iosr-JMCE   Volume-18 ~ Issue-5 ~ Sep. – Oct. 2021

Abstract: The relationship between tensile properties and microstructure of medium carbon steel which had its matrix toughened by an austempering process in rubber seed oil as quenchant was studied. The austempered medium carbon steel exhibits good mechanical properties with a unique microstructure consisting of a matrix of bainitic ferrite and retained austenite. The austempering time had effect on tensile properties (tensile strength(UTS), yield strength, percentage elongation, impact energy and hardness value). These properties have correlation with the microstructure of the austempered medium carbon steel. The results revealed that the yield and tensile strength of the medium carbon steel austempered in rubber seed oil was found to increase with an increase in austempering time up to 4 hrs when it attained a fully bainitic structure, and then decreases. The variation in the properties with the bainitic level reveals the relationship between mechanical properties and bainite content.

Key words: austempering, austenitized, bainite, Rubber seed oil, socked

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Abstract: The purpose of this paper is to compare two of welding processes, Metal Arc Gas Welding and Hybrid laser-assisted metal arc gas welding that consists of two processes; MAG Welding and laser beam welding. This paper attempts to determine which of these processes works better in industrial applications, and demonstrating the reasons.

Keywords: MAG welding process, Direct current, Shielding gas, Filler metal, Power, Energy, Laser beam, Laser beam welding, nd:YAG, Hybrid laser MAG welding, System, Process, Advantages, Disadvantages.

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Abstract: The increase in the number of private vehicles that are not balanced with spatial planning and transportation systems can cause various traffic problems. The existence of the Makassar–Parepare Railway network is expected to reduce traffic density in the Maros Regency. One of the development patterns that can be developed to support the railway system and settlement spread in Maros is the concept of Transit Oriented Development (TOD). The objectives of this study are: Analyzing the feasibility of the Marusu TOD location from the aspect of mixed use 'demand' and connectivity with bus transportation and develop the TOD concept as a support function of the Makassar-Parepare-South Sulawesi railway service function. Sources of data come from observations and document of spatial planning, Central Bureau of Statistics, analysis using image map interpretation with ArcGIS application.

Keywords: Transit Oriented Development, Railway, Connectivity, Settlement Spread

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Abstract: This paper demonstrates how a multi-response orthogonal array of gray relational analysis enhanced parameters in friction stir processing (FSP) of Aluminum Alloy AA 6061 and Al2O3 powder. The L9 orthogonal sequence of Taguchi configuration is used to streamline the FSP process parameters on ultimate tensile strength, micro-hardness, and percentage elongation. The optimization process parameters are traverse speed , rotational speed, weight composition percentages of Al2O3 and tool geometry.The aim of this article is to decide the best parameters for achieving the maximum ultimate strength, micro-hardness, and percentage elongation. In GRG, optimum parameter levels were determined and the significant parameter contribution was measured with ANOVA. The confirmation run specifies and confirms the optimum method parameter amounts.

Keywords: Gray relational analysis, Friction stir processing, Al2O3, L9 Orthogonal Array.

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Abstract: Maritime Science Polytechnic is a higher education with applied skills in shipping science is directed at producing professional graduates. The Sultan Hasanuddin training vessel is intended to prepare competent human resources. This study aims to analyze the performance of the training vessel unit and the level of competence of cadets using a qualitative descriptive method. The results showed that the performance of the training vessel unit was in a good category, had carried out the duties and responsibilities in improving the competence of cadets with an average value of 76.9%, seen from a total of 97 participants who passed the Seafarer Skill Test only 13 participants and according to the established regulations. The Seafarer Expertise Examiner who passes the seafaring skill test is competent cadets and get a level III nautical expert certificate. Furthermore, the graduation rate comparison of cadets prala prala in the last five years has increased since the existence of a training vessel in the environment of Makassar Maritime Science Polytechnic with a comparison in 2014 of 5% and in 2019 as much as 56%.

Keywords: Shipping, cadet competence, training vessel

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