013795   Wang L;Zou M;Wang G;Chen Z (School of Physics and Optoelectronic Engineering, Xidian Univ, Xi'an 710 071, Peoples R China) : Direction finding and information detection algorithm with an L-shaped CCD array. IETE Tech Rev 2015, 32(2), 114-22.

This paper proposes a quaternion-ESPRIT (estimate signal parameters via rotation invariance) algorithm for estimating frequency, direction of arrival (DOA) and polarization, using a collocated crossed dipole (CCD) L-shaped array configuration. First, two sets of synchronous sampling data are used to construct the data covariance matrix, the array steering vector of the whole array is estimated using a quaternion eigenvalue decomposition of the data covariance matrix. Second, the direction cosine of the x-axis and y-axis are acquired by applying block operation to the spatial steering vectors, hence the estimates of two-dimensional DOA are obtained. Finally, the polarization parameters are estimated using the relationship between the dipole sub-array steering vectors of the x-axis and y-axis. The closed-form solutions for each parameter are obtained and parameters can automatically match. The simulation results verify that the performance of quaternion method is obviously better than that of the long-vector method.

9 illus, 5 tables, 37 ref

013794   Venu Gopala Rao M;Venkata Ratnam D (NO, K.L. Univ, Guntur-522 502, Email: mvgr03@kluniversity.in) : Faster acquisition technique for software-defined GPS recievers. Def Sci J 2015, 65(1), 5-11.

Acquisition is a most important process and a challenge task for identifying visible satellites, coarse values of carrier frequency, and code phase of the satellite signals in designing software defined Global positioning system (GPS) receiver. This paper presents a new, simple, efficient and faster GPS acquisition via sub-sampled fast Fourier transform (ssFFT). The proposed algorithm exploits the recently developed sparse FFT (or sparse IFFT) that computes in sub-linear time. Further it uses the property of fourier transforms (FT): Aliasing a signal in the time domain corresponds to sub-sampling it in the frequency domain, and vice versa. The ssFFT is an FFT algorithm that computes sub-sampled version of the data by an integer factor 'd', and hence, the computational complexity is proportionately reduced by a factor of 'd log d' compared to conventional FFT-based algorithms for any length of the input GPS signal. The simulation results show that the proposed ssFFT based GPS acquisition computation is 8.5571 times faster than the conventional FFT-based acquisition computation time. The implementation of this method in an FPGA provides very fast processing of incoming GPS samples that satisfies real-time positioning requirements.

5 illus, 17 ref

013793   Usha T G;Anuradha R;Venkatasukbramani G S (NO, Karpagam Univ, Coimbatore-641 021, Email: anuradhastalin@gmail.com) : Performance of self-compacting geopolymer concrete containing different mineral admixtures. Indian J Engng Mater Sci 2015, 22(4), 473-81.

Self-compacting geopolymer concrete is an innovative concrete that does not require vibration for placing and compaction. It is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. In this paper fly ash was replaced by different mineral admixtures, which reduces the cost of self compacting geopolymer concrete especially if the mineral admixtures are waste or industrial by-product. This paper presents an experimental investigation on strength aspects like compressive, flexural and split tensile strength of self compacting geopolymer concrete containing different mineral admixtures and workability tests for different mineral admixtures (slump, L-box, U-box and T₅₀) are carried out. The methodology adopted is that mineral admixtures GGBFS and silica fume are replaced by 10%, 20%, 30% and 5%, 10% and 15% respectively for fly ash and performance is measured and compared. The influence of mineral admixtures on the workability, compressive strength, splitting tensile strength and flexural strength of self-compacting concrete is investigated. It is observed that when mineral admixtures used in self-compacting geopolymer concrete, only 6% of super-plasticizer necessary to achieve a given fluidity. From this view point, a cost effective self-compacting concrete design can be obtained.

10 illus, 8 tables, 17 ref

013792   Thind K S;Singh J;Saini J S;Bhunia H (Mechanical Engineering Dep, Thapar Univ, Patiala-147 004) : Mechanical and wear properties of hybrid epoxy nanocomposites. Indian J Engng Mater Sci 2015, 22(4), 421-8.

Modern composite materials are usually optimized to achieve a particular balance of properties for a given range of applications. As there are compromises with properties in the composites, efforts have been made to modify these materials at the nanoscale to optimize their performance. In the present study, epoxy hybrid nanocomposites are prepared and tested. Firstly, the epoxy nano clay composite is prepared by varying the nano clay content from 1 wt% to 4 wt%. The tested mechanical and wear properties are found to be maximum in specimen with 2 wt% of nano clay content. Thereafter, keeping the 2 wt% of nano clay constant, further nano TiO₂ material is added in the epoxy nano clay composite to prepare the hybrid nanocomposite material. Nano TiO₂ material is added in the variation of 2 wt% to 6 wt%. It was found that the mechanical and wear properties for the prepared hybrid nanocomposite improved with the addition of 2 wt% of nano TiO₂ material.

12 illus, 29 ref

013791   Sumathi A;Saravanan V (Dep of ECE, Adhiyaman Engineering College, Housur, Tamil Nadu, Email: v_saravanan18@yahoo.co.in) : Bandwidth based vertical handoff for tightly coupled WiMAX/WLAN overlay networks. J scient ind Res 2015, 74(10), 560-6.

Deployment of WLAN increases globally due to its low cost implementation and high speed connectivity. The maximum data rate of 600Mbps provided by 802.11n makes it a popular standard for deploying WLANs. The primary disadvantage in WLAN is its short coverage, which is not suitable for devices with high velocity. The alternate network technology for WLAN with almost equal bandwidth with wider coverage area is WiMAX, which is the growing technology throughout the world. Hence the integration of WLAN and WiMAX is considered to be a good approach in 4G. This paper presents handoff related issues in WiMAX/WLAN overlay networks, numerical methods for estimating network conditions of both WiMAX and WLAN networks and impact on 802.1ln clients by legacy 802.11a/b/g clients. Also, we propose throughput based proactive handoff algorithm for WiMAX/WLAN overlay networks which considers network condition, bandwidth requirements and client type. Simulation results show that the proposed handoff algorithm improves overall throughput considerably.

3 illus, 23 ref

013790   Sreedhar M;Reddy S P;Narender B; Muralikrishnan S (Aerial Services & Digital Mapping Area, National Remote Sensing Centre, Hyderabad, Email: sreedhar_m@nrsc.gov.in) : Evaluation of stereoscopic measurement accuracy for airborne large format digital camera. Int J Geomatics Geosci 2015, 6(1), 11-9.

Stereoscopic depth perception plays a vital role in photogrammetry, as it enables the formation of a 3-D stereo model by viewing a pair of overlapping photographs. The stereo model can then be studied, measured and mapped. In this study, the stereoscopic measurements of images from Ultracam-D digital camera, acquired at 10cm GSD are investigated by carrying out repetitive measurements of various geometric features by an experienced photogrammetrist. The features selected for measurements are having different contrast like dark tonal variations in shadows and bright tonal variations with bright background. The measurements are validated with that of ground values to evaluate the achievable horizontal and vertical accuracy. Traditional standards for map accuracy give the horizontal accuracy as 0.25mm of map scale and vertical accuracy in terms of contour interval. The study shows the images acquired with high radiometry and color information helps to measure the features in low contrast conditions with reasonable good accuracy. In this study the root mean square error (RMSE) achieved in different contrast conditions and for different geometrical features are 7.7cm in horizontal and 12.5cm in vertical. The results shows, by using 10cm GSD color data, geospatial information at 1:500 scale can be prepared with 0.5 m contour interval.

5 illus, 6 tables, 12 ref

013789   Soora N R;Deshpande P S (NO, Computer Science and Engineering, Visvesvaraya National Institute of T, Nagpur) : Robust feature extraction technique for license plate characters recognition. IETE J Res 2015, 61(1), 72-9.

This paper presents two novel geometrical feature extraction techniques for license plate (LP) characters recognition, written in English alphabets and numerals. A robust character recognition technique has to recognize different format, broken, and distorted characters by extracting invariant and discriminative character features. In this paper, we have extracted two types of geometrical features and a statistical crossing count feature with the help of horizontal, vertical, right diagonal, and left diagonal scan lines and centroid of the character to be recognized. For character recognition, we have used edit distance metric. The proposed technique can be enhanced to recognize any language scripts and is tested for Indian scripts. The proposed LP characters recognition technique is evaluated using 741 images of media-lab benchmark database, 49 images of Israeli vehicle LPs, and 110 images of proprietary Indian vehicle LPs having different environmental conditions and plate variations. The proposed technique achieved success rate of 98.8% for LP characters recognition which outperforms many LP character recognition techniques in the literature.

3 illus, 4 tables, 15 ref

013788   Sivasuthan S;Karthik V U;Rahunanthan A; Jayakumar P;Thyagarajan R S;Udpa L;Hoole S R H (Electrical and Computer Engineering Dep, Michigan State Univ, East Lansing, MI 48823, USA) : Script-based, parameterized finite element mesh for design and NDE on a GPU. IETE Tech Rev 2015, 32(2), 94-103.

Finite element mesh generators exist in the public domain, a few even based on a parametric device description. The typical mesh generator requires some man-machine interaction to define the points and boundary conditions, and does not work for non-stop optimization iterations for which we need a mesh dynamically evolving through the iterations with optimization variables as changing parameters. Such mesh generators as do exist are rare, commercial, and not easily available to researchers except at great cost and never with the code to modify them to suit individual needs. We take a regular open source mesh generator and write a script-based interface as open source to run non-stop for optimization. We then use it to create a non-destructive evaluation system for army ground vehicles' defect characterization and use it equally for machine design. A simple scheme of averaging neighbour heights gives us a smooth geometry without having to use Bezier curves. The mesh runs on the central processing unit but finite element optimization is on the graphics processing unit for speed and practicable testing times.

17 illus, 1 table, 43 ref

013787   Singh S;Saxena N;Roy A;Kim H S (Electrical and Computer Engineering Dep, Sungkyunkwan Univ, Suwon, South Korea) : Energy efficiency in wireless networks - a composite review. IETE Tech Rev 2015, 32(2), 84-93.

Energy efficiency is one of the most distinguished area on which several research groups and organizations across the globe are progressively working. This paper focuses on various technologies for truncating energy consumption in wireless communication. This incorporates new network architecture, network resource management, and supreme physical layer methods. Network architecture embraces multi-hop mobile networks, distributed antennas, diverse networks, etc. Furthermore, network resource management schemes comprise cross-layer optimization, multiple radio access technologies, and the dynamic power saving. The supreme physical layer methods encompass cognitive radio, multiple-input multiple-output (MIMO), concerted communications, network coding, orthogonal frequency division multiplexing (OFDM), etc. We render an exhaustive survey of such techniques proposed by several organizations across the globe. We also discussed energy efficiency prospect in future wireless communication systems like 5G, mobile cloud computing, Internet of things (IoT), and big data. Finally, we confer the major challenges and open issues in these technologies.

4 illus, 14 tables, 72 ref

013786   Sezer G I;Sezer A;Yazici S (Civil Engineering Dep, Ege Univ, 35100 Izmir, Turkey, Email: gozde.sezer@ege.edu.tr) : Evaluation of high temperature effects on concrete-reinforcement bar bond using automated digital image processing. Indian J Engng Mater Sci 2015, 22(5), 581-6.

Behavior of reinforced concrete is strongly affected by bonding between concrete and reinforcing bar. It is well known that adherence among concrete and reinforcing bar is remarkably influenced by several properties of reinforced concrete including compressive strength, tensile strength and cover depth. On the other hand, adherence of reinforcing bar is influenced from cross-sectional dimension, embedment length, corrosion and curing conditions. Another significant parameter which adversely affects bonding between concrete and reinforcing bar is high temperature. Thereby, in this investigation, an experimental study is performed to assess the effect of high temperatures on several properties of reinforced concrete. Consequently, an attempt is made to establish correlations among the determined parameters designating the bonding between concrete and reinforcement bar. Additionally, image processing techniques are utilized to quantify the morphological properties of cracks occurred. It is found that, when temperature rises beyond 500°C, behavior of reinforced concrete is dominated by bonding between concrete and reinforcing bar, rather than individual mechanical properties of concrete and reinforcing bar.

6 illus, 7 tables, 22 ref

013785   Senthil Saravanan M S;Kumaresh Babu S P (Mechanical Engineering Dep, UKF College of Engineering and Technology, Kollam-691 302, Email: bhatranitt@gmail.com) : Compressive deformation study on bimodal AA 4032 alloy produced by ball milling. Indian J Engng Mater Sci 2015, 22(4), 376-80.

Microstructure, mechanical properties and deformation behavior of bimodal structured nanocrystalline AA 4032 alloy are investigated in the present work. The bimodal structure alloy powders are fabricated using blending of coarse grained powders with nanocrystalline powders. The nanocrystalline powders are prepared by mechanical alloying using high energy ball mill for 30 h. A different mass fractions of coarse grained powders (micron size powders or micro powders) are taken for blending and the powders are consolidated by hot pressing to produce bulk bimodal alloys. The addition of micron sized powders is improved the ductility of the bimodal alloy along small reduction strength when compared with nanocrystalline alloy. The deformation of the bimodal alloy is due to highly localized plastic deformation under uniaxial compression. The failure of the alloy is due to shear localization and cavitations.

5 illus, 1 table, 16 ref

013784   Sandhya M;Rajarajeswari K;Seetaramaiah P (NO, Naval Science and Technology Laboratory, Visakhapatnam-530 027, Email: sanmsms@yahoo.co.in) : Detection inception of hydrodynamic cavitation noise of ships using quadratic phase coupling index as an indicator. Def Sci J 2015, 65(1), 53-62.

There is ever increasing interest in underwater noise control onboard ships as part of concerted efforts to reduce ship's radiated noise. Reduction of radiated noise is considered important as it will affect the performance of hydro-acoustic systems such as sonars, echo sounders, towed systems, etc. Out of three major sources of noise onboard ships, viz., machinery, propeller, and hydrodynamic noise, propeller noise is considered a major source beyond certain speed at which propellers cavitate produces cavitation noise. The inception speed of propeller cavitation is generally accompanied by sudden increase in radiated noise level of 8-15 dB when measured using a hydrophone placed on the seabed. This paper attempts to establish the concept of quadratic phase coupling index as an indicator to detect inception of cavitation of ship propellers. This concept was tested on actual ship radiated noise data measured at sea for evaluating its effectiveness.

12 illus, 15 ref

013783   Sakiewicz P;Nowosielski R;Babilas R (Institute of Engineering Materials and Biomaterials, Silesian Univ of Technology, Konarskiego 18a, 44-100 Gliwice, Poland, Email: piotr.sakiewicz@polsl.pl) : Production aspects of inhomogeneous hot deformation in as-cast CuNi25 alloy. Indian J Engng Mater Sci 2015, 22(4), 389-98.

Attempts are being made to achieve the best economic effects and material properties by optimizing the hot working process. Production requires an accurate, specified conditions and knowledge about the influence of almost all parameters on the manufacturing process. The misapplication of materials or technological parameters lead to increase in costs and often to destruction of materials during their production or operating. The fundamental problems associated with the hot working processes of many metals and commercial alloys focus on two associated phenomena: intermediate temperature loss of ductility and hot brittleness. This paper is the result of examination of these two phenomena on industrial CuNi25 alloys, with different chemical compositions and structures. Deformation rate has also been taken into consideration. All tests have been conducted in air, within 0.3-0.7 TH, selected ones in argon atmosphere. Numerous techniques are used to characterize material properties and to identify the inhomogeneities occurring, for example high temperature tensile tests, infrared thermography, SEM, EDS, WDS and TEM.

17 illus, 1 table, 31 ref

013782   Sahu R R;Gupta P K (NO, Tata Motors, Pune, Email: RamRanjan.Sahu@tatatechnologies.com) : Blast diffusion by different shapes of domes. Def Sci J 2015, 65(1), 77-82.

Domes have been used since ancient times in constructions. These are effective structures in supporting loads for large span. Dome has an added advantage of having good looking in structural applications. Many shapes of domes are being used nowadays for residential, commercial, and industrial purposes. Specific purpose domes are also used for nuclear containment. Main threats to structures are from the bomb blast. Hence, domes too are to be designed to withstand effectively the pressure energy generated by the blast. A comparative theoretical study is proposed on the different shapes of domes having same weight and thickness. Various responses are estimated through numerical method after simulating blast and comparing their intensities.

7 illus, 1 table, 12 ref

013781   Raunija T S K (Carbon and Ceramics Laboratory, Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram-695 022, Email: thakurskr@gmail.com) : Novel machine and method for milling continuous fibers. Indian J Engng Mater Sci 2015, 22(5), 541-9.

Novel machine for milling continuous fibers into discrete lengths is presented. Methodology for milling variety of fibers using present machine is devised. The machine is designed and developed based on the concept of cattle grass cutter. More specifically, it employs the principle of shaving razor, i.e., shearing. The machine chiefly comprises a stationary blade, a moving blade and a feeding roller. The cutting edge design and the usage of novel material for blades enable the minimum contact between stationary and moving blades, which results in highly accurate milling of continuous fibers to very fine lengths of the order of few micrometers. The discrete length milled fibers are characterized through scanning electron microscope (SEM) for the fineness and accuracy. The SEM micrographs show that the machine mills the fibers accurately and efficiently. The machine provides the flexibility of milling variety of fibers with un-interrupted feeding of multiple tows and produces milled fibers of uniform length with square cut ends by achieving close tolerance. The incorporation of the liquid bath, provision of multiple tows feeding and the novel carbide tip at the base of both the stationary blade and moving blade make it an efficient, user friendly and safe machine in milling multiple tows un-interruptedly to uniform length. Lab scale cost analysis of milling strategic fibers like carbon fibers is found very minimal, which shows the good scope of scaling the machine in a cost effective manner for the production of short fibers from continuous fibers.

10 illus, 1 table, 22 ref

013780   Paunoiu V;Saadatou M A;Nedelcu D;Octavian M (Manufacturing Engineering Dep, "Dunarea de Jos" Univ of Galati, 800 201, Romania, Email: viorel.paunoiu@ugal.ro) : Experimental and numerical investigations of sheet metal circular bending. Indian J Engng Mater Sci 2015, 22(5), 487-96.

Even the sheet metal bending is one of the most common metal working operations, the springback phenomenon that occurs after bending is necessary to be evaluated for obtaining a quality product. The aim of this paper is to study the influence of the bending angle, the punch radius and the sheet metal thickness toward the springback using a new experimental device for springback evaluation. This new device for springback evaluation is based on the circular bending of sheet metal. Using FEM, a numerical study is made in order to certify the experimental values results of the springback obtained by applying the circular bending method. The results validate the new bending device which could be used as a tool for dimensional control in bending and for prediction the suitable process parameters in springback reduction.

25 illus, 23 ref

013779   Panja B;Sahoo P (Mechanical Engineering Dep, Jadavpur Univ, Kolkata-700 032, Email: psjume@gmail.com) : Triobological behavior of electroless Ni-P coatings in alkaline environment and optimization of coating parameters using Taguchi based grey relational analysis. Indian J Engng Mater Sci 2015, 22(5), 503-12.

Electroless nickel coating is an autocatalytic coating whose behavior is very much dependent on the composition of electroless bath. The present paper studies the synthesis of electroless Ni-P (nickel-phosphorous) coatings on mild steel substrate and optimization of the coating process parameters for minimum friction and wear in alkaline (NaOH) solution using Taguchi based grey relation analysis. The study is carried out using different combinations of four coating process parameters, namely, concentration of nickel source (A), concentration of reducing agent (B), deposition temperature (C) and annealing temperature (D) with three level each (1, 2 and 3). The wear and friction tests are conducted with a pin-on-disk tribometer. Taguchi based grey relational analysis is employed for the optimization of this multiple response problem using an L₂₇ orthogonal array. The optimal combination of parameters is found as A3B3C1D2. ANOVA is performed to find out the significance of the coating parameters and their interactions. Annealing temperature and deposition temperature are most influence in controlling friction and wear behavior. The surface morphology and composition of coatings are studied with the help of scanning electron microscopy (SEM), energy dispersed X-ray (EDX) analysis and X-ray diffraction (XRD) analysis. It is found that Ni-P coating is amorphous in as-deposited condition but gradually turns crystalline with heat treatment. The worn surface morphology reveals abrasive wear mechanism.

6 illus, 8 tables, 26 ref

013778   Pandey Y;Tare S V;Jain A;Shishodia A (IM.E. Transportation Engineering, Shri G.S. Institute of Technology and Science, Indore, Madhya Pradesh) : New technology for road construction and maintenance. Bhartiya Vaigyanik Evam Audyogik Anusandhan Patrika 2015, 23(2), 105-7.

India is a developing country which is leading aggressively towards industrial and global development. India's economic growth rate is 7%. Maintaining this growth rate, construction of roads with premium technology and low rates is necessary. Implementation of road related projects should be done accordingly to ensure the suitability of top course of pavement and the harm of environment. To increase the quality of construction researches is being going on to facilitate the energy consumption and quality. In this research work the details for the new technology for road construction in Indian scenario is presented.

2 illus, 2 tables, 2 ref

013777   Pandey H;Dhakar K;Dvivedi A;Kumar P (Mechanical Engineering Dep, Graphic Era Hill Univ, Bhimtal. UK-263 136, Email: hpandey85@gmail.com) : Parametric investigation and optimization of near-dry electrical discharge machining. J scient ind Res 2015, 74(9), 508-11.

This study investigates near-dry Electric Discharge Machining (EDM) in order to achieve higher Material Removal Rate (MRR), lower Tool Wear Rate (TWR) and Better surface finish than conventional EDM on High Speed Steel (HSS) workpiece. Taguchi L27 orthogonal array was used for conducting experimentation. The experiments have been conducted by mixing of limited quantities of water with high pressure air (air-mist). This paper presents a relatively simple device to be used for applying the near-dry EDM. The near-dry EDM does not produce toxic fumes so called Environment friendly machining process for the applied operating conditions, the near-dry electrical discharge machining presents some advantages regarding the machined surface quality and the electrode tool wear, in comparison with the machining that uses liquid dielectric. The effect of different process parameters like applied current, duty factor, gap control, sensitivity, tool lift was analyzed on MRR, surface finish and tool wear rate.

3 illus, 3 tables, 9 ref

013776   Onan M;Baynal K;Unal H I (Metallurgical and Materials Engineering Dep, Umuttepe Campus, Kocaeli, Turkey, Email: mertonan@yahoo.com) : Determining the influence of process parameters on the induction hardening of AISI 1040 steel by an experimental design method. Indian J Engng Mater Sci 2015, 22(5), 513-20.

