012596   Menezes P L;Kishore;Kailas S V (Materials Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: lancy@mecheng.iisc.ernet.in) : Subsurface deformation and the role of surface texture-a study with Cu pins and steel plates. Sadhana 2008, 33(3), 191-201.

The extent of subsurface deformation below the worn surface influences friction and transfer layer formation during sliding. Thus, in this study, the extent of plastic deformation and strain localization events that occur at various depths beneath the worn surface in the subsurface zones of Cu pins slid against steel plate with various surface textures have been determined using simple metallographic techniques. Results showed that the magnitude of plastic strain gradient and the depth of highly deformed zone depend on both coefficient of friction and transfer layer formation, which in-turn depends on the surface texture of harder counterface, under both dry and lubricated conditions. In addition, it was seen that the gradient of equivalent strain, as it approached the worn surface, was higher under dry conditions when compared to that under lubricated conditions.

9 illus, 38 ref

012595   Menezes P L;Kishore;Kailas S V (Materials Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: lancy@mecheng.iisc.ernet.in) : Influence of roughness parameters on coefficient of friction under lubricated conditions. Sadhana 2008, 33(3), 181-90.

Surface texture and thus roughness parameters influence coefficient of friction during sliding. In the present investigation, four kinds of surface textures with varying roughness were attained on the steel plate surfaces. The surface textures of the steel plates were characterized in terms of roughness parameter using optical profilometer. Then the pins made of various materials, such as Al-4Mg alloy, Al-8Mg alloy, Cu, Pb, Al, Mg, Zn and Sn were slid against the prepared steel plates using an inclined pin-on-plate sliding tester under lubricated conditions. It was observed that the surface roughness parameter, namely, R_a, for different textured surfaces was comparable to one another although they were prepared by different machining techniques. It was also observed that for a given kind of surface texture the coefficient of friction did not vary with R_a. However, the coefficient of friction changes considerably with surface textures for similar R_a values for all the materials investigated. Thus, attempts were made to study other surface roughness parameters of the steel plates and correlate them with coefficient of friction. It was observed that among the surface roughness parameters, the mean slope of the profile, Del a(Δ_a), was found to explain the variations best.

4 illus, 2 tables, 27 ref

012594   Mathew M T;Srinivasa Pai P;Rocha L A (NO, Centre for Materials and Mechanical Technologies (CT2M), Azurem, 4800058 Guimaraes, Portugal, Email: mathew@dem.uminho.pt) : Effective sensor for tool wear monitoring in face milling: acoustic emission. Sadhana 2008, 33(3), 227-33.

Acoustic Emission (AE) has been widely used for monitoring manufacturing processes particularly those involving metal cutting. Monitoring the condition of the cutting tool in the machining process is very important since tool condition will affect the part size, quality and an unexpected tool failure may damage the tool, work-piece and sometimes the machine tool itself. AE can be effectively used for tool condition monitoring applications because the emissions from process changes like tool wear, chip formation i.e. plastic deformation, etc. can be directly related to the mechanics of the process. Also AE can very effectively respond to changes like tool fracture, tool chipping, etc. when compared to cutting force and since the frequency range is much higher than that of machine vibrations and environmental noises, a relatively uncontaminated signal can be obtained. AE signal analysis was applied for sensing tool wear in face milling operations. Cutting tests were carried out on a vertical milling machine. Tests were carried out for a given cutting condition, using single insert, two inserts (adjacent and opposite) and three inserts in the cutter. AE signal parameters like ring down count and rms voltage were measured and were correlated with flank wear values (VB max). The results of this investigation indicate that AE can be effectively used for monitoring tool wear in face milling operations.

8 illus, 1 table, 3 ref

012593   Manvi S S;Kakkasageri M S (Electronics and Communication Engineering Dep, Basaveshwar Engineering College, Bagalkot-587 102, Email: agentsun2002@yahoo.com) : Issues in mobile Ad hoc networks for vehicular communication. IETE Tech Rev 2008, 25(2), 59-72.

Vehicular ad hoc networks (VANETs) are a specific type of Mobile Ad hoc Networks (MANETs) that are currently attracting the attention of researchers around the world. With pervasiveness of mobile computing technology and wireless communications, VANETs could be a key networking technology of the future vehicle communications. VANETs can make a possible wide-range of interesting applications focusing on vehicle traffic safety, entertainment in vehicles, cooperative driver assistance, sharing traffic and road conditions for smooth traffic flow, user interactions, information services, etc. Key characteristics that distinguish VANETs from other networks are time-varying nature of vehicle density, high mobility, and time-critical safety applications. Hence, devising protocols for VANETs may not be successfully accomplished by simple adaptation of protocols designed for wired networks and MANETs. paper outlines the current research issues in VANETs, which may benefit the researchers to design and develop protocols for VANETs.

1 illus, 3 tables, 40 ref

012592   Malathi P;Vanathi P T (ECE Dep, PSG College of Technology, Peelamedu, Coimbatore-641 004) : Optimized multi-user resource allocation scheme for OFDM - MIMO system using GA & OGA. IETE Tech Rev 2008, 25(4), 175-85.

Implements an OFDM - MIMO system and analyze its performance, and implement an optimized dynamic resource allocation scheme for maximizing the minimum user's capacity. Performance of the system can be vastly improved by properly allocating resources among the different users. The bits, sub-carriers, the power among the users, and power among the channels are dynamically allocated depending on the channel conditions in such a way that the error-free capacity of the minimum user is maximized.

12 illus, 10 ref

012591   Madej W (Electronics and Computer Studies Dep, 2 Sniadeckich St. 75-453, Koszalin, Poland) : Measuring errors' spectrum of the artillery radar stations. Def Sci J 2009, 59(2), 162-5.

The simulation analysis of the measuring errors of the artillery radar stations is presented. This analysis enables the proper designing of the smoothing filters of the data for the baliist c module and determination of the components of the velocity of the target. They are derivatives of the signals representing coordinates of the target, and as such can introduce huge errors during computations of dervatives.

^ssc8 illus, 4 ref

012590   Liu C Y;C T Chen (NO, Lee-Ming Institute of Technology, Taipei, Taiwan, R.O.C) : Tracking the warhead among objects separation from the reentry vehicle in a clear environment. Def Sci J 2009, 59(2), 113-25.

