Response of the Head,Neck and Torso to Pendulum Impacts on the Back

Pendulum impacts on the back were conducted to determine human head, neck and torso biomechanics. Eight unembalmed cadavers were subjected to 23.4 kg pendulum impacts at 4.4 m/s and 6.6 m/s at T1 and T6. Twenty-four tests were conducted with accelerometers on the pendulum, spine, torso, and head in the WSU 3-2-2-2 array. High-speed photography was taken. Impact displaces the torso forward, deflects the chest, displaces and rotates the head, and extends the neck. Average responses and corridors were determined for head kinematics and chest force-deflection. The head-neck response occurs in two phases. First, the head displaces upwards and rearwards 30—40 mm with respect to the torso along a 45° trajectory. Head rotation is 1O°-15° with essentially no neck moment, but high neck compression forces. Second, the head rotates from 10°-15° to 40°-55° starting with a rapid rise in neck moment and displaces 80–100 mm rearward. Anterior cervical fractures correlate with neck tension. Rib fractures correlate with impact force and chest deflection. This study provides chest bio-mechanical responses for rear impacts resulting in head displacement and rotation, neck extension and cervical-thoracic injury.     

Desertification and Sustainable Development of the Heihe River Basin in Arid Northwestern China

Abstract

The Heihe River Basin of northwestern China is one of several areas severely affected by desertification. This article outlines the status of desertification in this basin. There are mainly 5 types of desertification in the Heihe River Basin, namely soil and water erosion, sandy desertification, soil aridization, soil salinization and vegetation degradation. Among the 5 types of desertification, the main desertification type is sandy desertification with an area of 10 771.97 km²; Second type is soil salinization with an area of 10 591.82 km²; Next to the soil salinization is the type of soil and water erosion with an area of 5 747.68 km² and the other types of desertification in the Heihe River Basin are soil aridization with just area of 1 369.96 km² and vegetation degradation type with an area of 1 490.48 km² respectively. Both natural and man-made factors are responsible for the causes of desertification development, among which the latter is the main driving force for desertification in the basin.     

紫外线消毒系统中强度分布的理论计算与生物验证对比

应用以MPSS模型为基础的计算软件UV calc对某饮用水紫外线消毒反应器进行强度分布的计算,同时,采用枯草芽孢杆菌(ATCC9372)作为受试菌种进行生物验证.结果显示,在该反应器中理论计算数值总体上明显高于生物验证的数值,反应器中最低紫外剂量区域出现在2支灯管之间的反应器壁附近.另外,理论计算和生物验证的误差与流量、透光率具有相关性.在高流量、低透光率的情况下,理论计算的数值更接近于生物验证数值.相对于理论计算,生物验证是确定紫外线反应器剂量反应曲线的可靠方法.     

Human resource management practices and organizational injury rates

Introduction: This study investigated the extent to which five human resource management (HRM) practices—systematic selection, extensive training, performance appraisal, high relative compensation, and empowerment—simultaneously predicted later organizational-level injury rates. Methods: Specifically, the association between these HRM practices (assessed via on-site audits by independent observers) with organizational injury rates collected by a national regulatory agency one and two years later were modeled. Results: Results from 49 single-site UK organizations indicated that, after controlling for industry-level risk, organization size, and the other four HRM practices, only empowerment predicted lower subsequent organizational-level injury rates. Practical Applications: Findings from the current study have important implications for the design of HRM systems and for organizational-level policies and practices associated with better employee safety.     

环境安全研究

在过去的二十多年里,在北美洲,欧洲和整个世界涌现出了大量探索现有的安全条件和环境之间存在潜在联系的文献。与此同时还探讨了一些想法,这些研究探索包含了一些经典思想的印记,并且是对两个几乎同时发生的重大事件的反应：一个是“冷战”的结束,迫使人们重新思考安全的概念。另一个是把全球变暖的科学证据提到了全球性的政策制定议程上的急迫性得到了广泛的认同和关注。大量的学术文献已经验证了大尺度的环境变化过程,如：气候变化和森林砍伐之间的关系。这些文献在各种尺度上探讨了自然资源的变化对于社会政治的影响。这些文献还从环境前景的角度分析了其对军事活动的影响,以便于了解环境因素对于国家冲突和化解国家冲突的影响。这些研究还从国家安全的角度探索了环境变化对于人类健康的影响。这些研究从不同的层面来考量安全问题,这些等级包括：全球,地区,国家,国家内行政区划以及全人类。这些研究还包括脆弱的人类安全体系在环境变化中可能发生的贫穷和不公正。这些研究还包括在不同的安全背景下的战略对于保护环境以及适应环境压力的影响。     

Estimation of terrestrial chemical spill risk factors using a modified Delphi approach

The large number of chemical spills each year in the United States presents a potentially significant risk to human health and the environment. In an effort to manage this risk, the authors are developing a screening tool to assess the immediate threat to human and environmental receptors from land-based chemical spills. As part of this development effort, a modified Delphi survey was employed to determine the most important factors governing this risk and the relative importance of these factors. Results of the survey indicate that accounting for the attributes of the spilled chemical as well as the characteristics of the surrounding environment is imperative in making informed decisions regarding spill planning and mitigation. Survey results further indicate the greatest concern during spill events to be the risk to human health, which must be considered directly as well as factored into decisions concerning the protection of environmental receptors.     

Concentration ratios for small mammals collected from the exposed sediments of a 137Cs contaminated reservoir

(137)Cs concentration ratios were computed for small mammals collected from the dried sediments of a partially drained, contaminated reservoir. Soil (137)Cs activity concentrations were heterogeneous on small and large spatial scales and had a geometric mean of 253 (range 23-2110) Bq/kg dry weight. Mean (137)Cs activity concentrations in composite cotton rat Sigmodon hispidus and cotton mouse Peromyscus gossypinus samples averaged 2480 (range 556-6670) and 471 (range 96-1000) Bq/kg whole body dry weight, respectively. About 50% of the variance in cotton rat tissue (137)Cs activity was explained by variation in soil (137)Cs activity. Soil-to-animal dry weight concentration ratios averaged 6.0 for cotton rats and 1.2 for cotton mice and were generally similar to (137)Cs concentration ratios for herbivorous, homeothermic animals from other contaminated ecosystems. In the RESRAD-BIOTA dose model, the default wet-weight concentration ratio for (137)Cs in terrestrial animals is 110 resulting in an estimate of internal and external radiation doses to terrestrial biota that is 44 times more than the dose calculated with the actual measured wet-weight concentration ratio for cotton rats (1.6). These results show that site-specific concentration ratios can significantly affect the estimation of dose.     

基于遥感影像的2019-2020年盐城市生态保护红线区人类活动动态分析

以盐城市生态保护红线区为研究对象,选用哨兵-2号卫星遥感影像进行目视解译及变化斑块提取,分析其区域内2019-2020年人类活动的变化趋势.结果显示,动态变化情况分为正变化和逆变化,其中逆变化占变化总面积的绝大部分,主要呈现为水田的减少;正变化主要呈现为农村居民点的拆除.总体来说,人类活动变化面积非常少,无工业用地的增...