Analysis of temperature distribution in wire electrical discharge machine on hybrid Al-MMCs

301-306Wire electrical discharge machine (WEDM) is a non-traditional machining technique for producing parts with higher accuracy Al6061 reinforced with 7% silicon carbide and 3% boron carbide is selected as a work-piece and molybdenum wire as an electrode in this work. The machining in WEDM may result in work-piece surface damage and this is due to the materials thermal properties. The work-piece surface consists of voids, cracks and residual thermal stress after machining due to the spark which is used in machining process. The materials which are machined in WEDM are used in aerospace applications. Particle reinforced aluminium metal matrix composites (Al-MMCs) are used as Fan Exit Guide vane in aerospace gas turbine engine and they are operating at very high temperature. The catastrophic failure may happen due to the availability of thermal damage layer. In this work, the WEDM is modelled based on the finite element method program by using the machining parameters such as voltage, current and pulse on time. In order to reduce the thermal damage layer, the set of parameter which is having the least temperature distribution on the material is analysed. It is determined that, the least temperature distribution over the material results in the least thermal damage layer thickness

Indigenous techniques of catching mudskipper in Bhavnagar and Bharuch districts, Gujarat

533-538Indigenous fishing techniques for catching the mudskipper in Bhavnagar and Bharuch districts of Gujarat coast were investigated during 2014-15. The complexities of its muddy habitat and behaviour characteristics make it difficult to catch the mudskipper. Documentation on the fishing methods for catching the mudskipper is not available. This paper describes the two techniques namely- wire mesh technique and noose trap technique employed traditionally by the ethnic communities of fishermen to catch the mudskipper, encountered during the course of the survey. Wire mesh technique is used by fisher folk of Bhavnagar district whereas noose traps technique used by fisher folk of Bharuch district. Fisher folk of these two districts are able to earn their livelihood by these indigenous techniques in the areas which are known for low productivity of marine fishes due to their geomorphological features. Habitat destruction due to growing salt pan activities and industrial set up which leads to continuous shrinking of the mudflats used by fisher folk is the major concern for future livelihood aspects of the fisher folk of these districts

A recent record of the Indo-Pacific Humpback Dolphin Sousa chinensis (Osbeck, 1765), (Mammalia: Cetartiodactyla: Delphinidae) from the western shores of Kachchh, Gujarat, India

A total of six individuals of S.chinensis were observed near the Jakhau creek, which is the western part of Gulf of Kachchh. The GPS location of the sighting is 23°14’28.5” N and 68°35’54.0" E. The dolphins were spotted in the mid-high tide time on 03 December 2014 at 9.53 hrs (IST). These dolphins were found less than 10 m away from the shore at a depth of 1-10 m. The dolphins were observed for a time period of 20 minutes. The dolphins while leaping continuously, kept following the boat for sometime and approaching as close as five meters during certain occasions. These dolphins were also observed at the same time on the same location on the following day. A questionnaire survey with nearby fishermen had confirmed that these dolphins were seen in this part of Gujarat during winter. Therefore, it is assumed that weather condition and prey availability is favorable for this species during this period. This is the first record of S. chinensis in western shore of Kachchh district detailed study regarding the distribution of this species is required across the creek system of Western Kachchh.</p