glenn mcrae | Carleton University (original) (raw)

Papers by glenn mcrae

Materials Science Forum, 2018

The corrosion resistance of Stellite 6 alloy in morpholine solution with pH 9.5 is investigated u... more The corrosion resistance of Stellite 6 alloy in morpholine solution with pH 9.5 is investigated using the electrochemical test method, simulating the amine environment of the boiler feed water service condition in coal power plants. Polarization test is performed on Stellite 6 alloy under the low potential varying from-0.4 VSCEto 1.2 VSCEand is also conducted under a constant high potential (4 VSCE) in order to fail the sample surface. 17-4PH stainless steel, which is also a common material for the application of the boiler feed water in coal power plants, is tested simultaneously under the same conditions for comparison. It is shown that the polarization curve 17-4PH steel from the low potential test has an apparent passivation region indicating a protective oxide film formed on the sample surface, but Stellite 6 only exhibits a tendency to passivate. Both samples after the failure tests under the high potential (4 VSC) are analyzed using SEM/EDX. The surface morphologies indicate ...

$Research paper thumbnail of Gamma-zirconium hydride on DHC fracture surfaces is a legitimate stable phase, not a metastable phase$

Journal of Nuclear Materials, 2021

Abstract X-ray diffraction of fracture surfaces of Zr-2.5Nb after delayed hydride cracking reveal... more Abstract X-ray diffraction of fracture surfaces of Zr-2.5Nb after delayed hydride cracking revealed both γ-phase and δ-phase after testing isothermally at temperatures between 25°C and 240°C. The fraction of hydrides that are γ-phase on the fracture surfaces depends on temperature with high values of γ-phase at low test temperatures. When similar amounts of each hydride phase are observed on the same fracture surface, the γ-phase fraction should diminish to zero at the trailing end, that is, the oldest region, if γ-phase is transforming to δ-phase. The absence of such an extreme difference of the γ-phase fraction indicates that γ-phase is a stable phase.

Journal of Phase Equilibria and Diffusion, 2020

A probe has been developed to determine the solubility of hydrogen in metals. The method is based... more A probe has been developed to determine the solubility of hydrogen in metals. The method is based on mass balance and high-pressure hydrogen produced in situ partitioning between a zirconium probe and the metal. As an example, the solubility of hydrogen in copper, S H in Cu , has been determined between 350 and 450°C: S H in Cu ¼ ð1000 AE 200Þ exp À 43000 AE 1300 RT [mol H 2 =m 3 ffiffiffiffiffiffiffiffiffi ffi MPa p : This solubility agrees with permeation and diffusivity measurements spanning 10 and 6 orders of magnitude, respectively.

Protection of Metals and Physical Chemistry of Surfaces, 2019

In this study, the electrical properties of Bi 4 Ti 3 O 12-based Aurivillius-type ceramics were t... more In this study, the electrical properties of Bi 4 Ti 3 O 12-based Aurivillius-type ceramics were tailored by a B-site co-doping strategy combining high valence Ta 5+ and low valence Cu 2+. A series of Bi 4 Ti 3−x (Cu 1/3 Ta 2/3) x O 12 (BTCT) (x = 0, 0.005, 0.01, 0.015, 0.02, 0.025, and 0.03) ceramics were prepared by the conventional solid-state reaction method. The effect of Cu/Ta co-doping on the crystal structure, microstructure, dielectric properties, piezoelectric properties, ferroelectric properties, and electrical conductivity of these ceramics was systematically investigated. Co-doping significantly enhanced the piezoelectric properties and DC electrical resistivity of the resulting composites. The optimized comprehensive performances were obtained at x = 0.015 with a large piezoelectric coefficient (34 pC/N) and a relatively high resistivity of 9.02 × 10 6 Ω cm at 500°C. Furthermore, the ceramic also exhibited stable thermal annealing behaviors and excellent fatigue resistance. The results of this study demonstrated great potential of the Cu/Ta co-doped Bi 4 Ti 3 O 12 ceramics for high-temperature piezoelectric device applications. K E Y W O R D S bismuth titanates, fatigue, piezoelectric materials/properties, resistivity How to cite this article: Li X, Chen Z, Sheng L, et al. Large enhancement of piezoelectric properties and resistivity in Cu/Ta co-doped Bi 4 Ti 3 O 12 hightemperature piezoceramics.

Journal of Molecular Spectroscopy, 1996

Abstract Pure rotational spectra of gaseous CH 3 SiH 3 in the two interacting torsional states ( ... more Abstract Pure rotational spectra of gaseous CH 3 SiH 3 in the two interacting torsional states ( v 12 = 0, v 6 = 3) and ( v 12 = 1, v 6 = 0) were observed in the region from 87 to 197 GHz using a mm-wave spectrometer. Here v 12 and v 6 are, respectively, the principal quantum numbers for the silyl rocking mode and for the torsion. A total of 79 rotational frequencies were measured for J = 4 ← 3 to J = 9 ← 8. These new measurements, 22 rotational frequencies in the ( v 12 = 0, v 6 = 3) state reported previously, but not analyzed satisfactorily, and 2607 frequencies from a variety of other earlier experiments were fitted to within the experimental uncertainty by an effective Hamiltonian which included 22 parameters for the ground vibrational state, 12 parameters for the ( v 12 = 1) vibrational state, and 3 parameters which characterize the interactions between these two states. Some of the mm-wave lines are perturbed by about 600 MHz. The form of the effective Hamiltonian is severely constrained by the large number of precision data on various torsional levels in the ground vibrational state, 0 ≤ v 6 ≤ 3, and on the excited vibrational state ( v 12 = 1, v 6 = 0). The model predictions for the ( v 12 = 0, v 6 = 4) torsional state and the measurements reported by Wong et al. ( J. Mol. Spectrosc. 102, 89, 1983) agree to better than 500 kHz.

Journal of Molecular Spectroscopy, 1998

The pure rotational spectrum driven by the small distortion dipole moment perpendicular to the sy... more The pure rotational spectrum driven by the small distortion dipole moment perpendicular to the symmetry axis has been investigated between 8 and 18 GHz for CH3CF3 in the ground vibrational state using a pulsed Fourier transform waveguide spectrometer. This molecule has been selected as a prototype for the case of a symmetric top with small ( approximately 500 kHz) torsional energy splittings in the ground torsional state (nu6 = 0). In this state, six (k +/- 3 <-- k) Q-branch series have been measured for lower state K = |k| between 3 and 8 with 27 </= J </= 75. For (nu6 = 1), three series with lower state K between 5 and 7 with 49 </= J </= 66 have been observed. In two of these series, the torsional fine structure extending over approximately 6.8 MHz has been fully resolved. The (A1 - A2) splitting has been measured in the (nu6 = 0) series (K = 6 <-- 3) for 37 </= J </= 74. The global data set of 443 frequencies included avoided-crossing molecular-beam splittings of Meerts and Ozier (1991. Chem. Phys. 152, 241-259) and mm-wave R-branch measurements of Bocquet et al. (1994. J. Mol. Spectrosc. 165, 494-499). In a weighted least-squares analysis, a good fit was obtained by varying 18 parameters in a Hamiltonian that represented both the torsional effects and the sextic splittings. Effective values have been determined for both rotational constants, eight torsional parameters including the barrier height, six diagonal centrifugal distortion constants, and two centrifugal distortion constants (epsilon and epsilonJ) that characterize the (Deltak = +/-3) matrix elements. The difficulties are discussed that arise in defining a unique model for the torsional terms in the Hamiltonian when a high barrier symmetric top is investigated by distortion moment spectroscopy. The redundancies are investigated that exist in the quartic and sextic Hamiltonian for a near-spherical top such as CH3CF3. Copyright 1998 Academic Press.

Journal of Molecular Spectroscopy, 2010

The m 1 and m 2 bands of DOBr centered near 2668.8 and 852:0 cm À1 respectively have been observe... more The m 1 and m 2 bands of DOBr centered near 2668.8 and 852:0 cm À1 respectively have been observed at 0:006 cm À1 resolution. The m 1 band is perturbed by a quintic anharmonic resonance ðDK a ¼ 0Þ with 3m 3 þ m 2. In addition, the millimeter wave spectra arising from the v 2 ¼ 1 and v 3 ¼ 1 states have been observed. All rotational and vibrational spectra from both bromine isotopologs have been fitted with a single calculation. The perturbation in the m 1 band has been well described. Equilibrium rotational and centrifugal distortion constants and changes in quadrupole coupling with the BrO stretch and DOBr bend have been determined. The equilibrium structure has been derived from the DOBr and HOBr rotational constants. The harmonic force field has been calculated and compared with those of related molecules as well as with those derived from ab initio calculations.

