The search for renewable and sustainable energy sources has heightened the significance of biodiesel. However, conventional production methods often rely on costly chemical catalysts that produce harmful waste, which this study addresses by introducing a low-cost, recyclable solid catalyst derived from abundant jackfruit peel waste in Indonesia. The novelty of this work lies in transforming underutilized biomass into a functional catalyst that improves both environmental sustainability and economic feasibility. Jackfruit peel was processed through cleaning, drying, grinding, open-air burning, and calcination at 500 °C for 120 minutes. The resulting material exhibited significant catalytic activity, with characterization confirming the presence of carbonates and metal oxides, particularly potassium (42.1%). Optimization of the transesterification reaction was carried out using a 1:9 molar ratio of oil to methanol, 12% catalyst loading, and a reaction temperature of 65 °C for 105 minutes. Under these conditions, the catalyst achieved a biodiesel yield of 98.9%. The produced biodiesel met the Indonesian National Standard (SNI 7182:2015) for key physicochemical properties. This research highlights the potential of agricultural waste as a sustainable catalyst source, offering an effective pathway toward cleaner biodiesel production and supporting circular economy practices in renewable energy development.

The current study builds upon the prior research (Mulkan et al., 2023) [1], which successfully created an innovative solid catalyst from discarded jackfruit peel waste (JPW) to produce biodiesel from waste cooking oil (WCO). Expanding on this initial research, our study's primary objective is to assess the performance and emissions attributes of a diesel engine when utilizing blends of WCO biodiesel and conventional diesel fuel under full load conditions, covering engine speeds from 1200 to 2400 rpm. The results show that as engine speed increases, brake-specific fuel consumption (BSFC) decreases by an average of 16.67%-22.69%, while brake thermal efficiency (BTE) increases by 16.67%. Engine torque initially decreases and drops significantly at higher speeds, while brake power (BP) proportionally rises. Notably, substantial reductions in CO emissions (ranging from 6.11% to 48.63%) were observed at all engine speeds compared to pure diesel. However, CO2 and NO emissions generally increased, although some fuel samples demonstrated reductions. Hydrocarbon emissions decreased with higher engine speeds, while smoke opacity increased, with slight reductions observed for specific fuel samples at 1800-2400 rpm. In conclusion, blending WCO biodiesel synthesized using the JPW catalyst with pure diesel results in improved engine performance and reduced exhaust emissions.

This study aims to develop and convert jackfruit (Artocarpus heterophyllus) peel waste (JPW) into a new solid catalyst suitable for biodiesel synthesis. The calcination process of JPW ash was carried out for 2 h at various temperatures ranging from 500, 600, 700, and 800 degrees C, and the results showed that ash calcined under 500 degrees C produced the highest yield of 92.38%. Based on the characterization result, potassium, calcium, and magnesium were significant components in the prepared catalyst. These components are desirable in biodiesel synthesis, making the catalyst a promising candidate for this process. The response surface methodology (RSM) revealed that the optimum conditions for the synthesis process include an oil-methanol molar ratio of 1:9, a catalyst weight of 12% (w/w), a reaction time of 105 min, and a constant temperature of 65 degrees C, yielding a methyl ester content of 98.88%. The reusability result indicated that the JPW catalyst could be used three times with the highest yield of 93.33%. Moreover, the WCO biodiesel properties were analyzed and found to fulfill ASTM D 6751 requirements. This study demonstrated that JPW can be successfully employed as a solid catalyst for biodiesel synthesis.

Modeling and simulation of batch adsorption of the organic dye methylene blue (MB) by modified metal-organic framework-5 (MOF-5) were investigated. The reported data on the adsorption of MB dye onto Wells-Dawson acids (H 6 P 2 W 18 O 62 )-immobilized MOF-5 were employed. The film-pore diffusion model was developed based on external mass transfer coefficient and pore diffusion coefficient that govern the mass transfer process in batch organic dye adsorption. Applying the estimated parameters, the MB adsorption by using modified MOF-5 was examined to evaluate the effects of MOF-5 modification, initial dye concentration, temperature, and the dosage of adsorbent. The adsorption capacity of modified MOF-5 (H 6 P 2 W 18 O 62 /MOF-5) was higher than pure MOF-5. Besides, a lower initial MB dye concentration, higher temperature, and lower adsorbent dosage resulted in higher MB dye adsorption capacity.

One of the concerns in wastewater pollution is the presence of colored compounds, such as dyes. Acid violet 7 (AV7) and brilliant green (BG) are examples of synthetic dyes that have been used in various applications. In this work, a comparison of AV7 and BG dye adsorption was investigated using an adsorbent prepared from the mixture of rice husk ash (RHA) and coal fly ash (CFA). The attention was focused on the major batch adsorption parameters, which include adsorbent dosage, initial dye concentration, contact time, pH, shaking speed, and temperature. A lesser amount of RHA-CFA adsorbent was found to be used for adsorbing the same concentration of BG as compared to AV7. In contrast to AV7, the adsorption of BG rapidly attained equilibrium. The effective pH for BG removal is in the pH range of 6–8, while the highest AV7 removal was obtained at a low pH value. The adsorption removal for AV7 and BG increases with rising shaking speed and temperature. Scanning electron morphology (SEM) analysis showed the morphological porous structure on the RHA–CFA adsorbent surface. X-ray diffraction (XRD) analysis indicated the presence of complex compounds containing cristobalite, quartz, and mullite compounds in the RHA–CFA adsorbent. The study revealed that RHA–CFA adsorbents can remove AV7 and BG from an aqueous medium.<br>

