Judul: Keanekaragaman dan Vegetasi Melastomataceae di Perkebunan Teh Nirmala, Kabupaten Bogor
Abstrak: Melastomataceae merupakan famili tumbuhan asing invasif yang memiliki kemampuan beradaptasi di berbagai macam lingkungan salah satunya di perkebunan teh. Tujuan penelitian ini adalah mengidentifikasi spesies Melastomataceae yang tumbuh di Perkebunan Teh Nirmala, Kabupaten Bogor serta mengetahui vegetasi spesies Melastomataceae. Pengambilan sampel dilakukan secara purposive sampling di dua ketinggian yaitu 1070 mdpl dan 1400 mdpl kemudian sampel dibuat herbarium untuk diidentifikasi dan dihitung kerapatan trikomanya. Hubungan faktor lingkungan dan spesies dianalisis dengan metode Canonical Correspondence Analysis. Dua spesies Melastomataceae tumbuh di Perkebunan Teh Nirmala yaitu Clidemia hirta dan Melastoma malabathricum. Melastoma malabathricum yang teramati memiliki dua varian yang berbeda pada tipe indumentum permukaan daun dan tangkai daun. Clidemia hirta di kedua ketinggian memiliki Indeks Nilai Penting yang mendominansi daripada spesies M. malabathricum. Kedua spesies tersebut memiliki pola sebaran mengelompok. Faktor lingkungan mempengaruhi keberadaan spesies. Clidemia hirta dipengaruhi oleh suhu, intensitas cahaya dan curah hujan sedangkan M. malabathricum dipengaruhi oleh kelembapan, dan kecepatan angin.
Keyword: software Canoco, Clidemia hirta, indumentum, invasif, Melastoma malabathricum

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: Synthesis of Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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