001521   Patel B P;Bhola S K;Ganapathi M;Makhecha D P (Institute of Armament Technology, , Pune-411 025) : Penetration of projectiles in compsite laminates. Def Sci J 2004, 54(2), 151-9.

Deals with the prediction of the penetration phenomenon of a cylindro-conical impactor on the kevlar/epoxy-laminated composites using C° eight-noded serendipity quadrilateral finite element based on first-order shear deformation theory (FSDT). Local as well as global deformations during impact is considered in the evaluation of indentation, penetration, and performation phases. Local strains during impact have been evaluated using the hypothesis made from the available experimental observations of bulging during penetration. A detailed parametric study, considering various projectiles and target plate variables, has been carried out to find their effect on the response of the plate, and ballistic parameters, such as ballistic limit and absorbed energy.

8 illus, 18 ref

001520   Parivallal S;Ravisankar K;Narayanan T; Sreeshylam P (Structural Engineering Research Centre, CSIR Campus, Taramani, , Chennai-600 113) : Fiber optic sensors for health monitoring of civil engineering structures. J Struct Engng 2004, 31(1), 9-14.

Large and complex structures are being built to meet the growing demands and are exposed to severe and harsh environmental conditions. Reliable measurement of strains over long periods is an essential requirement when monitoring important structures like prestressed concrete bridges, containment vessels, offshore structures, pipes etc. The type of strain gange and method of installation should provide reliable measurement of strain over a long period. Among the different strain sensors available, fiberoptic sensors are found to be reliable for long-term monitoring of structures. Experimental studies were carried out to evaluate the performance of Extrinsic Fabry-Perol interferometric (EFPI) fiber optic sensors for strain measurements. The stability and reliability of fiber optic sensor for long-term strain measurement in civil engineering structures is demonstrated from the laboratory studies.

7 illus, 1 table, 11 ref

001519   Parameswaran V;Jategaonkar R V (National Aerospace Laboratories, , Bangalore-560 017) : Calibration of 5-hole probe for flow angles from advanced technologies testing aircraft system flight data. Def Sci J 2004, 54(2), 111-23.

Describes the investigations carried out to calibrate the 5-hole probe for flow angles from advanced technologies testing aircraft system flight data. The flight tests were carried out with gear up and at nominal mid-centre of gravity location for two landing flap positions, δ=IN and 14°. Dynamic manoeuvres were executed to excite the short period and Dutch roll mode of the aircraft. In addition, pull up, push down and steady sideslip manoeuvres were also carried out. The data compatibility check on the recorded flight data has been carried out using maximum likelihood output error algorithm to estimate the bias, scale factor, and time delay in the pressure measurements from the 5-hole probe mounted on a noseboom in front of aircraft nose. Through a way of kinematic consistency checking, flight-validated scale factors, biases, and time delays are determined for the differential pressure measurements for both angle of attack and angle of sideslip. Also, the dynamic pressure measurement is found to have time delays. Based on the earlier investigations, it is once again confirmed that the measurements of attitude angles, obtained from the intertial platform, clearly indicate time delays referred to the other signals like linear accelerations and angular rates which are measured with the dedicated flight instrumentation package. The identified time delays in attitude angles agreed well with the inertial platform specifications. The estimates of sensitivity coefficients and scale factors from the flight data analysis correlates reasonably well with the manufacturer Rosemount calibration curves for the tested Mach range 0.23-0.53. The flight data analysis at Mach number of about 0.59 indicate Mach dependency for the angle of attack.

6 illus, 4 tables, 10 ref

001518   Pandian N;Jayachandran S A;Seetharaman S; Babasaheb K V (Structural Engineering Research Centre, , Madras) : Limit state design of cold formed steel compression members - codal comparisons. J Struct Engng 2003, 30(3), 173-8.

Cold formed steel Sections (CFSS) has the advantage of fabricating or building up several sections of the user's choice for example, sigma, angle with lip, channel with lip, hat, Zed, etc. unlike hot rolled sections. Also, CFSS had high strength to weight ratio. The increase in yield strength under certain circumstances, easiness of varying yield strengths, opening for laying cables etc further strengthens the idea of their use. CFSS can be used as building members economically for less than three floors. These members can also be used efficiently for compression or bending members wherever the load is light and the span is medium. However, the designer should consider local buckling criterion addition to other criteria. As usual, the design methodologies are allowable stress design and limit state designs. In western countries the limit design is called as Load and Resistance Factor Design (LRFD). There is no codal provision for limit design in India either for hot rolled sections or for cold formed sections. Recently, limit state design or LRFD assumes significance of saving in material due to the application of partial load and resistance factors. At present, only allowable stress design has been adopted as per Indian code. The present Indian code has to be upgraded with certain changes whether it adopts allowable stress design or LRFD on similar lines with American Iron and Steel Institute Code (AISI) or British Standard (BS).

