016450   Murali Krishna M V S;Krishna Murthy P V; Seshagiri RAO V V R;Chowdary R P (Mechanical Engineering Dep, Chaitanya Bharathi Institute of Technology, Gandipet, Hyderabad-500 075) : Matching of injection timing in high grade low heat rejection engine for improved performance with jatropha oil based bio-diesel. Indian J envir Prot 2009, 29(1), 69-80.

The growing demand coupled with high cost and uncertainty of crude oil supplies had led to an extensive search for a suitable alternate fuel which can be obtained from renewable sources. Among the many contestants, vegetable oil seems to be a viable alternative for use in diesel engines due to the fact its adoption requires no modification to the primeªmover. However, drawbacks associated with vegetable oils, such as high viscosity and low volatility call for low heat rejection (LHR) engine, which is constructed with the provision of air gap of 3 mm in the threaded piston and in the liner, with superni-90 (a low thermal conductivity nickel alloy material) inserts, and ceramic coating (500μ) on inside surface of cylinder head. Performance evaluation of the LHR diesel engine is carried out with jatropha oil based bio-diesel by varying injection timings and injection pressures. Brake thermal efficiency (BTE) increased by 20%, while at peak load operation, smoke levels decreased by 27% relatively with LHR engine with jatropha oil based bio-diesel at an injection timing of 30°bTDC (before top dead centre) in comparison with the conventional engine with pure diesel operation at 27μbTDC and an injection pressure of 190 bars.

4illus, 9 tables, 17 ref

016449   Mukherjee S;Shi Z (NO, School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma-73019, USA) : State-of-the-art IV-VI semiconductor light-emitting devices in mid-infrared opto-electronic applications. IETE Tech Rev 2009, 26(4), 236-46.

Presents recent developments in the field of lead-salt light-emitting devices, having enormous applications in mid-infrared (MIR) opto-electronics. For the first time, achievement of an electrically excited edge-emitting QW laser on PbSnSe substrate is described. Novel fabrications of freestanding microstructures in the form of rod, tube and pillar, having vast applications in MEMS and NEMS, are reported.

16 illus, 41 ref

016448   Mukherjee M;Mazumder N (Centre of Millimeter-Wave Semiconductor Devices and Systems (CMSDS), C, University of Calcutta, 1, Girish Vidyaratna Lane, Kolkata-700 009) : Effects of charge bump on high-frequency characteristics of α-SiC-based double-drift ATT diodes at millimeter-wave window frequencies. IETE J Res 2009, 55(3), 118-27.

Extensive simulation experiments have been carried out on the DC and high-frequency characteristics of α-(4H) Silicon Carbide based double-drift (p^{++ p n n ++ type) impact avalanche transit time (IMPATT) diodes at two important millimeter-wave window frequencies (35 and 140 GHz). The studies reveal that the IMPATT diode designed at Ka-band (at around 35.0 GHz) may yield an RF power density of 10.72 x 1012 Wm-2 with an efficiency of 21.5%, whereas the D-band (at around 140.0 GHz) IMPATT is capable of delivering an RF power density of 0.38 x 10 12 Wm-2 with an efficiency of 15.0%. These results are very encouraging to choose SiC as a suitable base material for developing high-power and high-frequency IMPATT diodes. Impurity charge spikes are introduced in the flatly doped n and p regions of the double-drift diodes in the form of single low-high-low (p++ p p+ n n+ n n++ type) bump. The effects of this charge bump on the mm-wave characteristics of the double-drift 4H-SiC IMPATTs are analyzed for the first time, through a modified simulation technique. It is interesting to note that the introduction of charge spikes improves the overall performance of the designed diodes at the window frequencies.}

6 illus, 3 tables, 29 ref

016447   Mubarak M A B;Ali B M;Noordin N K;Ismail A;Ng C K (Computer and Communication Systems Engineering Dep, Faculty of Enginee, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia) : Review of handover mechanisms to support triple play in mobile WiMAX. IETE Tech Rev 2009, 26(4), 258-67.

Handover (HO) mechanism is one of the critical operations in mobile WiMAX. It takes place when a mobile station (MS) moves from a serving base station (BS) to another BS. However, the HO latency in mobile WiMAX is still an issue that may affect continuity of real-time application sessions such as Voice over Internet Protocol (VoIP). Presents performance comparison of some HO mechanisms for real-time applications in mobile WiMAX, including HO, cross-layer HO, pre-coordination HO, passport HO mechanisms and fast intra-network and cross-layer HO (FINCH). Each one of these mechanisms reduces HO latency, especially during downlink traffic; however, they still produce insufficient HO latency during uplink traffic. Except for FINCH, they do not consider the scenario of HO between BSs that belong to different access service network-gateways (ASN-GWs) or to different connectivity service networks (CSNs); these two cases cause extra layer 3 (L3) HO latency.

9 illus, 5 tables, 27 ref

016446   Mohanalin J;Kalra P K;Nirmal Kumar (Electrical Engineering Dep, IIT, Kanpur-208 016) : Microcalcification segmentation using normalized Tsallis entropy: an automatic "q" calculation by exploiting type II fuzzy sets. IETE J Res 2009, 55(2), 90-5.

Proposes an alternative approach to Tsallis entropy by considering the nonextensive property of mammograms. The novel thresholding technique is performed by normalized Tsallis entropy characterized by another parameter q, which depends on the nonextensiveness of mammogram. In previous studies, q was calculated using the histogram distribution, which can lead to erroneous results when pectoral muscles were included. In the study, authors propose a new technique to calculate q, which is independent of mammogram grades. Authors use type-II fuzzy sets to find the optimal value of q. The proposed approach has been tested on various images, and the results have demonstrated that the proposed normalized Tsallis entropy approach outperforms the two-dimensional nonfuzzy approach and conventional Shannon entropy partition approach and can be equally effective as Tsallis entropy. Moreover, the technique is completely automatic, and trial and error method is avoided as in previous literatures.

5 illus, 3 tables, 24 ref

016445   Manoj Kumar (B.R.A. Bihar University, , Muzaffarpur, Bihar) : Theory for transport properties of semiclassical fluids. Ultra Scient phys Sci 2009, 21(2), 345-50.

The effective diameter hard sphere theory is employed to estimate the transport properties (TP's) of semiclassical fluids. The TP's of the fluids are expressed in terms of a classical hard sphere (HS) fluid of properly chosen hard sphere diameter. The explicit expressions for the shear viscosity and thermal conductivity for the HS fluid are given. The theory is applied to estimate the TP's of fluids Ar and Ne. The agreement is found to be fairly good.

