018531   Bagchi S S;Jadhav B T (Koradi Thermal Power Station, MSPGCL, Nagpur-441 111) : Blended cement using flyash for masonry and plstering work. Indian J envir Prot 2009, 29(7), 649-52.

The precious portland cement essentially meant for structural application is invariably used for masonry work, where as the masonry cement still remains far from common knowledge and usage. An attempt has been made in the present study to explore the possibilities of obtaining the characteristics of masonry cement from the blend of ordinary portland cement and class F flyash. Class-F flyash was used in making masonry mortars suitable for brick joints and for plastering. The mortars were made of a locally produced mixed cement and flyash at 0% and 50% cement replacement with and without the addition of an air entraining agent/plasticizer. The testing programme includes the determination of quality of ash according to IS standard and compressive strength. The need and suitability of flyash mortar mixes along with the test results is presented in this paper. It has been observed that 28 day strength obtained using 53 grade cement and flyash is much higher than the strength requirement of masonry cement IS 3466-1988 (second revision).

3 tables, 9 ref

018530   Ahmed M F;Gokhale S S (Computer Science and Engineering Dep, Univ of Connecticut, Storrs, CT 06269, USA, Email: mohamed.ahmed@engr.uconn.edu) : Reliable operating systems: overview and techniques. IETE Tech Rev 2009, 26(6), 461-9.

Traditional operating systems' architectures are primarily focused on achieving superior performance, albeit at the expense of sacrificing reliability. This approach is clearly inadequate, given our growing dependence on computer systems for essential and critical services. Reliability should thus be considered as a first-class citizen alongside functionality and performance, while designing future operating systems. The present paper summarizes the current trends and best practices employed to improve the reliability of operating systems. We also draw attention to the limitations and drawbacks of the prevalent approaches, discuss outstanding issues and propose some promising research directions, which may be explored to build highly reliable operating systems.

4 illus, 22 ref

017565   Yilmaz M;Kok B V (Civil Engineering Dep, Firat Univ, Elazig, Turkey, Email: myilmaz23@gmail.com) : Effects of ferrochromium slag with neat and polymer modified binders in hor bituminous mix. Indian J Engng Mater Sci 2009, 16(5), 310-18.

Properties of hot bituminous mix containing ferrochromium slag with neat and styrene-butadiene-styrene modified binders have been investigated. The ferrochromium slag is used as coarse aggregate and total aggregate. Three different binders, B 50/70, B 160/220 and B 160/220+3% SBS, are used in mixtures. The physical and mechanical properties of polymer modified binders and binder-aggregate mixes are evaluated in terms of their fundamental engineering properties such as dynamic shear rheometer (DSR), rotational viscometer (RV) for binders, Marshall stability, indirect tensile stiffness modulus, tensile strength and moisture susceptibility for mixtures. It has been concluded through the laboratory tests that using ferrochromium slag as coarse aggregate provided satisfactory results. The usage of ferrochromium slag as total aggregate does not exhibit good performance in terms of stability and stiffness modulus. However, the mixtures prepared entirely with ferrochromium slag showed good resistance to moisture damage. It is found that in spite of the similarity between high temperature performance grades of B 50/70 and B 160/220+3% SBS, the mechanical properties of the mixtures prepared with these binders do not show the same performance.

6 illus, 9 tables, 28 ref

017564   Ye Q;Wu S (School of Traffic and Transportation Engineering, Changsha Univ of Science and Technology, Changsha 410004, China, Email: yequnshan@126.com) : Rheological properties of fiber reinforced asphalt binders. Indian J Engng Mater Sci 2009, 16(2), 93-9.

Cellulose fiber, polyester fiber and mineral fiber are employed as additives to prepare fiber reinforced asphalt binders in this paper, with a concentration ranging from 0 to 1.0 %. Viscosity test, dynamic shear test and creep test arc conducted to investigate the rheological characteristics of fiber reinforced asphalt binders. Experimental results indicate that the viscosity of fiber reinforced asphalt binders is increased by the addition of fibers, especially when the fiber concentration is up to 0.5 % by mass of asphalt binder. Complex shear modulus of fiber reinforced asphalt binders are increased, which indicate that the stiffness of asphalt binders can be enhanced by the use of fiber additives. The clastic part of viscoclastic behaviours of asphalt binders are enhanced by the addition of fibers, which result in the reduction of the phase angle. The master curves of complex shear modulus of fiber reinforced asphalt binders are determined based on nonlinear least square regression according to the time-temperature superposition theory at a control temperature (20°C). It is implied that the reinforcing effects of fibers arc more significant at lower frequencies. The development of creep strain curves for asphalt binders varied remarkably by the addition of fibers. The total strain during loading period and the permanent strain are reduced greatly when fibers are added, which revealed that the resistance to permanent deformation can be significantly improved for asphalt binders containing fibers.

8 illus, 3 tables, 21 ref

017563   Wang W;Bubb H;Ikeuchi K;Cao Q (School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P R China, Email: wangwuhong@bit.edu.cn) : Measurement of dangerous traffic conditions through driving dependability analysis. J scient ind Res 2010, 69(4), 254-8.

Presents a concept of driving dependability analysis based on driver specific error-inducing behaviors in various information processing stages, using database of bus drivers to measure dangerous traffic conditions. Formalized expert judgment method based on fuzzy sets was applied to determine variability of driving behaviour under traffic accident conditions. Based on case study conducted, it effectively predicted effect of driving errors on road traffic safety in quantitative and qualitative terms.

3 illus, 10 ref

017562   Viswanathan K K;Sheen D (Mathematical Sciences Dep, Seoul National Univ, Seoul 151-747, South Korea, Email: visu20@yahoo.com) : Free vibration of layered annular circular plate of variable thickness using spline function approximation. Indian J Engng Mater Sci 2009, 16(6), 433-48.

Free vibration of layered annular circular plate of variable thickness, made up of isotropic or specially orthotropic materials, is studied using spline function approximation by applying the point collocation method. Three different thickness variations are considered, namely, linear, exponential and sinusoidal, along the radial directions. The equations of motion are derived by extending Love's first approximation theory. A system of coupled differential equations, in terms of longitudinal, circumferential and transverse displacement functions is obtained by assuming the solution in a separable form. These functions are approximated by using Bickley-type splines of suitable orders. A generalized eigenvalue problem is obtained by applying a point collocation technique with suitable boundary conditions, from which the values of a frequency parameter and the corresponding mode shapes of vibration, for specific values of various parameters, are obtained.

13 illus, 4 tables, 32 ref

017561   Vaiapury K;Nagarajan M;Jain S K (NO, , Open Design House - Mobile Technologies, Satyam Computer Services Limited, Singapore) : Ambience-based voice over internet protocol quality testing model. IETE J Res 2009, 55(5), 212-17.

In this paper, we explore a new voice quality management model under ambience environment suitable for voice over internet protocol (VoIP) calls in wireless WLAN 802.11 Linux environment. The system is based on a setup that assimilates environment noise level using noise detector and adaptive audio manager used to tune the audio level and thereby quality is ensured. Further, existing models such as E-model, PESQ model and adaptive model address QoS in a VoIP networking perspective but do not address voice quality management in real time environment to improve voice quality. We propose to use background noise and its associated source information in an adaptive environment to boost user perception, audio level, thereby ensuring quality. This issue is important because in real time, consumers might be interested in mobiles that address ambience effect to determine human audible effect based on environment conditions. The experimental results of the proposed method outperform the existing method in terms of QoS factor metric; we get extensive results with more number of calls.

6 illus, 2 tables, 14 ref

017560   Tyagi S K;Kim M S;Park S R;Anand S (School of Infrastructure Technology and Resource Management, Shri Mata Vaishno Devi Univ, Katra-182 320, Email: sudhirtyagi@yahoo.com) : Second law based performance of modified VAC hybrid heat pump system using NH₃-H₂O as the working fluid. Indian J pure appl Phys 2010, 48(3), 212-19.

Vapour compression/absorption modified hybrid heat pump system using ammonia-water as the working fluid has been presented. The experimental as well as the theoretical performance based on the exergy analysis has been given. The irreversibility rate (exergy loss) in the low pressure compressor is found to be the highest while it is found to be the lowest in the case of expansion valve. It is also found that the irreversibility rate in low and high pressure compressors as well as the solution pump increase as the ambient air temperature increases. The effect of ambient air temperature is found to be more pronounced for the desorber while it is found to be reversed in the case of solution heat pump.

5 illus, 2 tables, 14 ref

017559   Thundil Karuppa Raj R;Ganesan V (Mechanical Engineering Dep, Indian Institute of Technology, Chennai-600 036, Email: vganesan@iitm.ac.in) : Experimental study of recirculating flows induced by vane swirler. Indian J Engng Mater Sci 2009, 16(1), 14-22.

The core objective of this study is to present the details of the experimental procedure and measurements made in an axisymmctric swirler model. The flow through 8 blade 30° vane swirler is studied experimentally. An overlap angle of 30° is provided between the vanes for the proper guidance of the llow through swirler. A hemi spherical bluff body is attached to the hub in order to overcome the inlet flow field distortion. A 5 mm diameter five-hole pilot sphere of cobra type has been used along with electronic digital manometers for the measurements. A computer aided traversing mechanism supported with Streamware software automatically controls (he traversing of the probe. The recirculation velocities at the center core and corner regions are well captured with the live-hole probe. Five-hole pilot probe measurements along the entire length of the model at different stations, allow the determination of axial mean velocity component and pressure field parameters, which provide comprehensive information to aid and understand such complex recirculation Hows. Flow field characteristics downstream of the swirler at different axial locations are examined in detail. The recirculation length and width are found to be strongly dependent on the amount of turbulence created by the vane swirler.

10 illus, 1 table, 20 ref

017558   Thakur D;Ramamoorthy B;Vijayaraghavan L (Manufacturing Engineering Section, Mechanical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: dinnu74@yahoo.com) : Optimization of high speed turning parameters of superalloy inconel 718 material using Taguchi technique. Indian J Engng Mater Sci 2009, 16(1), 44-50.

Supcralloy, Inconcl 718 is widely used in sophisticated applications due to its unique properties desired for the engineering applications. Due to its peculiar characteristics machining of Supcralloy Inconcl 718 is difficult and costly. The present work is an attempt to make use of Taguchi optimization technique to optimize cutting parameters during high speed turning of Inconcl 718 using tungsten carbide cutting tool. Taguchi method is a powerful design of experiments (DOE) tool for engineering optimization of a process. It is an important tool to identify the critical parameters and predict optimal settings for each process parameter. Analysis of variance (ANOVA) is used to study the effect of process parameters and establish correlation among the cutting speed, feed and depth of cut with respect to the major machinability factor, cutting forces such as cutting force and feed force. Validations of the modeled equations are proved to be well within the agreement with the experimental data.

6 illus, 9 tables, 11 ref

017557   Tchouto J (NO, , 3, Avenue Pasteur, 76.186 Rouen Cedex, France, Email: juleric.tchouto@univ.rouen.fr) : Tradable emission permits and general equilibrium through applied OLG models. J Envir Res Dev 2007, 2(1), 48-61.

Describes and summarises the literature on applied general equilibrium models. Furthermore, it focuses on Overlapping Generations (OLG) models applied to environmental problems and it studies some recent papers on tradable emission permits in view to analyse economic impacts of those permits on greenhouse gas phenomena and/or climate change.

1 illus

017556   Suresh Kumar S;Krishnamoorthi J;Ravisankar B; Angelo P C (Metallurgical and Materials Engineering Dep, National Institute of Technology, Tiruchirapalli-620 015, Email: brs@nitt.edu) : Methodology to evaluate the quality of diffusion bonded joints by ultrasonic method. Indian J Engng Mater Sci 2009, 16(5), 331-4.

Quality and the soundness of diffusion bonded joints are generally evaluated by metallographic techniques, shear strengthTtensile strength etc. Since these conventional methods are of destructive in nature, inspection on actual products is difficult. Therefore, non-destructive testing of diffusion bonded joints is required to evaluate the quality and to study the interphase properties. The ultrasonic A-scan method is suitable for diffusion bonded joints, since the sensitivity is 0.01-0.0001% as compared to the X-ray and Gamma ray methods having sensitivity of 0.5-2% only. In the present work, T1-6A1-4V was bonded with Ti-6Al-4V at 1073 K at varying pressures of 1.6-4 MPa for a bonding time of 4 h so as to obtain bonds with interfaces of varying bonded area fraction. The shear strength of the bond is correlated with bonded area fraction which is measured using metallographic technique. The bonded samples are tested using ultrasonic flaw detector for the soundness of the joints. The ratio between the amplitude of interface wall echo to amplitude of surface echo is calculated and correlated with the bonded area fraction.

4 illus, 1 table, 16 ref

017555   Srivastava J K;Pandey P;Mishra V N;Dwivedi R (Electronics Engineering Dep, Center for Research in Microelectronics, Institute of Technology, Bana, Varanasi-221 005) : Nature of dopants and effects on sensitivity of SnO₂ based gas sensor. IETE J Res 2009, 55(6), 299-303.

In this work, a thick film SnO₂ sensor was fabricated on a 1" X 1" alumina substrate. It consists of a gas sensitive layer (SnO₂) doped with Pd and Pt; a pair of electrodes in array form underneath the gas sensing layers serves as a contact pad for sensor and a common heater element on the backside of the substrate. Alumina substrate (96%) has been used as a substrate for sensor fabrication. The fabricated sensor was tested for varying concentration of LPG and methane in a locally developed test chamber. The response of sensors to varying concentration of LPG and methane was studied at 350°C. The Pd-doped sensor was found to be more sensitive towards LPG and methane.

6 illus, 14 ref

017554   Sridhanya K V;Rajagopal K;Lakshmana Rao C (Civil Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: sridhanyakv@gmail.com) : Modeling of degradation of clayey soils under repeated loading. Indian Geotech J 2009, 39(2), 139-52.

The degradation of strength and stiffness of clayey soil under cyclic loading conditions is of serious concern to geotechnical engineers. Consequently, many models were developed in the past that can predict the cyclic loading response of the soil. But, these models used a large number of parameters, which in most cases did not have any physical significance. An attempt has been made in this paper to model the response of soil under cyclic loading using the concepts of Critical State Soil Mechanics (CSSM), which uses lesser number of parameters to predict the response. The Modified Cam Clay model, which was developed based on CSSM, is further modified to predict the response of soil under cyclic loading. The modification proposed in the present model is essentially based on the recognition that it is the accumulation of pore pressures under repeated loading in soft clay that causes degradation in yield stress with the number of cycles. The improvement in the predictive capabilities of the proposed modified model, in comparison with earlier similar models is verified by comparing against published experimental data on marine clays.

10 illus, 12 ref

017553   Somasundaram A;Srinivasan P S S (Mechanical Engineering Dep, Kongu Engineering College, Perundurai, Erode-638 052, Email: somas789@yahoo.com) : Design optimization of dosa making workstation for smooth ergonomic interface. J scient ind Res 2010, 69(3), 221-4.

Study presents design optimization of Dosa making workstation (DMW) used in preparation of South Indian food, dosa. Anthropometry of South Indian user population is considered in ergonomic interface analysis. Design of Experiments (DOE) was used for optimization of DMW. Four control parameters (shoulder height, arm length of worker, table width and table height of DMW) were considered in design optimization. Proposed parameters (height, 1150 mm; width, 750 mm) reduced risk of musculoskeletal disorder for users and enhanced quality of work at DMW.

1 illus, 5 tables, 5 ref

017552   Sivaraa M;Kandasamy S;Thirumurugan A (NO, Kongu Engineering College, Erode, Email: m.shivaraj2006@gmail.com) : Mechanical strength of fibrous concrete with waste rural materials. J scient ind Res 2010, 69(4), 308-12.

This study presents reusing of locally available waste fibrous materials as concrete composites. Mechanical strength properties (compressive strength, split tensile strength, modulus of elasticity, modulus of rupture and shear strength) of synthetic fibres (nylon, plastic and tyre) with volume fractions (0.5%, 1 % and 1.5%) and aspect ratios (30, 60 and 90) were evaluated. Empirical relation was proposed for mechanical strength in relation with fibre reinforcing index (FRI) and compared with experimental results. Concrete mixed with rural waste fibres improved mechanical strength.

1 illus, 3 tables, 11 ref

017551   Sivakumar Babu G L;Srivastava A (Civil Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: gls@civil.iisc.ernet.in) : Allowable bearing pressure on clays-reliability based approach. Indian Geotech J 2009, 39(2), 216-26.

The conventional design, the allowable bearing pressure on a shallow foundation is estimated by dividing its ultimate bearing capacity (evaluated from shear failure and settlement criteria) by a factor of safety. The selection of appropriate value of factor of safety depends on various factors that involve type of structure and its importance, type of soil, size of footing, and type and amount of load on the footing. Based on several theories, research work and experience, it is established that a minimum factor of safety of 3.0 is desirable from economic and safety considerations, however a designer may choose to use a factor of safety considerably greater than 3.0 in circumstances where the settlement is the governing factor or the type of soil compels to use a higher factor of safety. The work of Skempton (1951) is the basis for these guidelines in which measurements of settlements of buildings, a wide ranges of soil properties and types of soils are considered. In this paper, the results of Skempton (1951) are examined within the framework of reliability analysis and conclusions with regard to the allowable pressure are highlighted.

^ssc1 illus, 4 tables, 18 ref

017550   Sivakumar Babu G L;Singh V P (Civil Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: gls@civil.iisc.ernet.in) : Appraisal of soil nailing design. Indian Geotech J 2009, 39(1), 81-95.

Soil nailing is being used increasingly as a feasible alternative to support vertical/near vertical cuts and embankments. Field practitioners concerned with analyses, design and construction of soil nail walls invariably refer to established analysis and design procedure such as Federal Highway Administration (FHWA), U.S. Department of Transportation, Analysis and Design Guidelines for the Soil Nail Walls (2003). With the increasing use of such design guidelines, it is desirable to evaluate the analyses and design methodology adopted. An effort in this regard is made by designing three soil nail walls supporting vertical cuts of height 6 m, 12 m, and 18 m with reference to the procedure of the Federal Highway Administration. The response of the three wall sections is obtained using numerical simulations based on finite element analysis. Various analyses parameters such as development of axial forces in nails, maximum displacements, and important failure modes have been studied to assess the stability of soil nail walls. A comparative study showed that the soil nailed walls designed from conventional procedure are conservative.

9 illus, 3 tables, 8 ref

017549   Singh S S (Design Dep, Gallium Arsenide Enabling Technology Center (GAETEC), Vignankancha Post, Hyderabad-500 069) : Design and realization of electrostatic discharg protected DC to 2GHz GaAs monolithic microwave integrate circuits SP4T switch for TDMA communication applications. IETE J Res 2009, 55(4), 169-72.

Discusses the small signal simulated and measured results of a DC to 2GHz monolithic GaAs SP4T switch which has been designed and realized. The measured 1 dB compression point of SP4T switch at different frequency range has also been presented. The DC to 2GHz switch has been designed using series-shunt FETs topology. This topology has worked over very large bandwidth. In this topology series MESFETs allows the SP4T switch to operate down to DC. The SP4T switch has been achieved better than 1.1 dB of insertion loss, better than 32 dB of input to "Off" port isolation and better than 16 dB of the input and output return loss @2GHz. The performance of the SP4T switch has been measured on an FR4 PCB eval board. The on-chip higher value of ballast resistor has been used for ESD protection. The switch has designed using 0.7 μm Ion-Implanted recessed gates MESFET technology and used in switching matrices for TDMA communication system. The major advantages of the solid-state integrated switch are low power consumption, small size and lightweight. These features of solid state switch are more attractive for communication applications. The chip dimension is 1.2 x 1.2 mm.

5 illus, 6 ref

017548   Shnkar I B;Rao K M;Gopalakrishna A (Mechanical Engineering Dep, JNTU, Kakinada, Email: ibsankar@vizagsteel.com) : Optimization of steel bars subjected to tempcore process using regression analysis and harmony search algorithm. J scient ind Res 2010, 69(4), 266-70.

Study explores use of regression analysis (RA) and harmonic search algorithm (HSA) for optimization of process parameters of steel bars produced by Tempcore process. Nonlinear RA with logarithmic transformation was applied in developing empirical model. HSA was then applied to optimize influential process parameters.

3 illus, 3 tables, 25 ref

017547   Shibu G;Parthasarathy N S (Mechanical Engineering Dep, College of Engineering Guindy, Anna Univ, Chennai, Tamilnadu, Email: nsp@annauniv.edu) : Concise mathematical approach for establishing a rotation restraint operating requirement for a bimetallic stranded cable. Int J theor appl mech 2008, 3(2-3), 161-9.

Deals with the necessary conditions to achieve a rotational resistant, which is specially needed to resist spin or rotation of a stranded cable, under load. The rotational resistant characteristics is attained by designing of two or more layers of the strand having differing (right and left) directions of helix or lay angles. Under load, the rotation of one layer is counteracted by the tendency of the other layer(s) to rotate in the opposite direction. To impart the resistance to rotation, the layers can be designed by adjusting the helix angles, the number of wires, diameter and the material. Strength balance is yet another requirement for optimum design of a cable. This implies that wires betweens the layers will have equal strength. For a condition to satisfy a balance in torque and stresses amongst the layers together, the present paper focuses on a suitable design of helix angle of the outer wires keeping the other major parameters mentioned above intact. Among the several mathematical models for predicting the mechanical response of a helical wire strand to axisymmetric loading derived in the literature over five decades, the linear elastic symmetrical model which considered generalized strains is applied to accurately describe the physical behavior of the cable.

2 illus, 1 table, 7 ref

017546   Sherring A;Dwivedi M;Mishra A K (Soil Dep, Water, Land Engineering and Management, Allahabad Agricultural Institute, Allahabad-211 007, Email: asherring@rediffmail.com) : Development of autoregressive time series model for prediction of rainfall and runoff in Toriya watershed. Envir Ecol 2009, 27(1A), 354-9.

Study was conducted to develop a stochastic autoregressive time series model for prediction of annual rainfall and runoff in Tonya watershed located at Lalitpur district of Uttar Pradesh. The study area lies between 24°45' N latitude and 78°20 E longitude and has an area of 106 ha. The developed model is based on 14 years (1994-2007) annual rainfall and runoff data. Autoregressive (AR) model of order 0, 1 and 2 proposed earlier were tried. The goodness of fit and adequacy of model were tested by Box-Pierce Portmonteau test, Akai information criterion (AIC) and various statistical characteristics viz. mean forecast error (MFE), mean absolute error (MAE), mean relative error (MRE), root mean square error (RMSE) and integral square error (ISE). Based on the results, it was concluded that AR (1) model can be effectively used for prediction of rainfall and runoff in Toriya watershed of Lalitpur district.

4 illus, 3 tables, 10 ref

017545   Sharma S;Gaur D;Agarwal A;Baijal R (Classified Spl (Av Med), Sr Adv (AvMed) & Chief Research Officer, Cla, IAF, Bangalore) : Ground based spatial disorientation counter measure training: an approach to training for Indian air force. Indian J Aerospace Med 2008, 52(2), 27-34.

Indian Air Force (IAF) addresses Spatial Disorientation Counter Measure (SDCM) training with an accepted multi-pronged approach of education, training and research. Physiological training, using a spatial disorientation simulator, Airfox DISO^{®, is one of the SDCM strategies employed by the IAF. Such ground based training aims to provide an understanding amongst pilots about the physiology of orientation, its limitation in aviation, in turn helping them understand their susceptibility to spatial disorientation (SD), and demonstration of common illusions to help in early recognition of SD. Though, the training practices include a combination of didactics and demonstration; there is learning of the SD trainers as well, with the shared experiences, feedback and interactions with the pilots undergoing the SDCM training. Such training, therefore, is an ongoing 'teaching learning' process. The healthy, meaningful and mutually beneficial interaction, between the SD trainers and the pilots, helps in evolving the training practices. With a view to evaluate the ongoing 2 day SD training course for fighter pilots, this study was undertaken to define and plan the future SDCM training of the IAF aircrew. The data for the study was obtained from the selected analysis of the post-course written feedback; and interaction, formal and informal, with the aircrew undergoing training. The post-course feedback pertaining to this study was available from 105 pilots. The trainee pilots suggested procedural modifications (59.04%), modifications in the layout of display and control in DISO (22.85%) and various training, trainee, course content and course conduct related issues (18.09%). Based on the varied data and the inputs, ground based SDCM training schedule is proposed for the ab-intio to the operational pilots, as per the growth in their professional career. The need for refresher training and modifications in in-flight SD training is emphasized. This paper outlines the strategy for long term exploitation of the SD simulator for an enhanced SDCM training value for the IAF pilots.}

2 illus, 2 tables, 7 ref

017544   Sharma R S;Upadhyay V;Hans Raj K (University Science Instrumentation Centre, Dayalbagh Educational Institute, Agra-282 110, Email: khansraj@rediffmail.com) : Neuro-fuzzy modeling of hot extrusion process. Indian J Engng Mater Sci 2009, 16(2), 86-92.

Agile manufacturing systems require models that can predict in real time the effect of various process parameters of a production process. Hot extrusion is a commonly used production process in forging industry. The relationship between the process variables (input), viz., die-velocity, temperature of billet, die angle and co-efficient of friction of a given material and extrusion force (output) required to extrude a shaft is very complex and is amenable to neuro-fuzzy approach. In this paper, a soft computing approach, i.e., neuro-fuzzy technique is used in modeling hot extrusion process to predict the punch force required to extrude a transmission shaft from ck-45 steel billet. The neuro-fuzzy model has been created out of training data obtained from the finite element (FE) simulation and correlates well with the FE results. This work has considerable implications in selection and control of process variables in real time and ability to achieve energy and material savings, quality improvement and development of homogeneous properties throughout the component and is a step towards agile manufacturing. The close agreement of the values of the final extrusion force obtained by the NF model and the FE simulation clearly indicates that the model can be used for predicting the extrusion force in the range of parameters under consideration in real-time without having to perform any extensive and costly computations. This technique opens new avenues of parameter estimation, optimization and on-line control of complex agile manufacturing systems.

2 illus, 3 tables, 61 ref

017543   Sharma K G (NO, , Indian Geotechnical Conference IGC 2008, Bangalore) : Numerical analysis of underground structures. Indian Geotech J 2009, 39(1), 1-63.

Underground structures are increasingly used for various projects. With the phenomenal growth in the development of computers and software packages, various numerical methods such as finite element method, boundary element method and distinct element method are often adopted for the analysis and design of underground structures. These methods facilitate modelling of various complex features related to rock mass behaviour, support system and excavation sequence. The paper highlights some of the results of research carried out at NT Delhi on the numerical analysis of underground structures. The analysis of powerhouse caverns, interaction of tunnels, branching tunnels, tunnel in jointed rock mass, nuclear waste repository and rock support interaction analysis are presented and discussed. Elastic, elaso-plastic and strain softening models are used to characterize the rocks.

