012231   Atlihan G (Manufacture Engineering Dep, Faculty of Engineering, Pamukkale Univ, Kinikli 20070 Denizli, Turkey, Email: gatlihan@pau.edu.tr) : Buckling analysis of delaminated composite beams. Indian J Engng Mater Sci 2013, 20(4), 276-82.

Effects of stacking sequences, fiber orientation angles, boundary conditions and delamination numbers on the critical buckling loads of the laminated composite beams have been investigated analytically and numerically. Firstly, an analytical model is presented to take into consideration the reduction in stiffness of the beam due to the presence of the delamination in the beam. Then, two-dimensional finite element models for the composite beams having single/double middle delaminations have been established by using contact element at ANSYS commercial program. A good agreement between theoretical and finite element results has been found. It is seen that the buckling loads vary with changing stacking sequences, orientation angles and boundary conditions. The results show that a reduction in the critical buckling loads occurs when delamination length increases. In the numerical analysis, the appropriate buckling load values of the laminated beams are obtained by using normal penalty stiffness that is chosen as elasticity modulus for contact elements in the delamination region.

9 illus, 2 tables, 18 ref

012230   Arora V;Bhalke S;Ashok Kumar (Solidstate Physics Laboratory, , Lucknow Road, Delhi, Email: vijesharora@gmail.com) : 2.55 GHz wideband GaAs MMIC VCO. Invertis J Sci Technol 2013, 6(4), 217-20.

A 2.55 GHz MMIC Voltage Controlled Oscillator (VCO) with a tuning range of 31% has been developed using the indigenous 0.7 μm GoAs MESFET G7A process. The measured data indicates that a tuning range of 800 MHz (2550 ± 400MHz), and a minimum power output of 19.0 dBm were obtained in the first pass. The 7.9mm² chip comprises of an oscillator and a buffer amplifier, with the resonator on-chip and tuning varactors placed off-chip. The MMIC was operated at a bias of 5V and 120 mA and the measured single-sideband phase noise was better than -80dBc/Hz at an offset of 100 KHz.

7 illus, 4 ref

012229   Anayochukwu A V;Ndubueze N A (Electronic Engineering Dep, Nigeria Univ, Nsukka, Nigeria, Email: vincent_ani@yahoo.com) : Potentials of hybrid system in powering off-grid macro base transmitter station site. J Alternate Energy Sour Technol 2013, 4(2), 16-36.

This paper explores the possibility of hybridizing the diesel generator source system with renewable energy sources and demonstrate the potential of renewable energies to replace (partially) diesel as a source of power for mobile base station sites. The concept of hybridizing the diesel generator is to reduce both the operating cost and the quantity of different air pollutants. The patterns of load consumption by mobile base station are studied and suitably modeled for optimization using Hybrid Optimization Model for Electric Renewables (HOMER) software. The proposed Hybrid (Solar and Hydro) + DG system was simulated using the model which results in four different topologies. The solution with the highest optimization value is considered to be the best energy option (solution) for the Base Station Site. From the simulation results, the PV/Hydro-Diesel system solution has the highest optimization value. It saves $15,961,777 and 70.553 tonnes of CO₂ when compared with diesel only.

18 illus, 9 tables, 40 ref

012228   Anand G;Sinha A;Chattopadhyay P P (NO, School of Materials Science and Engineering, Bengal Engineering and S, Shibpur, Howrah-711 103, Email: anandgautam6@gmail.com) : Variation of tensile behaviour of interstitial free steel rolled at cryogenic and room temperature. J Instn Engrs : Ser D 2013, 93(2), 97-103.

Deformation behaviour of interstitial free/ferritic steel has been investigated at cryogenic and room temperature. The study concerns the occurrence of micro-structural damages during low temperature deformation conditions for such high stacking fault energy body centred cubic material and their role on the evolution of micro-structure and mechanical properties.

4 illus, 2 tables, 15 ref

011453   Thangavel P;Somasundaram P (Mechanical Engineering Dep, Kongu Engineering College, Perundurai-638 052, Email: vptvel@gmail.com) : Effects of evaporator load on vapour compression refrigeration system using eco friendly hydrocarbon refrigerants with sub cooling. J scient ind Res 2013, 72(11), 695-702.

Main objective is to study the effect of evaporator load on performance of vapour compression refrigeration system with eco friendly refrigerants with and without sub-cooling. Mixture of Propane (R290) and Isobutene (R600a) is used as alternate refrigerant to Hydro Fluorocarbon (HFC) and Chlorofluorocarbon (CFC) compounds in this analysis. Performance analysis is investigated at different loads in evaporator. Hydrocarbon mixture (HCM) is an alternative refrigerant for HFC and CFC compounds due to their lower Global Warming Potential (GWP) and zero Ozone Depletion Potential (ODP). Computational analysis is carried out to study the performance of the proposed mixture and also compared with conventional refrigerants R12 and R134a with respect to condensing temperature. In order to operate the refrigeration system at economical mode, the evaporator is loaded at various load conditions like 25%, 50%, 75% and 100%. Various performance parameters like discharge temperature, compressor input power, heat rejected in the condenser, refrigeration effect and Coefficient of Performance (COP) are investigated at various loads in the evaporator. The analysis is carried out for condensing temperature from 30°C to 65°C and evaporator is maintained at -10°C. As per computational analysis, discharge temperature and pressure ratio of HCM is about 3.9-7.4%, 16.4-24.9% lower than R134a and about 2.8-9.4%, 5.5-8.6% lower than R12. Volumetric efficiency of HCM is about 1.8-6.5%, 2% higher than R134a and R12 respectively. From the experimental load analysis, 75% load in the evaporator gave better results in terms of higher refrigeration effect and COP, lower discharge temperature and low compressor input power consumption as compared to other loads. Heat rejection rate for 75% load is moderate with 50% load. COP is about 8.5-24%, 2.9-11.9%, 1.9-5.5% higher than 25%, 50% and 100% loads respectively. Under sub cooling analysis in 3°C, 4°C and 5°C, the COP of the 75% load is about 1.1-9.3%, 2.5-13.4% and 2.5-14.5% higher than 50% load respectively. Based on computational analysis HCM could be used as an eco friendly refrigerant in the refrigeration system. The experimental results show that 75% load of evaporator having the feature of economic mode to operate the refrigeration system.

4 illus, 2 tables, 12 ref

011452   Ramasamy R;Gounder M K (Automobile Engineering Dep, K.S.R. College of Engineering, Tiruchengode, Email: rameshsumi@gmail.com) : Novel hybrid compact filter system for a down-draft gasifer: an experimental study. J scient ind Res 2013, 72(11), 663-8.

Major in biomass gasification is tar formation which in subsequent stages decomposes under the conditions such as temperature, pressure drop, gas flow rate and retention time. The potential of proposed hybrid filter for gas cleaning system analyzed here is excellent for reducing the tar and pariticulate in producer gas. Critical review of literature reveals that all existing system have maximum tar removal capacity of 90%. However, an exemption, catalytic crackers have efficiency in the range of 90 to 95%, but it operates at very high temperatures (900°C). An attempt has been made to develop an efficient hybrid filter system and analyze its performance characteristics that operates in a low temperature range of 50-70°C. The performance of developed compact hybrid filter was successfully tested with a 20 kW open core downdraft TNAU-SPRERI's gasifier. The concept of hybrid compact filter presented in this study, is first of its kind and it claims maximum tar reduction rate, than any other system reported and its magnitude varies from 93% - 97%. Moreover, the experimental results reveals that tar and particulate content is converged to 52 mg/Nm³ from an initial range of 1680 mg/Nm3 and greatly useful for reducing the engines wear and tear. Furthermore the filter design was developed with cost benefit on commercial basis.

5 illus, 2 tables, 25 ref

011451   Pramod Kumar;Singh A K (Electronics & Radar Development Establishment, Defence Research and Development Organisation, C V Raman Nagar, Bangalore-560 093, Email: pndk_itbhu@yahoo.co.in) : Phase only pattern synthesis for antenna array using genetic algorithm for radar application. Indian J Radio Space Phys 2013, 42(4), 259-64.

Author describes the phase only pattern synthesis for the active phased array antenna using genetic algorithm. The phase only synthesis is required to broaden and shape the beam in transmit mode of operation where all elements are fed through the saturated power of transmit/receive modules (TRM). This technique is very useful in multifunctional radar application where broadened beam can occupy more search volume (reduction in frame time). The real coded genetic algorithm (GA), which has ability to find solution of complex problems, has been exploited to get the required shaping of the beam. GA based software is a high performance optimizer and is very easy to understand and implement.

9 illus, 10 ref

011450   Palaskar V N;Deshmukh S P (Mechanical Engineering Dep, Veermata Jijabai Technological Institute, Mumbai, Email: vnpalskar@vjit.org.in) : Design configurations of hybrid photovoltaic/thermal solar system technology. Proc Indian Natn Sci Acad 2012, 78(4), 725-34.

Temperature of photovoltaic module increases when it absorbs solar radiation, causing a decrease in electrical efficiency. A hybrid photovoltaic/thermal collector or hybrid (PV/T) systems are used to partially avoid this undesirable effect. A water/air circulation system has found to be necessary to overcome the degradation in open circuit voltage (Voc) with PV panel temperature. The cooling of PV module helps to increase the electrical output and hot water can be obtained which will be improved the overall efficiency of the system. This paper gives a review of the trend of development in the technology of flat plate PV/Thermal water or air Collectors, in particular the advancements in recent years and the future work required.

^iia9 illus, 27 ref

011449   Mohindru P;Khanna R;Bhatia S S (Electronics and Communication Engineering Dep, College of Engineering Univ, Punjabi Univ, Patiala-147 004, Email: Pooja_citm13@rediffmail.com) : Analysis of chirp signal with fractional fourier transform. Proc Indian Natn Sci Acad 2012, 78(4), 637-44.

Fractional Fourier transform (FrFT) is well suited for processing of non-stationary signals especially linear frequency modulated signals and chirped signals. It is a parameterized transform which provides extremely compact representations. In this paper a closed-form expression of the fractional Fourier transform of chirp signal is derived. The FrFT of chirp is used in calculating the spread of the signal representation for linear chirp in any fractional domain. The derived expression establishes the dependence of chirp parameters on optimum FrFT angle and FrFT peak delta location. Based on this derivation, a fractional Fourier transform based filter for chirp noise removal is designed. The results derived show that the simulation results and analytical results closely match.

4 illus, 9 ref

011448   Guo L;Tian S;Wang Z (NO, School of Automation Engineering, Electronic Science and Technology of, Chengdu-611 731, China, Email: wangzhigang@uestc.edu.cn) : Research on broadband signal spectrum measurement technique based on channelization. J scient ind Res 2013, 72(11), 673-80.

With rapid development of radio technology, communication technology and digital signal processing technology, either carrier frequency or bandwidth of signal spectrum shows rapid growth. Classical measuring tools and methods cannot satisfy measuring requirements of broadband spectrum. Owning researches and breakthroughs in terms of broadband digital intermediate frequency processing technique is the top priority to realize broadband digital signal spectrum measurement. In this paper, channelized Weighed Overlap-add (WOLA) structure and parallel Fast Fourier Transform (FFT) are introduced to cut the input broadband signal into several adjacent narrowband parts, and a new method of pass-band splicing is proposed to combine the pass-band spectrum of the narrowband parts appropriately to get the frequency spectrum of the broadband signals.

8 illus, 10 ref

011447   Dhanamurugan A;Subramanian R (Mechanical Engineering & Aeronautical Engineering Dep, Nehru Institute of Technology Coimbatore, Anna Univ, Chennai, Tamil Nadu, Email: 1973dha@gmail.com) : Performance of single cylinder diesel engine with bael seed biodiesel. J scient ind Res 2013, 72(11), 690-4.

This paper presents application of biodiesel produced from bael (Aegle marmelos) seed oil in a single cylinder diesel engine and compares biodiesel performance and emissions characteristics with petro diesel. Performance parameters of B20 (Brake thermal efficiency and Brake Specific Energy Consumption) were quite close to petroleum diesel. B20 emits lesser emissions (CO, HC, NO_x, and CO₂) than petro diesel except smoke level. Thus, B20 (20% biodiesel + 80% diesel, by volume) can be effectively used as diesel fuel substitute in existing diesel engine without any engine modification.

4 illus, 1 table, 15 ref

011446   Baksi A;Putatunda S;Sen D;Sarkar A; Bhattacharjee C (Chemical Engineering Dep, Jadavpur Univ, Kolkata-700 032, Email: c.bhatta@gmail.com) : Protocol development for the carbohydrate quantification in black liquor with brix refractometer. J Instn Engrs : Ser E 2013, 93(2), 69-74.

Present work is a proposed methodology to quantify carbohydrates even at its trace level in black liquor (BL) in the presence of lignosulphonates (LS) using brix refractometer. Primarily, the detection accuracy was validated with the simulated solutions resembling BL used in the present work. A factor, resembling the weight fraction of LS and inorganics, was multiplied with the brix degree obtained for the simulated solution to convert it into the brix reading for a sole carbohydrate present in the solution along with other chemicals. It was found that the accuracy level of measuring carbohydrate was within ±1-2% of the actual.

3 illus, 3 tables, 14 ref

010216   Zakaria N M G (Naval Architecture & Marine Engineering Dep, Bangladesh Engineering & Technology (BUET) Univ, Dhaka 1000, Bangladesh, Email: utta108@gmail.com) : Moving forward with export oriented shipbuilding industries in Bangladesh. J Instn Engrs: Ser C 2012, 93(4), 373-82.

In the recent time, shipbuilding has been considered as a thrust sector in the economy of Bangladesh. But, there exist various problems that obstruct the development of this sector especially for export oriented shipbuilding. In this paper, the general shipbuilding related problems along with its nature have been identified. The prospects of export oriented shipbuilding in context of global and international demand have been highlighted. Also, the present initiatives towards export oriented shipbuilding has been focused. Finally some recommendations have been put forward in this paper in order to hold a firm position in world shipbuilding market by export oriented shipbuilding industry in Bangladesh.

6 illus, 1 table, 8 ref

010215   Yi Y;Li C;Lee K (Electroncs and Radio Engineering Dep, Kyung Hee Univ, Suwon, Korea) : Wavelength division-adaptive interference cancellation applied in OFDM visible light communication systems. IETE J Res 2012, 58(5), 390-7.

This paper studies the performance degradation caused by optical Doppler shift in light-emitting diode-based visible light communication systems, which integrate orthogonal frequency division multiplexing (OFDM). Through theoretical analysis and computer simulations, we can observe that frequency offset plays a significant role in the OFDM performance deterioration due to inter-carrier interference (ICI) and common phase error (CPE). Therefore, a scheme to correct the frequency offset by using wavelength division-adaptive interference cancellation (WD-AIC) was proposed. The main approach is to assign an estimated sub-carrier after every two adjacent sub-carriers to reduce the negative effects of both ICI and CPE. Finally, the simulation results declare that our proposed WD-AIC is indeed effective against the high degree of frequency offset.

9 illus, 1 table, 9 ref

010214   Yi Y;Li C;Lee K (Electronics and Radio Engineering Dep, Kyung Hee Univ, Suwon, Korea) : Adaptve MMSE equalizer for optical multipath dispersion in indoor visible light communication. IETE J Res 2012, 58(5), 347-55.

Multipath dispersion results from optical signals passing through more than one path. In this paper, we investigate a non-directed line of sight (LOS) model using white light emitting diode illumination. Typically in such a link, the optical signals are modeled as a reflection component and a directed LOS component over optical wireless (OW) channels. However, inter-symbol interference (ISI) induced by multipath dispersion critically influences the performance of OW communications. In this paper, we propose the adaptive minimum mean squared error (MMSE) equalizer scheme to suppress the multipath ISI, since this scheme can minimize the mean square error (MSE) between the desired equalizer output and the actual equalizer output. We compared the following two algorithms: Least mean square and recursive least square. Our computer simulations demonstrated that visible light communication using an adaptive MMSE equalizer can alleviate the serious effects of optical multipath dispersion.

13 illus, 21 ref

010213   Yadav S;Varun;Siddhartha;Kaushal M (Mechanical Engineering Dep, I.T.S. College of Engineering, Greater Noida-201 308, Email: varun7go@gmail.com) : Heat transfer and frictional characteristics of rectangular channel air heater duct having protrusion as roughness elements. J Instn Engrs: Ser C 2012, 93(4), 307-12.

An experimental investigation has been carried out to see the effect of roughness element on heat transfer and friction factor on the absorber plate of the solar air heater. The roughness provided is in the form of protrusions which are arranged in an arc pattern. This paper presents an investigation to study the effect of protruded geometry on heat transfer coefficient and friction factor in an artificially roughened solar air heater duct. The protrusions forming an arc having an arc angle (a) of 60° which is mounted on the test section of duct to create turbulent flow through the test section. Measurements are carried out for rectangular duct of having aspect ratio (W/H) of 11 and Reynolds number (Re) ranges from 3,500 to 18,000. The results obtained for various relative roughness pitch (P/e) has been compared with smooth one.

10 illus, 1 table, 23 ref

010212   Waware M;Agarwal P (Electrical Engineering Dep, Walchand College of Engineering, Sangli, Maharashtra) : Hardware realization of multilevel inverter-based active power filter. IETE J Res 2012, 58(5), 356-66.

This paper presents the development and implementation of multilevel inverter (MLI)-based active power filter (APF) using DSP of dSPACE. Implementation of MLI for APF in high-voltage system eliminates use of bulky and high-cost transformer to connect APF. This algorithm, to generate switching signal of devices, is developed in MATLAB SIMULINK. The reference signals of APF are generated by using instantaneous reactive power (p-q) theory. Carrier phase-shifted pulse width modulation (CPS-PWM) scheme is implemented to generate switching signals which reduces the individual device switching frequency. Experimental results of prototype model are presented under different loading conditions to investigate the steady-state and transient performance of the APF.

17 illus, 13 ref

010211   Wan W;Wang S (Mewbourne School of Petroleum and Geological Engineering, Oklahoma Unv, Norman, OK, USA, Email: wanw@ou.edu) : Determination of residual oil saturation and connectivity between injector and producer using interwell tracer tests. J Petrol Engng Technol 2013, 3(3), 18-24.

In this paper, based on simulation, a reservoir is first waterflooded and then the interwell tracer tests are used to determine the residual oil saturation (Sor) and connectivity in the region between the injector and producer pairs. In the end, the field wide average oil saturation from the simulation is compared with those from the interwell tracer test analysis. The simulation results shows that average Sor in the region between injector and producer pairs from tracer test analysis are much lower than the field wide average oil saturation obtained from simulation. This is probably because tracer tests only provide Sor in the region between different injector and producer pairs, without considering the oil in the upswept pore volumes, which may have higher oil saturations because their oil are bypassed by waterflood. Another reason is that significant percentage of oil is produced during the interwell tracer test. Final conservative tracer recovery percentage in the end of the interwell tracer test for four producers show that producer PI and P4 have a much higher connectivity to injector than producer P2 andP3.

10 illus, 2 tables, 13 ref

010210   Vijai K;Kumutha R;Vishnuram B G (Civil Engineering Dep, Sona College of Technology, Salem, Tamilnadu, Email: vijai_me@yahoo.co.in) : Feasibility study on effective utilisation of fly ash from two thermal power stations on the development of geopolymer concrete. J Ind Pollut Control 2012, 28(1), 35-40.

In order to address environmental effects associated with Portland cement, there is a need to develop alternative binders to make concrete. An effort in this regard is the development of geopolymer concrete, synthesized from the materials of geological origin or by product materials such as fly ash, which are rich in silicon and aluminum. This paper presents results of an experimental program on the mechanical properties such as density, compressive strength, split tensile strength and flexural strength of geopolymer concrete using fly ash collected from Mettur and Tuticorin thermal power stations. The various parameters of study for this investigation were i) Source of fly ash ii) Concentration of NaOH (8M, 12M and 16M) iii) Type of Curing (Ambient Curing at room temperature and Heat curing at 60°C for 24 Hours in Hot air Oven) iv) Age of Concrete (7 days and 28 days). The test results indicated that for both the sources of fly ash, there was an increase in compressive strength, split tensile strength and flexural strength of geopolymer concrete with increase in age, concentration of NaOH and also due to heat curing.

8 illus, 1 table, 14 ref

010209   Verma R;Singh H S;Verma A K (CSE Dep, Faculty of Engineering J.N.V. Univ, Jodhpur, Rajasthan, Email: rachna_mbm@yahoo.co.in) : Depth estimation from stereo images based on adaptive weight and segmentation. J Instn Engrs : Ser B 2012, 93(4), 223-9.

Stereo vision is one of the most researched areas to develop human like vision capability into machines for the purpose of automatic navigation and reconstruction of the real world from images. Point correspondence matching for disparity map calculation is a vital research issue of stereo vision system. Window-based cost aggregation methods used for the correspondence problem have attracted researches as it can be implemented in real time. In this paper, a new hybrid cost aggregation strategy for similarity evaluation based on adaptive weight and color segmentation of stereo image is proposed. In this strategy, pixels which lie on same segment and are spatially closer are given higher weight. Experimental results show that the proposed method is effective in improving overall disparity map and at depth discontinuity.

4 illus, 1 table, 12 ref

010208   Varghese B (Doctorate of Philosophy, Organizational Management and Diplomacy at Sofia Univ, Bulgaria-United Nations Campus, USA, Email: bjvarghese@gmail.com) : Empirical study summary on integrated building commissioning for new US federal domestic construction projects. J Constr Engng Technol Mgmt 2013, 3(3), 37-44.

Current management practices for federal domestic construction projects need to be modified to mitigate the negative effects newly constructed buildings have during the first few years of occupation. These negative effects include poor indoor air quality and poor performance of its tenants during the initial years of building occupancy. This empirical study focuses on the staff of the US Mission to the United Nations (USUN) as an off-site temporary facility was built for them in 2004 followed by a permanent office building in 2010. The newly constructed temporary facility exhibited indoor air quality deficiencies and the performance levels of USUN staff were also diminished during the initial years of occupancy. For the construction of the permanent building, the United States Department of State decided to employ a new project management practice of integrated building commissioning. Integrated building commissioning is the systematic, documented and collaborative process including inspection, testing and training conducted to confirm that a building and its component systems meet the requirement of the occupants and conform to the design intent. It involves the special expertise of the client government offices throughout the entire construction process by thoroughly integrating them within the networked process of a major construction project. The permanent USUN building yielded results that showed acceptable levels of satisfaction with the indoor air quality immediately after occupation and the performance levels of the USUN staff also increased comparatively in the initial years after occupation.

6 ref

010207   Ubaidullah S;Upadhyay R;Raut S A;Rahman I (NO, Institute of Chemical Technology Univ, North Maharashtra Univ, Jalgaon-425 001, Email: r.imran@ncl.res.in) : Optimization of continuous extraction column and solvent selection using differential evolution technique. J Instn Engrs : Ser E 2012, 93(1), 49-54.

This paper presents the solvent selection and optimal design of continuous liquid-liquid extraction column by differential evolution algorithm, a global optimization technique. The multi-component and multi-stage extraction column is simulated using equilibrium based method. Differential evolution technique is combined with column model and liquid-liquid equilibria model. A general case of extraction of acetic acid from water is explored when three solvent are available. The decision variables chosen are the solvent, number of stages and solvent flow-rate. The objective function is minimization of total annualized cost of column while selecting best solvent from cost perspective.

3 illus, 3 tables, 25 ref

010206   Thareja P (NO, PEC Technology Univ, Chandigarh, Email: prof.pthareja@gmail.com) : Innovative process renovation in phosphating for corrosion (resistance), energy & quality improvement. J Mater metall Engng 2013, 3(3), 23-7.

Phenomenon of corrosion is of unsolicited importance, but its obviating agent-phosphating- has more roles than of a mere preservation. Viz enhancement of lubricating properties for wiredrawing. The efficiencies need be studied, researched and monitored, for respective purpose(s). The modus operandi of protective film developed, in turn apart from improving the quality of product, also depends as to how the process parameters have been controlled. Criticality of the present case arose when the cost of energy arose exorbitantly, inviting a relook at the inefficient and ineffective process, both from cost and quality angle. The challenge had actually emanated because of excessive thermal energy usage, making process economics out of reach. The corrective endeavor based, 'Innovation' deployed helped not only reduced content/cost of energy by lowering temperature of the electrolyte, and the energy consumption; but also increased the quality and productivity. The motivation for this paper comes from the potential suitable innovation can play for improving the process dynamics for all round gains. The need is a secure planning and persistence in honing the process parameters.

1 illus, 4 ref

010205   Sundararaman K;Gopalakrishnan M (EEE Dep, Sri Venkateswara College of Engineering, Pennalur, Sriperumbudur, Email: sundararamank@svce.ac.in) : Topology review of isolated multi-output converters. J Pwr Elect Pwr Syst 2013, 3(1), 5-17.

This paper does a comprehensive review of isolated multi-output converter topologies. The converters are broadly grouped in to three different categories: Cross regulated converters, Post regulated converters and resonant converters. The working principles are discussed and the relative features of the topologies are brought out.

26 illus, 50 ref

010204   Srinivasan V;Jeya Kumar M P;Kausalya R (Automobile Engineering Dep, Bharath University, Chennai-73, Email: srinivasan_v9779@yahoo.co.in) : Pneumatic car performance and its application. J Innovative Res Solut 2013, 1(2), 82-7.

Compressed air kept under a pressure that is greater than atmospheric pressure serves many domestic and industrial purposes. In Europe 10% of all industrial electricity consumption is to produce only by compressed air amounting to 80% terawatt hour's consumption per year. The aim of this paper to discuss the results obtained from the performance of the pneumatic car constructed with a weight of 350 Kg (includes driver, pillion, air tank, air motor, car chassis, steering, disc, chassis and four wheels). This kind of system is called pneumatic car. In this car regenerative braking system is used to conserve the energy. This type of car can eliminate the pollution created by fuel vehicles in the environment. The maintenance cost can be minimized. The limited storage capacity can be modified using the technological develop.

5 illus, 7 ref

010203   Sivaramakrishnan J;Tiwari R (Electrical Engineering Dep, Indian Institute of Technology Delhi, New Delhi) : Controller design of twin spool gas turbine using reduced output feedback sliding mode control. IETE J Res 2012, 58(5), 367-74.

The twin spool gas turbine engine, which is an integral part of the avionics, is a nonlinear large order multi-input multi-output dynamical system. The design of a controller for the turbine engine using classical techniques is a tedious task and implementation of the complex controller is also an issue. The gas turbine system model is an uncertain one due to the existence of multiple operating points. Thus, a robust control technique is required for effective control of the system. Sliding mode control is a powerful technique which has the capability of handling systems with uncertainty. The basic philosophy of this paper is to design a sliding mode controller with model order reduction. DSP implementation of the tracking-designed tracking controller on the original system is easier due to reduced controller complexity.

14 illus, 20 ref

010202   Singh S;Bhuvaneswari G;Singh B (Electrical Engineering Dep, I.I.T. Delhi, New Delhi-110 016, Email: Ishikha.singh@gmail.com) : Improved power quality SMPS for personal computer applications. J Instn Engrs : Ser B 2012, 93(3), 151-61.

The design and control of an improved power quality two stage dc-dc converter based switched mode power supply (SMPS) is carried out for personal computer applications. The proposed SMPS is formed by a diode bridge rectifier which is connected to a non-isolated converter. The output of this stage is connected to a high frequency isolated multiple output dc-dc converter. The output dc voltage at both the stages is regulated for power quality improvement.

5 illus, 1 table, 14 ref

010201   Singh R;Singh J;Singh J (NO, Guru Nanak Dev Engineering College, Ludhiana-141 006, Email: rupindersingh78@yahoo.com) : Macro-model for development of Al-Al₂O₃ metal matrix composite with vacuum moulding: desgned experiments. J Instn Engrs: Ser C 2012, 93(4), 325-30.

Aluminum matrix composites (AMC) have many potential engineering applications. Not much work hitherto has been reported for development of AMC with vacuum moulding (VM). In this work; A1-A1₂O₃, AMC has been developed with VM. The study highlights the effect of input parameters like: moulding sand, vacuum pressure and component volume on properties of AMC produced by the VM. An approach to macro-model the hardness and dimensional accuracy during development of AMC has been proposed and applied. Relationship between hardness, dimensional accuracy and other parameters have been deduced by using Taguchi technique L9 OA for industrial applications. The comparison with experimental results will also serve as a future validation of the model.

13 illus, 5 tables, 9 ref

010200   Singh H (Fire Research Laboratory, CSIR-Central Building Research Institute, Roorkee, Email: harpalcbri@yahoo.com) : Review of fre retardants for commercially important polyurethane foams. J Constr Engng Technol Mgmt 2013, 3(3), 1-36.

Review covers various additive and reactive fire retardants used to render flexible and rigid polyurethane foams fire retardant. Literature sources are mostly from technical publications, patents, books and handbooks since 1962. Various fire retardants such as phosphorus-containing compounds, halogen-containing compounds, nitrogen-containing additives, silicone-containing products and miscellaneous organic and inorganic additives have been used to render polyurethane foams fire retardant. Some heat-resistant groups such as carbodiimide, isocyanurate and nitrogen-containing heterocycles formed with polyurethane foams also render polyurethane foams fire retardant. Fire-retardant additives reduce the flammability of polyurethane foams significantly with some degradation in physical and mechanical properties. It is concluded that a wide range of fire-retardant additives are available for polyurethane foams; however, most of the fire retardants degrade the physical and mechanical characteristics up to certain extent with significant improvement in the fire retardancy of polyurethane foams.

11 tables, 235 ref

010199   Singh B;Singh D;Saini J S (Mechanical Engineering Dep, Thapar Univ, Patiala-147 004, Email: jsaini@tapar.edu) : New method to design cam used in automobile heating, ventilating and cooling system. J Instn Engrs: Ser C 2012, 93(4), 275-86.

With the automotive air-conditioning industry aiming at better levels of quality, cost effectiveness and short time to market, the need for simulation is at an all time high. In the present study, the airflow control mechanism of an automotive heating, ventilating and cooling module for opening various doors/dampers were kinemat-ically analyzed. A new method for cam design was developed which is faster and simpler than the existing oscillating link method. The existing design was modified for the same output using the new cam design method. It is shown that the torque required in the modified design is lesser than that in the existing design, thus lowering the effort required to rotate the cam from the control panel.

20 illus, 22 ref

010198   Sharma R;Yadav B S;Aghwariya M K (Electronics Engineering Dep, Madhav Institute of Technology and Science, Gwalior-474 005, Email: ragini.mits@gmail.com) : Design a patch antenna with metamaterial for electromagnetic interference sensor. J Pwr Elect Pwr Syst 2013, 3(1), 18-21.

This paper proposes a design of a patch antenna by using pentagonal shaped metamaterial for Electromagnetic interference sensor. Pentagonal shaped metamaterial is used to increase bandwidth of patch antenna. Metamaterial possesses properties such as negative permittivity and negative permeability. It reduces return loss of antenna and increases the directivity. Two identical rectangular patch antennas have designed for transmitting and receiving purpose. This proposed antenna has been simulated at 2GHz frequency by using CST software. Transmitting patch antenna is connected to signal generator and receiving patch antenna is connected to spectrum analyzer. All the variation due to any interference is measured by Spectrum analyzer.

9 illus, 1 table, 12 ref

010197   Shah R D;Banerjee J (Mechanical Engineering Dep, S V National Institute of Technology, Surat-395 007, Email: jbaner@gmail.com) : Isothermal analysis of CAN type combuster using five hole probe. J Instn Engrs: Ser C 2012, 93(4), 313-24.

A five hole probe is developed and calibrated to carry out the isothermal flow analysis of a CAN type combustor. The axial, radial and tangential velocity distribution at different axial and radial locations of the combustor are measured using the five hole probe. The experimentally measured values of velocity distribution are then compared with the numerical results obtained using a κ-ε turbulence model. The experimental results predict that the swirler vane angles do not have significant effect on the axial and radial velocity profiles at the primary axis and secondary axis. Peak values of the tangential velocity increases at the primary axis for the higher values of the swirler vane angles due to increase in tangential momentum.

18 illus, 4 tables, 18 ref

010196   Sengupta A;Dey T;Ghosh M;Ghosh J;Ghosh S (Chemical Technology Dep, College of Science and Technologgy Univ, Calcutta Univ, 92, A.P.C. Road, Kolkata-700 009, Email: mahuag@gmail.com) : Enzymatic synthesis of furfuryl alcohol ester with oleic acid by Candida antarctica Lipase B and its kinetic study. J Instn Engrs : Ser E 2012, 93(1), 31-6.

This study investigated the successful enzymatic production of furfuryl oleate and its detailed kinetic study by Michaelis-Menten model. Esteriflcation of oleic acid and furfuryl alcohol by Candida antarctica lipase B (Novozym 435 preparation) in a solvent free system was studied in the present work at 1:1 molar ratio of furfuryl alcohol and oleic acid. About 99% conversion (on the basis of oleic acid) has been achieved within 6 h at 5% enzyme concentration. Ping-pong bi-bi mechanism (inhibition phenomenon taken into account) was applied to describe the ratios as a complex kinetic model. The kinetic parameters were determined using MATLAB language programme. The two initial rate constants KA And KB respectively were found out by different progress curves plotted with the help of MATLAB language programme. It was concluded from the results that furfuryl alcohol considerably inhibited the enzymatic reaction while oleic acid had negligible inhibitory effect. It was clearly seen that the initial rate was increased with the increase in the furfuryl alcohol concentration until 2 M/L after which there was a drop in the initial rate depicting the inhibitory effect of furfuryl alcohol. Surprisingly, it has been observed that addition of 0.1 mol of product activated the esterification reaction. Finally, the model was found to be statistically fitting well with the experimental data.

5 illus, 2 tables, 24 ref

010195   Sasiekalaa K;Malathy R (Civil Engineering Dep, M.A.M. College of Engineering, Trichy-621 105, Email: sasiekalaamam.68@gmail.com) : Behaviour of mortar containing silica fume and fly ash used for ferrocement laminates. J Ind Pollut Control 2012, 28(1), 13-20.

This paper reports the results from laboratory studies on the compressive strength of mortar for Ferro cement that contains ternary blends of Portland cement, silica fume and super plasticizer as water reducing agent. Cement mortars (1:2, 1: 2.5 and 1:3) incorporating various water cementitious ratios (0.32, 0.35 andO.38) were used. The silica fume content is constant at 5% by weight of cement. Fly ash content varying from 10% to 20% and super plasticizer were used to maintain uniform flow of mortar which varies from 0% to 1% by weight of cement, to ensure that no segregation would occur. Totally 586 mortar cubes for each mix with mineral admixtures were tested for their compressive strength. Finally suggestions were made for the proportion of mineral admixtures to achieve high strength mortar which can be used for rehabilitation of reinforced concrete structures particularly with Ferro cement composites.

3 illus, 5 tables, 16 ref

010194   Saied M M (Electrical Engineering Dep, Kuwait Univ, Kuwait, Email: mmsaied2@yahoo.com) : Effect of the background harmonics and the network's impedance characteristics on the operation of shunt capacitors. J Pwr Elect Pwr Syst 2013, 3(1), 22-32.

Deals with the possible adverse harmonic conditions associated with the connection of shunt compensating capacitors to certain network buses. It takes into account both the daily profile of the voltage background harmonics and the frequency dependence of the network's input impedance at these buses. These two factors will be incorporated in four established standards and recommendations used for assessing the severity of the harmonic pollution in the network. The presented approach is applied to a case study with available measurements for the variation of the different voltage harmonics during the day and a given impedance frequency spectrum. The results of several parameter studies are presented and discussed.

7 illus, 12 ref

010193   Roy M;Sengupta M (Electrical Engineering Dep, Bengal Engineering and Science Univ, Shibpur, Howrah-711 103, Email: molay.roy@gmail.com) : Design, fabrication and testing of two different laboratory prototypes of CSI-based induction heating units. J Instn Engrs : Ser B 2012, 93(3), 133-41.

Induction heating is a non-contact heating process which became popular due to its energy efficiency. Current source inverter (CSI) based induction heating units are commonly used in the industry. Most of these CSIs are thyristor based, since thyristors of higher ratings are easily available. These being load commutated apparatus a startup circuit is needed to initiate commutation. In this paper the design and fabrication of two laboratory prototypes have been presented. The first one, a SCR-based CSI fed controlled induction heating unit (IHU), has been tested with two different types of start-up procedures. Thereafter the fabrication and performance of another IGBT-based CSI is compared with the thyristor-based CSI for a 2 kW, 10 kHz application. These two types of CSIs are fully fabricated in laboratory along with the IHU. Performance analysis and simulation of two different CSIs has been done by using SequelGUI2. The triggering pulses for the inverter devices (for both CSI devices as well as auxilliary thyristor of start-up circuit) have been generated and closed-loop control has been done in FPGA platform built around an Altera make cyclone EPIC12Q240C processor which can be programmed using Quartus II software. Close agreement between simulated and experimental results highlight the accuracy of the experimental work.

9 illus, 3 tables, 17 ref

010192   Rout D K;Samantaray L;Panda R (Electronics and Telecommunication Engineering Dep, Veer Surendra Sai Technology Univ, Burla) : Novel modulation technique for high data rate body area networks. IETE J Res 2012, 58(5), 418-24.

Population of the world is growing at rapid pace. It is becoming difficult to provide healthcare facilities to people in highly populous countries like China and India. One way to solve this problem is the development of medical infrastructure in the form of wireless Body Area Networks. The body area networks (BANs) tend to provide medical monitoring for patients. Prime concern in the BANs is the communication, which needs to be energy and bandwidth efficient. The paper presents a novel modulation format for BANs. We propose a novel idea that combines properties of continuous phase modulation and pulse position modulation techniques. The new modulation technique takes into account the Rayleigh nature of body area channel. Apart from being power efficient, the technique does not require large bandwidth.

6 illus, 5 tables, 10 ref

010191   Rao C M;Kale R V (Civil Engineering Dep, National Institute of Technology, Jamshedpur, Email: madhu_chintalacheruvu@yahoo.co.in) : Performance evaluation of Sri Ram Sagar irrigation project. J Indian Wat Resour Soc 2013, 33(3), 1-11.

In this study, the performance evaluation of Sri Ram Sagar Project (SRSP) has been carried out through the formulation of a tri-seasonal (kharif, rabi and summer seasons) linear programming model developed using 396 decision variables and 528 constraint equations using 44 years (1950-1993) of historical data. Based on the long term historical data, a suitable operating policy has been developed for the better performance of SRSP reservoir. The results reveal that the release combination (3, 6), i.e., three irrigation releases for kharif season and six irrigation releases for rabi season gives 33 years of satisfaction with 11 deficit years out of the 44 years, which is said to be well within the 75% dependability condition. Hence, it is a practicable case of optimal release combination. Further, no irrigation releases during summer season can be assured. Subsequently, the verification of water use efficiency of the reservoir has also been carried out using the selected performance indicators.

9 illus, 2 tables, 23 ref

010190   Ramiah H;Keat C W;Kanesan J (Electrical Engineering Dep, Faculty of Engineering, Malaya Univ, 50603 Kuala Lumpur, Malaysia) : Design of low-phase noise, low-power ring oscillator for OC-48 application. IETE J Res 2012, 58(5), 425-8.

A low-power, low-phase noise, high tuning range, and fully integrated inductorless RC-VCO (voltage-controlled oscillator) for OC-48 application is designed and simulated in standard 0.18 μm CMOS technology. The proposed inductorless RC-VCO has a simulated phase noise of -141 dBc/Hz at 1 MHz offset from the carrier frequency of 2.4 GHz, with a bias current of 605 μA and voltage headroom of 1.8 V. It has 50% tuning range at 2.4 GHz of operating frequency and consumes 1.09 mW of power. This RC-VCO shows a figure of merit performance of -208.2 dBc/Hz at the desired frequency.

6 illus, 13 ref

010189   Pradhan S C;Mandal U (Aerospace Engineering Dep, Indian Institute of Technology, Kharagpur-721 302, Email: scp.aero@gmail.com) : Nonlocal finite element analysis of CNTs with timoshenko beam theory and thermal environment. J Instn Engrs: Ser C 2012, 93(4), 331-43.

Finite element formulation including nonlocal Timoshenko beam theory and thermal elasticity is carried out. For the bending, buckling and vibration analyses of carbon nanotube governing differential equations are derived. Simultaneous linear algebraic equations are solved employing developed Matlab code and structural response results are computed. Convergence study of finite element solution is conducted. Validation of developed finite element code is carried out. Based on nonlocal and thermal elasticity small scale effects and thermal effects on carbon nanotubes mechanical responses are investigated. Effects of (i) Carbon nanotubes geometrical parameters, (ii) nonlocal parameters and (iii) environmental temperature on the structural response of the carbon nanotubes are explored and reported.

8 illus, 3 tables, 47 ref

010188   Paul R N;Arya L D;Verma H K (NO, Daulat Ram Engineering Services (Pvt.) Ltd., Mandideep-464 993, Email: raghunathpaul@yahoo.com) : Starting phenomena and temperature-rise under vvvf supply of three-phase squirrel-cage at traction motor of electric locomotive. J Instn Engrs : Ser B 2012, 93(3), 203-8.

In three-phase squirrel-cage ac traction motor, temperature-rise calculation during variable-voltage and variable-frequency starting is of vital importance and has to be predicted and critically examined. Under voltage source inverter supply with PWM, the generation of harmonics by inverter supply reduces the output during starting due to higher harmonic losses, thereby reducing the starting tractive effort in kN on locomotive wheel. Stator and rotor temperature-rises during starting have been determined for average acceleration torque in seg-mental zone (calculated from variable acceleration) which have been presented in the paper with both copper and aluminium alloy rotor bars.

2 illus, 2 tables, 14 ref

010187   Pattanaik A;Mishra S C (MM Dep, NIT, Rourkela, Odisha, Email: ashungr@gmail.com) : Micro-structural analysis of fly ash and clay compacts. J Mater metall Engng 2013, 3(3), 28-31.

Industrial waste like fly-ash is mainly used as a good building material due to its low weight. But the main disadvantage of these bricks is its low compressive strength. So, a lot of research is going on to increase the strength of these bricks. Normal clay is used for making of bricks in a cheaper sense. So, a research is carried out to develop a new systematic procedure to produce a new type of brick which will have higher compressive strength than the normal clay bricks. Here the fly-ash is mixed with clay at different compositions, sintered at different temperatures and their microstructural analysis has been carried out to find out a solution to enhance its property.

8 illus, 4 tables, 14 ref

010186   Parmar H;Hindoliya D A (Mechanical Engineering Dep, Ujjain Engineering College, Ujjain, Madhya Pradesh, Email: hemant_parma1@rediffmail.com) : Solid desiccant cooling system employed with ventilation cycle: a sensitivity analysis. J Instn Engrs: Ser C 2012, 93(4), 351-6.

For better use of evaporative cooling techniques in humid climate, employment of desiccant cooling system (DCS) can be a suitable option. Desiccant augmented evaporative cooling system may be employed for energy saving in buildings in place of conventional vapour compression based cooling system. This article presents a sensitive analysis of DCS simulated under the humid climate of Mumbai, India. Mathematical computations have been performed using outdoor specific humidity, ambient dry bulb temperature and room supply temperature. A sensitive analysis considering some important forcing parameters was conducted. It was observed that the "effectiveness" of direct evaporative cooler to be predominantly high influencing parameter compared to others, for the performance of DCS.

7 illus, 1 table, 12 ref

010185   Pandit R K (Architecture Dep, Madhav Institute of Technology & Science, Gwalior, Madhya Pradesh, Email: drpanditrk@yahoo.com) : Re-engineering the engineered construction organization. J Constr Engng Technol Mgmt 2013, 3(3), 54-66.

Concept of organization as a basic information processings system to provide flexibility and adaptability in highly uncertain and turbulent construction environment was used to design a post-bureaucratic organizational structure particularly for construction industry. The different divisions/departments in the organization are developed as interacting information processing subunits generating and disseminating a continuous flow of data/information. In addition to proposing the efficient way of vertical communication for productivity improvement, the proposed model lays major emphasis on lateral information flow. Hence the coordination in the organization is the basis of reengineering it.

25 ref

010184   Otunniyi J O (Metallurgical and Materials Engineering, Federal Technology Akure Univ, Nigeria, Email: iootunniyi@futa.edu.ng) : In situ determination of surface porosity and pore characterization in refractories. J Mater metall Engng 2013, 3(3), 14-22.

