In-Situ Combination of Bipolar Membrane Electrodialysis with Monovalent Selective Anion-Exchange Membrane for the Valorization of Mixed Salts into Relatively High-Purity Monoprotic and Diprotic Acids.

The crystalized mixed salts from the zero liquid discharge process are a hazardous threat to the environment. In this study, we developed a novel electrodialysis (SBMED) method by assembling the monovalent selective anion-exchange membrane (MSAEM) into the bipolar membrane electrodialysis (BMED) stack. By taking the advantages of water splitting in the bipolar membrane and high perm-selectivity of MSAEM for the Cl- ions against the SO42- ions, this combination allows the concurrent separation of Cl-/SO42- and conversion of mixed salts into relatively high-purity monoprotic and diprotic acids. The current density has a significant impact on the acid purity. Both the monoprotic and diprotic acid purities were higher than 80% at a low current density of 10 mA/cm2. The purities of the monoprotic acids decreased with an increase in the current density, indicating that the perm-selectivity of MSAEM decreases with increasing current density. An increase in the ratio of monovalent to divalent anions in the feed was beneficial to increase the purity of monoprotic acids. High-purity monoprotic acids in the range of 93.9-96.1% were obtained using this novel SBMED stack for treating simulated seawater. Therefore, it is feasible for SBMED to valorize the mixed salts into relatively high-purity monoprotic and diprotic acids in one step.

[A study of the correlation between low back pain and occupational stress in coal miners].

Objective: To study the correlation between low back pain (LBP) and occupational stress in coal miners. Methods: From January 2015 to December 2016, a total of 472 front-line workers in a mining area of a large-scale coal mining enterprise in Shanxi, China were enrolled in the study. The general information, condition of LBP, and occupational stress level of the subjects were obtained by questionnaire survey. Dichotomous logistic regression (DLR) was used to analyze the correlation between LBP and occupational stress. Results: Of the 472 subjects, 186 subjects experienced LBP in the past year; the prevalence rate of LBP was 39.41%. The scores of the Occupational Role Questionnaire were significantly higher for workers in the LBP group than in the non-LBP group (P<0.01) . As revealed by the DLR analysis, age, marital status, length of service, occupational stress role, labor intensity, keeping single posture during work, and working in shifts were risk factors of LBP (P<0.01) , while smoking may be a protective factor against LBP (P<0.01) . Conclusion: Occupational stress role is a potential risk factor for LBP in coal miners (P<0.01) . Reasonable work assignment and timely alleviation of occupational stress may be one of the effective approaches to prevent LBP.

A study of the correlation between low back pain and occupational stress in coal miners / 中华劳动卫生职业病杂志

Objective@#To study the correlation between low back pain (LBP) and occupational stress in coal miners.@*Methods@#From January 2015 to December 2016, a total of 472 front-line workers in a mining area of a large-scale coal mining enterprise in Shanxi, China were enrolled in the study. The general information, condition of LBP, and occupational stress level of the subjects were obtained by questionnaire survey. Dichotomous logistic regression (DLR) was used to analyze the correlation between LBP and occupational stress.@*Results@#Of the 472 subjects, 186 subjects experienced LBP in the past year; the prevalence rate of LBP was 39.41%. The scores of the Occupational Role Questionnaire were significantly higher for workers in the LBP group than in the non-LBP group (P<0.01) . As revealed by the DLR analysis, age, marital status, length of service, occupational stress role, labor intensity, keeping single posture during work, and working in shifts were risk factors of LBP (P<0.01) , while smoking may be a protective factor against LBP (P<0.01) .@*Conclusion@#Occupational stress role is a potential risk factor for LBP in coal miners (P<0.01) . Reasonable work assignment and timely alleviation of occupational stress may be one of the effective approaches to prevent LBP.

A risk-based decision support framework for selection of appropriate safety measure system for underground coal mines.

In the context of underground coal mining industry, the increased economic issues regarding implementation of additional safety measure systems, along with growing public awareness to ensure high level of workers safety, have put great pressure on the managers towards finding the best solution to ensure safe as well as economically viable alternative selection. Risk-based decision support system plays an important role in finding such solutions amongst candidate alternatives with respect to multiple decision criteria. Therefore, in this paper, a unified risk-based decision-making methodology has been proposed for selecting an appropriate safety measure system in relation to an underground coal mining industry with respect to multiple risk criteria such as financial risk, operating risk, and maintenance risk. The proposed methodology uses interval-valued fuzzy set theory for modelling vagueness and subjectivity in the estimates of fuzzy risk ratings for making appropriate decision. The methodology is based on the aggregative fuzzy risk analysis and multi-criteria decision making. The selection decisions are made within the context of understanding the total integrated risk that is likely to incur while adapting the particular safety system alternative. Effectiveness of the proposed methodology has been validated through a real-time case study. The result in the context of final priority ranking is seemed fairly consistent.