Judul: Karakteristik Mikrobiologis Bakso Sapi yang Diawetkan dengan Substrat Antimikroba dari Lactobacillus plantarum 1A5 pada Penyimpanan Suhu Ruang.
Abstrak: Daging merupakan pangan sumber protein hewani yang memiliki kandungan nutrisi lengkap terutama komposisi proteinnya. Diversifikasi dari produk daging salah satunya adalah dengan dibuat bakso. Daging memiliki karakteristik mudah rusak (perishable) oleh aktivitas mikroorganisme. Salah satu cara yang biasa digunakan oleh produsen bakso untuk memperpanjang umur simpan adalah dengan penambahan bahan pengawet berbahaya untuk kesehatan seperti formalin dan boraks. Konsumen sekarang sudah cenderung untuk lebih memilih produk makanan yang berpengawet alami yang tidak menimbulkan masalah kesehatan. Bahan pengawet ini berasal dari salah satu bakteri asam laktat. Bakteri asam laktat mampu menghasilkan asam laktat, hidrogen peroksida dan hasil metabolisme lain yang dapat memberikan pengaruh positif bagi yang mengonsumsi.
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Judul: Karakteristik Mikrobiologis Bakso Sapi  yang Diawetkan dengan Substrat Antimikroba dari  Lactobacillus plantarum  1A5 pada Penyimpanan Suhu Ruang
Abstrak: The objective of this research was to observe the effect of antimicrobial substrate of Lactobacillus plantarum 1A5 origin as a natural preservative on beef meatball at room temperature storage. The complete randomized design of two factors was used to analyze the effect of antimicrobial substrate microbiological characteristics of beef meatball. The treatments and control were storage at room temperature (± 280 C) with antimicrobial substrat 100 % and 0 % for 0 hour, 9 hours, and 18 hours after conditioning process. The variables were total plate count, quantitative of Staphylococcus aureus, quantitative of Escherichia coli and qualitative of Salmonella spp. The result of this research showed that there were decreasing (P<0,05) of total microbe, quantitave of Staphylococcus aureus and quantitative of Escherichia coli were decreasing (P<0,05) during room storage until 9 hours. Salmonella spp. test showed negative result.
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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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