782 research outputs found
A-site- and/or B-site-modified PbZrTiO3 materials and (Pb, Sr, Ca, Ba, Mg) (Zr, Ti, Nb, Ta)O3 films having utility in ferroelectric random access memories and high performance thin film microactuators
A modified PbZrTiO.sub.3 perovskite crystal material thin film, wherein the PbZrTiO.sub.3 perovskite crystal material includes crystal lattice A-sites and B-sites at least one of which is modified by the presence of a substituent selected from the group consisting of (i) A-site substituents consisting of Sr, Ca, Ba and Mg, and (ii) B-site substituents selected from the group consisting of Nb and Ta. The perovskite crystal thin film material may be formed by liquid delivery MOCVD from metalorganic precursors of the metal components of the thin film, to form PZT and PSZT, and other piezoelectric and ferroelectric thin film materials. The thin films of the invention have utility in non-volatile ferroelectric memory devices (NV-FeRAMs), and in microelectromechanical systems (MEMS) as sensor and/or actuator elements, e.g., high speed digital system actuators requiring low input power levels
A-SITE-AND/OR B-SITE-MODIFIED PBZRTIO3 MATERIALS AND (PB, SR, CA, BA, MG) (ZR, TI,NB, TA)O3 FILMS HAVING UTILITY IN FERROELECTRIC RANDOM ACCESS MEMORIES AND HIGH PERFORMANCE THIN FILM MICROACTUATORS
A modified PbZrTiO.sub.3 perovskite crystal material thin film, wherein the PbZrTiO.sub.3 perovskite crystal material includes crystal lattice A-sites and B-sites at least one of which is modified by the presence of a substituent selected from the group consisting of (i) A-site substituents consisting of Sr, Ca, Ba and Mg, and (ii) B-site substituents selected from the group consisting of Nb and Ta. The perovskite crystal thin film material may be formed by liquid delivery MOCVD from metalorganic precursors of the metal components of the thin film, to form PZT and PSZT, and other piezoelectric and ferroelectric thin film materials. The thin films of the invention have utility in non-volatile ferroelectric memory devices (NV-FeRAMs), and in microelectromechanical systems (MEMS) as sensor and/or actuator elements, e.g., high speed digital system actuators requiring low input power levels
Early quantitative coronary angiography of saphenous vein grafts for coronary artery bypass grafting harvested by means of open versus endoscopic saphenectomy: a prospective randomized trial
AbstractObjectiveEndoscopic saphenectomy is associated with a decreased incidence of wound complications without an increase in histologic trauma or endothelial dysfunction in published reports. Concern remains about the patency of saphenous vein grafts harvested endoscopically and the development of early intimal hyperplasia. The purpose of this study was to compare early quantitative coronary analysis of saphenous vein grafts used for coronary artery bypass grafting harvested with the open versus endoscopic techniques.MethodsForty patients undergoing primary coronary artery bypass grafting surgery with at least 1 saphenous vein graft were randomized preoperatively to open versus endoscopic saphenectomy with bipolar cauterization of side branches. Quantitative coronary angiography was performed a mean of 3 months (range, 1-9 months) after the operation.ResultsThere was no statistically significant difference in the patency rates of internal thoracic artery grafts between the open and endoscopic groups and no statistically significant difference in the patency rates of saphenous vein grafts between both groups (85.2% vs 84.4%, P = .991). Quantitative coronary angiography showed no difference in graft stenosis (≥50% of the internal diameter of the graft) in the body of the saphenous vein grafts in the open versus endoscopic saphenectomy groups (3.7% vs 0%, P = .280).ConclusionAngiographic appearance and patency rates of saphenous vein grafts harvested with the endoscopic technique are similar to those of saphenous vein grafts harvested with the open technique. These results support the use of endoscopic saphenectomy because of the known lower incidence of wound and infectious complications and superior functional results
The early enhancement of rat liver deoxyribonucleic acid-dependent ribonucleic acid polymerase II activity by tri-iodothyronine
Probabilistic Clustering of Time-Evolving Distance Data
We present a novel probabilistic clustering model for objects that are
represented via pairwise distances and observed at different time points. The
proposed method utilizes the information given by adjacent time points to find
the underlying cluster structure and obtain a smooth cluster evolution. This
approach allows the number of objects and clusters to differ at every time
point, and no identification on the identities of the objects is needed.