Journal of Materials Engineering and Performance, 2014

ABSTRACT

Modern Physics Letters A, 2017

The most important radioisotope for nuclear medicine is [Formula: see text]Tc. After the supply c... more The most important radioisotope for nuclear medicine is [Formula: see text]Tc. After the supply crisis of [Formula: see text]Mo starting in 2008, the availability of [Formula: see text]Tc became a worldwide concern. Alternative methods for producing the medical imaging isotope [Formula: see text]Tc are actively being developed around the world. The reaction [Formula: see text]Mo(p, 2n)[Formula: see text]Tc provides a direct route that can be incorporated into routine production in nuclear medicine centers that possess medical cyclotrons for production of other isotopes, such as those used for Positron Emission Tomography. This paper describes a new approach for manufacturing targets for the (p, 2n) nuclear reaction on [Formula: see text]Mo and the foundation for the subsequent commercial separation and purification of the [Formula: see text]Tc produced. Two designs of targets are presented. The targets used to produce [Formula: see text]Tc are subject to a number of operational cons...

Zirconium in the Nuclear Industry: 19th International Symposium

Journal of Nuclear Engineering and Radiation Science

Simple, small-scale, experiments demonstrate the high deuterium concentrations found in the zirco... more Simple, small-scale, experiments demonstrate the high deuterium concentrations found in the zirconium pressure tubes at CANDU rolled joints comes from the initial as-received protium in stainless-steel end fittings exchanging with deuterium before being gettered by the zirconium. We propose to reduce the concentration of hydrogen isotopes at the ends of pressure tubes in heavy-water nuclear reactors with yttrium getters placed in the outer regions of the stainless-steel end fittings away from the heat-transport heavy water. Simple, small-scale, experiments demonstrate the operating principle showing that yttrium can getter hydrogen isotopes from the zirconium through the stainless steel.

AIP Conference Proceedings, 1993

Page 1. LASER ABLATION WITH RESONANCE IONIZATION FOR DETERMINATION OF HYDROGEN IN ZIRCONIUM Grant... more Page 1. LASER ABLATION WITH RESONANCE IONIZATION FOR DETERMINATION OF HYDROGEN IN ZIRCONIUM Grant A. Bickel, Glenn A. McRae, and Lawrence W. Green AECL Research, Chalk River, Ontario, CANADA K0J 1J0 ABSTRACT ...

$Research paper thumbnail of THE $ nu_{2}$ BAND OF HOBr$

Journal of Molecular Spectroscopy, Mar 1, 1986

Measurements of the pure rotational spectra of PH2D and PHD2 have been extended to include new Q-... more Measurements of the pure rotational spectra of PH2D and PHD2 have been extended to include new Q-branch transitions and R-branch transitions. The rotational constants have been independently evaluated for the first time, along with some quartic and sextic centrifugal distortion constants. The spectrum of PD3 has been reanalyzed to make the constants consistent with those reported for PH3. The new

IEEE Transactions on Nuclear Science, 2015

Spectrochimica Acta Part A: Molecular Spectroscopy, 1990

The selective multiphoton decomposition (MPD) process has the potential to provide a standalone h... more The selective multiphoton decomposition (MPD) process has the potential to provide a standalone heavy water process which is competitive with conventional processes. Twelve criteria are discussed for selecting a working molecule to give a process economically competitive with the Girdler-Sulphide process. The dependence of the MPD process on interacting parameters such as laser fluence, intensity and bandwidth as well as collisional effects are discussed. Finally, several potential working molecules are reviewed.

The Journal of Physical Chemistry, 1991

The multiphoton decomposition of tert-butyl methyl ether (TBME), (CHâ)âCOCHâ, has been investigat... more The multiphoton decomposition of tert-butyl methyl ether (TBME), (CHâ)âCOCHâ, has been investigated for the purpose of laser isotope separation (LIS) of oxygen isotopes. The multiphoton decomposition (MPD) of tert-butyl methyl ether (TBME) was studied with a 100-ns pulsed COâ laser operating on the 9R(20) line and at a fluence of 12 J/cmÂ². For TBME pressures up to 2.7 kPa, MPD gave the following products: 2-methylpropene (TMP), methanol, 2-methyl-2-butene, acetone, methane, hydrogen, ethane, and ethane. The products result from reactions among the species produced through two channels: (1) TMP + methanol; (2) acetone + 2CHâ. A collision-dependent reaction scheme is presented to explain the pressure dependence of the MPD. In this instance, significant energy transfer between two laser-excited TBME molecules occurs before decomposition takes place. The decomposition products deactivate excited TBME molecules and reduce subsequent decomposition.