64 illus, 18 tables, 77 ref

017542   Shaalan A A (Faculty of Engineering, Zagazig Univ, Zagazig, Egypt) : Performance evaluation of GPR system using gaussian pulse excitation to cover entire frequency band of operation. IETE J Res 2009, 55(4), 148-53.

A differential Gaussian pulse excitation of a transmitting antenna is applied to investigate GPR system performance using two types of proposed antennae, both, partially covered. The first using dipole antenna and the second using bowtie antenna. A good agreement of the calculated results of different antenna parameters with those achieved by applying a sinusoidal source at the feeding of transmitting antenna was predicted for both the cases.

12 illus, 9 ref

017541   Sengupta A;Mantri L R (Civil Engg Dep, IIT, Kharagpur-721 302, Email: sengupta@civil.iitkgp.erner.in) : Effect of orientation of micofabric on engineeirng behaviour of clays. Indian Geotech J 2009, 39(2), 188-200.

The effect of microfabric of clays on their engineering behavior is studied both experimentally as well as numerically. A commercially available kaolinite is utilized in this study. The stress-strain behavior and pore pressure development in the kaolinite samples are studied experimentally under undrained plane strain conditions. Two orientations of clay fabric - one with random orientation, referred to as "flocculated" microfabric, and another one with horizontally aligned orientation, referred to as "dispersed" microfabric, are considered. The laboratory biaxial test results indicate that the kaolinite with dispersed microfabric exhibits positive excess pore pressure. However it is significantly lower than the pore pressure developed in the flocculated microfabric indicating the less contractive nature of the dispersed microfabric. The kaolinite samples with dispersed microfabric indicate higher shear strength in comparison to the flocculated microfabric and also show well defined peak in the stress-strain curve. In dispersed microfabric, the parallel stacking of clay platelets has the ability of carrying a larger amount of axial load applied in a direction perpendicular to the faces of platelets. At the same time these platelets tend to slip suddenly at high stress levels leading to a looser configuration of platelets in a local zone induced by the dilative nature of dispersed clay specimens. These laboratory experiments are simulated numerically using a commercial finite element package called PLAXIS. The results of the PLAXIS are interestingly found to be comparable with the experimental observations.

13 illus, 2 tables, 5 ref

017540   Sawant S M;Gururaja Rao C (Mechanical Engineering Dep, National Institute of Technology, Warangal-506 004, Email: cgr_gcr@yahoo.co.in) : Fundamental sudies on buoyancy-aided conjugate mixed convection with surface radiation from a discretely heated vertical electronic board. Indian J Engng Mater Sci 2009, 16(5), 301-9.

Reports numerical results related to the problem of buoyancy-aided conjugate mixed convection with surface radiation from a discretely heated vertical electronic board. The board is equipped with three flush-mounted discrete heat sources of identical dimensions and volumetric heat generation, while air is used as the cooling medium. The governing continuity, Navier-Stokes and energy equations are taken without boundary layer approximations and are solved using finite volume method with the help of stream function-vorticity formulation. An extended computational domain is considered and is discretised with 151 grids along and 111 grids across the board. The nature of variation of local board temperature distribution, peak board temperature, local drag coefficient, mean friction coefficient and relative contributions of mixed convection and radiation to board heat dissipation with reference to some of the pertinent independent parameters has been looked into. Also, some of the contour plots related to isotherm distribution in the computational domain for typical sets of working conditions have been provided.

7 illus, 3 tables, 18 ref

017539   Sankarasubramanian G;Eswari S (Civil Engineering Dep, PSG College of Technology, Coimbatore-641 004, Email: gsa@civ.psgtech.ac.in) : Influence of size strength relation in modeling the behaviour of quasi-brittle materials. Indian J Engng Mater Sci 2009, 16(2), 100-10.

Modeling the behaviour of quasibrittle materials (concrete, rock, fiber composites, ceramics, etc.) is a challenging task for engineers. A comprehensive approach and methodology are required for the fracture mechanics problems of quasibrittle materials. In quasi brittle materials, the fracture process zone ahead of the crack tip is not negligible compared to the characteristic cross-sectional dimension of the specimen. Influence of strain softening zones due to cracking must be considered. This paper illustrates the importance of size effect and its salient features in the field of fracture mechanics. According to Bazant Size effect law1, the asymptotic deviation of nominal strength witli respect to structural size varies from strength criteria for small size specimen to linear elastic fracture mechanics (LEFM) for large size specimen. The salient characteristics of Weibull's statistical weak link theory and nonlocal damage theory for modeling are explained. Influence of size effect on modulus of rupture, brittleness number and rate of loading are illustrated. Salient features of crack band model, microplane model and their applications have also been summarized. Recent trends in developing virtual internal pair bond model for quasibrittle materials are also included. These concepts arc essential for carrying out analytical investigations and development of design guidelines. Relatively large fracture process zone present in concrete enhances the need for extensive research in experimental methods, appropriate physical process and numerical techniques to simulate the fracture behaviour of quasibrittle materials. A summary of various models for quasibrittle materials using fracture mechanics is also presented.

5 illus, 1 table, 35 ref

017538   Sachuthananthan B;Jeyachandran K (Mechanical Engineering Dep, Anna Univ, Chennai, Email: bsachu7@yahoo.co.in) : Combustion, performance and emissio characteristics of water-biodisel emulsion as fuel with DEE as ignition improver in a DI diesel engine. J Envir Res Dev 2007, 2(2), 164-72.

Investigations are carried out here to study the combustion, performance and emission characteristics on a single cylinder diesel engine by adding diethyl ether(DEE) as an additive with the constant ratio of Water-Biodiesel emulsion(WBE) as fuel. Literature review indicates that significant work is not carried out with respect to its performance analysis and in regard to pollution level. A four-stroke 5HP single cylinder DI diesel engine was used for the experiment with 5%, 10% and 15% blends of DEE with a constant 30% Water-Biodiesel emulsion as fuel. It was found that DEE when added to water-biodiesel emulsion can significantly lower NOx and smoke levels without adverse effect on brake thermal efficiency. High HC and CO which are problems with the water-biodiesel emulsions can be significantly lowered with the addition of DEE particularly at high outputs. Even at part loads the addition of DEE can improve the performance as compared to neat water-biodiesel emulsion without any adverse effect on NOx emission. Test results indicate that 15% DEE blend gives better performance and lower emissions compared to other blends of DEE and Water-Biodiesel emulsion. Hence 15% DEE can be blended with emulsified fuel to improve the performance and to reduce emissions like smoke density, paniculate matter and oxides of nitrogen.

9 illus, 1 table, 10 ref

017537   Sabrigiriraj M;Meenakshi M;Roopkumar R (Electronics and Communication Engineering Dep, Coimbatore Institute of Engineering and Information Technology, Narasipuram Post, Coimbatore-641 109) : Wavelength assignment for all-to-all broadcast in wavelength division multiplexing optical ring. IETE J Res 2009, 55(5), 236-41.

A novel wavelength assignment method is proposed for a bidirectional WDM ring network and the minimum number of wavelengths required to support all-to-all broadcast is determined. The new method can assign each wavelength directly and simultaneously to a group of non-overlapping connections on an N-node ring without the aid of any table or matrix. The presented wavelength assignment method is much faster than other direct methods with explicit formulas previously reported for WDM ring network.

2 illus, 11 ref

017536   Roy L;Sen A;Chetia R P;Borah M J (Mechanical Engineering Dep, National Institute of Technology, Silchar-788 010, Email: lintu_roy@yahoo.com) : Analysis and synthesis of fourbar mechanism. Int J theor appl mech 2008, 3(2-3), 171-86.

Computer programme and Genetic algorithm is used in analysis and synthesis of a planar four-bar mechanism. Link dimensions were varied to obtain coupler path maps. Position, velocity, acceleration and the force at the coupler point at various input angles were obtained and the designed path is utilized in the working models. Plot of variation of the link angles, variation of velocity and acceleration of the coupler point with the crank angle is obtained. It is found that ratio of velocity of crank and coupler point varies between 4.48 and 0.38, acceleration of the coupler point is maximum. The four bar mechanism can be used to transfer small jobs at regular interval of time. With addition of another four bar mechanism with this, a papad making machine is shown as an useful application.

20 illus, 8 ref

017535   Roy H;Ghosh D;Sahoo T;Shukla A (NDT and Metallurgy Div, Central Mechanical Engineering Research Institute, Durgapur-713 209, Email: h_roy@cmeri.res.in) : Failure analysis of a spring for a fuel pump bracket assembly. Indian J Engng Mater Sci 2009, 16(1), 33-6.

This investigation is primarily aimed to examine the premature failure of a spring used in a fuel pump bracket assembly. Preliminary visual examinations along with detailed SEM studies arc made on the damaged surface and fracture surface of the failed spring. In addition, microstructural investigations along with hardness measurements are carried out to understand the reason for the premature failure. Finally, it is concluded that improper heat treatment of the spring material is responsible for failure.

6 illus, 3 tables, 7 ref

017534   Rethaliya R P;Verma A K (Applied Mechanics Dep, BBIT, V.V.Nagar-388 120, Email: rprethaliya2009@yahoo.in) : Strip footing on sand overlying soft clay with geotextile interface. Indian Geotech J 2009, 39(3), 271-87.

A program of laboratory scale plane-strain bearing capacity tests under monotonic loading has been carried out which considers the reinforcing mechanism of the Geotextile. Analysis of the test results shows that the interpretation of the reinforcing mechanism is highly dependent upon the values assumed for the various model parameters. It was observed that for stiff layer overlying soft layer, failure occurs by the footing punching through the top sand layer, and with full development of the bearing capacity of the lower clay layer. The ultimate bearing capacity of the sand overlying soft clay with geotextile reinforcement at the sand-clay interface comprises of the contribution from stress distribution (qd), contribution due to shear layer effect (qs), and the contribution due to membrane action (qm). Considering all the three effects, bearing capacity equation for strip footing resting on geotextile reinforced sand layer overlying a soft clay subgrade has been developed. A comparison of experimental and predicted bearing capacities for reinforced sand over clay is presented. A study of effect of surcharge on the sides of the footing is also presented.

8 illus, 7 tables, 9 ref

017533   Ravi R;Taneja N (IAM, IAF, Bangalore) : Ergonomic evaluation of aviators' night vision imaging systm with head-up display (ANVIS-HUD). Indian J Aerospace Med 2008, 52(2), 54-9.

The ANVIS-HUD-24 system combines the standard Night Vision Goggle image with aircraft flight and engine parameters. The same information is also available during day by using a clear glass monocle. The system is meant to give the crew "head-out" capability by presenting important flight and engine parameters on NVG/ clear glass monocle. This precludes the need to look inside the cockpit and the system helps improve overall situational awareness of the pilot. Aeromedical evaluation of the ANVIS-HUD-24 system was carried out ergonomic aspects related to the system were evaluated; so also the human factors aspects related to the usage and operation of the system were assessed. A general assessment of the system was carried out with special reference to the operation of the adjustment knobs and the manner of attachments. Flight trials were carried out with the system and feedback on issues related to the operation of the ANVIS-HUD-24 system were obtained from the aircrew through a questionnaire which covered different aspects such as ease of use, fitment, fatigue, depth perception and disorientation potential. Ergonomic aspects related to the various components of the Day-HUD and Night-HUD systems are discussed. Human Factor issues in the usage and operation of ANVIS-HUD-24 system such as mounting and operation, eye relief, in-flight adjustment, cockpit compatibility, emergency egress, vision outside the cockpit, disorientation potential, discomfort, eye strain and HUD symbology characteristics were analysed. Recommendations for further objective testing for shift in the centre of gravity, decrement in visual acuity and optical characteristics of the system have been made.

6 illus, 6 ref

017532   Rathish Kumar P;Heeralal M;Rao Y V;Rakesh B (Civil Engineering Dep, National Institute of Technology, Warangal, Email: drrateesh@gmail.com) : Strength and performance aspects of recycled aggregate for use in rigid pavements. J Envir Res Dev 2009, 4(2), 449-64.

The utilization of recycled aggregate is now picking up with wide spread applications in many areas including rigid pavement applications. There are certain issues to be sorted out that are likely to hinder the utilization of recycled aggregate in rigid pavements. Two of the important aspects viz., type and level of crushing and influence of the old mortar adhering to the aggregate after crushing are taken up in this investigation. The strength and the performance aspects of machine and hand crushed aggregates and the influence of old mortar in recycled aggregate concrete is being brought out.

31 illus, 2 tables, 15 ref

017531   Rajgopal S;Sahu O P (E and CE Dep, NIT Kurukshetra, Kurukshetra) : Metrics to define probability of interception of conventional, frequency-hopping, spread spectrum radars. IETE J Res 2009, 55(6), 304-8.

Low probability of interception (LPI) is an important characteristic, especially for military radars. Manufacturers boast of the LPI performance of their radar but in the absence of a quantifiable metric, there is no method to compare the LPI characteristics of different radars. This paper proposes a novel method of defining metrics for the probability of interception (PI) of conventional, frequency hopping and Spread Spectrum radars. The PI of conventional radar depends on Azimuth beam width, pulse repetition frequency (PRF) and pulse width. The PI of frequency hopping radar is defined in terms of the bandwidth of transmission in each hop and the band of operation. The PI of spread spectrum radar is evaluated by comparing power spectral density (PSD) of the transmitted waveform with that of a random binary wave of similar time period.

3 illus, 1 table, 9 ref

017530   Rahman M M;Siddique A (Civil Engineering Dep, Dhaka Univ of Engineering and Technology, Gazipur, Bangladesh) : Tube sampling disturbances in normally consolidated and over-consolidated Dhaka clay. Indian Geotech J 2009, 39(2), 153-70.

The tube sampling disturbances and its solution on undrained shear characteristics of reconstituted normally consolidated and over consolidated samples of Dhaka clay were investigated. The values of undrained shear strength (s_u) and initial tangent modulus (E_i) were reduced while axial strain at peak deviator stress (ε_p) was increased because of disturbance caused by penetration of samplers. Disturbance also reduced initial effective stress (σ_i) and pore pressure (u) changes considerably. The changes in soil parameters between the "in situ" and "tube" samples depended markedly on the geometry of samplers used to retrieve "tube" samples. Values of s_u, E_i and σ'_i of samples were reduced while the values of ε_P was increased with increasing area ratio (or decreasing external diameter to thickness ratio) and increasing outside edge angle (OCA) of the samplers. For optimum and economic foundation design, the correction for undrained strength and stiffness parameters are proposed due to the soil sampling disturbance.

12 illus, 3 tables, 10 ref

017529   Pushpangadan R;Sukumaran V;Innocent R; Sasikumar D;Sundar V (ECE Dep, College of Engineering, Munnar, PB NO 45 County Hills, Idukki, Kerala) : High speed vedic multiplier for digital signal processors. IETE J Res 2009, 55(6), 282-6.

Digital signal processors (DSPs) are very important in various engineering disciplines. Fast multiplication is very important in DSPs for convolution, Fourier transforms etc. A fast method for multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among the various methods of multiplications in Vedic mathematics, Urdhva tiryakbhyam is discussed in detail. Urdhva tiryakbhyam is a general multiplication formula applicable to all cases of multiplication. This algorithm is applied to digital arithmetic and multiplier architecture is formulated. This is a highly modular design in which smaller blocks can be used to build higher blocks. The coding is done in VHDL (very high speed integrated circuits hardware description language) and synthesis is done using Xilinx ISE series. The combinational delay obtained after synthesis is compared with the performance of the modified Booth Wallace multiplier which is a fast multiplier. This Vedic multiplier can bring about great improvement in DSP performance.

4 illus, 2 tables, 6 ref

017528   Pullabatala S;Inavolu K R;Sivashanmugam P (Chemical Engineering Dep, National Institute of Technology, Tiruchirappalli-620 015, Email: psiva@nitt.edu) : Experimental studies on effect of cut in the baffle on power consumption. J Envir Res Dev 2009, 4(2), 545-8.

Experimental studies on effect of baffle cut on power consumption using standard Turbine agitator has been presented here. Modification was done by introducing V cut in the baffler. The power consumption for the agitated vessel fitted with standard plain baffle is higher than that of the cut baffle.

^ssc3 illus, 5 ref

017527   Prombutr N;Kirawanich P;Akkaraekthalin P (Electrical Engineering Dep, Mahidol Univ, Nakorn Pathom, 73170) : Bandwidth increasing technique using modified ground plane with diagonal edges. IETE J Res 2009, 55(5), 196-200.

Presents a bandwidth increasing technique using a modified ground plane with diagonal edges for the design of compact antennas. The proposed low-cost, compact-size circular patch antenna on 3 cm x 5.1 cm printed circuit board (FR-4) is designed and validated through simulations and experiments. Results show that with diagonal cuts at corners of the ground plane, the enhanced bandwidth can be tunable depending on the removed area. Return losses of minus 17 and minus 30 dBs for the first and second resonant frequencies, respectively, can be achieved when the depth of the diagonal cut is at optimum value of five mm, providing an 18.13% wider bandwidth (2.95-12.615 GHz) than the Federal Communication Commission (FCC) standard.

8 illus, 1 table, 6 ref

017526   Praveen Kumar P;Dodagoudar G R (Centre for Environmental Risk Assessment and Remediation, South Australia Univ, Mawson Lakes Campus, Mawson Lakes, South Australia, Email: Praveen.Rachakonda@unisa.edu.au) : Two-dimensional modeling of contaminant transport using meshfree method. Indian Geotech J 2009, 39(2), 171-87.

Presents an alternative numerical method to model two-dimensional contaminant transport through saturated porous media using a meshfree method called Element Free Galerkin Method (EFGM). In EFGM, an approximate solution is constructed entirely in terms of a set of nodes and no elements or characterisation of the interrelationship of the nodes is needed to construct the discrete equations. The two-dimensional advection-dispersion equation with sorption is considered to illustrate the applicability of the EFGM. The unknown concentration values are approximated by using moving least-square approximants, which are constructed by using a weight function, a linear basis function and a set of non-constant coefficients. The weak form of the governing equation is formulated and Lagrange multiplier method is used for enforcing the essential boundary conditions. MATLAB code has been developed to obtain the numerical solution. Three numerical examples are presented and the results are compared with those obtained from the analytical and finite element results and it is found that they match well.

10 illus, 3 tables, 31 ref

017525   Prasad M L V;P Rathish Kumar (Civil Engineering Dep, National Institute of Technology, Warangal, Andhra Pradesh, Email: prasadsmlv@gmail.com) : Mechanical properties of fiber reinforced conctes produced from building demolished waste. J Envir Res Dev 2007, 2(2), 180-7.

In virtually every field of industry, studies are being conducted to find ways and means to decrease burden on the environment as well as to make effective use of our limited natural resources. Preservation of the environment and conservation of the rapidly diminishing natural resources should be the essence of sustainable development. The enormous amounts of demolished concrete produced from deteriorated and obsolete structures create severe ecological and environmental problems. One of the ways to solve this problem is to use this Building Demolished Waste (BDW) concrete as aggregates. The brittleness of concrete can be overcome by spreading fibers discretely in concrete. In the present work, Fiber Reinforced Recycled Aggregate Concrete (FRRAC) was developed independently using two different types of fibers namely Glass Fiber and Polypropylene Fiber having individual applications. The mechanical properties were evaluated for a grade of concrete (M20), for different replacements of Recycled Concrete Aggregate (RCA) in Natural Aggregate (NA). It was observed that there was 15-17 % increase in split tensile strength and about 14 % improvement in flexural strength with addition of fibers in recycled aggregate concrete. The values obtained were also compared with the Indian Standard Codal Provisions. The increased energy absorption capacity in FRRAC indicates higher toughness and better post elastic deformations in the event of seismic actions.

5 illus, 5 tables, 14 ref

017524   Pise C P;Gidde M R;Bhalerao A R (Civil Engineering Dep, Sinhgad College of Engineering, Pune-411 041, Email: cppise_in@yahoo.co.in) : Blended coagulant alum and Moringa oleifera for turbidity removal. J Envir Res Dev 2009, 4(2), 517-27.

