Judul: Pertumbuhan tanaman jarak pagar (Jatropha curcas L.) pada lahan pasca tambang timah di Bangka yang diberi pupuk organik, anorganik, dan hayati
Abstrak: The experiment aimed to examine the physiology and adaptation of accessions of Jatropha curcas L. given organic material in post tin mining land; to examine physiological processes of physic nut fed organic matter and nutrient contained NPK, and to examine the role of the root endophytic fungi Aspergillus niger to physiology and accession adaptation of physic nut in post tin mining land. The main plots in experiment 1 were 7 accessions of physic nut i.e. Madiun, Ponorogo, Jember, Dompu, Lampung, Bengkulu, and Sukabumi. The subplots were control, compost, and cow dung. Experiment 2, the first factors were organic matter i.e. control and adding cow dung. The second factors were 0 g NPK, 50 g NPK, 90 g NPK, and 130 g NPK. Experiment 3, the first factors were seven accessions of physic nut similar to physic nut accessions in the first experiment. The second factors were control and adding endophytic fungi. The results showed that vegetative growth of seven accessions of physic nut not given organic material couldn’t reach the generative growth. Accession Dompu fed compost and accession Bengkulu fed cow manure showed the higher ability in generative growth of capsule number, seed number, and total grain yield per year. Physic nut growth in post tin mining land can be improved by providing nutrient NPK with 14% N, 14% P, and K 14% at 50 g dose of cow dung and adding as much as 4 kg per plant. Inoculation of endophytic fungi A. niger can enhance better vegetative growth for accessions of Sukabumi, Jember, and Dompu.
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Judul: Respon pertumbuhan beberapa aksesi jarak pagar yang berpotensi sebagai batang bawah terhadap pupuk hayati pada media tailing tambang emas
Abstrak: Physic nut (Jatropha curcas L.) is a potential plant for biofuels production. The objectives of this study were to analyze the germination of four physic nut accessions, seedling growth response to application of biofertilizer during seedling establishment, and plant growth response to application of biofertilizer in gold mine tailing media. Four consecutive experiments were carried out in green house and field laboratory used Block Randomized Design. The first experiment used three factors and three replications. The first factor was seed accessions of S1, J2, JB, and B3; second factor was pre-soaked in cow dung slurry and water; and third factor was germinated media on wet towel, compost, and soil. The second experiment used two factors and seventeen replications, and carried out in 900 g media per pot. The first factor was fertilizer treatment i.e with and without NPK, arbuscular mycorrhizal fungi (AMF), plant growth promoting rhizobacteria (PGPR), and combination of AMF and PGPR. The second factor of the second experiment was four plant accessions. The third experiment used two factors and three replications and carried out in 900 g media per pot. The first factor was fertilizer treatment i.e with and without NPK at recommended rate, 36 g of AMF, 10, 30, and 50 g of PGPR, and combination of 36 g AMF with each PGPR concentration. The second factor was four plant accessions. In the fourth experiment, all plant seedlings from second experiment were transfered to 15 kg of gold mine tailing and andosol soils. The results of first experiment showed that the pre-soaked seed with water and germinated in wet towel produced a higher germination rates than other treatments. The second experiment indicated that the AMF and combination of AMF with PGPR application increased vegetative growth and nutrient uptake of physic nut seedling. The third experiment showed that 30 g PGPR per pot produced best response of physic nut seedling growth. In the fourth experiment revealed that the AMF and combination of AMF with PGPR increased vegetative growth and nutrient uptake of plants. Accession of B3 had the best growth in both media tested, while JB grew better in andosol media. Gold mine tailing media reduced the growth response of physic nut up to 13.0% reduction.
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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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