Judul: Pertumbuhan tanaman pokok Gmelina arborea Roxb. pada beberapa pola agroforestri di Desa Cikanyere, Kecamatan Sukaresmi, Kabupaten Cianjur
Abstrak: Pemilihan kombinasi tanaman yang dibudidayakan dalam program RHLP Desa Cikanyere memungkinkan terjadinya perbedaan respon bagi pertumbuhan tanaman pokok. Penelitian ini bertujuan untuk mengkaji pertumbuhan tanaman pokok gmelina (Gmelina arborea Roxb.) pada beberapa pola agroforestri serta pengaruh sistem pengelolaan terhadap pertumbuhan tanaman pokok gmelina (Gmelina arborea Roxb.) yang dikembangkan oleh kelompok tani di Desa Cikanyere, Kecamatan Sukaresmi, Kabupaten Cianjur. Survei pendahuluan dilakukan untuk menentukan pola agroforestri yang diteliti. Data dimensi tanaman pokok diambil secara sensus terhadap tanaman gmelina pada masing-masing pola agroforestri yang terpilih berupa tinggi, diameter dan proyeksi tajuk. Parameter tanah yang diamati berupa sifat fisik dan kimia dari contoh tanah masing-masing pola agroforestri yang kemudian dianalisis di laboratorium. Data penutupan tajuk tegakan diambil dengan menggunakan alat spiracle densiometer. Sejarah pengelolaan lahan ditelusuri dengan melakukan kegiatan wawancara terhadap petani pengelola masing-masing pola agroforestri terpilih. Data yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan pola agroforestri tanaman pokok gmelina yang dominan dikembangkan meliputi AF 1 (gmelina, jagung, singkong, pisang), AF 2 (gmelina, jagung, kopi, pisang), AF 3 (gmelina, mahoni, singkong, petai), AF 4 (gmelina, mahoni, jagung, cabai) dan AF 5 (gmelina, mahoni, padi gogo, singkong, jagung). Pola agroforestri AF 3 menunjukkan pertumbuhan dimensi tinggi dan diameter paling rendah, sedangkan pola AF 1 dan AF 4 menunjukkan pertumbuhan dimensi yang paling tinggi dibandingkan dengan pola lain. Pola AF 3 mempunyai LCR dan LAI yang kecil sehingga proses fotosintesis berjalan kurang optimal sedangkan pada pola AF 1 dan AF 4 nilai LCR dan LAI paling besar sehingga fotosintesis berjalan optimal dan hasilnya pertumbuhan tanaman pokok lebih baik daripada pola yang lain. Unsur fosfor (P) pada pola agroforestri AF 3 diduga menjadi faktor pembatas bagi pertumbuhan tanaman pokok gmelina. Unsur P dan K dibutuhkan tanaman singkong dalam jumlah yang cukup untuk membentuk akar dan pembesaran umbi sehingga diduga sebagai penyebab rendahnya kandungan unsur P pada pola AF 3. Pemupukan yang paling intensif ditemukan pada pola AF 4 sedangkan yang yang paling rendah pada pola AF 3. Pertumbuhan tanaman pokok gmelina (Gmelina arborea Roxb.) dipengaruhi oleh interaksi antar komponen serta sistem pengelolaan lahan yang dilakukan petani pada masing-masing pola agroforestri.
Keyword: Agroforestry, Gmelina arborea, RHLP

Judul: Panjang dan Kedalaman Akar Lateral Gmelina (Gmelina arborea Roxb.) pada Beberapa Pola Agroforestri di Desa Sekarwangi, Kecamatan Malangbong, Kabupaten Garut
Abstrak: Along with the growing population, the need for land was growing. Therefore, it takes an effort that can harness land optimally as agroforestri. Agroforestry is a system of land use by plants of forestry with crop and/or livestock. This system also has the value of economic, ecological, and social events. However, agroforestry also have negative interactions such as competition, nutrient elements, water, and light between forestry with crop plants. So do research on rooting on some patterns of gmelina (Gmelina arborea) agroforestry different. Gmelina is a fast-growing species of forestry. Growth character of gmelina relatively rapid can be used as a species for rehabilitation of land such as in DAS Cimanuk-Citanduy residing in the land belongs to the people. The purpose of this study is to assess the depth and length of the lateral roots gmelina, knowing the biophysical environment and data processing system of land on three different patterns in the location of research. The study is expected to be a reference for the selection of a suitable type of crop grown under the stands gmelina. Gmelina rooting was obtained by digging the root depth and depth variations have different length. These variations are due to the existence of biophysical properties of differences as well as the processing of land environment is different in each pattern. This measurement is done in the Census of every pattern. As for the crop that can be applied on the system agroforestry on site research is robusta, grapefruit, cardamom, turmeric, curcumae, pineapple, panili, orchid, deer horns, and honey bees
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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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