john Saber | New Mexico State University (original) (raw)
Papers by john Saber
Physica D: Nonlinear Phenomena, Aug 1, 1981
... crystal; f and df are the resonant frequency and bandwidth of the crystal resonancecurve resp... more ... crystal; f and df are the resonant frequency and bandwidth of the crystal resonancecurve respectively. ... 152 DWAIN E. DILLER AND JOHN M. SABER Most of the differences between our ... Acknowledgments Howard JM Hanley participated in the planning and encouraged this work ...
Applied optics, Apr 15, 1988
We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies o... more We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 X 10-10 Torr). Our ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 X 10-8-Torr oxygen) and silicon (1 h at 10-7-Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. Our reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75% for aluminum and 50% for silicon.
Fuel, 1986
... Interaction of potassium carbonate with surface oxides of carbon* John M. Saber, John L. Falc... more ... Interaction of potassium carbonate with surface oxides of carbon* John M. Saber, John L. Falconer and Lee F. Brownt Department of Chemical Engineering ... Materials The five carbons {Table 1} were a Cabot Regal (oil-based black), a Cabot Sterling RX-76 (oil based black), a ...
Journal of Catalysis, 1984
Temperature-programmed reaction was used with labeled isotopes (13C and 18O) to study interaction... more Temperature-programmed reaction was used with labeled isotopes (13C and 18O) to study interactions between carbon black and potassium carbonate in pure He and 1.
Journal of Catalysis, 1988
Temperature-programmed reaction was used to study sodium oxide catalyzed CO* gasification of r3C.... more Temperature-programmed reaction was used to study sodium oxide catalyzed CO* gasification of r3C. The stoichiometry of the reaction is CO2 + a"C cf CO + (1-u)'~CO~ + (2~-l)')CO, where the factor a is dependent on CO2 conversion. This stoichiometry is consistent with a mechanism composed of a reversible catalyst oxidation step and an irreversible catalyst reduction step. On the surface the catalytic surface species is oxidized by CO2 and forms CO; during the reduction reaction the oxidized species decomposes. The reversible oxidation step, which incorporates substrate carbon into gas-phase carbon dioxide, is at equilibrium. Carbon monoxide, via the reverse of the oxidation reaction, inhibits gasification of the substrate by decreasing the number of oxidized catalytic sites on the surface. The catalyst appears both to increase the amount of oxygen on the surface and to decrease the activation energy of the reduction reaction. Similar mechanisms describe potassium-and calcium-catalyzed gasification, but NaZCO, does not interact with the carbon surface as readily as KZC03 does. A similar mechanism is also consistent with steam gasification results reported by others and shows that a separate water-gas shift reaction is not required for CO, production.
Journal of Catalysis, 1988
Temperature-programmed reaction was used to study sodium oxide catalyzed CO/sub 2/ gasification o... more Temperature-programmed reaction was used to study sodium oxide catalyzed CO/sub 2/ gasification of /sup 13/C. The stoichiometry of the reaction is CO/sub 2/ + a/sup 13/C equivalent to CO + (1 - a)/sup 13/CO/sub 2/ + (2a - 1)/sup 13/CO, where the factor a is dependent on CO/sub 2/ conversion. This stoichiometry is consistent with a mechanism composed of a reversible catalyst oxidation step and an irreversible catalyst reduction step. On the surface the catalytic surface species is oxidized by CO/sub 2/ and forms CO; during the reduction reaction the oxidized species decomposes. The reversible oxidation step, which incorporates substrate carbon into gas-phase carbon dioxide, is at equilibrium. Carbon monoxide, via the reverse of the oxidation reaction, inhibits gasification of the substrate by decreasing the number of oxidized catalytic sites on the surface. The catalyst appears both to increase the amount of oxygen on the surface and to decrease the activation energy of the reduction...
Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study... more Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO/sub 2//90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 K and 950 K, and in the presence of gaseous carbon dioxide, the complexes promoted carbon and oxygen exchange between the gas-phase CO/sub 2/ and the surface. Oxygen exchanged between the surface complexes; but carbon did not exchange between the carbonate and the carbon black. As the temperature rose, the complexes decomposed to produce carbon dioxide, and catalytic gasification then began. Elemental potassium formed, and the active catalyst appears to alternate between potassium metal and a potassium-oxygen-carbon complex.
