One of the fossil fuels is petroleum fuel. Petroleum is a non-renewable natural resource. Various aspects of life have felt its effects, where fuel oil has begun to experience scarcity. The higher price of fuel oil should make us realize that the amount of oil reserves has begun to run low. The purpose of this study was to determine the effect of electrodes, current strength, and concentration of NaHCO3 on the HHO gas generator output. HHO electrode generator material made of aluminum and brass. The electrode’s shape is rectangular with a size of 250 mm x 400 mm, with a gasket seal. The test begins with the HHO gas pressure test. The independent variable used is aluminum and brass electrode variations. The electric current given is 20A, 30A, 40A, and the amount of 5-25% NaHCO3 catalyst. Then proceed with analyzing the pressure obtained on the HHO gas flow rate. To test the HHO gas flow rate carried out with a duration of 1 to 3 minutes in each treatment, the measurement of the discharge using a gas regulator to determine the flow rate of H2 and O2 produced. The results showed that the lowest gas discharge value was on aluminum electrodes with a current of 20A, i.e., 0,00033554 m3/s, while the highest discharge value on brass electrodes with a current of 50A was 0,001657 m3/s. It shows that the better the metal element contained in the electrodes and the higher the current applied, the greater the flow of H2 and O2 gas flow.

Konsumen berhak mengonsumsi susu yang aman, sehat, utuh dan halal. Faktor yang memengaruhi produktivitas dan kualitas susu, di antaranya adalah ketinggian lokasi serta kondisi lingkungan di sekitar peternakan. Penelitian ini bertujuan menganalisis perbedaan kualitas mikrob dan jumlah sel somatik (JSS) susu dari peternakan yang berlokasi di dataran tinggi (Cijeruk, Bogor) dan peternakan yang berlokasi di dataran rendah (Pondok Ranggon, Jakarta Timur). Parameter yang diamati, ialah angka lempeng total (ALT) mikrob, jumlah Staphylococcus aureus, dan JSS. Pengujian mikrob menggunakan metode hitungan cawan dan penghitungan JSS menggunakan metode Breed. Data dianalisis secara statistik dengan uji Mann-Whitney U dan Chi-square. Hasil ALT mikrob, jumlah S. aureus, dan JSS dalam susu yang berasal dari peternakan Pondok Ranggon yang berlokasi di dataran rendah menunjukkan nilai yang lebih tinggi dibandingkan dengan susu yang berasal dari peternakan Cijeruk yang berlokasi di dataran tinggi. Rata-rata ALT mikrob, jumlah S. aureus, dan JSS dalam susu dari peternakan Cijeruk berturut-turut adalah 1,6×104 ± 1,5×104 CFU/mL; 1,3×103 ± 4,2×103 CFU/mL; dan 1.795.000  ± 1.838.791 sel/mL. Rata-rata ALT mikrob, jumlah S. aureus, dan JSS dalam susu yang berasal dari peternakan Pondok Ranggon berturut-turut adalah 3,5×105 ± 1,0×106 CFU/mL; 1,7×105 ± 6,3×104 CFU/mL; dan 3.032.222 ± 4.348.654 sel/mL. Penelitian ini menunjukkan terdapat hubungan yang signifikan antara lokasi peternakan dengan jumlah S. aureus dalam susu (P<0,05). Kesimpulan dari penelitian ini ialah status mikrob dan JSS dalam susu dipengaruhi oleh lokasi peternakan.

Stainless steels consist of several types such as Austenitic, Ferritic and Martensitic, Martensitic is one of the stainless steels that has a hardenability property, so it is suitable to be used as cutting tool components which require high hardness and corrosion resistance . The purpose of this study was to obtain information about the hardness of stainless steel martensitic type of hardening results with variations of cooling media. Methods of research used were experiments, ie hardening process by heating the material up to 1100oC temperature, held for 30 minutes, then cooled quickly on water, oil and the air, then heated back to 400oC temperature, cooled slowly, the results tested the hardness of Rockwell C method The results showed the type of stainless steel type martensitic 431 increased significantly after the Hardening process of 21.20 HRC before hardening, and after the hardening process to 47 , 6 HRC with water cooling, 47.9 HRC with oil cooling medium and 46.5 HRC for air cooling media, hardness after tempering down ranges from 6-7 HRC to 41.7 HRC for hardening with water cooling medium 41, 2HRC hardening results with oil cooling medium, and 40,4HRC un tuk hardening results with air conditioning medium.

The paper discusses magnetic power generators; if a conductor moves across the magnetic field, a voltage difference will occur at the ends of the conductors. The voltage rises as it approaches the area and vice versa, so electricity arises in cycles: positive - zero - negative - zero. In this study utilizing the rotation of a magnetic motor caused by the unbalance repulsive force between magnets. The design of the tool starts with designing a generator model that will be made. The design of generators is based on calculations obtained through the reference of generator design. The generator design uses magnets instead of anchor coils on the rotor (source of magnetic flux) and copper wire coils as anchor coils on the stator. This design considers rotor and stator parameters, including the distance between magnets, rotor diameter, rotor plate thickness, area of a magnetic area, number of stator coils, number of stator windings, and stator coil dimensions, and calculate generator output power. Tool testing is done to obtain data from tools that have been made. In testing the comparison of the results obtained from the study of the target to be achieved, if the results have not yet reached the target, then improvements are made to the results obtained as expected. Tests were carried out with no load and burden. The results showed that the rotor speed in the generator design could be achieved by determining the number of rotor poles, the generator voltage is influenced by the flux density produced by permanent magnets and the number of stator windings.

The groundwater physical condition in Sleman Regency, Indonesia is generally cloudy and contains high amount of iron (Fe) so it is not sufficient to use for daily needs drinking water. High levels of Fe are dangerous for humans. This study aims to process and purify ground water and reduce iron content using laban wood (Vitex pubescens Vahl). This media was chosen because it is a local waste furniture industry in Sleman Regency. Indeed, it is conducted as charcoal. Then, the charcoal is chemically activated by soaking with H2SO4 for 24 hours. Furthermore, it is activated physically by heating up to 120°C for 30 minutes. Laban wood (Vitex pubescens Vahl) activated charcoal was characterized using UV-Vis to determine iron (Fe) levels after filtration. In addition, the filtration water is measured using a pH meter to determine the degree of acidity, TDS meter and the efficiency of light transmission to determine the turbidity. To summarize, Laban wood activated charcoal was effectively used as a filtration media. It gives an effect for increasing the light transmission efficiency, decreasing TDS value, and absorption of iron (Fe) levels efficiency. However, it does not affect the pH value. The highest light transmission efficiency value is found in the adsorbent type of laban activated charcoal which is equal to (6.91 ± 0.005)% at a mass of 500 grams. As for the TDS value, the highest decrease in TDS value was TDS value of (140.0 ± 0.5) ppm when it was 500 grams. The highest efficiency of absorption of iron content is found in the composition of laban activated charcoal which is equal to Fe to (87.27 ± 0.2)%. This activated charcoal can be used as a medium to reduce iron content up to (2.27 ± 0.005) mg / L. Therefore, laban active charcoal which is chemically activated with H2SO4 for 24 hours effective to reduce iron (Fe) levels according to the stipulated clean water requirements Indonesian Minister of Health Regulation Number 416 / MENKES / PER / IX / 1990.