A dynamic recrystallization simulation based on phase-field and dislocation-crystal plasticity models

In this paper, so as to reproduce the dynamic recrystallization, the dislocationcrystal plasticity model devotes to a deformation analysis and multi-phase-field one to nucleus growth calculation. First, we place a few nuclei on the parent grain boundaries, i.e., high dislocation density site. Next, carrying out the simulation, dislocations start to accumulate in accordance with the deformation. Introducing the energy of dislocations stored locally in the matrix into the phase-field equation, the placed nuclei begin growing. In the region where the phase transitions from the matrix to the recrystallized phase, the values of dislocation density, crystal orientation and slip are reset. Moreover, applying the above information to the hardening modulus and crystal bases of the crystal plasticity model, the deformation is calculated again. With the progress of deformation, the dislocation density increases even inside the growing nuclei. Also, on the basis of the results obtained by the multiphysics simulation, we discuss the microstructure formations dependent on applied deformation

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in 2018

While primary percutaneous coronary intervention (PCI) has significantly contributed to improve the mortality in patients with ST segment elevation myocardial infarction even in cardiogenic shock, primary PCI is a standard of care in most of Japanese institutions. Whereas there are high numbers of available facilities providing primary PCI in Japan, there are no clear guidelines focusing on procedural aspect of the standardized care. Whilst updated guidelines for the management of acute myocardial infarction were recently published by European Society of Cardiology, the following major changes are indicated; (1) radial access and drug-eluting stent over bare metal stent were recommended as Class I indication, and (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. Although the primary PCI is consistently recommended in recent and previous guidelines, the device lag from Europe, the frequent usage of coronary imaging modalities in Japan, and the difference in available medical therapy or mechanical support may prevent direct application of European guidelines to Japanese population. The Task Force on Primary Percutaneous Coronary Intervention of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has now proposed the expert consensus document for the management of acute myocardial infarction focusing on procedural aspect of primary PCI

Tensile Testing with Cyclic Strain Holding to Analyze Dynamic Recrystallization of Pure Lead

We analyzed the dynamic recrystallization of pure lead by tensile testing with cyclic strain holding at room temperature. The specimens were held at an identical strain and subsequently reloaded, providing the strength before and after the strain holding process. The difference in strength enables factors affecting dynamic recrystallization behavior to be analyzed through mechanical testing. For instance, the effects of strain rate on dynamic recrystallization were analyzed by comparing the results obtained from tensile tests with and without strain holding. This experimental technique demonstrated some parts of contribution of elastic strain, dynamic recovery, dynamic recrystallization, and necking to stress-strain responses

Tensile Testing with Cyclic Strain Holding to Analyze Dynamic Recrystallization of Pure Lead

We analyzed the dynamic recrystallization of pure lead by tensile testing with cyclic strain holding at room temperature. The specimens were held at an identical strain and subsequently reloaded, providing the strength before and after the strain holding process. The difference in strength enables factors affecting dynamic recrystallization behavior to be analyzed through mechanical testing. For instance, the effects of strain rate on dynamic recrystallization were analyzed by comparing the results obtained from tensile tests with and without strain holding. This experimental technique demonstrated some parts of contribution of elastic strain, dynamic recovery, dynamic recrystallization, and necking to stress-strain responses