002865   Bhattacharyya S;Dev D;Nandy C;Dey S; Chakraborty S (NO, , ) : Design and numerical analysis of solar powered unmanned aerial vehicle using helium gas. J Aerospace Engng Technol 2015, 5(2), 22-6.

The fundamental of unmanned aerial vehicle has been designed and runs for quite a while. This paper mainly focuses on the reduction of payload and power consumption resulting in increase of efficiency further by the use of helium gas in a solar powered unmanned aerial vehicle. In addition to these, another aim of the aircraft is its use in surveying purpose. A highly powerful live steaming camera is attached to capture images and video feed of the surveillance zone thus can be used in defence purpose. Also a releasing mechanism is developed which can be used for defence or relief purpose. A wireless remote control is used to fly the aircraft; also a lithium three cell battery is incorporated in the system. Numerical analysis of drag and lift force on an airfoil shaped body at different angles is presented. This work presents the configuration optimization of an aerofoil body in air using SST computational fluid dynamics (CFD) modelling and compared with the experimental result. The governing equations are solved with a finite-volume-based numerical method. A three-dimensional non uniform grid was generated, in order to critically examine the flow. The wind tunnel was operated at nominal velocities during the coefficient measurement, a Reynolds number of about 100-2000. The airfoil, with a 10 inch chord, was analyzed at 0, 5, 10, 15, 20 and 25o angles of attack and with fixed load.

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002864   Bhardwaj R;Shukla S;Sexana S;Rawat A S (H.N.B. Garhwal Univ Campus Pauri, Pauri Garhwal, Uttarakhand-246 001, Email: rajeshbhardwajphysics@yahool.com) : Large area 3d self assembled photonic crystals of PMMA nanospheres. J Mount Res 2014, 9(Dec), 43-8.

It is to synthesize Poly-methylmethaacrylate (PMMA) 3D Photonic crystals (PhC's) by Inning the size of PMMA nanospheres via self-assembly (SA) method. SA of colloidal particles to fabricate the PhC's is a simple method to prepare 3D PhC's compared to nanolithography and other conventional methods. 3D PhC's made of closely packed PMMA nanospheres are fabricated here by self-assembly and characterized using DLS, SEM, HR-TEM and UV-Vis spectroscopy measurements. The experimental results of spheres from DLS fall in the size range 229.2 to 306.8 nm.

5 illus, 8 ref

002863   Asadi R;Sadati S H;Abaspour A (NO, , ) : Optimized adaptive feedback linearization control of wing rock by using neural network and NSGA_II. J Aerospace Engng Technol 2015, 5(1), 1-10.

Wing rock is one of the well-known instabilities that occur in aircraft dynamics at moderate to high angles of attack. In this phenomenon aircraft dynamics can display an oscillatory lateral behavior that manifests itself as a limit cycle known as wing rock. In this paper a new approach is introduced for designing the controller for this phenomenon which has the optimal performance while the controller is adaptive and robust against severe disturbances. In the proposed controller the non-dominated sorting genetic algorithm II (NSGA_II) method is used to tune the controller linear gains in aim to decrease the controller tracking error, and a neural network is used for adaptation purposes. The simulation result showed that the proposed approach has better performance in comparison with conventional controllers.

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002862   Aravind P;Karpagam G;Nalini M;Savithri G (NO, , ) : Real time implementation of cascade process using NI ELVIS in labview. J Control Instrumn 2015, 6(1), 36-50.

The main objective of this work is to enforce PID controller in a real time process, and to find out the best robust control settings for cascade process. In this work, process variable level is controlled in a cascade mode. Level and flow are considered as primary and secondary variable, respectively. Process models of flow and level are identified as First order plus dead time models. Validated model is used for controller design. Ziegler Nichol's (ZN), Tyreus-Luyben (TL) and Internal Model Control (IMC) are PID control settings, calculated and implemented in real time process in the LabVIEW environment through NI ELVIS interface. The set point tracking and servo responses are accumulated using NI LabVIEW platform for the comparison of desirable controller. Analysis is performed and best control setting is highlighted through time domain analysis, performance index and robustness test.

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002861   Aravind P;Karapagam G;Nalini M;Savithri G (NO, , ) : Comparison of flow process values for different PID controller techniques. J Control Instrumn 2015, 6(1), 9-13.

The main objective of this paper is to find the best and suitable controller that can be applied for a flow process in a real system. The flow process is done in a cylindrical tank of cascade system. The search of PID controller is done by the steps of acquiring transfer function from the real time open loop response and invoking it to the various tuning techniques of PID controller results in the proportional, integral and derivative values for our process. The calculated values are implemented in an Matrix Laboratory Environment using simulation which reaches the conclusion of desired controller based on the time domain specifications (Peak time, Rise time, Settling time) and performance error criteria (ITAE, IAE, ISE, MSE).

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002860   Appiah R;Gbadago J K (NO, , ) : Ghana's nuclear power option and associated safeguards technique. J nucl Engng Technol 2016, 6(2), 1-5.

The adequate supply of electricity is a pre-requisite for industrialization, sustainable development and a key policy agenda for national development. Economic consumption of electricity production would have to be augmented to satisfy Ghana's high level of economic growth and social well-being in the future. In 2008, cabinet decision was taken to proceed with the nuclear power plant construction roadmap. As part of the preparations being made towards the implementation of the nuclear power project, interim assessment on the choice of reactor has been made based on, economics and technological aspects of safety. A light water reactor (LWR), preferably the pressurized water reactor (PWR) with capacity up to 1500 maximum, has been proposed to commence commercial operation by 2020. Ghana's option for nuclear power in addition to the research reactor would expand the nuclear fuel cycle and give room for several nuclear material accounting procedures. Core conversion activities are underway to replace the highly enriched uranium (HEU) U235 with LEU of approximately, 13% enrichment. The general objective of this paper is to perform an assessment on available safeguards approaches and methods used to verify inventory and flow of nuclear material in accessible areas of Ghana's new nuclear fuel cycle, with focus on the safeguards measures to be prepared by facility operator to successfully support nuclear material verification. The elements of facility design relevant to safeguards in consultation with the regulatory body, supplier/designer and the international atomic energy agency (IAEA) have also been addressed. Indications of material balance areas, key measurement points as well as safeguards strategies relevant to the IAEA are outlined. The assessment and suggestions discussed are anticipated to support safeguards measures that may be applied to Ghana's first nuclear power plant's construction and operation.

002859   Alam M A;Mannan M A (NO, , ) : Design and analysis of EV controller using IPMSM taking core loss into account. J Control Instrumn 2015, 6(2), 1-8.

Now a days vehicles with electrical differentials are becoming more and more popular. The mechanical differentials are replaced by using two motors. In the electrical vehicle (EV) different types of electrical machines such as induction motor, permanent magnet synchronous motor etc. are used. The controller design for the different motors is a fascinating and challenging work to obtain desired performance properly. The interior-permanent magnet synchronous motor (IPMSM) has already been used to design electrical differential for an EV. The controllers which have been designed for this purpose depend on the mathematical model of IPMSM. Unfortunately, to design the controller for IPMSM the core loss has not been considered, but to obtain the precise torque control the core loss of an IPMSM should be considered. In this paper, the PI controllers of an electrical differential for an EV system based on the IPMSMs taking core loss is designed. The performances of designed controllers are evaluated by Matlab/Simulink software. In the simulation work three road conditions for EV are considered. One is when the road is curved to right. Other is when the road is curved to left and another one is for the slope type road. Their performances are shown separately as well as all together.

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002858   Alam A;Mannan M A;Rezwanuzzaman K;Amin M R; Islam K M S (NO, , ) : Modeling and performance analysis of electrical vehicle with SPWM inverter-FED IPMSM taking core loss into account. J Control Instrumn 2016, 7(1), 7-16.

Because of the advantages of electrical differentials, people are becoming more interested in using them rather than using mechanical differentials. The mechanical differentials are replaced by using the two rear motors. In the electrical vehicle (EV) different types of electrical machines such as induction motor, permanent magnet synchronous motor etc. are used. The design of a controller is a challenging work, as the output of the motor has to match with the vehicle input. There are already some works done with IPMSM (Interior Permanent Magnet Synchronous Motor) for designing electrical differentials. The controller which was designed in this paper mainly depends on the mathematical model of the IPMSM. Unfortunately, to design the controller for IPMSM the inverter portion was taken as ideal, but to observe natural response of the motors; an inverter should be added with the motors. In this paper, the PI controllers of an electrical differential for an EV system based on the IPMSMs taking core loss into account with SPWM inverter feed is designed. The performances of designed controllers are evaluated by Matlab/Simulink software. In the simulation work three road conditions for EV are considered. One is when the road is curved to right. Other is when the road is curved to left and another one is for the slope type road. Their performances are shown separately.

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002857   Advani K R;Swaroop C (NO, , ) : Review of numerical methods for bird impact simulation on aircraft components. J Aerospace Engng Technol 2015, 5(1), 23-9.

In today's world, aircraft flies on the risk of occurring bird strikes which lead to serious damage or failure of aircraft. Experimental methods being expensive, numerical methods are preferred for tests and certification purposes. This paper analyzes different approaches (Lagrangian, Eulerian, ALE, and SPH) which are used for numerical simulation of the bird. It also covers material Models, different geometries of bird, effect of parameters at windshield are highlighted. Furthermore, this paper also analyzes effect of impact angle and layup configuration on bird impact.

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001643   Yuvaraj R;Senthil Kumar D (Mechanical Engineering Dep, Sona College of Technology, Salem-636 005, Email: yuvarajr@sonatech.ac.in) : Heat transfer analysis of dropwise condensation on superhydrophobic copper surface. J Energy Heat Mass Transfer 2015, 37(1-4), 119-32.

The heat transfer coefficient of condensation is increased by modifying the bare copper condensing substrate into a superhydrophobic surface which exhibit the property of high water repellence that will make a contact angle about 160° ±2°. Simple solution immersion and thermo solution immersion methods are used to prepare the superhydrophobic surfaces on the copper plates. The superhydrophobic nature on the copper plates are obtained by immersing the plates into the solution of 0.003 - 0.007M ethanol and myristic acid then heating the plates in the solution at 40 - 65°C for 2 - 5 hours. The contact angle of water droplet is measured on the obtained superhydrophobic copper surfaces which gives the maximum contact angle of 162° and average value of 160° ± 2° with low inclination angle of 2°. The maximum contact angle is obtained by adjusting the composition of the solution, temperature of the solution and immersion time to 0.005M, 45° and 3 hours respectively. Further the prepared superhydrophobic copper surface is experimented for dropwise condensation and the values of vapour temperature, surface temperature and heat transfer coefficient are compared with the bare copper surface.

12 illus, 12 ref

001642   Wang Y;Zhou J;Kikuchi H (Communications Dep, Nanjing Univ of Information Science and Technology, Nanjing, China) : Performance of a double uniform circular array in a three-dimensional environment. IETE J Res 2016, 62(1), 35-44.

In this paper, an array configuration with double uniform circular arrays (DUCAs) is provided in a three-dimensional environmerit with the goal of optimizing compact multiantenna user terminals. The DUCA extends the general two-dimensional multiantenna model to three-dimensional space. To accurately consider the spatial fading correlation (SFC) between antennas and the capacity of multiple input multiple output (MIMO) muttipath channels, this paper uses the equivalent network model under mutual coupling (MC). Furthermore, the methods for calculating SFC with and without MC and capacity for a frequency non-selective Rayleigh fading channel are given. For simplicity, the azimuth and elevation angle distributions are assumed to be uniform. Simulation results show that the DUCA provided by this paper can decrease SFC between antennas, hence increasing capacity compared with UCAs of the same size. Taking MC into consideration, capacity will increase when the radius of the circle is smaller than 0.27λ. The parameters of arrival signals have a significant impact on the system performance as well. This investigation expands the application of a statistical channel model and optimizes the study of the terminal antenna array.

9 illus, 28 ref

001641   Wang C J (Electrical Engineering Dep, National Univ of Tainan, Tainan, Taiwan) : Low-pass filter based on the slotted-ground-plane horn-shaped resonator. IETE Tech Rev 2016, 33(2), 199-204.

Designs of a miniaturized low-pass filter (LPF) using the slotted-ground-plane resonator are introduced in this paper. The proposed filter consists of a horn-head slot in the ground plane, two modified arc-head resonators, and a parasitic patch connected at the microstrip line. The horn-head slot, which is a modified type of a horn-shaped slot, provides good band-stop characteristics. To enhance rejection performance, a pair of the modified arc-head slot is embedded inside the horn-head resonator to increase additional transmission zeros into frequency characteristics. Furthermore, a parasitically circular patch is added at the microstrip line for frequency reduction and rejection enhancement. The surface current distributions are presented to explain the resonance mechanism. For the proposed LPF, the measured rejection bandwidth over - 20 dB is from 1.75 to 12.0 GHz.

9 illus, 2 tables, 13 ref

001640   Venkatesh S M;Kishoor Kumar R;Ashwin Kumar R; Venkatesan M (School of Mechanical Engineering, SASTRA Univ, Tirumalaisamudram, Thanjavur-613 401, Email: mvenkat@mech.sastra.edu) : Heat transfer study of screw type fin under forced convection. J Energy Heat Mass Transfer 2015, 37(1-4), 109-18.

Fins are projections on a heat transfer surface to supplement the heat transfer rate from a surface. Fins improve the heat transfer rate through the surface by increasing the exposed area. In this study a threaded pin fin is analysed numerically. A cylindrical pin fin is fabricated and experiments are done under forced convection conditions. The experimental results are used for validating the numerical model. The numerical analysis for the threaded fin is done by varying pitch of the thread and air flow velocity. The threaded pin fin is found to enhance the heat transfer rate, when compared to an ordinary cylindrical pin fin with less material being used. Also the optimal pitch at which the minimal base temperature is obtained is also found out.

4 illus, 10 tables, 10 ref

001639   Velmathi G;Mohan S;Henry R (NO, Velammal College of Engineering and Technology, Madurai) : Analysis of factors for improving functionality of tin oxide gas sensor. IETE Tech Rev 2016, 33(2), 122-9.

The proposed work discusses different parameters which are considered to improve the performance of a tin oxide-based thin film gas sensor. This includes analysing and deducing suitable catalytic additives to enhance the performance of the sensor in terms of selectivity and sensitivity. Chemical sensitization and electronic sensitization are performed to improve the rate of response of the sensor.

6 illus, 77 ref

001638   Torabi Y;Bahri A;Sharifi A R (Electrical and Electronic Engineering Dep, Shahed Univ, Tehran, Iran) : Novel metamaterial MIMO antenna with improved isolation and compact size based on LSRR resonator. IETE J Res 2016, 62(1), 106-11.

A two-element multiple input-multiple output (MIMO) compact meander-line antenna with enhanced isolation performance using a novel metamaterial Labyrinth split-ring resonator (LSRR) is proposed. The reductioh of mutual coupling between two antenna elements is obtained by embedding the proposed resonator between two radiating elements and achieving negative effective permeability. The proposed MIMO antenna system has been designed to operate at 2.4 GHz with 150 MHz bandwidth from 2.33 to 2.48 GHz (approximately 6.25% FBW) which is sufficient for wireless local area networks (WLAN) (2400-2484 MHz) communication. The designed MIMO antenna separated by 0.1 wavelengths has better than -45 dB coupling isolation, -55 dB correlation coefficient and 0.1 bps/Hz capacity loss at the operating frequency (2.4 GHz). Moreover, the proposed MIMO antenna system has the advantage of compactness as its size is only 2.43 x 4.29cm^{2 (nearly 0.19 λ x 0.34 λ).}

10 illus, 18 ref

001637   Teltayev B;Aitbayev K (Kazakhstan Highway Research Institute, 2A, Nurpeissov Street, Almaty-050 061, Email: bagdatbt@yahoo.com) : Modeling of temperature field in flexible pavement. Indian Geotech J 2015, 45(4), 371-7.

The nonstationary temperature field is modeled by the finite element method. Results of the numerical analysis conform fully with the experimental data. By means of the developed finite element model, temperature variation has been obtained in points of asphalt concrete layers of pavement within one decade of the hottest period in the southern region of Kazakhstan. Using the solution of axisymmetric problem of elasticity theory for the layered media, stresses and deformations in specific points of flexible pavement under loading have been calculated at night period (when asphalt concrete layers temperature is minimum) and at day period (when asphalt concrete layers temperature is maximum). The obtained results showed that depending on temperature stresses and deformations in specific points of pavement change significantly. Therefore correct modeling of temperature field in flexible pavement is important in their designing.

4 illus, 6 tables, 14 ref

001636   Tarigonda H;Meenakshi Reddy R;Reddy K Pol;Rao P M (Mechanical Engineering Dep, G.Pulla Reddy Engineering College, Kurnool-518 007, Email: thprasads@gmail.com) : Experimental investigation of combined sensible and latent heat storage system using iron scrap and PCM. J Energy Heat Mass Transfer 2015, 37(1-4), 133-46.

Energy plays a major role in the economic prosperity and the technological competitiveness of a nation. Developing energy technologies should ensure energy security, efficiency and environmental quality. At present more than 80% of the world energy is obtained by the combustion of fossil fuels such as coal, oil and natural gas. The energy demand varies on daily, weekly and seasonal basis in the commercial, industrial and utility sectors. Energy storage units can be used with energy management systems in commercial and industrial sectors to reduce the energy consumptions by using waste heat or alternative energy sources. The main advantage of PCM is the ability to store large amounts of energy compared to conventional storage. Thermal energy storage (TES) plays the main role in energy conservation and it has a significant impact on modern technologies. TES appears to be most appropriate technology for correcting the mismatch heat occurs between the supply and demand of energy. TES is the temporary storage of high or low-temp energy for feature use. In the present study, experiments are conducted on a PCM based packed bed, to study the charging behavior of the storage system. It is found that the total heat capacity of TES tank at 700C is around 10,400 KJ. The output hot water at an Average of 450C is around 64 liters so it means the heat energy recovered from the TES tank is around 32 %. The system with Iron scrap + PCM filled in Spherical capsules able to give 25% of hot water Extra then the Same Capacity sensible heat storage system.

11 illus, 1 table, 27 ref

001635   Sutariya P;Mujumdar S;Sena D (Civil Engg. Dep, Faculty of Tech & Engg. The M.S. Univ of Baroda, Vadodara) : Morphometric analysis of Dhardhar river basin, Gujarat. J Indian Wat Resour Soc 2015, 35(2), 7-11.

The development of morphometric techniques was a major advance in the quantitative description of the geometry of the drainage basins and its network which helps in characterizing the drainage network, comparing the characteristic of several drainage networks and examining the effect of variables such as lithology, rock structure, rainfall etc. Morphometric analysis and their relative parameters have been quantitatively carried out for the Dhadhar basin, Gujarat, India. The quantitative analysis of the morphometric characteristics of the basin include Stream density, Stream order, Drainage density, Average stream slope, Compactness coefficient, Circulatory ratio, Elongation ratio, Form factor. The forgoing analysis clearly indicates some relations among the various attributes of the morphometric aspects of the basin and helps to understand their role in sculpturing the surface of the region. This study would help the local people to utilize the resources for sustainable development of the basin area.

3 tables, 7 ref

001634   Sudarshan S;Vasudevan K;Pragadeesh M; Venkatesan M (School of Medicinal Engineering, Sastra Univ, Tirumalaisamudram, Thanjavur-613 401, Email: mvenkat@mech.sastra.edu) : Enhanced turbulent heat transfer in a square duct with baffles. J Energy Heat Mass Transfer 2015, 37(1-4), 85-94.

The heat transfer through a baffled duct under turbulent conditions is studied numerically in this paper. The flow is characterised by chaotic changes in its flow parameters due to secondary flows and time varying components. The effects of secondary flow, recirculation zones and wall turbulence on heat transfer characteristics are briefly reported. The baffles deflect the flow and impinge on the opposing wall and the baffle surface, resulting in a higher heat transfer coefficient than a simple channel. The obtained results show that the boundary layer separation and recirculation regions are significantly affected with the geometry of baffles. Due to the mixing of fluid layers at a macroscopic level, the velocities and temperature tend to become uniform, but secondary flow dominates at the duct corners, thus creating a highly distorted velocity and temperature profile. Among the various geometries considered, rectangular baffle provided on the walls of the duct enhanced heat transfer.

3 illus, 10 tables, 10 ref

001633   Sreenivasan K (NO, Central Institute of Technology, Kokrajhar-783 370, Email: sreenivasan@cit.ac.in) : Cooling of multicore multiprocessors. J Energy Heat Mass Transfer 2015, 37(1-4), 1-9.

Authors report increasing cooling rates when carbon dioxide is circulated in rectangular channels of a multi-processor blade bundle. This improvement is expressed in terms of the watt temperature ratio, also referred to as benefit ratio. Circulating CO₂ flow is assumed to be developing and the gas is assumed to be optically thick. We account for heat loss by convection, heat loss by axial conduction, and heat loss by absorption by the flowing gas. Channel walls and circulating gas are assumed to be black. Energy equation is solved using a linearized radiation term. We account for the influence of workload, hitherto ignored, in the heat generation equation. Improvement in cooling for a four-core, three-channel system is presented in terms of benefit ratio formed by before and after values of wall temperature; the benefit ratio is correlated with the processor clock frequency, gas velocity, and the gas absorptivity. Magnitude of this improvement is presented for one particular case but the method developed is general and can be used for other cases as well.

3 illus, 7 ref

001632   Soon K L;Ramiah H;Tey Y Y (Electrical Engineering Dep, Faculty of Engineering, Univ of Malaya, Kuala Lumpur, Malaysia) : A 3.0-10.0 GHz UWB low-noise amplifier with forward body bias technique. IETE J Res 2016, 62(1), 91-9.

