Displacement Demand Effects in Vulnerable Reinforced Concrete Columns

The purpose of this study was to analyze the response of two full-scale reinforced concrete columns undergoing cyclic lateral loads. Specifically, columns were detailed to be similar to actual columns found in buildings constructed before 1970, under much less stringent seismic design requirements than today. Columns were constructed at the Structural Testing Laboratory at the University of Kansas and were instrumented and tested at the University of Minnesota NEES-MAST facility. Column cross sectional area was maintained constant between the two tests as well as material properties. Longitudinal and transverse reinforcement ratios, axial load ratio, and loading protocol were varied between tests. A constant axial compressive load was applied to both columns while being subjected to lateral deformations with increasing amplitude, until both lateral and axial load capacities were lost. Post-failure measurements were obtained to study the residual strength of the columns. Results show that all four of the aforementioned parameters affected column response. Data collected from this experiment are used to improve our understanding about the effect of displacement history and longitudinal reinforcement ratio on the drift ratio at axial failure of reinforced concrete columns

Atomic and Molecular Laser-induced Breakdown Spectroscopy Above a Titanium Target

The goal of this research is to use optical emission spectroscopy to investigate the processes occurring subsequent to laser ablation of a titanium sample. Laser-induced breakdown spectroscopy provides a procedure for atomic and molecular identification for particular constituents of a laser-induced plasma. Atomic spectral line shapes provide a diagnostic tool for characterizing laser induced plasma, particularly within the first hundreds of nanoseconds. Molecular recombination and/or excitation of selected molecules can lead to simultaneous detection of atomic and molecular species via spectral analysis. Nonlinear fitting of synthetic molecular spectra, calculated via diatomic quantum theory, provides tools for identification, temperature measurement, and further analysis of the diatomic molecules present. By computing accurate line strength values for the TiO molecule, synthetic spectra for the TiO transitions are used to analyze plasma emissions at delay times within the first hundreds of microseconds. In obtaining and analyzing results, numerical methods are implemented. Specifically, use of a Monte-Carlo simulation is studied, as a tool for error analysis. The resulting analysis characterizes the temperature and electron density as a function of time within the first hundreds of nanoseconds. Investigations of TiO spectral transitions along the height of the ablation plume, at time delays of tens of microseconds, reveal two distinct luminescent regions within the plasma with starkly different temperatures

Performance of 2 1/4 Cr-1 Mo steel in a coal liquefaction dissolver vessel environment

Smooth-bar and notched-bar tensile specimens of bainitic 2 1/4 Cr-1 Mo steel were exposed with and without an applied stress to argon gas or to a coal slurry-H(,2) environment for various conditions of time, temperature and pressure. Room temperature mechanical properties determined after each coal slurry-H(,2) exposure were compared to those of like samples exposed to the same conditions in argon. The coal slurry exposures produced very little change in the room temperature mechanical properties even after 1000 hours at temperatures as high as 426(DEGREES)C and total pressures of 27.6 MPa;Corrosion samples were exposed in both the liquid phase and the gaseous phase above the coal slurry-H(,2) environment. Scale growth rates, electron microprobe analyses and X-ray analyses of the scale region were obtained;Smooth-bar and notched-bar tensile specimens of normalized and tempered (bainitic) 2 1/4 Cr-1 Mo steel were exposed to hydrogen gas at 5.2 to 27.6 MPa in the temperature range from 482(DEGREES) to 593(DEGREES)C. Exposed samples were in three conditions: unloaded, with an applied load, or lightly prestrained. Applied stress, plastic deformation and increasing exposure times all lowered the temperature, at any given pressure, for the formation of hydrogen attack bubbles. The results have been plotted on Nelson Curve coordinates;Fatigue crack growth tests were conducted on normalized and tempered (bainitic) 2 1/4 Cr-1 Mo steel. Crack growth rates were determined for near threshold to intermediate growth rate regions at room temperature and 427(DEGREES)C. Testing was done in a partial vacuum, moist air, hydrogen and coal slurry gases. Crack growth rates for various hydrogen pressures were examined. The results suggest that corrosion products of the coal slurry gases may mitigate the tendency of hydrogen to enhance fatigue crack growth. Possible mechanisms are suggested;J integral tests were performed to determine JIC on normalizedand tempered (bainitic) 2 1/4 Cr-1 Mo steel. J values were obtainedfrom deep cracked compact tension specimens using single andmultiple specimen techniques. Testing was carried out in vacuum,argon, hydrogen and coal slurry gases at 427(DEGREES)C. Single specimentests were made using an electropotential crack growthmeasurement system described in detail. Values of J(,IC) for the singlespecimen tests are compared to those obtained from the multiple;specimen tests;(\u271)DOE Report IS-T-1024. This work was performed under ContractW-7405-Eng-82 with the Department of Oil, Gas, and Energy

"New" and distributed leadership in quality and safety in healthcare, or "old" and hierarchical? : An interview study with strategic stakeholders

Peer reviewedPostprin

ENCAPSULATION OF IMAGE METADATA FOR EASE OF RETRIEVAL AND MOBILITY

Increasing proliferation of images due to multimedia capabilities of hand-held devices has resulted in loss of source information resulting from inherent mobility. These images are cumbersome to search out once stored away from their original source because they drop their descriptive data. This work, developed a model to encapsulate descriptive metadata into the Exif section of image header for effective retrieval and mobility. The resulting metadata used for retrieval purposes was mobile, searchable and non-obstructive

Patient obesity and the practical experience of the plain radiography professional: on everyday ethics, patient positioning and infelicitous equipment

Patient obesity is increasingly placing significant and multifaceted strain upon medical imaging departments, and professionals, in (particularly Western) healthcare systems. The majority of obesity-related studies in radiology are, however, primarily focused only upon the technical business of collecting diagnostically-efficacious images. This study, using Interpretative Phenomenological Analysis (IPA), qualitatively explores the everyday clinical experiences of eight expert UK diagnosticians working in plain radiography. Focus herein falls particularly upon (a) problems with patient positioning during examination, and (b) challenges arising around available equipment. In line with extant research, participants reported that difficulties with positioning obese patients could have negative impacts on image quality, and that insufficient table weight limits and widths, and inadequate detector sizes, can adversely affect examination. They also raised some more novel issues, such as how the impact of available gown sizes upon a patient’s sense of dignity can cause practical and ethical dilemmas for a clinician in situ. The issue of how one might ‘train’ experience in positioning patients without bony landmarks as a reference point was also made salient, with strong implications for undergraduate radiography curricula. It is finally highlighted how the participating radiographers themselves seldom conceptualised any given problem as a purely ‘technical’ one, instead recurrently recognising the interlinking of material, socio-economic and moral matters in real healthcare contexts. By better understanding such nuance and complexity as lived by real radiographers, it is contended, a more context-sensitive and flexible path to effective training and guideline-production can be mapped