1 illus, 2 tables, 11 ref

016444   Lobo N (NO, BAeHAL (Joint venture of Hindustan Aeronautics Limited, India and BAE, UK, Email: nikhillobo@baehal.com) : Thinking outside conventional aerospace and defense technical publications using standard generalized markup language (SGML). Indian J Sci Technol 2009, 2(3), 60-5.

In aerospace and defense, documentation is of a very large size, highly structured and needs constant updating. Managing this documentation has been a constant challenge to the industry. At present, documentation is being created using traditional publishing software resulting in wastage of time and effort. Standard Generalized Mark-up Language (SGML) allows a document to be broken up into modules allowing reusability. SGML enforces content to be developed in a structured manner maintaining consistency across publications. This structured approach is achieved using a Document Type Definition (DTD). Separation of content from formatting is achieved using Format Output Specification Instance (FOSI).

3 illus, 1 table 12 ref

016443   Lin Y Y;Zou X C;Zhang J;Liu Z L;Chen X F (Electronic Science and Technology Dep, Huazhong University of Science and Technology, Wuhan-430074, People's Republic of China) : Designing efficiency enhanced low-dropout linear high-brightness LED drivers for automotive applications. IETE Tech Rev 2009, 26(3), 196-202.

Innovative efficiency-boosting technique is successfully applied to typical linear light emitting diode (LED) drivers. Furthermore, p-channel MOSFET (PMOS) pass element with elaborate metal layout pattern is used to reduce dropout loss and a 5V regulated voltage is obtained from the wide range input voltage to power some sub-circuits. This will further diminish power dissipation and thus enhance efficiency. The proposed driver has been fabricated on a 0.5 μm Bipolar CMOS DMOS (BCD) process. Post-simulation results show that when driving three high brightness light emitting diodes (HB-LEDs) in series, it can achieve maximum efficiency of 91.12% at I_LOAD = 350 mA, which is improved by 7.3%, as compared with that of the typical one under the same condition. Besides, the proposed driver is able to operate with a wide input voltage range (6V~32V) and deliver output current up to 350 mA, with an accuracy of ±3%, regardless of process voltage temperature (PVT) variations. Besides, the dropout voltage is only 450mV when I_LOAD =350 mA and V_IN =12V.

8 illus, 23 ref

016442   Kumar Krishen (NO, Innovation Partnership Office, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058 USA) : Technology needs for future space exploration. IETE Tech Rev 2009, 26(4), 228-35.

Human exploration and development of space is aimed at opening the space frontier by exploring, using, and enabling the development of space and expanding the human experience into the far reaches of space. This includes increasing human knowledge of nature's processes using the space environment, exploring and settling the solar system, achieving routine space travel, and enriching life on Earth through people living and working in space. NASA's Mars robotic explorations and the International Space Station provide extensive experience, research and technology (R&T), and infrastructure for other envisioned programs in support of human exploration and development of space. The missions to Moon by United States, Russia, China, India, and Japan have provided valuable data for the Moon. In addition, NASA has studied the development of a lunar habitat and human mission to Mars as possible future missions. These missions face common challenges of travel to these planets and for the survival of humans on the surface of the planets. With the human Mars mission being the first to such a distant planet, advanced technologies will be required to enable the mission and to provide cost effective and safer approaches. The R&T areas considered important for future human mission include advanced human support, renewable resources and utilization of planetary resources, space transportation, automation and robotics, space power, information processing and communications systems, sensors, and instruments.

4 illus, 8 ref

016441   Krishnamoorthy P;Mahadeva Prasanna S R (Electronics and Communication Engineering Dep, Indian Institute of Technology Guwahati, Guwahati-781 039) : Temporal and spectral processing methods for processing of degraded speech. IETE Tech Rev 2009, 26(2), 137-48.

Presents an overview of several most commonly used temporal and spectral processing methods for the enhancement of degraded speech. Three major sources of degradation, namely, background noise, reverberation and speech from the competing speakers, have been considered. Temporal processing refers to processing the degraded speech in the time domain, for enhancing the speech components. Spectral processing refers to processing the degraded speech in the frequency domain. Concludes with a summation that considers the possibility of combined Temporal and Spectral Processing (TSP) approach for the enhancement of degraded speech.

60 ref

016440   Koteswara Rao S;Raja Rajeswari K;Lingamurty K S (NO, NSTL, Visakhapatnam, Andhra Pradesh) : Unscented Kalman filter with application to bearings - only target tracking. IETE J Res 2009, 55(2), 63-7.

Unscented transformation coupled with certain parts of the classic Kalman filter, provides a more accurate method than the Extended Kalman Filter for nonlinear state estimation. Using bearings-only measurements, the unscented Kalman Filter algorithm estimates target motion parameters and detects target maneuver, using zero mean chi-square distributed random sequence residuals, in a sliding window format. During target maneuvering, the covariance of the process noise is sufficiently increased in such a way that the disturbance in the solution is minimized. When target maneuver is completed, the covariance of process noise is lowered. The performance of this algorithm is evaluated using Monte Carlo simulation and results are presented.

2 tables, 7 ref

016439   Kolhe K P;Kolhe P P;Dharaskar R M (Mechanical Engineering Dep, College of Agricultural Engineering and Technology, Dapoli, Ratnagiri) : Development of mathematical model for identifying bead geometry of arc welding for fabrication of farm machines. Asian Sci 2009, 4(1-2), 19-25.

Study was conducted to predict the weld geometry, mechanical properties and HAZ dimensions by developing mathematical models following statistical methods. The important process control variables of welding viz., voltage, current and travel speed were regressed with bead characteristics like quality, penetration, reinforcement, bead width etc. and the mechanical properties such as bead hardness, HAZ hardness etc. The purpose of such development of equation is to find the mathematical relation between the weld bead characteristics and mechanical properties with the welding parameters, as the dimensions and shape of the weld bead largely determine the strength of welded joint. For using automatic Submerged Arc Welding effectively, it is essential to develop equations that express mathematically the weld bead parameters in terms of process variables, the variation in HAZ dimension and microstructure. The relationship between welding variables and weld feature like hardness, bead geometry and HAZ width also reduces the cost of weld procedure development by decreasing the number of trial runs. In order to ensure adequate weld bead quality, it is necessary that various welding variables should be in proper balance. Therefore, it is essential to know the effect of the process variables individually and in combination on the resulting weld bead dimensions. These dimensions not only control the type of microstructure but also determine the stress carrying capacity of a welded joint. The developed mathamatical models in which the data is represented can be programmed, fed to a computer and used to develop an expert welding system. Statistical Analysis Software and MS Excel were used for the complete analysis.

1 illus, 1 table, 10 ref

016438   Khan M K (NO, Centre of Excellence in Information Assurance, King Saud University, Riyadh, Kingdom of Saudi Arabia) : Fingerprint biometric-based self -authentication and deniable authentication schemes for the electronic world. IETE Tech Rev 2009, 26(3), 191-5.

Presents fingerprint biometric-based self-authentication and deniable authentication schemes, which enable a receiver to identify source of the message but not to prove the identity of the sender to a third party. At first, authors identifies the security flaws of some recently proposed deniable authentication schemes by three application scenarios, and prove that those schemes are vulnerable to impersonation and eavesdropping attacks. For remedy, proposes two-factor-based self-authentication and deniable authentication schemes in which, firstly, each user has to perform self-authentication by something he knows (password) and something he is (biometrics), and then he can accomplish the transaction, e.g., e-commerce. Security analysis shows that the proposed schemes can overcome the security pitfalls of the previous schemes and are secure, reliable and practicable with high potential to be used in the electronic world.

22 ref

016437   Khan J A;Ravichandran S (Dr. MGR University, , Chennai-95, Email: vu3jak@rediffmail.com) : Object recognition using cellular neural networks on digital signal processors for network security. Icfai Univ J Inf Technol 2009, 5(1), 33-43.

Describes the necessity for network security using biometric systems, which are error free security systems. An attempt is made to use the fingerprint of an individual for accessing the secured network. On an experimental basis, a network of 25 systems was used to test and validate the working of the designed algorithm using Cellular Neural Network (CNN). Designing of the algorithm was carried out in code composer studio and implemented on Digital Signal Processor (DSP). Ideal fingerprint data was considered for analysis without any error.

6 illus, 8 tables, 12 ref

016436   Keshwani R T (Control Instrumentation Div, Bhabha Atomic Research Centre, Mumbai, Maharashtra) : Analysis of magnetic flux leakage signals of instrumented pipeline inspection gauge using finite element method. IETE J Res 2009, 55(2), 73-82.

Computational electromagnetics is used to study, design and optimize electromagnetic instruments. Introduces function of a magnetic instrument, namely, instrumented pipeline inspection gauge (IPIG), and various computational methods useful for its analysis. Usage of FEMLAB for detailed understanding of magnetic flux leakage (MFL) phenomenon both in 2D and 3D finite element analysis (FEA) is explained. It finally presents a method to perform an important step of defect characterization for IPIG by building large database using FEA tool.

25 illus, 1 table, 9 ref

016435   Kawasaki K (NO, Centre for Cooperative Research, Niigata University, Niigata 950 - 2181, Japan) : University-industry research collaborations of small-medium enterprises - an insight from Japan. IETE Tech Rev 2009, 26(2), 85-7.

Intensity and extent of university-industry research collaborations (UIRCs) are important for the support of small-medium enterprises (SMEs) and the activities of economy since the rate of SMEs is high in the regional area such as Niigata except in the urban area in Japan. Niigata, one of the areas in which SMEs are almost occupied, the joint research projects between the university and industry in Niigata University, schemes to joint research projects, and successful cases are discussed.

3 illus, 9 ref

016434   Kasal G;Bhim Singh (Electrical Engineering Dep, Indian Institute of Technology, Hauz Khas, New Delhi) : Design and control of voltage regulators for a standalone power generation. IETE Tech Rev 2009, 26(2), 115-36.

Presents various configurations of voltage source converter (VSC) based voltage regulators (VRs) for a stand alone power generation employing an isolated asynchronous generator (IAG). A set of VRs are designed and their performance is simulated using Simulink and Power System Blockset (PSB) toolboxes to demonstrate their capabilities as a voltage regulator, a harmonic eliminator, a load balancer and a neutral current compensator. It also discusses their merits and demerits, to select a suitable topology of the voltage regulator according to IAG system requirements.

27 illus, 2 tables, 60 ref

016433   Kannan R;Pillai V K (Physical and Materials Chemistry Div, National Chemical Laboratory, Pune-411 008, Email: vk_pillai@ncl.res.in) : Applications of carbon nanotubes in polymer electrolyte membrane fuel cells. J Indian Inst Sci 2009, 89(4), 425-36.

Carbonaceous materials play a vital role, in the performance of polymer electrolyte membrane fuel cells (PEMFC) irrespective of their use in cathode, anode and in bipolar plates. However, their use in composite electrolyte membrane has been only recognised recently especially after their functionalization to impart enhanced proton conductivity to the composite electrolyte. PEMFC development still has many material related challenges in terms of durability, degradation and more significantly cost reduction. Different methodologies have been adopted to deposit Pt electrocatalyst on CNTs and other carbonaceous materials, thus transforming them into the membrane electrode assembly. Functionalized carbon nanotubes with desired surface groups are found to be better for composite electrolytes since they increase the protonic conductivity along with increased mechanical stability. The use of CNTs doped with nitrogen indicates the possibility of total Pt removal from MEAs in the near future. Many of these recent advances in the application of carbon nanotubes and related materials in the functioning of polymer electrolyte fuel cells are discussed providing an overview of their possible role and limitations.

^iia4 illus, 3 tables, 84 ref

016432   Kandagal S B (Aerospace Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: sbk@aero.iisc.ernet.in) : Piezoceramic (PZT) patch in impulse hammer for modal analysis. Indian J Sci Technol 2009, 2(3), 1-4.

Novel application of Lead Zirconate Titanate (PZT) patch is explored to measure force imparted by the impulse hammer. It is built using cantilever aluminum with PZT patch. The characteristics of the impulse hammer are measured. Modal parameters estimated by both PZT patch based impulse hammer and that of force transducer are correlated by taking a cantilever beam configuration. The correlation of the performance parameters between the PZT based impulse hammer and force transducer based hammer establishes its potential application in modal analysis.

9 illus, 2 tables, 8 ref

016431   Kalanov T Z (NO, Home of Physical Problems, Pisatelskaya 6a, 100200 Tashkent, Uzbekistan, Email: tzk_uz@yahoo.com) : Correct theory of photon gas. Indian J Sci Technol 2009, 2(2), 1-10.

Correct theoretical analysis of the generally accepted foundations of theory of photon (quantum) gas is proposed. The principle of the unity of formal logic and of rational dialectics is the correct methodological basis of the analysis. The new results- the correct quantum-statistical foundations- obtained within the framework of the formulated master equation taking into consideration both the quantum states of the radiating molecule and the quantum states of the photon gas in the isolated macroscopic systems "molecule + molecular gas + monochromatic photon gas" are as follows: (a) Planck's, Einstein's, and Bose's works on the theory of photon (quantum) gas contain logical errors; (b) photon (quantum) gas being born by radiating molecule obeys "Gibbs statistics": equilibrium photon (quantum) gas is described by Gibbs quantum canonical distribution; (c) Planck function ("Bose's distribution") is an consequence of Gibbs quantum canonical distribution; (d) Einstein coefficients (i.e. the coefficients of spontaneous emission, induced emission and absorption) are equal to each other.

23 ref

016430   Jeevanandham A;Thanushkodi K (EEE Dep, Bannari Amman Institute of Technology, Sathyamangalam) : Reduction of generator rotor oscillations using improved simulated annealing technique. Indian J Pwr River Valley Dev 2008, 58(7-8), 122-8.

A classical lead-lag power system stabilizer is used for demonstration in this paper. Initially single first-order phase compensation block is considered. The stabilizer parameters are selected in such a manner to damp the rotor oscillations. The problem of selecting the stabilizer parameters is converted to a simple optimization problem with an eigen value based objective function and it is proposed to employ simulated annealing and improved simulated annealing for solving optimization problem. The objective function allows the selection of the stabilizer parameters to optimally place the closed-loop eigen values in the left hand side of the complex s-plane. The effectiveness of the stabilizer tuned using the best technique, in enhancing the stability of power system. Stability is confirmed through eigen value analysis and simulation results and suitable heuristic technique will be selected for the best performance of the system.

6 illus, 1 table, 9 ref

016429   Jayanna H S;Mahadeva Prasanna S R (Electronics and Communication Engineering Dep, Indian Institute of of Technology, Guwahati-781 039) : Analysis, feature extraction, modeling and testing techniques for speaker recognition. IETE Tech Rev 2009, 26(3), 181-90.

Speaker recognition system may be viewed as working in four stages, namely, analysis, feature extraction, modeling and testing. Gives an overview of the major techniques developed in each of these stages. Such a review helps in understanding the developments that have taken place in each stage and also the available choices of techniques, along with their relative merits and demerits. A comparative study of different techniques is done at the end of each section to justify the choice of techniques available in the state-of-the-art speaker recognition systems. Concluded with a discussion on the possible future direction for the development of techniques in each stage.

84 ref

016428   Jacob R;Thomas T;Unnikrishnan A (NO, Naval Physical and Oceanographic Lab, Kochi-682 021) : Applications of fractional fourier transform in sonar signal processing. IETE J Res 2009, 55(1), 16-27.

Underwater scenario with all its complexities has been always very challenging for sonar signal processing. The reverberation and the fast-fading nature of the channel make it necessary to use chirp waveforms for sonar transmissions. The conventional techniques based on Fourier transforms often fail to fully address the issues like Doppler estimation with chirp waveforms and low signal-to-noise ratio detection due to the vagaries of the medium. Alternately, the fractional Fourier transform (henceforth shortened as FrFT) can be used in sonar signal processing for improved chirp-detection performance. However, this useful signal-processing tool is largely unknown to the sonar signal processing community. Demonstrates the application of FrFT in active and intercept sonar signal processing. The motivation to adopt the proposed method is the ability of FrFT to process chirp signals better than the conventional Fourier transform. FrFT is a parameterized transform with parameter a, related to the chirp rate. Many active sonar systems choose to transmit chirp signals for better detection in the presence of reverberation. FrFT if used instead of FFT in the correlation receiver has great potential as it takes advantage of the knowledge of transmitted waveform and can be therefore implemented for the optimum order. In the simulations, performance of matched filtering with FrFT has been compared with performance using conventional FFT. In the case of intercept sonar, FrFT can be used to estimate the parameters of chirps from a multi-component signal. Presents a novel parameter-estimation procedure by which chirp parameters are calculated from the two primary estimates, namely, optimum order and FrFT peak position. Simulation results clearly demonstrate the potential advantages of the proposed methods.

27 illus, 8 ref

016427   Jacob K T;Rajitha G;Saji V S (Materials Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: materials.iisc.ernet.in) : Compatibility of RuO₂ electrodes with PZT ceramics. Bull Mater Sci 2009, 32(3), 313-19.

Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO₂) is a good electrode material for use with ferroelectric lead zirconate-titanate (PZT) solid solutions. Under certain conditions, RuO₂ can react with PZT to form lead ruthenate (Pb₂Ru₂O_6.5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO₂ and Pb₂Ru₂O_6.5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO₃ and PbTiO₃, the stability domain of Pb₂Ru₂O_6.5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO₃-rich compositions are more prone to react with RuO₂ at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973, 1173 and 1373 K.

9 illus, 2 tables, 19 ref

016426   Hsieh S P;Hwang T S;Ni C W (NO, Graduate Institute of Electrical and Communications Engineering, Taiwan 40724) : Twin-VCM controller design for the nutator system with evolutionary algorithms. IETE Tech Rev 2009, 26(4), 290-302.

Presents an evolutionary algorithm to optimize controller parameters for a nonlinear nutator system which is implemented in twin voice coil motors (VCMs). Genetics-based algorithm is applied to tune the proportional-integral-derivative (PID) controller for the multi-input multi-output (MIMO) coupling system. The result has been validated that this algorithm can find out all six PID control parameters in optimal and robust senses. The controller architecture of the nutator system is constructed to meet the specifications of the coupled mirror and rocker parallel loops, both adopting PID control. Two main linear VCMs operating in a push-pull organization drive the nutator subreflector. The mandatory operation mode for the nutator system is two-position switching. The required technical specifications for the nutator control system are extremely precise requirements, system tracking control with a disturbance force more challenging than that in ordinary systems. Simulation results have demonstrated the superiority of the evolutionary algorithm, satisfying the Atacama large ªmillimeter/submillimeter array (ALMA) severe conditions and requirements.

13 illus, 4 tables, 22 ref

016425   Hariharan V S;Vijaykumar Reddy K; (Mechanical Engineering Dep, Lakireddy Bali Reddy College of Engineering, Mylavaram, Krishna district, Andhra Pradesh, Email: hariharan_vs@rediffmail.com) : Performance, emission and combustion characteristics of a diesel engine using sea lemon oil-based fuels. Indian J Sci Technol 2009, 2(4), 43-7.

Experiments were conducted to study the performance, emission and combustion characteristics of a DI diesel engine using sea lemon oil-based fuels. Sea lemon oil and sea lemon oil methyl ester are tested as diesel fuels in diesel engine in neat form. The reduction in NOx emission and an increase in smoke, hydrocarbon and CO emissions were observed for Neat sea lemon oil compared to those of standard diesel. From the combustion analysis it was found that ignition delay was slightly more for both the fuels tested compared to that of standard diesel. The combustion characteristics of sea lemon oil and its methyl ester closely followed those of standard diesel.

10 illus, 18 ref

016424   Hanumantha Rao Y V;Voleti R S;Sitarama Raju A V;Nageswara Reddy P (Mechanical Engineering Dep, Koneru Lakshmaiah College of Engineering, Green Fields, Guntur-522 502, Email: rao_yvh@yahoo.co.in) : Experimental investigations on jatropha biodiesel and additive in diesel engine. Indian J Sci Technol 2009, 2(4), 25-31.

Performance of single cylinder water-cooled diesel engine using Multi-DM-32 diesel additive and methyl-ester of Jatropha oil as the fuel was evaluated for its performance and exhaust emissions. The fuel properties of biodiesel such as kinematic viscosity, calorific value, flash point, carbon residue and specific gravity were found. Results indicated that B25 have closer performance to diesel and B100 had lower brake thermal efficiency mainly due to its high viscosity compared to diesel. The brake thermal efficiency for biodiesel and its blends was found to be slightly higher than that of diesel fuel at tested load conditions and there was no difference between the biodiesel and its blended fuels efficiencies. For Jatropha biodiesel and its blended fuels, the exhaust gas temperature increased with increase in power and amount of biodiesel. However, its diesel blends showed reasonable efficiencies, lower smoke, CO₂ and CO. Multi- DM-32 additive with methyl ester of Jatropha offer fuel conservation as well as reduce pollution.

10 illus, 7 tables, 20 ref

016423   Hamdaoui B;Shin K G;Maiya M (NO, School of EECS, Oregon State University, USA) : Constraint design and throughput evaluation in multi-band wirelss network using multiple-input multiple-output links. IETE Tech Rev 2009, 26(2), 101-7.

Recent advances in radio technology enabled software-defined radios (SDRs), which can switch from one frequency band to another at minimum cost, are making dynamic multi-band access and sharing possible. Also, recent advances in signal processing combined with those in antenna technology, enabled MIMO (Multiple-Input Multiple-Output) capabilities, which created great opportunities for enhancing the throughput of wireless networks. Together SDRs and MIMO empower the next-generation wireless networks, such as mesh networks, with dynamic and adaptive bandwidth sharing and use along time, frequency, and space. Designs and model the radio and interference constraints on multi-hop wireless networks, when they are both SDR-capable and MIMO-equipped. The developed constraint models were then used to formulate and solve multi-hop routing problems in wireless networks with MIMO and multi-band capabilities. Evaluated and analyzed the throughput that multi-hop wireless networks can achieve, when they are both allowed to communicate on multiple bands and equipped with MIMO links.

2 illus, 11 ref

016422   Ghongade R B;Ghatol A A (NO, Vishwakarma Institute of Information Technology, Pune, Maharashtra, Email: rbghongade@gmail.com) : Deciding optimal number of exemplars for designing an ECG pattern classifer using MLP. Indian J Sci Technol 2009, 2(4), 40-2.

ECG pattern recognition using artificial neural networks is now an established paradigm. Diagnostic systems derive robustness, reliability and speed because of the automatic pattern classifiers. However, a common problem associated with these types of classifiers is to decide the optimal number of exemplars. Aattempts to find an optimal number of exemplars required for training a multilayer perceptron with acceptable accuracy. Extensive experimentation suggests a figure of 200. Although this figure is specific for multilayer perceptron based classifier, experimentation on similar lines can be performed for other ANN topologies.

5 illus, 1 table, 8 ref

016421   Ghate V N;Dudul S V (Electrical Engineering Dep, Government College of Engineering, Amravati, Maharashtra, Email: vng786@rediffmail.com) : SVM based fault classification of three phase induction motor. Indian J Sci Technol 2009, 2(4), 32-5.

Early detection of abnormal conditions during induction motor's operation would eliminate consequential damages on motor, so that outage time and costs of repairing can be reduced. Due to unique fingerprints from faults in line currents, it is possible to detect faults by extracting fault information from line currents. It is observed that in many model based on ANN based techniques, the stator current spectra is used as input feature space. Simple thirteen statistical parameters are used as an input feature space. Support Vector Machine (SVM) is proposed as a fault classifier. Since the basic SVM is essentially a 2-class classifier, the synergism of three classifiers is proposed to overcome the limitation. Principal Component Analysis (PCA) is used as data fusion method to reduce the dimension of classifier. To verify the performance various kernel function as (Radial Basis Function (RBF), Quadratic, Linear, Polynomial, Multilayer Perceptron (MLP)) are applied and tested with real experimental datasets. In order to generate the experimental data, specially designed 2 HP, three phase, 4 pole, 415V, 50 Hz induction motor is used.

7 illus, 11 ref

016420   Faro M L;Rosa D L;Antonucci V;Arico A S (NO, CNR-ITAE Institute, Via Salita S. Lucia sopra, Contesse 5 IT-98126 Messina, Italy, Email: arico@itae.cnr.it) : Intermediate temperature solid oxide fuel cell electrolytes. J Indian Inst Sci 2009, 89(4), 363-80.

Solid Oxide Fuel Cells (SOFCs) have suitable perspectives to replace their classical counterparts for the distributed generation of electrical energy with small and medium power sources (50 kWel). The main advantages of SOFCs rely on the high conversion efficiency and low environmental impact. Practical SOFC operating temperatures between 600°C and 800°C are aimed to increase life-time and reduce costs. These can be achieved only by using electrolytes with proper ionic conductivity at intermediate temperatures. Deals with a survey of the current research on advanced materials to be used as electrolyte for intermediate or low temperature solid oxide fuel cells. Specific properties such as reaction mechanism, chemical compatibility, effects of dopants, and conductivity are discussed.

^iia12 illus, 133 ref

016419   Deergha Rao K;Murthy T S N (NO, Research and Training Unit for Navigational Electronics, Osmania Univ, Hyderabad-500 007) : Mitigation of UWB signals spectral leakage to the GPS L1 band via filtering after clipping in the UWB transmitter. IETE J Res 2009, 55(1), 4-9.

Ultra-wideband (UWB) has recently attracted much attention as an indoor short-range high-speed wireless ªcommunication. However, the high peak-to-average power ratio (PAPR) limits its capacity due to distortion caused by nonlinear components such as high-power amplifiers. Hence it is necessary to reduce the PAPR of UWB signals. Deliberate clipping is a simple technique for PAPR reduction. But PAPR reduction of UWB signals by clipping may cause spectral leakage. The spectral power leakage to outside frequency bands causes interference with the other systems operating in the vicinity of UWB. Global Positioning System (GPS) has a pivotal role in so many critical systems upon which the public depends for its safety and well-being, and thus it is necessary to assess the interference to the GPS band due to UWB signals spectral leakage. Therefore, the interference to the GPS caused by spectral leakage of clipped direct-sequence UWB (DS-UWB) signals and multiband orthogonal frequency division multiplexing UWB (MB-OFDM UWB) signals is assessed, and the effect of filtering after clipping on the spectral leakage is evaluated using power spectral density (PSD) and bit-error rate (BER) as performance measures.

9 illus, 13 ref

016418   Das P K (Electrical Engineering Dep, , Kalyani Goverment Engineering College) : Present power scenario of seven north-eastern states of India. Indian J Pwr River Valley Dev 2008, 58(7-8), 115-21.

12 tables, 4 ref

016417   Chourasia V S;Mittra A K (Eelectronics Engineering Dep, MIET, Kudwa, Gondia, Maharashtra) : Comparative analysis of de-noising algorithms for fetal phonocardiographic signals. IETE J Res 2009, 55(1), 10-15.

Study is aimed at the selection of de-noising algorithm for de-noising of the fetal phonocardiographic (fPCG) signals. Fourier-based analyzing tools have some limitations concerning frequency and time resolutions. Although wavelet transform (WT) overcomes these limitations, it requires selection of appropriate de-noising algorithm. The universal threshold, minimax threshold and rigorous SURE (Stein's Unbiased Risk Estimate) threshold algorithms along with soft or hard thresholding rule have been compared for de-noising of these signals. The mean-squared error (MSE) is used to evaluate the performance of these algorithms. The results show that, the rigorous SURE threshold algorithm with soft thresholding rule has a better performance for the analysis of fPCG signals when using the fourth-order Coiflets wavelet. The proposed approach is simple and proves to be effective when applied for the selection of de-noising algorithm for the fPCG signals. These de-noised signals can be used for the accurate determination of fetal heart rate (FHR) and further diagnostic applications pertaining to the fetus.

6 illus, 15 ref

016416   Chellaram C;Edward J K P (Biomedical Engineering Dep, Vel Tech Multi Tech Dr. R.R. Dr. S.R. Engineering College, Avadi, Chennai-600 062, Email: dr.chellaram@gmail.com) : Anti-inflammatory potential of coral reef associated gastropod, Drupa margariticola. Indian J Sci Technol 2009, 2(2), 75-7.

Anti-inflammatory effect of the 100% acetone column purified extracts of gastropod, Drupa margariticola was experimented on albino rats shown promising result. The acute toxicity was noted, the LD₅₀ was found to be 375 mg/kg in 48 hrs of observation. Oral administration of doses up to 0.75g/kg did not show any toxic symptoms and did not provoke any significant change in their general behavior. The extract of D. margariticola at the concentration of 50 and 100mg/kg, p.o showed significant decrease in the paw thickness, 36.5 and 72.9 % respectively at the 5th hour of the experiment. The 100% column fraction of D. margarticola is potent inhibitors of exudative and proliferate phase of inflammation and might have provided valuable information with respect to the efficacy and safety of these compounds, when compared to standard drug, Diclofenac sodium. So it can be inferred that, upon further purification, these gastropod extract may be more potent than the standard drug. The 100% acetone column-purified fraction of Drupa margariticola has possible anti-inflammatory effect.

2 illus, 14 ref

016415   Chawla V;Jayaganthan R;Ramesh Chandra (Metallurgical and Materials Engineering and Centre of Nanotechnology, Institute Instrumentation Centre, Indian Institute of Technology Roork, Roorkee-247 667, Email: rjayafmt@iitr.ernet.in) : Microstructural characteristics and mechanical properties of magnetron sputtered nanocrystalline TiN films on glass substrate. Bull Mater Sci 2009, 32(2), 117-23.

Nanocrystalline TiN thin films were deposited on glass substrate by d.c. magnetron sputtering. The microstructural characteristics of the thin films were characterized by XRD, FE-SEM and AFM. XRD analysis of the thin films, with increasing thickness, showed the (200) preferred orientation up to 1.26 μm thickness and then it transformed into (220) and (200) peaks with further increase in thickness up to 2.83 μm. The variation in preferred orientation was due to the competition between surface energy and strain energy during film growth. The deposited films were found to be very dense nanocrystalline film with less porosity as evident from their FE-SEM and AFM images. The surface roughness of the TiN films has increased slightly with the film thickness as observed from its AFM images. The mechanical properties of TiN films such as hardness and modulus of elasticity (E) were investigated by nanoindentation technique. The hardness of TiN thin film was found to be thickness dependent. The highest hardness value (24 GPa) was observed for the TiN thin films with less positive micro strain.

5 illus, 1 table, 24 ref

016414   Charanjit Singh;Patterh M S;Sharma S (NO, University College of Engineering, Punjabi Univeristy, Patiala, Punjab, Email: charanjit@pbi.ac.in) : Design of programmable digital down converter for WiMAX. Indian J Sci Technol 2009, 2(3), 20-1.

Design of a programmable digital down converter (DDC) has been proposed, which can be used in digital receivers that meets IEEE 802.16d/e (WiMAX) standard in wireless communication system. The design is based on the idea of software radio technology and the theorem of multi-rate signal processing, It can be implemented on FPGAs and can replace traditional ASIC-based digital down converters in high channel count Software-Defined Radios.

