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: Pengaruh Penambahan Fungisida pada Bahan Pencuci dan Waktu Pencucian terhadap Kualitas Buah Mangga (Mangifera indica) Varietas Arumanis.
Abstrak: Getah yang terdapat pada kulit mangga merupakan masalah bagi petani, karena dapat menurunkan kualitas. Salah satu usaha yang dapat dilakukan untuk mengurangi penurunan kualitas tersebut yaitu dengan melakukan pencucian menggunakan bahan pencuci yang bersifat basa. Percobaan ini bertujuan untuk membersihkan buah dari getah dan kotoran serta menghambat terjadinya busuk pada buah mangga. Percobaan ini dilaksanakan di Kecamatan Haurgeulis, Indramayu dan Laboratorium Pasca Panen, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor pada Desember 2011 hingga Januari 2012. Rancangan percobaan yang digunakan adalah Rancangan Kelompok Lengkap Teracak (RKLT) dengan dua faktor. Faktor pertama terdiri dari lima macam perlakuan bahan pencuci, yaitu : P0 = tanpa perlakuan (kontrol), P1 = air, P2 = larutan Ca(OH)2 0.5 % dan deterjen, P3 = larutan Ca(OH)2 0.5%, deterjen 1%, dan fungisida, dan P4 = fungisida. Faktor kedua yaitu waktu pencucian yang terdiri dari dua macam yaitu : T1 = 0 jam setelah panen, dan T2 = 6 jam setelah panen. Pengamatan dilakukan kebersihan dari getah dan kotoran, luka bakar, dendritik, busuk pangkal buah, busuk buah, antraknosa, kekerasan, dan perubahan warna kulit buah. Hasil percobaan ini menunjukan bahwa larutan Ca(OH)2 0.5% + deterjen 1% + fungisida merupakan larutan paling baik untuk menghilangkan getah dan kotoran, mengurangi luka bakar sampai 6 HSP, mengurangi dendritik sampai 4 HSP, menunda busuk pangkal buah sampai 6 HSP, menunda busuk buah sampai 4 HSP dan menunda antraknosa sampai 8 HSP dibandingkan dengan buah mangga yang tidak dicuci dengan waktu pencucian 0 jam setelah panen dan 6 jam setelah panen. Bahan pencuci larutan Ca(OH)2 0.5% + deterjen 1% merupakan larutan yang dapat iii mempertahankan kualitas buah mangga, akan tetapi harus dilakukan pencucian 0 jam setelah panen untuk mendapatkan hasil yang baik.
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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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