Yohanes Aris Purwanto
Department of Machinery and Biosystem, Institut Pertanian Bogor, Bogor 16002, Indonesia

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Aplikasi Jaringan Syaraf Tiruan (JST) untuk Pendugaan Suhu Larutan Nutrisi yang Disirkulasikan dan Didinginkan Siang-Malam pada Tanaman Tomat Hidroponik Arief, Chusnul; Purwanto, Yohanes Aris; Suhardiyanto, Herry; Chadirin, Yudi
Jurnal Keteknikan Pertanian Vol. 24 No. 2 (2010): Jurnal Keteknikan Pertanian
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AbstractCultivation of tomato plant under hydroponics system in the greenhouse is suitable way to improve fruit quality since it is easier to control environmental parameters. In this system, water and nutrition are two important things for plant to growth. In the tropical area such as Indonesia, air temperature is main constraint in the plant production system. Increasing air temperature inside the greenhouse has positive correlation to the raising temperature of nutrient solution which affected to the ability of the plant to absord the nutrition. The effective way to anticipate increasing of its temperature is by using the cooling system of nutrient solution before circulated to the plant. This paper presented the application of Articificial Neural Network (ANN) to estimate the temperature of nutrient solution which was cooled on day-night time and circulated to the plant. ANN models, called time delay neural network, consist of 3 layers with 4 input nodes and 1 output node. As input model were t (time), Tg(i) (air temperature inside the greenhouse on time i), Tt(i) (temperature of nutrient solution in the tank on time i), Tb(i-1) (temperature of nutrient solution in the plant plots on time i-1) and as output model was Tb(i) (temperature of nutrient solution in the plant plots on time i). The model was developed well with validation result better than heat transfer model previously indicated by coefficient determination (R2) of 0.9498.Keywords: cooling, nutrient solution, hydroponic, tomato, artificial neural networkDiterima: 15 Juni 2010;Disetujui: 30 juli 2010
Effect of Heat Shock Treatment and Aloe Vera Coating on Chilling Injury Symptom in Tomato (Lycoperiscon asculantum Mill) ., Sutrisno; Purwanto, Yohanes Aris; M.Idris, Ismi; Hutabarat, Olly S.; ., Sugiyono
Jurnal Keteknikan Pertanian Vol. 24 No. 1 (2010): Jurnal Keteknikan Pertanian
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AbstractThis research was undertaken to determine the effect of length in heat shock and edible coating as prestorage treatment on Chilling Injury (CI) symptom reflected by ion leakage induced and quality properties in tomato (Lycopersicon asculantum Mill.). Heat Shock Treatment (HST) was conducted at three different levels of length, which were, 20, 40 and 60 min. Edible coating was conducted using aloe vera gel. The result showed that HST and Aloe Vera Coating (AVC) were more effective to reduce CI symptom at lower chilling storage. Prolong exposure to heated water may delay climacteric peak. The length of heat shock; AVC treatment and low temperature storage significantly affected the tomato quality parameter but not significantly different for each treatment except weight loss. HST for 20 min at ambient temperature was significantly different to other treatment.Keywords: ion leakage, chilling injury, climacteric, shelf-lifeDiterima: 2 Desember 2009; Disetujui: 22 Maret 2010
Evaluasi Kinerja Tarik Taktor Tangan Dengan Bahan Bakar Minyak Kelapa Murni ., Desrial; Purwanto, Yohanes Aris; Wiratama, Fandra
Jurnal Keteknikan Pertanian Vol. 24 No. 1 (2010): Jurnal Keteknikan Pertanian
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Abstract Past research shown that coconut oil can be used directly in Diesel engine by adding a heating element in the fuel delivery system. This study aims to evaluate the performance of a hand tractor pull using pure coconut oil fuel. The Diesel engine of the tractor was equipped with a fuel heater installed on the mufler. Traction performance parameters tested were wheel slippage, drawbar pull, forward speed and drawbar power on the path of concrete and soil. Besides, the tractor was also tested on plowing using a moldboard plow. The test results on the concrete track showed that the maximum drawbar pull was 1.21 kN generated at a speed of 0.92 m/s, with a maximum drawbar power of 1.21 kW at the wheel slip of 10.87%. While the drawbar pull on the soil track was 1.37 kN at a speed of 0.79 m/s, with a maximum value of 0.71 kW drawbar power when wheels slip 22.25%. The results of tillage test showed that field efficiency was 84.66%, which was not much different from the test result using Diesel fuel. Keywords: fuel heater, Diesel engine, pure coconut oil, drawbar pull performance Diterima: 8 Desember 2009; Disetujui: 16 Maret 2010
Model Pemberdayaan Masyarakat melalui Pengolahan Kopi di Desa Mandiri Energi Purwanto, Yohanes Aris; Murtilaksono, Kukuh; Yusuf, Sri Malahayati
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat Vol 1, No 1 (2015): Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat
Publisher : Institut Pertanian Bogor

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Development of energy self-sufficient village based on the local resources is purposed to reduce the poverty, to create the job opportunities as well as to substitute the fossil fuels. Energy self-sufficient village is also as sociated with the development of the productive economy. For the areas closed to national park, the development of the productive economy is important because it can reduce community activities for reaching the forest. Lebakpicung is energy self-sufficient village based on microhydro. This village has potency on coffee production. However, only dried coffee beans are produced from this village. The purpose of this community empowerment activity in Energy self-sufficient village was to utilize idle electricity from microhydro during day time as energy resource for coffee processing. This activity was carried out through training activity on the use of coffee processing machinery and packaging technology. The training participants were the community members who has activity on coffee processing.
Analisis Pengaruh Variasi Jumlah Lapisan Biji pada Akurasi Prediksi Kandungan Minor Biji Kopi Arabika Hijau Bondowoso dengan NIR Spectroscopy Madi, Sri Citra Yuliana; Budiastra, I Wayan; Purwanto, Yohanes Aris; Widyotomo, Sukrisno
Jurnal Ilmu Pertanian Indonesia Vol. 23 No. 2 (2018): Jurnal Ilmu Pertanian Indonesia
Publisher : Institut Pertanian Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (545.168 KB) | DOI: 10.18343/jipi.23.2.81

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Void space in the bean layers will lead to the occurrence of non-fully interacted radiation (NFIR) affecting the reproducibility of NIRS measurements. Void space in addition to being affected by particle size is also influenced by the number/thickness of the bean layers. The objective of this study was to analyze the effect of number of bean layer variation on prediction accuracy of caffeine, chlorogenic acid and trigonelline in Bondowoso green Arabica coffee beans by NIR Spectroscopy (NIRS). The study was conducted using three kind of layers, i.e. 3, 4, and 5 layers, with 100 samples each. Samples were measured by FT-NIR spectrometer in wavelength of 1.000-2.500 nm. The pretreatment method used were second derivative (dg2), the combination of first derivative (dg1) and Multiplicative Scatter Correction (MSC), and the combination of dg2 and MSC, while calibration method used was Partial Least Square (PLS). The results shows that the accuracy of 5 layers was better than 3 or 4 layers. The best calibration and validation for caffeine was obtained by dg2 pretreatment and 6 factors of PLS (r = 0.99; SEC = 0.01%; SEP = 0.01%; and RPD = 5.40), for chlorogenic acid was by dg2 pretreatment and 5 factors of PLS (r = 0.99; SEC = 0.09%; SEP = 0.09%; and RPD = 4.76), whereas for trigonelline was by combination of (dg2, MSC) and 5 factors of PLS (r = 0.99; SEC = 0.01%; SEP = 0.01%; and RPD = 4.86). Therefore, the 5 layers can be used as a reference in NIRS measurement of coffee beans.
Thermal Properties, Crystallinity, and Oxygen Permeability of Na-montmorillonite Reinforced Plasticized Poly(lactic acid) Film Yuniarto, Kurniawan; Purwanto, Yohanes Aris; Purwanto, Setyo; Welt, Bruce A.; Purwadaria, Hadi Karia; Sunarti, Titi Candra
Makara Journal of Technology Vol 20, No 1 (2016)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Introducing unmodified organically clay/Na-montmorillonite (Na-MMT) was applied into plasticized poly(lactic acid) PLA  to  produce  film  composites  by direct  casting.  Film  composite  structure,  the  crystallinity  degree  and  form, and thermal  properties  were  carried  out  using  X-ray  diffraction  and differential  scanning  calorimetry.  The effect  of NaMMT  to  the  tortuous path  and  the  crystallinity  degree  in  the  plasticized  film  composites  were calculated  in oxygen barrier  properties.  Chromatogram  film  composites resulted  in  an  intercalated  structure  that  showed  peak diffraction angle shift at about 0.2o. Then, a peak diffraction pattern was indicated in  Î±-form crystal structure. Plasticized PLA has a crystallinity degree at 34%, and the addition of  Na-MMT increased to 52%. Glass transition temperature improved from 53 °C to 57 °C, and melting temperature remained stable at 167 °C. Filling Na-MMT into plasticized PLA caused to enhance a tortuous path about 28% and improved the oxygen permeability to 80%. As a result, the addition of NaMMT of 3% into plasticized PLA during  film composite preparation using the mixing method resulted in balancing properties related to the crystallinity degree, thermal properties, and oxygen barrier properties. 
Pengaruh Receiver Terhadap Kinerja Refrigerasi Mesin Pembeku Sukusno, Paulus; Tambunan, Armansyah H.; Setiawan, Radite Praeko Agus; Purwanto, Yohanes Aris
Jurnal Keteknikan Pertanian Vol. 6 No. 3 (2018): JURNAL KETEKNIKAN PERTANIAN
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AbstractFreezing is the best method to preserve the quality of food for a long period of time compared to other technologies such as drying and canning. Technology of freezing requires more energy than other preservation technologies, however. Therefore, an energy efficient freezer is needed. This research aims to the effect of utilization of a receiver to improve the freezer performance efficency. The research is conducted on freezer used to cool and freeze 1 kg of water from a temperature of 27oC to -14oC, then a receiver is installed in the freezer and the same research is conducted (the type and setting of expansion valve and test materials are the same). The refrigerant medium is R404A working fluid. The receiver is installed between condenser and filter dryer in the system circuit of the freezer. The result shows that the utilization of receiver increases the coefficent of performance (COP) from 2.24 to 2.69 and reduce the electricity consumption. The time required for freezing becomes shorter particularly on the transition of liquid to solid phase (ice) . Consequently, the freezing rate becomes quicker and provides advantages for application of food freezing.AbstrakPembekuan merupakan metode yang paling baik untuk menjaga kualitas makanan dalam jangka waktu lama, dibanding dengan teknologi lain seperti pengeringan dan pengalengan. Namun teknologi pembekuan membutuhkan lebih banyak energi daripada teknologi pengawetan lainnya, karena itu diperlukan mesin pembeku yang hemat energi. Penelitian ini bertujuan untuk mempelajari pengaruh penggunaan receiver untuk meningkatkan efisiensi kinerja mesin pembeku. Penelitian dilakukan pada mesin pembeku yang digunakan untuk mendinginkan dan membekukan air 1 kg dari suhu 27oC sampai -14oC, selanjutnya penelitian mesin pembeku ditambahkan receiver dan dilakukan penelitian yang sama (bukaan katup ekpansi diatur tetap dan sama, serta bahan uji dilakukan dalam kondisi sama). Media pendingin menggunakan fluida kerja R404A. Receiver diletakkan di antara kondensor dan filter dryer pada rangkaian sistem mesin pembeku. Hasil penelitian menunjukkan bahwa penggunaan receiver pada mesin pembeku berdampak pada peningkataan koefisien kinerja (COP) dari 2.24 menjadi 2.69, dan terjadi penghematan konsumsi energi listrik. Waktu proses pembekuan menjadi lebih singkat, khususnya pada tahap perubahan fase cair menjadi es, sehingga laju pembekuan menjadi lebih cepat dan memberi keuntungan untuk penerapan pada pembekuan bahan pangan.
