Judul: Computational fluid dynamic approach on suction system of fish-shrimp harvesting machine
Abstrak: Shrimp harvesting using mechanical technique still has disadvantage when operated. By using it, percentage of dead fish-shrimp is high and some of them can be damaged because of the commodity touch the pump of machine directly. Thus, it need a new suction system to fix the problem. The aim of this research is to find the proper combination of inlet-outlet channel position based on CFD approach. CFD approach was used to analyze water flow model on three kind of reservoirs with 15 combination of inlet-outlet position on every reservoir type. The highest velocity (2.321 m/s) of the flow came from the combination where inlet on the middle, outlet on the bottom, and both were in the same side with reservoir type three. The smallest Reynolds number (24005.04) came from the combination where inlet on the middle, outlet on the bottom, and both were in the opposite side with reservoir type three. Determination of inlet-outlet combination not only based on flow velocity and Reynolds number but also turbulence and the number of reservoir edge. So that, the chosen combination was inlet on the bottom, outlet on the bottom, and both were in the opposite side with reservoir type three.
Keyword: shape of reservoir, water flow, position combination, CFD

Judul: Perancangan Mekanisme Sistem Penghisap pada Mesin Pemanen Udang dan Ikan
Abstrak: Fishery commodities have an important role in Indonesian economic. Commodity quality depends on several factors, for example harvesting process. So far, mechanism of fishery commodities harvesting is still it traditional way. Although recently there have been some mechanical shrimp harvesters, still is not widely used, not only because of the price but also the mechanical defect that becomes problem. The objective of this study is to design a vacuum system mechanism on the machine harvesters of shrimp and fish that can minimize the defect rate of harvested commodities. This vacuum system uses a reverse venturi mechanism, from a small hydraulic to a big hydraulic. The discharge during the process was relatively stable, ranging from 0.576 l/s - 0583 l/s. The most optimum combination for the positioning of inlet pipe and outlet pipe was a combination of top inlet and top outlet pipeline. It is not only affected by factors from the fluids flow itself but also by the commodity behavior. When the harvesting time occur the commodity congregate under the filter contained in the fish trap. From the performance test, the pecentage of rcommodities that were still alive was high which was 98.9%.
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Judul: Patogenesitas Botryodiplodia theobromae Pat. Terhadap Daun Kayu Afrika (Maesopsis eminii Engl.)
Abstrak: Kayu afrika (Maesopsis eminii Engl.) merupakan kayu perdagangan yang tergolong kayu cepat tumbuh yang memiliki banyak manfaat. Gangguan penyakit menjadi hambatan pertumbuhan dan menurunkan kualitas kayu. Botryodiplodia theobromae merupakan patogen penyebab penyakit yang merugikan dan memiliki banyak inang. Penelitian bertujuan menguji patogenisitas Botryodiplodia theobromae terhadap daun kayu afrika, menguji secara makroskopis dan mikroskopis patogen yang menyerang daun kayu afrika adalah Botryodiplodia theobromae. Rancangan percobaan yang digunakan adalah rancangan acak lengkap. Perlakuan yang digunakan terdiri dari tanpa pelukaan inokulasi, pelukaan, inokulasi dan pelukaan ditambah inokulasi. Hasil pengamatan menunjukkan gejala bercak daun dengan warna kecoklatan pada daun kayu afrika. Berdasarkan uji jarak berganda (Duncan) pelukaan ditambah inokulasi memberikan rataan terbesar terhadap keparahan penyakit sebesar 27.56% dan kejadian penyakit sebesar 82.67%. Hasil pengamatan makroskopis pada media PDA menunjukkan koloni isolat ini memiliki warna putih kapas hingga berumur 7 hari dan berwarna abu-abu hingga hitam pekat pada miselium yang tua. Koloni miselium memiliki tekstur seperti benang halus dengan miselium udara yang tebal dan koloni menyebar dari bagian tengah dengan alur tidak beraturan. Pengamatan mikroskopis daun yang bergejala penyakit hasilnya memperlihatkan karakter patogen Botryodiplodia theobromae, dengan ditemukan hifa bersekat hialin dan konidia yang berbentuk ellipsoid hialin.
Keyword: Botryodiplodia theobromae, disease incidency, disease severity, leaf spots, Maesopsis eminii Engl.