017269   Bhajantri M R;Eldho T I;Deolalikar P B (Civil Engineering Dep, Indian Institute of Technology Bombay, Mumbai-400 076) : Two-dimensional free surface flow over a spillway - a numerical model. ISH J Hydraul Engng 2006, 12(2), 7-24.

Spillway is a hydraulic structure that is usually provided at storage and diversion dams to release surplus or flood water that cannot be safely stored in the reservoir in order to prevent damage to the dam. Spillway flows are essentially rapidly varied flows near crest with pronounced curvature of the streamlines in vertical direction. Because of the changes of flow boundaries in a short distance, vertical acceleration plays a dominant role in the flow as compared to shear resistance at the solid boundary. The main difficulties while solving the spillway problem numerically are: rapidly varied flow, existence of both subcritical and supercritical flows, development of turbulent boundary layer, unknown free surface and air entrainment. Numerical simulation of rapidly varied, supercritical, free surface turbulent flow over spillway with all flow characteristics is a challenging task. Describes the formulation and development of a numerical model for flow over a spillway. The computer model is developed using the Finite Volume Method based on Euler form of weakly compressible flow equations. The model is applied to a case study to investigate the hydraulic characteristics of flow over spillway crest profile by simulating the velocity distribution, pressure distribution and discharge characteristics. The numerical model results are compared with the physical model results and found to be satisfactory.

8 illus, 11 ref

017268   Benal M M;Shivanand H K;Govindaraju N; Divyasree (Mechanical Engng Dep, Veisvesvaraya Inst of Technol, Bangalore-562 157) : Effect of thermal ageing on the wear behaviour of Al 6061 based hybrid composites. J Instn Engrs-Pt MM 2007, 88(Apr), 14-8.

Examines the abrasive wear rate of as-cast and heat-treated 6061 Al alloy reinforced with 5% by weight of SiC particulate and 1%, 3% and 5% by weight of E-glass fibre subjected to different ageing durations. The liquid melt technique route was used to produce the castings, which were then machined to ASTM standards and subsequently hea t-treated . All the specimens were artificially aged for different duration {namely, 1 h, 3 h, 5 h and 7 h ) at 175°C. Wear tests were performed on the composites in the both heat-treated and as-cast conditions using pin-on disc machine. The aged composites revealed the presence of the solute clusters (OP zones) and small coherent precipitates in the aluminium alloy matrices and mobl1e dislocations easily shear these. The wear rates of the hybrid composites were found to decrease with increase in ageing durations. However, in both as-cast and heat-treated hybrid composites, the wea rate increased with increase in the sliding distance. Solution heat treatment at 530°C followed by artificial ageing at 175°C was found to improve the wear resistance of every specimen tested. It is concluded that heat-treated hybrid composites are very effective in improving the wear resistance.

2 illus, 2 tables, 26 ref

017267   Achintya;Prasad M M (Civil Engng Dep, Muzaffarpur Inst of Technol, Muzaffarpur-842 003) : Behaviour of concrete in controlled humidity and temperature of marine environment. J Struct Engng 2006, 33(4), 349-54.

13 illus, 1 table, 9 ref

016373   Upadhye A (NO, Institute of Aramament Technology, Mumbai) : Role of ancillary industry in development of marine grade control and monitoring (C&M) systems. J Instn Engrs-Pt MA 2006, 87(Jul), 17-9.

C & M equipment manufacturers normally have all the pre-requisites except support from ancillary. There is an acute shortfall in ancillary support as far as marine grade C&M equipment are concerned. This shortfall no way implies a shortcoming on the part of instrumentation ancillary. The instrumentation industry has made deep forays in the area of industrial applications. The programmable logic controllers, microcontroller based embedded systems or PC based centralized monitoring systems have large scale applications in Indian industry and are being developed comfortably within India. However, marine grade C&M systems of non-proprietary nature continue to be distant reality.

8 ref

016372   Umarikar A C;Mishra T;Umanand L (Centre for Electronic Design and Technology, Indian Institute of Science, Bangalore-560 012, Email: lums@cedt.iisc.ernet.in) : Bond graph simulation and symbolic extraction toolbox in MATLAB/SIMULINK. J Indian Inst Sci 2006, 86(1), 45-8.

Bond graph toolbox, developed in the MATLAB/SIMULINK environment, has two-fold functions: First to simulate the system using bond graph and second to extract the dynamical system equations in symbolic form. This development is an amalgamation of simulation power of the MATLAB/SIMULINK and modelling power of the bond graph. The toolbox is divided into two parts. One deals with the numerical simulation of the bond graph model and the other handles extraction of dynamic equation in symbolic form. The process of toolbox development is discussed in detail, which is supplemented by an adequate number of examples that demonstrates its power.

20 illus, 25 ref

016371   Tungikar V B;Khadse P W (Engineering Dep, SGGS Institute of Engineering and Technology, Nanded) : Use of Zig-zag theory in finite element formulation for analysis of composite plates. J Instn Engrs-Pt AS 2006, 87(May), 24-8.

Deals with the application of a first-order zig-zag theory that accounts for realistic variation of in-plane displacements through thickness in a thick multi-layered composite plate for dynamic response analysis. The solutions of dynamic equations are obtained by employing the finite element procedure, based on a C° continuous, four-node isoparametric element with seven degrees of freedom at each node. A zig-zag shaped C° function is used for modelling the in-plane displacements through the thickness of the laminates. The comparison of in-plane response with exact solutions for symmetric cross ply laminate demonstrates that the present theory predicts the in-plane response very accurately, even for small span to depth ratios. The effects of aspect ratio, numbers of layers, and lamination scheme on the dynamic response of composite laminate are investigated.

5 illus, 2 tables, 14 ref

016370   Torre M D L;Rush C;Mulas V;Bernstein J;Dean C (Telecommunications Management Group Inc, , 1600 wilson Blvd, Suite 710, Arlington, Virginia-22209, Email: tmgetelecom.com) : Updating regulatory frameworks in an era of convergence. IETE Tech Rev 2006, 23(4), 231-8.

New and emerging wireless technologies have the potential to greatly increase the efficiency with which radio frequencies are used to support spectrum-dependent wireless systems. A number of such technologies are discussed in this paper, including the impact they are likely to have on the evolution of regulatory frameworks. In a convergent environment, the evolution of technology impacts every aspect of regulatory frameworks, including interconnection, numbering, universal service and spectrum management. In thisarticle, the authors argue that service and technology neutrality along with flexible regulations are key elements in being able to capitalize on the advantages that may ensue from the technology advances in today's telecommunications environment.

23 ref

016369   Thiagarajan V;Panneerselvam S (Defece Research and Development Laboratory, , Hyderabad-500 008) : Aerodynamic design and analysis of intake for hypersonic air-breathing vehicle using CFD approach. J Instn Engrs-Pt AS 2006, 87(Nov), 12-8.

Mixed compression air-intake has initially been designed using two-dimensional oblique shock method and subsequently refined by analysis using computational fluid dynamic software PARAS 3D. The design is aimed to get the required intake exit condition, which is compatible with scramjet combustor of a hypersonic flying vehicle at Mach 6.5. Effects of forebody side fence on the intake characteristics have been analyzed. The pressure distribution on body and cowl evaluated using 2D oblique shock method is compared with the computed results. Intake geometry has been appropriately modified based on the NS computations. Intake performance parameters, such as, total pressure recovery, mass flow captures, axial force coefficient and entry and exit conditions at design and off-design angle of attack conditions have also been analyzed on the selected configuration. Effect of sideslip angle on the intake performance is found quite significant both at design and off-design angle of attack conditions.

11 illus, 5 ref

016368   Suresh Kumar S;Ganesan V (Internal Combustion Engines Lab, Mechanical Engineering Dep, Indian Institute of Technology, Chennai-600 036) : Mean flow field measurements in an axisymmetric afterburner model with V-gutter flame stabiliser. J Instn Engrs-Pt MC 2006, 87(Oct), 34-41.

Presents the details on the experimental procedure and measurements made in a three-dimensional confined flow fields behind a V-shaped complex flame stabiliser in an isothermal model of an afterburner. The flame stabiliser consists of a central ring gutter with top and bottom radial gutters concentrically placed on the periphery within a cylindrical pipe. A 5 mm five hole pitot sphere of cobra type has been used along with electronic digital manometers for the measurements. The negative velocity regions are well captured with the five-hole probe near to the gutter. Five-hole pitot probe measurements along the entire length of the model in three different azimuthal planes, allow the determination of three mean velocity components which provide a comprehensive information to aid and understand such complex flows. Measurements were repeated several times to ascertain the accuracy since the main aim is to enable the researchers in the computational fluid dynamics (CFD) field to use these data for their predictions.

10 illus, 8 ref

016367   Singh J ;Singh N;Sharma J K (Mechanical and Production Engineering Dep, Beant College of Engineering and Technology, Gurdaspur-143 521) : Fuzzy modelling of vapour compression cycles for advanced controls in HVAC systems. J Instn Engrs-Pt MC 2006, 87(Oct), 52-8.

Presents fuzzy modelling of multi-input single output (MISO) control of vapour compression refrigeration cycles. The fuzzy model is for two input parameter, mass flow rate, and evaporating temperature, and one output parameter, superheat at the suction of compressor. Adaptive neuro-fuzzy inference system (ANFIS) and sugeno fuzzy inference system were used to develop this model in the MATLAB environment. The effect of input parameters on superheat through the fuzzy model developed was studied. Comparison of fuzzy and mathematical modelling was carried which showed that the MISO control could significantly improve the performance and energy efficiency of vapour compression refrigeration cycle.

5 illus, 10 ref

016366   Singh A (Botany Dep, Banaras Hindu Univ, Varanasi-221 005, Email: arvindsingh_bhu@yahoo.com) : Herbaceous species composition of an age series of naturally revegetated coal mine spoils on Singrauli Coalfields, India. J Indian Inst Sci 2006, 86(1), 75-9.

Herbaceous species composition of 2-, 5- and 10-year-old age series of coal mine spoils was studied at Singrauli coalfields, India. The number of species increased with increasing age of the spoil. Two- and five-year old spoils were dominated by species belonging to the families Poaceae and Fabaceae, while the 10-year-old spoil was dominated by species belonging to the families Poaceae and Asteraceae.

^ssc2 tables, 11 ref

016365   Shukla S N;Joshi S G (Corporate Research & Engineering Div, Kirloskar Brothers Limited, Pune-411 002) : Numerical simulation of flow through a horizontal split-case pump. Indian Pumps 2006, 38(3), 5-9.

Horizontal split-casing pump with double-suction impeller has a common incoming suction and common outgoing delivery. The geometry is complex for flow investigation. It is difficult to estimate losses in suction and delivery passages at the design stage by conventional methods. The paper describes use of computational to6ls to resolve these issues. A split-case pump of medium size was analysed using Navier-Stokes Solver for incompressible flow. The geometry consisting of stationary suction passage and delivery casing was analysed together with rotating double-suction impeller. The results are presented in the form of vector plots and streak lines to visualise the quality of flow. Quantitative results are presented in the form of total pressure generated by impeller, losses in suction passages, delivery casing and that in rotating impeller. The total magnitude of losses is used to estimate efficiency of the pump and is compared with experimental results.

7 illus, 1 table

016364   Sharma R (Huawei Telecommunication India, , DLF Square, DLF Phase-II, Gurgaon-221 002) : IP multimedia subsystem (IMS). IETE Tech Rev 2006, 23(4), 241-5.

1 illus

016363   Seshadri H S;Roy Chowdary P (QAE (WE), , Bangalore) : Indigenization of warship equipment and spares - a naval field establishment's perspective. J Instn Engrs-Pt MA 2006, 87(Jul), 12-6.

Indigenization of warship equipment and spares is a complex activity and has been high on the agenda of the Indian Navy in its path to self-reliance. The indigenization program of the Indian Navy spans over four decades and numerous agencies have been involved in the task of Indigenization since then. Indigenization of major equipments for the successful Leander Project has been the hallmark of the Indigenization brogram of the Indian Navy and has benefited the subsequent programs. Indian Navy has embarked on an ambitious shipbuilding program, which includes state-of-art submarines and ships-to meet its requirement in the 21st century. The technology being adopted is contemporary and mill be required to be service for more than three decades after their induction. Though the Shipbuilding is indigenous, a large number of equipments used on hoard continue to be sourced from foreign countries leading to dependency on these countries for sourcing the spares for supporting such equipment during the life of the Ship. It is therefore essential that such equipments are indigenously manufactured and used on board new construction Ships and submarines prior to their commissioning. India has a large manufacturing base and boasts of Indian companies with multinational stature. These companies have the requisite technology and are exporting a large number of complex equipments to developed countries including their armed forces. It would therefore be prudent to utilize the infrastructure available with such companies for manufacturing Indigenous equipment meeting the exacting standards of the Indian Navy. Further there is an urgent need to take up the indigenization of warship equipment and spares of ships and submarines in commission on a war footing to ensure their operational availability. A self-reliant Indian Navy would be of strategic importance. The disintegration of the erstwhile Soviet Union has given further impetus to the indigenization activity of the Indian Navy. The Indian Industries both in the private and public sector have proved to be useful partners in these programs. The paper attempts to highlight the constructive role that can be played by the Indian Industries both in the public and private sector and suggest measures for these Industries to partner the Indian Navy in its effort of Indigenization. Also highlights the benefits to the firms as a spin off from undertaking such indigenization projects and also states the various difficulties they may encounter whilst indigenizing.

2 tables

016362   Ray S K (Computer Sci & Engng Dep, Heritage Inst of Technol, Kolkata-700 107, Email: raysk@rediffmail.com) : Fourth generation (4G) networks: roadmap-migration to the future. IETE Tech Rev 2006, 23(4), 253-65.

Mobile communication generations has traversed a long way through different phases evolution since its birth early in the 1970s. The steady global boom in the number of mobile users each year has periodically spurned the development of more and more sophisticated technologies trying to strike the right chord primarily in terms of provision of seamless global roaming, quality services and high data rate. Today numerous different generation technologies with their individual pros and cons are existing globally. The coming era of 4G systems is foreseeing a potential smooth merger of all these heterogeneous technologies with a natural progression to support seamless cost-effective high data rate global roaming, efficient personalized services, typical user-centric integrated service model, high QoS and overall stable system performance. However, every step in such technological advancements presents huge research challenges. This article aims to focus upon some of these potential challenges along with different proposed feasible and non-feasible solutions in the areas of mobile terminals and users, mobile services, mobile and wireless access networks, and communication, in order to give an in depth view of the next-generation communication systems.

5 illus, 2 tables, 29 ref

016361   Ray M;Dey T;Bandyopadhyay N R (School of Materials Science and Engineering, Bengal Engineering and Science Univ, Shibpur, Howrah-711 103) : Oxide ion conmducting Electrolyte materials for solid oxide fuel cell applications. J Instn Engrs-Pt MM 2006, 87(Oct), 13-22.

Solid oxide fuel cell (SOFC), based upon a solid ceramic electrolyte has drawn formidable attention as a candidate for the generation of almost zero emission, silent and efficient alternative source of energy. Though it holds tremendous promise, large-scale commercial applications are yet to see the light of the day. A high operating temperature requirement imposes severe restrictions on the choice 6f materials and is one of the prime factors for enhanced cost of SOFCs. Compares the relative performance of some oxide ion conducting electrolytes based on their temperature dependent conducting and thermomechanical properties. Development of materials to meet the challenges of coupling high ionic conductivity, low electronic conductivity, chemical and structural stability, achieving almost zero porosity and compatibility with other cell components can definitely drive SOFC to play a leading role in the future of hydrogen economy.

12 illus, 83 ref

016360   Ravi Kumar N;Rama Krishna K (NO, Gudlavalleru Engineering College, Gudlavalleru-521 356) : Thermodynamic analysis of alternative regenerator gas turbine configuration based on exergy. J Instn Engrs-Pt MC 2006, 87(Oct), 47-51.

Paper deals with the thermodynamic analysis of a gas turbine power plant with an alternative configuration of regenerator. Compared to the conventional regenerative cycle the position of regenerator is kept immediately after the high pressure turbine. It results in preheating the compressor discharge air to a high temperature and also significantly lowers the low pressure turbine discharge temperature. The entry of air at a higher temperature into combustion chamber improves the system efficiency due to increase in mean temperature of heat addition. Further, the exergy analysis shows energy loss due to irreversibility in combustion chamber and in the exhaust gases are reduced considerably. With the help of model calculations and graphs the advantages of alternative configuration over a conventional regeneration plant and simple plant are brought out. It is established through graphs that peak efficiencies of alternative regeneration configuration occur at a lower optimum pressure ratio than that of a simple one even from exergy point.

6 illus, 8 ref

016359   Rao M A;Srinivas J;Satyanarayana M R S (Mechanical Engineering Dep, GITAM, Visakhapatnam-530 045) : Trajectory tracking control of flexible manipulators using inverse dynamic analysis. J Instn Engrs-Pt MC 2006, 87(Oct), 42-6.

Presents a methodology for trajectory control of flexible serial manipulators using non-linear inverse dynamic controller. Links of the manipulator system are modelled as flexible frame elements and the inverse dynamic controller supplies the joint torques. The bending deformation at each joint is obtained from modal analysis. The successive cycles of operation, the tracking errors and its derivatives are supplied to the controller. The process of control is repeated between the points on the trajectory until the error becomes a minimum. The approach is illustrated with a two- link planar manipulator.

6 illus, 2 tables, 8 ref

016358   Ramachandran H;Giridhar K;Jhunjhunwala A; Subramanian M (Electrical Engng Dep, Indian Inst of Technol, Madras-600 036) : Convergence and India - The tenet group perspective. IETE Tech Rev 2006, 23(4), 221-30.

Telecommunications in India has evolved greatly in the last two decades, and the number of lines has grown to over 100 million. However, these lines are disproportionate in the urban areas and are mainly low bandwidth wireless access links. Thus there is double challenge we are facing, namely how to take the Telecom revolution to the rural issue and how the TeNeT group at IIT Madras is trying to tackle some of the problems.

4 illus, 28 ref

016357   Rajvanshi A K (Mechanical Engineering Dep, Malaviya National Institute of Technology, Jaipur-302 017) : Bubble frequency measurement by probe method. J Instn Engrs-Pt MC 2006, 87(Oct), 10-2.

New method of measurement of bubble frequency is devised in nucleate pool boiling. An electrical resistance probe is used for the measurement of bubble frequency which utilises the principle of difference of electrical resistance between liquid and vapour phases due to which voltage drops are seen on the oscilloscope screen. The bubble frequecny is calculated by counting the number of voltage drops in a fixed time interval.

4 illus, 6 ref

016356   Neelamani S;Sumalatha B V (Coastal & Air Pollution Dep, Environment & Urban Development Div, Kuwait Institute for Scientific Research, P.O. Box 24885, 13109, Safat, Kuwait, Email: nsubram@kisr.edu.kw) : Wave reflection, run-up, run-down and pressures on seawalls defended by an offshore breakwater. J Indian Inst Sci 2006, 86(1), 15-31.

Hydrodynamic performance in terms of wave reflection, run-up and run-down and wave pressures on plane seawalls protected by an offshore breakwater has been studied in a random wave field. Plane seawalls with different slopes (i.e. θ = 90°, 60° and 30°) and for different water depths relative to the height of the offshore breakwater covering both the submergence and emergence of the offshore breakwater are used. The hydrodynamic performance of a plane seawall without an offshore breakwater is compared with one protected. For 2% probability of exceedence, the run-up on the seawall can be reduced by about 50-60%, when there is a detached breakwater with a crest level at the still water level. For the same condition, the wave pressure on the seabed near the seawall can be reduced by about 35-40%. With a detached breakwater of 20% emergence in air, the wave pressure on the seawall can be reduced by about 80-85% when compared to the wave pressures without any protection. The study reveals that when the crest of the breakwater is submerged by about 14% of the water depth, the configuration induces a water jetting effect over the detached breakwater and causes higher wave kinematics in front of the seawall and hence such conditions are recommended to be avoided in the field.

16 illus, 2 tables, 23 ref

016355   Murthy V R;Kulkarni S B (Applied Mathematics Dep, Finolex Academy of Management and Technology, Ratnagiri-415 639) : Effect of load and eccentricity parameters on the performance index of porous bearings. J Instn Engrs-Pt MC 2006, 87(Oct), 13-7.

Detailed mathematical analysis of various parameters and their effects on porous bearings on the lubrication characteristics is presented. The Reynolds equation for the case of moderate rotation under the assumptions of short bearings approximation is considered. Rayleigh-Ritz method is adopted in obtaining the solution. Variations in low capacity coefficient of friction, effect of eccentricity ratio have been studied. It is observed that the effect of eccentricity ratio is more pronounced in the anisotropic case compared to the classical case.

5 illus, 7 ref

016354   Mehta R K;Datta K;Goswami S K (Electrical Engineering Dep, Jadavpur Univ, Kolkata-700 032) : On incomplete state feedback design of missile autopilot in pitch plane. J Instn Engrs-Pt AS 2006, 87(May), 17-23.

Pole-placement method for designing a linear missile autopilot system for a class of tail-controlled cruciform missiles is presented in this article. A procedure for the choice of proper closed-loop pole locations has been proposed which assures desired transient performance. Developed pole-placement formulae are simple and can provide fast and stable acceleration in pitch plane. A forward path gain is introduced to ensure accurate tracking without any steady-state error for a step input. Also, some control over the missile body-rate, peak fin deflection and fin-rate can be achieved for specified stability margins. An incomplete state feedback controller has been designed to eliminate the need for an observer system. The design enables to achieve desired stability margins with different speed of responses and the capabilities of hardware resources might be utilised by a judicious choice of autopilot speed of response (GCF). A numerical example illustrates the effectiveness of the developed methodology.

7 illus, 3 tables, 18 ref

016353   Lande S B;Goel N (Kavikulguru Inst of Technol and Sci, , Ramtek-441 106, Email: landeeed@yahoo.co.in) : Road to multi-carrier CDMA. IETE Tech Rev 2006, 23(4), 247-52.

Paper presents an overview of the evolution of a new multiple access technique called the Multicarrier Code Division Multiple Access (MC-CDMA). Discussed basic techniques of Frequency division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) and explain the two schemes Orthogonal Frequency Division Multiplexing, (OFDM) and Dirtct Sequence CDMA (DS-CDMA), the merger of which has led to MC-CDM. Comparison is presented between the three proposed MC-CDMA techniques and their predecessor DS-CDMA and the superiority of MC-CDMA is exhibited through the simulation graphs of Bit Error Rate (BER) Vs Signal to Noise Ratio (SNR) for MCCDMA and, 1DS-CDM when serving multiple users.

9 illus, 6 ref

016352   Kumar R;Singh N (Aerospace Engineering Dep, Indian Institute of Technology, Kharagpur-721 302) : Three-dimensional unsteady transonic flow calculations using TSP formulation incorporating entropy and vorticity effects. J Instn Engrs-Pt AS 2006, 87(Nov), 26-31.

Modifications to unsteady transonic small perturbations (TSP) theory to include entropy and vorticity effects has been presented. The modifications have been implemented in the TSP code. Entropy and vorticity effects have been incorporated within the solution procedure to analyze flows with strong shock waves more accurately. The modified code includes these effects while retaining the relative simplicity and cost-efficiency of the TSP formulation. This paper presents detailed descriptions of the entropy and vorticity modifications along with calculated results and comparisons that assess the modified theory. The results are in good agreement with parallel Euler calculations and with experimental data. Therefore, the present method now provides the aeroelastician with an affordable capability to analyze relatively difficult transonic flows without having to solve the computationally more expensive Euler equations.

6 illus, 13 ref

016351   Kumar M L N D;Ramji K;Balasubrahmanyam V V (Mechanical Engineering Dep, College of Engineering, Andhra University, Visakhapatnam-530 003) : Analysis of strip rolling using FEM and numerical integration techniques. J Instn Engrs-Pt MC 2006, 87(Oct), 3-9.