6 illus, 3 tables, 7 ref

001517   Oommen Tharakan K T;Chandorkar A N;Rao S S S P (Indian Institute of Technology Bombay, , Mumbai-400 076) : Development of an abstract model for a non-volatile static random access memory. Def Sci J 2004, 54(2), 183-8.

The capability to protect against fluctuations, which eventually prevents the corruption of the memory contents makes non-volatile static random access memory a very good choice for use in highly reliability applications. These random access memories are protected against data writing in addition to preserving the desired contents. Energy source and control circuitries are embedded into it for achieving the same. The control circuritry constantly monitors supply voltage level, inhibits data corruption, and switches on the energy source once it falls beyond a threshold level. Development of an abstract model for such a non-volatile static random access memory chip has been presented. Test sequences based on this model have been generated for this memory chip. These test sequences have been implemented in VLSI tester and exercised on the chips.

1 illus, 1 table, 7 ref

001516   Murty C V R (NO, Indian Institute of Technology Kanpur, Kanpur) : Learning earthquake design and construction: earthquake tip - 15 - why is vertical reinforcement required in masonry buildings. J Struct Engng 2003, 30(3), 203-4.

5 illus, 4 ref

001515   Murty C V R (NO, Indian Institute of Technology Kanpur, Kanpur) : Learning earthquake design and construction earthquake tip - 14 - Why are horizontal bands necessary in masonry buildings. J Struct Engng 2003, 30(3), 201-2.

4 illus, 3 ref

001514   Murth C V R (NO, Indian Institute of Technology Kanpur, Kanpur) : Learning earthquake design and construction: Earthquake tip - 16 - how to make stone masonary buildings earthquake resistant. J Struct Engng 2003, 30(3), 205-6.

4 illus, 4 ref

001513   Mukherjee S;Kumar V;Mitra R (Electrical Engineering Dep, Indian Institute of Technology, Roorkee-247 667) : Ordered reduction of linear discrete system using an error minimization technique. J Instn Engrs-Pt EL 2004, 85(Jun), 68-76.

A computationally simple approach is proposed for order reduction of linear time invariant discrete system. Dominant poles are retained in the low order model using well-defined criteria for dominance. Steady state part of the transient response in exactly matched between the reduced order and original high order system. Zeros of the reduced order system are determined by minimizing the error between the transient parts of the responses of reduced and high order systems. Stability of the reduced order system is always assured in the proposed method. A number of examples have been tried using the method and a comparative analysis with existing methods highlights its relevance and strength.

7 illus, 2 tables, 32 ref

001512   Mukherjee G S;Shukla N;Singh R K;Mathur G N (Defence Materials & Stores Research & Development Establishment, , Kanpur-208 013) : Thermoplastic epoxide resin in the presence of polyethylene glycol as hot-melt adhesive in clean technology. Def Sci J 2004, 54(2), 249-55.

Pollution caused by the process involving handling of solvents is considered as one of the most serious ecological problems. In this perspective, thermoplastic epoxide resins were synthesised from the controlled reaction of bisphenol A, epichlorohydrine, and 3,5-dimethylaniline with a view to prepare ingredients for hot-melt adhesives without involving any solvents. Such thermoplastic epoxide resin (base polymer for hot-melt adhesive) was designated as HMA₃₅. Addition of polyethylene glycol (20 Wt per cent) of molecular weight 6000 (PEG6K) in the blend was found to be optimum towards providing maximum tensile lap shear strength with reference to aluminium/adhesive/aluminium bonding with a value of 5.05 MPa. The matrix of the blend remains optically transparent till the content of PEG6K remains up to 20 Wt per cent; however beyond 20 Wt per cent of PEG6K, the matrix becomes opaque with the appearance of spherulites due to the presence of excess PEG6K in the blend. Interestingly, blends containing ≤ 20 Wt per cent PEG6K showed no endotherm below 100 °C. FTIR data revealed the interactive role of PEG6K with the epoxide resin.

^ssc4 illus, 1 table, 13 ref

001511   Mittal V;Bhan R K;Singh R (Solid State Physics Laboratory, , Delhi-110 054) : Improved passivant-induced shunt resistance model for n-HgCdTe photoconducting infrared detector. Def Sci J 2004, 54(2), 219-28.

