Structural and Magnetic Properties of Trigonal Iron

First principles calculations of the electronic structure of trigonal iron were performed using density function theory. The results are used to predict lattice spacings, magnetic moments and elastic properties; these are in good agreement with experiment for both the bcc and fcc structures. We find however, that in extracting these quantities great care must be taken in interpreting numerical fits to the calculated total energies. In addition, the results for bulk iron give insight into the properties of thin iron films. Thin films grown on substrates with mismatched lattice constants often have non-cubic symmetry. If they are thicker than a few monolayers their electronic structure is similar to a bulk material with an appropriately distorted geometry, as in our trigonal calculations. We recast our bulk results in terms of an iron film grown on the (111) surface of an fcc substrate, and find the predicted strain energies and moments accurately reflect the trends for iron growth on a variety of substrates.Comment: 11 pages, RevTeX,4 tar'd,compressed, uuencoded Postscript figure

Quantum-based Atomistic Simulation of Transition Metals

First-principles generalized pseudopotential theory (GPT) provides a fundamental basis for transferable multi-ion interatomic potentials in d-electron transition metals within density-functional quantum mechanics. In mid-period bcc metals, where multi-ion angular forces are important to structural properties, simplified model GPT or MGPT potentials have been developed based on canonical d bands to allow analytic forms and large-scale atomistic simulations. Robust, advanced-generation MGPT potentials have now been obtained for Ta and Mo and successfully applied to a wide range of structural, thermodynamic, defect and mechanical properties at both ambient and extreme conditions of pressure and temperature. Recent algorithm improvements have also led to a more general matrix representation of MGPT beyond canonical bands allowing increased accuracy and extension to f-electron actinide metals, an order of magnitude increase in computational speed, and the current development of temperature-dependent potentials

Robust Quantum-Based Interatomic Potentials for Multiscale Modeling in Transition Metals

First-principles generalized pseudopotential theory (GPT) provides a fundamental basis for transferable multi-ion interatomic potentials in transition metals and alloys within density-functional quantum mechanics. In the central bcc metals, where multi-ion angular forces are important to materials properties, simplified model GPT or MGPT potentials have been developed based on canonical d bands to allow analytic forms and large-scale atomistic simulations. Robust, advanced-generation MGPT potentials have now been obtained for Ta and Mo and successfully applied to a wide range of structural, thermodynamic, defect and mechanical properties at both ambient and extreme conditions. Selected applications to multiscale modeling discussed here include dislocation core structure and mobility, atomistically informed dislocation dynamics simulations of plasticity, and thermoelasticity and high-pressure strength modeling. Recent algorithm improvements have provided a more general matrix representation of MGPT beyond canonical bands, allowing improved accuracy and extension to f-electron actinide metals, an order of magnitude increase in computational speed for dynamic simulations, and the development of temperature-dependent potentials

Implementation of an evidence-based guideline on fluid resuscitation: lessons learnt for future guidelines

There is little experience with the nationwide implementation of an evidence-based pediatric guideline on first-choice fluid for resuscitation in hypovolemia. We investigated fluid prescribing behavior at (1) guideline development, (2) after guideline development, and (3) after active implementation and identified potential barriers and facilitators for guideline implementation. In order to minimize costs and to optimize implementation effect, we continuously developed and adjusted implementation strategies according to identified barriers. Implementation success was evaluated using questionnaires, pharmaceutical data, and data from medical records. The most remarkable change occurred after guideline development and dissemination: Normal saline use by neonatologists increased from 22-89% to 100% and by pediatric intensivists from 43-71% to 88-100%, and synthetic colloid use by pediatric intensivists declined from 29-43% to 0-13% with a reduction in albumin use by neonatologists from 11-44% to 0%. After active guideline implementation, most of specialist's management behavior was according to the guideline. Stakeholders involved in the developmental process are of great importance in disseminating recommendations before active implementation. Therefore, to successfully implement guidelines and reduce costs of active implementation, any guideline development should consider implementation right from the beginning. Implementation strategies should target identified barriers and will therefore always be guideline specifi

US Monetary Regimes and Optimal Monetary Policy in the Euro Area

Monetary policy in the United States has been documented to have switched from reacting weakly to inflation fluctuations during the 1970s, to fighting inflation aggressively from the early 1980s onward. In this paper, I analyze the impact of the U.S. monetary policy regime switches on the Eurozone. I construct a New Keynesian two‐country model where foreign (U.S.) monetary policy switches regimes over time. I estimate the model for the U.S. and the Euro Area using quarterly data and find that the United States has switched between those two regimes, in line with existing evidence. I show that foreign regime switches affect home (Eurozone) inflation and output volatility and their responses to shocks, substantially, as long as the home central bank commits to a time‐invariant interest rate rule reacting to domestic conditions only. Optimal policy in the home country instead requires that the home central bank reacts strongly to domestic producer‐price inflation and to international variables, such as imported goods relative prices. In fact, I show that currency misalignments and relative prices play a crucial role in the transmission of foreign monetary policy regime switches internationally. Interestingly, I show that only marginal gains arise for the Euro Area when the European Central Bank (ECB) adjusts its policy according to the monetary regime in the United States. Thus, a simple time‐invariant monetary policy rule with a strong reaction to Producer Price Index (PPI) inflation and relative prices is enough to counteract the effects of monetary policy switches in the United States