Strip rolling of isotropic material is analysed under plane strain conditions using finite element analysis technique (FEM) for elasto-plastic case. The objective of the study is to predict the roll force and roll torque necessary for the deformation of workpiece. Incremental approach is adopted for obtaining required elasto-plastic stress-strain matrix. Similar analysis has been carried out by means of numerical integration (NI) method considering the pressure before and after neutral point. Simpson's one-third rule is applied to these values and roll force and roll torque values are computed. Both FEM and NI techniques are capable of predicting roll force and roll torque values with sufficient accuracy. Two empirical equations are suggested for estimation of roll force and torque.

8 illus, 12 ref

016350   Kumar L R;Datta P K;Prabhakara D L (Aerospace Engineering Dep, Indian Institute of Technology, Kharagpur-721 302) : Effect of aspect ratio and boundary conditions on tension buckling behaviour of curved panels subjected to non-uniform in-plane edge loading. J Instn Engrs-Pt AS 2006, 87(May), 12-6.

Tension buckling and vibration behaviour of curved panels with different aspect ratios and boundary conditions of rectangular planform subjected to non-uniform in-plane tensile edge loadings have been studied using the finite element method. In many applications of aerospace, mechanical, civil, naval, etc structures which are made of thin sheets, are often subjected to non-uniform in-plane stresses caused by concentrated or partial loading at the edges. The nature of these stresses also called membrane stresses, has marked effects on the buckling load and vibration characteristics of panels. Panels can also buckle when subjected to forces that are only tensile. If a thin sheet is subjected to eccentric tensile loading on the opposite edges, one observes the sheet wrinkling at some places away from the application of the load. Such wrinkling (that is, buckling) can occur whenever the solution to the plane elasticity problem yields internal stresses that are compressive in nature. Induced wrinkling may be important in certain practical applications, such as, stressed panels in aircraft structures. In the analysis, the first order shear deformation theory is used to model the doubly curved panels, considering the effects of transverse shear deformation and rotary inertia. The theory used is extended from the dynamic, shear deformable theory based on the Sanders' first approximation for doubly curved shells, which can be reduced to Love's and Donnell's theories by means of tracers. The in-plane non-uniform stress field has been analysed under plane-stress conditions with reasonable accuracy. The effects of aspect ratio, boundary conditions and different non-uniform loading conditions show significant influence on stability behaviour of the curved panels under tensile edge loading. The results have been discussed in this article.

6 illus, 9 ref

016349   Kumar A;Chandel P S;Kumar P (Mechanical Engineering Dep, Indian Institute of Technology, Kanpur-208 016) : Experimental study on thin sandwich panel. J Instn Engrs-Pt MC 2006, 87(Oct), 22-6.

Flexural properties and the failure mode of the thin composite sandwich-panel under four-point bend test are investigated experimentally by using theory of bending of beam and the results are compared to the monocoque structure and the mild steel sheet. The sandwich -panels are made by using short-fibre FRP face sheets and coremat having through holes along the thickness. For a comparable flexural rigidity of the sandwich-panel and the mild steel sheet, the area density is about 45% and the load bearing capability (critical load) is about 2.5 times for sandwich -panel as compared to mild steel sheet. Thus, the thin sandwich -panels have a good potential to replace the thin sheet-metals of steel.

9 illus, 2 tables, 10 ref

016348   Kshirsagar J T;Joshi S G (Corporate Research and Engineering Div, (CRED), Kirloskar Brothers Limited, Pune) : Investigation of air entrainment - a numerical approach. Indian Pumps 2006, 38(3), 15-20.

Air entrainment in sumps (Pump Intake) is a commonly observed phenomenon at low water level and high Froude number, corresponding to flow rates higher than the rated flow. The air entrainment initiates with the formation of small vortex-like structure on the surface with its position varying in the vicinity of pump intake portion. Normally, it calls for two-phase flow analysis (and possibly transient also) to correctly predict the air entrainment phenomenon, using computational fluid dynamics approach. Predicts the root cause for air entrainment by studying the vortex formation well within the flow. A single-phase steady-state flow was analysed. Two test cases were studied. IOWA University had published a sump case with results from computational fluid-dynamics studies. The other case was the actual sump model study carried out using an experimental set-up, wherein air entrainment was observed. The paper presents the comparison of the predictions with results from these two test cases.

14 illus, 4 ref

016347   Khan S A;Rathakrishnan E (Mechanical Engineering Dep, PA Engng Coll, Mangalore) : Active control of base pressure in supersonic regime. J Instn Engrs-Pt AS 2006, 87(Nov), 3-11.

Presents an experimental investigation to study the effectiveness of micro jets to control base pressure in suddenly expanded axi-symmetric ducts. Four micro jets of 1 mm orifice dia located at 90° intervals along a pitch circle dia of 1.3 times the nozzle exit dia in the base region are employed as active controls. The Mach numbers at the entry to the suddenly expanded duct studied in the present study are 1.25,1.30,1.48,1.60,1.80,2.00,2.50 and 3.00. The jets are expanded suddenly into an axi-symmetric tube with cross-sectional area 3.24 times that of nozzle exit area. The L/D ratio of the sudden expansion tube is varied from 10 to 1. As high as 40% increase in base pressure is achieved. It is found that the microjets can serve as active controllers for base pressure. Also, the microjets do not adversely influence the wall pressure distribution.

6 illus, 8 ref

016346   Khan M A;Kamil M;Alam S S (Post Harvest Engineering and Technology Dep, Aligarh Muslim University, Aligarh-202 002) : Performance of an inclined tube of open thermosiphon-an experimental study. J Instn Engrs-Pt MC 2006, 87(Oct), 27-33.

Rate of thermally induced flow and heat transfer in an inclined tube of open thermosiphon has been experimentally obtained under uniform heat flux conditions. The test section was a copper tube of 0.022 m internal diameter uniformly heated over a length of 2.13 m. Effects of heat flux and tube inclinations on heat transfer coefficient of water along the test section, were studied to evaluate the performance of an open-loop, inclined tube thermosiphon experimentally. The data have been presented graphically and discussed. Correlations for predicting the average heat transfer coefficient and mass flow rate are proposed.

9 illus, 14 ref

016345   Kaushik H B;Rai D C;Jain S K (Civil Engineering Dep, Indian Institute of Technology Kanpur, Kanpur-208 016, Email: dcrai@iitk.ac.in) : A cause for use of dynamic analysis in designing for earthquake forces. Curr Sci 2006, 91(7), 874-7.

^ssc3 illus, 1 table, 5 ref

016344   Kasthurirengan S;Jacob S;Karunnanithi R; Behera U;Nadig D S;Bahuguni A N (Centre for Cryogenic Technology, Indian Institute of Science, Bangalore-560 012, Email: ccf.iisc.ernet.in) : Development of a helium compressor from a reciprocating type refrigeration compressor. J Indian Inst Sci 2006, 86(1), 69-73.

Helium gas compressor is one of the critical components of a pulse-tube or Gifford-McMahon (GM) cryocooler. It serves as the gas source for generating the pressure waveform (with high and low pressures) in a pulse-tube/GM-type cryocooler. Commercial helium compressors of capacities less than 10 kW of input power are mostly of scroll type. A simple method is described for converting a reciprocating-type refrigeration compressor into a helium compressor. The performance of this system has been evaluated using a single-stage pulse-tube cryocooler. The compressor has already clocked more than 1000 h of operation. The method can be used to convert the reciprocating-type refrigeration compressor to other monoatomic gases such as argon or neon as well.

^ssc3 illus, 8 ref

016343   Kandagal S B;Venkatraman K (Aerospace Engineering Dep, Indian Institute of Science, Bangalore-560 012) : High frequency time varying resistive shunting of piezoceramic transducers. J Instn Engrs-Pt AS 2006, 87(May), 7-11.

Potential and more popular applications of piezoceramics an in the field of active vibration control. However, the objective of this study is to investigate the effect of shunted piezoceramics as passive vibration control devices when bonded to a host structure. Resistive shunting of a piezoceramic bonded to a cantileuered duralumin beam has been investigated. The effect of resistive shunting on the nature of damping enhancement to the host structure has been investigated. An increase of 60% in loss factor and one percent shift in natural frequency is observed due to time-invariant resistive shunting at optimal resistance. High frequency excitations to structure lead to stiffening effects. The stiffening behaviour of such system is realized by partitioning the beam dynamics into fast and slow motions. The effect of fast motion on slow dynamics is determined by averaging out the high frequency motion due to high frequency excitation. Based on this concept, apart from time-invariant resistance across the piezoceramics, the effect of frequency and amplitude of high-frequency time varying resistance are examined in terms of increase in damping and damped natural frequencies of the beam in slow flexural dynamics. The improvement in terms of added damping or change in damped/or undamped natural frequencies due to time varying resistance is marginal in comparison to constant time-invariant resistance.

6 illus, 1 table, 11 ref

016342   Kamat S A;Kshirsagar J T (NO, Kirloskar Brothers Limited, Pune-411 002) : Seismic analysis of end suction pump. Indian Pumps 2006, 38(3), 10-4.

End suction pumps installed in earthquake-prone zones are required to be checked for their mechanical behaviour, integrity and safe operations under seismic conditions. A pump supplied for installation in such area was analysed for developing confidence about its mechanical behaviour and integrity under anticipated seismic activity. Various modes of natural frequency were estimated, the first mode being higher than the specified threshold value. Equivalent static analysis was carried out under prevailing seismic loads. The paper presents the methodology used in the analysis and brings out the results showing mechanical integrity of the pump under specified loads.

8 illus, 2 tables, 7 ref

016341   Kalghatgi U S (NO, , ) : Role of ancillary industries in shipbuilding-Classification society view point. J Instn Engrs-Pt MA 2006, 87(Jul), 25-9.

Central theme of this paper is the symbiosis and mutual inter-dependence of shipyard, ship ancillary industry and ship classification society on each other. Historically, marine shipbuilding ambit and ambitions of industries converge and a symbiosis is born. The technical competence of the ancillary industry is a key factor in determining the effectiveness of a shipyard. Classification society also plays a key role thus ensuring synergy between all the players involved in shipbuilding. Shipyard is a key customer for the ancillary industry since the dawn of modern age and there is a dependence of industry on the shipyard. Progressive specialization renders it more and more unsuited for any other use. These rules are universal. The paper enlarges on this fundamental fact explaining why the symbiosis emerged and how it is manifested in the contemporary world. The classification society plays a supportive role in ensuring that a shipyard delivers a ship conforming to applicable rules and regulations. A good understanding is necessary amongst all the stakeholders so that in the end it is the society which gets benefit from this joint venture thus, contributing to the Country's economy. Ancillary industry can be bolstered by encouraging alignment between all the concerned parties; the government having an integrated policy and nurturing attitude; creating right kind of market conditions which will attract investment in local manufacturing facilities; joint venture programme between the ship building and ancillary industries; and educating marine ancillary industries on shipbuilding. After gaining sufficient expertise and confidence, we should strive for protection of Intellectual Property Rights (IPR), which will be a valid asset of our industry. The success of India's future shipbuilding industry lies in encouraging all the ancillary industries contributing to the completion of the ship and its subsequent maintenance.

1 illus

016340   Jishnu A;Sarath Kumar;Kumar N S (Tejas Networks, India Ltd. No 58, 1st Main road, JP Nagar 3rd Phase, B, , , Email: jishnu@tejasnetworks.com) : convergence in optical transport networks. IETE Tech Rev 2006, 23(4), 215-20.

Optical transport networks Interconnect switches and routers in the network core, or connect high-speed, typically business/enterprise, users to the network (access). These networks are almost entirely based on the Synchronous Digital Hierarchy (SDH) standards today (or the equivalent Synchronous Optical Network (SONET) standard In North America) Traditionally, SDH has been the sole transport network and thus has carried all of the telecommunication service provider's traffic, including voice and data. So, SDH has, in a sense, provided "converged" transport, all along. However, the Interfaces provided by SDH equipment for the first 10 years or so (since about 1990 to 2002) were restricted to the rates used by the older plesiochronous digital hierarchy (PDH) systems, namely, 2/34/140 Mbps, or the standard SDH rates, 155/622/2488 Mbps. Data typically originates within an enterprise local area network (LAN), invariably Ethernet at 10, 100 or 1000 Mbps, and had to adapted to a "standard" PDH or SDH data rate, typically using a router within the enterprise. (This application of a router is so prevalent that the PDH Interface on a router is called the wlde-area network, WAN, Interface.) The first step that the SDH standards, and equipment vendors, took to support a datafriendly network was to provide Ethernet interfaces (10/100/1000 Mbps) on the SDH equipment in addition to PDH and SDH Interfaces. The provision of Ethernet interfaces on SDH equipment is based on the Generic framing Procedure (GFP), Virtual Concatenation (VCAT) and Link Capacity Adjustment Scheme (LCAS) standards that were published and refined in 2001-03, and which are collectively referred to as the "Ethernet-over-SDH/SONET" or EoS standards. "Next-generation" SDH equipment supporting these EoS standards has been deployed since early 200.3; Tejas' first shipment of standards-based EoS equipment to carry commercial traffic was in January 2003.

