Judul: Pemulihan Vegetasi di Areal Hutan yang Dikelola dengan Sistem TPTJ (Studi Kasus di Areal IUPHHK-HA PT. Suka Jaya Makmur, Kalimantan Barat)
Abstrak: Massive utilization of forest resources became one factor which caused degradation on natural forest. Forest degradation which occurred continuously could cause a change in forest composition. This could happen because seedling from invasive species dominated the area of natural forest. This research aimed to determine the composition and structure recovery of forest stands managed by TPTJ system on area of IUPHHK-HA PT. Suka Jaya Makmur, West Kalimantan. The results showed that non-commercial Dipterocarp species group had the biggest value of density and proportion among all levels Dipterocarp. Curve diameter distribution showed a balanced logged forest. The diversity in all plotarea was high. Kelampai and meranti were dominated in canopy level. Jambu monyet and kelampai were the species that dominated in seedling level. Tree and seedling had a different composition, it was shown by the ID value at >50%. This was shown by cluster analysis which divided into four groups. Commercial species proportion was generally larger than other non-commercial species.
Keyword: selective cutting and line planting, vegetation recovery, forest utilization

Judul: Penentuan Sistem Silvikultur Berbasis pada Proses Pemulihan Vegetasi dalam Teknik Silvikultur Intensif (Studi Kasus di Areal PT Sarpatim, Kalimantan Tengah)
Abstrak: Mistakes in implementing the right silvicultural system with forest characteristic cause forest degradation. The aim of this observation is to determine the appropriate silvicultural system based on the forest standing structure and similarity of community. The analyzed data’s composition’s type and forest standing structure, forest regeneration type composition, type variety index value, ordination showed by important value index and community dissimilarity index, and cluster and biplot analysis. The result shows that non-Dipterocarpaceae commercial type community has the biggest density and proportion in all levels. Forest standing structure shapes J-reversed curve. The variety on all plots is high enough. Ubar and red meranti dominate all observation plots. Almost tree community has relatively different types in each plot. Regeneration community almost all has value for ID <50% that means the community is relatively the same. It can be seen from cluster analysis chart which part of three grup. The biplot analysis result shows that TJ6 has the most similarity between recovery and tree, while the other plots have different composition.
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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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