Sökning: "Symmetry methods"

Visar resultat 21 - 25 av 143 avhandlingar innehållade orden Symmetry methods.

1. 21. Development of NMR methods for studies of dynamics and structure : applications to motilin, Alzheimer β-peptide and ubiquitin

   Författare :Peter Damberg; Ad Bax; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biophysics; biofysik;

   Sammanfattning : NMR spin relaxation was used to study structure and dynamics of two biologically important peptides.The first case concerns the three-dimensional structure of the 22 amino acid residue peptide hormone motilin in the presence of SDS micelles, which mimic a biomembrane environment. LÄS MER

3. 22. Non Natural Aromatic Amino Acids Applications in cage-construction, metal ion coordination and asymmetric catalysis

   Författare :Ruxandra Ionescu; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diethylzinc additions.; spectroscopy; metal ion coordination; cage-like compounds; Amino acids; C3-symmetry; Organic chemistry; Organisk kemi;

   Sammanfattning : Aromatic non-natural amino acids, the outstanding feature of which was the presence of several arms, were synthesised and their properties investigated. The amino acids were synthesised following a standard procedure starting with a Horner-Wadsworth-Emmons or a Heck reaction, which provided didehydroamino acids. LÄS MER

4. 23. Taken for Granted – The Construction of Order in the Process of Library Management System Decision Making

   Författare :Nasrine Olson; Göteborgs universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Library Management Systems; System Selection Process within Libraries; Library System Procurement process; Consequences of Decision Making; Methodological Symmetry; Duality of Structure in Decision Making Process; Construction of Conceptual Order; Construction of Social Order; library management systems;

   Sammanfattning : This thesis is an empirically based, theoretical discussion of the process of decision making in relation to Library Management Systems (LMS). Although the conceptualization of the LMS decision process in rational terms, common in many LMS selection models, may be useful in different respects, here the process is viewed from a social constructivist stance. LÄS MER

5. 24. The Quest for M-theory

   Författare :Ulf Gran; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; supersymmetry; solitons; gauge symmetry; M-theory; string theory; duality; p-branes; D-branes; superspace; supergravity;

   Sammanfattning : In ten dimensions, there exist five consistent string theories and in eleven dimensions there is a unique supergravity theory. When trying to find the fundamental theory of nature this is clearly an "embarrassment of riches". In the mid 90s, however, it was discovered that these theories are all related via a kind of transformation called duality. LÄS MER

7. 25. Symmetry-protected topological phases: From Floquet theory to machine learning

   Författare :Oleksandr Balabanov; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topological quantum matter; neural networks; Floquet theory;

   Sammanfattning : It is by now a well known fact that boundary states in conventional time-independent topological insulators are protected against perturbations that preserve relevant symmetries. In the first part of this thesis, accompanying Papers A - C, we study how this robustness extends to time-periodic (Floquet) topological insulators. LÄS MER