1,158 research outputs found

    Quantifying resource footprints of products and services as the exergy extracted from nature by different countries

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    Although our whole society depends on the use of natural resources, they are not always used in a sustainable way. To achieve a more sustainable development, resource consumption needs to be measured. Therefore, resource footprint frameworks are being developed. These frameworks integrate inventory methodologies, which quantify the specific resources consumed by a system, with resource accounting impact methodologies, addressing the environmental impact of resource consumption, e.g. the Ecological Footprint. To calculate the inventory of systems at micro-level (processes, products), process-models are generally used, as applied in process-based Life Cycle Analysis (LCA). For systems at meso- and macro-level (sectors, countries), economic input-output/IO-models are mostly used instead of process-models, as applied in IO-analysis and IO-based LCA. The objective of this paper is the development of a new resource footprint framework called IO-CEENE, in which a world IO-model (Exiobase), providing a global perspective, is integrated with the CEENE methodology (Cumulative Exergy Extraction from the Natural Environment), providing a more complete resource range. CEENE is an exergy-based method, thus it considers not only the resource quantity but also the extent to which consumption removes resource quality. Among the exergy-based methods, CEENE covers the largest number of resource groups: fossil fuels, nuclear resources, metals, minerals, land resources, water resources, abiotic renewable resources and atmospheric resources. This new framework allows one to calculate resource footprints of products or services consumed in different countries as the exergy extracted from nature. The way the framework is constructed makes it possible to show which resources and countries contribute to the total footprint. This is illustrated by a case study on wheat production

    Zin en onzin van kennismanagement

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    Different perspectives on organizational learning

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    Development and validation of high- resolution mass spectrometry-based approaches for active and passive sampling of emerging organic micropollutants in the marine environment

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    Nowadays, a growing societal and scientific concern exists regarding the widespread occurrence of potential endocrine disrupting compounds (EDCs) in the aquatic environment. The most important potential EDC classes comprise the steroid hormones, plasticizers and plastics additives. Indeed, even at very low concentrations, steroidal EDCs may affect the hormonal system of aquatic organisms, while leaching of plasticizers and plastics additives into the aquatic environment is inevitable as a result of their extensive use in numerous applications. Until now, limited knowledge was available on the presence of steroidal EDCs, plasticizers and plastics additives in the marine environment. Therefore, an urgent need existed to monitor the fate and effects, as well as the environmental and human risks posed by these emerging micropollutants in marine ecosystems. Given our lack of knowledge on the occurrence of EDCs, the main goal of this dissertation was to investigate the prevalence of steroidal EDCs, plasticizers and plastics additives in the marine environment. To this end, new analytical methods targeting a broad range of compounds (n=97) were developed, optimized and validated. Not only instantaneous sampling techniques were examined, but also novel long-term sampling techniques were investigated (i.e.: active and passive sampling). Both were applied extensively in the Belgian Part of the North Sea (BPNS), from 2016 to 2018. Finally, the potential negative effects of the detected concentrations were assessed. Chapter I entails a comprehensive overview on the fate of EDCs in the aquatic environment. Additionally, a summary on the predominant analytical strategies employed for sampling, extraction and detection of EDCs is provided, including a detailed description of the analytical platforms and their capabilities. This chapter ends with the conceptual framework and research objectives of this PhD study, as outlined in research chapters II, III and IV. The aim of chapter II was to develop and validate two accurate ultra-high performance liquid chromatography (UHPLC) coupled to high-resolution mass spectrometry (HRMS) methods for the quantification of steroidal EDCs (n=70), plastics additives and plasticizers (n=27) in seawater. For each target group, the instrumental methods were combined with optimised large-volume solid phase extraction procedures, as it was the goal to detect residues in the marine environment. The developed methods showed excellent performance characteristics (according to 2002/657/EC and Eurachem guidelines) and versatility to fresh water samples. In chapter III, a new sorbent phase for passive sampling purposes was investigated that enables to capture a broad polarity range of emerging organic compounds (log P range between 1.30 to 9.85). For 131 compounds the sampler-water partition coefficients (Ksw) could be determined by using a static exposure design. Calculation of the thermodynamic parameters indicated that the main partitioning process for the (alkyl)phenols, personal care products, pesticides and pharmaceuticals was driven by physisorption, while the uptake of phthalates and steroidal EDCs was mediated by a combination of physisorption and chemisorption. It was clearly demonstrated in this chapter that hydrophilic divinylbenzene can be used for passive sampling. Using the newly developed methodologies from chapters II and III, active and passive samplers were intensively deployed in the Belgian Part of the North Sea, as discussed in chapter IV. The detected concentrations for the steroidal EDCs were mainly below 10 ng L-1, while for the plastics additives and plasticizers concentrations between 10 and 1000 ng L-1 were observed. Concentrations detected by passive sampling, were generally lower than those in active samples. Furthermore, it could be concluded that our proposed strategy for active and passive sampling offers a complementary approach for the measurement of potential EDCs in the marine environment. Ultimately, a risk assessment was performed to investigate the potential risks of the detected compounds to aquatic organisms. Finally, in chapter V, the general discussion and future perspectives of this PhD study are presented. Thereby, it was suggested that future research should focus on the implementation and use of an automized analysis pipeline for suspect and untargeted screening. Also, the development of new passive samplers containing hydrophilic DVB could be promising, as Speedisks showed reduced Ksw as compared to naked sorbent. Moreover, Speedisks could serve as a viable archive tool for sampled EDCs, but this should be investigated more extensively. Finally, a more in-depth evaluation of contaminant levels in Speedisk passive samplers as compared to those in biota could offer an added value towards environmental risk assessment of the findings obtained in this PhD. Overall, this thesis contributes to the establishment of integrated active and passive sampling approaches for monitoring potential EDCs in the marine environment, and more specifically the BPNS

    THE DIPLOMATIC CORRESPONDENCE OF GRAND PENSIONARY JOHAN DE WITT (1625–1672) ONLINE

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