Judul: Manajemen Panen Kelapa Sawit (Elaeis guineensis Jacq.) di Kebun Sei Dadap, PTPN III, Asahan, Sumatera Utara
Abstrak: The internship program was conducted at Kebun Sei Dadap, PTPN III, Asahan, North Sumatera from February 11th to June 10th 2013. This internship program was held to fulfill the purpose for studying the oil palm cultivation technique, understanding the factors related to oil palm harvesting process, and gaining experience and hard skill on oil palm production. The need of harvesters have become very decisive for oil palm production. Harvesters disciplinary level was still low as it was shown in areal harvest quality and became a problem that needed to be solved to increase more the plantation production quality. Kebun Sei Dadap had generally increased their production for three years in a row since 2008 to 2010, but then decreasing slightly for the last two years, since 2011, eventough the size of plantation areal has not significantly changed
Keyword: Sei Dadap, production, oil palm, harvest

Judul: Manajemen Panen Kelapa Sawit (Elaeis guineensis Jacq.) di Kebun Adolina, PT Perkebunan Nusantara IV, Serdang Bedagai, Sumatera Utara.
Abstrak: Internship aims to improve the ability and comprehension in the management of oil palm plantation. Internship implemented in Adolina Estate, PTPN IV. In the implementation of internship, harvest management in the oil palm harvesting was accentuated to observed and studied. Observation in harvest management consists of harvest rotation, harvest density, assessed daily production, harvester requirements, criteria of ripe harvest, harvester capacity, quality fruit, and transporting the fruit to oil palm mill. Data from observation were analyzed quantitatively using the average, percentage, and standard deviation (descriptive statistics) as well as the t-student test (comparison). The results from analyzed showed that harvest management of oil palm in Adolina Estate need to be improved. It is due to harvester capacity is lower of standard company and the high production percentage of fruits have not quality. The low capacity of harvesters affect the calculation of harvester requirements and disruption of harvest rotation. Harvest rotation is disturbed affect the high production percentage of fruits have not quality. Adolina Estate has implemented assessed harvest density quite accurately to the realization of the harvest density. The accuracy of the assessed harvest density to realization of harvest density affect the accuracy of the assessed daily production as well as calculation of harvester requirements and transport harvest.
Keyword: harvester capacity, harvest management, oil palm, harvester

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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