Objective In this study, we aimed at exploring the association between work-related musculoskeletal disorders（WMSDs） and work organization based on a case-control study. Methods A total of 1938 workers who claimed t...Objective In this study, we aimed at exploring the association between work-related musculoskeletal disorders（WMSDs） and work organization based on a case-control study. Methods A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors. Results A total of 13 variables（P〈0.1） were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance（P〈0.05）. The odds ratios（OR） of ＇work changing with season＇ and ＇sufficient rest time＇ did not reach 1（0.749 and 0.441, respectively）. In addition, ＇sufficient rest time＇ seemed to be the stronger protective factor according to its higher standardized coefficient. And ＇repetitive work every minute＇, ＇constantly repetitive work＇（every day）, ＇shortage of site personnel＇, and ＇often switching shifts with others＇ seemed to be the risk factors. Conclusion Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.展开更多
Scope of the Conference:The main theme is EAST MEETS WEST-Job Stress Prevention in a Global Perspective.The aspects covered will encom-pass strategies and methods of assessing,preventing and controlling job-related st...Scope of the Conference:The main theme is EAST MEETS WEST-Job Stress Prevention in a Global Perspective.The aspects covered will encom-pass strategies and methods of assessing,preventing and controlling job-related stress and its effects on health in different settings all over the world.Language:English(Some sessions will be offered also in Japanese).Topics:(1)New methodology in Occupational Health Psychology;(2)Recent trends in work organization and their impact on worker health;展开更多
Many advanced rock breaking methods are emerged form improving the ROP in deep formation drilling in recent years,such as electric pulse rock breaking,ultrasonic rock breaking and hydraulic rock breaking.However,the t...Many advanced rock breaking methods are emerged form improving the ROP in deep formation drilling in recent years,such as electric pulse rock breaking,ultrasonic rock breaking and hydraulic rock breaking.However,the traditional mechanical rock breaking is still the mainstream rock-breaking method.A detailed understanding of the rock cutting mechanism is essential to achieve high efficiency in rock breaking and to optimize the cutting parameters.This study establishes the simulation model of het erogeneous granite cut by polycrystalline diamond compact(PDC)cutter using FDEM,and the friction work factor is put forward to characterize the friction work proportion of PDC cutter in cutting process.Analysis is done on the variations in friction work factor,force,and failure mechanism of granite under different cutting depths.The results show that the three-dimensional force increase gradually with the increase of cutting depth.When the cutting depth is shallow,the tensile(Type I)failure is dominated,ductile failure mainly occurs to granite and the size of chips is small.When the cutting depth is deep,the proportion of tensile failure is low,the internal shear crack of granite gradually dominates,the failure mode of granite gradually changes to brittle failure,the chips gradually become larger.Friction work factor and failure factor can visualize the change of friction energy consumption of PDC cutter in rock cutting and the failure mode of rock.This study leads to an enhanced understanding of rock breaking mechanisms in rock cutting,and provides the basis to improve the PDC bit design.展开更多
基金supported by the Research Fund from National Science and Technology Infrastructure Program of the People’s Republic of China(2014BAI12B03)Major Project of Beijing Academy of Science and Technology(PXM2014-178304-000002-00131228)
文摘Objective In this study, we aimed at exploring the association between work-related musculoskeletal disorders（WMSDs） and work organization based on a case-control study. Methods A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors. Results A total of 13 variables（P〈0.1） were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance（P〈0.05）. The odds ratios（OR） of ＇work changing with season＇ and ＇sufficient rest time＇ did not reach 1（0.749 and 0.441, respectively）. In addition, ＇sufficient rest time＇ seemed to be the stronger protective factor according to its higher standardized coefficient. And ＇repetitive work every minute＇, ＇constantly repetitive work＇（every day）, ＇shortage of site personnel＇, and ＇often switching shifts with others＇ seemed to be the risk factors. Conclusion Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.
文摘Scope of the Conference:The main theme is EAST MEETS WEST-Job Stress Prevention in a Global Perspective.The aspects covered will encom-pass strategies and methods of assessing,preventing and controlling job-related stress and its effects on health in different settings all over the world.Language:English(Some sessions will be offered also in Japanese).Topics:(1)New methodology in Occupational Health Psychology;(2)Recent trends in work organization and their impact on worker health;
基金supported by the National Natural Science Foun dation of China(Grant No.52034006No.52004229)+1 种基金Regional Innovation Cooperation project of Sichuan Province(2022YFQ0059)Science and technology strategic cooperation project between Nanchong city and Southwest Petroleum Univer sity(SXHZ004).
文摘Many advanced rock breaking methods are emerged form improving the ROP in deep formation drilling in recent years,such as electric pulse rock breaking,ultrasonic rock breaking and hydraulic rock breaking.However,the traditional mechanical rock breaking is still the mainstream rock-breaking method.A detailed understanding of the rock cutting mechanism is essential to achieve high efficiency in rock breaking and to optimize the cutting parameters.This study establishes the simulation model of het erogeneous granite cut by polycrystalline diamond compact(PDC)cutter using FDEM,and the friction work factor is put forward to characterize the friction work proportion of PDC cutter in cutting process.Analysis is done on the variations in friction work factor,force,and failure mechanism of granite under different cutting depths.The results show that the three-dimensional force increase gradually with the increase of cutting depth.When the cutting depth is shallow,the tensile(Type I)failure is dominated,ductile failure mainly occurs to granite and the size of chips is small.When the cutting depth is deep,the proportion of tensile failure is low,the internal shear crack of granite gradually dominates,the failure mode of granite gradually changes to brittle failure,the chips gradually become larger.Friction work factor and failure factor can visualize the change of friction energy consumption of PDC cutter in rock cutting and the failure mode of rock.This study leads to an enhanced understanding of rock breaking mechanisms in rock cutting,and provides the basis to improve the PDC bit design.
