Sökning: "Hydrogen Storage"

Visar resultat 26 - 30 av 152 avhandlingar innehållade orden Hydrogen Storage.

1. 26. Theoretical modeling of metal- and enzyme catalyzed transformations

   Författare :Jonas Nyhlén; Jan-Erling Bäckvall; Timofei Privalov; Walter Thiel; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functinal theory; computational chemistry; directed evolution; enzyme; mechanistic studies; catalysis; ruthenium; hydrogen transfer; racemization; artificial photosynthesis; frustrated lewis pairs; hydrogen storage; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis is focused on describing and predicting catalytic reactions. The major part of the work is based on density functional theory (DFT). In some cases where the size of the investigated system precluded the use of more accurate methods molecular dynamics was employed. LÄS MER

3. 27. Storage of Hydrogen Peroxide Bleached Mechanical Pulp : Reduction in Reflectance over the Visible Spectrum

   Författare :Sofia Enberg; Per Engstrand; Magnus Paulsson; Mats Rundlöf; Patrik Axelsson; Øyvind Eriksen; Yonghao Ni; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The objective of this thesis is to determine possible causes of the darkening of hydrogen peroxide bleached mechanical pulp over the visible spectrum and their relative contributions. It focuses on both process conditions and the composition of the pulp and the dilution water, including additions or losses of material along the process line from the bleach tower to the paper machine. LÄS MER

4. 28. Hydrogen diffusion and storage mechanisms in diopside

   Författare :Rickard Sundvall; Henrik Skogby; Alasdair Skelton; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mineralogy; Mineralvetenskap; mineralogi; petrologi och geokemi; Mineralogy; Petrology and Geochemistry;

   Sammanfattning : Hydrogen is a widespread trace element in many nominally anhydrous minerals (minerals without water or hydroxyl ions in their structural formula) from the Earth's crust and mantle. The hydrogen is normally incorporated in the form of hydroxyl ions and can be regarded as structurally bound water. LÄS MER

5. 29. The role of methane and hydrogen in a fossil-free Swedish transport sector

   Författare :Mårten Larsson; Per Alvfors; Stefan Grönkvist; Max Åhman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; renewable transport fuels; biogas; methane; hydrogen; electrofuels; pyrolysis; well to wheel; transport policy; energy policy; Chemical Engineering; Kemiteknik;

   Sammanfattning : Drastic reductions of greenhouse gas emissions are required to limit the severe risks associated with a changing climate. One measure is to disrupt the fossil-fuel dependency in the transport sector, but it appears difficult and costly in comparison to other measures. LÄS MER

7. 30. Ab initio Lattice Dynamics : Hydrogen-dense and Other Materials

   Författare :Duck Young Kim; Rajeev Ahuja; Richard Needs; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Density functional perturbation theory; Hydrogen-dense materials; Phase transition; High pressure; Ab initio lattice dynamics; Superconductivity; Quasi-particle approximation; Physics; Fysik;

   Sammanfattning : This thesis presents a theoretical study of materials under high pressure using ab initio lattice dynamics based on density functional theory and density functional perturbation theory using both super-cell and linear response approach. Ab initio lattice dynamics using super-cell approach is applied to compare our theoretical predictions with experimental findings. LÄS MER