Judul: Lintasan dan Model Spasial Deforestasi di Kalimantan Periode 2000-2013
Abstrak: Carbon emissions in Indonesia was contributed by the forestry sector. Yet, forest absorbs carbon emissions by photosynthesis processes and stores it in the forest biomass. This conditions causes the forestry sector could played a main role in the efforts to reduce global warming. Emission in forestry sector is mainly caused by deforestation for various purposes. Sustainable forest management approaches as important mechanisms to ensure balance in the use of forest resources for humans and the environment. Kalimantan island has large forest cover and has high rate deforestation. The trajectory and spatial model of deforestation was expected to provide more detailed information about the phenomenon of deforestation in Kalimantan that could be organized on sustainable forest management planning. This study used time-series land cover data from Ministry of Forestry in 2000–2013 and validated with SPOT 5/6 images in 2013. land cover data was used to analyzed the trajectory and spatial model of deforestation. The spatial model of deforestation were developed using logistic regression with data in 2000–2006 and then implemented in 2006–2013. The variables that used to predicted influence on the models were slope, altitude, peatlands, distance from forest edge, distance from plantations edge, distance from road, distance from river, farmer households, human population and Gross Regional Domestic Product (GDRP). Trajectory analysis of deforestation in Kalimantan in the period 2000-2013 suggests that a deforested has not been optimally exploited because most of land cover were still in the form of shrubs until the end of the period. The results of logistic regression analysis that obtained spatial model of deforestation in Kalimantan Pi = 1.1480714 - (0.033262*slope) - (0.002242*elevation) - (0.000413*distance from forest edge) + (0.000045*GDRP). The result of validation test of deforestation model in 2000–2006 has a value of overall accuracy about 79.64% and model of deforestation in 2006–2013 has value of overall accuracy about 77.01%.
Keyword: trajectory, spatial model, logistic regression, deforestation, Kalimantan

Judul: Model Spasial Deforestasi di Provinsi Jambi
Abstrak: Dalam dua dekade terakhir, deforestasi telah menjadi masalah internasional karena perannya pada perubahan iklim. Penelitian ini menjelaskan pemodelan spasial untuk memprediksi deforestasi di Provinsi Jambi. Tujuan penelitian utama adalah untuk mengetahui model spasial terbaik untuk memprediksi deforestasi dengan mempertimbangkan konteks spasial. Data utama yang digunakan untuk analisis meliputi gambar Landsat Multitemporal yang diperoleh pada tahun 1990, 2000, dan 2011, peta tutupan lahan yang diterbitkan oleh Departemen Kehutanan, data statistic, dan pembuktian lapang. Sebelum melakukan analisis lainnya, semua kecamatan di wilayah studi digolongkan menjadi dua tipologi atas dasar faktor-faktor sosial dan ekonomi dengan menggunakan pendekatan clustering, yaitu deforestasi kecepatan rendah dan kecepatan tinggi. Model spasial dikembangkan dengan menggunakan metode least-square. Studi ini menemukan bahwa model spasial deforestasi untuk wilayah deforestasi kecepatan rendah Logit (Deforestasi) = -2,7046 - 0,000397 * JH90 (jarak dari tepi hutan tahun 1990) + 0,000002 * JJ (jarak dari jalan) - 0,000111 * JKBN90 (jarak dari real tepi tanaman tahun 1990) + 0,000096 * JP90 (jarak dari tepi tanaman pertanian tahun 1990) + 0,044227 * PDK90 (kepadatan penduduk tahun 1990) + 0,148187 * E (elevasi) - 0,131178 * S (kemiringan), sedangkan untuk wilayah deforestasi kecepatan tinggi Logit (Deforestasi) = -9,1727 - 0,000788 * JH90 (jarak dari tepi hutan tahun 1990) - 0,000065 * JJ (jarak dari jalan) - 0,000091 * JKBN90 (jarak dari tepi perkebunan tahun 1990) + 0,000005 * JP90 (jarak dari tepi tanaman pertanian tahun 1990) - 0,070372 * PDK90 (kepadatan penduduk tahun 1990) + 11,268539 * E (elevasi) - 1,495198 * S (kemiringan). Model deforestasi kecepatan rendah dan kecepatan tinggi masing-masing memiliki ROC (Karakteristik Operasi Relatif) dari 91,32% dan 99,08%. Studi ini menyimpulkan bahwa tipologi dapat dibuat atas dasar kepadatan penduduk. Tingkat deforestasi secara signifikan dipengaruhi oleh aksesibilitas (jarak dari tepi hutan, jarak dari tepi perkebunan, tepi dari lahan pertanian), kondisi biofisik (elevasi dan kemiringan) serta kepadatan penduduk.
Keyword: clustering, deforestasi, gambar landsat multitemporal, model spasial, tipologi

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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