Judul: Penawaran dan permintaan susu segar di Jakarta, Bogor, Tanggerang dan Bekasi Jawa-Barat
Abstrak: Tujuan penelitian adalah: (1) mempelajari karakteris- tik peternakan sapi perah di daerah Jabotabek; (2) mempelajari penawaran susu segar oleh peternak dan koperasi primer/KUD serta mengidentifikasi faktor-faktor yang mempengaruhinya; (3) mempelajari permintaan susu segar oleh IPS serta mengidentifikasi faktor-faktor yang mempengaruhinya; dan (4) menelaah peranan koperasi dalam pemasaran susu segar."
Keyword: Animal products, Milk products, susu segar

Judul: Marketing Analysis of Milk in Cijeruk Area Bogor Regency and Pondok Rangon East Jakarta
Abstrak: Pengembangan subsektor peternakan khususnya ternak perah sangat potensial, salah satu ternak perah yang potensial untuk dikembangkan adalah sapi perah. Pengembangan suatu usaha dipengaruhi salah satunya oleh efisiensi tata niaga produknya. Penelitian ini bertujuan untuk menganalisis sistem tata niaga susu sapi di Cijeruk dan Pondok Rangon yang meliputi saluran tata niaga, fungsi tata niaga, dan struktur pasar . Penentuan sampel peternak dilakukan dengan teknik purposive sampling dengan melibatkan jumlah masing masing 20 peternak sapi perah yang berada di kawasan Cijeruk dan Pondok Rangon. Lembaga-lembaga tata niaga yang terlibat dan berperan dalam saluran pemasaran susu sapi segar yaitu konsumen, loper dan kelompok pengumpulan susu ditentukan berdasarkan informasi dari peternak sampel. Berdasarkan hasil penelitian terdapat 4 saluran tata niaga di Kelompok Ternak Mandiri Sejahtera, dan terdapat 3 saluran tata niaga di Kelompok Tani Swadaya Pondok Rangon. Peternak yang ada di Kelompok Ternak Mandiri Sejahtera dominan memasarkan susu melalui kelompok, sedangkan peternak yang ada di Kelompok Tani Ternak Swadaya Pondok Rangon dominan memasarkan susu melalui loper. Saluran tata niaga paling efesien adalah saluran yang memiliki biaya pemasaran sebesar Rp.0 dengan hasil farmer,’s share 100% yaitu peternak menjual susu segar langsung ke konsumen (jalur tata niaga terpendek)., The development of the livestock sub-sector, especially dairy cattle, is very potential, one of the dairy cattle that has the potential to be developed is dairy cattle. The development of a business is influenced by the efficiency of its product trading system. This study aims to analyze the trading system of cow's milk in Cijeruk and Pondok Rangon which includes the trading system, the function of the trade system, and the market structure. The determination of the farmer sample was carried out by purposive sampling technique involving the number of each of 20 dairy farmers in the Cijeruk and Pondok Rangon areas. The trading institutions that are involved and play a role in the marketing channel of fresh cow's milk, namely consumers, deliverymen and milk collection groups are determined based on information from sample farmers. Based on the results of the study, there are 4 channels of trade in the Independent Prosperous Livestock Group, and there are 3 channels of trade in the Independent Farmer Group of Pondok Rangon. Farmers in the Independent Sejahtera Livestock Group dominantly market milk through groups, while farmers in the Pondok Rangon Self-Help Cattle Farmers Group market milk through deliverymen. The most efficient trading channel is a channel that has a marketing cost of Rp. 0 with a farmer's share of 100%, that is, farmers sell fresh milk directly to consumers (shortest trade route).
Keyword: peternak rakyat, sapi perah, susu segar, tata niaga, commerce, dairy cows, fresh milk, smallholder farmers

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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