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

Engineering Commons

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

Articles 1 - 6 of 6

Full-Text Articles in Engineering

Prevention Of Environmentally Induced Degradation In Carbon/Epoxy Composite Material Via Implementation Of A Polymer Based Coati, Bradford Tipton Jan 2008

Prevention Of Environmentally Induced Degradation In Carbon/Epoxy Composite Material Via Implementation Of A Polymer Based Coati, Bradford Tipton

Electronic Theses and Dissertations

As the use of fiber reinforced plastics increases in such industries as aerospace, wind energy, and sporting goods, factors effecting long-term durability, such as environmental exposure, are of increasing interest. The primary objectives of this study were to examine the effects of extensive environmental exposure (specifically UV radiation and moisture) on carbon/epoxy composite laminate structures and to determine the relative effectiveness of polymer-based coatings at mitigating degradation incurred due to such exposure. Carbon/epoxy composite specimens, both coated and uncoated, were subjected to accelerated weathering in which prolonged outdoor exposure was simulated by controlling the radiation wavelength (in the UV region), …


Berkovich Indentation Of Diamondlike Carbon Coatings On Silicon Substrates, Ayesha J. Haq, Paul Munroe, Mark Hoffman, Phil Martin, Avi Bendavid Jan 2008

Berkovich Indentation Of Diamondlike Carbon Coatings On Silicon Substrates, Ayesha J. Haq, Paul Munroe, Mark Hoffman, Phil Martin, Avi Bendavid

Faculty of Engineering and Information Sciences - Papers: Part A

The deformation behavior of diamondlike carbon (DLC) coatings on silicon substrates induced by Berkovich indentation has been investigated. DLC coatings deposited by a plasma-assisted chemical vapor deposition technique were subjected to nanoindentation with a Berkovich indenter over a range of maximum loads from 100 to 300 mN. Distinct pop-ins were observed for loads greater than 150 mN. However, no pop-out was observed for the loads studied. The top surface of the indents showed annular cracks with associated fragmented material. The cross sections showed up to 20% localized reduction in thickness of the DLC coating beneath the indenter tip. Cracking, {111} …


Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies Jan 2008

Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies

Faculty of Engineering - Papers (Archive)

An extra-low-carbon steel was alloyed with 0.78 wt% Cr and subjected to three different processing schedules involving: (i) warm rolling to 65 % reduction at 640°C, (ii) warm rolling to 80% reduction at 580°C and (iii) warm rolling to 65% reduction at 640°C followed by cold rolling to 40% reduction. Increasing the severity of the deformation resulted in an increase in the number of grains containing in-grain shear bands. X-ray bulk texture analysis indicates that the g -fibre intensity was slightly higher in the steel warm rolled at 580°C than at 640°C and after cold rolling. Transmission electron microscopy and …


Carbon Nanotube Electroactive Polymer Materials: Opportunities And Challenges, Liangti Qu, Qiang Peng, Liming Dai, Geoffrey M. Spinks, G G. Wallace, Ray H. Baughman Jan 2008

Carbon Nanotube Electroactive Polymer Materials: Opportunities And Challenges, Liangti Qu, Qiang Peng, Liming Dai, Geoffrey M. Spinks, G G. Wallace, Ray H. Baughman

Faculty of Engineering - Papers (Archive)

Carbon nanotubes (CNTs) with macroscopically ordered structures (e.g., aligned or patterned mats, fibers, and sheets) and associated large surface areas have proven promising as new CNT electroactive polymer materials (CNT-EAPs) for the development of advanced chemical and biological sensors. The functionalization of CNTs with many biological species to gain specific surface characteristics and to facilitate electron transfer to and from them for chemical- and bio-sensing applications is an area of intense research activity. Mechanical actuation generated by CNT-EAPs is another exciting electroactive function provided by these versatile materials. Controlled mechanical deformation for actuation has been demonstrated in CNT mats, fibers, …


Development Of Plain Carbon And Niobium Microalloyed Ultra-Thin Cast Strip Products Produced By The Castrip® Process, Chris R. Killmore, Harold R. Kaul, Joshua Burg, Kristin R. Carpenter, James G. Williams, Daniel G. Edelman, Peter C. Campbell, Walter N. Blejde Jan 2008

Development Of Plain Carbon And Niobium Microalloyed Ultra-Thin Cast Strip Products Produced By The Castrip® Process, Chris R. Killmore, Harold R. Kaul, Joshua Burg, Kristin R. Carpenter, James G. Williams, Daniel G. Edelman, Peter C. Campbell, Walter N. Blejde

Faculty of Engineering and Information Sciences - Papers: Part B

The CASTRIP facility at Nucor Steel's Crawfordsville, Indiana plant is the world's first commercial installation for production of Ultra-Thin Cast Strip (UCS), via twin-roll strip casting. The facility has been producing plain, low-carbon sheet steel since 2002, with a range of structural grades available. The paper outlines some of the main parameters that influence the final microstructure and resultant mechanical properties of plain, low carbon UCS steels that have been recently made by the CASTRIP process, and then describes new Nb microalloyed UCS products that have been made in the CASTRIP process, significantly expanding the range of thin high strength …


Analytical Expression For The Impedance Response For A Lithium-Ion Cell, Godfrey Sikha, Ralph E. White Jan 2008

Analytical Expression For The Impedance Response For A Lithium-Ion Cell, Godfrey Sikha, Ralph E. White

Faculty Publications

An analytical expression to predict the impedance response of a dual insertion electrode cell (insertion electrodes separated by an ionically conducting membrane) is presented. The expression accounts for the reaction kinetics and double-layer adsorption processes at the electrode-electrolyte interface, transport of electroactive species in the electrolyte phase, and insertion of species in the solid phase of the insertion electrodes. The accuracy of the analytical expression is validated by comparing the impedance response predicted by the expression to the corresponding numerical solution. The analytical expression is used to predict the impedance response of a lithium-ion cell consisting of a porous LiCoO …