016000   Yasuda H;Ohnaka I;Dhindaw B K;Takezawa N; Tamayama T;Fujimoto S;Tsuchiyamal A;Nakano T;Uesugi K (Dep of Adaptive Machine Systems, Osaka Univ, Osaka, 565-0871, Japan, Email: yasuda@ams.eng. osaka-u.ac.jp) : Evolution of regular monotectic structure during unidirectional solidification under static magnetic field. Trans Indian Inst Meterol 2005, 58(4), 625-30.

Presents effect of the static magnetic field imposition on the unidirectional solidification of the monotectic Al-In, Cu-Pb and Cu-Pb-Al alloys. Imposition of magnetic fields up to 10T sufficiently reduced convection in the microscopic scale and consequently revealed that the coupled growth in which two constituent phases cooperatively grow can occur even at the hypermonotectic composition for the Al-In alloys. The unidirectionally solidified Al-10at %In structure shows the uniformly aligned structure of the In rods (10-20 mm in diameter) in the Al matrix. For the Cu-Pb-Al alloys, the static magnetic fields also improved the regular alignment of the Pb-rods in the Cu-Al matrix. The micro X-ray computerized tomography showed the rods are continuous and highly cylindrical. Selective dissolution of the In rod by a electrochemical process produced the porous Al or Cu with highly deep pores.

7 illus, 16 ref

015999   Yaragal S C;GovindaRam H S;Tamura Y (Dep of Civ Engng, Natn Inst of Technol Karnataka, Surathkal PO: Srinivasnagar-575 025) : Experimental investigation of the 2-D flow field associated with bleed flows. J Instn Engrs-Pt CI 2005, 86(November), 109-12.

Wind tunnel experiments were conducted on a series of two-dimensional perforated plates normal to an air stream to study the characteristics of unsteady wake pressures and to ascertain the parameters amongst which a certain level of correlation can be established. The velocity ranged from 5 m/s to 15 m/s in the study. The pressure field gets significantly modified as the perforation level increases. The study is concerned with three plates with perforation level of 0%, 25% and 35%. There appears to be a correlation between the maximum normalized value of the RMS pressure fluctuation levels, base pressure and the perforation level of the normal plate.

6 illus, 1 table, 5 ref

015998   Yamamoto K;Shibata H;Mizoguchi S (NO, IMRAM Tonoku Univ 2-1-1 Katahira, Aobaku, Sendai, Japan 980-8577, Email: smizoguc@tagen.tohoku.ac.jp) : Defective ok effective?- tramp elements in steels. Trans Indian Inst Meterol 2005, 58(4), 695-702.

Tramp elements such as copper (Cu) or tin (Sn) cause a severe hot shortness. Many efforts have been done to remove such elements from molten steel but found hopeless. The only possible way to avoid the problem was thought to dilute the contaminated steels by virgin iron sources but it is costly. Hot shortness is due to the fact that the preferential oxidation of iron on the surface causes the enrichment of Cu and then formed liquid Cu penetrates into the austenite grain boundaries to tear the grains. Based on this mechanism there are two solutions. The first solution is to avoid the oxidation and mechanical stress at the temperature around 1150°C. The second is to enhance the heterogeneous nucleation of liquid Cu at MnS precipitates inside the austenite grains. Once this problem is solved, Cu or Sn may be utilized as effective micro-alloy elements. Compares behaviour of the heterogeneous nucleation of ultra-fine Cu precipitates using Fe-10 mass % Cu alloys with or without MnS. The Cu precipitates are classified into three types. "A" type is liquid Cu at the grain boundaries and "B" type is the globular Cu particle nucleated at MnS or inclusions. "C" type is ε-Cu of the fee structure and the size is 20-100 nm which may be effective for physical properties. Finally, the effect of Sn on the precipitation will be mentioned.

11 illus, 1 table, 27 ref

015997   Wadhawan V K (NO, , 2/111/H, Modular Laboratories, Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085, Email: wadhawan@apsara.barc.ernet.in) : Smart structures and materials. Resonance 2005, 10(11), 27-41.

Structure is an assembly that serves an engineering function. It is reasonable to expect that all engineering design should be smart, and not dumb. But one can still make a distinction between smartly designed structures and smart structures. The latter term has acquired a specific technical meaning over the last few decades. A smart structure is that which has the ability to respond adaptively in a pre-designed useful and efficient manner to changes in environmental conditions, including any changes in its own condition; the response is adaptive in the sense that two or more stimuli or inputs may be received as anticipated and yet there is a single response function as per design. Smartness ensures that the structure gives optimum performance under a variety of environmental conditions. While structures with some degree of smartness have been designed from times immemorial, the current activity and excitement in this field derives its impetus from the level of sophistication achieved in materials science, information technology, measurement science, sensors, actuators, signal processing, nanotechnology, cybernetics, artificial intelligence, and biomimetics.

2 illus, 6 ref

015996   Verma A K;Chandra S;Dhindaw B K (R&D Div, The Tata Iron and Steel Co. Ltd., Jamshedpur-831 001, Email: akverma@tatasteel.com) : Fully implicit fixed-grid finite difference formulation for phase change problems. Trans Indian Inst Meterol 2005, 58(4), 517-23.

Fully implicit control volume technique has been presented to solve phase change problems. A source of heat balance error for the numerical solution of phase-change problems has been identified. It has been shown that the conventional heat flux equation for the phase change given by the Stefan condition gives rise to a cumulative heat balance error. This error has been minimised by proposing a modification to the Stefan condition to compute the interface velocity for the classical one phase Stefan problem. The model is based on one-dimensional formulation of the phase change problem and its numerical solution has been realized using the fixed-grid finite difference scheme. The model predictions have been found to be in agreement with analytical solutions.

5 illus, 1 table, 19 ref

015995   Thakur S K;Dieringa H;Dhindaw B K;Hort N; Kainer K U (Dep of Metall & Mater Engng, Indian Inst of Technol, Kharagpur-721 302, Email: thakur@SIMTech.a-star.edu.sg) : Thermal cycling and creep studies of AM50+Nd magnesium alloy based carbon fiber, SiC particulate and in-situ Mg₂Si reinforced hybrid composites. Trans Indian Inst Meterol 2005, 58(4), 653-9.

Magnesium based hybrid composites with carbon fiber, SiC_p and in-situ Mg2Si reinforcements have been prepared through squeeze infiltration technique. The results of the studies done on measurement of the coefficient of thermal expansion (CTE) after thermal cycling have been presented. An attempt has been made to characterize the micro-structural evolution and the plastic deformation behaviour of these hybrid composites in the as cast condition and after thermal cycling. Attempt has also been made to study the effect of thermal treatment on the thermal expansion behaviour of the AM50+Nd magnesium based hybrid composites in terms of CTE values. Composites containing Nd show lower values of CTE compared to the base alloy. Further creep compression tests were carried out on these composites. Composites consisting of rare earth element Nd show much better creep properties as compared to the base alloy matrix. Results of creep compression tests carried out for some other Mg and Al base alloys and composites have also been included for comparison.

6 illus, 2 tables, 21 ref

015994   Srinivasan R (NO, Raman Res Inst, C.V. Raman Avenue Sadashivanagar, Bangalore-560 080, Email: rsv2rri.res.in) : Spintronics 2. devices and materials. Resonance 2005, 10(11), 8-17.

In this part, the commercial applications of spin-tronics are described briefly to indicate the potential of spintronics. This is followed by a description of some of the proposed devices. Some devices have been commercially exploited while others are still in the development stage. A discussion of materials suitable for spintronic devices will be given.

5 illus, 4 ref

015993   Sordelet D;Yang X (Mater and Engng Phys Program Ames Lab (USDOE), Iowa St Univ, Ames IA 5001 USA, Email: sordeled@ameslab.gov) : Linkage between oxygen content and metastable phase formation in melt spun Zr₈₀Pt₂₀ alloys. Trans Indian Inst Meterol 2005, 58(4), 749-60.

Continue previous studies that show melt spun Zr₈₀Pt₂₀, ribbons having oxygen contents ranging from <60> 200 to approximately 5000 mass ppm form various metastable phases during quenching. In the presence of sufficient oxygen, a big cube Zr₆ Pt₃₀ phase forms, but this structure is destabilized towards an icosahedral quasicrystalline structure at lower oxygen levels. Further reduction of oxygen promotes increasingly stable Zr-Pt bonds, and a metastable β-Zr(Pt) structure is formed.

9 illus, 1 table, 20 ref

015992   Sinha G P;Bagchi D K;Mukherjee U C (NO, Cent Mech Engng Res Inst, Durgapur-731 209) : Strategies to make Indian steel industry globally competitive. J Instn Engrs-Pt MC 2005, 86(October), 45-53.

India offers special opportunity to steel producers. From raw materials to finished steel production optimised operations and optimised blend of input can lead to globally competitive and world-class steel output. The paper works out the methodology for deriving the optimum levels based on the fundamental principles. It also suggests the areas where national level and plant level strategies need to be evolved.

14 illus, 7 tables, 10 ref

015991   Singha Roy R;Chand A;Basu D (Oxide and Bio-ceramics Sect, Cent Glass and Ceram Res Inst, Kolkata-700 032) : Comparative study of alumina wear in air and distilled water. J Instn Engrs-Pt MC 2005, 86(October), 59-63.

Wear behaviour of high density high purity alumina against itself was studied at low speeds in air as well as in distilled water using a pin-on-disc machine. Depending on the apparent contact pressure and environment used, different wear mechanisms were identified. It was observed that in dry sliding (ie, without lubrication), abrasive ploughing and grain boundary microcracking causing grain pull out were dominant mechanisms at low contact pressure while at higher contact pressure, asperity melting due to high flash temperature was found. In wet sliding, the mechanism was different and associated with the formation of aluminium hydroxide that acted as a solid lubricant between the contacting surfaces reducing the wear at lower contact pressure. At higher pressure, clear intergranular fracture was noticed.

8 illus, 2 tables, 28 ref

015990   Singh V K (Slope Stability Dep, Cent Min Res Inst, Dhanbad-826 001) : Slope stability study for optimum design of an opencast project. J scient ind Res 2006, 65(1), 47-56.

Stability of an opencast mine slope, investigated by the limit equilibrium method, indicates that 148 m deep open pit is stable with 60° overall slope angle. Geotechnical mapping was undertaken to determine the critical orientation of structural discontinuities. Geomechanical properties were determined in the laboratory and subsequently modified to approximate those of in situ rock mass. Sensitivity analysis was done to determine the influence of the slope design parameters on the safety factor. It was also used in determining the most suitable remedial measure for the critical slope. Slope monitoring did not reveal any movement in and around the pit.

6 illus, 13 table, 17 ref

015989   Singh J;Singh N;Sharma J K (Dep of Mech and Production Engng, Beant Coll of Engng & Technol, Gurdaspur-143 521) : Fuzzy modeling and identification of intelligent control for refrigeration compressor. J scient ind Res 2006, 65(1), 22-30.

Fuzzy modeling and mathematical analysis for the intelligent control of compressor in order to regulate refrigerant mass flow in vapour compression refrigeration system has been described. The compressor speed and delivery pressure are taken as input parameters and mass flow rate is considered as output parameter. To develop an effective model for control design, fuzzy rule base is designed with and without sub clustering. Intelligent control is used to receive the input signal and generate the output signal to control the mass flow rate from the compressor. Swept volume, suction pressure and densities are considered as fixed parameters.

10 illus, 1 table, 8 ref

015988   Shini-chiro A;Kaoru O;Masayuki M;Akio K (Dep of Mater Sci and Engng, Nagasaki Univ, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan, Email: akagawa@net.nagasaki-u.ac.jp) : Fabrication of metallic components by fused deposition method. Trans Indian Inst Meterol 2005, 58(4), 679-86.

Cylindrical and rectangular castings were produced by fused spinning deposition (FSD) method. The optimum conditions to control the shape of castings having different sizes were investigated. The castings produced by the FSD method was 1.4 times higher than those of the specimens cast into metal-mold and sand-mold, due to the finer equiaxed grain structure of the FSD castings. Some applications to the fabrication of metallic components were given.

12 illus, 2 ref

015987   Sharma B K;Satish Kumar;Mittal S K;Shamshi M A (NO, Cent Scientific Instruments Organisation, Chandigarh-160 030) : Design improvements in digital seismograph for recording long duration seismic events and aftershocks. J scient ind Res 2006, 65(1), 36-41.

New design approach to overcome technical limitations of digital seismographs by incorporating optimum hardware and efficient software modules etc has been discussed. New design approach has enhanced the limited 64 kbytes addressing capability of 8-bit microprocessor based seismograph to 16 Mbytes capacity. Instrument based on this design philosophy can now record many long duration seismic events and the series of subsequent aftershocks, which need storage of several mega bytes. The technique has enabled uninterrupted data acquisition and processing even when the data of earlier recorded events is being transferred from main storage to PC hard disk. The design concept has been validated successfully by operating the instrument based on this technique for long time in the field.

3 illus, 19 ref

015986   Sengar S H;Kurchania A K (Dep of Renewable Energy Sources, Coll of Technol and Engng Maharana Pratap Univ of Agric and Technol, Udaipur-313 001) : Experimental performance analysis of composite solar dryer cum cooker. J Dairying Fd Home Sci 2005, 24(2), 123-9.

Solar Dryer cum Cooker (SDC) device for cooking and drying was designed and fabricated at Department of Renewable Energy Sources, C.T.A.E., Udaipur and tested for no load condition and full load condition in winter and summer to find out its performances. F₁, F₂ values of solar cooker were 0.119, 0.120 and 0.32, 0.30 for winter and summer. Time required for rice, tur, dal, moong dal was 90, 130 and 100 minutes in winter 60, 90 and 75 minutes in summer. The efficiency for drying maize, wheat and potato was found to be 15.55%, 10.89% and 10.42%, for solar dryer in winter, 12.97%, 8.90% and 10.16% for solar dryer in summer respectively. The total cost of SDC was Rs. 2715.

5 illus, 2 tables, 3 ref

015985   Sen S;Kar S K;Catalina A V;Stefanescu D M; Dhindaw B K (Bae Systems/SD 46, NASA Marshall Space Flight Cent, Huntsville, AL, USA, Email: sisen@knology. net) : Evolution of in-situ generated reinforcement precipitates in metal matrix composites. Trans Indian Inst Meterol 2005, 58(4), 709-14.

Due to certain inherent advantages, in-situ production of Metal Matrix Composites (MMCs) have received considerable attention in the recent past. In-situ techniques typically involve a chemical reaction that results in precipitation of a ceramic reinforcement phase. The size and spatial distribution of these precipitates ultimately determine the mechanical properties of these MMCs. In the paper author has investigated the validity of extending the mathematical expression derived to quantify the interaction between an inert particle and a planar solid-liquid interface (SLI) to predict the spatial evolution of the in-situ generated precipitates within an equiaxed grain. Measurements made on size and distribution of TiC precipitates in a Ni₃Al matrix will be presented to test the validity of such an approach.

4 illus, 1 table, 22 ref

015984   Sekhar Babu P;Rajendran P;Rao K N (Mech Engng Dep, Vignan Inst of Technol and Sci, Deshmukhi, Nalgonda-508 284) : Cryogenic treatment of M1, EN19 and H13 tool steels to improve wear resistance. J Instn Engrs-Pt MC 2005, 86(October), 64-6.

Cryogenic treatment is said to improve wear resistance of tool and die steels and implemented at many places for that purpose. Although it has been confirmed that cryogenic treatment improves wear resistance and tool life, the process has not been standardised with inconsistent results varying from researcher to researcher. ln this work the authors have studied the improvement in near resistance of M1, EN 19 and H13 tool steels after cryogenic treatment. The materials were tested for improvement in abrasive wear resistance after cryognic treatment at different temperatures below 0øC. All the samples were first heat treated as per standard norms and re tempered after cryogenic treatment. The samples were treated at 0°C, -20°C, -40°C, -80°C and-190°C. It was observed that the wear resistance improved for all the samples from 315% to 382% depending on the material.

7 illus, 5 tables, 4 ref

015983   Ray S K;Bandopadhyay L K;Singh R P;Sahay N; Ahmad I;Narayan A;Bhowmick B C (NO, Cent Min Res Inst, Barwa Road, Dhanbad-826 001) : Microprocessor based flow meter for measuring flow rate of cryogenic liquids. J scient ind Res 2006, 65(1), 42-6.

Design of a microprocessor-based flow meter to optimize the flow rate of liquid nitrogen required to control fire in underground coalmines has been presented . The salient features of the device and its set-up procedure with the liquid nitrogen tanker are illustrated with suitable schematic diagram. The program logic of the proposed device is illustrated in the form of a flow chart.

4 illus, 10 ref

015982   Ray M;Bandyopadhyay N R (Sch of Mater Sci and Engng, Bengal Engng and Sci Univ, Shibpur, Howarh-701 103) : Nanotechnology: current trends in application oriented research. J Instn Engrs-Pt MC 2005, 86(October), 67-70.

This paper gives overviews of the current trends in nanotechnology research.

4 illus, 16 ref

015981   Ray A;Bhattacharya V;Chattopadhyay K (Dep of Metallurgy, Indian Inst of Sci, Bangalore-560 012, Email: victoria@platinum.metal) : Evolution of morphology of undercooled droplets in Cu-Cu₃P near eutectic alloy. Trans Indian Inst Meterol 2005, 58(4), 761-7.

Reports results of an investigation on phase evolution from undercooled Cu-Cu₃P eutectic liquid entrained in a copper matrix. The results indicate attainment of large undercooling of the droplets during solidification and a variation in the droplet microstructure as a function of size. It is argued that the achievable undercooling and hence nucleation of the Cu₃P phase is related to size of the droplets.

5 illus, 16 ref

015980   Ravi Kumar S;Chakraborty M;Dhindaw B K (Dep of Metall and Mater Engng, Indian Inst of Technol, Kharagpur-721 302, Email: Brij.Kumar.Dhindaw@iitkgp.ac.in) : Influence of reinforcement coating on interfacial characteristics in stir-cast Al/SiC composites. Trans Indian Inst Meterol 2005, 58(4), 721-30.

In Metal Matrix Composites reinforced with ceramic particulates, the interfacial physical and chemical characteristics play a significant role in determining the composite properties. In order to study the influence of reinforcement surface coatings on interface strength properties, pure Al-10 Vol. % SiC particle composites were prepared by melt stn casting technique. In the present work, composites were reinforced with Cu coated and dynamically oxidized SiC particles and the properties of the composites were compared with the uncoated one. Microhardness measurements on the panicles and interparticle distances have been used as tools in defining the interfacial strength of the composites. The effect of Mg as an alloying addition in pure Al matrix has also been studied. Composites with dynamically oxidized SiC reinforcement show superior interface strength properties when compared to composites with copper coated and uncoated SiC particles. Mg addition and the surface modification of the ceramic reinforcement have improved the wetting characteristics in Al matrix resulting in enhanced microhardness on the particles and wear properties of the composites.

7 illus, 24 ref

015979   Ratke L;Muller A (NO, Inst of Space Simulation German Aerospace Cent, DLR, 51147 Cologne, Germany, Email: Lorenz. Ratke@dlr.de) : Stability of microstructures in directionally solidified monotectic alloys. Trans Indian Inst Meterol 2005, 58(4), 571-7.

Al-Bi of exact monotectic composition was directionally solidified with solidification velocities from 0.3 μ m/sec to 5 μm/sec and temperature gradients from 2 K/mm to 6.5 K/mm. Three distinct microstuctures could be observed: fibers, strings of pearls and irregular arrays of second phase droplets. The transitions from fibers to strings of pearls or irregular arranged drops are discussed theoretically and compared with the experimental results. One transition seems to be a Nichols and Mullins instability of the fibers, the other an effect of periodic nucleation ahead of the solidification front.

7 illus, 30 ref

015978   Ratke L et al, (NO, Insititute of Space Simulation, DLR, Cologne, Germany, Email: Lorenz.ratke@dlr.de) : Effect of magnetically controlled fluid flow on microstructure evolution in cast technical al-alloys:the micast project. Trans Indian Inst Meterol 2005, 58(4), 631-8.

MICAST research program focuses on a systematic analysis of the effect of convection on the microstructure evolution in cast Al-alloys. The experiments of the MICAST team are carried out under well defined thermally and magnetically controlled, convective boundary conditions and analyzed using advanced diagnostics and theoretical modeling, involving phase field simulation, micro-modeling and global simulation of heat and mass transport. The MICAST team uses binary, ternary and technical alloys of the Al-Si family. Gives an overview on recent experimental results and theoretical modelling of the MICAST team.

9 illus, 21 ref

015977   Ramirez J C;Beckermann C (Dep of Mech and Industrial Engng, The Univ of Iowa, Iowa City, Iowa 52242, Email: becker@engineering.uiowa.edu) : Simulation of binary alloy free dendritic growth with a phase-field model. Trans Indian Inst Meterol 2005, 58(4), 525-30.

Free dendritic growth of dilute binary alloys into a supercooled melt is simulated using a two-dimensional phase-field model. The model accounts for coupled heat and solute transport in the melt and allows simulations to be performed in a thin-interface limit, with a vanishing kinetic effect and no solute trapping. An adaptive grid that permits calculations for large ratios of thermal to solutal diffusivity (Lewis number) is used. Good agreement between numerically predicted and theoretical values of growth Peclet numbers is obtained. The selection parameter σ is shown to vary with initial melt concentration, Lewis number, and imposed supercooling.

illus, tables, ref

015976   Rama Raju K;Mehar Prasad A;Lakshmanan N; Muthumani K;Jagadish D R;Amuthasheela R (NO, Structural Engng Res Cent Chennai, CSIR Campus, Chennai-600 113) : Optimum distribution of viscous fluid dampers in structural systems. J Instn Engrs-Pt CI 2005, 86(November), 103-8.

The paper demonstrates the usefulness of viscous fluid dampers (VFDs) with toggle bracing mechanism in controlling the vibration of three-storey frame model by comparing their performance with buildings having only diagonally placed VFDs. It has been shown from the studies carried out that provision of VFDs with toggle bracing mechanism at ground floor level would act like vibration dampers. This results in controlling the vibration levels at higher floor levels. The optimum distribution of VFDs with toggle bracing mechanism in three-storey moment resistant steel framed buildings has been studied. For this building frame the placement of VFDs with toggle brace mechanism along the height of the building is found to be effective. The results suggest that the bracing system proposed in this paper can be effectively used in retrofitting of existing buildings and in performance based design of new ones for earthquake loads.

5 illus, 6 tables, 7 ref

015975   Rajashekhar;Chaudhuri S (Dep of Electl Engng, Indian Inst of Technol Bombay, Powai, Mumbai-400 706, Email: {raja, sc}@ee.iitb.ac.in) : Logo retrieval using morphological pattern spectrum. IETE J Res 2005, 51(5), 339-50.

Paper proposes a geometric approach to capture the shape and spatial relation attributes in binary images to build an efficient logo retrieval system. Authors had extracted the shape feature by computing the morphological pattern spectrum (MPS) for various structuring elements. The spatial relation among the disjoint components in the logo image is described by defining a simple and computationally inexpensive spatial relation graph (SRG). The SRG is obtained by joining the centroids of the two largest components with the centroids of the rest of the components. For retrieval purposes, the similarity measure is defined with respect to similarities in both shape and spatial relationship (MPS and SRG). The joint shape and spatial relation features enable us to obtain a very good precision rate. A relevance feedback mechanism is used to obtain the weights for various components in the similarity measure. The details of the method as well as results of experimentations are presented.

17 illus, 34 ref

015974   Radha S;Rajkumar S (Dep of ECE, Sri Shiva Subramaniyan Nadar Coll of Engng, Kalavakkam-603 110, Email: radha_kumaran@yahoo.com) : Enhanced intrusion detection algorithm for NTP based routing protocol for wireless ad hoc networks. IETE J Res 2005, 51(5), 353-9.

MANETS are particularly vulnerable to intrusion, as they operate in the open medium and use co-operative strategies for network communications. Paper is mainly to identify the misbehaviors caused by some malicious node for reactive routing protocol, mainly Node Transition Probability (NTP) based routing, and eliminate them from the network. The cooperative Intrusion Detection Model and the Intrusion Response Model along with independent intrusion detection model are implemented, to accomplish the above-mentioned assignment. An unanimous and distributed intrusion detection model for mobile ad hoc networks has been proposed. In contrast to the previously proposed intrusion detection models for ad hoc networks, an efficient and bandwidth-conscious framework that takes into distributed nature of ad hoc wireless network management and decision policies are implemented.

8 illus, 11 ref

015973   Praveen Kumar;Mehndiratta H C;Chandranarayana S;Singh S P (Transportation Engng Sect Dep of Civ Engng, Indian Inst of Technol, Roorkee-247 667) : Effect of randomly distributed fibres on flyash embankments. J Instn Engrs-Pt CI 2005, 86(November), 113-18.

The paper presents the effect of inclusion of polypropylene fibres with flyash. Laboratory CBR tests, triaxial shear tests, plate load and field CBR tests were carried out to investigate the effect of fibre inclusion on the strength behaviour of flyash. Tests were conducted on flyash with different percentages of polypropylene fibres. Laboratory CBR tests were conducted on flyash in both soaked and unsoaked conditions. The CBR value of flyash increases with increase in fibre content in both soaked and unsoaked conditions. The percentage increase in CBR value is higher at lower percentage of fibre content. Triaxial tests were conducted at optimum moisture content with 0.7 kg/cm²,1.2 kg/cm² and 1.8 kg/cm² confining pressures. Based on the CBR values and shear strength parameters, 0.5% fibre content is seen to be the optimum. Plate load and field CBR tests were conducted on flyash and flyash with 0.5% fibre content. The addition of fibre to flyash shows significant improvement in CBR value, angle of internal friction and modulus subgrade reaction.

12 tables, 5 ref

015972   Pillai T M M;Karthekeyan P I (Dep of Civ Engng, Natn Inst of Technol, Calicut-673 601) : Artificial neural network based approach for design of RCC columns. J Instn Engrs-Pt CI 2005, 86(November), 127-32.

Recent developments in artificial neural network have opened up new possibilities in the field of structural engineering. The paper demonstrates the usefulness of artificial neural network (ANN) for design of RCC columns subjected to combined axial load and biaxial moments. The design of column is affected by many factors such as the initial crookedness, eccentricity of loading, shape and size of the column cross section, grade of steel, and grade of concrete. Therefore, design code adopts formulae, which requires a number of scalar constants and ends up with trial and error design. Hence, an attempt has been made to capture the mapping between the design variables using ANN. A feed forward network and backpropagation training algorithm has been used. Training data are generated from a 'C' program that designs RCC column by conventional design method. For training, about 500 data sets have been generated for each type of column cross-section.

6 illus, 4 tables, 6 ref

015971   Patnaik S;Konar A;Mandal A K (Dep of Electl Engng, Univ Coll of Engng, Burla-768 018, Email: srikantapatnaik@hotmail.com) : Improving the multi-agent coordination through learning. IETE J Res 2005, 51(5), 395-405.

Problem "Coordination" among multiple agents is an active and open-ended problem of robotics. The coordination problem, considered in the paper, has been divided into three categories: (i) Spatial coordination; (ii) Temporal coordination; (III) Spatio-temporal coordination. The principles of "Situation Calculus" have been extended to model the spatial coordination problem of robot. The concept of temporal coordination has been introduced with Situated Automata and Q-learning. The collective learning behavior of a multi-agent system has been improved by the principles of Q-learning. The spatio-temporal coordination, that deals with the coordination problem involving both space and time has been modeled using the timed Petri nets. The special emphasis has been given to the behavioral model of eye and hand coordination of a mobile robot. One typical application of the multi-agent coordination in the soccer playing robot has been proposed at the end of the paper.

11 illus, 11 ref

015970   Pathak K K;Jain H (NO, Regional Res Lab, Hoshangabad Road, Bhopal-462 026) : Shape optimisation of beams on elastic foundation. J Instn Engrs-Pt CI 2005, 86(November), 93-5.

8 ref

015969   Park S S;Lee J G;Kim N J (NO, Cent for Advd Aerospace Mater Pohang Univ of Sci and Technol, Pohang 790-784, Korea, Email: njkim@postech.kr) : Development of high performance alloy sheets by strip casting. Trans Indian Inst Meterol 2005, 58(4), 687-93.

Three exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting has shown a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. Reviews activities in the development of high performance alloys by strip casting.

^iia4 illus, 3 tables, 31 ref

015968   Pandey A;Kothari D P;Bhim Singh (Cent for Energy Stud, Indian Inst of Technology-Delhi, Hauz Khas, New Delhi-110 016, Email: dkothari@ces.iitd.ernet.in) : Sliding mode control of PFC converter. IETE J Res 2005, 51(5), 371-7.

Controllers in Power Factor Corrected (PFC) converters are conventionally designed in frequency or time domain using linearized model of the converter system. These controllers are not always adequate for PFC converters due to presence of hard nonlinearity in the system. Theoretically, linear feedback designs can only ensure stability and satisfactory operation under restrictive operating conditions for which the linearized model is valid. However, as the application base of PFC converters increases, the need for more robust control schemes becomes imperative. To this end, the sliding mode approach, described in the work, inherently addresses hard nonlinearity present in the PFC converters. The controller design and simulations results has been presented and discussed in detail. As expected, the results show that sliding mode controller improves converter dynamics and large-signal stability without compromising on the intrinsic simplicity of the conventional control scheme. The sliding mode controller is found to be more robust and appropriate control scheme for PFC converters as compared to conventional linear controllers.

6 illus

015967   Padhi P;Panigrahi S C;Ghosh S (Metall and Mater Engng, Indian Inistitute of Technol, Kharagpur-721 302, Email: scp@metal.iitkgp.ernet.in) : Particle size distribution in Al-ZrSiO4 under centrifugal action. Trans Indian Inst Meterol 2005, 58(4), 715-19.

Preliminary studies on a novel technique for manufacturing Metal Matrix Composites (MMC) have been carried out. The technique involves rotation of the mould, which is cooling from all sides, around random axes (multi-axial rotation). This technique was found to give a uniform distribution of ZrSiO₄ (Zircon) in aluminum matrix for 0.65-volume fraction of Zircon. Paper briefly discusses the mechanism of uniform particle distribution. Presently work is going on to develop a comprehensive model for prediction of particle size distribution in this technique. Also efforts are being made to improve upon the preliminary technique. Attempts are also being made to manufacture functionally graded Al-Zircon composite by rotation of mold, in which unidirectional solidification is occurring and centrifugal force is acting perpendicular to solidification front. A first stage stochastic model based on Newtonian dynamics has been developed to predict the distribution of the Zircon particles in the centrifugally cast Al-Zircon functionally graded MMC. Effects of rotation speed on the size distribution of Zircon particles in the composite have been studied.

3 illus, 2 tables, 8 ref

015966   Ohnaka I;Yasuda H;Sugiyama A;Ohmichi T (Dep of Entrepreneur Engng, Grad Sch of Engng Dsaka Sangyo Univ, Nakagaito 3-1-1, Daito-shi, Osaka, 574-8530, Japan, Email: ohnaka@ams.eng.osaka-u.ac.jp) : Direct observation of casting and solidification. Trans Indian Inst Meterol 2005, 58(4), 603-10.

Presents two direct observation methods, namely the conventional X-ray absorption image method for mold filling and a new method using monochromatic synchrotron radiation for solidification. Observation results include gas entrapment during mold filling in sand casting, mold filling through a filter, mold filling in a vacuum suction casting and a lost foam process, detachment of dendrites during unidirectional solidification of Sn-Bi alloys. Although numerical simulation agreed well with some of these observations, there are still challenging problems such as the simulation of mold filling in the lost foam process and droplet formation on the melt front and defects formation in unidirectionally solidified turbine blade casting.

10 illus, 30 ref

015965   Masayuki M;Shigeki N;Akio K (Dep of Mater Sci and Engng, Nagasaki Univ, 1-14 Bunkyo-machi, Nagasaki 852-8521, JAPAN, Email: mizumoto@net.nagasaki-u.ac.jp) : Grain refining of inconel 718 by addition of Ni-Nb-C alloy. Trans Indian Inst Meterol 2005, 58(4), 597-602.

It is well known that in the welding of the Inconel 718, microcracks are generated as a result of the dissolution of Laves phase on the grain boundary in HAZ. In the study, Ni-Nb-C alloys were employed as the additives in order to prevent the generation of microcracks by grain refining. When the melt temperature was 1623K and holding time was 5 sec, the grain size was significantly reduced to about 100 μm and equiaxed grains were observed. The grain refining was achieved when the amount of the additives was over 0.3 mass%.

9 illus, 1 table, 9 ref

015964   Lagerstedt A;Adolfi S;Fredriksson H (Casting of metal, Royal Inst of Technol, KTH SE - 100 44 Stockholm, Sweden, Email: andersl@matpr.kth.se) : Crack formation during continuous casting of tool steel. Trans Indian Inst Meterol 2005, 58(4), 671-8.

Formation of cracks has been studied during continuous casting of a tool steel. Experimental work was performed in a continuous slab caster and the position of the cracks was determined as a function of distance from the cooling surface. Numerically calculated temperatures and elastic stresses were combined with experimentally determined thermomechanical data of the cast material in order to predict crack positions. The model was extended to include the effect on the strain from both thermal shrinkage and the shrinkage caused by condensation of vacancies during the solidification process.

13 illus, 2 tables, 16 ref

015963   Kumar A;Roy G K (Dep of Civ Engng, Natn Inst of Technol, Rourkela-769 008) : Statistical analysis of bed fluctuation ratio in gas-solid fluidized bed with rod promoter. J Instn Engrs-Pt CI 2005, 86(November), 119-22.

A model equation for the prediction of bed fluctuation ratio in rod promoted gas-solid fluidized (condition above quicksand) bed has been developed using statistical design of experiments approach. Four rod promoters of varying volume blockage together with bed materials of four densities and four initials static bed heights have been used in the investigation. A comparison has been presented between the predicted values of bed fluctuation ratio using proposed model equation and the corresponding experimental ones for the test data. The mean and standard deviations of the predicted values of bed fluctuation ratio from the corresponding experimental ones show fair agreement.

