Corrosion of hot-dip-galvanised steel and zinc alloy-coated steel in ammonia and ammonium chloride

There are many potential causes of corrosion in animal buildings. Animals exhale large quantities of moisture into the air creating high relative humidity in the building if the moisture is not properly vented. High humidity increases the potential for condensation. In addition, ammonia may be found in large quantities in animal buildings. Ammonia is released from manure and urine. In addition, ammonium chloride is used as a nitrogen source in fertilisers. In this study, the atmospheric corrosion of hot-dip-galvanised steel and zinc alloy-coated steel such as zinc–aluminium and zinc–aluminium–magnesium has been studied in atmospheres containing different levels of ammonia. Investigations have also been conducted at different levels of ammonium chloride. The results are discussed in view of the mechanisms of corrosion of zinc and zinc alloy-coated steel in ammonia and ammonium chloride-containing environments.     

Investigation on the effectiveness of the repair method 8.3 “Corrosion protection by increasing the electrical resistivity” in chloride-containing concrete Part 2: Chloride redistribution in concrete after application of a system sealing surface protective coating

This DFG-funded research project aimed to gain a better understanding of the mechanisms of the W-Cl repair principle within the framework of fundamental investigations, to contribute to the creation of the necessary basis for a broader application of the repair principle in practice. The focus was on the development of a model to describe the chloride redistribution after the application of a system sealing surface protective coating. On the basis of Fick's second law of diffusion, a mathematical model with a self-contained analytical solution was developed, with the help of which the chloride redistribution after application of a system sealing surface protective coating can be calculated under the idealized assumption of complete water saturation of the concrete. Furthermore, the influence of the dehydration of the concrete, expected as a result of the application of the repair principle W-Cl, on the chloride redistribution was investigated. On the basis of laboratory tests and numerical simulations, material-specific reduction functions were developed to quantify the relationship between the chloride diffusion coefficient and the ambient humidity.     

Inferring kinetic dissolution of NaCl in aqueous glycol solution using a low-cost apparatus and population balance model

An experimental methodology for inferring brine dissolution rate in monoethylene glycol (MEG) solutions at different temperatures using a webcam combined with a mathematical model is presented. The measurement system is designed to track the RGB (red, green, and blue) colour variations during the dissolution process. A dynamic model augmented with the population balance equation is applied to describe the dissolution process. Moreover, the dissolution rate is consistently related to the temperature and MEG concentration through the driving force based on the Gibbs energy and chemical affinity. The applied low-cost measurement apparatus proved to be a useful resource for tracking the dissolution dynamics in a wide range of undersaturation.     

Volatile organic compound profiles of yoghurt produced from cow's milk with different somatic cell counts

The present study aimed to investigate the effect of somatic cell count (SCC) of raw cow's milk on the volatile organic compound (VOC) profiles of yoghurt. Test yoghurt samples were produced from three batches of cow's milk with low, medium and high SCC, respectively. The VOCs were determined by gas chromatography–mass spectrometry (GC–MS) analysis. A lower diacetyl and acetoin content and a higher content of 2‐heptanone, and butanoic and hexanoic acids were established in the yoghurt samples from batches with high SCC of above 1 000 000 cells/cm³. The increased SCC of cow's milk had a negative effect on the volatile organic compound profiles of yoghurt.     

对海水进行混凝除浊预处理研究

介绍采用聚合氯化铁（PFC）为絮凝剂，对海水进行混凝除浊预处理方法。考察了原海水pH、搅拌速度、反应时间及PFC用量对海水预处理效果的影响。结果表明，在原海水pH凋至9．0，搅拌速度控制在200min^-1，反应时间选择8—10min，PFC用量0．10μg／g的最佳条件下，能使处理后的海水浊度降至0．05mol／L，而联产的酸性废水中和剂浆料中Mg（OH）2含量在25％～45％，大肠菌群的去除率大于89．3％。     

氢型丝光沸石催化剂催化α-蒎烯合成α-松油醇

在相转移助剂苄基三乙基氯化铵(BTEAC)存在下,以氢型丝光沸石(HM)为催化剂,原料α-蒎烯经开环、重排及水合反应一步法合成了α-松油醇。研究了各种因素对α-蒎烯转化率及α-松油醇收率的影响,采用5因素4水平L16(45)进行了正交实验,得出最佳的工艺条件:反应温度80℃,w(BTEAC)=15%,m(HM)∶m(α-蒎烯)=0.6,反应时间40h,m(乙酸乙酯)∶m(α-蒎烯)=0.9。在此条件下,α-蒎烯转化率为75.2%,α-松油醇收率为42.0%。用气相色谱-质谱联用仪对反应产物进行分析,共鉴定出14种化合物,主要成分为α-松油醇、α-蒎烯、柠檬烯、桉叶油素、异松油烯、龙脑等。实验得到的α-松油醇具有光学活性,旋光值[α]=+61°,同时香气纯正,可用于制作香料。     

直接氯化法合成对硝基氯化苄

介绍了以对硝基甲苯和氯气为原料 ,在催化剂存在下合成对硝基氯化苄的方法 ,考察了催化剂种类、反应温度、溶剂配比等因素对反应的影响 ,优化的反应条件为 :对硝基甲苯用量 1 3 7g,对硝基甲苯 /邻二氯苯 (摩尔比 ) =1∶ 0 .6,w (偶氮二异丁腈 ) =0 .6% ,反应时间 3 h,反应温度 1 60℃ ,产物单程收率大于 65 % ;将反应混合物中未反应的原料分离后 ,以无水乙醇为溶剂结晶纯化 ,物料 /溶剂 (摩尔比 ) =1∶ 1 .5时晶体含量在 99.0 %以上 ,结晶收率达 67     

医用聚氯乙烯材料的表面光接枝改性

研究了在不排氧氛围下 ,紫外光照射 ,以二苯甲酮 (BP)为光引发剂 ,甲基丙烯酸缩水甘油酯(GMA)在医用聚氯乙烯 (PVC)薄膜表面的气相接枝聚合。探讨了反应条件对接枝结果的影响 ,并用正交法指出了影响因素的显著性。用傅立叶红外 (FT- IR)、水接触角作为接枝改性结果的表征。FT- IR谱图表明 GMA已接枝到 PVC膜表面。水接触角由接枝前的 78°下降到 5 4°