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Aluminium uptake and tight binding were studied in multilayered phospholipid liposomes, as a model for cellular uptake of aluminum ions. Most of these studies were conducted with an initial aluminum concentration of 10 μM, while aluminum superficially bound to liposomes was removed by citrate chelation. Maximum uptake and tight binding of aluminium were pH‐dependent. In dimyristoyl phosphatidylcholine (DMPC) liposomes, this maximum occurred in the neutral pH region, while it was shifted towards more acidic pH values in DMPC liposomes containing 20% of acidic phosphatidylserine. The initial rate of aluminum uptake was apparently dependent on the physical state of the liposome membrane. Prior formation of an aluminum‐citrate chelate prevented aluminum uptake and tight binding to DMPC liposomes. 相似文献
855.
《Journal of environmental science and health. Part. B》2013,48(5):501-516
Soil taken from a former cattle tick dip site in NSW Australia, was remediated with a chemical leaching technology. The pre- and post-remediated soil (20g) was dispersed in water (100mL) and subjected to passive diffusion using polymeric membranes. The remediation reduced tDDT from 1174.3μg/g to 102.9μg/g (ash weight basis), which was further reduced to 43.2μg/g with composting. The membranes accumulated 41.3μg tDDT/g from the dip soil, 49.2μg tDDT/g from the chemically leached soil and 3.1μg tDDT/g from the leached composted soil. The chemical leaching removed over 90% of the tDDT, but released soil bound DDT, which was converted to DDE, while 2.99μg/g was accumulated by the membranes from dip soil, 37.52μg/g was accumulated from remediated soil. Composting, however, almost eliminated the availability for passive diffusion by the membranes from 50 – 60μg/g in remediated soil to 3–3.5μg/g in composted soil. Variability studies of the membranes using eight replicates demonstrated that the accumulation by the membranes was reproducible with an average relative error of 20.3% for p,p'-DDT in soil type two, whilst the lowest average relative error for p,p'-DDE was 4.3%, suggesting that triplicate analyses will achieve acceptable accuracy. 相似文献
856.
《International Journal of Sustainable Engineering》2013,6(1):75-83
Ultrafiltration membranes were prepared using cellulose acetate (CA) as a polymer, LiCl and CaCl2 as porogens and methyl-(S)-lactate as a solvent. CA, methyl lactate and the porogens used in this work are obtained from renewable resources; they are biodegradable, non-toxic and non-volatile organic compounds. Flat sheet ultrafiltration membranes were prepared by the phase inversion technique. A molecular weight cut-off between 15 and 35 kDa (polyethylene glycol) and pure water permeability between 13 and 177 litres h? 1m? 2 bar? 1 were obtained. These parameters are in the ideal range for water treatment industry. Improvement of pollutant degree and ecotoxicity of the process was evaluated by ‘green’ metrics by the P (pollutants, persistent and bioaccumulative) and E (ecotoxicity) parameters. Both of these variables were recorded as zero using our method. This study represents a step ahead towards the production of ultrafiltration polymeric membranes by a ‘greener’ process than current methods. 相似文献
857.
烧结烟气选择性催化还原(SCR)脱硝系统补热烟气与热风掺混的均匀性是保证系统脱硝效率的关键。为提高烟风掺混的均匀性,基于伯努利方程设计了等压热风掺混装置,采用数值模拟的方法对全系统流场分布特性进行了研究。结果表明:等压掺混方式可实现大截面、短距离烟道内烟风的迅速混合;SCR脱硝催化剂入口截面温度和氨氮摩尔比均匀稳定,优化后的温度场温度偏差小于±5 ℃,氨氮摩尔比相对标准偏差小于5%;出口NOx含量为15~28 mg/Nm3,低于50 mg/Nm3的超低排放技术指标要求。 相似文献
858.
本文通过对KZ1床层、KZ2床层、KZ1和KZ2复合床层在不同床层厚度条件下,对氯化氰蒸气的动活性进行对比试验,并对试验结果进行分析,得出了后者并非前两者之和,而有了大幅提高的结论。 相似文献
859.
成志钢 《中国特种设备安全》2013,(12):1-3
运用有限元分析软件,分析了不同的自紧压力对车用玻璃纤维环向缠绕气瓶疲劳性能的影响,采用新的许用应力幅度一循环次数曲线代替JB4752,对不同自紧压力下的疲劳寿命进行了计算,认为不经过自紧只打水压试验是无法满足气瓶疲劳试验要求的。 相似文献
860.
本文以博罗县2005—2011年间的环境空气监测数据为依据,采用空气污染综合指数法评价大气环境质量,并运用Spearman秩相关系数预测未来发展趋势。结果表明:博罗县环境空气质量为优,主要污染物为二氧化氮,年日平均浓度呈上升趋势,不显著。 相似文献