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Full-Text Articles in Engineering

Thin Film Coatings For Solar And Thermal Radiation Control Prepared By Physical Vapour Deposition , Yamna El Mouedden, Ramzy Alghamedi, Mohammad Nur E Alam, Mikhail Vasiliev, Kamal Alameh Apr 2015

Thin Film Coatings For Solar And Thermal Radiation Control Prepared By Physical Vapour Deposition , Yamna El Mouedden, Ramzy Alghamedi, Mohammad Nur E Alam, Mikhail Vasiliev, Kamal Alameh

Mikhail Vasiliev

Growth of multilayer thin film structures containing dielectric and metal layers using physical vapor deposition is investigated for use in applications requiring the control of thermal and solar radiation propagating through glass windows. In particular, metal-dielectric multilayer structures reflecting UV, near-infrared and thermal radiations whilst maintaining a maximum transmission in the visible range are prepared using both an E-Beam and Thermal evaporator and a RF Magnetron sputtering system. Measured transmittance spectra for the developed structures are in agreement with simulation results and demonstrate that with the use of optimum metal-dielectric layer combination it is possible to realize a coated glass …


Atomic Roughness Enhanced Friction On Hydrogenated Graphene, Yalin Dong, Xiawa Wu, Ashlie Martini Apr 2015

Atomic Roughness Enhanced Friction On Hydrogenated Graphene, Yalin Dong, Xiawa Wu, Ashlie Martini

Dr. Yalin Dong

Atomic friction on hydrogenated graphene is investigated using molecular dynamics simulations. Hydrogenation is found to increase friction significantly, and the atomic-level information provided by the simulations reveals that atomic roughness induced by hydrogenation is the primary cause of the friction enhancement. Other proposed mechanisms, specifically adhesion and rigidity, are excluded based on the simulation results and analyses performed using the Prandtl–Tomlinson model. In addition, it is found that friction does not monotonically increase with hydrogen coverage on the graphene surface; instead, a maximum friction is observed at a hydrogen coverage between 5 and 10%.


Effects Of Substrate Roughness And Electron–Phonon Coupling On Thickness-Dependent Friction Of Graphene, Yalin Dong Apr 2015

Effects Of Substrate Roughness And Electron–Phonon Coupling On Thickness-Dependent Friction Of Graphene, Yalin Dong

Dr. Yalin Dong

Molecular dynamics simulation and the two-temperature method are carried out to model the effects of substrate roughness as well as electron–phonon coupling on thickness-dependent friction on graphene. It is found that substrate roughness can significantly enhance friction of graphene, which is orders of magnitude larger than that on smooth substrate due to puckering effect. Additionally, the adhesive force between graphene and substrate plays opposite roles for smooth and rough substrates. While on a smooth substrate, a larger adhesion hinders the wrinkle formation in graphene, therefore suppressing friction, on a rough substrate, adhesion helps induce atomic roughness in graphene and leads …


Applications Of High Throughput Screening Tools For Thermoelectric Materials, W. Wong-Ng, H. Joress, J. Martin, Y. Yan, M. Otani, E. Thomas, M. Green, Jason Hattrick-Simpers Mar 2015

Applications Of High Throughput Screening Tools For Thermoelectric Materials, W. Wong-Ng, H. Joress, J. Martin, Y. Yan, M. Otani, E. Thomas, M. Green, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.


Combinatorial Approach To Turbine Bond Coat Discovery, Christopher Metting, Johnathan Bunn, Ellen Underwood, Stephen Smoak, Jason Hattrick-Simpers Mar 2015

Combinatorial Approach To Turbine Bond Coat Discovery, Christopher Metting, Johnathan Bunn, Ellen Underwood, Stephen Smoak, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.


An Infrared Imaging Method For High-Throughput Combinatorial Investigation Of Hydrogenation-Dehydrogenation And New Phase Formation Of Thin Films, H. Oguchi, Jason Hattrick-Simpers, I. Takeuchi, E. Heilweil, L. Bendersky Mar 2015

An Infrared Imaging Method For High-Throughput Combinatorial Investigation Of Hydrogenation-Dehydrogenation And New Phase Formation Of Thin Films, H. Oguchi, Jason Hattrick-Simpers, I. Takeuchi, E. Heilweil, L. Bendersky

Jason R. Hattrick-Simpers

We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg2Si phase in a Mg thin …


Microwave Dielectric Properties Of Epitaxial Mn-Doped Ba(Zr,Ti)O-3 Thin Films On Laalo3 Substrates, Ming Liu, Chunrui Ma, Jian Liu, Gregory Collins, Chonglin Chen, Andy Alemayehu, Guru Subramanyam, Chao Dai, Yuan Lin, Amar Bhalla Mar 2015

Microwave Dielectric Properties Of Epitaxial Mn-Doped Ba(Zr,Ti)O-3 Thin Films On Laalo3 Substrates, Ming Liu, Chunrui Ma, Jian Liu, Gregory Collins, Chonglin Chen, Andy Alemayehu, Guru Subramanyam, Chao Dai, Yuan Lin, Amar Bhalla

Guru Subramanyam

Environmental friendly ferroelectric relaxor Ba(Zr0.2Ti0.8)O3 thin films with an additional 2% Mn dopant were epitaxially fabricated on the (001) LaAlO3 single crystal substrates by pulsed laser deposition. Microstructure characterizations from x-ray diffraction suggest that the films are c-axis oriented with the interface relationship of [101]Mn:BZT//[100]LAO and (001)Mn:BZT //(001)LAO. The microwave dielectric property measurements (13–17.5 GHz) reveal that the films have excellent dielectric properties with large tunability, high dielectric constant, and low dielectric loss, which the average value is 25.9%, 169 and 0.054, respectively. It is indicated that the additional 2% Mn doped Ba(Zr0.2Ti0.8)O3 thin films can be used for the …


Reduced Area Specific Resistance For Iron-Based Metallic Interconnects By Surface Oxide Coatings, Kevin Huang, Peggy Hou, John Goodenough Feb 2015

Reduced Area Specific Resistance For Iron-Based Metallic Interconnects By Surface Oxide Coatings, Kevin Huang, Peggy Hou, John Goodenough

Kevin Huang

No abstract provided.