Desain Sistem Kontrol dan Monitoring Kondisi Udara pada Controlled Atmosphere Storage Berbasis Mikrokontroler Arduino Uno Widyaningrum, Widyaningrum; Purwanto, Yohanes Aris; Mardjan, Sutrisno
Jurnal Keteknikan Pertanian Vol. 6 No. 1 (2018): JURNAL KETEKNIKAN PERTANIAN
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AbstractStorage by controlling the composition of air or oxygen and carbon dioxide concentration settings is called controlled atmosphere storage. Controlled atmosphere storage aims at controlling metabolism of fresh product to extended the shelf-life. The concentration of oxygen and carbon dioxide in product aremaintained at a desired concentration. The objective of this research was to design a control and monitoring system of oxygen, carbon dioxide, temperature and relative humidity in the storage by using Arduino Uno microcontroller. Design approach consists of functional and structural design. The main function of thesystem control were to control gas injection, open and close the solenoid valve, control the amount of injection, and reading the sensor. Measurements and testing included sensor calibration and functional testing of the control and monitoring system with no-load conditions. Analysis of the experiment resultswas conducted by using statistical analysis of repeated measures ANOVA. The result of observation and measurements of temperature with no-load conditions was 9.88ºC, RH 73.73%, concentration of carbon dioxide 2.22% and concentration of oxygen 4.63%. Accuracy between setpoint and actual temperature was of 98.84%. Accuracy between setpoint and actual RH was of 97.55%. Accuracy between setpoint and actual oxygen was of 83.98%. Accuracy between setpoint and actual carbon dioxide was of 74.26%.AbstrakPenyimpanan dengan cara pengaturan komposisi udara atau pengaturan konsentrasi oksigen dan karbondioksida dikenal dengan penyimpanan dengan pengendalian atmosfer. Teknik atmosfer terkendali sekitar produk bertujuan untuk mengendalikan metabolisme produk segar sehingga masa simpan dapat diperpanjang. Konsentrasi oksigen dan karbondioksida disekitar produk dijaga pada suatu konsentrasi yang diinginkan. Penelitian ini bertujuan untuk merancang sistem kontrol dan monitoring oksigen dan karbondioksida serta suhu dan kelembaban di dalam ruang penyimpanan dengan mengimplementasikan mikrokontroler Arduino Uno. Pendekatan rancangan terdiri dari dua jenis yaitu rancangan fungsional dan rancangan struktural. Fungsi dan struktur utama dari sistem yang dibuat adalah sistem pengontrolan terhadap injeksi gas, buka tutup solenoid valve, mengontrol lama injeksi, dan melakukan pembacaan sensor. Pengukuran dan pengujian meliputi kalibrasi sensor dan pengujian fungsional kinerja kontrol dan monitoring. Analisis hasil percobaan dilakukan dengan menggunakan analisis statistik repeated measures ANOVA. Hasil pengamatan dan pengukuran suhu adalah 9.88ºC, RH 73.73%, karbondioksida 2.22% dan oksigen 4.63%. Perbandingan antara setpoint dan aktual diperoleh akurasi suhu 98.84%. Perbandinganantara setpoint dan aktual diperoleh akurasi RH 97.55% Perbandingan antara setpoint dan aktual diperoleh akurasi oksigen 83.98%. Perbandingan antara setpoint dan aktual diperoleh akurasi karbondioksida74.26%.
Prediksi Tanin dan Total Padatan Tidak Terlarut Buah Kesemek (Diospyros kaki L.) Menggunakan Spektroskopi NIR Kurniasari, Indah; Purwanto, Yohanes Aris; Budiastra, I Wayan; Ridwani, Sobir
Jurnal Keteknikan Pertanian Vol. 5 No. 3 (2017): JURNAL KETEKNIKAN PERTANIAN
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AbstractDetermination of tannin and non-soluble solid content of persimmon are usually carried out by a chemical method, these methods are destructive, time-consuming and can not be applied to the development of online grading. The objective of this study was to develop rapid prediction method of tannin and non-soluble solid content of persimmon non-destructively using NIR Spectroscopy. NIR spectra were measured by NIRFlex N-500 fiber optic solid with the wavelength of 1000-2500 nm. For the reference method, tannin and non-soluble solid content were measured using conventional method. Some pre-processing methods were applied, and the results were calibrated to chemical data using principal component regression (PCR) and partial least square (PLS). The best model for prediction of non-soluble solid content was multiplicative scatter correction (MSC) pre-processing and PLS with a correlation coefficient (r), standard error prediction (SEP) and the ratio of standard deviation to SEP (RPD) of 0.83, 1.48% and 1.59 respectively. The best model for predicting tannin was first derivative Savitzky-Golay (dg1) and PLS with r, SEP and RPD of 0.72, 0.14% and 1.06 respectively. PLS method was better than PCR in predicting non-soluble solid content and tannin of persimmon. AbstrakPenentuan tanin dan total padatan tidak terlarut buah kesemek biasa dilakukan dengan metode kimia, metode ini bersifat destruktif, memakan waktu dan tidak dapat diterapkan untuk pengembangan grading secara on-line. Tujuan penelitian ini adalah untuk memprediksi secara cepat tanin dan padatan tidak terlarut buah kesemek secara non destruktif menggunakan Spektroskopi NIR. Spektrum NIR diukur dengan NIRFlex N-500 fiber optic solid pada panjang gelombang 1000-2500 nm, Untuk metode referensi, kandungan tannin dan total padatan tidak terlarut diukur dengan menggunakan metode konvensional. Beberapa metode pra-pengolahan data NIR diterapkan, dan hasilnya dikalibrasi dengan data kimia menggunakan metode principal component regression (PCR) dan partial least square (PLS). Model terbaik untuk memprediksi non-soluble solid content adalah menggunakan pra-pengolahan multiplicative scatter correction (MSC) dan PLS dengan r, SEP dan RPD masing - masing 0.83, 1.48%, dan 1.59. Model terbaik untuk memprediksi tanin diperoleh dengan menggunakan turunan pertama Savitzky-Golay (dg1) dan metode PLS dengan r, SEP dan RPD masing - masing 0.72, 0.14% dan 1.06. Metode PLS menghasilkan model kalibrasi lebih baik daripada PCR dalam memprediksi tanin dan non-soluble solid content buah kesemek.
