Judul: Pemanfaatan Ruang oleh Bekantan (Nasalis larvatus Wunnb) pada Habitat Terisolasi di Kuala Samboja, Kalimantan Timur
Abstrak: Proboscis monkeys (Nasalis larvatus Wurmb) is an endemic primate species to the island of Borneo and has been classified as endangered species by IUCN. Fourty percent of this habitat has been lost and only 4.1% of this habitat occurs within designated conservation areas. Kuala Samboja River is an unprotected habitat of proboscis monkey. This area was narrow, isolated, and fragmented. The objectives of the research were to obtain habitat conditions, population, food source, and space use. Data were collected through vegetation analysis by line-plot sampling method, activity budget and use of space by instantaneous sampling method, whereas food sources by individual activity records of feeding (IARF) method. The groups were observed were Stan, Zacky, and Raja. The results of this study showed that the community of habitat are dominated by Sonneratia caseolaris, Cerbera manghas, Vitex pinnata, and Elaeocarpus stipularis. Twenty one of plant species were found as food sources, five of those were preferred i.e. S. caseolaris, V. pinnata, Deris sp., Hevea braziliensis, and Avicenia cf. officinalis. The population of proboscis monkey more than 143 monkeys, 98 monkeys divided to 9 groups (6 one-male groups, 3 all-male groups), whereas 45 monkeys unidentified. Generally, the monkeys spent more time for feeding in the morning and afternoon and resting in noonday. Feeding and moving activity of female greater than male but resting was lesser, whereas social activity was done by female only. Each mean daily range groups were 289 m (Stan), 260 m (Zacky), and 449 m (Raja), while home range size were 4.92, 4.52, and 6.92 ha, respectively. The groups of Stan, Zacky and Raja spent most of their time at heights of 9-12 m, 0-6 m, and 3-9 m, respectively. Use of canopy stratum influence by habitat conditions, temperature, blown of wind, and predators.
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Judul: Populasi dan Perilaku Bekantan (Nasalis larvatus) in Samboja Koala, East Kalimantan
Abstrak: The proboscis monkey (Nasalis larvatus) is a member of sub-family Colbinae, and a sexuall dimorphic species, endemic to Kalimantan. The Habitat of the monkey is confined mainly to mangrove, riverine forest and pest swamp forest.
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Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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