Surface pore characterization and surface porosity determination of test refractories produced to varying porosities were done using image analysis. The surface pore count, pore size and pore area distributions were presented in a surface porosity chart that is characteristic of the surface. Instant visual information from these chart were noted. The sharp beak pattern, for instance, is notable as a chart signature characteristic of a dent or rupture on the refractory surface. Based on the production compositions, the surface porosity values show that the method is self consistent. Image analysis technique therefore gives far more information about the surface pore condition than the single apparent porosity value obtained with the immersion techniques. Given the high computing and memory capacities on most PCs and devices now, refractories surfaces can be monitored and quantitative data obtained in situ and non-destructively. With some improvement and standardization, image analysis has more space in refractory porosity assessment than at present.

5 illus, 1 table, 20 ref

010183   Nimbalkar V M;Rao B R K;Deshmukh V P;Marathe K V;Eswara Prasad N (Navel Materials Research Laboratory, DRDO, Ambernath, Email: nep@cemilac.drdo.in) : Centrifugal casting of nano crystalline TiB₂ reinforcement particulate reinforcement in Al-alloy matrix. J Mater metall Engng 2013, 3(3), 7-13.

Method of producing Nano size TiB₂ particles within an aluminium matrix is the in situ reaction synthesis method, using KBF₄ and K₂TiF₆ potassium based bearing fluxes. The advantages of this in situ reactive process are a small particle size and good particle/matrix interfacial bonding. However, this method is limited to producing low particulate volume percentage material (<60>6 vol%). To overcome this limitation, centrifugal casting has been investigated. A series of the casts was made to observe the influence of centrifugal acceleration "G" value on final TiB₂ distribution. This was done by the casting at 1400 RPM rotational speed and 570 G value. The TiB₂ particulates content was concentrated towards the outer radius with a clear interface between this region and the remaining unreinforced Aluminium matrix. The final concentration of the TiB₂ particles increased with increase in rotational speed and particle clustering was found to influence the settling behavior of the TiB₂ particles. The present paper demonstrates that centrifugal casting may be employed to yield a 6 Vol% of TiB₂ reinforced particulate metal matrix composites.

8 illus, 1 table, 7 ref

010182   Naidu V P S;Mukherjee J (MSDF Lab, FMCD, CSIR- National Aerospace Laboratories, Bangalore, Email: vpsnaidu@gmail.com) : Aircraft altitude estimation using un-calibrated onboard cameras. J Instn Engrs: Ser C 2012, 93(4), 287-95.

Implementation and study of aircraft altitude estimation using un-calibrated onboard camera is obtained. A camera model has been implemented to simulate the test data. From the results, it was observed that the rounding nature of pixel coordinates creates fluctuations around the true vanishing point (VP) angle and height computations. These fluctuations were smoothened using a Kalman filter based state estimator. The effects of camera tilt and focal length on VP angle and height computations were also studied. It is concluded that the camera should be perpendicular to the runway for there to be no effect of the focal length on the height computation. It is being planned to apply this algorithm for real time imaging data along with Integrated Enhanced Synthetic Vision (IESVS) on HANSA aircraft.

13 illus, 2 tables, 7 ref

010181   Mukhopadhyay P (NO, Defence Metallurgical Laboratory, Kanchanbagh, Hyderabad, Email: prantikmukherje@gmail.com) : Structure and cube texture development trend of A14.5MgMn alloy at variable annealing conditions. J Mater metall Engng 2013, 3(3), 32-8.

Hot-rolled Al4.5MgMn alloy was cold rolled to true strain levels 0.8, 1.6 and 2.3. Annealing at 300°C, 350°C and 400 °C was done to develop annealing structure. The annealed structures were measured by SEM-EBSD. The average grain size and grain size distributions were measured using Sigma-scan-Pro 5 structure analysis software. The average grain size and grain size distributions showed higher number frequency of lower annealing grain size with the increase of prior true strain and increase in annealing grain size for same level of prior straining during annealing at 400 than 350 °C. Mainly recovery occurred at 300 °C annealing for samples with initial prior strain levels. Bulk textures of deformed and annealed samples were measured by X-ray texture Goniometer. The texture strength of ideal texture components was derived. The analysis of annealing and rolling textures of individual components showed that some texture components like cube, cube RD, Goss, cube TD, and cube ND were strengthened during annealing. Selective measure (TSK) of these components was derived. Strong TSK was associated with ND cube component for initial prior strain levels and TSK strength of ND cube increased with annealing temperature due to accelerated recrystallization kinetics. At 2.3 prior strain level the selected T_SK strengths of Goss, TD cube, and cube texture component became prominent.

8 illus, 12 ref

010180   Monga A;Vig R (NO, Institute of Engneering and Technology Univ, Panjab Univ, Chandigarh, Email: eramonga@gmail.com) : Ultra miniature MEMS capacitor for arterial pressure measurement. J Instn Engrs : Ser B 2012, 93(4), 271-5.

In biomedical field, there is a need for improving medical technologies to provide accurate diagnosis to patients. The objective is to develop a minimally invasive, implantable, pressure sensing system that continuously monitors physiological changes in real-time. For implementing, three different shapes of MEMS capacitive pressure sensor having same area of diaphragm 0.126 mm² is designed and simulated for blood pressure measurement. The various shapes which are taken are circular, square and rectangular. COMSOL multiphysics tool is used for simulation. For these shapes capacitance and deflection variation of membrane with applied pressure is studied. Result shows a sensitivity of 0.255 aF/kPa, 0.125 aF/kPa and 0.09 aF/kPa for circular, square and rectangular shape, respectively. So, circular MEMS capacitor provides the greater sensitivity than all other shapes and also provides greater deflection of diaphragm due to applied pressure of 40 kPa. Also deflection is more in circular diaphragm capacitive pressure sensor.

5 illus, 3 tables, 8 ref

010179   Mohamid I;Dmaidi N (Civil Engineering Dep, Hail Univ, Hail, 2440, KSA, Email: imahamid@ymail.com) : Time overrun cases in public construction projects in Saudi Arabia: contractors' view. J Constr Engng Technol Mgmt 2013, 3(3), 67-75.

Time schedule in construction projects is one of the prime measures for project success. However, the construction industry worldwide is full of projects that were completed with significant time overrun. This problem is critical and has negative effects on construction parties in terms of growth in adversarial relationships, mistrust, litigation, arbitration and cash flow problems. This study aims at identifying the time overrun causes in public construction projects in Saudi Arabia from contractors' viewpoint. To do so, 62 contractors from Northern Province of Saudi Arabia who are working on public construction completed a structured questionnaire survey. 35 time overrun causes were identified through literature review. The results indicated that the top affecting causes are: additional work, bid award for lowest price, changes in material types and specifications during construction, contract management, fluctuation of prices of materials, improper planning, inflationary pressure, lack of contractor experience, poor labor productivity, and rework.

6 tables, 17 ref