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The pulsatile flow of blood through a tapered constricted narrow artery is investigated in this study, treating the blood as Carreau fluid model. The constriction in the artery is due to the formation of asymmetric stenosis in the lumen of the artery. The expressions obtained by Sankar (2016) for the various flow quantities are used to analyze the flow with different arterial geometry. The influence of various flow parameters on the velocity distribution, wall shear stress and longitudinal impedance to flow is discussed. The velocity of blood increases with the increase of the power law index and stenosis shape parameter and it decreases considerably with the increase of the maximum depth of the stenosis. The wall shear stress and longitudinal impedance to flow decrease with the increase stenosis shape parameter, amplitude of the pulsatile pressure gradient, flow rate, power law index and Weissenberg number. The estimates of the percentage of increase in the wall shear stress and longitudinal impedance to flow increase with the increase of the angle tapering and these increase significantly with the increase of the maximum depth of the stenosis. The mean velocity of blood decreases considerably with the increase of the artery radius (except in arteriole), maximum depth of the stenosis and angle of tapering and it is considerably higher in pulsatile flow of blood than in the steady flow of blood.

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Aluminum alloy 6082 (AA6082) should be a suitable material for use as casings in offshore based sensors due to its mechanical strength and corrosion resistance. However, there is concern with this materials remaining strength after a fire. This paper will discuss the room temperature creep behavior of AA6082 samples after thermal aging at various temperatures. Samples were aged at a constant temperature in the range 373 K to 423 K and for durations ranging from 4 hr to 24 hr. The creep behavior was investigated using loads slightly exceeding the yield strength of aged samples. We propose an empirical model to relate steady state creep rate at room temperature with aging temperature and time. Such empirical relationship can potentially be used in deciding whether AA6082 casings can still be used to carry loads after exposure to elevated temperatures such as platform fires.

Abstract. Experimental work on the axial crushing of empty and polyurethane foam filled bitubular composite cone-tube has been carried out. Hand lay-up method was used to fabricate the bi-tubes using woven roving glass, jute and hybrid jute-glass/epoxy materials. The tubes were of 56 mm diameter, and the cones top diameters were 65 mm. Cone semi-apical angles of 5°, 10°, 15 o , 20° and 25 o were examined. Height of 120 mm was maintained for all the fabricated specimens. Effects of material used, cone semi apical angle and foam filler on the load-displacement relation, maximum load, crush force efficiency, and the specific energy absorption and failure mode were investigated. Results show that the foam filler improved the progressive crushing process, increased the maximum load and the absorbed energy of the bitubes. The maximum crushing load and the specific energy absorption increased with increasing the cone semi apical angle up to 20 o for the empty bi-tubes and up to 25 o for the foam filled bi-tubes. Progressive failure mode with fiber and matrix cracking was observed at the top narrow side of the fractured bi-tubes as well as at the bottom surface of 20 o and 25 o cone semi-apical angle bi-tubes.