005055   Prasad M V S N;Gupta M M;Sarkar S K;Iqbal A (Radio and Atmospheric Sciences Division, National Physical Laboratory, Dr K S Krishnan Road, New Delhi-110 012, Email: mvprasad@mail.nplindia.ernet.in) : Antenna beam tilting effects in fixed and mobile communications links. Curr Sci 2005, 88(7), 1142-7.

Several remedial measures like space diversity, frequency diversity, route diversity, increase in antenna height, antenna tilting, etc. have been tried by many workers to overcome the debilitating effect of multipath fading in fixed line-of-sight microwave and mobile communication links. Among these remedial measures, diversity techniques have been extensively studied in terms of improvement factor, whereas the concept of antenna tilting is relatively less explored compared with other remedial measures. In the study, the effect of antenna tilting on fixed and mobile communication links is investigated to find out the optimum tilting angles in terms of design parameters.

7 illus, 14 ref

005054   Mital A;Arora V K (Civil Engg Deptt, N I T, Kurukshetra) : Effect of height of the opening on roof deformation using EMM. Indian Min Engng J 2005, 44(5), 28-32.

4 illus, 1 table, 4 ref

005053   Kute S;Deodhar S V (Head of Civil Engg Department, S S V Ps L B S D College of Engineering, Dhule) : Improvement in compressive strength of brick masonry by using mortar with MS fibre. J Struct Engng 2005, 32(2), 123-6.

2 illus, 3 tables, 7 ref

005052   Krishnan V;Paliwal L K;Singh R S (Institute of Technology, Banaras Hindu University, Varanasi, Email: ram_sharans@rediffmail.com) : Model for predicting final temperature and residence time of urea prills. Indian J Fertil 2005, 1(1), 17-18, 21-3.

Mathematical model was developed for predicting temperature of urea prills at the bottom of the prilling tower and residence time of different size of urea prills at different air flow rate in the tower. The model incorporated important aspects such as calculation of velocity of the individual prill, temperature of the individual prill, final temperature of prill at the bottom and the optimum RPM of the prill bucket to get the optimum prill size in the given condition of the variables. Simulation studies were performed to assess the model behavior under various operating conditions. The result demonstrated that the temperature of urea prill at the bottom of the prilling tower for prill size between 0.5 mm to 1.5 mm was constant and nearly equal to ambient air temperature. For size range of 1.5 mm to 2.5 mm, the final prill temperature increased rapidly with the inlet air temperature. Residence time of prills decreases rapidly when size changes from 0.5 to 1 mm and slowly for particle size above 1 mm.

3 illus, 31 ref

005051   Kawitkar R;Wakde D G (NO, S S G M College of Engineering, Shegaon-444 203, Email: rskawitkar@rediffmail.com) : Advances in smart antenna system. J scient ind Res 2005, 64(9), 660-5.

A brief account on smart antenna (SA) system has beeen presented. Smart or adaptive antenna arrays consist of an array of antenna elements with signal processing capability that optimizes the radiation and reception of a desired signal dynamically. SAs can place nulls in the direction of interferes via adaptive updating of weights linked to each antenna element. SAs thus cancel out most of the co-channel interference resulting in better quality of reception and lower dropped calls. SAs can also track the user within a cell via direction of arrival algorithms.

2 illus, 27 ref

005050   Kalaga S (NO, , 480, Roxbury Circle, Jackson, Michigan-49203, USA) : Ultimate strenth analysis of square concrete columns. J Struct Engng 2005, 32(2), 127-30.

6 illus, 2 tables, 8 ref

005049   Jain S;Ajay Kumar;Bhatnagar K B (Guru Premsukh Memorial College of Engineering, , 245, Budhpur Village, G T Karnal Road, Delhi-110 036, Email: jain_sanjay73@yahoo.com) : Periodic orbits around the collinear liberation points in the restricted three body problem when both the primaries are triaxial rigid bodies. Indian J Phys 2005, 79(6), 583-90.

Periodic orbits around the collinear liberation points in the restricted three body problem have been studied when both the primaries are triaxial rigid bodies. The effects of perturbations on the semi-axes of the earth and the moon in the respective periodic orbits have been studied. The Liapunov stability of each periodic solution has also been examined.

3 illus, 5 tables, 3 ref

005048   Ganguly S;Rao M L (Detroit, U.S.A. 26150, W. 12 Mile Road, B52) : Elasto-plastic contact stress analysis of plates by FEM. J Struct Engng 2005, 32(2), 117-21.

8 illus, 13 ref

005047   Elavenil S;Radhakrishnan R;Elangovan A; Arumugam N (Department of Civil Engineering, S R M Engineering College, Kattankulathur-603 203) : Dynamic response of fibre reinforced concrete plates under impact load. J Struct Engng 2005, 32(2), 93-100.

Concrete structures are often subjected to various types of dynamic forces. Fibre reinforcement improves the dynamic behaviour of reinforced concrete plates under impulse loading. An experimental investigation on the dynamic behaviour of steel fibre reinforced cement concrete (SFRC) plates. The variables considered were percentage volume fraction of steel fibres, aspect ratio, the angle of impact and the thickness of the platehas been reported. The observations of acceleration, frequency response and the shape of the impulse curve were studied.The frequency response is lower for sections which is supported on two sides than for the plate supported on all four sides and it increases with the thickness of the plate. Instantaneous peak acceleration increased with increased angle of impact. The shape of the impulse curve can be either triangular or trapezoidal.

6 illus, 4 tables, 7 ref

005046   Dubey S K (Department of Civil Engineering, Maulana Azad National Institute of Technology, Bhopal, M.P.) : Analysis of homogeneous orthotropic deep beams. J Struct Engng 2005, 32(2), 109-16.

Beams whose depths are comparable to their spans are used in a variety of structures. The distribution of bending and shear stresses in such deep beams are different from that given by the ordinary, simple formulas for shallow members. The method of initial functions (MIF) has been applied for analysis of deep beams. The equations of two dimensional elasticity have been used. Numerical solutions of the governing equations have been presented for simply supported beams loaded with sinusoidal load and uniformly distributed load. Three cases with varying depth to span ratio have been considered for analysis. The results are compared with theory based on Bernoulli's Hypothesis.

16 illus, 3 tables, 11 ref

005045   Dolas A;Pandharipande S L;Chandak B S (Laxminarayan Institute of Technology, , Nagpur-440 033, Email: anantdolas@rediffmail.com) : Modeling of three phase inverse fluidized bed using artificial neural network. Indian J chem Technol 2005, 12(3), 327-31.

Fluidization of a three-phase system can be achieved either with co-current up flow of gas and liquid or down flow of liquid and up flow of gas. Three Phase Inverse Fluidised Bed (TPIFB) falls in the second category. Because of high gas hold up and residence time, this type of fluidized bed has more mass transfer coefficient. Experiments were conducted using polyethylene hollow spheres coated with benzole acid and using water as solvent with air as the fluidizmg medium. The data thus generated was used for developing models using Artificial Neural Networks (ANN). It has been observed that the ANN model developed has excellent accuracy level of more than 90%.

6 illus, 2 tables, 14 ref

005044   Dikshit M P;Gupta M L (Dy G M Kumda Group of Mines, , Bishrampur Area, SECL, Bilaspur) : "Hard roof management" - a tool for successful longwall caving at Kumda group of mines, Bisrampur area, SECL. Indian Min Engng J 2005, 44(5), 10-17.

3 illus, 5 ref

005043   Dewangan P;Mishra A K (Mining Engg, Govt. Engg. College, Raipur) : Effect of total explosive charge fired and direction of initiation on the magnitude of blast induced ground vibration. Indian Min Engng J 2005, 44(5), 20-7.

Ever growing demand of mineral has demanded growth of mineral industry. In result of that most of the projects have expanded their size, which in turn are operating near habitat area. Now with increased consciousness of general public it is difficult to operate the miner without super control over blast hazards. Vibration resulting from blasting has been a source of concern from the inception of the use of the explosives. While reviewing the literature available on blast induced ground vibration, authors has realised that the total explosive charge fired in the round along with the maximum charge weight per delay and the direction of initiation with respect to the blast site may also have some influence on the magnitude of ground vibration. Hence in order to establish their role in the variation of peak particle velocity level, the study has been carried out at Giridih Opencast Mine of Central Coal Fields Limited. (A subsidiary of Coal India Limited) The results of this study may serve as a useful aid to the mining industry, where safety and environmental concern are paramount.

1 illus, 1 table, 6 ref

005042   Chaturvedi A K;Dhekne P Y;Mishra D K (Department of Mining Engineering, Govt Engineering College, Raipur, Chhattisgarh) : GPS - a modern surveying equipment. Indian Min Engng J 2005, 44(4), 29-32.

After the Second World War a need was felt by the US Department of Defence to find the solution of determining to the problem of accurate and absolute positioning. Several projects and experiments were conducted thereafter. In 1973 US Department of Defence decided to establish, develop and deploy a space borne GPS. GPS is the shortened form of NAVSTAR GPS, which stands for NAVigation System with Time And Ranging Global Positioning System. With the introduction of GPS, engineering surveys have become more accurate and fast. Today GPS is the only system, which is able to show your exact position on earth at any time, anywhere and in any weather. In the paper a system overview of GPS, its working principle, surveying methods, sources of errors and uses are outlined.

^iia4 illus, 7 ref

005041   Chandran S;Prasad A M;Menon D (Department of Civil Engineering, Indian Institute of Technology Madras, Chennai-600 036) : Structural distress of the corbelled vaults in the a Prohm temple of Angkor Wat. J Struct Engng 2005, 32(2), 131-4.

7 illus, 1 table, 4 ref

005040   Chandra Kishen J M;Bhasha S M;Sudheer Kamble (Department of Civil Engineering, Indian Institute of Science, Bangalore-560 012) : Fracture mechanics based sliding failure analysis of concrete gravity dams. J Struct Engng 2005, 32(2), 85-91.

A concrete gravity dam with a shear key is analysed using the concepts of fracture mechanics. The wedge crack model developed by Kaneko et al is used to assess the strength of the shear key in resisting sliding of the dam. Further, using a probabilistic assessment, it is found that the shear friction factor of safety is more sensitive to the pool elevation, fracture toughness and coefficient of friction of the interface between concrete damand rock foundation.

8 illus, 3 tables, 23 ref

005039   Chakraborthy A;Mohanty D K;Roul A (DGM, NALCO, , Damanjodi-763 008) : Dust control at Asia's largest open cast bauxite mine a case study at Nalco's Panchapatmali bauxite mine. Indian Min Engng J 2005, 44(4), 23-8.

Attempt has been made through the paper to bring some of the means & techniques adopted at Panchpatmali Bauxite Mines, NALCO to combat the huge dust generated due to mining activities.

61 ref

005038   Armouti N S (NO, University of Jordan, P O Box 712 506, Amman 11171, Jordan) : Transverse earthquake-induced forces in discontinuous bridges. J Struct Engng 2005, 32(2), 75-84.

A simplified method to find transverse earthquake-induced forces in bridges with expansion joints (discontinuous) is developed. A one-dimensional, modeling approach is developed as an alternative to a cumbersome three dimensional, modeling approach. A rigid deck model is proposed which considers the bridge deck segment between expansion joints as rigid pieces analogous to rigid diaphragms in buildings. In the transverse direction the bridge is modeled as a beam on elastic foundation where the deck is modeled as a series of one-dimensional rigid beams supported by the columns as elastic foundations. The expansion joints are the only degrees of freedom of the rigid beams at their ends. The principle of minimum total potential for multiple degrees of freedom system is used to formulate the problem. Comparison with results from AASHTO (three-dimensional) procedures, shows excellent agreement.

8 illus, 7 tables, 8 ref

004023   Zakaria A K M;Asgar M A;Stanciu V;Svedilindh P (Institute of Nuclear Science & Technology, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh, Email: zakariam@bangla.net) : Magnetization studies of spinel oxides Zn_xNi_1-xFeCro₄ (0.2<131>x<131>0.8). Indian J Phys 2005, 79(5), 485-90.

The spinel system Zn_x Ni_1-xFeCrO₄ (x =0.2, 0.4, 0.6 and 0.8) are prepared by the ceramic sintering method. X-ray diffraction results show that all the samples have single phase spinel structure. Using a Vibrating Sample Magnetometer (VSM), the temperature-dependence and the field-dependence of-rnagnetization measurement have been carried out. From the temperature-dependence of magnetization, ferrimagnetic ordering temperature (T_C) and from the hysteresis curves, the values of the saturation magnetization (M_s), coercive force (H_c) have been determined for the different compositions. It is observed that with the increase of diamagnetic substitution, the value of saturation magnetization first increases and then decreases, the optimum value of the diamagnetic Zn substitution being 0.5. The variation of the net magnetic moment with Zn substitution has been discussed in terms of the distribution of magnetic and non-magnetic ions over the A and B sub-lattices and their exchange coupling. The ferrimagnetic transition temperature and coercive force decrease with increasing Zn contents in Zn_xNi_1-xFeCrO₄.

6 illus, 1 table, 30 ref

004022   Venkateswarlu K;De P K;Ray A K;Chakraborty M; Murty B S (National Metallurgical Laboratory, , Jamshedpur-831 007) : Effect of rolling on Al-5Ti binary master alloy (spong route) and its grain refining performance in aluminium. J Metall Mater Sci 2004, 46(2), 107-13.

The influence of rolling on the microstructure and the grain-refining efficiency of Al-5Ti master alloy that has been prepared by addition of Ti sponge to molten Al has been studied in detail. Rolling of Al-5Ti master alloy has resulted in significant refinement in TiAl₃ particle size and change in its morphology from plate like to blocky type. The mean particle size of TiAl₃ has decreased with increase in the rolling reduction levels. The grain refining performance of the master alloy has improved with increase in the rolling reduction levels. These changes are attributed to the fracture of TiAl₃, particles during rolling, which results in an increase in the number of nucleating sites for Al.

6 illus, 18 ref

004021   Thangaraj A (Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai-600 036) : Rate compatible LDPC codes for wireless applications. IETE Tech Rev 2004, 21(5), 325-33.

Low-density parity-check codes have been shown to perform very close to capacity over many channels with a constant signal-to-noise ratio. In wireless communications, the channel conditions vary with time at a reasonably fast rate. Adaptive coding methods such as ARQ schemes are very effective in varying channel conditions. ARQ schemes use a set of codes with varying rate and performance in a rate compatible manner. Investigates ARQ schemes that use rate compatible low-density parity-check codes. Recent research has shown that performance within 0.5dB of capacity is possible over a wide range of channel conditions using such ARQ schemes.

2 illus, 1 table, 19 ref

004020   Suman Y;Rajpal N (NO, NISTADS, K S Krishnan Marg, Pusa, New Delhi-110 012) : Mobile location tracking techniques: analysis and evaluation. IETE Tech Rev 2004, 21(5), 351-6.

Information about the location of a mobile station (MS) can be very useful in providing critical services required during rescuing operations. It can be useful in providing navigational services. Additionally it can help in tackling issues like co-channel interference and limitations of frequency spectrum. Analyses and evaluates mobile location tracking techniques in terms of accuracy, cost and processing load.

2 illus, 7 ref

004019   Subrahmanya P;Sundaresan R;Shiu D (NO, Qualcomm Inc, 675 Campbell Technology Parkway, Campbell, CA 95008, USA) : An overview of high-speed packet data transport in CDMA systems. IETE Tech Rev 2004, 21(5), 305-15.

Rapid growth of data services in wireless communication systems requires an efficient means for high speed data transport. Modern CDMA systems have evolved to support this need. Presents an overview of the key techniques for improving high speed data transport in the following standards: 1xEV-DO (IS-856 Rev A), 1xEV-DV (cdma2000 Rev D), and HSDPA & EUL (WCDMA FDD Release 6). The emphasis is on identifying the common themes for high speed data transport in all these systems: adaptive modulation and coding, incremental redundancy and hybrid ARQ, smart scheduling to exploit channel variations, limited downlink macro-diversity aided by fast sector switching, and the use of shared channels to improve perceived latency.

5 illus, 6 tables, 8 ref

004018   Srivastava L (Telecommunication Policy Analyst, Strategy and Policy Unit, Office of the Secretary General, Internation, Ch-1211, Geneva 20, Switzerland) : Mobility unplugged: technologies, Policy challenges and market opportunities. IETE Tech Rev 2004, 21(6), 417-21.

In this article the success of mobile telecommunication services and mobility are discussed, and the challenges and future opportunities have been highlighted.

2 illus

004017   Srikanth S;Paul Reuben V;Kannu A P;Sivanadyan T (AU-KBC Research Centre, MIT, Anna University, Chennai-600 044) : Performance of adaptive modulation techniques for wireless local area networks. IETE Tech Rev 2004, 21(5), 345-50.

The Orthogonal Frequency Division Multiplexing (OFDM) technique has been used in Wireless Local Area Networks (WLANs) for combating the multipath distortion. The severe intersymbol interference (ISI) which results from the multipath distortion can be mitigated by simple scalar division operation when OFDM is used. However, in addition to the ISI mitigation capability, the use of OFDM enables us to adaptively load the various subcarriers used for communication. Adaptive loading can be done to optimize various system parameters which can result in benefits compared to uniform loading. We present the performance of adaptive loading schemes for WLANs based on the IEEE 802.11 a standard. Simulation results illustrate the performance advantages of adaptive loading techniques in such systems.

6 illus, 1 table, 7 ref

004016   Shukla S K;Prasad S N;Pratihar T K; Mukhopadhyay S;Chaudhuri S K (R & D Centre for Iron & Steel, SAIL, Ranchi-834 002) : Development of low carbon EDD steel for superior formability at Bokaro steel plant. Steel India 2004, 27(1), 25-9.

A new grade of EDD steel having carbon <60> 0.04<37> has been developed through the Combined Blowing Technology, particularly for the automobile and cold reducer segments. Suitable modification of the steelmaking parameters, especially the blowing pattern and coke and ferroalloy additions, helped in achieving lower carbon and nitrogen levels in the range of 0.03-0.04<37> and 35-40 ppm, respectively, in addition to improvement in cleanliness (inclusion vol.:0.13<37> max.). Further, optimisation of the processing parameters in hot rolling, cold rolling and annealing resulted in superior formability properties in CR sheets/coils. Typical mechanical properties obtained are comparable to those of similar grades of EDD steel available in the market.

5 illus, 3 tables, 5 ref

004015   Sen M;Singh A P;Kumar P;Gupta I N P;Singh R N (R & D Centre for Iron & Steel, SAIL, Ranchi-834 002) : An overview of the combustion systems used in steel industry. Steel India 2004, 27(1), 30-40.

The paper gives an overview of various combustion systems used for firing liquid and gaseous fuels (mainly by-product fuels) in different units of steel plant, namely coke-oven, sinter plant, blastfurnace stove, soaking pit, re-heating furnace, ladle and tundish heating stands and rotary kilns . This paper also covers some of the latest developments in this area such as slit burners and multi-fuel burners, which are economical and energy efficient.

13 illus, 13 ref

004014   Sastry R G;Praveer Kumar (Department of Earth Sciences, IIT, Roorkee-247 667) : Comparative performance of focused and normal devices through a numerical study. J Indian Geophys Union 2005, 9(3), 147-66.

The superiority of focussed devices over traditional Normal devices has remained a controversy in geophysical literature. A two-dimensional finite-difference scheme for numerical modeling of Normal and Laterlog (LL7) is undertaken to clarify the matters concerned. Spacing for spacing, normal log is better than LL7 for e/AM <62> 1 with R_s=R_m and R_t/R_m <131> 500. Unlike the model tank experiment limitations (Roy & Appa Rao, 1976, 1978), in our numerical simulations, we could achieve perfect current focussing and evaluate the performance of existing alternate geometric factors due to Roy (1975) and Moran (1976). The computed R_a/R_m for LL7 was not even close to R_a/R_m under ideal conditions. But a simple two electrode device performs better in comparison to LL7 device provided AM = A₁A₂. This assertion is valid even for dynamic current ratio settings also.

18 illus, 6 tables, 28 ref

004013   Samuel V R;Manoharan S (WRI, BHEL, Tiruchirappalli) : Principles of electrical measurements for welding parameters- Part III. WRI Jl 2004, 25(2), 31-40.

Various types of measuring instruments are available and used for measurement of electrical parameters such as voltage, current and resistance. Some common types of instruments are Electro-mechanical instruments, Electronic instruments, Analog (graphical) instruments, Digital instruments, Microprocessor/micro controller based instruments. Part I of this article describe different types of electro-mechanical instruments such as moving coil galvanometer, D'Arsonval meter movement used in a DC ammeter, D'Arsonval meter movement for a DC voltmeter and the ohmmeter. Other movements such as electrodynamometer movement, iron-vane meter movement, hermocouple meter, and electrostatic meter movement were also discussed. These discussions include principles of rectifying instruments, electronic nstruments such as differential amplifier, a sensitive dc voltmeter, AC voltmeter using rectifiers and amplifier and True RMS Voltmeter. The Part II of this article discussed about various electronic measuring techniques and instruments of analog types. Electronic computational and processing devices such as an operation amplifier, sample and hold circuit and true RMS to DC converter circuit measurement of temperature using semiconductor transducers as well as thermocouple transducers were discussed in addition to principles of measuring force, pressure, strain, displacement, flow, etc. Transducers such as strain gauge, LVDT, flow sensors for sensing the above quantities were also described.

43 illus, 4 ref

004012   Sahasranaman K (uhde India Ltd, , , Email: ce55@rediffmail.com) : Energy-efficient pumping-energy conservation with centrifugal pumps. Indian Pumps 2005, 37(1), 19-23.

Over the years, usage of energy-efficient pumps in gaining popularity in the process industry, which in turn is leading to finding new ways for conservation of energy. Most processes in chemical industry involve transportation of liquids and/or transfer from a lower to higher energy level. Pumping systems are one of the major consumers of electrical energy globally. It is thus natural that pumping operation should be the primary target for energy globally. It is thus natural that pumping operation should be the primary target for energy reduction and conservation. The article examines how pumping energy can be reduced by proper selection, sizing, operationand maintenance of centrifugal pumps.

3 illus, 1 table

004011   Rohira K L;Manoharan K;Raja A;Sivan V (WRI, BHEL, Tiruchirappalli) : Study on effect of test temperature and plate thickness on the impact strength of electorgas welds. WRI Jl 2004, 25(2), 16-21.

Thousands of production welds have been made successfully in a variety of steels by electrogas welding process (EGW) in many countries. In most applications, electrogas welding is preferred over Elctroslag welding process (ESW) since as welded properties are found satisfactory using appropriate flux cored wires and shielding gas. Since it is usually operated as a single-pass process, the weld metal and heat-affected zone are subjected to no subsequent weld thermal cycles, such as in common with connventional multipass arc welding of thick materials. The relatively wide heat-affected zone (HAZ) on thick plates is often characterized by large grains. On these of applications, the impact properties of the weld could be adequately tested and evaluated for the intended application. The present work has been carried out to study the effect of test temperature and thickness in 20mm and 30mm thick welds of pressure vessel grade steel confirming to ASTM A 515 Gr 70. Flux cored wire of 1.6mm diameter confirming 5.26 EG60T3 and CO₂ shielding gas were employed for conducting the welding trials. Ductile to brittle transition temperature (DBTT) was found using 40J criterion & SEM study was conducted on ** welds to establish the relation.

9 illus, 5 tables, 10 ref

004010   Riihimaki A;Paley R (NO, , Sulzer Pumps) : Stepping outside the standards for higher corrosion resistance. Indian Pumps 2005, 37(1), 13-14,23.

