| 1. |
- Abbott, R., et al.
(författare)
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Hybridization and speciation
- 2013
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 26:2, s. 229-246
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Forskningsöversikt (refereegranskat)abstract
- Hybridization has many and varied impacts on the process of speciation. Hybridization may slow or reverse differentiation by allowing gene flow and recombination. It may accelerate speciation via adaptive introgression or cause near-instantaneous speciation by allopolyploidization. It may have multiple effects at different stages and in different spatial contexts within a single speciation event. We offer a perspective on the context and evolutionary significance of hybridization during speciation, highlighting issues of current interest and debate. In secondary contact zones, it is uncertain if barriers to gene flow will be strengthened or broken down due to recombination and gene flow. Theory and empirical evidence suggest the latter is more likely, except within and around strongly selected genomic regions. Hybridization may contribute to speciation through the formation of new hybrid taxa, whereas introgression of a few loci may promote adaptive divergence and so facilitate speciation. Gene regulatory networks, epigenetic effects and the evolution of selfish genetic material in the genome suggest that the Dobzhansky-Muller model of hybrid incompatibilities requires a broader interpretation. Finally, although the incidence of reinforcement remains uncertain, this and other interactions in areas of sympatry may have knock-on effects on speciation both within and outside regions of hybridization.
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| 2. |
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| 3. |
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| 4. |
- Smith, A., et al.
(författare)
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LunarEX-a proposal to cosmic vision
- 2009
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Ingår i: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:3, s. 711-740
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Tidskriftsartikel (refereegranskat)
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| 5. |
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| 6. |
- Armand, M., et al.
(författare)
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Review-Development of Huckel Type Anions: From Molecular Modeling to Industrial Commercialization. A Success Story
- 2020
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 167:7
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Forskningsöversikt (refereegranskat)abstract
- This paper reviews the battery electrolyte technologies involving Huckel-type salts as a major electrolyte component. The concept was initially proposed by M. Armand in 1995 and then explored by several research groups. In the present review studies on the optimization of the electrolyte composition starting from molecular modeling through enhancing the yield of the salt synthesis to structural characterization and electrochemical performance are described. Furthermore, the use of the optimized electrolytes in a variety of lithium-ion and post-lithium batteries is presented and discussed. Finally, the commercialization of the up to date technology by Arkema is discussed as well as the performance of the present Huckel anion based electrolytes as compared to other marketed electrolyte technologies.
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| 7. |
- Blachnio, Magdalena, et al.
(författare)
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Chitosan-Silica Hybrid Composites for Removal of Sulfonated Azo Dyes from Aqueous Solutions
- 2018
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Ingår i: Langmuir. - : AMER CHEMICAL SOC. - 0743-7463 .- 1520-5827. ; 34:6, s. 2258-2273
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Tidskriftsartikel (refereegranskat)abstract
- In this study,. the influence of the chitosan immobilization method on the properties of final hybrid materials was performed. Chitosan was immobilized on the surface of mesoporous (ChS2) and fumed silica (ChS3) by physical adsorption and the sol gel method (ChS1). It was found that physical immobilization of chitosan allows to obtain hybrid composites (ChS) with a homogeneous distribution of polymer on the surface, relatively wide pores, and specific surface area of about 170 m(2)/g, PHpzc = 5.7 for ChS3 and 356 m(2)/g and pH(pzc) = 6.0 for ChS2. The microporous chitosan silica material with a specific surface area of 600 m(2)/g and a more negatively charged surface (pH(pzc) = 4.2) was obtained by the sol gel reaction. The mechanisms of azo dye adsorption were studied, and the correlation with the composite structure was distinguished. The generalized Langmuir equation and its special cases, that is, Langmuir-Freundlich and Langmuir equations, were applied for the analysis of adsorption isotherm data. The adsorption study showed that physically adsorbed chitosan (ChS1 and ChS2) on a silica surface has a higher sorption capacity, for example, 0.48 mmol/g for the acid red 88 (AR88) dye (ChS2) and 0.23 mmol/g for the acid orange 8 (AO8) dye (ChS1), compared to the composite obtained by the sol-gel method [ChS1, 0.05 mmol/g for the A08 dye]. For a deeper understanding of the behavior of immobilized chitosan in the adsorption processes, various kinetic equations were applied: first-order, second-order, mixed 1,2-order (MOE), multiexponential, and fractal-like MOE as well as intraparticle and pore diffusion model equations. In the case of AO8 dye, the adsorption rates were differentiated for three composites: for ChS3, 50% of the dye was removed from the solution after merely 5 min and almost 90% after 80 min. The slowest adsorption process controlled by the diffusion rate of dye molecules into the internal space of the pore structure was found for ChS1 (225 min halftime). In the case of ChS2, the rates for various dyes change in the following order: acid orange (AO7) > orange G (OG) > acid red 1 (AR1) > AR88 > AO8 (halftimes: 10.5 < 15.7 < 23.7 < 34.9 < 42.9 min).
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| 8. |
- Budnyak, Tetyana M., et al.
(författare)
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Chitosan Deposited onto Fumed Silica Surface as Sustainable Hybrid Biosorbent for Acid Orange 8 Dye Capture : Effect of Temperature in Adsorption Equilibrium and Kinetics
- 2020
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 124:28, s. 15312-15323
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Tidskriftsartikel (refereegranskat)abstract
- Chitosan was deposited on fumed silica without the addition of cross-linkers or activating agents. The chitosan surface layer has a high affinity toward organic molecules, e.g., Acid Orange 8 (AO8) dye, robust to a broad range of simulated conditions (variance with respect to temperature, time, and concentration of solute). Experimental equilibrium data were analyzed by the generalized Langmuir equation taking into consideration the energetic heterogeneity of the adsorption system. The effect of temperature on dye uptake and adsorption rate was studied. According to the calculated thermodynamic functions Delta G degrees, Delta H degrees, and Delta S degrees from the equilibrium data at different temperatures, the adsorption of AO8 onto chitosan-fumed silica composite is exothermic and spontaneous. The studies of temperature effect on adsorption equilibrium show that the maximum adsorption capacity (determined from the Langmuir-Freundlich equation) of synthesized composite toward AO8 is about one-third higher in the case of an isotherm measured at 5 degrees C than this value obtained for the isotherm measured at 45 degrees C. The quantitative binding of dye molecules to chitosan coating on the surface of silica was proved by H-1 MAS NMR. The deep kinetics study through the application of various theoretical models-the first-order equation, pseudo-first-order equation, second-order equation, pseudo-second-order equation, mixed first, second-order equation, and multiexponential equation-was applied for getting inside the mechanism of AO8 binding to the chitosan coating. Structural characteristics of chitosan-coated silica were obtained from the low-temperature adsorption/desorption isotherms of nitrogen and imaging by scanning electron microscopy. The effects of a synthetic route for polymer coating on thermal stability and the ability to degrade were studied by differential scanning calorimetry.
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| 9. |
- Jankowski, Piotr, 1990, et al.
(författare)
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Understanding of Lithium 4,5-Dicyanoimidazolate-Poly(ethylene oxide) System: Influence of the Architecture of the Solid Phase on the Conductivity
- 2016
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 120:41, s. 23358-23367
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Tidskriftsartikel (refereegranskat)abstract
- Solid polymer electrolytes (SPEs) with high lithium conductivity are very beneficial as a safe material for lithium battery applications. Herein we present new set of a SPEs based on lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI) with wide range of ether oxygen to lithium molar ratios. The phase composition was characterized in detail with thermal, diffraction, and spectroscopic techniques, and its influence on conductivity behavior was examined. Two detected crystalline phases of LiTDI poly(ethylene oxide) (PEO) were simulated with computational methods. The obtained results allowed insight into the structure of these electrolytes and helped us to understand on the molecular level factors influencing electrochemical properties and phase behavior. It was shown that ability to form a low-melting phase can be used to lower the temperature window of operation. That made it possible to keep such SPEs amorphous at 30 degrees C during 80 days. The thermal stability of the samples was checked to prove the safety of the electrolytes.
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| 10. |
- Kottarathil, Aginmariya, et al.
(författare)
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The Role of the Anion in Concentrated Electrolytes for Lithium-Sulfur Batteries
- 2024
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Ingår i: Journal of the Electrochemical Society. - 1945-7111 .- 0013-4651. ; 171:7
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Tidskriftsartikel (refereegranskat)abstract
- Highly concentrated electrolytes show promise in enhancing lithium-sulfur (Li-S) battery performance by mitigating polysulfide (PS) solubility. The role of the salt anion for the performance improvement(s) is however not well understood. Here a systematic characterization using (concentrated) electrolytes based on three different salts: LiTFSI, LiTf, and LiTDI, in a common DOL:DME solvent mixture is reported for a wide range of physicochemical and electrochemical properties: ionic conductivity, density, viscosity, speciation, and PS solubility. While increased salt concentration in general improves Li-S battery performance, the role of the salt anion introduces complexity. The 2 m LiTDI-based electrolyte, with a slightly higher viscosity and lower PS solubility, outperforms the LiTFSI-based counterpart in terms of accessible reversible capacity. Conversely, the 2 m LiTf-based electrolyte exhibits subpar performance due to the formation of ionic aggregates that renders more free solvent and, therefore higher PS solubility, which, however can be improved by using a 5 m concentrated electrolyte. Hence, using electrolyte salt concentration as a rational design route demands an understanding of the local molecular structure, largely determined/affected by the choice of anion, as well as how it connects to the global properties and in the end improved Li-S battery performance.
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