Judul: Efforts to Control Escherichia coli and Salmonella spp. Contamination in Dangke, Traditional Processed Cow’s Milk in Enrekang Regency.
Abstrak: Usaha Pengendalian Kontaminasi Escherichia coli dan Salmonella spp. pada Dangke, Olahan Susu Sapi Tradisional Kabupaten Enrekang
Keyword: dangke, pathogen, contamination, control, Enrekang

Judul: Quality of Raw Milk from Dairy Farms in Pondok Ranggon Based on the Presence of Salmonella spp. and the amount of Escherichia coli
Abstrak: Salmonella spp. dan Escherichia coli merupakan mikroorganisme patogen yang dapat menjadi indikator keamanan pangan susu segar. Menurut SNI Nomor 7388 tahun 2009 tentang Batas Maksimum Cemaran Mikroba dalam Pangan pada susu segar, Salmonella harus negatif/25 ml dan E. coli <3 MPN/ml. Penelitian ini bertujuan untuk mengetahui keamanan susu segar dari Peternakan Sapi Perah di wilayah Pondok Ranggon, Jakarta Timur berdasarkan keberadaan Salmonella spp. dan jumlah E. coli. Sebanyak 12 peternakan ditentukan secara purposif dan dipilih dengan cara simple random sampling. Sampel susu diambil dengan 3 kali ulangan, sehingga total sampel yang diperoleh sebanyak 36 susu segar. Pengujian keberadaan Salmonella spp. dan penghitungan jumlah E. coli menggunakan metode Most Probable Number (MPN) mengacu pada SNI Nomor 2897 Tahun 2008 tentang Metode Pengujian Cemaran Mikroba dalam Daging, Telur dan Susu, serta Hasil Olahannya. Hasil penelitian ini menunjukkan tidak ditemukan adanya Salmonella spp. dalam susu segar dari 12 peternakan. Jumlah E. coli dalam susu segar 3,306 ± 1,344 MPN/ml dengn jumlah tertinggi 6,7 ± 4,619 MPN/ml dan terendah 2 ± 0 MPN/ml. Sebanyak 36,11% (13/36) sampel susu memiliki Jumlah E. coli yang melebihi batas maksimum cemaran mikroba, yaitu di atas <3 MPN/ml. Sebagian peternakan (6/12) telah menghasilkan susu yang memenuhi standar SNI berdasarkan keberadaan Salmonella spp. dan jumlah E. coli. Belum semua peternak menerapkan higiene dan sanitasi yang baik di peternakannya. Kata kunci : Escherichia coli, higiene, sanitasi, Salmonella, susu segar, Salmonella spp. and Escherichia coli are pathogenic microorganisms that can be the key to indicate the food safety of raw milk. According to SNI 7388:2009 concerning the Maximum Limit of Microbial Contamination in Food, the standard of raw milk is negative/25 ml for Salmonella and <3 MPN/ml for E. coli. This research aimed to determine the safety of raw milk from dairy farming in Pondok Ranggon, East Jakarta based on the presence of Salmonella spp. and the number of E. coli. A total 12 farms used as research objects were chosen purposively and were selected by simple random sampling. Samples of raw milk were taken from each farm with 3 replications, so the total sample examined were 36 raw milk. Identification the presence of Salmonella spp. and calculating the estimate number of E. coli were using the Most Probable Number (MPN) method based on SNI 2897:2008 concerning Testing Methods for Microbial Contamination in Meat, Eggs and Milk, and Processed Products. The results showed that the raw milk contained no Salmonella spp. The average number of E. coli in raw milk was 3,306 ± 1,344 MPN/ml, wich the highest amount obtained was 6,7 ± 4,619 MPN/ml and the lowest was 2 ± 0 MPN/ml. A total of 36.11% (13/36) milk samples had the amount of E. coli that exceeded the maximum limit of microbial contamination. Half of the farms (6/12) have produced milk that meets SNI standards based on the presence of Salmonella spp. and the number of E. coli. Not all dairy farmers have implemented good hygiene and sanitation on their farms. Keywords: Escherichia coli, hygiene, raw milk, sanitation, Salmonella
Keyword: Escherichia coli, higiene, sanitasi, Salmonella, susu segar

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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