Musculoskeletal disorders among female carpet weavers in Iran

The aim of this study was to determine factors associated with self-reported upper extremity musculoskeletal disorders (UEMSDs) among female carpet weavers. Data on demographic characteristics and workplace factors were collected from 626 female carpet weavers. Type of carpet weaving looms, weaving style (Persian vs. Turkish), daily working hours and work experience as well as personal factors including age and marital status were significantly and independently associated with self-reported UEMSDs (p < 0.05), while education, handedness and weight of weaving comb were not. A major finding of this study was the significant association between weaving style and UEMSDs. Better measures of the biomechanical requirements of carpet weaving tasks in Persian and Turkish weaving types are required to understand better their influences on the health of weavers and on UEMSDs in particular. Poor workstation design, in particular, design inappropriate for the anthropometric dimensions of weavers, was a major risk factor for musculoskeletal symptoms in carpet weaving. Therefore, this industry should develop equipment adapted to women's sizes and shapes. PRACTITIONER SUMMARY: This article provides an insight into the risk factors associated with self-reported UEMSDs among female carpet weavers, identifying major factors associated with upper extremity musculoskeletal symptoms and exploring guidelines for designing weaving workstations.     

横向剪切和旋转惯性影响下管道内流动液体的小振动

当考虑旋转惯性的影响时,流经管道横截面的液体在剪切作用下,会产生小振动.本文推导出无量纲参数表示的系统微分方程.对于某些问题的确定值,使用Galerkin方法,可以得到主振动频率和临界速度.在此基础上,还将研究结果和经典理论值进行了比较.     

创造水经济系统发展有利条件的探讨

根据地区、年代和季节的不同,许多由水资源缺乏合理分配的复杂问题出现在水资源和水系统管理中.为创建水经济系统发展的有利条件,因此必需要开发和提供长期、计划合理的饮用水和生活用水系统,使其具有可维护性和高生产能力,要减少水的损失,提高水供应的持续时间,并且提升供水和水处理的质量.     

The Feasibility of Immobilization of Bioflocculant-producing Bacteria Using Mycelial Pellets as Biomass Carriers

Bioflocculant-producing bacteria Agrobacterium tumefaciens F2 and Bacillus sphaeicus F6 were immobilized onto mycelial pellets to investigate the bioflocculant-producing potential of this combined organism and the corresponding flocculating efficiency. The atomic force microscope (AFM) images of mycelial surface indicate that the mycelia pellet can immobilize bioflocculant-producing bacteria F2 and F6 as a biomass carrier. The flocculating efficiency of bioflocculant produced by this combined organism was studied under the optimum flocculating conditions obtained by Response Surface Methodology (RSM). The fermentation yield of the combined mycelial pellet is about 2.6 g/L, which is higher than that of the free bacteria (only 2.2 g/L). Flocculating efficiency of the combined mycelial pellet was comparable with that of bioflocculant generated by the free bacteria. The bioflocculant yield is enhanced and the flocculating efficiency of the co-culture is uninfluenced after immobilized with mycelial pellet as a carrier. In conclusion, the mycelial pellet is feasible as a biomass carrier for the immobilization of bioflocculant-producing bacteria.     

Inhibition effect of a synthesized N, N＇-bis（2-hydroxybenzaldehyde）- 1, 3-propandiimine on corrosion of mild steel in HC1

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.     

Comparison of two suspension control strategies for multi-axle heavy truck

Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver’s seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.     

解决问题：从以人为中心转变为基于原则

在解决事件型问题时,应用不同的策略会得到不同的结果。遗憾的是,使用传统的问题解决策略,例如鱼刺图和五问法,所得到的结果有很大的偶然性,缺乏必然性,这主要是因为它们采用的是以人为中心的、主观的方式,而不是基于原则的、客观的方式。以人为中心的过程取决于个人的解释和视角。因此,通过这些策略得出的解决办法可能让人感觉满意,但却没有效果。     

统计工程和应用统计学的正确结合

自从我们提出了统计工程的观点和理论后（译者注：本文作者先后在2010年5月、6月和12月的《质量进展》杂志上发表了3篇关于统计工程的文章,译文分别刊登于《中国认证认可》杂志2011年第1期、第2期和第8期）,     

一种全局LBF主动轮廓模型

LBF模型的能量函数对于水平集函数是非凸的,从而导致应用LBF模型分割的最终结果对水平集函数的初始化非常敏感。通过凸化LBF模型的能量函数,提出一种全局的LBF模型(GLBF)。该模型针对水平集函数是凸的,从而可以通过任意初始化水平集函数得到全局最优解。此外,该模型不必重新初始化水平集函数为符号距离函数,从而极大地提高运算效率。对灰度不均匀医学图像的分割结果表明,GLBF模型对水平集函数的初始化不敏感,优于传统的LBF模型以及目前具有代表性的LIF模型。     

基于单片机的凝析油撬控制系统设计

提出了一种基于单片机的凝析油撬控制系统的设计方案,该系统能有效地控制凝析油撬塔顶的气体压力、稳定塔的液位,换热器的温度及凝析油输出的流量。保证凝析油撬的稳定可靠的工作。该系统具备安全保护、工艺自动报警及管理功能。