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811.
812.
Research on the job involvement-organizational tenure relationship has shown no consistent relationship, but recent job and career experience models suggest that a relationship should be found. Using data from three organizations (n = 216), polynomial regression analysis revealed a curvilinear job involvement-organizational tenure relationship. This finding is discussed with reference to changes in workplace sensemaking that occur as work experience is accumulated. 相似文献
813.
The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products (DBPs). Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the environment. Only a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes (THMs) and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water. 相似文献
814.
Clara H. Jeong Edward J. Machek Morteza Shakeri Stephen E. Duirk Thomas A. Ternes Susan D. Richardson Elizabeth D. Wagner Michael J. Plewa 《环境科学学报(英文版)》2017,29(8):173-182
The presence of iodinated X-ray contrast media (ICM) in source waters is of high concern to public health because of their potential to generate highly toxic disinfection by-products (DBPs). The objective of this study was to determine the impact of ICM in source waters and the type of disinfectant on the overall toxicity of DBP mixtures and to determine which ICM and reaction conditions give rise to toxic by-products. Source waters collected from Akron, OH were treated with five different ICMs, including iopamidol, iopromide, iohexol, diatrizoate and iomeprol, with or without chlorine or chloramine disinfection. The reaction product mixtures were concentrated with XAD resins and the mammalian cell cytotoxicity and genotoxicity of the reaction mixture concentrates was measured. Water containing iopamidol generated an enhanced level of mammalian cell cytotoxicity and genotoxicity after disinfection. While chlorine disinfection with iopamidol resulted in the highest cytotoxicity overall, the relative iopamidol-mediated increase in toxicity was greater when chloramine was used as the disinfectant compared with chlorine. Four other ICMs (iopromide, iohexol, diatrizoate, and iomeprol) expressed some cytotoxicity over the control without any disinfection, and induced higher cytotoxicity when chlorinated. Only iohexol enhanced genotoxicity compared to the chlorinated source water. 相似文献
815.
Environmental assessment of green hardboard production coupled with a laccase activated system 总被引:1,自引:0,他引:1
Sara González-García Gumersindo FeijooCarol Heathcote Andreas KandelbauerM. Teresa Moreira 《Journal of Cleaner Production》2011,19(5):445-453
European consumption of wood-based panels reached record levels in recent years driven mostly by demand from end-use sectors: residential construction, furniture, cabinets, flooring and mouldings. The main panel types are composite boards such as particleboard, high density fiberboard (HDF), medium-density fiberboard (MDF) and other adhesively bonded composites such as plywood and wet-process fiberboard (hardboard). The synthetic resins used in their manufacture come from non-renewable resources, such as oil and gas. Several consequences are associated to this type of adhesives: variation in the availability and cost of these wood adhesives depends on raw materials, the formaldehyde emissions as well as the limited recyclability of the final product. Hence, in the search for alternatives to petroleum-based wood adhesives, efforts are being devoted to develop adhesives by using phenolic substitutes based on lignin, tannin or starch. In this context, the forest industry is increasingly approaching to enzyme technology in the search of solutions. The main goal of this study was to assess the environmental impacts during the life cycle of a new process for the manufacture of hardboards manufacture, considering the use of a two-component bio-adhesive formulated with a wood-based phenolic material and a phenol-oxidizing enzyme. This new product was compared to the one manufactured with the conventional phenol-formaldehyde resin. The study covers the life cycle of green hardboards production from a cradle-to-gate perspective, analysing in detail the hardboard plant and dividing the process chain in three subsystems: Fibers Preparation, Board Forming and Board Finishing.Auxiliary activities such as chemicals, bio-adhesive, wood chips, thermal energy and electricity production and transport were included within the system boundaries.Global warming (GW), photochemical oxidant formation (PO), acidification (AC) and eutrophication (EP) were the impact categories analysed in this study. Additionally, the cumulative energy demand was evaluated as another impact category. According to the results, four stages significantly influenced the environmental burdens of the production system: laccase production, on-site thermal energy and electricity production as well as wood chipping stage. Due to the environmental impact associated to the production of green bonding agents, a sensitivity analysis with special focus on the eutrophying emissions was carried out by evaluating the amount of laccase and lignin based phenolic material used. The combined reduction in both bonding agents may slightly reduce the contributions to this impact category. In addition, a hypothetical scenario with no laccase and with a higher concentration of the lignin based material (25% more) could improve the environmental profile in all impact categories with a reduction of 1.5% in EP.Further research should focus mainly on laccase production, in order to reduce its energy demand as well as on the amount of green adhesive required to obtain mechanical and swelling properties similar to those of conventional hardboard. 相似文献
816.
817.
Xianbao Shen Zhiliang Yao Qiang Zhang David Vance Wagner Hong Huo Yingzhi Zhang Bo Zheng Kebin He 《环境科学学报(英文版)》2015,27(5):209-220
A database of real-world diesel vehicle emission factors, based on type and technology, has been developed following tests on more than 300 diesel vehicles in China using a portable emission measurement system. The database provides better understanding of diesel vehicle emissions under actual driving conditions. We found that although new regulations have reduced real-world emission levels of diesel trucks and buses significantly for most pollutants in China,NOx emissions have been inadequately controlled by the current standards, especially for diesel buses, because of bad driving conditions in the real world. We also compared the emission factors in the database with those calculated by emission factor models and used in inventory studies. The emission factors derived from COPERT (Computer Programmer to calculate Emissions from Road Transport) and MOBILE may both underestimate real emission factors, whereas the updated COPERT and PART5 (Highway Vehicle Particulate Emission Modeling Software) models may overestimate emission factors in China. Real-world measurement results and emission factors used in recent emission inventory studies are inconsistent, which has led to inaccurate estimates of emissions from diesel trucks and buses over recent years. This suggests that emission factors derived from European or US-basedmodels will not truly represent real-world emissions in China. Therefore, it is useful and necessary to conduct systematic real-world measurements of vehicle emissions in China in order to obtain the optimum inputs for emission inventory models. 相似文献
818.
Hanning Sara M. Hua Changji Baroutian Saeid Burrell Rob Taylor Matthew Wright L. James Svirskis Darren 《Journal of Material Cycles and Waste Management》2022,24(4):1603-1611
Journal of Material Cycles and Waste Management - This study aimed to quantify the amount of pharmaceutical waste produced in New Zealand, and determine the composition of pharmaceutical waste from... 相似文献
819.
Grouping Lakes for Water Quality Assessment and Monitoring: The Roles of Regionalization and Spatial Scale 总被引:1,自引:0,他引:1
Cheruvelil KS Soranno PA Bremigan MT Wagner T Martin SL 《Environmental management》2008,41(3):425-440
Regionalization frameworks cluster geographic data to create contiguous regions of similar climate, geology and hydrology
by delineating land into discrete regions, such as ecoregions or watersheds, often at several spatial scales. Although most
regionalization schemes were not originally designed for aquatic ecosystem classification or management, they are often used
for such purposes, with surprisingly few explicit tests of the relative ability of different regionalization frameworks to
group lakes for water quality monitoring and assessment. We examined which of 11 different lake grouping schemes at two spatial
scales best captures the maximum amount of variation in water quality among regions for total nutrients, water clarity, chlorophyll,
overall trophic state, and alkalinity in 479 lakes in Michigan (USA). We conducted analyses on two data sets: one that included
all lakes and one that included only minimally disturbed lakes. Using hierarchical linear models that partitioned total variance
into within-region and among-region components, we found that ecological drainage units and 8-digit hydrologic units most
consistently captured among-region heterogeneity at their respective spatial scales using all lakes (variation among lake
groups = 3% to 50% and 12% to 52%, respectively). However, regionalization schemes capture less among-region variance for
minimally disturbed lakes. Diagnostics of spatial autocorrelation provided insight into the relative performance of regionalization
frameworks but also demonstrated that region size is only partly responsible for capturing variation among lakes. These results
suggest that regionalization schemes can provide useful frameworks for lake water quality assessment and monitoring but that
we must identify the appropriate spatial scale for the questions being asked, the type of management applied, and the metrics
being assessed. 相似文献
820.
Impact of Lime and Ash Applications on Soil Solution Chemistry of an Acidified Podzolic Soil 总被引:2,自引:0,他引:2
Geibe Christine E. Holmström Sara J. M. Van Hees Patrick A. W. Lundström Ulla S. 《Water, Air, & Soil Pollution: Focus》2003,3(4):77-96
Soil solution samples were taken from two sites (Horröd and Hasslöv) in the south part of Sweden to evaluate how soil solution chemistry responded to different treatmentswith dolomite and wood ash. At Horröd, samples were taken four years after application of wood ash, 4.28 ton ha-1 and dolomite, 3.25 ton ha-1. At Hasslöv dolomite, 3.45 ton ha-1 and 8.75 ton ha-1 was applied and samples were taken 15 yr later. It was found that treatment with dolomite at one site (Hasslöv) resulted in higher pH values (<2 pH units) and higher nitrification. It was also found at this site that the total Al and the inorganic Al concentrations decreased with dolomite treatment. The Ca, Mg, DOC, Fe, SO4
2- and Cl- concentrations, mainly in the topsoil, were found to be higher at both sites, following dolomite treatment; Ca and Mg concentrations were 2–8 times higher (<820 M) than in controls (<70 M). Wood ash was found to have less impact. The PO4 concentration in the O2 horizon at Hasslöv decreased due to dolomite-treatment. ANOVA (Analyse of Variance) and PLS (Partial Least Square) were used to evaluate the data from the two sites. 相似文献