Chris N McCowan

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Changes in the compliance properties of large blood vessels are critical determinants of ventricular afterload and ultimately dysfunction. Little is known of the mechanical properties of large vessels exhibiting pulmonary hypertension, particularly the trunk and right main artery. We initiated a study to investigate the influence of chronic hypoxic(More)
Author(s) of this paper may load this reprint on their own web site provided that this cover page is retained. Republication of this article or its storage in electronic databases or the like is not permitted without prior permission in writing from the IUCr. The results of both a line-broadening study on a ceria sample and a size–strain round robin on(More)
Results of comparative tests on pulmonary arteries from untreated Long-Evans rats are presented from three sections of the artery: the trunk, and the right and left main extrapulmonary arteries. Analyses were conducted looking for mechanical differences between the flow (longitudinal) and circumferential directions, between the right and left main arteries,(More)
A series of tests were conducted to quantify the difference in the mechanical properties of normo- and hypertensive pulmonary arteries. A bubble-test design was employed to measure the biaxial properties of a segment of artery. The test results compare the properties at multiple orientations of the trunk, right, and left pulmonary arteries from normal(More)
The possibility for NIST to certify Charpy reference specimens for testing at room temperature (21 °C ± 1 °C) instead of -40 °C was investigated by performing 130 room-temperature tests from five low-energy and four high-energy lots of steel on the three master Charpy machines located in Boulder, CO. The statistical analyses performed show that in most(More)
National Institute of Standards and Technology, Boulder, Colorado 80303 Valid comparison of impact test energies reported by various organizations and over time depends on consistent performance of impact test machines. This paper investigates the influence of various specimen and test parameters on impact energies in the 1 J to 2 J range for both Charpy(More)
We investigate material models for a porous, polymeric scaffold used for bone. The material was made by co-extruding poly(e-caprolactone) (PCL), a biodegradable polyester, and poly(ethylene oxide) (PEO). The water soluble PEO was removed resulting in a porous scaffold. The stress-strain curve in compression was fit with a phenomenological model in(More)
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