Judul: Keragaman Mangga Cengkir di Kabupaten Indramayu
Abstrak: Cengkir (Mangifera indica L.) is known as a mango variety from Indramayu Regency, West Java. So that are often called as indramayu or dermayu mango. Mango trees usually planted from seeds or graftings. The source of seeds and grafting could be come from different genotipe mango trees. So that the variability of cengkir mango trees in Indramayu need to be analyzed. The objective of this study was to analyze the diversity of cengkir mango in Indramayu based on morphological and anatomical characters. Five subdistrics (kecamatan) were chosen in Indramayu Regency, one mango plantation was chosen from each subdistrics and 2 – 3 sample trees were observed such as morphology characters of trees, leaves, and fruits. Paradermal and transversal sections of leaf anatomy for microscopical preparation was conducted in laboratory. Morphological, anatomical, and both characters were analyzed using the NTSYS program version 2.1. the dendrogram of similarity had showed cengkir mango trees in Indramayu had diversity with similarity value between 48 – 68 %.
Keyword: 

Judul: Marketing Analysis of Cengkir Mango (Mangifera indica l.) in  Temiyangsari Village, Kroya District, Indramayu Regency
Abstrak: Desa Temiyangsari merupakan salah satu desa di Kecamatan Kroya, Kabupaten Indramayu yang dikenal sebagai penghasil Mangga Cengkir. Selain fluktuasi harga pada panen raya, buah mangga yang mudah rusak ketika melalui saluran pemasaran juga diperhitungkan sehingga memengaruhi harga jual Mangga Cengkir. Semakin panjang saluran pemasaran, maka semakin banyak lembaga pemasaran yang terlibat sehingga semakin banyak lembaga yang menentukan harga. Marjin yang tinggi dapat menyebabkan penerimaan petani Mangga Cengkir rendah sedangkan posisi tawar Petani Mangga Cengkir lemah dalam menentukan harga di pasar. Penelitian ini bertujuan untuk (1) menganalisis saluran dan fungsi pemasaran usahatani Mangga Cengkir di Desa Temiyangsari, Kecamatan Kroya, Kabupaten Indramayu, (2) menganalisis struktur, perilaku, dan kinerja pasar Mangga Cengkir di Desa Temiyangsari, Kecamatan Kroya, Kabupaten Indramayu. Hasil penelitian menunjukkan bahwa: (1) terdapat empat lembaga pemasaran yang membentuk lima saluran pemasaran dengan berbagai fungsi pemasaran kecuali fungsi pengolahan, (2) Struktur pasar di setiap lembaga pemasaran adalah oligopsoni terkonsentrasi tinggi, kecuali di tingkat pedagang pengecer luar yang merupakan oligopoli terkonsentrasi tinggi terhadap lembaga pemasaran sebelumnya sehingga berimplikasi pada penentuan harga, keterikatan petani, dan sistem pembayaran. Oleh karena itu, sebagian besar petani menggunakan saluran pemasaran 2 dan 3 dengan marjin terbesar dan farmer’s share terkecil sehingga kinerja pasar belum efisien.
Keyword: kinerja pasar, marjin pemasaran, perilaku pasar, saluran pemasaran, struktur pasar

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: