70 research outputs found
Large orbital magnetic moments in carbon nanotubes generated by resonant transport
The nonequilibrium Green's function method is used to study the ballistic
transport in metallic carbon nanotubes when a current is injected from the
electrodes with finite bias voltages. We reveal, both analytically and
numerically, that large loop currents circulating around the tube are induced,
which come from a quantum mechanical interference and are much larger than the
current along the tube axis when the injected electron is resonant with a
time-reversed pair of degenerate states, which are, in fact, inherent in the
zigzag and chiral nanotubes. This results in large orbital magnetic moments,
making the nanotube a molecular solenoid.Comment: 5 pages, 4 figures; typos correcte
Exaggerated Texture and Grain Growth in a Supperplastic SiAlON
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65254/1/j.1151-2916.1992.tb05497.x.pd
Pleiotropic Benefit of Monomeric and Oligomeric Flavanols on Vascular Health - A Randomized Controlled Clinical Pilot Study
BACKGROUND: Cardiovascular diseases are expanding to a major social-economic burden in the Western World and undermine man's deep desire for healthy ageing. Epidemiological studies suggest that flavanol-rich foods (e.g. grapes, wine, chocolate) sustain cardiovascular health. For an evidenced-based application, however, sound clinical data on their efficacy are strongly demanded. METHODS: In a double-blind, randomized, placebo-controlled intervention study we supplemented 28 male smokers with 200 mg per day of monomeric and oligomeric flavanols (MOF) from grape seeds. At baseline, after 4 and 8 weeks we measured macro- and microvascular function and a cluster of systemic biomarkers for major pathological processes occurring in the vasculature: disturbances in lipid metabolism and cellular redox balance, and activation of inflammatory cells and platelets. RESULTS: In the MOF group serum total cholesterol and LDL decreased significantly (P ≤ 0.05) by 5% (n = 11) and 7% (n = 9), respectively in volunteers with elevated baseline levels. Additionally, after 8 weeks the ratio of glutathione to glutathione disulphide in erythrocytes rose from baseline by 22% (n = 15, P<0.05) in MOF supplemented subjects. We also observed that MOF supplementation exerts anti-inflammatory effects in blood towards ex vivo added bacterial endotoxin and significantly reduces expression of inflammatory genes in leukocytes. Conversely, alterations in macro- and microvascular function, platelet aggregation, plasma levels of nitric oxide surrogates, endothelin-1, C-reactive protein, fibrinogen, prostaglandin F2alpha, plasma antioxidant capacity and gene expression levels of antioxidant defense enzymes did not reach statistical significance after 8 weeks MOF supplementation. However, integrating all measured effects into a global, so-called vascular health index revealed a significant improvement of overall vascular health by MOF compared to placebo (P ≤ 0.05). CONCLUSION: Our integrative multi-biomarker approach unveiled the pleiotropic vascular health benefit of an 8 weeks supplementation with 200 mg/d MOF in humans. TRIAL REGISTRATION: ClinicalTrials.gov NCT00742287
Teilchenwachstum durch Koaleszenz waehrend des Fluessigphasensinterns von Fe-Cu und Cu-Ag
SIGLEDEGerman
Silent in situ thrombus within a hypoplastic left ventricle in a teenager with Fontan palliation
Effect of Silicon Content on Iron Loss and Magnetic Domain Structure of Grain-Oriented Electrical Steel Sheet
High temperature microstructural stability and recrystallization mechanisms in 14YWT alloys
In-situ neutron diffraction experiments were performed on room temperature compressed 14YWT nanostructured ferritic alloys at 1100 degrees C and 1150 degrees C to understand their thermally activated static recrystallization mechanisms. Existence of a high density of Y-Ti-O rich nano-oxides ( and {112} texture components during annealing, in contrast to the conventional recrystallization textures in body centered cubic alloys. Furthermore, nano-oxide size, shape, density and distribution are considerably different in unrecrystallized and abnormally grown grains. Transmission electron microscopy analysis shows that oxide particles having a size between 5 and 30 nm play a critical role for recrystallization mechanisms in 14YWT nanostructured ferritic alloys
Speckle Reduction of Kinoform Reconstruction Utilizing the 2? Ambiguity of Image Phase Differences
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