Judul: Pengaruh Perebusan terhadap Kandungan Gizi Kerang Pokea (Batissa violacea celebensis Martens 1897) dan Aktivitas Antioksidannya
Abstrak: Pokea mussel is a bivalves Family Corbiculidae from the Pohara River Southeast Sulawesi. Pokea mussel are usually boiled before consumption, and believed to be able to cure various diseases such as jaundice, malaria, asthma, lower blood pressure, and fever. This study aimed to determine the effect of boiling on nutrient content of pokea mussel and their antioxidant activity. Nutrient content were determined in raw and boiled pokea mussel, while the antioxidant activity determined by DPPH method. Relativelly in general boiling did not significantly decrease nutrient contents of pokea mussel, but it did decrease the lipid content of pokea mussel as far as 6.09%; carbohydrate 16.37%; potassium 51.48%, total amino acids especially lysine 38.36%; glycine 48.87%; cysteine 75.15%; serine 26.47%; free amino acids especially lysine 44.87%; valine 90.79%; threonine 92.96%; leucine 83.64%; isoleucine 89.80%; histidine 89.80%; methionine 50%; alanine 83.45%; proline 98.13%; glutamic acid 83.33%; glycine 88.61%; aspartic acid 86%; and taurine 56.92%. Althought the antioxidant activity in crude extract of pokea mussel are still below BHT standard, but the results of toxicity test shows that crude extract of pokea mussel has potential as a cytotoxic compound.
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Judul: Pengaruh Lama Perebusan terhadap Kandungan Gizi dan Komponen Bioaktif Keong Matah merah (Cerithidea obtusa)
Abstrak: Indonesia has a great potential with marine life, matah merah snail is one from many marine life is used to consume. People generally serve matah merah snail using boiling manner. This study aims to determine the effect boiling time on nutrition and bioactive components of matah merah snail. The design of the research is completely randomized design (CRD) with 1 factor and 4 levels, there was fresh (M0), boiling (M1), boil + 10 minutes (M2), boil + 20 minutes (M3) with 2 replications. The test that conducted was proximate test, phytochemical test and BSLT test . Data were analyzed by analysis of variance, if the analysis of variance significant effect on the level of 5%, then the test is continued by real difference test. Based on the results of the statistical analysis of variance factor treatment were not significant effect on moisture, ash and fat. The significant results of statistical analysis on the protein content gained followed by Duncan test, the results are treatment M0 is significantly different to the treatment M1, M2, and M3. Phytochemical test results, the M0 metanol extract compounds contains ninhydrin, flavonoids, alkaloids, tanins and terpenes. Compounds that Contained on M1 and M2 are ninhydrin, flavonoids, alkaloids, tanins and terpenes, while the M3 contains flavonoids, ninhydrin, alkaloids and terpenes. The M0 ethyl acetate extract containing flavonoids and ninhydrin, alkaloids and terpenes weak. M1 contains ninhydrin, polyphenols and terpenes, whereas in M2 and M3 contains ninhydrin, alkaloids and terpenes. Hexan extract M0 contains flavonoids, terpenes, saponins, while the M1, M2 and M3 contains terpenes and saponins. LC50 values in the M0, M1, M2, and M3 metanol extract are 15.58; 22.54; 25.68; 39.8 ppm. Ethyl acetate extract M0, M1, M2, and M3 LC50 values at 40.08; 364.58; 146.12; 130.27 ppm. N-hexane extract M0, M1, M2, and M3 have LC50 values of 1100.43; 352.5; 90.49; 14.95 ppm.
Keyword: bioactive compounds, gastropods, matah merah snails, nutrition

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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