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: Aplikasi Kalium Permanganat sebagai Oksidan Etilen dalam Penyimpanan Buah Pepaya IPB Callina.
Abstrak: Papaya is a climacteric fruit that have good nutrient content. The main problem in papaya fruit postharvest is short shelf life so it needs postharvest handling to increase fruit shelf life. Pottasium permanganate (KMnO4) can extend shelf life by oxidize ethylene that released by fruit. Ethylene oxidant treatment was assumed can extend fruit shelf life. The research aims to obtain right dosage of ethylene oxidant in storage of IPB Callina papaya fruit and to study inhibition of respiration by ethylene oxidant treatment. The fruits were harvested at green ripe stage. The experiment was conducted in one factor completely randomized block design that blocked depend on harvest date. The treatment that given was dosage of ethylene oxidant: 0 g (control), 15 g, 30 g and 45 g for one papaya fruit. The results of this research indicated that 15 g and 30 g of ethylene oxidant could delay climacteric respiration of IPB Callina papaya. Fruits with 0 g, 15 g, and 30 g of ethylene oxidant treatment reached peak of respiration rate at 8 days of storage. The peak of respiration rate in the fruit with ethylene oxidant treatment lasted for 2 days, while the fruits without ethylene oxidant straight decreased. Ethylene oxidant treatment had not been able to extend shelf life and did not affect the physical and chemical character of papaya fruit at same postharvest maturity stages.
Keyword: shelf life, ripening, respiration rate, postharvest, climacteric

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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