Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Materials Science and Engineering

In Vitro Assessment Of Laser Sintered Bioactive Glass Scaffolds With Different Pore Geometries, Krishna C. R. Kolan, Albin Thomas, Ming-Chuan Leu, Greg Hilmas Aug 2014

In Vitro Assessment Of Laser Sintered Bioactive Glass Scaffolds With Different Pore Geometries, Krishna C. R. Kolan, Albin Thomas, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The pore geometry of bioactive glass scaffolds intended for use in bone repair or replacement is one of the most important parameters that could determine the rate of bone regeneration. The pore geometry would also affect the mechanical properties of the scaffolds and their rate of degradation. Scaffolds with five different architectures, having ~50% porosity, were fabricated with silicate (13–93) and borate (13–93B3) based bioactive glasses using a laser sintering process. An established, late-osteoblasts/early-osteocytes cell line was used to perform cell proliferation tests on the scaffolds. The results indicated that the cells proliferate significantly more on the scaffolds which mimic …


Modulating Notochordal Differentiation Of Human Induced Pluripotent Stem Cells Using Natural Nucleus Pulposus Tissue Matrix, Yongxing Liu, M. N. Rahaman, B. Sonny Bal Jul 2014

Modulating Notochordal Differentiation Of Human Induced Pluripotent Stem Cells Using Natural Nucleus Pulposus Tissue Matrix, Yongxing Liu, M. N. Rahaman, B. Sonny Bal

Materials Science and Engineering Faculty Research & Creative Works

Human induced pluripotent stem cells (hiPSCs) can differentiate into notochordal cell (NC)-like cells when cultured in the presence of natural porcine nucleus pulposus (NP) tissue matrix. The method promises massive production of high-quality, functional cells to treat degenerative intervertebral discs (IVDs). Based on our previous work, we further examined the effect of cell-NP matrix contact and culture medium on the differentiation, and further assessed the functional differentiation ability of the generated NC-like. The study showed that direct contact between hiPSCs and NP matrix can promote the differentiation yield, whilst both the contact and non-contact cultures can generate functional NC-like cells. …


Characterization Of 3d Interconnected Microstructural Network In Mixed Ionic And Electronic Conducting Ceramic Composites, William M. Harris, Kyle S. Brinkman, Ye Lin, Dong Su, Alex P. Cocco, Arata Nakajo, Matthew B. Degostin, Yu-Chen Karen Chen-Wiegart, Jun Wang, Fanglin Chen, Yong S. Chu, Wilson K. S. Chiu May 2014

Characterization Of 3d Interconnected Microstructural Network In Mixed Ionic And Electronic Conducting Ceramic Composites, William M. Harris, Kyle S. Brinkman, Ye Lin, Dong Su, Alex P. Cocco, Arata Nakajo, Matthew B. Degostin, Yu-Chen Karen Chen-Wiegart, Jun Wang, Fanglin Chen, Yong S. Chu, Wilson K. S. Chiu

Faculty Publications

The microstructure and connectivity of the ionic and electronic conductive phases in composite ceramic membranes are directly related to device performance. Transmission electron microscopy (TEM) including chemical mapping combined with X-ray nanotomography (XNT) have been used to characterize the composition and 3-D microstructure of a MIEC composite model system consisting of a Ce0.8Gd0.2O2 (GDC) oxygen ion conductive phase and a CoFe2O4 (CFO) electronic conductive phase. The microstructural data is discussed, including the composition and distribution of an emergent phase which takes the form of isolated and distinct regions. Performance implications are considered …


Ceramic Welds, And A Method For Producing The Same, Greg Hilmas, William Fahrenholtz, Jeremy Lee Watts, Harlan James Brown-Shaklee May 2014

Ceramic Welds, And A Method For Producing The Same, Greg Hilmas, William Fahrenholtz, Jeremy Lee Watts, Harlan James Brown-Shaklee

Materials Science and Engineering Faculty Research & Creative Works

A method of producing a ceramic weld, including identifying a ceramic first surface and a ceramic second surface to be bonded together, maintaining a non-oxidizing atmosphere over the first and second surfaces, and engaging the first and second surfaces to define a joint. An arc is generated between an electrode and the joint to create a liquid phase, and the liquid phase is cooled to yield a solid fusion layer, wherein the first and second surfaces are joined in the fusion layer.


Selection Of The Process Parameters For The Mass Plating Of Discrete Electronic Components, Ann Hopper May 2014

Selection Of The Process Parameters For The Mass Plating Of Discrete Electronic Components, Ann Hopper

Articles

The miniaturisation of electronic components coupled with requirements for high temperature lead free soldering has forced the improvement of the termination finish of surface mount components to meet the critical demands of the electronic industry. In the present work the processing parameters necessary to plate miniature multilayer varistors (MLV’s) have been explored. The tooling selected was a “Rotary flow-thru’ plater” which achieved high volume plating with


Synthesis And Accelerated Testing Of Oxynitride Films For High Temperature Applications, Robert J. Lad, Rosemary Smith Feb 2014

Synthesis And Accelerated Testing Of Oxynitride Films For High Temperature Applications, Robert J. Lad, Rosemary Smith

University of Maine Office of Research Administration: Grant Reports

NON-TECHNICAL DESCRIPTION:
There is a critical need for new protective ceramic coatings that can operate in harsh environments with service temperatures in the 1000-1500oC range. These ceramic coatings must exhibit excellent heat resistance, chemical stability, fracture toughness and wear durability so they can be reliably be used in applications such high performance engines, shrouds, rotors, seals, slides, and bearings. A major problem is that conventional ceramic coatings crack and delaminate during thermal cycling in reactive gases at extreme temperatures. This project focuses on developing and testing Si-Al-O-N and Si-Zr-O-N thin film coatings and tailoring their properties to achieve high performance …


Nanostructured Dielectric Materials For High Energy Density Multilayer Ceramic Capacitors, Fatih Dogan, Alan Devoe, Ian Burn Feb 2014

Nanostructured Dielectric Materials For High Energy Density Multilayer Ceramic Capacitors, Fatih Dogan, Alan Devoe, Ian Burn

Materials Science and Engineering Faculty Research & Creative Works

A multilayer ceramic capacitor, having a plurality of electrode layers and a plurality of substantially titanium dioxide dielectric layers, wherein each respective titanium dioxide dielectric layer is substantially free of porosity, wherein each respective substantially titanium dioxide dielectric layer is positioned between two respective electrode layers, wherein each respective substantially titanium dioxide dielectric layer has an average grain size of between about 200 and about 400 nanometers, wherein each respective substantially titanium dioxide dielectric layer has maximum particle size of less than about 500 nanometers. Typically, each respective substantially titanium dioxide dielectric layer further includes at least one dopant selected …


Design, Fabrication, And Properties Of 2-2 Connectivity Cement/Polymer Based Piezoelectric Composites With Varied Piezoelectric Phase Distribution, Xu Dongyu, Cheng Xin, Sourav Banerjee, Huang Shifeng Jan 2014

Design, Fabrication, And Properties Of 2-2 Connectivity Cement/Polymer Based Piezoelectric Composites With Varied Piezoelectric Phase Distribution, Xu Dongyu, Cheng Xin, Sourav Banerjee, Huang Shifeng

Faculty Publications

The laminated 2-2 connectivity cement/polymer based piezoelectric composites with variedpiezoelectric phase distribution were fabricated by employing Lead Zirconium Titanate ceramicas active phase, and mixture of cement powder, epoxy resin, and hardener as matrix phase with a mass proportion of 4:4:1. The dielectric, piezoelectric, and electromechanical coupling properties of the composites were studied. The composites with large total volume fraction ofpiezoelectric phase have large piezoelectric strain constant and relative permittivity, and thepiezoelectric and dielectric properties of the composites are independent of the dimensional variations of the piezoelectric ceramic layer. The composites with small total volume fraction of piezoelectric phase have large …


A Novel Injectable Borate Bioactive Glass Cement As An Antibiotic Delivery Vehicle For Treating Osteomyelitis, Hao Ding, Cunju Zhao, Xu Cui, Yifei Gu, Weitao Jia, M. N. Rahaman, Yang Wang, Wenhai Huang, Changqing Zhang Jan 2014

A Novel Injectable Borate Bioactive Glass Cement As An Antibiotic Delivery Vehicle For Treating Osteomyelitis, Hao Ding, Cunju Zhao, Xu Cui, Yifei Gu, Weitao Jia, M. N. Rahaman, Yang Wang, Wenhai Huang, Changqing Zhang

Materials Science and Engineering Faculty Research & Creative Works

Background: A novel injectable cement composed of chitosan-bonded borate bioactive glass (BG) particles was evaluated as a carrier for local delivery of vancomycin in the treatment of osteomyelitis in a rabbit tibial model. Materials and Methods: The setting time, injectability, and compressive strength of the borate BG cement, and the release profile of vancomycin from the cement were measured in vitro. The capacity of the vancomycin-loaded BG cement to eradicate methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in rabbit tibiae in vivo was evaluated and compared with that for a vancomycin-loaded calcium sulfate (CS) cement and for intravenous injection of vancomycin. Results: …