Judul: Karakterisasi mutu jeruk siam banjar (Citrus nobilis var microcarpa) di Lahan Rawa pasang Surut dan Lahan Lebak Kalimantan Selatan
Abstrak: The objective of this study is to determine quality characteristics of Siam Banjar Citrus in tidal swamp land of Barito Kuala Regency and low swamp land of Banjar Regency according to standard quality of Indonesia (SNI), and to study the quality change during storage. Citrus are harvested at optimum maturity then sorted and classified based on SNI. The physical, chemical and organoleptic properties are determined. The classified citrus are then stored at room temperature and 15o C. The result showed in the tidal swamp land A type,citrus has quality characteristics of super class (17%), size 2 (67%), diameter of 6.56 cm,firmness of 14.49 N, total sugar content of 13,970Brix, vitamin C of 36,98 gvitC/100g and yellow color. In the tidal swamp land B type,citrus has quality characteristic of super class (2%), size 3 (39.5%), diameter of 6.13 cm,firmness of 25 N, total sugar content of 12,240Brix, vitamin C of 35,35 gvitC/100g and yellowish green color. In the tidal swamp land C type,citrus has quality characteristic of super class (19%), size 2 (60%), diameter of 6.46 cm,firmness of 19.42 N, total sugar content of 12.450Brix, vitamin C of 35.27 gvitC/100g and yellowish green color. In the low swamp ,citrus has quality characteristic of super class (16%), size 2 (69.5%), diameter of 6.55 cm,firmness of 14.71 N, total sugar content of 12.460Brix, vitamin C of 36,45 gvitC/100g and yellow color. During storage, the color of citrus changed to yellow brownish,firmness and vitamin C decreased, and total sugar content increased.
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Judul: Penyimpanan Jeruk Siam (Citrus Nobilis L.) Setelah Proses Degreening.
Abstrak: Buah jeruk siam memiliki warna kulit yang hijau meskipun telah matang di pohon. Untuk menghasilkan warna jingga pada kulit buah diperlukan penanganan pascapanen dengan penerapan metode degreening. Selain itu, diperlukan penyimpanan untuk memperpanjang umur simpan. Penelitian ini bertujuan: 1) Menentukan pengaruh suhu dan lama penyimpanan buah jeruk hasil degreening, 2) Menganalisis perubahan fisiologi selama penyimpanan. Perlakuan chilling dan non chilling merupakan perlakuan awal pascapanen sebelum proses degreening. Perlakuan degreening dilakukan dengan pemaparan gas etilen 200 ppm, suhu 20 oC selama 48 jam. Selanjutnya, jeruk hasil degreening disimpan pada suhu 10 oC , 15 oC, 20 oC, dan suhu ruang. Pengukuran kuantitatif dilakukan setiap tiga hari sekali selama penyimpanan yang mencakup susut bobot, warna (CCI), kekerasan, total padatan terlarut, vitamin C dan total asam. Hasil penelitian menunjukkan penggunaan gas etilen pada proses degreening secara efektif dapat mendegradasi klorofil pada kulit buah jeruk kemudian menghasilkan warna jingga. Perlakuan chilling dan non chilling pada buah jeruk hasil degreening berpengaruh nyata (p<0.05) terhadap susut bobot dan total padatan terlarut. Sedangkan pada nilai CCI, kekerasan, total asam dan vitamin C tidak berpengaruh nyata (p>0.05). Perlakuan suhu penyimpanan pada buah hasil degreening berpengaruh nyata (p<0.05) terhadap nilai CCI, susut bobot, kekerasan, dan total asam. Sedangkan pada vitamin C dan total padatan terlarut tidak berpengaruh nyata (p>0.05). Perlakuan penyimpanan menunjukkan pengaruh yang nyata (p<0.05) terhadap semua parameter kualitas buah. Nilai CCI, susut bobot dan total padatan terlarut menunjukkan peningkatan, sedangkan nilai kekerasan, vitamin C dan total asam mengalami penurunan. Perubahan nilai CCI selama 42 hari penyimpanan pada suhu 10 oC menghasilkan nilai CCI dari 0.168 menjadi 10.046 dengan warna optimum yang dihasilkan adalah jingga cerah.
Keyword: chilling and non chilling, degreening, gas etilen, jeruk siam, penyimpanan

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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