Judul: Deteksi Residu Antibiotik dalam Susu Segar yang Digunakan sebagai Bahan Baku Utama Pembuatan Keju
Abstrak: Antimicrobial drugs have been used in dairy industry for more than five decades. Dairy herd health is closely associated with milk production and economic sustainability. Therefore, maintenance of herd health is closely dependent upon disease prevention and therapeutic drug use for a range of diseases. The presence of antibiotic residues in milk is a public health issue. The purpose of the present study ware to know the relationships of farmer characteristics and antibiotic residues presence in raw milk, wich used as cheese production. Farmer characteristics (age, education, breeding time, training, and number of lactating cows) were used to find the relationship between the farmer’s knowledge and the presence of antibiotic residues in raw milk. The yoghurt tests method was used to figure out the existence of antibiotic residues in raw milk as the basic material for making cheese. Eighteen raw milk samples were taken from three farmer groups that supply the milk to the cheese factory in Sukabumi. Yoghurt test showed that the milk from group A did not contain antibiotic residues, while the milk from group B and C contained antibiotic residues. Farmer characteristics indicating significant correlation with antibiotic residues presence were farmer’s education and number of lactating cows.
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Judul: Kualitas Mikrobiologis Susu Segar sebagai Bahan Baku Keju
Abstrak: The aim of this study was to observe microbiological quality of fresh milk as the raw material of cheese. There were 35 milk samples taken from six farms. The total count of microorganisms, Staphylococcus aureus, and coliforms were examined with plate count method (pour plate method). The result showed that the milk samples from the third farm had the highest number of total plate count (6 973 333.3 + 4 712 126.2 cfu/ml), the fifth farm showed the highest number of Staphylococcus aureus (1 950.0 + 636.4 cfu/ml), and of coliform (321 139.2 + 4 177 723.8 cfu/ml). Compared to the maximum number of microbial contamination according to the Indonesia National Standard (SNI 01-3141-2011), all the samples (100%) from the six farms were higher than the standard. The high number of Staphylococcus aureus and coliform contamination in milk due to the inadequate personal hygiene practices and the poor cleanliness level of water, cages, and equipment. This condition should be considered as a risk of food contamination that can cause disease for the consumers.
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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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