Switching substations are usually supplied from one express feeder which can cause a low level of reliability due to disruption or outage on the express feeder. Also, the lack of power supply at the ends of the network causes voltage drops. One way to solve this problem is to reconfigure the network. In this study, testing was carried out on a distribution system in the Nagan Raya Regency, namely the distribution system of PT. PLN (Persero) ULP Jeuram originally had a radial system. Furthermore, the distribution system was reconfigured with the Krueng Isep hydroelectric power plant which was included in the PLN ULP Jeuram grid so that the system that was originally radial became a loop configuration. The method used in analyzing the network reconfiguration process is to use the ETAP 12.6 application. As a result, after reconfiguring the network the voltage increased from 19.2 kV to 20.7 kV, the highest increase was at the Beutong Substation which reached 1.5 kV and decreased power losses in the network with a total of 188.2 kW and 263.1 kVAR. Furthermore, before the network reconfiguration, ULP Jeuram SAIFI value was 22.25 times/customers and SAIDI values 1337.74 minutes/ customers. However, after reconfiguring the network, ULP Jeuram SAIFI value fell to 15.39 times/customers and SAIDI to 945.6 minutes/customers, resulting in an increase in system reliability by 70.69%. Keyword:Reconfiguration of network, distribution system, hydroelectric power plant, SAIDI, SAIFI

The environmental temperature has increased significantly reaching 33oC as felt by the community, one of which is in the Aceh region which triggers Global Warming. As a result of the increase in temperature in the Aceh area, many buildings and houses become uncomfortable especially during the daytime because most house with zinc roof. This will cause the temperature in the house and the air around it to increase. Therefore, it is necessary to do research on the study of heat absorption on colored zinc roofs. This research method is to calculate the heat absorption (sun intensity) in zinc that has been coated with several kinds of colors such as white, red, blue, yellow and black. The purpose of this study was to determine the color that has the least amount of heat absorption to the sun's intensity. The highest room temperature on zinc-coated black is 49.2° C and the lowest is in white. 40.9°C from the pen. In the environmental temperature observation, there is the highest temperature at 12.00. Room temperature increased the highest temperature at 12.00 on black zinc. The distribution of room temperature can be averaged with a yellow color of 46.0°C, a black color of 49.2°C, a blue of 45.5°C and a white zinc of 40.9 oC. The heat absorbed in the room is 47.9 joules, so from the overall average of the test it can be described that the room temperature is 45.6 and the zinc temperature is 53.8oC from the highest temperature difference at 12.00 WIB, room temperature and 13.00 WIB the highest absorption occurs at zinc temperature.

Sistem drainase yang tidak baik merupakan salah satu permasalahan yang sering terjadi di beberapa daerah di kawasan Aceh besar yang merupakan areal pertanian. Berbagai macam usaha telah dilakukan oleh para petani diantaranya dengan mengalirkan air dari sumur dengan menggunakan pompa listrik. Keadaan ini membuat para petani harus mengeluarkan biaya tambahan untuk membuat instalasi listrik untuk menggerakkan pompa air dimana diperlukan kabel listrik yang panjang agar pompa dapat teraliri arus listrik. Untuk mengatasi permasalahan ini maka perlu dilakukan analisa potensi energi angin sebagai sumber energi listrik pada sistem pengairan di daerah pertanian Aceh Besar, terutama di desa Blang Krueng. Tujuan dari penelitian ini adalah untuk menganalisis sumber energi angin sebagai sumber listrik untuk menggerakkan pompa pada sistem drainase pertanian di Desa Blang Krueng Kabupaten Aceh Besar. Luas lahan pertanian yang menjadi analisis dalam penelitian ini adalah ± 0,5 Hektar. Metode pengambilan data penelitian ini dilakukan dengan mengukur kecepatan angin dan analisa kebutuhan daya yang diperlukan untuk menggerakkan pompa. Dari hasil analisa diketahui bahwa kecepatan angin rata-rata pada Bulan April, Mei dan Juni 2019 berturut-turut adalah 2,93 m/s, 3,12 m/s dan 2,91 m/s dengan rata-rata selama tiga bulan 2,98 m/s. Nilai kecepatan ini dapat dikatagorikan untuk penggunaan turbin angin kecepatan rendah (low speed wind turbine).

Wind power is dominant energy converted into electricity through wind turbine generators used in wind energy conversion systems. Technological developments produce various types of generators for use in wind power plants of various scales. Permanent magnet generator (PMG) has advantage of being able to produce electrical energy of 500 watts at rotation 600 rotate per minute with an input wind speed of 2.5-12 m/s. The potential for average wind speed throughout the year in Aceh is around 1.5-6.5 m/s cannot be generate electric power because mechanical energy from turbine rotation is not sufficient to meet the minimum demand for RPM generators. The design of a horizontal axis wind turbine (HAWT) with Air Foil Naca 2410 is used to increase the efficiency of the turbine rotation. It’s influenced by variations in the number of blades and material used. Stages of simulation are prioritized to get efficient variations of the number of blades and the most effective material testing is performed. The results showed that variation of the axis of a three-blade wind turbine type has a higher coefficient of power that is 50 percent compared the other, the type of material wind turbines made from pinus more optimal than fiberglass.