Ring-Opening Polymerization of Cyclic Esters onto Liquefied Biomass

Ring-opening polymerization of cyclic esters (-caprolactone, -valerolactone, and l-lactide) onto liquefied biomass (LB) was conducted to obtain the polyester-type polyol and to regulate the characteristics of LB. IR and ¹H-NMR spectra of the obtained polyol showed that the polymerization was successfully conducted in the presence of acid catalyst, which is used in liquefaction. The molecular weight (M_w), hydroxyl value, and viscosity were controllable by changing the reaction conditions. Polyester-type polyurethane foams with a wide range of properties were prepared from the obtained polyol with the appropriate combinations of foaming agents.     

Disparity of a Seat Cushion and Its Influence on Postural Control

Properties of supporting surfaces of a seat have an influence on postural control. Centre of pressure (COP) displacement parameters reflect both the balance controlling process and movements of the centre of a mass of entire body. The subjects of the study were 9 healthy men. A seat cushion was examined with a 2-force platform setup. Force exertion at a seat pan and feet and COP displacement at a seat pan were measured to analyse postural control. Analysis of variance determined the differences in postural control depending on a cushion type among the subjects. Significant differences in COP displacement parameters were in COP trajectory length, medio-lateral COP displacement and COP velocity. The results of the study showed that foam cushion ensures better postural control.     

Electrochemical remediation of copper (II) from an industrial effluent Part II: three-dimensional foam electrodes

A batch recycle removal of copper ions from an industrial effluent by means of copper foam cathodes was tested. A constant current of 750 A was applied to the cell in order to perform the reduction. Copper depletion was investigated at different solution flow rates and a removal greater than 98% was obtained with a flow rate of 1000 l/h. The influence of initial metal concentration on copper deposition and current efficiency is also discussed.     

三相生物流化床处理低C/N污水的亚硝化过程控制研究

将短程硝化与生物流化床相结合,采用低碳氮比的人工合成污水进行启动,考察进水COD、氨氮、DO、p H对硝化和亚硝化过程的影响。研究表明,较短的水力停留时间(HRT)和较少的接种污泥量有利于生物膜的生长,能够成功实现生物流化床的快速启动。高进水氨氮浓度有助于反应器实现亚硝酸盐的积累,但是这种积累并不稳定。当反应器中p H为7.5~8.1,ρ(DO)为1.5~2.5 mg/L时,最大亚硝化率达到75%左右,氨氮去除率达85%以上。出水NO-2-N和NO-3-N浓度随进水COD浓度的增加而减少;当进水COD浓度为50 mg/L时,出水硝酸盐浓度急剧减少,亚硝酸盐浓度有所降低,反应器发生同步硝化反硝化脱氮现象。     

压缩空气泡沫在长距离管路输送中压降的数值模拟

基于Fluent对压缩空气泡沫在长距离管道中的流动特性进行了数值模拟研究,将压缩空气泡沫近似为弥散流,采用Saplart-Allmaras模型模拟了不同管径下压缩空气泡沫以及不同泡沫原液浓度的AFFF泡沫在长距离管道内的流动及压降变化。模拟结果表明,随着距离变化,各管径管道内压降均呈现线性变化,且随着压缩空气泡沫的流动,压降线性增大。管道管径对管内压降变化具有显著影响,管道直径越小,管道内压降越大;泡沫原液浓度对压降的影响较小,且压缩空气泡沫在长距离输送中的压力随距离线性衰减。将模拟结果与长距离输送的试验结果进行了对比,误差在10%以内。     

外浮顶储罐泡沫灭火设施的选型

分析了外浮顶储罐火灾危险性及火灾类型,对目前泡沫灭火设施在外浮顶储罐中的应用及存在的问题进行阐述,建议外浮顶储罐的泡沫灭火设施采用边缘泡沫消防系统.     

TiO2/SiO2催化剂光催化降解罗丹明B的表观动力学

采用多孔硅胶为载体的TiO₂/SiO₂光催化剂,建立了三相内循环流化床光催化氧化体系,并以罗丹明B染料为典型污染物,研究其降解规律.通过对罗丹明B降解过程的表观动力学研究,发现在该体系中罗丹明B的降解并不符合Langmuir-Hinshelwood反应动力学模型.实验表明,其降解反应动力学符合双曲型模式,即降解率的倒数1/X和时间的倒数1/t成线性关系.反应速率常数与反应物初始浓度无关,与光源强度和相对体积能量吸收速率成正比.将不同实验条件下的罗丹明B的降解率实测值与模型计算值相比较,二者能很好吻合,平均相对偏差仅为3.25%.     

煤矿综掘面泡沫降尘技术研究与实施

针对煤矿综掘面粉尘治理技术中存在的不足,采用泡沫降尘新技术结合长压短抽式通风方式进行粉尘防治。以霍尔辛赫矿为例,根据井下实际情况,利用GAMB IT和FLUENT建立掘进巷道的几何模型,并对巷道掘进通风过程中粉尘分布规律进行解算,将模拟结果和现场实测数据对比,确定掘进面回风侧的高浓度粉尘分布区。对掘进面煤样进行湿润性试验,确定最佳的发泡剂添加比例。综合以上情况,泡沫降尘技术实施时采用环形前置式喷头布置,发泡剂添加比例定为10‰,并在回风侧距掘进面5 m、距底板2 m处设置风筒,将高浓度粉尘抽出并沉降。现场实测数据显示,泡沫降尘技术降尘效率明显高于喷雾降尘技术。使用泡沫降尘时,在司机侧测得全尘及呼吸性粉尘降尘效率分别达到75.4%和74.7%。     

膨胀聚苯乙烯热分解动力学分析和寿命预测

针对既有聚苯乙烯泡沫类外墙外保温系统的防火问题,在空气和氮气气氛下对非阻燃和阻燃型膨胀聚苯乙烯泡沫进行了热重分析。样品由10℃/min、20℃/min、40℃/min和50℃/min四个升温速率从室温加热至800℃。热分解动力学参数由Flynn-Wall-Ozawa(FWO)等转化率方法和多参数非线性回归方法(multivariate non-linear re-gression method)计算,结果表明六溴环十二烷(HBCD)阻燃剂可一定程度上提高EPS的热稳定性。EPS在空气和氮气气氛下热解可认为是单步反应。非阻燃聚苯乙烯泡沫在空气和氮气气氛下的热解过程可由自催化n阶反应机理描述。阻燃EPS在空气气氛下的热解机理为自催化n阶反应,在氮气气氛下则为n阶反应机理。基于动力学参数和反应机理,对聚苯乙烯泡沫在不同温度下的寿命进行了预测。     

三相内循环流化床光催化反应器及其性能

依据流态化原理,设计出一种三相内循环流化床光催化反应器,对反应器的水力特性做了推算,确定了反应器的操作影响因素.对罗丹明B的降解实验结果显示出优越的性能,依据催化剂投加量及初始光强的不同,反应半衰期在4-10.5min之间.