Judul: Productivity and Economic Value of Bali Cattle at Different Age Groups
Abstrak: Sapi bali adalah ternak asli dari Indonesia dan memiliki persentase karkas yang lebih tinggi dibandingkan dengan sapi lokal lainnya. Produktivitas sapi yang tinggi akan menghasilkan nilai ekonomis yang tinggi pula. Tujuan penelitian ini adalah untuk membandingkan produktivitas karkas dan non karkas serta nilai sapi bali pada kelompok umur berbeda. Ternak yang digunakan adalah sapi bali sebanyak 16 ekor yang dipotong dalam rangka hari raya Iduladha. Penelitian yang dilakukan mencangkum pengukuran bobot potong, bobot dan persentase karkas, komponen karkas (daging dan tulang), dan komponen non karkas yaitu kepala, kulit, kaki, jeroan (offal) merah, dan jeroan (offal) hijau, serta nilai dari sapi hidup dan masing-masing komponen karkas dan non karkas. Hasil penelitian menunjukkan bahwa produktivitas komponen karkas dan non karkas sapi bali relatif sama pada kelompok umur yang berbeda. Persentase kulit merupakan satu-satunya yang menunjukkan hasil yang berbeda nyata pada kelompok umur yang berbeda. Nilai komponen karkas dan non karkas sapi bali yang dipotong untuk hari raya Iduladha tidak menghasilkan nilai tambah yang ditunjukkan dengan nilai negatif jika divaluasi dengan nilai bobot hidupnya, sehingga sapi bali yang dijual dalam kondisi hidup untuk hari raya Iduladha menunjukan nilai tertinggi., Bali cattle are indegenous livestocks from Indonesia and it’s known to have higher carcass percentage than other local cattle. High productivity in cattle leads to its high economical value as well. This study aimed to compare the carcass and non-carcass yield and economic value of Bali cattle that were slaughtered at different age groups. The study used 16 heads of Bali cattle sold for Eid al-Adha. The study included measurement of slaughter weight, weight and percentage of carcass, carcass components comprising meat and bone, and non-carcass components including head, skin, foot, red offal, green offal, and economic values of live cattle and components of carcass and non-carcass. The results showed that the productivity of carcass and non-carcass components of Bali cattle were relatively the same at different age groups. The skin percentage was the only indicator that was significantly different among age groups. Bali cattle that were slaughtered for Eid al-Adha had no added value shown with negative value when they were valued as carcass and non-carcass components and therefore live cattle sold for Eid al-Adha had the highest economic value.
Keyword: karkas, nilai, non karkas, sapi bali, umur, age, Bali cattle, carcass, economic value, non-carcass

Judul: The Productivuty and Value of Bali Cattle Slaughtered at Different End Point
Abstrak: Harga sapi menjelang hari raya Iduladha biasanya melonjak tajam dan oleh karena itu dapat berpengaruh terhadap nilai ternak, karkas dan daging sapi. Penelitian ini bertujuan menganalisis perbedaan produktivitas dan nilaisapi bali yang dipotong pada bobot potong berbeda di PT. RPH Pramana Pangan Utama. Penelitian menggunakan 16 ekor sapi bali dengan Rancangan Acak Lengkap dengan empat kategori bobot potong (BP) yaitu BP I 250 - 275 kg, BP II 276 - 300 kg, BP III 301 - 325 kg, dan BP IV 326 - 350 kg. Data dianalisis menggunakan analisis ragam, kemudian dilanjutkan dengan Uji Jarak Berganda Duncan jika terdapat perbedaan antar perlakuan. Hasil penelitian menunjukkan bahwa bobot potong berpengaruh nyata (P<0,05) terhadap bobot karkas, bobot daging, persentase tulang, bobot kulit, bobot jeroan, dan persentase kaki. Peningkatan bobot potong menghasilkan peningkatan nilai ternak. Dalam kondisi normal, komponen karkas (daging dan tulang) dan non karkas memiliki nilai yang lebih tinggi daripada sapi bali hidup. Sebaliknya pada saat Iduladha, sapi bali hidupmemiliki nilai yang lebih tinggi dari pada komponen daging, tulang dan non karkasyang dihasilkannya., Local cattle price could increase sharply during Iduladha festival and this will have an effect on animal, carcass and beef valuations. This study aimed to examine the differences in productivity and economic value of bali cattle slaughtered at different end point in PT. Pramana Pangan Utama abattoir during Iduladha festival. The study used 16 bali cattle alloted to a completely randomized design with four categories of slaughter weights (BP), namely BP I 250 - 275 kg, BP II 276 - 300 kg, BP III 301 - 325 kg, and BP IV 326 - 350 kg. Data were analyzed using variance, then tested by Duncan's Multiple Range Test to determine the differences between treatments. The results showed that slaughter weight had a significant effect (P<0,05) on carcass weight, meat weight, bone percentage, skin weight, green offal weight, and leg percentage. Increased slaughter weight resulted in an increase in economic value of bali cattle. The economic value of carcass (meat and bone) and non-carcass components would be higher at normal market situation and conversely that of live cattle would higher during Iduladha festival.
Keyword: bobot potong, nilai, produktivitas, sapi bali, bali cattle, economic value, productivity, slaughter weights

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.
Keyword: