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Full-Text Articles in Engineering
Resistance To Helium Bubble Formation In Amorphous Sioc/Crystalline Fe Nanocomposite, Qing Su, Tianyao Wang, Jonathan Gigax, Lin Shao, Michael Nastasi
Resistance To Helium Bubble Formation In Amorphous Sioc/Crystalline Fe Nanocomposite, Qing Su, Tianyao Wang, Jonathan Gigax, Lin Shao, Michael Nastasi
Department of Mechanical and Materials Engineering: Faculty Publications
The management of radiation defects and insoluble He atoms represent key challenges for structural materials in existing fission reactors and advanced reactor systems. To examine how crystalline/amorphous interface, together with the amorphous constituents affects radiation tolerance and He management, we studied helium bubble formation in helium ion implanted amorphous silicon oxycarbide (SiOC) and crystalline Fe composites by transmission electron microscopy (TEM). The SiOC/Fe composites were grown via magnetron sputtering with controlled length scale on a surface oxidized Si (100) substrate. These composites were subjected to 50 keV He+ implantation with ion doses chosen to produce a 5 at% peak He …
Dose Dependence Of Radiation Damage In Nano-Structured Amorphous Sioc/Crystalline Fe Composite, Qing Su, Lloyd Price, Lin Shao, Michael Nastasi
Dose Dependence Of Radiation Damage In Nano-Structured Amorphous Sioc/Crystalline Fe Composite, Qing Su, Lloyd Price, Lin Shao, Michael Nastasi
Department of Mechanical and Materials Engineering: Faculty Publications
Through examination of radiation tolerance properties of amorphous silicon oxycarbide (SiOC) and crystalline Fe composite to averaged damage levels, from approximately 8 to 30 displacements per atom (dpa), we demonstrated that the Fe/SiOC interface and the Fe/amorphous FexSiyOz interface act as efficient defect sinks and promote the recombination of vacancies and interstitials. For thick Fe/SiOC multilayers, a clear Fe/SiOC interface remained and no irradiation-induced mixing was observed even after 32 dpa. For thin Fe/SiOC multilayers, an amorphous FexSiyOz intermixed layer was observed to form at 8 dpa, but no further …
On The Importance Of Modeling Stent Procedure For Predicting Arterial Mechanics, Shijia Zhao, Linxia Gu, Stacey R. Froemming
On The Importance Of Modeling Stent Procedure For Predicting Arterial Mechanics, Shijia Zhao, Linxia Gu, Stacey R. Froemming
Department of Mechanical and Materials Engineering: Faculty Publications
The stent-artery interactions have been increasingly studied using the finite element method for better understanding of the biomechanical environment changes on the artery and its implications. However, the deployment of balloon-expandable stents was generally simplified without considering the balloon-stent interactions, the initial crimping process of the stent, its overexpansion routinely used in the clinical practice, or its recoil process. In this work, the stenting procedure was mimicked by incorporating all the above-mentioned simplifications. The impact of various simplifications on the stent-induced arterial stresses was systematically investigated. The plastic strain history of stent and its resulted geometrical variations, as well as …
The Relation Between The Arterial Stress And Restenosis Rate After Coronary Stenting, Linxia Gu, Shijia Zhao, Aswini K. Muttyam, James M. Hammel
The Relation Between The Arterial Stress And Restenosis Rate After Coronary Stenting, Linxia Gu, Shijia Zhao, Aswini K. Muttyam, James M. Hammel
Department of Mechanical and Materials Engineering: Faculty Publications
Two commercially available stents (the Palmaz–Schatz (PS) and S670 stents) with reported high and low restenosis rates, respectively, have been investigated in this paper. Finite element models simulating the stent, plaque, and artery interactions in 3 mm stenosed right coronary arteries were developed. These models were used to determine the stress field in artery walls after stent implantation. The material properties of porcine arteries were measured and implemented in the numerical models. The stress concentration induced in the artery by the PS stent was found to be more than double that of the S670 stent. It demonstrated a good correlation …