KN95颗粒物防护口罩适合性与头面部尺寸关系研究

测量两种KN95颗粒物防护口罩的适合性和人体头面部尺寸,分析影响口罩适合性的人体尺寸因素。选择80名受试对象,使用弯角规和直角规进行头面部尺寸测量。受试者分别佩戴3M 8210、3M 8210v颗粒物防护口罩,使用TSI 8038进行定量适合性检验。两种口罩的适合性检验通过率无差异（P＞0.05）,通过率无性别差异（P＞0.05）。男性鼻宽对3M 8210的适合性有影响（P＜0.05）,女性面宽和两耳屏点间颌下弧长对3M 8210v的适合性有影响（P＜0.05）。面宽和鼻宽可作为初步选择颗粒物防护口罩的参考指标,但仍需经过定量适合性检验。     

常用防护口罩对气溶胶的防护性能研究

为指导劳动者选择适合自身的口罩型号,对11种口罩防护气溶胶颗粒物的性能进行测试,对部分口罩进行适合性检验。使用TSI8130测定常用口罩对氯化钠气溶胶的过滤效率、吸气阻力,使用3M FT-30定性检验Bacou801,3M9332口罩的适合性。所测试口罩中,3M,Bacou口罩过滤效率与阻力值均符合标准值要求,其余某些口罩的过滤效率最低值为23.200%,吸气阻力最高值达260.9 Pa;某些口罩的处理样与未处理样在2项指标上存在差异(P<0.05)。6名受试者的脸型均与Bacou801口罩不适合,其中,3名的脸型与3M9332口罩不适合。结果表明,3M,Bacou所检测型号的口罩能够达到防颗粒物防护用品的要求,部分国产口罩尚不能用于颗粒物防护,首次使用某种口罩前,要进行适合性检验。     

一体化防护头罩的研究

长期以来,我国一直把口罩作为呼吸防护的一个主要品种,但对口罩防护机理、防护指标和测试设备的研究没有大的进展,与国际上执行的两个主要标准(美国标准和欧洲标准)相比,有较大的差距。在“非典”病毒猖獗和向全国蔓延的时候,才紧急出台一个具有较高指标的国标GB1983-2003《医用防护口罩技术要求》。但在高风险传染的场合如“非典”病区,头面部还不能得到全面的安全防护。针对这种情况,我们从全新的角度研制了一种新式防护头罩———一体化防护头罩,对高风险传染区工作的人员具有很好的防护作用。1现行防护装备的缺点目前抗“非典”的面部…     

地铁员工保健谈

长期在地铁部门工作的员工,如果不注意保健,易患一些特定的疾病。如上呼吸道感染、鼻炎、咽喉炎、气管炎等,常反复发病,且病程长;还有风湿性关节炎、神经衰弱、失眠、健忘、听力下降、视力下降等。 地铁员工应该怎样进行自我保健呢? (1)调整好工作时间。地铁员工不宜长时期上日班,最好是日、夜班交替上。这样可以有充足的时间接受日光。 (2)上日班时,可以每隔2小时到地面活动10～15分钟,呼吸新鲜空气。若条件不允许,可戴防护口罩,以免因空气污浊、粉尘所致的呼吸道疾病。 (3)多饮水。每天至少喝8～10怀水,大约3升。 (4)夏季地下虽然凉爽,但较潮湿,     

某化工公司聚醚生产项目职业病危害预评价

目的:分析与评价建设项目可能产生的职业病危害因素种类及其危害程度,为建设项目职业病危害分类管理提供依据。方法:采用类比法、检查表法和经验法相结合的原则进行评价。结果:该项目的选址、总体布局、生产工艺和设备布局、建筑卫生学、职业病危害因素和危害程度、职业病危害防护设施、辅助用室、应急救援、个人使用的职业病防护用品、职业卫生管理等内容基本符合国家有关规定;该项目在生产过程中可能产生的职业病危害因素有:有害化学物质、粉尘及物理因素,其中环氧乙烷在储罐投料(CSTEL1.0mg/m3—422.3mg/m3)及分析环节(CSTEL7.4mg/m3—438.8mg/m3)超过职业接触限值;冷冻车间定点噪声测量结果,反应外操、包装岗位、冷冻站操作工、动力车间操作工个体噪声测量结果均超过职业接触限值要求。结论:经综合评价分析,该项目可定为职业病危害严重的建设项目,在认真落实各项职业卫生管理制度和职业病防护设施情况下,可达到预防和控制职业病危害的目的。     

不同等级农村公路交通事故严重程度预测研究

为准确分析各因素及其组合对农村公路发生严重交通事故的影响,将道路类型、路侧防护设施、时间段、天气状况、事故位置等11个因素作为自变量,事故严重程度作为因变量,采用改进的Apriori关联算法,找出各影响因素间的内在联系,并求解得到关键因素的组合。然后,分别构建随机森林、梯度提升决策树(Gradient Boosting Decision Tree, GBDT)、极端梯度提升(eXtreme Gradient Boosting, XGBoost)预测模型对农村公路事故严重程度进行预测。结果显示：与改进前相比,改进后的Apriori算法的运行效率和挖掘准确度都有较大提升;相对于随机森林和GBDT模型,XGBoost模型在准确率、召回率、精确率和F1得分等方面表现最优;照明条件、路侧防护设施、道路类型,天气状况是影响农村公路事故严重程度的重要因素,且各影响因素间存在显著的交互效应。     

在企业生活区因不安全因素受伤能定为工伤吗?

编辑同志:现有一个问题,请给予解答。2006年8月8日晚,我公司电力检修部锅炉管阀班工人刘保国因设备紧急消缺加班。他于当晚22点55分结束工作,23点25分离开车间骑自行车回家(家在电厂生活区)。因生活区马路正在维修,刘保国在回家的路上,撞到堆在路边的一堆沙子上(车速快),人从上面翻过去碰在铺路用的硬石堆上,导致头、面部受伤。经诊断为:额颞叶脑挫裂伤,右侧眉部约2cm创口,上唇右侧一长约3cm“J”型创口、尾部豁口,下牙床中央2颗牙齿撞断,面部及牙床共缝十七八针。出事地段情况为:照明较差,路边堆有修路材料,警示标志不明显,防护围栏缺失。…     

过滤式防毒面具

防毒面具是预防毒物进入人体呼吸器官的有效防护用具。按防护原理分为过滤式(通过滤毒罐净化空气)、隔离式(自身带供气装置,如氧气、空气呼吸器)两种。选用适合的防毒面具,对减少尘毒危害十分重要。过滤式防毒面具由滤毒罐、橡胶面罩、导气管、帆布背包等组成。 一、滤毒罐 滤毒罐起过滤空气中尘、毒的作用。现国内生产的有铁皮的和塑料皮的两种。罐颈带有螺纹,用以连结导气管。罐底有一进气孔,用橡皮塞塞紧。罐内装填经过特种处理的活性炭等吸附剂和滤层,分为1、2、3、4、5、7六种型号,全国产品标志统一,各型号罐涂有不同颜色。 1.性能(见…     

电焊烟尘防护口罩过滤模式研究

为了研发过滤效果好、呼吸阻力低的电焊烟尘防护口罩烟尘过滤模式,以电焊烟尘为研究对象,利用扫描电镜分析了电焊烟尘的微观结构和元素构成,利用激光粒子计数器检测并统计分析了电焊烟尘的粒径分布,发现电焊烟尘中的颗粒物99%以上均为对人体危害严重的呼尘;直径0. 1～0. 3μm颗粒物粒子占粒子总数的68%以上,直径2μm以上颗粒物虽然粒子数所占比例仅为1%,但体积分数高达20%。在设计防护口罩时,上述二者均应充分考虑。利用CAD建立了a(3层过滤孔径分别为2μm、1μm、0. 1μm)、b(3层过滤孔径分别为1μm、0. 2μm、0. 1μm)、c(3层过滤孔径分别为0. 3μm、0. 2μm、0. 1μm) 3种由滤料最外层至最内层不同孔径的过滤模式,利用Fluent对3种过滤模式下速度场、压力差和电焊烟尘浓度分布等进行了数值模拟与对比分析,结果发现a模式吸气阻力最小,但粉尘过滤效果最差;c模式吸气阻力最大,但粉尘过滤效果最好,b模式居于a和c模式之间,并得出不同孔径滤料组合方案对于吸气阻力和过滤效率具有较大影响的结论。     

