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: Effect of Harvest Ages on Production, Seeds Quality, Biomass of Sorghum of Varieties of Samurai 2
Abstrak: Tujuan dari penelitian ini adalah mengevaluasi produksi, kualitas benih, dan biomassa tanaman sorgum berdasarkan umur panen yang berbeda. Penelitian ini menggunakan tanaman sorgum varietas samurai 2 dan didesain menggunakan rancangan acak kelompok (RAK) dengan 4 perlakuan dan 5 ulangan. Data penelitian dianalisis menggunakan ANOVA, apabila berbeda nyata, dilakukan uji lanjut menggunakan uji Duncan Multiple Range Test (DMRT). Perlakuan umur panen tanaman sorgum terdiri dari 95 HST (U1), 100 HST (U2), 105 HST (U3), dan 110 HST (U4). Peubah yang diukur pada penelitian ini adalah kadar air benih, panjang malai, berat malai, berat kering malai, berat benih pipil, berat kering benih pipil, berat 1000 benih, dan viabilitas benih. Hasil penelitian menunjukkan perlakuan umur panen tanaman sorgum 105 HST signifikan meningkatkan berat benih dan berat 1000 benih. Perlakuan umur panen 105 HST juga signifikan meningkatkan viabilitas benih dan hasil terbaik pada hari ke 4 dan 7, serta biomassa produksi tertinggi., The aim of this study was to evaluate the production, seeds quality, and biomass of sorghum varieties of samurai 2 at harvest ages. This study used sorghum varieties of samurai 2 and designed a Randomized Block Design (RDB) with 4 treatments and 5 replication. The data were analyzed using ANOVA and any significant differences were further tested using Duncan Multiple Range Test (DMRT). Sorghum was harvested at the age of 95 DAH (U1), 100 DAH (U2), 105 DAH (U3), and 110 DAH (U4). The measured variable were moisture content of seed, panicle length, panicle weight, panicle dry weight, weight of pipil seed, dry weight of pipil seed, weight of 1000 seeds, and viability of seed. The results showed that the treatment of sorghum at 105 DAH significantyly increased weight of seed and weight of 1000 seeds. Furthermore, the treatment of sorghum at 105 DAH significantly increased viability of seed and get the best value of day-4 and day-7, and highest of biomassa production.
Keyword: harvest age, panicle, seed, sorghum, 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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