A multilayer model for the majority carrier distribution is employed to calculate the shunt resistance due to passivant-induced electric field in the accumulated n⁺ region. The carrier depth profile drops sharply away from the surface, finally attaining the bulk value. The effect of complete sidewall passivation on the shunt resistance is considered. The results show that if the contribution of sidewall passivation is neglected, the total detector resistance is overestimated by ~ 35 per cent. The detector responsivity calculations using the present model are compared with the Siliquini's model and the experimental data of Siliquini. It has been found that the present model yields relatively better agreement with the experimental data in shunt-dominated region.

5 illus, 2 tables, 15 ref

001510   Kumar V S S;Hanna A S (Department of Civil Engineering, University College of Engineering (A), Osmania University, Hyderabad-500 007) : A fuzzy logic approach to selection of cranes. J Struct Engng 2003, 30(4), 215-24.

Selection of a crane on construction projects is a central element in the planning phase of the life cycle of the project. An appropriately selected crane is the lifeblood of many multistorey construction projects and contributes largely to the efficiency, timeliness, and profitability of the project. An error in selection can lead to large and unnecessary expenses arising from operational inadequacy or failure, and can produce an unsafe working environment. On a large project, a contractor may have an assortment of various cranes for different purposes. However, contractors typically choose between mobile, tower, and derrick cranes. Decision to select a particular crane depends on many input parameters such as site conditions, economy, safety, and weather conditions and their variability. Many of these parameters are qualitative, and subjective judgements implicit in these terms cannot be directly incorporated into the classical decision making process. A fuzzy logic approach to translate these qualitative factors into mathematical measures, to aid the contractor in the proper crane selection has been presented. Experts' opinions in terms of membership values of fuzzy sets are aggregated by modified pessimistic aggregation procedure and final selection is achieved by max-min criteria.

1 illus, 7 tables, 16 ref

001509   Krishna Kumar (Information Technology Dep, , New Delhi) : World electronic production. Elect Inf Plann 2003, 30(6-7), 163-86.

35 illus, 12 tables

001508   Krishna Kumar (Information Technology Dep, , New Delhi) : Hazardous impact on environment due to electronic hardware manufacturing : issues and remedies. Elect Inf Plann 2002, 30(3), 75-82.

The usage of electronic hardware has made a rapid and deep penetration in the Indian society, Electronic gadgets are now used in all walks of human activity such as health, education, commerce, security, transport, governance, entertainment, defense, energy etc. The industrial progress of the country is now being defined by the amount of electronics used on per capita basis. India has been making a rapid stride towards industrialization by increasing the usage of telecommunication, information technology and other related infrastructure. This is evident from increasing usage of electronic gadgets at personal level such as radio, tape recorder, TV, telecommunication equipment such as telephone, fax, computers, office automation equipments, white goods etc. and wider usage of electronics in all manufacturing and infrastructure generation activities. These electronic hardware goods are disposed off along with other city garbage after the expiry of their useful life or obsolescence in their features. These equipments contain many non-degradable components and hazardous materials and cause environmental pollution in both short and long run. The manufacturing of these electronic products also employ a variety of chemicals, gases and materials which is released into the atmosphere/soil during the manufacturing process. The present article proposes to discuss impact on environment due to electronic hardware manufacturing and disposal: issue and remedies.

1 table

001507   Kim J S;Varadan V K (Center for the Engineering and Acoustic Materials and Devices, Pennsylvania State University, University Park, PA 16801, USA) : Wireless health monitoring of thin plates using PVDF interdigital transducers for the detection of crack and the determination of crack size. J Struct Engng 2004, 31(1), 31-4.

This paper provides experimental results of using PVDF interdigital transducer for the detection of cracks on aluminum plates, and the determination of crack size. Furthermore, the results of using a wireless telemetry system for monitoring a structure is shown. The approach described here is useful in real time health monitoring of structures. A self-calibrating technique is applied to estimate the crack on an aluminum plate.

6 illus, 7 ref

001506   Katkhuda H;Flores R M;Haldar A (Department of Civil Engineering and Engineering Mechanics, The University of Arizona, Tucson A.Z. 85721-0072 USA) : A novel defect identification and structural health assessment technique. J Struct Engng 2004, 31(1), 1-8.

