Judul: Akumulasi kadar Xanthone kulit manggis(Garcinia mangostana L.) pada berbagai stadia umur buah dan setelah buah dipanen
Abstrak: Penelitian ini bertujuan untuk mengetahui akumulasi kadar xanthone kulit mugs (Garcinia mangostana L.) selama perkembangan buah dan setelah buah dipanen. Penelitian ini dilaksanakan di Leuwiliang untuk pengambilan sampel, Laboratorium Ekofisiologi Departemen Agronomi dan Hortikultura untuk pengamatan morfologi dan ekstraksi, Laboratorium Hortikultura Departemen Agronomi dan Hortikultura untuk kegiatan evaporasi, sedangkan penentuan kadar xatione dilakukan di Balitro, Cimanggu. Penelitian ini terdiri dari dua penelitian yaitu penelitian akumulasi ampone kulit manggis selama perkembangan buah dan penelitian kadar xanthone kolit manggis setelah buah dipanen. Penelitian pertama terdiri dari empat perlakuan yaitu umur buah 1 bulan setelah anthesis (BSA) (P1), umur buah 2 BSA (2) umur buah 3 BSA (P3) dan umur buah 4 BSA (P4). Penelitian kedua terdiri dari tiga perlakuan yaitu buah tanpa penyimpanan (S0), buah yang disimpan sam 2 minggu setelah panen (MSP) (S2) dan buah yang disimpan selama 4 MSP (S4). Masing-masing perlakuan diulang tiga kali. Selama perkembangan buah mulai umur buah 1 BSA hingga umur buah 4 BSA tidak terdapat perbedaan yang signifikan terhadap akumulasi xanthone pada kulit manggis. Akumulasi xanthone sudah terdapat pada umur buah 1 BSA dengan kadar xanthone sebesar 1.97 g/100 g kulit manggis kering dan akumulasi xanthone tertinggi ditemukan pada umur buah 4 BSA yaitu sebesar 4.78 g/100 g kali manggis kering. Buah manggis setelah dipanen tidak mengalami perubahan kadar xanthone yang signifikan selama penyimpanan. Kadar xanthone tertinggi ditemukan pada penyimpanan 2 MSP yaitu 2.62 g/100 g kulit manggis kering.
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Judul: Karakter Kulit Manggis, Kadar Polifenol Dan Potensi Antioksidan Kulit Manggis (Garcinia mangostana L.) Pada Berbagai Umur Buah Dan Setelah Buah Dipanen
Abstrak: The objective of this study were to know the character of mangosteen rind during development of the mangosteen fruit, studying the total phenol content and antioxidant potential of mangosteen rind. Research was done at Plant Analysis and Chromatoghrapy Laboratory, Deparment of Agronomy and Horticulture, Bogor Agricultural University. This research used Completely Randomized Desain Group (RKLT) single factor wich is harvesting, with continue test Duncan Multiple Range Test (DMRT) at level 5%. Harvesting one month after anthesis (BSA), 2 BSA, 3 BSA, 4 BSA and the rind storage two and four weeks after harvesting were done separately. Mangosteen fruit was harvested from Leuwiliang, Bogor. The result showed that total phenolic at crude extract mangosteen and antioxidant capacity to reach IC50 of harvesting and storage have negative correlation. Harvesting handling have effect to fruit weight, aril weight, wet weight rind and vitamin C content. Total phenolic of Harvesting and storage handling have a negative correlation with antioxidant capacity to reach IC50 which are value about -0.53 and -0.91. Assumed that total phenolic content will increase antioxidant capacity in mangosteen rind. Antioxidants capacity on harvesting and sorage handling of mangosteen have IC50<50 (capability of antioxidant are very strong).
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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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