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UV disinfection is a relatively simple and cost-efficient disinfection method, especially for in-home greywater treatment. In this study, a bench scale experiment was performed using a LED collimated UV-C beam with a peak wavelength of 256?nm to determine if potentially pathogenic bacteria such as Staphylococcus aureus may become enriched in a semi-recirculating greywater system with UV as the sole disinfection step. A statistically significant (P?<?0.001) decreasing trend in UV-C efficacy was observed between the 1st and 6th UV exposure-growth cycles of S. aureus (ATCC 25923), resulting in a 1.5 decrease in log10 removal (P?<?0.00000) by the 5th iteration. An eleven-point dose-response curve of the 7th iteration of S. aureus was estimated and compared to the dose-response curve of the original strain; due to a longer apparent shoulder period and a decay constant of lesser degree, the dose required for a 4-log reduction of the enriched S. aureus was estimated to be ~1.9 times greater (22.0?mJ?cm?2 versus 11.8?mJ?cm?2). However, experimental results with S. epidermidis (ATCC 12228) and two wild strains, S. aureus and S. warneri, exhibited no trend of increased resistance. UV doses exceeding 20?mJ?cm?2 are generally sufficient in achieving a 4-log reduction of bacteria in drinking water systems; however, the results exhibited in this study suggest that when recirculation is involved, there may be a need for UV doses exceeding what is necessary for a 4-log reduction to suppress the enrichment of strains which could pose a public health risk.  相似文献   
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It is often, though sometimes only implicitly, assumed that biological/genetic evolution sets neural substrates, that neural substrates fix cognitive abilities, and that cognitive abilities determine the spectrum of cultural practices exhibited by a biological species. We label this view as the “bottom‐up‐only” view. In this paper we will show that such a “chain of dependence” is much looser than usually assumed, especially as far as recent periods (the last 800,000 years vs. the last 7 million years or more) are considered. We will provide evidence and arguments supporting the idea that cultural innovation may have direct and ascertainable effects both on the cognitive capabilities of populations of hominins (via what we call “cultural exaptation”) and on the neural substrates of the individuals in those populations (via what we call “cultural neural reuse”). Together, cultural exaptation and cultural neural reuse may give raise to a plausible general mechanism for cognitive evolution in which culture is the driving force, thus offering a “top‐down‐also” view of human evolution.  相似文献   
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Bottom ash (BA) is an industrial solid waste formed by the burning of coal. The environmental problems and storage costs caused by this waste increase with every passing day. In this study, the use of BA as an additive (clay substitute) in fired brick production was investigated. The study consisted of two stages. In the first stage, cylinder blocks were produced from clay used in brick production. The second stage was the examination of the experimental substitution of clay with 10, 20, 30 and 40% BA. Samples were fired at 900, 1000, 1100 and 1150 °C to produce fired brick samples. The unit weight, compressive strength (before and after freeze–thawing) and water absorption were analyzed for the samples. The unit weight values decreased in the samples containing BA. The mechanical properties met the conditions prescribed in the relevant standards; i.e., all of the samples fired at 1100 and 1150 °C had a sufficient compressive strength over 20 MPa. The high potential of fired bricks for the construction industry was proved. BA can be used as a clay substitute, while the developed protocol can be used to effectively produce fired bricks.  相似文献   
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Ontologies are useful tools for sharing and exchanging knowledge. However ontology construction is complex and often time consuming. In this paper, we present a method for building a bilingual domain ontology from textual and termino-ontological resources intended for semantic annotation and information retrieval of textual documents. This method combines two approaches: ontology learning from texts and the reuse of existing terminological resources. It consists of four steps: (i) term extraction from domain specific corpora (in French and English) using textual analysis tools, (ii) clustering of terms into concepts organized according to the UMLS Metathesaurus, (iii) ontology enrichment through the alignment of French and English terms using parallel corpora and the integration of new concepts, (iv) refinement and validation of results by domain experts. These validated results are formalized into a domain ontology dedicated to Alzheimer’s disease and related syndromes which is available online (http://lesim.isped.u-bordeaux2.fr/SemBiP/ressources/ontoAD.owl). The latter currently includes 5765 concepts linked by 7499 taxonomic relationships and 10,889 non-taxonomic relationships. Among these results, 439 concepts absent from the UMLS were created and 608 new synonymous French terms were added. The proposed method is sufficiently flexible to be applied to other domains.  相似文献   
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Background. To evaluate the benefits of dialyzer reuse for hemodialysis (HD) patients, including the cost of HD treatment and patient's survival, a comparison was made regarding the standard practice of single-use dialysis. Methods. From January 1, 2005, to December 31, 2005, a total of 128,232 successive HD treatments in 822 patients in Chang Gung Memorial Hospital-Kaohsiung Medical Center were included in this study. Results. Approximately 54.25% (446/822) of patients reused dialyzers. The average times of dialyzer reuse was 2.54. The annual hollow fiber cost is reduced by $241,054.08 U.S. dollars (NT $7,834,257.60). The annual cost of hollow fiber was reduced by $540.48 U.S. dollars (NT $17,565.60) in one patient with dialyzer reuse. The mortality rates in dialyzer reuse and single use groups were 3.1% and 10.9% within one year (p < 0.0001). Multiple logistic regressions showed that single use compared with reuse was associated with higher mortality after adjusting co-morbid conditions including age, diabetes mellitus, etc. Conclusions. We concluded that the benefits of dialyzer reuse included safety in our center and reduction in cost during a 12-month period. Dialyzer reuse may be a safe alternative.  相似文献   
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介绍了分散式污水处理系统的概念、类型及特点.综述了近年来国内外分散式污水处理系统的研究现状,以德国DEUS 21系统为例着重介绍了分散式污水处理工艺、处理技术等方面的研究进展.  相似文献   
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