Judul: Diversity of epiphytic ferns and Its host in Campus Darmaga of Bogor Agricultural University, West Java
Abstrak: Paku epifit merupakan kelompok tumbuhan paku yang unik, hidup menempel di permukaan pohon inang tanpa merusaknya. Paku epifit memanfaatkan pohon inang sebagai tempat untuk memperoleh kondisi lingkungan tertentu, sementara nutrisi dan air diperoleh dari deposit yang berada di sekitar permukaan pohon inang. Kampus IPB Darmaga memiliki jenis pohon yang beragam dengan kondisi lingkungan yang lembab, sehingga memungkinkan ditemukannya jenis tumbuhan paku epifit yang beragam. Penelitian ini bertujuan untuk mengetahui keanekaragaman tumbuhan paku epifit dan pohon inangnya beserta faktor-faktor yang mempengaruhinya di kawasan kampus IPB Darmaga- Bogor. Penelitian dilakukan di kawasan kampus IPB Darmaga dengan mengumpulkan spesimen tumbuhan paku epifit dan mencatat karakteristik permukaan pohon inang. Data yang diperoleh kemudian dikelompokkan berdasarkan jenis tumbuhan paku dan jenis pohon inang yang ditempati. Faktorfaktor yang mempengaruhi keberadaan tumbuhan paku dianalisis menggunakan analisis Regresi dan Principal Component Analysis (PCA). Sebanyak 22 jenis paku epifit dan 25 jenis pohon inang ditemukan. Jenis tumbuhan paku yang dominan ialah Davalia denticulata (26,59%), Asplenium nidus (25,99%), Vittaria ensiformis (22,97%), Drymoglossum pilloselloides (20,55%), dan Nephrolepis falcata (20,55%). Jenis pohon inang yang dominan ditempati oleh paku epifit ialah pohon kelapa sawit (Elaeis guineensis). Faktor yang mempengaruhi keanekaragaman jenis paku epifit ialah kekasaran permukaan kulit pohon dan posisi paku pada batang pohon, Epiphytic ferns live attaching on its host without damaging it. Epiphytic ferns use the host to obtain certain environmental condition while nutrients and water obtained from deposits around the host surface. Campus Darmaga of Bogor Agricultural University has various tree species and environmental conditions that suitable for the growth of epiphytic fern. The aim of this study was to describe the diversity of epiphytic ferns and its host in Campus Darmaga of Bogor Agricultural University. The study was conducted in Campus Darmaga of Bogor Agricultural University by collecting the speciments of epiphytic ferns and recording the characteristic of tree stem surface. Data was analyzed using Regression Analysis and Principal Component Analysis (PCA). There are 22 species of epiphytic ferns and 25 species of tree hosts. The dominant species of ferns are Davalia denticulata (26,59%), Asplenium nidus (25,99%), Vittaria ensiformis (22,97%), Drymoglossum pilloselloides (20,55%), and Nephrolepis falcata (20,55%). The dominant host is Elaeis guineensis. The diversity of ferns in Campus Darmaga were affected by the roughness of tree surface and the position of ferns on the tree trunk.
Keyword: paku epifit, pohon inang, keanekaragaman, kulit pohon, posisi paku

Judul: Keanekaragaman Paku Epifit pada Berbagai Tipe Kulit Pohon Anggota Meliaceae di Kebun Raya Bogor
Abstrak: Kebun Raya Bogor merupakan lembaga konservasi tumbuhan yang koleksi tumbuhannya memiliki habitus yang sangat beragam mulai dari tumbuhan merambat, herba, perdu sampai ke pohon-pohon besar berkayu. Sebagai penciri dari keanekaragaman tumbuhan yang memiliki habitus pohon diantaranya adalah tipe kulit pohon atau pepagan luar. Berbagai epifit termasuk tumbuhan paku, dapat tumbuh dengan menempelkan akarnya pada permukaan kulit pohon. Penelitian ini bertujuan mengidentifikasi spesies paku epifit dan menganalisis keterkaitan spesies paku epifit yang ditemukan berdasarkan tipe kulit pohon inang. Penelitian dilakukan di Blok Famili Meliaceae, Kebun Raya Bogor, dengan mengumpulkan spesimen tumbuhan paku epifit dan mencatat tipe kulit pohon inang. Pengamatan dilakukan pada 45 pohon inang dari 29 spesies yang memiliki 12 tipe kulit pohon yang berbeda. Keterkaitan jumlah spesies paku epifit dengan tipe kulit pohon inangnya dianalisis secara deskriptif. Sebanyak sembilan spesies paku epifit dijumpai di lokasi pengamatan yaitu: Asplenium nidus, Davallia denticulata, Dicranopteris linearis, Drymoglossum piloselloides, Goniophlobium percussum, Nephrolepis bisserata, Nephrolepis brownii, Microsorum sp., dan Vittaria elongata. Tipe kulit pohon retak-retak, lepas berkotak berpuru, licin berpuru, berpuru, dan licin menyerpih berpuru merupakan tipe kulit pohon yang paling banyak menjadi inang paku epifit. Tipe kulit pohon yang hanya dijadikan inang oleh satu spesies paku epifit ialah tipe berlekah dalam dan lepas berkotak. Asplenium nidus merupakan spesies paku epifit yang paling banyak tumbuh pada pohon anggota Famili Meliaceae, tumbuh di semua tipe kulit pohon dan di hampir semua bagian pohon. Dicranopteris linearis, Drymoglossum piloselloides, dan Goniophlobium percussum masing-masing hanya tumbuh pada satu pohon inang. Kata kunci: keanekaragaman, kulit pohon, Meliaceae, paku epifit.
Keyword: bark type, diversity, epiphytic fern, Meliaceae

Judul: Resonance technique HHO generator for internal combustion engine
Abstrak: Application of HHO gas as fuel had been generaly used. Though there was still controversy regarding its efficiency and efectiveness . In this research, hydrogen that hopefully could become an alternative renewable energy was produced by the electrolysis process. HHO was the mixture of hydrogen gas and oxygen gas that was formed in HHO dry generator. In HHO cell (dry) generator contained 10 cells, and each cell required 2.4 voltage. Furthermore, resonance DC application was evaluated to gain the better electrolysis efficiency. The test was held by using 2 level of electrolyte consentration, 0.178 M KOH and 0.446 M KOH. Each concentration was tested by 3 size of inductors, 8uH, 40uH, and 100uH. Not only single frequency was used, but modulatedfrequency was used also as well. In order to measure the improvement of resonance techinique application, specific energy was compared between using resonance technique and conventionaltechnique.Specific energy was calculated between output (mass of hydrogen) and input energy (watt hour). In this test,input of specific energy was measured in two condition:energy from the source (total) and energy in HHO generator only. From the test, it could be concluded that modulated frequency, by using40 Hz and 2405 Hz frequency, 100uH inductor, and 0.446 M OH, only 61% of total specific energy that was used in HHO generator. It needed23.91 watt hour energy (total) to produce 1 gram of hydrogen gas.On the other hand, the worst performance was happened in single frequency, 11270Hz, 8uH of inductor, and 0.178 KOH, where the loss of specific energy was 82%. The conventional technique only loosed about 0.5% of specific energy in 0.178 KOH needed 51.37watt hour to provide one gram of hydrogen. The loss was happened due to the excess of current that was converted into head in MOSFET. Hopefully the further research will be held again by using wet type of HHO generator because dry generator did not have fixed capacity value and it maked difficulty for calculating the perfect resonance condition.
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