Judul: Deteksi Visual dan Analisis Luas Kontak Roda Traksi pada Beberapa Kondisi Permukaan
Abstrak: The intensive application of tractors had an impact to the soil condition of farm through all the forces applied to the soil. Those forces applied through the traction elements which contact to soil. The portion of the wheel or tire in contact with the supporting surface referred to the term of contact area. The measurement of tire contact area is needed due to its effect on tractor performance. The objectives of this research were to study the tire contact area on asphalt road and soil surface also its relation with the sinkage; to compare tire contact area based on the actual measurement with the theoretical tire contact area; to study the lug angle resulted between asphalt road and soil. The biggest average contact area on soil with 47.69% water content was 364.40 cm2, while the smallest was on the asphalt with 121.77 cm2. The biggest average lug angle on soil with 47.69% water content was 37.25°, while the smallest was on the asphalt that is 25.52°. The value of tire contact area in the soil was directly proportional with the soil moisture content and sinkage.
Keyword: asphalt., soil, sinkage, lug angle, tire contact area

Judul: Pendugaan Kedalaman Tekan Roda Traktor Roda Empat Berbasis Uji Kedalaman Tekan Telapak Kaki Manusia
Abstrak: Load of a tractor on certain terrain condition may cause sinkage, which results motion resistance on its four wheels. This motion resistance reduces its mobility and decreasing work capacity. This research was aimed to predict the sinkage of a fourwheel tractor based on human footprint approximation. The parameters examined for the sinkage prediction were pressure and the physical properties of soil. Based on the observations, water content can be used as representative of other soil properties. Through linear regression analysis, some equation models for predicting human footprint and tractor sinkage were obtained. The equation models employed water content and normal pressure as the independent variables. Those models were then compared with the observed tractor’s sinkage to find the best fitted model. Equation model zkskid = 12.804 - 0.275(ka) + 6.56(P) through male subject and zkdkab = 18.028 - 0.262(ka) - 7.304(P) through female subject were the best fitted model that can be used for sinkage prediction of four-wheel tractors.
Keyword: soil, equation model, sinkage, footprint, tractor, Bogor Agricultural University (IPB)

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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