Judul: Pengaruh Nanokapsulasi Terhadap Aktivitas Antioksidan Ekstrak Mengkudu (Morinda citrifolia)
Abstrak: Research and innovation on mengkudu (Morinda citrifolia) extract is needed to increase the efectivity of it’s function as antioxidant. Therefore, mengkudu extract nanocapsule technology was researched for development of mengkudu as antioxidant source. The purpose of this research was to analyzed the influence of mengkudu extract nanocapsulation process to their antioxidant activity with chitosan as the coating agent. Mengkudu extract nanocapsule was made by ionic gelation method. Mengkudu extract nanocapsules were in amorphic phase and the in the size range of 89.15-9774.96 nm for water extraction and 48.99-192.03 nm for ethanol extraction. However, nanocapsulation gave a controlled release effect.
Keyword: antioxidant., nanocapsule, Mengkudu

Judul: Antiproliferasi sel kanker dan karakterisasi nanokapsul ekstrak mengkudu (morinda citrifolia l)
Abstrak: Badan Kesehatan Dunia (WHO) tahun 2008 menyatakan bahwa sebanyak 7.6 juta orang meninggal akibat kanker. Mengkudu merupakan salah satu tumbuhan herbal yang banyak dijumpai yang bisa mengobati kanker akan tetapi pemanfaatannya belum efisien. Nanokapsulasi dari kitosan merupakan salah satu alternatif peningkatkan efisiensi pemanfaatan ekstrak mengkudu. Ekstrak mengkudu didapat dengan metode maserasi dengan pelarut air. Nanokapsulasi ekstrak mengkudu dibuat dengan metode gelasi ionik menggunakan magnetic stirrer (pengaduk magnetik) dengan kecepatan 1500 rpm lalu hasilnya dikarakterisasi dengan Fourier Transform Infrared (FTIR), Particle Size Analyzer (PSA), dan X-ray Difraction (XRD). Hasil yang diperoleh berdasarkan analisis FTIR adalah terdapat gugus kitosan dan ekstrak mengkudu dalam nanokapsul. Hasil uji PSA menunjukkan ukuran nanokapsul sebesar 192.03 nm. Hasil uji XRD menunjukkan bahwa nanokapsul ekstrak mengkudu memiliki kristalinitas 34.83%. Sitotoksitas (uji potensi hayati) nanokapsul adalah 1.843 ppm. Nanokapsul lalu diuji menggunakan enzim pencernaan, hasil yang didapat menunjukkan bahwa nanokapsul terhidrolisis pada menit ke sembilan. Nanokapsul ekstrak mengkudu diuji menggunakan sel kanker paru-paru (A549), didapatkan hasil konsentrasi 0.5 ppm dapat menghambat proliferasi sel kanker secara signifikan sebesar 4.38%.
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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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