Judul: Penundaan Kematangan Buah Alpukat (Persea americana, Mill) dengan Penyerap Etilen Arang Aktif-Kalium Permanganat.
Abstrak: Alpukat adalah buah yang memiliki waktu simpan singkat karena laju respirasi dan produksi etilen yang tinggi. Zat yang dapat digunakan untuk menghambat pematangan adalah KMnO4 yang digunakan untuk menyerap etilen. Tujuan dari penelitian ini yaitu menentukan kombinasi arang aktif dan KMnO4 yang efektif sebagai bahan penyerap etilen. Percobaan menggunakan rancangan dengan 2 bobot arang aktif (15 gram, 10 gram) dan 2 konentrasi KMnO4 (100 mg, 50 mg). Parameter yang di ukur selama penelitian meliputi susut bobot, total padatan terlarut (TPT), dan uji warna. Kombinasi yang efektif antara arang aktif dan KMnO4 untuk memperpanjang waktu simpan alpukat adalah arang aktif 15 gram dan KMnO4 100 mg., Avocado is a fruit that has a short storage life due to its high respiration rate and ethylene production. The substance that can be used to hold up maturation process is KMnO4 which can be used to absorb ethylene. The purpose of this study was to determine an effective combination of active carbon and KMnO4 as an ethylene absorbent. The experiment was conducted using 2 weights of active carbon (15 grams, 10 grams) and 2 concentrations of KMnO4 (100 mg, 50 mg). Parameters measured during the study included weight loss, total soluble solids (TSS), and color test. An effective combination of active carbon and KMnO4 to extend the storage life of avocados is 15 grams of activated charcoal and 100 mg of KMnO4.
Keyword: Avocado, Active carbon, KMnO4, Ethylene

Judul: Pengaruh penggunaan KMnO4 sebagai bahan penyerap Etilen selama penyimpanan Buah Alpukat(Persea americana, Mill)
Abstrak: Alpukat adalah salah satu buah yang memiliki waktu simpan singkat karena produksi etilen dan laju respirasinya yang tinggi. Salah satu zat yang dapat digunakan untuk menghambat proses pematangan adalah KMnO4 yang dapat digunakan untuk menyerap etilen. Tujuan dari penelitian ini adalah untuk menentukan kombinasi antara KMnO4 dan arang aktif terbaik yang akan digunakan sebagai penyerap etilen. Percobaan menggunakan rancangan acak lengkap faktorial terbagi dengan 2 taraf konsentrasi KMnO4 (75 mg, 100 mg) dan 2 taraf bobot arang aktif (10 gram, 15 gram). Uji anova digunakan untuk mengetahui bagaimana pengaruh tiap perlakuan. Parameter yang diukur selama penelitian meliputi laju respirasi, susut bobot, kekerasan, total padatan terlarut (TPT), dan uji warna. Kombinasi terbaik antara konsentrasi KMnO4 dan arang aktif untuk memperpanjang waktu simpan alpukat adalah konsentrasi KMnO4 100 mg dan arang aktif 15 gram., Avocado is one of the fruit that have short storage life because its high ethylene production and respiration rate. One of the substances that could restrain the maturation process is KMnO4 which can be used to absorb ethylene. The purpose of this study was to determine the best combination of KMnO4 and active carbon for ethylene absorbent. The experiments was conducted using factorial design with 2 levels of KMnO4 concentration (75 mg, 100 mg) and 2 levels of active carbon mass (10 gram, 15 gram). ANOVA test was used to know the effect of the treatment given. The parameters measured during the study were respiration rate, weight loss, firmness, total soluble solids (TSS), and color test. The best combination between KMnO4 concentration and active carbon to prolong the storage life of avocado was 100 mg concentration of KMnO4 and 15 gram of active carbon.
Keyword: arang aktif, alpukat, etilen, KMnO4

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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