Corrosion-resistant pumps are critical to many industrial processes. While some duties may use plastics for pump construction, the mechnical limitation of this material mean that for most applications, cast metals are used. Traditionally, high-alloy steels have been widely used with limited success in more severe duties. Around thirty years ago, when austenitic-ferritic steels (duplex) became available, Sulzer Pumps was the first company in the world to use the material in seawater injection pumps. The following examines the latest high-alloy cast steel used by Sulzer Pumps for demanding industrial processes that deliver improved performance over duplex types.

5 illus

004009   Reddy Babu G;Mallikarjuna Rao K;Ramana Reddy I V (Department of Civil Engineering, S V U College of Engineering, S V University, Tirupati-517 502) : Value addition for sludge generated from sand beneficiation treatment plant. Nat Envir Pollut Technol 2005, 4(2), 203-6.

Recovery of waste constituents from industrial waste is a cost effective solution in control of environmental pollution. Investigation deals with the feasibility of usage of sludge from sand beneficiation treatment plant in the production of bricks. The experimental results show that the brick earth can be replaced with treatment plant sludge up to 40<37> by weight without loss in strength and other brick characteristics considered satisfactory for conventional purposes. At 5<37> to 10<37> of replacement, the quality of bricks is superior to the bricks made from brick earth alone and can be used for superior work of permanent nature.

2 tables, 13 ref

004008   Ray S K (R & D Centre for Iron & Steel, SAIL, Ranchi-834 002) : Diagnosis of surface defects in cold-rolled steel products. Steel India 2004, 27(1), 20-4.

The present paper describes the knowledge-base developed on the genesis of 'hole', 'sliver' and 'lamination' type 'material' defects in CR products of different grades of steel. The intensity and the incidence of these defects were correlated with process parameters of secondary refining and continuous casting, and grade-specific solidification behaviour. Based on these correlations, specific remedial measures were identified. Implementation of these measures helped in achieving significant reduction of the defects.

2 illus, 5 ref

004007   Ravi K;Srikant S;Bhattacharyya A;Jha S (R & D Centre for Iron & Steel, SAIL, Ranchi-834 002) : Evaluation of chromic acid based passivators for improving corrosion resistance of galvanized steel sheets. Steel India 2004, 27(1), 15-9.

The poor quality of passivators used for hot dip galvanized (HDG) steel sheets leads to rejections of the coated sheets due to white rust formation. In the present study, an attempt was made to evaluate ten different passivators available in the market. These passivators were characterized in terms of CrO₃ content pH conductivity and also the content of various activators present. Galvanized sheet samples were subjected to passivation treatment, and subsequently to salt spray and humidity tests for 100 and 2000 hours, respectively The passivated samples were evaluated for their corrosion resistance by observing the white rust formation on the surface of the sheets at periodic intervals. Only two passivators were found to pass both the salt spray and humidity tests.

1 illus, 2 tables, 6 ref

004006   Rangaraj G V;Jalihal D;Giridhar K (Telecommunication and Computer Networks (TeNeT) Group, Department of, Indian Institute of Technology, Madras-600 036) : On usefulness of multipath diversity for multiple antenna OFDM systems. IETE Tech Rev 2004, 21(5), 317-24.

Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) technology hold much promise in realizing broadband wireless systems which are both power efficient and bandwidth efficient. This review article focuses on MIMO-OFDM wireless systems, and the usefulness of multipath diversity in such systems are addressed. With increasing data rate requirements for wireless access, the technology challenges of the physical layer designers are moving towards wideband wireless communications. One of the key issue to be confronted in such systems is the frequency selective fading of the wireless channel due to multipath propagation. Orthogonal frequency division multiplexing helps in transforming this frequency selective channel into multiple narrowband flat sub-channels which facilitate a computationally efficient equalization. Usually multipath delay spread is considered as an annoyance factor. However, such channels are rich in multipath diversity, which could potentially be exploited to yield performance benefits. Using simple frequency domain processing in OFDM systems with closely spaced antennas, this multipath diversity could be exploited to achieve performance close to that of space diversity systems using well separated antennas. With such closely spaced antennas, it appears as though there is sampling in the spatial domain. Linear dispersion codes are capacity achieving space-time codes designed by optimizing the information-theoretic capacity function. Multipath diversity available as frequency diversity could be exploited by linear dispersion codes when the dispersion is over OFDM sub-channels in frequency and space. Reviews such space-frequency linear dispersion codes which are particularly useful at low rate and for low complexity systems.

5 illus, 21 ref

004005   Ramanathan S;Karthik G;Sumathi G (Department of Computer Science, Sri Venkateswara College of Engineering, Sriperumbudur-602 105) : Load balancing in WDM networks through dynamic route changes. IETE Tech Rev 2004, 21(6), 379-84.

This study deals with the formulation of an effective and efficient algorithm for load balancing in WDM networks. Developes a Load Balancing algorithm for IP-like Routing. The considered networks are based on a routing protocol where the next hop at a given node depends only on the destination of the communication. The aim of this work is to consider the applicability of this approach in the context of optical networks, by taking into account the routing and wavelength assignment constraints simultaneously which is a NP-Complete problem. The algorithm performs at each iteration, a basic change in the network by rerouting the traffic to the destination from the given source by finding an alternate path thereby reducing the load on the common link. As a result a single entry change in the routing table is performed, which is very important for the stability of the network.

1 illus, 9 ref

004004   Rai R;Gupta S;Ratan S (Department of Mining Engineering, Institute of Technology, Benaras Hindu University, Varansi-221 005) : Determination of dust generation potential number using rock properties. J Mines Metals Fuels 2005, 53(3-4), 65-8.

Dust is defined as the fine particles (generally below 100 microns) of organic or inorganic substances suspended in the atmosphere. These air borne particles are environmental nuisance and cause health hazards as an ill effect of mining activities. Different rocks have different dust generation potential (DGP). The study correlates physico-mechanical properties of rocks with their dust generation potential. Six physico-mechanical properties namely compressive strength, brittleness, Protodyakonov index, Impact Strength Index and specific gravity for a sample of eight different rock type were studied in this analysis.

6 illus, 6 tables, 6 ref

004003   Pemberton M (Business Development & Marketing, ITT IPG Pump Smart Control solutions, ITT Goulds Pumps, Email: Pemberton@itt.com) : Variable speed pumping: myths and legends. Indian Pumps 2005, 37(1), 9-12.

Variable speed drives offer many advantages in the operation of centrifugal pumps but, in spite of this, many barriers remain to implementing the technology to its potential. In the article from the USA, Mike Pemberton of ITT Goulds Pumps seeks to dispel the myths and legends surrounding variable frequency technology and its application, arguing that it has now developed to the point that these barriers are, for the most part, perceived rather than actual.

2 illus

004002   Pattanaik D K;Patnaik S (Department of Electronics and Telecommunication Engineering, University College of Engineering, Burla, Sambalpur-768 018) : Intelligent robots and their level of intelligence: a short review. IETE Tech Rev 2004, 21(6), 385-402.

The paper is written keeping in mind the popularisation of the research of intelligent robots among the science and engineering community of India. The technical details of a sample intelligent robot PIONEER 2DX has been elaborated with its client-server architecture. Developments of various mobile robots and robotic vehicles by various laboratories and companies have been reported along with their capabilities and limitations. At the end intelligent test of different robots Is highlighted. Some typical examples and informative tables have been listed.

1 illus, 2 tables, 38 ref

004001   Patil R S;Ghodekar J G (Electronics Engineering, Walchand College of Engineering, Sangli-416 415) : Artifical neural network based system using transform domain methods for ECG abnormality detection. IETE Tech Rev 2004, 21(6), 409-16.

The Electrocardiogram (ECG) is a major tool for detecting abnormal condition of the heart. Coronary artery disease is reduction of blood supply to the heart muscles resulting in ischemic condition. The deposition of fat, cholesterol and calcium results in narrowing of the blood vessels. The narrowing of coronary arteries, if severe, results in heart attack. The various parameters obtained from ECG in time domain help to diagnose the coronary artery disease. Effort this made to illustrate methods to detect ECG abnormality using Fourier Transform, Windowed Fourier Transform and the Wavelet Transform. Training and testing sets are prepared for Artificial Neural Networks using each of these transforms. Thus Artificial Neural Networks are used to detect the ECG abnormality. The suitability of each of these transforms for the ECG abnormality detection is also discussed.

6 illus, 2 tables, 6 ref

004000   Neelakantan T R;Suribabu C R (School of Civil Engng, SASTRA Deemed Univ, , Thanjavur-613 402) : Performance evaluation of urban water distribution networks. J Indian Wat Wks Ass 2005, 37(1), 45-52.

Drinking water distribution system should be designed to satisfy the demand at various nodes with minimum required pressure and quality. Designing of water distribution network by keeping cost minimisation as prime objective yields an economical design rather than a reliable design. However, the intended mission of a network is to satisfy the demands while respecting minimum pressure even under the failure of a link/links in looped water distribution network. In the paper, a new index is introduced to evaluate the performance of distribution system under failure of a single link in the system, which accounts for combined effect of importance of a link and its probability of failure.

1 illus, 3 tables, 29 ref

003999   Nabiullah;Emranuzzaman;Jagdish;Pingua B M P; Khan M;Choudhary M K (NO, Central Mining Research Institute, Dhanbad) : A study on bulk emulsion product and bulk delivery system. J Mines Metals Fuels 2005, 53(3-4), 62-4.

