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An Energy Savings Model for the Heat Treatment of Castings
An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models
MyD88 in lung resident cells governs airway inflammatory and pulmonary function responses to organic dust treatment.
Inhalation of organic dusts within agriculture environments contributes to the development and/or severity of airway diseases, including asthma and chronic bronchitis. MyD88 KO (knockout) mice are nearly completely protected against the inflammatory and bronchoconstriction effects induced by acute organic dust extract (ODE) treatments. However, the contribution of MyD88 in lung epithelial cell responses remains unclear. In the present study, we first addressed whether ODE-induced changes in epithelial cell responses were MyD88-dependent by quantitating ciliary beat frequency and cell migration following wounding by electric cell-substrate impedance sensing. We demonstrate that the normative ciliary beat slowing response to ODE is delayed in MyD88 KO tracheal epithelial cells as compared to wild type (WT) control. Similarly, the normative ODE-induced slowing of cell migration in response to wound repair was aberrant in MyD88 KO cells. Next, we created MyD88 bone marrow chimera mice to investigate the relative contribution of MyD88-dependent signaling in lung resident (predominately epithelial cells) versus hematopoietic cells. Importantly, we demonstrate that ODE-induced airway hyperresponsiveness is MyD88-dependent in lung resident cells, whereas MyD88 action in hematopoietic cells is mainly responsible for ODE-induced TNF-α release. MyD88 signaling in lung resident and hematopoietic cells are necessary for ODE-induced IL-6 and neutrophil chemoattractant (CXCL1 and CXCL2) release and neutrophil influx. Collectively, these findings underscore an important role for MyD88 in lung resident cells for regulating ciliary motility, wound repair and inflammatory responses to ODE, and moreover, show that airway hyperresponsiveness appears uncoupled from airway inflammatory consequences to organic dust challenge in terms of MyD88 involvement
Kondo effect of non-magnetic impurities and the co-existing charge order in the cuprate superconductors
We present a theory of Kondo effect caused by an induced magnetic moment near
non-magnetic impurities such as Zn and Li in the cuprate superconductors. Based
on the co-existence of charge order and superconductivity, a natural
description of the induced moment and the resulting Kondo effect is obtained in
the framework of bond-operator theory of microscopic t-J-V Hamiltonian. The
local density of state near impurities is computed in a self-consistent
Bogoliubov-de Gennes theory which shows a low-energy peak in the middle of
superconducting gap. Our theory also suggests that the charge order can be
enhanced near impuries.Comment: 5 pages, 4 figure
Numerical Renormalization Group Study of Kondo Effect in Unconventional Superconductors
Orbital degrees of freedom of a Cooper pair play an important role in the
unconventional superconductivity. To elucidate the orbital effect in the Kondo
problem, we investigated a single magnetic impurity coupled to Cooper pairs
with a () symmetry using the numerical
renormalization group method. It is found that the ground state is always a
spin doublet. The analytical solution for the strong coupling limit explicitly
shows that the orbital dynamics of the Cooper pair generates the spin 1/2 of
the ground state.Comment: 4 pages, 2 figures, JPSJ.sty, to be published in J. Phys. Soc. Jpn.
