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Full-Text Articles in Engineering
Measurement And Modeling Of The Efficiency Of Constructed Wetlands In Removing Lead And Zinc From Neutral Ph Mine Drainage, Chang Ye
Dr. Chang Ye
"Adsorption by organic matter, Fe hydroxide association, and sulfide precipitation are primary mechanisms for Pb and Zn removal from neutral pH mine drainage by constructed wetlands. A mathematical model was developed with the geochemical modeling tool PHREEQC to simulate the constructed wetland processes, including both kinetic and equilibrium aspects of the above removal mechanisms...This research provides a quantification method to evaluate removal mechanisms of a constructed wetland and is also a direct support for previous research on wetland removal mechanisms"--Abstract, leaf iii.
Bimodal Nanocrystallization Of Niti Shape Memory Alloy By Laser Shock Peening And Post-Deformation Annealing, Chang Ye, Sergey Suslov, Xueling Fei, Gary J. Cheng
Bimodal Nanocrystallization Of Niti Shape Memory Alloy By Laser Shock Peening And Post-Deformation Annealing, Chang Ye, Sergey Suslov, Xueling Fei, Gary J. Cheng
Dr. Chang Ye
In this paper, surface nanocrystallization of NiTi intermetallic alloy by a novel method is reported. The NiTi alloy is processed by laser shock peening (LSP) and controlled annealing. The microstructure of the NiTi alloy after processing is characterized by transmission electron microscopy. At the top surface of the material, a nanostructure with bimodal grains is obtained. The mechanism of the formation of the bimodal microstructure is discussed. At the material subsurface, deformation twins are generated by LSP and retained after controlled annealing. Tensile test results showed that both strength and ductility are significantly improved through LSP and controlled annealing.
An Extended Finite Element Method (Xfem) Study On The Effect Of Reinforcing Particles On The Crack Propagation Behavior In A Metal–Matrix Composite, Chang Ye, Jay Shi, Gary J. Cheng
An Extended Finite Element Method (Xfem) Study On The Effect Of Reinforcing Particles On The Crack Propagation Behavior In A Metal–Matrix Composite, Chang Ye, Jay Shi, Gary J. Cheng
Dr. Chang Ye
In this paper, the eXtended Finite Element Method (XFEM) was integrated in ABAQUS to simulate crack propagation and to predict the effect of reinforcing particles to the crack propagation behavior of Al2O3/Al6061 composite materials. It has been demonstrated that, higher reinforcing particle volume fraction leads to improved fatigue resistance and smaller particles size is more effective than larger particles at the same particle volume fraction. The underlying mechanisms of these effects are systematically investigated. The stress fields captured by XFEM during the crack propagation help in understanding the crack propagation behavior during cyclic loading.