Judul: Keragaman Cempedak (Artocarpus integer (Thunb.) Merr.) di Pulau Bengkalis dan Pulau Padang Provinsi Riau.
Abstrak: Cempedak (Artocarpus integer (Thunb.) Merr.) adalah tanaman buah tropis asli Indonesia. Tanaman buah tropis ini tersebar luas di banyak pulau di kawasan Malesia. Di Indonesia, cempedak tersebar di Pulau Sumatera, Kalimantan, Sulawesi, Kepulauan Riau, Maluku, Irian Jaya dan pulau-pulau kecil. Cempedak termasuk ke dalam famili Moraceae yang memiliki ciri buah semu majemuk, manis, berdaging lembut dan tebal, beroma kuat dan menyengat, berwarna kuning hingga jingga, tekstur halus, licin, berlendir, berserat, dan bersifat klimakterik. Riau merupakan salah satu daerah persebaran cempedak di Indonesia, namun informasi tentang keanekaragamannya sangat terbatas. Cempedak di Riau perlu diidentifikasi, dieksplorasi dan diangkat potensi keragamannya agar sumber kekayaan plasma nutfah buah-buahan tropis dapat dipertahankan, dilestarikan dan dimanfaatkan. Penelitian ini bertujuan untuk memperoleh informasi keragaman ciri morfologi dan agronomi cempedak yang tumbuh di Pulau Bengkalis dan Pulau Padang, Provinsi Riau dan untuk mengetahui hubungan kekerabatan fenetik diantara aksesi cempedak. Eksplorasi cempedak dilakukan di Pulau Bengkalis dan Pulau Padang, Provinsi Riau menggunakan metode jelajah. Sebanyak 21 aksesi cempedak dan 2 aksesi nangka diamati menggunakan 82 ciri berdasarkan deskriptor nangka. Analisis keserupaan dan pengelompokan berdasarkan data morfologi dan agronomi menggunakan koefisien Simple Matching (SM) dan metode Unweighted Pair Group Method with Arithmetic Average (UPGMA). Keragaman cempedak di Pulau Bengkalis dan Pulau Padang, Provinsi Riau terdapat pada bentuk kanopi, bentuk helaian daun, bentuk pangkal helai daun, bentuk ujung helai daun, bentuk perbungaan, bentuk buah, panjang tangkai buah, permukaan buah, bentuk duri, warna bulbus, bentuk bulbus dan bentuk biji. Beberapa ciri baru ditemukan pada cempedak dari Pulau Bengkalis dan Pulau Padang. Ciri baru tersebut yaitu adanya cempedak panjang (BN3), bentuk ujung daun bertakik (BN2), bentuk perbungaan dan buah menjantung (BN12), kulit buah rata (BN6), dan total padatan terlarut 40 oBrix (BN9, BN12, dan BS4). Hasil dendrogram menunjukkan bahwa cempedak di Pulau Bengkalis dan Pulau Padang memiliki indeks keserupaan sebesar 44-83%. Dendrogram menunjukkan bahwa cempedak di Pulau Bengkalis dan Pulau Padang tidak mengelompok berdasarkan asal pulau.
Keyword: buah tropis, ciri morfologi, ciri agronomi, dendrogram, koefisien Simple Matching, Pulau Bengkalis, Pulau Padang

Judul: Keragaman Genetik Aksesi Pinang (Areca catechu L.) Asal Papua, Sulawesi Utara, dan Sumatera Utara Berdasarkan Karakter Morfologi dan Penanda RAPD (Random Amplified Polymorphic DNA)
Abstrak: Areca nuts (Areca catechu L.) is a palm plant that has not been studied intesively than other palm crops (coconut). Areca nuts is used as ingredients of medicines, cosmetics, and ceremonial, as well as a symbol of social and cultural relationship. The objectives of these studies were to explore genetic diversity of areca nuts accessions (Areca catechu L.) from Papua, North Sulawesi and North Sumatera that were collected and planted in Experimental Station Kaiwatu, Indonesian Coconut and Palmae Research Institute (Balitka), Manado. These studies were conducted in July 2010 - June 2011. Plant morphological characters were observed and measured and DNA markers were identified using two primers RAPD. Data were analyzed using the program NTsys 2.02. Morphological characters for eight accessions of areca nuts has a similarity level 6%. However, the similarity of six areca nuts accessions, representing three provinces, based on DNA markers was 49%. Individual areca nuts palms are not groupped into their accession, based on either morphological or DNA markers.
Keyword: 

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: