016065   Eswarana U;Ramiaha H;Kanesan J (Electrical Engineering Dep, University of Malaya, ) : Power amplifier design methodologies for next generation wireless communications. IETE Tech Rev 2014, 31(3), 241-8.

As wireless communication standard continues to evolve accommodating the demand of high data rate operation, the design of radio frequency (RF) power amplifier (PA) becomes ever challenging. PAs are required to operate more efficiently while maintaining stringent linearity requirement. In this paper, the design concepts of the PA in addressing these challenges are reviewed. The concepts are divided into two main categories, namely the linearization technique and efficiency enhancement technique. The mandatory attempt in realizing a low-cost design is also discussed.

6 illus, 1 table, 54 ref

016064   Desai S R;Prasad R (Electrical Engineering Dep, Indian Institute of Technology Roorkee, Roorkee) : Novel technique of optimizing FOPID controller parameters using BBBC for higher order system. IETE J Res 2014, 60(3), 211-17.

The authors present a computer-aided mode to optimize the fractional-order proportional integral derivative (FOPID) controller parameters including the integral order "A" and derivative order "μ". Big Bang-Big Crunch (BBBC) optimization technique is used here to serve the purpose. The proposed method is realized with a numerical example and unit step responses are obtained for various values of λ and μ. The simulated results justify the superiority of FOPID controller using BBBC, when compared with the recently published/available well-known method.

12 illus, 1 table, 20 ref

016063   Deng J;Xie Z;Cheng L;Su K;Zhang L (National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical Univ, Xi'an, Shaanxi 710072, P.R. China, Email: dengj1@chd.edu.cn) : Thermodynamics of the production of condensed phases in the CVD process of B_xC with BCl₃-C₃H₆ (propylene)-H₂ precursors. Indian J Engng Mater Sci 2014, 21(4), 465-72.

The temperature, pressure and the molar ratio of the injected gas mixture for the deposition of the condensed phases in the CVD process of B_xC with BCl₃-C₃H₆ (propylene)-H₂ precursors are investigated in detail thermodynamically with a revised database including 329 species. The results show that the composition of the condensed phases is quite sensitive to both temperature and the molar ratios of BCl₃/(BCl₃+C₃H₆) and H₂/(BCl₃+C₃H₆) while it is less sensitive to pressure. The ideal conditions for the deposition of B_xC are BCl₃/(BCl₃+C₃H₆) ratio within 0.88-0.92, H₂/(BCl₃+C₃H₆) ratio within 10<126>10^{5.2 and temperature above 1100 K at lower pressures. The co-deposition of C or B with B_xC is mainly controlled by the ratios of BCl₃/(BCl₃+C₃H₆) and H₂/(BCl₃+C₃H₆). The co-deposition of C with B_xC should be in low BCl₃/(BCl₃+C₃H₆) (0.0-0.88) and H₂/(BCl₃+C₃H₆) (10-2<102.4) ratios while the co-deposition of B with B_xC needs higher BCl₃/(BCl₃+C₃H₆) (0.92-1.0) and H₂/(BCl₃+C₃H₆) (104-105) ratios.}

6 illus, 31 ref

016062   Dakwale V A;Ralegaonkar R V (NO, Shri Ramdeobaba College of Engneering and Management, Nagpur-440 013, Email: vaidehi.dakwale@gmail.com) : Development of sustainable construction material using construction and demolition waste. Indian J Engng Mater Sci 2014, 21(4), 451-7.

Construction and demolition of old structures generates large quantity of masonry waste in urban areas. This waste is generally diverted towards landfill. In the present study, a sustainable construction material (brick) using construction and demolition (C&D) waste is developed. Cement and fly ash are used as binder and C&D waste is used as fine and coarse aggregates.Construction and demolition waste bricks (eco-bricks) of size 230 mm x 90 mm x 90 mm are developed for the six different compositions (BR90-1 to BR90-6). Physico-mechanical tests (block density, compressive strength and water absorption) are carried out as per Indian standards and embodied energy for the considered compositions is estimated. The test results are compared to commercially available fly ash bricks. The eco-bricks that achieved the least embodied energy is considered as the best combination of sustainable construction material. Amongst the various trials carried out the brick BR90-6 with the ratio of binder, fine aggregate and coarse aggregate as 1:2.75:2.25 exhibit compressive strength and water absorption within the limits of Indian standards with minimum self weight and embodied energy. The developed sustainable product can be practically implemented over any specific location by the manufacturer which serves the purpose of solid waste management.

4 illus, 3 tables, 17 ref

016061   Cucak D;Vasic M;Garcia O;Oliver J;Alou P; Cobos J A (NO, Universidad Politecnica de Madrid, Centro de Electronica Industrial, Madrid 28006, Spain) : Filter design methodology and application of GaN HEMTs in high-frequency DC/DC converter. IETE J Res 2014, 60(3), 240-7.

Optimization of the radio frequency (RF) transmitter performance in envelope tracking (ET) and envelope elimination and restoration (EER) techniques directly implies optimization of the envelope amplifier (EA) design. Since EA should have fast dynamic response together with high efficiency, synchronous buck is a suitable topology for this kind of application. The key issues for optimization of the converter design are the characteristics of the switching devices, the LC filter design, and the driving circuit for the switches. In this paper, design optimization of the LC filter for sinusoidal output voltage together with new technological solution for switching devices based on gallium nitride is proposed, while the applied drivers are commercially available ones, suitable for aforementioned GaN switches. Design of the output filter in synchronous buck converter for high-frequency application is important from two points of view: the first one is sufficient attenuation of the unwanted harmonics of the switching frequency so that envelope reference has minimum level of distortion and the second one is the overall impact of the filter design on the converter's efficiency. In order to increase the efficiency, the LC filter should be designed in a way to obtain compromise between the conduction and switching losses of the buck converter. In the case of sinusoidal output voltage, filter design parameter has been defined as the ratio between the maximum values of the inductor current and load current and power losses dependence on this parameter has been obtained. Theoretically obtained optimum design has been confirmed through experimental measurements, where four different designs were built and tested. On the other hand, application of new switching devices based on gallium nitride provided significant efficiency enhancement in comparison to Si MOSFETs and laterally diffused MOS transistors, due to the lower values of the gate charge and on-resistance. Tests with 64QAM and wideband code division multiple access (WCDMA) RF signals showed that these devices are the best choice for this kind of application, where the main challenge is to increase the efficiency of the signal transmission simultaneously with the bandwidth.

9 illus, 4 tables, 25 ref

016060   Bhandari K;Parida P;Chakraborti N;Gupta K (NO, CSIR - Central Road Research Institute, New Delhi-110 025) : Assessment of policies towards an environmentally friendly urban transport system : A case study of Delhi, India. Bhartiya Vaigyanik Evam Audyogik Anusandhan Patrika 2014, 22(1), 21-30.

