Judul: Effects of shade at different stages of plant development and plant population on growth, yield, and yield components of soybean [Glycine max (L.) Merr.]
Abstrak: Dua percobaan lapangan dilakukan pada tanah latosol di kebun Percobaan IPB, Babakan Darmaga, Bogor, Indonesia selama musim kemarau 1977 dan musim kemarau 1978. Percobaan pertama bertujuan mengetahui pengaruh naungan yang diberikan pada berbagai tahap perkembangan terhadap pertumbuhan, hasil biji, dan komponen hasil tanaman kedelai varietas Orba dan galur harapan No. 1667. Percobaan kedua bertujuan mengetahui populasi yang tepat pada keadaan ternaungi untuk memperoleh hasil biji tertinggi pada tanaman kedelai.
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Judul: Pengaruh sistem olah tanah dan pemupukan terhadap pertumbuhan dan produksi beberapa genotipe kedelai di lahan kering masam
Abstrak: Indonesia has quite extensive dry land for the development of the soybean plants. Low of pH and water availability in the dry season are the main factors that become obstacles on planting soybean in dry land. It can be overcome with tolerant genotypes of dry land and cultivation techniques of tillage. The objective of the research was to determine the response of soybean genotypes under cultivation techniques of tillage on acid dry land. The research was conducted at Krawangsari, Natar, South Lampung District, and Lampung Province, Indonesia from June to November 2011. The experiment was performed using a split plot design with three replications. The main-plot of the experiment was soybean genotype consisted of SP-30-4, PG-57-1, Tanggamus and Anjasmoro. The subplot was combination of tillage systems (furrow and convensional) and input types (fertilizers, lime, compost and organic mulch). The results showed that the dry weight, number of fill pods and seed weight per plot were not significantly different among genotypes. Furrow tillage system combined with fertilizers, lime, compost and organic mulch can increase plant nutrient uptake, dry weight, number of fill pods and seed weight per plot.
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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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