| 1. |
- Mahaffy, Peter G., et al.
(författare)
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Can Chemistry Be a Central Science without Systems Thinking?
- 2019
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Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 96:12, s. 2679-2681
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- What is the history and justification of the claim that chemistry is "the central science"? Are our students able to see and appreciate such centrality of the knowledge of chemistry in the curriculum as well as in its broader interconnections with other fields of study and with societal issues? In this editorial for the special issue Reimagining Chemistry Education: Systems Thinking, and Green and Sustainable Chemistry, we, as guest editors, highlight the case made in the collective contributions to the special issue that systems thinking, including green and sustainable chemistry, shows promise as an approach to help chemistry students zoom out from detailed and fragmented disciplinary content to obtain a more holistic view of chemistry and its integral connection to earth and societal systems. Indeed, we ask the following question: How can we as a community of chemists and chemistry educators live up to the claim of being practitioners of the central science if we do not equip our students to engage in systems thinking? We further invite the community to make use of and build upon the contributions in this special issue and participate in a paradigm change in chemistry education that will help prepare our students to be citizens and scientists who are better equipped to deal with the grand challenges in the world.
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| 2. |
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| 3. |
- Barclay, Victoria K.H.
(författare)
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Development of LC-MS/MS Methods for the Analysis of Chiral and Achiral Pharmaceuticals and Metabolites in Aqueous Environmental Matrices
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes the development of liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for the trace analysis of active pharmaceutical ingredients (APIs) and their metabolites in aqueous environmental matrices. The research was focused on the development of chiral LC-MS/MS methods for the analysis of fluoxetine and metoprolol, as well as their chiral metabolites in environmental water samples. A method was also developed for the achiral compounds, diazepam and nordiazepam. The LC-MS/MS methods were validated by the use of the isotope-labeled compounds. As these isotope-labeled compounds were not found in the wastewater samples, the validation could be assessed at trace level concentrations in the actual matrices in which the analytes were detected. The analytes were extracted from the water samples using solid phase extraction methods. Different types of solid phase extraction sorbents were evaluated. Fluoxetine and norfluoxetine were extracted through the use of a mixed mode polymeric based extraction sorbent. A hydrophilic and lipophilic balanced sorbent was employed for the simultaneous extraction of metoprolol and its metabolites, the base α-hydroxymetoprolol and the acidic metabolite deaminated metoprolol. Moreover, silica based C18 extraction discs were applied for the sample preparation of diazepam and nordiazepam. The chromatographic separations were conducted in reversed phase LC with MS compatible mobile phases. The enantiomers of fluoxetine and norfluoxetine were simultaneously separated using the chiral stationary phase (CSP), α1-acid glycoprotein (AGP). The Chiral AGP column was also applied for the separation of the enantiomers of deaminated metoprolol. For the simultaneous separation of the metoprolol enantiomers and the four stereoisomers of α-hydroxymetoprolol, the cellobiohydrolase (CBH) protein based CSP was used. An octadecyl silica based LC column was applied for the separation of diazepam and nordiazepam. The analytes were detected by the use of tandem quadrupole mass spectrometry operating in selective reactive monitoring mode. High resolution MS, employing a quadrupole time-of-flight (QqTOF) mass analyzer, was utilized for the identification of an unknown compound in wastewater samples. The APIs and their metabolites, as well as their respective enantiomers, were quantified in raw and treated wastewater from Uppsala, Sweden along with surface water from the River Fyris in Uppsala.