Urban transport plays an important role in city development and is also a leading sector in energy consumption and air pollutant emissions. To examine the effectiveness of policies in reducing transport influences on environment and energy use, this paper takes passenger transport system in Delhi as a case and develops a system dynamics model for scenario analysis from the base year 2006 to 2020. It is found that the implementation of certain policies will lead to a significant reduction of energy use and emissions of CO₂, CH₄ CO, NMVOC, and SO₂ by 7-14, 7-15, 4-9, 12-23, 12-24, and 11-23%, respectively, in 2020. Bus, car, and two-wheeler need particular attention to mitigate their environmental impacts while MRTS would be an effective solution to restrict the booming energy demand and associated air pollutant emissions. The implications for policy are that accelerating the development of railway network, together with decreasing the fuel intensity, slowing down road network extension and imposing fuel taxes will be effective instruments to build an environmentally friendly urban transport system.

4 illus, 6 tables, 17 ref

016059   Benga L Y;Ramadassa S;Manickama S;Fun T S (National Advanced IPv6 Center, Universiti Sains Malaysia (USM), 11800 Penang, Malaysia) : Survey of intrusion alert correlation and its design considerations. IETE Tech Rev 2014, 31(3), 233-40.

In recent years, network intrusion attempts have been on the rise. Malicious attempts, including hacking, botnets, and worms are used to intrude and compromise the organization's networks affecting their confidentiality, integrity and availability of resources. In order to detect these malicious activities, intrusion detection systems (IDSs) have been widely deployed in corporate networks. IDS sends alerts to security personnel in case of anomalous activities in the network. Unfortunately, one of the IDSs' drawbacks is they produce a large number of false positives and non-relevant positives alerts that could overwhelm the security personnel. Existing efforts to address this are done via identification of the similarities and causality relationships between alerts, grouping them into different clusters and prioritizing them after conducting the assessment on them. In this paper, we present commonly used alert correlation approaches and highlight the advantages and disadvantages from various perspectives. Existing alert correlation models are critically reviewed and compared in this paper. Subsequently, we emphasize four main considerations in alert correlation design which are: attack scenario either single packet or multi-stage attack, its architecture either centralized or distributed, performance assessment on accuracy of alert detection, and its processing time and the data to be used for testing.

1 table, 42 ref

016058   Baskar V V;Abhishek B;Logashanmugam E (Faculty of Electrical and Electronics, Sathyabama Univ, Chennai) : Comparison of fourier bessel (FB) and EMD-FB based noise removal techniques for underwater acoustic signals. J scient ind Res 2014, 73(12), 756-62.

Purpose of this paper is to compare the efficacy of two algorithms used for denoising underwater acoustic signals affected by ambient noise. The two denoising techniques are, (i) Fourier Bessel (FB) expansion based denoising algorithm and (ii) Empirical Mode Decomposition (EMD)-Fourier Bessel (FB) based denoising algorithm. Sea water normally contains unwanted background noise called ambient noise which is non-stationary produced by man-made or natural sources. In practical applications it is absolutely necessary to denoise underwater acoustic signals. The information that will be received through hydrophones shall be unaffected, pristine and original. In this paper, initially the two techniques are applied to a stationary input and the outcomes of both the techniques are compared. Later the two methods are once again applied to anon-stationary input and the results are then compared.

3 illus, 12 ref

016057   Arunachalam U;Moorthi N S V;Veeramani P (NO, Anna Univ Tirunelveli Region, Tamilnadu, Email: arunachalam_u@yahoo.com ) : Conductive heat transfer behaviour of electro-deposited nickel-tungsten alloy coating. J scient ind Res 2014, 73(12), 777-80.

Thermal barrier coatings are normally employed over the base metals subjected to elevated temperatures to protect the base materials from the severe operating thermo cyclic load conditions and to improve their performance. This paper deals with the conductive heat transfer behaviour of nano-crystalline nickel- tungsten electro-deposit over the mild steel substrate by choosing optimum parameters for the electro-deposition technique. The high quality deposit was prepared with 10 μm and 50 μm thickness, and the conductive heat transfer performance of the coatings was studied by a specially designed and fabricated experimental setup. The characterizations of the coated surfaces were carried out by various surface topography methodologies (XRD, EDAX and SEM). The heat transfer studies on the nano-sized nickel-tungsten alloy coatings reveal that the nano-coatings with a particle size of around 92 nm, exhibits nearly 9 - 18% of temperature reduction in the 50μm thickness coating, whereas an observation of 9 - 13% of temperature reduction was notified in the 10 μm thickness deposit.

3 illus, 18 ref

016056   Aldas K;Eskil M;Ozkul I (Mechanical Engineering Dep, Faculty of Engineering, Aksaray Univ, 68100 Aksaray, Turkey, Email: iskender@aksaray.edu.tr) : Prediction of A_f temperature for copper based shape memory alloys. Indian J Engng Mater Sci 2014, 21(4), 429-37.

This study presents the gene expression programming (GEP) soft computing technique as a new tool for the formulation of the Austenite finish (A_f) temperature of Cu-based shape memory alloys (SMA) for various compositions and heat treatments. The objective of this study is to provide an alternative formulation to related design composition and verify the robustness of GEP for the formulation of such structural problems. The training and testing patterns of the proposed GEP formulation is based on well established experimental results from the literature. The GEP based formulation results are compared with the experimental results and found to be quite reliable.

10 illus, 7 tables, 38 ref

016055   Afzal M H B (Faculty of Science Engineering and Technology (FSET), University of Science and Technology Chittagong (USTC), Chittagong 4202, Bangladesh) : Large scale IT projects: study and analysis of failures and winning factors. IETE Tech Rev 2014, 31(3), 214-19.

Federal Bureau of Investigation (FBI) embarked on developing a case management software project titled "The Virtual Case File (VCF)" in 2000 to facilitate the FBI agents in progress in active investigations and connects them with each other. But FBI ultimately discarded the project in April 2005. This study demonstrates why the project titled "Virtual Case File" failed and analyses the reasons behind this failure. This meticulous analysis thoroughly examines the VCF project and suggests a few effective pointers to identify a dwindling IT project. This analytical study also explores the exclusivity of this project failure. This study discusses about a few effective suggestions that could have saved this huge IT project failure and future large IT projects. A dedicated chapter in this paper explains the possible winning factors for an IT project success. Finally, a selective chronology of the over-hyped VCF project has been illustrated in the final part of this paper.

3 illus, 1 table, 18 ref

015270   Zhang Y P;Wang H;Xu J W;Yang L;Qiu W;Li Z D (School of Materials Science and Engineering, Guilin Univ of Electronic Technology, Guilin 541004, P.R. China, Email: wh65@tom.com) : Effect of ZnMn₂O₄ thickness on its resistive switching characteristics. Indian J Engng Mater Sci 2014, 21(5), 563-6.

In this paper, the ZnMn₂O₄ resistive switching characteristics are investigated for different layer thicknesses. The ZnMn₂O₄ films, with a thickness of 180 nm, 255 nm, 340 nm, exhibited bipolar resistive switching behaviours. It is observed that the RESET voltage of Ag/ZnMn₂O₄/p^{+-Si devices increase with the increase of ZnMn₂O₄ layer thickness and the SET voltage shows weak dependence on film thickness. The 255 nm thick ZnMn₂O₄ film is proved to have the best read/write endurance characteristics, in which it shows steady and reproducible bipolar resistive switching behaviours after 1000 switching cycles. However, large fluctuation of resistance is observed obviously for the device with 180 nm thick ZnMn₂O₄ film and that with 340 nm thickness shows weak resistive switching ability after 1000 switching cycles.}

4 illus, 16 ref

015269   Yong-an L (School of Physics and Electronic Engineering, Xianyang Normal Univ, Xianyang 712000, China, Email: lya6189@yahoo.com) : Systematic synthesis of OTA-based wien oscillators. Indian J pure appl Phys 2014, 52(12), 846-50.

Nodal admittance matrix (NAM) expansion method for systematic synthesis of seven-OTA Wien oscillators is given. The paper presents 32 Wien oscillators using OTAs by means of NAM expansion method. Each oscillator employs seven OTAs and two grounded capacitors, it is easy to be integrated and the oscillation condition and frequency can be tuned electronically, linearly and independently through tuning bias currents of OTAs. The circuit analysis and computer simulation results are in agreement with theory and then the realizability of the derived circuits is verified.

3 illus, 1 table, 17 ref

015268   Xu F;Zhao S D (School of Mechanical Engineering, Xi'an Jiaotong Univ, Xi'an, 710049, China, Email: sdzhao@mail.xjtu.edu.cn) : Predicting the shear strength of round clinched joint. Indian J Engng Mater Sci 2014, 21(5), 510-18.

The quality of clinching joints is evaluated by visual and strength tests. This paper describes the shear strength of the round clinched joints of three sheets materials including the Al6061, Al5052, and Q235. The strength of mechanical clinching is affected by sheet thickness, the geometry of the tool, the material performance and the direction of the applied shear (i.e., the press joint orientation). To obtain the shear strength and reduce cost of the tensile tests, two equations for predicting the maximum failure load can be derived by using these parameters. A total of 180 shearing tests are conducted to check the maximum failure load obtained by predictive equations, and the results are in agreement with our predictions.

6 illus, 2 tables, 24 ref

015267   Wang H;Zhang Y;Li Z;Sun C (Mechanical & Electrical Engineering Dep, Suzhou Vocational Univ, Suzhou 215104, China, Email: whb@jssvc.edu.cn) : V-shaped small linear ultrasonic motor with multilayered piezoelectric stacks. Indian J Engng Mater Sci 2014, 21(5), 495-500.

For accomplishing of a linear ultrasonic motor with low driving voltage, small size and large output force, a novel V-shaped linear ultrasonic motor with multilayered piezoelectric stacks has been developed. Firstly, the piezoelectric ceramic used in the stack is fabricated. The piezoelectric ceramic has excellent multilayered co-firing characteristic with Ag electrode to form the multilayered piezoelectric stack. Secondly, the motor which consists of a stator, a slider and a fixed base is proposed. The stator of the motor is composed of a drive tip and two piezoelectric stacks. The stator has two resonance vibration modes, symmetrical and unsymmetrical. The elliptic track motion of the drive tip would be formed by exciting the symmetrical and unsymmetrical vibrations synchronously and the slider compressed on the stator can be driven via friction for moving linearly. The design of the stator make symmetrical and unsymmetrical mode frequencies become equal. In the condition of driving voltage 5 V, frequency 96.915 kHz and driving electric current 0.8 A, the no-load maximum speed is 25.78 mm/s, and the maximum output forces 2.14 N. The tests indicate the proposed motor accomplishes large output force with small size and low diving voltage.

20 illus, 14 ref

015266   Wang H F;Wang J L;Zuo D W;Song W W;Duan X (College of Mechanical & Electrical Engineering, Huangshan Univ, Huangshan 245041, China, Email: wanghnfeng@163.com) : Effect of friction stir welding on microstructure and wear properties of 7022 aluminium alloy. Indian J Engng Mater Sci 2014, 21(5), 557-62.

The 7022 aluminium alloy generally presents low weldability by traditional fusion welding. The development of the friction stir welding (FSW) has provided an alternative improved way of satisfactorily producing 7022 aluminium alloy welded components. The influence on microstructure of welding parameters and wear properties of 7022 aluminium alloy joints produced by FSW are analysed. From the investigation it is found that welded joints fabricated at a rotational speed of 400 rpm and a welding speed of 100 mm/min have better wear properties compared to traditional types of such joints.

8 illus, 1 table, 13 ref

015265   Wang D G;Wang Z X;Xu B;Yang B (Key Laboratory of Solid Waste Treatment and Recycle, Ministry of Education, Southwest Univ of Science and Technology, Mianyang, 621010, China, Email: dan_wangguo@163.com) : Micromechanical elastic-plastic-brittle damage model of concrete. Indian J Engng Mater Sci 2014, 21(5), 519-26.

Based on micromechanics, an elastic-plastic-brittle damage model of concrete is developed by considering the aggregate gradation curve algorithms and the heterogeneity of concrete. In the model, the concrete is taken as a three-phase composite material that consists of the mortar matrix, aggregates and bonds between matrix and aggregates. The numerical experiment of the uniaxial compression shows that the model can clearly simulate microscopic plastic yield, and the initiation and extension of crack. The relevant physical simulation is used to validate the model. In the numerical experiment of bending failure of concrete beam strengthened by bonded steel plate, the strength of the steel plate is relatively lower, and it firstly yields. The bending stress born on the steel plate is transferred to the concrete beam, which results in that the inner cracks of concrete beam increase rapidly and coalesce until the failure of the whole specimen. The final failure mode of concrete beam strengthened by bonded steel plate is the ductile bending failure.

8 illus, 3 tables, 18 ref

015264   Vijay Kumar V;Ramachandra Rao V S;Chidambaram M (Chemical Engineering Dep, Indian Institute of Technology, Madras, Chennai-600 036, Email: chidam@iitm.ac.in) : Centralised multi-input multi-output controllers for non-minimum phase systems. Indian chem Engr 2014, 56(2), 106-22.

In the present work, the method of designing the centralised controllers for the minimum phase multivariable systems proposed by Vijay Kumar et al. is extended to non-minimum phase systems. The controller is designed based on the direct synthesis method. Inverse of process transfer function matrix in the direct synthesis method is approximated based on relative gain array concept. Maclaurin's series is applied to reduce it to a standard proportional and integral form. The method is further improved by using equivalent transfer function matrix derived from relative normalised gain array and relative average residence time array as process inverse transfer function matrix. Effective transfer function is the equivalent transfer function of g_ij(s) when all other loops are closed. The desired closed-loop transfer function should contain the process right half plane zero. Quadruple tank process with non-minimum phase behaviour is considered to analyse the performance of the proposed centralised controllers. The performance of centralised controllers is compared with a recently proposed decentralised controller.

5 illus, 3 tables, 9 ref

015263   Tripathi S;Chakravarty P;Agrawal A (Mechanical Engineering Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: amit.agrawal@iitb.ac.in) : On non-monotonic variation of hydrodynamically focused width in a rectangular microchannel. Curr Sci 2014, 107(8), 1260-74.

Article presents a comprehensive theoretical model and limited experimental results for describing two-dimensional hydrodynamic focusing in micro-channels involving immiscible fluids. It is shown that the normalized focused sample width depends on three non-dimensional parameters - the flow rate ratio, viscosity ratio and aspect ratio. A theory encompassing the effects of all these parameters is developed. Whereas the effects of flow rate ratio and viscosity ratio on the focused sample width are monotonic in nature, those of aspect ratio can be non-monotonic. We report existence of a viscosity ratio beyond which the normalized width decreases with an increase in the aspect ratio, and for viscosity ratio less than a critical value the normalized width increases with increase in the aspect ratio. This parameter range where the minimum sample width is obtained is further analysed. The effect of aspect ratio arid flow rate ratio have been validated experimentally using oil and water based systems. A physical explanation of the variation of sample width with aspect ratio along with microchannel-design guidelines are also provided in this study. We demonstrate that the derived results are more general than the available theoretical models. This comprehensive theory can eventually be employed for predicting hydrodynamically focused width in microdevices and for employing optimal aspect ratio microchannels, without incurring the cost of experiments and human effort.

13 illus, 2 tables, 33 ref

015262   Tamizharasan T;Kingston Barnabas J (NO, TRP Engineering College, Irungalur, Tiruchirappall-621 105, Email: kingstonmech@gmail.com) : Optimization of cutting tool geometry based onflank wear - DoE, PSO and SAA approach. Indian J Engng Mater Sci 2014, 21(5), 543-56.

In this analysis, an attempt has been made to study the effects of included angle, hardness, rake angle, tool approach angle and nose radius of cutting inserts on flank wear with the surface roughness as constraint. The selected parameters are varied through three levels. A new parametric study without considering any kind of benchmark problems in this area is performed and methodology has been developed to analyze the effects of selected parameters on the flank wear of cutting insert. As per the L₁₈ orthogonal array, the values of flank wear after machining are measured and recorded. The best levels of selected parameters for the minimization of flank wear are identified by using Taguchi's Design of Experiments. A validation experiment is conducted with the identified best levels of parameters, and the corresponding flank wear is recorded. Also this analysis inter-relates the performances of design of experiments (DoE), regression analysis, particle swarm optimization and simulated annealing algorithm (SAA) to obtain the best possible solution. The result of this analysis identifies the optimal values of selected parameters for effective and efficient machining. The experimental, optimized and predicted values of flank wear are compared and correlated for all the test conditions.

12 illus, 6 tables, 34 ref

015261   Swadesh Kumar;Yadav A;Jain S M;Mahboob Ahmed; Singh S P (NO, Aerial Delivery Research and Development Establishment, Agra-282 001, Email: watchswadesh@rediffmail.com) : Performance investigation of nylon-kevlar ringslot parachute. Def Sci J 2014, 64(4), 406-10.

Kevlar material is being used in parachute systems require high strength-to-weight ratios or becoming resistance to sustain high temperatures. However, Nylon-Kevlar parachutes are popular these days and are first preference of the parachute designers specially for recovery system of reentry vehicles. Tests of using Kevlar suspension lines, radials, vent and skirt re-enforcements, risers demonstrated that the Kevlar material can be used successfully in Ringslot parachute. The opening shock experienced by the parachute does not differ from all-Nylon parachutes. The parachute is much lighter and capable of withstanding higher load and therefore can be used for extraction or deceleration in recovery system of reentry vehicles. The design and performance of a hybrid Ringslot was investigated experimentally in sled test. The experimental method and performance data are described in this paper.

7 illus, 1 table, 8 ref

015260   Suresh Kumar G (Ocean Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: gskumar@iitm.ac.in) : Mathematical modelling on transport of petroleum hydrocarbons in saturated fractured rocks. Sadhana 2014, 39(5), 1119-39.

Present paper addresses critical issues that describe the dissolution mass transfer of petroleum hydrocarbons in a saturated subsurface system. The field procedure associated with the estimation of Light Non-Aqueous Phase Liquid (LNAPL) thickness in site monitor wells is revisited. A brief theory has been included on the composition and transport of petroleum hydrocarbons following an onshore oil spill in order to demonstrate the level of complexity associated with the LNAPL dissolution mass transfer even in a classical porous medium. However, such studies in saturated fractured rocks are highly complex and limited, and hence, deserve a special attention as the fate and transport of the petroleum hydrocarbons are not uncommon in saturated fractured rocks. In this context, an improved mathematical model has been proposed that will better describe the dissolution kinetics of petroleum hydrocarbons in saturated fractured rocks at the scale of a single fracture using dual-porosity concept. The lumped mass transfer coefficient in a classical porous medium proposed depends on mean grain size, while the same parameter has been replaced by an equivalent average thickness of fracture aperture that better describes the LNAPL dissolution rate in a coupled fracture-matrix system. A set of nonlinear coupled partial differential equations is deduced for a coupled fracture-matrix system in analogy with the differential equations of a classical porous medium. The proposed mathematical model may work well for the fracture aperture thicknesses varying between 100 and 500 microns with a relatively low Reynolds Number and initial NAPL saturation.

2 tables, 55 ref

015259   Srinivas Kumar A;Dharma Rao V (NO, Naval Science and Technological Laboratory, Vigyan Nagar, Visakhapatnam-530 027, Email: adapakaeskay@yahoo.com) : Modeling of cooling and solidification of TNT based cast high explosive charges. Def Sci J 2014, 64(4), 339-43.

Cast trinitrotoluene (TNT) based high explosive charges suffer from different defects such as cracks, voids, etc. One of the quality control measures is to cool the castings gradually, so that the entire charge solidifies without a large temperature gradient from core to the periphery of the cast charge. The fact that the solidification of high explosive casting starts from the periphery (cooler side) and travels towards the center enables us to predict the solidification profile of TNT based explosive castings. Growth of solidification thickness and cooling temperature profiles of TNT based cast high explosive charges are predicted as functions of time and space using unsteady state heat transfer principles, associated with heat balance at solid to liquid interface as a moving boundary of solidification. This will enable adoption of proper quality control during solidification of the molten TNT to eliminate inherent drawbacks of cast high explosive charges. The solidification profiles of TNT based cast charges under controlled and natural conditions are predicted and the model is validated against 145 mm diameter TNT cast charge which is found to be in broad agreement with experiments.

6 illus, 2 tables, 18 ref

015258   Sreedhar S;Gundawar M K;Venugopal Rao S (Advanced Centre of Research in High Energy Materials, Hyderabad Univ, Hyderabad-500 046, Email: manojsp@uohyd.ernet.in) : Laser induced breakdown spectroscopy for classification of high energy materials using elemental intensity ratios. Def Sci J 2014, 64(4), 332-8.

A simple, yet efficient, methodology is proposed to classify three high energy materials (HEMs) with diverse composition using nanosecond laser induced breakdown spectroscopic data. We have calculated O/N, N/H, and O/H elemental peaks ratios using a ratiometric method. The present work describes a novel way to construct 1D, 2D, and 3D classification model using the above mentioned ratios. Multivariate statistical methods are followed for construction of the classification models. A detailed procedure for classification of three different HEMs is presented here.

5 illus, 2 tables, 37 ref

015257   Singh R P (NO, Indian Institute of Science Education and Research, Pune-411 008, Email: singh.prakash.ram@gmail.com) : Case of polymer photovoltaics in India. Curr Sci 2014, 107(9), 1377-9.

3 illus, 35 ref

015256   Singh K L;Madhu K S;Vaggar M (Structural Technologies Div, National Aerospace Laboratories, Bangalore, Email: krishnalok72@gmail.com) : Computation of onset and growth of delamination in double cantilever beam specimens subjected to fatigue loading. Def Sci J 2014, 64(4), 400-5.

In this article, the delamination onset and growth behavior of double cantilever beam (DCB) specimens has been presented. The modeling of a debonded region using master and slave surface technique for DCB specimens is done in ABAQUS CAE. The analysis of DCB specimens comprising of fatigue cyclic load has been done in ABAQUS. An onset and Paris delamination growth regimes are plotted. The growth regime being linear in log-log scale, the prediction of constants of this regime has been obtained using the polyfit command in the MATLAB environment. To obtain these constants has been explained in this article. Comparison of experimental and analytical results is shown for delamination growth. The strain energy release rate values for threshold and critical are indicated on the graphs. The number of cycles for delamination onset and growth has been tabulated for various load cases.

6 illus, 4 tables, 26 ref

015255   Sikarwar R S;Velmurugan R (NO, Indian Institute of Technology Madras, Chennai-600 036, Email: ramanav@iitm.ac.in ) : Ballistic impact on glass/epoxy composite laminates. Def Sci J 2014, 64(4), 393-9.

Glass/epoxy composite laminates are subjected to impact loading and the energy absorbing capacity of the laminates is studied. In the present study, laminates with four different orientations and thickness values are considered. Analytical study is carried out based on energy method and results are compared with FE results obtained from Abaqus/Explicit software. Results obtained from the analytical methods are showing good agreement with the FE results. It is found that cross-ply laminates are most efficient in ballistic resistance when compared with the laminates of other orientations. It is also noticed that the energy absorbing capacity is decreasing with increase in velocity of the projectile for a given lay-up and thickness value.

4 illus, 6 tables, 17 ref

015254   Shihab S K;Khan Z A;Mohammad A A S;Siddiquee A N (Mechanical Engineering Dep, Jamia Millia Islamia (A Central Univ), New Delhi-110 025, Email: suhakrim_10@yahoo.com) : Optimization of surface integrity in dry hard turning using RSM. Sadhana 2014, 39(5), 1035-53.

This paper investigates the effect of different cutting parameters (cutting speed, feed rate, and depth of cut) on surface integrity defined in terms of surface roughness and microhardness in dry hard turning process. The workpiece material used was hardened alloy steel AISI 52100 and it was machined on a CNC lathe with coated carbide tool under different settings of cutting parameters. Three cutting parameters each at three levels were considered in the study. Central composite design (CCD) of experiment was used to collect experimental data for surface roughness and microhardness. Statistical analysis of variance (ANOVA) was performed to determine significance of the cutting parameters. The results were analysed using an effective procedure of response surface methodology (RSM) to determine optimal values of cutting parameters. Several diagnostic tests were also performed to check the validity of assumptions. The results indicated that feed rate is the dominant factor affecting the surface roughness whereas the cutting speed is found to be the dominant factor affecting the microhardness. Results also revealed that within the range investigated, good surface integrity is achieved when feed rate and depth of cut are near their low levels and cutting speed is at high level. Finally, the optimal cutting parameters and model equations to predict the surface roughness and microhardness are proposed.

17 illus, 5 tables, 35 ref

015253   Sharma S;Mukherjee A (Mechanical Engineering Dep, Thapar Univ, Patiala-147 004, Email: sksharma@thapar.edu) : Damage detection in submerged plates using ultrasonic guided waves. Sadhana 2014, 39(5), 1009-34.

This paper describes a non-contact and non-invasive health monitoring strategy for submerged plate structures using guided waves. The structure under consideration is immersed in water and subjected to longitudinal ultrasonic waves at specific angles of incidence using a cylindrical piezoelectric transducer using the surrounding water as coupling medium. Suitable ultrasonic guided wave modes with optimum scanning capabilities have been generated and identified in submerged plate system. Finally, the propagation of selected modes through submerged notched plates is investigated. Sensitivity of leaky waves to the notches has been studied. The methodology would help in identifying damages in the submerged plate structures.

19 illus, 4 tables, 13 ref

015252   Sharma N;Tiwari D P;Singh S K (NO, B M Institute of Engineering and Technology, Sonepat-131 001, Email: sharma.neetu80@gmail.com) : Efficiency of chemically treated potato peel and Neem bark for sorption of direct red-81 dye from Aqueous solution. Rasayan J Chem 2014, 7(4), 399-409.

Adsorption is a well recognized and exercised process to decolourise the coloured water from last few decades. Numerous agricultural adsorbents in raw and chemically modified forms have been exploited in past to remove the synthetic dyes from aquatic ecosystem. Many of these adsorbents were reported to have remarkable performance for sorption of dyes. In the present study, two agricultural adsorbents, potato peel and Neem bark were treated with HCHO and H₂SO₄ separately and were further used to remove the toxic organic dye, Direct Red-81. The removal efficiency of all the four adsorbents viz. HCHO treated Potato peel and Neem bark (PP, NB) or H₂SO₄ treated potato peel and Neem bark (APP, ANB) was critically examined by constructing the breakthrough curve with the help of column study and by confirming the adsorption isotherms, kinetics and thermodynamic study besides the effects of change of dose, concentration, pH and temperature through batch experiments. The results found revealed that the adsorption process was non-spontaneous, exothermic and reversible in nature. Among all the adsorbents, formaldehyde treated Potato peel showed significant dye removal. The maximum amount of dye adsorbed by all the four adsorbents through batch study were measured in the order of PP (58.8 mg/gm)> APP (10.4 mg/gm)> NB (8.4 mg/gm) <62> ANB (5.7 mg/gm).

7 illus, 4 tables, 24 ref

015251   Sharma B;Uniyal D P;Dobhal R;Kimothi P C; Grischek T (NO, Uttarakhand Science Education and Research Centre (USERC), Dehradun, Email: dpuniyal.ucost@gmail.com) : Sustainable solution for safe drinking water through bank filtration technology in Uttarakhand, India. Curr Sci 2014, 107(7), 1118-24.

Bank filtration (BF) has emerged as an economical and sustainable water pre-treatment technology for drinking water supply. In this method, subsurface water of a water body moves into the well by seepage. BF wells adjacent to a river or lake pump the stored groundwater abstracted from the surface through aquifers. Chemical and biological contaminants such as turbidity, microbes, dissolved chemicals and natural organics are removed by the channel of aquifers present in the area. The whole process follows a series of physical, chemical and biological processes with some redox reactions. This study highlights the role of BF method in regulating water quality and quantity improvement. Besides, attempts have been made to discuss the mechanism, significance and the development of BF technology in the hilly state of Uttarakhand. Water quality status of Srinagar and Satpuli river BF sites of Uttarakhand are also described and compared with the Bureau of Indian Standards guidelines.

2 illus, 1 table, 44 ref

015250   Shanthi S;Bhaskaran V M (NO, Kongu Engineering College, Erode-638 052, Email: shanthi.kongumca@gmail.com) : Novel approach for classification of abnormalities in digitized mammograms. Sadhana 2014, 39(5), 1141-50.

Feature extraction is an important process for the overall system performance in classification. The objective of this article is to reveal the effectiveness of texture feature analysis for deteeting the abnormalities in digitized mammograms using Self Adaptive Resource Allocation Network (SRAN) classifier. Thus, we proposed a feature set based on Gabor filters, fractal analysis, multiscale surrounding region dependence method (MSRDM) to identify the most common appearance of breast cancer namely microcalcification, masses and architectural distortion. The results of the experiments indicate that the proposed features with SRAN classifier can improve the classification performance. The SRAN classifier produces the classification accuracy of 98.44% for the proposed features with 192 images from MIAS dataset.

2 illus, 2 tables, 22 ref

015249   Sangeeth K;Hegde G M (NO, Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore-560 012, Email: nanogopal@cense.iisc.ernet.in) : Fabrication and characterization of sub 100 n m period polymer gratings for photonics applications. Curr Sci 2014, 107(5), 749-62.

Reports on the fabrication of polymethylmethacrylate (PMMA) nanogratings on silicon (Si) and glass substrates using electron beam lithography technique. Various aspects of proximity corrections using Monte Carlo simulation have been discussed. The fabrication process parameters such as proximity gap of exposure, exposure dosage and developing conditions have been optimized for high-density PMMA nanogratings structure on Si and glass substrates. Electron beam exposure is adjusted in such a way that PMMA acts as a negative tone resist and at the same time resolution loss due to proximity effect is minimum. Both reflection and transmission-type, nanometre period gratings have been fabricated and their diffraction characteristics are evaluated.

5 illus, 25 ref

015248   Samuel M P (NO, Center for Military Airworthiness and Certification, Bangalore-560 093, Email: mathews@cemilac.drdo.in) : Differential degradation assessment of helicopter engines operated in marine environment. Def Sci J 2014, 64(4), 371-7.

The helicopters used for marine operations encounter harsh environment laden with salt mist, sand and dust which could accelerate the deterioration of components. Assessment of the effect of operational environment on component degradation of such helicopter engines is crucial in scheduling their maintenance and ensuring flight safety. The objective of this study is to understand and assess the differential degradation pattern of aeroengines operated in marine environment in comparison to their counterparts operated in non-marine environment. In this study, a sample of 257 ex-service aeroengines of same type and make, operated in marine and non-marine environment were randomly selected and their degradation pattern observed. After obtaining the data on component degradation, further statistical analysis was carried out and the statistical significance of the observations were computed. Out of the ten major components considered in this study, five of them were found to have statistically significant differential degradation due to operation in marine environment. For the remaining components adequate evidence was not available to substantiate differential degradation due to operation in marine environment. These findings serve as valuable input for maintenance inventory planning as well as component improvement programme.

3 illus, 4 tables, 21 ref

015247   Salkalachen S (NO, Bharat Heavy Electrical Limited, Bangalore-560 055, Email: sajisalk@gmail.com) : Sun power. Curr Sci 2014, 107(8), 1247-52.

Rapidly growing solar and wind energy programmes in India have created a techno-economic opportunity in the energy market. Apart from the possibility of providing the much-needed energy solution to our citizens, the promise to young academicians and workforce is significant in the new clean energy sector. All these have happened in the last four to five years and, if the country were to take the National Solar Mission initiative forward, developments in solar photovoltaic power generation are likely to realize grid parity within the next few years and mitigate the energy deficiency to a great extent.

11 illus, 3 ref

015246   Said A;Djamel B (NO, Solid Mechanics and Systems Laboratory, (LMSS) Univ M'Hamed Bougara Bo, Boumerdes 35000, Algeria, Email: alem-said@umbb.dz) : Bond graph to digraph conversion: a sensor placement optimization for fault detection and isolation by a structural approach. Sadhana 2014, 39(5), 1151-64.

In this paper, we consider the optimal sensors placement problem for faults detection and isolation using a novel structural and qualitative approach. This approach is based on the conversion of Bond Graph to Digraph representation of a structural system. When the fault detection and isolation of an existing system's sensors are impossible or uncertain, a reconfiguration sensor placement of this system should be reconsidered. This paper proposes how this reconfiguration takes place by recovering all missing or redundant parts of the system. This novel approach is illustrated over a thermo-fluid application.

7 illus, 7 tables, 24 ref

015245   Ray A K;Shit R C;Yadav R S (Integrated Test Range, Defence Research & Development Organisation, Chandipur-756 025, Email: arun3_bls@yahoo.co.in) : Development of C-band RF front-end of precision coherent mono-pulse C-band radar. Def Sci J 2014, 64(4), 358-65.

A compact, robust and high performance front-end of a radar receiver is designed and demonstrated in this paper. The important parameters like noise figure, sensitivity, selectivity, dynamic range and tracking range are superior to that of the existing systems and facilitate online monitoring of the above important parameters. The gain and phase matching facility are incorporated. The local oscillator is integrated within the module which in turn reduces the losses as compare with the existing local oscillator, placed in the instrumentation cabin. The frequency, amplitude, delay between skin and transponder frequency can be controlled remotely by computer program. Therefore, the mixed mode operation (skin and transponder) of radar receiver is possible. Moreover, the SPDT switch is integrated in the same module for RF simulation to facilitate the three channel mono-pulse receiver calibration, receiver health monitoring and range calibration of precision coherent mono-pulse C-band radar. The components used are monolithic microwave integrated circuit based technologies with superior specifications, makes the total module miniaturized and reduced the hardware complications. The total power consumption is much less and improves the overall performance than the existing front-end.

5 illus, 3 tables, 21 ref

015244   Rao L;Tao W W;Wang S J;Geng M P;Cheng G X (College of Mechanical and Electronic Engineering, Hohai Univ, 200 Jinling Road, Changzhou, Jiangsu, 213022, China, Email: rao_lei@163.com) : Influence of the composition ratio of manganese and copper on the mechanical properties and the machining performance of ductile iron. Indian J Engng Mater Sci 2014, 21(5), 573-9.

In the present investigation, we studied the influence of the composition ratio of manganese and copper on the mechanical properties and the machining performance of a ferritic-pearlitic ductile iron. A series of Y-block specimens and stair specimens were casted using different manganese and copper levels. The experiments indicated that manganese can efficiently improve the strength of ductile iron, but the plasticity and machining performance decrease significantly when the manganese content exceeds 0.9%. To obtain high strength castings at low manganese levels, the Mn-Cu alloying treatment was also investigated here. The results indicated that with 0.6%-0.8% of Mn and 0.5%-0.8% of Cu, the tensile strength of ductile iron can be in the range of 600-725 MPa, the elongation can remain above 5.5%, and the machining performance is satisfactory. Furthermore, the distribution of manganese and copper in the ductile iron matrix was also investigated.

8 illus, 2 tables, 16 ref

015243   Raju S V;Mathur N;Sarmah M K (NO, Oil India Limited, Duliajan-786 602, Email: svraju@oilindia.in) : Geochemical characterization of neoproterozoic heavy oil from Rajasthan, India: implications for future exploration of hydrocarbons. Curr Sci 2014, 107(8), 1298-1305.

Discovery of heavy oil in the Bikaner-Nagaur basin of Rajasthan in western India in reservoirs of Neoproterozoic age during the early nineties was one of the most significant events in the history of oil and gas exploration in India. Recently, discovery of heavy oil in the Punam Structure in the same basin has reconfirmed the hydrocarbon potential of the basin and has regenerated tremendous interest in exploration activities. Another significant factor that enhances exploration interest and hydrocarbon prospectivity of this basin relates to the fact that the Indian Mesopro-terozoic and Neoproterozoic sedimentary basins share similar tectonic settings and depositional environments as their producing counterparts elsewhere (Oman, China, Siberian Platform, North Africa, Australia and so on). In this study, geochemical characterization of the heavy oil from Punam-X has been carried out for determining the source, maturity and extent of biodegradation using established biomarker ratios. Organic geochemical studies on the heavy oil from Punam-X indicate that the oil was generated in an anoxic hypersaline environment from marine clastic source rock. The oil is found to be generated from early mature source rock. Gas chromatograph analysis of the oil shows that it has also undergone some degree of biodegradation. Various similarities have been found between the Punam-X oil and other heavy oils of similar age found in Oman, Pakistan and in the adjoining areas in the Bikaner-Nagaur basin.

10 illus, 2 tables, 32 ref

015242   Rajagopal S;Prabavathy S (Civil Engineering Dep, Mepco Schlenk Engineering College, Sivakasi-625 005, Email: srajagopals@gmail.com) : Exterior beam-column joint study with non-conventional reinforcement detailing using mechanical anchorage under reversal loading. Sadhana 2014, 39(5), 1185-200.

Reinforced concrete structures beam-column joints are the most critical regions in seismic prone areas. Proper reinforcement anchorage is essential to enhance the performance of the joints. An attempt has been made to appraise the performance of the anchorages and joints. The anchorages are detailed as per ACI-352 (mechanical anchorages), ACI-318 (conventional bent hooks) and 1S-456 (conventional full anchorage). The joints are detailed without confinement in group-I and with additional X-cross bar in group-II. To assess the seismic performance, the specimens are assembled into two groups of three specimens each and were tested under reversal loading, The specimen with T-type mechanical anchorage (Headed bar) and T-type mechanical anchorage combination with X-cross bar exhibited significant improvement in seismic performance: load-displacement capacity, displacement ductility, stiffness degradation, controlled crack capacity in the joint shear panel and also reduced congestion of reinforcement in joint core.

22 illus, 2 tables, 18 ref

015241   Mondal S;Sarkar P P (Engineering Dep, Technological Studies Univ of Kalayani, Kalyani-741 235, Email: santanumondal2008@rediffmail.com) : Novel design of compact wideband planar metal antenna. Indian J pure appl Phys 2014, 52(12), 851-6.

In the present paper, a novel design of compact wideband planar metal antenna has been presented for wireless communication. The proposed antenna is fed by a Coaxial to CPW transition to match with 50 Ω input impedance line. A shorting strip is used to reduce the size of the antenna. The modified CPW feed line is in the same plane with the radiating element to achieve complete planar antenna and bi-directional radiation pattern. The impedance bandwidth for |S11| <60> 10 dB of the antenna ranges from 1.05 to 25 GHz. So this antenna can work in various frequency bands like WLAN and UWB. A circular hole at the centre of radiating element is introduced to reduce the volume, weight and cost of the antenna. Various characteristics of the proposed antenna have been computed using finite integration technique based commercial software CST studio. The simulated and measured reflection coefficients are in good agreement.

15 illus, 14 ref

015240   Mazumder M H;Barbhuiya A K (Civil Engineering Dep, Silchar Polytechnic, Silchar-788 010, Email: akbarbhuiya@yahoo.com) : Live-bed scour experiments with 45° wing-wall abutments. Sadhana 2014, 39(5), 1165-83.

Live bed scour experiments were conducted using four types of non-cohesive bed sediments with median diameters d₅₀ - 0.26 mm, 0.42 mm, 1.06 mm and 1.92 mm and five 45°wing-wall abutments of lengths 1 = 0.04 m, 0.06 m, 0.08 m, 0.10 m and 0.12 m. The tests were conducted in the range of flow velocity varies from 0.71 to 5 times of the critical velocity. The plotting of non-dimensional scour depths (scour depths/abutment lengths) vs non-dimensional flow intensity (flow intensity/critical velocity) show one peak value of scour depth close to the threshold velocity and thereafter, it reduces and again attain a live-bed maximum in the range of flow intensity 3 to 5 times of the critical velocity. It is also observed that the scour depth increases with the increase in sediment sizes up to threshold value of flow for all sediment sizes and abutment lengths. Further, the scour depth decreases with the increase of non-uniformity under all flow conditions. A design equation is proposed for estimating maximum scour depth at 45°wing-Wall abutment under live bed condition. The calculated values of scour depths using proposed equation, and also with three different live-bed local scour equations, are compared with the measured values of scour depths.

8 illus, 3 tables, 27 ref

015239   Manmohan Singh;Jaybhaye M D;Basu S K (NO, Vehicle Research and Development Establishment, Ahmednagar-414 006, Email: manmohananjs@gmail.com) : Risk quantification and evaluation modelling. Def Sci J 2014, 64(4), 378-84.

In this paper authors have discussed risk quantification methods and evaluation of risks and decision parameter to be used for deciding on ranking of the critical items, for prioritization of condition monitoring based risk and reliability centered maintenance (CBRRCM). As time passes any equipment or any product degrades into lower effectiveness and the rate of failure or malfunctioning increases, thereby lowering the reliability. Thus with the passage of time or a number of active tests or periods of work, the reliability of the product or the system, may fall down to a low value known as a threshold value, below which the reliability should not be allowed to dip. Hence, it is necessary to fix up the normal basis for determining the appropriate points in the product life cycle where predictive preventive maintenance may be applied in the programme so that the reliability (the probability of successful functioning) can be enhanced, preferably to its original value, by reducing the failure rate and increasing the mean time between failure. It is very important for defence application where reliability is a prime work. An attempt is made to develop mathematical model for risk assessment and ranking them. Based on likeliness coefficient β1 and risk coefficient β2 ranking of the sub-systems can be modelled and used for CBRRCM.

7 illus, 5 tables, 9 ref

015238   Mandal B C;Mazumdar H P;Dutta S S (Civil Engineering Dep, Jalpaiguri Government Engineering College, Jalpaiguri-735 102, Email: bcmjgec@gmail.com) : Mean flow structure of non-equilibrium boundary layers with adverse pressure gradient. Sadhana 2014, 39(5), 1211-26.

In this paper Spalding's formulation for the law of the wall with constants modified by Persen is used to describe the inner region (viscous sub-layer and certain portion of logarithmic layer) and a wake law due to Persen is used to describe the wake region (outer region). These two laws are examined in the light of measured data by Marusic and Perry for non-equilibrium adverse pressure gradient layers. It is observed that structure of turbulence for this flow is well-described by these two laws. From the known structure of turbulence eddy viscosity for the flow under consideration is calculated. Self similarity in eddy viscosity is observed in the wall region.

11 illus, 2 tables, 21 ref

015237   Maji S;Reddy P;Hanmaiahgari;Dey S (Civil Engineering Dep, Indian Institute of Technology Kharagpur, Kharagpur-721 302, Email: hpr@civil.iitkgp.ernet.in) : Experimental studies of local scour in the pressurized OCF below a wooden log across the flow. Sadhana 2014, 39(5), 1245-57.

Proposed study examined and reviewed the published experimental results related to clear water scour below a cylinder across the flow. It also highlighted the limitations of existing methods for estimating the scour depth below a submerged cylinder. In the present study, experiments were performed for 50% and 75% submergences of a 70 mm diameter cylinder in the free surface flow over a uniform sand bed with d₅₀ - 0.98 mm downstream of an apron. Based on the experimental results, an empirical equation was proposed to estimate the amount of gap flow between the cylinder and the bed for an equilibrium scour for a given flow depth and sediment properties. Measured scour profile consisted of a scour hole and immediately followed by a dune. However, no general sediment transport was occurring away from the cylinder due to the undisturbed bed shear stress less than or equal to the critical shear stress required for the sediment entrainment. Different submergence ratios of the cylinder resulted in different longitudinal and vertical extensions of the scour hole and the dune. The maximum equilibrium scour depth occurred when the cylinder is fully submerged in the unidirectional flow with water depth equals to the cylinder diameter. The non-dimensional measured scour profiles were found to be similar. The characteristic lengths of the scour hole and the dune were computed analytically by approximating the measured scour profile by third degree polynomials. The computed non-dimensional scour profiles compared satisfactorily with the measured profiles. It was found that analytical non-dimensional scour profiles were identical for a given diameter of a cylinder with different submergences for the same flow conditions.

8 illus, 2 tables, 21 ref

015236   Lei Z;Xiling L;Jinping S;Songtao L (School of Electronic and Information, Engineering, Beihang Univ, Beijing-100 191, Email: luoxiling@buaa.edu.cn) : An efficient Δ-STAP detector for radar seeker using RPCA post-processing. Def Sci J 2014, 64(4), 344-9.

Adaptive detection of moving targets in sea clutter environment is considered as one of the crucial tasks for radar seekers. Due to the severe spreading of the sea clutter spectrum, the ability of space-time adaptive processing with sum and difference beams (S-STAP) algorithms to suppress the sea clutter is very limited. This paper, investigated the low-rank property of the range-Doppler data matrix according to the eigenvalue distribution from the eigen spectrum, and proposed an efficient S-STAP detector based on the robust principle component analysis (RPCA) algorithm to detect moving targets, which meets the low-rank matrix recovery conditions. The proposed algorithm first adopts S-STAP algorithm to preprocess the sea clutter, then separates the sparse matrix of target component from the range-Doppler data matrix through the RPCA algorithm, and finally, effectively detects moving targets in the range-Doppler plane. Simulation results demonstrate the effectiveness and robustness of the proposed algorithm in the low signal-to-noise ratio scenarios.

3 illus, 18 ref

015235   Lee M H;Khil B S;Yun H D (Architectural Engineering Dep, Chungnam National Univ, 99 Daehak-ro Yuseong-gu, Daejeon 305-764, Korea, Email: wiseroad@cnu.ac.kr) : Influence of cement type on heat of hydration and temperature rise of the mass concrete. Indian J Engng Mater Sci 2014, 21(5), 536-42.

This paper provides experimental and analytical study results aiming to evaluate the effects of ternary cement types with different binder combinations on the heat of hydration in mass concrete by conducting the adiabatic temperature rise test and finite element thermal analysis of mass concrete mixtures with specified compressive strength of 30 MPa. A finite element thermal analysis for mat foundation with 15 m wide, 30 m long and 3 m thick were conducted based on concrete thermal properties from adiabatic temperature rise test. Test results reveal that concrete mixture mixed with Type IV cement displays the higher rate of heat evolution generated from hydration than those of concrete mixtures with ternary cements. It indicates that the ternary cements, which provide economic and environmental advantages by reducing Portland cement production and CO₂ emission, can be used as an alternative of Type IV cement for massive members.

2 illus, 2 tables, 12 ref

015234   Kuo C C;Zhuang B C (Mechanical Engineering Dep, Ming Chi Univ of Technology No. 84, Gungjuan Road, Taishan Dist., New Taipei City 24301, Taiwan, Email: jacksonk@mail.mcut.edu.tw) : Simple and low-cost method to the development of a micro-featured mold insert for micro-hot embossing. Indian J Engng Mater Sci 2014, 21(5), 487-94.

Micro-hot embossing is a cost-effective approach for polymer-based microfabrication. Micro devices must be more quickly and cheaply developed, manufactured and introduced to the market because of the pressure of global competition. Two major troublesome issues in the mold industry are the time and expense needed for producing a mold insert for pilot run in the new product development phase. This study demonstrates a technique for fabricating a mold insert with microfeatures using rapid tooling technology. Bridge tooling is the key technology for making a precise micro-featured mold insert with high successful rate. The main advantages of this technique include simple operation and low cost compared to mold insert made by conventional methods. The replication rate in the micro-featured mold manufacturing process is about 95.37% using the optimal manufacturing processes. The transcription rate in the micro-hot embossing process is about 99.15% using the optimal processing conditions.

13 illus, 21 ref

015233   Krishna R (Van't Hoff Institute for Molelcular Sciences, Amsterdam Univ, Amsterdam, The Netherlands, Email: r.krishna@uva.nl) : A smorgaasbord of separation strategies using microporous crystalline materials. Indian chem Engr 2014, 56(2), 147-74.

Ordered crystalline microporous materials such as zeolites, metal-organic frameworks and zeolitic imidazolate frameworks, with pores in the 3-20Angstrom range, offer considerable potential for use in a wide variety of separations in the process industries. For many separation tasks, microporous adsorbents and membranes are energy-efficient alternatives, or adjuncts, to conventional distillation technology. Molecular insights and molecular simulation techniques allow us to identify the microporous material with the ideal pore size that offers the right degree of interactions (such as van der Waals, electrostatic, p-electron exchange) with the guest molecules to achieve the best separation. Particularly noteworthy are possibilities of separations on the basis of subtle differences in molecular configurations, and the efficiencies with which molecules pack or stack within the microporous channels.

23 illus, 90 ref

015232   Korla K;Mitra C K (School of Life Sciences, Hyderabad Univ, Hyderabad, Email: c_mitra@yahoo.com) : Kinetic modelling of coupled transport across biological membranes. Indian J Biochem Biophys 2014, 51(2), 93-9.

Auther have modelled a secondary active co-transporter (symport and antiport), based on the classical kinetics model. Michaelis-Menten model of enzyme kinetics for a single substrate, single intermediate enzyme catalyzed reaction was proposed more than a hundred years ago. However, no single model for the kinetics of co-transport of molecules across a membrane is available in the literature. We have made several simplifying assumptions and have followed the basic Michaelis-Menten approach. The results have been simulated using GNU Octave. The results will be useful in general kinetic simulations and modelling.

5 illus, 2 tables, 14 ref