Judul: Pertumbuhan, Biomassa Daun, dan Kerapatan Trikoma Kelenjar pada Kumis Kucing (Orthosiphon stamineus Benth.) dengan Pemberian Berbagai Pupuk Organik dan Naungan
Abstrak: One of the medicinal plants which are cultivated in Indonesia is java tea plant (Orthosiphon stamineus Benth.). Influence of shade and fertilizer factor to the growth of plants needs to be known in cultivating this plant. This study aimed to examine the effect of various types of organic fertilizers and shading conditions on growth of the plant, leaf biomass, chlorophyll content, and density of glandular trichomes on the java tea plant. This experiment used a factorial completely randomized design with two factors. The first factor was shading conditions, consist of no-shade (N0) and 50% shade (N1). The second factor was the planting medium, which consist of soil (V1), mixture of soil and goat manure (V2), soil and chicken manure (V3), and soil and compost (V4). Parameters observed were growth parameters, chlorophyll content, and density of glandular trichomes. The results showed that the optimal growth of java tea plant was provided by planting medium with enrichment of goat and chicken manure fertilizers no-shade. Shading treatment increased chlorophyll content, but decreased density of glandular trichomes in both adaxial and abaxial leaf surfaces. Density of glandular trichomes in abaxial was higher than that of adaxial surface.
Keyword: shading, Orthosiphon stamineus Benth, organic fertilizers, glandular trichomes

Judul: Penentuan Tingkat Naungan dan Jarak Tanam untuk Pertumbuhan, Produksi, dan Kandungan Sinensetin Tanaman Kumis Kucing (Orthosiphon aristatus Bl. Miq)
Abstrak: Produksi tanaman obat tradisional di Indonesia masih rendah. Salah satu penyebab rendahnya faktor produksi ialah setiap tanaman obat memiliki syarat tumbuh berbeda-beda sehingga tidak dapat dibudidayakan di tempat yang tidak sesuai dengan syarat tumbuh tanaman tersebut. Penelitian dilakukan untuk memperoleh informasi pengaruh naungan dan jarak tanam terbaik terhadap pertumbuhan, produksi, dan kadar sinensetin tanaman kumis kucing (Orthosiphon aristatus). Penelitian dilakukan di Kebun Unit Konservasi dan Budidaya Biofarmaka (UKBB) Cikabayan, Dramaga, Bogor dari Desember 2013 hingga November 2014. Kegiatan analisis kadar sinensetin dilakukan di Laboratorium Biofarmaka, Taman Kencana, Bogor pada Desember 2014. Penelitian ini menggunakan rancangan tersarang (Nested Design). Faktor pertama merupakan naungan, yaitu 0%, 25%, 55%, dan 75% sebagai petak utama. Faktor kedua merupakan jarak tanam, yaitu 30 cm x 30 cm, 30 cm x 40 cm, dan 40 cm x 40 cm sebagai anak petak. Hasil percobaan menunjukkan bahwa tanaman kumis kucing lebih efisien ditanam dengan menggunakan kombinasi jarak tanam 30 cm x 40 cm dan naungan 55% untuk menghasilkan pertumbuhan, produksi, serta kualitas kandungan sinensetin yang terbaik.
Keyword: java tea, shading, sinensetin, spacing

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.
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