Judul: Modifikasi Penukar Panas Model Pengering Hybrid Tipe Rak untuk Pengeringan Chip Mocaf
Abstrak: The main problems of previous experiment using rack type greenhouse effect dryer (GHE) equipment were low level of drying efficiency and high level of energy consumption, therefore the purposes of this experiment were to develop the design of heat exchanger and biomass stove from rack type GHE dryer and to develop the performance of hybrid rack type GHE dryer for drying mocaf chips. One of the developments of the design was the addition of circle type fins on heat exchanger as much as 9 fins per pipe. The dimension of each fin was 0.093 m x 0.063 m. Materials of the stove were bricks by dimension of 0.58 m x 0.58 m x 0.3 m (L x W x H). The drying experiment during daylight period using mocaf chips with capacity of 18.04 kg from moisture content of 69.88%db to 12.56%db needed 11.5 hours with drying temperature of 43.65C. The drying efficiency was 9.37%, thermal efficiency was 24.84% and specific energy consumption was 28.19 MJ/kg vapor. In the experiment capacity of 18.09 kg mocaf chips during daylight and night period from moisture content of 70.74%db to 13.76%db required drying time of 15 hours with drying temperature of 45.83C, drying efficiency was 6.79%, thermal efficiensy was 24.32%, and specific energy consumption was 32.80 MJ/kg vapor. This research resulted increased efficiency of 1.697% than previous design.
Keyword: Bogor Agricultural University (IPB), efficiency, stove, fin, mocaf chip

Judul: Uji Performansi Pengering Efek Rumah Kaca (ERK)-Hybrid Tipe Rak Berputar untuk Pengeringan Sawut Ubi Jalar (Ipomoea batatas L.)
Abstrak: Rotating rack green house effect (GHE) solar dryer is one type of dryer with the source of energy from solar and biomass energy for drying of agricultural products on the racks that can be rotated verticaly. The capacity of the drying chamber is 48 kg of chopped sweet potatoes. The objective of this study is to test the performance of the hybrid green house effect dryer for drying chopped sweet potatoes and to define modeling of heat transfer in the drying chamber. There are three experiments of drying: the first is without products, the second and the third are drying products without rotating rack and implement the rotating rack 45° every 60 minutes, respectively. The results of chopped sweet potatoes drying show that drying temperature on the dryer chamber ranged between 31.6-61.5°C. To reduce moisture content from around 71.3 %wb to 9.96 %wb for Experiment 2 and to reduce moisture content of 72.76 %wb to 9.5 %wb for Experiment 3, it is needed 14.5 hours and 13.5 hour, respectively. The specific energy consumption of both experiments were 42.83 MJ/kg of moisture evaporated and 35.15 MJ/kg of moisture evaporated and the drying efficiency of 5.78 % and 7.47%, respectively. Based on the performance test, it can be concluded that rotating rack dryer shows better performance than that of without rotating rack.
Keyword: solar dryer, biomass, Chopped sweet potatoes

Judul: Infeksi leucocytozzon simondi (Mathis dan Leger, 1910) pada itik
Abstrak: Leucocytozoonosis pada itik adalah penyakit protozoer yang disebabkan oleh parasit darah Leucocytozoon simondi. Protozoa ini ditularkan oleh lalat penghisap darah (Simulium sp.). Di dalam tubuh induk semang antara (vektor) Simulium parasit mengalami tahap gametogoni yang kedua (pembentukan gamet dan pembuahan) dan sporogoni. Pembuahan makrogamet oleh mikrogamet terjadi segera sesudah vektor menghisap darah itik yang mengandung gametosit. Pembuahan menghasilkan zigot yang dapat bergerak (ookinet) yang masuk dinding usus vektor dan kemudian memasuki tahap sporogoni. Tahap sporogoni memerlukan waktu kira-kira 1 minggu (Fallis dan Desser, 1977) untuk menghasilkan sporozoit. Sporozoit bergerak menuju kelenjar ludah vektor, tempat mereka berkumpul. Sporozoit dipindahkan ke dalam tubuh itik pada saat vektor menghisap darah itik. Di dalam tubuh itik, parasit mengalami tahap skizogoni dan tahap gametogoni yang pertama (pembentukan gametosit). Sporozoit memasuki peredaran darah itik dan memasuki sel-sel parenkhim hati membentuk skizon hepatik (Fallis et al., 1974). Setelah 4 6 hari, skizon hepatik dewasa menghasilkan merozoit dan sinsitia. Merozoit dari skizon hepatik memasuki eritrosit dan eritroblas membentuk gametosit bundar, sedangkan sinsitia memasuki sel-sel RES di seluruh tubuh membentuk megaloskizon. Megaloskizon dewasa terbentuk dalam waktu 5 hari di dalam sel-sel itu dan menghasilkan merozoit. Merozoit dari megaloskizon memasuki limfosit dan leukosit lainnya membentuk gametosit memanjang. ...
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