Judul: Analisis tataniaga pupuk organik UD. AMA Kabupaten Solok, Sumatera Barat
Abstrak: Organic fertilizer is one kind of fertilizer that supports the agricultural sector development in Indonesia and used to recover back the natural elements of soil nutrients. The purpose of this study was to analyze the trading system that includes an organic fertilizer marketing channels, institutions, function, structure and behavior. In addition, this study analyzed the efficiency of fertilizer in each channel trading system with the margin approach, the firm’s share and the profit ratio per charge. The results of the analysis of operatinal efficiency indicators and qualitative indicators show that the channel has formed and efficient trading system due to high bergaining power of producer. In addition, it takes more number of distribution channels to increas sales through the company and benefits to the end consumer
Keyword: marketing, fertilizer, firm’s share, efficiency

Judul: Analisis Efisisensi pemasaran sayur organik di Okiagaru Farm Kabupaten Cianjur Jawa Barat
Abstrak: Sayuran organik merupakan salah satu produk tanaman hortikultura yang memiliki nilai ekonomis yang tinggi dan memiliki peluang pasar yang baik. Tujuan penelitian ini adalah menganalisis lembaga dan fungsi pemasaran, saluran pemasaran, marjin pemasaran, farmer’s share dan rasio keuntungan terhadap biaya sayur organik di Okiagaru Farm. Pengambilan responden menggunakan snowball sampling untuk responden petani dan lembaga pemasaran yang pengambilan data dilakukan pada bulan januari sampai februari 2019. Hasil penelitian ini menunjukan bahwa terdapat 2 jenis saluran pemasaran. Pada komoditas Terong Jepang, Zukini dan Kubis terdapat 2 saluran pemasaran. Saluran 1 dianggap lebih efisien karena memiliki nilai marjin pemasaran yang lebih rendah, nilai farmer’s share yang lebih tinggi dan jumlah lembaga yang lebih sedikit.
Keyword: biaya pemasaran, efisiensi, fungsi pemasaran, farmer’s share, marjin harga

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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