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Articles 1 - 7 of 7
Full-Text Articles in Engineering
Method For Stripping Metals In Solvent Extraction, Thomas J. O'Keefe
Method For Stripping Metals In Solvent Extraction, Thomas J. O'Keefe
Materials Science and Engineering Faculty Research & Creative Works
Aqueous solutions containing metal cations, that may include cations of both desired metal and impurity or secondary metal, are treated with an organic liquid extractant suitable for the extraction of cations of the desired metal, cations of at least one secondary metal being co-extracted. After phase disengagement, the loaded organic phase containing cations of either a desired metal or desired metal together with at least one secondary metal is contacted with a solid metal or solid metal alloy capable of reducing in the organic phase cations of either a desired metal or a secondary metal from a higher to a …
A Study Of Fatigue Failure In Superalloys Using Positron Annihilation, D. Hoeckelman, Hollis P. Leighly
A Study Of Fatigue Failure In Superalloys Using Positron Annihilation, D. Hoeckelman, Hollis P. Leighly
Materials Science and Engineering Faculty Research & Creative Works
This study shows there are significant changes occurring in the open volume defect concentration during fatigue cycling as measured by the S parameter. These changes are dependent upon the stress ratio, R = σmin/σmax, the maximum stress, σmax, and the number of fatigue cycles. The decline in the S parameter is due to the elimination of the residual vacancies. This decline is followed by an increase due to the generation of dislocations and the formation of small microcracks. This is followed by a decline in the S parameter due to growth of the microcracks ultimately leading to failure. Copyright © …
Defect Structure Of Y1-Ycaymno3 And La1-Ycaymno3. Ii. Oxidation-Reduction Behavior, J. W. Stevenson, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin
Defect Structure Of Y1-Ycaymno3 And La1-Ycaymno3. Ii. Oxidation-Reduction Behavior, J. W. Stevenson, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin
Materials Science and Engineering Faculty Research & Creative Works
Electrical conductivity, Seebeck coefficient, and thermogravimetric behavior of compositions in the systems Y1-yCayMnO3 and Y1-yCayMnO3 were studied as functions of temperature and ambient oxygen activity in order to determine the mechanism of electrical transport and defect structure. Compositions in Y1-yCayMnO3 exhibited very slight oxygen activity-dependent behavior as the ambient oxygen activity was reduced. A defect model which includes the thermally excited disproportionation of Mn3+ into Mn2+ and Mn4+ pairs was applied to the oxygen-activity-dependent data for La0.80Ca0.20MnO3 …
Solid-State Science And Technology: Synthesis And Characterization Of (Ceo2)0.8(Smo1.5)0.2 Thin Films From Polymeric Precursors, C. C. Chen, Harlan U. Anderson, M. M. Nasrallah
Solid-State Science And Technology: Synthesis And Characterization Of (Ceo2)0.8(Smo1.5)0.2 Thin Films From Polymeric Precursors, C. C. Chen, Harlan U. Anderson, M. M. Nasrallah
Materials Science and Engineering Faculty Research & Creative Works
(CeO2)0.8(CSO) has been suggested for solid oxide fuel cell (SOFC) applications, because of its higher electrical conductivity and chemical stability, compared to other ceria-based materials. However, CSO is difficult to densify under conditions compatible with other SOFC components. A thin film synthesis technique has been developed for the fabrication of dense CSO films from precursor solutions at relatively low temperatures. Dense, smooth, and homogeneous films were obtained on Pt, single-crystal Si, and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) substrates by spin-coating a polymeric precursor and subsequent heat-treatment. Crystallization of the film …
The Influence Of Matrix Microstructure, G. M. Vyletel, J. E. Allison, David C. Van Aken
The Influence Of Matrix Microstructure, G. M. Vyletel, J. E. Allison, David C. Van Aken
Materials Science and Engineering Faculty Research & Creative Works
The low-cycle and high-cycle fatigue behavior and cyclic response of naturally aged and artificially aged 2219/TiC/15p and unreinforced 2219 Al were investigated utilizing plastic strain-controlled and stress-controlled testing. The cyclic response of both the reinforced and un-reinforced materials was similar for all plastic strain amplitudes tested except that the saturation stress level for the composite was always greater than that of the unreinforced material. The cyclic response of the naturally aged materials exhibited cyclic hardening and, in some cases, cyclic softening, while the cyclic response for the artificially aged materials showed no evidence of either cyclic hardening or softening. The …
Defect Structure Of Y1-Ycaymno3 And La1-Ycaymno3. I. Electrical Properties, J. W. Stevenson, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin
Defect Structure Of Y1-Ycaymno3 And La1-Ycaymno3. I. Electrical Properties, J. W. Stevenson, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin
Materials Science and Engineering Faculty Research & Creative Works
Electrical conductivity and the Seebeck coefficient of compositions in the system Y1-yCayMnO3 and La1-yCayMnO3 were studied to determine the mechanism of electrical transport and defect structure. Electrical conduction appeared to occur via a small polaron hopping mechanism for compositions with 0.30 ≤ y ≤ 0.80. The Seebeck coefficient data did not support the assumption that Mn is present in Cadoped Mn perovskites only in the +3 and +4 valence states. A new defect model was developed which includes the thermally excited disproportion of Mn3+ and Mn4+ pairs. The …
Evaluation Of Yba₂Cu₃O₇₋ₓ Bulk Superconductors For High Field Magnet Applications, Michael Strasik, Fatih Dogan, J. Liu, Mehmet Sarikaya, K. Y. Blohowiak, D. F. Garrigus, T. S. Luhman, Kevin E. Mccrary, I. A. Aksay, W. B. Hicks
Evaluation Of Yba₂Cu₃O₇₋ₓ Bulk Superconductors For High Field Magnet Applications, Michael Strasik, Fatih Dogan, J. Liu, Mehmet Sarikaya, K. Y. Blohowiak, D. F. Garrigus, T. S. Luhman, Kevin E. Mccrary, I. A. Aksay, W. B. Hicks
Materials Science and Engineering Faculty Research & Creative Works
Processing of YBCO single crystals was carried out by solidification of semi-liquid YBCO composition using a seeding technique. Microstructural characterization of the pinning centers was investigated by transmission electron microscopy. Characterization of single crystals was carried out, relating grain size and shape to the corresponding flux profiles. Current densities were calculated based on measured trapped fields. Once circulating currents were established, flux pumping and quenching experiments were conducted. These large single crystals will be incorporated into electromagnetic forming devices for use in the military and commercial aircraft manufacturing and service industries.