Judul: Angka bentuk dan model volume Kayu afrika (Maesopsis eminii Engl) di Hutan Pendidikan Gunung Walat, Sukabumi, Jawa Barat^
Abstrak: Some volume models and form factors have been developed for several trees species in Gunung Walat University Forest (GWUF), but no volume model and form factor are available yet for Maesopsis eminii. The objective of this study was to determine form factor and to develop volume model for M. eminii in GWUF. Eighty seven sample trees were used to develop volume models and 37 sample trees were used to validate the volume models, which were purpossively selected from the M. eminii stands with diameters ranging from 5.7 to 73.5 cm. The measurements of sample trees were conducted by using a Laser Criterion (for measuring tree diameter) and Laser Rangefinder (for measuring tree height). The results showed that M. eminii had an absolute form factor of 0.562 and an artificial form factor of 0.699, while the best model for estimating its volume was V = 0.000264D2.35. This volume model provided better precision (with a bias of 0.032) than the use of form factors.
Keyword: Bogor Agricultural University (IPB), Gunung Walat University Forest, volume model, Maesopsis eminii, form factor

Judul: Angka Bentuk dan Model Volume Puspa (Schima wallichii (Dc.) Korth) di Hutan Pendidikan Gunung Walat, Sukabumi, Jawa Barat
Abstrak: Volume pohon merupakan salah satu data penting untuk mengetahui manfaat kayu hutan, seperti di Hutan Pendidikan Gunung Walat (HPGW). Model volume Schima wallichii yang dikembangkan pada tahun 1985, perlu diperbaiki karena kondisi tegakan telah berubah dari waktu ke waktu. Oleh karena itu, penelitian ini bertujuan untuk mengetahui angka bentuk yang tepat dan mengembangkan model untuk memperkirakan volume S. wallichii di HPGW. Penelitian ini menggunakan 94 sampel pohon untuk menyusun model volume dan 39 pohon sampel untuk validasi model, yang dipilih secara purpossive mewakili kisaran diameter 10,5-71,8 cm terhadap tegakan S. wallichii. Diameter dari pohon sampel diukur dengan menggunakan Laser Dendrometer, sedangkan tinggi pohon sampel diukur dengan menggunakan Laser Rangefinder. Hasil penelitian ini menegaskan bahwa S. wallichii memiliki angka bentuk buatan 0,71 dan angka bentuk mutlak 0,52, sedangkan model volume yang terbaik bagi spesies ini adalah V=0,000237 D2.32 (R2adj=94,8%). Model volume tersebut dapat digunakan karena menghasilkan nilai dugaan volume pohon S. wallichii yang lebih akurat daripada model volume yang sudah ada.
Keyword: angka bentuk, model volume, Schima wallichii

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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