006105   Kannan R;Valsan M;Srinivasan V S;Bhanu Shankara Rao K;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: rkannan@igcar.ernet.in) : Effect of temperature on low cycle fatigue behaviour of 316L(N) and 304L(N) stainless steels. Trans Indian Inst Metals 2005, 58(2-3), 317-22.

Low cycle fatigue (LCF) behaviour of 304L(N) and 316L(N) austenitic stainless steels in the temperature range 298-923 K is presented. Total axial strain controlled fatigue tests were performed in air employing a strain rate of 3x10^-3s^-1 and at a fixed strain amplitude of ±0.6%. Dynamic strain ageing (DSA) was found to influence the cyclic deformation behaviour of the alloys under appropriate testing conditions. The manifestations of DSA observed include negative temperature dependence of half-life cyclic stress, decrease in half-life plastic strain amplitude and serrations in the plastic portions of stress - strain hysteresis loops. The fatigue life of both the alloys exhibited a peak at an intermediate temperature. The lower fatigue life noticed at 298 K has been attributed to the occurrence of deformation induced martensite and its adverse influence on crack initiation life.

4 illus, 3 tables, 14 ref

006104   Kale M U;Gadge S R;Lambe S P (AICRP on RSE, , ) : Chulhas of western Vidarbha region of Maharashtra state and durable improved cook stoves. J Instn Engrs-Pt ID 2005, 86(May), 1-4.

Jalnigam improved mud chulha and modified TNAU durable improved chulhas were tested in two villages Barlinga and Manaki in Akola district of Vidarbha region of Maharashtra State during 2000 and 2004, respectively. The information on the prevailing chulhas, different types of fuels and cooking practices were collected. It was observed that the durable improved chulha takes over the problem of short life span of traditional and improved mud chulha. An actual fuel saving of 31.87% (687.71 GJ/year) and 30.14% (514.30 GJ/year)for all type of fuels, was obtained due to adoption of the Jalnigam improved chulha and modified TNAU durable improved chulha in village Barlinga and Manaki, respectively. About 0.16% monetary saving in fuel bill per month per adult was also observed.

7 tables, 2 ref

006103   Johan Singh P;Mannan S L;Achar D R G (NO, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: johan@igcar.ernet.in) : Fatigue life estimation of welded joints - a two stage propagation approach. Trans Indian Inst Metals 2005, 58(2-3), 291-5.

Fatigue life of flawed materials such as cruciform joints with lack of penetration (LOP) defects may be separated into two portions: that fraction of the life in which flaws sharpen to become active fatigue cracks (initiation), and that fraction in which the sharpened cracks steadily enlarge until fracture occurs (propagation). A two-stage propagation model for life prediction based on fracture mechanics approach incorporating near-threshold crack growth data has been offered. The experimental part consists of fatigue tests for cruciform joints of AISI 304L stainless steel. Constant amplitude fatigue tests with stress ratio, R = 0 have been carried out with a frequency of 30 Hz. The study suggests that the life prediction using the proposed two-stage propagation model was simple, accurate and requires limited and known parameters.

6 illus, 1 table, 12 ref

006102   Jain A;Saxena R;Saxena S C (Dep of Electron and Instrumentation Engng, Samrat Ashok Technological Inst (Degree Coll, Vidisha-464 001) : Window based FIR half-band filters: design and comparison. J Instn Engrs-Pt ET 2005, 86(July), 16-20.

Half-band FIR filters have been designed using two novel variable window functions having high Side-Lobe-Fall-Off-Rate (SLFOR). A comparative performance analysis of these filters with Kaiser window FIR half-bandfilters and Parks-McClellan (PM) FIR half-band filters has been made. The concept of half-band symmetry has been extended for designing bandpass filters, so far not reported in the literature. The impulse response of these bandpass filters is observed to have more-than 70% zero valued coefficients. Thus, significant saving in computation and storage requirements can be achieved. These filters have got applications, in multirate signal processing and filter banks.

5 illus, 1 table, 10 ref

006101   Isaac Samuel E;Choudhary B K;Bhanu Sankara Rao K;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: isaac@igcar.ernet.in) : Creep rupture properties of indigenousely developed modified 9Cr-1Mo steam generator tube steel. Trans Indian Inst Metals 2005, 58(2-3), 297-301.

Results of the creep tests performed on the modified 9Cr-lMo steel specimens, machined from steam generator (SG) tubes of 17.2 mm outer diameter and 2.3 mm wall thickness, in the temperature range 823-873 K indicated that the creep deformation is characterised by a small amount of instantaneous strain followed by a decreasing creep rate (primary), a minimum creep rate (secondary) and an accelerating creep rate (tertiary) regimes. At all temperatures, stress dependence of minimum creep rate obeyed Norton's power law and exhibited a high value of stress exponent. The stress exponent decreased from 13.3 at 823 K to 12.3 at 873 K. Rupture life decreased with increasing temperature and stress. The SG tube exhibited high creep ductility and loss of creep ductility was not observed with increasing rupture life. The fracture mode remained transgranular characterised by dimples resulting from micro-void coalescence. The creep-rupture strength of SG tube material was found to be higher than the average creep strength values specified for the steel in French Nuclear Design Code, RCC-MR.

10 illus, 15 ref

006100   Harikumar R;Sukanesh R;Bharathi P A (Dep of ECE, Thiagrajar Coll of Engng, Maduari) : Genetic algorithm optimization of fuzzy outputs for classification of epilepsy risk levels from EEG signals. J Instn Engrs-Pt ID 2005, 86(May), 9-17.

The paper aims to optimize the output of epilepsy activity namely electro encephalogram (EEC) signal by Fuzzy Logic techniques using Genetic Algorithms (GA). The fuzzy techniques are applied to classify the levels of epilepsy based on extracted parameters like energy, variance, peaks, sharp and spike waves, duration, events and covariance obtained from the EEG of the patient. A Binary GA and Continuous GA are then applied on the classified data to obtain the optimized risk level that characterizes the patient's epilepsy risk level. The performance index (PI) and quality value (QV) are calculated for both method. A group of eight patients with known epilepsy findings are used for the study. High PI, such as, 92% (BGA) and 96% (CGA) were obtained at QVs of 80% and 90%, respectively. It is found that the Continuous Genetic Algorithm provides a good tool for optimizing the epilepsy risk levels.

6 illus, 5 tables, 24 ref

006099   Harikumar R;Sukanesh R (Thiagarajar college of Engng, , Madurai) : Fuzzy techniques and statistical tests for epilepsy risk level classification using EEG signals. J Instn Engrs-Pt ID 2005, 86(May), 29-36.

The paper aims to classify the epilepsy risk level from EEC (Electro encephalogram) signals from two known techniques such as Fuzzy Techniques and Statistical Tests. The statistical analysis is used in quantifying the central effects, of epilepsy to obtain control limits for its occurrence and to remove the artefacts. The fuzzy techniques are used to classify the risk levels of epilepsy based on extracted parameters like energy, variance, peaks, sharp and spike waves, duration, events and covariance obtained from the EEC of the patient. The performance index (PI) and computation time (CT) are calculated for both methods. A comparison of the statistical and fuzzy techniques based on the PI and CT is done. A group of six patients with known epilepsy findings are used for this study. High PI such as 81.75% is obtained in fuzzy techniques at the cost of high CT(3 min). On the other hand, the statistical tests need lesser CT(1 min) but give less PI (47.6%). It is found that the statistical tests are used to remove the noise from EEG signals before employing , fuzzy techniques to obtain classified epilepsy risk levels.

12 illus, 4 tables, 12 ref

006098   Gupta P K;Khapre R K (Civil Engng Grp, Birla Inst of Technol and Sci, Pilani, Rajasthan-333 031) : An efficient parallel solver using matrix inversion method for linear and non-linear finite element problems. J Instn Engrs-Pt CI 2005, 86(May), 44-8.

Paper presents a modified parallel matrix inversion algorithm to solve a set of linear equations. It also discusses its suitability for finite element analysis. This algorithm is implemented on supercomputer PARAM10000. Computational time results were obtained by solving a problem of analysis of anchorage zone in prestressed post-tensioned concrete beam. These results are compared and discussed with the existing results of a parallel matrix inversion algorithm which one available in literature. This algorithm is then implemented in computer codes for linear and non-linear finite element analysis. One typical problem from each category is solved and the computational time variation results are obtained and discusses.

6 illus, 1 table, 10 ref

006097   Gupta P;Jai Singh;Singh I P (Mechanical Engng Dep, Sant Longowal Inst of Engng and Technol, Longowal-148 106) : Mission reliability and availability prediction of flexible polymer powder production system. Opsearch 2005, 42(2), 152-67.

The expressions for mission reliability and steady state availability of flexible and complex polymer powder production system a part of acrylic fiber mill are derived. Explains mathematical formulation of the problem with more realistic and practical assumptions to evaluate reliability parameters of interest. The system under consideration is a complex and flexible mechanical system being used in a chemical plant manufacturing dry polymer powder from monomers. This is a multicomponent system and on failure of some of its units, this system remains operative for a short specified period of time. Here the mission becomes to repair these failed units within the specified repair time to run the system continuously, otherwise the system will transit to non-operative state. Failure rates for all the units are constant while their repair times are arbitrarily distributed. The problem is formulated using probability considerations and supplementary variable technique. Lagrange's method for partial differential equations is used to solve the system governing equations.

3 illus, 6 tables, 4 ref

006096   Gupta C;Agamennone R;Chakravartty J K;Blum W (Mater Sci Div, Bhabha Atom Res Cent, Trombay-400 085, Mumbai) : Creep resistance behavior at 923 K of A modified 12CrMoVNb steel for power stations. Trans Indian Inst Metals 2005, 58(2-3), 361-5.

The creep properties of a new 12CrMoVNb steel (modified by additions of 5%Co and 2%W and micro-alloyed with B, Al, and N) have been investigated at 923 K. The fine initial sub-grain structure of the steel (average sub-grain size 480 nm) results from the martensitic transformation, and the recovery of the dislocation structure accompanied with precipitation of carbo-nitrides during final heat treatment. Creep tests at 923 K lead to further precipitation of Laves phase and coarsening of subgrains in dependence of strain and stress. Coarsening of the subgrain during creep leads to onset of tertiary creep with final fracture. The creep resistance of the present alloy at 923 K is distinctly higher than that of the well known alloy P92 in the investigated range during short term creep tests. Extrapolation of creep rate minima to low stresses was found to overestimate the creep resistance determined from long term tests due to the precipitation of Z phase.

3 illus, 2 tables, 10 ref

006095   Goyal S;Valsan M;Bhanu Sankara Rao K;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: goyal@igcar.ernet.in) : Low cycle fatigue properties of A SA-508 grade carbon steel welds and weld joints. Trans Indian Inst Metals 2005, 58(2-3), 331-6.

Low cycle fatigue properties of SA-508 carbon steel bimetallic weld joint and weld metal is presented. The bimetallic weld joints are prepared initially by buttering on both sides of the base metal with Inconel 600 by Shielded Metal Arc Welding (SMAW) process using ENiCrFe3 electrodes. The weld root pass is carried out by Gas Tungsten Arc Welding (GTAW) by using ERNiCr3 electrodes and subsequently by SMAW process using ENiCrFe3 electrodes. Ultrasonic testing of the butted layer, radiography of the weld metal and liquid penetrant tests of the root pass are performed to ensure soundness of the weld pad. Fully reversed total axial strain controlled low cycle fatigue tests were carried out on all-weld and weld joint samples taken from the top, middle and bottom portions of bi-metallic joint. The fatigue tests were conducted at room temperature employing strain amplitudes in the range ±0.3 to ±0.5% at a constant strain rate of 3 x 10^-3 s^-1. Both the weld metal and the weld joint samples exhibited an initial hardening followed by a continuous softening regime that ends with stress saturation prior to failure. Comparison of the fatigue life of the specimens from root pass region (bottom) indicates that all-weld samples have a better fatigue life than the weld joints. However, weld joint specimens from the top and the middle portions of the weld pad showed a better fatigue life than the corresponding all-weld samples. Fatigue life is found to increase with decrease in strain amplitude. The observed differences in fatigue life are discussed with the evidences from fractography and metallography conducted on the longitudinally sectioned samples.

9 illus, 1 table, 6 ref

006094   Girish Shastry C;Mathew M D;Sreenivasan P R; Bhanu Sankara Rao K;Bandyopadhyay G;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: girish@igcar.ernet.in) : On the creep, tensile and impact properties of a 120, 000 h service-exposed 2.25Cr-1Mo steel. Trans Indian Inst Metals 2005, 58(2-3), 281-5.

Residual life analysis of thermal power plant components is important because of the need to avoid costly forced outages, catastrophic failures and premature retirement of components fit for service even after completion of the original design life. Such components include boiler tubes, superheater outlet headers, reheater headers, steam pipes, steam turbine casings and steam chests. Creep, tensile and fracture toughness are important considerations in the design of these components. Thus, extension of life depends on extent of degradation in these properties due to service exposure. Presents the creep, tensile and impact properties of a 2.25Cr-1Mo ferritic steel reheater header pipe after being in service for 120,000 hours at 813 K under a steam pressure of 2.4 MPa. Creep tests were carried out in the temperature range 813-913 K. Tensile tests were carried out between 813 and 913 K at four strain rates between 2.9 x 10^-5 and 2.9 x 10^-3 s^-1. Tensile and creep properties did not show any appreciable degradation due to service exposure. Charpy impact properties were determined from instrumented impact tests. The Charpy indices like upper-shelf energy and fracture appearance transition temperature did not exhibit any significant change as compared to the properties of virgin material.

5 illus, 1 table, 16 ref

006093   Girish Shastry C;Mathew M D;Bhanu Shankara Rao K;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: girish@igcar.ernet.in) : Creep deformation and fracture behavior of type 316L(N) stainless steel. Trans Indian Inst Metals 2005, 58(2-3), 275-9.

Nitrogen-alloyed, low carbon grade of type 316 stainless steel has been developed indigenously in collaboration with Alloy Steel Plant (ASP), Durgapur for the nuclear steam supply system components of Prototype Fast Breeder Reactor. Creep properties of this material have been determined at 873 and 923 K at various stress levels and compared with the creep properties of imported steel of similar chemical composition. Material developed at ASP was found to be comparable to the imported steel with respect to its creep properties at 873 and 923 K.

4 illus, 1 table, 15 ref

006092   Ghosh B;Madabhushi S P G (Univ of Cambridge, , Cambridge CB3 OEL, UK) : Comparison of free field ground response in layered soil under liquefiable conditions. Indian Geotech J 2005, 35(2), 198-219.

14 illus, 2 tables, 26 ref

006091   Ghangrekar M M (Dep of Civil Engng, Indian Inst of Technol, Kharagpur-721 301, Email: ghangrekar@civil.iitkgp.ernet.in) : Role of biogas production in uasb reactor performance. J Indian Ass Envir Mgmt 2005, 32(2), 53-63.

Biogas generation rate is one among many parameters, which plays an important role in performance and granulation of biomass in UASB reactor. The study was conducted to evaluate the effect of different biogas production rates on reactor performance and on the characteristics of the sludge developed. The effect of biogas production rate on various aspects of reactor performance,-such as, mixing conditions inside the reactor, strength of the granules developed, methane content in biogas, and on the solids concentration in the effluent are discussed. It is observed that biogas yield higher than 0.7 m³/m³ _reactor.d is sufficient to carry out natural mixing inside the/reactor. However, very high biogas yield, greater than 2.3 mm³/mm³ _reactor.d is observed to be unfavorable for maintaining requisite sludge age and necessary strength of granules. In addition, based on COD mass balance, a mathematical model has been developed to predict the methane production. The model has been validated with separate set of experimental results.

6 illus, 3 tables, 15 ref

006090   Ganesan N;Sekar T (Dep of Civil Engng, Natn Inst of Technol, Calicut-673 601) : Permeability of steel fibre reinforced high performance concrete composites. J Instn Engrs-Pt CI 2005, 86(May), 8-11.

Experimental investigation has been carried out to study the combined effect of addition of micro-silica and steel fibres on the durability of steel fibre reinforced-high performance concrete (SFR-HPC) composites. A high performance concrete of M60 grade was considered and water permeability test was conducted to find the durability of SFR-HPC composites. The main variables considered in the study are: five different percentages of micro-silica, namely, 0.0, 2.5, 5.0, 7.5 and 10.0; three different aspect ratios of steel fibres and three different volume fractions of steel fibres. A total of 84 numbers of concrete specimens were cast with and without micro-silka and steel fibres, and tested as per IS: 3085 specifications for permeability. Test results indicate that the addition of micro-silica to plain concrete reduces its permeability by about 63% and further addition of steel fibres to micro-silica added concrete reduces its permeability again by about 73%. Thus, an overall reduction in permeability of as high as 90% could be achieved by adding both micro-silica and steel fibres to plain concrete.

2 illus, 3 tables, 15 ref

006089   Dudul S V;Ghatol A A (Appl Electron, Amravati Univ, Amravati-444 602) : Identification of pH neutralization process using the simplest neural network model. J Instn Engrs-Pt ID 2005, 86(May), 18-23.

Paper investigates the identification of the pH Neutralization process in a constant volume stirring tank using a two-layer multi-layer perceptron neural network. It is shown that the neural network based state-space innovations form model has clearly outperformed the equivalent linear model in simulation and thus, it is possible to obtain good results for this process with neural network based state-space innovations from model. It is by no means designed that the 'optimal' solution is found, however, it is shown that the proposed neural network based model provides a simple means to identify the given nonlinear multi-input-single-output system.

