coefficient varies as cube of electric number in artificial as well as natural joints and hence an increase in electric number increases the dispersion of HA, glycoprotein and other macro molecular components from synovial fluid to cartilage, as needed for an effective functioning of biological bearing.

4 illus, 31 ref

012696   Bross S;Muller B (NO, , ) : Causes and effects of hydraulically induced vibrations in pumps. Indian Pumps 2005, 37(3), 5-8.

Excessive vibrations count among the most frequent causes of pump failure. They destroy primarily mechanical seals and bearings, thus drastically reducing the pump's anticipated service life If the frequencies of the relevant excitations match the natural frequencies of individual components and make them vibrate in resonance, such components can suffer catastrophic failure. Especially under low-flow operating conditions, such vibrations can be generated by hydraulic excitation which, in spite of identical symptoms, may have quite different origins.

6 illus

012695   Brodersen S;Kuhl A (NO, , ) : Containment shell and can materials for zero-leakage pumps. Indian Pumps 2005, 37(3), 9-12.

In chemical and process engineering applications, it is of overriding importance that the relevant equipment satisfy very stringent requirements as to zero leakage, operating reliability, safety and energy consumption. This applies in particular to components as essential as pumps. Consequently, in the further development of their products, pump manufacturers must pay special attention to those requirements.

6 illus

012694   Berge G;Prangenberg M (NO, , ) : Trend towards decentralised automation. Indian Pumps 2005, 37(3), 13-20.

With deference to the environment, and due to enormous cost pressure in the industry, the safety, reliability and quality criteria for pumps and valves employed in industrial systems and processes are becoming increasingly stringent. More and more information is needed about the local processes and the involved components and machinery. All that information has to be quickly analysed, and appropriate actions and reactions must be derived from the results. Never before have such large amounts of data had to be handled and processed, and that can only be accomplished with the aid of powerful electronic components. This, in turn, imposes new demands on automation technology, both with regard to the basic concepts and in connection with the requiste components.

6 ref

012693   Basu M (Dep of Pwr Pl Engng, Jadavpur Univ, Kolkata-700 098) : Evolutionary programming-based goal-attainment method for economic emission load dispatch with non-smooth fuel cost and emission level functions. J Instn Engrs-Pt EL 2005, 86(September), 95-9.

Novel multi-objective optimisation approach for economic emission had dispatch with non-smooth fuel cost and emission level functions is presented. The problem treats economy and emission as competing objectives. Assuming that the decision maker (DM) has goals for each of the objective functions, the multi-objective problem is converted into a single-objective optimisation by the goal-attainment method, which is then handled by the evolutionary programming technique. The solution methodology can offer a global or near-global non-inferior solution for the DM. Numerical results for a sample test system have been presented to demonstrate the performance and applicability of the proposed method.

1 illus, 3 tables, 17 ref

012692   Ballal M S;Khan Z (NO, M S Elect Bd, Chandrapur) : ANN based stator winding inter-turn insulation level detector for single phase induction motor. J Instn Engrs-Pt EL 2005, 86(September), 103-6.

Presents an ANN approach for the detection of winding insulation level in the single-phase induction motor. A neural network is trained and tested with realtime data generated in laboratory. Detailed simulation results using MATLAB are presented. The training and testing results for 1.25 kW induction motor are compared and it is found that the two results have consistency.

6 illus, 11 ref

012691   Arya L D;Titare L S;Kumar V (Electl Engng Dep, Shri G S Inst of Technol and Sci, Indore) : Transmission system failure probability evaluation accounting static voltage stability limit using cut-set method. J Instn Engrs-Pt EL 2005, 86(September), 117-22.

Describes a methodology for obtaining failure probability of a transmission network with the help of cut-set method of reliability evaluation. Further the method accounts the loadability of the network from voltage stability consideration viewpoint. Specifically the methodology calculates the probabilistic risk of voltage collapse for a specific load on the system. Static voltage stability limit for different configurations of the network have been obtained using continuation power flow program. The methodology has been implemented on a 6-bus, 7-line system.

4 illus, 2 tables, 16 ref

012690   Abhyankar S L (NO, , ) : Blame it on pumps. Indian Pumps 2005, 37(3), 27-28.

1 illus