The present study proposes a comprehensive 3D computational fluid dynamics-discrete element method (CFD-DEM) coupled simulation model to investigate the particle dynamics induced by SS316L metal vapor spouting during single-scan-track laser powder bed fusion (L-PBF) processing. The model provides the ability to examine the effects of nonconventional process variables such as the chamber pressure and gravitational force on the suppression of the spatter and denudation phenomena. The simulation results imply that adjusting the gravitational force provides an effective technique for suppressing both spatter formation and powder bed denudation.
View Article and Find Full Text PDFLaser powder bed fusion (LPBF) provides a rapid and versatile approach for producing parts with complex geometries. However, many parts with intricate geometries have overhang structures, which are not easily fabricated by using LPBF and are often downgraded by staircase effects, warpage, cracks, and dross formation. Thus, the present study proposes a combined numerical and experimental approach for determining the optimal settings of the laser power and scanning speed that minimize the surface roughness and maximize the density of Inconel 718 LPBF overhang structures.
View Article and Find Full Text PDF(1) Background: Individuals with gene mutations are at increased risk of breast and ovarian cancer. The prevalence of mutations varies by race and ethnicity, and the prevalence and the risks associated with most mutations has not been unknown in the Vietnamese population. We herein screen the entire and genes for breast and ovarian cancer patients with a family history of breast cancer and ovarian cancer, thereby, suggesting a risk score associated with carrier status and history for aiding personalized treatment; (2) Methods: Between December 2017 and December 2019, Vietnamese patients who had a pathological diagnosis of breast and epithelial ovarian cancer were followed up, prospectively, after treatment from two large institutions in Vietnam.
View Article and Find Full Text PDFThis study proposes an integrated cattle breeding and cultivation system that provides zero emission and sustainable livelihood for the community in rural areas. The proposed integrated farming system improves agricultural productivity and environmental and sanitation conditions, minimizes the amount of waste, and increases the family income up to 41.55%.
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