Alkyl polycyclic aromatic hydrocarbons (APAHs) are more toxic and persistent than their parent compounds. Here, the concentrations, composition profiles, and spatial distribution of polycyclic aromatic compounds (PACs) in 127 topsoil samples from Huaibei coalfield were analyzed. The PAC concentrations in different functional areas were significantly different: mining area > industrial area > residential area > agricultural area. APAHs were the major contributors to PACs, accounting for 71–83% of total PACs. Alkylnaphthalenes and alkylphenanthrenes were the primary APAH components, accounting for 83–87% of APAHs. Principal component analysis showed that petrogenic source, coal and biomass combustion, and vehicle emissions were the primary sources of PACs. By comparing the fingerprint information of soil, coal, and coal gangue, it was hypothesized that the petrogenic source of PAC pollution in typical mining areas and surrounding areas are coal particle scattering and coal gangue weathering. Some coal mining and industrial areas potentially pose risks to children, whereas others do not. There are limited evaluation criteria for alkyl PAHs; hence, the estimated risk is likely lower than the actual risk. In addition to the conventional 16 PAHs, it is critical to consider a broader range of PACs, especially APAHs.
At present, in the domestic condom manufacturing industry, the method of the pin hole detection of the condom is the electric test, and because of the uncertainty of the attitude before the electric test of the condom, the automatic electric test can not be carried out. In order to solve the attitude and order of the condom, the automatic electric test is realized. In this paper, a transfer system based on the Mitsubishi PLC controller is put forward based on the physical property of the condom, and the mutual action of the various sensors and the air cylinder is used to achieve the aim of the research. The delivery system solves the problem of disorder and overlap of condoms, realizes automatic detection, reduces labor cost, and provides an effective system for the transportation of flexible materials.
The Jartai Pass site is a Late Bronze Age (3600–3000cal. a B.P.) settlement site in Nilka County, Xinjiang, China, containing the world’s earliest coal-burning remains including coal and ash. To investigate possible sources of coal used at the Jartai Pass site, extractable polycyclic aromatic hydrocarbons (PAHs) of the coal remains and coals around the site were analyzed. The concentrations of total PAHs (∑PAHs), 16 US Environmental Protection Agency prioritized PAHs (∑16PAHs), and alkylated PAHs (∑aPAHs) in 14 coal remains samples ranged from 1680–8579, 1090–4193, and 180–4066 ng/g, respectively. Four samples had higher PAH concentrations than the other 10 samples and were dominated by parent 4–6-ring PAHs and alkylated 2–3-ring PAHs. The other 10 samples were dominated by parent 2–3-ring PAHs, indicating different sources for the coal remains at the site. Total PAH concentrations in six coal samples around the site ranged from 2858–21582 ng/g. Three raw coal samples from mines were dominated by parent 2–3-ring PAHs, and the other three outcrop coals were dominated by parent 4–6-ring PAHs and alkylated 2–3-ring PAHs, revealing a significant difference in the PAH composition between raw coal and weathered outcrop coal. Based on the regional coalfield geology and development history of coal utilization in China, we suggest that the coals used at Jartai Pass site were from outcrop coal seams. The four high-PAH coal remains might have been from the coal line on the bank of the Kashgar River. Considering the amount used at the site over a long period, we speculate that the remaining coal may have been from the subsurface layer of the outcrop coal seam, indicating variation in mining depth. This study provides a basis for understanding coal remains unearthed at an archeological site in northwestern China and early coal utilization by humans.
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