Interface-related magnetic and vibrational properties in Fe/MgO heterostructures from nuclear resonant spectroscopy and first-principles calculations

We combine ⁵⁷Fe Mössbauer spectroscopy and ⁵⁷Fe nuclear resonant inelastic x-ray scattering (NRIXS) on nanoscale polycrystalline [bcc−⁵⁷Fe/MgO] multilayers with various Fe-layer thicknesses and layer-resolved density-functional-theory (DFT)-based first-principles calculations of a (001)-oriented [Fe(8 ML)/MgO(8 ML)](001) heterostructure (where ML denotes monolayer) to unravel the interface-related atomic vibrational properties of a multilayer system. Being consistent in theory and experiment, we observe enhanced hyperfine magnetic fields B_(hf) in the multilayers as compared to B_(hf) in bulk bcc Fe; this effect is associated with the Fe/MgO interface layers. NRIXS and DFT both reveal a strong reduction of the longitudinal acoustic phonon peak in combination with an enhancement of the low-energy vibrational density of states (VDOS) suggesting that the presence of interfaces and the associated increase in the layer-resolved magnetic moments results in drastic changes in the Fe-partial VDOS. From the experimental and calculated VDOS, vibrational thermodynamic properties have been determined as a function of Fe thickness and were found to be in excellent agreement

Magneto‐elastic coupling in compressed Fe 7 C 3 supports carbon in Earth's inner core

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94986/1/grl29522.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/94986/2/grl29522-sup-0002-txts01.pd

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Search for Dijet Resonances in 7 TeV pp Collisions at CMS (vol 105, 211801, 2010)

Publisher’s Note: Search for Dijet Resonances in 7 TeV pp Collisions at CMS [Phys. Rev. Lett. 105, 211801 (2010)

Image segmentation with unified region and boundary characteristics within recursive shortest spanning tree [Özyineli en kisa kapsayan aǧaç algoritmasinda bölgesel ve sinirsal bilginin birleçtirimi ile i̇mge bölütleme]

The lack of boundary information in region based image segmentation algorithms resulted in many hybrid methods that integrate the complementary information sources of region and boundary, in order to increase the segmentation performance. In compliance with this trend, we propose a novel method to unify the region and boundary characteristics within the canonical Recursive Shortest Spanning Tree algorithm. The main idea is to incorporate the boundary information in the distance metric of RSST with minor changes in the algorithm. Additionaly, we still benefit from the simple yet powerful structure of RSST. The results indicate the superiority of the proposed algorithm with respect to the conventional RSST. The object boundaries are successfully preserved. Therefore, the proposed algorithm is a candidate for video object segmentation where object boundaries coincide with motion field boundaries

ModuIar (Werconstrained Weak-Link Mechanism for Ultraprecision Motion Control

Abstract. We have designed and constructeda novel miniatureoverconstrainedweak-linkmechanismthat will . allow positioning of two crystals with better than 50nrad angular resolution and nanometer linear driving sensitivity.The precision and stability of this structureallow the user to align or adjust an assembly of crystals to achieve the same performanceas does a singlechannel-cutcrysta~so we call it an "artificialctiel-mt qstal." Unlike the traditionalkinematic linearspringmechanisms, the overconstrained weak%nkmechanismprovides much higher structure stifhess and stability. Usinga Iaminarstructurecofigured and manufacturedby ehemieal etching and lithographyteebniques, we are able to design and build a planar-shape,high stifhss, high precision weak-linkmeebaniam. In this paper, we present recent developmentsfor the overconstrainedweak-linkmechanism. Applicationsof this new techniqueto synchrotrons radiationinstrumentation are also discussed

Characteristics and analysis of risk factors for mortality in infective endocarditis

WOS: 000235061600003PubMed ID: 16450203Objective: The aim of our study was to establish the etiology of and risk factors for infective endocarditis (IE) and determine the prognostic factors for adverse outcome during hospital admission in a Turkish population. Material and Methods: Between January 2002 and January 2004, the clinical and laboratory features of 112 consecutive adult patients (> 18 years) with diagnosis of IE who were referred to the infectious diseases clinics/departments of 17 teaching hospitals in Turkey were evaluated. Cases of IE were defined according to the modified Duke Criteria. Mortality was defined as death occurring within 30 days or during hospital stay period. Univariate and multivariate analyses were performed to predict the factors related to fatal outcome. Results: A total of 112 consecutive patients presented with 101 definite and 11 probable IE episodes were defined according to the modified Duke Criteria. The mean age was 45.2 +/- 19.9. Fifty percent of the patients were male. Ninety (60.4%) of the 112 patients had risk factors for IE and 48 (42.9%) of them had >= 2 risk factors. On the other hand, 49.1% of patients had cardiac risk factors. Blood cultures were positive in 94 (83.9%) cases. Staphylococci were the most common agents (50.0%), followed by streptococci (28.7%) and enterococi (16.0%). Native cardiac valves were detected in 93 (83%) of the episodes of suspected IE. Valvular involvement was present in 103 (92%) patients; the mitral valve, alone or in combination with other valves, was affected in 70 (62.5%) of the patients. Echocardiography detected vegetations in 105 patients (93.8%). The mortality rate was 28.6%. Three factors were independently associated with mortality: haemodialysis OR: 14.5 (95% CI: 1.5-138.2), mobile vegetation OR: 4.8 (95% CI: 1.5-15.4) and mental alteration OR: 4.1 (95% CI: 1.1-15.6). Conclusion: Mortality is still high in IE. Our data indicate that patients with altered mental status, mobile vegetation, or on haemodialysis had poorer prognosis

Moment-Volume Coupling in La(Fe1−x Si x )13

We investigate the origin of the volume change and magnetoelastic interaction observed at the magnetic first-order transition in the magnetocaloric system La(Fe1-xSix)(13) by means of first-principles calculations combined with the fixed-spin moment approach. We find that the volume of the system varies with the square of the average local Fe moment, which is significantly smaller in the spin disordered configurations compared to the ferromagnetic ground state. The vibrational density of states obtained for a hypothetical ferromagnetic state with artificially reduced spin-moments compared to a nuclear inelastic X-ray scattering measurement directly above the phase transition reveals that the anomalous softening at the transition essentially depends on the same moment-volume coupling mechanism. In the same spirit, the dependence of the average local Fe moment on the Si content can account for the occurence of first- and second-order transitions in the system

Spinel–olivine–pyroxene equilibrium iron isotopic fractionation and applications to natural peridotites

Eight spinel-group minerals were synthesized by a flux-growth method producing spinels with varying composition and Fe^(3+)/Fe_(tot) ratios. The mean force constants of iron bonds in these minerals were determined by synchrotron nuclear resonant inelastic X-ray scattering (NRIXS) in order to determine the reduced isotopic partition function ratios (β-factors) of these spinels. The mean force constants are strongly dependent on the Fe^(3+)/Fe_(tot) of the spinel but are independent, or weakly dependent on other structural and compositional parameters. From our spectroscopic data, it is found that a single redox-dependent calibration line accounts for the effects of Fe^(3+)/Fe_(tot) on the β-factors of spinels. This calibration successfully describes the equilibrium Fe isotopes fractionation factors between spinels and silicates (olivine and pyroxenes). Our predictions are in excellent agreement with independent determinations for the equilibrium Fe isotopic fractionations for the magnetite–fayalite and the magnetite–hedenbergite couples. Our calibration applies to the entire range of Fe^(3+)/Fe_(tot) ratios found in natural spinels and provides a basis for interpreting iron isotopic variations documented in mantle peridotites. Except for a few exceptions, most of the samples measured so far are in isotopic disequilibrium, reflecting metasomatism and partial melting processes