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| 4. |
- Ahlgren, Joakim, 1972-
(författare)
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Organic Phosphorus Compounds in Aquatic Sediments : Analysis, Abundance and Effects
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Phosphorus (P) is often the limiting nutrient in lacustrine and brackish eco-systems, and enhanced input of P into an aquatic system might therefore negatively impact the environment. Because modern waste water manage-ment have reduced external P input to surface waters, internal P loading from the sediment has become one of the main P sources to aquatic ecosys-tems, in which relatively unknown organic P compounds seem to be more active in P recycling than previously thought. This thesis focus is on improving analysis methods for organic P com-pounds in lacustrine and brackish sediments, as well as determining which of these compounds might be degraded, mobilized and subsequently recycled to the water column and on what temporal scale this occur. In both lacustrine and brackish environments, the most labile P compound was pyrophosphate, followed by different phosphate diesters. Phosphate monoesters were the least labile organic P compounds and degraded the slowest with sediment depth. In regulated lakes, it was shown that pyrophosphate and polyphos-phate compound groups were most related to lake trophic status, thus indi-cating their involvement in P cycling. This thesis also indicates faster P turn-over in sediment from the brackish environment compared to sediment from the lacustrine environment. A comparison of organic P extraction procedures showed that pre-extraction with EDTA, and NaOH as main extractant, was most efficient for total P extraction. Using buffered sodium dithionite (BD) as a pre-extractant and NaOH as main extractant was most efficient for extracting the presuma-bly most labile organic P compound groups, pyrophosphate and polyphos-phate. Furthermore, it was determined that organic P compounds associated with humic substances were more recalcitrant than other P compounds, that the BD step used in traditional P fractionation might extract phosphate monoesters, and that NMR is a statistically valid method for quantification of organic P compounds in sediment extracts.
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| 5. |
- Boström, Magnus, 1972-, et al.
(författare)
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Towards responsible procurement in relation to chemical risks in textiles? Findings from an interview study
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the present study, we ask whether and how different organizations work with sustainable procurement and how this work relates to the complexity of the product chain. We have chosen to focus on chemical risks in relation to textiles – an issue that increasingly is becoming part of the public discourse and a target for journalists. In the case of textiles, the product chain from raw material to consumption often involves a great number of production steps, sub-contractors and users, often on a global scale. Sustainable management of the supply chain would improve health, quality of life, and labour conditions, for instance in the areas and factories in developing countries where production and processing often take place. However, such management faces great difficulties and challenges in terms of capabilities, knowledge, communication, and policy instruments. These difficulties are related to high uncertainties and other problems that in turn are related to the high complexity of global product chains. The objective of the present report is to gain insights into the opportunities and challenges that private and public organizations face regarding the development of responsible procurement in relation to a complex and uncertain issue. The report focuses on chemicals in textiles and uses a qualitative methodology with semi-structured interviews. Key elements of a pro-active, responsible procurement strategy are defined in the report and include criteria such as using a preventive, systematic, responsive, integrative, and reflective approach. The analysis includes the following topics: (i) priorities and knowledge, (ii) communicative strategies, (iii) policy instruments, (iv) monitoring and trust in relation to suppliers. The results show a fairly modest level of organizational responsibility, although it is possible to observe an initial positive development among the cases investigated. The report ends by suggesting a number of topics that require further investigation.
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| 6. |
- Hylander, Lars Daniel, 1954-, et al.
(författare)
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Phosphorus recycling at a household-size wastewater facility at Norrbäck farm.
- 2008
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Ingår i: Phosphorus management in Nordic-Baltic agriculture - reconciling productivity and environmental protection.. ; , s. 130-135
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Wastewater has the potential to interfere with the Swedish Environmental quality objectives, such as a Non-Toxic Environment, Zero Eutrophication, Flourishing Lakes and Streams, Good-Quality Groundwater, A Balanced Marine Environment, Thriving Wetlands, a Good Built Environment, and a Rich Diversity of Plant and Animal Life (Swedish Environmental Objectives Council, 2008). A general introduction of the evaluated concept for wastewater treatment in the country side would make away with rural household wastewater as a potential threat to these objectives. In addition, such an approach would fulfil the goal of recycling P as a nutrient in crop production (Naturvårdsverket, 2004).
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| 7. |
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| 8. |
- Cooray, Vernon, et al.
