Judul: Occurance of Escherichia coli O157:H7 in Chicken Meat at Traditional Markets in Pangkalpinang City
Abstrak: Penelitian ini bertujuan untuk mengetahui keberadaan E. coli O157:H7 dan menganalisis hubungan faktor-faktor dengan kejadian E. coli pada daging ayam yang dijual di Pasar Kaget, Pasar Pagi, dan Pasar Pembangunan Kota Pangkalpinang. Sampel daging ayam diambil sebanyak 30 sampel secara proporsional menggunakan simple random sampling. Metode cross sectional digunakan untuk penelitian ini. Pengujian E. coli berdasarkan SNI 2897:2008 tentang Metode Pengujian Cemaran Mikroba dalam Daging, Telur, dan Susu serta Hasil Olahannya. E. coli O157 dikonfirmasi dengan uji aglutinasi lateks O157 dan uji antiserum H7. Analisis data menggunakan uji deskriptif dan analisis faktor risiko menggunakan chi-square dan odds ratio. Hasil penelitian menunjukkan bahwa E. coli O157:H7 ditemukan pada 2 dari 30 sampel (6,7%) yang diisolasi dari Pasar Kota Pangkalpinang. Faktor risiko yang signifikan (P<0,005) terhadap keberadaan E. coli adalah pedagang yang berumur lebih dari 45 tahun, jarak kios kurang dari 5 m dari jalan raya, dan cuci tangan menggunakan air yang tidak bersih. Keberadaan E. coli O157:H7 dapat menimbulkan risiko bagi kesehatan konsumen.
Keyword: chicken meat, E. coli O157:H7, risk factors

Judul: Cemaran Eschericia coli pada Daging Ayam di Pasar Tradisional Kota Tangerang Selatan
Abstrak: The aim of this study was to observe the total count of Eschericia coli in chicken meat in tradisional markets in South Tangerang City. This study was conducted using survey method by interviewing the vendors of chicken meat as respondents, observing the condition of marketplace using questionnaires, and sampling the chicken meat for laboratory examination. A total of 24 chicken meat samples was obtained purposively from three markets, i.e., Pasar Modern, Pasar Bukit, and Pasar Jombang, and was examined using spread plate method (plate count method). The result of the study showed that Pasar Modern had the best criteria of general hygienic practices. Nevertheless, the laboratory result found that the chicken meat samples from Pasar Jombang showed the highest number of E. coli (5.59 ± 5.64 log10 cfu/gram) and it was followed by Pasar Modern (5.38 ± 5.59 log10 cfu/gram) and Pasar Bukit (5.11 ±5.39 log10 cfu/gram), with the mean of 5.40 ± 5.55 log10 cfu/gram. Compared to the maximum limit of microbial contamination according to the Indonesia National Standard (SNI 7688:2009), 100% of chicken samples from Pasar Jombang were higher than the standard (maximum limit = 1 log10 cfu/gram), and then 100% of samples from Pasar Modern and 100% of samples from Pasar Bukit were higher than standard. The high number of E. coli contamination in chicken meat was supposed in relation with market sanitation, proces eviceration, cross contamination with other food, inadequate personal hygiene practices and lack of cold chain from poultry processing plant until market place.
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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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