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All Journal Mechatronics, Electrical Power, and Vehicular Technology Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Rawa Sains: Jurnal Sains STIPER Amuntai International Journal of Renewable Energy Development
Rajani, Ahmad
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Agriculture, Biological Sciences & Forestry Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering

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Three axis deviation analysis of CNC milling machine Subagio, Dalmasius Ganjar; Subekti, Ridwan Arief; Saputra, Hendri Maja; Rajani, Ahmad; Sanjaya, Kadek Heri
Journal of Mechatronics, Electrical Power and Vehicular Technology Vol 10, No 2 (2019)
Publisher : Research Centre for Electrical Power and Mechatronics, Indonesian Istitutes of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3373.202 KB) | DOI: 10.14203/j.mev.2019.v10.93-101

Abstract

The manufacturing technology has developed rapidly, especially those intended to improve the precision. Consequently, increasing precision requires greater technical capabilities in the field of measurement. A prototype of a 3-axis CNC milling machine has been designed and developed in the Research Centre for Electrical Power and Mechatronics, Indonesian Institute of Sciences (RCEPM-LIPI). The CNC milling machine is driven by a 0.4 kW servo motor with a spindle rotation of 12,000 rpm. This study aims to measure the precision of the CNC milling machine by carrying out the measurement process. It is expected that the CNC milling machine will be able toperform in an optimum precision during the manufacturing process. Accuracy level testing is done by measuring the deviations on the three axes namely X-axis, Y-axis, and Z-axis, as well as the flatness using a dial indicator and parallel plates. The measurement results show the deviation on the X-axis by 0.033 mm, the Y-axis by 0.102 mm, the Z-axis by 0.063 mm, and the flatness of the table by 0.096 mm, respectively. It is confirmed that the deviation value is within the tolerance standard limits set by ISO 2768 standard. However, the calibration is required for this CNC milling machine to achieve more accurate precision. Furthermore, the design improvement of CNC milling machine and the application of information technology in accordance with Industry 4.0 concept will enhance the precision and realibility.
Multi-objective optimisation and sensitivity analysis of component influences on efficiency in air-based bifacial photovoltaic thermal systems (B-PVT) Rajani, Ahmad; Mat Said, Dalila; Noorden, Zulkarnain Ahmad; Ahmad, Nasarudin; Arifin, Muhammad Subhan; Komarudin, Udin; Atmaja, Tinton Dwi; Subagyo, Subagyo; Fudholi, Ahmad
International Journal of Renewable Energy Development Vol 13, No 4 (2024): July 2024
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2024.60212

Abstract

Bifacial Photovoltaic Thermal (B-PVT) technologies have seen significant advancements in sustainable energy production by converting solar energy into useful electric and thermal energies simultaneously. The present study explored the optimisation of these systems by first performing sensitivity analysis on design parameters to identify key variables affecting their performance efficiencies. The system design and performance were then studied simultaneously using a multi-objective optimisation algorithm NSGA-II. It was found that increasing packing factors from 0.4 to 0.8 leads to a 15% increase in both electrical and thermal efficiencies, while an asymmetry in channel depths could lead to an 8% increase in thermal efficiency.  Key design parameters such as transmissivity cover, mass flow rate, packing factors and channel depth ratios were found to have the most significant influence on overall system performance. Multi-objective optimisation of design variables results in a Pareto front describing trade-offs between solutions of conflicting objectives of performance. Optimisation with preferences towards overall efficiency over temperature differential produces solutions with a high overall efficiency yield of 70.79%, requiring specific values for mass flow rate (0.197 kg/s) and channel ratio (0.129), however at the expense of a reduced temperature differential of 5.12oC. Solutions with a balanced preference towards both objectives could produce a solution that is less biased in performance.
Sustainable energy production: Performance evaluation of a generator-set using cow dung-based biogas Kusnadi, Kusnadi; Wahid, Mazlan Abdul; Yasin, Mohd Fairus Mohd; Rajani, Ahmad; Fudholi, Ahmad
Journal of Mechatronics, Electrical Power, and Vehicular Technology Vol 15, No 2 (2024)
Publisher : National Research and Innovation Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/j.mev.2024.967

Abstract

Interest in utilizing new and renewable energy sources, commonly known as bioenergy, has significantly grown in the past decade due to the mounting environmental concerns, such as air pollution, global warming, and ozone layer depletion, resulting from the accelerated consumption of fossil fuels. Biogas, derived from the anaerobic decomposition of organic materials like cow dung, presents a viable solution due to its high methane content and calorific value. This study aims to assess the performance of biogas-fueled generator sets utilizing cow dung as the raw material for biogas production. The generator set employed has a power capacity of 2,500 Watts, and various load variations ranging from 150 to 350 Watts were applied. The parameters measured include voltage, current, biogas discharge, and efficiency. The findings indicate that the generator's output power for the five load variations of 150, 200, 250, 300, and 350 Watts are 150, 226.7, 266, 298.3, and 372.3 Watts, respectively. Moreover, the fuel consumption rates range from 0.013 to 0.009 kg/minute for the 150 to 350 Watts load, respectively. Notably, the 350 Watts loading exhibits the highest efficiency compared to other load variations, with an efficiency percentage of 14.51 %. This research advances our knowledge of the useful uses of biogas in generating systems, where its use is growing.
Kontribusi Pendapatan Usaha Sarang Burung Walet (Collocalia Spp) Di Desa Namun Kecamatan Jaro Kabupaten Tabalong Rajani, Ahmad; Zuraida, Ana; Ilma Ifada, Inda
Rawa Sains: Jurnal Sains STIPER Amuntai Vol 11 No 2 (2021): Edisi Desember 2021
Publisher : LPPM Sekolah Tinggi Ilmu Pertanian Amuntai

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36589/rs.v11i2.198

Abstract

Penelitian ini bertujuan untuk mengetahui teknis usaha sarang burung walet, biaya, penerimaan, pendapatan dan kontribusi usaha sarang burung walet serta permasalahan yang di hadapi peternak sarang burung walet di Desa Namun Kecamatan Jaro Kabupaten Tabalong.Waktu penelitian dimulai dari bulan April sampai dengan Juni Tahun 2021.Penelitian ini menggunakan metode survey dan metode pengambilan sampel secara Purposive Sampling dengan kriteria usaha sarang burung walet aktif berjalan dan usaha sudah menghasilkan. Tahap-tahapan / teknik dalam usaha sarang burung walet meliputi menyiapkan gedung buat burung walet, membunyikan suara speker buat mengundang burung walet, pemeliharaan seperti penyemprotan dan mengisi air di baskom-baskom, melakukan pemanenan dan pengendalian hama dengan cara menyemprot dengan obat hama. Hasil penelitian ini menunjukkan bahwa rata-rata untuk biaya total sebesar Rp. 5.443.350,- per tahun. Total rata-rata penerimaan sebesar Rp. 36.000.000,- per tahun. Pendapatan untuk usaha sarang burung walet per tahun adalah Rp. 33.412.650,- per responden, untuk usaha diluar sarang burung walet sebesar Rp. 68.400.000,- per tahun. Rata-rata kontribusi pendapatan sebesar 52% termasuk kriteria sangat baik. Permasalahan yang di hadapi oleh peternak sarang burung walet dalam melakukan usahanya adalah kurangnya pengetahuan tentang usahanya tersebut, dan dari usaha nya sendiri permasalahan yang sering di hadapi yaitu hama seperti kelelawar, tikus, kecoa, dan burung burung gereja.
Investigation of Drying Time and Final Moisture Content of Arabica beans in a Solar Drying Chamber Ramdhani, Rendi; Septianissa, Selly; Rajani, Ahmad
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol. 14 No. 6 (2025): December 2025
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtepl.v14i6.2239-2249

Abstract

Drying is a critical stage that affect directly the quality, storability, and market value of Arabica coffee beans. The objective of this study was to investigate the performance of a solar drying chamber integrated with a thermal collector and phase change material (PCM), operated under a constant airflow velocity of 9.2 m/s. Arabica beans of 1500 g were dried over two observation days, with chamber temperatures ranging from 40 °C to 46.5 °C and peak solar radiation of 1122 W/m². The results showed that the system effectively maintained thermal stability and drying performance despite fluctuations in solar input. The analysis revealed at Day 2 achieved a higher and faster moisture reduction due to improved solar conditions and absorber efficiency, with drying rates peaking at over 42 g vapor per hour in the third hour. In contrast, at Day 1 the drying rate peaked in the third hour at approximately 22.45 g vapor/h. Day 1 exhibited a more stable but slower drying trend. Overall, the system successfully reduced the beans’ moisture content to below 12.8% in within under 14 hours, with Tray 2 delivering the most consistent results. These findings demonstrate that the integration of solar thermal energy, PCM, and forced convection application significantly improved drying efficiency and reliability, offering a sustainable alternative for post-harvest processing, especially in regions with variable weather conditions.
Co-Authors Ahmad Fudholi Ahmad, Nasarudin Arifin, Muhammad Subhan Dalmasius Ganjar Subagio Hendri Maja Saputra Ilma Ifada, Inda Jayawarsa, A.A. Ketut Komarudin, Udin Mat Said, Dalila Noorden, Zulkarnain Ahmad Ramdhani, Rendi Ridwan Arief Subekti Sanjaya, Kadek Heri Selly Septianissa Subagyo Subagyo Tinton Dwi Atmaja Wahid, Mazlan Abdul Yasin, Mohd Fairus Mohd Zuraida, Ana