两起钢丝绳芯输送带断裂事故的分析及对策

通过两起钢绳芯胶带断裂事故的分析,提出了具体和有效的对策措施。     

Application of human factors evaluation in engineering design and safe operation of dense phase ethylene treaters

Ethylene treaters are widely used in the petrochemical industry to remove impurities from ethylene feedstock imported from pipeline networks or storage caverns. The safety concerns of dense phase ethylene treaters due to the reactive and highly flammable nature of ethylene are well known and studied. Under certain conditions, ethylene may self-polymerize and decompose violently with heat release. Under other conditions, ethylene will auto-refrigerate, generating cold liquids that may cause potential brittle fracture hazards. Therefore, dense phase ethylene treaters present design challenges with the unique combination of high temperature decomposition and cold temperature brittle fracture hazards.Due to these safety concerns, it is important to select the appropriate engineering design options for dense phase ethylene treaters and the associated regeneration facilities. Totally automated treater regeneration systems add complexity and instrument maintenance requirements while manually operated systems rely heavily on operator training and procedures. Unfortunately, little or no information or design guidance is available from published research findings in the literature on the evaluation and risk assessment of current industrial design options and practices for dense phase ethylene treaters.This paper presents a systematic risk assessment method to evaluate the engineering design and safe operation options for dense phase ethylene treaters. The proposed risk assessment method integrates human factors task analysis into the traditional HAZOP, LOPA and fault tree analysis to allow evaluation of automated, manual and hybrid approaches with a goal of selecting and optimizing design options to ensure plant safety. This approach provides a realistic assessment of the operational risk and allows identification of fit-for-purpose risk reduction. Applying this systematic risk assessment approach, a simpler and more cost effective design solution can be justified, thereby avoiding the need for a high integrity protective system.     

Children's and Adults’ Comfort Experience of Extra Seat Belts When Riding in the Rear Seat of a Passenger Car

Objective: The objective of this study was to explore passengers’ comfort experience of extra seat belts during on-road driving in the rear seat of a passenger car and to investigate how the use of extra belts affects children's and adults’ attitudes to the product.

Methods: Two different seat belt systems were tested, criss-cross (CC) and backpack (BP), consisting of the standard 3-point belt together with an additional 2-point belt. In total, 32 participants (15 children aged 6–10, 6 youths aged 11–15, and 11 adults aged 20–79, who differed considerably in size, shape, and proportions) traveled for one hour with each system, including city traffic and highway driving. Four video cameras monitored the test subject during the drive. Subjective data regarding emotions and perceived discomfort were collected in questionnaires every 20 min. A semistructured interview was held afterwards.

Results: All participant groups accepted the new products and especially the increased feeling of safety (P <.01); 56% preferred CC and 44% preferred BP but the difference was not significant. In total, 81% wanted to have extra seat belts in their family car. CC was appreciated for its symmetry, comfort, and the perceived feeling of safety. Some participants found CC unpleasant because the belts tended to slip close to the neck, described as a strangling feeling. BP was simpler to use and did not cause annoyance to the neck in the way CC did. Instead, it felt asymmetric and to some extent less safe than CC. Body size and shape affected seat belt fit to a great extent, which in turn affected the experience of comfort, both initially and over time. Perceived safety benefit and experienced comfort were the most determinant factors for the attitude toward the extra seat belts. The extra seat belts were perceived as being better than the participants had expected before the test, and they became more used to them over time.

Conclusion: This exploratory study provided valuable knowledge from a user perspective for further development of new seat belt systems in cars. In addition to an increased feeling of safety, seat belt fit and comfort are supplementary influencing factors when it comes to gaining acceptance of new seat belt systems.     

Risk quantification framework of hydride-based hydrogen storage systems for light-duty vehicles

This study aims to develop a quantitative risk assessment (QRA) framework for on-board hydrogen storage systems in light-duty fuel cell vehicles, with focus on hazards from potential vehicular collision affecting hydride-based hydrogen storage vessels. Sodium aluminum hydride (NaAlH₄) has been selected as a representative reversible hydride for hydrogen storage. Functionality of QRA framework is demonstrated by presenting a case study of a postulated vehicle collision (VC) involving the onboard hydrogen storage system. An event tree (ET) model is developed for VC as the accident initiating event. For illustrative purposes, a detailed FT model is developed for hydride dust cloud explosion as part of the accident progress. Phenomenologically-driven ET branch probabilities are estimated based on an experimental program performed for this purpose. Safety-critical basic events (BE) in the FT model are determined using conventional risk importance measures. The Latin Hypercube sampling (LHS) technique has been employed to propagate the aleatory (i.e., stochastic) and epistemic (i.e., phenomenological) uncertainties associated with the probabilistic ET and FT models. Extrapolation of the proposed QRA framework and its core risk-informed insights to other candidate on-board reversible and off-board regenerable hydrogen storage systems could provide better understanding of risk consequences and mitigation options associated with employing this hydrogen-based technology in the transportation sector.     

Numerical modeling of water spray suppression of conveyor belt fires in a large-scale tunnel

Conveyor belt fires in an underground mine pose a serious life threat to miners. Water sprinkler systems are usually used to extinguish underground conveyor belt fires, but because of the complex interaction between conveyor belt fires and mine ventilation airflow, more effective engineering designs are needed for the installation of water sprinkler systems. A computational fluid dynamics (CFD) model was developed to simulate the interaction between the ventilation airflow, the belt flame spread, and the water spray system in a mine entry. The CFD model was calibrated using test results from a large-scale conveyor belt fire suppression experiment. Simulations were conducted using the calibrated CFD model to investigate the effects of sprinkler location, water flow rate, and sprinkler activation temperature on the suppression of conveyor belt fires. The sprinkler location and the activation temperature were found to have a major effect on the suppression of the belt fire, while the water flow rate had a minor effect.     

钦杭结合带加里东期榴闪岩超高压变质作用研究

对钦杭结合带首次发现的加里东期榴闪岩进行了详细的年代学、矿物学和变质作用研究。结果表明,榴闪岩的变质时代为454±4Ma,经历了早期角闪岩相进变质、中期榴辉岩相峰期变质和晚期角闪岩相退变质三个阶段,具顺时针P-T-t轨迹。早期角闪岩相进变质作用阶段的矿物共生组合为角闪石+斜长石+石英,温压条件分别为719℃~795℃和7.56Kpa~8.30Kpa;中期榴辉岩相峰期变质作用阶段的矿物共生组合为石榴子石+绿辉石(后期退变为透辉石+钠长石)±石英,温压条件分别为668℃~821℃和26.42Kpa~33.46Kpa;晚期角闪岩相退变质作用阶段的矿物共生组合为石榴子石+角闪岩+斜长石±石英(即榴闪岩),相应的温压条件分别为611℃~854℃和4.76Kpa~9.30Kpa。结合前人资料推断,区域内加里东期可能经历了榴辉岩相超高压变质→高温麻粒岩相退变质→角闪岩相退变质的演化过程。钦杭结合带首次厘定出加里东期超高压变质作用,表明华夏和扬子两大陆块碰撞拼合发生在加里东期。     

北京平原区夏垫断裂的多源遥感影像特征

1679年9月2日三河—平谷8.0级地震在地表形成总体走向N40°~45°E,倾角60°~70°,长达10 km的破裂带。该文采用Landsat-8、SPOT-5、SAR、GDEM、Google Earth多源遥感影像研究夏垫断裂的遥感影像特征。利用ERDAS软件,对Landsat-8影像按7∶4∶2依次为R、G、B分量作彩色合成增强处理,突出影像的线性构造特征;对Landsat-8和SPOT-5影像、Landsat-8和SAR影像分别进行融合处理,丰富影像的光谱信息;对GDEM与SPOT影像进行三维叠加,突出影像的三维特征;对SAR影像进行斑点压缩、方向滤波处理,突出影像平行断裂方向的线性特征。文中分析、对比了Google Earth和SPOT-5影像上地震陡坎的特征,陡坎在SPOT-5影像上表现较明显,但在影像上表现不出较低陡坎,同时,在两种影像上容易将绿色植被、狭窄道路或其它地物误认为陡坎;SAR滤波后的影像表现出暗色的线性条带;Landsat-8和SAR融合后的影像表现出较宽的异常条带,该条带指示断裂带所在位置。     

Encouraging compliance with graduated driver licensing restrictions

PROBLEM: Although graduated driver licensing (GDL) programs have reduced the high crash rates for 16-and 17-year-old drivers, research suggests that some teenagers fail to comply with restrictions on nighttime driving and carrying passengers. METHOD: A program to encourage compliance with GDL restrictions and seat belt requirements was implemented in Guilford County, North Carolina. The program combined increased enforcement with a multi-faceted publicity campaign drawing attention to the enforcement activity. A comparison community was studied to assess whether changes over time could be reasonably attributed to the program. RESULTS: Several measures indicate that greater enforcement did occur in the intervention community and that teenagers perceived the increase. However, self-reported data and direct observations of young drivers in the intervention and comparison communities showed the program resulted in only modest changes in compliance with GDL restrictions. DISCUSSION: The program put in place the mechanisms known to produce changes in driver behavior, but these may have been insufficient to alter the behavior of the minority of teenagers (and parents) who were not already complying with restrictions. However, the modest changes in young driver behavior plus the clear changes in both actual and perceived enforcement suggest that high visibility enforcement programs merit further use and evaluation in other communities, particularly those where compliance with GDL provisions is lower than in Guilford County.     

三峡库区生态经济复合产业带的构建研究

由于自然尤其是人为因素的影响 ,三峡库区生态环境遭受严重破坏 ,农民增收缺少支撑 ,加上三峡工程的修建 ,淹没了大批肥田沃土 ,更加激化了人地矛盾 ,导致该地区生态环境恶化、生态承载容量减少、经济贫困化恶性循环 ,最终致使生态环境保护和经济发展严重对立。要从根本上解决库区生态环境与经济的协调发展问题 ,关键在于发展生态经济。从三峡库区以山地、丘陵为主的地形特征及其分布特点和气候、土壤条件以及资源特色出发 ,根据生态学、生态经济学的基本原理要求 ,提出了建立由水域生态经济产业带、沿江经济支撑产业带、腹地生态农业带、高山垂直绿色产业带构成的生态经济复合产业带的构想 ,其中每个产业带又由若干关联性强的产业有机复合而成。还提出了发展三峡库区生态经济的具体政策建议和措施。     

用于生产过程的故障诊断专家系统

讨论了利用人工智能技术来实现生产过程故障检测与诊断的原理。以液位控制系统为例，说明了“基于规则”和“规则架＋ 规则体”两种方法建立专家系统的过程及知识表达的思路