Aerosol and bioaerosol particle size and dynamics from defective sanitary plumbing systems

Aerosols are readily transported on airstreams through building sanitary plumbing and sewer systems, and those containing microbial pathogens (known as bioaerosols) are recognized as contributors to infection spread within buildings. When a defect occurs in the sanitary plumbing system that affects the system integrity, a cross-transmission route is created that can enable the emission of bioaerosols from the system into the building. These emission occurrences are characterized as short-burst events (typically <1 min in duration) which make them difficult to detect and predict. The characterization of these emission events is the focus of this research. Two methods were used to characterize bioaerosol emission events in a full-scale test rig: (a) an Aerodynamic Particle Sizer (APS) for particle size distribution and concentrations; and (b) a slit-to-agar sampler to enumerate the ingress of a viable tracer microorganism (Pseudomonas putida). The APS data confirmed that most particles (>99.5%) were <5 μm and were therefore considered aerosols. Particles generated within the sanitary plumbing system as a result of a toilet flush leads to emissions into the building during system defect conditions with an equivalence of someone talking loudly for over 6 and a half minutes. There were no particles detected of a size >11 μm anywhere in the system. Particle count was influenced by toilet flush volume, but it was not possible to determine if there was any direct influence from airflow rate since both particle and biological data showed no correlation with upward airflow rates and velocities. Typical emissions resulting from a 6 L toilet flush were in the range of 280–400 particles per second at a concentration of typically 9–12 number per cm³ and a total particle count in the region of 3000 to 4000 particles, whereas the peak emissions from a 1.2 L toilet flush were 60–80 particles per second at a concentration of 2.4–3 number per cm³ and a total particle count in the region of 886 to 1045 particles. The reduction in particles is in direct proportion to the reduction in toilet flush volume. The slit-to-agar sampler was able to provide viable time course CFU data and confirmed the origin of the particles to be the tracer microorganism flushed into the system. The time course data also have characteristics consistent with the unsteady nature of a toilet flush.     

国产T800级炭纤维表面特性及其复合材料微观界面性能

采用扫描电镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱(XPS)等测试方法表征了两种国产上浆/去浆T800级炭纤维的表面特性,并通过单丝断裂实验测试了单丝复合体系微观界面剪切强度(IFSS),在此基础上研究了炭纤维表面特性对单丝复合体系微观界面性能及其耐湿热性能的影响。结果表明:去浆后炭纤维表面含氧活性官能团含量降低,粗糙度增加,与基体树脂的界面结合强度增大;湿热环境对复合材料的微观界面性能影响显著,尤其是破坏了纤维/基体间的化学键合作用,但去湿后部分界面性能可恢复。     

上浆剂对国产T700级碳纤维复合材料界面性能的影响

采用扫描电镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱(XPS)等测试方法表征了上浆/未上浆国产T700级(MT700)碳纤维的表面特性,并通过单丝断裂实验测试了单丝复合体系微观界面剪切强度(IFSS),在此基础上研究了碳纤维表面特性对单丝复合体系微观界面性能及其耐湿热性能的影响.研究表明:MT700碳纤维表面上浆剂改善了纤维/基体微观界面强度及其耐湿热性能;湿热环境对复合材料的微观界面性能影响显著,尤其是造成纤维/基体间的化学键合作用破坏,去湿后部分界面性能可恢复.     

利用动态光散射研究包覆材质对纳米茄红素胶囊粒径的影响

利用微乳化技术与复合团聚法制备了单层、双层及多层包覆的纳米茄红素胶囊,并以动态光散射法先后测量分析了包覆材质对这些纳米胶囊的粒径大小及其分布的影响。研究结果表明,以碱处理动物胶单层包覆的纳米茄红素胶囊,其在pH为6.5的磷酸盐缓冲液中会出现比较严重的聚集现象;以碱处理动物胶与k-红藻胶双层包覆的纳米茄红素胶囊,其在pH为5.5的磷酸盐缓冲液中也会出聚集现象,但比单层包覆时要小很多;而多层包覆的纳米茄红素胶囊可在pH为5.5的磷酸盐缓冲液中具有良好的分散性,且没有出现聚集现象。     

XQ-CR系列造纸松香胶的应用研究

XQ-CR系列松香胶系由国家“九五”科技攻关项目“造纸用高效中性施胶剂、增干强剂、助留助滤剂的研究开发与应用”西北轻工业学院课题组研究开发 .本文对该系列的 8种松香胶进行了造纸应用试验 ,对其施胶条件进行了优化和讨论 ,并与 TL阴离子松香胶进行了施胶效果对比 .实验证明 XQ-CR系列松香胶中以 CR-1 (-)和 CR-2 0 6( )施胶效果最好 ,且抗张强度增加 ,完全达到项目合同要求的技术指标     

经纱上浆浆料及浆纱机的现状与发展

本文综述了变性淀粉、聚乙烯醇、丙烯酸（酯）３大类主浆料的现状及发展方向，并概述了新型浆纱机的特点     

新型液状强化松香皂胶的研制

试制了二种液状强化松香皂胶 ,其施胶性能超过国内膏状松香皂胶 ,达到日本同类产品的性能。     

用异型孔轧制消除钢管定减径内多边形缺陷

就钢管定减径中普遍出现的内多边形缺陷进行了分析 ,提出用孔型适当变异的轧制方法并给出计算公式 .结果表明 ,通过异型孔定减径可使内多边形缺陷得到有效缓解     

从环保角度谈织物后整理对上浆的要求

文章通过对酶退浆、碱退浆、氧化剂的作用机理、上浆性能、效果及对环境的影响，分析得出从退浆的性能、对纤维的损伤、退浆废水对环境的污染等方面考虑，应该大力提倡少用、不用PVA浆料，特别是完全醇解型的1799PVA浆料。     

Sizing oxidation systems as heat and power recovery

There are large numbers of manufacturing processes that involve emissions of controlled chemical vapours also referred to as volatile organic compounds (VOC). The two most common processes used in industry to separate VOCs before they are emitted to the atmosphere are condensation and oxidation. Condensation requires a refrigeration system that would separate the VOC from the exhaust stream. Oxidation, sometimes known as afterburner or incineration, requires high thermal energy to combust the VOC. Both abatement technologies involve large capital costs. In the case of combusting the VOC, fuel is usually added to the air/VOC mixture for proper air/fuel ratio. The resulting high temperature gas from the energy intensive process is sometimes recovered as an offshoot of the VOC destruction process. Typically, oxidation systems are sized solely with elimination of VOC in mind; heat recovery from the system is opted for as a secondary opportunity, usually at a later stage. This paper demonstrates that combining the oxidation process with combined heat and power (CHP) to address the total site energy requirement could have significant energy saving and economic benefits to sizing the oxidation for VOC destruction marking heat recovery as a spin‐off. Copyright © 2005 John Wiley & Sons, Ltd.