Coal industry is the major consumer of explosives and accessories. About 80<37> of coal is being produced from open cast mines. Till 1980 the coal was produced using cartridge explosive products, which need safety in production transportation and storage as well as during the charging of explosive in the blast hole. A number of accidents is on record during production, transportation, storage and its usage in surface mines. The problems is overcome with the development of fourth generation of explosive i.e. site-mixed slurry and site-mixed emulsion. The number of companies producing site mixed emulsions include Indian Detonators Ltd. (IDL), IBP Co. Ltd. (IBP), Navbharat fuse Co. Ltd. (NFCL), Keltech Energy Ltd. (KEL), Indian Explosives Ltd. (IEL) and Black Diamond etc. IDL, IEL, Black Diamond and IBP are only supplier in ECL and BCCL mines.

4 illus, 4 tables, 6 ref

003998   Munavalli G R;Mohan Kumar M S (Civil Engng Dep, Indian Institute of Science, Bangalore-560 012) : Source strength identification of chlorine in a distribution system under dynamic state. J Indian Wat Wks Ass 2005, 37(1), 53-61.

6 illus, 4 tables, 19 ref

003997   Munavalli G R;Mohan Kumar M S (Civil Engng Dep, Indian Institute of Science, Bangalore-560 012) : Source strength identification of chlorine in a distribution system under dynamic state. J Indian Wat Wks Ass 2005, 37(1), 53-61.

6 illus, 4 tables, 19 ref

003996   Mohan D M (Hyderabad Metropolitan Water Supply & Sewerage Board, , Hyderabad) : Water supply and sanitation sector reforms for sustainability. J Indian Wat Wks Ass 2005, 37(1), 11-24.

003995   Mishra N C;Chakravarty S;Sarda K L (NO, MECON Ltd, Ranchi-834 002) : A heat transfer model for predicting location of freeze line in blast furnace hearth. Steel India 2004, 27(1), 1-9.

The paper presents a two dimensional heat transfer model for predicting the location of various temperature isotherms inside the hearth alongwith the freezeline. The heat transfer model consists of two dimensional partial differential equations, solved by finite element technique to determine temperature at every node. A FEM program has been developed, which interfaces with a graphics program to draw the hearth profile and plots the temperature isotherms. The model has been validated with field thermocouple readings obtained from designated furnaces. Effects of hearth wall cooling and thermal conductivity of refractory lining on nature of isotherms and hearth wear pattern (shape and location of freeze line) have been discussed.

6 illus, 1 table ,10 ref

003994   Manoharan S;Buvanashekaran G;Samidurai M (WRI, BHEL, Tiruchirappalli) : General electrical safety and safety practices in arc welding. WRI Jl 2004, 25(2), 22-30.

10 ref

003993   Mandal S K;Singh M M (Central Mining Research Institute, , Barwa Road, Dhanbad-826 001) : Deflection of walls as the cause of structural damage - a conceptual model. J Mines Metals Fuels 2005, 53(3-4), 55-61.

Ground vibration and air overpressure are the natural environmental hazards of blasting. Due to increased sprawl of dwellings around the mine workings and the need of cost-effective excavation operation, a need of managing risk associated with blasting operation is increasing in day-today mining activities. Structures might be damaged due to various reasons, even not related to blasting. But the poor blasting knowledge and fear psychosis towards the noise heard during blasting, brings an erratic level of judgment of human perception towards the risk of structures getting damaged. The erratic judgment of the dwellers even at times invites confrontation between dwellers and mine management and in the worst case might cause closure of mines. The authors feel that damage of structures depends upon structure quality, thickness of walls and soil/rock structure response towards vibration. Therefore, prior to estimation of safe magnitude of vibration for structural safety, structures should be analyzed through structural response and mathematical concepts of structural dynamics with respect to blasting. The paper, with the help of conceptual structural dynamic model, attempts to put forward the requirement of structural analysis for estimation of safety of structures. The paper also communicates the methodology to be adopted for construction of new buildings around the mining area.

4 illus, 52 ref

003992   Kumar A (Applied Chemistry & Corrosion Division, National Metallurgical Laboratory, Jamshedpur-831 007) : Hot - dip zinc coatings - a comparative study : part II. J Metall Mater Sci 2004, 46(2), 115-21.

Hot dip coating is one of the oldest methods for coating on the metals. The demand for zinc coated steel sheet has risen in recent years due to an increase in the use of zinc based coatings for corrosion resistant applications in the construction, automotive and domestic appliance industries. Zinc coatings provide cosmetics, perforation and general atmospheric corrosion protections against aggressive environmental conditions. Comparative characteristics studies were done by physical and chemical analysis of zinc coated materials obtained from different sources. Several techniques were used to characterise by coatings, such as EDAX for elemental analysis, thickness measurements using SEM and evolution of corrosion resistance of galvanised sheets in a salt spray, sulphur dioxide and immersed in 5M sodium hydroxide solution. It was found that SC type of samples produced the best coating in the environment of marine and industrial pollution of sulphur dioxide but in sodium hydroxide environment, it was not best.

4 illus, 6 tables, 7 ref