Judul: Pengaruh penambahan fungisida pada bahan pencuci serta suhu penyimpanan terhadap peningkatan kualitas Mangga (Mangifera indica L.) cv. Gedong
Abstrak: Mango sap is acidic and contain oil and sugar that attracts fungi infection that induce damage to the fruit, such as fruit rot and anthracnose infection. Previous research demonstrated that mango washer able to clean the sap but did not able to delay the occurrence of fruit rot. Therefore, fungicides were added in the washing material in the present study in order to delay the occurrence of fruit rot and anthracnose infection. Objective of present study was to obtain the best washing material composition, fungicide, and storage temperature in order to delay the occurrence of fruit rot and anthracnose infection in mango cv. Gedong. Research was conducted in Girinata Village, Cirebon and Postharvest Laboratory of Bogor Agricultural University from December 2014 to January 2015. The experiment was designed in a randomized complete design with two factors, named the combination of washing material and storage temperature. The first factor consists of 5 treatment, i.e., control (not washed), detergent 1% + Ca(OH)2 0.5%, detergent 1% + Ca(OH)2 0.5% + benomyl fungicide 0.025%, detergent 1% + Ca(OH)2 0.5% + azoxystrobin fungicide 0.025%, and detergent 1% + Ca(OH)2 0.5% + fludioxonil fungicide 0.025%. The second factor was 4 levels of temperature, i.e., room temperature, 18°C, 15°C and 12°C. All of factors has 3 replicaton and each replication contained 3 sample of fruits. All combinations of washing materials markedly better in cleaning sap and dirt on the mango, compare to control. Application detergent 1% + Ca(OH)2 0.5% + fludioxonil fungicide or azoxystrobin fungicide 0.025% and 12°C temperature is the best combination in delaying the occurrence of fruit diseases up to 30 days after harvest.
Keyword: Bogor Agricultural University, anthracnose, azoxystrobin, body rot, fludioxonil

Judul: Pengaruh Penambahan Fungisida pada Bahan Pencuci dan Waktu Pencucian terhadap Kualitas Buah Mangga (Mangifera indica L.) Varietas Gedong
Abstrak: The objective of this research was to study the effect of fungicide addition in the washing materials and the washing time were effective to prevent body rots and anthracnose on mango fruits. The experiment was arranged in Completely Randomized Block Design with two factors. The first factor was the washing materials consists of five treatments, there were : P0 = no treatment, P1 = water, P2 = detergent 1% + Ca(OH)2 0.5%, P3 = detergent 1% + Ca(OH)2 0.5% + fungicide benomyl 0.025%, and P4 = fungicide benomyl 0.025%. The second factor was the washing time consist of two treatments, there were : T1 = 0 hour after harvest and T2 = 6 hours after harvest. The result of experiment showed that the washing materials of detergent 1% + Ca(OH)2 0.5% + fungicide benomyl 0.025 % was effective to delaying body rots for 4 days after harvest and anthracnose for 8 days after harvest on mango fruits. The washing time at 0 hour after harvest and 6 hours after harvest were effective to removing sap and dirty, prevent of sapburn, lenticel spottings, dendritic spottings, stem end rots, stem rots, anthracnose, delaying fruit softness and development colour on mango fruits.
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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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