Judul: Analisis Profitabilitas Usaha dan Nilai Tambah Produk Pada Usaha Keripik Singkong Geprek Di Kabupaten Bogor
Abstrak: Cassava chips is one of the processed cassava, which is one of snack. The average of cassava chips in Bogor was done in small and medium scale enterprises that go into home industry. The purpose of this study are analyzing the profitability in 2014, analyzing the value added in 2014, and seeing the the effect of the increasing price on the level of profitability and value added in 2015 with projecting from 2014 of profitability and value added in 2015 with projecting from 2014 of cassava chips ma’nyos of Mr.Unandar.This study was conducted using a survey method. The location was done intentionallyby selecting the business unit cassava chips ma’nyos of Mr.Unandar. The results show that the business is able to generate profits. Value profitability of cassava chips ma’nyos of Mr Unandar is 26.1 percent for 150 and 75 gram, 28.3 pertcent for 130 gram, 25.2 percent for 500 gram, and 4.1 for 20 gram.The analysis shows that the value added of cassava chips of Mr Unandar is 7 013 rupiah with ratio of value added 27 percent.
Keyword: Bogor Agricultural University, value added, cassava chips, profitability, Home industry

Judul: Analisis Nilai Tambah Pengolahan Tepung Tapioka di Kabupaten Bogor
Abstrak: Cassava added value will be increased if it is processed to other varieties of food such us tapioca. Tapioca was processed by every level of processing unit. Though processing is certainly will increase the added value of tapioca, the certain amount of the added value increased is still unkown. This study aimed to analyze the added value and profit that was obtained from cassava processing. The analysis was conducted by comparing the added value and the profit per kilogram of tapioca for every scale of processing unit. The result indicated that the added value and the profit of large scale processing unit was higher, by Rp 273.60 per kg of added value and Rp 285.23 per kg of profit, than the added value and the profit of small scale processing unit, which were Rp 206.74 per kg added value and Rp 165.13 of profit. Production cost large scale processing unit had lower cost, which was Rp 1 352.27 per kg, than that of small scale processing unit which was 1 463.00 per kg.
Keyword: tapioca, profit, cassava, added value

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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