Separating a reentry vehicle into warhead, main body, and debris is a conventional and efficient means of producing a huge decoy and increasing the kinetic energy of die warhead. This procedure causes the radar to track the main body and debris, which radar cross section arc large, and ignore the warhead, is the most important part of he reentry vehicle. The warhead is difficult to identify after separation using standard tracking criteria. This study presents a novel tracking algorithm by integrating input estimation and modified probabilistic data association filter to identity warhead among objects separation from the reentry vehicle in a clear environment. The proposed algorithm provides a good tracking capability for the warhead ignoring the radar cross section. Simulation results reveal that he errors between the updated and warhead trajectories are reduced to a small interval in a short time. Therefore, he radar can generate a beam to illuminate the right area and keep tracking the warhead all the time. This algorithm is worthy of further study and application.

25 illus, 5 tables, 23 ref

012589   Lin D C;Kovacevic R;Srivatsan T S;Wang G X (Research Center for Advanced Manufacturing, Mechanical Engineering De, Southern Methodist Univ, 1500, International Parkway, Suite No. 100, Richardson, Texas 75081, Email: tsrivatsan@uakron.edu) : Study aimed at characterizing the interfacial structure in a tin-silver solder on nickel-coated copper plate during aging. Sadhana 2008, 33(3), 251-59.

This paper highlights the intcrfacial structure of tin-silver (Sn-3-5Ag) solder on nickel-coated copper pads during aging performance studies at a temperature of 150°C for up to 96 h. Experimental results revealed the as-solidified solder bump made from using the lead-free solder (Sn-3-5Ag) exhibited or showed a thin layer of the tin-nickel-copper intermetallic compound (IMC) at the solder/substrate interface. This includes a sub-layer having a planar structure immediately adjacent to the Ni-coating and a blocky structure on the inside of the solder. Aging performance studies revealed the thickness of both the IMC layer and the sub-layer, having a planar structure, to increase with an increase in aging time. The observed increase was essentially non-linear. Fine microscopic cracks were observed to occur at the interfaces of the planar sub-layer and the block sub-layer.

7 illus, 3 tables, 8 ref

012588   Lebl A;Markov Z (NO, , IRITEL d.d, Batajnicki put 23, 11080 Zemum, Serbia, Europe, Email: lebl@iritel.com) : Telephone caller-ID signal sending over internet. IETE Tech Rev 2008, 25(2), 49-58.

This paper describes two methods of calling subscriber number sending over Internet to the called subscriber who is connected to the classic telephone exchange by Internet. One, faster, method uses two event codes, while the other method uses only one event code, but it is significantly slower.

7 illus, 8 ref

012587   Kuryan S;Abraham R;Jayakumari Isac (NO, St.Stephen's College, Kollam, Kerala, Email: renykuryan@rediffmail.com) : Microwave studies on yttrium barium oxalate crystals. Int J mathl Sci 2008, 3(1), 47-52.

Rare earth compounds are recognized for outstanding physical, magnetic, electrical and optical properties. Using cavity perturbation technique dielectric parameters of the sample such as complex permittivity and conductivity at microwave frequency were determined. Using X-ray diffraction study the crystalline nature of the sample was established. Photoconductivity studies of the Yttrium Barium Oxalate (YBaOx) crystals revealed the negative photo conducting nature.

3 illus, 12 ref

012586   Kuruvilla M;Srivatsan T S;Petraroli M;Park L (Materials Science and Engineering Div, Mechanical Engineering Dep, The Univ of Akron, Akron, Ohio 44325 3903, USA, Email: tsrivastsan@uakron.edu) : Investigation of microstructure, hardness, tensile behaviour of a titanium alloy: role of orientation. Sadhana 2008, 33(3), 235-50.

In this technical paper, the microstructure, hardness, tensile deformation and final fracture behaviour of an emerging titanium alloy for performance-critical applications are presented and discussed. Both longitudinal and transverse test specimens were prepared from the as-provided sheet stock of the alloy and deformed in uniaxial tension. The yield strength and tensile strength of the alloy sheet in the transverse orientation was higher than the longitudinal orientation. The ductility of the test specimens, quantified in terms of reduction-in-cross-sectional area, was higher for the transverse specimen when compared to the longitudinal counterpart. The elongation-to-failure of the test specimens was identical in the two orientations of the sheet stock. The tensile fracture behaviour of the alloy was quantified by careful examination of the fracture surfaces in a scanning electron microscope. The intrinsic fracture features on the tensile fracture surface were discussed taking into consideration the nature of loading and contribution from intrinsic microstructural features.

10 illus, 4 tables, 10 ref

012585   Kumaresan R;Ibrahim S H;Viruthagiri T (Chem. Engg. Dep, Mohamed Sathak Engineering College, Kilakarai) : Simultaneous heat and mass transfer studies in drying of ammonium chloride in fluidized bed dryer. Process Pl Engng 2007, 25(3), 60-6.

Fluidized bed dryer is more sensitive to the variation of moisture content of the material being dried and less dust emission is another advantage of fluidized bed dryer. Operation and maintenance costs are less because lesser moving parts involved. Wet Ammonium chloride crystals obtained after centrifuging will have around 5-6% moisture. It is observed while drying the Ammonium chloride in a fluidized bed dryer, the energy consumption is 12.9% lesser than the conventional rotary dryer. To improve the design of fluidized bed dryers for very fine powder like Ammonium chloride and highly corrosive in nature, a fundamental research work has been carried out.

3 illus, 3 tables, 8 ref

012584   Khan A M;Sheikh M M;Ganesh;Hanumaiah B; Siddappa K (Electronics Dep, Mangalore Univ, Mangalagangori-574 199, Email: asifabc@yahoo.com) : An automated beam extraction system for microtron. IETE Tech Rev 2008, 25(3), 99-104.

Reports computer based system developed for the automated control of the Beam Extraction System (BES) of Microtron (electron accelerator facility at Mangalore University). The BES helps in extracting the electron beam from a desired orbit. The automated system is designed with two levels. At the system level, there is a microcontroller along with some circuit components to place the mouth of the extraction channel at a particular orbit so that an electron beam of a particular energy can be extracted from the microtron for experimental studies. The computer kept in the control room away from the microtron machine (i.e. user level) passes the orbit number from which the beam is to be extracted to the microcontroller. This automated system is very simple, easy to operate and cost effective. It also helps in accurate setting of extraction channel and extraction of electron beam of desired energy. The work described here is an attempt to improvise on the existing system and computerise the same for accurate settings and control from a remote distance.