5 illus, 2 tables, 22 ref

006088   Dhanasekaran N (NO, , ) : Non destructive testing. WRI Jl 2005, 26(1), 19-24.

In continuation of the series of articles on "Back to basics", deals with the salient features of "Radiographic film interpretation". There are multitude of structures, assemblies and materials involved in fabrication which require radiography to check for the integrity. Radiography completes its mission with the interpretation. Interpreter as an individual has the key role to interpret with his thorough knowledge in the subject coupled with extensive experience and training. If it is to be meaningful, interpretaion must be admitted with a complete understanding of the following: 1. Part geometry 2. Material 3. Radiographic technique employed 4. Film processing 5. Applicable code, standard 6. Other useful informations desired from the examination. Gives an overview of the essential features of interpretation, radiographic appearance of various forms of discontinuities encountered in weld testing.

3 ref

006087   Deb S K;Bhattacharyya B (Mechanical Engng Dep, Jorhat Engng Coll, Jorhat-785 007) : Manufacturing facilities layout design considering pick up / drop-off positions. Opsearch 2005, 42(2), 98-111.

A modeling and solution methodology for manufacturing facilities laout design (FLD) considering pickup/drop-off (P/D) points on the periphery of the rectangular machine block. The model considers a set of P/D points under different possibilities to make the loading/unloading closer in order to generate a cost effective machine layout. The method simultaneously generates and improves the layout thus resulting a hybrid algorithm. It minimizes flow cost (FC) and dead space (DS) by using a bi-criterion objective function. The suggested procedure is coded in C language and implemented in a personal computer. The experimental tables and related analysis revealed that the proposed modeling of FLD considering P/D and its solution as suggested is worth pursuing.

5 illus, 5 tables, 17 ref

006086   De P;Chaudhari S S;Sule A D (The Synth & Art Silk Mills Res Ass, , Sasmira Marg, Worli, Mumbai-400 030) : Design and development of a scientific colour viewing cabinet: Part II. Man Made Text India 2005, 48(9), 328-33.

Precision type colour viewing cabinet using maximum light sources under one viewing area is developed, standardised and calibrated using spectroradiometer. The indigenous metameric scale was also developed to indicate the metamerism, i.e., magnitude of shade difference in different sources of lights.

7 illus, 2 tables, 5 ref

006085   Das S K;Basudhar P K (Dep of Civil Engng, Indian Inst of Technol, Kanpur-208 016, Email: sarat@iitk.ac.in) : Parameter estimation of Hoek-Brown rock failure criterion. Indian Geotech J 2005, 35(2), 144-53.

6 illus, 1 table, 9 ref

006084   Das B N;Gayen A;Poddar D R (Dep of Electron and Electl Comminication engineering, Indian Inst of Technol, Kharagpur-721 302) : Potential and field distribution in a cylindrical tube filled with a dielectric material with a centre hole. Indian J Radio Space Phys 2005, 34(3), 197-205.

Presents a method of analysis of potential and field distribution in a cylindrical tube (metallic), covered at both ends with metallic plates, and containing a dielectric cylindrical shell whose axis coincides with the axis of the cylinder. The cylindrical surface and lower end are maintained at ground potential and the top plate is insulated and maintained at high potential. The resulting Laplace's equation is solved using the method of separation of variables. The constants appear in the resulting equation are found from the boundary conditions followed by representation of the functions satisfying orthogonality condition in cylindrical co-ordinates. If the field intensity exceeds the breakdown limit, the resulting breakdown of the gas leads to plasma generation inside the structure, which can provide a convenient method of generation of laser beam.

6 illus, 11 ref

006083   Christ H J;Maier M J;Teteruk R (NO, , , Email: christ@ifwt.mb.uni-siegen.de) : Thermomechanical fatigue behaviour of Metallic high temperature materials. Trans Indian Inst Metals 2005, 58(2-3), 197-205.

The study three widely used life models were modified to allow for life prediction under thermomechanical fatigue (TMF) loading conditions. Two of these models are based on the accumulation of creep as the main damaging effect, while the third model assumes that the energy expenditure can be used as measure of damage. A new model is introduced which comprises both fatigue and time-dependent effects (creep and oxidation) and does not require fit parameters. In order to assess the predictive capabilities of the models, life prediction results, which were calculated solely on isothermal data, were compared with TMF data obtained on a stainless steel and a SiC paniculate reinforced aluminium alloy. The analysis of the data obtained demonstrated that TMF tests are not sufficient per se to evaluate a life model. Rather TMF tests chosen for validation of life models should be conducted under loading conditions such that coupling effects between various damage mechanisms become apparent.

6 illus, 2 tables, 23 ref

006082   Choudhary B K;Isaac Samuel E;Bhanu Sankara Rao K;Mannan S L (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: bkc@igcar.ernet.in) : Influence of processing route and section thickness on the creep rupture properties of 9Cr-1Mo steel. Trans Indian Inst Metals 2005, 58(2-3), 309-15.

Presents the influence of processing method and section thickness on creep-rupture properties of 9Cr-1Mo ferritic steel. Creep tests were performed on specimens machined from tube plate forging (1000 mm diameter and 300 mm thickness) and plate (20 mm thickness) at 793 K employing stress levels ranging from 100 to 275 MPa. In both the forging and the plate, the stress dependence of secondary creep rate obeyed power law creep and exhibited two stress regimes with stress exponent values of <126> 4 in the low stress regime and <126>10 in the high stress regime. Comparison of creep rupture properties of the plate material with that of tube plate forging suggested better creep strength of the plate material in terms of lower secondary creep rate and higher rupture life. The secondary creep rate of the plate material was lower than that of the forging by factors of <126> 3.25 and <126> 3 in the high and low stress regimes, respectively. Similarly, rupture life values of the plate material was higher by a factor of <126> 2 in high stress regime. No significant difference in creep ductility values was observed between the plate and tube plate forging. The ductility values remained high in both the material conditions. The fracture mode remained transgranular characterised by dimples resulting from coalescence of micro-voids. The inferior creep-rupture properties of tube plate forging were ascribed to the coarseness of microstructure.

9 illus, 23 ref

006081   Choudhary A K;Verma B P (Civil Engng Dep, Natn Inst of Technol, Jamshedpur-831 014) : Behaviour of reinforced flyash subgrades. J Instn Engrs-Pt CI 2005, 86(May), 19-21.

Presently about 100 Mt of flyash are being produced in India annually, of which less than 5% is being gainfully utilised. To increase its scale of utilisation, efforts are now underway to use flyash as fill material in highway embankments and engineered fills. Flyash fulfills the engineer ing properties required for use as a fill. But inadequate awareness among the users at various levels has resulted in its limited use as a fill material. As part of a project on reinforced fly ash undertaken at this institute, a series of laboratory CBR tests were conducted on flyash specimens with and without reinforcement. Two different types of reinforcement, namely, model geogrid and jute geotextde, were used in the investigation. The effect of depth of reinforcement from the top surface of the compacted flyash specimen as well as varying number of reinforcing layers at equal vertical spacing within the specimen on the CBR characteristics of flyash were studied. The paper summarises the results of this study, which were found to be encouraging for the use of flyash in landfills as well as road embankment constructions.

4 tables, 14 ref

006080   Chetal S C;Srinivasan R (Indira Gandhi Cent for Atom Res, , Kalpakkam-603 102, Email: chetal@igcar.ent.in) : Design and material issues for elevated temperature service components designed as per ASME section VIII division 1. Trans Indian Inst Metals 2005, 58(2-3), 233-40.

ASME Code Section VIII Division 1 is a popular design code in many countries and provides rules for design of pressure vessels, which operate at temperatures that are in the creep regime of the materials of construction. However, the code does not directly address some design, materials and fabrication issues that become relevant for pressure vessels that operate at high temperature. Further, the code does not provide rules for design of pressure vessels beyond 1089 K and multiple design conditions including short time excursion. The design rules imply a design life of 10?5 h less and thus providing no guidance for life shorter or longer than 10?5 h. Less knowledgeable users may end up either in increased capital cost in merely following the code or increased risk of premature pressure vessel failure in certain cases. Attempts to bring out the gaps in ASME Section VIII Division 1 code for design of vessels for elevated temperature service and the recommendations to bridge the same.

7 illus, 3 tables, 6 ref

006079   Chellapandi P;Biswas A;Srinivasan R;Chetal S C;Bhoje S B (Indira Gandhi Cent for Atom Res, , Kalpakkam-603 102, Email: pep@igcar.ernet.in) : Qualification of creep, fatigue and fracture design of PFBR components based on tests. Trans Indian Inst Metals 2005, 58(2-3), 207-19.

In 500 MWe Prototype Fast Breeder Reactor, the critical out-of-core components are main vessel (MV), control plug, inner vessel, intermediate heat exchangers, steam generators (SG) and hot pipelines. The salient structural mechanics features are large size thin walled shell structures, relatively low operating pressure (<60> 1 MPa, except SG which operates at 17 MPa), high operating temperatures (820 K for hot pool) and large thermal gradients (ΔT of 150 K between hot and cold pool). These components are designed by analysis (employing numerical techniques such as FEM) to meet the requirements of French Design Code RCC-MR for the design life of 40 y. In order to ensure that the design, analysis, indigenous material and indigenous manufacturing technology comply with the design and construction code rules, tests are carried out on a few important full scale components and mockups having component features such as welds, multiaxiality and stress concentration effects under simulated loading conditions. Particularly in the domain of creep, fatigue and fracture design, a series of tests were conducted in Structural Mechanics Laboratory (SML) with the objectives of qualifying the performance of components in the reactor and the fracture assessment procedure for the FBR application and for demonstrating leak before break (LBB) argument for MV, sodium piping and SG. Highlights the summary of theoretical analyses that have been carried out on creep, fatigue and fracture design of critical components. Subsequently, deals with a few of the experimental investigations that have been carried out essentially to qualify the creep-relaxation behaviour of IHX tube to tubesheet joint, creep rupture strength of Steam generators (SC) tubes, fatigue and fracture assessment of SG tube bends and Leak before break (LBB) justification of a typical full scale Tee of secondary sodium circuit.

19 illus, 2 tables, 13 ref

006078   Chaurasia P K;Gopal K A;Murugan S (Mater Dev Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: pramod@igcar.ernet.in) : Thermal creep experiments on zirconium alloys using pressurised capsules. Trans Indian Inst Metals 2005, 58(2-3), 347-51.

Alloys of Zirconium (Zircaloy-2 and Zr-2.5% Nb alloy) are used as pressure tube materials in Pressurised Heavy Water Reactors (PHWRs). The data on the creep rate of these materials during the actual service condition is required to predict the performance of the pressure tubes during their service lifetime. In the irradiation experiments carried out in Fast Breeder Test Reactor (FBTR), miniature pressure tubes with 15.3 mm O.D. and wall thickness of 0.65 mm were used in the form of pressurised capsules to determine the in-reactor creep rate of these materials. The pressurised capsules were subjected to biaxial stress conditions with stress levels that are allowable in pressure tubes. The creep strain obtained in irradiation experiments includes strain due to thermal and irradiation creep, and irradiation growth. An out-of-pile experimental work was carried out to determine the steady state thermal creep rate in the pressurised capsules to know the contribution due to thermal creep. In the work, pressurised capsules of Zircaloy-2 and Zr-2.5% Nb alloy were subjected to temperatures of 579 K and 613 K in an electrical furnace. The creep strain accumulated due to thermal creep was measured after predetermined intervals of time and the steady state creep rate was determined. The experimental procedure of thermal creep experiments and the comparison of the creep strain between thermal and irradiation experiments are given.

5 illus, 3 tables, 5 ref

006077   Chatterjee P;Karan B M;Sinha P K (Dep of Electl and Electron Engng, Birla Inst of Technol, Mesra-835 215) : Cost effective neuro observer for induction motor. J Instn Engrs-Pt CP 2005, 86(May), 18-21.

Artificial neural network (ANN) has become an exciting field to control induction motor. The property of ANN prediction without formulation has been utilised in this work to reduce the number of input parameters, which resulted in cost reduction for the estimation of torque, flux and flux angle of induction motor.

6 illus, 1 table, 4 ref

006076   Chakraborty B (Res and Dev Division, MECON Limited, Ranchi-834 002) : Optical fiber based confocal microscope. J Instrum Soc India 2005, 35(3), 282-91.

Confocal microscopy is the latest state-of-art in the field of optical microscopy with wide ranging applications in the areas of surface microstructuring of metal and non-metal surfaces, finger print observations in forensic sciences, 3D volume rendering of biological specimen etc. A compact confocal microscope layout in reflection mode is setup in laboratory by utilizing He-Ne green laser, 50X infinity corrected plan objective as focusing optics and a single mode optical fiber as confocal detector. The object to be scanned is mounted on a precision XYZ translation stage with one micron resolution in XYZ directions. Electronic scanning software is developed for reconstruction of confocal images. The system also incorporates anti flex condition for blocking stray lights and thereby increasing contrast. The depth resolution of the setup is studied by scanning a mirror axially and lateral resolution is studied with the help of 1951 USAF test target. A 20μm X 10μm area copper-beryllium surface (SIM card) is scanned at focus and at a depth of 2μm away from focus. The reconstructed confocal image at focus clearly shows black patches of oxide formation on metal surface.

6 illus, 22 ref

006075   Buvanashekaran G;Manoharan S (WIRI, BHEL, Tiruchirappalli) : Investigations on laser welding of austenitic stainless steel using solid state Nd:YAG sourced beam. WRI Jl 2005, 26(1), 5-12.

Effect of beam power and welding speed on bead geometry at low (up to 450 watt) and high beam power (up to 1400 watt) are investigated. The experiments were conducted using 500 watt and 2000 watt Nd:YAG solid-state laser sources. Influence of heat input on the microstructural changes in the AISI 304 grade austenitic stainless steel has been also studied for laser welding process at nine different heat input levels by varying the laser beam welding input parameters, viz, laser beam power, beam angle, welding speed and gas flow rate at three levels. The effect of heat input and cooling rate on the resultant microstructure was studied in detail. Micro hardness survey was carried out along the cross section of the weld and correlated with the associated heat inputs, cooling rates and resultant microstructures. The study revealed the possibility of achieving welds with near-complete austenitic structure.

10 illus, 3 tables, 10 ref

006074   Borage M;Tiwari S;Kotaiah S (Power Supplies Div, Cent for Advd Technol, Indore, Madhya Pradesh) : On the development of a low-cost, transformer-isolated voltage probe for differential measurements. J Instrum Soc India 2005, 35(3), 266-74.

Development of a transformer-isolated voltage probe for differential measurement is reported. It is simple to design and implement. It is a low-cost alternative for isolated measurement of differential signals. Optimum passive damping is described for the resonant circuit composed of magnetizing inductance of transformer and the dc blocking capacitor. The prototype development and experimental results on a full-bridge resonant converter demonstrate the effectiveness of this technique.

7 illus, 1 table, 6 ref

006073   Bhaumik S K;Venkataswamy M A;Bhaskaran T A; Rangaraju R;Sujata M;Krishnan R V (Mater Sci Div, Natn Aerospace Laboratories, Bangalore-560 017, Email: krishnan@ccs.nal.res.in) : Fatigue failure of a connecting rod of a piston engine. Trans Indian Inst Metals 2005, 58(2-3), 423-30.

Fatigue failures are frequently observed in various components of piston engines. The reasons for such failures can be improper material selection, improper design, misalignment, improper lubrication etc. Failure of a connecting rod of a piston driven aeroengine is described. The connecting rod is manufactured from an alloy steel of nominal composition Fe(base)-0.4C-0.8Mn-0.3Si-0.5Ni-0.5Cr-0.3Mo. The engine served about 350 h of life, since the last overhaul against the Time Before Overhaul (TBO) life of 1200 h. Analysis showed that intermittent breakdown of the lubricant film led to fatigue failure at the big end of the connecting rod.

14 illus

006072   Bhaumik S K;Sujata M;Krishnan R V (Mater Sci Div, Natn Aerospace Laboratories, Bangalore-560 017, Email: krishnan@ccs.nal.res.in) : Fatigue failure of engineering structures. Trans Indian Inst Metals 2005, 58(2-3), 187-96.

Majority of service failures in engineering structures occur by fatigue and it amounts to about 60% of the total failures. A number of factors influence the fatigue life of a component in service, viz., (i) complex stress cycles, (ii) engineering and design, (iii) manufacturing and inspection, (iv) service conditions and environment and (v) material of construction. Discusses the fatigue failures of engineering components with examples drawn from case histories.

20 illus, 1 table, 3 ref

006071   Bauer V;Christ H J (Institut fur Werkstofftechnik, Universitat Siegen, D-57068 Siegen, Germany, Email: christ@lfwt.mb.uni-siegen.de) : Application of a fracture mechanics concept to life prediction of austenitic stainless steels under TMF loading conditions. Trans Indian Inst Metals 2005, 58(2-3), 475-80.

A life prediction method based on fatigue crack propagation is suggested in order to account for damage caused By thermomechanical loading conditions. The cyclic J-integral or the J-integral extended by the C* parameter has been correlated with crack propagation rates representing the evolution of fatigue and creep/fatigue damage. This approach was proposed by Riedel (D_CF-parameter) for isothermal fatigue conditions and has been successfully applied in several works. The excellent accordance of the D_CF-parameter with isothermal fatigue test data promises reasonable prediction results for the application of this parameter to thermomechanical loading conditions. For this purpose, data from crack propagation experiments were collected from publications of the last two decades and analysed with regared to the effects of several test parameters. The influence of temperature, cycle frequency, loading waveform and cyclic stress ratio on crack growth rates were considered as relevant for the study. To account for different environments, crack length data from tests executed in sodium and vacuum environments were evaluated separately for the calculations. In order to verify both the applicability of the fracture mechanics approach to TMF and the resulting predictive capabilities of the method, the isothermal and thermomechanical fatigue test data generated on a type 304L austenitic stainless steel were used.

3 illus, 2 tables, 18 ref

006070   Baldev Raj;Jayakumar T;Mukhopadhyay C K (Metallurgy and Mater Grp, Indira Gandhi Cent for Atom Res, Kalpakkam-603 102, Email: dir@igcar.ernet.in) : Damage assessment using NDE Techniques:. Trans Indian Inst Metals 2005, 58(2-3), 141-57.

Number of non-destructive evaluation (NDE) techniques such as ultrasonic, micro-magnetic, eddy current, acoustic emission, infrared thermography, laser interferometry, positron annihilation, X-Ray diffraction, small angle neutron scattering and in-situ metallography are employed for assessing creep and fatigue damage in materials. An assessment on the current scenario and directions for damage assessment using various NDE techniques is given.

006069   Babu P E J;Pillai U T S;Savithri S;Pai B C (Metal Processing Div Computational Modelling and Simulation Sect, Regional Res Laboratory (CSIR), Thiruvananthapuram-695 019, Email: pillai@csrrltrd.ren.nic.in) : Mathematical modelling of steady state creep in metal matrix composites. Trans Indian Inst Metals 2005, 58(2-3), 287-90.

Novel micromechanical approach has been developed for predicting the steady state creep behavior of metal matrix composites (MMCs). The developed micromechanical model is an analytical formulation based on strain compatibility. Further, the theory embodies the non-linear and rate-dependent nature of the ductile matrix, as well as the elasticity of both the matrix and the fiber. The proposed formulation presented in a generalized manner can be applied to a large class of MMC systems. The predicted creep rate for the composite using the present model is compared with the available results in the literature.

3 illus, 9 ref

006068   Azeem M A;Mandal A K;Kumar S (Dep of Metallurgy, Indian Inst of Sci, Bangalore-560 012, Email: skumar@met.iisc.ernet.in) : Creep behaviour of short fibre reinforced QE22 magnesium alloy using impression creep test. Trans Indian Inst Metals 2005, 58(2-3), 489-92.

Creep properties of QE22 magnesium based alloy and composites reinforced with 20 volume percent of shortfibers - Maftech®, Saffil® or Supertech®, were evaluated using the impression creep test. In the impression creep test, a load is applied with the help of a cylindrical tungsten carbide indenter of 1 mm diameter. This has advantages over conventional creep testing in terms of small specimen size requirement and simple machining. Depth of impression is recorded with tune and steady state strain rate is obtained from the slope of the secondary strain (depth of impression divided by indenter diameter) vs. time plot. The results are compared with the creep obtained from conventional creep performed in tension on the same materials earlier. Microstructural examination of the plastically deformed regions is carried out to explain creep behaviour of these composites.

5 illus, 2 tables, 10 ref

006067   Aseri T C;Bagai D (Dep of Computer Sci & Engng, Punjab Engng Coll, Sector-12, Chandigarh) : Comparative analysis of rate-based and credit-based flow control schemes in ATM networks. J Instn Engrs-Pt ET 2005, 86(July), 1-8.

Flow control plays an important role in the effective and stable operation of ATM networks. The results of study of flow control in ATM networks are presented in this paper. Two classes of control are described: preventive and reactive. Preventive control is static and Reactive control is dynamic that employs a closed loop feedback mechanism, which is more suitable in ATM networks. Four ATM service categories are provided to serve a variety of users. To enable each service class to function effectively, two closed loop flow control mechanisms: Rate-based and Credit-based, have been introduced for ATM networks. Rate based uses the rate of traffic flowing from the source to control the transmission rate. Credit based uses window flow control where a traffic source is allowed to transmit data only when there is available buffer space in the downstream node. In the paper, a number of rate-based and credit-based schemes are described and analyzed.

10 illus, 32 ref

006066   Anne Ligoria S;Samouel Knight G M;Ramachandra Murthy D S (Structural Engng Div, Anna Univ, Chennai-600 025, Email: anne_lal@yahoo.com) : Fatigue crack growth analysis of a plate with semi-elliptical surface crack subjected to tension. Trans Indian Inst Metals 2005, 58(2-3), 467-74.

Thick plate with a semi-elliptical surface crack of different initial crack sizes subjected to tension fatigue loading was considered for the analysis. The material was assumed to have isotropic fracture toughness in the surface and thickness directions and the property values reported by Burande and Sethuraman were used. Mode I Stress Intensity Factor (SIF) under plane strain condition was calculated using Finite Element technique (ANSYS Software) and compared with the predictions using the expression from SIF Handbook. The crack growth rates were further calculated by Foreman's equation. Math CAD software was used to perform the iterations of the crack growth study until failure. The finite element model underestimates the cycles to failure by 4% as compared to that predicted using SIF equation.

10 illus, 2 tables, 9 ref

005065   Thanoon W A;Paul D K;Jaafar M S;Noorzaei J (Civil Engineering, Faculty of Engineering, , UPM 43400 Serdang, Malaysia) : Inelastic moment redistribution of reinforced concrete frames. J Struct Engng 2005, 32(2), 65-74.

Inelastic moment redistribution in the reinforced concrete frames have been investigated. The stiffness of the reinforced concrete member having a plastic hinge at one (or both) end(s) has been evolved by integrating the results obtained from the analysis of the reinforced concrete section with the theory of plasticity. The inelasticity algorithm developed can predict the continuous deterioration of the stiffness of the frame due to on-set of plasticity in the frame members. A computer code has been written to run the inelastic analysis. The results obtained show that the redistribution process during inelastic analysis will alter the structural capacity of the reinforced concrete section, due to the allowance of inelastic deformations at plastic hinges.

10 illus, 1 table, 12 ref

005064   Sudhakar K J;Goli H B (NO, A.U., Visakhapatnam-530 003) : Limit state coefficients for trapezoidal-shaped slabs supported on three sides. J Struct Engng 2005, 32(2), 101-8.

A trapezoidal reinforced concrete balcony slab can be analyzed and designed by using yield line method proposed by Johansen. Many researchers using yield line method published many papers on analysis and design of rectangular balcony slabs in the past. However, some virtual work equations for selected cases are presented. Analysis and design examples are also presented using tables/charts generated for various parameters of trapezoidal shape balcony slabs.

6 illus, 3 tables, 10 ref

005063   Sivaraman B;Krishna Mohan N (Department of Mechanical Engineering, Annamalai University, Annamalainagar-608 002, Email: siv_gee@rediffmail.com) : Experimental analysis of heat pipe solar collector with different L/d_i ratio of heat pipe. J scient ind Res 2005, 64(9), 698-701.

Heat pipe solar collector has better collecting efficiency compared to the conventional collectors. Experiments on the effect of L/dⁱ ratio of heat pipe on heat pipe solar collector are presented. Two solar collectors with different L/dⁱ have been designed and fabricated. A heat pipe with stainless steel wick replaces the transport tubes of the solar collector. Copper and stainless steel were used as container and wick material and methanol was used as working fluid of heat pipe. Heat pipes are designed to have heat transport factor of around 194 W and 260 W of thermal energy. Experiments were conducted during summer season with a collector tilt angle of 13° to the horizontal. The collector with L/d_i ratio of 52.63 was found to be more efficient than the collector with L/d_i ratio of 58.82. This improved efficiency is due to increase in heat transport factor of heat pipe, which increase with decrease in L/d_i ratio.

9 illus, 1 table, 12 ref

005062   Singh P K;Singh R K (Blasting Department, CMRI, Barwa Road, Dhanbad-826 001m) : Importance of Seismograph calibration for accurate vibration monitoring. Indian Min Engng J 2005, 44(5), 18-19.

1 illus

005061   Sharma N;Chaudhry K K;Chalapati Rao C V (Traffic Engineering and Transportation Planning Area, Central Road Research Institute, New Delhi-110 020, Email: sharmaniraj1990@rediffmail.com) : Vehicular pollution modeling using artificial neural network technique: a review. J scient ind Res 2005, 64(9), 637-47.

Air quality models form one of the most important components of an urban air quality management plan. An effective air quality management system must be able to provide the authorities with information on the current and likely future trends, enabling them to make necessary assessments regarding the extent and type of the air pollution control management strategies to be implemented throughout the area. Various statistical modeling techniques (regression, multiple regression and time series analysis) have been used to predict air pollution concentrations in the urban environment. These models calculate pollution concentrations due to observed traffic, meteorological and pollution data after an appropriate relationship has been obtained empirically between these parameters. Recently, statistical modeling tool such as artificial neural network (ANN) is increasingly used as an alternative tool for modeling the pollutants from vehicular traffic particularly in urban areas. A review of the applications of ANN in vehicular pollution modeling under urban condition and basic features of ANN and modeling philosophy, including performance evaluation criteria for ANN based vehicular emission models have been described.

4 illus, 1 table, 60 ref

005060   Sathiyanathan R A L;Maruthamuthu S; Selvanayagam M;Mohanan S;Palaniswamy N (Department of Biotechnology, Alagappa University, Karaikudi-630 003, Email: sathiyalouise@yahoo.com ) : Corrosion inhibition of mild steel by ethanolic extracts of Ricinus communis leaves. Indian J chem Technol 2005, 12(3), 356-60.

Extracts of Ricinus communis leaves were tested for corrosion inhibitory effects towards mild steel in 100 ppm sodium chloride solution. The anticorrosion efficiency of plant extracts was studied by means of weight loss, electrochemical polarization and impedance measurements. It was found from weight loss measurements that the corrosion inhibition efficiency was about 84 % in 300 ppm of the plant extract. Polarization measurements indicated that the plant extract acted as anodic inhibitor. Electrochemical impedance results also showed that the plant extract increased the corrosion resistance of mild steel and the formations of iron-organic complex reduced the corrosion of mild steel in neutral system.

4 illus, 3 tables, 16 ref

005059   Sahoo B (NMDC Ltd, DMP, Panna, Madhya Pradesh) : Kimberlite mining and its beneficiation for diamond - the present technology. Indian Min Engng J 2005, 44(4), 33-6.

The Diamond Mining Project of NMDC Ltd. is the only mine producing diamond in India as well as in Asia. Its parent rock. Kiberlites which is supposed to have occurred some 1100 million years ago by process of volcanic eruption with subsequent subsidence due to cooling effect along with the top portion weathered, behaves erratically with respect to quality (incidence per hundred tonnes), compressive strength, and associated fracture planes. Paper deals the process of mining the kimberlite ore originated in a pipe form involving drilling, blasting, and excavation etc. The system of stacking the ore for exposing it to weathering, which plays a vital role in better liberation of diamonds is also delineated. The crushing process involving at the primary stage as well as secondary stage with proper screening before feeding to HMS (Heavy-Media Separation) plant has been also highlighted in detail. The most sophisticated and state-of-the-art HMS plant along with the heavy-media cyclone, addition of controlled Ferro Silicon, staged magnetic separators of CRC (Conacentrate Reduction Circuit) etc. have also been described in the paper. The end process i.e. W-ray sorter which plays a key tasks for separating the diamond concentrates ore" as well as the picking of diamonds by hand at the final stage etc. are also covered.

4 tables

005058   Roy S S (Central Mechanical Engineering Research Institute, , Durgapur-713 209, Email: ssroy_cmeri@yahoo.co.in) : Design of adaptive neuro-fuzzy inference system for predicting surface roughness in turning operation. J scient ind Res 2005, 64(9), 653-9.

Proposes an Adaptive Neuro-Fuzzy Inference System (ANFIS) for predicting the surface roughness in turning operation for set of given cutting parameters, namely cutting speed, feed rate and depth of cut. Two different membership functions, triangular and bell shaped, were adopted during the training process of ANFIS in order to compare the prediction accuracy of surface roughness by the two membership functions. The comparison of ANFIS values with experimental data indicates that the adoption of both triangular and bell shaped membership functions in proposed system achieved satisfactory accuracy. The bell-shaped membership function in ANFIS achieves slightly higher prediction accuracy than triangular membership function.

4 illus, 8 tables, 12 ref

005057   Revathi P;Menon D (Structural Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai-600 036) : Nonlinear finite element analysis of reinforced concrete beams. J Struct Engng 2005, 32(2), 135-7.

4 illus, 1 table, 3 ref

005056   Rajendran R;Prem SaiK;Bhattacharya A S;Basu S (BARC Facilities, , Kalpakkam-603 102) : Shock assessment of cylindrical bodies impacting on a rigid unyielding surface. J Struct Engng 2005, 32(2), 139-42.

10 illus, 6 ref