Journal of the Chemical Society Chemical Communications, 1987
Physica A-statistical Mechanics and Its Applications, 1981
The shear viscosity coefficient of compressed gaseous and liquid methane has been measured at tem... more The shear viscosity coefficient of compressed gaseous and liquid methane has been measured at temperatures between 100 and 300K and at pressures up to 30MPa (4350psia) with a torsionally oscillating quartz crystal viscometer. The estimated precision and accuracy of the measurements are about 0.5% and 2%, respectively. The measurements have been compared with an equation previously proposed for calculating the viscosity of gaseous and liquid methane. Most of the differences between the equation and the measurements reported here are within our experimental error. Larger differences (up to 6%) are reported at the lowest temperature (100 K) and high pressures, and along a supercritical isotherm at 200 K (T = 1.05 TJ.
Physica A-statistical Mechanics and Its Applications, 1981
The shear viscosity coefficient of compressed gaseous and liquid ethane has been measured at temp... more The shear viscosity coefficient of compressed gaseous and liquid ethane has been measured at temperatures between 95 and 320 K and at pressures up to 30 MPa (4350 psia) with a torsionally oscillating quartz crystal viscometer. The estimated precision and accuracy of the measurements are about 1 percent and 2 percent respectively. The measurements have been compared with an equation previously proposed for calculating the viscosity of gaseous and liquid ethane. Differences between the equation and the measurements reported here are less than 6 percent. The largest differences are found at low temperatures and high pressures, and along a supercritical isotherm at 320 K (T~1.05 Tc).
Journal of The Chemical Society, Chemical Communications, 1987
Temperature-programmed reaction was used with labeled isotopes (¹³C and ¹â¸O) to study intera... more Temperature-programmed reaction was used with labeled isotopes (¹³C and ¹â¸O) to study interactions between carbon black and potassium carbonate in pure He and 10% COâ/90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 K and 950 K, and in the presence
Journal of The Chemical Society, Chemical Communications, 1984
Applied Optics, 1988
In situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum a... more In situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 x 10 to the -10th Torr) have been performed. The present ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 x 10 to the -8th Torr oxygen) and silicon (1 h at 10 to the -7th Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. The reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75 percent for aluminuma and 50 percent for silicon.
Applied Optics, 1988
We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies o... more We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 X 10-10 Torr). Our ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 X 10-8-Torr oxygen) and silicon (1 h at 10-7 -Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. Our reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75% for aluminum and 50% for silicon.
Physica D: Nonlinear Phenomena, Aug 1, 1981
... crystal; f and df are the resonant frequency and bandwidth of the crystal resonancecurve resp... more ... crystal; f and df are the resonant frequency and bandwidth of the crystal resonancecurve respectively. ... 152 DWAIN E. DILLER AND JOHN M. SABER Most of the differences between our ... Acknowledgments Howard JM Hanley participated in the planning and encouraged this work ...
Applied optics, Apr 15, 1988
We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies o... more We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 X 10-10 Torr). Our ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 X 10-8-Torr oxygen) and silicon (1 h at 10-7-Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. Our reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75% for aluminum and 50% for silicon.
Fuel, 1986
... Interaction of potassium carbonate with surface oxides of carbon* John M. Saber, John L. Falc... more ... Interaction of potassium carbonate with surface oxides of carbon* John M. Saber, John L. Falconer and Lee F. Brownt Department of Chemical Engineering ... Materials The five carbons {Table 1} were a Cabot Regal (oil-based black), a Cabot Sterling RX-76 (oil based black), a ...
Journal of Catalysis, 1984
Temperature-programmed reaction was used with labeled isotopes (13C and 18O) to study interaction... more Temperature-programmed reaction was used with labeled isotopes (13C and 18O) to study interactions between carbon black and potassium carbonate in pure He and 1.
Journal of Catalysis, 1988
Temperature-programmed reaction was used to study sodium oxide catalyzed CO* gasification of r3C.... more Temperature-programmed reaction was used to study sodium oxide catalyzed CO* gasification of r3C. The stoichiometry of the reaction is CO2 + a"C cf CO + (1-u)'~CO~ + (2~-l)')CO, where the factor a is dependent on CO2 conversion. This stoichiometry is consistent with a mechanism composed of a reversible catalyst oxidation step and an irreversible catalyst reduction step. On the surface the catalytic surface species is oxidized by CO2 and forms CO; during the reduction reaction the oxidized species decomposes. The reversible oxidation step, which incorporates substrate carbon into gas-phase carbon dioxide, is at equilibrium. Carbon monoxide, via the reverse of the oxidation reaction, inhibits gasification of the substrate by decreasing the number of oxidized catalytic sites on the surface. The catalyst appears both to increase the amount of oxygen on the surface and to decrease the activation energy of the reduction reaction. Similar mechanisms describe potassium-and calcium-catalyzed gasification, but NaZCO, does not interact with the carbon surface as readily as KZC03 does. A similar mechanism is also consistent with steam gasification results reported by others and shows that a separate water-gas shift reaction is not required for CO, production.
Journal of Catalysis, 1988
Temperature-programmed reaction was used to study sodium oxide catalyzed CO/sub 2/ gasification o... more Temperature-programmed reaction was used to study sodium oxide catalyzed CO/sub 2/ gasification of /sup 13/C. The stoichiometry of the reaction is CO/sub 2/ + a/sup 13/C equivalent to CO + (1 - a)/sup 13/CO/sub 2/ + (2a - 1)/sup 13/CO, where the factor a is dependent on CO/sub 2/ conversion. This stoichiometry is consistent with a mechanism composed of a reversible catalyst oxidation step and an irreversible catalyst reduction step. On the surface the catalytic surface species is oxidized by CO/sub 2/ and forms CO; during the reduction reaction the oxidized species decomposes. The reversible oxidation step, which incorporates substrate carbon into gas-phase carbon dioxide, is at equilibrium. Carbon monoxide, via the reverse of the oxidation reaction, inhibits gasification of the substrate by decreasing the number of oxidized catalytic sites on the surface. The catalyst appears both to increase the amount of oxygen on the surface and to decrease the activation energy of the reduction...
Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study... more Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO/sub 2//90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 K and 950 K, and in the presence of gaseous carbon dioxide, the complexes promoted carbon and oxygen exchange between the gas-phase CO/sub 2/ and the surface. Oxygen exchanged between the surface complexes; but carbon did not exchange between the carbonate and the carbon black. As the temperature rose, the complexes decomposed to produce carbon dioxide, and catalytic gasification then began. Elemental potassium formed, and the active catalyst appears to alternate between potassium metal and a potassium-oxygen-carbon complex.
Journal of the Chemical Society Chemical Communications, 1987
Physica A-statistical Mechanics and Its Applications, 1981
The shear viscosity coefficient of compressed gaseous and liquid methane has been measured at tem... more The shear viscosity coefficient of compressed gaseous and liquid methane has been measured at temperatures between 100 and 300K and at pressures up to 30MPa (4350psia) with a torsionally oscillating quartz crystal viscometer. The estimated precision and accuracy of the measurements are about 0.5% and 2%, respectively. The measurements have been compared with an equation previously proposed for calculating the viscosity of gaseous and liquid methane. Most of the differences between the equation and the measurements reported here are within our experimental error. Larger differences (up to 6%) are reported at the lowest temperature (100 K) and high pressures, and along a supercritical isotherm at 200 K (T = 1.05 TJ.
Physica A-statistical Mechanics and Its Applications, 1981
The shear viscosity coefficient of compressed gaseous and liquid ethane has been measured at temp... more The shear viscosity coefficient of compressed gaseous and liquid ethane has been measured at temperatures between 95 and 320 K and at pressures up to 30 MPa (4350 psia) with a torsionally oscillating quartz crystal viscometer. The estimated precision and accuracy of the measurements are about 1 percent and 2 percent respectively. The measurements have been compared with an equation previously proposed for calculating the viscosity of gaseous and liquid ethane. Differences between the equation and the measurements reported here are less than 6 percent. The largest differences are found at low temperatures and high pressures, and along a supercritical isotherm at 320 K (T~1.05 Tc).
Journal of The Chemical Society, Chemical Communications, 1987
Temperature-programmed reaction was used with labeled isotopes (¹³C and ¹â¸O) to study intera... more Temperature-programmed reaction was used with labeled isotopes (¹³C and ¹â¸O) to study interactions between carbon black and potassium carbonate in pure He and 10% COâ/90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 K and 950 K, and in the presence
Journal of The Chemical Society, Chemical Communications, 1984
Applied Optics, 1988
In situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum a... more In situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 x 10 to the -10th Torr) have been performed. The present ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 x 10 to the -8th Torr oxygen) and silicon (1 h at 10 to the -7th Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. The reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75 percent for aluminuma and 50 percent for silicon.
Applied Optics, 1988
We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies o... more We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 X 10-10 Torr). Our ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 X 10-8-Torr oxygen) and silicon (1 h at 10-7 -Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. Our reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75% for aluminum and 50% for silicon.