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: Idetifikasi Cemaran Bakteri Staphylococcus aureus Pada Daging Ayam yang di Jual di Pasar Tradisional dan Modern di Sekitar Kampus Institut Pertanian Bogor
Abstrak: Chicken meat is one of foodstuffs which derived from animal that can be used by bacteria as a medium to grow and multiply. One of bacteria which uses this medium is Staphylococcus aureus. Staphylococcus aureus is one of the microbial pathogens that can cause food intoxication. The purpose of this research is to determine the contamination of S. aureus in chicken meat which is sold in traditional and modern markets. The meat samples were taken ten times from a traditional and modern market once a week regularly. This research used Gram Coloring test, Catalase test, glucose and mannitol fermentation in aerobic test, coagulase test, and Mannitol Salt Agar (MSA). The results of this study showed that the bacteria in the samples was identified as S. aureus.
Keyword: Traditional market., Staphylococcus aureus, Modern market, Chicken

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.
Keyword: