Judul: Total Phenolic, Flavonoid, and Antioxidant Activity Content of Purslane (Portulaca oleracea L.) Resulting from Streptomycin Mutation
Abstrak: Krokot (Portulaca oleracea L.) merupakan tanaman yang mengandung polifenol, seperti asam fenolik dan flavonoid yang berperan sebagai sumber antioksidan dalam alternatif pengobatan penyakit degeneratif. Penelitian ini bertujuan menentukan konsentrasi dan durasi perendaman streptomycin yang optimum untuk menghasilkan mutan putatif dengan kandungan fitokimia serta aktivitas antioksidan terbaik. Krokot diekstraksi secara basah menggunakan metode MAE dengan pelarut etanol 96%. Uji kadar total fenolik dan flavonoid ditentukan menggunakan metode Folin-Ciocalteu dan AlCl3 serta aktivitas antioksidan menggunakan metode DPPH juga FRAP. Kadar total fenolik dan aktivitas antioksidan DPPH tertinggi terdapat pada sampel A1B1 dan A2B2 (0,4507 ± 0,0115 mg GAE g¯? bb dan 0,0062 ± 0,0002 µmol TE g¯? bb) dengan peningkatan sebesar 3,59 kali dan 1,41 kali dibandingkan kontrol. Kadar total flavonoid dan aktivitas antioksidan FRAP tertinggi terdapat pada sampel A1B4 (2,3383 ± 0,0493 mg QE g¯? bb dan 5,5622 ± 0,0909 µmol TE g¯? bb) dengan peningkatan 4,4 kali dan 5,42 kali dibandingkan kontrol. Hasil karakteristik stomata dengan analisis dendogram menunjukkan bahwa A1B4 terbukti mengalami mutasi ditandai fenomena kimera., Purslane (Portulaca oleracea L.) contains polyphenols like phenolic acids and flavonoids, serving as antioxidants for treating degenerative diseases. This study aimed to determine the optimal concentration and duration of streptomycin soaking to produce mutants with the best phytochemical content and antioxidant activity. Wet extraction was performed using the MAE method with 96% ethanol. Total phenolic and flavonoid contents were measured using the Folin-Ciocalteu and AlCl3 methods, and antioxidant activity using DPPH and FRAP methods. The highest phenolic content and DPPH activity were in samples A1B1 and A2B2 (0,4507 ± 0,0115 mg GAE g¯? bb and 0,0062 ± 0,0002 µmol TE g¯? bb), showing increases of 3,59 and 1,41 times compared to the control. The highest flavonoid content and FRAP activity were in sample A1B4 (2,3383 ± 0,0493 mg QE g¯? bb and 5,5622 ± 0,0909 µmol TE g¯? bb), with increases of 4,4 and 5,42 times compared to the control. The dendrogram analysis of stomatal characteristics indicates that A1B4 has undergone mutation, as evidenced by the presence of chimera phenomena.
Keyword: antioxidant, flavonoid, phenolic, chimera, mutation, streptomycin

Judul: Content of Total Flavonoids, Phenolics, and Antioxidant Activity of Purslane (Portulaca grandiflora Hook.) Result of the Colchicine Mutation
Abstrak: Kandungan total flavonoid, fenolik dan aktivitas antioksidan pada tanaman krokot (Portulaca grandiflora Hook.) hasil mutasi dengan kolcisin belum diketahui. Penelitian bertujuan mengetahui konsentrasi kolcisin yang menyebabkan peningkatan kandungan total flavonoid dan fenolik yang terbaik sehingga meningkatkan aktivitas antioksidannya pada tanaman krokot. Krokot diekstraksi dengan metode Microwave Assisted Extraction dan pelarut metanol 96%. Kadar total fenolik dihitung dengan metode Folin-Ciocalteu, kadar total flavonoid dengan metode AlCl3, serta aktivitas antioksidan dengan metode DPPH dan FRAP. Kadar total fenolik dan aktivitas antioksidan DPPH tertinggi terdapat pada sampel K2G3 (0,789 ± 0,026 mg GAE g-1 bobot basah dan 0,964 ± 0,011 µmol TE g-1 bobot basah). Kadar total flavonoid dan aktivitas antioksidan FRAP tertinggi terdapat pada sampel K1G3 (0,477 ± 0,030 mg QE g-1 bobot basah dan 5,776 ± 0,279 µmol TE g-1 bobot basah). Pemberian mutagen kolcisin sebesar 0,05% meningkatkan total flavonoid (46%) dan aktivitas antioksidan FRAP krokot (1,13 kali), sedangkan mutagen kolcisin sebesar 0,1% meningkatkan total fenolik (44%) dan aktivitas antioksidan DPPH krokot (3,56 kali).
Keyword: Antioksidan, Fenolik, Flavonoid, Kolcisin, Mutasi

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.
Keyword: