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91.
《Ergonomics》2012,55(5):488-496
The extent to which a glove modifies the risks from hand-transmitted vibration is quantified in ISO 10819:1996 by a measure of glove transmissibility determined with one vibration magnitude, one contact force with a handle and only three subjects. This study was designed to investigate systematically the vibration transmissibility of four ‘anti-vibration’ gloves over the frequency range 16–1600 Hz with 12 subjects, at six magnitudes of vibration (0.25–8.0 ms?2 r.m.s.) and with six push forces (5 N to 80 N). The four gloves showed different transmissibility characteristics that were not greatly affected by vibration magnitude but highly dependent on push force. In all conditions, the variability in transmissibility between subjects was as great as the variability between gloves. It is concluded that a standardised test of glove dynamic performance should include a wide range of hands and a range of forces representative of those occurring in work with vibratory tools. Statement of Relevance: The transmission of vibration through anti-vibration gloves is highly dependent on the push force between the hand and a handle and also highly dependent on the hand that is inside the glove. The influence of neither factor is well reflected in ISO 10819:1996, the current standard for anti-vibration gloves. 相似文献
92.
《Ergonomics》2012,55(7):967-978
To investigate the influence of the injured disc, frequency, load and damping on the facet contact forces of the low lumbar spine on the condition of whole body vibration, a detailed 3-D nonlinear finite element model was created based on the actual geometrical data of embalmed vertebrae of lumbar spine. The denucleation and facetectomy, together with removal of the capsular ligaments was employed to mimic the injury conditions of lumbar spine after surgery. The compression cyclic force was assumed to mimic the dynamic loads of transport vehicles. The results show that the high frequency vibration might increase both of the value and the vibration amplitude of facet contact forces of the lumbar spine under whole body vibration. The nucleus removal may increase significantly the facet contact forces. Although damping can decrease the vibration amplitude of facet contact forces for intact models, it has less effect on the vibration amplitude of facet contact force for the denucleated models. The denucleation of intervertebral discs is more harmful to the facet articulation on the condition of whole body vibration. 相似文献
93.
The corrosion inhibition of mild steel in 1 mol/L HCl by N, N′-bis (2-hydroxybenzaldehyde)-1, 3-propandiimine (2-HBP) has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as E a , ΔH, ΔS, K ads and ΔG ads were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope (AFM) images. 相似文献
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在电磁弹射过程中,抑制推力波动具有很重要的意义,并且要保持推力恒定,而速度对推力具有很大的影响,因此在本文中重点分析速度对推力的影响.首先建立了非换相期间无刷直线直流电机(BLDCLM)的数学模型,对数学模型进行了求解,推导出电流、推力的解析式;详细分析了PWM调制占空比、速度、反电动势系数对推力的影响,其中反电动势系数的分析结果对电机的设计具有重要的参考意义.最后,通过采用直接搜索的方法获得最优的占空比,来补偿增大的速度引起的推力下降. 相似文献
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针对汽车转向系统和防抱死制动系统的协调控制问题,提出一种新的非线性鲁棒协调控制系统.该控制结构由转向控制器和制动控制器组成.为了改善整个系统的鲁棒性和协调性,根据汽车转向和制动非线性综合模型,基于Hamilton函数方法设计了汽车非线性鲁棒协调控制器.该控制器通过预置状态反馈完成系统的耗散Hamilton函数实现.设计了适用于复杂工况的制动力分配策略.仿真结果验证了所设计控制算法的稳定性和有效性. 相似文献
100.
Argues that W. W. Ronan (1980) presents a one-sided picture of "work force control" by the "entrepreneur–capitalist–management group" and discredits the contributions of many psychologists to workers' well-being. Ronan's contentions that (1) psychological concepts are applied to programs that are motivated by management's desire to avoid unionization, (2) psychological experiments and interventions are unilaterally imposed on workers by management, and (3) economic benefits of psychological interventions should be shared equally with workers are discussed. It is concluded that psychologists have every reason to be proud of their colleagues' contributions to making companies more profitable while improving the work environment for employees. (1 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献