According to the research from FM Global (Factory Mutual Insurance Company), most of the incidents that have occurred in semiconductor plants in the past two decades were reported as “Fire Cases”. They claim that the fires in wet chemical cleaning processes were mainly caused by heater failure. However, depending on the process conditions, electrical heaters are designed to turn off automatically when the temperature reaches a set point. Therefore, a thorough study of the situations related to possible fires in wet chemical cleaning processes is necessary.
This study focused on the incompatible behaviors of cleaning materials used in the wet bench stage. These results can be applied to determine the causes of fires in the wet bench stage from using reactive chemicals for cleaning purposes.
Another purpose of this study was to investigate the potential hazards of widely used chemicals (hydrogen peroxide, concentrated sulfuric acid, hydrochloric acid and isopropyl alcohol) within similar processes in semiconductor plants. Experimental data were also verified in order to establish a concentration triangular diagram, which could be used to identify a combustion, deflagration or even detonation zone. Finally, this study can provide basic design data for an inherently safer process to avoid potential hazards caused by dangerous mixtures, which may result in large property loss in semiconductor plants. 相似文献
Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons (PAHs) is crucial to developing strategies for PAHs bioremediation. In this study, the linkage between the type of PAHs and microbial community structure was fully investigated through 16S rRNA gene sequencing on four PAH-degrading cultures. Putative degradation products were also detected. Our results indicated that naphthalene (Nap)/2-methylnaphthalene (2-Nap), phenanthrene (Phe) and anthracene (Ant) sculpted different microbial communities. Among them, Nap and 2-Nap selected for similar degrading bacteria (i.e., Alicycliphilus and Thauera) and methanogens (Methanomethylovorans and Methanobacterium). Nap and 2-Nap were probably activated via carboxylation, producing 2-naphthoic acid. In contrast, Phe and Ant shaped different bacterial and archaeal communities, with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader. Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture, respectively. These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment. 相似文献
Negative events within and outside of work can disrupt coworkers' relationships, triggering a re-evaluation of relationship quality. The subjective experience of these events – which we term relationship threats – harms relationships, resulting in long-lasting negative interpersonal and organizational consequences. Coworkers' responses to a relationship threat determine whether relationships are repaired or whether the threat leads to a loss of commitment, lowered satisfaction, and increased negative affect. Because of the critical role that relationships play in organizational life, it is vital that we have a comprehensive understanding of the repair process. To date, researchers have focused on one of three repair processes: trust repair. In reconceptualizing relationship repair, we flesh out the remaining two processes: relationship work and sensemaking. Our reconceptualization balances the restorative actions that mitigate in-the-moment harm with those that sustain these benefits over time. We expand our understanding of relationship repair by highlighting the role that narrative foundations play in determining a relationships' vulnerabilities and determining effective repair processes. We highlight the importance of considering relationship threats as events embedded within a relationship's history; identify narrative foundations as a bridging mechanism between disrupted relationships and their repair; and expand our conceptualization of the processes that repair relationships. 相似文献