702 research outputs found
Is low phosphorus content in steel a product requirement
An attempt is made, on the basis to published literature, to assess the amount
of phosphorus that might be present in the steels without making it susceptible
to grain boundary embrittlement. Embrittlement occurs when the
general resistance to plastic flow is comparable to the stress required to separate
crystals at their boundaries. A criterion is developed that enables a
simple assessment to be made of the tendency to embrittle as a function
of yield strength and the fraction of grain boundary sites that are covered
by phosphorus. The latter is also sensitive to chemical composition, since
some elements such as carbon segregate preferentially to phosphorus, giving
rise to site competition that can permit a greater tolerance to the impurity.
Other solutes affect the embrittling potency by different mechanisms, not all
of which are clear.This is the author accepted manuscript. The final version is available from Maney at http://www.maneyonline.com/doi/abs/10.1179/1743281214Y.0000000261
Hydrogen diffusion and the percolation of austenite in nanostructured bainitic steel
The diffusion of hydrogen in austenite is slower than in ferrite. Experiments have been conducted to study the behaviour of hydrogen in a nanostructured steel sample consisting of a mixture of thin plates of bainitic ferrite and intervening films of retained austenite, with the latter phase present in a quantity larger than the percolation threshold, i.e. it has three-dimensional connectivity. The structure was then heat treated to control the fraction of austenite, and hence to study the role of hydrogen when the austenite decomposes below the value required to sustain percolation. The experiments have involved both thermal desorption analysis and permeation, and when combined with theoretical analysis, indicate a significant influence of percolating austenite in hindering the passage of hydrogen into the steel during hydrogen charging, and its permeation through the composite nanostructure. The effect is not as large as might be expected from a simple comparison of independent data on the diffusivities of hydrogen in the two lattices, because the effective diffusivity in ferrite is found to be much smaller than in the defect-free ferrite, owing to trapping effects. The morphology of the austenite is demonstrated to play a role by comparing with a sample containing a larger volume fraction of austenite but present as isolated grains which are ineffective to the permeation of hydrogen.X1199Ysciescopu
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Novel and simple patterning process of quantum dots via transfer printing for active matrix qd-led
© 2020 SID. The next generation of a self-emitting display requires precise and stable patterning techniques to shape Red, Green, and Blue pixels using quantum dots. In this study, we propose the novel and simple transfer printing process for the active matrix QD-LEDs
Black Carbon Exposure, Oxidative Stress Genes, and Blood Pressure in a Repeated-Measures Study
BACKGROUND. Particulate matter (PM) air pollution has been associated with cardiovascular morbidity and mortality, and elevated blood pressure (BP) is a known risk factor for cardiovascular disease. A small number of studies have investigated the relationship between PM and BP and found mixed results. Evidence suggests that traffic-related air pollution contributes significantly to PM-related cardiovascular effects. OBJECTIVES. We hypothesized that black carbon (BC), a traffic-related combustion by-product, would be more strongly associated with BP than would fine PM [aerodynamic diameter ≤ 2.5 μm (PM2.5)], a heterogeneous PM mixture, and that these effects would be larger among participants with genetic variants associated with impaired antioxidative defense. METHODS. We performed a repeated-measures analysis in elderly men to analyze associations between PM2.5 and BC exposure and BP using mixed-effects models with random intercepts, adjusting for potential confounders. We also examined statistical interaction between BC and genetic variants related to oxidative stress defense: GSTM1, GSTP1, GSTT1, NQO1, catalase, and HMOX-1. RESULTS. A 1-SD increase in BC concentration was associated with a 1.5-mmHg increase in systolic BP [95% confidence interval (CI), 0.1-2.8] and a 0.9-mmHg increase in diastolic BP (95% CI, 0.2-1.6). We observed no evidence of statistical interaction between BC and any of the genetic variants examined and found no association between PM2.5 and BP. CONCLUSIONS. We observed positive associations between BP and BC, but not between BP and PM2.5, and found no evidence of effect modification of the association between BC and BP by gene variants related to antioxidative defense.National Institute of Environmental Health Sciences (ES015172, ES014663); National Cancer Institute (2-T32-CA009330); United States Environmental Protection Agency (R832416); United States Deparment of Veterans Affairs; Massachusetts Veterans Epidemiology Research and Information Cente
