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: Peroksidasi Lipid pada Tikus Hiperkolesterolemia selama Pemberian Ekstrak Kulit Batang Mahoni (Swietenia macrophylla)
Abstrak: Mahogany’s bark is known as wood industrial waste that contains potential secondary metabolites. However, its potency as an antioxidant, especially in rats which are subjected to hypercholesterolemic treatment, has not been carried out. The aim of this study was to test the effect of mahogany’s water extract consumption on the concentration of lipid peroxides in hypercholesterolemic rats. Thirty five male rats were divided into 5 groups (n=7) namely normal group fed with standard rat chow, hypercholesterolemic group (HK) fed with cholesterol chow (1,5%) and PTU (0,5 mg/KgBW), lovastatin group (HK+lovastatin 0,2857 mg/KgBW), E1 group (HK+ mahogany’s extract 4,2 mg/KgBW), and E2 group (HK+mahogany’s extract 21 mg/KgBW). Experiments were carried out for 8 consecutive weeks. The concentration of lipid peroxides in blood were measured with thiobarbituric acid assay at week 0, 2, 4, 6, and 8 using spectrophotometer. Cholesterol chow (0.86%) and PTU increased the lipid peroxides concentration of HK group by 20.92% compared to the normal group (3.380±0.436 nmol/mL). However, it is not statistically significant (p=0.239). The lipid peroxides concentration in E1 and E2 weren’t increased and relatively similar to normal group at concentration of 2.353±0.196 nmol/mL, 2.786±0.256 nmol/mL, and 2.673±0.279 nmol/mL, respectively. Although it is not statistically significant, both doses of extracts tend to prevent the lipid peroxidation in the rat’s blood.
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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