26,426 research outputs found
Elastic and plastic analysis of pressure vessel weld lands with mismatch
Elastic and plastic analysis of pressure vessel weld lands with mismatc
Application and sensitivity investigation of Fourier transforms for microwave radiometric inversions
Existing microwave radiometer technology now provides a suitable method for remote determination of the ocean surface's absolute brightness temperature. To extract the brightness temperature of the water from the antenna temperature equation, an unstable Fredholm integral equation of the first kind was solved. Fast Fourier Transform techniques were used to invert the integral after it is placed into a cross-correlation form. Application and verification of the methods to a two-dimensional modeling of a laboratory wave tank system were included. The instability of the Fredholm equation was then demonstrated and a restoration procedure was included which smooths the resulting oscillations. With the recent availability and advances of Fast Fourier Transform techniques, the method presented becomes very attractive in the evaluation of large quantities of data. Actual radiometric measurements of sea water are inverted using the restoration method, incorporating the advantages of the Fast Fourier Transform algorithm for computations
Elastic and plastic stresses at weld sinkages and other discontinuities in pressure vessels
Mismatch and weld sinkage problems of pressure vessel geometric discontinuities studied in design graphs and test progra
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A whole-health-economy approach to antimicrobial stewardship: Analysis of current models and future direction.
Antimicrobial stewardship (AMS) strategies are widely implemented in single healthcare sectors and organisations; however, the extent and impact of integrated AMS initiatives across the whole health economy are unknown.
Assessing degree of integration of AMS across the whole health economy and its impact is essential if we are to achieve a ‘One Health’ approach to addressing antimicrobial resistance (AMR), and therefore we searched systematically for and analysed published examples of integrated AMS initiatives to address this gap.
Application of a system-level framework to analyse integration of AMS initiatives across and within healthcare sectors shows that integration is emerging but needs strengthening.
Findings from a small number of evaluations in high-income countries suggest that antimicrobial prescribing and healthcare-associated infections can be reduced using a multisectoral integrated AMS approach.
More robust research designs to evaluate and understand the impact of multisectoral integrated AMS are needed, particularly with respect to differing health systems in different countries and local organisational contexts.
Our analysis highlights a number of challenges and ways forward for enhancing the delivery of AMS through an integrated approach
Total focussing method for volumetric imaging in immersion non destructive evaluation
This paper describes the use of a 550 (25x22) element 2MHz 2D piezoelectric composite array in immersion mode to image an aluminum test block containing a collection of artificial defects. The defects included a 1mm diameter side-drilled hole, a collection of 1mm slot defects with varying degrees of skew to the normal and a flat bottomed hole. The data collection was carried out using the full matrix capture; a scanning procedure was developed to allow the operation of the large element count array through a conventional 64-channel phased array controller. A 3D TFM algorithm capable of imaging in a dual media environment was implemented in MATLAB for the offline processing the raw scan data. This algorithm facilitates the creation of 3D images of defects while accounting for refraction effects at material boundaries. In each of the test samples interrogated the defects, and their spatial position, are readily identified using TFM. Defect directional information has been characterized using VTFM for defect exhibiting angles up to and including 45o of skew
Anisotropy, disorder, and superconductivity in CeCu2Si2 under high pressure
Resistivity measurements were carried out up to 8 GPa on single crystal and
polycrystalline samples of CeCu2Si2 from differing sources in the homogeneity
range. The anisotropic response to current direction and small uniaxial
stresses was explored, taking advantage of the quasi-hydrostatic environment of
the Bridgman anvil cell. It was found that both the superconducting transition
temperature Tc and the normal state properties are very sensitive to uniaxial
stress, which leads to a shift of the valence instability pressure Pv and a
small but significant change in Tc for different orientations with respect to
the tetragonal c-axis. Coexistence of superconductivity and residual
resistivity close to the Ioffe-Regel limit around 5 GPa provides a compelling
argument for the existence of a valence-fluctuation mediated pairing
interaction at high pressure in CeCu2Si2.Comment: 12 pages, 7 figure
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