Judul: Validation of Global Allometric Models for Estimating Various Tree Species in Indonesia
Abstrak: Pendugaan biomassa hutan seringkali menggunakan model alometrik global ketika model alometrik lokal tidak tersedia. Namun, belum banyak pengujian akurasi model alometrik global untuk pendugaan biomassa pohon. Penelitian ini bertujuan menguji keakuratan model alometrik global (yaitu model Chave dan Komiyama) untuk pendugaan biomassa pohon pada hutan lahan kering sekunder, hutan tanaman, dan hutan mangrove sekunder di Indonesia. Penelitian ini menggunakan metode studi pustaka, data biomassa pohon diperoleh dari pustaka yang telah dipublikasikan. Keakuratan pendugaan biomassa dari model alometrik global dinilai dengan menghitung beberapa nilai statistik (yaitu ME, PE, RMSE, dan MAPE), semakin kecil nilai statistik, semakin tinggi akurasi model alometrik global. Hasil penelitian menunjukkan bahwa model alometrik global Chave yang menggunakan variabel kerapatan kayu, diameter pohon, tinggi pohon lebih akurat untuk pendugaan biomassa pohon di hutan lahan kering sekunder, sedangkan model alometrik global Chave yang menggunakan variabel kerapatan kayu dan diameter pohon lebih akurat untuk menduga biomassa pohon hutan tanaman. Model alometrik global Komiyama lebih akurat untuk menduga biomassa pohon hutan mangrove., Estimation of forest biomass often uses global allometric models when local allometric models were not available. However, there have not been many tests on the accuracy of global allometric models for estimating tree biomass. This study aimed to test the accuracy of global allometric models (i.e. Chave and Komiyama models) for estimating tree biomass at secondary dryland forests, plantation forests, and mangrove forests in Indonesia. This study used a literature review method, where tree biomass data were obtained from published literatures. The accuracy of biomass estimation from the global allometric models was assessed by calculating some statistical values (i.e. ME, PE, RMSE, and MAPE), in which the smaller the statistical values, the higher the accuracy of the global allometric models. The results showed that the Chave's global allometric model, which uses wood density, tree diameter, tree height variables, was more accurate for estimating tree biomass of secondary dryland forests, while the Chave's global allometric model that use, wood density and tree diameter variables was more accurate for estimating tree biomass of plantation forests. The Komiyama's global allometric model was more accurate for estimating tree biomass of mangrove forests.
Keyword: Bias, Tree Biomass, Validation, Allometric Model

Judul: Model Persamaan Alometrik Penduga Biomassa dan Masa Karbon Pohon Di Hutan Alam Tropika Basah (Studi Kasus Di ArealIUPHHK-HA PT Suka Jaya Makmur, Kalimantan Barat)
Abstrak: Global warming is one of green house effect phenomena which cause by increasing the concentrations of greenhouse gases (GHG) emissions in the atmosphere, such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF6). Forests can absorb CO2 from the air and store in the trees. Tropical natural moist forest is one of the forest types, which can absorb CO2 very well so it has quite high potential carbon stock. This studies was conducted in IUPHHK-HA PT Suka Jaya Makmur, West Kalimantan. The main goal of this study is to get tree biomass and carbon allometric equations of tropical natural moist forest in IUPHHK- HA PT Suka Jaya Makmur. Sampling conducted by purposive sampling. Laboratory analysis of sample materials were done in the Laboratory of wood chemistry, Department of Forest Product, Faculty of Forestry to determine the carbon content in each part of the tree. The best equations was selected based on the highest R2(adj) and the smallest standard deviation (s) value. Estimation of biomass and carbon mass were done on roots, stems, branches, twigs, and leaves of the tree. The results of this study indicate that the carbon content of every part of the trees (roots, main stems, branches, twigs and leaves) are very significant difference. Allometric equations for tree biomass was selected Btot=0.2729D2.53Tbc-0.332, and model allometric equations to estimate potential carbon Ctot=0.1503D2.57Tbc-0.357. The potential of biomass and carbon mass location of each study is 68.35 ton/ha and 41.69 ton/ha.
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Judul: Struktur dan Karakteristik Optik Lapisan Semikonduktos Cu2O (Cuprous oxide) Hasil Deposisi Elektrokimia
Abstrak: Ballan semikonduktor Cu2O (Ctiprotis oxide) dipilih karena lnemiliki banyak keuntungan antara lain ; relatif murah, bahan dasar (Cu) mudah didapat, dan tidak beracun. Banyak metode deposisi telah digunakan untuk menghasilkan lapisan semikonduktor Cu,O, dalam penelitian ini digunakan metode deposisi elektrokimia. Deposisi elektrokimia dilakukan scbanyak dua salnpel dengan variasi tegangan -500 mV (sampel I ) dan 4 0 0 mV (sampel 2) terhadap SCE. Lapisan selnikonduktor Cu20 diatas kaca TCO yang dihasilkan dikal-akterisasi kristalografi (XRD), morfologi (SEM), dan optiknya (Spektrofotometer UV-VIS). Melalui karakterisasi XRD diketahui semikonduktor Cu20 yang terbentuk adalah polikristal.
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