SINTEK JURNAL: Jurnal Ilmiah Teknik Mesin

The Effect of Variation in Electrode Type and Area on Electrical Productivity of MFC With Sago Stem Substrate

Muhammad Nizar Ramadhan, Rizal Hamdani — Sun, 01 Dec 2024 00:00:00 +0000

Microbial Fuel Cells (MFC) offer a promising solution for developing efficient and environmentally friendly alternative energy sources. MFCs convert chemical energy into electrical energy through anaerobic reactors equipped with anode and cathode electrodes containing substrates and microbes. This study investigates the effect of electrode type and area on the production of current, voltage, and power density using sago stem substrates in an MFC system enhanced with Lactobacillus plantarum. These bacteria play a critical role in facilitating electrolysis, thereby increasing electrical energy output. A dual-chamber MFC design was employed, testing electrode materials (copper, aluminum, nickel, and graphite carbon) and areas (30 cm², 40 cm², and 60 cm²). Measurements of current, voltage, and power density were taken over 36 hours. Results indicate that electrode area significantly influences voltage and current, while electrode type determines power density. The highest average power density, 432.953 mW/m², was achieved using nickel electrodes with a 30 cm² surface area. These findings underscore the importance of optimizing electrode properties to enhance the performance of MFCs.

Experimental Analysis of Climate Parameters Effect on Structural Steel Atmospheric Corrosion Rate in Medan City Environment

Sun, 01 Dec 2024 00:00:00 +0000

This study aims to explore the important role of weather parameters i.e. humidity, rainfall, temperature, and wind speed on the corrosion rate in the Medan City atmospheric environment. Three forms of material with low carbon steel type were prepared in this investigation. The exploration process was conducted for six months starting from June to December 2023, in the open area of the Engineering Faculty, Universitas Muhammadiyah Sumatera Utara. Corrosion rate assessment is carried out monthly using the weight loss method and climate parameter data is obtained from the Medan City Meteorology and Geophysics Agency (BMKG). The dimensions, initial preparation, data collection, post-test material preparation, and corrosion rate calculations refer to the ASTM G1 and G50 standards. Regression analysis and Pearson correlation explain the relationship between corrosion rate and climate parameters. The investigation showed that the corrosion rate fluctuated monthly from 0.1 to 0.5 mpy. By referring to corrosion resistance data on metal materials, it was found that the corrosion level was in the good resistance category "outstanding". Based on the regression analysis results, humidity, local temperature, and rainfall play an important role in the atmospheric corrosion rate in Medan City. The percentage of closeness between variables is ± 98% and the standard deviation is ± 0.0001. Further development is needed to determine other parameters that also play an important role in atmospheric corrosion rate and forming a random forest model for predicting future corrosion rates.

Optimisation of Air-water Harvester Machine Performance With Variations of Inlet Air Flow Velocities

Mirmanto Mirmanto, Made Wirawan, Ahmad Tarmisi — Sun, 01 Dec 2024 00:00:00 +0000

In the dry season, some parts of Indonesia experience drought and clean water crisis which results in scarcity and difficulty in drinking water. One way to overcome this problem is to present a water-producing device from air called a water harvester machine. The purpose of this study was to examine the effect of the inlet air velocity of 4 m/s, 5 m/s, and 6 m/s on the mass of water produced and the rate of heat transfer. This study was conducted experimentally with R134a refrigerant working fluid, and a 1 PK rotary compressor and centrifugal fan. The results showed that the highest water mass, which was 5.99 kg, was obtained at an air velocity of 6 m/s. The highest heat transfer rate, which was 2080.2 W, was also obtained at a speed of 6 m/s. This can be caused by the high inlet air velocity, the inlet air mass flow rate is also high so that the water vapor content that enters is greater. As a result, the mass of water produced is greater and the rate of heat transfer that occurs is also greater.

Development of a Special Service Tool for Hydraulic Piston Maintenance on Excavator PC 210-10M0

Sun, 01 Dec 2024 00:00:00 +0000

Excavators are essential machinery widely utilized in mining, construction, plantation, and other industries. The Komatsu PC210-10M0, a small-sized excavator model, performs critical operations such as material digging and transportation. However, during component overhauls, particularly for the boom cylinder, bucket, and arm, significant challenges arise due to the absence of suitable tools for efficiently removing and installing hydraulic cylinder pistons. The current reliance on generic tools such as screw wrench sets (L-keys) is suboptimal, leading to inefficiencies, increased risks of workplace accidents due to tool slippage, and longer processing times. This study addresses these limitations by employing the Seven Up++ method to develop a specialized service tool specifically designed for hydraulic cylinder piston maintenance. The methodology encompasses three critical phases: Analysis, Solution, and Results, ensuring a systematic and innovation-focused approach. The developed tool securely positions itself on the piston cylinder, utilizing two pins inserted into pre-existing holes on the piston surface. The results demonstrate significant improvements: maintenance processing time is reduced by up to 70%, operational safety is enhanced due to the tool's secure attachment, and labor requirements are halved, with manpower reduced from two operators to one. These findings highlight the tool's potential to optimize maintenance operations and improve overall efficiency in the use of Komatsu PC210-10M0 excavators.

Analysis of Corrosion Rate Al 7075 Using Seawater and Rainwater Media Using the K2CRO4

Brillian Rakha Paramarta, Sehono Sehono, Ikbal Rizki Putra — Sun, 01 Dec 2024 00:00:00 +0000

Aluminum is one of the most widely used materials today due to several advantages, including its lightweight nature, relatively high tensile strength, good formability, corrosion resistance, and non-magnetic properties, making it a preferred choice in industries such as aerospace. However, metals, including 7075 aluminum alloy commonly used in the aerospace industry, are still susceptible to corrosion in corrosive environments. One effective method to control corrosion is the use of inhibitors. An inhibitor is a chemical substance that, when added in small amounts to a corrosive environment, can effectively slow down or reduce the corrosion rate. This study investigates the corrosion rate using the potentiodynamic polarization method (Tafel plot) in seawater from Parangtritis Beach and rainwater from Yogyakarta City. The inorganic inhibitor used in this research is K₂CrO₄ with a concentration of 0.3%. The results show that the corrosion rate in seawater without inhibitors (pH 7.34) is 0.027799 mm/yr, while with inhibitors (pH 7.50), it decreases to 0.0053243 mm/yr. Similarly, the corrosion rate in rainwater without inhibitors (pH 6.66) is 0.0021987 mm/yr, while with inhibitors (pH 7.74), it reduces to 0.0017807 mm/yr. These findings demonstrate the effectiveness of K₂CrO₄ inhibitors in minimizing corrosion rates in both seawater and rainwater environments.