Judul: Identifikasi Dan Karakterisasi Gulma-Gulma Ruderal Invasif Di Kebun Raya Bogor
Abstrak: Invasive weeds become important issues in Indonesia due to ecological and economical production concern of agriculture. Plant invation effected consequences of very high ecological loss and economical cost. Several thing of economic cost be able to quantification such as herbiside cost and yield loss. The ecological loss is the priceless disadvantages and difficult to quantified eg ecosystem damage, decrease recreation area, extinct of certain species etc. This research intent on identify and characterization of ruderal invasive weeds, looking for spreading pattern along with those influence factors to get the precisely controlling method and to know economic consequences from the existense of ruderal invasive weeds in Kebun Raya Bogor. This researh used scoring method and continued with multivariate analysis which showed by dendogram. The dendogram is made by neighbour joining single linkage method. The results showed that there are seven species invasive weeds from six familly which divided into three groups according to its aggresiveness. Component of Group 1 is Dioscorea bulbifera L. (Dioscoreaceae) with total score 69. Group 2 consist of Cissus sicyoides L. (Vitaceae) with total score 75, Cissus nodosa L. (Vitaceae) with total score 67 and Mikania micrantha H.B.K. (Asteraceae) with total score 78. Group 3 consist of Ficus elastica Roxb. (Moraceae) with total score 56, Paraserianthes falcataria (Fabaceae) with total score 48 and Cecropia adenopus (cecropiaceae) total skor 45. Component of Group 1 and Group 2 are woody climber those included in kind of vines whereas component of Group 3 are kind of tree. Based on our investigation invasive weed species which have score more than 50 be able to made significant disturbance and threaten the ecosystem stabillity of Bogor Botanical Garden.
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Judul: Keragaman Tumbuhan Invasif di PT Perkebunan  Nusantara II Deli Serdang, Sumatra Utara
Abstrak: Salah satu penghambat produktivitas perkebunan sawit adalah gulma. Beberapa gulma termasuk dalam kategori tumbuhan invasif. Penyebaran serta pertumbuhan dari tumbuhan invasif yang tidak terkendali dapat menyebabkan kerugian serta ancaman secara ekonomi maupun ekologi. Penelitian ini bertujuan menganalisis keragaman tumbuhan invasif di kawasan kebun kelapa sawit PT Perkebunan Nusantara II. Sampel tumbuhan diambil dengan membuat petak contoh pada 3 blok yang berbeda dan ditempatkan secara purposive sampling. Selanjutnya, dilakukan identifikasi spesies dan analisis data yang mencakup Indeks Nilai Penting (INP), indeks keanekaragaman, indeks kesamaan dan indeks kemerataan. Spesies tumbuhan invasif yang ditemukan sebanyak 20 dari 61 spesies gulma yang berasal dari 13 famili. Spesies invasif yang ditemukan memiliki habitus herba, semak dan perdu. Spesies invasif didominasi oleh tumbuhan dari famili Poaceae dan Asteraceae. Jenis Asystasia gangetica, Mitracarpus hirtus, Peperomia pellucida dan Phyllanthus urinaria ditemukan dalam tiga blok. Namun, berdasarkan nilai INP hanya tiga spesies yang dapat tergolong memiliki pengaruh pada komunitasnya yaitu Phyllanthus urinaria, Setaria plicata dan Peperomia pellucida., Several species of weeds which are categorized as invasive plants are one of the causes of inhibiting plantation productivity. The uncontrolled spread andgrowth of invasive plants can cause economic and ecological losses. This study aimed to analyze the diversity of invasive species in the palm oil plantation area of PT Perkebunan Nusantara II. Plant samples were taken by making sample plots in 3 different blocks and placed by purposive sampling. Furthermore, species identification and data analysis were carried out including the Important Value Index (IVI), diversity index, similarity index and evenness index. There are 20 invasive species from 61 weed species belonging to 13 families. The invasive species have a habitus of herbs, bushes and shrubs. Invasive species are dominated by species from the families Poaceae and Asteraceae. Asystasia gangetica, Mitracarpus hirtus, Peperomia pellucida and Phyllanthus urinaria species were found in all three blocks. However, based on the IVI value, only three species can be categoried affecting the community, namely Phyllanthus urinaria, Setaria plicata and Peperomia pellucida.
Keyword: diversity, IVI, invasive species, purposive sampling, weeds

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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