http://repository.president.ac.id/xmlui/handle/123456789/3264 2026-04-07T14:13:56Z http://repository.president.ac.id/xmlui/handle/123456789/11753 Thin Plate Welding of Al 5083 Alloy by GMAW Applied for Electric Substations Equipment Anggraini, Lydia; Erwin Siahaan; Lutfi Fadilah In order to fill the manufacture demand of electric substation equipment, materials with the characteristics of rust-resistant, lightweight and easy to find are required. Aluminum 5083 alloy is the best candidate to use because one of advantages is excellent thermal conductivity. Gas Metal Arc Welding (GMAW) is used because it has high welding efficiency, it does not need to change welding wire frequently, can be used for all types of materials and welding positions, and does not produce scale or slag. The purpose of this research is to evaluate the GMAW welding parameters on the mechanical properties of Al 5083 alloy. The specimen of Al 5083 alloy is cut into V Groove with 30° or 60° angle each side, for 6 pieces with dimension of 300 mm length and 150 mm width, before welding process. The welding process is done using the manipulator machine with constant speed and various currents followed by mechanical testing. The mechanical testing results obtained, there is no significant difference on the tensile strength results of all specimens with different welding parameters. However, the elongation percentage result obtained, the highest strain is about 17% of the Al 5083 alloy thin plate specimen with 225 A current. It can be concluded that the Al 5083 alloy material through the GMAW process with appropriate has met the requirement of mechanical properties to be applied for the electric substation equipment. International Symposium on Advances in Mechanical Engineering 2021. p. 1-6. 2021-01-01T00:00:00Z http://repository.president.ac.id/xmlui/handle/123456789/11752 The J-value as the measurement tool of the bonds investor's behavior Ginting, Joseph; Lydia Anggraini For many years, mathematics has been used to solve the problem in economic and finance instead of natural science and engineering. This paper shows how accurate mathematics reads financial behavior. One of the financial areas using the mathematics approach is the bond valuation technique. Bond is one of the long term debt instruments. The finding in this research is that mathematics can be used to read the changes in the concept of a pricing model where the par value of bonds is always going to 100% at the maturity date. Theoretically, the bonds fair price is resulted by calculating the present value of future coupon interest of bonds, but not in practice, caused by the bonds investor behavior. The difference in price, resulted from both different approaches, in this paper is defined by a new mathematical concept to reflect the bonds' investor behavior. It is the aim of this research. To address the differences, we have evaluated the fair price of bonds calculation by creating new mathematics equations by combining the calculation of the present value of future coupon interest of bonds with the market concept models. The result is a new mathematical model called J-Value. To prove the eligibility of J-Value, a simulation was done. The mathematics model in this paper is found by combining the usage of a qualitative method and supported by a quantitative method. The 2nd Science and Mathematics International Conference (SMIC 2020); p. 1-9. 2021-01-01T00:00:00Z http://repository.president.ac.id/xmlui/handle/123456789/11751 The Crispness of Cassava Crisps with Random Shape by Compression Test Anggraini, Lydia; et al The most popular term that is used to represent brittleness texture of dry food is its crispness. Based on the previous studies, the crispness becomes the most essential quality of crisps that define the enjoyment when eating the food. Despite its importance, crispness is still determined qualitatively by human sensory perception which is very ambiguous. Thus, a measurement technique to quantitatively define the crispness level of dry food is needed. This study introduces a measurement technique by means of compression test to quantitatively determine the crispness of dry food with random shapes. The evaluated specimen is cassava crisps with three different thicknesses: 1, 2, and 3 mm. The parameters utilized to express the crispness level are strain energy and jaggedness obtained from the load-displacement curve. According to the evaluation, the results show that the 1 and 2 mm specimens are 29.2 and 16.5% crispier than the thickest specimen of 3 mm. Proceedings of the Symposium on Advance of Sustainable Engineering 2021 (SIMASE 2021); p. 1-5. 2021-01-01T00:00:00Z http://repository.president.ac.id/xmlui/handle/123456789/11750 Machine Tonnage Optimization by Reused Scrap Material Applied for Car Propeller Shaft Guard Anggraini, Lydia; Ventika Aurora Pratiwi The purpose of this research is to analyze how the scrap material or metal scrap can be reused as a regular material in a production process. The reused scrap material is prepared to use in propeller shaft guard production. This propeller shaft guard is used with the main function to guard the propeller shaft in the car. Therefore, calculating the total mass of the scrap material and propeller shaft guard is needed to know the ratio of the usage of material, the machine tonnage calculation for propeller shaft guard production using reused scrap material, and the new design for blanking material. The total machine tonnage for producing propeller shaft guard using reused scrap material is 260.09 T. The new design for the propeller shaft guard can fit the reused scrap blanking material is created. The total usage of scrap material increased from 49.46% to 79.69% after the material was used in the propeller shaft guard production. The comparison between the condition before and after using reused scrap material as the propeller shaft guard indicates the factors of the total amount of blanking material, the total amount of dies, and dandori are described in this research. 2019 International Conference on Sustainable Engineering and Creative Computing (ICSECC); p. 24-29. 2019-01-01T00:00:00Z