4,988 research outputs found

    Effect of microstructure and crystallography on sulfide stress cracking in API-5CT-C110 casing steel

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    Microstructure and crystallography have been characterized on an API-5CT-C110 casing steel. Regions near a crack, more distant from a crack, and from specimen with no cracks were analyzed through electron backscatter diffraction (EBSD). A higher proportion of low-angle grain boundaries appeared in the regions near the crack, while regions distant from cracks presented primarily high-angle grain boundaries. The high Kernel Average Misorientation value and more grains with higher Taylor factor emerged in areas beside cracks. The corrosion reactions observed in the cracks would be expected to promote crack growth

    Effects of microstructure and crystallography on mechanical properties of cold-rolled SAE1078 pearlitic steel

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    The evolution of the microstructure and crystallography in SAE1078 pearlitic steel sheets under different cold-rolling reductions of up to 90% were quantified using transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). The mechanical properties were determined by tensile testing at room temperature. TEM analysis showed that the pearlite structure was obviously refined with the interlamellar spacing decreasing to about 57 nm at the rolling reduction of 90%. EBSD investigations indicated that the ferrite exhibited a {001}texture in the 90% cold-rolled pearlitic steel. The dislocations were mainly concentrated during cold rolling between the 10% and 70% reduction ratios as the average kernel average misorientation (KAM) angle increased from 0.75° to 1.20°. XRD examination revealed that a transformation from bcc to bct crystal structure of ferrite occurred at 90% rolling reduction due to the supersaturation of carbon. Significant augmentation in the ultimate tensile strength during cold rolling results from the boundary, dislocation, and solid solution strengthening mechanisms

    Re-colonizing spaces of memorializing: the case of the Chattri Indian Memorial, UK

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    This article inspects the ways that spaces of war memorialization are organized and reorganized through official and unofficial meaning-making activities. It aims to contribute to the discussion of the ‘value’ of memorializing by examining a multifaceted space of remembrance and commemoration: the Chattri Indian Memorial built near Brighton, UK. The article brings postcolonial perspectives to explore how memorializing has been organized here, focusing on the activities of once-colonized people and the affective, embodied aspects of organizing practices. Built in 1921 to honour Indian soldiers who fought in WWI, the Chattri evolved from a colonial instrument to symbol and space for ethnic-Indian group activities. The study employed historical, visual and ethnographic methods to study the tangible monument and the changing nature of the memorializing activities carried out around the monument. Memorializing is conceptualized within three inter-related processes: colonizing, de-colonizing and re-colonizing to examine how forms and practices of memorialization constitute a values-laden organizing system

    Designing hollow nano gold golf balls.

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    Hollow/porous nanoparticles, including nanocarriers, nanoshells, and mesoporous materials have applications in catalysis, photonics, biosensing, and delivery of theranostic agents. Using a hierarchical template synthesis scheme, we have synthesized a nanocarrier mimicking a golf ball, consisting of (i) solid silica core with a pitted gold surface and (ii) a hollow/porous gold shell without silica. The template consisted of 100 nm polystyrene beads attached to a larger silica core. Selective gold plating of the core followed by removal of the polystyrene beads produced a golf ball-like nanostructure with 100 nm pits. Dissolution of the silica core produced a hollow/porous golf ball-like nanostructure

    Symbiosis between the TRECVid benchmark and video libraries at the Netherlands Institute for Sound and Vision

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    Audiovisual archives are investing in large-scale digitisation efforts of their analogue holdings and, in parallel, ingesting an ever-increasing amount of born- digital files in their digital storage facilities. Digitisation opens up new access paradigms and boosted re-use of audiovisual content. Query-log analyses show the shortcomings of manual annotation, therefore archives are complementing these annotations by developing novel search engines that automatically extract information from both audio and the visual tracks. Over the past few years, the TRECVid benchmark has developed a novel relationship with the Netherlands Institute of Sound and Vision (NISV) which goes beyond the NISV just providing data and use cases to TRECVid. Prototype and demonstrator systems developed as part of TRECVid are set to become a key driver in improving the quality of search engines at the NISV and will ultimately help other audiovisual archives to offer more efficient and more fine-grained access to their collections. This paper reports the experiences of NISV in leveraging the activities of the TRECVid benchmark

    CAP interacts with cytoskeletal proteins and regulates adhesion‐mediated ERK activation and motility

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102140/1/emboj7601406-sup-0001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102140/2/emboj7601406.pd

    Simulation of the Zero Temperature Behavior of a 3-Dimensional Elastic Medium

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    We have performed numerical simulation of a 3-dimensional elastic medium, with scalar displacements, subject to quenched disorder. We applied an efficient combinatorial optimization algorithm to generate exact ground states for an interface representation. Our results indicate that this Bragg glass is characterized by power law divergences in the structure factor S(k)∌Ak−3S(k)\sim A k^{-3}. We have found numerically consistent values of the coefficient AA for two lattice discretizations of the medium, supporting universality for AA in the isotropic systems considered here. We also examine the response of the ground state to the change in boundary conditions that corresponds to introducing a single dislocation loop encircling the system. Our results indicate that the domain walls formed by this change are highly convoluted, with a fractal dimension df=2.60(5)d_f=2.60(5). We also discuss the implications of the domain wall energetics for the stability of the Bragg glass phase. As in other disordered systems, perturbations of relative strength ÎŽ\delta introduce a new length scale L∗∌Ύ−1/ζL^* \sim \delta^{-1/\zeta} beyond which the perturbed ground state becomes uncorrelated with the reference (unperturbed) ground state. We have performed scaling analysis of the response of the ground state to the perturbations and obtain ζ=0.385(40)\zeta = 0.385(40). This value is consistent with the scaling relation ζ=df/2−ξ\zeta=d_f/2- \theta, where Ξ\theta characterizes the scaling of the energy fluctuations of low energy excitations.Comment: 20 pages, 13 figure

    Orthogonal Decomposition of Left Ventricular Remodeling in Myocardial Infarction

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    BACKGROUND: Left ventricular size and shape are important for quantifying cardiac remodeling in response to cardiovascular disease. Geometric remodeling indices have been shown to have prognostic value in predicting adverse events in the clinical literature, but these often describe interrelated shape changes. We developed a novel method for deriving orthogonal remodeling components directly from any (moderately independent) set of clinical remodeling indices. RESULTS: Six clinical remodeling indices (end-diastolic volume index, sphericity, relative wall thickness, ejection fraction, apical conicity, and longitudinal shortening) were evaluated using cardiac magnetic resonance images of 300 patients with myocardial infarction, and 1991 asymptomatic subjects, obtained from the Cardiac Atlas Project. Partial least squares (PLS) regression of left ventricular shape models resulted in remodeling components that were optimally associated with each remodeling index. A Gram-Schmidt orthogonalization process, by which remodeling components were successively removed from the shape space in the order of shape variance explained, resulted in a set of orthonormal remodeling components. Remodeling scores could then be calculated that quantify the amount of each remodeling component present in each case. A one-factor PLS regression led to more decoupling between scores from the different remodeling components across the entire cohort, and zero correlation between clinical indices and subsequent scores. CONCLUSIONS: The PLS orthogonal remodeling components had similar power to describe differences between myocardial infarction patients and asymptomatic subjects as principal component analysis, but were better associated with well-understood clinical indices of cardiac remodeling. The data and analyses are available from www.cardiacatlas.org
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