PCA-SVM模型在煤层瓦斯涌出量预测中的应用

针对煤层瓦斯涌出量影响因素众多且各因素间呈复杂非线性的特点,文章利用主成分分析法(PCA)和支持向量机(SVM)的理论基础,构建了PCA-SVM的煤层瓦斯涌出量预测模型,该模型利用SPSS20.0软件中的主成分分析模块对影响煤层瓦斯涌出量的12个因素进行降维,提取其中3个最能反映原始数据本质特征的主成分因子,再将主成分因子的前25组数据作为训练集,后10组数据作为测试集,借助MATLAB中的LIBSVM工具箱进行支持向量机预测,最后将PCA-SVM、SVM及使用较为广泛的多元线性回归3种方法的瓦斯涌出量预测结果进行对比,预测结果表明PCA-SVM模型在预测精度、稳定性方面都优于其他两种预测方法,更适合煤层瓦斯涌出量的预测。     

Investigating the relationship between person–environment fit and safety behavior: A social cognition perspective

Introduction: This study explored the relationship between person–job fit and safety behavior, as well as the mediating role played by psychological safety, from the perspective of social cognitive theory and person–environment fit theory. Method: A total of 800 employees from petroleum enterprises were recruited, with cluster random sampling used to collect data in two stages. Results: The results showed that employees’ safety behavior is higher under the condition of “high person–job fit—high person–organization fit” than under that of “low person–job fit—low person–organization fit.” In other words, the more congruent the level of person–job fit and person–organization fit for a given employee, the higher their level of safety behavior. Practical Applications: Psychological safety plays a mediating role between the congruence of both person–job fit and person–organization fit and employees’ safety behavior.     

Predicting vehicle belt fit for children ages 6–12

Objective: To predict shoulder belt fit and lap belt fit as a function of child age, vehicle seat characteristics, and belt geometry.

Methods: In a previous study, the lap belt and shoulder belt fit of 44 children aged 5–12 were measured in a simulated vehicle seat while varying cushion length, cushion angle, seatback angle, and belt anchorage geometry. A regression model was developed to predict lap belt fit and shoulder belt fit as a function of vehicle parameters and child stature. These regression models were applied to the stature distribution of 6- to 12-year-olds using a range of vehicle geometry data to predict the proportion of children expected to achieve good belt fit in the second-row, outboard seating positions of 46 vehicles when not using belt-positioning boosters.

Results: Across the ranges observed in vehicles, lap belt angle had the strongest effect on lap belt fit, although vehicle cushion length also contributed. Shoulder belt fit was most strongly affected by D-ring location. Vehicles with the geometric conditions most suitable for children are estimated to provide good lap belt fit for 25% of children aged 6 to 12. In 20% of vehicles, the shoulder belt is too far inboard for the target child population; 20% of vehicles are estimated to have shoulder belt fit too far outboard for children ages 6 to 12.

Conclusions: Based on this geometric analysis, the rear seats of most vehicles are unlikely to provide good lap belt fit for up to 75% of children ages 6–12. Shoulder belt fit is outside the target range for 40% of children. Consequently, children under 12 years of age are likely to experience markedly poorer belt fit when transitioning out of a booster seat.     

Are two cynics better than one? Toward understanding effects of leader–follower (in‐)congruence in social cynicism

Prior research suggests that leaders' social cynicism can undermine important follower outcomes such as followers' motivation and performance. However, these studies have exclusively focused on leaders' social cynicism and neglected that followers' views on the social world might also influence the leadership process. On the basis of theories of social beliefs and person–supervisor fit, we offer an integrative perspective and predict that it is the congruence between leaders' and followers' social cynicism that shapes leadership dynamics. Data from 116 leader–follower dyads from a broad range of organizations and industries support our model: Polynomial regression and response surface analyses show significant congruence effects of leaders' and followers' social cynicism on followers' extra‐role behaviors and followers' proactive work behaviors. These positive effects of congruence on follower outcomes are transmitted by leader–member exchange quality. Finally, congruence effects are stronger when leaders' and followers' social cynicism is low rather than high. Overall, our study suggests that it is the correspondence between leaders' and followers' social cynicism that influences followers' leader–member exchange, extra‐role, and proactive behavior. We discuss the theoretical and practical implications of these findings for designing functional leader–follower dyads in organizations.     