(författare)
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On the NOx generation in Corona, streamer and low-pressure electrical discharges
- 2012
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Ingår i: Lightning Electromagnetics. - : Institution of Engineering and Technology. - 9781849192163 - 9781849192156 ; , s. 789-797
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- An assessment of the global distribution of nitrogen oxides (NOx) is required for a satisfactory description of tropospheric chemistry and in the evaluation of the global impact of increasing anthropogenic emissions of NOx. In the mathematical models utilized for this purpose, it is necessary to have the natural as well as man-made sources of NOx in the atmosphere as inputs. Thunderstorms are a main natural source of NOx in the atmosphere and it may be the dominant source of NOx in the troposphere in equatorial and tropical South Pacific.
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| 9. |
- Zdanowicz, Christian, 1966-, et al.
(författare)
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Strategies and Best Practices for Monitoring Seasonal Snow Cover Composition
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Seasonal snow covers up to 45 million km^2 every winter. As such, it represents a major interface between the Earth's surface and atmosphere. It also offers a convenient sampling medium to monitor water isotopes in solid precipitation and the net deposition of a wide variety of atmospheric species, including nutrients, organic compounds (OCs), trace metals, dust, black carbon (BC), and many others. Impurities such as dust and BC are light-absorbing and as such can modify the radiative properties of snow, while other atmospheric species such as OCs or certain metals can adversely affect the aquatic environment and drinking water quality in meltwater-fed basins. Systematic monitoring of seasonal snowpack composition may therefore offer a way of supplementing direct observations of air and precipitation chemistry. It may also lend itself well to certain "citizen science" activities, provided a set of standardized protocols can be adopted, and an adequate platform for data collection and sharing be established. In recent years, some recommendations to this effect were made by the snow science community through the IASC Cryosphere Working Group, the WMO Global Cryosphere Watch and EU Harmosnow initiative. The purpose of this presentation is to stimulate a continued discussion of the merits, challenges and caveats of establishing a network of coordinated snowpack composition observations. Examples of existing or recently-developed monitoring protocols for snowpacks in Arctic and montane regions will be presented and discussed.
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| 10. |
- Sveinbjörnsson, Kári
(författare)
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Preparation and Characterization of Lead Halide Perovskites : Towards sustainable, cost-effective and upscalable solar cell manufacture
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The perovskite solar cell (PSC) is a recent contender within the photovoltaic research field. In a matter of a few years, the power conversion efficiency (PCE) of the PSC has catapulted from 4% to above 22%, which represents one of the fastest developments in the field. The PSC band-gap tunability makes them interesting for use in tandem solar cells with other established solar cell technologies. This thesis focuses on exploring the photophysics of the perovskite material as well as the development of different perovskite preparation processes and materials for potential use in large-scale manufacture and tandem solar cell applications.First, the photoconductivity of a perovskite film deposited on different metal oxide nanoparticle layers is investigated. The results show that the perovskite can generate free charge carriers without the presence of an electron acceptor.Secondly, we constructed PSCs with a conducting carbon-nanotube film, as a replacement for both the hole-selective layer and the metallic back electrode, which yielded a PCE of 15.5%. Furthermore, we explored the preparation of semitransparent PSCs for tandem solar cells by using atomic-layer deposition (ALD) for depositing a thin electron-selective metal-oxide layer. We were successful using ALD directly on a perovskite layer without damage to the perovskite. Although the PSCs did not yield high PCE, the study marks a step in further development for direct ALD deposition onto the perovskite.Finally, we developed two different methods concerning sustainable manufacture of PSCs. The first method was based on the synthesis of the mixed-ion (FAPbI3)0.87(MAPbBr3)0.17 perovskite in ambient air, which had hitherto only been possible in inert atmosphere. The best PSC was obtained by depositing the perovskite onto a 50°C warm substrate in ambient air yielding a PCE of 17.7%. In the second method, only non-hazardous solvents, water and isopropanol, were used in the synthesis of Cs0.1FA0.9Pb(I0.83Br0.17)3. It is the first publication of mixed inorganic and organic cation perovskite synthesis using a two-step preparation procedure with only non-hazardous solvents and the process yielded a PCE of 13.0%. The method allows for complete ionic control of the perovskite and further variation and improvements are therefore possible.
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