Judul: The effect of mineral soil enriched with basic slag on the productivity and stability of peats
Abstrak: Rendahnya produktivitas dan stabilitas tanah gambut disebabkan oleh berbagai faktor pembatas, diantaranya kandungan asam-asam fenolat yang tinggi sehingga bersifat racun bagi tanaman, kemasaman tanah yang tinggi, kapasitas tukar kation yang sangat tinggi dengan kejenuhan basa sangat rendah serta tingginya laju kehilangan karbon organik dari tanah garnbut. Penambahan kation polivalen Fe serta basa-basa dari bahan tanah mineral yang diperkaya dengan pernberian terak baja sebagai bahan amelioran diharapkan dapat mengurangi pengaruh buruk dari asam-asam fenolat serta dapat membentuk ikatan komplek yang dapat mengurangi laju dekomposisi bahan organik pada tanah gambut.
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Judul: Pengaruh tebak baja terhadap sifat kimia tanah dan produksi padi sawah pada tanah gambut mukok, Sanggau
Abstrak: Utilization of peat lands as agricultural land especially for wetland rice Eeld faces some prob!ems such as low availability of macro and micro nutrients. Some research results indicated that the availability of silicate in p a t land of Kalimantan and Sumatra is low. The role of silicate oi, wetland rice are increasing the resistafice to lodging, pzst, and disease ss well as improving photosynthesis. This research were conducted ir two steps incubztio~a nd field experiment. In the two experiments, the dosage sf steel slag applied were : 3.0 , 2.5; 5.0; 7.5, and 10 ton /ha or eyuivclen? to 0,3.65,7.03, 11.03 and 14.70 g /kg for kcubation experiment. Result of incubztion experiment indicated that the effect of steel slag on chemical properties of soil were significant. The contents of exchangeable K, Ca and Mg; available Si, Fe, Mr., a~laC u; and soil pH were incresed with incresing the dgsage of steel slag. Results of field experiment indicated that application of steel slag as silicon fertilizer significantly incresed plant height, dry weight of total and filled spikelets; and decreased the percentage of unfillet spikellets. On the other land, the effect of steel slag treatments OI? number of inaximum and productive tilier rice werc not significant. The plant height, dry weight of total and filled spikelets were increased 14-22 %, 61-67 % and 65-96 %; respectively, with application of steel slag; and the percentage of unfilled spikelets was decreased 2.63-4.42 %.
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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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