70 (2001) No. 1
Persistence of Li Induced Kondo Moments in the Superconducting State of Cuprates
We measure the magnetic susceptibility nearby Li spinless impurities in the
superconducting phase of the high Tc cuprate YBaCuO. The induced moment which
was found to exist above Tc persists below Tc. In the underdoped regime, it
retains its Curie law below Tc. In contrast, near optimal doping, the large
Kondo screening observed above Tc (T_K=135 K) is strongly reduced below Tc as
expected theoretically when the superconducting gap develops. This moment still
extends essentially on its 4 near neighbour Cu, showing the persistence of AF
correlations in the superconducting state. A direct comparison with recent STM
results of Pan et al. is proposed.Comment: accepted for publication in Phys. Rev. Lett. (issue of 30 april 2001)
Revised version : 8 pages including 4 pages of text and 4 figure
Bayesian Parameter Estimation for Latent Markov Random Fields and Social Networks
Undirected graphical models are widely used in statistics, physics and
machine vision. However Bayesian parameter estimation for undirected models is
extremely challenging, since evaluation of the posterior typically involves the
calculation of an intractable normalising constant. This problem has received
much attention, but very little of this has focussed on the important practical
case where the data consists of noisy or incomplete observations of the
underlying hidden structure. This paper specifically addresses this problem,
comparing two alternative methodologies. In the first of these approaches
particle Markov chain Monte Carlo (Andrieu et al., 2010) is used to efficiently
explore the parameter space, combined with the exchange algorithm (Murray et
al., 2006) for avoiding the calculation of the intractable normalising constant
(a proof showing that this combination targets the correct distribution in
found in a supplementary appendix online). This approach is compared with
approximate Bayesian computation (Pritchard et al., 1999). Applications to
estimating the parameters of Ising models and exponential random graphs from
noisy data are presented. Each algorithm used in the paper targets an
approximation to the true posterior due to the use of MCMC to simulate from the
latent graphical model, in lieu of being able to do this exactly in general.
The supplementary appendix also describes the nature of the resulting
approximation.Comment: 26 pages, 2 figures, accepted in Journal of Computational and
Graphical Statistics (http://www.amstat.org/publications/jcgs.cfm
A High Docosahexaenoic Acid Diet Alters the Lung Inflammatory Response to Acute Dust Exposure
Agricultural workers are at risk for the development of acute and chronic lung diseases due to their exposure to organic agricultural dusts. A diet intervention using the omega-3 fatty acid docosahexaenoic acid (DHA) has been shown to be an effective therapeutic approach for alleviating a dust-induced inflammatory response. We thus hypothesized a high-DHA diet would alter the dust-induced inflammatory response through the increased production of specialized pro-resolving mediators (SPMs). Mice were pre-treated with a DHA-rich diet 4 weeks before being intranasally challenged with a single dose of an extract made from dust collected from a concentrated swine feeding operation (HDE). This omega-3-fatty-acid-rich diet led to reduced arachidonic acid levels in the blood, enhanced macrophage recruitment, and increased the production of the DHA-derived SPM Resolvin D1 (RvD1) in the lung following HDE exposure. An assessment of transcript-level changes in the immune response demonstrated significant differences in immune pathway activation and alterations of numerous macrophage-associated genes among HDE-challenged mice fed a high DHA diet. Our data indicate that consuming a DHA-rich diet leads to the enhanced production of SPMs during an acute inflammatory challenge to dust, supporting a role for dietary DHA supplementation as a potential therapeutic strategy for reducing dust-induced lung inflammation
Kondo screening in d-wave superconductors in a Zeeman field and implications for STM spectra of Zn-doped cuprates
We consider the screening of an impurity moment in a d-wave superconductor
under the influence of a Zeeman magnetic field. Using the Numerical
Renormalization Group technique, we investigate the resulting pseudogap Kondo
problem, in particular the field-induced crossover behavior in the vicinity of
the zero-field boundary quantum phase transition. The impurity spectral
function and the resulting changes in the local host density of states are
calculated, giving specific predictions for high-field STM measurements on
impurity-doped cuprates.Comment: 5 pages, 4 figs, (v2) remark on c-axis field added, discussion
extended, (v3) final version as publishe
Specific Heat of Zn-Doped YBa_{2}Cu_3O_{6.95}: Possible Evidence for Kondo Screening in the Superconducting State
The magnetic field dependence of the specific heat of Zn-doped single
crystals of YBa_{2}Cu_3O_{6.95} was measured between 2 and 10 K and up to 8
Tesla. Doping levels of 0, 0.15%, 0.31%, and 1% were studied and compared. In
particular we searched for the Schottky anomaly associated with the Zn-induced
magnetic moments.Comment: 5 pages, 6 figure
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