Mode-Decay Molecular Dynamics for Frequency-Dependent Phonon Scattering Rates

The thermal conductivity of crystalline materials can be determined in a statistical mechanical framework as long as phonon relaxation rates are known. Unfortunately, these quantities are difficult if not impossible to measure directly, and attempts to deduce these quantities yield gross averages not energy dependent relationships. Consequently, researchers often rely on heuristic models such as Holland’s suite of scattering rates for various phonon modes. A new molecular dynamics method was developed to estimate mode-dependent scattering rates by tracking the decay of an initially imposed standing wave. The wave vector is systematically changed and the corresponding decay is collected. Ultimately, the the thermal conductivity can be reconstructed using a Landauer formalism. The phonon scattering rates of a LJ crystal are calculated using this method. The standing wave decay approach allows scattering rates to be probed more directly than wave packet simulations, which are often used to obtain transmission coefficients.</jats:p

Influence of the 15-HETE on cytosolic [ Ca2+] i of the rabbit pulmonary artery smooth muscle cells

Extracellular Ca2+ influx was blocked by L-type Ca2+ channel blocker nifedipine to observe the effects of 15-hydroxyeicosatetraenoic acid on the constriction of rabbit pulmonary artery rings and on the changes of Ca2+ level in the rabbit pulmonary artery smooth muscle cells, and further to investigate the mechanism of the calcium mobilization induced by the 15-HETE under hypoxic conditions. The effect of extracellular Ca2+ on tension of the rabbit PA rings was also studied. Nifedipine (10 µ mol/L) had no effect on 1 µ mol/L 15-hydroxyeicosatetraenoic acid induced vasoconstriction under normoxic and hypoxic conditions. Intracellular Ca2+ increased markedly in the 15-HETE group (cells were exposed to 1 µ mol/L 15-HETE for 8 min during culture) compared to the control group (P < 0.05). The study demonstrated that the 15-HETE could induce the elevation of Ca2+ in the pulmonary artery smooth muscle cells and the elevated calcium came from the release of the intracellular calcium

Accounting recognition of information as an asset

Attempts to recognize ‘information’ as an asset have led to an increased awareness of why and how this invisible valuable resource does not appear in the financial statements. This paper aims to develop a model based on three-circled sets of criteria for the pre-measurement phase of an asset recognition process. This model should be applicable to all types of assets, but we mainly focus on information as an intangible-based asset. Semi-structured, in-depth interviews and a questionnaire survey were used to provide triangulating perspectives to follow the grounded theory approach and generate artefact-based asset recognition criteria. The generated theory is applied to information as a candidate asset to explain how this invisible resource can be recognized in financial statements

Accounting as a social and institutional practice: perspectives to enrich our understanding of accounting change

C1 - Refereed Journal Articl