Further, the model does not require the number of clusters being specified in
advance -- they are instead determined automatically using a Dirichlet process
prior. We validate our model on synthetic data showing that the proposed method
is more accurate than state-of-the-art clustering methods. Finally, we use our
dynamic clustering model to analyze and illustrate the evolution of brain
cancer patients over time
A Two-dimensional Splashing Model for Investigating Impingement Characteristics of Supercooled Large Droplets
This document is the Accepted Manuscript of the following article: C. Wang, S. Chang, M. Leng, H. Wu, and B. Yang, 'A two-dimensional splashing model for investigating impingement characteristics of supercooled large droplets', International Journal of Multiphase Flow, Vol. 80, April 2016, pp. 131-149. This manuscript version is made available under the terms of the Creative Commons CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. The Version of Record is available online at doi: https://doi.org/10.1016/j.ijmultiphaseflow.2015.12.005. © 2015 Elsevier Ltd. All rights reserved.In this article, a two-dimensional (2D) splashing model is proposed to investigate the dynamics when supercooled large droplets (SLD) impinging on a wall surface in the aircraft-icing field. Energy conservation for droplet motion and impingement is used to capture the properties of the splashed droplets. A new statistical treatment of the droplet impinging energy and angle during the droplet-wall interaction is introduced in order to calculate the average dynamics of the SLD within a micro-control volume on wall surface. Based on the LEWICE predictions of droplet collection efficiencies and the available experimental ones, a new criterion for droplet splashing/deposition as well as a new formulation for the splashed mass is suggested. Lagrangian approach is adopted to describe the movement and impingement of SLD. The proposed model together with the previously developed droplet tracking method (DTM) for calculating droplet collection efficiency with the effect of droplet reimpingement constitute a relatively complete predicting approach of SLD impingement characteristics. Comparisons between the current predictions and the experimental observations, including SLD impingement over clean and contaminated airfoil surfaces as well as shapes of ice accretion in typical icing conditions, are carried out. Further, results obtained with the LEWICE splashing model are also plotted on the same graphs in order to assess the accuracy of the current splashing model in predicting SLD impingement. Results show that good agreement is achieved between the current predictions, including SLD impingement and ice accretion shapes, and the experimental ones. The predictions of the impingement distribution over contaminated surfaces obtained with the current splashing model show a much closer agreement with the experimental results than the ones obtained with LEWICE splashing model. For further investigation of SLD impingement, the properties of the droplet splashing and reimpingement during the ice accretion process are also addressed.Peer reviewe
Calculation of the positron bound state with the copper atom
A new relativistic method for calculation of positron binding to atoms is
presented. The method combines a configuration interaction treatment of the
valence electron and the positron with a many-body perturbation theory
description of their interaction with the atomic core. We apply this method to
positron binding by the copper atom and obtain the binding energy of 170 meV (+
- 10%). To check the accuracy of the method we use a similar approach to
calculate the negative copper ion. The calculated electron affinity is 1.218
eV, in good agreement with the experimental value of 1.236 eV. The problem of
convergence of positron-atom bound state calculations is investigated, and
means to improve it are discussed. The relativistic character of the method and
its satisfactory convergence make it a suitable tool for heavier atoms.Comment: 15 pages, 5 figures, RevTe
Practical mammography
‘Digital health’ is an overarching concept that currently lacks theoretical definition and common terminology. For instance, this broad and emerging field includes all of the following terms within its lexicon: mHealth, Wireless Health, Health 2.0, eHealth, e-Patient(s), Healthcare IT/Health IT, Big Data, Health Data, Cloud Computing, Quantified Self, Wearable Computing, Gamification, and Telehealth/Telemedicine [1]. However, whilst a definition is difficult to provide, in this overview it is considered that digital health is the use of digital media to transform the way healthcare provision is conceived and delivered. We consider it does this through three basic features
Improved Neutron-Capture Element Abundances in Planetary Nebulae
Spectroscopy of planetary nebulae (PNe) provides the means to investigate
s-process enrichments of neutron(n)-capture elements that cannot be detected in
asymptotic giant branch (AGB) stars. However, accurate abundance determinations
of these elements present a challenge. Corrections for unobserved ions can be
large and uncertain, since in many PNe only one ion of a given n-capture
element has been detected. Furthermore, the atomic data governing the
ionization balance of these species are not well-determined, inhibiting the
derivation of accurate ionization corrections. We present initial results of a
program that addresses these challenges. Deep high resolution optical
spectroscopy of ~20 PNe has been performed to detect emission lines from
trans-iron species including Se, Br, Kr, Rb, and Xe. The optical spectral
region provides access to multiple ions of these elements, which reduces the
magnitude and importance of uncertainties in the ionization corrections. In
addition, experimental and theoretical efforts are providing determinations of
the photoionization cross-sections and recombination rate coefficients of Se,
Kr, and Xe ions. These new atomic data will make it possible to derive robust
ionization corrections for these elements. Together, our observational and
atomic data results will enable n-capture element abundances to be determined
with unprecedented accuracy in ionized nebulae.Comment: 6 pages, 6 figures, to appear in "The Origin of the Elements Heavier
than Fe", Sep 25-27, 2008, Turin, Italy, PASA, eds. John C. Lattanzio and M.
Lugar
Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging
Citation: Ablikim, U., Bomme, C., Xiong, H., Savelyev, E., Obaid, R., Kaderiya, B., . . . Rolles, D. (2016). Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging. Scientific Reports, 6, 8. doi:10.1038/srep38202An experimental route to identify and separate geometric isomers by means of coincident Coulomb explosion imaging is presented, allowing isomer-resolved photoionization studies on isomerically mixed samples. We demonstrate the technique on cis/trans 1,2-dibromoethene (C2H2Br2). The momentum correlation between the bromine ions in a three-body fragmentation process induced by bromine 3d inner-shell photoionization is used to identify the cis and trans structures of the isomers. The experimentally determined momentum correlations and the isomer-resolved fragment-ion kinetic energies are matched closely by a classical Coulomb explosion model
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