Judul: Dinamika Infestasi dan Karakter Ekofisiologi Gulma di Daerah Penyangga Taman Nasional Lore Lindu
Abstrak: The objectives of the study were (1) to evaluate the weed dynamic infestation as one component of ecosystem changes from forest to agricultural ecosystems, especially the changes in diversities and type of weed due to different system of agronomic practices, (2) to identify morphological, anatomical, and physiological traits of weed in relation to its adaptation and competition. (3) to study the competition effect of weed on the yield of maize, and (4) to find out critical periods on control weed and its affect on the growth and yield of maize as well as to know the appropriate time to control weed on maize production
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Judul: Infestasi Gulma pada Agroekologi yang Berbeda di Perkebunan Kelapa Sawit (Elaeis guineensis Jacq.) Tambusai Estate, Kab. Rokan Hulu, Riau
Abstrak: Weed control in oil palm plantation can improve the productivity of oil palm trees. This in was carried out internship Tambusai Estate, Rokan Hulu, Riau, from February to May 2012. The objective of this apprentice was to improve the knowledge, skills, work experience and analyze factors that affect weed dynamic in different agroecological areal at oil palm plantation. Data were collected by direct method for primary data and indirect method for secondary data. Data of weed were collected using vegetation analysis of 1 m x 1m kuadran. The number of samples were 264. Weed were scored and tested using cluster analysis and shown as a dendogram. The results showed that agro-ecological factors, especially soil subgroup determined weed population and dominance in Tambusai Estate. Weed invasion on palm oil plantation spread based on the nature of the morphology, botany, and nature of damage to plants as well as palm oil is the difference in the form agroekologi subgroup of land. The humid soil conditions is an optimum for weeds Asystasia intrusa (Forssk.) Blume., Nephrolepsis bisserata (Sw.) Schott, and various kinds of other ferns which is the dominant weeds in Tambusai Estate.
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Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4