管理者的威权领导风格对矿工安全行为的影响研究

矿工安全行为是煤矿安全生产的基础保障,而管理者的领导风格对矿工安全行为有重要影响。引入调节焦点理论和认同理论,构建威权领导风格对安全行为影响关系的理论模型。以544份调查问卷的数据对理论模型进行检验,结果发现:威权领导风格是影响矿工安全行为的重要情境因素;威权领导风格会通过矿工对管理者认同而正向影响安全行为,矿工对管理者认同在二者间具有中介作用;管理者-矿工间的调节焦点适配在矿工对管理者认同和安全行为之间有调节效应,而且调节焦点的高适配度会强化矿工对管理者认同的中介效果。研究丰富了领导风格与矿工安全行为的作用机制和边界条件,对煤矿安全管理实践有一定的启示意义。     

Posture and belt fit in reclined passenger seats

Abstract

Objective: Highly reclined postures may be common among passengers in future automated vehicles. A laboratory study was conducted to address the need for posture and belt fit in these seating configurations.

Methods: In a laboratory vehicle mockup, the postures of 24 men and women with a wide range of body size were measured in a typical front vehicle seat at seat back angles of 23°, 33°, 43°, and 53°. Data were gathered with and without a sitter-adjusted headrest. Posture was characterized by the locations of skeletal joint centers estimated from digitized surface landmarks.

Results: Regression analysis demonstrated that the pelvis rotated rearward and lumbar spine flexion decreased with increasing recline. The lap portion of the 3-point belt was more rearward relative to the pelvis in more-reclined postures, and the torso portion crossed the clavicle closer to the midline of the body. Regression equations were developed to predict posture and belt fit variables as a function of passenger characteristics, seat back angle, and the use of the headrest.

Conclusions: Spine posture changes as the torso reclines in an automotive seat, and belt fit is altered by the change in posture. The results can be used to accurately position crash test dummies and computation human models and to guide the design of belt restraints.     

Collective fit perceptions: A multilevel investigation of person–group fit with individual‐level and team‐level outcomes

This study describes a multilevel examination of person–group (PG) fit perceptions in a sample of 1023 individuals working in 92 teams at a private sector R&D firm. Using confirmatory factor analysis and multilevel random coefficient modeling, we provide evidence that perceptions of team‐level collective fit are unique from aggregated individual‐level PG fit perceptions at the individual and team levels. We demonstrate that collective values‐based and abilities‐based fit perceptions showed unique and positive relationships with team cohesion, team efficacy, and team performance, after accounting for aggregated individual perceptions of PG fit. Results also demonstrate that cohesion partially mediates the relationship between collective fit and team performance. Cross‐level effects were also supported, indicating that collective fit explains additional variance in individual‐level outcomes, beyond individual‐level PG fit perceptions. The usefulness of employing a multilevel approach to studying PG fit is discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

Compatibility of booster seats and vehicles in the U.S. market

Objective: The objective of this study was to analyze booster and rear vehicle seat dimensions to identify the most frequent compatibility problems.

Methods: Measurements were collected from 40 high-back and backless boosters and 95 left rear and center rear row seating positions in 50 modern vehicles. Dimensions were compared for 3,800 booster/vehicle seat combinations. For validation and estimation of tolerance and correction factors, 72 booster installations were physically completed and compared with measurement-based compatibility predictions. Dimensions were also compared to the International Organization for Standardization (ISO) volumetric envelopes of forward-facing child restraints and boosters.

Results: Seat belt buckles in outboard positions accommodated the width of boosters better than center positions (success rates of 85.4 and 34.7%, respectively). Adequate head restraint clearance occurred in 71.9 to 77.2% of combinations, depending on the booster's head support setting. Booster recline angles aligned properly with vehicle seat cushion angles in 71.5% of combinations. In cases of poor angle alignment, booster angles were more obtuse than the vehicle seat angles 97.7% of the time. Head restraint interference exacerbated angle alignment issues. Data indicate success rates above 90% for boosters being fully supported by the length of the seat cushion and for adequate height clearance with the vehicle roofline. Comparison to ISO envelopes indicates that most boosters on the U.S. market are taller and angled more obtusely than ISO target envelopes.

Conclusions: This study quantifies some of the common interferences between boosters and vehicles that may complicate booster usage. Data are useful for design and to prioritize specific problem areas.     

Person–organization and person–supervisor fits: Employee commitments in a Chinese context

The present study simultaneously examined people's perceptions of person–organization (PO) and person–supervisor (PS) fit and related these perceptions to employees' commitments. Three‐hundred‐and‐sixty employee–supervisor dyads from Taiwanese organizations reported about their PO fit and PS fit perceptions. In addition, supervisors reported about their perceptions of fit and guanxi with each of their employees. Results indicated that PO and PS fit perceptions both had an independent and additive relationship with organizational commitment. The link between employee PS fit perceptions and organizational commitment was mediated by commitment to the supervisor. Both employee and supervisor fit perceptions contributed to commitment to the supervisor through their influence on the quality of the leader‐member exchange (LMX). Guanxi could not explain additional variance in LMX and supervisor commitment. Implications for theory and practices regarding person–environment fit, commitment, and LMX are discussed. The study findings offered suggestions for a new Theory of Multiple Fits. Copyright © 2010 John Wiley & Sons, Ltd.     

Congruence work in stigmatized occupations: A managerial lens on employee fit with dirty work

Although research has established that it is often difficult for individuals engaged in dirty work to adjust to stigma and the attributes giving rise to stigma, little theory or empirical work addresses how managers may help workers adjust to dirty work. Interviews with managers across 18 dirty work occupations—physically tainted (e.g., animal control), socially tainted (e.g., corrections), and morally tainted (e.g., exotic entertainment)—indicate that managers engage in “congruence work”: behaviors, sensemaking, and sensegiving that they perceive as helping individuals adjust and develop a stronger sense of person–environment fit. Specifically, congruence work focuses on 3 phases of managerial practices that correspond to individuals' growing experience in the occupation. First, recruitment/selection involves overcoming individuals' aversion to dirty work by selecting individuals with an affinity for the work and providing a realistic stigma preview. Second, socialization involves helping newcomers adjust to distasteful tasks and to stigma by using targeted divestiture, developing perspective taking, helping newcomers manage external relationships, and utilizing desensitization or immersion. Third, ongoing management roles involve cementing individuals' fit by fostering social validation, protecting workers from dirty work hazards, and negotiating the frontstage/backstage boundary. The practices identified as congruence work highlight the important role that managers can play in facilitating adjustment for both “dirty workers” and presumably their less stigmatized counterparts.     

Seat belt use and fit among drivers aged 75 years and older in their own vehicles

Objective: This article aims to describe seat belt wearing patterns and quality of seat belt fit among drivers aged 75 years and older. A secondary aim is to explore associations between body shape, comfort, and seat belt use patterns.

Methods: This is an observation and survey study of a cohort of 380 drivers aged 75 years and over. During home visits, photographs were taken of the drivers in their vehicles for later analysis of belt fit and a short survey was also administered to collect demographic data and information about seat belt use and comfort. Seat belt fit and use of belt and seat accessories were analyzed from the photographs.

Results: Data from 367 participants with photographs were analyzed. Whereas 97% reported using a seat belt and 90% reported their seat belt to be comfortable, 21% reported repositioning their seat belt to improve comfort. Good sash and lap belt fit were achieved in 53 and 59% of participants, respectively, but only 35% achieved overall good fit. Both poor sash and lap belt fit were observed in 23% of participants. Drivers who were in the obese category had over twice the odds (95% confidence interval [CI], 1.2–4.1) of having a poor lap belt fit than those in the normal body mass index [BMI] range, and drivers who were overweight had 1.8 times the odds (95% CI, 1.1–2.9) of having poor lap belt fit. Older females also had twice the odds (95% CI, 1.3–3.5) of poor lap belt fit compared to older males, regardless of BMI. Sash belt fit did not vary significantly by BMI, stature, or gender. However older drivers who reported that they had not made any adjustments to the D-ring height had 1.7 times the odds of having poor sash belt fit than those who made adjustments (1.2–2.9). Females were 7.3 times more likely to report comfort problems than males (95% CI, 3.2, 16.3) but there was no association between reported comfort and BMI or seat belt fit. Drivers who reported comfort problems had 6 times the odds (3.2–13.6) of also reporting active repositioning of the belt.

Conclusions: The results suggest that older drivers face challenges in achieving comfortable and correct seat belt fit. This may have a negative impact on crash protection. Belt fit problems appear to be associated with body shape, particularly high BMI and gender. There is a need for further investigation of comfort accessories; in the interim, older drivers and occupants should be encouraged to use features such as D-ring adjusters to improve sash belt fit.