5 illus, 3 tables, 8 ref

015962   Kron J;Lagerstedt A;Fredriksson H (Casting of Metals, Royal Inst of Technol, KTH, SE-10044 Stockholm, Sweden, Email: andersl@matpr.kth.se) : Modelling of air gap formation in solidification processing. Trans Indian Inst Meterol 2005, 58(4), 531-8.

Different models are used today to model air gap formation during a solidification process. In the work air gap modelling is discussed with reference to experimental work with air gap measurements during casting. Thermal and thermomechanical modelling were done with thermal boundary conditions found experimentally. The measured displacements of the mould and the solidifying metal were used in order to check the validity of the simulation results and compare it with reality. The description of the thermal shrinkage and its connection to air gap formation is especially discussed. Al- and Fe-based alloys investigated elsewhere have been used in this work.

9 illus, 13 ref

015961   Kazakov V A;Rodriguez S D (Dep of Telecommun of the Sch of Mech and Electl Engng, Natn Polytechnic Inst of Mexico, Mexico) : Reconstruction of Gaussian processes with an arbitrary number of samples and discrete jitter. IETE J Res 2005, 51(5), 361-70.

Sampling-Reconstruction Procedure (SRP) of the Gaussian processes with an arbitrary number of samples has been considered when all or some of the samples have jitter. The investigation method is based on the conditional mean rule. The optimal error reconstruction function and the basic functions of each sample are calculated in the time domain for some non trivial examples when the type of covariance function and the discrete distribution law of the jitter are changed. The jitter of each sample is independent and has different discrete distribution law. In order to get all the results author has applied the operation of the statistical average to the conditional mean and the conditional variance with regard to the random intervals.

10 illus, 18 ref

015960   Juretzko F R;Stefanescu D M (NO, The Univ of Alabama, Tuscaloosa, AL, USA, Email: juretzko@bama.ua.edu) : Evaluation of mold filling simulation by video recording. Trans Indian Inst Meterol 2005, 58(4), 645-52.

Computer simulation of mold filling and solidification has significantly impacted the casting industry by reducing scrap rate and improving soundness. However, experimental data are needed for simulation verification. In the past, model substances and X-ray film recordings were employed. Since actual mold filling is much faster than that can be captured in detail with conventional video equipment, this work uses a higher frame rate. The results of a high speed video camera study are presented for the filling of a vertical mold with cast iron. Details of the dynamic filling are compared with simulation results. The influence of filters on mold filling will be assessed and use of this technique to select filter coefficients for computer simulations will be discussed.

11 illus, 3 tables, 18 ref

015959   John S;Tare V (NO, Punjab Tech Univ, Jalandhar-144 001) : Methanogenic activity test as an aid in evaluating performance and stability of anaerobic bioreactors. J envir Sci Engng 2005, 47(2), 125-30.

Correlation between methanogenic activity and anaerobic reactor performance is intuitive. An attempt has been made to suggest a new parameter, defined on the basis of the relative activity of acetoclastic and hydrogen oxidising methanogens, to aid in evaluating the performance and stability of anaerobic reactors. Performance of three bench scale reactors was assessed at different relative populations of the trophic groups of methanogens as estimated through acetoclastic and total methanogenic activity tests. Results indicated that the acetoclastic to total methanogenic activity ratio 0.7 yielded stable and optimal reactor performance. The acetoclastic and total methanogenic activity tests provide a simple technique that may aid in evaluating the performance and stability of anaerobic bioreactors.

4 illus, 2 tables, 13 ref

015958   Joanna P S;Samuel Knight G M (Dep of Civ Engng, Hindustan Coll of Engng, Padur-603 103) : Dynamic response of steel beams with semi-rigid connections. J Instn Engrs-Pt CI 2005, 86(November), 123-6.

The paper presents the dynamic response of semi-rigid steel beams. Since, in reality many field assembled beam-to-column connections are semi-rigid in nature and possess certain flexibility, the consideration of the influence of joint stiffness is essential for an accurate study on the dynamic behaviour of steel beams. Neglect of semi-rigidity leads to an artificial stiffening of the beams resulting in a shorter fundamental period, which in turn result in a significant error in the evaluation of dynamic loads. Examples are presented to illustrate how connection stiffness affects the fundamental frequency, deflection and bending moments of the beam. Normalised curves for fundamental period and deflections are provided to facilitate quick assessment of the error involved based on the study of beam it was observed that flexibility of pints could be advantageously used to exploit inertial effects and at the same time resist unanticipated dynamic loads acting on a system designed for normal static loads.

6 illus, 4 ref

015957   Jeyakumar M;Subodh Kumar (Dep of Metallurgy, Indian Inst of Sci, Bangalore 560 012, Email: skumar@met.iisc.ernet.in ) : Microstructural evolution of spray formed 7075 Al alloy. Trans Indian Inst Meterol 2005, 58(4), 617-23.

Spray deposition is a novel manufacturing process, which is currently being developed for producing near-net-Shape preforms. Spray deposition involves the creation of a spray of droplets by a gas atomizer and the consolidation of these droplets on a substrate to create a preform. In order to maximize the metallurgical benefits of spray deposition, a thorough study of the solidification process is important. In the study, 7075 Al alloy is atomized by high velocity argon gas and atomized droplets are collected on the fixed copper substrate. The microstructure of over spray powder and the preform are studied. Spray atomization produces various sizes of droplets, ranging from 5 to 300 μm. A variety of microstructures are observed for different size of powders. Microstructural changes occur due to the difference in the cooling rates of the atomized droplets. The cooling rate of the fine droplets is high compared with coarse droplets. Generally the cooling rate of the droplet changes from 102 to 106 K s^-1. In the spray deposition the preform shows equiaxed grains, while the size of the grain changes from bottom to top of the preform. The grain size measurements at the bottom, centre and top of the preform gives 25, 40 and 20 μm respectively. This happens because of the fact that different portions of the preform experiences different cooling rates. The bottom and top of the preform have high cooling rate compared with the centre portion.

