Phototransformation of selected pharmaceuticals during UV treatment of drinking water

The kinetics of Ultraviolet C (UV-C)-induced direct phototransformation of four representative pharmaceuticals, i.e., 17alpha-ethinylestradiol (EE2), diclofenac, sulfamethoxazole, and iopromide, was investigated in dilute solutions of pure water buffered at various pH values using a low-pressure and a medium-pressure mercury arc lamp. Except for iopromide, pH-dependent rate constants were observed, which could be related to acid-base equilibria. Quantum yields for direct phototransformation were found to be largely wavelength-independent, except for EE2. This compound, which also had a rather inefficient direct phototransformation, mainly underwent indirect phototransformation in natural water samples, while the UV-induced depletion of the other pharmaceuticals appeared to be unaffected by the presence of natural water components. At the UV-C (254 nm) drinking-water disinfection fluence (dose) of 400 Jm(-2), the degree of depletion of the select pharmaceuticals at pH=7.0 in pure water was 0.4% for EE2, 27% for diclofenac, 15% for sulfamethoxazole, and 15% for iopromide, indicating that phototransformation should be seriously taken into account when evaluating the possibility of formation of UV transformation products from pharmaceuticals present as micropollutants.     

Older adults' configural processing of faces: Role of second-order information.

Problems with face recognition are frequent in older adults. However, the mechanisms involved have only been partially discovered. In particular, it is unknown to what extent these problems may be related to changes in configural face processing. Here, we investigated the face inversion effect (FIE) together with the ability to detect modifications in the vertical or horizontal second-order relations between facial features. We used a same/different unfamiliar face discrimination task with 33 young and 33 older adults. The results showed dissociations in the performances of older versus younger adults. There was a lack of inversion effect during the recognition of original faces by older adults. However, for modified faces, older adults showed a pattern of performance similar to that of young participants, with preserved FIE for vertically modified faces and no detectable FIE for horizontally modified faces. Most importantly, the detection of vertical modifications was preserved in older relative to young adults whereas the detection of horizontal modifications was markedly diminished. We conclude that age has dissociable effects on configural face-encoding processes, with a relative preservation of vertical compared to horizontal second-order relations processing. These results help to understand some divergent results in the literature and may explain the spared familiar face identification abilities in the daily lives of older adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

CAPACITY OF ACTIVATED SLUDGE SOLIDS FOR VIRUS ADSORPTION

The first significant reduction in wastewater virus concentration occurs in the biological treatment process, either by removal of solid matter in which virus is embedded or by adsorption of virus to the biomass. In addition, the effectiveness of subsequent disinfection and the ultimate fate of treatment plant effluent virus are dependent on the extent of virus association with small suspended particles. This report is a study of adsorption of Type I poliovirus to solids collected from an activated sludge unit and resuspended in filtered final effluent. Virus adsorption capacity was correlated by an isotherm relationship which includes the effect of decreasing capacity with increasing solids concentration. This effect is probably caused by decreased solids surface area due to solids aggregation. The results indicate smaller capacity at typical activated sludge mixed liquor solids concentration than would be predicted from previous studies, and that only about 20% of total virus are adsorbed at low solids concentration typical for treatment plant effluent.     

上转换纳米棒NaGdF_4:Yb~(3+),Tm~(3+)的合成、形貌调控及其荧光研究

水热法制备了高纯度六方相NaGdF_4:Yb~(3+),Tm~(3+)纳米颗粒,采用以聚乙烯吡咯烷酮(PVP)为表面活性剂,通过X射线衍射(XRD),透射电镜(TEM),元素分析(mapping),荧光光谱学等手段对所制备的NaGdF_4纳米棒的结构与形貌进行表征,发现提高反应时间对粒子尺寸和形貌的影响不明显,表面活性剂的浓度对发光强度有明显影响,并着重研究粒子长径比和发光强弱关系的特点。结果表明:共掺杂NaGdF_4纳米颗粒在980 nm下可发射出475 nm蓝光,以及695 nm红光800 nm的强近红外光。且发现颗粒长径比越大,荧光强度越强,进一步探索了颗粒长径比调控的荧光增强机理。     

The effect of microwave energy on three-way automotive catalysts poisoned by SO2

Recent studies suggest that microwave energy can be employed in catalysis and that the results differ from conventional heating. The influence of microwave energy on automotive exhaust catalysis in the presence and absence of a catalyst poison (SO₂) was studied. The conclusion is that microwave energy can induce carbon monoxide (CO) lightoff (the temperature where 50% of final conversion is achieved) more efficiently than conventional heating and can reverse the poisoning by SO₂ for a commercial three-way catalyst.     

Design,Realization, and Characterization of Advanced Adhesives for Joining Ultra‐Stable C/C Based Components

The aim of this work is to develop high‐performance adhesives to join carbon fiber reinforced composites (C/C) for use in aerospace applications; in order to guarantee sound mechanical strength, a low coefficient of thermal expansion, and ease of application on large components. Several different adhesive formulations, based on phenolic or cyanate‐ester resins (charged with the maximum experimentally feasible amount of carbon‐based fillers), are developed and tested. The measurements of the lap shear strength at room temperature of the C/C joined by means of one phenolic and one cyanate ester‐based resin demonstrates that these formulations are the most suitable for the given application. A complete characterization, by means of viscosimetry, dilatometry, and thermal gravimetric analysis, coupled with gas analysis by means of mass spectroscopy, confirms that the phenolic‐based formulation is the most promising joining material. A nano‐indenter is used to obtain its Young modulus and hardness, both inside the joint and as a bulk cured adhesive.