Judul: Evaluasi produksi dan kualitas sorgum samurai 1 pada umur panen berbeda periode generatif
Abstrak: Penelitian ini dilakukan untuk mengevaluasi produksi dan kualitas sorgum samurai 1 pada umur panen berbeda periode generatif. Penelitian dilaksanakan di Unit Pendidikan Penelitian Peternakan Jonggol (UP3J) dan juga di laboratorium agrostologi dan laboratorium Ilmu dan Teknologi pakan Fakultas Peternakan Institut Pertanian Bogor selama 6 bulan. Penelitian ini menggunakan sorgum samurai 1 dengan metode rancangan acak kelompok (RAK) dengan 3 kelompok umur panen 80 HST (U1), 87 HST (U2) dan 94 HST (U3), dengan 5 kali ulangan. Analisis data menggunakan sidik ragam anova dan dilanjutkan dengan uji DMRT. Hasil penelitian menunjukkan bahwa umur panen yang berbeda berpengaruh nyata terhadap berat segar malai dan juga nilai dari NDF. Nilai brix berbanding lurus dengan umur panen, dimana semakin lama umur panen maka nilai brix juga akan semakin meningkat. Umur panen 87 HST memiliki nilai paling tinggi pada berat total sorgum, berat batang, berat daun, dan juga berat malai., This research was conducted to evaluate the production and quality of Sorghum Samurai 1 at different harvesting ages during the generative period. The research was carried out at the Jonggol Animal Husbandry Research Education Unit (UP3J) and also at the agrostology laboratory and feed science and technology laboratory, Faculty of Animal Husbandry, Bogor Agricultural University for 6 months. This study used Sorghum Samurai 1 using a randomized block design (RBD) method with 3 harvesting age groups of 80 DAP (U1), 87 DAP (U2) and 94 DAP (U3), with 5 replications. Data analysis used analysis of variance and continued with the DMRT test. The results showed that different harvest ages had a significant effect on the fresh weight of panicles and also the value of NDF. The value of brix was directly proportional to the age of harvest, where the longer the harvest age, the value of brix will also increase. The harvest age of 87 HST has the highest value on the total weight of sorghum, stem weight, leaf weight, and also panicle weight.
Keyword: DAP, NDF, harvest age, panicle, sorghum

Judul: Production and Physiological Quality of Sorghum  Seeds bicolor Samurai 1 in Phase F1 with Different Harvesting Ages
Abstrak: Penelitian ini bertujuan mempelajari pengaruh umur panen terhadap mutu fisiologis dan viabilitas benih sorgum Samurai 1 pada fase F1. Penelitian dilakukan di laboratorium lapang UP3J IPB dan Laboratorium Agrostologi Fakultas Peternakan IPB University. Rancangan percobaan yang digunakan yaitu rancangan acak kelompok (RAK) dengan 5 perlakuan umur panen yaitu pada hari ke-90, 95, 100, 105, dan 110, serta 4-5 kali pengulangan. Peubah yang diamati berupa diameter batang, tinggi tanaman, berat kering biomassa malai, berat segar biomassa per ha, berat kering batang, berat kering daun, berat kering malai, berat kering daun, berat benih, jumlah benih, berat 1000 benih, dan uji viabilitas. Hasil penelitian yang didapat memberikan pengaruh nyata (P<0,05) pada produktivitasnya. Umur panen terbaik untuk mendapatkan mutu fisilogis dan viabilitas terbaik, yaitu pada perlakuan P100 dan P105, sedangkan untuk mendapatkan biomassa kering terbaik yaitu terdapat pada perlakuan P95 yaitu saat sorgum berumur 95 hari setelah tanam., This study aims to find out the effect of harvest age on the physiological quality and viability of Samurai 1 sorghum seeds in the F1 phase. The research was conducted in the field laboratory of UP3J IPB and the Agrostology Laboratory of the Faculty of Animal Science, IPB University. The experimental design used was a randomized block design (RBD) with 5 treatments at harvest age, namely on the 90th , 95th , 100th , 105th , 110th days, and 4-5 replicaty. The variables observed were stem diameter, plant height, dry weight of panicle biomass, total fresh weight, stem dry weight, leaf dry weight, panicle dry weight, leaf dry weight, seed weight, quantity of seeds, weight of 1000 seeds, and viability test. The results obtained showed a significant effect (P<0.05) in productivity. The best harvest age to get the best physiological quality and viability, at the P100 an P105 treatment, while to get the best dry biomass that is found in the P95 treatment, namely when sorghum is 95 days after planting.
Keyword: harvest age, sorghum samurai 1, viability

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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