A study was carried out in the settling columns with no coagulant and with traditional coagulant Alum, natural coagulant Moringa oleifera, and blended Coagulant Alum and Moringa oleifera. The jar-tests were conducted to determine the optimum dosage of coagulants such as traditional coagulant Alum, Natural coagulant Moringa oleifera, and blended Coagulant Alum and Moringa oleifera to maximize the removal of turbidity from the turbid water. The optimum coagulant dosage showed that the coagulation with blended coagulant Alum and Moringa oleifera was better than Alum. A study was carried out in a specially designed two settling column of diameter 18.5 cm and 30 cm to investigate the settling characteristics of different initial turbidity samples such as 150 NTU (Low), 450 NTU (Medium), 1000 NTU (High). For the alum coagulant with initial turbidity 150 NTU, 450 NTU, 1000 NTU the optimum dosage was found to be 50 mg/ 1, 100 mg/ 1, 200 mg/l, respectively. The Optimum dosage for Moringa oleifera coagulant was found to be 125 mg/ 1, 200 mg/l, 350 mg/l, respectively. Also for Blended coagulant Alum and Moringa oleifera the optimum dosage was found to be Alum-12.5 mg/l and M.6- 75 mg/ 1, Alum-37.5 mg/l and M.O- 150 mg/ 1, Alum- 75 mg/ 1 and M.O- 200 mg/ 1, respectively. In this blending process we reduce the Alum dose up to 75 % for 150 NTU initial Turbidity samples and for 450 NTU, 1000 NTU the Alum dose is reduced up to 62.5 %. So we can reduce the drawbacks of the Alum Coagulant.

11 illus, 3 tables, 17 ref

017523   Paul S;Dey A K (Civil Engineering Dep, National Institute of Technology, Silchar-788 010, Email: sanjaypaul_76@yahoo.com) : Experimental study of horizontal vibration of footing on dry cohesionless soil. Indian Geotech J 2009, 39(4), 436-52.

The seismic effect on shallow foundations are usually analysed by the pseudo-static approach in which the effects of earthquake forces are accounted by constant horizontal and vertical accelerations attached to the inertia. In the present analysis the horizontal acceleration coefficients of soil mass (k_hs), footing (k_hf) and tank (K_hi) under dynamic loadings are correlated. Horizontal and vertical displacements of footings were also measured after each horizontal vibration test. It is observed that the horizontal acceleration coefficients and footing displacements depend upon several parameters like, type of footing, void ratio of soil deposit, embedment ratio of the footing, etc. It is also observed that both horizontal and vertical vibration of footings depend upon the parameters like, type of footing, void ratio of soil deposit, embedment ratio of the footing.

14 illus, 4 tables, 9 ref

017522   Paul B S;Hasan A;Madheshiya H;Bhattacharjee R (Electronics and Communication Engineering Dep, Indian Institute of Technology, Guwahati, Assam) : Time and angle of arrival statistics of mobile-to-mobile communication channel employing circular scattering model. IETE J Res 2009, 55(6), 275-81.

Mobile-to-mobile communication becomes necessary in many emerging wireless communication systems. Characteristics of mobile-to-mobile communication channel have been studied through a geometrical single bounce scattering model and analytical expressions for angle of arrival and time of arrival probability density functions have been derived for such models. Analytical expressions have been verified through computer simulations. This paper aims to provide a better understanding of mobile-to-mobile channel behavior in terms of the parameters studied.

9 illus, 11 ref

017521   Patil S A;Udupi V R (NO, Textile & Engineering Institute, Ichalkaranji-416 115, Email: shrinivasapatil@gmail.com) : Chest X-ray features extraction for lung cancer classification. J scient ind Res 2010, 69(4), 271-7.

Study presents a computer algorithm, which consists of four main steps (image acquisition, image pre-processing, nodule candidate detection, and feature extraction) for nodule detection in chest radiographs. Algorithm is applied on small-cell type of lung cancer (SCLC) and non-small-cell type of lung cancer (NSCLC) images. Total 50 images (25 from each category) were used to estimate geometrical and texture features. Active shape model (ASM) was used for lung field segmentation. Gray level co-occurrence matrix (GLCM) was used to estimate texture features.

7 illus, 6 tables, 32 ref

017520   Pathak K K;Lomash S;Jha A K (NO, Advanced Materials and Processes Research Institute (CSIR), Bhopal-462 026, Email: kkpathak1@rediffmail.com) : Process and die design for square tube extrusion. Indian J Engng Mater Sci 2009, 16(1), 51-5.

In this study, die profile oflhe square tube extrusion process is optimized to produce microstructuarliy sound product at maximum production speed and minimum left out material in the die. The design problem is formulated as a nonlinear programming model, which is solved using genetic algorithms (GA). Selection of the processing parameters is carried out using dynamic material modeling (DMM). Using this approach a square tube extrusion process is successfully designed.

10 illus, 1 table, 21 ref

017519   Pathak K K;Dwivedi K K;Shukla M;Ramadasan E (Advanced Materials and Processes Research Institute, (CSIR), Bhopal-462 064, Email: kkpathak1@rediffmail.com) : Influence of key test parameters on SPT results. Indian J Engng Mater Sci 2009, 16(6), 385-9.

In order to assess the strength of aged material during the service life, small punch test (SPT) has emerged as a powerful NDT tool of engineers. It is a promising technique for those circumstances where only a small amount of material is available for characterization. SPT involves use of small size samples tested by bending or shearing to fracture in a specially designed die and punch assembly. As the sample and tooling sizes go down, the sensitivity of test parameters on the SPT output becomes an important issue. In order to get realistic material properties, sensitivity of test parameters should be studied. The parameters found to be critical can be given due attention. In this study, influence of several key parameters like fillet radius, ball diameter, sample thickness, yield stress and friction are studied using finite element simulations and their effects are critically examined. The analyses indicate that yield stress is less sensitive parameter as it does not affect peak load and corresponding displacement but fillet radius, ball diameter, plate thickness and friction considerably affect the value of peak load and corresponding displacement. So, these parameters must be precisely and carefully measured during small punch tests. Based on these findings, experimental load stroke data, obtained due to faulty test parameters, may be corrected rather than going for a new test with correct parameters.

11 illus, 12 ref

017518   Pathak K K;Arya R;Hora M S (CSD Group, AMPRI, CSIR, Bhopal-462 026, Email: kkpathak1@rediffmail.com) : Generation of profile maps for preform design in upsetting process. Int J theor appl mech 2008, 3(2-3), 123-32.

Design of the optimum preform for near net shape manufacturing is a crucial step in many manufacturing process design. In this study, the same is arrived at using profile maps which are generated using the results of FE simulations of 81 cases of varying geometrical, material and processinging parameters. These maps are further verified using two new problems. It is shown that profile maps are very powerful tool for preform design.

10 illus, 18 ref