Dalam mencegah eksploitasi energi fosil secara berlebihan, maka energi terbarukan menjadi satu-satunya solusi dalam hal ini. Hidrogen merupakan salah satu pembawa energi terbarukan bila proses produksinya berasal dari sumber daya yang tidak dapat habis. Salah satu metode proses produksi hidrogen yang terbarukan adalah alkaline water electrolysis. Penelitian ini bertujuan untuk meneliti proses produksi hydrogen, hubungan antara distribusi ukuran gelembung dan volume hidrogen yang dihasilkan, serta efisiensi waktu pelepasan gelembung hidrogen. Dalam penelitian ini digunakan campuran KOH dan aquades sebagai elektrolit serta arus listrik searah untuk daya listriknya. Konsentrasi KOH dan daya listrik divariasikan untuk mendapat perbandingan yang signifikan. Terdapat 3 variasi konsentrasi yang digunakan yaitu 5%, 7%, dan 10%, lalu untuk daya listrik, digunakan daya 0,01 watt, 0,07 watt, serta 0,14 watt. Hasil penelitian ini menunjukkan bahwa distribusi ukuran gelembung hidrogen tidak memiliki pengaruh yang signifikan terhadap volume gas hidrogen yang dihasilkan. Dalam proses produksi hidrogen, larutan elektrolit dan daya listrik yang digunakan sangat berpengaruh terhadap volume hidrogen dan efisiensi waktu yang dihasilkan, dimana semakin tinggi persentase elektrolit dan daya listrik yang diberikan, maka semakin efisien pula waktu pelepasan gelembung hidrogen dan volume hidrogen yang dihasilkan semakin tinggi.
This study investigates the influence of wheel rotational speed and brake pad material on the temperature of disc braking systems. The experimental setup incorporates an LM393 speed sensor and a MAX6675 thermocouple temperature sensor, both interfaced with an Arduino microcontroller, with data output displayed via a MATLAB GUI and an LCD screen. Testing was conducted in three repetitions across four rotational speed variations (1000, 1500, 2000, and 2500 rpm) and three types of brake pad materials: standard, semi-metallic, and full-metallic. The results indicate a direct correlation between rotational speed and braking temperature. At 2500 rpm, the highest temperatures recorded were 83.3°C for full-metallic pads, 59°C for semi-metallic pads, and 47°C for standard pads. These findings confirm that both the pad material and wheel speed significantly affect the heat generation during braking.
As the use of the KZR 150CC motorbike experiences a decrease in the torque power produced, it is necessary to make modifications to increase the torque power. This study is to analyze the effect of porting variations on the cylinder head of the Honda KZR 150CC engine using Pertalite fuel on the torque power produced. Porting modifications are carried out on the intake port channel with a diameter of 24.5 mm, 26.5 mm, and 28.5 mm and the exhaust with a diameter of 20.5 mm, 22.5 mm, 24.5 mm. Engine performance testing is carried out using a dyno test to measure torque values at various engine speeds. The test results show that each porting variation produces different torque characteristics. The standard engine has an advantage at low speeds with a peak torque of 11.66 Nm at 6520 RPM, porting 1 excels at medium speeds with a torque of 11.46 Nm at 7270 RPM, while porting 2 shows the best performance at rotations with a peak torque of 12.32 Nm at 7270 RPM. In terms of horsepower, the standard engine has an advantage at low revs with a peak torque of 10.71 HP at 6520 RPM, porting 1 excels at medium revs with a torque of 11.76 HP at 7270 RPM, while porting 2 shows the best performance at revs with a peak torque of 12.62 HP at 7270 RPM.
Ketergantungan sistem manajemen mesin pada electronic control unit (ECU) memicu kebutuhan akan alat diagnosis off-board yang aman dan efisien. Penelitian ini mengembangkan simulator ECU berbasis Arduino Uno dengan pendekatan hardware-in-the-loop (HIL) untuk mensimulasikan sinyal sensor CKP, CMP, dan analog. Pengujian dilakukan secara komparatif pada tiga unit: ECU Toyota Avanza K3-VE, Daihatsu Ayla 1KR-DE (normal), dan Daihatsu Ayla (fault). Hasil menunjukkan akurasi status output aktuator sebesar 100% dibandingkan kondisi nyata. Simulator berhasil mengidentifikasi kegagalan aktivasi koil silinder 3 pada unit fault, menampilkan kode DTC yang relevan melalui OBD-II scanner, serta menunjukkan karakteristik hysteresis fan relay sebesar 5 °C yang stabil. Alat ini terbukti efektif sebagai media pembelajaran logika kerja sistem mesin dan instrumen pra-diagnosis kerusakan ECU yang terkontrol dan ekonomis.
The performance of automatic motorcycles is influenced by the Continuously Variable Transmission (CVT), particularly the roller component that regulates the transmission ratio. The use of alternative fuels such as 5% ethanol (E5) is also relevant to improve energy efficiency and reduce emissions. This study analyzes the effect of roller weight variation on the power and torque of a 125 cc indirect injection motorcycle fueled with E5. The independent variable is roller weight (12 g, 15 g, 18 g), while the dependent variables are power (HP) and torque, with controlled variables including motorcycle type, fuel, and dynamometer. The experiment was conducted through dynotest and analyzed descriptively. Results show that 12 g rollers provide the best initial acceleration (9.82 HP at 7500 rpm), 15 g rollers are more stable at mid–high rpm (8.57 HP at 8000 rpm), and 18 g rollers produce the highest torque (9.27 Nm at 6000 rpm).
