Mogens B. Christensen

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ARhizomucor miehie cDNA library constructed inEscherichia coli was screened with synthetic oligonucleotides designed from knowledge of a partial amino acid sequence of the secreted triglyceride lipase (triacyl-glycerol acylhydrolase EC 3.1.1.3) from this fungus. Lipase-specific recombinants were isolated and their insert sequenced. Unlike characterized(More)
By converting waste heat into electricity, thermoelectric generators could be an important part of the solution to today's energy challenges. The compound Zn(4)Sb(3) is one of the most efficient thermoelectric materials known. Its high efficiency results from an extraordinarily low thermal conductivity in conjunction with the electronic structure of a(More)
The cDNA encoding the precursor of theRhizomucor miehei triglyceride lipase was inserted in anAspergillus oryzae expression vector. In this vector the expression of the lipase cDNA is under control of theAspergillus oryzae α-amylase gene promoter and theAspergillus niger glucoamylase gene terminator. The recombinant plasmid was introduced intoAspergillus(More)
Engineering of materials with specific physical properties has recently focused on the effect of nano-sized 'guest domains' in a 'host matrix' that enable tuning of electrical, mechanical, photo-optical or thermal properties. A low thermal conductivity is a prerequisite for obtaining effective thermoelectric materials, and the challenge is to limit the(More)
Thermoelectric clathrates hold significant promise for high temperature applications with zT values exceeding 1.3. The inorganic clathrates have been shown to be both chemically and thermally stable at high temperatures, and high performance can be obtained from both single crystals and processed powders. The clathrates also show excellent compatibility(More)
The high thermoelectric figure of merit zT of Ba8Ga16Ge30 makes it one of the best n-type materials for thermoelectric power generation. Here, we describe the synthesis and characterization of a Czochralski pulled single crystal of Ba8Ga16Ge30 and polycrystalline disks. Measurements of the electrical conductivity, Hall effect, specific heat, coefficient of(More)
Supercritical growth: The formation and evolution of ceria nanoparticles during hydrothermal synthesis was investigated by in situ total scattering and powder diffraction. The nucleation of pristine crystalline ceria nanoparticles originated from previously unknown cerium dimer complexes. The nanoparticle growth was highly accelerated under supercritical(More)
The formation and growth mechanisms in the hydrothermal synthesis of SnO(2) nanoparticles from aqueous solutions of SnCl(4)·5H(2)O have been elucidated by means of in situ X-ray total scattering (PDF) measurements. The analysis of the data reveals that when the tin(IV) chloride precursor is dissolved, chloride ions and water coordinate octahedrally to(More)
Understanding the mechanism of nanoparticle formation during synthesis is a key prerequisite for the rational design and engineering of desirable materials properties, yet remains elusive due to the difficulty of studying structures at the nanoscale under real conditions. Here, the first comprehensive structural description of the formation of a(More)
Bismuth-oxide-based materials are the building blocks for modern ferroelectrics, multiferroics, gas sensors, light photocatalysts and fuel cells. Although the cubic fluorite δ-phase of bismuth oxide (δ-Bi2O3) exhibits the highest conductivity of known solid-state oxygen ion conductors, its instability prevents use at low temperature. Here we demonstrate the(More)