Structure-specific synthesis processes are of key importance to the growth of polymorphic functional compounds such as TiO₂, where material properties strongly depend on structure as well as chemistry. The robust growth of the brookite polymorph of TiO₂, a promising photocatalyst, has been difficult in both powder and thin-film forms due...
Plants develop a vast array of cell shapes and sizes by selectively modifying their surrounding cell walls to expand in some regions and not in others. This process of morphogenesis requires the delivery of secretory vesicles to specific locations at the cell periphery, where exocytosis adds new membrane and proteins...
This paper synthesizes various works Wang tiles up to this point, including: the reduction from the Halting Problem to Wang Tiling Problem and notions around various aspects of periodicity, including minimal period, aperiodicity, and axis-aligned periodicity. Additionally it includes new work, including: a proof that a tiling can be periodic...
The infrared spectra of the metaborate monomer and trimer
ions in NaC1, KC1, and KBr were studied. These spectra contain
bands due to the trimer in solid solution, in a second phase of the appropriate
potassium or sodium salt, and perhaps on adjacent lattice
sites. Furthermore, complex equilibria exist between...
Aerogels are interesting material systems with outstanding properties such as low density, high surface area, and low thermal conductivity. They can be used for a variety of applications, such as solar cells, sensors, or catalysts. Additionally they provide a unique model system to study the properties of small particles. Cellulose...
Molecular dynamics simulations, conventional and metadynamics, were performed to determine the interaction of model protein Gb1 over kaolinite (001), Na⁺-montmorillonite (001), Ca²⁺-montmorillonite (001), goethite (100), and Na⁺-birnessite (001) mineral surfaces. Gb1, a small (56 residue) protein with a well-characterized solution-state nuclear magnetic resonance (NMR) structure and having α-helix, 4-fold β-sheet,...
Full Text:
biological and
natural organic matter (NOM) with mineral surfaces, involving
multiple techniques, such as
Several approaches to the synthesis of penicillin from 2-iminothioazolidine
50, from 2-thiothiazolidine 66 and by photocyclization of
77 and 78 were investigated. 2-Iminothiazolidine 50 was prepared
from dibromoester 45 by the action of benzylamine followed by treatment
of aziridine 46 with potassium or ammonium thiocyanate. Attempted
introduction of a two-carbon...