11 illus, 1 table, 26 ref

015956   Jalihal S A;Reddy T S;Nataraju (Transportation Plan and Engng Div, Cent Rd Res Inst, Mathura Road, New Delhi-110 020) : Evaluation of automatic traffic counters under mixed traffic conditions. J Instn Engrs-Pt CI 2005, 86(November), 96-102.

Automatic traffic counting station on NH-8 near Manoharpur, was established in order to collect continuous traffic data for toll audit purpose. In the paper the traffic counter cum classifier (TCC) which works using inductive loops/sensors, is evaluated under mixed traffic/low conditions. There are at least eight major types of motorized vehicles on Indian roads that carry passengers and goods traffic. Therefore, the paper illustrates the accuracy of both classified and total count of vehicles being collected from TCC compared with manual counts under mixed traffic flow conditions. Further, the variation in the accuracy of counting due to violation of lane discipline is described. Finally the recommendations for installation of loop/sensor based TCC are presented.

2 illus, 7 tables, 8 ref

015955   Hort N;Dieringa H;Kainer K U (NO, GKSS Res Cent, Geesthacht, Germany, Email: Norbert.Hort@gkss.del) : Hot tearing of magnesium alloys. Trans Indian Inst Meterol 2005, 58(4), 703-8.

Magnesium alloys are gaining increasing interest in light weight applications in automotive industry. Due to industrial requirements alloy development is of major importance to achieve an improvement of the property profile. Unfortunately the use of alloying elements like rare earth elements, calcium, silicon, strontium etc. is also decreasing the castability and alloys containing these elements have not yet been introduced to continuous casting as well. Therefore the new alloys have to be selected carefully in accordance to their castability regarding different casting processes. In the work AZ based alloys modified with Ca and Zn will be investigated regarding their hot tearing behavior.

5 illus, 2 tables, 22 ref

015954   Harikumar R;Sukanesh R (Dep of ECE, Thiagarajar Coll of Engng, Madurai-625 015, Email: harikumar_psgit@rediffmail.com) : Fuzzy techniques with aggregation operators for classification and optimization of epilepsy risk level from EEG signals. IETE J Res 2005, 51(5), 379-88.

Purpose of paper is to develop a fuzzy classification model for epilepsy risk level analysis from EEG signals. The parametric values such as energy, variance, and duration, covariance, positive and negative peaks, sharp and spike waves and events are derived in each epoch of two second duration in the EEG signal channels. Fuzzy techniques are used to classify the risk level in each epoch for all the channels, the risk level patterns obtained are found to have low values of sensitivity, specificity, performance index and quality value. In order to increase the classification rate, an optimization technique based on aggregation operators is used and a quality value of 23.78 is achieved when compared to the value 6.25 achieved in the previous case. A comparison of fuzzy techniques without and with optimization is studied. The focal epilepsy problem in normal fuzzy classification is solved using this new approach. A group of ten patients with known epilepsy findings are used in the study. Further research work can be carried out in the classification of epilepsy risk level of a long-term EEG signals about 3 minute's durations. The number of samples may be increased to improve the classification rate.

3 illus, 5 tables, 23 ref

015953   Gupta N;Ray G G;Gupta S;Patel S M (NO, Coll of Hom Sci, Vallabh Vidyanagar) : Experimental study to redesign visual display terminal workstation for bifocal operators. J scient ind Res 2006, 65(1), 31-5.

Bifocal VDT (Visual Display Terminal) operators (50) were studied from different fields (data entry, conversational task, programming, CAD/CAM etc.) through user-product-environment system. Users profile includes experiments pertaining to users reactions, while products profile covers designs, manufacturing arid marketing of existing computer furniture in the market Existing VDT workstations were observed inappropriate for bifocal people feeing vision problem, which was analysed thoroughly in simulated laboratory conditions by preparing a test rig with adjustable monitor angle from horizontal. Work posture of VDT operators was assessed with EMG, Photogram Metric Technique, and Centre of Gravity in four stages of test rig. An ergonomics criterion for redesigning VDT workstation was developed. It is appropriate and natural for the man-machine-environment system and also allows comfortable posture and greater efficiency of bifocal and normal VDT operators.

1 illus, 3 table, 2 ref

015952   Engles D;Malik S S (Dep of Electron Technol, Guru Nanak Dev Univ, Amritsar-143 005, Email: derickengles@yahoo.com) : Coupling characteristics of an asymmetric rectangular core optical wave-guide coupler. IETE J Res 2005, 51(5), 389-94.

Analytical method based on the boundary value technique has been developed to study the systematic of symmetric as well as asymmetric wave-guide couplers. Authors has tested their model for symmetric and asymmetric couplers and the results are in good agreement with those of Takagi et al. The technique is simple, straightforward with few mathematical simplifications and approximations. Author's obtain unique self-consistent single solution for the given guide geometry, therefore implying the mono-mode character of the waveguide coupler. Author has formulism can predict the performance and the field characteristics of the coupler from the knowledge of the coupler geometry. Thus it may help in the design of diffused channel single mode rectangular core optical wave-guide couplers when adequate data is available.

7 illus, 5 ref

015951   Dutta S K;Sah R (Metall Engng Dep Fac of Technol and Engng, M S Univ of Boarda, Vadodara-390 001) : Characteristics of foaming slag in smelting reduction processes. J Instn Engrs-Pt MC 2005, 86(October), 54-8.

Smelting reduction processes, without using coke, are alternative, ironmaking technologies for production of hot metal. Gases, which are generated due to reaction, cannot be removed from the reactor without foaming of the slag. Characteristics of foaming slag are important in the smelting reduction processes. Main foaming parameters are foaming index and foam life. In this paper, measurement of foaming index and influence of additives on foam an discussed.

5 illus, 3 tables, 13 ref