Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Materials Science and Engineering (4)
- Condensed Matter Physics (3)
- Physical Sciences and Mathematics (3)
- Physics (3)
- Applied Mathematics (2)
-
- Chemistry (2)
- Electrical and Computer Engineering (2)
- Materials Chemistry (2)
- Other Applied Mathematics (2)
- Physical Chemistry (2)
- Signal Processing (2)
- Applied Mechanics (1)
- Biological Engineering (1)
- Biomedical Engineering and Bioengineering (1)
- Bioresource and Agricultural Engineering (1)
- Mechanical Engineering (1)
- Metallurgy (1)
- Keyword
Articles 1 - 7 of 7
Full-Text Articles in Engineering
Brittle Composites Modeling: Compazisons With Mosi2/Zro2, S.P. Chen, Richard Alan Lesar, A. D. Rollett
Brittle Composites Modeling: Compazisons With Mosi2/Zro2, S.P. Chen, Richard Alan Lesar, A. D. Rollett
Richard Alan Lesar
We have calculated the mechanical properties of brittle composites with spring-network (SN) model. The composites that we studied involve the transformation toughening effects and the accompanying micro-cracking. Our simulation results are consistent with experiments of MoSi2 toughened with ZrO2. By monitoring the stress changes due to the transformation and micro-cracking we are able to separate, for the first time, the contributions from these two competing effects. We also found that the fracture toughness of the composite increases as the modulus, interfacial cohesion of particle increases.
Parallel Image Segmentation Using A Hopfield Neural Network With Annealing Schedule For Neural Gains, Yungsik Kim, Sarah A. Rajala
Parallel Image Segmentation Using A Hopfield Neural Network With Annealing Schedule For Neural Gains, Yungsik Kim, Sarah A. Rajala
Sarah A. Rajala
Neural network architectures have been proposed as new computer architectures and a Hopfield neural network has been shown to find good solutions very fast in solving complex optimization problems. It should be noted, however, that a Hopfield neural network with fixed neural gains only guarantees to find local optimum solutions, not the global optimum solution. Image segmentation, like other engineering problems, can be formalized as an optimization problem and implemented using neural network architectures if an appropriate optimization function is defined. To achieve a good image segmentation, the global or the nearly global optimum solutions of the appropriate optimization function …
Inclusion Of Charge Correlations In Calculations Of The Energetics And Electronic Structure For Random Substitutional Alloys, Duane D. Johnson, F. J. Pinski
Inclusion Of Charge Correlations In Calculations Of The Energetics And Electronic Structure For Random Substitutional Alloys, Duane D. Johnson, F. J. Pinski
Duane D. Johnson
Currently, the coherent-potential approximation (CPA) implemented via the multiple-scattering theory of Korringa, Kohn, and Rostoker (KKR) gives the best first-principles description of the electronic structure for random substitutional alloys. However, the total energy has an important component of electrostatic energy missing, namely, that arising from the correlation of charges with varying atomic environments. We develop a ‘‘charge-correlated’’ CPA method (cc-CPA) which includes (some) local environmental charge correlations within the KKR-CPA method. We investigate the cc-CPA energetics for several alloys and show that the formation energies are in better agreement with experimental results. These calculations show that the excess charge on …
Optimum Displacement Estimates Using Mean Field Annealing, Ikhlas M. Abdelqader, Sarah A. Rajala, Griff L. Bilbro, Wesley E. Snyder
Optimum Displacement Estimates Using Mean Field Annealing, Ikhlas M. Abdelqader, Sarah A. Rajala, Griff L. Bilbro, Wesley E. Snyder
Sarah A. Rajala
In this paper a new algorithm to estimate dense displacement fields from a sequence of images is developed. The algorithm is based on modeling the displacement fields as Markov Random fields. The Markov Random fields-Gibbs equivalence is then used to convert the problem into one of finding an appropriate energy function that describes the motion and any constraints imposed on it. Mean field annealing, a technique which finds global minima in nonconvex optimization problems, is used to minimize the energy function, and solve for the optimum displacement fields. The algorithm results in accurate estimates even for scenes with noise or …
Evaluation Of A Ceramic Roof Coating, William H. Allen, Jay D. Harmon, Dale E. Linvill, Matthew V. Bramblett
Evaluation Of A Ceramic Roof Coating, William H. Allen, Jay D. Harmon, Dale E. Linvill, Matthew V. Bramblett
Jay D. Harmon
Surfaces treated with a ceramic roof coating (CRC) marketed as AZTEC No. 100 were compared to untreated and white painted surfaces. Dry-bulb and black globe temperatures in the space below or behind the surface were the criteria for comparison. Comparisons included small horizontal panels with open sides, small unvented galvanized steel and styrofoam boxes, and an open-side steel poultry building. The CRC was effective in reducing temperatures in the enclosed test boxes, but less effective with open-side test panels and the open-side steel building. Tests also indicated the CRC is characterized by high emissivity (0.95) and reflectivity (0.87). The evidence …
Tables Of Coincidence Orientations For Ordered Tetragonal L Lo Alloys For A Range Of Axial Ratios, Abha Singh, Alexander H. King
Tables Of Coincidence Orientations For Ordered Tetragonal L Lo Alloys For A Range Of Axial Ratios, Abha Singh, Alexander H. King
Alexander H. King
In this paper we develop and apply techniques for computation of CSL, DSCL and step-vector data for grain boundaries in tetragonal materials for a range of axial ratios. This has application to L10 alloys including TiA1, which is a candidate for lightweight high-temperature structural applications. Our results are compared with others and found to be more accurate and complete. We provide data for a wider range of axial ratios than those considered by previous workers. We have also derived equivalent quaternions for tetragonal crystals in tetragonal-crystal coordinates and listed conditions for selecting a unique reduced rotation in tetragonal-crystal coordinates so …
A Geometrical Rationalization Of The Special Properties Of The 14° [001] Grain Boundary In Yba2cu3o7−Δ, Alexander H. King, Abha Singh
A Geometrical Rationalization Of The Special Properties Of The 14° [001] Grain Boundary In Yba2cu3o7−Δ, Alexander H. King, Abha Singh
Alexander H. King
14° [001] tilt grain boundaries in YBa2Cu3O7−δ have been found to exhibit anomalously good superconducting critical currents, associated with magnetic flux pinning, although no special interfacial structure has heretofore been associated with this misorientation. We present an analysis of the geometry of the grain boundary in question and show that it can correspond to a special interface, within the definition of constrained lattice coincidence, which may lead to new understanding of the superconducting behavior of grain boundaries. Our analysis shows that the tetragonal‐to‐orthorhombic phase transformation may have important effects upon grain boundary structure and properties, indicating new approaches to producing …