in this work, dynamic mechanical properties of three high-manganese steels with trip/twip or fully twip characteristics are studied. high strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. all the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). bu...

in this study, the turbulent kinetic energy redistribution process is investigated. to this aim, the direct numerical simulation (dns) of incompressible flow of a newtonian fluid through a channel at a shear reynolds number of reτ = 180 is used to produce a flow data base. then, these data are statistically analyzed. the turbulent kinetic energy redistribution is studied using the pressure-stra...

Processing map for hot working of Ti-IF steel has been developed in the temperature range of 750 to 1100 °C and strain rate of 0.01 to 100 s-1. This map in the austenite region exhibits a single domain with a peak efficiency of 45% occurring at 1025 °C and strain rate of 0.02 s-1. The domain extends over the temperature range of 1000 to 1100 °C and strain rate range of 0.01 to 1 s-1. The true s...

We investigated left atrial (LA) function in relation to hypertension using 2-dimensional speckle-tracking echocardiography (STE) in subjects with preserved left ventricular (LV) ejection fraction, while accounting for LA enlargement and LV mass and diastolic function.We performed standard 2-dimensional and Doppler echocardiography and LA volumetric measurements and STE strain imaging in hypert...

in this study, the strain rate effect on the bending properties of fiber reinforced composites for three types of polymer composites namely phenolic resin reinforced by woven basalt fibers, woven carbon fibers, and woven basalt/ woven carbon fibers at a total volume fraction of approximately 35% has been determined. flexural tests have been conducted at low range of strain rates included 0.03 m...

Background and Objectives:Conservation of the normal atrial size and architecture by preventing the structural atrial remodeling that’s due to atrial fibrillation (AF) seems to be of prime importance for the management of AF patients. We attempted to assess the relevance of performing strain echocardiography for quantitatively assessing the left atrial (LA) status in AF patients. Subjects and M...

BACKGROUND The diagnosis of thrombus in the left atrium in patients with persistent atrial fibrillation (AF) and may be inconsistent because of variability in thrombus morphology. In some cases it is challenging and requires unusual approach. New Doppler-derived methods might be helpful to identify such thrombi. We evaluated quantitative differences in mechanical function of the left atrial app...