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Articles 1 - 9 of 9

Full-Text Articles in Engineering

Glass Microspheres, D. E. Day, Gary J. Ehrhardt Dec 1988

Glass Microspheres, D. E. Day, Gary J. Ehrhardt

Materials Science and Engineering Faculty Research & Creative Works

A radioactive microsphere for radiation therapy of a mammal comprising a biologically compatible glass material containing a beta or gamma emitting radioisotope distributed substantially uniformly throughout the glass. Advantageously, the radioisotope is produced by irradiation of the microsphere.


Anomalous Temperature Dependence Of The Electric Field Gradient At The Y Site In In₀.₁Y₀.₉Ba₂Cu₃O9- Δ, Gary L. Catchen, Michael Blaszkiewicz, Anthony Baratta, Wayne Huebner Aug 1988

Anomalous Temperature Dependence Of The Electric Field Gradient At The Y Site In In₀.₁Y₀.₉Ba₂Cu₃O9- Δ, Gary L. Catchen, Michael Blaszkiewicz, Anthony Baratta, Wayne Huebner

Materials Science and Engineering Faculty Research & Creative Works

Perturbed angular correlation (PAC) spectroscopy has been used to measure a well-defined static electric quadrupole interaction in a superconducting ceramic, In0.1Y0.9Ba2Cu3O9-δ. Perturbation functions, Fourier transforms, and the derived PAC parameters are given for data taken at temperatures ranging from 77 to 1070 K. Indirect evidence is presented for the occupation of the Y site by the 111In-111Cd PAC probe. The derived electric field gradients were found to increase linearly with temperature. This result suggests the presence of soft, anisotropic vibrations in the structure. Additional evidence is presented …


Premartensitic Anelasticity In Indium-Thallium Alloys., Manfred Wuttig, C. Y. Lei, Tetsuro Suzuki Apr 1988

Premartensitic Anelasticity In Indium-Thallium Alloys., Manfred Wuttig, C. Y. Lei, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

The linear and nonlinear low frequency internal friction of In-24 at. pct Tl displays a Curie-Weiss type behavior in the temperature range above the transformation temperature. The critical temperature equals the martensite start temperature. It is proposed that the origin of the observed internal friction is the diffusion-controlled interaction of substitutional atoms with the premartensitic strain modulation, tweed.


Structural Characterization Of A High-Temperature, Ionic Conducting Ceramic Using Perturbed Angular Correlation Spectroscopy, Gary L. Catchen, Michael Blaszkiewicz, Khalid Jamil, Dinesh K. Agrawal, Wayne Huebner, Herbert A. Mckinstry, Lorenz H. Menke Jr. Apr 1988

Structural Characterization Of A High-Temperature, Ionic Conducting Ceramic Using Perturbed Angular Correlation Spectroscopy, Gary L. Catchen, Michael Blaszkiewicz, Khalid Jamil, Dinesh K. Agrawal, Wayne Huebner, Herbert A. Mckinstry, Lorenz H. Menke Jr.

Materials Science and Engineering Faculty Research & Creative Works

Perturbed angular correlation (PAC) spectroscopy has been used to characterize several structural aspects of a high-temperature, ionic conducting ceramic, CaZr3.95Hf0.05P6O24. Hafnium was introduced into the material to provide the PAC probe nuclei, 181Hf/181Ta, which were located primarily at Zr sites. PAC measurements were made over a range of temperatures from 77 to 1180 K, and they have been analyzed and interpreted using several simple models. The distorted octahedral crystal field at the Zr site produced a (low-frequency) static electric quadrupole interaction which can be accurately described by the point-charge model. But, the temperature dependence of the associated electric field gradient …


South East Missouri Lead Belt - A Review 1987, Johh L. Watson Jan 1988

South East Missouri Lead Belt - A Review 1987, Johh L. Watson

Materials Science and Engineering Faculty Research & Creative Works

The south-east Missouri Lead Belt is, and has been for many years, a major world producer of lead concentrate. This paper reviews the current mill operations in the area and presents detailed information on equipment, operating parameters and metallurgical performance. © 1988.


Sealing Glasses For Titanium And Titanium Alloys, Richard K. Brow, R. D. Watkins Jan 1988

Sealing Glasses For Titanium And Titanium Alloys, Richard K. Brow, R. D. Watkins

Materials Science and Engineering Faculty Research & Creative Works

Glass compositions containing calcium oxide, alumina, boric oxide, strontium oxide and barium oxide in various mole % combinations were studied. These compositions are capable of forming stable glass to metal seals with titanium and titanium alloys for use as seals for battery headers.


Comments On A Paper By No, Esnouf, San Juan, And Fontozzi, Hollis P. Leighly Jan 1988

Comments On A Paper By No, Esnouf, San Juan, And Fontozzi, Hollis P. Leighly

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.


Effect Of Excess Pbo On The Sintering Characteristics And Dielectric Properties Of Pb(Mg1/3nb2/3)O3–Pbtio3‐Based Ceramics, Jyoti P. Guha, Dyllan J. Hong, Harlan U. Anderson Jan 1988

Effect Of Excess Pbo On The Sintering Characteristics And Dielectric Properties Of Pb(Mg1/3nb2/3)O3–Pbtio3‐Based Ceramics, Jyoti P. Guha, Dyllan J. Hong, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

Additions of excess PbO to the perovskite Pb[(Mg1/3Nb2/3)0.92Ti0.08]O3 solid solution enhanced the formation of a liquid phase at 840°C, which served as a densification aid for the ceramics. The liquid phase allowed elimination of pores and promoted grain growth during sintering. With additions of 1 to 2 wt% excess PbO, densities in excess of 97% of theoretical were obtained at a sintering temperature of 950°C. The peak dielectric constants of the resulting ceramics were over 18 000 at 30°C and dissipation factors less than 1%. Additions of PbO in excess of …


Microstructural Analysis In Processing Of The High‐Tc Superconductor Ba2ycu3o7‐X In Air, Jyoti P. Guha Jan 1988

Microstructural Analysis In Processing Of The High‐Tc Superconductor Ba2ycu3o7‐X In Air, Jyoti P. Guha

Materials Science and Engineering Faculty Research & Creative Works

In the synthesis of the superconducting compound Ba2YCu3O7‐x from a stoichiometric mixture containing BaCO3, Y2O3, and CuO In air, a low‐melting liquid phase is formed at about 890°C. The liquid phase was identified as a ternary eutectic located within the compatibility triangle Ba2YCu3O7‐x–BaCuO2–CuO. The implication of this finding for the processing of Ba2YCu3O7‐x is discussed. Copyright © 1988, Wiley Blackwell. All rights reserved.