Judul: Pengaruh terak baja terhadap sifat kimia tanah serta pertumbuhan dan produksi tanaman Padi (Oryza Sativa) pada tanah gambut dalam dari Kumpeh, Jambi
Abstrak: Serious efforts to achieve self sufficiency in rice to fullfil consumption of population growth in Indonesia become very important. One of the most important problems was the decrease of fertile land in Java along with significant numbers of land conversion to nonagricultural usage. One of the important effort to overcome this problem was utilizing peatlands outside Java. Utilizing of peatland for rice cultivation faces many problems such as soil acidity and toxicity of organic acid which effect to crop growth. Steel slag is a by-product furnace in the process of steel manufacturing. These materials can be used as liming material for improving chemical properties of peat soil. This research purposed to evaluate effect of steel slag on chemical properties of soils and also rice growth and yield. Research was carried out of pot experiment in greenhouse by using peat soils from Kumpeh, Jambi. Slags were applied in dosage 0, 1, 2, 3, 4, and 5% or 0, 30, 60, 90, 120, and 150 g / pot, combined with NPK fertilizer in dosage 50 and 75% from standard, compared with control and standard. The result shows that steel slag significantly improved chemical properties of soils such as raised soil pH, exchangeable Ca and Mg, and available Mn in soils. Toxic heavy metal in rice and soils were given by NPK fertilizer treatment. Steel slag also significantly increased rice yield and growth, reduced unfilled spikelets, and also increased nutrient rate of Ca and Mg in crop. In addition, steel slag reduced usage of conventional fertilizer. This was shown by higher value of fertilizer efficiency on steel slag treatment.
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Judul: Pengaruh Electric Furnace Slag, Silica gel dan Unsur Mikro terhadap Sifat Kimia Tanah Serta Pertumbuhan dan Produksi Tanaman Padi Sawah (Oryza sativa L.) pada Tanah Gambut dari Kumpeh, Jambi
Abstrak: The staple food of Indonesian is rice, concequently paddy is the most important crop in agriculture. Peat soil is one of marginal land which potential to create the availability of land for paddy in Indonesia. Generally, peat soil in Indonesia has low fertility and availability of silicon (Si). Silicon is beneficial element for paddy rice. Recently, general material used as sources of Si in some countries is steel slag of which consist calcium silicate. One kind of steel slag produced in Indonesia is electric furnace slag. However, according to regulation of government (PP No. 18, 1999 and No. 85, 1999), steel slag is categoried at hazardous waste. The objectives of this research were to determine the effect of EF slag, silica gel, and micro elements on chemical properties of soil, growth and yield of paddy rice on peat soil and to evaluate content of heavy metal in rice for worthiness of rice consumption. This research used peat soil from Kumpeh Regency, Jambi. The research consisted of two experiments, they were incubation experiment in laboratory and pot experiment in greenhouse. The dosage applied for treatment of EF slag and silica gel were 0%, 2%, 4%, 6%, and 8%. Application of EF slag significantly increased pH, exchangeable Ca and Mg, available-Fe, Mn, Zn, SiO2, and P. Growth and yield of paddy rice with EF slag was better than with silica gel and micro nutrients. Furthermore, the content of heavy metal in rice was very low, so that the rice produced is not harmful and can be consumed.
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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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