025797   AN Z, LI Z, FENG T, QIE J (Chongqing Jiaotong Univ, Chongqing- 400074, China, Email: azgcqu@163.com) : Study on an automotive refill opening cap compound process based on punching and incremental forming. Indian J Eng Mater Sci 2018, 25(3), 250-6.

An automotive refill opening cap manufactured through the traditional punching process usually performs with lower rigidity, and the punching process increases the production cost and manufacturing cycle, which goes against the fast fabricating requirement in modern industry because of the multi-die produced. In this paper, the compound process, adopting incremental sheet forming (ISF) and punching forming, was used to manufacture the part to solve the problems above by utilizing ISF in the pre-forming stage and punching forming in the subsequent stage. Four parameters, including the pre-forming height (PH), the pre-forming press amount (PPA), the pre-forming tool diameter (PTD) and the pre-forming angle (PA), were taken as test factors in the pre-forming stage, and the max thickness reduction percentage (MTRP) was taken as the test target. The effect of the factors was analyzed using the finite element method and an orthogonal test for the target. The orthogonal test result shows that the major factors were the PH and the PPA, and the secondary factors were the PA and the PTD. The PTD and the PA were obtained through a mean analysis as 8 mm and 40°, respectively. A function showing the relationship between the major factors and the target was established through the response surface method to obtain the interaction effect between the PH and the PPA for the target. The PH and the PPA were found by a response surface methodology to be 15 mm and 0.5 mm, respectively. The compound process was verified through an experiment.

8 illus, 7 tables, 13 ref

025796   SINGLA A K, SINGH J, KUMAR P, KUMAR A, SHARMA V S (Mechanical Engineering Dep, Sant Longowal Institute of Engineering and Technology, Longowal - 148 106, Email: singlakiran1996@gmail.com) : Effect of cryogenic treatment on the wear resistance and microstructure of Ti-6Al-4V. Indian J Eng Mater Sci 2018, 25(3), 243-9.

Titanium and its alloys exhibit a unique combination of mechanical, physical and corrosion resistance properties, which have led to their desirable response for critical and demanding aerospace, industrial, chemical, medical and energy industry services. Poor wear resistance is the major drawback of titanium alloys that restrict its usage in many of the potential applications especially in biomedical implants. In this investigation, an attempt has been made to improve the wear resistance of the most widely used titanium alloy, i.e., Ti-6Al-4V through cryogenic treatment. Experimental results clearly indicate that deep cryogenic treatment improves the wear resistance which can be attributed largely to grain refinement. The findings have been further strengthened through microstructure investigations based on optical microscopy and X-ray diffraction. Improvement in other mechanical properties like hardness,tensile strength and plasticity has also been investigated.

6 illus, 3 tables, 19 ref

025795   ABHINAVARAM J, SHANMUGASUNDARAM A, PRASHANTH R, JAGADEESH S, ARUL S, SELLAMUTHU R (Mechanical Engineering Dep, Amrita School of Engineering, Coimbatore - 641 112, Email: a_shanmugasundaram@cb.amrita.edu) : Study of hardness and wear behavior of surface modified AA 7075 with tungsten carbide using GTA as a heat source. Indian J Eng Mater Sci 2018, 25(3), 233-42.

The aim of this work is to evaluate the role of tungsten carbide (WC) in increasing the hardness and improving the wear resistance of AA 7075 alloy. WC is reinforced into the surface of AA 7075 by using gas tungsten arc (GTA) as a heat source. Some of the GTA process parameters are maintained as constant, viz, contact-to-work distance and electrode tip angle, whereas the heat source current and the work speed are varied. With reference to the proper fusion of base metal, optimum GTA heat source parameter is finalized based on a number of trials. It is found that the hardness is reduced after the application of heat. To improve the properties, the alloy is subjected to heat treatment which included solution treatment, water quenching, and artificial aging. The hardness and wear behavior of the WC reinforced surface composite resulted in a positive trend. A comprehensive study on the microstructure of AA 7075 at different stages of the work is done using optical microscopy (OM), scanning electron microscopy (SEM), EDX analysis and X-ray diffraction (XRD).

10 illus, 2 tables, 29 ref

025794   GARG S, PANT M (Mechanical Engineering Dep, National Institute of Technology, Hamirpur - 177 005, Email: sahil.garg1017@gmail.com) : Numerical simulation of thermal fracture in coatings using element free Galerkin method. Indian J Eng Mater Sci 2018, 25(3), 217-32.

The work presented, broadens the adeptness of element free Galerkin method (EFGM) for analysis of thermal fracture in case of materials with coatings under plane stress conditions. A modeling approach has been used by clubbing jump function approach with enrichment criterion in order to model multiple weak and strong discontinuities in the domain. The weak discontinuity, i.e., the interface of two materials is modeled via a jump function methodology. The stress fields around the crack tip are modeled using intrinsic enrichment criterion. Modified interaction integral scheme for thermal fracture has been put to use for generating mode-I stress intensity factors (SIFs). The effect of mechanical properties on crack under sudden temperature change is compared using three cases in which zinc and steel substrates are used (steel/zinc/steel configuration and zinc/steel/zinc configuration) and compared with results of mono-material configuration.

17 illus, 5 tables, 60 ref

025793   PARIDA A K, SOREN S, JHA R N, KRISHNAMURTHY N (Fuel and Mineral Engineering Dep, Indian Institute of Technology (ISM), Dhanbad - 826 004, Email: anil_kumar_parida@yahoo.co.in) : Multistage cup drawing of AISI 1040 graded medium carbon steel. Indian J Eng Mater Sci 2018, 25(3), 209-16.

In this paper a new modified processing route, as an innovative approach, has been proposed for producing cylindrical cups from thicker circular blanks, like 12 mm thick and 60 mm diameter. Rolled strips of aluminium (Al)-killed AISI 1040 graded medium carbon steel in hardened and tempered condition was used as an alternative high strength material. The processing route mainly consisted of pre-forming of flat blanks to a little draw in shape, followed by multistage deep drawing accompanied with wall ironing held without blank-holders and with inter-stage stress relief annealing. Thus, evolution of different processing effects such as cup dimension and cup quality, wall thickness distribution profiles, drawability and ironability parameters, strain distribution profiles, spring back tendency of cups in terms of residual hoop stress distributions, and microstructures at cup wall zones, were obtained and discussed.

8 illus, 4 tables, 20 ref

025792   MOHAN D G, GOPI S, RAJASEKHAR V (Production Engineering Dep, Government Coll of Technology, Coimbatore - 641 013, Email: dhaneshgm@gmail.com) : Effect of induction heated friction stir welding on corrosive behaviour, mechanical properties and microstructure of AISI 410 stainless steel. Indian J Eng Mater Sci 2018, 25(3), 203-8.

In the current scenario, the industry requires a joining or welding method, which does not produce any environmental hazards. Friction stir welding (FSW) is the future of all metal joining methods because FSW does not produce any harmful by products and it enhances the joining strength too. The main limitation of friction stir welding was the difficulty to weld hard metals. The tool damage is very high while welding hard metals. These problems happen while using FSW can be recovered by using an additional heating source such as induction heating, arc heating or resistance heating. The induction heating is the quickest heating method as well as an economic method compared to other heating methods. AISI 410 stainless steel (SS) plate is difficult to weld by conventional welding methods, due to the glassy surface and this glassy surface cause sputtering. AISI 410 SS is chosen for this work and welded by using induction heated friction stir welding method (IH-FSW). The tool used for welding AISI 410 SS is made by using tungsten carbide with a hexagonal profile. A sound joint is fabricated at a spindle speed of 1200 rpm, welding speed of 45 mm/min, plunge depth of 0.05 mm and an additional heat input by using the induction-heating coil is about 100°C at 50 W power respectively.

8 illus, 3 tables, 25 ref

025791   ISLAM M S, REZA K M S, ISLAM M R (Electrical and Electronics Engineering Dep, Islamic Univ of Technology, Bangladesh, Email: mdsohidul@gmail.com) : Topas based high birefringent and low loss single mode hybrid-core porous fiber for broadband application. Indian J Pure Appl Phys 2018, 56(5), 399-404.

We present a through numerical analysis of a low loss and highly birefringent hybrid porous core with octagonal cladding structure for terahertz (THz) wave guidance. The proposed photonic crystal fiber (PCF) offers simultaneously low effective material loss (EML) as well as high birefringence in the frequency range of 0.8-1.05 THz with single mode operation. To attain high birefringence we introduce asymmetry in the core using both elliptical and circular air holes (hybrid). The numerical results obtained from the finite element method (FEM) which confirms low EML of 0.044 cm^–1 as well as a high birefringence of ~0.043 at 0.73 THz operating frequency. Therefore, the fiber is likely to be useful in different THz polarization maintaining applications.

9 illus, 1 table, 41 ref

025790   DESHWAL M, ARORA A (Electronics and Communication Engineering Dep, Thapar Univ, Patiala - 147 004, Email: anil.arora@thapar.edu) : Enhanced sensitivity with thickness optimization of ZnO based acetone sensor. Indian J Pure Appl Phys 2018, 56(5), 367-72.

Zinc oxide (ZnO) thin film based acetone gas sensor has been studied with variation of sensing layer thickness towards 500 ppm of acetone. The effect of thickness variation of the sensing layer on the structural, surface morphological, optical and gas sensing properties of ZnO thin film has been studied. A significant increase from 7.19 to 63 in the sensing response has been observed with bare ZnO thin film for the samples with an optimised thickness of 410 nm at an optimised operating temperature of 320 °C. This study conducts the variations in structural, optical and the gas sensing characteristics while varying the thickness of ZnO based thin films for an acetone gas sensor. Further, the study concludes with an optimised thickness as 410 nm for an oxidizing gas.

10 illus, 1 table, 31 ref

025789   MONIKA, BHATT K, RANI C, KAPOOR A, KUMAR P, SHILPI, SANDEEP, KUMAR S, SINGH R, TRIPATHI C C (Electronics and Communication Engineering Dep, Institute of Engineering and Technology Univ, Kurukshetra - 136 119, Email: kapilbhattuiet@gmail.com) : A facile approach to fabricate graphene based piezoresistive strain sensor on paper substrate. Indian J Pure Appl Phys 2018, 56(5), 361-6.

Sensors, FETs and chemi resistors are few of the devices which show potential in the area of flexible electronics for health monitoring applications. In the present work, piezoresistive strain sensors based on graphite and graphene on cellulose paper substrate has been reported. Graphite sensor has been fabricated by rubbing pencil on paper and graphene sensor by directly coating graphene ink using paint brush. The resistance of the fabricated sensor increases with outwards bending and vice-versa, further the piezoresistive effect has also been evaluated by applying variable longitudinal stress. A comparative study of gauge factor (GF) depending upon different type of strains has been presented and it has been observed that the GF of graphene piezoresistive strain sensor decreases with increase in number of layers, the GF for graphene sensor is higher as compared to graphite sensor. Fabricated piezoresistive strain sensors may find applications as human body motion detection, gait analysis etc.

6 illus, 1 table, 27 ref

025788   ARUN B H, VYAS J, GOPALSAMY B M, CHIMMAT M (Structural Technologies Div, UVCE, Bangalore, Email: jaidev.vyas@nal.res.in) : Ejector pump CFD model validation and performance studies improvement. J Sci Ind Res 2018, 77(6), 353-8.

The ejector pump is the noiseless operating and the simplest of all pumping devices with no moving parts involved. Ejector pumps are used in many pumping applications owing to their low first cost, simplicity in operation and the ability to mix fluids thoroughly. Though the ejector pump has advantages, more efforts need to be done to improve the efficiency. In the present study, an experimental test rig is set up for a single-phase (incompressible fluid) ejector pump. A CFD simulation model has been developed on ANSYS-FLUENT platform for the ejector pump and results are validated with the established test rig data. Further, the validated CFD model is applied for geometry optimization studies to maximize the efficiency. Critical parameters affecting the efficiency are identified and reported.

4 illus, 3 tables, 15 ref

025787   KADAPPARAMBIL S, YADAV K, RAMCHANDRAN M, SELVAM N V (Chemical Engineering Dep, National Institute of Technology, Chhattisgarh- 492 010, Email: snvictoria.che@nitrr.ac.in) : Tectona grandis leaf extract as environmental friendly corrosion inhibitor for SS304 stainless steel in hydrochloric acid. J Sci Ind Res 2018, 77(6), 349-52.

The corrosion inhibitory effects of Tectona grandis (teak) leaves extract, for stainless steel 304 (SS304) in 2 M hydrochloric acid was investigated using gravimetric technique and scanning electron microscopy (SEM). The gravimetric results showed that the corrosion rate decreases with increase in inhibitor concentration. The maximum inhibition efficiency of 65 % for teak leaves was obtained at 1000 ppm extract concentration. It was found that the inhibition efficiency increased with temperature. The studies revealed that the teak leaf extract acts as a mixed type inhibitor. Adsorption of the inhibitor molecules on the surface of stainless steel followed comprehensive adsorption.

3 illus, 3 tables, 17 ref

025786   GURAU V S, SANDHU S S (Mechanical Engineering Dep, Dr B R Ambedkar, NIT Jalandhar, Punjab, Email: sandhuss@nitj.ac.in) : Optimization and characterization of biodiesel production from India originated bitter apricot kernel oil. J Sci Ind Res 2018, 77(6), 345-8.

With an objective to reduce dependence on imported crude oil in order to enhance the country’s energy security, an indicative target of 20 % blending of biodiesel by 2017 has been proposed by the Government of India. The production of biodiesel in India has remained focused primarily on Jatropha oil. As dependence on the certain source may be undesirable in the long run, the biodiesel feed stock should be as diversified as possible. This research paper explores the potential of bitter Apricot kernel oil as biodiesel feedstock. Taguchi method was employed for the optimization of biodiesel production from bitter Apricot kernel oil. The biodiesel produced was tested for physicochemical properties as per ASTM D6751 standards and compared with those of Jatropha biodiesel.

1 illus, 3 tables, 25 ref

025785   KACHHAP S, SINGH A, DEBNATH K (Mechanical Engineering Dep, National Institute of Technology Meghalaya, Shillong – 793 003, Email: debnath.iitr@gmail.com) : Electric discharge drilling of hybrid metal matrix composites using different tool electrodes. J Sci Ind Res 2018, 77(6), 325-9.

In this paper, the machinability characteristics of hybrid metal matrix composites (HMMCs) (Al6063/SiC/Gr/Al2O3) have been experimentally evaluated during electro-discharge drilling (EDD) with solid and hollow tool electrodes made of copper and brass. The influence of different parameter such as (i) discharge current, (ii) tool material, and (iii) tool geometry on (i) material removal rate (MRR) and (ii) tool wear rate (TWR) has been experimentally investigated. The end face wear of the tool electrode has also been presented with the help of microscopy imaging. The results of the experimental investigation indicated that the MRR is improved with hollow brass tool electrode and TWR is reduced with solid copper tool electrode during EDD of developed composites.

3 illus, 2 tables, 14 ref

025781   KATARIA A, GHOSH S, KARAR V (Electrical and Instrumentation Engineering Dep, Thapar Institute of Engineering & Technology, Patiala - 147 004, Email: smarajitg@hotmail.com) : Data prediction of optical head tracking using self healing neural model for head mounted display. J Sci Ind Res 2018, 77(5), 288-92.

Helmet Mounted Display (HMD) is an essential part in field of avionics. It is worn by the pilot to sight the external environment along with synchronized view of the important parameters of the airplane on its visor. To achieve the perfect synchronized view on the visor of HMD, the coordinates of the external environment and the coordinates of the pilot’s head motion should be in proper synchronization. To acquire the coordinates of the pilot’s head motion, the head tracking process is involved. Head tracking can be done using different tracking techniques such as Optical tracking, Magnetic tracking or Inertial tracking. In this paper, a six-degrees-of-freedom (6-DoF) optical tracker (TrackIRTM) was used to record the coordinates of the pilot’s head motion in real time on the simulator bed. During the process of acquisition of the coordinates of head movement by optical tracker, the data may get missed due to stray light interference or any other kind of occlusion. To predict the missing data Self Healing Neural Model (SHNM) was applied. More than 88 % of accuracy was achieved in prediction of three different sets of missing data. Results were also compared with Back Propagation Neural Network (BPNN).

3 illus, 3 tables, 11 ref

025779   RAJ V D, PRASAD A M, PRASAD G M V (Electronics and Communication Enggineering Dep, JNTUK, A. P, Email: profvdr@yahoo.com) : Radiation performance of log periodic Koch Fractal Antenna Array with different materials and thickness. J Sci Ind Res 2018, 77(5), 276-81.

A frequency independent Printed Log Periodic Dipole antenna (PLPDA) with and without fractals for different materials and thickness is proposed for UWB applications. The impedance bandwidth of PLPD without fractal for FR4 of 4.71GHz to 9.99GHz. Similarly, for the RT/Duroid, the impedance bandwidth of 3.09GHz to 12.13GHz with VSWR less than two is achieved. The radiation patterns for different combinations are also observed to be an end-fire radiation pattern. In this paper, the first iteration is proposed, the parametric and performance observations are also made for different thickness (63mil, 62mil, and 31mil) of the dielectric substrate. Antennas are fabricated, and its performance is authenticated using vector network analyzer (E5071C) to carry out return loss and VSWR measurements. The obtained results are insensible agreement with the theoretical results.

4 illus, 2 tables, 6 ref

025769   SHANTHARAM Y, ELANGOVAN K (Civil Engineering Dep, Mahendra Engineering Coll, Namakkal- 637 503, Email: shantham1311@gmail.com) : Groundwater potential zones delineation using geo-electrical resistivity method and GIS for Coimbatore, India. Indian J Geo-Mar Sci 2018, 47(5), 1088-95.

Resistivity meter was used to conduct vertical electrical sounding (VES) using the Schlumberger electrical resistivity in the study region for a depth of 150 m. Geophysical study indicates four layers such as top soil, weathered first fractured zone and second fractured zones. 68.52 % of study area is dominated by AA, AK and HA type curve-indicating low to moderate groundwater prospective zones. The survey result indicates that Calc-granulite and limestone rock types are better aquifers than the other rock types. GIS overlay indicate that good groundwater potential zone constitutes 93.37 sq.km (36.32 %), in the study area located in Northeast, East and South edges of the study region. High groundwater potential zones fall in an area of 9.37 sq.km (3.65 %).

9 illus, 1 table, 19 ref

025765   NACHIMUTHU B, SUNDRAMOORTHY S (Electrical and Electronics Engineering Dep, Syed Ammal Engineering Coll, Ramanathapuram-623 502, Email: perumal.om@gmail.com) : Intelligent controller for speed control of three phase induction motor using indirect vector control method in marine applications. Indian J Geo-Mar Sci 2018, 47(5), 1069-74.

Marine electric propulsions generally use variable speed electric propulsion motors associated to propellers in which numerous types of converter control schemes are applied. This paper, reviews existing control schemes of the propulsion drive system and an accomplishment of intelligent controller for speed control of three phase induction motor (IM) using indirect vector control with Anti-Windup (AW) technique has been developed and analyzed. This manuscript is fully mathematical model of field orientation control (FOC) induction motor is described and simulated in MATLAB for induction motor has been considered. In this paper the performance and results have given analyzed for the proposed controller using indirect vector control method with Neural Network and antiwindup techniques. Due to high installation cost and mechanical robustness the use of flux and speed sensors are to be avoided. From this analysis IVCNN with AW based controller is found to be a very useful technique to attain a high accuracy speed control. This strategy IVCNN with AW is proposed to enhance the performance of the drive.

7 illus, 1 table, 25 ref

025761   JANARDHAN P, RAO S, SHIRLAL K G (Civil Engineering Dep, NIT Silchar, Assam, Email: prashnitk.hsn@gmail.com) : Reshaping Berm breakwaters: A physical model study. Indian J Geo-Mar Sci 2018, 47(5), 1050-7.

In the present study, the structural stability of statically stable reshaping berm breakwater for different wave parameters and armour weights were verified by physical model study carried out at NITK Surathkal Mangalore. Wave run-up and run- down studies were also carried out. The results show that a safe structure can be evolved with reduction in armour weight by up to 25 % for all the relative berm position values. The position of berm greater than or equal to 1.3 was found to be good in reducing recession as well as wave run-up. An empirical new berm recession formula was derived for berm recession based on sea state and structural parameters.

12 illus, 1 table, 25 ref

025851   PATIL S G, MENON A, DODAGOUDAR G R (Civil Engineering Dep, Indian Institute of Technology, Chennai - 600 036, Email: arunmenon@iitm.ac.in) : Probabilistic seismic hazard at the archaeological site of Gol Gumbaz in Vijayapura, South India. J Earth Syst Sci 2018, 127(2), 16.

Probabilistic seismic hazard analysis (PSHA) is carried out for the archaeological site of Vijayapura in south India in order to obtain hazard consistent seismic input ground-motions for seismic risk assessment and design of seismic protection measures for monuments, where warranted. For this purpose the standard Cornell-McGuire approach, based on seismogenic zones with uniformly distributed seismicity is employed. The main features of this study are the usage of an updated and unified seismic catalogue based on moment magnitude, new seismogenic source models and recent ground motion prediction equations (GMPEs) in logic tree framework. Seismic hazard at the site is evaluated for level and rock site condition with 10 % and 2 % probabilities of exceedance in 50 years, and the corresponding peak ground accelerations (PGAs) are 0.074 and 0.142 g, respectively. In addition, the uniform hazard spectra (UHS) of the site are compared to the Indian code-defined spectrum. Comparisons are also made with results from National Disaster Management Authority (NDMA 2010), in terms of PGA and pseudo spectral accelerations (PSAs) at T = 0.2, 0.5, 1.0 and 1.25 s for 475- and 2475-yr return periods. Results of the present study are in good agreement with the PGA calculated from isoseismal map of the Killari earthquake, M_w = 6.4 (1993). Disaggregation of PSHA results for the PGA and spectral acceleration (S_a) at 0.5 s, displays the controlling scenario earthquake for the study region as low to moderate magnitude with the source being at a short distance from the study site. Deterministic seismic hazard (DSHA) is also carried out by taking into account three scenario earthquakes. The UHS corresponding to 475-yr return period (RP) is used to define the target spectrum and accordingly, the spectrum-compatible natural accelerograms are selected from the suite of recorded accelerograms.

18 illus, 6 tables, 81 ref

025850   ONEY O (Mining Engineering Dep, Usak Univ, Usak, Turkey, Email: ozcan.oney@usak.edu.tr) : Optimization of operating parameters of graphite flotation circuit using Box-Behnken design. Indian J Chem Technol 2018, 25(2), 170-8.

Flotation is a continuous process, therefore conventional tree analysis tests do not fit to determine the quantity and quality of the products. Hence, it is necessary to incorporate flotation circuits. The present study presents optimization of three stage graphite flotation circuits. Response Surface Methodology (RSM) is used to determine the optimum flotation conditions. In addition, the relationship between process variables (diesel oil dosage, methyl isobutyl carbinol dosage and sodium silicate dosage) and the responses (weight, carbon content and recovery) has been investigated. Analysis of variance has been performed to check the suitability and significance of the quadratic models. The results are found to be compatible withproposed models (R² > 0.97) which lead to obtain 13.48 weight % of clean graphite, 78.91 % carbon content and 54.55 % carbon recovery fromthree-stage flotation circuit.

4 illus, 7 tables, 23 ref

025849   IMITIYAZ D, SINGH E R (Food Process Engineering, Sam Higginbottom Univ of Agricultural Technology and Sciences, Allahabad (U.P.), Email: arshdeemi@yahoo.com) : Development and quality evaluation of carrot pineapple blended juice. Plant Arch 2018, 18(1), 242-6.

Juice carrot (Daucus carota) and pineapple (Ananas comosus), were optimised to a blended beverage which was stored for 45 days in pet bottles (400 ml capacity) at refrigerated temperature. Physico-chemical and sensory analysis were evaluated. Marginal changes in pH, total soluble solids, acidity, vitamin C and beta-carotene were observed. The beta carotene content of juice was found (1697 μg) to be increased with increasing the proportion of carrot juice. Estimation of vitamin C content of sample (17.50mg) showed high improvement in nutritional value of carrot juice incorporated with pineapple juice. The acidity increased (0.47-1.45) and pH of the juice decreased progressively during the storage period. This may be due to the excessive fermentation and presence of lactic acid reducing micro-organism. It was found that the sample having ratio 65:35 (carrotpineapple) had the best acceptability, which will also be helpful in providing dietary requirement of beta carotene to the consumer. Heat pasteurisation (90$°$C for 25 sec) was more effective for inactivating the microbial flora. However, the shelf life of juice was established within 45 days. The product is recommended children, youth and elderly persons to be used within 45 days.

5 illus, 6 tables, 14 ref

025848   DALAVI P, MANKAR A N, WADATKAR S B (Irrigation and Drainage Engineering Dep, Krishi Vidyapeeth, Akola, Email: pradipdalavi@gmail.com) : Modeling evaporation from farm pond in semi-arid region. Plant Arch 2018, 18(1), 129-34.

The present study was undertaken with major objective to develop a mathematical model for estimating evaporation from a farm pond in a semi-arid region. The study was conducted to develop and evaluate different evaporation estimation models considering importance and difficulty in measurement of evaporation. Models were developed for predicting pond evaporation on multiple linear regression, and energy balance method. For pond evaporation the model developed by stepwise multiple linear regression analysis gave results with highest coefficient of determination (R² = 0.967), lowest root mean square error (0.737 mm day^-1) with closer association between estimated and observed evaporation. The present study used three existing models to estimate the rate of evaporation from farm pond. Statistical analysis was performed to screen the models. The root mean square error (RMSE), percent deviation, coefficient of determination (R²) and scatter plot analysis reveal that for pan and pond evaporation Dalton model predict the evaporation rate close to the actual observed evaporation.

4 illus, 2 tables, 17 ref

025845   CHOUDHURY A, SAHU S, MEENA R (Inter Univ Accelerator Centre, New Delhi– 110 067, Email: choudhury.anup@gmail.com) : Cryocooler based helium liquefier development- A practical usage. Indian J Cryog 2018, 43(1), 51-5.

A helium liquefier using a 1.5 watt at 4.2KGifford Mac Mohan (GM) cryocooler was developed at IUAC having a liquefaction capacity of 17.4 litres per day (lpd) at STP. This standalone setup could not be used for any other experimental facility which requires liquid helium for its functioning and so another portable experimental liquefier was designed and fabricated using the same technology, which can be used to hook up very easily using its liquid inlet line port. In the present experimental demonstration setup the cryocooler liquefier was hooked up to a commercial 100 l helium Dewar. The Dewar was cooled starting from room temperature with the cryocooler liquefier in 2 days and 50 litresof liquid helium was collected inside the Dewar. The measured production rate of liquefaction was 14.2 litres per day. Successful liquefaction of helium in such a portable setup opens up the door for using this technology for other experimental purpose requiring liquid helium.

5 illus, 1 table, 2 ref

025844   SHAFI K A, SKARIA M, THOMAS R J, VASUDEVAN K, KRISHNACHANDRAN C, PRAKHYATH A M, HATTI M, KASTHURIRENGAN S, DRABEHERA U, GANGRADEY R, MUKERJEE S (TKM Coll of Engineering, Kollam- 691 005, Email: shafika@tkmce.ac.in) : Design and development of an emissivity measurement set-up for use at 100 K. Indian J Cryog 2018, 43(1), 45-50.

For the best performance of the Activated carbon based cryopumps, the activated carbon should be at the lowest possible temperature. For this, the heat load from the surroundings has to be minimized. Radiation heat load is significant and depends on the emissivity of surfaces. Since the emissivity data are scarce at cryogenic temperatures, we have developed an experimental setup based on the calorimetric method for the measurement of emissivity of various coatings or parts at these temperatures around 100 K. The setup consists of a heater located inside a vacuum vessel at 77K. When the heat transfer between the heater and the receiving surface is nearly by radiation, using the measurements of heat load and the temperatures, the emissivities of the different surfaces can be estimated. The design and fabrication of the experimental setup along with the preliminary results are presented in this paper. 

6 illus, 3 tables, 6 ref

025843   PATEL M, CHAKRABORTY A K, BANDYOPADHYAY M, ROTTI C, PARMAR D, SHISHANGIYA H, TYAGI H, YADAV R, PATEL K, MISTRY H, PANDYA K (ITER-India, Institute for Plasma Research, Gandhinagar- 382 428, Gujarat, Email: milind.patel@iter-india.org) : A prototype experiment on cryocooler based cryopump. Indian J Cryog 2018, 43, 40-4.

