Judul: Analisis Lipid Peroksida Hati Tikus Hiperkolesterolemia Pasca Terapi Ekstrak Kulit Kayu Mahoni
Abstrak: Mahogany (Swietenia macrophylla King.) bark contains bioactive compounds which are efficacious as antioxidant. Several in vitro studies on antioxidant activity have been carried out previously. However, there is no evidence about the effectiveness of antioxidant activity against lipid peroxidation in liver hypercholesterolemic rat. The aim of this research was to determine the effect of water extract of mahogany bark againist lipid peroxidation by analyzing the lipid peroxide of hypercholesterolemic rats liver. Thirty one male rats were divided into two parts, six were pre-treatment rats and the rest were treatment rats. The latter groups were divided into 5 groups. One normal group fed with standard rat diet and four treatment groups fed with cholesterol diet (1.5%) and propil tiouracil (PTU) (0.5 g/kg bw) during 6 weeks. Positive control group of treatment induced lovastatin (0.2875 mg/kg bw), 1st dose extract (E1) group (150 mg/kg bw), and 2nd dose extract (E2) group (300 mg/kg bw), respectively, during a week. Antioxidant activity of lipid peroxide in the liver were measured with thiobarbituric acid (TBA) assay using spectrophotometer. The diet of hypercholesterolemia 1.5% and PTU as long as 6 weeks increased lipid peroxide concentration of liver pre treatment 141.00%, significantly (p=0.032). Therapy of E1 and E2 tend to decrease lipid peroxide concentration of liver 20.95% and 15.54%. Statistically two doses of the extracts were not significantly different (p> 0.05).
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Judul: Khasiat antioksidasi ekstrak kulit kayu mahoni (Swietenia macrophylla King) terhadap peroksidasi lipid pada hati tikus hiperurisemia
Abstrak: The bark of mahogany (Swietenia macrophylla King) contains bioactive compounds, which has been reported as an antioxidant. But there had been very few in vivo evidence of the antioxidant effectiveness on the liver lipid peroxidation in hyperuricemic rats. This study aimed to test the effect of mahogany (Swietenia macrophylla King) bark extracts against lipid peroxidation in hyperuricemic rat liver. Thirty three rats were divided into 5 groups, namely normal, hyperuricemic (HU), allopurinol (HU I), aqueous extract (HU II) and methanol extract (HU III). Hyperuricemic induction was carried out by giving the juices of chicken liver and sodium carboxyl methyl cellulose 0.5%. The induction was administered orally for 4 weeks with dosage of 25 g/kg BW. Afterwards, rat were administered by aqueous extract and methanol extract at 500 mg/Kg BW day for 7 days. Liver lipid peroxides analysis was determined by using thiobarbituric acid (TBA) method. The results showed that the lipid peroxide concentrations of hyperuriemic, allopurinol and methanol extracts group were 101.51 ± 54.74 nmol/gram, 108.55 ± 45, nmol/g and 101.04 ± 26.68 nmol/gram, respectively. The aqueous extract has the antioxidants effect on rat liver lipid peroxidation with the concentration of 63.57 ± 16.84 nmol/g, smaller than that of the normal group (93.83 ± 29.55 nmol/gram). Statistically, the aqueous extract tend to decrease the liver lipid peroxide concentration of hiperuricemic rat by 32.25% (p = 0.054).
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Judul: Pemanenan Energi Listrik dari Kincir Angin Vertikal
Abstrak: Usaha pemanenan energi angin di Indonesia masih sedikit. Sampai Tahun 2016 hanya 3.54 MW alat pemanenan energi angin yang sudah terpasang. Kendala utamanya ialah dibutuhkan investasi yang besar untuk membuatnya. Pembuatan kincir angin dengan ukuran yang lebih kecil dengan bahan yang dapat dibeli di pasar lokal menjadi solusi agar pembuatan kincir angin lebih ekonomis. Pembuatan kincir vertikal tipe Savonius dapat menjadi solusinya. Kincir vertikal Savonius dapat beroperasi pada kecepatan < 3 m/s dan ketinggian < 50 m. Kincir angin ini terdiri dari tiga sistem, yaitu generator, rotor kincir dan transmisi pulley-belt. Generator dibuat dari modifikasi motor AC dan magnet neodymium. Rotor kincir dibuat dari pipa PVC 4”, pipa alumunium ¾”, dan papan polikarbonat. Transmisi pulley-belt dibuat dari plastik dan karet. Kincir ini membutuhkan gaya minimal 3 N untuk dapat berputar atau torsi minimalnya 0.75 Nm. Kecepatan angin yang dibutuhkan untuk merotasikannya sebesar 1.9 m/s. Daya maksimal yang dapat dihasilkan ialah 5.76 watt berupa tegangan sebesar 36 volt dan arus 160 mA.
Keyword: energi terbarukan, generator, motor AC, sudu Savonius