7 illus, 4 ref

016413   Chakravorty J;Banerjee T;Ghatak R;Bose A; Sarkar B C (Physics Dep, University of Burdwan, Golapbag, Burdwan-713 104) : Generating chaos in injection-synchronized Gunn oscillator. IETE J Res 2009, 55(3), 106-11.

Chaotic dynamics of electronic circuits and systems is attracting the interest of researchers for the last few decades, mainly because of its potential for application in electronic communication systems. Different methods can be proposed to drive a microwave Gunn oscillator into chaotic mode. Among them, an injection-locked Gunn oscillator driven by a weak co-channel signal may be a feasible technique. The study considers this method through a hardware experiment and finds that under certain conditions of interference strength and detuning, chaotic oscillations of a Gunn oscillator can be observed.

7 illus, 12 ref

016412   Brindha V;Saravanan A;Manimekalai R (Bioinformatics Dep, Dr. MGR Janaki College, Chennai-28, Email: brindhav2@gmail.com) : Drug designing for ring finger protein 110 involved in adenocarcinoma (human breast cancer) using casuarinin extracted from Terminalia arjuna. Indian J Sci Technol 2009, 2(2), 22-6.

Breast cancer is the most common malignancy in women. Ring finger protein 110 was involved in the development of oncogenes, which mediate protein-protein interactions and involved in the formation of multi protein complexes. The investigation of the study reveals the modeling of the 3D structure of the protein with the final refinement of -9700.41KJ/Mol. Casuarinin, a hydrolysable tannin isolated from the bark of Terminalia arjuna was investigated for its antiproliferative activity in human breast Adenocarcinoma. The energy value -40.87 Kcal/ mol and the Rms score value -1.00 showed the hydrolysable tannin (Casuarinin) has higher specificity and efficiency towards the target protein ring finger 110.

8 illus, 16 ref

016411   Bin H;Justice A (NO, Beijing University of Chemical Technology, Beijing, China-100029) : Design of an unmanned aerial vehicle based on the ArduPilot. Indian J Sci Technol 2009, 2(4), 12-15.

Focuses on the design, modeling, implementation and testing of an autonomous unmanned aerial vehicle. The controller is based on an Ardupilot board which is a custom PCB with an embedded processor (ATMega168) combined with circuitry to switch control between the RC control and the autopilot control. It controls navigation (following GPS waypoints) and altitude by controlling the rudder and throttle. It uses flight stabilization system (co-pilot), a sensor pack, Global Positioning System (GPS) and an RF transceiver to monitor and report crucial parameters such as altitude, speed, pitch, roll, and position. An embedded software algorithm has been developed to enable the aerial vehicle accomplish the required autonomy and maintain satisfactory flight operation. The autopilot features an advanced, highly autonomous flight control system with an auto-launch and auto landing algorithms.

6 illus, 1 ref

016410   Batra D;Sharma S;Ratan R (ECE Dep, C.I.T.M. Faridabad, Faridabad, Haryana) : Axis controlled movement of robot using brushless DC motor drive. Indian J Sci Technol 2009, 2(4), 36-9.

Attempts to study the simulation of the kinematics routine for the axis control of the robot using brushless DC motor drive. The main motivation is to perform kinematics routines as well as control the robot in real-time. The graphical user interfaces (GUI) has been developed in Matlab. The GUI has been designed such that the user can get a feel for the kinematics of the 5-axis articulated robot. The system was developed for demonstrating the basic trajectory planning method for the axis control of robot. Further the trajectory planning platform was tested for a particular experiment and was found to be accurate enough for experimental purposes. This comprehensive software package allows the user to learn the various aspects of serial manipulator basics and also helps in exploring the concepts better by working in real-time.

10 illus, 11 ref

016409   Banerjee D;Roy T;Kar S (NO, Institute of Radio Physics and Electronics, University of Calcutta, 92, A.P.C. Road, Calcutta-700 009) : Computer-aided analytical study on the characteristics of left handed material structures at microwave frequencies. IETE J Res 2009, 55(3), 112-17.

Computer-aided analytical studies and physical understanding of important characteristics of some commonly used left-handed material (LHM) structures (wire-array and split-ring resonator), to realize negative effective permittivity and permeability leading to negative refractive index over a desired frequency band have been reported. The transmission of electromagnetic wave through LHMs and right-handed materials (RHMs) has some fundamental differences. This issue of electromagnetic wave transmission through LHM has been characterized, and a ªphysical insight of the phenomena has also been included. The LHM characterization using computer-aided analytical modeling shows good agreement with the previous numerical simulation and experimental results reported for such microstructures operating at microwave frequencies.

11 illus, 13 ref

016408   Audhkhasi K (Electrical Engineering Dep, Signal Analysis and Interpretation Lab (SAIL), University of Southern, Los Angeles, CA 90089-2564, USA) : Automatic evaluation of fluency in spoken language. IETE Tech Rev 2009, 26(2), 108-14.

Introduces the problem of automatic evaluation of spoken language fluency, and reviews some techniques proposed in the literature to solve it. In the first section, the need for automatically evaluating human spoken language skills is motivated through real life scenarios ranging from call centers to kindergarten classes. This is followed by a definition of the problem. Next, some important works in the domain are presented. Definitions of various relevant terms from speech and language processing subjects are intertwined to aid the uninitiated reader. Concludes by discussing the research challenges in the area.

3 tables, 24 ref

016407   Albaker B M;Rahim N A (UMPEDAC Research Centre, Faculty of Engineering, Univeristy of Malaya, 50603, Kuala Lumpur, Malaysia) : Signal acquisition and parameter estimation of radio frequency pulse radar using novel method. IETE J Res 2009, 55(3), 128-34.

Introduces a new functional architecture, together with a direct and efficient method of estimating signal parameters of a single pulse radar, in an electronic warfare digital receiver. The implemented architecture consists of three main units connected through different buffer hierarchy. These units are: Data acquisition and pre-processing unit; data analysis and radar parameter estimation unit; and the human computer interface unit. These units, invoked independently, allowed simple algorithms to be executed concurrently. In the data acquisition unit, the signal is digitized continuously after it is down converted into intermediate frequency signal. This signal is then converted into a video signal which stores radar pulse data upon signal existence. A double threshold noise gate is deployed, together with moving average sampling filter, to refine incoming data steam and avoid multi-triggering problem. In the data analysis unit, the processed radar signal parameters are estimated. This includes the estimation of intermediate ªfrequency, pulse width, time of arrival, time of departure, pulse repetition interval and pulse amplitude.

6 illus, 9 ref

016406   Abadi M S E (Electrical Engineering Dep, Shahid Rajaee Teacher Training University, Tehran, Iran) : Mean-square performance of selective partial update subband adaptive filters. IETE J Res 2009, 55(1), 35-9.

Presents a general formalism for the mean-square performance analysis of selective partial update subband adaptive filter (SPU-SAF) algorithms. This analysis is based on energy conservation arguments and does not need to assume a Gaussian or white distribution for the regressors. Demonstrates through simulations that the results are useful in predicting the performance of this family of adaptive filters.

6 illus, 16 ref

014031   Yakkundi V K;Mantha S S (Navi Mumbai, Mumbai Univ, Mumbai, Email: vivekyakkundi_itcoe@rediffmail.com) : CFD analysis of flow over car variants & validation with ahmed body. J Coop Univ Res Ind Enterpr 2010, 3(1), 1-12.

Wind force is considered as one of the dominating forces of nature which has influence on road vehicle dynamics & therefore on the vehicle stability & fuel economy. Also, wind resistance is amongst the three significant factors- namely efficiency of engine, weight & aerodynamic drag which influence the fuel efficiency (Hucho 1998). Therefore it needs a proper focus in the early stage of design. CAE/CFD serves the purpose of analyzing the design variants using virtual prototypes & virtual flowbench thus reducing the development' cycle time. Generally, for research purpose, motlified Ahmed body i.e. simplified car/Generic shape body is analysed which is considered as benchmark shape of a car and also designs adaptive to wind environment are not practical to design. Therefore in the present paper Ahmed body experimental data is used to validate the results of analysis of a midsegment car model generated from image in IDEAS. The subject midsegment car in absence of actual CAD model and its variants can be analysed in this manner and validated with Ahmed body data. The subject car is modeled from its image tracing & overall dimensions to achieve accuracy. The rear slant angle is observed to be 30 The aerodynamic analysis of two variants namely i) Original model ii) Streamlined model, (Rounded roof & rear top) is done using CFX 5.7 & the drag values and flow patterns are validated with that of Ahmed body. (Ahmed et al, 1984 & Emmanuel Guilmanaeu, 2007). The validation gives a fair amount of insight into the flow details and scope for improvement.

17 illus, 12 tables, 77 ref

014030   Warudkar V;Ahirwar B;Shah D K;Ahmed S (Mechanical Engineering Dep, Maulana Azad National Institute of Technology, Bhopal, Email: vilas_warudkar@rediffmail.com) : Design, development, fabrication and testing of small vertical axis wind turbine using 7% cambered plate. J Envir Res Dev 2010, 4(3), 854-65.

Among the different vertical axis wind turbine (VAWT) rotor is a slow running wind machine driven by drag force and has a lower efficiency as compared to lift type machine but it is also inexpensive. The present work is to design and develop a modified rotor for low windy regions, to develop a self starting and more efficient wind turbine, which can be used domestically; it is portable and easily fabricated with locally available materials. In this work, Plate profile of the rotor was modified by using 7% of cambered plate which is giving higher efficiency. The rotor is designed and fabricated for application in rural areas for generating electricity.

13 illus, 15 ref

014029   Sunil Kumar;Chaube A;Jain S K (Mechanical Engineering Dep, RGPV Bhopal, Madhya Pradesh, Email: shashi.k.jain@gmail.com) : Issues pertaining to substitution of diesel by jatropha biodiesel in India. J Envir Res Dev 2010, 4(3), 877-84.

Petroleum resources are depleting day by day and it is assumed that they are going to last at the most next forty to fifty years. Recent volatility in the price of petroleum has led to severe impact on economic health of most of the countries dependent on imported crude oil for meeting the domestic petroleum requirements. India needs to import crude oil to meet nearly seventy percent of its petroleum requirements; hence it has become a necessity to look out for suitable alternatives to petroleum based fuels. Considering forty percent of total petroleum based fuel used in India is diesel, Jatropha biodiesel is being promoted as a viable alternative to petroleum diesel. Before using Jatropha biodiesel as a substitute to diesel as well as in blended form with diesel several important issues like: crude price, diesel demand in future, supply of Jatropha biodiesel, impact on climate, impact on society, food versus fuel, impact of rupee depreciation etc. needs critical analysis.

3 illus, 5 tables, 9 ref

014028   Subhas C;Rama Naidu K;Venkatarami Reddy Y (NO, Sree Vidyanikethan Engineering College, Tirupati-517 102, Email: schennapalli@gmail.com) : Performance degradation in pre-rake frequency-division duplex/direct sequence-code division multiple access systems. Def Sci J 2010, 60(3), 282-9.

The transmitter-based pre-rake diversity combining technique reduces the complexity, size and cost of the mobile unit (MU), while achieving the same inter symbol interference (ISI) mitigation effects of rake receiver for direct sequence-code division multiple access (DS-CDMA) systems. The technique is based on preprocessing of transmitted signal relying on knowledge of the channel state information (CS1) before transmission. In most of the previous works, this a priori information is either assumed or estimated for the uplink and the same is applied to the downlink in time division duplex (TDD) systems due to channel reciprocity. In this paper, a method for channel prediction to evaluate the pre-rake system using binary phase-shift keying (BPSK) modulation in frequency-division duplex (FDD) through analytical and computer simulations for DS-CDMA downlink has been proposed. The performance of the system was also evaluated under ideal and predicted channel conditions using different spreading codes. The findings will have widespread applications in defence communication equipment.

5 illus, 17 ref

014027   Singh M;Alcantara R B;Skrzypczak S;Aldea A (Engineering Science Dep, Oxford Univ, Oxford, OX1 3PJ, United Kingdom, Email: minerva_singh@yahoo.co.in) : System to support policy development for the sustainable production of biofuels. Asian J Chem 2009, 21(4), 3279-94.

The authors present a system that supports the development of policies, in particular those related to food security. It does so by facilitating the communication between policy makers through the explicit computer representation of policy intent, content and rationale. A prototype software system has been implemented as an extension of Compendium (http://compendium.open.ac.uk) and its potential impact as a tool to be used during policy making is explained with the help of a case study on the sustainable production of biofuels in Zambia.

10 illus, 11 ref