1. |
- Scheutz, C., et al.
(författare)
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Mitigation of methane emission from an old unlined landfill in Klintholm, Denmark using a passive biocover system
- 2014
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 34:7, s. 1179-1190
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Tidskriftsartikel (refereegranskat)abstract
- Methane generated at landfills contributes to global warming and can be mitigated by biocover systems relying on microbial methane oxidation. As part of a closure plan for an old unlined landfill without any gas management measures, an innovative biocover system was established. The system was designed based on a conceptual model of the gas emission patterns established through an initial baseline study. The study included construction of gas collection trenches along the slopes of the landfill where the majority of the methane emissions occurred. Local compost materials were tested as to their usefulness as bioactive methane oxidizing material and a suitable compost mixture was selected. Whole site methane emission quantifications based on combined tracer release and downwind measurements in combination with several local experimental activities (gas composition within biocover layers, flux chamber based emission measurements and logging of compost temperatures) proved that the biocover system had an average mitigation efficiency of approximately 80%. The study showed that the system also had a high efficiency during winter periods with temperatures below freezing. An economic analysis indicated that the mitigation costs of the biocover system were competitive to other existing greenhouse gas mitigation options. (C) 2014 Elsevier Ltd. All rights reserved.
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2. |
- Timmer, Brian J.J., et al.
(författare)
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Spatially well-defined carbohydrate nanoplatforms : synthesis, characterization and lectin interaction study
- 2016
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 52:83, s. 12326-12329
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Tidskriftsartikel (refereegranskat)abstract
- Two novel dodecasubstituted carbohydrate nanoplatforms based on molecular Borromean rings and dodecaamine cages have been prepared for use in evaluating the importance of the spatial distribution of carbohydrates in their interaction with lectins. The binding affinities of the glyconanoplatforms were characterized using quartz crystal microbalance technology and compared with a monovalent reference and dodecaglycosylated fullerenes.
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3. |
- Monster, J. G., et al.
(författare)
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Quantifying methane emission from fugitive sources by combining tracer release and downwind measurements - A sensitivity analysis based on multiple field surveys
- 2014
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 34:8, s. 1416-1428
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Tidskriftsartikel (refereegranskat)abstract
- Using a dual species methane/acetylene instrument based on cavity ring down spectroscopy (CRDS), the dynamic plume tracer dispersion method for quantifying the emission rate of methane was successfully tested in four measurement campaigns: (1) controlled methane and trace gas release with different trace gas configurations, (2) landfill with unknown emission source locations, (3) landfill with closely located emission sources, and (4) comparing with an Fourier transform infrared spectroscopy (FTIR) instrument using multiple trace gasses for source separation. The new real-time, high precision instrument can measure methane plumes more than 1.2 km away from small sources (about 5 kg h(-1)) in urban areas with a measurement frequency allowing plume crossing at normal driving speed. The method can be used for quantification of total methane emissions from diffuse area sources down to 1 kg per hour and can be used to quantify individual sources with the right choice of wind direction and road distance. The placement of the trace gas is important for obtaining correct quantification and uncertainty of up to 36% can be incurred when the trace gas is not co-located with the methane source. Measurements made at greater distances are less sensitive to errors in trace gas placement and model calculations showed an uncertainty of less than 5% in both urban and open-country for placing the trace gas 100 m from the source, when measurements were done more than 3 km away. Using the ratio of the integrated plume concentrations of tracer gas and methane gives the most reliable results for measurements at various distances to the source, compared to the ratio of the highest concentration in the plume, the direct concentration ratio and using a Gaussian plume model. Under suitable weather and road conditions, the CRDS system can quantify the emission from different sources located close to each other using only one kind of trace gas due to the high time resolution, while the FTIR system can measure multiple trace gasses but with a lower time resolution.
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4. |
- Svenningsson, Birgitta, et al.
(författare)
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Hygroscopic growth and critical supersaturations for mixed aerosol particles of inorganic and organic compounds of atmospheric relevance
- 2006
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Ingår i: Atmospheric Chemistry and Physics. - 1680-7324. ; 6:7, s. 1937-1952
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Tidskriftsartikel (refereegranskat)abstract
- The organic fraction of atmospheric aerosols contains a multitude of compounds and usually only a small fraction can be identified and quantified. However, a limited number of representative organic compounds can be used to describe the water-soluble organic fraction. In this work, initiated within the EU 5FP project SMOCC, four mixtures containing various amounts of inorganic salts (ammonium sulfate, ammonium nitrate, and sodium chloride) and three model organic compounds (levoglucosan, succinic acid and fulvic acid) were studied. The interaction between water vapor and aerosol particles was studied at different relative humidities: at subsaturation using a hygroscopic tandem differential mobility analyzer (H-TDMA) and at supersaturation using a cloud condensation nuclei spectrometer (CCN spectrometer). Surface tensions as a function of carbon concentrations were measured using a bubble tensiometer. Parameterizations of water activity as a function of molality, based on hygroscopic growth, are given for the pure organic compounds and for the mixtures, indicating van't Hoff factors around 1 for the organics. The Zdanovskii-Stokes-Robinson (ZSR) mixing rule was tested on the hygroscopic growth of the mixtures and it was found to adequately explain the hygroscopic growth for 3 out of 4 mixtures, when the limited solubility of succinic acid is taken into account. One mixture containing sodium chloride was studied and showed a pronounced deviation from the ZSR mixing rule. Critical supersaturations calculated using the parameterizations of water activity and the measured surface tensions were compared with those determined experimentally.
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5. |
- Van Den Berg, F. D., et al.
(författare)
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In-line Characterisation of Microstructure and Mechanical Properties in the Manufacturing of Steel Strip for the Purpose of Product Uniformity Control
- 2016
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Ingår i: DGZfP-Proceedings BB 158. - 9783940283788
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Konferensbidrag (refereegranskat)abstract
- The uniformity of the microstructure of steel strip over the entire coil length and between different coils of the same grade is key to stable and consistent material behaviour in steel manufacturers’ proprietary processes, like rolling and levelling, and customers’ processes, like pressing and deep-drawing. In particular for high-strength steels, like dual phase and complex phase steels, the microstructure is very sensitive to processing variations resulting in a potentially larger spread in the mechanical properties of the product. In July 2013, a large European consortium consisting of 15 institutes started an RFCS [1] – funded project called “Product Uniformity Control” (PUC) with the primary objective to achieve enhanced and sustained product uniformity of steel strip by improved interpretation of data from inline measurement methods that aim 2 for real-time and non-destructive characterisation of microstructure and technomechanical parameters. Commonly, these techniques are based on electromagnetic (EM) or ultrasonic (US) measurement principles, which are favoured because of their non-destructive and potentially contact-free nature. To improve the techniques for inline materials characterisation, the PUC consortium takes a systematic approach to investigate the interrelations between mechanical properties -- microstructural parameters -- EM & US properties -- inline measurement thereof. The studies involve dedicated laboratory experiments, modelling of the EM and US properties of steel, modelling of inline measurement setups and statistical analysis of data from inline measurement systems. The synthesis of these activities should result in improved, model-based, calibrations and finally in a broader deployment and integration of the inline material characterisation techniques in steel manufacturing, adding value to the product and enhancing the process efficiency throughout the production chain from hot-rolling to finishing. This paper outlines the project approach, highlights interconnecting modelling and experimental research work, and demonstrates first results. Various contributions being presented at this WCNDT conference originate from the collaborative activities of this PUC project.
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