5 illus, 9 ref

016339   Javed A;Chakraborty D (Defence and Development Laboratory Div, , Kanchanbagh, Hyderabad-500 058) : Numerical simulation of supersonic combustion of pylon injected hydrogen fuel in scramjet combustor. J Instn Engrs-Pt AS 2006, 87(May), 1-6.

Combustion process in a hydrogen fuelled Scramjet combustor has numerically been studied. Hydrogen is injected at sonic speed in supersonic air stream from a pylon type of injector at 120° from the airflow. The supersonic airstream is at Mach number of 2.15 and total temperature of 1350 K. The 3-D Navier Stokes equations with Shear Stress Transport (SST) turbulence model art solved using commercial Computational Fluid Dynamics (CFD) software CFX-TASC Flow. Combustion is modelled using multi-step Eddy Dissipation Model (EDM) with seven species and five reactions. A good match is obtained for wall static pressure distribution with multi-step chemistry which could be obtained with single-step chemistry.

7 illus, 1 table, 7 ref

016338   Chaudhury S;Chattopadhyay S (Electronics and Electrical Communication Engineering Dep, Indian Institute of Technology Kharagpur, Kharagpur-721 302, Email: (saurabh,santanu)@ece.iitkgp.ernet.in) : Output phase assignment for area and power minimization in PLAs. J Indian Inst Sci 2006, 86(1), 33-43.

Fairly good amount of optimization can be achieved in PLA-based two-level realization of circuits using a proper choice of phases for the subfunctions. Presents a genetic algorithm-based approach for selection of output phases to optimize the PLA for area and power. The results obtained are superior to those reported in the literature. Finally, a trade-off has been made to perform a weighted minimization of area and power. It has been shown that a range of solutions can be achieved with varying degree of area and power optimization using different weightages to the area requirement and the power consumption of the resulting PLA.

2 illus, 4 tables, 8 ref

016337   Chaudhuri S;Shanmugam V;Umakant J (Directorate of Aerodynamics, Defence Research and Development Laboratory, Kanchanbag, Hyderabad-500 058) : Component and vehicle aerodynamics characteristics of a low aspect ratio winged aerospace vehicle configuration. J Instn Engrs-Pt AS 2006, 87(Nov), 19-25.

Component-wise aerodynamic characteristics of a low aspect ratio winged flight vehicle configuration has been investigated using an Euler CFD code and limited wind-tunnel tests has been and discussed. Interference factors K_w and K_B have been generated from the results. These will be used to augment the capability of an existing in-house rapid prediction code.

8 illus, 3 tables, 5 ref

016336   Bhoi B;Jouhari A K;Ray H S;Mishra V N (Regional Research Laboratory, , Bhubaneswar-751 013) : Reduction of iron oxide in liquid slag by solute carbon. J Instn Engrs-Pt MM 2006, 87(Oct), 7-12.

In smelting reduction processes, reduction of FeO in liquid slag is a fundamental reaction. This reduction can be achieved by solid carbon, solute carbon, CO gas or by a combination of these. In the paper, experimental data on FeO reduction in slag are reported for varying values of the initial FeO content in the slag, slag basicity and bath temperature. All experiments were conducted in a 30 kW capacity induction furnace using pig iron bath as a source of solute carbon in an alumina crucible. The data are analyzed to study the order of reduction reaction.

8 illus, 22 ref

016335   Bhagwat R (Symtronics Automation Private Limited, , Mumbai) : Indegenous manufacture of marine electronic equipment. J Instn Engrs-Pt MA 2006, 87(Jul), 9-11.

Recent events on the front of U S-Indian co-operation in the transfer of conventional military hardware and dual-use technology promise a boost to India's military modernization. Still, U S naval sales continue to show a greater inclination toward Pakistan, which is expected, as per media reports, to receive two U S frigate warships and eight patrol aircraft. Besides, as far as equipment from western countries is concerned, the price factor can play a major role in going in for indigenous development. In the globalisation-liberalisation scenario, private firms have aggressively invested in capacity and technology improvements. While investments dedicated to defence needs have not been apparent (except the very large companies who are handling major projects), their expertise and capacities developed for industrial production are all available to the defence services, provided they reap commercial rewards from deploying these.

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016334   Ashwin T R;George J M (Mechanical Engineering Dep, TKM, College of Engineering, Kollam-691 005) : Exergy analysis on vortex tubes. J Instn Engrs-Pt MC 2006, 87(Oct), 18-21.

Vortex tube, commonly known as Ranque-Hilsch tube is a device with no moving parts in which compressed gas injected through tangential nozzles into a vortex chamber results in the separation of the inlet flow into two streams, one of which is warmer than the inlet gas while the other is cooler. The mechanism of energy separation has been investigated by several scientists and exergy approach has emerged as an important tool for optimising the vortex tube performance. Saidi and Yazdi1, developed separate equations for a vailability analysis and entropy generation based on Gouy-Stodola relation. Realising the importance of exergy analysis, as an important tool for optimising the existing vortex tube operation, an exergy model of the tubes based on the methods developed by Saidi have been presented.

5 illus, 1 table, 13 ref

016333   Acharya S K;Prasad N;Uma Shanker (Mechancial Engineering Dep, National Institute of Technology, Rourkela-700 008) : Wear behaviour of aluminium red mud composite. J Instn Engrs-Pt MM 2006, 87(Oct), 3-6.

Deals with an experimental investigation of wear behaviour of aluminium redmud composite with different volume fractions under dry sliding condition and under different working conditions using a pin-on disc machine. The wear rate and coefficient of friction were found to be functions of normal load, sliding velocity and redmud content. Wear rate of the composite was also found to be less than that of pure aluminium and decreased with increase in redmud content.

6 illus, 21 ref

016332   Abhyankar S L (Indian Pump Manufacturers Association, , 105 Kabad Chambers, 132, Dr. A.B. Road, Wonli, Mumbai-400 018) : Unravelling the synergy - between pumps, valves and systems. Indian Pumps 2006, 38(3), 21-2.

015285   Shibata J;Murayama N;Horai K;Matsumoto S (Chemical Engineering Dep, Faculty of Engineering, Kansai University, Suita, Osaka 5648680, Japan, Email: shibata@kansai-u.ac.jp) : Dispersion phenomena of α-Al₂O₃ in aqueous solutions in presence of polyacrylic acid polymers. Trans Indian Inst Metals 2006, 59(3), 373-9.

The effect of polyacrylic acid on the dispersion phenomena of α-Al₂O₃ in aqueous solution was investigated. The degree of dispersion of α-Al₂O₃ was evaluated from the measurements of average particles size of α-Al₂O₃, turbidity, sedimentation volume and viscosity. The dispersion phenomena of α-Al₂O₃ were explained by measuring the adsorption amount of the polymer and the zeta potential of α-Al₂O₃. The dispersion of α-Al₂O₃ is enhanced with addition of polyacrylic acid (PAA). The conformation of the polymer is found to be a controlling factor in determining the stability of α-Al₂O₃ particle. Effect of polymer molecular weight on dispersion was also studied. PAA of molecular weight 6000 was found to be the best dispersant.

10 illus, 24 ref

015284   Sevim I;Kulekci M K (Mechanical Engineering Dep, Faculty of Engineering, Tarsus Technical Education faculty, Mersin Un, Turkey, Email: mkkulekci@mersin.edu.tr) : Abrasive wear behaviour of bio-active glass ceramics contaning apatite. Bull Mater Sci 2006, 29(3), 243-9.

Abrasive wear behaviour of bio-active glass ceramic materials produced with two different processes is studied. Hot pressing process and conventional casting and controlled crystallization process were used to produce bio-active ceramics. Fracture toughness of studied material was calculated by fracture toughness equations using experimental hardness results of the bio-active glass ceramic material. Two fracture toughness equations in the literature were used to identify the wear behaviour of studied ceramics. Wear resistance results that identified with both of the equations were similar. The results showed that the abrasive wear resistance of the bio-active glass ceramics produced with hot pressing process was found to be higher than that of the ceramics produced by conventional casting and controlled crystallization process.

7 illus, 5 table, 14 ref

015283   Sankar M;Batra N K;Shekhar R;Mehrotra S P (Materials and Metallurgical Engineering Dep, Indian Institute of Technology, Kanpur-208 016, Email: nml@nmlindia.org) : Roasting, reduction and leaching of an Indian ilmenite ore for producing synthetic rutile. Trans Indian Inst Metals 2006, 59(3), 381-7.

In conversion of ilmenite to synthetic rutilc roasting, reduction and leaching steps play an important role in removing of iron economically and efficiently. In the investigation the ilmenite ore was first subjected to oxidation roasting at the temperatures ranging between 850 - 950° C to convert ferrous oxide in the ilmenite to ferric state. The calcine was then reduced with hydrogen in the temperature range 850 - 950 °C to produce metallic iron and TiO₂. This reduced ilmenite ore was subsequently leached with hydrochloric acid to remove iron. Based on the roasting, reduction and subsequent leaching steps the optimum roasting and reduction temperatures for better removal of iron from ilmenite ore are 950 °C and 900 °C respectively.

6 illus, 1 table, 12 ref

015282   Roopesh K K;Umesha P K;Kalappa M S (Strucutral Engineering Research Centre, CSIR Campus, Taramani, Chennai-600 013) : Software based on heuristic technique for optimization of transmission line towers. J Struct Engng 2006, 33(2), 157-66.

Towers and tower like structures are, literally speaking, the 'pillars' of the infrastructure for the transmission of electrical power, telecommunication and broad casting. Substantial savings in material and total cost can be achieved through the selection of efficient structural configuration, and rational and optimum designs without compromising on the structural safety and reliability of towers. Genetic algorithms have been shown to be very effective in engineering design and optimization including the size, configuration and topology. Hence in this paper a genetic algorithm based methodology is described for the optimum weight design of Transmission line towers. A software has been developed which, is capable of computing various loads and load combinations specified by the current IS specifications for Transmission line towers. The developed code has been tested on three large problems and the optimal designs have been compared with the results reported in literature. A 66kV transmission line tower is optimized for the loads and load combination specified by IS:802 (Part1/Sec1)-1995, by considering stress, deflection and buckling criteria specified by IS:802 (Part1/Sec2)-1992. Since the wind loads and dead loads of the structure depend upon the section (area) selected, the program will automatically update the loads and load combinations and will produce an optimal solution. It is found that genetic algorithms work irrespective of whether stress or deflection is the governing criterion.

9 illus, 8 tables, 18 ref

015281   Ravindaran V;Murlidharan V S (NO, Central Electrochemical Research Institute, Karaikudi-630 006, Email: visalakshi@yahoo.com) : Characterization of zinc-nickle alloy electrodeposits obtained from sulphamate bath containing substituted aldehydes. Bull Mater Sci 2006, 29(3), 293-301.

Zinc alloy offers superior sacrificial protection to steel as the alloy dissolves more slowly than pure zinc. The degree of protection and the rate of dissolution depend on the alloying metal and its composition. Zinc-nickel alloy may also serve as a less toxic substitute for cadmium. Physico-chemical characterization of zinc-nickel electrodeposits obtained from sulphamate bath containing substituted aldehydes was carried out using hardness testing, X-ray diffraction, and corrosion resistance measurements. The corrosion behaviour of these samples in a 3.5% NaCl solution was examined. The decrease in I_corr and high charge transfer resistance indicated the improved corrosion resistance of these deposits.

4 illus, 6 tables, 12 ref