Papers by Keyword: Carbon Ratio

Abstract: The production of xylanase by Aspergillus niger ATCC 16404 via solid state fermentation (SSF) system using oil palm leaves (OPL) as substrate was investigated. Fermentation parameters studied using one factor at a time (OFAT) technique, were carbon-nitrogen (C/N) ratio, mineral solution size and inoculums size. It was found that the optimum C/N ratio was at 0.4 with xylanase activity at 16.046 U/min. Meanwhile, the optimum size for both mineral solution size and inoculum size were at 1 ml with the xylanase activity recorded at 14.500 U/min and 19.057 U/min respectively. This shows that that the utilization of OPL as substrates in xylanase production using Aspergillus niger ATCC 16404 was a successful.

Abstract: Many parameters are involved in reduction process but carbon availability, process temperature and process time hold the role. This research conducted to find the relation effects of three main factors mention previously. This research used lateritic rocks from Sebuku Island as the iron source and coal as carbon source. Particle size with the highest Fe content is used for reduction process. Variations in reduction process made in mass ratio, process temperature, and process time. The mass ratios are 1:4 and 1:5. The process temperatures are 900^OC and 1000^OC. Process times are 10, 20, and 30 minutes. Characterization process used XRD and XRF. The results show that carbon availability is important and combinations of higher carbon supplies and process temperature are able to prevent further oxidation.

Abstract: Limitation of iron ore reserve having high quality ore and of energy has enhanced development in iron and steel producing technology and method. The ITmk3 process is one of iron making technology that can cope with the problems. It uses composite pellet as feeding material. In this process the ratio between iron and carbon are very important. Carbon holds an important role in the reduction process of iron. The transformation from iron oxides to iron metal will complete if composite pellet contains enough carbon. This paper discusses the influence of carbon ratio in iron reduction process. Nickel saprolite and coal are used as iron and carbon source. They are grinded, crushed, sieved, mixed and formed in cylinders. The weight ratios of ores to coal are 1:1 and 2:1. The reduction held in a furnace at 1100^OC for 60 minutes and 1250^OC for 120 minutes. The results show that the reduction could not complete. Weak peak of FeNi is due to reduction process do not immediately follow the dehydroxylation process.

Abstract: Carbon nanotubes (CNTs) were functionalized using a simple method of heat treatment under oxygen atmosphere followed by an immersion in a tin nitrate aqueous solution. And well-dispersed SnOx nanodots were decorated on the surface of CNTs. X-ray photoelectron spectroscopy (XPS) analysis showed that the O/C ratio increases with oxygen-treated time. The distribution of carbon-containing functional groups on the CNTs surface, i.e., C−C, C−O, C=O, O−C=O, and π−π* shake up bonds can be identified and deconvoluted by a symmetrical Gauss function. The contact angle of H2O and CNTs is dependent on O/C ration. The relationships between the fraction of carbon-containing functional groups and various oxygen treatment times are also discussed.