Judul: Keanekaragaman Morfologi Sisik Tumbuhan Paku Terestrial di Kampus Institut Pertanian Bogor, Dramaga
Abstrak: Kampus IPB Dramaga memiliki keanekaragaman hayati yang tinggi, salah satunya ialah tumbuhan paku terestrial. Kelimpahan ini berkaitan dengan tingkat kelembapan yang tinggi dan intensitas cahaya yang rendah. Tumbuhan paku memiliki sisik atau rambut berupa indumentum yang menutupi bagian rimpang, tangkai daun serta bagian muda helaian daun. Morfologi sisik dapat digunakan dalam identifikasi jenis tumbuhan paku. Penelitian ini bertujuan mengetahui keanekaragaman morfologi sisik tumbuhan paku terestrial yang dikoleksi dari lingkungan kampus IPB Dramaga. Bagian sisik paku diamati morfologinya di bawah mikroskop cahaya yang disambungkan dengan indomicro dan dihitung kerapatannya. Hasil pengamatan morfologi sisik pada 20 jenis tumbuhan paku dari 3 suku dijumpai sisik rimpang dan sisik tangkai daun berbentuk lanset, garis, bundar telur, mendabus, dan mengginjal. Bagian ujung sisik beragam mulai dari ujung menebal, tipis, dan seperti jarum. Selain itu, bagian tepi sisik bervariasi yaitu rata, berbenang, atau berseta. Penempelan pangkal sisik yang dijumpai yaitu basifix, pseudopeltate, dan peltate. Warna sisik bervariasi mulai dari putih, kuning, cokelat kekuningan, cokelat muda, dan cokelat tua. Sisik yang diamati memiliki satu sampai dua lapis sel. Kerapatan sisik yang dihitung berkisar dari 0,6 sampai 21,3/mm2. Suku Pteridaceae memiliki persamaan ciri lebih banyak antar marganya dibandingkan dengan kedua suku lainnya, namun persamaan ciri ini tidak dapat digunakan untuk identifikasi dan klasifikasi taksonomi, karena tidak ciri spesifik dari setiap marga. Kata kunci: indumentum, peltate, rimpang, sisik, tangkai daun, IPB Dramaga Campus has high biodiversity, one of which is terrestrial ferns. This abundance is related to high humidity levels, and low light intensity. Ferns have scales or hairs in the form of an indumentum that covers the rhizome, petiole, and young part of the leaf blade. The morphology of scales can be used in the identification of fern species. This study aims to determine the morphological diversity of terrestrial fern scales collected from the IPB Dramaga campus. The morphology of the nail scales was observed under a light microscope connected to an indomicro and the density was calculated. The results of morphological observations of scales on 20 species of ferns from 3 families found rhizome scales and petiole scales in the form of lanceolate, linear, ovate, subulate, and reniform. The tip of the scales varies from thick, thin, and needle-like. In addition, the edges of the scales vary, namely flat, threaded, or banded. The attachments of the base of the scales found were basifix, pseudopeltate, and peltate. The color of the scales varies from white, yellow, fawn, light brown, and dark brown. The scales observed have one to two layers of cells. The calculated scale density ranged from 0.6 to 21.3/mm2 Pteridaceae have more common characteristics between their genera than the other two families, but these similarities cannot be used for taxonomic identification and classification, because there are no specific characteristics of each genus. Keywords: indumentum, peltate, petiole, rhizome, scale
Keyword: indumentum, peltate, petiole, rhizome, scale

Judul: Diversity of morphology and reproductive structure of terrestrial pteridophytes in Bogor Agricultural University, Darmaga
Abstrak: Tumbuhan paku terestrial dan kerabatnya (Pteridophyta) di kampus Institut Pertanian Bogor - Darmaga telah teridentifikasi sebanyak 56 spesies, termasuk ke dalam 30 genus dan 18 famili. Karakter struktur vegetatif diamati dan dicatat untuk keperluan identifikasi dan pembuatan kunci identifikasi. Karakter struktur vegetatif yang diamati meliputi habitus, frond, stipe, dan sisik. Karakter struktur reproduksi yang diamati menggunakan mikroskop cahaya meliputi lokasi sori, tipe indusium, tipe spora, jumlah spora per sporangium, bentuk spora, perispor, dan ornamentasi eksin. Habitus dan tipe frond membedakan antar famili Pteridophyta, sedangkan bentuk frond membedakan antara genera dalam satu famili. Spesies dalam satu genus dapat dibedakan dari bentuk sisik dan tepi lamina. Lokasi sori, tipe spora, dan bentuk spora merupakan karakter pembeda antar famili. Tipe indusium dan bentuk spora membedakan genus dalam satu famili, sedangkan ornamentasi eksin dan perispor dapat membedakan spesies dalam satu genus. Bentuk spora yang ditemukan yaitu monolet, trilet, dan globose. Ornamentasi eksin yang ditemukan yaitu glabrous, granulate, cristate, pappilous, dan echinate. Kata kunci: Pteridophyta terestrial, kunci identifikasi, struktur reproduksi, spora, ornamentasi eksin., Terrestrial Pteridophytes in Darmaga campus of Bogor Agricultural University have been identified as many as 56 species, classified into 30 genera and 18 families. Vegetatif characters were examined and reported for identification and constructing identification key. The observed characters were habit, frond, stipe, and scale. The characters of reproductive structure observed using light microscope were sori location, indusium, spore type, spore number per sporangium, spore shape, perispore, and exin ornamentation. Habit and frond type can be used to distinguish among families of terrestrial Pteridophyta, while frond shape can be used to distinguish among genera within a family. Among species within a genus can be distinguished by scale and lamina margin. Sori location, spore type, and spore shape were differed among families. Indusium and spore shapes differenciated species within a genus. Three various spore shapes were found, monolete, trilete, and globose. Five exin ornamentation were observed, glabrous, granulate, cristate, pappilous, and echinate. Keywords: Terrestrial Pteridophytes, identification key, reproductive structure, spores, exin ornamentation.
Keyword: Pteridophyta terestrial, kunci identifikasi, struktur reproduksi, spora, ornamentasi eksin

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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