Judul: Simulation of temperature distribution of growing media in a polybag of hydroponic substrate for production of seed potatoes with computational fluid dynamic (CFD)
Abstrak: Potato cultivation is often carried out on the highland areas and it is rarely done on the lowland areas are facing the problem of land erosion and widespread disease. Therefore, it is necessary to study which examines the possibility of seed potato production in the lowlands. The lowlands tend to have higher temperatures compared with the optimum temperature for the cultivation of potatoes. The aim of this research is to know the distribution of temperature in a polybag planting media after being given a nutrient solution that is cooled 10 ºC with Computational Fluid Dynamic (CFD) in lowland areas. Further simulations validated with measurements, using linear regression method and percentage error. The results showed that the distribution of the planting medium temperatures given nutrient solution 10 ºC can maintain the temperature of the media remain low. The results showed that the results of validation simulations using CFD approach the value of temperature measurement on media in polybag.
Keyword: substrate hydroponic system, CFD, Potato cultivation

Judul: Pengembangan zone cooling system untuk produksi benih kentang secara aeroponik di dataran rendah tropika basah
Abstrak: Potato plant (Solanum tuberosum L) is one of the major food crops in the world after paddy, wheat, and corn. Carbohydrate content of potato is very high; therefore, it can be used to substitute rice, wheat flour, and maize. As one of the most important commodities, potato has comparative and competitive advantages, as well as good domestic and export market. However in Indonesia, the volume of potato production is lower than the volume of potato consumption. Therefore, Indonesia is importing potato from other countries. To increase potato production, Indonesia is facing difficulties in fulfilling the required potato seeds with high quality, right time and right variety. Using low quality potato seeds causes low productivity. In addition, increasing potato production is also facing problems related to the decrease in area for potato plant in highland, pest and plant diseases. In Indonesia, potato plant is generally cultivated on highland. This is very often accompanied by high rate in soil erosion. Shifting the orientation for potato cultivation to lowland is one of the most prospective solutions to increase potato production while solving the problems related to soil erosion. However, potato cultivation in humid tropical lowland is facing problems related to high air temperature and humidity. To overcome these problems, root zone cooling for aeroponically grown potato cultivation could be used. Zone cooling system could decrease temperature of certain zone but it also prevents the increase in air humidity. The objective of this research in general was to develop technology for aeroponically grown potato seed production in humid tropical lowland by using root zone cooling. To achieve the objective, three stages of research were conducted: (1) to apply zone cooling in aeroponic system for potato seed production in humid tropical lowland, (2) to predict temperature distribution in the growth chamber of aeroponic system with root zone cooling, (3) to calculate the heat load in the growth chamber of aeroponic system with root zone cooling. The research on zone cooling application was conducted in a greenhouse at the Department of Mechanical & Bio-system Engineering, Faculty of Agricultural Engineering and Technology, Bogor Agricultural University, at 250 m above the sea level, from April to July, 2012. The size of the aeroponic chamber used was 1.5 m x 1 m x 1 m. The material used for the outer wall of the chamber was wooden multiplex board and the inner side was insulated with styrofoam board. Plant bedding was made of styrofoam board. Plant spacing was 15 cm x 15 cm. Therefore, one chamber consisted of 45 plants. The variety of potato seedling was Granola, produced by tissue culture laboratory, Vegetable Research Institute, Indonesian Ministry of Agriculture, after acclimatization. The research results indicated that the values of average height and number of leave of the potato plant cultivated in aeroponic system with zone cooling were higher than that of without cooling. The best tubers were obtained in aeroponic system with 10 °C zone cooling, i.e., average productivity (579 tubers/m2), average number of tuber (14.85 tubers/plant), and average tuber weight (409.15 mg/tuber). The 15 °C zone cooling resulted in 55
Keyword: potato, humid tropical lowland, aeroponics, zone cooling, CFD

Judul: Isolasi komponen hemotoksin bisa ular kobra (Naja naja sputatrix)
Abstrak: Elisa ular adalah racun yang diproduksi oleh kelenjar bisa dan digunakan ular untuk mempertahankan dinat mencari mangsa. Bisa ini merupakan campuran dari berbagai komponen. Enzim adalah kompoth utama selain air. Enzim pada bisa ular sangat beragam jenis dan fungsinya. Fosfolipase dan arginin ipadase adalah enzim yang sering terdapat dalam bisa ular dan telah digunakan pada penanganan penyak seperti trombosis Penttian ini bertujuan mengisolasi komponen dari bisa ular kobra dan mengujinya menggunakan sel darah merah sapi 4% untuk aktivitas hemolisis dan bekuan fibrin sapi untuk aktivitas fibrinolisis. Uji aktivitas dilakukan terhadap ekstrak kasar dan fraksi kolom bisa ular. Fraksi kolom diperoleh dari pemurutan ekstrak kasar menggunakan kromatografi filtrasi gel (Sephadex G-75) untuk memperoleh fraksa paksu dengan serapan tertinggi pada A. 280 nm. Ekstrak kasar dan fraksi kolom dengan serapan tertinggi dilakukan pengukuran kandungan protein, Fraksi aktif hasil uji aktivitas selanjutnya ditentukan berat molekulnya (BM) dengan elektroforesis SDS PAGE. Basaglar kobra merupakan cairan pekat berwarna kuning dengan kadar air 71.45%. Dari hasil uji aktivitas diperoleh bisa ular hanya memiliki aktivitas hemolisis sel darah merah sapi secara langsung. Aktivitas ini ditunjukkan oleh fraksi kolom nomor 15 dan 16 tetapi tidak dalam ekstrak kasar. Penurunan konsentrasi ekstrak kasar tidak mempengaruhi terhadap adanya aktivitas hemolisis. Hal ini diduga karena mungkin terdapat inhibitor dalam ekstrak kasar bisa. Inhibitor memiliki BM yang berbeda dengan enzim hemalisis sehingga dapat dipisahkan menggunakan filtrasi gel. Berdasarkan hasil elektroforesis diperolch enzim bemolisis terdapat dalam ekstrak kasar dan tersebar pada fraksi kolom nomor 15 dan 16 dengan BM sekitar 27300 Da
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