Effect of Washing Treatment on the Morphology of Vertically Aligned ZnO Nanorods

Vertically oriented ZnO nanorods were synthesized in a two steps technique involving the preparation of ZnO seed layer and the growth of ZnO nanorod on the glass substrate. ZnO seed layer was firstly deposited on the glass substrate by dip coating method, while well aligned ZnO nanorod were grown on seed layer coated substrate by hydrothermal method at 110 oC for 20 min. Crystalline structure, morphologies and band gap energy of the as-prepared ZnO nanorod were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and specular reflectance UV-Visible spectrophotometer, respectively. The XRD results showed that ZnO nanorods were wurtzite-structured with preferential orientation along (002) plane. It is shown that washing treatment on the as-prepared ZnO films provides a facile way to eliminate randomly oriented ZnO nanorods and results in vertically oriented nanorods on the glass substrate. Its textural coefficient is almost two times higher than ZnO nanorods previously reported

The Effect of Additives and Reductors in Selective Reduction Process of Laterite Nickel Ore

THE EFFECT OF ADDITIVES AND REDUCTORS IN SELECTIVE REDUCTION PROCESS OF LATERITE NICKEL ORE. Selective reduction of laterite nickel ore followed by magnetic separation was carried out to produce ferronickel products. The effect of adding additives and reductor types in the selective reduction process was studied in this study. Reductors used were anthracite coal and palm shell charcoal with variations of 5 to 15% by weight, while the additive used was sodium sulfate (Na2SO4). The reduction process was carried out at temperatures of 950 ºC, 1050 ºC and 1150 ºC for 60 minutes. The addition of 10% sodium sulfate additives by weight in the reduction process of laterite nickel ore produced higher concentrations of nickel as 6.09%, compared to no additives, i.e. 2.45%. The addition of reductors in the selective reduction process of laterite nickel ore shows that the higher the amount of reductors causes a decrease in the concentrate level of nickel. Furhtermore, the type of reductors used shows that the concentrate from the reduction result using anthracite coal reductor produces higher level of nickel and lower level of iron compared to the use of palm shell charcoal reductor

Efek Pengeringan pada Bagian Buah Labu Kuning (Cucurbita Moschata) terhadap Aktivitas Antioksidan, Sifat Kimia dan Struktur Morfologi

Labu kuning (C. moschata) merupakan salah satu tanaman yang banyak terdapat di Indonesia. Penelitian ini bertujuan untuk mempelajari aktivitas antioksidan, struktur morfologi, sifat kimia dan fisikokimia dari tiga komponen tepung yakni kulit, biji dan daging buah dari labu kuning. Ekstrak biji, kulit dan daging buah labu kuning diperoleh dengan maserasi menggunakan pelarut etanol. Dua metode pengeringan yang digunakan yakni pengeringan dengan sinar matahari dan oven pada suhu 50oC. Hasil uji aktivitas antioksidan dengan metode DPPH (2,2-diphenyl-1-picrylhydrazyl) menunjukkan bahwa biji labu kuning dengan metode pengeringan oven, memiliki aktivitas antioksidan yang paling tinggi, yakni memiliki aktivitas penangkapan radikal bebas sebesar 22,6% pada konsentrasi ekstrak 400 ppm, diikuti oleh kulit dan daging buah labu kuning masing-masing sebesar 16,7 dan 14,2%. Tepung kulit, biji dan daging buah labu kuning juga sudah dilakukan karakterisasi menggunakan SEM (Scanning Electron Microscopy) untuk mengetahui struktur morfologi permukaan, FTIR (Fourier Transform Infrared Spectroscopy) untuk mengetahui gugus fungsional senyawa dari labu kuning, XRD (X-ray diffraction) dan Uji Warna. Hasil analisis proksimat menunjukkan bahwa kandungan protein dan lemak dari biji labu kuning dengan metode pengeringan oven memiliki kandungan paling tinggi yakni sebesar 33,5% dan 33,3% sedangkan kandungan karbohidrat tertinggi dimiliki oleh daging buah labu kuning dengan pengeringan oven sebesar 75,3%. Hasil yang diperoleh menunjukkan bahwa perbedaan metode pengeringan menghasilkan karakteristik yang berbeda dari tepung labu kunin