A novel non-destructive defect identification and structural health assessment procedure is presented in this paper. It can detect defects at the local element level of large structures under normal operating conditions or just after a major natural disaster. The procedure is essentialy a linear time-domain system identification technique. A structure is represented by finite elements. The procedure tracks changes in the stiffness properties of all the elements in a structure. Since the input excitation information is not available in most cases, the proposed non-destructive evaluation (NDE) algorithm identifies a structure in the absence of such information. Noise in the response information cannot be avoided, and the proposed approach is capable of identifying a structure with noise-laden output response information. With the help of examples, it is shown that the algorithm can identify defect-free and defective structures very accurately even in the presence of noise when excited by earthquake loadings. A real earthquake time history recorded during the Loma earthquake of 1989 is used to excite the structures for verification purposes. Once a defective element is identified in a structure, the exact location of the defect can be identified with the proposed algorithm. The procedure is elaborated with the help of examples. The results indicate that the accuracy of the proposed NDE is much better than other currently available methods even when input excitation information was used for identification purposes. It is established that the proposed NDE method can be used for health assessment of existing structure on a continuing basis or just after a major natural event.

5 illus, 2 tables, 13 ref

001505   Karkare B S;Bonde S B (Army Institute of Technology, , Dighi Hills, Pune-411 015) : Numerical model and validation for a modular girder of an emergency bridge. J Struct Engng 2003, 30(3), 189-95.

5 illus, 9 tables, 3 ref

001504   Kapil J C;joshi S K;Rai A K (G B Pant University of Agriculture & Technology, , Pantnagar-263 145) : Fabrication of a resonant photoacoustic cell for samples study. Def Sci J 2004, 54(2), 209-18.

Nondestructive treatment of a sample in photoacoustic spectroscopy is helpful in the study of thermal and optical properties of ice and snow. A low-temperature resonant photoacoustic cell, based on Helmholtz resonator model, has been designed and fabricated for the study of samples like ice or snow. Its performance has also been studied using carbon black as a standard sample and various other samples like water, ice, glass, plexi-glass, polycarbonate, etc. Thermal diffusivity of ice, water, and many other transparent materials has been determined by varying chopping frequency and recording corresponding phase changes in the photoacoustic signal. The results obtained are in good agreement with those predicted by Rosencwaig-Gersho (R-G) theory.

7 illus, 1 table, 18 ref

001503   Kalaga S;Collins R;Mooberry D (Commonwealth Associates, Inc, , 2700 W Argyle Street, Jackson, Michigan 49202 USA) : Reliability assessment of transmission structures. J Struct Engng 2003, 30(4), 225-37.

The structural reliability of transmission and communication towers, monopoles and their foundations is investigated on the basis of a probabilistic model developed and reported in an earlier paper. The concepts are validated via application to a full-scale transmission tower tested till failure, a self-supporting lattice steel communication tower, a guyed tower and a wooden antenna-supporting monopole system. Results indicate that reliability models are reasonably accurate in assessing the performance of the tower structures and that foundations are better assessed in terms of a safety margin rather than a reliability index.

9 illus, 8 tables, 15 ref

001502   Kalaga S;Collins R;Mooberry D (Commonwealth Associates, , Inc 2700 W. Argyle Street Jackson, Michigan 49202 USA) : Reliability assessment of steel transmission poles. J Struct Engng 2003, 30(3), 197-200.

2 illus, 3 tables, 11 ref

001501   Juhasova E (Slovak Academy of Sciences, Institute of Construction and Architecture, Dubravska cesta 9, 845 03 Bratislava, Slovakia) : Effect of structural integrity in improving the resistance to dynamic loads - some studies. J Struct Engng 2004, 31(1), 65-72.

The paper deals with the analysis of vibration effects of traffic, propagated through soil strata and affecting the nearby structures. The effects are discussed by considering them as though they are generated by a near field moderate earthquakes. Special attention is devoted to the impacts of road transport and, that of last moderate earthquake in Eastern Slovakia (occurred in May 2003) as they affected the masonry dwelling houses. The field observations are compared to the results of experimental research related to the effects of near field soil vibration to simple masonry structures. The study focusses on possible use of strengthening and retrofitting techniques taking into account the latest progress in material technologies. The cases of promising use of polymeric grids and fibre mortars are analysed in depth. It is pointed out that in addition to the basic crucial parameters such as stiffiness, strength and damping, the integrity is another parameter that should be taken into account in reducing the damage to structures due to vibrations considered.

8 illus, 3 tables, 18 ref

001500   Ibraheem;Kumar P;Ahmad S (Electrical Engineering Dep, Jamia Millia Islamia, New Delhi-110 025) : Dynamic performance enhancement of hydro-power systems with asynchronous tie-lines. J Instn Engrs-Pt EL 2004, 85(Jun), 23-34.

