Penggunaan Ekstrak Antosianin Kol Merah Sebagai Fotosensitizer Pada Sel Surya Tio2 Nanokristal Tersensitisasi Dye

The use of Red Cabbage’s anthocyanine extract as a photosensitizer on a Dye-Sensitized Nanocrystalline TiO2Solar Cell. A solid-state dye-sensitized nanocrystalline TiO2 solar cell utilizing anthocyanin extract form red cabbageas photosensitizer was fabricated. The solar cell was formed in sandwich structure, which two electrodes sandwichingpolymer electrolyte containing a redox couple (I-/I3-). One of the electrodes, namely working electrode, TiO2 layer onTCO (transparent conducting oxide) coated glass substrate was sensitized with anthocyanin dye as electron donor in thesystem. Another electrode was a carbon sheet as a counter electrode. Gel electrolyte based on PEG (polyethyleneglycol) containing a redox couple (I-/I3-) used instead of liquid electrolyte in this photoelectrochemical cell. Twofabricated cells have an active area of 1 cm2 were soaked with anthocyanine dye for 1 hr and 24 hrs, respectively. Thecells were tested by irradiation with halogen lamp of 24 Watt with intensity 4 mW/cm2 at a distance 30 cm. The testingresults of the cells show an ideal I-V characteristic with output parameters: open circuit voltage (VOC) of 500 mV, shortcircuit current (ISC) of 5,6 μA and 7,2 μA for each cells, fill factor (FF) of 48% for both cells, energy conversion (η) of0.023 % and 0,055 % for the cells with 1 hr and 24 hrs dye soaked, respectively

Application of Nanocrystalline Tio2 Particles Synthesized by Sonochemical Methods as Dye Sensitized Solar Cell (Dssc)

Nanocrystalline TiO2 (titania) particles have been synthesized using sonochemical method. Two ultrasonic wave sources with different powers were used, 21 W 55 kHz (low power) and 130 W 20 kHz (high power), resulting in 5 different titania powders with different characteristics. This paper presents the performance of the synthesized titania powders and also of the commercially available titania powder Degusa P25, when applied as dye sensitized solar cell in the same setup as comparison. The best values of open circuit voltage (Voc) and short circuit current density (JSC) for solar cell sample using synthesized powder was 442 mV and 1.40 mA/cm2 respectively, obtained from powders sonicated for 8 hours. This VOC value is near the value of solar cell prepared by comercial titania (450 mV), while the JSC value is bigger compare to that prepared by commercial titania (0.89 mA/cm2). The fill factor of all samples, including the one prepared using Degusa P25, is low which is probably due to low catalytic activity of the carbon-coated counter electrode used

Struktur dan Sifat Optik Film Zno Hasil Deposisi dengan Teknik Spin-coating melalui Proses Sol-gel

STRUKTUR DAN SIFAT OPTIK FILM ZnO HASIL DEPOSISI DENGAN TEKNIK SPIN-COATING MELALUI PROSES SOL-GEL. Film ZnO telah dibuat pada substrat kaca dengan teknik deposisi spin coating melalui proses sol-gel. Pembuatan film ZnO dari prekursor zinc acetate dengan laju putaran 3.000 rpm selama 60 detik di atas pelat spin coater. Film yang diperoleh dikeringkan pada suhu ruang kemudian dilakukan annealing pada suhu 500 oC selama 3 jam. Hasil XRD menunjukkan bahwa film ZnO yang terbentuk adalah polikristal wurtzite heksagonal dengan nilai parameter kisi masing-masing adalah a = 3,290 Å dan c = 5,2531 Å. Ukuran kristal rata-rata ZnO adalah 29,554 nm. Berdasarkan morfologi permukaan hasil foto SEM menunjukkan film ZnO berbentuk lempengan-lempengan (disks) yang tidak seragamdan tidak beraturan. Karakterisasi spektroskopi UV-Vis menghasilkan karakteristik optik film ZnO, yaitu spektrum transmitansi optik dalam rentang panjang gelombang 370 nm sampai dengan 970 nm. Dari data spektrum UV-Vis tersebut ditentukan lebar celah energi ZnO sebesar 3,2 eV

Respons Pertumbuhan Kedelai Terhadap Pemangkasan Dan Pemberian Kompos Tkks Pada Lahan Ternaungi

Response growth of soybean by cutting and giving empty fruit bunches of oil palm compost inshaded area.Using of shaded area for soybean plantation faced trouble such yield decreasing.For that purpose cutting and giving empty fruit bunches of oil palm (EFBOP) compost aimed toincrease growth of soybean in shaded area. This research was conducted at experimental field ofFakultas Pertanian USU in January-April 2013 using factorial randomized block design with twofactor, i.e. time of cutting (no cutting, cutting in V5, cutting in R1) and dose of EFBOP compost(0, 10, 20 and 30 ton per ha). Parameter observed were plant height, summarize of leaf area, stemdiameter, and shoot root ratio. The result showed that cutting significantly decreased plant heightbut increase all parameter observed. Dose of EFBOP compost significantly increased summarize ofleaf area and stem diameter. The interaction of two factor significantly increased summarize of leafarea. The best result were showed by cutting in V5 and giving 30 ton per ha EFBOP compost

Respons Pertumbuhan Dan Produksi Tanaman Selada (Lactuca Sativa L.) Terhadap Pemberian Pupuk Organik Cair Urin Kambing Pada Beberapa Jarak Tanam

This research was carried out on land the area residents,pasar 1 street No.89 Tanjung Sari, Medan at altitude of ± 25 asl from May 2015 through July 2015, using factorial randomized block design with two treatment factors, namely liquid organic fertilizer goat urine with treatments of 0, 200, 400, 600 cc/ L of water and Plant Spacing with treatment 20x20 cm, 25x20 cm and 30x20 cm. Parameters measured were plant height, number of leaves, fresh weight total per sample, selling fresh weight per sample, fresh weight of roots per sample, harvest index and shoot-root ratio.The results showed that the liquid organic fertilizer goat urine application had no significant effect on all parameters. Plant spacing significantly affected parameters plant height, number of leaves, fresh weight total per sample, selling fresh weight per sample, and fresh weight of roots per sample. Interaction of liquid organic fertilizer goat urine and spacing of treatment had no significant effect on all parameters of existing observations

Pengujian Pemberian Fungi Mikoriza Arbuskula Dan Pupuk Fosfat Pada Budidaya Tanaman Sorgum (Sorghum Bicolor (L.) Moench)

The examinating of giving Arbuskula Mycorrhizal Fungi (AMF) and phosphate fertilizer on the cultivation of sorgum (Sorghum bicolor (L.) Moench.). The research aimed at gaining dosage and phosphate fertilizer dosage and interactions of both the better for the growing and production of sorghum (Sorghum bicolor (L) Moench.). This research was conducted in UPT BBI Tanjung Selamat, Sumatera Utara, height of 25 meters above sea level, started on April to July 2012. using a randomized block design with two factors. The first factor is the FMA dosage (0, 5, 10 g / plant). The second factor is the phosphate fertilizer (0, 1, 2, 3, g / plant). The parameters observed are the plant height, the number of leaves, the flowering age, the harvest age, production per sample, production per plot, production per hectare and the degree of root infection. FMA has an obvious influencethe number of leaves ages 3 weeks after planting, the degree of root infection. Phosphate fertilizer has an obvious influence production per sample and production per hectare. Interaction between FMA and phosphate fertilizer has an obvious influence toward the height of plant age 2 and 3 weeks after planting, the number of leaves aged 2 weeks after planting