To characterize ITER Diagnostic Neutral Beam (DNB) in Indian test facility (INTF), ~ 106 l/s installed pumping speed is required to ensure low re-ionization losses and stripping losses of extracted negative hydrogen ions from the ion source in presence of ~ 14.6 Pa.m³/s hydrogen gas throughputs. Such large pumping speed will be provided using 12 cryopumps based on Cryo-sorption mode of operation and are dispersed symmetrically along the 9 m length of the test vessel. Each pump has a speed of ~ 1 x 105 l/s.The engineering configurations of the pumps are charcoal based Cryosorption type with cryopanel at 15K temperature, cooled by a cryocooler. The pumping surface is surrounded by Chevron shaped liquid nitrogen cooled radiation shield at 85K temperature. An experimental validation of the temperature distribution on the Helium surface has been carried out on a prototype using a 20 W @ 15 K cryocooler (Sumitomo make). The experiment establishes temperature uniformity within 0.5 K at the extremities of the Helium panel for heat loads that is a factor of 1.5 higher than the estimates, and closely corroborates the simulation data, thereby ensuring a reliable pumping performance. The results of the prototype experiment leads to a technical decision of incorporating 12 cryocooler based cooling for the Helium section, thereby obviating the need for a dedicated 15 K Gaseous Helium Supply System. The paper shall present a brief configuration of the Cryopump, the details of the prototype, the experimental results and the conclusions arrived at.

7 illus, 4 tables, 8 ref

025841   NITIN B, SANDILYA P (Indian Institute of Technology, Kharagpur, Email: profsandilya@gmail.com) : Structural and thermal analysis of Dewar supports for low boil-off long duration storage of cryogenic liquids. Indian J Cryog 2018, 43(1), 33-9.

Design of a cryogenic liquid-storage system for various applications is unique and hence, is still an evolving field of research and development as newer applications of cryogens are being envisaged. The conventional way of storing cryogenic liquid is the use of dewars, which are double walled containers using evacuated insulation materials to reduce heat in leak from the ambient. Design of the dewar support system to store and transport cryogenic liquids on a mobile platform poses considerable challenge. The present study lays the foundation for addressing a long duration storage of cryogenic liquid under very high-stress levels. The study involves the evaluation of the structural and thermal performances of such vessels in order to ensure structural stability of the vessel while allowing minimal boil off loss of the stored cryogenic fluid. A FEM based numerical study is underway to compare support systems in terms of the stresses, and heat inleak.

8 illus, 2 tables, 13 ref

025838   SHAFI K A, SKARIA M, THOMAS R J, VASUDEVAN K, FAIZAL H M, VISHNU P, KASTHURIRENGAN S (TKM Coll of Engineering, Kerala- 691 005, Email: shafika@tkmce.ac.in) : Design development and studies on a liquid nitrogen based cryosorption pump. Indian J Cryog 2018, 43(1), 27-32.

Cryosorption pumps are the vacuum pumping method for many high and ultra-high vacuum applications due to their reliability, cleanliness, and high pumping speeds. They are used in several industrial applications such as Semiconductor, Optical Coating, Particle Accelerators, Medical devices etc. and in Research and Development. These pumps generally use activated carbon as the sorbent material for pumping of various gases. Such a pump can be either cryocooler based or cryogenic fluid based. Supercritical liquid helium cooled cryosorption pumps are used in fusion tokamaks for pumping of helium and hydrogen. In our efforts towards the development of cryosorption pumps, we have designed, fabricated and studied cryosorption pumps cooled with liquid nitrogen (LN2). Specially developed activated carbon are adhesively bonded on the surface of copper panels and filled in a vessel made of stainless steel mesh. These are mounted in vacuum chamber. This chamber when cooled with LN2 forms the cryopump operating at 77 K. In this work, we report the performances of these pumps such as the ultimate vacuum. 

8 illus, 7 ref

025752   ADDIS D, HUSSAIN F (Jiangsu Univ, China) : Reduced differential transform method for fourth order parabolic partial differential equations. Int J Multidiscip Res Dev 2018, 5(4), 209-13.

In this work, reduced differential transform method is proposed for fourth order Parabolic Partial Differential Equations with variables coefficients. The approximate solution of this equation is calculated in the form of a series with easily computable terms. Exact solution can be achieved by the known forms of the series solutions. Some examples solved which shows its ability, efficiency, reliability, effectiveness and simplicity.

1 table, 9 ref

025751   KADIR A, MURSIDI B (Civil Engineering Dep, Halu Oleo Univ, Indonesia) : The effect of wire mesh confinement to compressive strength and deformability of cylindrical concrete. Int J Multidiscip Res Dev 2018, 5(4), 110-3.

The research is intended to evaluate the effectivity of of wire mesh confinement on cylindrical concrete. Six of specimens that consist of a standard cylinder with one layer, two layers, and three layers of wire mesh. The result shows that wire mesh confinement can improve the compressive strength and greater deformation before repture. Compressive strength and deformation have also improved during an increasing of number wire mesh layer or an increasing of confinement volumetric. The maximum stress improvement range is about 1.004 – 1.42 times or 0.397 % - 41.98 % of strength compared to cylindrical control with no wire mesh.

7 illus, 4 tables, 6 ref

025746   CHO J Y, LEE S H, JANG W K (Electronic Engineering Dep, Hanseo Univ, Chungcheongnam-do- 31962, Email: jwk@hanseo.ac.kr) : Empirical two step approximation for characterizing thermal properties of ultrathin graphite sheet. Asian J Chem 2018, 30(3), 689-92.

The estimation method for unknown thermal properties of ultrathin graphite sheet is suggested in this work. Based on the well known thermal properties of a few materials, the estimation was done by two step approximation algorism. The experimental measurement for four materials of copper, aluminum, indium and graphite was performed at the restricted laboratory environment to get the mutual relation indicating special regularity between those materials. The estimated value of thermal conductivity for a graphite ultrathin thermal sheet was 646 W/m·K that was reasonable comparing to its functional capacity.

4 illus, 7 ref

025743   KALRA P, GARG R K, KUMAR A (Chemical Engineering Dep, I.K. Gujral Punjab Technical Univ, Kapurthala-144 603, Email: pankajkalra75@gmail.com) : Kinetics analysis of reactions at triple phase boundaries of anode supported tubular solid oxide fuel cell. Asian J Chem 2018, 30(3), 561-6.

Solid oxide fuel cells are solid-state ceramic cells, operating at a high temperature and recently been discovered one of the most efficient power generation devices causing no environmental pollution. In this paper, kinetic analysis study typical solid oxide fuel cell reactions has been done particularly methane steam reforming, water gas shift and electrochemical cell reactions on the active three phase boundaries of highly porous Ni-YSZ anode of an anode supported tubular solid oxide fuel cell. The reforming and water gas shift reactions occur in the gas phase due to the high temperature predominant in the solid oxide fuel cell leading to the production of hydrogen, CO and CO₂. The hydrogen produced acts as a fuel for the solid oxide fuel cell reacts with O^2- ions at triple phase boundary forming water (steam) and DC current due to conventional electron flow from anode to cathode of solid oxide fuel cell. The variation of Gibb’s free energy, equilibrium constant and rate of reactions has been represented and analyzed.

5 illus, 3 tables, 22 ref

025736   TARAFDAR A, PATNAIK U (Agricultural and Food Engineering Dep, Indian Institute of Technology, Kharagpur- 721302, Email: ayontarafdar@gmail.com) : Clothing urban heat islands with a vegetative cover to combat climate change. Clim Chang Environ Sustain 2018, 6(1), 16-9.

Urbanisation has led to the creation of layers of concrete and asphalt. These structures or ‘heat islands’ absorb enormous amounts of radiation on the surface causing average global temperatures to rise. Changes in characteristics of the Earth’s surface like the thermal capacity, heat capacity and albedo are increasing with depleting vegetation. In a developing country like India, where the urban growth is in its early phase, it is possible to strategise for a climate-sensitive infrastructure. In this work, therefore, we have investigated the influence of vegetation on the change in interior temperatures. It was observed that an average temperature reduction of 7.88 ± 0.02 °C as compared with structures exposed to direct sunlight can be achieved at < 95 % relative humidity. The study highlights an efficient cost-effective measure to minimise global warming by covering urban rooftops with grass layers.

3 illus, 1 table, 11 ref

025814   SINGH K G K, HALDER S, PATI S, WANG J (Mechanical Engineering Dep, National Institute of Technology, Silchar- 788 010, Email: gknits2014@gmail.com) : Microencapsulation of paraffin wax microspheres with silver. Def Sci J 2018, 68(2), 218-24.

Microencapsulation of phase change materials (PCMs) with metallic shell materials is a very innovative and challenging task. This can mitigate the problems related to thermal barrier for conventional nonconductive shell materials as well as enhance mechanical properties of PCM microcapsules. Such microcapsules can be integrated into microelectronic devices for their intermittent thermal management in mission critical components. The present work is aimed at developing a new method to synthesise phase change material encapsulated with metallic shell material and characterising the same. Paraffin wax microspheres were first synthesised and then encapsulated with silver through in situ chemical reduction. Further more, a new set of experiments were identified to analyse the quality of encapsulation. The thermal properties were investigated under differential scanning calorimeter and thermogravimetric analyser. The average diameter of paraffin wax microspheres (PW) is found to be ± 329 µm. It reveals from DSC analysis that the enthalpy of fusion is minimum for PW@Ag-PVA amongst all others. Accordingly, higher deposition of Ag is possible for PW@Ag-PVA. This is also supported by TGA results where PW@Ag-PVA has only 40 per cent mass loss and the remaining samples have 100 per cent. However, even for PW@Ag-PVA the encapsulation is found incomplete. The present work provides knowhow of the difficulties associated with encapsulation of PCMs with metallic shell material.

10 illus, 1 table, 22 ref

025813   KUMAR A, RAGHAVAN S (Electronics and Communication Engineering Dep, National Institute of Technology, Trichy- 620 015, Email: arvindkr.nitt@gmail.com) : Bandwidth enhancement of substrate integrated waveguide cavity-backed bow-tie-complementary-ring-slot antenna using a shorted-via. Def Sci J 2018, 68(2), 197-202.

In this study, a planar cavity-backed bow-tie-complementary-ring-slot antenna is proposed, and a new approach for bandwidth enhancement using a shorted-via is introduced. A shorted-via concept overcomes the narrow impedance bandwidth of a conventional substrate integrated waveguide cavity-backed antenna. By adjusting the location of the shorted-via (placed just above the centroid of the radiating slot), the individual bandwidth of the lower and higher order resonances has been tuned below -10 dB criterion, which results in the broadening of the bandwidth. Finally, the antenna is proficient to operate for an impedance bandwidth of 15.71 per cent, ranging from 12.02~14.07 GHz. The proposed antenna shows a gain of better than 4 dBi within the operating band with less than 0.5 dBi variation. Moreover, the antenna preserves good radiation characteristics, which is similar to that of the conventional metallic counterpart. To validate the simulated results, an antenna is fabricated and tested. The simulated results in terms of the reflection coefficient, gain, and radiation patterns are in good agreement with the measured results.

12 illus, 2 tables, 15 ref

025812   CHATURVEDI D, RAGHAVAN S (Electronics and Communication Engineering Dep, National Institute of Technology, Tiruchirappalli - 620 015, Email: divyanitt31@gmail.com) : A triangular-shaped quarter-mode substrate integrated waveguide based antenna for WBAN applications. Def Sci J 2018, 68(2), 190-6.

In this study, a compact quarter-mode substrate integrated waveguide (QMSIW) based dual-band antenna is proposed for wireless body area network applications. A QMSIW resonator is realised by splitting the full-mode substrate integrated waveguide cavity along the perfect magnetic conductor walls. The proposed antenna preserves the fundamental mode TE₁₁₀ and the third order mode TE₂₂₀ of the square SIW cavity. The proposed antenna is linearly polarised in the lower band at 2.45 GHz and circularly polarised in the higher frequency band at 5.8 GHz. The on-body performance of the antenna is validated on a piece of pork muscle tissue and it has been found to be stable with respect to surroundings. The proposed antenna covers the ISM bands 44 MHz (2.445 GHz - 2.489 GHz) and 225 MHz (5.730 GHz - 5.955 GHz) at 2.45 GHz and 5.8 GHz, respectively. The measured gain of the antenna on pork tissue is 1.87 dBi and 5.5 dBi at two bands. In addition, the specific absorption rate is obtained of 0.65 mW/g and 1.51 mW/g at two bands (w_ext = 2 mm), averaged over 1 g of muscle with 100mW input power. Moreover, the simulated and experimental results demonstrate a good agreement.

13 illus, 2 tables, 24 ref

025811   PANCHU K P, RAJMOHAN M, SUNDAR R, BASKARAN R (Industrial Engineering Dep, Anna Univ, Chennai - 600 025, Email: panchu81@gmail.com) : Multi-objective optimisation of multi-robot task allocation with precedence constraints. Def Sci J 2018, 68(2), 175-82.

Efficacy of the multi-robot systems depends on proper sequencing and optimal allocation of robots to the tasks. Focuses on deciding the optimal allocation of set-of-robots to a set-of-tasks with precedence constraints considering multiple objectives. Taguchi’s design of experiments based parameter tuned genetic algorithm (GA) is developed for generalised task allocation of single-task robots to multi-robot tasks. The developed methodology is tested for 16 scenarios by varying the number of robots and number of tasks. The scenarios were tested in a simulated environment with a maximum of 20 robots and 40 multi-robot foraging tasks. The tradeoff between performance measures for the allocations obtained through GA for different task levels was used to decide the optimal number of robots. It is evident that the tradeoffs occur at 20 per cent of performance measures and the optimal number of robot varies between 10 and 15 for almost all the task levels. This method shows good convergence and found that the precedence constraints affect the optimal number of robots required for a particular task level.

6 illus, 4 tables, 26 ref

025810   RAMASAMY V, BASHA A M J (Electronics and Communication Engineering Dep, Sathyabama Univ, Chennai – 600 119, Email: rmvramasamy@gmail.com) : Effect of internal clearance on buckling of multistage hydraulic cylinder. Def Sci J 2018, 68(2), 167-74.

Multistage cylinders are generally used to lift and tilt heavy loads under controlled speed. In defence applications multistage cylinders are used in missile tilt platform and antenna mast. Earth moving equipment’s such as tippers, dumpers, cranes and compactors uses multistage cylinders for operations. In the present work multistage hydraulic cylinder (telescopic cylinder) with three stage has been analysed using strain energy method and verified with finite element analysis. The research work investigates the effect of internal clearances which reduces the critical buckling load of hydraulic cylinders. The results are validated by buckling load test. The clearances between the tube to piston guides, gland guide to piston rod, clearances due to tube expansion under pressure, initial curvature in the tube, eccentricity of cylinder components and tube ovality are considered in the buckling load test. Describes the comparative study of buckling load tests of three stage hydraulic cylinders having fixed free and hinged mounting with five different internal clearances.

12 illus, 6 tables, 23 ref

025809   KIM Y K, CHOI W C (Mechanical Engineering Dep, Korea University, Korea, Email: gokkolove@korea.ac.kr) : Ricochet of spheres on sand of various temperature. Def Sci J 2018, 68(2), 150-8.

The debris generated by the explosion of a building or ammunition is flown far away through the ricochet phenomenon. The debris contains a very large amount of energy, and a risk factor surrounding it may be applied. The safety distance from debris is set from experiments or FEM analysis. The ricochet of debris is affected not only by the initial conditions of the debris, but also by the conditions of the medium. In this paper, the effect of sand temperature on the ricochet of sphere projectiles was investigated through experiments and FEM, by measuring the shear stress and internal friction angle when the sand temperature increases. As the temperature of the sand increases, the shear stress and the internal friction angle decrease, and the penetration depth of the projectile increases. As the depth of penetration becomes longer, the kinetic energy is lost more by the friction force with the sand and, the sphere projectile speed decreases more. This is mainly caused by the energy loss of the projectile, so the kinetic energy of the ricocheted projectile is reduced. Therefore, when setting the optimized inhabited building distance (IBD), the conditions of the medium should be taken into account.

11 illus, 5 tables, 29 ref

025806   MADHUMITHA S, MANIKANDAN M (Electronics Engineering Dep, Anna Univ, Chennai- 600 044, Email: smadhucool@gmail.com) : Quantitative analysis of marker-based watershed image segmentation. Curr Sci 2018, 114(5), 1007-13.

A methodology is proposed by combining the application of markers along with watershed transformation and thresholding for image segmentation. Use of the traditional watershed algorithm is widespread because of its advantage of being able to produce a complete division of the image. However, its drawbacks include over-segmentation and noise sensitivity. Therefore, the marker-based watershed segmentation is proposed here to overcome these effects. First, the original image is preprocessed by filtering techniques in order to smoothen it. Secondly, the foreground objects are marked. Then, the background markers are computed. Finally, the marked image is transformed through watershed transformation. The area is computed for the segmented objects in the image. It has been proved that this method reduces the error percentage.

4 illus, 2 tables, 27 ref

025784   SENGUPTA S, DEBNATH S (ICAR-National Institute of Research on Jute and Allied Fibre Technolog, Kolkata- 700 040, Email: ssg_42@rediffmail.com) : Production and application of engineered waste jute entangled sheet for soil cover: A green system. J Sci Ind Res 2018, 77(3), 240-5.

Soil covering for weed control and moisture retention during cultivation is an age-old practice. Presently, the thin polyethylene sheet is widely used for this purpose. In this study, a uniform, porous and bulky mechanically entangled fibrous sheet from ecofriendly and natural, low-grade/process waste jute fibre has been designed for strawberry cultivation. The agricultural performance of this engineered textile material has been compared with the commonly used polyetheylene sheet and traditionally used sawdust, straw and banana leaf in the same strawberry field under same conditions using random complete block design with three replicas. It was observed that process waste jute nonwoven shows better performance than other materials. Among other natural materials, straw gives good results. Hence, the application of jute nonwoven promotes the bio-waste utilization for the sustainable and green agriculture and is a promising alternative as a soil cover.

1 illus, 3 tables, 5 ref

025783   KANADE P S, DESAI T A (Textile Engineering Dep, The Maharaja Sayajirao University of Baroda, Vadodara, Email: p.s.kanade-ted@msubaroda.ac.in) : Improved design of wound filters for enhanced water filtration performance. J Sci Ind Res 2018, 77(3), 237-9.

Wound filters are incapable of removing sub-micron particles, discharge particles under influence of rising pressure drop besides having lower particle retention efficiency compared to membranes. Producing wound candles with distinct density zones could offer a possible solution to the aforementioned drawbacks. In the present work wound density graded cartridges have been produced by changing winding pattern. Experimental results show improvement in their water filtration performance. The wound filters usually serve as pre-filter and if their performance is better then service life of the final filter will also be more.

1 illus, 1 table, 9 ref

025782   CHAKRABORTY S, KAR S, DEY V, GHOSH S K (Production Engineering Dep, NIT, Agartala, Email: ersujoymech05@gmail.com) : Multi attribute decision making for determining optimum process parameter in EDC with Si and Cu mixed powder green compact electrodes. J Sci Ind Res 2018, 77(3), 229-36.

This paper aims at determining optimum operating process parameters influencing multiple responses in Electro Discharge Coating (EDC) process. Combination of Taguchi and FTOPSIS is applied for optimization. Aluminium 6351 alloy is used as substrate and powder metallurgy compact SiC/Cu of mesh size 325 is used as tool electrode. A Taguchi design of experiments is employed to analyze the sensitivity of EDC response parameters like Material Deposition Rate (MDR), Tool Wear Rate (TWR), Surface Roughness (Ra), Layer Thickness (LT) and also Micro-Hardness (MH) by varying process parameters such as compaction load (P), tool composition (C_T), current (I_P) and pulse duration (T_ON). Weight factors of the responses are determined using triangular fuzzy numbers and the most suitable factor level combination were selected by TOPSIS method. A confirmation test is then conducted based on the optimal parameter setting to illustrate the effectiveness of the approach where material deposition rate of 0.6 (mg/min), tool wear rate of 15.132 (mg/min), surface roughness of 2.92 (µm), layer thickness of 85.38 (µm) and micro hardness of 295.15 (HV) have been successfully obtained.

3 illus, 3 tables, 21 ref

025780   GHIME D, GHOSE P (Chemical Engineering Dep, National Institute of Technology, Raipur- 492 010, Email: prabirg.che@nitrr.ac.in) : Kinetic model for the oxidative degradation of aqueous p-Nitrophenol by Fenton?s reagent. J Sci Ind Res 2018, 77(3), 208-12.

This work investigates the oxidative degradation of p-Nitrophenol (PNP) pollutant in aqueous solution using an environmentally friendly advanced chemical oxidation (Fenton’s) process. Degradation experiments of PNP present in aqueous solutions in the concentration range between 3.597 x 10^-3 moles/L (500 ppm) and 7.188 x 10^-3 moles/L (1000 ppm) were carried out in a batch rector. This work describes a mechanistic study for the reaction kinetics between the PNP and hydroxyl (• OH) radical. A model of mechanistic study was planned for degradation of an aqueous PNP in Fenton’s process and that model was used for the calculation of rate constant of the reaction showing the influence of hydroxyl radicals on PNP degradation. Around 96.80 % of degradation was achieved after 60 min of reaction time [700 ppm of PNP concentration, 0.1006 moles/L H₂O₂, 1.798 x 10^-3 moles/L of Fe²⁺ catalyst and pH 3]. Our main purpose was to determine the reaction rate constant between PNP and the hydroxyl radical. The reaction rate constant for the reaction of PNP removal with • OH radicals is estimated as 2.76 x 10¹⁰ L/mole-s.

3 illus, 22 ref

025778   RAO Y M, SUBRAMANYAM M V, PRASAD K S (Electronics & Communication Engineering Dep, JNTUK, Kakinada, Email: mallikyamarthy@live.com) : QoS based mobility management for wireless mesh networks. J Sci Ind Res 2018, 77(3), 203-7.

Radio resource is one among the prime resources in wireless networks which is expected to use in an efficient way especially when the mobile user is on move. This paper proposes QoS Based Mobility Management (QBMM) for Wireless Mesh Networks. It is aimed to decrease the overall network traffic due to the mobility of the users within the network while ensuring the QoS. To accomplish this, pointer forwarding mechanism with Expected Transmission Count as routing metric is used. The proposed algorithm is analyzed for signaling cost, data delivery cost and throughput for both Internet sessions and Intranet sessions. Significant throughput improvement is achieved while maintaining the overall communication cost at low.

3 illus, 2 tables, 23 ref

025777   SULTANA R, AKTER R, QADIR M R, GAFUR M A, ALAM M Z (Applied Chemistry and Chemical Engineering Dep, Dhaka Univ, Dhaka, Bangladesh, Email: zahangir@du.ac.bd) : Porcelain reinforced polyester resin composites: Preparation and characterization. J Sci Ind Res 2018, 77(3), 184-7.

Porcelain reinforced polyester resin composites containing 10-60 % porcelain with respect to the weight of unsaturated polyester resin were prepared by compression molding. Synergistic improvements in the composite properties were achieved and are superior to those of the individual components. The effects of porcelain content on some important physical and mechanical properties such as water absorption, compressive strength and hardness of the composites were investigated in detail. It is evident from the XRD spectra of the composites that porcelain has been incorporated into polyester resin of the composites resulting in better mechanical properties.

4 illus, 1 table, 17 ref

025776   GUPTA A, BHARDWAJ R, BAKSHI A (Electronics and Communication Engineering Dep, IKG PTU Jalandhar, Punjab, Email: amitguptacgc@gmail.com) : Implementation of highly loss budget NG-PON incorporating the direct modulation and advance pulse formats. J Sci Ind Res 2018, 77(3), 181-3.

This paper presents the different modulation formats Return to zero (RZ), Non-return to zero (NRZ) and differential phase shift key (DPSK) and these formats have been investigated in wavelength division multiplexing passive optical network (WDM-PON) at 40 Km. It has been observed that DPSK performs better at long range than return to zero (RZ) and non-return to zero (NRZ) techniques. It is further investigated that with increase of link length, value of quality (Q) -factor decreases and there is increase in the bit error rate (BER). System performance studied at different input powers and it is observed that system performance increase with increase in power but after some value results tend to decrease due to nonlinearities Self phase modulation (SPM), Four wave mixing (FWM), Cross phase modulation (XPM) comes into play.

3 illus, 1 table, 19 ref

025775   KESHTKAR M M, TALEBIZADEHSARDAR P (Mechanical Engineering Dep, Islamic Azad Univ, Iran, Email: mkeshtkar54@yahoo.com) : Investigation of transient conduction?radiation heat transfer in a square cavity using combination of LBM and FVM. Sadhana 2018, 43(3), 64.

In this paper, the effect of surface radiation in a square cavity containing an absorbing, emitting and scattering medium with four heated boundaries is investigated, numerically. Lattice Boltzmann method (LBM) is used to solve the energy equation of a transient conduction–radiation heat transfer problem and the radiative heat transfer equation is solved using finite-volume method (FVM). In this work, two different heat flux boundary conditions are considered for the east wall: a uniform and a sinusoidally varying heat flux profile. The results show that as the value of conduction–radiation decreases, the dimensionless temperature in the medium increases. Also, it is clarified that, for an arbitrary value of the conduction–radiation parameter, the temperature decreases with decreasing scattering albedo. It is observed that when the boundaries reflect more, a higher temperature is achieved in the medium and on boundaries.

7 illus, 1 table, 32 ref

025774   LIJIN J, JOTHI T J S (Mechanical Engineering Dep, National Institute of Technology Calicut, Kozhikode- 673 601, Email: tjsjothi@nitc.ac.in) : Aerodynamic characteristics of an ogive-nose spinning projectile. Sadhana 2018, 43(3), 63.

This work experimentally investigates the Robins–Magnus effect on a 5-caliber spinning projectile at a low subsonic Mach number of 0.1 corresponding to a Reynolds number of 3.2 × 10⁵ based on the model length. The model configuration tested was a cylinder with spherically blunt tangent ogive nose portion. The normal, axial and side force coefficients were obtained for various angles of attack (α) ranging from 0° to 34° with non-dimensional spin rates (Ω) of 0–0.05. Results indicate that the side force coefficient increases with a up to a value of around 28° and decreases thereafter. Interestingly, in the range of spin rates considered in the present study, normal and axial force coefficients are not affected due to spin. However, the side force coefficients are seen to increase with spin rates at higher α. Flow visualization studies are demonstrated to explain the underlying mechanism behind the variation of these aerodynamic coefficients.

10 illus, 1 table, 21 ref

025773   KUMAR H, NAGARAJAN G (Mechanical Engineering Dep, National Institute of Technology Karnataka, Mangalore- 575 025, Email: harsha84.nitk@gmail.com) : A Bayesian inference approach: estimation of heat flux from fin for perturbed temperature data. Sadhana 2018, 43(3), 62.

This paper reports the estimation of the unknown boundary heat flux from a fin using the Bayesian inference method. The setup consists of a rectangular mild steel fin of dimensions 250915096 mm³ and an aluminium base plate of dimensions 250915098 mm³. The fin is subjected to constant heat flux at the base and the fin setup is modelled using ANSYS14.5. The problem considered is a conjugate heat transfer from the fin, and the Navier–Stokes equation is solved to obtain the flow parameters. Grid independence study is carried out to fix the number of grids for the study considered. To reduce the computational cost, computational fluid dynamics (CFD) is replaced with artificial neural network (ANN) as the forward model. The Markov Chain Monte Carlo (MCMC) powered by Metropolis–Hastings sampling algorithm along with the Bayesian framework is used to explore the estimation space. The sensitivity analysis of the estimated temperature with respect to the unknown parameter is discussed to know the dependency of the temperature with the parameter. This paper signifies the effect of a prior model on the execution of the inverse algorithm at different noise levels. The unknown heat flux is estimated for the surrogated temperature and the estimates are reported as mean, Maximum a Posteriori (MAP) and standard deviation. The effect of a-priori information on the estimated parameter is also addressed. The standard deviation in the estimation process is referred to as the uncertainty associated with the estimated parameters.

16 illus, 10 tables, 27 ref

025772   ABAS A, FEI CHONG NG, GAN Z L, ISHAK M H H, ABDULLAH M Z, CHONG G Y (School of Mechanical Engineering, Univ of Science Malaysia, Malaysia, Email: aizatabas@usm.my) : Effect of scale size, orientation type and dispensing method on void formation in the CUF encapsulation of BGA. Sadhana 2018, 43(3), 59.

Prediction of void occurrence during capillary underfill encapsulation process is vital to avoid package failure due to incomplete filling during the encapsulation process. Two design variables, namely the gap height and package orientations, together with different types of industrial standard design of dispensing methods were identified as possible influences to the void formation in encapsulated package. In this paper, all these factors have been closely related to the void formation and subsequently the best chip design has been formulated to improve package reliability. From the study, air entrapment is clearly visualized in the experiment, which can be detrimental as it contains trapped oxygen, which can combust at high temperature. A series of experiments eventually showed higher possibility of air void formation by U-type dispensing method compared with the L-type dispensing method. In addition, it is found that the chip design parameters that include the scaling size and ball grid array orientation have an effect on the size of void formed. Our experimental findings were validated using lattice-Boltzmann method simulation and great consensus is found between both approaches. These findings provide additional insights to the electronic packaging developer to effectively reduce the formation of void during encapsulation process.

11 illus, 5 tables, 21 ref