An ultra-wideband (UWB) low-noise amplifier (LNA) based on cascaded common source stage with shunt-shunt resistive feedback architecture is proposed. The wideband input impedance matching is accomplished by shunt-shunt resistive branch with inductor degeneration and parallel resistor-inductor-capacitor (RLC) load, forming two parallel RLC branches having inherently two wideband band-pass filter characteristics, resonating both at lower frequency and higher frequency. The output matching is achieved via a shunt inductor and a series resistor without the use of a buffer. Additionally, both series and shunt-inductive peaking techniques are employed in the proposed UWB LNA circuit design for bandwidth extension. To reduce the supply voltage headroom consumption, the forward body bias technique is also employed in the proposed topology. The resistor-capacitor (RC)-extracted results obtained in this paper are competitive in comparison with recent reported work in appreciating good noise figure (NF) performance as well as low-voltage headroom consumption. In the post-layout simulation results, the proposed complementary-metal-oxide-semiconductor (CMOS) UWB LNA dissipates only 13 mW while achieving the S11 below -11.4 dB, S22 below -11.7 dB, a flat S21 of 11.5 ± 0.6 dB, a maximum NF of 3.48 dB, within the range of 3.04 - 3.48 dB over the 3.0-10.0 GHz band of interest. Moreover, the IIP3 is within the range of -6.3 to -7.8 dBm, P1 dB of -14.7 to -16.8 as well as the K-factor of above 1 throughout the entire bandwidth operation, attesting the fact that the resistive feedback circuit is stable. The chip area consumption is approximated to 0.997 x 0.933 mm^2.

11 illus, 3 tables, 19 ref

001631   Shome S;Bera R;Maji B;Sur S N;Bera S (Electronics & Communication Engineering Dep, Surendra Institute of Engineering & Management, Siliguri) : Embedded digital MIMO radar using SDR for target detection and RCS measurement. IETE J Res 2016, 62(1), 100-5.

Multiple input multiple output (MIMO) radar has superior performance to conventional one. It has been introduced in almost every field of conventional radar now days. The MIMO techniques have been well studied where they offer benefits in multipath fading environments. Inspired by these, MIMO are applied to radar and offer advantages such as improved resolution and sensitivity. But these systems consist of large antenna, a lot of electronic equipment and powerful computational unit. In these applications, small size embedded software define radio (SDR) can be used. Then real time processing of a radar signal can also be much simpler. For above-mentioned applications, it is possible and reasonable to have small devices with low power consumption that perform real time correlation-based processing. Moreover, dimensions of the processor boards are very compact and they can be easily integrated into small cases. That is why it is good to transfer radar signal processing algorithms to the embedded system. The recent development of digital MIMO radar is now module in these SDR systems. Our motivation is to design a spread spectrum-based digital MIMO SDR radar which is small in size and may be a low-cost solution where we can bypass all the huge instrumentation complexity.

12 illus, 12 ref

001630   Sharma D;Pandey K M (Mechanical Engineering Dep, National Institute of Technology Silchar, Cachar-788 010, Email: kmpandey2001@yahoo.com) : 3D CFD steady state heat transfer in nuclear fuel rod assembly and effect of increasing road diameter on different properties. J Energy Heat Mass Transfer 2015, 37(1-4), 95-108.

In this paper research is focused on steady state heat transfer in hexagon nuclear fuel rod assembly using code ANSYS CFX 14, which is commercial computational fluid dynamics (CFD) code. Computational simulations are reported on convective heat transfer to carbon dioxide as a coolant whose pressure is just above the thermodynamic critical value of 7.38MPa. These have been carried out using a variable property, elliptic computational formulation incorporating low Reynolds number turbulence models of k-ε. Firstly, the simulations present steady state heat transfer in hexagonal nuclear fuel rod assembly and also shows the effect of increasing rod diameter on heat transfer coefficient. The rod diameter in this simulation has been taken 0.6, 0.8 and 0.9cm. It has been found that the effect on heat transfer coefficient decreases with increasing diameter of the rod and bulk fluid temperature, rod temperature increases with increase in the rod diameter. It is clear that new heat transfer correlations are needed to account for such effects on heat transfer to supercritical pressure fluids as they come to be used more and more in new energy systems applications such as, advanced water-cooled nuclear reactors, high-pressure water oxidation plant for waste processing.

21 illus, 2 tables, 10 ref

001629   Shaman H;Almorqi S;AlAmoudi A (National Centre for Sensors and Defense System Technologies (NCSDST), KACST, Riyadh, Saudi Arabia) : Ultra-wideband(UWB) bandpass filter with cascaded lowpass filter on multilayer liquid-crystal polymer(LCP) substrate. IETE J Res 2016, 62(1), 63-7.

An ultra-wideband (UWB) bandpass filter with extended upper-stopband on multilayer liquid-crystal-polymer (LCP) substrate is presented in this paper. The proposed filter is designed to select the frequency band from 1.0 to 20 GHz. The filter consists of two parallel-coupled stub-loaded resonators separated by a composite lowpass filter. The composite lowpass filter is implemented to obtain a very wide rejection band. The proposed filter is fabricated using multilayer LCP technology. Excellent agreement between expected and measured results of the filter is obtained. The measurement results show that the fabricated filter has a fractional bandwidth of 180% and a very low insertion loss of less than 0.6 dB at center frequency of 10.5 GHz. The measured filter has a wide stopband and an excellent rejection level higher than 40 dB.

9 illus, 15 ref

001628   Sathya T;Muruganandam L (CO2 Research and Green Technologies Center Chemical Engineering Div, S, VIT Univ, Vellore-632 014) : Comparison of kenics and SMX static mixers pressure drop and heat transfer behaviours using CFD simulation. J Energy Heat Mass Transfer 2015, 37(1-4), 195-203.

Static mixers are greatly used for heating and cooling of viscous fluids. Though it is useful very limited data have appeared in the study of static mixers and mostly deals with hydrodynamics. A deep understanding of hydrodynamics and heat transfer is still lacking when highly viscous and Theologically complex, fluids are involved. So it is necessary to study the hydrodynamics and heat transfer of static mixers for viscous applications. In this work comparison of the Kenics and SMX static mixer designs using various Newtonian fluids under laminar and turbulent conditions is performed. The hydrodynamics, heat transfer behaviours are analysed by computational fluid dynamic modelling using Ansys Fluent. The friction factor charts and Nusselt number correlations for Kenics and SMX designs are developed. From the results, it is observed that, for laminar operating regime SMX section design gives high heat transfer and in turbulent operating regime, the Kenics design gives high heat transfer.

5 illus, 3 tables, 17 ref

001627   Saride S;Rayabharapu V K;Vedpathak S (Civil Engineering Dep, Indian Institute of Technology Hyderabad, Ordnance Factory Campus, Yeddumailaram-502 205, Email: sireesh@iith.ac.in) : Evaluation of rutting behaviour of geocell reinforced sand subgrades under repeated loading. Indian Geotech J 2015, 45(4), 378-88.

