Judul: Biosystematics of Alpinia zerumbet Clade in West Malesia.
Abstrak: Alpinia Roxb. is a genus of the family Zingiberaceae and tribe Alpinieae. Alpinia classification based on morphological characteristics is not congruent with molecular classification. Incongruence in this genus (including the Alpinia zerumbet clade) is thought to occur because the rate of evolution at the molecular level is not accompanied by morphological changes or changes that do not occur simultaneously. The evolutionary process also causes many morphological variations in one member of this clade, namely Alpinia malaccensis, a species that has two varieties. The taxonomic status of the two varieties is debated as to whether they should be treated as the same or different species. Another problem is harvesting the essential oil of A. malaccensis rhizomes from the forest directly, without cultivation. It is a concern that the existence of this species will decrease. Therefore, several approach studies need to be carried out to create reference data for A. malaccensis conservation and clarify the status of the two varieties and support the classification of the genus Alpinia for the better. The purpose of this study was to analyze the diversity and distribution of members of Alpinia zerumbet clade in West Malesia, analyze genetic variation, predict habitat suitability and essential oil content of A. malaccensis, and phylogenetic analysis of Alpinia based on the plastid genome. The research method for analyzing the diversity and distribution of members of the Alpinia zerumbet clade consisted of sample collection, observation of morphological characteristics, and recording of environmental data. The description of each species and the key to determining the species are constructed. The method for analyzing genetic diversity consisted of DNA isolation from A. malaccensis leaves, DNA amplification using Inter Simple Sequence Repeat (ISSR) marker, electrophoresed, and visualization. DNA band data was used to determine genetic diversity, population structure, and genetic relationships. In the predictions of habitat suitability, the coordinate points of each A. malaccensis accession were determined based on herbarium data and field observations, the environmental variables were taken from Bioclim2. Both data types were analyzed using the MaxEnt software to determine the most influential environmental variables and model the prediction of habitat suitability. The content of volatile compounds in the two varieties of A. malaccensis was taken from rhizomes and prepared for GC-MS analysis. The GC-MS results data were used for profiling the types of compounds produced and their concentrations as well as for grouping volatile compounds. Alpinia phylogenetic analysis was carried out based on the plastid genome. The phylogeny analysis procedure consists of several steps, DNA isolation and purification, DNA sequencing, plastid genome rearrangement, and construction of an Alpinia phylogenetic tree using the Maximum Parsimony method. The Alpinia zerumbet clade in West Malesia consists of 17 species. They share several characteristics: i.e. absent or caducous secondary bracts, small or reduced lateral staminodes, and often having a petaloid and showy labellum. The highest diversity of this clade is the Borneo regions (8 species), while the lowest diversity is Java (2 species). The members are distributed at an elevation of 2 to 1600 m above sea level (m asl). Most species of Alpinia zerumbet clade are found
Keyword: Alpinia zerumbet, essential oil, genetic diversity, plastome, suitability habitat prediction, West Malesia, Zingiberaceae

Judul: Phylogenetic analysis of subgenus Dieramalpinia (Alpinia carolinensis clade) - Zingiberaceae based on ITS sequences
Abstrak: The most recent infra-generic classification of Alpinia Roxb. by Smith divided the genus into two subgenera (Alpinia and Dieramalpinia) with 11 sections and 12 subsections. One of the sections of Alpinia subgenus Dieramalpinia is Myriocrater which contains about 16 species. The most recent phylogenetic study that included species from Alpinia subgenus Dieramalpinia was done by Kress et al. (2007). They sampled only eight species and found that these were nested within a clade referred to as the Alpinia carolinensis clade. This clade was well supported and may be separated as a genus if sampling more species confirms the result. The objectives of the present project are to compare ITS within one species; to test the monophyly of Alpinia section Myriocrater; to test whether adding more samples still supports the Alpinia carolinensis clade. The present study included thirty-nine samples representing nineteen taxa from Alpinia; seven samples are still unidentified at species level. Sequences of the Internal Transcribed Spacer were used in the analysis. The result showed that ITS sequence of Myriocrater’s species are more conserved than another group in Zingiberaceae. There are base variations within species level. The Alpinia section Myriocrater plus five species from other section is not monophyletic. The Alpinia carolinensis clade still includes three sections of Smith classification (Dieramalpinia, Myriocrater and Pycnanthus) from subgenus Dieramalpinia. Alpinia subgenus Dieramalpinia section Eubractea and one species of section Dieramalpinia are separated into another clade.
Keyword: Alpinia, Myriocrater, Dieramalpinia, Alpinia carolinensis clade

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