Judul: Sinkage prediction model of a four-wheel tractor based on plate sinkage test
Abstrak: Sinkage of a tractor on a field will cause motion resistance which reduces its traction. This will lead to the reduction of tractor’s efficiency. This study was conducted to predict the sinkage of a four-wheel tractor based on plate sinkage test. The parameters used for the plate sinkage test were load, physical and mechanical properties of soil (water content, bulk density and penetration resistance) and the dimensional parameters of the plate (the plate area and contact shape ratio). The method used were predicting sinkage using plate sinkage test with special consideration on contact shape ratio and comparing the model with Bekker’s sinkage model (1960). The test resulted that water content and load on area of plate were significantly affect the depth of sinkage as a parameters. The model which is has the best correlation to the sinkage of tractor is k2 model i.e. 7 6 6 69
Keyword: tractor, sinkage, shape ratio index, plate sinkage

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: Ekologi merak hijau jawa (Pavo muticus muticus) Linnaeus 1758 pada beberapa tipe habitat di Ujung Timur Penyebarannya Jawa Timur, Indonesia
Abstrak: Merak hijau jawa merupakan salah satu jenis burung yang dilindungi.di Indonesia berdasarkan SK Mentan No 66/Kpts/Um/2/1973 dan Peraturan Pemerintah Republik Indonesia No 7 tahun 1999. Menurut ICBP (The International Council for Bird Preservation) merak hijau sebagai jenis burung yang tergolong terancam secara keseluruhan (globally threatened) baik populasi maupun habitatnya, sedangkan CITES mencantumkan merak hijau ke dalam Appendix II, merak hijau dari alam tidak bisa langsung diperdagangkan dan BirdLife International (2007) memasukkan golongan burung yang endangered. Tekanan terhadap populasi dan habitat merak hijau jawa sangat besar, sehingga kondisi populasinya menurun pada setiap penyebaran lokalnya, habitatnya terfragmentasi bahkan terisolasi. Tekanan terhadap populasi terutama karena perburuan liar. Namun demikian fakta menunjukan bahwa merak hijau jawa masih ada (exist), hal ini memberikan gambaran bahwa burung ini tentunya memiliki strategi ekologi tertentu untuk tetap bertahan hidup di alam pada berbagai tipe habitat.
Keyword: Pavo muticus muticus, Call count transect method, Pavo cristatus, Pavo muticus, Pavo muticus spicifer, Pavo muticus imperator, Pavo muticus muticus, Javan Green Peafowl, East Java