Judul: Desain Jaringan Irigasi Tetes Pada Lahan Terbuka
Abstrak: Lahan pertanian Food Estate Humbang Hasundutan Sumatera Utara memiliki topografi yang bergelombang sehingga dalam mendesain jaringan irigasi harus mempertimbangkan kondisi tersebut untuk memperoleh efisiensi irigasi yang tinggi. Penelitian ini bertujuan untuk menganalisis kebutuhan air irigasi, mendesain layout dan dimensi jaringan perpipaan subunit irigasi tetes, mendesain layout dan dimensi jaringan perpipaan submain, menghitung kebutuhan panjang pipa manifold dan pipa submain, serta menghitung biaya jaringan perpipaan. Kebutuhan air irigasi sebesar 4,23 mm/hari pada bulan Agustus dan 2,65 mm/hari pada bulan September. Layout jaringan perpipaan sub-unit terdiri dari pipa manifold yang didesain searah lereng, sedangkan pipa lateral searah dengan kontur. Pipa manifold direncanakan dengan pipa PVC berdiameter 63mm. Pipa submain didesain agar 1 pipa submain melayani 1 subunit dengan dimensi pipa submain 63mm berbahan HDPE. Pipa submain yang diperlukan sepanjang 1792 meter sedangkan pipa manifold sepanjang 735 meter. Total biaya jaringan perpipaan skenario 1 (dengan watermeter) sebesar Rp. 256.070.170,- atau setara dengan Rp. 64,017,542.50,-/Ha. Total biaya bahan jaringan perpipaan skenario-2 (tanpa water meter sebesar) Rp. 221.870.120,- atau setara dengan Rp. 55,467,542.50,-/Ha. Sebelum melakukan konstruksi perlu dilakukan pemetaan dan penataan lahan, verifikasi jalur pipa, serta perencanaan operasi yang baik.
Keyword: Drip irrigation design, drip irrigation costs, subunit design criteria, piping network design layout

Judul: Design of Layout and Dimensions of Submain and Manifold Pipe Network of Drip Irrigation
Abstrak: Kendala utama penerapan irigasi tetes di kawasan Food Estate Humbang Hasundutan adalah kondisi topografi yang bergelombang. Tujuan penelitian ini untuk menganalisis kebutuhan air irigasi, mendesain layout dan dimensi jaringan perpipaan sub-unit irigasi tetes, mendesain layout dan dimensi jaringan perpipaan submain, menghitung panjang pipa manifold dan pipa submain, serta menghitung biaya bahan jaringan perpipaan. Nilai satuan kebutuhan air (SKA) irigasi sebesar 3.79 mm/hari atau setara dengan 0.14 l/det/ha – 0.29 l/det/ha. Desain layout pipa manifold dibuat memotong arah kontur sedangkan pipa lateral searah kontur dengan pipa yang digunakan adalah jenis pipa PVC diameter 2 inci untuk pipa manifold dan pipa LDPE 1/2 inci untuk pipa lateral. Pipa submain digunakan jenis pipa HDPE diameter 2 inci dengan prinsip satu sub-unit dihubungkan dengan satu submain dari riser/outlet tertentu. Total kebutuhan pipa manifold di lima petak lahan sepanjang 637 meter, sedangkan pipa submain sepanjang 989 meter. Biaya bahan jaringan perpipaan irigasi tetes “dengan” water meter sebesar Rp. 46.206.065,-/ha dan “tanpa” water meter sebesar Rp.35.865.929,-/ha., The main obstacle to the application of drip irrigation in the Humbang Hasundutan Food Estate area is the undulating topography. The purpose of this study was to analyze irrigation water requirements, design of layout and dimensions of drip irrigation sub-unit piping network, design of layout and dimensions of sub-main piping network, calculate length of manifold pipe and sub-main pipe, and calculate piping network material costs. The unit value of irrigation water demand (SKA) is 3.79 mm/day or equivalent to 0.14 l/sec/ha – 0.29 l/sec/ha. The layout design of the manifold pipe is made to cut the contour direction while the lateral pipe is in the direction of the contour with the pipe used is a 2 inch diameter PVC pipe for the manifold pipe and 1/2 inch LDPE pipe for the lateral pipe. The submain pipe is a 2 inch diameter HDPE pipe with the principle of one sub-unit connected to one submain from a particular riser/outlet. The total demand for manifold pipes in five plots of land is 637 meters long, while the submain pipe is 989 meters long. The cost of drip irrigation piping network materials "with" a water meter is Rp. 46,206,065,- /ha and “without” water meter is Rp.35,865,929,-/ha.
Keyword: Sub-unit design, drip irrigation, pipe network

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