Judul: Hubungan antara Brix Kebun dan Pengukuran Rendemen Individu melalui Core sampler di PTPN VII Unit Usaha Bungamayang, Lampung
Abstrak: The main variable of calculation for production sharing between sugarcane farmers and sugar factory is sucrose. Core sampler is a sampling machine to decide the individual sucrose. The aimed of this intership was to analyze the correlation between field brix and core sampler brix, field brix and core sampler sucrose, and core sampler brix and core sampler sucrose. The internship activities was conducted at PTPN VII Unit Usaha Bungamayang, Lampung and was carried out on four months from February to June 2013. The observation concerned to sugarcane from farmers who cooperated with sugar factory. The correlation between field brix and core sampler brix showed very weak and not significant (r = 0.170). The correlation between core sampler brix and core sampler sucrose showed strong positive and significant (r = 0.723), whereas correlation between field brix and core sampler sucrose showed very weak and not significant (r = 0.180).
Keyword: sucrose, production sharing, brix

Judul: Analisis Efisiensi Produksi Tebu Rakyat di Wilayah Kerja PTPN VII Unit Usaha Bungamayang Kabupaten Lampung Utara Propinsi Lampung
Abstrak: The objectives of this study are: (1) to analyze smallholder sugarcane farm system (plant-cane and ratoon cropping patterns) in partnerships that Tebu Rakyat Kredit (TRK-Credit Sugarcane Smallholder partnership) and Tebu Rakyat Bebas (TRB-Independent Sugarcane Smallholder partnership) in the working area of PTPN VII Bungamayang Business Unit and influence partnerships on sugarcane farmers' income levels of sugarcane smallholder, (2) to analyze production efficiency rate on sugarcane smallholders in the working area of PTPN VII Bungamayang Business Unit and influence of partnership on production efficiency on sugarcane smallholders. The results of farm income analysis indicate that smallholder sugarcane farm in the study area on plant-cane and ratoon cropping pattern financially feasible. Farmers' income on ratoon greater than plant-cane cropping pattern and farmers' income on TRK partnership greater than TRB. The estimation results of smallholder sugarcane farms using a frontier production function shows that land, fertilizer (Urea, TSP, KCL), pesticide (solid and liquid) and labour variable have positive significant effect in plant-cane cropping pattern. While land, fertilizer (Urea, TSP, KCL), pesticide (liquid) and labour variable have positive significant effect on ratoon cropping patterns. The technical inefficiency of farmers on plant-cane and ratoon cropping pattern is influenced by education, experience and farm size. Farm size has greatest influence to reducing technical inefficiencies. The partnership has positive influence because it makes farmers efficient technically on plant-cane and ratoon cropping patterns. The farmers have been able to reach allocative and economic efficiency on ratoon but have not on plant-cane cropping patterns. Based on partnership TRB farmers more efficient in technical, allocative and economic efficiency than TRK.
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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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