| 1. |
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| 2. |
- Gericke, Martin, et al.
(författare)
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The European Polysaccharide Network of Excellence (EPNOE) research roadmap 2040: Advanced strategies for exploiting the vast potential of polysaccharides as renewable bioresources
- 2024
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 326
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Tidskriftsartikel (refereegranskat)abstract
- Polysaccharides are among the most abundant bioresources on earth and consequently need to play a pivotal role when addressing existential scientific challenges like climate change and the shift from fossil-based to sustainable biobased materials. The Research Roadmap 2040 of the European Polysaccharide Network of Excellence (EPNOE) provides an expert's view on how future research and development strategies need to evolve to fully exploit the vast potential of polysaccharides as renewable bioresources. It is addressed to academic researchers, companies, as well as policymakers and covers five strategic areas that are of great importance in the context of polysaccharide related research: (I) Materials & Engineering, (II) Food & Nutrition, (III) Biomedical Applications, (IV) Chemistry, Biology & Physics, and (V) Skills & Education. Each section summarizes the state of research, identifies challenges that are currently faced, project achievements and developments that are expected in the upcoming 20 years, and finally provides outlines on how future research activities need to evolve.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Jedvert, Kerstin, et al.
(författare)
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Adsorption Studies of Amino Cellulose on Cellulosics
- 2017
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Ingår i: Macromolecular materials and engineering. - : Wiley. - 1438-7492 .- 1439-2054. ; 302:7
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption of a typical example of a new class of amino cellulose, namely 6-deoxy-6-(2-aminoethyl)amino cellulose at different pH-values and in the presence of electrolytes, onto cellulose model substrates is studied with surface plasmon resonance and quartz crystal microbalance with dissipation monitoring. Unexpectedly, adsorption is consistently higher at a higher pH-value of 10, indicating that solubility and interactions between amine moieties and cellulose are more important than electrostatic interactions. The findings are highly relevant for the process to modify material surfaces with amino cellulose in water-based systems as a universal tool for changing the surface properties and chemistry. Potential applications for an antimicrobial all biobased material could be found, e.g., as medical textiles or in the biotechnology sector.
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| 7. |
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| 8. |
- Achtel, Christian, et al.
(författare)
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Dissolution capacity of novel cellulose solvents based on triethyloctylammonium chloride
- 2017
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Ingår i: Macromolecular Chemistry and Physics. - : Wiley. - 1022-1352 .- 1521-3935. ; 218:21
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Tidskriftsartikel (refereegranskat)abstract
- Dissolution of cellulose from various sources (microcrystalline cellulose and different dissolving grade pulp fibers) is investigated in solvent systems based on triethyl(n-octyl)ammonium chloride (N2228Cl). Clear cellulose solutions are obtained with N2228Cl in a variety of solvents, e.g., dimethyl sulfoxide, N,N-dimethylacetamide, and acetone. It is possible to prepare clear cellulose solutions from pulp fibers with concentrations up to 15 wt%. However, it is found that the cellulose is degraded, especially when neat (i.e., molten) N2228Cl is used as a solvent. The present work includes comprehensive rheological characterization of the cellulose solutions, both with shear and extensional rheology. In most cases, the viscosity values are low (complex viscosities below 100 Pa s for 5–10 wt% dissolved cellulose), and the solutions show more Newtonian than viscoelastic behavior.
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| 9. |
- Achtel, Christian, et al.
(författare)
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Surprising Insensitivity of Homogeneous Acetylation of Cellulose Dissolved in Triethyl(n-octyl)ammonium Chloride/Molecular Solvent on the Solvent Polarity
- 2018
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Ingår i: Macromolecular materials and engineering. - : Wiley-VCH Verlag. - 1438-7492 .- 1439-2054. ; 303:5
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Tidskriftsartikel (refereegranskat)abstract
- The homogeneous acetylation of microcrystalline cellulose (MCC) by acetyl chloride and acetic anhydride in triethyl(n-octyl)ammonium chloride (N2228Cl)/molecular solvents (MSs) is investigated. The reaction with both acylating agents shows the expected increase of the degree of substitution (DS) on reaction temperature and time. Under comparable reaction conditions, however, DS is surprisingly little dependent on the MS employed, although the MSs differ in empirical polarity by 7 kcal mol−1 as calculated by use of solvatochromic probes. The empirical polarities of (MCC + N2228Cl + MS) differ only by 0.8 kcal mol−1. The formation a polar electrolyte sheath around cellulose chains presumably contributes to this “leveling-off†of the dependence DS on the polarity of the parent MS employed. N2228Cl recovery and recycling is feasible. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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| 10. |
- Dierks, Philipp, et al.
(författare)
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Ground- And Excited-State Properties of Iron(II) Complexes Linked to Organic Chromophores
- 2020
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 59:20, s. 14746-14761
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Tidskriftsartikel (refereegranskat)abstract
- Two new bichromophoric complexes, [Fe(bim-ant)2]2+ and [Fe(bim-pyr)2]2+ ([H2-bim]2+ = 1,1′-(pyridine-2,6-diyl)bis(3-methyl-1H-imidazol-3-ium); ant = 9-anthracenyl; pyr = 1-pyrenyl), are investigated to explore the possibility of tuning the excited-state behavior in photoactive iron(II) complexes to design substitutes for noble-metal compounds. The ground-state properties of both complexes are characterized thoroughly by electrochemical methods and optical absorption spectroscopy, complemented by time-dependent density functional theory calculations. The excited states are investigated by static and time-resolved luminescence and femtosecond transient absorption spectroscopy. Both complexes exhibit room temperature luminescence, which originates from singlet states dominated by the chromophore (1Chrom). In the cationic pro-ligands and in the iron(II) complexes, the emission is shifted to red by up to 110 nm (5780 cm-1). This offers the possibility of tuning the organic chromophore emission by metal-ion coordination. The fluorescence lifetimes of the complexes are in the nanosecond range, while triplet metal-to-ligand charge-transfer (3MLCT) lifetimes are around 14 ps. An antenna effect as in ruthenium(II) polypyridine complexes connected to an organic chromophore is found in the form of an internal conversion within 3.4 ns from the 1Chrom to the 1MLCT states. Because no singlet oxygen forms from triplet oxygen in the presence of the iron(II) complexes and light, efficient intersystem crossing to the triplet state of the organic chromophore (3Chrom) is not promoted in the iron(II) complexes.
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| 11. |
- Graham, Jesse R., et al.
(författare)
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The pipeline project: Pre-publication independent replications of a single laboratory's research pipeline
- 2016
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Ingår i: Journal of Experimental Social Psychology. - : Elsevier. - 1096-0465 .- 0022-1031. ; 66, s. 55-67
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Tidskriftsartikel (refereegranskat)abstract
- This crowdsourced project introduces a collaborative approach to improving the reproducibility of scientific research, in which findings are replicated in qualified independent laboratories before (rather than after) they are published. Our goal is to establish a non-adversarial replication process with highly informative final results. To illustrate the Pre-Publication Independent Replication (PPIR) approach, 25 research groups conducted replications of all ten moral judgment effects which the last author and his collaborators had “in the pipeline” as of August 2014. Six findings replicated according to all replication criteria, one finding replicated but with a significantly smaller effect size than the original, one finding replicated consistently in the original culture but not outside of it, and two findings failed to find support. In total, 40% of the original findings failed at least one major replication criterion. Potential ways to implement and incentivize pre-publication independent replication on a large scale are discussed.
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| 12. |
- Hallonsten, Olof, et al.
(författare)
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Formation and expansion of a new organizational field in experimental science
- 2015
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Ingår i: Science and Public Policy. - : Oxford University Press (OUP). - 1471-5430 .- 0302-3427. ; 42:6, s. 841-854
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the formation and expansion of a new organizational field in experimental science: synchrotron radiation laboratories. These labs were once peripheral servants of some specialisms of solid-state physics, but over the 40 years studied they have grown into a worldwide generic resource for tens of thousands of users in a broad spectrum of disciplines. The paper uses insights primarily from historical institutionalism, but also neo-institutional theory, to analyze the formation and expansion of the organizational field of synchrotron radiation laboratories, and thus contributes to the analysis of the rather dramatic growth of this tool for experimental science from a small-scale lab curiosity to a generic research technology. But the key contribution of the paper is to provide insights into multi-level and multi-dimensional change in science systems by analyzing the emergence and expansion of a new organizational field in experimental science, which has implications not least for science policy.
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| 13. |
- Hallonsten, Olof, et al.
(författare)
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From particle physics to photon science : Multi-dimensional and multi-level renewal at DESY and SLAC
- 2013
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Ingår i: Science and Public Policy. - : Oxford University Press (OUP). - 0302-3427 .- 1471-5430. ; 40:5, s. 591-603
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Tidskriftsartikel (refereegranskat)abstract
- Studies of institutional transformation in science have largely overlooked Big Science installations, despite far-reaching changes to the roles and functions of such large labs in the past decades. Here, we present and analyze two Big Science labs that have undergone profound transformations from single-purpose particle physics labs to multi-purpose centers for so-called photon science: SLAC in the USA and DESY in Germany. We provide brief historic accounts of the labs and an analysis of the processes of change on different levels and from different aspects informed by a theoretical framework of institutional change in science. Thus, we describe the relevance of the study of Big Science labs from the perspective of institutional change and in terms of science policy/management. We also prove the aptness of the framework used and pave the way for a detailed analysis of particular forces of change and their interrelatedness.
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| 14. |
- Hallonsten, Olof, 1979, et al.
(författare)
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Institutional persistence through gradual adaptation: analysis of national laboratories in the USA and Germany
- 2012
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Ingår i: Science and Public Policy. - : Oxford University Press (OUP). - 0302-3427 .- 1471-5430. ; 39:4, s. 450-463
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the institutional persistence of systems of national laboratories (SNLs) that unlike other public and private research organizations appear to have experienced only minor institutional shifts in recent years. Although national laboratories started as time-limited mission-oriented projects, most of them have remained in operation as continuously renewed multi-purpose organizations. By comparing the SNLs in Germany and the USA, this paper discusses the relationship between the system and the organizational level and concludes that incremental organizational rearrangements have enabled the institutional persistence of SNLs despite considerable changes in their political and funding environments. The paper applies recent advances in institutional theory and thus contributes to a better understanding of institutional change in path-dependent public R&D systems.
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| 15. |
- Hallonsten, Olof, et al.
(författare)
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Institutional persistence through gradual organizational adaptation : Analysis of national laboratories in the USA and Germany
- 2012
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Ingår i: Science and Public Policy. - : Oxford University Press (OUP). - 0302-3427 .- 1471-5430. ; 39:4, s. 450-463
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the institutional persistence of systems of national laboratories (SNLs) that unlike other public and private research organizations appear to have experienced only minor institutional shifts in recent years. Although national laboratories started as time-limited mission-oriented projects, most of them have remained in operation as continuously renewed multi-purpose organizations. By comparing the SNLs in Germany and the USA, this paper discusses the relationship between the system and the organizational level and concludes that incremental organizational rearrangements have enabled the institutional persistence of SNLs despite considerable changes in their political and funding environments. The paper applies recent advances in institutional theory and thus contributes to a better understanding of institutional change in path-dependent public R&D systems.
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| 16. |
- Heinze, Thomas, et al.
(författare)
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From Periphery to Center: Synchrotron Radiation at DESY : Part I: 1962–1977
- 2015
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Ingår i: Historical Studies in the Natural Sciences. - : University of California Press. - 1939-1811 .- 1939-182X. ; 45:3, s. 447-492
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Tidskriftsartikel (refereegranskat)abstract
- In its fifty-year history, the German national research laboratory DESY (Deutsches Elektronen-Synchrotron, German Electron Synchrotron) has undergone a gradual transformation from a single-mission particle physics laboratory to a multi-mission research center for accelerator physics, particle physics, and photon science. The last is an umbrella term for research using synchrotron radiation and, in later years, free-electron laser. Synchrotron radiation emerged initially as a peripheral part of the laboratory activities but grew to become a central experimental activity at DESY via a series of changes in the organizational, scientific, and infrastructural setup of the lab, and in its contextual scientific, political, and societal environment. This article chronicles the first sixteen years (1962-77) of the history of synchrotron radiation at DESY and its gradual transformation from peripheral and parasitic to a regular and recognized research program. The article complements previous writings on DESY history by focusing on synchrotron radiation, and it adds to the body of knowledge about the crucial renewal of Big Science laboratories toward the end of the twentieth century. This renewal culminated in the close-down of several particle physics machines in the early 2000s and their replacement by facilities dedicated to the study of the structure, properties, and dynamics of matter by the interaction with vacuum ultraviolet/X-ray photons. Therefore, this article contributes to the knowledge about the emergence and growth of synchrotron radiation as a laboratory resource, the understanding of processes of renewal in Big Science, and the general history of late-twentieth-century science.
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| 17. |
- Heinze, Thomas, et al.
(författare)
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From Periphery to Center: Synchrotron Radiation at DESY, Part II: 1977–1993
- 2015
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Ingår i: Historical Studies in the Natural Sciences. - : University of California Press. - 1939-1811 .- 1939-182X. ; 45:3, s. 513-548
-
Tidskriftsartikel (refereegranskat)abstract
- In its fifty-year history, the German national research laboratory DESY (Deutsches Elektronen-Synchrotron, German Electron Synchrotron) has undergone a gradual transformation from a single-mission particle physics laboratory to a multi-mission research center for accelerator physics, particle physics, and photon science. The last is an umbrella term for research using synchrotron radiation and, in later years, free-electron laser. Synchrotron radiation emerged initially as a peripheral part of the laboratory activities but grew to become a central experimental activity at DESY via a series of changes in the organizational, scientific, and infrastructural setup of the lab, and in its contextual scientific, political, and societal environment. Together with an earlier publication on the issue in this journal, 1 this article chronicles the first thirty years in the history of synchrotron radiation at DESY. The focus is on the gradual transformation of DESY's research program in synchrotron radiation from peripheral and parasitic into mainstream and mission. We provide insights about the crucial renewal of Big Science laboratories toward the end of the twentieth century. This renewal culminated in the close-down of several particle physics machines in the early 2000s and their replacement by facilities dedicated to the study of the structure, properties, and dynamics of matter by the interaction with vacuum ultraviolet and X-ray photons. Therefore, we contribute to better understanding the growth of synchrotron radiation as a laboratory resource, and processes of renewal in Big Science as part of the general history of late-twentieth-century science.
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| 18. |
- Heinze, Thomas, et al.
(författare)
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From Periphery to Center: Synchrotron Radiation at DESY, Part II: 1977—1993
- 2015
-
Ingår i: Historical Studies in the Natural Sciences. - : University of California Press. - 1939-182X .- 1939-1811. ; 45:4, s. 513-548
-
Tidskriftsartikel (refereegranskat)abstract
- In its fifty-year history, the German national research laboratory DESY (Deutsches Elektronen-Synchrotron, German Electron Synchrotron) has undergone a gradual transformation from a single-mission particle physics laboratory to a multi-mission research center for accelerator physics, particle physics, and photon science. The last is an umbrella term for research using synchrotron radiation and, in later years, free-electron laser. Synchrotron radiation emerged initially as a peripheral part of the laboratory activities but grew to become a central experimental activity at DESY via a series of changes in the organizational, scientific, and infrastructural setup of the lab, and in its contextual scientific, political, and societal environment. Together with an earlier publication on the issue in this journal,1 this article chronicles the first thirty years in the history of synchrotron radiation at DESY. The focus is on the gradual transformation of DESY’s research program in synchrotron radiation from peripheral and parasitic into mainstream and mission. We provide insights about the crucial renewal of Big Science laboratories toward the end of the twentieth century. This renewal culminated in the close-down of several particle physics machines in the early 2000s and their replacement by facilities dedicated to the study of the structure, properties, and dynamics of matter by the interaction with vacuum ultraviolet and X-ray photons. Therefore, we contribute to better understanding the growth of synchrotron radiation as a laboratory resource, and processes of renewal in Big Science as part of the general history of late-twentieth-century science.
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| 19. |
- Heinze, Thomas, et al.
(författare)
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The reinvention of the SLAC National Accelerator Laboratory, 1992–2012
- 2018
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Ingår i: History and Technology. - : Informa UK Limited. - 0734-1512 .- 1477-2620. ; 33:3, s. 300-332
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Tidskriftsartikel (refereegranskat)abstract
- This article examines the most recent history of the SLAC National Accelerator Laboratory, with particular emphasis on how this laboratory shifted its research program from accelerator-based particle physics towards astroparticle physics, cosmology and multi-disciplinary photon science. Photon science became the central experimental research program through a series of changes in the organisational, scientific, and infrastructural set-up and in its science policy context. The article shows that SLAC’s reinvention unfolded in a science policy context in which funding priorities drifted towards the materials sciences and the life sciences at the expense of nuclear and particle physics, which had dominated science budgets during the Cold War. SLAC took a lead position in this global development by partly dismantling and also redeploying scientific and technical capabilities from its particle physics program for these new fields, thus, providing novel experimental facilities for user communities to expand across academia and industry.
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| 20. |
- Heinze, Thomas, et al.
(författare)
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Turning the Ship : The Transformation of DESY, 1993–2009
- 2017
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Ingår i: Physics in Perspective. - : Springer Science and Business Media LLC. - 1422-6960 .- 1422-6944. ; 19:4, s. 424-451
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Tidskriftsartikel (refereegranskat)abstract
- This article chronicles the most recent history of the Deutsches Elektronen-Synchrotron (DESY) located in Hamburg, Germany, with particular emphasis on how this national laboratory founded for accelerator-based particle physics shifted its research program toward multi-disciplinary photon science. Synchrotron radiation became DESY’s central experimental research program through a series of changes in its organizational, scientific, and infrastructural setup and the science policy context. Furthermore, the turn toward photon science is part of a broader transformation in the late twentieth century in which nuclear and particle physics, once the dominating fields in national and international science budgets, gave way to increasing investment in the materials sciences and life sciences. Synchrotron radiation research took a lead position on the experimental side of these growing fields and became a new form of big science, generously funded by governments and with user communities expanding across both academia and industry.
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| 21. |
- Jedvert, Kerstin, et al.
(författare)
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Cellulose modification and shaping – a review
- 2017
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Ingår i: Journal of polymer engineering. - : Walter de Gruyter GmbH. - 0334-6447 .- 2191-0340. ; 37:9, s. 845-860
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Tidskriftsartikel (refereegranskat)abstract
- This review aims to present cellulose as a versatile resource for the production of a variety of materials, other than pulp and paper. These products include fibers, nonwovens, films, composites, and novel derivatized materials. This article will briefly introduce the structure of cellulose and some common cellulose derivatives, as well as the formation of cellulosic materials in the micro- and nanoscale range. The challenge with dissolution of cellulose will be discussed and both derivatizing and nonderivatizing solvents for cellulose will be described. The focus of the article is the critical discussion of different shaping processes to obtain a variety of cellulose products, from commercially available viscose fibers to advanced and functionalized materials still at the research level.
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| 22. |
- Kostag, Marc, et al.
(författare)
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Recent Advances in Solvents for the Dissolution, Shaping and Derivatization of Cellulose : Quaternary Ammonium Electrolytes and their Solutions in Water and Molecular Solvents.
- 2018
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 23:3
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Tidskriftsartikel (refereegranskat)abstract
- There is a sustained interest in developing solvents for physically dissolving cellulose, i.e., without covalent bond formation. The use of ionic liquids, ILs, has generated much interest because of their structural versatility that results in efficiency as cellulose solvents. Despite some limitations, imidazole-based ILs have received most of the scientific community's attention. The objective of the present review is to show the advantages of using quaternary ammonium electrolytes, QAEs, including salts of super bases, as solvents for cellulose dissolution, shaping, and derivatization, and as a result, increase the interest in further investigation of these important solvents. QAEs share with ILs structural versatility; many are liquids at room temperature or are soluble in water and molecular solvents (MSs), in particular dimethyl sulfoxide. In this review we first give a historical background on the use of QAEs in cellulose chemistry, and then discuss the common, relatively simple strategies for their synthesis. We discuss the mechanism of cellulose dissolution by QAEs, neat or as solutions in MSs and water, with emphasis on the relevance to cellulose dissolution efficiency of the charge and structure of the cation and. We then discuss the use of cellulose solutions in these solvents for its derivatization under homogeneous and heterogeneous conditions. The products of interest are cellulose esters and ethers; our emphasis is on the role of solvent and possible side reactions. The final part is concerned with the use of cellulose dopes in these solvents for its shaping as fibers, a field with potential commercial application.
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| 23. |
- Kuncarayakti, Hanindyo, et al.
(författare)
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SN 2017dio : A Type-Ic Supernova Exploding in a Hydrogen-rich Circumstellar Medium
- 2018
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 854:1
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Tidskriftsartikel (refereegranskat)abstract
- SN 2017dio shows both spectral characteristics of a type-Ic supernova (SN) and signs of a hydrogen-rich circumstellar medium (CSM). Prominent, narrow emission lines of H and He are superposed on the continuum. Subsequent evolution revealed that the SN ejecta are interacting with the CSM. The initial SN Ic identification was confirmed by removing the CSM interaction component from the spectrum and comparing with known SNe Ic and, reversely, adding a CSM interaction component to the spectra of known SNe Ic and comparing them to SN 2017dio. Excellent agreement was obtained with both procedures, reinforcing the SN Ic classification. The light curve constrains the pre-interaction SN Ic peak absolute magnitude to be around M-g = -17.6 mag. No evidence of significant extinction is found, ruling out a brighter luminosity required by an SN Ia classification. These pieces of evidence support the view that SN 2017dio is an SN Ic, and therefore the first firm case of an SN Ic with signatures of hydrogen-rich CSM in the early spectrum. The CSM is unlikely to have been shaped by steady-state stellar winds. The mass loss of the progenitor star must have been intense, M similar to 0.02 (epsilon(H alpha)/0.01)(-1) (nu(wind)/500 km s(-1)) (nu(shock)/10,000 km s(-1))M--3(circle dot) yr(-1), peaking at a few decades before the SN. Such a high mass-loss rate might have been experienced by the progenitor through eruptions or binary stripping.
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| 24. |
- Naderi, Ali, et al.
(författare)
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Sulfoethylated nanofibrillated cellulose : Production and properties
- 2017
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 169, s. 515-523
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Tidskriftsartikel (refereegranskat)abstract
- Sulfoethylated nanofibrillated cellulose (NFCsulf) was produced by an industrially relevant process. The properties of the NFCsulf were compared with those of carboxymethylated nanofibrillated cellulose (NFCcarb), which has been identified as an attractive NFC for several industrial applications. The investigations revealed that NFCsulf is characterized by a higher degree of fibrillation and has superior redispersion properties. Furthermore, NFCsulf displays higher stability in varying pH values as compared to NFCcarb. Hence, NFCsulf may be a more attractive alternative than NFCcarb in applications such as rheological modifiers or adsorbing components in personal care products, in which the performance of NFC must remain unaffected in varying ambient conditions. The superior properties of NFCsulf compared to NFCcarb were proposed to be due to the combination of the unique chemical characteristics of the sulfoethylated reagent, and the larger size of the sulfonate group compared to the carboxymethyl group.
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| 25. |
- Naserifar, Shirin, 1991, et al.
(författare)
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Investigation of cellulose dissolution in morpholinium-based solvents: impact of solvent structural features on cellulose dissolution
- 2023
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Ingår i: RSC Advances. - 2046-2069. ; 13:27, s. 18639-18650
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Tidskriftsartikel (refereegranskat)abstract
- A series of N-methylmorpholinium salts with varying N-alkyl chains and Cl−, OAc− and OH− as counter ions have been synthesized and investigated for their ability to dissolve cellulose, aiming at elucidating solvent structural features affecting cellulose dissolution. Synthesis procedures have been developed to, to a high extent, rely on conversions in water and microwave-assisted reactions employing a reduced number of work-up steps and ion-exchange resins that can be regenerated. Water solutions of morpholinium hydroxides proved capable of dissolving cellulose, with those of them possessing alkyl chains longer than ethyl showing surprising dissolution ability at room-temperature. Morpholinium acetates behaved as ionic liquids, and were also capable of dissolving cellulose when combined with DMSO. The obtained cellulose solutions were characterized according to their chemical and colloidal stability using 13C NMR spectroscopy, size exclusion chromatography and flow sweep measurements, while the ethanol coagulates were investigated in terms of crystallinity using solid state NMR. In contrast, the morpholinium chlorides obtained were hygroscopic with high melting points and low solubility in common organic solvents e.g., acetone, DMSO and DMAc, thus lacking the ability to swell or dissolve cellulose.
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| 26. |
- Seland, Øyvind, et al.
(författare)
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Overview of the Norwegian Earth System Model (NorESM2) and key climate response of CMIP6 DECK, historical, and scenario simulations
- 2020
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 13:12, s. 6165-6200
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Tidskriftsartikel (refereegranskat)abstract
- The second version of the coupled Norwegian Earth System Model (NorESM2) is presented and evaluated. NorESM2 is based on the second version of the Community Earth System Model (CESM2) and shares with CESM2 the computer code infrastructure and many Earth system model components. However, NorESM2 employs entirely different ocean and ocean biogeochemistry models. The atmosphere component of NorESM2 (CAM-Nor) includes a different module for aerosol physics and chemistry, including interactions with cloud and radiation; additionally, CAM-Nor includes improvements in the formulation of local dry and moist energy conservation, in local and global angular momentum conservation, and in the computations for deep convection and air-sea fluxes. The surface components of NorESM2 have minor changes in the albedo calculations and to land and sea-ice models. We present results from simulations with NorESM2 that were carried out for the sixth phase of the Coupled Model Intercomparison Project (CMIP6). Two versions of the model are used: one with lower (similar to 2 degrees) atmosphere-land resolution and one with medium (similar to 1 degrees) atmosphere-land resolution. The stability of the pre-industrial climate and the sen- sitivity of the model to abrupt and gradual quadrupling of CO2 are assessed, along with the ability of the model to simulate the historical climate under the CMIP6 forcings. Compared to observations and reanalyses, NorESM2 represents an improvement over previous versions of NorESM in most aspects. NorESM2 appears less sensitive to greenhouse gas forcing than its predecessors, with an estimated equilibrium climate sensitivity of 2.5 K in both resolutions on a 150-year time frame; however, this estimate increases with the time window and the climate sensitivity at equilibration is much higher. We also consider the model response to future scenarios as defined by selected Shared Socioeconomic Pathways (SSPs) from the Scenario Model Intercomparison Project defined under CMIP6. Under the four scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5), the warming in the period 2090-2099 compared to 1850-1879 reaches 1.3, 2.2, 3.0, and 3.9 K in NorESM2-LM, and 1.3, 2.1, 3.1, and 3.9 K in NorESM-MM, robustly similar in both resolutions. NorESM2-LM shows a rather satisfactory evolution of recent sea-ice area. In NorESM2-LM, an ice-free Arctic Ocean is only avoided in the SSP1-2.6 scenario.
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| 27. |
- Stone, Thomas, et al.
(författare)
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An Anatomically Constrained Model for Path Integration in the Bee Brain
- 2017
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Ingår i: Current Biology. - : Elsevier BV. - 1879-0445 .- 0960-9822. ; 27:20, s. 11-3085
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Tidskriftsartikel (refereegranskat)abstract
- Path integration is a widespread navigational strategy in which directional changes and distance covered are continuously integrated on an outward journey, enabling a straight-line return to home. Bees use vision for this task-a celestial-cue-based visual compass and an optic-flow-based visual odometer-but the underlying neural integration mechanisms are unknown. Using intracellular electrophysiology, we show that polarized-light-based compass neurons and optic-flow-based speed-encoding neurons converge in the central complex of the bee brain, and through block-face electron microscopy, we identify potential integrator cells. Based on plausible output targets for these cells, we propose a complete circuit for path integration and steering in the central complex, with anatomically identified neurons suggested for each processing step. The resulting model circuit is thus fully constrained biologically and provides a functional interpretation for many previously unexplained architectural features of the central complex. Moreover, we show that the receptive fields of the newly discovered speed neurons can support path integration for the holonomic motion (i.e., a ground velocity that is not precisely aligned with body orientation) typical of bee flight, a feature not captured in any previously proposed model of path integration. In a broader context, the model circuit presented provides a general mechanism for producing steering signals by comparing current and desired headings-suggesting a more basic function for central complex connectivity, from which path integration may have evolved.
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