Judul: Karakteristik Anatomi Daun beberapa Spesies Hoya spp. Bertipe Daun Sukulen serta Analisis Hubungan Kekerabatannya
Abstrak: Hoya (Hoya spp.) is an epiphyte or lithophyte vine or shrub. Hoya’s flower has beautiful unique shape and it is considered as original plant from Southeast Asia and surroundings. This plant has two type of leaf, succulent and non succulent. Succulent plant can adapt well in extreme condition, especially in dry period. Anatomy characters can be used to identify, classify, and determine plant relationship. The aims of this research were to identify anatomical character of succulent Hoya’s leaf and to determine their relationship. Ten exmined species Hoya spp. (H. diversifolia, H. latifolia, H. dolichosparte, H. bilobata, H. lacunosa, H. verticillata, H. purpureofusca, H. kuhlii, H. oblanceolata, and H. micrantha) showed anatomical similarity which was epidermal layer, hipodermal, mesophil, and the absence of sponge tissue at mesophil. However there were many diversities between specieses. Based on paradermal section of the leaf, stomata was only found on the abaxial side and have two type, individual stomata and both individual and stomatal cluster. Hoya diversifolia had the smallest stomatal size, while Hoya latifolia had the biggest. Hoya lacunosa had the lowest stomatal density, while Hoya bilobata had the highest. Hoya diversifolia, Hoya lacunosa, and Hoya oblanceolata had the lowest stomatal index, while Hoya bilobata had the highest. Observation on transversal section showed that Hoya purpureofusca had the lowest leaf thickness, while Hoya kuhlii had the highest. The hierarchical cluster analysis based on anatomical leaf character showed different patterns of relationship which diversed as three groups at relationship scale 15.
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Judul: Evaluasi Karakter Vegetatif Hoya (Apocynaceae) di Kebun Raya Bogor
Abstrak: Hoya is epiphyte, lithophyte plant, or shrub. Information of morphological diversity is essential to it’s development as an ornamental plant. The aim of this research was to study the morphological diversity of vegetative characters of Hoya that are collected in Bogor Botanical Garden, in order to facilitate identification in the field. This research provides the diversity of vegetative characters of Hoya as one of the library reference, and provides a Hoya identification key based on vegetative characters. Twenty six Hoya species were morphologically characterized their vegetative organs. The data then were tabulated, and used for constructing an identification key. The results showed that Hoya has variation in several vegetative characters i.e shape, size, base and tip of the leaf, vein shape of leaf, leaf blade surface (indumentum), leaf blade color, petiole shape, indumentum, size and color of the stem. The best characters for distinguishing among Hoya species were the form of the leaf blade and leaf venation. Some species have some unique characters that can be used to distinguish among species of Hoya, for example H. imbricata has imbricate leaf arrengement, reniform shape and purple abaksial surface. The leaf venation of H. finlaysonii is pinnate that has contrast color between venation and blade. The specific features of other species will be discussed further in this paper.
Keyword: identification key, vegetative characters, morphology, Hoya

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