Influence of pozzolanic activity of coal gangue on hydration products in coal gangue-cement system
Qualitative and quantitative analysis of the composition in the paste of complex cements have been determined by means of X-ray diffraction (XRD),differential scanning calorimetry (DSC) and directly-heating method. Results show that the composition of hydration products in coal gangue-cement complex system is similar to that in pure cement system, but the content of hydration products for per unit cement in former is higher than that in later at the early hydration stage. The pozzolanic reaction between coal gangue and cement hydration products mainly occurs in 3d. The content of Ca(OH)2 and that of C-S-H in the paste are related to the activity and the content of coal gangue. The content of C-S-H in high activity coal gangue-cement system is related to the activity of coal gangue rather than the content, but that is opposite in low activity one.
On Study of Development Expansive Coal Gangue Portland Cement by Microwave Technology
Added carbon powder or M mineral powder in unburned kaolinite coal gangue, the mixtures could be changed better expansive mineral additive of Portland cement by microwave irradiation. The microwave activation coal gangue mixtures 5%, 10%, 15%, 20%, 25%, 30% and 35% (by weight) were respectively added intoⅠ42.5 Portland cement. The compressive/flexural strength of various expansive coal gangue Portland cements were determined after 3 and 28 day. The fineness, initial and final setting time, soundness and volume expansive ratio was also measured. 　　　The expansive reasons of coal gangue Portland cement were considered that there were lots of thicker and bigger flaky crystal during hydration processes by scanning electron microscope, and found the Al, Si, O and other elements in flaky crystal by Edax. 　　　The expansive mechanism of coal gangue Portland cement is different from traditional expansive cements theories by microwave irradiation.
The Liverpool Cholera Epidemic of 1832 and Anatomical Dissection--Medical Mistrust and Civil Unrest
Asiatic cholera reached Britain for the first time in late 1831, with the main epidemic occurring during 1832. The disease caused profuse diarrhea, severe dehydration, collapse, and often death. There was widespread public fear, and the political and medical response to this new disease was variable and inadequate. In the summer of 1832, a series of "cholera riots" occurred in various towns and cities throughout Britain, frequently directed against the authorities, doctors, or both. The city of Liverpool, in the northwest of England, experienced more riots than elsewhere. Between 29 May and 10 June 1832, eight major street riots occurred, with several other minor disturbances. The object of the crowd's anger was the local medical fraternity. The public perception was that cholera victims were being removed to the hospital to be killed by doctors in order to use them for anatomical dissection. "Bring out the Burkers" was one cry of the Liverpool mobs, referring to the Burke and Hare scandal four years earlier, when two men had murdered people in Edinburgh in order to sell their bodies for dissection to the local anatomy school. This issue was of special concern to the Liverpool citizenry because in 1826, thirty-three bodies had been discovered on the Liverpool docks, about to be shipped to Scotland for dissection. Two years later a local surgeon, William Gill, was tried and found guilty of running an extensive local grave-robbing system to supply corpses for his dissection rooms. The widespread cholera rioting in Liverpool was thus as much related to local anatomical issues as it was to the national epidemic. The riots ended relatively abruptly, largely in response to an appeal by the Roman Catholic clergy read from church pulpits, and also published in the local press. In addition, a respected local doctor, James Collins, published a passionate appeal for calm. The Liverpool Cholera Riots of 1832 demonstrate the complex social responses to epidemic disease, as well as the fragile interface between the public and the medical profession.