Sökning: "Water chemistry"

Visar resultat 11 - 15 av 1177 avhandlingar innehållade orden Water chemistry.

  1. 11. Time-resolved Structural and Mechanistic Studies of Water Oxidation in Photosystem II : water here, water there, water everywhere

    Författare :Casper de Lichtenberg; Johannes Messinger; Wolfgang P. Schröder; Holger Dau; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oxygenic Photosynthesis; Photosystem II; TR-MIMS; isotope exchange; EPR; EDNMR; water splitting; water oxidation;

    Sammanfattning : Oxygenic photosynthesis is undisputedly one of the most important chemical processes for human life on earth as it not only fills the atmosphere with the oxygen that we need to breathe, but also sustains the accumulation of biomass, which is not only used as nourishment but is also present in almost every aspect of our lives as building material, textiles in clothes and furniture, or even as living decorations to name a few.The photosynthetic water-splitting mechanism is catalyzed by a water:plastoquinone oxido-reductase by the name of photosystem II (PSII), which is embedded in the thylakoid membranes of plants, algae and cyanobacteria. LÄS MER

  3. 12. (Photo)electrochemical Water Oxidation: From Catalysis to Functional Device

    Författare :Hao Yang; Licheng Sun; Marc Koper; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; artificial photosynthesis; solar fuels; water oxidation; nucleophilic attack; conjugated microporous polymer; host-guest chemistry; photoanode; perovskites; artificiell fotosyntes; solbränslen; vattenoxidation; nukleofil attack; konjugerad mikroporös polymer; värd-gästkemi; fotoanoder; perovskiter; Kemi; Chemistry;

    Sammanfattning : The key challenge within artificial photosynthesis is achieving efficient electro- or photo-driven water oxidation catalysis, a necessary process to supply the protons for the reduction reactions, thereby enabling solar fuel production. To facilitate efficient water (photo)electrolysis for solar fuel production, this thesis focuses on two aspects: 1) elucidating the O-O bond formation mechanism and developing efficient, stable, and economical water oxidation catalysts (WOCs); 2) exploring stable, low-cost, light-absorbing photoanode materials that have suitable band structures and excellent charge diffusion properties. LÄS MER

  4. 13. Reactions of aqueous radiolysis products with oxide surfaces : An experimental and DFT study

    Författare :Cláudio Miguel Lousada Patrício; Mats Jonsson; Jean-Philippe Renault; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hydrogen peroxide; hydrogen production; metal; oxides; lanthanide; catalysis; density functional theory; surface; reactions; chemistry; SRA - Energy; SRA - Energi; SRA - Production; SRA - Produktion;

    Sammanfattning : The reactions between aqueous radiolysis products and oxide surfaces are important in nuclear technology in many ways. In solid-liquid systems, they affect (and at the same time are dependent on) both the solution chemistry and the stability of materials under the influence of ionizing radiation. LÄS MER

  5. 14. Exploring Biopolymer-Clay Nanocomposite Materials by Molecular Modelling

    Författare :Yan Wang; Hans Ågren; Vincenzo Carravetta; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; bio-nanocomposite; interfacial mechanism; binding affinity; dimensional stability; counterions; hydration; stress-strain behavior; xyloglucan; chitosan; chitin; molecular dynamics; montmorillonite.; 生物复合材料，界面机理，分子间亲和力，材料尺寸稳定性，抗衡离子，水合作用，应力应变表现， 木葡聚糖，壳聚糖，甲壳素，分子动力学模拟，蒙脱土; bio-nanokompositer; gränsytor; affinitet; dimensionsstabilitet; jonhydrering; spännings-töjningsbeteende; xyloglukan; kitosan; kitin; molekyldynamisk; montmorillonit.; Kemi; Chemistry; Fiber- och polymervetenskap; Fibre and Polymer Science; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : In this thesis, bio-nanocomposites made from two alternative biopolymers and montmorillonite (Mnt) clay have been investigated by molecular modelling. These biopolymers are xyloglucan (XG) and chitosan (CHS), both of which are abundant, renewable, and cost-effective. LÄS MER

  7. 15. Solving Analytical Challenges with Thin Layer Electrochemistry

    Författare :Alexander Wiorek; Gaston A. Crespo; Maria Cuartero; Gregoire Herzog; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Thin Layer Electrochemistry; Polyaniline; Carbon nanotubes; Ion-selective electrodes; Ionophores; Electrochemical Sensors; Alkalinity; Deionization; Chemical Imaging; Tunnskiktselektrokemi; polyanilin; kolnanorör; jonselektiva elektroder; jonoforer; elektrokemiska sensorer; Alkalinitet; avjonisering; chemical imaging; Kemi; Chemistry;

    Sammanfattning : The decentralization of chemical sensing to attain environmental-related information is today highly desirable to increase the knowledge on biological or geological events as well as effluents. The current state of the field moves toward submersible probes; chemical sensors implemented into submersible devices for quantifying analytes over extended times. LÄS MER