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Full-Text Articles in Engineering

Integrated Reliability And Sizing Optimization Of A Large Composite Structure, Christopher D. Eamon, Masoud Rais-Rohani Apr 2009

Integrated Reliability And Sizing Optimization Of A Large Composite Structure, Christopher D. Eamon, Masoud Rais-Rohani

Civil and Environmental Engineering Faculty Research Publications

In this paper, we present the application of probabilistic design modeling and reliability-based design optimization (RBDO) methodology to the sizing optimization of a composite advanced submarine sail structure under parametric uncertainty. With the help of probabilistic sensitivity analysis, the influence of individual random variables on each structural failure mode is examined, and the critical modes are treated as probabilistic design constraints under consistent lower bounds on the corresponding reliability indices. Whereas the failure modes are applied to structural components in the solution of the RBDO problem, the overall system reliability is also evaluated as a post-optimization step. The results indicate …


Biocompatibility Of Poly-Ε-Caprolactone-Hydroxyapatite Composite On Mouse Bone Marrow-Derived Osteoblasts And Endothelial Cells, Haiying Yu, Paul H. Wooley, Shang-You Yang Jan 2009

Biocompatibility Of Poly-Ε-Caprolactone-Hydroxyapatite Composite On Mouse Bone Marrow-Derived Osteoblasts And Endothelial Cells, Haiying Yu, Paul H. Wooley, Shang-You Yang

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Tissue-engineered bone may be developed by seeding the cells capable of both osteogenesis and vascularization on biocompatible composite scaffolds. The current study investigated the performance of mice bone marrow-derived osteogenic cells and endothelial cells as seeded on hydroxyapatite (HA) and poly-ε-caprolactone (PCL) composite scaffolds.

Methods

Mononuclear cells were induced to osteoblasts and endothelial cells respectively, which were defined by the expression of osteocalcin, alkaline phosphatase (ALP), and deposits of calcium-containing crystal for osteoblasts, or by the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) and von Willebrand factor (vWF), and the formation of a capillary network in Matrigel™ …


The Effect Of Sodium On The Catalytic Activity Of Zno-Al2o3/Zsm-5 And Sno-Al2o3/Zsm-5 For The Transesterification Of Vegetable Oil With Methanol, Manhoe Kim, Shuli Yan, Steven O. Salley, K.Y. Simon Ng Jan 2009

The Effect Of Sodium On The Catalytic Activity Of Zno-Al2o3/Zsm-5 And Sno-Al2o3/Zsm-5 For The Transesterification Of Vegetable Oil With Methanol, Manhoe Kim, Shuli Yan, Steven O. Salley, K.Y. Simon Ng

National Biofuels Energy Laboratory

In order to elucidate the effect of sodium on the activity of ZSM-5 supported metal oxides catalysts (ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5) for the transesterification of soybean oil with methanol, ZSM-5 supported metal oxides were prepared with and without sodium hydroxide by impregnation. The metal compositions of the ZSM-5 supported metal oxide catalysts and the metal concentrations dissolved from the catalysts to the methylester phase were measured by SEM-EDS and inductive coupled plasma spectroscopy, respectively. The catalytic activity of ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5 containing sodium did not originate from surface metal oxides sites, but from surface sodium sites or dissolved sodium leached from …