D. Northwood | University of Windsor (original) (raw)
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Papers by D. Northwood
Journal of Physics D: Applied Physics, 2010
ABSTRACT In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide c... more ABSTRACT In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide coatings on commercially pure aluminium (1100 alloy) at a pulsed dc power mode. The effects of process parameters (i.e. current density and treatment time) on the plasma discharge behaviour during the PEO treatment were investigated using optical emission spectroscopy (OES) in the visible and near ultraviolet (NUV) band (285–800 nm). The elements present in the plasma were identified. Stark shifts of spectral lines and line intensity ratios were utilized to determine the plasma electron concentrations and temperatures, respectively. The plasma electron temperature profile, coating surface morphology and coating composition were used to interpret the plasma discharging behaviour. The different coating morphologies and compositions at different coating surface regions are explained in terms of three types of discharge, which originate either at the substrate/coating interface, within the upper layer, or at the coating top layer. The high spike peaks on the plasma intensity and temperature profiles corresponded to discharges originated from the substrate/coating interface, while the base line and small fluctuations were due to discharges at the coating/electrolyte interface.
Materials Science and Engineering
Journal of Materials Engineering
International Heat Treatment and Surface Engineering
The Proceedings of the JSME Materials and Processing Conference (M&P)
Fuel and Energy Abstracts
Journal of the Less Common Metals
... Phys., 45 (1974) 2313. 29 GC Vayenas and JN Michaels, Surf. Sei., 120 (1982) L405. 30 WE Bell... more ... Phys., 45 (1974) 2313. 29 GC Vayenas and JN Michaels, Surf. Sei., 120 (1982) L405. 30 WE Bell and M. Tagami, J. Phys. Chem., 67 (1963) 2432. 31 M. Hecq and A. Hecq, J. Less-Common Met., 56 (1977) 133. 32 M. Hecq, A. Hecq and T. Robert, J. Vac. Sei. ...
Materials Science and Technology
Materials Science and Technology
Research Letters in Materials Science
Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of eitherAg2Naor PtNa at... more Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of eitherAg2Naor PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst forH2Oformation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.
Journal of Materials Engineering, 1988
The influence of various alloying elements on the thermoelectric power (TEP) of zirconium is dete... more The influence of various alloying elements on the thermoelectric power (TEP) of zirconium is determined. The data indicate that the thermoelectric power is very sensitive to both the type of alloying element and its solubility in the α-phase of zirconium. For example, where tin strongly reduces the thermoelectric power of zirconium, the magnitude of the reduction increasing as the amount of tin in solution in α-Zr increases, the effect of niobium is much less pronounced and variable with first a decrease and then an increase in TEP with increasing niobium.
Tribology and Design, 2010
Materials and Manufacturing Processes, Mar 11, 2009
MgNi2 has been shown to exhibit a hydrolysis behavior similar to that previously found for Mg2Ni.... more MgNi2 has been shown to exhibit a hydrolysis behavior similar to that previously found for Mg2Ni. The Ni nanoparticles prepared by hydrolysis of MgNi2 were spherical in shape with a mean diameter of about 16 nm. Utilizing the hydrolysis behavior of MgNi2 to produce Ni nanoparticles offers a higher efficiency than by using Mg2Ni, saves raw material and reduces any pollution resulting from the dissolution of the hydrolysis byproduct (Mg(OH)2) by using an acid.
Journal of Power Sources, Dec 1, 2006
Journal of Physics D: Applied Physics, 2010
ABSTRACT In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide c... more ABSTRACT In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide coatings on commercially pure aluminium (1100 alloy) at a pulsed dc power mode. The effects of process parameters (i.e. current density and treatment time) on the plasma discharge behaviour during the PEO treatment were investigated using optical emission spectroscopy (OES) in the visible and near ultraviolet (NUV) band (285–800 nm). The elements present in the plasma were identified. Stark shifts of spectral lines and line intensity ratios were utilized to determine the plasma electron concentrations and temperatures, respectively. The plasma electron temperature profile, coating surface morphology and coating composition were used to interpret the plasma discharging behaviour. The different coating morphologies and compositions at different coating surface regions are explained in terms of three types of discharge, which originate either at the substrate/coating interface, within the upper layer, or at the coating top layer. The high spike peaks on the plasma intensity and temperature profiles corresponded to discharges originated from the substrate/coating interface, while the base line and small fluctuations were due to discharges at the coating/electrolyte interface.
Materials Science and Engineering
Journal of Materials Engineering
International Heat Treatment and Surface Engineering
The Proceedings of the JSME Materials and Processing Conference (M&P)
Fuel and Energy Abstracts
Journal of the Less Common Metals
... Phys., 45 (1974) 2313. 29 GC Vayenas and JN Michaels, Surf. Sei., 120 (1982) L405. 30 WE Bell... more ... Phys., 45 (1974) 2313. 29 GC Vayenas and JN Michaels, Surf. Sei., 120 (1982) L405. 30 WE Bell and M. Tagami, J. Phys. Chem., 67 (1963) 2432. 31 M. Hecq and A. Hecq, J. Less-Common Met., 56 (1977) 133. 32 M. Hecq, A. Hecq and T. Robert, J. Vac. Sei. ...
Materials Science and Technology
Materials Science and Technology
Research Letters in Materials Science
Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of eitherAg2Naor PtNa at... more Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of eitherAg2Naor PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst forH2Oformation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.
Journal of Materials Engineering, 1988
The influence of various alloying elements on the thermoelectric power (TEP) of zirconium is dete... more The influence of various alloying elements on the thermoelectric power (TEP) of zirconium is determined. The data indicate that the thermoelectric power is very sensitive to both the type of alloying element and its solubility in the α-phase of zirconium. For example, where tin strongly reduces the thermoelectric power of zirconium, the magnitude of the reduction increasing as the amount of tin in solution in α-Zr increases, the effect of niobium is much less pronounced and variable with first a decrease and then an increase in TEP with increasing niobium.
Tribology and Design, 2010
Materials and Manufacturing Processes, Mar 11, 2009
MgNi2 has been shown to exhibit a hydrolysis behavior similar to that previously found for Mg2Ni.... more MgNi2 has been shown to exhibit a hydrolysis behavior similar to that previously found for Mg2Ni. The Ni nanoparticles prepared by hydrolysis of MgNi2 were spherical in shape with a mean diameter of about 16 nm. Utilizing the hydrolysis behavior of MgNi2 to produce Ni nanoparticles offers a higher efficiency than by using Mg2Ni, saves raw material and reduces any pollution resulting from the dissolution of the hydrolysis byproduct (Mg(OH)2) by using an acid.
Journal of Power Sources, Dec 1, 2006