This paper summarizes the results from a series of large scale cyclic model load tests on geocell reinforced and unreinforced homogeneous sand subgrades. The sand subgrades are prepared at 70% relative density thru plu-viation technic in a large steel tank measuring 1 m^{3. A cyclic load of 0.7 and 7 kN was applied on a circular steel plate of 150 mm diameter to replicate a portion of load transfer frorn, an equivalent single axle wheel load (ESAL) on the sand subgrade. The cyclic load was applied through a double acting dynamic hydraulic 100 kN actuator. A series of tests were conducted to study the effects of width and height of a geocell reinforcement on the cyclic behavior of sand subgrades. The performance improvement is quantified in terms of traffic benefit ratios (TBR), cumulative plastic deformations (CPD), modulus of sub-grade reaction (ks), resilient modulus (Mr) and rut depth reduction (RDR) for different number of cycles and plate settlements. The configuration of the geocell that provides highest performance in terms of TBR, CPD, and RDR, is considered to be the optimum size of the geocell. It is observed that the optimum geometry of the geocell is capable of reducing the rut depth of about 75% at 100 cycles and provide about a TBR of 23 at 10% of settlement ratio.}

17 illus, 4 tables, 30 ref

001626   Saride S;Avirneni D;Javvadi S C P;Puppala A J;Hoyos L R (Civil Engineering Dep, IIT Hyderabad, Ordnance Factory Campus, Yeddumailaram-502 205, Email: sireesh@iith.ac.in) : Evaluation of fly ash treated reclaimed asphalt pavement for base/subbase applications. Indian Geotech J 2015, 45(4), 401-11.

Reclaimed asphalt pavement (RAP) is a term given to removed and/or milled pavement materials containing asphalt and aggregates. This material is obtained from recycling the existing flexible pavements which have reached the end of their design life or shown excessive cracking. The use of RAP has grown widely reducing the use of virgin material thus helps to conserve the natural resources. It also reduces the amount of construction debris reaching the landfills. RAP can be used in construction of base/subbase of a new pavement which results in huge savings. A 100% RAP cannot be used directly in base/subbase layers because of its inferior properties such as unconfined compressive strength (UCS), California bearing ratio (CBR) and resilient modulus (M_r). This is because RAP material has a very low or limited bonding as the particles are coated with aged bitumen. These properties can be improved by using RAP in combination with virgin aggregates (VA) and/or calcium based additives such as lime, cement or fly ash. Calcium rich fly ash and a fraction of VA have been used in the present study to evaluate the strength in terms of UCS and stiffness in terms of Mr of RAP to promote as a pavement base/subbase material. The RAP material was collected from an ongoing national highway (NH) expansion project in India. Class "C" fly ash was collected from Neyveli Lignite Corporation (NLC), Tamil Nadu for stabilization studies. Specimens were prepared with 100% RAP, 80% RAP + 20% VA and stabilized with 10, 20, 30 and 40%; dosages of fly ash by weight. In this study, emphasis is given to the mixing methodologies adopted to amend base materials and stabilizer. Traditionally, addition method is preferred for stabilization studies and replacement is preferred for mixture of two materials by weight of the principal material. Two methodologies were compared in terms of results obtained from the M_r and UCS studies and a balanced method was suggested. To know the level of interaction of fly ash with the bitumen coated aged aggregate, X-ray powder diffraction (XRPfo) and Scanning Electron Microscope (SEM) studies were also performed. It was observed that the balanced addition method of mixing the stabilizer by weight of principal material would be more beneficial in terms of the strength and stiffness of the mixes. The new design mix consisting of 80:20 proportion of RAP and VA stabilized with 40% fly ash by Weight of the total mix has met the design specifications laid down by Indian roads congress (IRC) for a base/subbase material of low volume roads.

11 illus, 3 tables, 24 ref

001625   Sangavi S;Subha Sankari T;Arunkumar S; Venkatesan M (School of Mechanical Engineering, SASTRA Univ, Tirumalaisamudram, Thanjavur-613 401, Email: mvenkat@mech.sastra.edu) : Experimental analysis of impact droplet cooling over stainless steel plates. J Energy Heat Mass Transfer 2015, 37(1-4), 187-94.

In the present work, cooling of heated stainless steel plate induced by a droplet impinging on it under gravitational potential is studied. Visualization of the droplet falling on the stainless steel plate is done using a high speed camera. Real time temperature measurement is done using a Data Acquisition system. The synchronized high speed camera recording of droplet and the temperature allows characterization of droplet dynamics which is responsible for variation in plate temperature. It is found that the impingement of a droplet leads to a sudden decrease in plate temperature as a result of absorption of heat by the droplet. Gradual increase in temperature is seen as the droplet evaporates. Bubble formation inside the droplet is said to have a pronounced role in causing a variation in base plate temperature.

7 illus, 11 ref

001624   Reddy R M;Prasad T H;Reddy K P;Rao P M (Mechanical Engineering Dep, G. Pulla Reddy Engineering College, Kumool-518 007, Email: rmreddy123@gmail.com) : Experimental investigation of performance of parabolic solar cooker with different reflactors. J Energy Heat Mass Transfer 2015, 37(1-4), 147-60.

Solar energy inexhaustible source of energy. The main aim of this paper is performance evaluation of parabolic solar cooker with different reflector. Given the prevalent energy crises across the globe, it is always desired to exploit new and renewable energy sources which are readily available at almost negligible cost. Solar cookers have come in various farms: parabolic cookers, panel cookers, box cookers, and funnel cookers; each with its own design and performance peculiarities. For efficient utilization of solar energy, focusing type parabolic solar cooker was designed and fabricated, having a focal length of 43 cm. The performance evaluation gave a maximum temperature of 123°C at an ambient temperature of 30°C. A black pot which absorbs heat more readily than other materials was used for the performance test. By using different reflector (aluminum sheet, Aluminum foil & glass), performance of the solar cooker was found and glass reflector was found efficient for cooking a food items compare to other two reflectors.

13 illus, 3 tables, 19 ref

001623   Razaque A;Elleithy K (Computer Science and Engineering Dep, Univ of Bridgeport, Bridgeport, CT-06604, USA) : Nomenclature of medium access control protocol over wireless sensor networks. IETE Tech Rev 2016, 33(2), 160-71.

Wireless sensor networks (WSNs) are considered as the appealing research area. WSNs require highly robust medium access control (MAC) protocol to enhance the performance in several application areas, such as intrusion detection, target detection, industrial automation, environmental monitoring, surveillance system, medical diagnosing system, and tactical system. On the other hand, there are several factors that affect the performance of these applications particularly selection of weak MAC protocol. In this paper, we provide performance impairing drivers for MAC protocols, which affect the efficiency and robustness of MAC protocols in WSN applications. We classify MAC protocols into six categories, as compared with previous MAC surveys that only focused on classifying the MAC protocols into two, three, or four major categories. In addition, we show the link of each category with another based on their existing features. Furthermore, this survey provides a detailed nomenclature in which protocols are categorized based on synchronous and asynchronous communication. This survey also discusses the possible threats and some existing solutions at the MAC layer from 2000 to 2014. Finally, we identify the future research challenges and raise directions for controlling these challenges.

2 illus, 2 tables, 59 ref

001622   Rajpuria V;Mishra P;Naiya T K (NO, , ) : Development of nanoparticles as additive to drilling mud to be used as viscosity and filtrate loss modifier. J Modern Chem chem Technol 2016, 7(1), 22-30.

Conventional drilling fluids are often unable to fulfill certain functional tasks that are very important in challenging environment. This inefficiency of drilling fluid in performing certain task is mainly because of lack in particular rheological or filtrate loss properties. Hence, the industry is looking for a new kind of additives which can be helpful in maintaining these properties in desired range even under extreme conditions. Rice husk is an abundantly available agricultural waste which contains almost 15% silica in it. In this work, silica nanoparticles were synthesized from rice husk and used as an additive to improve the rheological and filtration loss properties. Synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), field emission electron microscopy (FESEM) and energy dispersive spectroscopy (EDX). A general fluid was prepared that contained barite (6%), bentonite (3%) and carboxymethyl cellulose (3%) and the composition of nanomud was barite (6%), bentonite (3%), carboxymethyl cellulose (3%) and prepared silica nano particles (1%). Rheological studies were conducted on the two drilling fluids at different temperatures in the range of 30 to 100°C. API filtrate loss study was also conducted on both drilling fluids. Initial test results indicate that the newly developed nano-based drilling fluid exhibits improved rheological properties and shows less fluid loss as compared to the normal drilling fluid.

001621   Radhaboy G;Pugazhvadivu M;Yamunadevi V (Mechanical Engineering Dep, Pondicherry Engineering College, Puducherry-605 014, Email: yamunadevi64@gmail.com) : Thermogravimetric analysis of calotropics procera. J Energy Heat Mass Transfer 2015, 37(1-4), 205-13.

Calotropis procera (C.procera) is a weed that grows profusely without management on waste lands. In this work, the plant of C.procera was characterized to evaluate the suitability for use as renewable energy feedstock. The ultimate and proximate analyses were carried out to determine the elemental composition. Thermogravimetric analyses (TGA) were performed to study thepyrolysis and combustion characteristics. The proximate and ultimate composition of C.procera was similar to other lignocellulosic biomass. The TGA and DTG profiles under nitrogen atmosphere presented significant mass loss in which the shoulder and sharp peaks represented hemicellulose and cellulose pyrolysis respectively. The combustion profile presented two distinct degradation stages indicating the oxidation of hemicellulose, cellulose, lignin and char. The ignition and burnout temperature estimated from the TG and DTG curves is 240°C and 492°C respectively. The thermal behaviors under nitrogen and oxygen environment indicated that the plant is suitable for both pyrolysis and combustion processes.

3 illus, 1 table, 10 ref

001620   Pratibha R;Sivakumar Babu G L;Latha G M (Civil Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: pratibha2388@gmail.com) : Stress-strain response of unbound granular materials under static and cyclic loading. Indian Geotech J 2015, 45(4), 449-57.

Resilient modulus is an important parameter in flexible pavement engineering design. The stress-strain behavior of unbound granular base materials under static and cyclic loading and the effects of the state of stress, moisture content and loading conditions have been ana-lyzed in the present study. In this paper, the resilient behavior of unbound granular materials and the applica-bility of different constitutive models are examined in order to understand the behavior of granular material under static and cyclic loading. Since the aggregate material exhibits a complex stress-strain behavior, more than one model will be required to predict the stress-strain response of granular materials. Hence, different constitutive models have been considered in the present study which can adequately predict the stress-strain response of aggregate materials. Considering the constitutive models used in the present study, it could be said that the Lentz and Baladi model and the normalized degradation model suitably bring out a relation between static and cyclic tests. This is a useful input in pavement design and explains the variation of modulus with load repetitions.

5 illus, 7 tables, 24 ref

001619   Prakash P;Abegaonkar M P;Kurra L;Basu A;Koul S K (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, New Delhi) : Compact electromagnetic bandgap (EBG) structure with defected ground. IETE J Res 2016, 62(1), 120-6.

In this paper, a compact defected ground mushroom electromagnetic bandgap (DG-MEBG) structure is presented Compactness is achieved by employing a DG in the conventional MEBG. DG-MEBG exhibits a low pass transmission response with a cut-off frequency of 4.2 GHz and wide stop band up to 17 GHz as against a cut-off frequency of 10.4 GHz observed in a conventional MEBG. Thus the proposed DG-MEBG is 60% compact in comparison with a conventional MEBG structure. The measured results show a very good agreement with the simulated ones.

9 illus, 16 ref

001618   Paul D K;Theivakularatnam M;Gnanendran C T (Civil and Architectural Engineering Dep, Qatar Univ, Doha, Email: dalim49@yahoo.com) : Damage study of a lightly stabilised granular material using flexural testing. Indian Geotech J 2015, 45(4), 441-8.

This paper investigates the damage characteristics of a lightly stabilized granular material using cyclic load flexural testing with an improved deflection mea-surement setup. Beam specimens were prepared from a typical granular base material lightly stabilised with 1.5% cement-flyash, cured for 28 days and tested at different stress ratios (SRs) until the fracture occurred. Fatigue life was established as the number of cycles required to break the specimen under stress-controlled cyclic loading at a frequency of 3 Hz. Fatigue induced damage was evaluated using the dissipated energy approach. Experimental results indicated that damage accumulation due to fatigue approximately follows the Miner's linear cumulative damage rule. The study also found that the accumulated permanent deformation of lightly stabilised materials showed good correlation with number of load cycles and the developed empirical equations at different SRs can be used to predict the fatigue life. Progressive damage accumulation due to permanent deformation with increases in the load cycles is also presented in this study.

9 illus, 2 tables, 29 ref

001617   Patel O P;Patel S A;Raja A H;Chhabra R P (Chemical Engineering Dep, Indian Institute of Technology Kanpur, Kanpur-208 016, Email: chhabra@iitk.ac.in) : Forced convection heat transfer from a hemisphere in bingham plastic fluids: effects of orientation and thermal boundary condition. J Energy Heat Mass Transfer 2015, 37(1-4), 27-56.

Forced convection in Bingham plastic fluids from a heated hemisphere has been investigated for the inverted and upright configurations over the range of conditions as: Reynolds number, 0.1 ≤Re ≤ 160, Prandtl number, 10 ≤Pr ≤ 100 and Bingham number, 0 ≤ Bn ≤ 1000 for the two common boundary conditions,i.e., an isothermal (CWT) and isoflux (CHF) hemisphere. Detailed kinematics in the vicinity of the hemisphere is examined in terms of yielded/unyielded regions, streamlines and isotherms. Next, the variation of the local Nusselt number along the surface of the hemisphere has been analysed for each case. While the drag coefficient is augmented over and above the Newtonian value at a given Reynolds number due to the fluid yield stress, the average Nusselt number exhibits the familiar scaling of Nu <126> (Pe*)^{1/3. All else being equal, the CHF condition yields slightly higher values than the CWT condition.}

16 illus, 5 tables, 39 ref

001616   Nithin S;Rajagopal K;Veeraragavan A (Geotechnical Engineering Div, Civil Engineering Dep, IIT Madras, Chennai-600 036) : State-of-the art summary of geosynthetic interlayer systems for retarding the reflective cracking. Indian Geotech J 2015, 45(4), 472-87.

Reflective cracking is the phenomenon of propagation of cracks from an existing cracked pavement surface into and through the newly laid overlay due to the load or temperature induced stresses or both. The reflective cracking mechanism is a, complex phenomenon due to the large number of parameters that influence the propagation of cracks. For this reason, a simple design procedure could not be developed to arrest the reflection cracking till date. The distress due to reflective cracking can be retarded by the installation of different interlayer systems. The geosynthetic interlayer system is gaining popularity due to its ease in installation and adaptability to varying climatic conditions. Choosing an effective geosynthetic interlayer needs proper understanding about the mechanism of reflection cracking and the improvement it can cause in the performance of pavement. The service life of the overlay can be enhanced with the installation of geosynthetic interlayer system thereby decreasing the long term costs. The minimum specifications for the paving fabric have been recommended by different standards organisations like AASHTO, ASTM and IRC. This paper presents an overview on reflective cracking, investigations on the performance of geosynthetic products in retarding the reflective cracking, mechanism of geosynthetic interlayer systems and specifications for selecting the appropriate geosynthetic material for the desired performance.

3 illus, 9 tables, 69 ref

001615   Nitesh Kumar;Agrawal A;Singh S G;Sridharan A (Mechanical Engineering Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: amit.agrawal@iitb.ac.in) : On bubble dynamics during flow boiling in microchannel. J Energy Heat Mass Transfer 2015, 37(1-4), 57-64.

The present study pertains to bubble dynamics during flow boiling in microchannels. Experimental data for elapsed time, bubble detachment time, waiting period and bubble growth rate have been presented; effect of input power on the above parameters has also been documented. A remarkable difference in growth of bubble with time is noted as compared to available results at conventional scales. These results help bring out importance differences in the bubble growth and its dynamics at the microscales as compared to conventional scales. This novel data is expected to give impetus to development of theoretical models at the microscales.

4 illus, 10 ref

001614   Nayak R;Chatterjee D;Das S K (Mechanical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: rajlakshmi02@gmail.com) : Experimental and numerical investigation of the effect of aspect ratio on friction constant in microchannels. J Energy Heat Mass Transfer 2015, 37(1-4), 65-75.

Experimental and numerical flow characteristics in rectangular microchannels with different hydraulic diameters and aspect ratios have been reported. The aspect ratio is varied between 0.1 and 1 for constant hydraulic diameters. The microchannels were fabricated on acrylic sheets by micro end-mill cutter and water was used as working fluid. The effect of aspect ratios for constant hydraulic diameter and vice-versa on pressure drop and friction constant is analyzed. Pressure drop characteristics obtained from experiments show difference with empirical formulation available in literature. A new correlation is proposed for friction constant for this range of hydraulic diameter and aspect ratio. It is inferred that shape effects, in conjunction with the size of microchannel, affects the flow characteristics.

9 illus, 1 table, 21 ref

001613   Narayanan C M;Biswas S (NO, , ) : Studies on waste water treatment in three phase semifluidized bed bioreactors: computer aided analysis and software development. J Modern Chem chem Technol 2016, 7(1), 1-21.

Design and performance analysis of three phase semifluidized biofilm reactors for aerobic treatment of industrial effluents have been attempted. Bioconversion processes that follow Monod-type kinetics and those following Haldane-Andrews kinetics (involving substrate inhibition to microbial growth) have been considered as typical cases. The bioreactor has been modelled mathematically by solving performance equations separately for the packed section and for the fluidized section, considering dispersed flow in both of these sections, the degree of axial dispersion being of larger magnitude in the fluidized section. The developed CAD package has been verified by comparing with typical pilot plant data. The attractive features of semifluidized bioreactors of this kind (operation at high capacity, high degree of BOD removal/pollutant degradation, which increases with increase in feed flow rate, low reactor volume requirement as compared to fluidized bed bioreactors operating on the same feedstock) have been adequately highlighted.

001612   Naik N V;Thankachan J;Singh S P (Electrical Engineering Dep, Indian Institute of Technology Roorkee, Roorkee) : Neuro-fuzzy direct torque control using bus-clamped space vector modulation. IETE Tech Rev 2016, 33(2), 205-17.

This paper presents proportional integral direct torque control (PIDTC) and neuro-fuzzy-based DTC (NFDTC) using bus-clamped space vector modulation for two-level inverter. The PIDTC provides more ripples in flux, speed, and torque during speed/load changing conditions, and also gives more total harmonic distortion (THD) in current of the induction motor (IM). In order to improve the dynamic and the ripple performance of IM drive, the NFDTC is used in which the Pi-controllers (speed and torque) are replaced with neuro-fuzzy controls using hybrid learning algorithm. The hybrid algorithm divides into two parts such as back propagation and least square estimation methods to improve the controller performance. Also, the duty ratios are controlled as independent of sampling time to improve the gating pulse of the inverter. A prototype IM drive is developed with a DSPACE DS-1104 controller to validate their simulated performance. The experimental results show that the NFDTC has less current THD than PIDTC leading to significant improvement in torque and flux ripples with fast dynamic response of IM drive.

13 illus, 3 tables, 27 ref

001611   Muzzammil M;Alam J;Danish M (Civil Engineering Dep, ZH College of Engineering & Technology, AMU, Aligarh-202 002) : Application of gene expression programming in flood frequency analysis. J Indian Wat Resour Soc 2015, 35(2), 1-6.

Flood frequency and its magnitude are essential for the proper design of hydraulics structures such as bridges, spillways, culverts, waterways, roads, railways, flood control structures and urban drainage systems. Since, flood is a very complex natural event depending upon characteristics of catchment, rainfall conditions and various other factors, thus its analytical modelling is very difficult to pursue. Recently, artificial intelligence techniques such as gene expression programming (GEP), artificial neural network (ANN) etc. have been found to be efficient in modelling complex problems in hydraulic engineering. The performance of GEP model has been reported to be better than that of the ANN. Moreover, GEP provides mathematical equation which makes it more superior over other soft computing techniques that do not give any analytical mathematical equation. Therefore, in present study, GEP is implemented in flood frequency analysis for typical Indian river gauging station. The results obtained in the present study are highly promising and suggest that GEP modelling is a versatile technique and represents an improved alternative to the more conventional approach for the flood frequency analysis.

4 illus, 2 tables, 22 ref

001610   Muzaffar K;Tuli S;Koul S K (Centre for Applied Research in Electronics, Indian Institute of Technology, Delhi) : Determination of polarisation of microwave signals by lock-in infrared thermography. IETE J Res 2016, 62(1), 81-90.

Detection of polarisation of microwave signals using infrared thermography is described in this paper. A metal grating consisting of parallel, equally spaced metallic strips is placed in between a microwave source (antenna) and a microwave absorption screen for permitting the determination of direction of electric field vector (polarisation). Very low frequency modulation of the microwave source is added to permit lock-in thermography which enhances thermal resolution. In case of linear polarisation when the metallic strips of the grating are parallel to the direction of electric field vector, the temperature rise on the screen as observed by an infrared camera, is minimum. On the other hand if the metallic strips are perpendicular to the electric field vector the temperature rise observed on the screen is maximum. The orientation of the grid is changed by rotating the grid about a central axis perpendicular to its plane. With each different orientation of the grid a change in temperature rise is observed on the screen. In case of circular polarisation the temperature rise on the absorption screen is almost independent of the grid orientation i.e. there is negligible change in temperature rise with each different orientation of the grid, as the electric field strength perpendicular to grid strips is almost constant for all grid orientations, corresponding to an axial ratio of unity. While in case of elliptical polarisation the temperature change is appreciable depending on the axial ratio. The proposed method is validated on linearly, circularly and elliptically polarised patch antennas radiating at 8 GHz. Simulation is carried out in CST MICROWAVE STUDIO (CST MWS2013) and a good agreement between simulated and experimental (thermographic) results is observed.

25 illus, 11 ref

001609   Muralidharan E;Tharun Kumar B;Pravinjith K P (NO, , Ecoparadigm, Bangalore-560 008, Email: dremurali@gmail.com ) : DTS EcoSTP: a novel sewage water treatment system. J Energy Heat Mass Transfer 2015, 37(1-4), 77-84.

