Judul: Analisis sifat fisikokimia dan sifat fungsional beras (Oryza sativa) Varietas Beras Hitam dan Beras Merah asal Cianjur, Solok, dan Tangerang
Abstrak: Black rice and red rice are claimed to be safely consumed by the diabetic patients and known to have high antioxidant content. Rice which is grown in different area may have different physical and chemical properties, thus it may also affect the rice functional properties. The purposes of this study were to determine the physical properties (hardness, color and gelatinization profile), chemical properties (proximate composition, total phenolic content, total flavonoid content and digestibility of starch) and the functional properties (antioxidant activity) of the black rice and red rice from Cianjur, Solok and Tangerang and also to observe the effect of cooking on the reduction of total phenolic content, flavonoids and antioxidant activity. In vitro analysis of starch digestibility with α-amylase showed that the starch digestibility of rice which had anthocyanin pigments (black and red varieties) ranged from 56.10-83.43%, smaller than white rice which was 87.35%. In addition, the result also showed that the total phenolic content, flavonoid and antioxidant activity in black, red and white rice were decreasing after cooking process. Black rice and red rice from Solok and Cianjur had the better chemical content and functional properties than the Tangerang one.
Keyword: Bogor Agricultural University (IPB), total flavonoid content, total phenolic content, red rice, black rice, Antioxidant activity

Judul: Karakterisasi Aksesi Padi Beras Merah dan Hitam (Oryza sativa L.)
Abstrak: Red rice and black rice has more advantage than white rice, including higher nutrient content than white rice. Red and black rice has anthocyanin, a substance causing the colors on the rice pericarp. Most of the red rice and black rice that has been cultivated are landrace cultivars. The local varieties can be one source of characters for plant breeding. Characterization was done to find out the potential characters that contained in the landraces. Plant material used were local rice accessions 22 red and black rice varieties with Aek Sibundong as check. The research results showed that local red and black rice accessions gave very significant effect on the observed variables . Accessions that has the potential to be developed are Sidrap (G7), Malang (G9), Pasaman (G13), Temanggung (G21), Purworedjo (G23), Mesuji (G25), Garut (G26), Meulaboh (G27), and Nisam (G34). They achieved productivity more than 4 ton.ha-1.
Keyword: red rice, landrace cultivar, characterization, accession

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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