Judul: Studi Implementasi Sistem Kendali On-Off Pada In Store Dryer (ISD) Untuk Komoditas Jagung
Abstrak: In Store Drying is a drying method that uses ambient air as the drying medium and usually applied for grain. In Indonesia, although the humidity is relatively high, this drying method can still be applied by using an appropriate control system. In this research, a control system algorithm had been developed based on comparing the potential of ambient air with the air condition inside the ISD. The control system hardware was constructed based on the algorithm and then was tested for two different ambient air conditions. Corn was used as the material being dried. Simulation based on heat and mass balance was also performed in order to obtain the performed of the control system. The control system constructed in this research included a power supply, a control circuit, a parallel port circuit with IC74244, and circuit for sensor SHT75. The control system selected the ambient air used for drying of grain in store dryer. The performance test showed that with the average ambient air temperature of 32,8oC and relative humidity of 51,93%, the system could dry 1201,2 kg of shelled corn from the initial moisture content of 17,61% to 12,37%d.b. within 50 hours while the system could dry 915,0 kg from the initial moisture content of 18,02% to 12,25%d.b. within 40 hours when the average temperature was 31,14oC and relative humidity was 54,16%. The simulation performed showed that by using on-off control system, an amount of 350 kg/m2 shelled corn can be dried from moisture content of 18% to 15%d.b. within 33 hours with energy consumption 175MJ. Without the control system the same amount of the shelled corn the drying time was 68 hours and then the energy consumption was 360MJ.
Keyword: 

Judul: Analisis distribusi suhu, aliran udara, Rh dan kadar air dalam In-store dryer (ISD) untuk biji jagung
Abstrak: In-Store Dryer (ISD) is commonly used as second step in drying process of grains. ISD is usually utilized ambient temperature and consist of dryer and storage system. Temperature, air flow and RH are key parameters during drying process using ISD. The objective of this study were to analyze the distribution of temperature, air flow, RH and water content inside ISD and to analyze the quality of shelled corn during drying process. Computational Fluid Dynamic (CFD) was used to analyze the distribution of temperature, air flow and RH inside ISD. Deep bed drying process was used to analyze the distribution of water content. The capacity of ISD used in this study was 7500 kg of corn, with dimensions of 3.5 m in high and 2.5 m in diameter. ISD have 13 aeration pipes of air flow, consist of 9 input pipes and 4 output pipes. All walls of ISD were assumed to be in condition of adiabatic. Validation of water content that simulation with the measurement has been done at capacity of ISD were 1500 kg. The result showed that CFD simulation of temperature, air flow and RH have coefficient of correlation of 0.66, 0.73 and 0.66 respectively. Deep bed drying simulation of water content at Layer 10 and 40 have coefficient of correlation of 0.90 and 0.35 in rainy season, 0.88 and 0.84 in dry season. The results showed that only a minor changes in the quality of shelled corn dried and stored using ISD.
Keyword: 

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
Keyword: