Judul: Phenolic total and Antioxidant Activity of 20 Genotype Temu Ireng in the Second Growing Season
Abstrak: Temu ireng (Curcuma aeruginosa Roxb) merupakan tanaman obat yang termasuk dalam famili Zingibaracae. Varietas unggul temu ireng harus stabil dan dapat tumbuh di berbagai kondisi lingkungan. Penelitian ini bertujuan untuk mengevaluasi total fenolik dan aktivitas antioksidan melalui interaksi antara genotipe dan lingkungan (GEI) dari 20 genotipe ekstrak etanol rimpang temu ireng yang ditanam pada musim tanam kedua dan tumbuh di tiga lingkungan agroekologi yang berbeda. Pengujian total fenolik menggunakan metode Folin Ciocalteu. Genotipe yang stabil pada pengujian total fenolik adalah G1, G2, G3, G4, G6, G12, G13, dan G16. Pengujian aktivitas antioksidan menggunakan metode DPPH. Genotipe yang stabil aktivitas antioksidannya adalah G1, G5, G6, G13, G16, dan G17. Genotipe unggul yang stabil di ketiga lokasi pada kedua parameter adalah G1, G6, G13, dan G16., Temu ireng (Curcuma aeruginosa RoxB) is a medicinal plant that belongs to the Zingibaracae family. Superior varieties of temu ireng should be stable and can be grown in various environmental conditions. This research was conducted to evaluate the total phenolic and antioxidant activity through Genotype by Environment Interaction (GEI) of 20 genotypes of ethanol extract temu ireng rhizomes that grown in the second growing season and grown in three different agro-ecological environments. Total phenolic was tested using the Folin-Ciocalteu method. The stable genotypes of total phenolic are G1, G2, G3, G4, G6, G12, G13, and G16. Antioxidant activity was tested using the DPPH method. The stable genotypes of antioxidant activity are G1, G5, G6, G13, G16, and G17. The stable superior genotypes in all three locations on both parameters are G1, G6, G13, and G16.
Keyword: DPPH, Stabilitas genotipe, Temu Ireng, Total Fenolik

Judul: Kandungan Flavonoid dan Aktivitas Antioksidan 20 Genotipe Rimpang Temu Ireng pada Musim Tanam Kedua
Abstrak: Temu ireng (Curcuma aeruginosa Roxb.) merupakan salah satu jenis tanaman golongan temu-temuan (Zingiberaceae) yang mengandung metabolit sekunder seperti flavonoid. Rendahnya produksi temu ireng disebabkan karena belum tersedianya varietas unggul dari temu ireng. Penelitian ini bertujuan menentukan genotipe terbaik dari total flavonoid dan aktivitas antioksidan yang dilihat dari segi stabilitas dan daya adaptasi dari 20 genotipe temu ireng yang ditanam pada tiga lokasi yang berbeda yaitu di Bogor, Sukabumi dan Cianjur. Tahapan penelitian meliputi pengujian kadar flavonoid dan aktivitas antioksidan metode FRAP serta daya adaptasi genotipe temulawak pada penanaman multilokasi dengan metode AMMI (Additive Main Effect and Multiplicative Interaction). Produktivitas kadar total flavonoid tertinggi dihasilkan sebesar 1.8980 mg QUE/g bobot kering di lokasi Bogor dan genotipe G4 sebesar 1.6170 mg QUE/g bobot kering. Nilai aktivitas antioksidan tertinggi dihasilkan di lokasi Bogor sebesar 18.5959 µmol TE/g bobot kering, dan genotipe G1 sebesar 30.6045 µmol TE/g bobot kering. Keragaman genotipe berpengaruh nyata terhadap kadar total flavonoid, akan tetapi tidak berpengaruh nyata pada aktivitas antioksidan. Interaksi lokasi dan genotipe tidak berpengaruh nyata terhadap kedua parameter uji. Genotipe yang stabil pada ketiga lokasi (Bogor, Cianjur, Sukabumi) adalah G5, G7, G8, G9, G17, G18 untuk kadar flavonoid, serta G1, G3, G4, G5, G7, G8, G10, G18, dan G20 untuk aktivitas antioksidan. Kata kunci: temu ireng, genotipe, flavonoid, antioksidan, stabilitas, Temu ireng (Curcuma aeruginosa Roxb.) is a type of plant that belongs to the group of plants belonging to the curvature family (Zingiberaceae) which contains secondary metabolites such as flavonoids. The low production of temu ireng is due to the unavailability of superior varieties of temu ireng. This study aims to determine the best genotype of total flavonoid and antioxidant activity in terms of stability and adaptability of 20 genotypes of temu ireng grown in three different locations, namely in Bogor, Sukabumi and Cianjur. The research stages included testing the levels of flavonoids and antioxidant activity using the FRAP method as well as the adaptability of the temulawak genotype in multilocation planting using the AMMI method. The highest productivity of total flavonoid content was 1.8980 mg QUE/g dry weight at the Bogor location and the G4 genotype was 1.6170 mg QUE/g dry weight. The highest antioxidant activity value was obtained at the Bogor location of 18.5959 mol TE/g dry weight, and the G1 genotype was 30.6045 mol TE/g dry weight. Genotype diversity had a significant effect on total flavonoid levels, but had no significant effect on antioxidant activity. The interaction of location and genotype did not significantly affect the two test parameters. Stable genotypes at the three locations (Bogor, Cianjur, Sukabumi) were G5, G7, G8, G9, G17, G18 for flavonoid content, and G1, G3, G4, G5, G7, G8, G10, G18, and G20 for activity antioxidants. Keywords: Curcuma aeruginosa, genotype, flavonoids, antioxidant, stability
Keyword: temu ireng, genotipe, flavonoid, antioksidan, stabilitas

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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