Effect of nano silver coating on thermal protective performance of firefighter protective clothing

The main aim of this experimental work is to find out possible improvement in thermal protective performance of firefighter protective clothing when subjected to different level of radiant heat flux density. Firefighter protective clothing normally consists of three layers: outer shell, moisture barrier and thermal liner. When thermal protective performance of firefighter protective clothing is enhanced, the time of exposure against radiant heat flux is increased, which will provide extra amount of time to firefighter to carry on their work without suffering from severe skin burn injuries. In this study, the exterior side of outer shell was coated with nano-silver metallic particle through magnetron sputtering technology. Coating of outer shell with nano-silver particles was performed at three level of thickness, i.e. 1, 2 and 3?µm, respectively. All the uncoated and silver coated specimens were then characterized on air permeability tester, Permetest and radiant heat transmission machine. It was observed that coating has insignificant difference on the air and water vapor permeability of specimen and a significant decline was recorded for the value of transmitted heat flux density Q_c (kW/m²) and percentage transmission factor (%TF Q_o) as compared to uncoated specimen when subjected to 10 kW/m² and 20?kW/m² indicating improvement of thermal protective performance. These values go on further reduction with increase in thickness of coating layer of nano-silver particles.     

Quantitative investigation of air gaps entrapped in multilayer thermal protective clothing in low‐level radiation at the moisture condition

The effects of air gaps entrapped within the multilayer protective clothing system on the thermal performance were studied during low‐level radiation (2–10 kW/m²). A bench‐scale apparatus was designed to produce the liquid droplets and simulate human sweat transferring through the multilayer fabric system. Two air gaps located between the outer shell and the moisture barrier (Gap A) and between the moisture barrier and the thermal liner (Gap B) were used with different gap sizes (0, 2, and 5 mm). The thermal resistance analysis for the heat transfer with a multilayer flat wall was used to interpret the effects of air gap. The results show that the total thermal resistance of a multilayer clothing system and the thermal resistances of the two air gaps are linearly related with the level of heat flux. It is also indicated that the air gap position affects the beneficial effect of the gap size. The effect of Gap B to improve the thermal performance is better than that of Gap A. Copyright © 2014 John Wiley & Sons, Ltd.     

盘区收缩与南翼风井保护煤柱工作面资源回收技术研究

为了增加煤炭回采量,达到精采细采的目的,根据云冈矿406盘区工作面的实际情况,通过合理布置保护煤柱巷道方案,按照掘进施工工艺,保证回采工作面的正常接替,采用倾斜长壁后退式普采工艺,以提高资源的回收率。结果表明:406盘区在收缩过程中,成功回采了南翼风井保护煤柱,回采出30万t煤炭资源,约收益3000万元,效益显著。     

黑山铁矿露天采场边坡稳定性研究与治理实践

黑山露天采场西边坡由于断层节理发育，造成大面积滑坡，给采场安全生产造成极大威胁。采取现场编录和工程钻等手段，详细摸清了西边坡岩体断层节理情况。通过对边坡进行稳定性分析研究，制定出具体治理方案。采用地表截洪沟阻水、770 m水平预留宽台阶并在宽台阶外缘砌筑干砌石挡墙、对宽台阶实施喷锚支护加固等措施，消除了770 m水平以上边坡对下部各台阶生产作业的威胁，保证了露天采场深部的安全生产。     

远程下保护层开采被保护层防突技术研究

针对平煤十矿丁5,6卸压区域内的煤层和未卸压区域内的煤层区域制定合理的防突措施,并对区域措施效果进行了检验和验证.同时对局部煤层的情况实施了综合防突措施,最后对反向风门、压风自救系统、避难硐室、爆破作业等安全防护措施进行了论述.     

Metals in organic and conventional wheat flours determined by an optimised and validated ICP‐MS method

This study was undertaken (i) to optimise and validate a suitable method for multi‐element determination in cereal products and (ii) to evaluate multi‐element content differences in commercially available conventional vs. organic wheat flours. Presented ICP‐MS method is simple and accurate for the determination of eighteen elements in cereal food. Obtained results show differences in metal content between conventional and organic wheat flours and confirm that both types of production are well within the toxicological safety limits regarding the metal contents. The significant differences among conventional vs. organic wheat flours were obtained for As, Cd, Cr, Fe, Mg, Mo, Ni and V. Toxic metals (Al, As, Cd and Pb) input was higher in conventional compared with organic wheat flours. However, further and long‐term research is needed to clearly underline the effects of organic agricultural practice on the quality of food products.     

THE EFFECTS OF PHYSICAL TRAINING IN A TEMPERATE AND HOT CLIMATE ON THE PHYSIOLOGICAL RESPONSES TO HEAT STRESS

Abstract

The effects of vigorous physical training in a hot climate were assessed and compared with those produced by identical physical training under cooler ambient conditions. Both types of training resulted in a lowering of physiological strain during a standardized heat exposure. The effect was greater for those trained in the hot climate. The results are discussed in relation to other artificial acclimatization techniques.     

储层敏感性机理及防治对策研究

王庄油田郑408块沙三段属于敏感性储层,现场采用冷采、蒸汽吞吐、注入CO2、HDCS等多种开采方式,效果均不理想。在对该区块储层特征、敏感性机理深入研究的基础上,得出黏土矿物含量相对较高,其中蒙脱石含量平均高达41%,致使储层具有强~极强水敏性,因此认为黏土矿物是影响储层渗透率、制约开发效果的主要因素。蒙脱石在富钙环境中会产生钙基蒙脱石,在富钠环境中会产生钠基蒙脱石。蒙脱石具有三层水结构:表层水、层间水和晶格水,失水由易到难,当温度达到300℃时,蒙脱石失去膨胀性能;长期在高温(800~1000℃)下,蒙脱石晶格破坏,产生相变,转化为莫来石和方石英。因此,实施注汽热采需把蒸汽温度提高到250~300℃,干度保持在70%。室内防膨静态和防膨流动实验表明,当SLAS-3防膨剂浓度为1.5%,黏土膨胀率为0,可以很好地起到抑制黏土膨胀的作用。该项成果的取得对指导王庄油田郑408块的开发具有重要的实用价值,同时也为同类油藏的开发提供了一定的借鉴。