Judul: Cemaran Enterobacteriaceae pada Daging Ayam dari Tempat Potong Unggas Kota Bogor
Abstrak: One of the popular meat in community of Indonesia is chicken meat. The information on microbiological status in chicken meat is required to determine the quality and safety. The objective of this research was to determine the contamination of Enterobacteriaceae in chicken meat collected from poultry slaughterplace at Sentra Pemotongan Ayam Pondok Rumput, Bogor City. A total of 30 samples of chicken carcass was analysed for total of Enterobacteiaceae using plate count method with violet red bile glucose agar (VRBGA). The average number of Enterobacteriaceae in chicken was 37 536.7 cfu/g (minimum 0 and maximum 500 000 cfu/g). This results indicated a lack of hygiene practices.
Keyword: Enterobacteriaceae, chicken meat, poultry slaughterplace Bogor

Judul: Identifikasi cemaran escherichia coli pada daging ayam yang dijual di pasar tradisional dan pasar modern daerah Bogor Barat
Abstrak: The aim of this research was acknowledge about contaminated chicken meat from Eschericia coli which sold in traditional market and modern market. About two traditional markets and two modern markets where the samples were takenly for thirteen times, frequently once for a week. The research used Gram colouring test and biochemical test (IMViC test). Result of Gram colouring test shown that all the samples from both of traditional markets and both of modern markets was Gram negative bacterian, from IMViC test, all samples from both of traditional markets and both of modern markets were negative from Indol test and Red Metil test and positive from Voges Proskauer test and Sitrat test. Otherwise, from the result of Gram colouring test and IMViC test, bacteria which was found in thirteen samples from both of traditional and modern markets was not Eschericia coli.
Keyword: Escherichia coli, chicken meat, traditional markets, modern markets.

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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