Judul: The Quality Testing of Bio-slurry Solid Fertilizer Mixed Rumen Contents and Cow's Blood on Productivity of Spinach Plant
Abstrak: Pemanfaatannya untuk biogas berupa bio-slurry yang potensial sebagai pupuk organik. Penelitian ini bertujuan untuk mengetahui kualitas pupuk padat dari bio-slurry campuran isi rumen sapi dan darah sapi pada produktivitas tanaman bayam hijau. Penelitian di design dengan rancangan acak lengkap (RAL) yang terdiri dari 5 perlakuan dan 5 pengulangan, yaitu P0 (pupuk padat komersial 10 ton. ha−1 polybag-1 dan pupuk anorganik (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), P1 (pupuk padat komersial 5 ton. ha−1 polybag-1 dan pupuk anorganik (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), P2 (pupuk bio-slurry A 10 ton. ha−1 polybag-1 dan pupuk anorganik (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), P3 (pupuk bio-slurry B 10 ton. ha−1 polybag-1 dan pupuk anorganik (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), dan P4 (pupuk bio-slurry C 10 ton. ha−1 polybag-1 dan pupuk anorganik (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)). Hasil penelitian menunjukan jika pupuk bio-slurry A (100% isi rumen sapi) memiliki hasil yang tidak berbeda jauh dengan pupuk padat komersial setengah dosis tetapi tidak dapat menggantikan efektivitas pupuk padat komersial., Its utilization for biogas produces bio-slurry which has the potential as organic fertilizer. The study is about determine the quality of solid fertilizer from bio-slurry a mixture of cow rumen contents and cow blood on the productivity of green spinach. The study was designed with completely randomized design (CRD) consisting of 5 treatments and repetition, namely P0 (commercial solid fertilizer 10 ton. ha−1 polybag-1 and anorganic fertilizer (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), P1 (commercial solid fertilizer 5 ton. ha−1 polybag-1 and anorganic fertilizer (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl, P2 (fertilizer bio-slurry A 10 ton. ha−1 polybag-1 and anorganic fertilizer (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), P3 (fertilizer bio-slurry B 10 ton. ha−1 polybag-1 and anorganic fertilizer (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl)), dan P4 (fertilizer bio-slurry C 10 ton. ha−1 polybag-1 and anorganic fertilizer (0.25 ton. ha−1 Urea, 0.1 ton. ha−1 SP-36 dan 0.15 ton. ha−1 KCl). The results showed that bio-slurry A (100% rumen of cow) has results don’t have much different from half-dose commercial solid fertilizer but cant replace it.
Keyword: Bio-Slurry, Solid Fertilizer, Spinach

Judul: Kualitas Bio-Slurry Campuran Rumen dan Darah Sapi Sebagai  Pupuk Cair Pada Tanaman Bayam (Amaranthus sp)
Abstrak: Bio-Slurry atau limbah biogas merupakan produk dari hasil pengolahan biogas berbahan campuran limbah ternak, proses pengolahannya dengan cara mencampur limbah ternak dengan air secara anaerob. Penelitian ini bertujuan menganalisis kualitas pupuk cair hasil samping pembuatan biogas dari campuran rumen dan darah sapi serta menganalisis efektivitasnya pada bayam hijau (Amaranthus sp) dengan konsentrasi berbeda. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan enam perlakuan, P0 (pupuk cair komersial 300 ml. polybag-1 dan pupuk anorganik (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)), P1 (pupuk cair komersial 150 ml. polybag-1 dan pupuk anorganik (75 kg ha-1 urea, 50 kg ha-1 SP-36, 50 kg ha-1 KCl)), P2 (pupuk Bio-Slurry cair A 300 ml. polybag-1 dan pupuk anorganik (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)). P3 (pupuk Bio-Slurry cair B 300 ml. polybag-1 dan pupuk anorganik (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)). P4 (pupuk Bio-Slurry cair C 300 ml. polybag-1 dan pupuk anorganik (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)) masing-masing dengan tiga kali pengulangan. Hasil penelitian menunjukan bahwa pupuk Bio-Slurry cair terbaik yang digunakan dalam penelitian ini yaitu pupuk Bio-Slurry cair C, namun tingkat efektivitas pada tanaman bayam hijau (Amaranthus sp.) belum bisa menggantikan pupuk cair komersial dosis 100% tetapi memiliki hasil yang sama dengan pemberian pupuk komersial setengah dosis., Bio-Slurry or biogas waste is a product of biogas processing made from a mixture of slag waste, the processing process is by anaerobically mixing livestock waste with water. This study aims to analyze the quality of liquid fertilizer by product of making biogas from a mixture of rumen and cow's blood and analyze its effectiveness on green spinach (Amaranthus sp) with different concentrations. The experimental design used was a completely randomized design (CRD) with six treatments, P0 (commercial liquid fertilizer 300 ml. polybag-1 and inorganic fertilizer (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 1 KCl)), P1 (commercial liquid fertilizer 150 ml. polybag-1 and inorganic fertilizer (75 kg ha-1 urea, 50 kg ha-1 SP-36, 50 kg ha-1 KCl)), P2 (Bio-fertilizer Liquid slurry A 300 ml polybag-1 and inorganic fertilizer (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha 1 KCl)). P3 (Liquid Bio-Slurry fertilizer B 300 ml. polybag-1 and inorganic fertilizer (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)). P4 (Liquid Bio Slurry fertilizer C 300 ml. polybag-1 and inorganic fertilizer (150 kg ha-1 urea, 100 kg ha-1 SP-36, 100 kg ha-1 KCl)) each with three repetitions. The results showed that the best liquid Bio-Slurry fertilizer used in this study was liquid Bio-Slurry C fertilizer, but the level of effectiveness on green spinach (Amaranthus sp.) has not been able to replace 100% commercial liquid fertilizer but has the same results as half dose of commercial fertilizer.
Keyword: bio-slurry, green spinach, liquid fertilizer

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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