4 illus, 7 ref

012583   Kandikattu R;Jacob L (Electronics and Communication Engineering Dep, National Institute of Technology Calicut, Calicut-673 601, Email: k_ramnarayan@rediffmail.com) : Light-weight secure key setup and signaling architecture for wireless mesh networks. IETE Tech Rev 2008, 25(4), 168-74.

Wireless mesh network (WMN) is advocated as the major supporting technology for next generation wireless Internet. To support anywhere-anytime communications for highly mobile users, WMN needs to have mobility management architecture that supports frequent handover. Hierarchical Mobile IPv6 (HMIPv6) is one such architecture that reduces handover signaling, but has inefficient address space utilization, poor key setup procedure, and IPSec-based security. Proposes a secure and light-weight architecture for IPv6-based WMN called secure WMN (SWMN) that is built upon HMIPv6. SWMN allocates address space optimally among the clients and uses a secure procedure for user registration and key setup. It has light-weight and secure mobility management mechanism. A simple analysis is also presented to compare SWMN with HMIPv6.

1 illus, 6 tables, 8 ref

012582   Kand C V (NO, , E-2/136, Mahavir Nagar, Bhopal) : Utility services along urban roads. Indian Highw 2008, 36(10), 37-48.

14 illus, 1 table, 10 ref

012581   Kamath M P;Tripathi P K;Kulkarni A P;Chandra R;Joshi A S;Navathe C P;Gupta P D (Laser Plasma Div, Raja Ramanna Centre for Advanced Technology, Indore-452 013, Email: kamath@cat.ernet.in ) : Design, development and performance characteristics of a large aperture disc amplifier for high power Nd: glass laser chain. Sadhana 2008, 33(4), 443-53.

A large aperture disc amplifier has been designed, set-up and characterized for its performance on small signal gain, spatial variation of gain, and thermal recovery time. This amplifier, consisting of three elliptical Nd: phosphate glass discs of size 214 x 114 x 20mm mounted at Brewster angle and pumped by ten xenon filled flash lamps of 600 mm arc length, provided a small signal gain of 6 at electrical pump energy of 36 kJ (in a pulse of 450 μs) using an in-house developed dual-polarity capacitor bank based power supply. It was coupled to a high power Nd: phosphate glass laser chain and a maximum output pulse energy exceeding 100 J in a 1.5 ns (FWHM) pulse has been measured. A dry nitrogen gas based cooling system was developed for cooling the glass discs with a thermal recovery time of ~ 20 minutes.

7 illus, 8 tables, 18 ref

012580   Kamali A R;Mehdi Hadavi S M;Razavizadeh H (Materials Science Dep, Iran Univ of Science and Technology, Tehran, Iran, Email: alirezakam@yahoo.com) : Production of Ti-8Al-1 Mo-1V alloy by using of new master alloys. Int J mathl Sci 2008, 3(1), 61-7.

Production of a titanium alloy with nominal composition of Ti-8A1-1Mo-1V (w%) was studied. Melting of elemental raw materials in an arc remelting furnace under argon atmosphere led to evaporation of aluminum and formation of high molybdenum inclusions. Using of TiA1 and Mo₃A1₈ raw materials led to production of an alloy with acceptable deviation of elements with a microstructure free from inclusions.

5 illus, 5 tables, 10 ref

012579   Kalantri S (A, B, C, Email: skalantr@qualcomm.com) : MediaFLO<. IETE Tech Rev 2008, 25(2), 73-79.

The exponential growth in wireless penetration and advancement in technology has accelerated the development of new and exciting wireless services. Given the mass appeal for video and multimedia content, technology providers have debated the feasibility and economical viability of large scale delivery of high-quality multimedia content to a wide range of wireless subscribers. Although delivery of this type of content is technically feasible over today's existing unicast networks such as 3G, these networks cannot support the volume and type of traffic required for a fully realized multimedia delivery service (many channels delivered on a mass market scale). Offloading multicast (one-to-many) multimedia traffic to a dedicated broadcast network is more efficient and less costly than deploying similar services over 3G networks. Multicast services, such as the FLO mobile broadcast platform, are built ground up to address the market demand for mobile media and provide the critical link between technical feasibility and economic viability. Designed to work in concert with existing cellular data networks, FLO effectively addresses the issues in delivering multimedia content to a mass consumer audience. Unencumbered by legacy terrestrial or satellite delivery formats, this technology offers better performance for mobility and spectral efficiency than other mobile broadcast technologies, offering twice the channel capacity. FLO is a globally-recognized, open technology standard with a broad-based licensing program. The FLO Forum, with 90+ active members, including Huawei, LG Electronics, Motorola, Samsung and Sony Sharp, is driving the global standardization of MediaFLO Technology.

3 illus, 2 tables, 4 ref

012578   Joshi R;Mandava M;Saraph G P (Electrical Engineering Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: rajeshj@ee.iitb.ac.in) : End-to-end quality of service (QoS) over internet. IETE Tech Rev 2008, 25(4), 216-21.

With the significant increase in traffic on the internet in the recent past and the resources on the internet being shared, the need of end-to-end quality of service (QoS) guarantee has become critical. The existing QoS mechanisms provide the path selection mechanism in distributed manner which do not necessarily support the end-to-end QoS requirements. Builds upon the routing control platform concepts to propose an evolutionary framework which provides help for optimal end-to-end QoS support. The proposed end-to-end QoS framework fall under three distinct planes: session control plane, network control plane, and data forwarding plane. This framework also introduces a novel concept of AS Designated QoS Provider Entities to assist each autonomous system in information exchange, decision making, and signaling spanning across these planes. Describes architectural requirements, choices for end-to-end QoS framework, and implementation scheme.

6 illus, 25 ref

012577   Joshi C V;Sutaone M S;Yadav A;Bhoyar M;Barve A (Electronics and Telecommunication Engineering Dep, College of Engineering, Pune, Wellesley Road, Shivaji Nagar, Pune-411 005) : Challenges in the implementation of next-generation ZigBee networking. IETE Tech Rev 2008, 25(4), 161-7.

One of the key challenges in the implementation of ZigBee networks is the development of algorithms which provide autonomous meshing of beacons with minimal or no interference. This feature is out of the scope of current ZigBee capabilities. The energy and bandwidth constraints and the potential large-scale deployment pose challenges in efficient resource allocation and sensor management. Focuses on the problems which hinder the reliable and low-latency operation of deeply-embedded wireless sensor networks. Also analyzes the proposed solutions which play a key role in bolstering ZigBee as the true mediator in making the current scenario of wireless sensor networks (WSN) networking more reliable and thus paving the way for meeting the challenges and requirements demanded by next-generation ZigBee networks. The study has been divided into two parts. In the first part, briefly introduces the beaconing mechanism of IEEE 802.15.4 and analyze it from the point of view of mesh networks. In the second part, reviews the hidden-node problem from the perspective of IEEE 802.15.4. Finally concludes with some remarks on the future scope of ZigBee networking.

^iia10 illus, 7 ref

012576   Jaya N;Sivakumar D;Anandanatarajan R (Electronics and Instrumentation Engineering Dep, Annamalai Univ, Annamalai) : Two region fuzzy logic controller for a two capacity interacting nonlinear level process. Karpagam J Comput Sci 2008, 2(6), 813-19.

Although a fuzzy logic controller is generally nonlinear, a PI- type single region fuzzy controller that uses only control error and change in control error is not able to detect the process nonlinearity and make a control move accordingly. In this work, a two region fuzzy logic controller is developed for a nonlinear second order process. The simulation study is carried out on a two capacity interacting process and the results are compared with those obtained using a conventional PI controller based on the transfer function model and single region fuzzy logic controller about the operating point of 50%.

9 illus, 5 tables, 8 ref

012575   Jalali R S;Trifunac D (Civil Engineering Dep, Iran University of Science and Technology, Narmak, Tehran 16846, Iran) : Strength-reduction factors for structures subjected to near-source differential strong ground motions. ISET J Earthquake Technol 2007, 44(1), 285-304.

Efects of differential motions on strength-reduction factors are described for the structures subjected to propagating horizontal, vertical, and rocking near-source, fault-normal, and fault-parallel strong-motion displacements. It is shown that the common design rules for selection of the strength reduction factors are not conservative for both fault-normal pulse and fault-parallel displacement. It is recommended that for the design of structures close to active faults the strength-reduction factors for all components of strong motion be constant and equal to (2Δ-1)^1/2 , where μ is ductility, for long periods, but only up to the collapse boundaries (where dynamic instability and gravity loads dominate). For the periods shorter than about 2 s, these strength-reduction factors should be further reduced by 30 to 50 percent.

9 illus, 2 tables, 68 ref

012574   Jagtar Singh;Jain V K (Electrical Engineering Dep, I.I.T. Delhi, New Delhi-110 016) : Performance analysis of BPPM and M-ary PPM optical communication systems in atmospheric turbulence. IETE Tech Rev 2008, 25(4), 146-53.

Performance of FSO system, working under weak and strong turbulence scenarios, has been compared in terms of their bit error rates (BERs). The modulation schemes considered are binary pulse position modulation (BPPM) and M-ary pulse position modulation ( M -ary PPM). The photodetector used is an avalanche ªphotodiode (APD). The comparison of performance in weak and strong turbulence for either system clearly brings the requirement of additional signal photons as the turbulence level increases. The results obtained in the paper also show the suitability of BPPM over M-ary PPM in strong turbulent environment. Further, optimum gain of APD to achieve minimum probability of error in the turbulent environment is given.

9 illus, 3 tables, 11 ref

012573   Jadhao A M;Ghatol A A (NO, Directorate of Technical Education, Maharasahtra State, 3, Mahapalika Marg, Mumbai-400 001, Email: ajadhao@gmail.com) : Effect of carrier frequency offset on cooperative Alamouti STC OFDM systems. IETE Tech Rev 2008, 25(4), 186-91.

Effect of carrier frequency offset on a network where multiple independent devices cooperate to form virtual multiple input multiple output networks is analyzed. The common phase error and inter-carrier interference effect on Cooperative Alamouti space-time code orthogonal frequency division multiplexing system due to carrier frequency offset is investigated.

5 illus, 12 ref

012572   Ikram N;Zaman S;Yousuf R;Tanveer M;Saeed Y (Centre for Solid State Physics, Punjab Univ, Lahore Pakistan) : Structural and electronic properties of CuZn, AgZn, and Cu_xAg_1-xZn. Int J mathl Sci 2008, 3(1), 69-74.

The electron band structure, density of states and other structural properties such as lattice constant, elastic constant and bulk modulus of Cu, Ag, Zn and their binary and ternary compounds, CuZn, AgZn and Cu_xAg_{1- x}Zn are calculated using Density Functional Theory (DFT). The results are compared with other theoretical and experimental data. The band structure of CuZn and AgZn show metallic behavior of these alloys and elastic constant calculation indicate that they are stable in CsC1-type of structure. Further, the addition of Copper in AgZn improves the strength of Cu_xAg_1-xZn alloy.

2 illus, 1 table, 18 ref

012571   Hossain S M (Chemical Engg Dep, Mohamed Sathak Engineering College, Kilakarai) : Effect of titanate coupling agent on rheological rpoperties of clay filled polychloroprene rubber. Process Pl Engng 2007, 25(3), 67-70.

Kaoline clay was treated with varying titanate coupling agent dose. The treated filler was incorporated in polychloroprene rubber (PCR) rubber. The composites are molded in sheets using compression molding technique at different temperatures and different times. The mechanical properties such as tensile strength and modulus at 300 % elongation are measured and encouraging to enhance the plasticity of polychloroprene rubber (PCR). The maximum tensile strength was measured as 109.72 M Pa at optimum conditions with treated clay. The maximum modulus at 300% elongation with treated clay as noticed as 59.82 M Pa. The maximum tensile strength was measured as 72.26 M Pa at optimum conditions without treated clay. The maximum modulus at 300% elongation without treated clay as noticed as 28.65 M Pa.

3 illus, 1 table, 11 ref

012570   Gunaseelan K;Venkateswari R;Kandaswamy A (Electronics and Communication Engineering Dep, PSG College of Technology, Coimbatore-641 004, Email: gunaseelanpsg@gmail.com) : Novel efficient resource allocation algorithm for multiuser OFDM systems. IETE Tech Rev 2008, 25(4), 201-8.

Key issues in the design of a multiuser orthogonal frequency division multiplexing (MU-OFDM)-based systems are the subcarrier, power, and the bit allocation. Conventionally, the sum capacity of MU-OFDM is maximized when each subchannel is assigned to the user with the best channel-to-noise ratio for that subchannel, with power subsequently distributed by water-filling algorithm. Several adaptive resource allocation techniques for multiuser OFDM system under various constraints are analyzed. During the analysis, certain techniques strictly maintain proportional rate among users to achieve high quality-of-service (QoS). Few other techniques maximize the sum capacity by efficiently utilizing the unused subchannels, but it fails to maintain the proportional rate among users and thus poor QoS. To maintain target bit error rate (BER), bit allocation algorithms are also analyzed in this paper. In the proposed algorithm, however, the water-filling power allocation is not fully performed; instead, by adjusting only the water-filling level, the transmit power and number of bits are allocated with low computational complexity. Assuming knowledge of the instantaneous channel gains for all users, a resource allocation scheme for a MU-OFDM-based system to simultaneously provide dual services with different QoS is proposed. The proposed algorithm yields less signal to noise ratio (SNR) to achieve same sum capacity of the existing algorithms.

7 illus, 1 table, 15 ref

012569   Govindarajan N;Gnanamoorthy R (NO, , Flat B, Raj Enclave, Balaji Colony, 4th Cross Street, Velachery, Chennai-600 042, Email: nggovind@yahoo.com) : Ferrography - a procedure for measuring wear rate. Indian J Engng Mater Sci 2008, 15(5), 377-81.

Contact fatigue phenomenon is most common failure seen in the structural components, which are under high-cyclic fatigue loads. Rail wheels, mating gears, ball bearing and wherever the formal contact between the two structural elements, are affected by contact fatigue failure, is commonly referred as pitting of surface. Those structural elements are manufactured by powder metallurgy technology since it has more technical as well as commercial advantages over the conventionally made structural parts. Development in powder metallurgy manufacturing technologies, will give us confident to use of more powder metallurgy structural parts in place of conventional parts. Rolling-sliding contact fatigue (RSCF) experiments on powder metallurgy (PM) steels have been carried out in the laboratories with available experimental set-up. The lubrication oil is collected for regular interval and ferrography test is involved to predict the wear rate of the powder metallurgy steels. Wear morphology of porous steel is predicted.

4 illus, 7 ref

012568   Gicev V;Trifunac M D (NO, , Rudarsko-Geoloski Fakultet, Goce Delcev 89, 2000 Stip, Republic of Macedonia) : Energy and power nonlinear waves in a seven-story reinforced concrete building. ISET J Earthquake Technol 2007, 44(1), 305-23.

Limitations of the classical Response Spectrum Method (RSM) for the design of earthquake-resistant structures in the near field of strong earthquakes are noted. The main limitation is that the RSM is based on the largest peak of the relative response and does not consider the duration of strong motion. To illustrate an alternative approach the recorded response of a seven-story reinforced concrete hotel (VN7SH) in Van Nuys, California, damaged during January 1994, Northridge earthquake is described in terms of one-dimensional layered shear beam model, undergoing nonlinear wave excitation. Shows the time and space variations of wave energy and of power in the building response, and to set a physical basis for a new design method based on the power of strong motion pulses propagating through a building.

12 illus, 2 tables, 70 ref

012567   Freeman S A (NO, Wiss, Janney, Elstner Associates, Inc., 2200 Powell Street, Suite 925 Emeryville, CA 94608, U.S.A) : Response spectra as a useful design and analysis tool for practicing structural engineers. ISET J Earthquake Technol 2007, 44(1), 25-37.

Although response spectra have been in general use for decades by researchers, academics, and geotechnical professionals, their use by structural design professionals has generally been limited. However, as response spectra and dynamic analysis are being included within the newer building codes and as performance-based design (PBD) techniques are becoming acceptable, there is a need for the design professional to more clearly understand the meaning and usefulness of response spectra. Reviews the concept of response spectra for design engineers not familiar with their significance and to summarize a variety of uses that can be applied for purposes such as rapid evaluation for a large inventory of buildings, performance verification of new construction, evaluation of existing structures for seismic vulnerability, and post earthquake estimates of potential damage of buildings.

17 illus, 20 ref

012566   Eren I (Mechanical Engineering Dep, Yildiz Technical Univ, 34349, Besiktas, Istanbul, Turkey, Email: er@yildiz.edu.tr ) : Determining large deflections in rectangular combined loaded cantilever beams made of non-linear ludwick type material by means of different arc length assumptions. Sadhana 2008, 33(1), 45-55.

In this study, large deflection of cantilever beams of Ludwick type material subjected to a combined loading consisting of a uniformly distributed load and one vertical concentrated load at the free end was investigated. In calculations, both material and geometrical non-linearity have been considered. Horizontal and vertical deflections magnitudes were calculated throughout Euler-Bernoulli curvature-moment relationship assuming different arc lengths. Vertical deflections were calculated by using Runge-Kutta method. More simple and easily understandable results have been obtained compared to the previous studies about the issue and compatible values have been obtained for most of the compared values.

1 illus, 4 tables, 15 ref

012565   El-Khodary A;Oraby A H;Youssef A E (Physics Dep, Faculty of Science, Mansoura Univ, P.O. Box 55, 35516 Mansoura, Egypt, Email: elkhodary@mans.edu.eg) : Effect of AgNO₃ filler on the physical properties of polystyrene films. Int J mathl Sci 2008, 3(1), 11-24.

The prepared polystyrene (PS) films filled with different filling levels (FLs) of AgNO₃ were studied. The X-ray diffraction (XRD) scans exhibited two main characteristic peaks, the amorphous and the polymerization peaks. The evolution of these two peaks with filling was discussed. The infrared (IR) transmission spectra were recorded where the most notably PS characterizing peaks were assigned. Certain IR peaks were taken as an evidence for the formation of polaron and/or bipolaron states in the polymeric matrix. The direct current (dc) electrical conduction mechanism was discussed on the bases of the modified interpolaron hopping model. The temperature dependence of the dc magnetic susceptibility obeyed Curie - Weiss law. The obtained positive values of the paramagnetic Curie temperature suggest the existence of a ferromagnetic exchange interaction at low temperatures. The electron spin resonance (ESR) spectra displayed weak and very narrow signals. The magnetic centers responsible of the observed narrow ESR signals can basically be assigned to delocalized or mobile polarons formed during filling.

11 illus, 1 table, 38 ref

012564   Dhabale A;Banavar R N;Dhekane M V (Systems and Control Engineering, Indian Institute of Technology Bombay, Mumbai-400 076, Email: banavar@iitb.ac.in) : LQG controller designs from reduced order models for a launch vehicle. Sadhana 2008, 33(1), 1-14.

The suppression of liquid fuel slosh motion is critical in a launch vehicle (LV). In particular, during certain stages of the launch, the dynamics of the fuel interacts adversely with the rigid body dynamics of the LV and the feedback controller must attentuate these effects. Describes the effort of a multi-variable control approach applied to the Geosynchronous Satellite Launch Vehicle (GSLV) of the Indian Space Research Organization (ISRO) during a certain stage of its launch. The fuel slosh dynamics are modelled using a pendulum model analogy. We describe two design methodologies using the Linear-Quadratic Gaussian (LQG) technique. The novelty of the technique is that we apply the LQG design for models that are reduced in order through inspection alone. This is possible from a perspective that the LV could be viewed as many small systems attached to a main body and the interactions of some of these smaller systems could be neglected at the controller design stage provided sufficient robustness is ensured by the controller. The first LQG design is carried out without the actuator dynamics incorporated at the design stage and for the second design we neglect the slosh dynamics as well.

9 illus, 7 ref

012563   Demirdag O (Civil Engineering Dep, Engineering Faculty, Pamukkale Univ, 20070 Kinikli Campus, Denizli, Turkey, Email: oktaydemirdag@pau.edu.tr) : Free vibration analysis of elastically supported timoshenko columns with attached masses by transfer matrix and finite element methods. Sadhana 2008, 33(1), 57-68.

Deals with the free vibration of Timoshenko columns with attached masses having rotary inertia. The support of the model is elastically restrained against rotation. The concept of fixity factor is used to define the stiffness of the elastic connection relative to that of the column. The governing equation of the column elements is solved by applying the separation of variables method in the transfer matrix method (TMM) algorithm. The same problems are solved, also, by finite element method (FEM) algorithm in which the matrices in equation of motion are obtained for Timoshenko column, and the results are compared with the ones of TMM. The comparison graphs are presented in numerical analysis to show the effectiveness of the considered methods, and it is resulted that FEM gives closer results to TMM.

8 illus, 1 table, 24 ref

012562   Das S;Prasad J K (Birla Institute of Technology, Mesra, Ranchi-835 215) : Cowl deflection angle in a supersonic air intake. Def Sci J 2009, 59(2), 99-105.

A numerical study for a two-dimensional mixed compression supersonic air intake with different cowl deflections has been made with and without back pressure. Numerical simulations have been made with RANS solver using a k-w turbulence model. Overall flow field existing inside intake has been captured which indicates the change in flow field with cowl deflection angle. Overall performance has been obtained. Compulations have been also made with bleed. The computed data are compared with available experimental and numerical results and indicated a good comparison. Results obtained through the present series of computation indicate an improvement in performance with small cowl deflection which is comparable to performance with 2.8 per cent bleed.

19 illus, 13 ref

012561   Das D;Sahoo P;Saha K (Mechanical Engineering Dep, Jadavpur Univ, Kolkata-700 032, Email: kashinathsaha@gmail.com) : Elasto-plastic strain analysis by a semi-analytical method. Sadhana 2008, 33(4), 403-32.

Develops a simulation model of large deformation problems following a semi-analytical method, incorporating the complications of geometric and material non-linearity in the formulation. The solution algorithm is based on the method of energy principle in structural mechanics, as applicable for conservative systems. A one-dimensional solid circular bar problem has been solved in post-elastic range assuming linear elastic, linear strain hardening material behaviour. Type of loading includes uniform uniaxial loading and gravity loading due to body force, whereas the geometry of the bar is considered to be non-uniformly taper. Results are validated successfully with benchmark solution and some new results have also been reported. The location of initiation of elasto-plastic front and its growth are found to be functions of geometry of the bar and loading conditions. Some indicative results have been presented for static and dynamic problems and the solution methodology developed for one-dimension has been extended to the elasto-plastic analysis of two-dimensional strain field problems of a rotating disk.

16 illus, 2 tables, 17 ref

012560   Chitale V (NO, , Burckhardt Compression (India) Pvt. Ltd., Pune) : Reciprocating compressors for process gas applications. Process Pl Engng 2007, 25(3), 41-2.

Reciprocating compressors are an indispensable part of process industry viz. Oil & Gas processing plants and chemical plants. Compressors serve various purposes in industry like transportation of gases, hydrogenation of oils, polymerization of ethylene etc. Gases behave quite differently at different pressures and temperatures and with different gas compositions. It is, hence, very essential to know the thermodynomic behavior and gas properties for a selection of correct metallurgy for the compressor components. Experience and know how of gas compression technology plays an important role here! Burckhardt Compression's range of process compressors consists of 6 frame sizes - From frame Q - with 200 kW rating to frame C with 12 MW. Burckhardt Compression's Indian subsidiary - Burckhardt Compression India - is the centre of competence for Q & Y frames of process compressor family since 2006. Process Compressor type Y is a rugged design fully compliant to API 618 and is offered in both lubricated and non-lubricated versions. If could also be offered in horizontal balanced opposed version known as BY or vertical in-line version known as CY. This frame is available in multistage, multi cylinder configuration with feature of modular construction in 2 cranks, 4 cranks & 6 cranks versions.

5 illus

012559   Chaudhari D S (Electronics and Telecommunication Dep, Government College of Engineering, Amrarali-111 604, Email: ddsscc@yahoo.com) : Binaural dichotic presentation of speech signal for improving its perception to sensorineural hearing-impaired using auditory filters. IETE Tech Rev 2008, 25(2), 81-90.

Sensorineural hearing loss relates to spread of spectral masking resulting in reduction in frequency resolving capacity. Such hearing-impaired persons find difficulties while identifying consonantal 'place' feature cued by spectral differences. In binaural dichotic presentation scheme splitting of speech signal in real-time into two signals with complementary short-time spectra using filters with magnitude response based on two auditory filter banks with linear phase was implemented and evaluated. Filter banks corresponding to eighteen critical bands over 5 kHz frequency range were used. Listening tests were performed on subjects with 'mild' to 'very severe' bilateral sensorineural hearing loss. The usefulness of the scheme for better reception of spectral characteristics was evident as the results indicated improvement in speech quality, response time, recognition scores and transmission of 'place' feature particularly.

5 illus, 1 table, 12 ref

012558   Banerjee G (Central Glass & Ceramic Research Institute, P.O. Jadavpur University, Kolkata-700 032) : Fuzzy cognitive maps for identifying critical path in strategic domains. Def Sci J 2009, 59(2), 152-61.

Fuzzy cognitive maps (FCM) are hybrid tools of artificial neural network and fuzzy logic systems. One of their major uses is in decision support systems. To arrive at correct decisions the fuzzy interconnections between attributes arc either (rained or assigned by domain experts. The network target may be fixed or unknown. The FCM has been illustrated in a strategic domain in which the target is fuzzily defined and unknown. The target value is therefore estimated first by fuzzy inference rules for a collection of imprecisely defined attributes and then the fuzzy gradation to which the value belongs is used as the basis to tune the cognitive map The domain concerns a research institution. The target risk is the lime by which the projects run-off beyond the stipulated time of completion. The paper shows that certain instinctively chosen membership functions to tune the cognitive map are able to reproduce the belief surrounding the criticality of the domain.

3 illus, 5 tables, 16 ref

012557   Bagish B P;Sreenivas R L;Jaigopal R K (NO, , Scott Wilson India Pvt. Ltd., New Delhi) : Proof load testing of rob: different acceptance criteria by railways and IRC. Indian Highw 2008, 36(10), 23-36.

Proof load testing of Bridges is conducted for operational rating as stipulated in IRC: SP-37 and IRC: SP-51. Accordingly prestressed concrete superstructure of ROB at km 162.425 of Nellore Bypass, a part of GQ scheme, was proof load tested in May-June 2004. It being ROB acceptance of Railways is mandatory. Acceptance criteria of Railways are marginally different from that of IRC. The ROB satisfied the acceptance criteria of IRC and Railways, including maximum deflection and its recovery without appearance of any crack in shear or flexure zone. It is proposed that IRC and RDSO should have common acceptance criteria.

17 illus, 6 tables

012556   Anantheshwara K;Murali N S;Bobji M S (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: anantha@mecheng.iisc.ernet.in) : Effect of friction on the performance of inertial slider. Sadhana 2008, 33(3), 221-26.

Inertial sliders are friction based drives used to position with a resolution of a few hundred of nanometers to over a range of few millimeters. The compactness and simple construction enabled it to be used as a coarse positioner in various Scanning Probe Microscopes (SPM). Even heavy masses has been thought off earlier to use the inertial slider to position precisely, lack of understanding in the dynamical friction behaviour has been the main reason why the inertial sliders potential has not been explored fully in any practical device. In this paper, we have studied the effect of different operating parameters on the step size of the slider. The inertial mass is kept on three sapphire balls, which are attached to shear piezoelectric material. The behaviour of inertial mass was studied for different input waveforms and different surface conditions that come in contact with the sapphire balls. It was observed that under lubricated conditions the step size was reduced.

5 illus, 11 ref

012555   Alfa (NO, , Alfa Laval (India) Ltd., Pune) : Compact heat exchangers in ammonia / urea production. Process Pl Engng 2007, 25(3), 43-6.

The shell-and-tube heat exchanger is the most tried and tested of all heat exchanger designs. If dates back to the beginnings of the industrial revolution, when it was the basis of some of the earliest industrial steam boilers. If was the centrepiece of almost, if not absolutely, every steam locomotive that was ever built. It is still the most widely used single design type for heat exchangers. Its biggest advantage was its robustness and durability. But in relation to its heat transfer capacity if is both bulky and exceedingly massive.

7 illus

012554   Albert Alexander S;Karthikeyan J (NO, Kongu Engineering College, Perundurai) : Applications of artificial neural networks in power electronics. Karpagam J Comput Sci 2008, 2(3), 608-14.

Power Electronics is defined as electronic circuits used for electrical conversion. The conversion includes rectification and inversion. For a UPS inverter the output voltage obtained for the linear load is sinusoidal whereas for the non linear loading conditions the output voltage waveform is highly distorted. Hence it is necessary to maintain a sinusoidal output voltage for all loading conditions with minimum total harmonic distortion (THD). In this paper a neural network controller for UPS inverter applications is presented. The proposed neural network controller is trained offline using the patterns obtained from a simulated controller, which had an idealized load current reference. A sinusoidal Pulse width modulation (PWM) based switching UPS inverter has been modeled. The error in the output voltage and current are traced especially under non-linear loads. Simulation results shows that the proposed neural network controller can achieve low total harmonic distortion under nonlinear loading condition and good dynamic response under transient loading condition.

6 illus, 1 table, 15 ref

011635   Vivekanandan N (Statistics Div, Central Water and Power Research Station, PO : Khadakwasla Research Station, Pune-411 024) : Intercomparison of estimators of Weibull distribution for low-flow analysis. J Instn Engrs-Pt CI 2008, 89(May), 8-15.

Evaluation of low-flow characteristics of a river is fundamental to the assessment of water resources for many direct and indirect uses, such as, municipal, irrigation, hydropower and public water supply. Frequency analysis approach involving fitting of distribution to the series of annual minimum average flows derived from the recorded discharge data is employed for estimation of low-flow. The paper gives details of a study involving the use of five parameter estimation methods of Weibull (WB2) distribution for estimation of low-flow for different return periods for the rivers Godavari at Pathagudam, Mahanadi at Basantpur and Narmada at Mandleshwar sites. Goodness-of-Fit tests like Anderson-Darling and Kolmogorov-Smirnov are used for checking the adequacy of fitting of five methods of WB2 to annual minimum d-day average flow data of different values of d, such as, 7~days, 10-days, 14-days, and 30-days. Diagnostic analysis involving relative absolute error and mean square error is used for selection of an appropriate method of WB2 for low-flow estimation. The paper presents that the maximum likelihood method amongst the five methods is found to be suitable for evaluation of low-flow using WB2 for the river basins considered in the study. Low-flow frequency curves are developed and presented.