Induction hardening is often used in the automotive sector to give steel superior mechanical properties. Compared to steel, induction-hardened AISI 1040 steel has higher hardness and better toughness. In the hardening process, various operating variables (e.g., power supply, scan rate, distance between work-piece and coil) are considered and optimized using the Taguchi approach. An L27 orthogonal array is chosen for the experimental design based on the operating variables and their levels. These optimized operating variables improved surface hardness and core toughness under industrial conditions. The formation of martensite is expected for suitable operating parameters. Due to the transformed/developed structure of the AISI 1040 steel, the response variables (i.e., surface hardness, case depth) are measured following the induction hardening process. Signal-to-noise (S/N) ratios and analysis of variance (ANOVA) were employed to determine the optimal process conditions and significant operating variables, respectively. As a result of the analyses, the optimization of the operating variables for induction-hardened AISI 1040 steel is investigated. The results from using the optimal operating variables changed from 55 HRc to 18 HRc on the surface of the steel compared to the core. As a consequence of the optimization, light and scanning electron microscopy are performed to determine the effects of the hardness from the outer surface to the center. Transformations associated with structural changes are investigated, and the results are discussed.

6 illus, 24 ref

013775   Oluwasola E A;Hainin M R;Aziz Md M A (Geotechnics and Transportation Dep, Faculty of Civil Engineering, Univ Teknologi Malaysia, 81310 Skudai, Johor, Malaysia, Email: mrosli@utm.my) : Evaluation of rutting potential and skid resistance of hot mix asphalt incorporating electric arc furnace steel slag and copper mine tailing. Indian J Engng Mater Sci 2015, 22(5), 550-8.

In order to promote the use of waste materials in road construction, this paper presents the laboratory results of a study investigating the rutting potential and skid resistance of hot mix asphalt incorporating electric arc furnace (EAF) steel slag and copper mine tailings. To achieve this objective, four different mixes incorporating copper mine tailings and EAF steel slag in different proportions are investigated. The aggregates are blended with the optimum bitumen content of PG_76-22 and 80/100 bitumen binders. The rutting potential of all the mixes is evaluated by the asphalt pavement analyzer (APA), while the skid resistance is measured by the British Pendulum Skid Resistance Tester. The results show that the mix with 20% copper mine tailing and 80% EAF steel slag has the highest skid number, mean texture depth and the least rut depth. It is also observed that the rate of rutting decreased with loading cycles and 70 to 80% of the rut depth is attained at 4000 cycles using the APA.

12 illus, 6 tables, 38 ref

013774   Nedelcu D;Plavanescu S;Paunoiu V (NO, "Gheorghe Asachi" Technical Univ of Iasi, Blvd. Mangeron, Np. 59A, 700 050 Iasi, Romania, Email: dnedelcu@tcm.tuiasi.ro) : Microstructure and mechanical properties of injection molded arboform parts. Indian J Engng Mater Sci 2015, 22(5), 534-40.

Industry of petroleum-based plastic materials is one of the major responsible for numerous unpleasant environmental impacts. The biggest negative effect is given by absence of plastics biodegradability and recyclability, leading to accumulation of huge amount of waste. The experimental study is planed over the Taguchi methodology with two levels and six input parameters. Experimental data show that the tensile strength reached 58.61±2.73 MPa at 23°C and 5.45±0.34 MPa at 60°C. The friction coefficient exhibits a slight decrease during the first 100 s, in case of disk rotation, and then the value is stable throughout the whole testing. Considering disk oscillation, there is an increase in the friction coefficient, which reaches a peak after about 50 s and then decreases within the range of 50-150 s. The material seems to have a completely amorphous structure, without being able to accurately determine the type of existing constituents. It includes C, O and other accompanying elements in very small proportions. The SEM analysis shows a randomly oriented structure. In the chemical elements spectrum, carbon and oxygen predominate, in both percentage and atomic mass. According to the analyses performed Arboform L, V3 Nature can replace plastic materials in many industries, such as automotive, toys, construction, electrical, computers, mobile phone cases, etc.

7 illus, 5 tables, 14 ref

013773   Muruganandam D;Rafuraman D;Kumaraswamidhas L A (Production Engineering Dep, Sri Sairam Engineering College, Chennai-600 044, Email: murudurai@gmail.com) : Effect of post-welding heat treatment on mechanical properties of butt FSW joints in high strength aluminium alloys. Indian J Engng Mater Sci 2015, 22(4), 381-8.

The friction stir welding (FSW) is a solid state welding process for joining two dissimilar metals using non consumable tools. This paper deals with experimental investigation on the effect of post welded heat treatment on mechanical properties of butt joint using FSW in aluminium alloys 2024 T6 (soft metal) and 7075 T6 (hard metal). In the post weld treated joint, the increase in hardness homogeneity is analysed in the nugget zone along the profile using micro hardness profile measurement. When the hardness homogeneity is attained, fracture occurs in nugget zone. The butt FSW joint after post welding heat treatment at low temperatures (200°C and 300°C) have tensile properties comparable with the FSW joints and fracture occurs in base metal 7075 T6. In 50% of FSW joints, deformation occurs after heat treatment at low temperature and also failure occurs inside stir zone. This work reveals that the progressive changes in the grain size and morphology in higher temperature post weld heat treated joint owing to abnormal grain growth (AGG) in the stir zone.

13 illus, 4 tables, 23 ref

013772   Mishra O;Raunija T S K;Mathew M;Sharma S C (Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvanathapuram) : Carbon fabric manufactured through catalytic route. Bhartiya Vaigyanik Evam Audyogik Anusandhan Patrika 2015, 23(2), 114-18.

Carbon fabric is the key constituent of ablative liner used in rocket nozzle. It can be manufacture by oil and catalytic route. In oil process, the carbon fabric is manufactured by dipping rayon fabric in furnace oil. In this, the oil acts as the mediator of heating medium. In catalytic route, catalyst is used in place of oil. Oil process is simple technique of manufacturing carbon fabric. But several issues like low yield, wrinkle formation, shrinkage etc., are associated with it. In addition to this, due to slow heating, it takes more time for producing carbon fabric. Further, in oil process, the oil vapors pollute the working area and create the possibility of fire whereas catalytic process is advantageous over these issues. The yield can be enhanced through this process. Further, this route sorts out the issues of wrinkle and shrinkage formation, which are associated in oil process. Further, the carbon fabric can be manufactured in short duration through this route. In this research papers, the catalytic route of carbon fabric manufacture is described in detail.

7 ref

013771   Meenakshipriya B;Saravanan K;Krishnamurthy K; Kanthabhabha P (Mechatronics Engineering Dep, School of Building and Mechanical Sciences, Kongu Engineering College, Perundurai, Tamilnadu) : pH control of industrial effluent using CDM based PI controllers. Indian J chem Technol 2015, 22(3-4), 141-7.

Coefficient Diagram Method (CDM) based PI controllers (CDM-PI and CDM-PI-P) has been implemented in a pH neutralization system to control the pH value of industrial effluent. The proposed techniques are tested with collected effluent in lab-scale pH neutralization system. Experimental runs are carried out at the operating point of pH 8 as per the requirement of PCETP and the regulatory performance in terms of Error Indices (ISE and IAE) and Total variations (TV) are reported. The results of the proposed control techniques are compared with conventional control techniques such as Ziegler Nichols PI controller (ZN-PI) and Internal Model Control based PI controller (IMC-PI). The experimental results show that the proposed CDM based PI controllers had impeccable performance with industrial effluent in pH neutralization system.

2 illus, 5 tables, 23 ref

013770   Maheswari C;Krishnamurthy K;Parameshwaran R; Meenakshipriya B (Mechatronics Engineering Dep, School of Building and Mechanical Sciences, Kongu Engineering College, Perundurai, Email: maheswarikec@gmail.com) : Experimental investigations on pilot plant SO₂ emission control system. J scient ind Res 2015, 74(9), 522-5.

This paper provides experimental investigations for optimizing the parameters to work with pilot plant experimental system for achieving maximum SO₂ removal efficiency. It is analysed with different absorbers such as, water, NaOH, H₂O₂ and H₂SO₄ with different combinations and concentrations. The results reveal that, the removal efficiency acquired is 98.4% by adding 0.1M hydrogen peroxide (H₂O₂) externally on 0.01M sulphuric acid (H₂SO₄) solution. From the analysis, polypropylene pall rings with diameter of 15 mm, liquid flow rate of 150 lph, gas flow rate of 40 m^{3/hr and packed height of 1M are chosen based on their performance in increasing the SO₂ absorption rate.}

2 illus, 1 table, 12 ref

013769   Li L;Cheng X;Sima Z;Niu Z (School of Mechanical Engineering, Shandong Univ of Technology, Zibo, China, Email: sdutili@163.com) : Machinability of NdFeB magnet via wire and sinking EDM methods. Indian J Engng Mater Sci 2015, 22(4), 407-13.

NdFeB magnet is widely used in many industries due to their powerful magnetic properties. However, it belongs to hard-to-machine material because of its mechanical characteristics. Electrical discharge machining (EDM) is an alternative competitive process to machine any material with high hardness and low flexural strength. Machinability and surface characteristics of EDMed NdFeB magnet surfaces are poorly understood. Wire EDM and sinking EDM with Cu-SiC electrode are explored the machining characteristics. Surface roughness, surface topography, surface alloying, and material removal efficiency have been characterized. Results show that EDM is an effective method to machine NdFeB magnet. The machined quality could be modified with the multiple cuts at reduced discharge energy in wire EDM. Six-sigma distribution of Ra in rough cut mode is different from that of trim cut modes. Electrode alloying to the work-piece can be negligible by using low discharge energy. The low toughness of NdFeB magnet would be the major contributing factor to the appearance of microcracks. The fabricated Cu-SiC electrode has better performance in terms of MRR and surface roughness.

7 illus, 3 tables, 17 ref

013768   Krishnamachary S;Mohan S K;Kulkarni S G; Jayaraman D;Rao M R;Dev Singh L;Prasad S K (NO, Defence Research and Development Laboratory, Hyderabad-500 058, Email: kcsenapathi@gmail.com) : Propellant grade hydrazine in mono/bi-propellant thrusters: Prepatation and performance evaluation. Def Sci J 2015, 65(1), 31-8.

Propellant grade hydrazine was prepared with 64 per cent yield and 95.5 per cent purity. Purity of the propellant grade hydrazine was determined using wet chemical, gas chromatographic (GC) and eudiometric methods. It was observed that the compositions containing blends of hydrazine-methyl alcohol-ammonium nitrate and hydrazine-methyl alcohol-ammonium perchlorate were not found to be frozen even after cooling to -65 °C for 30 minutes. Mono and bi-propellant thrusters were designed and developed to demonstrate the performance of prepared propellant grade hydrazine as a promising rocket fuel. Five static tests with 22 N thruster and one static test with 1 N thruster were performed successfully in mono-propellant mode. The hurdles of chamber pressure oscillations were overcome by compact packing of the catalyst. The desired decomposition and chamber pressure were achieved. One static test was performed successfully with 60 N bi-propellant thruster. The desired chamber pressure and thrust were achieved. The combustion was smooth and C* achieved was higher than that of UH-25, N₂O₄ combination. The performance of prepared propellant grade hydrazine shows it as a promising rocket fuels.

8 illus, 10 tables, 32 ref

013767   Katunin A (NO, Institute of Fundamentals of Machinery Design, Faculty of Mechanical Engineering, Silesian Univ of Technology, Konarskiego 18A, 44-100 Gliwice, Poland, Email: andrzej.katunin@polsl.pl) : Impact damage assessment in composite structures based on multiwavelet analysis of modal shapes. Indian J Engng Mater Sci 2015, 22(4), 451-9.

Low-velocity impact damage of composite structures is an important problem in various industrial branches, especially in the aircraft and aerospace industriess. Due to the nature of impact damage initiation and propagation and its poor ability of detection based on surface inspection, the appropriate non-destructive damage assessment methods need to be developed. One of the extensively developed groups of methods is the technique based on modal testing and further processing of modal shapes using wavelet analysis. Since the wavelet analysis is very sensitive to even small abrupt changes in an analyzed signal, this approach is chosen for extraction of diagnostic information. In the following study, the novel approach based on multiwavelet analysis of modal shapes, achieved from measurements using a laser vibrometer, is applied to the composite plates damaged following various scenarios. Based on the comparative study, the Donovan-Geronimo-Hardin-Massopust multiwavelet is selected as the best for evaluation of damage sites. The proposed algorithm makes possible detection and localization of cracks and accompanying delaminations, resulted from the impact loading, with high precision, which is verified by comparison with ultrasonic C-scans of the analyzed plates. The obtained results allow for application of the presented method in the industrial non-destructive testing as well.

10 illus, 16 ref

013766   Jiang C;Yang Y;Hu Q (Construction Engineering Dep, Zhejiang College of Construction, Hangzhou-311 231, China, Email: yangyang@zjut.edu.cn) : Autogenous deformation of high performance concrete exposed to semi-adiabatic and isothermal conditions. Indian J Engng Mater Sci 2015, 22(5), 587-96.

This paper presents an experimental investigation on early-age autogenous deformation (AD) of high performance concrete (HPC) exposed to isothermal and semi-adiabatic conditions. A new testing apparatus equipped with eddy-current displacement sensors is used for monitoring deformation from final setting to 28 days. Deformation measurements are conducted on a series of HPC mixtures with different water-binder ratios (w/b) and cementitious materials. In order to accurately separate AD from the measured deformation, time-dependent coefficients of thermal expansion (CTEs) of HPC, other than a constant value, are employed. The results indicated that AD under semi-adiabatic condition is fundamentally different from the one under isothermal condition. The former undergoes three stages successively (i.e., initial rapid shrinkage, abrupt expansion and stable shrinkage stages), while the latter shows continuous shrinkage only. The considerable expansion under semi-adiabatic condition can be explained from delayed ettringite formation and thermal shock effect of early-age AD.

24 illus, 3 tables, 43 ref

013765   Hashim I A;Sadah J W A;Saeed T R;Ali J K (Electrical Engineering Dep, Technology Univ, Baghdad, Iraq) : Recognition of QAM signals with low SNR using a combined threshold algorithm. IETE J Res 2015, 61(1), 65-71.

This paper presents the recognition of digital signal modulation by combining four cumulants as signal features and a threshold discriminator assigned for each cumulant. In this paper, the problem of recognition has been solved by finding a suitable relationship among these features and their classifier. The decision of each classifier has been compared with other classifier outputs. Then, the classifier with the highest priority has been considered as the final efficient decision. The priority of each classifier is based on how its cumulant is robust against a wide range of signal to noise ratio (SNR), for different types of digital modulations under investigation. Many types of quadrature amplitude modulation (16, 32, 64, 128, and 256) have been recognized with low SNR down to -5 dB. Using such combination, the average recognition percentage was increased with low SNR. The recognition gained 81.166%-100% for 4096 samples while the percentages are from 86.9% to 98.6% with a variable number of samples (256, 512, 1024, and 2048).

3 illus, 8 tables, 10 ref

013764   Gupta P;Rajput S P S (Aircraft Upgrade Research and Design Centre, Hindustan Aeronautics Ltd, Nasik-422 207, Email: pareshgupta1977@gmail.com) : Optimised cockpit heat load analysis using skin temperature predicted by CFD and validation by thermal mapping to improve the performance of fighter aircraft. Def Sci J 2015, 65(1), 12-24.

Designing of optimum environmental control system (ECS) plays a major role for increasing performance of fighter aircraft depending upon requirement of engine bleed air for running of ECS. Accurate estimation of cockpit skin temperature for obtaining optimised cockpit heat load helps in estimation of engine bleed air for ECS. Present research evolved a methodology for comparing the theoretically calculated skin temperature with computational fluid dynamics (CFD) analysis to obtain optimum skin temperature. Results are validated by flight tests under critical flight conditions using thermal crayons. Based on which the optimized heat load and bleed air requirements has been computed. Uncertainty analysis of skin temperature measurement for thermal crayons have been undertaken. The results indicate that the theoretical skin temperature is -26.70 per cent as that of CFD estimated skin temperature. Optimized average cockpit heat load at critical flight profiles is 0.74 times the theoretical cockpit heat load, leading to reduction of bleed air requirement by 26 per cent as compared to theoretical. Due to this literature survey has pridicted the increase in performance parameters like increase in bleed air pressure by 78 per cent, increase in thrust by 60 per cent, and decrease in specific fuel consumption (SFC) by 40 per cent to improve the endurance of aircraft. The research has generated governing equations for variation of cockpit heat loads w.r.t aircraft skin temperatures.

6 illus, 4 tables, 13 ref

013763   Gorka J (Welding Dep, Faculty of Mechanical Engineering, Silesian Univ of Technology, Konarskiego 18A Street, 44-100 Gliwice, Poland, Email: jacek.gorka@polsl.pl) : Structural changes in S700MC steel thermomechanically treated under the influence of simulated welding thermal cycles. Indian J Engng Mater Sci 2015, 22(5), 497-50.

This paper describes the structural changes of S700MC steel under the influence of simulated welding thermal cycles that have been completed to develop a continuous cooling transformation (CCT) chart. This includes controlled analysis of the chemical composition of S700MC steel with nitrogen content, simulation studies, performance chart of phase transformation of austenite for CCT welding conditions and metallographic microscopy and hardness measurements of samples of S700MC steel as a function of the cooling time t_8/5. Methodology of structural changes is based on the simultaneous use of three measurement methods: dilatometric, magnetometer and thermal analysis. In this study, three different techniques are carried out: dilation of the sample material, the magnetic flux changes and temperature. Three types of thermal cycles implemented are fast, natural and free. The obtained results show that the processes associated with the allotropic transformation of γ-α, occurring in S700MC steel during cooling cannot be the basis for the assessment of its welding properties. Carbon in solution has a small extent effect on strengthening the steel and it is not the dominant factor in the transformation phase. The S700MC steel has a low hardenability due to the low concentration of unbound carbon (about 0.03%), and other alloying elements. With a short cooling time, martensite is formed, but it is a low carbon martensite, which does not reduce the yield strength of the steel.

6 illus, 2 tables, 14 ref

013762   Feng M;Yu K;Hao R (Donlinks School of Economics and Management, Univ of Science and Technology Beijing, No. 30, Xueyuan Road, Haidian District, Beijing, 100 083, P R China, Email: haorongnfc@hotmail.com) : Analysis of the regional competitiveness of the telecommunications industry. J scient ind Res 2015, 74(10), 541-4.

This study presents the development status of the domestic telecommunications industry based on panel data from the 31 provinces in China, demonstrates the influence of the principal factors on the regional competitiveness of the industry by using the factor analysis method and calculates and ranks the comprehensive competitiveness of the industry in each province. Finally, the study determines the insufficiency of the regional development of the telecommunications industry and discusses some policy and regulation recommendations for healthy development of the industry.

4 tables, 9 ref

013761   Fan E;Xie W;Liu Z;Peng fei L (NO, Xidian Univ, Xi'an-710 071, China) : Range-only target localisation using geometrically constrained optimisation. Def Sci J 2015, 65(1), 70-6.

Problem of optimal range-only localisation of a single target is of considerable interest in two-dimensional search radar networking. For coping with this problem, a range-only target localisation method using synchronous measurements from radars is presented in the real ellipsoidal earth model. In the relevant radar localisation scenario, geometric relationships between the target and three radars were formed. A set of localisation equations was derived on range error in such a scenario. Using these equations, the localisation task has been formulated as a nonlinear weighted least squares problem that can be performed using the Levenberg- Marquardt (LM) algorithm to provide the optimal estimate of the target's position. To avoid the double value solutions and to accelerate the convergence speed for the LM algorithm, the initial value was approximately given according to observations from two radars. In addition, the relative validity has been defined to evaluate the performance of the proposed method. The performance of the proposed approach is evaluated using two simulation experiments and a real-test experiment, and it has been found to possess higher localisation accuracy than the other conventional method.

5 illus, 2 tables, 17 ref

013760   Erden R T;Gucuyen E;Kantar E;Bagct M (Engineering Faculty, Celal Baya Univ, 45140, Manisa, Turkey, Email: tugrul.erdem@cbu.edu.tr) : Impact effect on different sized reinforced concrete specimens. Indian J Engng Mater Sci 2015, 22(5), 597-603.

Behavior of structural members under various loads has been a major interest. However, impact loading type is the least known one among them. Researchers have investigated the behavior of structural members under impact effect recently. For this reason, a well-instrumented experimental program is used to understand the impact behavior of six different sized reinforced concrete specimens. All specimens both have longitudinal and transverse reinforcements. A testing apparatus is developed to perform tests under impact loading. Accelerometers, optic photocells, dynamic force sensor, a data logger and connecting cables are used as well as testing apparatus. Free falling height and mass of steel hammer are taken constant in the study. Test program has been successful to provide several data to understand the impact behavior. Drop numbers and rebound movements of the hammer are determined according to damage situations. Acceleration values are measured from four different points of the specimens. The change of velocity and displacement values is determined for all specimens. Impact force is also measured for each free falling movement and absorbed energy values are calculated according to the area under the curve of impact force-displacement graphs. Test results give substantial information about impact resistances of reinforced concrete members.

12 illus, 8 tables, 17 ref

013759   Ege Y;Kalender O;Citak H;Nazlibilek S;Coramik M (Physics Dep, Balikesir Univ, Necatibey Faculty of Education, 10100 Balikesir, Turkey, Email: yege@balikesir.edu.tr) : New real time temperature monitoring and evaluation system. Indian J pure appl Phys 2015, 53(10), 652-63.

The storage of many drugs, serum and vaccines at specified temperature limit is very important. Therefore, it is necessary to read and record the ambient temperature and control the refrigerating device according to the limiting values specified by the user. Taking into account these requirements, a new PIC microprocessor-based temperature monitoring system that triggers the DS18B20 temperature sensor and controls the running of the refrigerator system is designed and developed. At the controlling operation, performed by this system, temperature limits are specified by the user. In case these limit values are exceeded, a warning message is sent to the user through GSM module. Furthermore, the temperature values that are read between the time intervals specified by the user are sent to a GLCD screen and presented in a graphical form. The temperature readings can be transferred to the computer environment as text file through a Visual Basic based interface with using a serial port. At this system which has one year data storage capacity, it is possible that the temperature values can be transferred to the computer by wireless communication facility. Differently from the present systems, recording, evaluation, warning and device control operations are performed in the same system. In the present paper, the system operation and its performance at the fields of application are expressed in detail.

14 illus, 4 tables, 32 ref

013758   Dohare Y S;Maity T;Das P S;Paul P S (Electrical Engineering Dep, Indian School of Mines, Dhanbad) : Wireless communication and environment monitering in underground coal mines- Review. IETE Tech Rev 2015, 32(2), 140-50.

Environment monitoring in underground coal mines has been a mandatory requirement to ensure safe working conditions in mines. There is a need to develop active communication and information network to quickly detect the underground condition and accurately provide location references to evacuate workers from the dangerous zone. This paper addresses the recent technological comprehensive developments in the area of communication and environment monitoring in underground coal mines. It points out the suitability of application of recently developed wireless sensor network for this purpose as proposed by different researchers all over the world. The possibility of image, video surveillance, and use of robot are also explored here. Need of real-time implementation of proper system inside regulated and hazardous mining environment is evaluated in details.

10 illus, 2 tables, 48 ref

013757   Devimeena S;Venkatesh D (NO, Dr. Mahalingam College of Engineering and Technology, Pollachi-642 003, Email: meenudeepthi@gmail.com) : Design and implementation of a beam forming network for a phased array antenna. Def Sci J 2015, 65(1), 46-52.

This dissertation presents a beam forming network (BFN) for phased array antenna-based on coherently radiating periodic structure (CORPS). The elements of CORPS are selected in such a way to obtain broad band characteristics, good return loss and good isolation between the radiating elements. These elements were arranged in such a way that the BFN naturally produces Gaussian amplitude. This methodology reduces the complexity of the conventional phased array design making it more flexible and minimizing the loss of energy inside the structure. A phase shifter design is proposed for the CORPS. The entire BFN's sub-blocks have been designed for the frequency band of 5.925 GHz to 6.425 GHz, which find applications in communication satellite, fixed wireless systems.

8 illus, 2 tables, 16 ref

013756   Dastanpoor E;Enayati M H (Materials Engineering Dep, Isfahan Univ of Technology, Isfahan 84156-83111, Iran, Email: e.dastanpoor@ma.iut.ac.ir) : Effect of milling intensity on mechanical alloying of Cu-Zr-Al system. Indian J Engng Mater Sci 2015, 22(5), 521-6.

Mechanical alloying (MA) is known as a non-equilibrium materials processing technique. The final structure obtained by MA for a given alloy system depends on milling conditions. In this study, the mechanical alloying behaviour of Cu₅₀Zr₄₃Al₇ alloy is studied. The solid state reactions and structural changes occurred during milling in different mill machines including low-energy planetary, Spex (shaker) and high-energy planetary mills are investigated. The structure and phase composition of milled powders are characterized by X-ray diffraction. The results indicate that low-energy planetary mill with input energy of 1440 J.s/g led to a Cu-rich solid solution. With increasing of milling intensity to 4320 J.s/g in Spex (shaker) ball mill, nanostructured Cu-rich solid solution and Zr₂Al₃ intermetallic compound are formed. Final products of milling in high-energy planetary mill with input energy of 4564 J.s/g are nanocrystalline Zr₂Al₃ and Cu₁₀Zr₇ intermetallic compounds.

4 illus, 3 tables, 26 ref

013755   Comaneci R;Zaharia L;Nedelcu D (NO, Technical Univ "Gheorghe Asachi" Iasi, D. Mangeron 61A, 700 050, Iasi, Romaniaa, Email: dnedelcu@tcm.tuiasi.ro) : Combining circular-to-rectangular direct extrusion and equal channel angular pressing: analysis and simulation. Indian J Engng Mater Sci 2015, 22(5), 527-33.

Experimental and numerical study of equal channel angular pressing (ECAP) - as the most effective severe plastic deformation (SPD) process and circular-to-rectangular direct extrusion (CRDE) - as traditional deformation process - has been conducted as separate and combined processes, respectively. An analysis of the deformation mechanisms based on grain fragmentation due to the velocity discontinuities and corresponding shearing along them has been undertaken. To reveal the main aspects of the deformation processes in a comparative manner, a finite element analysis (FEA) is performed and the results are depicted in terms of strain distribution and working-load. Experimental tests have confirmed the FEA. To evaluate the improvement of the mechanical properties as effect of applying the two processing methods as separate and combined procedures, tensile tests are performed. An increase of the yield and tensile strength without a further reduction in ductility is found. The results of this study highlight the potential of combining CRDE and ECAP as an efficient processing route for production of high-performance materials.

9 illus, 25 ref

013754   Chiu S W;Sung P C;Tseng C T;Chiu Y S P (Business Administration Dep, Chayang Univ of Technology, Taiwan, Email: ypchiu@cyut.edu.tw) : Multi-product FPR model with rework and multi-shipment policy resolved by algebraic approach. J scient ind Res 2015, 74(10), 555-9.

This study resolves a multi-product finite production rate (FPR) model with rework and a multi-shipment delivery policy1 using algebraic approach. Conventional method for solving multi- product FPR model is to use differential calculus on system cost function to prove its convexity first, and then derive optimal common production cycle time that minimizes the long-run average system cost. Whereas the proposed approach obtains the optimal common cycle time in simplified algebraic way without using differential calculus. Simplification may enable managing practitioners to resolve real-life multi-item FPR systems more effectively.

1 illus, 35 ref

013753   Cai B;Ren S;Zhou S;Li P;Lv W;Tao J;Zhu X (Faculty of Materials Sciences and Engineering, Kunming Univ of Science and Technology, Kunming, Yunnan-650 093, China, Email: xk_zhu@hotmail.com) : Effects of stacking fault energy on the deformation mechanisms and mechanical properties of Cu and Cu alloys processed by rolling at different temperatures. Indian J Engng Mater Sci 2015, 22(4), 399-406.

Effects of stacking fault energy (SFE) on the deformation mechanisms and mechanical properties of Cu, Cu-2.5 at.% Al-2.5 at.% Zn, and Cu-12.1 at.% Al-4.1 at.% Zn alloys processed by different rolling temperatures have been systematically investigated. Tensile tests at room temperature indicate that, as SFE decreased, strength and ductility increased, and at constant SFE the samples deformed via rolling at liquid nitrogen temperature (77 K) exhibit higher strength and better ductility than those deformed via rolling at room temperature (293 K). With lowering SFE, the crystallite size decreases while the microstrain, dislocations and twin densities increase. With decreasing temperature, there is a transition of deformation mechanism from that dominate by dislocation activities to that dominate by deformation twinning. The results indicate that decreasing SFE is an optimum method for improving the ductility of Cu and Cu alloys without loss of strength, and that temperature plays a key role in the rolling process.

5 illus, 51 ref

013752   Bugoreanu L G;Comaneci R I;Gurau G;Lohan N M; Suru M G;Pricop B;Goanta V;Musat V;Istrate B;Mihalache E (Faculty of Materials Science and Engineering, "Gheorghe Asachi" Technical Univ of Iasi, Bd.D. Mangeron 41, 700050, Iasi, Romania, Email: lgbujor@tuiasi.ro) : Thermomechanical traing effects of multifunctional modules processed by high-speed pressure torsion. Indian J Engng Mater Sci 2015, 22(4), 367-75.

Specimens with truncated cone shell shapes (modules) are processed by high-speed high pressure torsion (HS-HPT), from circular crowns cut from shape memory alloy (SMA) ingots with nominal chemical composition Fe-28Mn-6Si-5Cr (mass%). Mechanical tests are performed comprising hardness measurements and loading-unloading compression cycles applied between dry or lubricated flat surfaces. A hardness gradient of 22 HV/mm is obtained along truncated cone generator, increasing from inner to outer areas, due to different deformation degrees, in these zones. Each loading and unloading stage was accompanied by steady and reproducible force plateaus, attributed to gradual elastic flattening of the modules, due to hardness gradient, suggesting a "superelastic-like" behaviour which is never reported in Fe-Mn-Si based SMAs. During cycling, the modules experienced a training effect consisting in the increase of relative shape recovery degree, up to 97%, with the number of cycles. Trained modules displayed multifunctional character, being able to develop constrained recovery forces when heated in compressed state, above a certain critical temperature. Constrained recovery forces are higher than those reached during isothermal compression. The modules are characterized, in different training stages, by optical and scanning electron microscopy, as well as by X-ray diffraction (XRD). As an effect of HS-HPT processing the formation of highly distorted martensite plate variants is revealed on the XRD patterns, which also emphasized the stress-induced formation of crystalline reoriented e hexagonal close-packed martensite after compression cycles.

10 illus, 1 table, 34 ref

013751   Bian C;Tian Z;Mao L;Wu J (College of Water Conservancy and Hydropower Engineering, Hobai Univ, Nanjing, Jiangsu, 210 098, China, Email: zhtianhhu@163.com) : Influence of electro-osmosis applied to concrete demoulding on its properties. Indian J Engng Mater Sci 2015, 22(5), 559-69.

Influence of voltage applied for better demoulding concrete on its properties including hydration process at early age, formed pore structure, surface permeability and compressive strength is studied through a series of methods such as conductivity, non-evaporable water content and mercury intrusion porosimetry (MIP). Test results show that : (i) increasing voltage results in a drop in degree of hydration caused by assemble of cement grains on one hand and on the other hand the increase of quantity of water transported toward cathode and anode due to the effect of electro-osmosis; (ii) as the voltage increases, the porosity, critical pore radius and volume fraction of larger capillary pores decrease at first mainly due to reduction of water-cement ratio (w/c) by displacing water then increase caused by reduction of degree of hydration and water block at the concrete/mold interface, but placing filter cloth on the mold walls could slow down the adverse changes of properties; (iii) variation of surface permeability with voltage is similar with that of porosity as well as critical pore radius and the permeability has a good correlation with the two parameters while compressive strength is good correlated with volume fraction of larger capillary pores.

23 illus, 7 tables, 20 ref

013750   Bhashya V;Sundarkumar S;Ramesh G;Bharathkumar B H;Krishnamoorthy T S;Iyer N R (NO, CSIR- Structural Engineering Research Centre, Taramani, Chennai-600 113, Email: bhashya@serc.res.in) : Long term studies on FRP strengthened concrete specimens. Indian J Engng Mater Sci 2015, 22(4), 465-72.

This paper presents the results of long term studies on fiber reinforced polymer (FRP) strengthened concrete cylinders and reinforced concrete (RC) beams. The specimens strengthened with one and two layers of carbon or glass fibers are tested for long term performance under natural seasonal environmental conditions. The results of compression test on cylinders and flexural test on RC beam exposed for duration of zero (unexposed), one and two years have been reported. From the results it is observed that the ultimate load carrying capacity of the RC specimens strengthened with CFRP are more when compared with GFRP strengthened specimens exposed to a period of one and two years. This study recommends that the strengthening with CFRP will serve better in long term performance when compared with GFRP.

14 illus, 6 tables, 13 ref

013749   Azadeh A;Ghaderi S F;Mirjalili M;Moghaddam M; Haghighi S M (School of Industrial Engineering, College of Engineering, Tehran Univ, Iran, Email: aazadeh@ut.ac.ir) : Optimization of human resource and industrial banks with ambiguous inputs using intelligent fuzzy mathematical programming approach. J scient ind Res 2015, 74(10), 545-54.

This paper presents an integrated fuzzy data envelopment analysis (FDEA) and analytical hierarchy process (AHP) approach for optimization and ranking of industrial banks with ambiguous human resources indicators. FDEA is proposed to consider the uncertainty existed within qualitative indicators since in actual cases the criteria for evaluating human resources cannot precisely be measured. Also, AHP is used for identifying weights and priorities of different human resources indicators. Results were validated and verified by conventional mathematical models. The proposed approach can also be used for optimum human resources operation in large industrial banks. This is the first study that presents an integrated FDEA-AHP approach for ranking and optimization industrial banks with ambiguous human resources indicators.

3 tables, 12 ref

013748   Athimoolam M;Moorthy T V (Manufacturing Engineering Dep, Anna Univ, Chennai-600 025, Email: aathi.m101@gmail.com ) : Tensile behavior and characterization of amine treated nanoclaay reinforced epoxy/polyurethane blends and composites for shape memory applications. Indian J Engng Mater Sci 2015, 22(4), 435-42.

Polymer nanocomposites are the better choice for most of the applications because of its less weight and tailorability to suit different applications. Several nanocomposites have been fabricated with nanoparticles reinforcement and fibre reinforcement. But most of them were made to satisfy few criteria or one or two functions. Shape memory polymers composites (SMPCs) and blends exhibit novel properties that are different from the conventional materials and thus can be utilized in various applications. These composites are needed for applications such as smart clothing, flexible displays, stretchable circuits, strain gauges, implantable devices, high-stroke microelectromechanical systems (MEMS), and actuators where both mechanical properties and shape memory properties are important. The processing and characterization of these materials with nanoparticles produces better mechanical properties. Epoxy is the resin having good mechanical properties, when blended with polyurethane and nanoparticles fillers exhibit shape memory properties. This paper gives the fabrication and characterization methods for shape memory polymer composites developed with amine treated nanoclay as reinforcement and analyses tensile behaviour and moisture absorption and surface characteristics. Fourier transform infrared spectroscopy (FTIR) is used to identify the bond and functional groups and thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) are done to identify the glass transition temperature and scanning electron microscope (SEM) analysis for studying the morphology and tensile test is done to test the stress-strain behaviour. The reinforcement has shown significant improvement in glass transition temperature and mechanical properties compared to pure shape memory polymers.

9 illus, 1 table, 15 ref

013747   Arun Kumar;Anjaneyulu L (NO, Advanced Systems Laboratory, Hyderabad-500 058, Email: arunkumar1959@rediffmail.com ) : Emerging trends in instrumentation in rocket motor testing over three decades. Def Sci J 2015, 65(1), 63-9.

Rocket motors are designed, developed, and evaluated for performance, and after repeated tests, are qualified for use in a spacecraft or missile system. Comprehensive instrumentation measurement plan is made to record physical parameters during evaluation and testing. In the last thirty years, a revolution has happened in the field of electronics that has benefited instrumentation in terms of accuracy, bandwidth, capacity, reliability and analysis. This paper describes the improvements in instrumentation that have happened in the field of rocket motor testing over a period of last three decades.

4 illus, 1 table, 7 ref

013746   Ananthi G B G;Vishuvardhan S;Samuel Knight G M (Structural Engineering Div, CEG Campus, Anna Univ, Chennai-600 025, Email: beulah28@annauniv.edu) : Experimental, theoretical and numerical study on thin walled steel single and compound channel sections in axial compression. Indian J Engng Mater Sci 2015, 22(5), 570-80.

This investigation presents a detailed description of experimental, theoretical and numerical studies of the flexural buckling strength of cold-formed steel (CFS) channel stub columns. A total of 24 single channels, double channels welded back to back and double channels welded as box sections both with and without lip stub columns are tested till failure with hinged ends and their behavior is studied. An attempt is made to study the effect of lip, and the effect of symmetricity of cross-section on the ultimate load carrying capacity. The flat width to thickness ratio of all the specimens are kept less than the limiting value as per IS 801-1975. Geometric and material non-linearity have been included in the finite element model. The design column strengths calculated using the finite element analysis (FEA) are compared with the IS: 801(1975), BS: 5950 (Part 5) and NAS manual. It is shown that the design column strengths calculated based on the codal specifications generally are conservative with experimental and numerical strengths.

10 illus, 5 tables, 14 ref