Judul: Diversity and Use of Plants in Kelekak in Air Mesu Village, Central Bangka
Abstrak: Kelekak merupakan kebun tradisional masyarakat Kabupaten Bangka Tengah yang termasuk dalam sistem agroforestri. Terdapat beberapa spesies tumbuhan yang dibudidayakan di kelekak. Penelitian bertujuan untuk mengidentifikasi komposisi spesies tumbuhan, potensi pemanfaatan dan bioprospeksi, sistem kepemilikan lahan kelekak, dan upaya konservasi kelekak. Penelitian dilakukan dengan menggunakan metode analisis vegetasi, wawancara, dan studi literatur di tiga tipe kelekak yaitu, kelekak belakang rumah, pinggir desa, dan hutan. Spesies tumbuhan yang ditemukan terdiri atas berbagai macam famili dan habitus. Spesies tumbuhan yang mendominasi di kelekak yaitu durian (Durio zibethinus L.). Flavonoid dan saponin menjadi kandungan bioaktif yang paling sering ditemukan pada spesies tumbuhan di kelekak. Vitamin B dan C menjadi kandungan nutrisi yang paling sering ditemukan pada spesies tumbuhan di kelekak. Hasil panen dan harga jual spesies tumbuhan di kelekak dibedakan atas satuan butir dan kilogram (kg). Pendistribusian hasil panen masih dilakukan secara sederhana melalui tengkulak dan pasar. Upaya konservasi yang dilakukan di kelekak yaitu dengan membuat kebun bibit khusus spesies-spesies yang terdapat di kelekak., Kelekak is a traditional garden of the Central Bangka Regency community that is included in the agroforestry system. There are several plant species cultivated in kelekak. The study aimed to identify plant species composition, potential utilization and bioprospection, kelekak land ownership system, and kelekak conservation efforts. The research was conducted using vegetation analysis, interviews, and literature studies in three types of kelekak, namely backyard kelekak, village edge and forest. The plant species found consisted of various families and habitus. The dominant plant species in kelekak is durian (Durio zibethinus L.). Flavonoids and saponins are the most common bioactive ingredients found in plant species in kelekak. Vitamins B and C are the most common nutrients found in plant species in kelekak. The harvest and selling price of plant species in kelekak are differentiated by pieces and kilogram (kg). The distribution of crops is still done simply through middlemen and markets. Conservation efforts carried out in kelekak include creating a special nursery for the species found in kelekak.
Keyword: agroforestry, Composition, potential, kelekak, plants

Judul: Komposisi Vegetasi dan Potensi Tumbuhan Obat di Hutan Kerangas Kabupaten Belitung Timur Provinsi Kepulauan Bangka Belitung
Abstrak: Heath forest on East Belitung is thought to have a diversity of plant species that can be used for medications. However, the information about it has not been revealed yet. Therefore, research about composition of vegetation and potential medicinal plants in the heath forest is necessary. This research was conducted in the primay heath forest (Rimba), secondary heath forest (Bebak) and particular heath forest (Padang) at East Belitung on July to Agustus 2011. The collected data includes species of plants (local name and scientific name), species of plants used medicine and part of plants that is used for medicine. Methods that is used to collect the data is the analysis of vegetation and interview method. Analysis vegetation was done by using combination of line and compartment method. The number of lines in each forest type are 10 with each line size is 10 m × 100 m and the distance between the lines is 50 m. The research results 224 species of plants in the heath forest obtained from different habitus and growth rates. Species with the highest value of importance on seedling, bush/shrub, herbaceous, liana, rattan and pandan is the samak (Syzygium lepidocarpa) amounted to 20.2% in the primary heath forest, pulas (Guioa pleuropteris) amounted to 12.57% in the secondary heath forest and kucai padang (Fimbristylis sp.) amounted to 51.14% in the particular heath forest. Species with the highest value of important on sapling is betor belulang (Calophyllum lanigerum) amounted to 17.27% in the primary heath forest, kiras (Garcinia hombroniana) amounted to 21.50% in the secondary heath forest and sekuncong (Leptospermum flavescens) amounted to 88.46% in the particular heath forest. Species with the highest value of important on tree is seru (Schima wallichii) amounted to 53.36% in primary heath forest, seru (Schima wallichii) amounted to 103% in secondary heath forest and sekuncong (Leptospermum flavescens) amounted to 180.2% in the particular heath forest. The number of medicinal plant species are identified based on knowledge of local communities as much as 101 species. Plant family which were most widely utilized is Myrtaceae. Tree is the most common habitus of medicinal plant to be used. The part of plants which is widely used is root and the most numerous group of diseases cured with medicinal plant is diseases of body resilience system (fever). Composition of vegetation in heath forest is potential as a germ plasm reserve of medicinal plants in Indonesia. Heath forest resources conservation can support sustainability of species and benefits to community around the forest.
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Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik