023820   Nibudey R N;Nagarnaik P B;Parbat D K;Pande A M (NO, Yashvantrao Chavhan College of Engineering, Nagpur-441 110, Email: ramnidubey@yahoo.co.in) : Cube and cylinder compressive strengths of waste plastic fiber reinforced concrete. Int J civ struct Engng 2013, 4(2), 174-82.

Concrete has main advantage that it has a better compressive strength. The compressive strength of concrete can be represented as cube or cylinder compressive strength. The compressive strength of concrete is depending on size and shape of the test specimens. In this study, the conventional concrete was reinforced by the plastic fibers obtained from waste plastic bottles. The cube and cylinder compressive strength of conventional concrete and plastic fibers reinforced concrete were determined in the laboratory. The M20 and M30 grades of concrete and two fiber geometry at volume fractions 0.0% to 3.0% were used in the experimentations. All specimens were tested after curing age 28 days. In this paper the relationship between cube and cylinder compressive strength for conventional and plastic fibers reinforced concrete were established and compared with standards.

11 illus, 8 tables, 16 ref

023819   Murugan A;Senthilvelan T;Balasubramanian V (Mechanical Engineering Dep, Pondicherry Engineering College, Puducherry-607 402, Email: a_murugaa@rediffmail.com) : Developing diffusion bonding windows for joining powder metallurgically produced pure aluminium and pure copper. Indian Weld J 2014, 47(1), 43-8, 53-6.

In this investigation, pure aluminium (Al) and pure copper plates manufactured by powder metallurgy (P/M) technique were bonded by diffusion bonding. Joining of these materials by fusion welding is difficult because of the formation oxide films and brittle intermetallic compounds in the bond region which affect the quality of bonds. However, diffusion bonding is a suitable process to join these materials without much difficulties. In this investigation, an attempt was made to develop the diffusion bonding windows to join pure Al with pure Cu plates produced by P/M technique using different combinations of process parameters such as bonding temperature, bonding pressure and holding time The quality of bonds was checked by the microstructure analysis. Diffusion bonding windows (DBW) presented in this paper will act as reference maps for selecting appropriate process parameters to join pure Al with pure Cu plates fabricated by P/M technique.

17 ref

023818   Madheswaran C K;Gnanasundar G;Gopalakrishnan N (Advanced Seismic Testing and Research Laboratory, CSIR-Structural Engineering Research Centre, Taramani, Chennai, Email: ckm@serc.res.in) : Effect of molarity in geopolymer concrete. Int J civ struct Engng 2013, 4(2), 106-15.

Geopolymer Concrete (GPCs) is a new class of concrete based on an inorganic alumino-silicate binder system compared to the hydrated calcium silicate binder system of concrete. It possesses the advantages of rapid strength gain, elimination of water curing, good mechanical and durability properties and are eco-friendly and sustainable alternative to Ordinary Portland Cement (OPC) based concrete. In the construction industry mainly the production of Portland cement causes the emission of air pollutants which results in environmental pollution. This paper presents the details of the studies carried out on development of strength for various grades of geopolymer concrete with varying molarity. The alkaline liquids used in this study for the geopolymerization are sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Different molarities of sodium hydroxide solution (3M, 5M and 7M) are taken to prepare different mixtures. The test specimens were 150 x 150 x 150 mm cubes, 150 x 300mm cylinders prepared and ambient temperature curing conditions. The geopolymer concrete specimens are tested for their compressive strength at the age of 7 and 28 days. GPC mix formulations with compressive strength ranging from 15 to 52MPa have been developed. Experimental investigations have been carried out on workability, the various mechanical properties of GPCs. The test results indicate that the combination of fly ash and ground granulated furnace slag (GGBS) - 203 - can be used for development of geopolymer concrete.

2 illus, 4 tables, 16 ref

023817   Kushwaha D;Ahmad A (Electrical & Electronics Engineering Dep, Gold Field Institute of Technology and Management (GFITM), Faridabad, Haryana, Email: dhirendrakushwaha15@gmail.com) : Power quality improvement generator for distributed wind-solar-power generation hybrid system based on genetic algorithm. Invertis J renewable Energy 2014, 4(1), 50-6.

Best possible solutions to these problems are reviewed and their control systems are elaborated on. Solutions present in the field are explained and field results are presented. It is shown that by using the right technology a variety of Power Quality problems can be solved rendering installations trouble free and more efficient, and can render them compliant with even the strictest requirements. This paper aims at seeking reasonable power dispatching scheme for distributed wind-Solar power generation hybrid system, to satisfy some basic requirements, such as dispersed electric power demand, electric power quality and reducing generation cost and so on. Firstly we represented some elements of the main parts in the hybrid system; and then made basic dispatching strategies according to different situations; Change mutation range and so on. In the end, we try to solve the units commitment for dispatching plan problem based on the improved genetic algorithm, and the application seem proved it reasonable.

12 ref

023816   Kumar R;Arthanariee A M (Research and Development Centre, Bharathiar Univ, Coimbatore, Tamil Nadu, Email: dhimanrajiv2000@yahoo.co.in) : K-region-based clustering algorithm for image segmentation. J Instn Engrs : Ser B 2014, 94(4), 221-9.

In this paper, authors have proposed K-region-based clustering algorithm which is based on performing the clustering techniques in K number of regions of given image of size N x N. The K and N are power of 2 and K <60> N. The authors have divided the given image into 4 regions, 16 regions, 64 regions, 256 regions, 1024 regions, 4096 regions and 16384 regions based on the value of K. Authors have grouped the adjacent pixels of similar intensity value into same cluster in each region. The clusters of similar values in each adjacent region are grouped together to form the bigger clusters. The authors have obtained the different segmented images based on the K number of regions. These segmented - 202 - images are useful for image understanding. The authors have been taken four parameters: Probabilistic rand index, variation of information, global consistency error and boundary displacement error. These parameters have used to evaluate and analyze the performance of the K-region-based clustering algorithm.

4 illus, 7 tables, 18 ref

023815   Kumar A;Ohri M L;Bansal R K (NO, DBRA National Institute of Technology, Jalandhar, Email: agnihotriak@nitj.ac.in ) : Pressure settlement characteristics of strip footings on reinforced layered soil. Int J civ struct Engng 2013, 4(2), 136-46.

Method has been proposed to obtain the pressure-settlement characteristics of strip footings resting on layered reinforced sand based on constitutive laws of soils. The confining effect of the reinforcement provided in the soil at different layers has been incorporated in the analysis by considering the equivalent stresses generated due to friction at the soil-reinforcement interface. The prerequisite of the method is the value of ultimate bearing capacity of reinforced layered soil, which can be obtained from an empirical method proposed for the same. The value of settlement may be read directly from pressure-settlement curves for the given pressure intensity. Therefore, the strip footing resting on layered sand can be proportioned satisfying shear failure and settlement criteria.

6 illus, 23 ref

023814   Khandelwal P;Pachori A;khandelwal T (NO, , Indira Nagar, Lucknow, Uttar Pradesh, Email: preet.newone@gmail.com) : Insight on right of way and its cost for power transmission cable and conventional overhead transmission lines. J Instn Engrs : Ser B 2014, 94(4), 257-62.

This paper provides the complete information related to Right of Way (RoW) for the construction of new power transmission line (TL) in terms of present cost for overhead transmission line and underground XLPE transmission cable. The former part of the paper describes the general procedure and rules for acquisition of land for RoW by transmission asset owner (TAO) while in the later part the cost associated to acquire RoW and its impact on the cost of adjacent land have been detailed. It also discusses the actual dismantling cost including the cost of waste metal what TAO get after completion of lifecycle of TL due to increase in metal prices. In this paper cost of RoW after completion of lifecycle of TL is also highlighted. This paper compares the cost of RoW for overhead transmission line and underground XLPE transmission cable for construction of new TL. Also for old transmission infrastructure cost of RoW for change from overhead transmission line to underground XLPE transmission cable is detailed by application of replacement model.

6 ref

023813   Kamatham Y;Sarma A D;Ashwani Kumar; Satyanarayana K (ECE Dep, ACE Engineering College, Ankushapur, Ghatkesar Mandal, Ranga Reddy District, Andhra Pradesh) : Spectral analysis and mitigation of GPS multipath error using digital filtering for static applications. IETE J Res 2013, 59(2), 156-66.

Multipath is one of the prominent error sources in Global Positioning System (GPS), which adversely affects the accuracy of the user's position. This paper describes the estimation of frequency components of multipath error signal using spectral analysis and its effective mitigation using time-varying digital filters. Four types of 2nd order filters, namely, Butterworth, Type I and II Chebyshev and Elliptic filters, are examined for mitigation of multipath and their performance is compared. It is observed that by applying digital filters of different cut-off frequencies over the spectrum of the multipath, one can significantly reduce the multipath errors. The designed filters are applied to GPS data acquired from a typical urban environment site and found that Butterworth filter reduced the error most effectively. To extract the magnitude of error contribution in low and medium multipath frequency ranges, its mitigation is carried out with Butterworth filter. The performance of the filter is validated by the spectral analysis for multipath signals before and after filtering process. However, this spectral analysis followed by digital filtering is different from the approaches reported elsewhere in the open literature. This new approach is very useful in identifying least-affecting multipath sites for GPS applications.

9 illus, 7 tables, 29 ref

023812   Kachhal P;Sharma P;Pathak R P;Vyas S;Mahure N V;Ratnam M (NO, Central Soil & Materials Research Station, Olof Palme Marg, Hauz Khas, New Delhi-110 016, Email: pan2256@gmail.com) : Concrete exposed to hot water springs-it's designing and monitoring post construction performance-a case study. Int J civ struct Engng 2013, 4(2), 125-35.

Aim is to full fill country's irrigation and power requirements various large capacity dams have been constructed on major rivers in last 50 years. The long term sustainability of these structures is largely dependent on hydro-environment and the capacity of these structures to resist weathering action, chemical attack, abrasion, or any other process of deterioration. The concrete deterioration is directly influenced by various geographical, climatic and ecological conditions. These are therefore the major factors to be considered during the designing and construction of the projects for enhancing their sustainability. Water plays an important role in the production of concrete. The chemical reactions between cement and water enable the setting and hardening of cement, resulting in a binding medium for the aggregates and development of strength. Concrete can be made which will perform satisfactorily when exposed to various atmospheric conditions, to most waters and soils containing chemicals etc. There are, however, certain aggressive conditions under which the useful life of even the best concrete will be short. Understanding these conditions permit measures to be taken to prevent or reduce deterioration. Peculiar problems like deterioration of concrete due to poor water quality, problem of leaching of lime in seepage galleries, high temperature of water springs inside head race tunnels etc. have been encountered during the pre and post construction investigations at various projects. The present study discusses the details of such problems and the suggested remedial measures for Nathapa Jhakri Hydroelectric power project, Himachal Pradesh, India.

9 tables, 16 ref

023811   Joshi R (Civil Engineering Dep, School of Technology, Pandit Deendayal Petroleum Univ, Gandhinagar-382 007, Email: ramjoshi1992@gmail.com) : Effect of using selected industrial waste on compressive and flexural strength of concrete. Int J civ struct Engng 2013, 4(2), 116-24.

Main idea of the presented work is to examine the effect of adding industrial waste in the form of Gray Cast iron (GCI) and Ductile Cast Iron (DCI) from the casting industry in the concrete mix. GCI and DCI turnings were used as a partial replacement material for the usual fine aggregates to study the effect on compressive strength and flexural strength of the mix. Partial replacement of fine aggregates by increasing percentage (0-30%) of GCI and DCI turnings reveals that increased GCI and DCI turnings proportions result in increased compressive strength and flexural strength of the concrete against the controlled specimen of concrete mix. The mix with 30% sand replacement by GCI and DCI turnings showed 32.5% increase in compressive strength in comparison to the target strength i.e. 38.25 MPa and 63.83% increase in the flexural strength as compared to the controlled specimen i.e. 23.5 MPa on 28th day.

5 illus, 3 tables, 21 ref

023810   Jena D J;Panigrahi S N (School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar-751 103, Email: jena.dibya@gmail.com) : Experimental investigation of motor current signal signature for developing an operator assistance system for a food processor. J Instn Engrs : Ser B 2014, 94(4), 263-74.

Perturbations in the drawn current due to the fluctuation in load on the blade during the processing of food in a food processor has been used to design an operator assistance system. A robust signal processing scheme has been proposed in order to analyze the extremely feeble current fluctuations in the motor controller circuit. An enveloping technique followed by a wavelet based denoising filter has been proposed for extracting useful information from the acquired current signal. Output of this scheme is fed into an intelligent decision making algorithm, which primarily is able to take two kinds of. decisions, finally assists the user in making certain informed judgments. One of these decisions deals with the completion of the mixing or grinding operation whereas the other deals with cautioning the user about the presence of undesirable impurities in the substance being processed. Effectiveness of the developed method has been demonstrated, first on an appropriately formulated simulation, and then on the acquired signal from the experimental setup.

14 illus, 32 ref

023809   Guarneros O;de Vicente J;Maya M;Ocana J L; Molpeceres C;Garcia-Ballesteros J J;Rodriguez SR;Duran H M (Mechanical and Electrical Dep, San Luis Potosi Univ, Dr. Manuel Nava St. No. 8, 78290 San Luis Potosi, Mexico, Email: orlando.guarneros@uaslp.mx) : Uncertainty estimation for performance evaluation of a confocal microscope as metrology equipment. MAPAN 2014, 29(1), 29-42.

Both in industry and research, the quality control of micrometric manufactured parts is based on the measurement of parameters whose traceability is sometimes difficult to guarantee. In some of these parts, the confocal microscopy shows great aptitudes to characterize a measurand qualitatively and quantitatively. The confocal microscopy allows the acquisition of 2D and 3D images that are easily manipulated. Nowadays, this equipment is manufactured by many different brands, each of them claiming a resolution probably not in accord to their real performance. The Laser Center (Technical - 199 - University of Madrid) has a confocal microscope to verify the dimensions of the micro mechanizing in their own research projects. The present study pretends to confirm that the magnitudes obtained are true and reliable. To achieve this, a methodology for confocal microscope calibration is proposed, as <62> well as an experimental phase for dimensionally valuing the equipment by 4 different standard positions, with its seven magnifications and the six objective lenses that the equipment currently has, in the x-y and z axis. From the results the uncertainty will be estimated along with an effect analysis of the different magnifications in each of the objective lenses.

24 illus, 12 tables, 11 ref

023808   Goswami R S;Chakraborty S K;Bhunia A;Bhunia C T (NO, National Institute of Technology, Itanagar, Arunachal Pradesh, Email: rajat.nitap@gmail.com) : Generation of automatic variable key under various approaches in cryptography system. J Instn Engrs : Ser B 2014, 94(4), 215-20.

One of the finest approach for achieving the perfect security is the time variant key or variable key from session to session or to data. Automatic Variable Key (AVK) is a novel approach in respect of time variant key technique. In AVK, the key is generated by a variable data transmitted in prior session. The AVK was widely experimented by many researchers and the superiority of AVK over a single key/fixed key has been duly established. In this paper few new techniques to generate time variant key is proposed. Comparison to find out the superiority of different key generation techniques is also made.

6 illus, 1 table, 14 ref

023807   Dhale S A;Pande A M (NO, Priyadarshini College of Engineering, Nagpur, Email: shri_dhale@rediffmail.com) : Investigation and comparative study of effect of silica fume in cementitious grouts. Int J civ struct Engng 2013, 4(2), 183-91.

Critical investigation to study the effect of silica fumes on the compressive strength of cementitious grouts. The silica fume was added in different percentages of total mix, the percentages were 2%, 3.5%, 5%, 6.5%, and 8%. Cement component in the grout mix was varied between 30% to 50%, 13% water and 0.7% Salphonated naphthalene-formaldehyde condensate (SNF) were added in all mixes. Cementitious material like plaster of paris and aluminium powder were also added in fixed percentages of 3% and 0.005%. Total number of mixes studied was 25. Increase in cement component is found to have increased the compressive strength, however the addition of silica fume in different proportions have contributed to compressive strength development. It is observed that 2% of silica fume and 3.5% of silica fume has resulted in better compressive strengths. The results obtained are critically analysed and are presented and discussed.

6 illus, 5 tables, 13 ref

023806   Deka B;Bora P K (Electronics and Communication Engineering Dep, Tezpur Central Univ, Tezpur) : Wavelet-based despeckling of medical ultrasound images. IETE J Res 2013, 59(2), 97-108.

This paper presents a new wavelet-domain technique for despeckling of medical ultrasound (US) images for improved clinical diagnosis. The method uses the generalized Gaussian distribution and generalized gamma distribution to model the image and the speckle, respectively, in the detailed sub-bands of wavelet decomposition of the log-transformed US image. Combining these, a priori distributions with the Bayesian maximum a posteriori criterion, shrinkage estimators are derived for processing the wavelet coefficients of the - 198 - detail sub-bands. The visual comparison of despeckled US images and the higher values of quality metrics indicate that the new method suppresses the speckle noise well while preserving the texture and organ surfaces.

7 illus, 4 tables, 28 ref

023805   Das S R;Jun-Feng L;Nayak A R;Assaf M H;Petriu E M;Biswas S N (Computer Science Dep, College of Arts and Sciences, Troy Univ, Montgomery, AL 36103 USA) : Circuit architecture test verification based on hardware software co-design with modelsim. IETE J Res 2013, 59(2), 132-40.

In view of the recent paradigm shift from system-on-board to designs embracing embedded cores-based system-on-chips (SOCs), the complexity of digital circuits has enormously increased. This growing complexity has resulted in a huge challenge in developing their appropriate and efficient fault testing environment. Despite significant efforts directed toward implementing effective testing strategies of very large scale integrated circuit chips with reasonable cost, new frontiers emerged with advances in technology. The subject paper endeavors to develop method to test verify circuit architecture under hardware software co-design environment, targeting specifically embedded cores-based SOCs. The concept of design-for-testability is utilized in the paper together with ModelSim simulation and verification tool to test synthesize the entire design. Some simulation results on the International Symposium on Circuits and Systems (ISCAS) 85 combinational and ISCAS 89 full-scan sequential benchmark circuits are also included with a comparison of the results with some earlier worKs.

5 illus, 6 tables, 11 ref

023804   Daei M;Shahryari L (Civil Engineering Dep, Faculty of Engineering, Isfahan Univ, Iran) : Efficient mathematical modeling based on moment distribution method for plastic analysis of frames. Int J civ struct Engng 2013, 4(2), 167-73.

This paper proposes a linear programming model for plastic analysis of planar frames. The fundamental concept - 197 - of the proposed model is obtained from moment distribution method, which is based on safe theorem. The balanced moment at the structure nodes are considered as the decision variables of the model, in which the objective function is collapse load factor that is to be maximized, while equilibrium and yield conditions are satisfied due to model constraints. Since there are different plastic moments (Mp) in a structure due to the elements with different cross sections, the collapse load factor for each element is obtained by dividing the Mp of the element by its minimum bending moment, which called element load coefficient. The minimum element load coefficient is the collapse load factor of the frame. Modeling the problem based on the mentioned approach results in a nonlinear mathematical model, in which the objective function is a nonlinear function of decision variables. Since the linear mathematical models are more attractive from solution approach point of view, in this paper the mentioned nonlinear model is modified to an equivalent linear one due to some mathematical modeling techniques. Contrary to moment distribution method, the proposed approach is independent of user decision during the solution process, and therefore this make the proposed approach more efficient. The proposed approach is illustrated by numerical examples which is solved by LINGO software.

4 illus, 1 table, 7 ref

023803   Chaitanya Kumar J D;Venkat L (Civil Engineering Dep, GVP College of Engineering (A), Visakhapatnam-530 048, Email: lutevenkat@gmail.com) : Analysis of multi storey building with precast load bearing walls. Int J civ struct Engng 2013, 4(2), 147-56.

Pre-cast construction is gaining significance in general and urban areas in particular. It is gaining more popularity with the rapid urban infrastructure growth. In this context G+11 storey residential building with precast reinforced concrete load bearing walls has been attempted for analysis. The structural system consists of load bearing walls and one-way slabs for gravity and lateral loads have been taken for analysis using ETABS. Various wall forces, displacements and moments have been worked out for different load combinations. Data base is presented for the worst load combination. This work is limited to the analysis of structural elements only not the connection details.

11 illus, 4 tables, 13 ref

023802   Carrasco E V M;Duarte R S;Bremer C F;Alves R C;Mantilla J N R (Structural Engineering Dep, Federal Minas Gerais Univ (UFMG), Belo Horizonte-MG, Brazil, Email: mantilla@dees.ufmg.br) : Determination of eucalyptus grandis boards properties through non-destructive testing. Int J civ struct Engng 2013, 4(2), 157-66.

This work evaluated the results of non-destructive testing to determine the following properties of Eucalyptus grandis boards: moisture content, basic and apparent densities, longitudinal modulus of elasticity and parallel to the fibers compressive strength. The properties of the boards were also determined by destructive testing according to the Brazilian Standard, NBR7190. The results of these tests allowed to evaluate the effectiveness of non-destructive testing and find correlations for a rapid determination of the properties of the boards. The equation found to determine the boards longitudinal moduli of elasticity from the propagation velocity of longitudinal waves and apparent density in loco was efficient and can contribute to the classification and to glulam beams optimized manufacturing.

7 illus, 3 tables, 7 ref

023801   Bhamre P R;Kulkarni S D;Rangnekar M N;Patil S P;Patil S A (NO, MERI, Nashik) : Designing RCC mixes for various cementitious contents by using fly ash from five different thermal power stations in India. Wat Energy int 2013, 70(10), 44-52.

Study was undertaken to fix the optimum percentage of fly ash to be used in RCC mix M-15 for given cementitious content for fly ash from five different thermal power stations in India. One of the aim of the study was to prepare develop database of RCC mix proportions using fly ash from five different thermal power stations in India. The study comprises of developing RCC mix design procedure for high paste RCC and to study various properties along with adiabatic behaviour of RCC mixes using fly ash from five different thermal power stations in India.Database thus produced will be of immense use for further RCC research study.

7 tables, 27 ref

023800   Bayat B;Zulkifli M;Ghazali M;Tahir M (NO, , Faculty of Civil Engineering, Teknologi Malaysia Univ(UTM), Email: bayat.behzad@gmail.com) : Space shear wall as an innovative seismic resistant system for structures. Int J civ struct Engng 2013, 4(2), 203-14.

Optimisation of stiffness, ductility and construction cost is the main challenge for structural engineers in attempting to create an excellent lateral system. Conventional seismic systems like braced frames and shear walls could not completely satisfy engineers due to excess rigidity, and low ductility. Then innovators developed advanced ductile structural systems like viscous elastic dampers to dissipate earthquake forces and insulate important structural elements in safe zone; however these systems have not been pervasive in construction industry due to high production cost. This paper introduces an innovative application of space frame system as Space Shear Wall (SpaSW) to overview its feasibility and advantages for seismic performance enhancement. This concept has initially been formed based on the double-layer diagonal spatial structures with Mero connections. In conclusion high stiffness, ductility and energy dissipation, lightness, industrialization, maintainability and reparability, compatibility with architectural considerations, low cost, simple and fast fabrication are the main expected advantages of this system. Developing this concept would be considered in the future studies through optimization of material, grid patterns, connection, and additional dampers.

9 illus, 2 tables, 14 ref

023799   Atia D M;El-Madany H T (NO, Electronics Research Institute, Cairo, Egypt) : Optimal design of hybrid renewable energy sources for cardboard factory. Wat Energy int 2013, 70(10), 31-5.

The cardboard industry is considered the major important industries that depend on most productive companies in the packaging products and it is characterized by shock durability and resistance to tearing. So, the cardboard industry has widely used because of their importance and the availability of the necessary raw materials. This paper presents the optimal sizing of renewable energy sources for a small cardboard factory. The renewable energy resources include wind, diesel, biomass and battery storage system. The El-Tahrir is chosen to be the site under consideration. Moreover, the sensitivity analysis is done to study the variation of wind speed, the diesel fuel prices, biomass capacity, and biomass price on the total net present cost of the system.

6 illus, 3 tables, 12 ref

023798   Arya L D;Kela K B (Electrical Engineering Dep, Shri Govindram Seksaria Institute of Technology and Science, Indore, Madhya Pradesh, Email: ldarya@rediffmail.com) : Reliability performance optimization of meshed electrical distribution system considering customer and energy based reliability indices. J Instn Engrs : Ser B 2014, 94(4), 237-46.

Describes a methodology for determination of optimum failure rate and repair time for each component of a meshed distribution system. In this paper the reliability indices for a sample meshed network are - 195 - optimized. An objective function incorporating customer and energy based reliability indices and their target values is formulated. These indices are function of failure rate and repair time of a section of a distribution network. Modification of failure rate and repair time modifies the cost attached to them. Hence the optimization of the objective function is achieved by modifying the failure rate and repair time of each section of the meshed distribution system accounting constraint on budget allocated. The problem has been solved using population based differential evolution and bare bones particle swarm optimization techniques and results have been compared for a sample meshed distribution system.

4 illus, 8 tables, 23 ref

023797   Albert C B;Shashikumar D (ECE Dep, Christ Univ, Faculty of Engineering, Kumbalagodu, Bangalore, Karnataka, Email: albertbazil@gmail.com) : Effect of adaptive filters and windowing function on bandwidth, directivity and time of digital single beam forming. Int J civ struct Engng 2013, 4(2), 192-202.

Antenna array exhibit flexibility in the design of radiation patterns. Conventionally, arrays are designed by controlling excitation levels, phase levels and space distribution of elements. In practice, for pre designed radiating elements in the array, one of the above parameters is considered for the design keeping the others fixed. When the elements of the array are uniformly excited, the first sidelobe level is found to be -13.5 dB. It is of interest here to reduce the sidelobe levels, increase the directivity by decreasing the beamwidth and also to reduce the time required to minimize the error minimization time using different window functions and adaptive filters.

2 illus, 7 ref

023796   Ajay Kumar;Singh H;Maheshwari S (NO, Noida Institute of Engg. & Technology, Gr. Noida-201 306, Email: ajayagrohi@gmail.com) : Element transfer study of developed agglomerated fluxes during submerges arc welding. Indian Weld J 2014, 47(1), 57-65.

The aim of this work is to study the chemistry of element transfer in respect to developed agglomerated flux constituents during submerged arc welding. Fluxes have been designed by altering different minor constituents e.g. MnO, CaF₂, NiO, MgO and Fe-Cr. The ratio of major constituents i.e. CaO, SiO₂ and Al₂O₃ has been kept as a constant. Through this study it could be inferred that the chemical analysis of the element transfer during submerged arc welding can be correlated with the mechanical properties.

3 illus, 6 tables, ref

023795   Acharyya A;Banerjee J P (Radio Physics and Electronics Dep, Institute of Radio Physics and Electronics, Calcutta Univ, Kolkata) : Potentiality of IMPATT devices as terahertz source: an avalanche response time-based approach to determine the upper cut-off frequency limits. IETE J Res 2013, 59(2), 118-27.

Potentiality of Impact Avalanche Transit Time (IMPATT) devices based on different semiconductor materials such as InP, 4H-SiC, and Wurtzite-GaN (Wz-GaN) has been explored for operation at terahertz (THz) - 194 - frequencies. Drift-diffusion model is used to design double-drift region (DDR) IMPATTs based on above mentioned materials at different millimeter-wave (mm-wave) and THz frequencies and the upper cut-off frequency limits of those devices are obtained from the avalanche response times at those mm-wave and THz frequencies. Results show that the upper cut-off frequency limits of both InP and 4H-SiC DDR IMPATTs are 1.0 THz; whereas, the same is 5.0 THz in Wz-GaN DDR IMPATTs. The Wz-GaN DDR IMPATTs emerge as the most suitable devices for generation of THz frequencies due to their small avalanche response time, high DC to RF conversion ratio, and sufficiently high RF power output at THz frequencies. But, it is observed that up to 1.0 THz, 4H-SiC DDR IMPATTs excel Wz-GaN DDR IMPATTs due to their higher output power densities. Thus, the wide bandgap semiconductors such as Wz-GaN and 4H-SIC are highly suitable materials for DDR IMPATTs at both mm-wave and THz frequency ranges.

9 illus, 3 tables, 41 ref

023794   Abd-Elrehim T;Raouf M H A (Measurement Science Dep, Science and Technology Univ (UST), Daejeon, Republic of Korea, Email: mohammed_makka@yahoo.com) : Detection of ultrasonic signal using polarized homodyne interferometer with avalanche detector and electrical filter. MAPAN 2014, 29(1), 1-8.

