Judul: Keanekaragaman Famili Asteraceae di Kawasan Kampus IPB Darmaga, Bogar
Abstrak: Asteraceae is the second larger family after Leguminosae. The diversity of species in this family could be assessed by morphological and anatomical characters. This research aims to study the diversity of family Asteraceae in Campus Area of IPB Darmaga, Bogor by describing their morphological character and anatomical character of stomata and trichome. Sampling was conducted in 12 locations in the area of green space by using the methode of exploration. Type of stomata and trichome were observed using whole mount method. The family of Asteraceae were found as many as 26 species, belonging to 24 genera and 8 tribe. Tricomes of family Asteraceae are unicellular glandular trichome, multicellular glandular trichome, and multicellular non glandular trichome. The most often found trichome was multicellular non glandular trichome. The type of stomata of observed species are anomocytic
Keyword: Bogor Agricultural University (IPB), type of trichome., type of stomata, whole mount, exploration, Asteraceae

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: 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: