Judul: Efektivitas Jumlah Kemasan Oksidan Etilen terhadap Kualitas dan Daya Simpan Buah Pepaya
Abstrak: The objective of this research was to find out the effectivity of ethylene oxidant bag quantity towards quality and shelf life storage of papaya Bangkok and IPB 9 type. This research was conducted at Post Harvest Laboratory, Agronomy and Horticulture IPB, Darmaga, Bogor from August 2012 to October 2012. The experiment was arranged in completely randomized block design with single treatment. The treatment was the quantities of ethylene oxidant bags in each type of papaya with four replication. The result of this research was that the 30 g of ethylene oxidant was not effective to preserve the shelf life storage and quality of papaya Bangkok and IPB 9 type. Papaya Bangkok has the shelf life of 13-16 day storage and papaya IPB 9 has 12-15 day storage. The distribution of ethylene oxidant based on bag quantity has no respond towards shelf life, peel color index, physiological weight loss, firmness, total soluble solid, titrable acidity, and total ascorbic acid of Bangkok and IPB 9.
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Judul: Studi Penggunaan Oksidan Etilen dalam Penyimpanan Pascapanen Buah Pisang Raja Bulu (Musa sp. AAB Group).
Abstrak: Penelitian ini dilakukan untuk mengetahui efektivitas jumlah kemasan oksidator etilen untuk memperpanjang umur simpan. Oksidan etilen yang digunakan adalah campuran kalium permanganat (KMnO4) dan tanah liat. Penelitian dilaksanakan dalam percobaan yang berlangsung dari bulan April 2012 sampai dengan Mei 2012 di Laboratorium Pascapanen, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, IPB, Bogor. Percobaan dilakukan dengan Rancangan Kelompok Lengkap Teracak (RKLT) faktor tunggal dengan lima perlakuan dan lima ulangan. Pengamatan yang dilakukan berupa pengamatan destruktif dan non destruktif. Pengamatan non destruktif meliputi pengukuran indeks skala warna kulit buah dan susut bobot buah pada 3, 6, 9, 12, 15, dan 16 hari setelah perlakuan (HSP). Pengamatan destruktif dilakukan pada 3, 6, 12, 15, dan 16 HSP untuk mengukur kekerasan kulit buah, edible part, padatan terlarut total (PTT), asam tertitrasi total (ATT), dan vitamin C. Daya simpan buah terpanjang (15 hari penyimpanan) dan daya simpan terpendek yaitu 13 hari penyimpanan. Perlakuan pembungkus bahan oksidan etilen (tanah liat + KMnO4) dapat menurunkan susut bobot buah pisang. Perlakuan pembungkus bahan oksidan etilen tidak mempengaruhi indeks skala warna kulit buah, bagian buah yang dapat dimakan (edible part), PTT, vitamin C kecuali pada 12 HSP, kekerasan kulit buah kecuali pada 16 HSP, susut bobot buah kecuali pada 6, 9, 12 HSP, ATT dan rasio PTT dengan ATT. Perlakuan oksidan etilen dengan pembagian pembungkus dapat meningkatkan daya simpan buah tiga hari lebih lama dibandingkan kontrol. Dengan demikian pembagian pembungkus yang terbagi dalam satu bungkus dengan dosis 30 g bahan oksidan etilen dapat direkomendasikan untuk digunakan dalam penyimpanan buah pisang Raja Bulu.
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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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