Informatics Publishing Limited

Aravinda Pai ¹, Shaju K. Albert ², Prabhat Kumar ¹, T. K. Mitra ¹, Irappa Sogalad ³, S. Basavarajappa ³

Affiliations
1 Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
2 Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
3 Department of Studies in Mechanical Engineering, U.B.D.T. College of Engineering, Davanagere, Karnataka, IN

Abstract

Modified 9Cr-1Mo material is selected as principal material of construction of Steam Generators (SG) for India's first of its kind 500MWe Prototype Fast Breeder Reactor (PFBR). The fabrication of PFBR Steam Generators involves welding of 12mm, 30mm and 90mm thick modified 9Cr-1Mo components which were carried out by combination of hot wire and cold wire Gas Tungsten Arc Welding processes. Hot wire Gas Tungsten Arc Welding (GTAW) is a relatively new process and limited machines/facilities are available in India for welding with this technique. The most important benefit from the use of a hot wire GTAW system is high weld deposition rate and reduced dilution & porosities from the weld deposits. Eventhough welds were meeting the specification requirements during welding procedure qualification, limited information available on hot wire GTAW process in open literature motivated authors for characterization of welds produced by this specialized technique. During welding procedure qualification, it was found that impact test results of weld metal produced by cold wire GTAW process is superior than weld metal produced by hot wire GTAW process. In light of this, detailed investigation & micro-structural analysis is carried out to find out the ischolar_main cause for variation in impact properties. This paper details the systematic evaluation and interesting observations during characterization of microstructure & mechanical properties of modified 9Cr-1Mo welds produced by hot wire and cold wire GTAW processes.

Keywords

Modified 9Cr-1Mo, Hot Wire GTAW, Mechanical Properties, Cold Wire GTAW.

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B. Latha Shankar ¹, S. Basavarajappa ², Rajeshwar S. Kadadevaramath ¹, R. Vezhavendhan ³

Affiliations
1 Dept. of Industrial Engg. & Management, Siddaganga Institute of Technology, Tumkur, IN
2 Dept. of Studies in Mechanical Engg., University BDT College of Engg., Davangere, IN
3 VIT University, Vellore, IN

Abstract

In the traditional inventory systems, demand and lead time data are assumed to be available and follow some probability distribution mostly normal. But in reality supply chain is dynamic in nature and associated with lots of uncertainties. In this paper an attempt is made to model (Q,r) (optimum order quantity, reorder point) policy in uncertain supply chain environment. Imprecise demand is modeled using fuzzy set theory and an iterative procedure is developed to calculate optimum order quantity, reorder point and total cost of maintaining inventory. The iterative procedure is demonstrated using a numerical example and obtained numerical results are compared with their crisp counterpart.

Keywords

Continuous Review, (Q,R) Policy, Fuzzy Demand, Triangular Fuzzy Number, Extension Principle.

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S. Basavarajappa ¹, G. Chandramohan ², Ajith G. Joshi ¹

Affiliations
1 Dept. of Studies in Mechanical Engg., University BDT College of Engg., Davangere, IN
2 Karpagam College of Engg., Coimbatore, IN

Abstract

An attempt has been made in the present investigation to study the effect of graphite incorporation in Al2219/15SiC_p composite. This study evaluates the influence of independent parameters such as cutting speed and feed rate on Thrust force and surface roughness. Taguchi design of experiments is used to collect the data in a controlled way and a linear regression model was developed. This paper aims to model thrust force and surface roughness with drilling parameters using a statistical approach. The results obtained in this work enable influence and significance of various parameters on drilling characteristics of Al2219/15SiC_p-graphite to be better understood. It was found that SiC_p-Gr reinforced composites exhibit less thrust force but detrimental effect on surface roughness compared to SiC_p composite. Feed rate is the most significant factor affecting the drilling parameters followed by cutting speed.

Keywords

Drilling, Metal Matrix Composites, Al/SiC_p-Gr, Surface Roughness, Taguchi Technique.

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Senthoorraja R. ¹, Subaharan K. ², Ankita Gupta ², S. Basavarajappa ¹, Lalitha Y. ², Bakthavatsalam N. ², Chandran K. P. ³

Affiliations
1 Department of Zoology Studies, University of Mysore, Mysore - 570006, Karnataka, IN
2 ICAR - National Bureau of Agricultural Insect Resources, H. A. Farm Post, Bellary Road, Hebbal, Bengaluru - 560024, Karnataka, IN
3 ICAR - Central Plantation Crops Research Institute, Kasaragod - 671124, Kerala, IN

Abstract

Housefly, Musca domestica is used as an alternate host to rear a eulophid, Nesolynx thymus (Girault), a pupal parasitoid of the tachinid fly, Exorista bombycis (Louis) which in turn is an endolarval parasitoid of Bombyx mori (L.). An attempt was made to evaluate the host factors like pupal size, age and exposure periods of N. thymus for developing robust mass multiplication methods. The host size had significant effect on mean parasitism by N. thymus. Mated females of N. thymus when exposed to host pupae of varying size, revealed that mean per cent parasitisation was significantly higher (74%) in large sized pupae having a volume of 263.89 mm3. Regarding host age, 24 - 48 h old host pupae had higher level of parasitism (65%) by N. thymus. The parasitism rate declined with an increase in host age after 72 h. In field evaluation, release of N. thymus at weekly interval resulted in the reduction of housefly population as evinced from the higher parasitism (56 %) of the sentinel cards placed in the treated poultry sheds. The information on host factors generated will help to enhance the mass multiplication of parasitoid for the release of which would aid to bring down the M. domestica population in poultry and dairy units.

Keywords

Biological control, Musca domestica, Nesolynx thymus

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R. Senthoorraja ¹, K. Subaharan ², Deepak Kumar Patel ³, Vppalayam Shanmugam Pragadheesh ⁴, S. Basavarajappa ¹, N. Bakthavatsalam ²

Affiliations
1 Department of Studies in Zoology, University of Mysore, Mysore 570006, IN
2 ICAR-National Bureau of Agricultural Insect Resources, H A Farm Post, Bellary Road, Hebbal, Bengaluru 560024, Karnataka, IN
3 CPMU, Jawaharlal Nehru Centre for Advanced Scientific Research 560064, Bangalore, IN
4 National Centre for Biological Sciences- TIFR, Bengaluru 560065, IN

Abstract

House fly Musca domestica L. is a pest of humans, poultry, and livestock across the world. Dependence on chemical insecticides to contain the flies provided varying results and their continued use has led to development of insecticide resistance. Bioactive compounds in plants are an alternative source to manage M. domestica. Lemon grass, Cymbopogon citratus, Stapf essential oil caused fumigant toxicity to eggs (LC501.299 mg/dm3) and adults (16.56 mg/ dm3). The C. citratus EO caused larval repellence. Polyvinylpyrrolidone when used as polymer matrix to load C. citratus at 1:1, 1:2, and 1:3 caused toxicity to flies for a longerperiod as compared to use of EO alone. The EO loaded in polymer matrix had a slower dissipation, EO+PVP polymer mixed at 1:3 retained over 80% of EO after 72 hr when exposed to 60oC. EO, whilst EO alone without a dispenser dissipated in 3 hr. The biological effect of C. citratus EO on M. domestica canbe enhanced for a longer period if loaded into a polymer matrix and this would be an effective strategyto manage M. domestica.

Keywords

Cymbopogon citratus, essential oil, fumigant toxicity, Musca domestica, polyvinyl pyrrolidone, polymer matrix, slow delivery, repellence activity, ovicidal toxicity, GC-MS

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