Future prospects of hydropower generation in the country has been presented. Subsequently, a comprehensive study on dynamic system performance of two area interconnected power systems when subjected to small load perturbation, is carried out. For the present study, two power system models are identified. Power system model-1 consists of two power system areas with hydro power plants whereas power system model-2 has one power system area with hydro power plants and the other area with reheat thermal power plants. The dc link is used as system interconnection in parallel with ac tie-line. The dc link is considered to be operating in constant current control mode and the power flow deviation through dc link is modelled based on frequency deviation at rectifier end. To investigate the system dynamic performance, optimal AGC regulators using proportional-plus-integral control strategy are designed and implemented in the wake of 1% step load disturbance. It has been shown that the dynamic response of interconnected hydro power system areas are sluggish and degraded in all aspects of response qualities. The degradation in system dynamic performance can be compensated effectively using dc link in parallel with ac tie-line as system interconnection between two power system areas. An appreciable improvement in system dynamic performance can further be achieved by operating a power system area consisting of reheat thermal power plants in interconnected manner.

15 illus, 2 tables, 35 ref

001499   Ibraheem;Kumar p (Electrical Engineering Dep, Jamia Millia Islamia, New Delhi-110 025) : Study of dynamic performance of power systems with asynchronous tie-lines considering parameter uncertainties. J Instn Engrs-Pt EL 2004, 85(Jun), 35-42.

A comprehensive study on dynamic performance of a two-area power system interconnected via parallel ac/dc transmission links when subjected to parametric uncertainties has been presented. The dynamic model of incremental power flow through dc transmission link is derived based on frequency deviation at rectifier end. Moreover, the dc link is considered to be operating in constant current control mode. To carry out the investigations, optimal AGC regulators are designed using full state vector feedback control strategy and implemented on the system under consideration in the wake of 1% load perturbation in one of the areas. The effect of ± 50% variation in system parameters from their nominal parameter values on system dynamic performance has been studied by investigating the response plots of frequency deviation of disturbed area (ΔF₂) with nominal system parameters and ± 50% variation in system parameter values. The most significant parameters which influence the system dynamic performance are identified.

20 illus, 26 ref

001498   Hosur V I;Shetty A N (NO, Gogte Institute of Technology, Udyambag, Belgaum (Karnataka)) : Design charts for steel compression members as per IS:800-1984 and AISC-LRFD. J Struct Engng 2003, 30(4), 281-91.

illus, tables, ref

001497   Hooda D S (CCS Haryana Agricultural University, , Hisar-125 004) : Generalised measures of useful directed divergence and information improvement with applications. Def Sci J 2004, 54(2), 125-33.

Describes a new generalised measure of useful directed divergence based on m-1 probability distributions, and a probability distribution closest to these probability distributions has been proposed. The technique has been applied in solving problems related to crops production, export, and industries. Further, a generalised measure of useful information improvement has been developed and its applications in the assessment of balanced military requirements for a country, in ranking and pattern recognition, have been discussed.

illus, tables, ref

001496   Gupta D C;Gutch P K;Lal G;Vyas K D;Jaiswal D K (Defence Research & Development Establishment, , Gwalior-474 002) : Fluorinated epoxy resins-based sorbent coating materials for quartz piezoelectric crystal detector. Def Sci J 2004, 54(2), 229-34.

Fluorinated epoxy resins were synthesised and evaluated as sorbent coating materials for the detection of organophosphorus compounds using quartz piezoelectric crystal detector. These resins were prepared by reacting excess of epichlorohydrin with each of or in combination of fluorinated diols, ie,α, α, α, α' tetrakis (trifluoromethyl) 1, 3 benzene dimethanol (TTFMBD), 4,4' bis-2 hydroxy hexafluoro isopropyl) biphenyl (BHHFIBP), 4,4' dihydroxyocta fluorodiphenyl (DHOFDP) and 2,2,3,3,4,4 hexafluoro 1,5 pentanediol (HFPD) in the presence of sodium hydroxide at reflux temperature. These polymers were extracted in organic solvents and dried. Each of these fluoroepoxy resins were coated over quartz piezoelectric crystal by solution-casting method and tested using dimethylmethyl phosphonate (DMMP) as model compound. Change in the frequency (ΔF) of quartz piezoelectric crystal oscillator was recorded. Sensitive and potential fluorinated epoxy resins, ie, diglycidylethers (DGE) of HFPD-TTFMBD (in the molar ratio 6:4) and DGE (HFPD-BHHFIBP in the molar ratio 4:6) were characterised by viscosity, number average molecular weight (Mn), epoxy equivalent, infrared spectroscopy, and thermal stability.