Usually, ultrasonic detection is obtained by conventional contact techniques. In some critical cases such as working at hard environmental conditions (hot oven or nuclear field) or sensitive surfaces, then non-contact optical techniques should be used. However, for all optical techniques, low sensitive ultrasonic detection still a common problem. This paper presents a self building homodyne laser interferometer system which is modified by polarization state to improve the detection performance and to increase the sensitivity limit. The introduced interferometer system has been used to detect ultrasonic signal generated in coated quartz sample around its 10 MHz resonance frequency. He-Ne laser source has been used at 633 nm wavelength with low optical power of 1 μW. The generated ultrasonic signal has been observed by two different photodetectors to investigate the better performance one. Band pass electrical filter with certain specifications has been used to obtain suitable signal to noise ratio as demonstrated through this work.

7 illus, 22 ref

023000   Zhang Y;Wang Z;Zhao Y;Shang L (NO, Ningbo Institute of Technology, Zhejiang Univ, Ningbo-315 100, China, Email: lashang@nit.zju.edu.cn) : Synthesis and electromagnetic characteristics of ZnO micro-crystal with varying morphology. Indian J Engng Mater Sci 2014, 21(1), 44-8.

ZnO micro-crystals are prepared by hydrothermal reaction using PEG-20000/cyclohexane as additive, and Zn(OH)₄^2- and Zn(NH₃)₄²⁺ as precursors. Characterizations of the ZnO samples are conducted with X-ray diffraction (XRD), scanning electron microscopy (SEM) and selected area electron diffraction (SAED). The results show that the synthesized crystals belong to hexagonal crystalline system with typical morphology of ZnO aggregates composed of nano rod-like monocrystals which grew into various morphologies such as robust, tapered and clustered under different reaction conditions. The aggregates could be assembled with a controllable size of 2<126>4 μm. In the aid of PEG-20000, the specific face of crystal formed nucleus preferentially and then grew directionally. In addition, the tests of the microwave electromagnetic performance show a significant effect of the crystal morphology on the dielectric loss of ZnO. With the higher polar growing ability, the faster velocity, the shorter growing period and the more lattice defects, the polarization would become more intense to cause more dielectric loss of ZnO consequently.

5 illus, 1 table, 23 ref

022999   Zende A M;Nagarajan R;Atal K R (NO, Centre for Studies in Resource Engineering, Indian Institute of Techno, Bombay, Email: zenabhi31@gmail.com) : Analysis of surface runoff from Yerala river basin using SCS-CN and GIS. Int J Geomatics Geosci 2014, 4(3), 508-16.

Watershed Management - 316 - plays vital role in water resources engineering. It is necessary to plan and conserve the available resources. Remote Sensing (RS) and Geographic Information System (GIS) techniques can be effectively used to manage spatial and non spatial database that represent the hydrologic characteristics of the watershed. The present study area is of Yerala River Basin, located in upper Krishna basin, Western Maharashtra, India. The daily rainfall data of 10 rain gauge stations (1998 - 2011) was collected and used to predict the daily runoff from the watershed using Soil Conservation Service - Curve Number (SCS - CN) and GIS. For the duration 1998-2011, minimum and maximum of (a) the yearly average rainfall are 232.55 mm and 759.87 mm respectively and (b) the yearly average runoff are 39.40 mm³ and 153.63 mm³ respectively. The developed rainfall-runoff model has been used to understand the characteristics of the watershed and its runoff.

5 illus, 4 tables, 9 ref

022998   Zakaria K A;Abdullah S;Ghazali M J;Nuawi M Z; Beden S M;Nopiah Z M (Mechanical and Materials Engineering Dep, Kebangsaan Malaysia Univ, 43600 UKM Bangi, Selangor, Malaysia, Email: kamarull@eng.ukm.my) : Fatigue strain signal behaviour and damage assessment of an engine mount bracket. J scient ind Res 2014, 73(2), 112-6.

This paper discusses the fatigue strain signal behaviour of different road surface conditions and its relationship to the fatigue damage of an engine mount bracket. Two different sets of fatigue strain signals were obtained from an engine mount bracket of an automobile: when the automobile was driven on a highway surface and on a residential area road surface. The behaviour of the strain signal was then analysed and classified using both statistical and signal processing tools. Damage values as a result of the corresponding fatigue strain signals also determined using commercial finite element software. The fatigue strain signal behaviour was influenced by the road surface conditions, which affected the damage to the engine mount bracket. The integrated kurtosis-based algorithm for the Z-filter and power spectral density calculation were found to be the most suitable signal analysis approaches to correlate the fatigue strain signal behaviour with the engine mount bracket damage.

2 illus, 3 tables, 21 ref

022997   Yoshida N (Civil and Environmental Engineering Dep, Tohoku Gakuin Univ, Chuo 1-13-1, Tagajo, Miyagi, Japan) : Comparison of seismic ground response analyses under large earthquakes. Indian Geotech J 2014, 44(2), 119-31.

Equivalent linear, truly nonlinear, and effective stress analyses are compared at 268 sites under 11 large earthquake motions in order to grasp general feature of the applicability of the equivalent linear method and total stress analysis. Equivalent linear analysis shows larger peak acceleration and smaller peak displacement than total stress nonlinear analysis, but other indices such as instrumental seismic intensity, peak velocity, and spectral intensity are nearly same to each other. Therefore, it is applicable when truly nonlinear analysis is applicable. On the other hand, all earthquake motion indices are much smaller in the effective stress analysis compared with the total stress analysis at the liquefiable sites, except two indices peak ground displacement and maximum strain that are much larger. Therefore, it is recommended to use effective stress analysis at these sites. However, as indices are overestimated, use of the total stress can be said to result in conservative design when inertia force is interested at.

19 ref

022996   Yazdian N;Karimzadeh F;Tavoosi M (Materials Engineering Dep, Nanotechnology and Advanced Materials Institute, Isfahan Technology Un, Isfahan 84156-83111, Iran, Email: m.tavoosi@ma.iut.ac.ir) : Fabrication and precipitation hardening characterization of nanostructure Al7075 alloy. Indian J Engng Mater Sci 2014, 21(1), 30-4.

In this paper the fabrication and precipitation hardening behavior of bulk nanostructure A17075 alloy is investigated. In order to produce this alloy, the elemental powder based on the nominal composition of conventional A17075 alloy is milled up to 15 h and then hot pressed. The milled and hot pressed samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The results show that after 15 h of milling, the alloying elements - 315 - are dissolved in Al matrix and a supersaturated solid solution with average crystallite size of about 30±5 nm is obtained. Hot pressing the powder samples at 500°C under 400 MPa led to the fully dense bulk nanostructure A17075 alloy. The consolidated sample has a hardness value of 165 HV which increases to 240 HV after appropriation hardening.

8 illus, 21 ref

022995   Yang J W;Hyun-Lark Do (Electronic & Information Engineering Dep, Seoul National Science and Technology Univ, seoul-139 743, South Korea, Email: hldo@seoultech.ac.kr) : Analysis and design of a high-efficiency zero-voltage-switching setp-up DC-DC converter. Sadhana 2013, 38(4), 653-65.

A high-efficiency zero-voltage-switching (ZVS) step-up DC-DC converter is proposed. The proposed ZVS DC-DC step-up converter has fixed switching frequency, simple control, and high efficiency. All power switches can operate with ZVS. The output diodes are under zero-current-switching (ZCS) during turn-off. Due to soft-switching operation of the power switches and output diodes, the proposed ZVS DC-DC converter shows high efficiency. Steady-state analysis of the converter is presented to determine the circuit parameters. A laboratory prototype of the proposed converter is developed, and its experimental results are presented for validation.

9 illus, 15 ref

022994   Yan C;Deng J;Lai X;Hu L;Chen Z (State Key Lab of Petroleum Resources and Prospecting, China Petroleum Univ, Beijing-102 249, China) : Critical drawdown pressure of depleted reservoir. Indian Geotech J 2014, 44(1), 101-6.

For long time production, most oilfields have entered the later development stage, and the pore pressure is seriously depleted. The pressure depletion will affect in situ stress, and change the stress state around the borehole, and then the affect the critical drawdown pressure to cause sand production. The theoretical formula of two horizontal in situ stress changes with pore pressure is obtained based on generalized Hoek's law, and then the stress distribution formula around the borehole in pressure depleted reservoir is established. The calculation model of sand production critical bottom hole flowing pressure in depleted reservoir is established using the Mohr-Coulomb criterion, Drucker-Prager criterion and Mogi-Coulomb criterion, respectively. The influence of pressure depletion on critical drawdown pressure is analyzed. The results show that: with the pore pressure decreasing, the horizontal in situ stress and critical drawdown pressure become smaller; the error of prediction model based on Mogi-Coulomb criterion is the minimum, and it is more in line with the actual field data; the prediction model based on Mohr-Coulomb criterion is conservative but most safe. The establishment of prediction model provides a guidance for actual production decisions in pressure depleted reservoir.

27 ref

022993   Wei-Jer W;Cheng-Der W;Hsu-Hung C;Veeragouni A;Tzen-Chin L (Civil and Disaster Prevention Engineering Dep, National United Univ, Miao-Li, 360-03, Taiwan, Email: ltc6@nuu.edu.tw) : Reuse of light-emitting diode manufacturing process sludge in cement concrete. Indian J Engng Mater Sci 2014, 21(1), 57-66.

Purpose of this study is to investigate the use of the sludge that is a by-product of the light-emitting diode (LED) manufacturing process to partially replace cement in cement concrete. Two water-to-cementitious-material ratios, w/c = 0.5 and 0.7, are used. LED sludge powder replaced 5, 10 and 20 wt% of the cement in sludge-blended cement concrete (SBCC) specimens. These molded cylindrical specimens, 10 cm in diameter and 20 cm in height (10 cm Φ x 20-cm H), are subjected to compressive strength test and other mechanical properties tests. The properties of the LED sludge samples are determined using scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDS) and X-ray diffraction (XRD). The experimental tests reveal that the compressive strengths of SBCC specimens are comparable to those of ordinary Portland cement concrete (OPCC) specimens at all curing ages and that the other mechanical properties are also similar. These findings indicate that LED sludge can be converted into a useful resource, thereby avoiding the problems associated with its disposal and improving its environmental sustainability.

9 illus, 5 tables, 19 ref

022992   Wang J;Li Y;Li H (DSP Lab, School of Communication and Information Engineering, Electronic Scienc, ChengDu, China) : Efficient link bandwidth design method for application-specific network-on-chip. IETE Tech Rev 2012, 30(2), 102-7.

In this paper, an efficient link bandwidth design method for the Network-on-Chip (NoC) is proposed to satisfy NoC performance requirements with less bandwidth cost. First, the relationship between link bandwidth and the data delay is constructed. Then, a bandwidth allocation method is proposed to assign proper bandwidth to each link in NoC. Finally, the effectiveness of our method is validated through simulation. The simulation results show that the NoC can satisfy the system performance requirements after using our bandwidth allocation method. Moreover, compared with the NoC with uniform link bandwidth, the method can reduce the cost of link bandwidth.

5 illus, 3 tables, 27 ref

022991   Vijeyakumar K N;Sumathy V;Pramod P; Saravanakumar S (Electronics and Communication Engineering Dep, Anna Regional Centre Univ, Coimbatore Jothipuram, Coimbatore-641 047, Email: vijey.tn@gmail.com) : Design of high speed low power counter using pipelining. J scient ind Res 2014, 73(2), 117-23.

Present high-speed scalable counter architectures for high operating frequencies. The design methodology implemented in a 16 bit counter architecture uses basic module and - 313 - subsequent modules for count generation. The triggering pulses for a subsequent module is generated from state transitions of basic module and preceding subsequent modules using State Exciting Logic (SEL) in case of synchronous operation where clock pulses trigger all the modules simultaneously. As an extension, we connected the modules in asynchronous mode where the most significant bit (MSB) of module/stage is used as clock pulse for the immediate succeeding module. The novelty of the design is the realization of all subsequent modules with equal number of gates, which maintain uniform setup time for all the D Flip Flops (FFs) in the module. And, thus the D FFs when triggered by clock pulse gives uniform output. The proposed counter is designed using VHDL code and simulated using Altera Quartus II EP1C20F400C7 device. Analysis reveals that the power dissipation of our proposed counter is 80.47 mW and 80.46 mW with delay parameter of 9.097 ns and 22.476 ns for synchronous and asynchronous connection respectively at 250 MHz.

2 illus, 2 tables, 26 ref

022990   Vidjeapriya R;Bahurudeen A;Jaya K P (Structural Engineering Div, Civil Engineering Dep, College of Engineering, Guindy, Anna Univ, Chennai, Email: vidjeapriya@annauniv.edu) : Nonlinear analysis of exterior precast beam-column J-bolt and cleat angle connections. Int J civ struct Engng 2013, 4(1), 87-97.

In this study a 3-D nonlinear FE model was developed to study the response of an exterior precast beam to column connection subjected to reverse cyclic loading. Tests of a one-third scale exterior beam column precast concrete connections was conducted. Two types of connections were compared. The connections included a monolithic connection and two precast beam - column connections (i) using J-bolt (ii) using Cleat Angle. ANSYS finite element software was used for the non-linear analysis of the precast beam column connection. For the nonlinear analysis, one-third scale model was developed. Two types of elements were used including solid elements and contact elements. The finite element analysis results compared well with the experimental data. It is concluded that if the material constitutive relation and failure criterion can be selected suitably, the finite element model can accurately predict the overall seismic behavior and the inelastic performance of these two kinds of joints.

5 illus, 3 tables, 14 ref

022989   Verma H K;Thote N R (NO, Central Institute of Mining & Fuel Research, Regional Centre, CBRI Cam, Roorkee-247 667, Email: drharsh77@gmail.com) : Investigation of delay time precision in pyrotechnic detonators. J Rock Mech Tunnelling Technol 2013, 19(1), 19-28.

Despite advancement of initiating devices, use of electrical detonators with pyrotechnic composition is common in Indian mining and construction industry. The cost benefit achieved by electrical detonators over shock tube initiation system and electronic detonators is huge. Delay detonators made with pyrotechnic delay compositions have inherent scattering in their delay timings. It is desirable to use precise detonators to achieve better fragmentation, less vibration and noise. Overlapping of delay period is undesirable from production as well as safety point of view. In order to assess delay accuracy of electrical pyrotechnic detonators of a domestic manufacturer, randomly selected fifty units from each delay period (0 to 6) from the same batch of detonators that were found suitable for use in underground coal mines in respect of their incendivity, handling & electrical safety, performance and water resistance characteristics were evaluated. Overlapping possibilities amongst delay periods were evaluated by calculating Winzer index and graphical methods. The findings reveal that significant scattering exist in all the delay periods. Scattering increases with higher delay periods. Overlapping possibilities between delay period 5 and 6 is found to be significantly high. Winzer index for the pair of delay period 5 and 6 is found to be very close to the threshold value for overlapping.

7 illus, 1 table, 13 ref

022988   Verma H K;Goel R K;Prasad V V R (NO, Central Institute of Mining and Fuel Research, Regional Centre, CBRI, Roorkee-247 667, Email: drharsh77@gmail.com) : Assessment and mitigation of blast induced vibration and overbreak in Kol Dam hydroelectric power project, India- a case study. J Rock Mech Tunnelling Technol 2013, 19(1), 47-59.

Pre-splitting is the commonly used controlled blasting technigue for perimeter control in mining and construction industry. Overbreak and damage to the final slope of excavation adversely affect safety as well as economics of the project. Apart from unsafe slope at the perimeter of rock excavation, pre-split blasting techniques prevents extra cost of rock excavation, backfill material and rock reinforcement. This technique has several advantages such as minimum damage from back-break, enhanced carrying capacity of rock, higher structural stability and stable final pit walls or slope at the designed angle thus improving overall safety of wall/slope. This paper presents a case study of Kol dam hydroelectric power project (KHEPP). This 800 MW project is under construction on river Satluj in Himalaya, India. The excavation in the project consists of preparation of seven benches having slope of 1:4 starting from elevation level (EL) 715.0 m to EL 618.0 m in the approach channel area, each bench having height 15 m and berm width of 5 m. Three sets of joints in the two dominant rock types of approach channel area namely pink limestone and yellowish dolomite, posed geological challenges for the safe excavation. Spacing of the these parallel joints ranges from 0:30 m to 2m. the rock is intensely folded in some parts and shear zones are also present in this area. The joint set in limestone and dolomite made whole rock formation in a block size ranging from as small as 0.5 m² to as large as 5.0 m². The block formation was prone to overbreak leading to unstable slope. Apart from the geological challenges, the domestic houses close, to excavation area are also susceptible to damage due to possible high level of blast induced ground vibration. In all such situations, pre-splitting was carried out in a controlled manner. The blast design gave good result with minimum overbreak and vibration less than 10 mm/s. The technique helped in preparation of the stable slope in the benches as per the required profile and also prevented damages to the domestic structures. This paper gives details of site specific technical challenges and details of the blast design, details of an in-house arrangement for maintaining drilling accuracy and the techniques evolved for preventing structural damages induced by blast vibrations.

10 illus, 4 tables, 6 ref

022987   Venkateswaran P R;Ganesh Kumar K;Ramakrishnan M;Buvanashekaran G (NO, Welding Research Institute, BHEL, Tiruchirappalli-620 014) : ANN prediction of weld bead geometry in cold wire tandem submerged arc welding process. WRI Jl 2013, 34(1), 16-23.

Artificial Neural Networks (ANN), an adaptation of biological nervous - 311 - system is equipped to address nonlinear modeling and learning problems. Welding being a typical nonlinear process with large number of interdependent variables, ANN has the scope to be used at various stages in welding, starting from modeling of weld process till testing of the mechanical properties of weldments. A case study for prediction of weld bead geometry in tandem SAW process is considered in this paper. A multi-layer perceptron network is used as a model for predicting the weld bead geometry parameters of tandem SAW process. The model was trained with the data of in-house trials and the results are validated with experimental verification. The model is successful with a prediction accuracy of ± 8% and compares favoruably with peer works listed in the literature survey.

3 illus, 5 tables, 8 ref

022986   Venkatesh T N;Mathew J (Flosolver Unit, CSIR-National Aerospace Laboratories, PB 1779, Bangalore-560 017) : Problem of clear air turbulence: changing perspectives in the understanding of the phenomenon. Sadhana 2013, 38(4), 707-22.

Due to rapid improvements in on-board instrumentation and atmospheric observation systems, in most cases, aircraft are able to steer clear of regions of adverse weather. However, they still encounter unexpected bumpy flight conditions in regions away from storms and clouds. This is the phenomenon of clear air turbulence (CAT), which has been a challenge to our understanding as well as efforts at prediction. While most of such cases result in mild discomfort, a few cases can be violent leading to serious injuries to passengers and damage to the aircraft. The underlying physical mechanisms have been sought to be explained in terms of fluid dynamic instabilities and waves in the atmosphere. The main mechanisms which have been proposed are: (i) Kelvin-Helmholtz instability of shear layers, (ii) waves generated from flow over mountains, (iii) inertia-gravity waves from clouds and other sources, (iv) spontaneous imbalance theory and (v) horizontal vortex tubes. This has also undergone a change over the years. We present an overview of the mechanisms proposed and their implications for prediction.

8 illus, 47 ref

022985   Umamaheswari G;Vanithamani R (ECE Dep, PSG College of Technology, Coimbatore, Email: uma@ece.psgtech.ac.in) : Adaptive window hybrid median filter for despeckling of medical ultrasound images. J scient ind Res 2014, 73(2), 100-2.

Speckle is a random multiplicative noise which obscures the perception and extraction of fine details in ultrasound image and despeckling is necessary for better diagnosis. The main aim of despeckling is to keep the important features such as edges of the ultrasound image. In this paper an adaptive window hybrid median filter is proposed for despeckling of medical ultrasound images. In the proposed algorithm the size of the window of the hybrid median filter is selected based on the image region and to differentiate between the smooth and edge regions it uses Sobel edge operator. A window size of 3x3 is used if the center pixel to be processed is identified as an edge pixel and in smooth regions a window size of 5x5 is used. The proposed algorithm is tested on ultrasound image of the liver and synthetically speckled image and the performance is evaluated using image quality assessment parameters Peak Signal to Noise Ratio (PSNR) and Edge Preservation Factor (EPF). The results demonstrate that the proposed algorithm reduces the speckle noise effectively and also preserves edges.

3 illus, 10 ref

022984   Tandon R;Singh A;Khanna S;Gupta P (EC Dep, MIT, Moradbad, Uttar Pradesh, Email: ritikatandon15@gmail.com) : Wireless communication networks and technical challenges. Int J latest Technol Engng Mgmt appl Sci 2014, 3(1A), 25-31.

This paper presents an overview of wireless networks, with emphasis on the most popular standards: IEEE802.11. The arrival of wireless technology has reduced the human efforts for accessing data at various locations by replacing wired infrastructure with wireless infrastructure and also providing access to devices having mobility. - 310 - Since wireless devices need to be small and bandwidth constrained, some of the key challenges in wireless networks are Signal fading, mobility, data rate enhancements, minimizing size and cost, user security and (Quality of service) QoS.

3 illus, 1 table, 28 ref

022983   Takalkar S M;Mohite A P (NO, Takalkar Power Engineers & Consultants Pvt. Ltd., Vadodara) : Techno-economic considerations for design & construction of transmission line tower foundations. Wat Energy int 2013, 70(7), 13-18.

Transmission Line Tower Foundations cost about 10% to 15% of the total cost of transmission line. The cost of foundation work depends upon type of soil in which the tower is to be founded and the design loads on the towers. In the construction of EHV Transmission line, the cost of foundation is variable with the provision of unit rates for excavation, concrete work and steel re-inforcement. The quantity of foundation work depends upon the soil/rock strata along the route of the line. Harder the soil/rock, lesser is the foundation quantity and vise-a-versa. Design philosophy and approach also make difference in the costing of foundation work. A stringent load transfer considerations and steel provision, may lead to high cost of foundation work. On the other hand, too liberal approach may jeopardize the strength and reliability of the foundation while transferring the set of downward, upward and lateral loads to the mother earth. The paper here under makes an attempt to bring out salient points for cost optimization with assured reliability of transmission line tower foundations.

7 illus, 3 tables, ref

022982   Tafheem Z;Khusru S (Civil Engineering Dep, , Dhaka 1208, Bangladesh, Email: zasiah_tafheem@yahoo.com) : Structural behavior of steel building with concentric and eccentric bracing: a comparative study. Int J civ struct Engng 2013, 4(1), 12-9.

Many existing steel buildings need to be retrofitted to overcome the deficiencies to resist the lateral loading. In the present study, a six storied steel building has been modeled and then analyzed due to lateral earthquake and wind loading, dead and live load. The performance of the same steel building has been investigated for different types of bracing system such as concentric (crossed X) bracing and eccentric (V-type) bracing using HSS sections. The performance of the building has been evaluated in terms of lateral storey displacement, storey drift as well as axial force and bending moment in columns at different storey level. The effectiveness of various types of steel bracing on the structure has also been investigated. More importantly, the reduction in lateral displacement has been found out for different types of bracing system in comparison to building with no bracing. From the present study, it has been found that the concentric (X) bracing reduces more lateral displacement and thus significantly contributes to greater structural stiffness to the structure.

14 illus, 2 tables, 6 ref

022981   Suresh Babu Reddy C;Sekar P;Tirumalaiah S (NO, Larsen & Toubro Limited, ) : Case study on using special star towers for multiple overhead power line crossings. Wat Energy int 2013, 70(7), 19-22.

In present days acquiring a corridor for construction of a new transmission line without crossing of existing power lines is almost not possible. As the number of transmission lines increasing every year by year, it is inevitable that a new line cannot be constructed without any existing power line crossings. In general there are two ways of crossing any power line i.e., under crossing or overhead crossing. If the conductor level of existing power line is in a sufficient height from ground level and if it is possible to maintain required phase clearances by taking the proposed line underneath the existing line, under crossing can be done. If it is not possible to make under crossing, the other option is to make overhead crossing of the existing lines. This requires high extension towers depending upon the height of the top conductor/Earthwire (OPGW) of existing power line and the required vertical clearances to be maintained for the particular kV lines. Due to this, the tower weight and foundation volumes increase significantly. If the power lines have to be crossed in the residential areas, providing such huge extension towers is very difficult in many aspects such as acquiring land for such huge foundations, aeronautical clearance etc., we have encountered similar kind of situations for power line crossings where we cannot cross by under crossing. Thus, to make the crossings in a simple and economical way, we have adopted a new kind of tower configuration which is called as STAR tower. In this case study, we are presenting the difficulties faced in the power line crossing while executing 380 kV D/C OHL in Saudi Arabia and the methodology adopted for overcoming - 309 - the difficulties in multiple overhead crossing by using these STAR towers.

6 illus, 3 ref

022980   Surendra Kumar;Abhishek;Gopal Ji (TL Engineering Dep, Power Grid Corporation of India Limited, New Delhi) : Best practices for transmission line O&M in powergrid. Wat Energy int 2013, 70(7), 10-2.

Powergrid is the third largest transmission utility in the World and operates a transmission network of 101,334 circuit-km of 765 kV, 400 kV, 220 kV and 132 kV AC lines and 500 kVHVDC lines connecting 168 sub-station with transformation capacity of 164,813 MVA as on 31st May'2013. Many of the assets are under operation for more than 30 years. To provide uninterrupted quality power to the nation, effective management of this gigantic network is essential. Hence the need to adopt innovative and best practices for O&M of the network. Aging of the transmission asset and rapidly changing environmental conditions-including increase in pollution level and changing wind patterns in many parts of the country pose serious threat to the transmission assets. It requires evolution of new ways of preventive and outage maintenance to tackle the situation. POWERGRID has taken various initiatives involving new innovative solutions/new technologies for preventive maintenance to prevent assets failure as well as quick restoration in case of failure.

4 illus, ref

022979   Sunita;Sarwar S (Computer Science and Engineering Dep, Al-Falah School of Engineering & Technology (AFSET), Faridabad, Email: sunitasani89@@gmail.com) : Digital image steganography with analogies tools for open sub-system environment. Invertis J renewable Energy 2013, 3(2), 97-105.

Steganography should not be confused with cryptography. Cryptography actually transforms the message that is being transmitted to make it obscure to anyone who may actually intercept the message on the Internet. Unlike cryptography where the message is enciphered Steganography programs actually hide the message within another file, whether it is a text, audio or image file. Before discussing Steganography there are a few basic terms that need to be explained. The term "cover" is used to describe the original message; this could be the original digital image file, audio message or text message. The information that is hidden inside of the original message is called the "embedded" data. The term "stero" is used to describe the original data and the embedded data. Steganography means "covered zvriting". In Steganography, confidential data is hidden in images to protect it from unauthorized users. So basically it means, hiding a secret message within a cover-medium in such a way that others cannot detect the presence of the hidden message. In contemporary terms, - 308 - Steganography has evolved into a digital strategy of hiding a file in some form of multimedia, such as an image, an audio file (like a wav or mp3) or even a video file. In digital Steganography, electronic communications may include Steganography coding-inside of a transport layer, such as a document file, image file, program or protocol. Media files are ideal for Steganography transmission because of their large size.

1 illus, 7 ref

022978   Sumithra T R;Nirmal Kumar A (Faculty of Electrical and Electronics Engg., K.S.R. College of Engineering, Tiruchengodu, Email: sumithra.trs@gmail.com) : Experimental investigation on off-grid solar photovoltaic power system using matrix converter. J scient ind Res 2014, 73(2), 124-8.

This article investigates the possibility of providing electricity from off grid solar photovoltaic power systems (OGSPVPS) for a remote location without electricity connection in the state of Tamil Nadu. Crucial review of literature disclose that, in the design of a solar photovoltaic power system, matrix converters are not dealt with so far to produce better quality and low distortion power efficiently to the loads. However, cascaded H bridge multilevel inverters are widely used to obtain a stepped sinusoidal output voltage in solar photovoltaic application. In this work, an attempt has been made to design and develop an OGSPVPS by incorporating single phase matrix converters in order to obtain a feasible solution for medium power applications at remote locations. Also, the proposed matrix converter for solar photovoltaic application claim a total harmonic distortion of less than 7%. Finally, simulation results are presented to prove the feasibility and the experimental work was investigated to validate the results. Furthermore, the capability of matrix converters to operate in rectifier mode is presented, thereby substantiating that it can facilitate grid connected solar photovoltaic uninterruptible power supply (UPS) in addition to off-grid system.

3 illus, 20 ref