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: Rancang Bangun Mesin Pemanen Udang Tipe Vakum
Abstrak: Shrimp is an important commodity for Indonesia, both in domestic and international markets. That quality is influenced by several factors including the harvesting process. So far, the harvesting process for fishery commodities in Indonesia is still using the traditional way. This research aims to design a vacuum-type shrimp harvester to improve the efficiency and effectiveness of farming productivity. So that the quality of shrimp harvested can be maintained high. Stages of this research starts from the problems identification, functional analysis, structural analysis, prototyping, and functional test. This design uses a vacuum system that is applied starting from the inlet channel, tanks, to the outlet channel. By using centrifugal water pump power, commodities in pond are inhaled and trapped in the tank without passing through the impeller. In addition, this design also uses a vacuum pump to maintain pressure in the system. It aims to solve the undetected leaks on the system. From the data obtained, the highest flow rate could reach 5.27 l/s with suction speed of 0.65 m/s, while the lowest flow rate is 4.75 l/s with suction speed of 0.59 m/s. Commodity that can be inhaled by this prototype is shrimp that has burst speed ranging in average of its suction speed, ie 0.61 m/s. It needs the next research to make the other harvesting mechanism to avoid the undetected leaks on the system
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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.