Judul: Analisis Keragaman Pertumbuhan, Produktivitas dan Kandungan Nutrien Berbagai Varietas Brachiaria brizantha
Abstrak: Brachiaria brizantha memiliki beberapa varietas antara lain B. brizantha var. brauna, B. brizantha var. ecotype b4, B. brizantha var. ecotype eth. 13726, B. brizantha var. ecotype eth. 1377, B. brizantha var. ecotype eth. 13809, B. brizantha var. marandu, B. brizantha var. mg4, B. brizantha var. paiaguas, B. brizantha var. piata, B. brizantha var. toledo dan B. brizantha var. xaraes. Penelitian ini bertujuan untuk menganalisis keragaman produktivitas dan kandungan nutrisi berbagai varietas Brachiaria brizantha, sehingga diketahui varietas yang memiliki pertumbuhan, produksi dan kualitasnya. Pada 30 peneliti dari tahun 2010-2020, terdapat 7 parameter yang diamati dan dicatat di Microsoft Excel 2010. Parameter tersebut meliputi data pertumbuhan, produksi dan kualitas nutrien, yaitu produksi tanaman, bahan kering (BK), protein kasar (PK), total digestible nutrient (TDN), neutral detergent fiber (NDF) dan acid detergent fiber (ADF). Kemudian data dianalisis menggunakan software Rgui. Hasil penelitian menunjukkan bahwa varietas Brachiaria brizantha berpengaruh nyata terhadap tinggi tanaman pada musim hujan (P<0,05) dan musim kemarau (P<0,01), produksi pada musim kemarau (P<0,01), BK pada musim kemarau (P<0,01), PK pada musim kemarau (P<0,01), TDN pada musim hujan (P<0,01), NDF pada musim hujan (P<0,01) dan musim kemarau (P<0,05), serta ADF pada musim hujan (P<0,01) dan musim kemarau (P<0,01). Pertumbuhan, produksi dan kandungan nutrien terbaik pada B. brizantha var. xaraes., Brachiaria brizantha has several varieties, including B. brizantha var. brauna, B. brizantha var. ecotype b4, B. brizantha var. ecotype eth. 13726, B. brizantha var. ecotype eth. 1377, B. brizantha var. ecotype eth. 13809, B. brizantha var. marandu, B. brizantha var. mg4, B. brizantha var. paiaguas, B. brizantha var. piata, B. brizantha var. toledo dan B. brizantha var. xaraes. This study aims to analyze the productivity and nutrient content of various varieties of Brachiaria brizantha. Within 30 studies from 2010-2020, production and quality parameters were observed and recorded in Microsoft Excel 2010. These parameters include data on growth, production and nutrient quality, namely plant production, dry matter (BK), crude protein (PK), total digestible nutrients (TDN) and neutral detergent fiber (NDF). Then data was analyzed using Rgui software. The results showed that the Brachiaria brizantha varieties had a significant effect on plant height rainy seasons (P<0.05) and dry seasons (P<0.01), production dry seasons (P<0.01), BK dry seasons (P<0.01), PK dry seasons (P<0.01), TDN rainy seasons (P<0.01), NDF rainy seasons (P<0.01) and dry seasons (P<0.05), and ADF rainy seasons (P<0.01) and dry seasons (P<0.01). The best growth, production and nutrient content were obtained by Brachiaria brizantha var. xaraes.
Keyword: Brachiaria brizantha variety, growth, production, nutrient content

Judul: Kualitas Dedak Padi Berdasarkan Perbedaan Musim Terhadap Standar Nasional Indonesia
Abstrak: Tujuan dari penelitian ini adalah menganalisis perbedaan kualitas nutrien dedak padi pada musim hujan dan kemarau pada semua tingkatan pengguna di Provinsi Jawa Barat periode 2016- 2020 disandingkan SNI 3178 tahun 2013. Penelitian ini menggunakan data sekunder dari 292 sampel dari dua laboratorium, yaitu Balai Pengujian Mutu dan Sertifikasi Pakan (BPMSP) Bekasi dan Balai Pengujian Mutu dan Keamanan Pakan/Bahan Pakan (BPMKP/BP) Cikole, Lembang, Jawa Barat. Penelitian ini menggunakan distribusi frekuensi untuk memberikan gambaran sederhana dari kumpulan suatu data sedangkan pada pengguna dedak padi menggunakan persentase dari data hasil pengujian dengan kesesuaian dedak padi menurut SNI 3178 tahun 2013. Hasil penelitian menunjukkan bahwa kesesuaian nutrien dedak padi terhadap SNI pada saat musim kemarau lebih baik dibandingkan saat musim hujan. Pada tingkat pengguna dedak padi persentase terbaik terhadap kesesuaian SNI yaitu pengguna besar, pemasok, pengguna kecil, dan pengguna lainnya (bukan dari ketiga tingkatan tersebut), The aim of the research is to analyze differences in the nutrient quality of rice bran in the rainy and dry seasons at all user levels in West Java Province for the 2016–2020 period compared to SNI 3178 in 2013. Secondary data was used from 292 samples from two laboratories: Feed Quality and Certification (BPMSP) Bekasi and Feed/Feed Ingredient Quality and Safety Testing Center (BPMKP/BP) Cikole, Lembang, West Java. In this study, frequency distribution was used to provide a simple description of the collected data, while percentages were used to display the rice bran users test data compared to rice bran suitability according to SNI 3178 of 2013. The results showed that the suitability of rice bran nutrients for SNI in the dry season was better compared to the rainy season. At the rice bran user level, the best percentage of SNI conformity is among large users, suppliers, small users, and other users (not from these three levels)
Keyword: rice bran, rice bran quality, rice bran SNI 2013

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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