3 illus, 6 tables, 11 ref

011634   Vijayakumar V;Sukanesh R (Electronics and Communication Engineering Dep, Thiagarajar College of Engineering, Madurai-625 015) : Analysis of avalanche effect in quantum cryptography for wireless environment. J Instn Engrs-Pt CP 2008, 88(May), 14-18.

Quantum cryptography (QC) based on the laws of quantum physics, is the first application of quantum information methods. Emphasizes on the implementation of quantum cryptographic techniques for maintaining security at a noisy environment during daylight and at night, using single photon as a source. This is accomplished by the polarization property of photons for implementation ol quantum key distribution (QKD) and quantum-key exchange (QKE). In order to enhance the security, the symmetric key encryption cipher is combined with quantum key distribution protocol. The new protocol has been developed, with the modifications in data encryption standard (DES), which proves that it satisfies all security needs, ie, avalanche effect. Gives a complete analysis of the new protocol. This protocol performs well in the open air environment, where eavesdropping and the measured error rate are predominant. This security protocol offers higher quantum transmission rate and will result in more secured key distribution.

5 illus, 4 tables, 11 ref

011633   Venkaiah M;Kaushik S C;Dewangan M L;Ghade A (Mechanical Engineering Dep, Rungta College of Engineering and Technology, Bhilai-490 020) : Electricity model for energy security in India. J Instn Engrs-Pt ID 2008, 89(May), 14-20.

Energy is supplied in the form of electricity, heat or fuels and an energy supply system must guarantee sustainable energy supply, production and distribution of energy. An integrated energy system has been developed that can satisfy the demand of electricity in the country in appropriate and sustainable manner. Integrated Energy System for electricity generation is modeled and optimized using LINGO 10.0 software. The objective function targets at minimizing the cost and the constraints take care of various other factors such as demand, potential, reliability and emission. The production and demand for various energy sources in India is estimated with the help of data from various governmental departments. The electricity optimization model is prepared for the base year 2004. This model is a top-down optimization which requires energy requirement as a prerequisite and can be used to forecast the future energy mix for electricity generation in India. It is found that for the base year, 56.76% of the total demand is met by coal indicating that the country is mostly dependent on coal which is the primary energy resource. Gas meets about 8.21 % of the total electricity demand while from nuclear energy only 0.875% of demand is being met. Amongst the renewable energy sources hydro meets 10.61%, wind 17.33% and biomass 6.2% of the total demand. Oil and solar PV does not contribute in meeting the energy demand, as the unit cost of electricity generation from these resources is comparatively higher.

1 illus, 3 tables, 16 ref

011632   Tripathy C R;Dash R K (Computer Science and Engineering and Information Technology Dep, Univ College of Engineering, Burla, Orissa) : New fault-tolerant interconnection topology for parallel systems. J Instn Engrs-Pt CP 2008, 88(May), 8-13.

Introduces a new fault-tolerant interconnection topology called extended varietal hypercube (EVH). The proposed topology is recursive and has reduced diameter, average distance and constant degree of nodes. Illustrates various other important properties of the proposed system, such as fault-tolerance, reliability, message traffic density, message routing, broadcasting, cost factor, cost-effectiveness factor and time -cost-effectiveness factor.

4 illus, 4 tables, 10 ref

011631   Suryawanshi C S (NO, , PWD, Maharashtra) : Risk & incentives in infrastructure contracts. Indian Highw 2008, 36(12), 57-66.

Construction industry is also adopting new ways of acquiring business and enhancing profit. Two areas in particular have been subject to close scrutiny in recent years: the definition of risk, and the optimizing of incentives. Both these factors, risk and incentive, come hand-in-hand in the construction industry. Contractors who succeed have learned to manage risk and maximize profit taking, often in conditions of almost suicidal competition. But for every contractor who succeeds, many are victims of poor planning, poor budgeting, and poor resource management. The failed contractors are a measure of the industry's inefficiency, and their failures necessarily affect the facility owner and his expectation of results from the economic asset that was under construction. Paper focuses on risk and incentive provisions in the revised formats of FIDIC.

10 ref

011630   Sukanesh R;Harikumar R (ECE Dep, Thiagarajar College of Engineering, Madurai-625 015) : Pattern recognition and classification for medical diagnosis from bio-signals. J Instn Engrs-Pt ID 2008, 89(May), 24-32.

Reviews the usefulness of pattern recognition techniques for classification purpose in medical diagnosis from extracted features (patterns) of bio -signals. The main focus is given to different signal-processing techniques associated with ECG and FECG signals. The study of neural network and wavelet transforms models are given special emphasis. A new methodology of wavelet network, a hybrid structure, which is applied to identify the ventricular tachycardia (VT) patients is reviewed. The chaotic analysis is also discussed to demonstrate its capabilities in identifying the congestive heart failure (CHF) patients. Auto-regressive model for FECG signals to model the random white noise is also discussed. Of all these methods AI technique is stand apart in performing the pattern recognition tasks.

^iia4 illus, 24 ref

011629   Sudhakar A V;Raju V R;Rao K M (Production Engineering Dep, V R Siddhartha Engineering College, Vijayawada-520 007) : Thermoelastic analysis of skew laminated composite plate with a circular cutout. J Instn Engrs-Pt MC 2008, 89(July), 36-41.

The behaviour of a laminated composite skew plate with holes and fibres oriented parallel to the sides of the plate, subjected to temperature as well as combined temperature and transverse pressure loading has been investigated in the present analysis. A finite element method, which works on the basis of three-dimensional theory of elasticity, has been employed to evaluate the transverse deflection, in plane stresses and interlaminar stresses. The results obtained by varying the skew angle and the hole diameter have been discussed in this work. It has been observed that the magnitude of the stresses and deflection in case of combined loading are more when compared with the respective values in case of pure thermal loading. The magnitudes of the transverse deflection and in-plane normal stresses for combined loading have been observed to be less at higher skew angles for larger size of the hole. The solutions of skew structures considered in the present analysis would be useful for the construction of safe and efficient structures like skew bridges and swept wings of aircraft structures.

9 illus, 10 ref