Water and electricity are the most important commodities essential for the human civilization. Water is very basic for the survival of humans as well as all other living beings. Electric power is very vital for the development of the modern society and economic prosperity. These two commodities are in scarcity worldwide specifically in the developing and under developed countries. So, there is an urgent need to preserve the water and power. The Decentralised Treatment System (DTS) - EcoSTP process has been designed to save and recycle the sewage water. EcoSTP treats the sewage water during the gravitational over flow through the series of chambers embedded with bacteria. EcoSTP operates without the conventional electrical powered motor and can treat the sewage water with biological oxygen demand (BOD) of 350 - 450 to less than 20. EcoSTP has a multiple advantages of effectively treating the sewage, preventing the environmental pollution and saves the cost of electrical power.

1 table, 6 ref

001608   Mallick R B;Sivakumar Babu G L (Civil and Environmental Engineering, Worcester Polytechnic Institute (WPI), 100 Institute Road, Worcester, MA 01609, Email: rajib@wpi.edu) : Novel use of geosynthetic reinforced chip seal in asphalt pavements. Indian Geotech J 2015, 45(4), 488-95.

High temperature causes a number of problems including rutting and premature aging/cracking in asphalt pavements. The high temperature results primarily from high absorptivity and low conductivity of the asphalt binder and the hot mix asphalt (HMA). This paper presents a novel approach of utilizing geosynthetic reinforced chip seal (GRCS) with high reflectivity (reflectivity greater than * 0.2) aggregates to reduce the amount of heat that is absorbed at the surface and the heat that is conducted to the lower layers. Results of small scale and full scale tests as well as finite element analyses are presented. The results show that GRCS is highly effective in reducing pavement temperatures at different depths, specifically, at a depth of 12.5 mm below the surface, which corresponds with the depth of maximum temperature for most asphalt pavements. The GRCS section used in the full scale test shows a reduction of 8 °C, compared to a conventional HMA section. Mechanistic-empirical analysis shows that for such a reduction, an extension of pavement life by 8 years is achievable. It is recommended that GRCS section be constructed along with conventional HMA section, and trafficked, for evaluation of life cycle cost benefits.

11 illus, 2 tables, 17 ref

001607   Madhumitha R;Arun Kumar S;Venkatesan M (School of Mechanical Engineerig, SASTRA Univ, Tirumalaisamudram, Thanjavur-613 401, Email: mvenkat@mech.sastra.edu) : Numerical study on the evaporation of liquid droplets in a rectangular enclosure. J Energy Heat Mass Transfer 2015, 37(1-4), 161-72.

Evaporation of single isolated droplet plays an important role in studying the mechanics of fuel cooling and spraying systems. Process operations such as liquid hydrocarbon combustion and meteorology are some fields which use the mechanics of droplet evaporation. Though there has been a large number of works in the field of droplet evaporation, very little attention has been given to the droplet evaporation in an enclosure. When the enclosure width is less than the spreading radius during droplet evaporation, quite a few interesting characteristics can be envisaged which is the motivation behind the paper. In the present work, Volume of flu ids (VOF) based framework is used to study the characteristics of droplet evaporation in fluids of different viscosities in a 2D rectangular enclosure. VOF based validated numerical model available in literature is used to study the transient nature of evaporating droplet over a plate of infinitesimal thickness. The analysis is carried out using commercial CFD code ANSYS FLUENT c. It has been observed that, there is a marked difference in the transient characteristics such as contact angle with the surface of enclosure, volume fraction and temperature distribution in droplets with different viscosities. This difference can be used to define optimal process parameters for effective functioning of various chemical and thermal systems.

8 illus, 2 tables, 13 ref

001606   Kurra L;Abegaonkar M P;Koul S K (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, New Delhi) : Equivalent circuit model of resonant-EBG bandstop filter. IETE J Res 2016, 62(1), 17-26.

In this paper, we present an equivalent circuit model of a uni-planar electromagnetic bandgap (EBG) structure. The equivalent circuit is developed by the combination of lumped element representation of distributed elements. The EBG structure is coupled to the transmission tine and the coupling is modelled by a capacitor between the structure and the transmission line. The circuit simulated results match well with the electromagnetic simulation results.

11 illus, 20 ref

001605   Kumbhani B;Kshetrimayum R S (Electronics and Electrical Engineering Dep, Indian Institute of Technology Guwahati, Guwahati) : Performance analysis of MIMO systems with antenna selection over generalized κ-√ fading channels. IETE J Res 2016, 62(1), 45-54.

In this paper, we derive closed form expression for outage probability and infinite series expressions for exact and approximate symbol error rate (SER) and capacity of multiple input multiple output systems with transmit antenna selection (TAS) over generalized independent and identically distributed K - μ fading channels. The results are applicable to systems employing maximal ratio combining or selection combining at the receiver. Furthermore, by taking special cases, we present closed form expressions for outage probability of TAS systems over Nakagami-m and Rayleigh fading channels. The closed form expressions of outage probability for Nakagami-m and Rayleigh fading are computationally efficient than the expressions reported in the existing literature. The expressions of SER and channel capacity are in the form of sum of fast converging infinite series for all values of fading parameters. The analytical results are validated by comparing them with Monte Carlo simulation results for different values of fading parameters. The results of channel capacity shows that increased strength of line of sight component and decreased severity of fading degrades the channel capacity.

8 illus, 38 ref

001604   Korulla M;Gharpure A;Rimoldi P (NO, Maccaferri India, New Delhi, Email: minikorulla@maccaferri-india.com) : Design of geogrids for road base stabilization. Indian Geotech J 2015, 45(4), 458-71.

Geogrids are extensively used for the stabilization of paved and unpaved road bases on soft soils. The design methods presently available for use of geogrids in road base stabilization provide no or insufficient information about the required number of layers and the mechanical characteristics of geogrids. Hence, a new design method has been developed which includes the design of geogfids for road base stabilization, based on a 4 layer model: asphalt (binder and wearing course), base, subbase and subgrade. The base and/or subbase thickness has to be defined with one of the available methods such as AASHTO method, Giroud-Han method, Leng-Gabr method, etc. The proposed design method can be used to calculate the tensile forces in the geogrids generated by: self weight of the different layers; wheel load of heavy vehicles; membrane effect at the base (or subbase)-sub-grade interface. It is then possible to set the number and the mechanical characteristics of geogrid layers required for absorbing the horizontal forces generated by these three mechanisms.

13 illus, 14 tables, 15 ref

001603   Kief O;Schary Y;Pokharel S K (PRS-Med, Tel Aviv, Israel, Email: yitzchak@prs-med.com) : High-modulus geocells for sustainable highway infrastructure. Indian Geotech J 2015, 45(4), 389-400.

Technological innovation in geosynthetics such as high modulus (stiff) geocells (cellular confinement systems) can help achieve a more sustainable highway infrastructure. Research, testing, field trails, and case studies demonstrate how geocells increase pavement per-formance on one hand, while achieving sustainable goals on the other. Recent published research and testing of high-modulus Novel Polymeric Alloy (NPA) geocell-reinforced bases are briefly reviewed in this paper. NPA geocells improved strength and rigidity of flexible pavements as indicated by: increased modulus of structural layers, reduced stresses to the lower layers and decreased surface degradation. Field trials validate that NPA geocells improve the modulus of road base layers, even while reducing the structural thickness and utilizing on-site or recycled materials for structural infill. Sustainable roads can be built with less virgin resources and a smaller environmental footprint, while extending the pavement service life and decreasing maintenance.

16 illus, 1 table, 39 ref