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All Journal International Journal of Renewable Energy Development Jurnal Keteknikan Pertanian Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management) agriTECH Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat Warta IHP (Warta Industri Hasil Pertanian) Jurnal Ilmiah Rekayasa Pertanian dan Biosistem Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Jurnal Teknik Mesin Indonesia International Journal of Renewable Energy Development
Nelwan, Leopold Oscar
Departemen Teknik Mesin Dan Biosistem, Fakultas Teknologi Pertanian, Institut Pertanian Bogor, Kampus IPB Dramaga, Bogor, 16680
Aerospace Engineering Agriculture, Biological Sciences & Forestry Automotive Engineering Chemistry Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Mechanical Engineering

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Mendeteksi Anomali Termal Pada Prospek Panas Bumi Lahendong Menggunakan Aster TIR dan Landsat 8 Mohammad Aftaf Muhajir; Kudang Boro Seminar; Leopold Oscar Nelwan
Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management) Vol 13 No 3 (2023): Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (JPSL)
Publisher : Pusat Penelitian Lingkungan Hidup, IPB (PPLH-IPB) dan Program Studi Pengelolaan Sumberdaya Alam dan Lingkungan, IPB (PS. PSL, SPs. IPB)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jpsl.13.3.494-503

Abstract

This study intends to determine geothermal anomalies area using remote sensing data in the form of Landsat 8 and ASTER satellite imagery data which have Thermal Infrared Sensor (TIRS). Through pre-processing like georeferencing, radiometric calibration, and atmospheric correction, the Landsat 8 TIRS and ASTER data were wont to invert the land surface temperature of the study area during the daytime and night time using the inversion of planck function and emissivity separation algorithm. Result shows the land surface temperatures during daytime and night time of four natural land cover —water, vegetation, built up area, and bare soil—were classified and analyzed. According to the results, vegetation and bare soil show relatively thermal anomalies during the day and comparatively cold anomalies during the night. Otherwise water shows relatively cold anomalies during the day and relatively thermal anomalies during the night. Meanwhile built up area shows relatively thermal anomalies during the day and cold anomalies during the night. Superimposed and calculating mean of the night and day surface temperature can adequately eliminate the relatively cold/thermal anomalies of land cover caused by solar radiation, thus effectively highlighting geothermal anomalies. Thus, Nine geothermal anomalies areas were successfully extracted.
Exergoeconomic Analysis of Integrated Rice Mill Systems with Gasifiers Omil Charmyn Chatib; I Wayan Budiastra; Mohamad Solahudin; Y. Aris Purwanto; Leopold Oscar Nelwan
Jurnal Keteknikan Pertanian Vol. 11 No. 2 (2023): Jurnal Keteknikan Pertanian
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.011.2.128-137

Abstract

Applying the concept of utilizing rice mill waste as an energy source can support the increase in the productivity of renewable energy. The exergonomic concept can be used as one of the steps to see opportunities for husks to be used as an energy booster in a rice mill system that has been integrated with a gasifier. Specific Exergy Cost (SPECO) is used as the method, that combines exergy and economic analysis by applying the cost concept to the thermal system. Based on the analysis results, gas producers can replace diesel fuel in small-sized rice mill systems. Compared with these inputs, husks and energy products from the gasifier can produce nearly 6 and 4 times the exergy, respectively. In addition, gas utilization producers can also reduce fuel expenditure costs by up to 84.67%.
Thermal Characteristics of Coconut Shells as Boiler Fuel Muhamad Yulianto; Edy Hartulistiyoso; Leopold Oscar Nelwan; Sri Endah Agustina; Chandra Gupta
International Journal of Renewable Energy Development Vol 12, No 2 (2023): March 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.48349

Abstract

Agricultural waste products, such as wood, rice husk, corn waste, and coconut shells, are abundantly available  and can potentially be used as an energy source, particularly  for direct combustion in boilers. Because coconut production increases every year, it would be useful to find an alternative use for coconut shells, which are a type of coconut waste. As coconut shells can be used as fuel in boilers, the aim of this study was to evaluate the thermal characteristics of coconut shells in this regard. This study used experimental results to evaluate the performance of a boiler when coconut shells were used as solid fuel. The variations in feed rate were 5, 7.5, and 10 kg/h, and the water flow rates varied between 1 litre per minute (lpm), 2 lpm, and  3 lpm. Temperature data were collected every second via data acquisition , and the mass flow rate of the flue gas was collected every 5 min using a pitot tube equation. One of the parameters evaluated in determining the success of coconut shells as boiler fuel is the thermal efficiency of the boiler. The results showed that the maximum thermal efficiency reached approximately 62.04%, and the maximum flue gas temperature was approximately 500 ℃ for a biomass mass flow rate of 7.5 kg/h. The maximum water temperature of the boiler was 99 ℃, which was reached at a minimum water flow rate of 1 lpm. The results showed that coconut shells are suitable for use as boiler fuel. 
KOMBINASI METODE PENJEMURAN DAN PENGERINGAN TUMPUKAN UNTUK MEMPERBAIKI MUTU BIJI KAKAO KERING Tya Lestari; Leopold Oscar Nelwan; Emmy Darmawati; Samsudin Samsudin; Eko Heri Purwanto
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol 9, No 3 (2020): September 2020
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtep-l.v9i3.264-275

Abstract

Deficiencies in the drying and stacking methods of cocoa beans can be minimized by using a combination of both to improve quality. The purpose of this study was to obtain physicochemical and organoleptic quality information of dried cocoa beans produced by a combination of drying and stack drying. The treatments analyzed were drying 3, 8 and 16 hours followed by mechanical drying using an air flow of 0.05 m/s and 0.2 m/s at a temperature of 55 °C. As a control is only mechanical drying with two flow rates, up to a water content <6%. Measurement data were analyzed using descriptive statistics and mean values. The best combination of drying and mechanical drying is found in 8 hours of drying with an air flow velocity of 0.05 m/s and 0.2 m/s. The combination of sun and mechanical drying has no effect on physical parameters namely water content and pH, chemical parameters namely total fat and fermentation index. The best color of cocoa beans is produced from a combination of 16 hours of drying with an air flow rate of 0.05 m/s. The lowest free fatty acid levels come from full mechanical drying with an air flow velocity of 0.05 m/s and 3 hours drying in the air flow velocity of 0.2 m/s. The combination of the best treatment based on the special requirements of SNI 2008 about the quality of defective seeds and organoleptic test results were produced by 8 hours drying air velocity of 0.05 m/s and 0.2 m/s. Included in the IB quality class and has the aroma, texture and color most preferred by panelists.       Keywords:   air flow, bed dryer, cacao quality, dried cacao, sundrying
Analisis keseragaman kolektor surya pelat datar glazed dan unglazed Efendi, Rustam; Nelwan, Leopold Oscar; Wulandani, Dyah
Jurnal Teknik Mesin Indonesia Vol. 19 No. 1 (2024): Jurnal Teknik Mesin Indonesia
Publisher : Badan Kerja Sama Teknik Mesin Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36289/jtmi.v19i1.599

Abstract

Solar collectors, as a means of converting solar energy into thermal energy, are the focus of this study. Two types of solar collectors used, namely glazed flat plates (KSPDG) and unglazed flat plates (KSPDU), are tested to evaluate uniformity of performance. The study was conducted using a testing setup that included a tank, water pump, thermocouple, flowmeter, anemometer, and pyranometer. Uniformity testing is performed by analyzing inlet temperature, outlet temperature, ambient temperature, and solar irradiation during 8 hours of testing. Test results show that both types of solar collectors show similar trends in performance, with increases in water temperature aligned with increased solar irradiation. Statistical analysis shows a similar level of uniformity between KSPDU I and KSPDU II, as well as between KSPDG I, KSPDG II, and KSPDG III.
Combination of Osmotic Dehydration and Further Drying to Improve the Quality of Dried Carrots Ranti - Ranti; Leopold Oscar Nelwan; Emmy - Darmawati
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol 13, No 1 (2024): March 2024
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtep-l.v13i1.232-241

Abstract

The food industry needs carrots as a processed product for dry products using drying technology to maintain product quality. The aim of the research was to examine the effect of osmotic dehydration temperature with ternary solution on the quality of carrots. The treatments studied were osmotic media temperatures of 25°C and 50°C combined with oven drying and infrared until the water content reached ±10%. Parameters measured after osmotic dehydration were loss of water and increase in solids, quality parameters after further drying were water content and post-storage quality parameters were carotenoids and rehydration test. The dehydration treatment resulted in a reduction of water of 27.25%-44.24% and addition of solids of 15.37%- 18.31%. The initial water content of carrots before osmotic treatment was 90%, the water content after osmotic at 25°C was 65.72% and 50°C was 63.29%. Combination of osmotic with oven requires 22-24 hours of drying time while infrared requires 8- 10 hours of drying time. The best carotenoid value was osmotic dehydration at 25°C followed by an oven or infrared with a value of 32.95(mg/100g)–31.94(mg/100g). Whereas at 50°C the rehydration values were in the range 271.14%-301.42% Keywords: Carrots, Infrared drying, Osmotic dehydration, Osmotic solution, Oven drying
Pendugaan Umur Simpan Manisan Kering Jambu Biji dalam Kemasan Menggunakan Metode ASLT Siregar, Gokma Ampetua; Ahmad, Usman; Nelwan, Leopold Oscar
Jurnal Ilmiah Rekayasa Pertanian dan Biosistem Vol 13 No 1 (2025): Jurnal Ilmiah Rekayasa Pertanian dan Biosistem
Publisher : Fakultas Teknologi Pangan & Agroindustri (Fatepa) Universitas Mataram dan Perhimpunan Teknik Pertanian (PERTETA)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jrpb.v13i1.1145

Abstract

Processing guava into dried candied is an alternative to extend the shelf life of guava. The purpose of this study was to estimate the shelf life of dried candied guava in polypropylene plastic packaging at any storage temperature. Through changes in the values of the quality parameters, the shelf life of candied guava at various storage temperatures was determined using the Accelerated Shelf Life Testing (ASLT) method of the Arrhenius model. Dried candied guava that had been packaged in polypropylene plastic packaging (0,08 mm thickness) and then was stored in an incubator with several storage temperatures, which are 35ºC, 40 ºC, 45 ºC, and 50ºC. Quality analysis was conducted on changes in water content, color value, and vitamin C. Estimation of the shelf life of the Arrhenius model is based on critical quality parameters, in this study the deterioration of vitamin C content is the critical parameter. The shelf life of dried candied guava in polypropylene plastic packaging when stored at 20˚C is 282 days, at 25˚C storage is 134 days, and storage at 30˚C lasts up to 65 days. Shelf life will increase if the dried candied guava is stored at a lower temperature and vice versa.
The Effectiveness of Zero Energy Cool Chamber in Extending the Shelf Life of Cherry Tomatoes with Packaging Treatment Syahputra, Sufri Yanto; Darmawati, Emmy; Nelwan, Leopold Oscar
Jurnal Keteknikan Pertanian Vol. 13 No. 2 (2025): Jurnal Keteknikan Pertanian
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.013.2.227-248

Abstract

Cherry tomatoes are of high economic value due to their better nutrition, sweet flavor, and crunchy texture. They are in modern markets due to specific demand and intensive cultivation. Periodic harvesting poses distribution and storage challenges as cherry tomatoes are perishable, leading to price fluctuations and quality deterioration. Temporary storage is required to maintain quality before marketing. Zero Energy Cool Chamber (ZECC) is a low-cost and environmentally friendly cold storage alternative. This study aims to determine the combination of zeolite particle size combined with sand as a cooling medium on the ZECC wall that produces a shelf room temperature according to the temporary storage needs of cherry tomatoes. Cherry tomatoes were stored in retail (250 g) and bulky (1500 g) packaging to assess the effectiveness of the packaging in maintaining quality. Parameters measured included moisture content, texture, color, vitamin C content, and organoleptic. The results showed that chamber 1 (zeolite No. 1 mesh 14-20) was more stable than chamber 2 (zeolite No. 2 mesh 8-16). When loaded, the temperature of chamber 1 ranged from 24.6°C to 27.7°C with RH 94.7% to 95.4%. Retail packaging gave the best results with an organoleptic score of 4.03-4.16 on day 15, higher than the control. The vitamin C content in the retail packaging reached 35.83 mg/100 g, higher than the control (28.94 mg/100 g).
Energi Terbarukan dari Berbagai Varietas Kelapa Sawit di Penajam Paser Utara, Indonesia Usman, Ali; Seminar, Kudang Boro; Nelwan, Leopold Oscar; Sjaf, Sofyan
Jurnal Keteknikan Pertanian Vol. 13 No. 2 (2025): Jurnal Keteknikan Pertanian
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.013.2.284-301

Abstract

Kelapa sawit berpotensi menjadi sumber energi terbarukan strategis dalam mendukung transisi energi nasional. Penelitian ini bertujuan mengkaji potensi empat varietas sawit (Sain, Lonsum, Dumpy, Marihat) di Kabupaten Penajam Paser Utara untuk biodiesel, minyak konsumsi, dan biomassa. Metode yang digunakan mencakup analisis kadar lemak, komposisi asam lemak, dan skenario pemanfaatan berbasis data produksi TBS dan CPO tahun 2023. Hasil menunjukkan bahwa varietas Lonsum dan Sain cocok untuk biodiesel, sementara Dumpy dan Marihat lebih sesuai untuk minyak konsumsi. Dengan alokasi proporsional dan konversi limbah TBS menjadi briket, diperoleh potensi produksi sebesar ±41.200 ton biodiesel, ±26.159 ton minyak konsumsi, dan ±115.104 ton biomassa padat per tahun. Total potensi energi mencapai ±3,49 juta GJ per tahun. Temuan ini menunjukkan peluang besar pengembangan agroindustri mandiri energi berbasis kelapa sawit di wilayah penyangga IKN.
Improvement of cured vanilla pod qualities (Vanilla Planifolia A.) with a combination of advanced sweating and drying methods”. Budiastra, I Wayan; Nelwan, Leopold Oscar; Distriani, Putri Ayu Ira
Jurnal Keteknikan Pertanian Vol. 13 No. 1 (2025): Jurnal Keteknikan Pertanian
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.013.1.147-161

Abstract

Buah vanili kering merupakan bahan pangan yang digunakan sebagai pemberi rasa dan aroma pada berbagai makanan seperti es krim, kue kering, dan sirup. Buah vanili kering dihasilkan petani melalui proses pasca panen yang panjang meliputi pemanenan, pelayuan, pemeraman dan pengeringan dengan mutu yang bervariasi. Penelitian ini bertujuan untuk mempelajari kombinasi metode pemeraman lanjut dan pengeringan untuk meningkatkan mutu buah vanili kering dan mempersingkat waktu pengeringan. Sebanyak 33 kg buah vanili dipanen, dilakukan proses pelayuan dengan cara direndam dalam air panas bersuhu 60-65°C selama 2 menit, dilanjutkan dengan proses pemeraman selama 48 jam. Setelah itu, buah vanili diberi perlakuan tiga waktu pemeraman lanjutan (4,6, dan 8 hari) dan dua metode pengeringan (pengering efek rumah kaca dan pengering tipe rak). Proses ini berlanjut hingga kadar air mencapai 30-35%. Pengukuran fisika-kimia dan uji organoleptik dilakukan untuk memantau perubahan kualitas buah vanili selama perlakuan. Hasil penelitian menunjukkan bahwa penambahan pemeraman lanjutan selama 4 hari, 6 hari, dan 8 hari pada proses pengeringan berpengaruh nyata terhadap kadar air, warna, dan kadar vanilin buah vanili kering. Buah vanila yang diberi perlakuan pemeraman lanjutan selama 8 hari dengan pengering tipe rak menghasilkan kualitas buah vanila kering terbaik dengan waktu pengeringan yang lebih singkat yaitu 8 hari, dibandingkan dengan pengeringan tradisional 20 hari dan pengering efek rumah kaca 10 hari untuk mencapai kadar air 35%.
Co-Authors Achmad Fitrah Maulidin Ali Usman, Ali Bandul Suratmo Budi Rahardjo Chandra Gupta Damawidjaya Biksono Darmawati, Emmy - Devi Tanggasari Distriani, Putri Ayu Ira Dwi Setyaningsih Dyah Wulandani Dziyad Dzulfansyah Edy Hartulistiyoso Eko Heri Purwanto Emmy Darmawati Erlanda Augupta Pane Hayatri Sali Setia Herry Suhardiyanto I Nengah Suastawa I Wayan Astika I Wayan Budiastra Irwansyah Irwansyah Kudang Boro Seminar M Ridwan Dwi Astanto Mila Siti Amalia Mohamad Solahudin Mohammad Aftaf Muhajir Muhamad Yulianto Muhamad Yulianto Nurul Choerunnisa Omil Charmyn Chatib Ranti - Ranti Ranti, Ranti - Rokhani Hasbullah Rustam Efendi Samsudin Samsudin Sigit Triwahyudi Siregar, Gokma Ampetua Sofyan Sjaf Sri Endah Agustina Sulikah . Sutrisno . Syahputra, Sufri Yanto Tamaria Panggabean Tineke Mandang Tri Yulni Tya Lestari Usman Ahmad Wawan Hermawan Winny Purnama Sari Y. Aris Purwanto Yogi Sirodz Gaos Yusnita Oni Napitu