^ssc2 illus, 2 table, 10 ref

001495   Ganguly S;Gonsalves T H;Paul Vizhian S (NO, , Detroit, U S A) : Parametric studies in the fracture mechanics of lugs. J Struct Engng 2003, 30(4), 273-80.

10 illus, 4 tables, 12 ref

001494   Ekram S;Sarkar B (EED, SIG College of Engineering, , Mumbai) : Effects of harmonics on PWM inverter fed induction machines. J Instn Engrs-Pt EL 2004, 85(Jun), 1-12.

Effects of harmonics upon, current, torque and speed of pulse width modulation (PWM) inverter fed induction machine have been discussed. It is shown through simulation that if the number of pulses at the PWM inverter output are either small or very large then the magnitude of the harmonics vary accordingly. To understand the effects of harmonics on the induction machines the machine has also been modelled and simulated. It is shown that if number of PWM pulses is less than the magnitude of pulsations in the transients of current, torque and speed is significant due to the prominence in low-order harmonics. It is further shown that if the number of pulses of PWM output is large then the effects of harmonics cease to be present in the transients but the magnitude of the fundamental reduces. Further it is shown that there is some optimum number of pulses that will give required fundamental and much higher significant harmonics so that the machine exhibits torque speed characteristics with less pulsations in the transients. The effects of harmonics especially 6th order harmonics on current, torque and speed has been obtained through simulation of 500 hp induction machine.

^iia6 illus, 1 table, 16 ref

001493   Dey K;Sen P (Mining Engg Dep, Indian School of Mines, , Dhanbad-826 004) : Concept of blastability - an update. Indian Min Engng J 2003, 42(8-9), 24-31.

The main objective of fragmentation by blasting is to achieve the optimum powder factor, which may be defined as the powder factor required for the optimum fragmentation, throw, ground vibration, etc. for a specified blast condition to minimize the overall mining cost. Presently, the powder factor is established through the trial blasts. However, powder factor may be approximated using rock, design and explosive parameters. The term blastability is used to indicate the susceptibility of the rock mass to blasting and is closely related with the powder factor. This paper presents a review of some of the important studies made on blastability and powder factor determination using rock and design parameters.

5 illus, 6 tables, 22 ref

001492   Danraj R M S;Gajendran F (NO, Sri Krishna College of Engineering and Technology, Coimbatore-641 008) : An efficient algorithm to find optimal economic load dispatch for plants having discontinuous fuel cost functions. J Instn Engrs-Pt EL 2004, 85(Jun), 64-7.

In real situations the fuel cost equations can be discontinuous. A new and efficient algorithm is presented to solve the problem of economic load dispatch for plants having discontinuous fuel cost equations. It uses transformation of variables technique and directional search quadratic programming. It is applied to the system having multiple fuel options and combined cycle cogeneration plant. The results which clearly demonstrate the efficiency of this algorithm.

5 tables, 10 ref

001491   Chatterjee D;Ganguli A K;Chakraborti R N (Electrical Engineering Dep, Jadavpur University, Kolkata-700 032) : Definite method of winding fault detection of tube lamp ballast using frequency response technique. J Instn Engrs-Pt EL 2004, 85(Jun), 13-17.

Tube lamp ballasts usually have a large number of turns of very small cross section. In the process of manufacturing if a number of turns (less than 10) are short circuited then it would not be possible to find the fault with normal voltage and frequency. However, if left undetected the performance of the ballast would deteriorate progressively and shortly thereafter it will burn out. Frequency response of the ballast has been found out where the impedance becomes totally resistive and if the ballast is tested at this frequency then the change in primary current visible even if a small number of turns are short circuited.

8 illus, 4 ref

001490   Chandra Kishen J M;Sain T (Department of Civil Engineering, Indian Institute of Science, Bangalore-560 012) : Damage detection using static test data. J Struct Engng 2004, 31(1), 15-21.

A method for damage detection and quantification is presented using static displacement test data. Displacements are measured along the length of the member at adequately spaced points when subjected to suitable static load. Using these displacements, the curvatures are obtained and any abrupt change in curvature gives the location of damage. A finite element model is developed using a cracked beam element through a compliance approach to quantify the damage in terms of a dominant discrete crack. A few case studies, including a single crack, multiple cracks and inclined crack as damage are presented and the crack sizes are successfully and accurately evaluated.

13 illus, 2 tables, 13 ref

001489   Biswas R N (NO, , N-354, Baishnobghata Patuli Housing Complex, Kolkata-700 094) : Superconductor materials - a revolutionary value addition to space electronics. Def Sci J 2004, 54(2), 235-47.

An early success in low temperature superconductor-technology has led to the development of a number of high temperature superconductor (HTS) materials, which have critical temperature above 77 K. When the temperature of a solid is lowered below critical temperature, the material loses its electrical resistivity. Because resistance is almost zero, superconductors can carry very high current, generating very large homogeneous magnetic fields. Due to these features, it is possible to design electronic devices with extremely thin profile, offering less weight and low manufacturing cost. Such exceptional properties have made HTS materials useful in military and space sectors, where airbone systems have already provided with cryogenic infrastructure which can be used for cooling a high temperature superconductor at no extra cost.

11 illus, 8 ref

001488   Bhowmik J (NO, , ) : Water in oil - its significance. Indian Min Engng J 2003, 42(8-9), 51-2.

Water in lubricating oil has been a point of keen debate as long as oil analysis has been used to monitor equipment and lubricant condition. How much is too much? Where does it come from? Does it really hurt equipment? What form of water is of concern? How is it controlled? This article addresses these questions and tries to simplify the issues often discussed about water in oil.

1 table

001487   Bhasin I J;Goyal N K;Jain V K (Instruments Research & Development Establishment, , Dehra Dun-248 008) : Electrooptical evaluation techniques of image intensifier tubes - I. Def Sci J 2004, 54(2), 199-208.

Passive night vision devices are used for viewing the military targets at low light levels of illuminations during night. In these passive night vision devices, image intensifier tubes are used to amplify scence imagery. The performance of these tubes depends upon electrooptical parameters. The techniques of evaluating these parameters, eg, luminous gain, automatic rightness control and maximum screen luminance, photocathode sensitivity, radiant gain, equivalent background illumination, magnification and distortion, signal-to-noise ratio, veiling glare, screen brightness variation, etc. have been described.

10 illus, 4 tables, 5 ref

001486   Balaji Rao K;Anoop M B;Lakshmanan N; Gopalakrishnan S;Appa Rao T V S R (Structural Engineering Research Centre, CSIR Campus, , Taramani, Chennai-600 113) : Risk-based remaining life assessment of corrosion affected reinforced concrete structural members. J Struct Engng 2004, 31(1), 51-64.

Remaining life assessment of corrosion affected reinforced concrete structural members is a topic of current R & D Wordwide. There is an urgent need to develop more scientific and rational methodologies for this purpose. Number of investigations have already been carried out to assess the damage/distress due to corrosion, that would help in remaining life aessment. While most of these studies are deterministic in nature, efforts are also being made to use probabilistic methods for damage assessment. However aspect in remaining life estimation is the interpretation of the data related to damage/distress and making expert judgement about damage/distress level. Due consideration needs to be given to the quality of the data and the expert interpreting the data. In this paper expert judgement regarding corrosion damage level is integrated with the structural risk, expressed in terms of probability of attaining a particular damage level, for the remaining life assessment of corrosion affected reinforced concrete structural members. In the proposed methodology, the thinking process of the expert, in corrosion damage assessment, is medelled within a probabilistic framework using Brunswikian theory. The performance of each expert is determined by computing the achievement index. The damage assessment procedure is integrated with Markov Chain model for risk-based remaining life assessment. To illustrate the usefulness of the proposed methodology in determining more rationally the remaining life, an example problem of remaining life assessment of a reinforced concrete bridge is considered.

5 illus, 11 tables, 33 ref

001485   Ashok Kumar;Karmakar G (University of Delhi, , Delhi-110 007) : Fault detection in systems-a fuzzy approach. Def Sci J 2004, 54(2), 189-98.

The task of fault detection is important when dealing with failures of crucial nature. After detection of faults in a system, it is advisable to suggest maintenance action before occurrence of a failure. Fault detection may be done by observing various symptoms of the system during its operational stage. Sometimes, symptoms cannot be quantified easily but can be expressed in linguistic terms. Since linguistic terms are fuzzy quantifiers, these can be represented by fuzzy numbers. Two cases have been discussed, where a fault likely to affect a particular system/systems, is detected. In the first case, this is done by means of a compositional rule of inference. The second case is based on modified similarity measure. For both these cases, linguistic terms have been expressed as traoezoidal fuzzy numbers.

3 tables, 20 ref

001484   Appa Rao G;Raghu Prasad B K (Civil Engineering Dep, Indian Institute of Technology, Madras-600 036) : Strength and fracture toughness of interface in high strength concrete. J Struct Engng 2003, 30(3), 153-61.

