The aim of this study is to present a reliable computational scheme to serve in pulse wave velocity (PWV) assessment in large arteries. Clinicians considered it as an indication of human blood vessels' stiffness. The simulation of PWV was conducted using a 3D elastic tube representing an artery. The constitutive material model specific for vascular applications was applied to the tube material....

A numerical model is developed to describe the flow and heat transfer behavior of liquid metals in a cold delivery tube during gas atomization. Numerical calculations for liquid In, Sn, Bi, Pb, Zn and Sb are performed to investigate the influence of processing parameters and material properties on the flow and cooling of the liquid metals, and to predict the minimum melt superheat that is neces...

This paper presents a control model of the hydroforming and the dual hydroforming process of a tube. The theoretical part includes calculations to measure the change in tube thickness through the developed process. The hydroforming and the dual hydroforming processes are simulated in the SOLIDSIMULATION software and the static and the dynamic simulations are modeled. The obtained results for th...

Marchand and Duffy tested thin-walled steel tubes in a split Hopkinson torsion bar at a nominal strain-rate of approximately 1600/s and could not determine conclusively whether a shear band initiating at a point in the tube propagated around the circumference in one direction or in both directions. They estimated the speed of propagation to be 520 m/s in the former case and 260 m/s in the latte...

Material and methods Ten male volunteers without a history of abnormal gastric function, fasted for 10 hr overnight. A nasogastric tube was then passed and the resting juice aspirated. A 200 ml wash of water was instilled down the tube and immediately aspirated to check that the stomach was free of food debris and the tube was in the correct position. Gastric juice was then collected for a peri...

Simulated acoustic emission signals were induced in a thinwalled graphite/epoxy tube by means of lead breaks (Hsu-Neilsen source). The tube is of similar material and layup to be used by NASA in fabricating the struts of Space Station Freedom. The resulting waveforms were detected by broad band ultrasonic transducers and digitized. Measurements of the velocities of the extensional and flexural ...

An isothermal reactor in which reaction solutions can be controlled at constant temperature under constant microwave irradiation was developed. This is useful for investigating microwave effects on chemical reactions that are not observed under conventional heating conditions. We devised a structure in which a heat-transfer medium with a low dielectric loss factor, which hardly absorbs any micr...

Sexual reproduction of flowering plants depends on delivery of the sperm to the egg, which occurs through a long, polarized projection of a pollen cell, called the pollen tube. The pollen tube grows exclusively at its tip, and this growth is distinguished by very fast rates and reaches extended lengths. Thus, one of the most fascinating aspects of pollen biology is the question of how enough ce...