Judul: Analisis Kebutuhan Jumlah Alat Sarad Excavator berdasarkan Produksi Kayu dan Produktivitas Alat pada Hutan Tanaman Industri di Sumatera
Abstrak: Excavator adalah salah satu alat yang digunakan untuk memindahkan kayu dari tunggak ke tempat pengumpulan kayu di lokasi pemanenan kayu pada Hutan Tanaman Industri di Sumatera. Penelitian ini dilakukan dalam rangka menganalisis perhitungan jumlah alat sarad berdasarkan realisasi produksi kayu untuk kegiatan pemanenan kayu. Tujuan penelitian untuk menganalisis jumlah excavator yang dibutuhkan perusahaan berdasarkan data realisasi produksi kayu dan menganalisis pengaruh luas areal HTI terhadap jumlah alat dan realisasi produksi kayu. Metode penelitian menggunakan rumus kebutuhan jumlah alat dan analisis regresi sederhana. Hasil penelitian menunjukkan jumlah alat berdasarkan realisasi produksi kayu didapat PT Sumatera Riang Lestari membutuhkan 56 unit, PT Wira Karya Sakti 201 unit, PT Toba Pulp Lestari 17 Unit, PT Mitra Kembang Selaras 9 unit, PT Arara Abadi 148 unit, dan PT Perawang Sukses Perkasa Industri 12 unit. Luas areal HTI berpengaruh terhadap jumlah alat. Jumlah alat berpengaruh terhadap realisasi produksi.
Keyword: excavator, Industrial Plantation Forest, timber product realization, Sumatra

Judul: Optimization of Timber Harvesting Equipments of Industrial Plantation Forest ( Case Study: PT. Sumatera Riang - Block I, Sei Kebaro, South Labuhanbatu Regency, North Sumatera)
Abstrak: Salah satu cara agar tercapainya waktu dan biaya yang efesien dengan cara mengupayakan kesesuaian penggunaan peralatan pemanenan kayu. Penelitian dilaksanakan di Hutan Tanaman Industri PT. Sumatera Riang Lestari-Blok I , Sei Kebaro, Kab. Labuhanbatu Selatan, Sumatera Utara). Peneltian ini bertujuan untuk menganalisis jumlah kebutuhan alat pemanenan yang dibutuhkan berdasarkan produktivitas kerja, taget produksi dan biaya peralatan. Hasil penelitian menunjukkan bahwa jumlah alat pemanenan kayu dari tahapan penebangan sampai pemuatan terdapat kelebihan alat. Alat pemanenan kayu yang efesien berdasarkan target produksi terdiri atas 13 unit chainsaw, 10 unit excavator, dan 5 unit debarker. Biaya produksi yang dikeluarkan pada scenario jumlah alat ideal lebih efesien dibandingkan dengan biaya produksi pada scenario jumlah alat aktual.
Keyword: number of equipment, optimization

Judul: Hybrid solar cells of ZnO nanoparticles/chlorophyll was modified metal ions (Zn2+ and Cu2+ )
Abstrak: Zinc Oxide (ZnO) is a n-type semiconductor with a wide the energy band (Band Gap) is 3.37 eV at room temperature and 3.34 eV at low temperature with a large exiton binding energy is 60 meV. ZnO has been synthesized by hydrothermal method, resulting in a decrease in particle size over the duration of the hydrothermal changes. Crystallographic structure of ZnO were characterized using XRD, has shown the characteristic pattern of a hexagonal wurtzite structure, the crystallite size increases to changes in particle size. Changes in particle size has also led to a change in the absorption peak of ZnO as has been demonstrated posted under test using the optical properties of UV-Vis spectrophotometer. Changes of this uptake has also led to changes in the energy band gap, which increases its band gap energy of the particle size. In electronic applications, especially in solar cells. Chlorophyll is considered less effective, because of their very nature are easily degraded as a result of several reactions which are acid, lighting and temperature. The results of the stability test using a halogen lamp 34 W/m2 for 5 hours, that the substitution of chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form more stable than natural chlorophyll. The characterization of the optical properties, the combination of ZnO / chlorophyll in the form of hybrid films has led to a shift in the absorption region of ZnO becomes more widely from the UV to Visible. ZnO/chlorophyll has absorption range of 350-515 nm, ZnO / Zn-feofitin 332-401 nm and 332-632 nm for Cu-feofitin. The combination of ZnO/chlorophyll and CuSCN as a solid electrolite in hybrid solar cell, a modified chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form a more stable I-V curve. It is characterized by its fill factor value greater than natural chlorophyll. Nevertheless, solar cells with natural chlorophyll has been able to produce higher efficiency values of chlorophyll were substituted.
Keyword: Hydrothermal, ZnO/Chlorophyll modified, Hybrid Solar Cell