A shell model for ferroelectric perovskites fitted to results of first-principles density functional theory (DFT) calculations is strongly affected by approximations made in the exchange-correlation functional within DFT, and in general not as accurate as a shell model derived from experimental data. We have developed an isotropic shell model for...
Double excitonic absorption peaks are observed in textured BaCuSF and BaCuSeF thin films. The excitonic doublet separation increases with increasing fraction of heavy chalcogen in the thin-film solid solutions, in good agreement with the spin-orbit splitting of the valence bands calculated by density-functional theory. In BaCuSF and BaCuSeF, the excitons...
Climate models predict a gradual weakening of the North Atlantic meridional overturning circulation (MOC) during the twenty-first century due to increasing levels of greenhouse gas concentrations in the atmosphere. Using an ensemble of 16 different coupled climate models performed for the Fourth Assessment Report (AR4) of the Intergovernmental Panel on...
Most climate models predict a weakening of the North Atlantic thermohaline circulation for the 21st century when forced by increasing levels of greenhouse gas concentrations. The model spread, however, is rather large, even when the forcing scenario is identical, indicating a large uncertainty in the response to forcing. In order...
Native point defects, defect complexes, and oxygen impurities in BaCuChF were studied using density
functional theory calculations, self-consistent thermodynamic simulations, and various experimental techniques.
Unintentional p-type conductivity in BaCuChF is explained by the presence of copper vacancies with
transition levels in the valence band. These acceptor-like defects are partially compensated...
The p-type semiconductor Cu₃PSe₄ has recently been established to have a direct band gap of 1.4 eV and an optical absorption spectrum similar to GaAs [Foster et al., Appl. Phys. Lett. 99, 181903 (2011)], suggesting a possible application as a solar photovoltaic absorber. Here we calculate the thermodynamic stability, defect...
The early Pliocene warm phase was characterized by high sea surface temperatures and a deep thermocline in the eastern equatorial Pacific. A new hypothesis suggests that the progressive closure of the Panamanian seaway contributed substantially to the termination of this zonally symmetric state in the equatorial Pacific. According to this...
Published January 1988. A more recent revision exists. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
High-quality forages, such as alfalfa and grasses, are important for efficient milk production from dairy cows. Forages provide the effective fiber that is critical for good health and longevity. Inadequate
effective fiber in the cow’s diet is one reason for acidosis and milk fat
depression. Historically, when forage quality changed,...