Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif di Cagar Alam Pulau Sempu, Jawa Timur
Abstrak: The presence of invasive alien plant species has been known to cause various negative impacts on ecosystems in the invaded conservation area. This research aims to identify the diversity and distribution pattern of invasive alien plants species occurred in Sempu Island Nature Reserve, and to determine the most influential environmental factors to their dispersion. The methods used were the standard vegetation analysis and rapid assessment technique. According to the results, as many as 10 invasive alien plants species (belonging to 7 families) have been identified to occurred in this conservation area, e.g., Pistia stratoites, Ageratum mexicanum, Vernonia cinerea, Cyperus rotundus, Passiflora foetida, Centotheca lappacea, Eleusine indica, Imperata cylindrica, Hedyotis corymbosa, and Lantana camara. All invasive alien plant species found in the sampling plots had a clumped distribution pattern. The most influential environmental factors to the invasive alien plants dispersion were land slope and distance from shoreline.
Keyword: Sempu Island Nature Reserve, invasive alien plants, environmental factors, distribution pattern

Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif Di Cagar Alam Yan Lapa
Abstrak: Invasive alien plants species were plant species which come from other regions or countries and gift negative impact to the native species diversity. This research aimed to identify the vegetation composition and structure, invasive alien plant species diversity, and distribution pattern of invasive alien plant species in Yan Lapa Nature Reserve. The methods used were vegetation analysis using combination of line transect and nested plot and rapid assessment. The most dominant family was Araceae. As many as twelve invasive alien plants species were identified exist in Yan Lapa Nature Reserve. Those twelve species were Acmella uliginosa, Ageratum conyzoides, Centotheca lappace, Cyathula prostrata, Paspalum conjugatum, Clidemia hirta, Chromolaena odorata, Elephantopus scaber, Mikania micrantha, Cecropia peltata, Swietenia macrophylla dan Lantana camara. All invasive alien plant species distribution patterns were clustered.
Keyword: Bogor Agricultural University (IPB), distribution pattern, invasive alien plants species, Yan Lapa Nature Reserve, Vegetation analysis

Judul: Pemanasan Sekunder Reaksi Fusi Plasma dengan Menggunakan Radio Frequency
Abstrak: Plasma merupakan bentuk ke-empat dari materi setelah padat, cair dan gas yang terbentuk dari proses ionisasi gas. Plasma dapat digunakan dalam reaksi fusi, yaitu reaksi penggabungan dua inti atom ringan menjadi inti atom yang lebih berat sambil melepaskan energi. Untuk mendapatkan energi dari reaksi fusi, inti yang akan direaksikan harus dipanaskan pada temperatur yang sangat ekstrem tingginya. Salah satu cara agar dapat mencapai kondisi ini adalah memberikan pemanasan tambahan atau pemanasan sekunder kepada plasma dalam reaksi fusi tersebut. Nilai daya serap rata-rata ion Deuterium yang sesuai dengan selang nilai daya dari data ITER adalah daya yang menggunakan frekuensi 50 MHz sampai dengan 60 MHz. Dengan menggunakan frekuensi 60 Hz diperoleh nilai daya rata-rata yang diserap sebesar 1,235.10-12 W.
Keyword: gelombang radio, pemanasan sekunder, plasma, reaksi fusi