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151.
152.
Maija Lintula Nina Nevala-Puranen Veikko Louhevaara 《International journal of occupational safety and ergonomics》2013,19(1):103-116
The effects of Ergorest® arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit (VDU). Twenty-one women were randomized into 3 groups (1 arm support, 2 arm supports, and control). Measurements were carried out before and after the 6-week intervention. The wrist extension of the mouse hand, the muscle activity of the trapezius muscle, and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse. The Ergorest® arm support alleviates muscle and joint strain in VDU work when used for both arms. 相似文献
153.
Addressing criticality for rare earth elements in petroleum refining: The key supply factors approach 总被引:1,自引:0,他引:1
The group of elements known as the rare earth elements (REEs) is comprised of the 15 lanthanides. REEs are used in a number of technologies including catalysts for automobiles and petroleum refining, magnets for wind turbines and defense technologies, and phosphors in lighting and computer and TV screens. REEs are actually quite abundant in the earth′s crust. The elements are deemed “rare” because they are found in low concentrations and are difficult to extract economically. China holds 48% of the global REE reserves, and until 2012, production of REEs was almost exclusive to China. Over the past decade, China has been steadily decreasing its REE export quotas, reducing the supply of REEs available to the rest of the world. REEs are considered critical materials according to the National Science and Technology Council, which defines critical elements as those serving an essential function in the manufacture of a product, the absence of which would cause significant social consequence. Thus, it is extremely important for consumers of REEs to be aware of and understand the risks facing the supply REEs, as awareness is the first and most important step in developing strategies to mitigate risk. This report presents a mechanism for identifying the risks present in a supply–demand scenario and determining the criticality of an individual rare earth element under specific circumstances. 相似文献
154.
洛阳石化总厂五联合装置对含硫污水汽提装置的技术改造,不改变塔体,仅采用新型梯型立体喷射塔盘就能使其处理能力扩大70%-100%,运行效果较好,对国内炼厂同类环保装置的扩改及推行清洁生产有借鉴之处。 相似文献
155.
M. R. Karlinger D. P. Guertin B. M. Troutman 《Journal of the American Water Resources Association》1987,23(2):271-279
ABSTRACT: Discharge hydrographs computed from the theory of linear flow through topologically random channel networks are compared to actual discharge hydrographs for basins in semiarid regions of central Wyoming. The basins drained by the channel networks range in size from 0.69 to 10.8 square miles. Topological information consisting of stream-network magnitude and link -length distribution parameters are used in calibrating celerity values that ensure that the peak discharge and excess rainfall volume of the resulting computed hydrographs match the peak discharge and excess-rainfall volume of the actual hydrographs. Results indicate that, for a given peak discharge and excess-rainfall volume in a basin, the sensitivity of the calibrated celerity values to excess-rainfall duration is small if the ratio of excess-rainfall volume to peak discharge is at least 1.75 times the excess-rainfall duration. 相似文献
156.
通过对催化裂化装置生产过程中职业病危害因素调查,找出职业病危害的关键控制点,并提出防护要求。 相似文献
157.
介绍了常减压装置的设备腐蚀主要存在于低温轻油和高温重油部位,对其腐蚀机理进行了分析,并提出了相应的腐蚀防护措施。 相似文献
158.
姚永明 《安全.健康和环境》2010,10(3):31-32
分析了尿素水解装置存在的问题及采取的改进措施,提高了水解装置处理能力与处理效果,实现了清洁生产、节能降耗、保护环境的目的。 相似文献
159.
白越强 《安全.健康和环境》2010,10(5):35-38
运用美国道化学公司(DOW)火灾爆炸危险指数法(七版),对中国石化北京燕山分公司合成橡胶厂DMF抽提装置的火灾爆炸危险性进行了分析评价,结合评价结果给出采取的对策和措施,以降低生产装置的危险陛。 相似文献
160.
分析了空分装置可能发生设备爆炸的部位及形成爆炸的原因,指出碳氢化合物(尤其是乙炔)的积聚是导致空分装置爆炸的主要因素,提出了防止空分装置爆炸的安全防控措施。 相似文献