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: Pertumbuhan Gmelina (Gmelina arborea Roxb) pada Beberapa Pola Agroforestri di Desa Sekarwangi, Kecamatan Malangbong, Kabupaten Garut
Abstrak: Agroforestry is a system of land use which combines wooden plants (trees, shrubs, rattan) with plants is not a wooden or may with grass (pasture), sometimes there is a component of livestock and other animals so that ecological interactions between plant formed a wooden and other components. Selection of inappropriate agroforestry pattern will affect the growth of plants by the existence of high competition to get nutrient elements, air, and light of the Sun. Agroforestry patterns which were selected as a treatment are agroforestry pattern one (AgF1) consists of gmelina, suren, mahoni, pete, the dominance of chili plants, and corn. Agroforestri pattern two (AgF2) consists of gmelina, sengon, dominance of plant corn, and cassava. Agroforestri pattern three (AgF3) consists of gmelina, suren, crop the dominance of cassava, peanut, and corn. Observed parameters is gmelina dimension, which are total tall, total diameter trunk, tall branch without crown, and the crown diameter. This research aims to analyze the effect of agroforestry pattern on the growth of G. arborea and analyze the relationship of land use management system with the growth of G. arborea. The research held in the Sekarwangi Village, Malangbong, Garut in December 2011 up to February 2012. This research uses a Complete random Design (RAL) with one factorial analysis, i.e. agroforestry pattern. The result showed that agroforestry pattern one give the best effect to gmelina growth. It obtained based on the test and test fingerprints variegated Duncan. Agroforestry pattern one gives highest average on all parameters. Besides that, land management system agroforestry pattern one also exert the best effect to the gmelina growth
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Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model