Pretreatment of municipal solid waste incineration fly ash and preparation of solid waste source sulphoaluminate cementitious material.

Municipal solid waste incineration fly ash (MSWI-FA) is a kind of hazardous waste, and it is of great significance to treat it harmlessly and resourcefully. This study proposes the preparation of sulphoaluminate cementitious materials using water-washed MSWI-FA, flue-gas desulfurization gypsum, and aluminum ash. The changes in the composition and morphology of MSWI-FA before and after washing were investigated, and the effects of various washing conditions on the removal rate of chloride salt from MSWI-FA were analyzed. The effect of firing temperature on the mineral content of the sulphoaluminate cementitious material was also investigated. In addition, the strength and heavy metal leaching characteristics of the corresponding materials were tested. The results show that more than 90% of chloride salts were removed by water washing MSWI-FA two times. Using MSWI-FA as the main raw material, the sulphoaluminate cementitious material containing mostly calcium sulphoaluminate and dicalcium silicate could be prepared successfully at 1270 °C; the amount of MSWI-FA in the raw material can be as high as 35% (dry weight). Moreover, the sulphoaluminate cementitious material can effectively solidify heavy metals in the raw materials. The leaching concentrations of eight heavy metal ions, i.e., Cu, Zn, Cd, Pb, Cr, Ni, Ba, and As are far lower than the concentration limits set by national standards.

Event-related brain potentials suggest a late interaction of pitch and time in music perception.

Given the key role of pitch and time in the mental representation of music, the way the two dimensions combine is a crucial question in music cognition. In the present study, using electroencephalography (EEG), we manipulated both musical pitch and time structures and investigated how the two dimensions work together. Musicians were presented with eight-chord sequences, in which the last target chord was harmonically or temporally expected or unexpected based on the preceding contexts. ERP analysis showed that listeners track both dimensions as music unfolds in time. For the time dimension, irregular temporal events induced greater MMN than regular temporal events. For the pitch dimension, harmonically less-related chords revealed greater ERAN and N5 than harmonically related chords. Moreover, there was an interaction between musical pitch and time dimensions in the N5 effect. These results indicate that for music perception, pitch and time dimensions are processed independently at the early stage and interactively at the late stage.