走向工作面贯通上山与支架快速回撤技术

针对走向工作面停采线与上山之间的护巷煤柱造成煤炭损失,支架回撤工艺复杂、巷道掘进量大等问题,提出走向工作面贯通上山与支架快速回撤技术。工作面贯通采区上山,利用上山回撤支架。在贯通前,利用压力拱模型分析剩余煤柱应力变化规律,并结合极限平衡区公式,确定让压煤柱为8 m;对贯通前基本顶合理断裂位置、让压调节机制、末采阶段采高进行了分析确定,并采取上山巷内补强支护及挂绳铺网措施。贯通上山后,首先利用支架对上山留巷,完成留巷后,利用上山回撤支架,先将上部端头3架逆时针旋转90°作为掩护架,在对剩余支架逐架回撤时,3个掩护架呈现台阶型。提出的技术取消了护巷煤柱及回撤通道,提高了煤炭采出率,减少了巷道掘进量,简化了回撤工艺。     

我国安全生产行政执法统计指标体系研究与应用

我国安全生产行政执法统计指标体系自施行以来,一直存在统计指标体系过于繁杂、部分统计指标较笼统,未充分体现安全生产重点工作及其成效等问题,创新改革安全生产行政执法统计制度具有重要的理论意义和实用价值。通过梳理安全生产行政执法统计指标体系演变脉络,在实地调研和现场访谈的基础上,基于PDCA理论提出以执法人员-执法对象-执法行为“三位一体”的安全生产行政执法统计指标体系,明确包含执法力量、执法对象、执法检查和事故查处等方面的综合评价指标,并在实践中得以应用和检验,为全面分析安全生产执法效能拓展空间,统计制度的后续修订和安全生产综合分析工作奠定基础。     

高应力巷道底臌变形机理及控制技术分析

为了分析高应力巷道底臌变形机理,以铜川玉华煤矿2407工作面巷道为研究背景,采用理论分析和现场观测相结合的研究方法。根据巷道底臌主要由原岩应力、支承应力、围岩遇水膨胀、流变作用而引起进行分析,推导出计算底臌量的表达式。针对玉华煤矿高应力巷道底臌变形,提出在巷道顶板采用锚网梁索支护,帮部采用锚网支护的原支护条件下,底板采用锚杆注浆和切槽联合支护方式控制底臌。现场观测结果表明:这种联合支护方式能够有效控制巷道底臌变形,底臌量降低了61.5%。将底臌量理论解与现场监测的结果进行比较,误差小于8.93%,验证了理论的合理性,为巷道底臌量分析提供了参考。     

时间因素对钻屑瓦斯解吸指标K1值测定的影响分析

针对时间因素对钻屑瓦斯解吸指标K1测定结果的影响,采用恒温瓦斯放散试验深入分析钻屑瓦斯解吸指标K1测定理论的准确性,总结因时间因素导致K1值测定误差所带来的现场问题。研究结果表明:K1值的测定误差与时间关系密切,测定启动时间越晚,误差越大;测定启动时间由第1 min延后至第2 min,绝对误差和相对误差最大值分别增加0.081 cm3/(g·min1/2)和2.20%;高瓦斯压力条件矿井或煤层的局部高瓦斯压力区域、构造煤发育区的钻屑瓦斯解吸指标K1值测定结果偏低,测定误差偏大。研究结果可为煤与瓦斯突出预测水平的提升提供技术支撑。     

基于社会技术系统的复工企业疫情防控风险路径研究*

为对复工企业疫情防控中的风险致因因素进行分析,探寻复工企业疫情防控的风险路径,基于社会技术系统理论,建立宏观工效学模型,通过查阅并分析国家、地方政府、企业文件以及相关文献,从人员、技术、组织管理、内部环境及外部环境5个子系统出发,识别出16个复工企业疫情失控致因因素;运用社会网络分析（SNA）构建复工企业疫情防控关系网络,对各因素节点中心度进行计算,分析各节点在网络中的位置及影响程度;采用贝叶斯网络（BN）进行参数学习和推理学习,找出复工企业疫情失控的最大致因链。结果表明:复工企业疫情失控关系网络中,存在政府监督管理不力→防疫物资筹备不足→日常监管不到位,政府监督管理不力→ 防疫宣传、培训缺失→员工防疫知识欠缺,政府监督管理不力→防疫宣传、培训缺失→日常监管不到位3条最长风险路径。研究结果可帮助复工企业针对最长风险路径中的因素进行管理,从而有效地为复工企业防疫提供理论支持。     

Mitigating Impact of Devils Lake Flooding on the Sheyenne River Sulfate Concentration

Devils Lake is a terminal lake located in northeast North Dakota. Because of its glacial origin and accumulated salts from evaporation, the lake has a high concentration of sulfate compared to the surrounding water bodies. From 1993 to 2011, Devils Lake water levels rose by ~10 m, which flooded surrounding communities and increased the chance of an overspill to the Sheyenne River. To control the flooding, the State of North Dakota constructed two outlets to pump the lake water to the river. However, the pumped water has raised concerns about of water quality degradation and potential flooding risk of the Sheyenne River. To investigate these perceived impacts, a Soil and Water Assessment Tool (SWAT) model was developed for the Sheyenne River and it was linked to a coupled SWAT and CE‐QUAL‐W2 model that was developed for Devils Lake in a previous study. While the current outlet schedule has attempted to maintain the total river discharge within the confines of a two‐year flood (36 m³/s), our simulation from 2012 to 2018 revealed that the diversion increased the Sheyenne River sulfate concentration from an average of 125 to >750 mg/L. Furthermore, a conceptual optimization model was developed with a goal of better preserving the water quality of the Sheyenne River while effectively mitigating the flooding of Devils Lake. The optimal solution provides a “win–win” outlet management that maintains the efficiency of the outlets while reducing the Sheyenne River sulfate concentration to ≤600 mg/L.     

An application of a modified theory of planned behavior model to investigate adolescents’ job safety knowledge,norms, attitude and intention to enact workplace safety and health skills

Introduction: For many reasons, including a lack of adequate safety training and education, U.S. adolescents experience a higher rate of job-related injury compared to adult workers. Widely used social-psychological theories in public health research and practice, such as the theory of planned behavior, may provide guidance for developing and evaluating school-based interventions to prepare adolescents for workplace hazards and risks. Method: Using a structural equation modeling approach, the current study explores whether a modified theory of planned behavior model provides insight on 1,748 eighth graders’ occupational safety and health (OSH) attitude, subjective norm, self-efficacy and behavioral intention, before and after receiving instruction on a free, national young worker safety and health curriculum. Reliability estimates for the measures were produced and direct and indirect associations between knowledge and other model constructs assessed. Results: Overall, the findings align with the theory of planned behavior. The structural equation model adequately fit the data; most path coefficients are statistically significant and knowledge has indirect effects on behavioral intention. Confirmatory factor analyses suggest that the knowledge, attitude, self-efficacy, and behavioral intention measures each reflect a unique dimension (reliability estimates ≥0.86), while the subjective norm measure did not perform adequately. Conclusion: The findings presented provide support for using behavioral theory (specifically a modified theory of planned behavior) to investigate adolescents’ knowledge, perceptions, and behavioral intention to engage in safe and healthful activities at work, an understanding of which may contribute to reducing the downstream burden of injury on this vulnerable population—the future workforce. Practical application: Health behavior theories, commonly used in the social and behavioral sciences, have utility and provide guidance for developing and evaluating OSH interventions, including those aimed at preventing injuries and promoting the health and safety of adolescent workers in the U.S., who are injured at higher rates than are adults.     

Inherent thermal runaway hazard evaluation method of chemical process based on fire and explosion index

Thermal runaway hazard assessment provides the basis for comparing the hazard levels of different chemical processes. To make an overall evaluation, hazard of materials and reactions should be considered. However, most existing methods didn't take the both into account simultaneously, which may lead the assessment to a deviation from the actual hazard. Therefore, an integrated approach called Inherent Thermal-runaway Hazard Index (ITHI) was developed in this paper. Similar to Dow Fire and Explosion Index(F&EI) function, thermal runaway hazard of chemical process in ITHI was the product of material factor (MF) and risk index (RI) of reaction. MF was an indicator of material thermal hazards, which can be determined by initial reaction temperature and maximum power density. RI, which was the product of probability and severity, indicated the risk of thermal runaway during the reaction stage. Time to maximum rate under adiabatic conditions and criticality classes of scenario were used to indicate the runaway probability of the chemical process. Adiabatic temperature rise and heat of the desired reaction and secondary reaction were used to determine the severity of runaway reaction. Finally, predefined hazard classification criteria was used to classify and interpret the results obtained by this method. Moreover, the method was validated by case studies.     

Risk assessment and risk reduction of an acrylonitrile production plant

Reducing accident occurrence in petrochemical plants is crucial, thus appropriately allocating management resources to safety investment is a vital issue for corporate management as international competition intensifies. Understanding the priority of safety investment in a rational way helps achieve this objective.In this study, we targeted an acrylonitrile plant. First, Dow Chemical's Fire and Explosion Index (F&EI) identified the reaction process as having the greatest physical risk. We evaluated the severity of accidents in the reaction process using the Process Safety Metrics advocated by the Center for Chemical Process Safety (CCPS); however, this index does not express damages a company actually experience. To solve this problem, we proposed a new metric that adds indirect cost to CCPS metrics. We adopted fault tree analysis (FTA) as a risk assessment method. In identifying top events and basic events, we attempted to improve the completeness of risk identification by considering accidents from the past, actual plant operation and equipment characteristics, natural disasters, and cyber-attacks and terrorist attacks. Consequently, we identified the top events with high priority in handling because of serious accidents as fire/explosion outside the reactor, fire/explosion inside the reactor, and reactor destruction. The new CCPS evaluation index proposed in this study found that fire and explosion outside the reactor has the highest severity. We considered the creation of the fault tree (FT) diagram of the top event, estimating the occurrence probability, and identifying the risk reduction part and capital investment aimed at risk reduction. As an economically feasible selection method for risk reduction investment, using the difference in loss amounts before and after safety investments indicated investment priority.     

The passion bug: How and when do leaders inspire work passion?

Drawing from signaling theory, we propose a work passion transfer model where leaders' passion is transmitted to employees through the former's leadership style and is contingent on employees' perceived importance of performance to self-esteem (IPSE). Data from 201 supervisor–employee dyads from the health-care industry show that leaders' harmonious passion led to employees' harmonious passion through charismatic leadership, whereas contingent reward leadership accounted for the transfer of obsessive passion; IPSE did not play a moderating role for either form of passion. Results from a supplementary study further reveal that the link between leadership and employee passion operated through employees' perception of leader passion and that employees' IPSE accentuated for the relationship between perceived leader obsessive passion and employees' obsessive passion. This study advances research in work passion, leadership, and signaling theory and provides important implications for managerial practice.