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Municipal wastewater is supposed to be one of the most important sources of endocrine-disrupting compounds (EDCs) in water. Therefore, advanced treatments and cost-efficient techniques should be developed to prevent the spread of this type of pollution into the environment. In this view, experiments were conducted in which the removal of 17alpha-ethynylestradiol (EE2), a synthetic and persistent estrogen, from water was monitored in three upstream bioreactors (UBRs), filled with, respectively, sand, granulated activated carbon (GAC) and MnO(2) granules. Tap water, spiked with 15,000ngEE2/L was filtered through the reactors with a hydraulic retention time of approximately 1h. The removal of EE2 in the sand, GAC and MnO(2) reactors was, respectively, 17.3%,>99.8% and 81.7%. The removal in the GAC reactor was mainly due to adsorption. The MnO(2) reactor, however, removed significantly more EE2 than could be predicted from its adsorption capacity, probably thanks to its catalytic properties. These catalytic properties could make it a cost-efficient technique for the removal of EE2, but further research at more environmentally relevant concentrations is needed.  相似文献   
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CAD/CAM systems are the important interface for automating manufacturing processes to accommodate the varying market demands. However, they are often operated in an isolated environment and are unable to communicate with each other. Rapid development and enhancement of the network technology had made it possible for manufacturing processes to be implemented in a distributed environment. The purpose of this study is to develop a dispersed networked multi-axis surface manufacturing system. The proposed research uses the Integrated Definition for Function Modelling (IDEF0) methodology to analyze the manufacturing activities and adopts the Common Object Request Broker Architecture (CORBA) standard as the infrastructure of software components. Using IDEF0, the manufacturing activities can be analyzed and represented as a hierarchical and structural functional model. The developed system has the “plug-and-play” capability and can be integrated with other development teams to achieve information sharing. On-line test of the prototype system has been implemented collaboratively by three development teams and the effectiveness of the developed system has also been confirmed. The developed system has successfully integrated resources of different locations through a network and can effectively reduce the product development and manufacturing time, thus enhancing the global competitiveness of the industry.  相似文献   
4.
Respiratory viral infections have been associated with exacerbations of asthma in humans, and are known to produce airway obstruction and hyperresponsiveness in rats. Virus-induced airway dysfunction may result in part from inflammatory cells and their products, and agents that target these mechanisms might therefore attenuate viral airway injury. The 21-aminosteroid class of drugs has been reported to attenuate tissue injury in a variety of models, and we hypothesized that U-83836E, an orally-active aminosteroid, would prevent the development of airway dysfunction during acute viral illness. Adult rats were inoculated with either parainfluenza type 1 (Sendai) virus or sterile vehicle, treated with either U-83836E 20 mg/kg or water by oral gavage twice daily, and studied on postinoculation day 5, 6 or 7. Anesthetized, paralysed, mechanically ventilated rats were placed in a body plethysmograph for measurements of airway obstruction (resistance, dynamic compliance, eucapneic PaO2), and responsiveness to i.v. methacholine; lungs were lavaged to obtain inflammatory cells. The water-treated virus group was significantly different from the non-infected controls for all variables. Virus-induced hyperresponsiveness was attenuated (P = 0.027) by aminosteroid treatment, although airway obstruction and inflammation were not improved by the treatment. We conclude that 21-aminosteroids may protect airways from virus-induced hyperresponsiveness.  相似文献   
5.
A prospective study of head and neck cancer patients was started to gather information about topographic and clinical characteristics of head and neck cancer, alcohol and nicotine abuse and the delay in diagnosis. More than half of the patients consulted our institution with an advanced stage of disease. As was expected, we found a positive association between the size of the tumour and the clinical stage of the neck. Concerning nicotine and alcohol abuse, our results support the hypothesis that tobacco smoking is more strongly associated with lesions in sites heavily exposed to inhaled smoke, whereas alcohol consumption has a stronger effect on structures belonging to the 'food channel' and reservoir systems. We found no association between delay and tumour stage at diagnosis, but a statistically significant correlation was found between the delay and the tumour site. This leads us to conclude that the tumour stage is determined mostly by the biology of the tumour.  相似文献   
6.
This review was completed in 1976 and describes the then-current knowledge on the problem of reheat cracking in weldments of nuclear pressure vessel steels. The incidence of underclad cracks and structural weld cracks in heat affected zones (HAZ) is described and current theories on the cracking mechanism and controlling factors discussed. Problems concerned with detecting the cracks by destructive and non-destructive methods are outlined. The paper then deals in detail with testing techniques for reheat crack susceptibility and with methods of controlling the problem of underclad and structural weld cracking. Finally, the engineering significance of the cracks in relation to hydrotesting and service is discussed. An appendix gives recommendations for additional work on the subject.  相似文献   
7.
Conventional enrichment of microorganisms on branched nonylphenol (NP) as only carbon and energy source yielded mixed cultures able to grow on the organic compound. However, plating yielded no single colonies capable, alone or in combination with other isolates, of degrading the NP in liquid culture. Therefore, a special approach was used, referred to as "serial dilution-plate resuspension," to reduce culture complexity. In this way, one isolate, TTNP3, tentatively identified as a Sphingomonas sp., was found to be able to grow on NP in liquid culture. Remarkably, this isolate was able to be filtered through a 0.45-micrometer-pore-diameter filter. Moreover, isolate TTNP3 did not form visible colonies on mineral medium with NP, and it formed visible colonies on R2A agar only after a prolonged incubation of 1 week. High-performance liquid chromatography and gas chromatography-mass spectroscopy analysis of the culture media indicated that the strain starts the degradation of NP with a fission of the phenol ring and preferably uses the para isomer of NP and not the ortho isomer. No distinct accumulation of an intermediary product could be observed.  相似文献   
8.
In 3 experiments, subjects named pictures with low- or high-frequency superimposed distractor words. In a 1st experiment, we replicated the finding that low-frequency words induce more interference in picture naming than high-frequency words (i.e., distractor frequency effect; Miozzo & Caramazza, 2003). According to the response exclusion hypothesis, this effect has its origin at a postlexical stage and is related to a response buffer. The account predicts that the distractor frequency effect should only be present when a response to the word enters the response buffer. This was tested by masking the distractor (Experiment 2) and by presenting it at various time points before stimulus onset (Experiment 3). Results supported the hypothesis by showing that the effect was only present when distractors were visible, and if they were presented in close proximity to the target picture. These results have implications for the models of lexical access and for the tasks that can be used to study this process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
A tight correspondence has been postulated between the representations of number and space. The spatial numerical association of response codes (SNARC) effect, which reflects the observation that people respond faster with the left-hand side to small numbers and with the right-hand side to large numbers, is regarded as strong evidence for this correspondence. The dominant explanation of the SNARC effect is that it results from visuospatial coding of magnitude (e.g., the mental number line hypothesis). In a series of experiments, we demonstrated that this is only part of the story and that verbal-spatial coding influences processes and representations that have been believed to be purely visuospatial. Additionally, when both accounts were directly contrasted, verbal-spatial coding was observed in absence of visuospatial coding. Relations to other number–space interactions and implications for other tasks are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
This paper deals with the hybrid (plasma + gas tungsten arc) welding properties of 12 mm thick modified 12% Cr ferritic stainless steel complying with EN 1.4003 and UNS S41003 steels with a carbon content of 0.01% to improve the weldability. The root passes of the butt welds were produced with plasma arc welding (PAW) without filler metal while gas tungsten arc welding (GTAW) was used to accomplish filler passes with 309 and 316 austenitic stainless steel type of consumables, respectively. The joints were subjected to tensile and bend tests as well as Charpy impact toughness testing at −20 °C, 0 °C and 20 °C. Examinations were carried out in terms of metallography, chemical analysis of the weld metal, ferrite content, grain size and hardness analyses. Although 309 consumables provided higher mean weld metal toughness values compared to 316 (90 J vs. 75 J), 316 type of consumables provided better mean HAZ toughness data for the joints (45 J vs. 20 J) at −20 °C. Toughness properties of the welds correspond with those of microstructural features including grain size and ferrite content.  相似文献   
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