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: Optimisasi Kondisi Pascapanen Buah Mengkudu (Morinda citrifolia) sebagai Antioksidan
Abstrak: Mengkudu (Morinda citrifolia) merupakan tanaman yang mengandung aktivitas antioksidan dengan kandungan flavonoid dan fenolik pada bagian buah. Tujuan penelitian ini adalah menentukan kondisi pascapanen optimum buah mengkudu sebagai antioksidan menggunakan rancangan faktorial 2×3×2 dalam rancangan acak kelompok. Kondisi yang dioptimumkan adalah kondisi pengirisan, pengeringan, dan penyangraian. Kondisi pascapanen optimum terdapat pada sampel pengirisan dadu besar dengan pengeringan matahari dan sangrai. Hasil uji ANOVA untuk kadar air, rendemen, total fenolik, persen inhibisi menggunakan DPPH, dan kapasitas antioksidan ekuivalen trolox pada buah mengkudu menghasilkan interaksi 3 faktor yang dicoba signifikan (nilai probabilitas < 0.05) pada berbagai parameter uji, sedangkan penentuan total flavonoid hanya memiliki interaksi 2 faktor yang signifikan. Semakin cepat waktu pengeringan dan penyangraian, semakin rendah kadar air tanpa menurunkan aktivitas antioksidan yang terkandung pada buah mengkudu.
Keyword: antioksidan, buah mengkudu, faktorial dalam rancangan acak kelompok, Morinda citrifolia

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: