Judul: Design of gathering-conveying unit of mobile sugar cane trash chopping machine
Abstrak: A machine for gathering and chopping the piles of sugarcane trash on the field after harvesting is being designed. As a part of the machine, a gathering-conveying unit was designed. Important data including condition and characteristics of trash were collected and used for designing the unit. The average bulk density of trash on the field was 7.7 kg/m3, the average pressure to compress the trash from 40 cm to 30 cm thickness was 50.65 N/m2, and the pressure to compress the trash from 27 cm to 8 cm thickness was 1166.60 N/m2. The unit was designed to be operated at 0.3 m/s forward speed, and having 60 cm working width. The unit was consisted of: a gathering reel, a pair of conveyors, cover-frame and power transmission components. Size and operational speed of moving components were determined by analyzing mass flow rate of the trash, and operating power of the components. The gathering reel was 100 cm in diameter and having 4 series of gathering fingers for drawing and feeding the trash into the conveyors. A pair of chain-conveyors equipped with L-shaped steel bars was set face to face on lower side and upper side for conveying and feeding the leaves to the chopping unit. The stationary test showed that the gathering reel and the conveyors could work properly. The average rotational speed of the conveyor shaft and the gathering reel were 34.03 rpm and 9.97 rpm, respectively. The working capacity of the unit was 400-500 kg/hour.
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Judul: Desain dan kinerja unit pemotongan serasah tebu dengan menggunakan pisau tipe reel
Abstrak: The problem of sugarcane trash after harvesting is experienced by the world's sugarcane plantations, including those in Indonesia. Large amount of sugarcane trash left in the field makes difficulties in soil management and plant maintenance. Current practice done by the sugarcane plantations was “burning before soil tillage”. However, the practice of burning cause unwanted impact to the environment and human health. Meanwhile, sugarcane trash still rich of nutrients for the land. Widely studied and has been proven that many sugarcane trash is very useful to increase the soil fertility. The trash size is still long so that it should be reduced to improve composting process. A prototype of reel type trash chopper has been designed and constructed with dimensions of 240 cm width, 268 cm length, and 133 cm height. The prototype was tested on 4 levels of reel rotational speeds (400, 450, 500, and 550 rpm) and 4 levels of trash densities (8, 16, 24, and 32 kg/m3). During the tests, cutting torque and rotational speed of the reel were measured using a torque-meter and a digital tachometer. The output of trash chopping were measured to know the quality of the chopping procces. The prototype chopped up sugarcane trash of about 1.7 - 3.2 cm length, with chopping capacity of 398 kg/hour. Results of the tests showed that cutting torque was in the range of 1.75 to 4.03 kg.m with the average of 2.88 kg.m, and average cutting power was 1.87 hp. Higher trash density caused a higher cutting torque and cutting power, while higher rotational speed caused a lower cutting torque and a higher cutting power. The highest cutting torque was 4.03 kg.m, when chopped sugarcane trash of 32 kg/m3 in trash density on 400 rotational speed. Increasing the rotational speed caused a shorter trash size.
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Judul: Psittacosis Sebagai Zoonosis Penting Yang Berasal Dari Burung
Abstrak: Psittacosis atau ornithosis adalah penyakit menular dari burung kepada manusia. Agens penyebab psittacosis termasuk ke dalam virus psittacosis-lymphogranuloma venereum group yang disebut Chlamydia psittaci. C. psittaci hanya dapat berkembang biak di dalam jaringan hidup tetapi peka terhadap antibiotik. Penyebaran penyakit ini sangat luas, terdapat hampir di seluruh dunia. Di Indonesia penyakit ini belum pernah di diagnosa, tetapi mengingat terdapat demikian banyaknya jenis burung maka diperkirakan psittacosis ini sudah ada. Kasus pada manusia pertamakali ditemukan oleh Ritter pada tahun 1879, di Eropa. Waktu itu dikenal sebagai pneumotyphus. Chlamydia psittaci tidak hanya sebagai penyebab infeksi pada burung, juga bisa menyebabkan infeksi pada mamalia diantaranya sapi, kerbau, kambing, domba, babi dan kucing. Pada kucing dikenal sebagai feline pneumonitis. Pada domba atau kambing mengakibatkan enzootic abortion. Pada burung, kalkun merupakan unggas paling rentan diikuti oleh burung psittacine dan burung lain di luar famili psittacidae. Virulensinyapun berbeda-beda. Yang berasal dari kalkun bervirulensi tinggi, sedangkan yang berasal dari burung merpati bisa bervirulensi tinggi bisa juga bervirulensi rendah. Penularan terjadi melalui kontak langsung maupun ti- dak langsung. Penularan melalui telur tidak terjadi. Umumnya penyakit ini memperlihatkan gejala klinis berupa deman, lesu, lemah, anorexia, kurus, diarrhea ber- warna kekuningan, discharge dari mata dan hidung, conjunc- tivitis. Gejala khas pada kalkun adalah istirahat dengan sternum sebagai dasarnya, karena adanya tekanan dari bagian perut yang sakit. Sedangkan pada manusia memperlihatkan adanya demam, kadang-kadang merasa dingin, lesu, sakit kepala yang hebat, sakit pada bagian belakang badan dan photophobia…dst
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