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 Reproductive Structures in Epiphytic Ferns in the Campus Area of IPB, Dramaga, Bogor
Abstrak: Institut Pertanian Bogor merupakan kampus dengan biodiversitas tinggi. Tumbuhan paku epifit menjadi salah satu tumbuhan yang sangat melimpah jumlah dan jenisnya, tetapi informasi struktur reproduksinya masih terbatas. Penelitian ini bertujuan mengkarakterisasi struktur reproduksi tumbuhan paku epifit yang tumbuh di kawasan kampus IPB, Dramaga, Bogor. Metode penelitian terdiri dari koleksi sorus, pengawetan dengan alkohol 70%, pengamatan menggunakan mikroskop majemuk yang dihubungkan pada kamera optilab, dan pengukuran menggunakan aplikasi imageRaster v2.1. Tumbuhan paku epifit yang diamati bervariasi pada susunan dan letak sorus serta ciri sporanya. Sorus berbentuk bulat dan garis. Sebagian besar sorus terletak pada tepi daun. Sebanyak 22 jenis tumbuhan paku yang memiliki spora bentuk monolete dengan laesura garis, satu jenis bentuk bulat, dan satu jenis bentuk tetrahedral-globose dengan laesura triradiate. Ukuran spora yang dijumpai yaitu medium, besar dan sangat besar. Semua spora memiliki nilai rasio P/E ≤1,00 dengan tipe peroblate, oblate, suboblate, oblate bulat dan prolate bulat. Permukaan perispora sangat beragam yaitu alate-angular, globules, shallow verrucae, verrucate, echinulate, tuberculate, rugate, globules, echinate, laevate, cristate, regulate, colliculate, granulose, dan costate-alate., Bogor Agricultural University is a campus with high biodiversity. Epiphytic ferns are one of the most abundant plants in terms of numbers and types, but information on their reproductive structures is still limited. This study aims to characterize the reproductive structure of epiphytic ferns that grow in the IPB campus area, Dramaga, Bogor. The research method consisted of a collection of sorus, preserving it with 70% alcohol, observing using a compound microscope connected to an optilab camera, and measuring using the imageRaster v2.1 application. The observed epiphytic ferns varied in the arrangement and location of the sorus and the characteristics of the spores. The sorus was round and line. Most of the sorus were located on the leaf margins. A total of 22 fern species had monolete spore with line laesura, one species had round spore, and one species had tetrahedral-globose spore with triradiate laesura. Spore sizes found were medium, large, and very large. All spores had a P/E ratio value of ≤1.00 with peroblate, oblate, suboblate, round oblate, and round prolate types. The surface of the perispora is very diverse, namely alate-angular, globules, shallow verrucae, verrucate, echinulate, tuberculate, rugate, globules, echinate, laevate, cristate, regulate, colliculate, granulose, and costate-alate.
Keyword: biodiversity, characterization of spores, perispore surface, sorus

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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