Article Per Year (5 Year)
p-Index From 2021 - 2026
3.266
P-Index
This Author published in this journals
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

Published : 33 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 33 Documents
Search

 1   2   3   4 
Combination of Osmotic Dehydration and Further Drying to Improve the Quality of Dried Carrots Ranti, Ranti -; Nelwan, Leopold Oscar; Darmawati, Emmy -
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
Design and Development of a Web-Based Thermal Application for Vapor Compression Refrigeration Systems Ratu Yanra Dewi; Muhamad Yulianto; Mohamad Solahudin; Leopold Oscar Nelwan; Ida Afriliana; Roni Darpono; N Nasruddin
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol. 15 No. 1 (2026): February 2026
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtepl.v15i1.19-32

Abstract

The growth of the global food industry has led to an increased demand for cold storage systems to maintain product quality. Cold storage systems based on the vapor compression cycle offer high energy efficiency. However, their design involves multiple stages, ranging from cooling load calculations to prototype development for performance evaluation. This study integrates digital twin–based thermal simulation with Life Cycle Climate Performance (LCCP) analysis into a single web-based platform, namely THE POCI, for cold storage design. The application allows system design, performance calculation, and estimation of the system emission. The development process followed the System Development Life Cycle (SDLC) methodology. Functional testing was conducted using Black-box Testing, while user evaluation was performed using the System Usability Scale (SUS). The results show that all modules provide the expected information and can be used effectively. Model validation against experimental data resulted in Mean Absolute Percentage Error (MAPE) values of 11% for compressor power, 17% for cooling capacity, and 14% for the coefficient of performance (COP). User evaluation involving 47 respondents across the four modules yielded a SUS score of 64.41, indicating that the application is well accepted and has an adequate level of usability.
Design and Performance Evaluation of an IoT-Based Automatic Airflow Control System for a PV/T Solar Dryer with Silica Gel Adsorption Heat Storage Putri Arsyafdini Oktavionry; Leopold Oscar Nelwan; I Dewa Made Subrata
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol. 15 No. 1 (2026): February 2026
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtepl.v15i1.153-163

Abstract

Solar energy is one of the most promising renewable energy sources, yet solar drying operating costs often remain prohibitive for small-scale farming. This research aims to design and evaluate the performance of an automated air flow control system for a PV/T collector integrated with an adsorption channel. The methodology focuses on developing a real-time monitoring and control logic based on environmental parameters. The system utilizes a microcontroller-based unit for data acquisition of temperature and humidity, coupled with a high-torque motor actuation system to regulate valve positioning between the collector and the desiccant unit. Results indicate that the control system manages air distribution effectively across a temperature control range of 40 °C to 4 3°C. The system demonstrated high responsiveness with a mechanical actuation speed of 3 seconds for a full 90-degree valve rotation. During the adsorption phase, the silica gel's moisture content rose from 23.57% to 27.38%. Furthermore, the silica gel adsorption unit contributed to thermal stability by maintaining a temperature gradient of 3-7 °C between the plenum and the environment, effectively recycling adsorption heat to enhance the drying air temperature even during low solar radiation.
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 Dewa Made Subrata I Nengah Suastawa I Wayan Astika I Wayan Budiastra Ida Afriliana Irwansyah Irwansyah Kudang Boro Seminar M Ridwan Dwi Astanto Mila Siti Amalia Mohamad Solahudin Mohammad Aftaf Muhajir Muhamad Yulianto Muhamad Yulianto Muhamad Yulianto N Nasruddin Nurul Choerunnisa Omil Charmyn Chatib Putri Arsyafdini Oktavionry Ranti - Ranti Ranti, Ranti - Ratu Yanra Dewi Rokhani Hasbullah Roni Darpono 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