Abstract: This study aims to determine the in-vehicle and outdoor fine particle (PM2.5) concentration and particle number concentration (PNC) for six size ranges (0.3-0.5 μm, >0.5-1.0 μm, >1.0-3.0 μm, >3.0-5.0 μm, >5.0-10 μm, and >10 μm). The measurement campaign was conducted in the morning and evening onboard the Metrobus, red-bus and outdoors. PM2.5 concentration in the Metrobus and red bus were observed as 58.8±10.2 μg/m3 and 76.2±30.9 μg/m3 respectively, and the outdoor value was about 2 times more. For both types of public transportation, the ratio of the amount of internal environment PM and the amount of external environment PM displayed a high level of correlation (redbus/ outdoors, R=0.97; Metrobus/outdoors, R=0.88) with the PM size. The number of commuters, vehicle ventilation type and outdoor air entering the vehicles probably caused the differences in in-vehicle particle concentrations.

• Publication Date: 11-Dec-2015
• DOI: 10.15224/978-1-63248-078-1-90
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Abstract: Curing conditions as well as type and content of silica in raw mixture seem to be very important in both producing quality as well as stability of red-mud-based geopolymers. The influence of amorphous SiO2 along with the other components of raw mixture was studied in this paper. The presence of amorphous silica turned to be a very important factor influencing the strength of red-mud-based geopolymers. The results confirm that the compressive strength of geopolymers increases (up to 41MPa) with the presence of amorphous silica in raw mixture up to the certain point (50 wt %). Excessive content of amorphous silica causes sharp decrease in strength. Microstructure analysis confirms the existence of homogenous structure. The presence of gluing geopolymer phase is also detectable by various techniques.

• Publication Date: 11-Dec-2015
• DOI: 20151223_062136
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