Pemanfaatan TKKS Sebagai Pengisi Komposit Epoxy Untuk Struktur Bergerak Mesin CNC Perkayuan ., Farkhan; Purwanto, Yohanes Aris; Hambali, Erizal; Hermawan, Wawan
Jurnal Keteknikan Pertanian Vol. 5 No. 1 (2017): JURNAL KETEKNIKAN PERTANIAN
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AbstractCNC machinery is widely used at various kind of industrial sector to manufacture of art products up to satellite products. Instead of its massive utilization in automotive and electronic industry which mostly use metallic component, wood working industry has been using it to produces furniture’s, merchandises, and other house ware products which apply light weight non-metallic low density material. High removalrate in wood machining process needs high speed application due to its low density material; however most of wood working CNC machine is built on heavy steel structure for both its supporting structure and moving structure. In fact, the raw material is much lighter than the carrier itself. Its wasteful dynamic movement causes energy loses and vibrations that effect on machining accuracy, live of cutting tool, andproductivity. This research applied new light weight composite material base on renewable resource of oil palm empty fruit bunch (EFB) natural fiber as filler material combine with polymer epoxy as it’s matrix to be constructed as moving mechanical structure of high speed 3D CNC woodworking machine to improve its dynamic performance. Comparative analysis showed that it has better dynamic performance on high speed machining process compared with traditional cast iron materialAbstrakMesin Perkakas CNC (Computerized Numerical Control) digunakan luas oleh industri untuk memproduksi mulai dari benda-benda seni kerajinan hingga untuk membuat satelit. Selain pemanfaatannya secara besar-besaran di industri otomotif dan elektronika yang umumnya menggunakan komponen logam, industri perkayuan telah banyak menggunakannya untuk memproduksi mebel, barang kerajinan, dan peralatan rumah tangga lainnya dengan mengaplikasikan bahan bukan logam seperti kayu yang berberat jenis rendah dan ringan. Tingkat pemotongan yang tinggi pada proses permesinan kayu membutuhkanpermesinan cepat akibat berat jenis bahannya yang rendah tersebut, namun mesin CNC perkayuan umumnya dibangun dengan struktur logam yang berat, baik untuk struktur penopang maupun struktur bergeraknya. Kenyataannya, bahan baku kayunya sendiri jauh lebih ringan ketimbang struktur yang menggerakkannya. Dinamika gerakan pada struktur bergerak yang berat ini menyebabkan pemborosandaya dan getaran berlebih yang mempengaruhi ketelitian, keawetan pahat potong, dan produktivitas. Penelitian ini mengembangkan bahan komposit ringan baru dengan memanfaatkan sumber terbarukan dari limbah tandan kosong kelapa sawit (TKKS) sebagai bahan pengisinya dengan matriks polimer epoxy untuk dibangun sebagai struktur bergerak mesin CNC perkayuan metode permesinan cepat 3 dimensi, untuk meningkatkan unjuk kerja dinamiknya. Analisa perbandingan menunjukkan bahan ini memiliki unjuk kerja dinamik lebih baik pada proses permesinan cepat ketimbang menggunakan besi tuang sebagai bahan tradisionalnya.