Judul: Pengaruh Kombinasi Media Tanam dengan Bobot Umbi Mini terhadap Pertumbuhan Tanaman Taka (Tacca leontopetaloides (Linn.) O. Kuntze)
Abstrak: Tacca (Tacca leontopetaloides (Linn.) O. Kuntze) is an indigenous plant that is widely used for it’s starch. The purpose of this study was to find out the best of combination of planting media with a mini tuber weight for growing tacca. Experiments using Randomized Completely Block Design, two factors and three replications. This research planting media i.e: sand : rice-hull charcoal : cow manure (1:1:1 v/v), soil : sand : cow manure (1:1:1 v/v), soil : rice-hull charcoal : cow manure (1:1:1 v/v), and soil : cow manure (1:1 v/v) with mini-tuber weight of 1-5 and 5.1-20 g. The result showed significant increased vegetative variables i.e: height of plant, number of leaves, leaf area, and widht of canopy and the difference beetwen due to media combination sand : rice-hull charcoal : cow manure (1:1:1 v/v) and soil : rice-hull charcoal : cow manure (1:1:1 v/v). The mini-tuber treatment of 5.1-20 g showed significantly increased vegetative variables i.e: height of plant, leaf area, and widht of canopy, secondary-tuber weight, mother-tuber diameter, secondary-tuber and mother-tuber dense.
Keyword: Tacca leontopetaloides., organic media planting, secondary-tuber, mother-tubeR, mini-tuber

Judul: Pengaruh Pengaturan Kombinasi Media terhadap Cabutan Anakan Tumih [Combretocarpus rotundatus (Miq.) Danser]
Abstrak: The unwise utilization of peat-land has been causing a very rapid rate of peat destruction in Indonesia. Therefore, it is neccesary to conduct the effort to protect the function of these ecosystems so it can become sustain until the next generation. One effort for the initial rehabilitation is through an appropriate selection of local species by local ecological conditions. One of the local species that can grow in the peatland is tumih (C. rotundatus (Miq.) Danser). C. rotundatus can be classified as of fast-growing types (fast growing species) and tolerant of dry and open condition so it is good for initial pre-planting in the rehabilitation of disturbed peatlands. Development of C. rotundatus species can be done through natural stump seedling with media combination. This study aimed to obtain a preliminary information of the best media composition treatment which capable of enhancing the growth of C. rotundatus in order to develop the silvicultural techniques. This research used Completely Randomized design with six treatment combinations of media which is (K1) sand: compost: rice husk with composition (1:1:2), (K2) sand: compost: sawdust with a composition of (1:1:2), (K3) sand: compost: cocopeat with composition (1:1:2), (K4) compost: cocopeat: sawdust with composition (1:2:2), (K5) compost: cocopeat: rice husk with a composition (1 : 2:2), and (K6) compost: rice hulls: sawdust with composition (1:2:2). Each treatment had three replications, each test contained 15 seedling, so the total of unit observation were 270 units of seed plants. This study discovered that the average of height increment per week on treatment were (K1) 0,099 cm, (K2) 0,083 cm, (K3) 0,081 cm, (K4) 0116 cm, at (K5) 0,088 cm, and (K6) 0,078 cm. The results of variance showed that the treatment did not give the real effect of the increase in plant height. While the percentage of living plants on the media combination treatment were 86.67% (K1), (K2) 80.00%, 35.56% for K3, 62.22% for K4, 71.11% for K5 and 86.67% for K6. After the data were analyzed using SAS 9.3.1 Software, we got the result recaled that the treatment gave a real influence on the percentage of living seedling. Then on the advanced test with Duncan's test showed that K6 treatment is similar with K1 and K2 treatment. This was shown in the living percentation of K6 toward K1 and K2 which is 86.67% at 80.00%. K6 treatment is similar with K5 and K4 treatment, but significantly different from K3. As for the K4 and K5 combination treatment was also similar with the K3 treatment. Percentage of life for K4 and K5 were respectively by 62.22% and 71.11% respectively, while for K3 showed the lowest percentage of life was 35.56%.
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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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