Judul: Unjuk Kerja Lysimeter Otomatis dengan Bantuan Tipping Bucket
Abstrak: Evapotranspiration can be measured using lysimeter. The purpose of this study was to test lysimeter design with tipping bucket flowmeter. Lysimeter are tested with size of 2600 cm2 and 5200 cm2. Measurement of evapotranspiration made with closed water balance on the lysimeter. Lysimeter automatically record the drainage water from the tipping bucket signal. Measurement result of the lysimeter indicating similar with evaporation on class A pan evaporimeter. Lysimeter automatically can provide information on the character of soil infiltration and character of rate drainage lysimeter during rain. Lysimeter automatically with size of 2600 cm2 and 5200 cm2 having character the same performance to measure potential evapotranspiration which the design is recommended for use with the lysimeter size of 2600 cm2.
Keyword: tipping bucket, potential evapotranspiration, automatic lysimeter

Judul: Pengembangan Lysimeter Elektronik
Abstrak: Evapotranspirasi potensial (ETp) merupakan laju kehilangan air maksimum pada tanaman yang disebabkan oleh kondisi atmosfer. Nilai ETp dapat diketahui secara langsung menggunakan lysimeter. Pembuatan dan pengujian lysimeter elektronik portable beresolusi tinggi dengan luas penampang berukuran 1012 cm2 dan kedalaman 7.5 cm serta sistem pengairan kontinu yang tertutup. Selisih jumlah air pada input dan output counter adalah kehilangan air pada lysimeter. Pengujian lysimeter yang digunakan untuk mengukur ETp dalam satu hari adalah 0.95 mm dengan nilai maksimum sebesar 0.15 mm/jam pada siang hari dan ETp yang terukur pada malam hari berkisar antara 0 sampai 0.03 mm/hour.
Keyword: Evapotranspirasi potensial, Kapasitas lapang, Lysimeter portable

Judul: Peptides Hydrolysate Derived from Collagen of Snakehead Murrel (Channa striata) Skin Demonstrate Anti-oxidant and Anti-cholesterol Activities.
Abstrak: Anti-cholesterol and anti-oxidant play crucial role to combat cardiovascular disease (CVD) related to formation of arterial plagues from oxidation of cholesterol. In the past decades, research on bioactive peptides demonstrating anti-cholesterol and anti-oxidant activities have been reported as the alternative drugs. In this study, acid soluble collagen was extracted from the skin of snakehead murrel and employed to induce production of collagenase by Bacillus licheniformis F11.4. The collagenases secreted were in turn purified through AKTA Purifier (ion exchange, DEAE column) and used to produce peptides hydrolysate. The purified enzymes were grouped in two distinct collagenase fractions, designated as fraction D and F. Peptides hydrolysate produced by the fraction D was found to demonstrate HMG-CoA inhibitor activity comparable to pravastatin and limited anti-oxidant activity. Meanwhile, peptides hydrolysate generated using the fraction F demonstrated anti-oxidant activity comparable to BHT (2mM), vitamin C (2mM) and vitamin E (2mM), but limited HMG-CoA activity. Combination of the fraction D and F resulted in substantial HMG-CoA inhibition and anti-oxidant activities.
Keyword: Anti-cholesterol, anti-oxidant, bioactive peptide, collagen, collagenase, snakehead murrel