Judul: Tingkat cemaran mikroorganisme pada daging ayam dan daging sapi dari pasar tradisional di provinsi Jawa Barat berdasarkan jumlah total mikroorganisme, Staphylococcus aureus, dan Escherichia coli
Abstrak: This study was aimed to determine the level of microorganisms contamination in chicken and beef meat from traditional markets in West Java. A total of 36 samples of chicken meat and 24 samples of beef meat were taken purposively from traditional markets in West Java. The average of Total Plate Count (TPC), Staphylococcus aureus, and Escherichia coli in chicken meat were 4.5 x 106cfu/g, 5.3 x 105 cfu/g, and 2.3 x 101 MPN/g. The average of TPC, S. aureus, and E. coli in beef meat were 3.9 x 106 cfu/g, 1.5 x 106 cfu/g, and 2.6 x 101 MPN/g. Comparing to the Indonesian Standard National (SNI) minimal requirement, the result showed that TPC in chicken meat was 47.22%, for S. aureus and E. coli were 97.22% and 69.44% above SNI 3924:2009, in other hands TPC, S. aureus, and E. coli in beef meat were 58.3%, 100%, and 66.67%, above SNI 3932:2008.
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Judul: Cemaran Staphylococcus aureus pada Daging Ayam yang Dijual di Pasar-Pasar di Tangerang Selatan
Abstrak: The aim of this study was to observe the total of Staphylococcus aureus in chicken meat sold in markets in South Tangerang City. This study was conducted using survey method by interviewing the vendors of chicken meat as respondents and observation the condition of marketplaces using questionnaires and sampling the chicken meat for laboratory examination. Total of 24 chicken meat samples was obtained purposively from 3 traditional markets, i.e., Pasar Modern, Pasar Bukit, and Pasar Jombang, and was examined with the spread plate method (the plate count method). The result of observation showed that Pasar Modern had the best criteria of general hygienic practices. Nevertheless, the laboratory result found that the chicken meat samples from Pasar Modern showed the highest amount of S. aureus (1116.0 + 1461.0 cfu/gram) and it was followed by Pasar Bukit (618.2 + 1045.8 cfu/gram) and Pasar Jombang (433.3 + 665.8 cfu/gram), with the mean of 802.5 + 1194.2 cfu/gram. Compared to the maximum limit of microbial contamination according to the Indonesia National Standard (SNI 7688:2009), 80% of chicken samples from Pasar Modern were higher than the standard (maximum limit = 100 cfu/gram), and then 66.7% of samples from Pasar Jombang and 54.5% of samples from Pasar Bukit were higher than the standard. The high number of S. aureus contamination in chicken meat was supposed in relation with inadequate personal hygiene practices and lack of cold chain from poultry processing plant until marketplace. This condition should be considered as a risk of food intoxication for the consumers since the presence of S. aureus in food in high number could produce the toxin which is heat-stable.
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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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