Observation of micro-scale surface morphology with microtexture development during plane strain tensile deformation in AZ31 magnesium alloy
The change of microstructure including microtexture and surface morphology in AZ31 magnesium alloy under plane strain tension was investigated by 3D observation combined confocal microscope and high-resolution electron backscattered diffraction. Micro-scale changes in the surface morphology were observed on the area including tensile twin bands. The mechanism for surface morphology variation was discussed with the nucleation of tensile twinning and the strain partitioning caused by continuing deformation after the nucleation of the twins.open1111sciescopu
Opposing Effects of Particle Pollution, Ozone, and Ambient Temperature on Arterial Blood Pressure
Background: Diabetes increases the risk of hypertension and orthostatic hypotension and raises the risk of cardiovascular death during heat waves and high pollution episodes
Waterproof Flexible InP@ZnSeS Quantum Dot Light-Emitting Diode
The development of flexible displays for wearable electronics applications has created
demand for high-performance quantum dot (QD) light-emitting diodes (QLEDs) based on QD
core@shell structures. Emerging indium phosphide (InP)-based core@shell QDs show
promise as lighting material in the field of optoelectronics because they are environmentally
friendly material, can be produced in a cost-effective manner, and are capable of tunable
emission. While efforts have been made to enhance the performance of InP-based QLED, the
stabilities of InP@ZnSeS QDs film and InP@ZnSeS-based QLED in water/air are not yet
fully understood, limiting their practical applications. Herein, a highly durable, flexible
InP@ZnSeS QLED encapsulated in an ultrathin film of CYTOP, a solution-based amorphous
fluoropolymer, is demonstrated. The CYTOP-encapsulated green flexible QLED shows an
external quantum efficiency (EQE) of 0.904% and a high luminescence of 1593 cd/m2
as
well as outstanding waterproof performance. The flexible device emits strong luminescence
after being immersed in water for ~20 minutes. Even when subjected to continuous tensile
stress with a 5 mm bending radius, the high luminescence is preserved. This waterproof
architecture can be a promising strategy for wearable electronics applications
CD45 Isoform Expression in Microglia and Inflammatory Cells in HIV-1 Encephalitis
CD45 is a membrane tyrosine phosphatase that modulates the function of the hematopoietic cells. In vitro, agonist antibodies to CD45RO or CD45RB isoforms have been shown to suppress microglial activation, but whether microglia in vivo express these isoforms in HIV encephalitis (HIVE) is unknown. Brain sections from control and HIVE were immunostained for CD45 isoforms using exon-specific antibodies (RA, RB, RC and RO). RA and RC were limited to rare lymphocytes, while RB expression was robust in microglia and inflammatory cells. RO was low in control microglia, but increased in HIVE. RO was also localized to macrophages and CD8+ T cells. Targeting CD45 in vivo with isoform-specific antibodies remains a therapeutic option for neuroinflammatory diseases
Dynamics of conflicts in Wikipedia
In this work we study the dynamical features of editorial wars in Wikipedia
(WP). Based on our previously established algorithm, we build up samples of
controversial and peaceful articles and analyze the temporal characteristics of
the activity in these samples. On short time scales, we show that there is a
clear correspondence between conflict and burstiness of activity patterns, and
that memory effects play an important role in controversies. On long time
scales, we identify three distinct developmental patterns for the overall
behavior of the articles. We are able to distinguish cases eventually leading
to consensus from those cases where a compromise is far from achievable.
Finally, we analyze discussion networks and conclude that edit wars are mainly
fought by few editors only.Comment: Supporting information adde
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