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Journal : Rotasi

The Effect of Pressure Variations on the Characteristics of Coconut Shell Based Briquettes Using Tapioca Starch Adhesive Devia Gahana Cindi Alfian; Marone J Tambunan; Fajar Paundra; Dicky J Silitonga; Lathifa Putri A; Muhammad Syaukani
ROTASI Vol 25, No 3 (2023): VOLUME 25, NOMOR 3, JULI 2023
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.25.3.23-32

Abstract

The very limited availability of energy on this planet is one of the main problems that concerns almost all countries. The presence of emergency energy indicates that energy usage is very high. Therefore, encouraging the use of new and sustainable energy sources is of utmost importance. Biomass energy can be the answer to overcoming the limitations of decreasing fossil assets, especially through the production of charcoal briquettes. Biomass energy is derived from plants or easily traceable natural materials that are abundant, such as wood waste, rice husks, bagasse, and coconut shells. Coconut shells, for example, can be a primary ingredient for making charcoal briquettes, using tapioca flour or starch as an adhesive. The briquettes can be produced using pressure variations of 50 kg/cm², 60 kg/cm², and 70 kg/cm², with a drying temperature of 100°C for 3 hours. The recommended ratio for making charcoal briquettes is 3 parts coconut shell to 1 parts tapioca flour adhesive. The purpose of this study is to compare the briquettes produced with coconut shell and tapioca flour adhesive to the SNI Briquette standard No.1/6235/2000. For the conducted tests, the results were as follows: the water content was 6.06%, the ash content was 5.9695%, the carbon content was 43.5946%, and the calorific value was 34,182.6808 calories. Additionally, the substance score yield was 26.845%, and the combustion rate was 0.12179 g/minute.
Investigating the Tribological Performance of Natural Rubber Additives in Palm Oil-Based Lubricants Aji, Ahmad Frantoni; Alfian, Devia Gahana Cindi; Prasetyo, Tri Wahyu; Firjatullah, Ahmad Labib; Sufra, Rifqi; Pujiyulianto, Eko; Silitonga, Dicky Januarizky; Auriyani, Wika Atro; Yusupandi, Fauzi
ROTASI Vol 26, No 3 (2024): VOLUME 26, NOMOR 3, JULI 2024
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.26.3.57-64

Abstract

Human dependence on mineral-based energy sources poses challenges related to toxicity, depletion, degradation, and environmental hazards. An appropriate replacement for mineral-based lubricants has yet to be realized; one available option for humans is alternative, renewable, environmentally friendly, and biodegradable energy sources. Lubricants play an important role in product processing, transportation, agriculture, and other key sectors in industrial development. This study was conducted to explore the potential use of palm oil as the main ingredient with the addition of rubber as an additive. The method of making the lubricant involved mixing 3%, 5%, and 7% rubber latex with sonicated palm oil using UAE. Next, wear testing was performed using a tribometer based on the ball-on-disc principle, utilizing a modified bench-top drill machine. The testing was carried out at room temperature, maintaining a constant load of 8.83 N and a rotational speed of 180 rpm for 5 minutes per sample. Microscopic analysis of the wear scars on the plate samples showed different wear patterns and characteristics for each lubricant, with measurements taken at various positions for accuracy. The results indicated that the lubricant with a 5% rubber mixture was the best, with a wear width of 535.9126 µm, compared to the commercial lubricant (SAE 15W 40) which had a wear width of 539.906 µm. This research demonstrates the potential use of a palm oil and rubber mixture as a more environmentally friendly lubricant alternative.
Simulation Study of Pin-Type Heatsinks on Convection Heat Transfer Characteristics in Electronic Devices Chaniago, Noverto Zhorif; Alfian, Devia Gahana Cindi; Syaukani, Muhammad; Pujiyulianto, Eko; Nurullah, Fajar Perdana; Silitonga, Dicky Januarizky
ROTASI Vol 26, No 4 (2024): VOLUME 26, NOMOR 4, OKTOBER 2024
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.26.4.47-53

Abstract

Electronic components are components that require an optimal design in order to provide good heat release performance. The heat sink component is a relevant solution to help cool an electronic component by flowing heat energy into the environment either naturally or forcibly with the help of a fan. The purpose of this study is to determine the effect of material type on heat sink temperature distribution, determine the phenomenon of velocity boundary layer and thermal boundary layer that occurs in each heat sink variation, determine the effect of design shape and pin arrangement on pressure drop, determine the best design according to the final results of the study. This research uses 6 variations of design shape, 2 variations of arrangement (inline and staggered), and 3 types of materials (Aluminum, Copper, and Iron). The method used in this research is a simulation method with three stages of process, namely, pre processing, processing, and post processing. The results showed that copper material is the best in conducting heat with a temperature drop of 98.5% from the base temperature. The inline arrangement obtained a lower pressure drop than the staggered arrangement and the best design was obtained by fillet square perforation with an inline arrangement.