Fracture properties of the interface in high strength concrete has been reported. The fracture properties included in this study are: strength, fracture toughness and ductility factors. Experiments were conducted on composite specimens in Mode-I and Mode-II loading effects. Two types of composite specimens were designed. In the first type, the mortar was cast against the hardened concrete on only one face, and in the second type, the mortar was cast on both the faces of the aggregate material. The latter type has been designated as sandwiched type. For Mode-I case, both the types of composite specimens were used, while for the Mode-II loading only sandwiched type of composite specimens were adopted. Two types of aggregate materials have been adopted: granite rock and hardened HSC. In the case of granite rock aggregates, rough and smooth surfaces were used, while in the case of HSC concrete, rough, smooth and casting surfaces have been adopted. Three types of mortar mixes were used at 0.40 water-binder ratio with 1:3, 1:2 and 1:4 cement-sand ratios. Silica fume was used 10% by weight of cement. Strong interface has been noticed with rough aggregate surface. The fracture toughness of the interface seems to be very high with rougher aggregate surface in Mode-I. The type of mortar matric significantly alters the type of interface. The influence of size of interface area on the fracture properties has also been reported....

4 illus, 5 tables, 27 ref

001483   Ammanagi S;Venkatesha S;Manohar C S (Department of Civil Engineering, Indian Institute of Science, Bangalore-560 012) : Analytical and experimental investigations into structural damage identification using vibration data. J Struct Engng 2004, 31(1), 73-84.

The paper reports on relative performance of inverse eigensensitivity and response function methods for structural damage detection, location and quantification using vibration data. In implementing each of these methods, a validated baseline finite element (FE) model for the structure, in its undamaged state, is assumed to be available. Depending on this, a matrix of sensitivity of structural dynamic characteristics, in frequency or modal domains, to changes in values of structural parameters, is constructed. An inverse procedure, based on pseudoinverse theory of matrices, is subsequently applied to identify structural damages on observed changes in vibration response of the structure. Issues arising out of mismatch between degrees of freedom of the FE model and number of measured degrees of freedom are dealt with by using alternative model reduction/expansion schemes. Illustrative examples on synthetically and experimentally generated vibration data on cantilever beams and a three-storied building frame are presented.

5 illus, 11 tables, 15 ref

000613   Yamaha Hatsudoki Kabushiki Kaisha (NO, , 2500, Shingai, Iwata-Shi, Shizuoka, Japan) : Internal combustion engine. 0000, (NULL), (NULL).

000612   Yamaha Hatsudoki Kabushiki Kaisha (NO, , 2500, Shingai, Iwata-Shi, Shizuoka, Japan) : Internal combustion engine. 0000, (NULL), (NULL).

000611   Worldwide Water Inc (NO, , 518, E. Blanco, Boerne, Texas 78006, USA) : Portable water recovery and dispensing system. 0000, (NULL), (NULL).

000610   Werner Grabher (NO, , Oberwingertstrasse 8, CH-9436, Balgach, Switzerland) : Folding can and device for producing such a can. 0000, (NULL), (NULL).

000609   W. Schlafhorst AG & Co (NO, , Postfach 100435, D-4100, Monchengladbach, Germany) : Method for preparin grandomly cross-wound bobbin. 0000, (NULL), (NULL).

000608   Usinor Sacilor (NO, , "LA Pacific" - 11/13 Cours Valmy La Defense 7-92800 - Puteaux, France) : Device for supporting a side wall of a plant for the continuous twin-roll casting of thin metal products. 0000, (NULL), (NULL).

000607   Usinor (NO, , 11/13 Cours Calmy, La Defense 7, F-92800 Puteaux, France) : Twin-roll continuous casting device. 0000, (NULL), (NULL).

000606   Umesh Raichand Shoney (NO, , No 8, Salai Mariamman Koil Second Street, Muthialpet, Pondicherry-605 003) : Clutch release bearing. 0000, (NULL), (NULL).

000605   Ultralight AG (NO, , Gewerbeweg, 9486 Schaanwald, Liechtenstein) : Method and apparatus for the purification of the polluted gases and liquids. 0000, (NULL), (NULL).

000604   Thyssen Stahl Ag (NO, , Kaiser-Wilhelm-Strasse 100, 47167 Duisburg, Germany) : Exchange device for a blow lance. 0000, (NULL), (NULL).

000603   The Tomngton Company (NO, , 59 Field Street, Tomngton, Connecticut 06790, USA) : Process for inceasing the fatigue life anc corrosion resistance of a steel alloy rolling bearing. 0000, (NULL), (NULL).