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Faculty Publications

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1996

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Articles 31 - 38 of 38

Full-Text Articles in Engineering

Use Of A Hydrogen Anode For Nitrate Waste Destruction, E. E. Kalu, Ralph E. White, D. T. Hobbs Jan 1996

Use Of A Hydrogen Anode For Nitrate Waste Destruction, E. E. Kalu, Ralph E. White, D. T. Hobbs

Faculty Publications

No abstract provided.


Galvanostatic Pulse And Pulse Reverse Plating Of Zinc–Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, Ken-Ming Yin Jan 1996

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc–Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, Ken-Ming Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …


Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin Jan 1996

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …


A Computational Method For Determining Global Fuel-No Rate Expressions. Part 1, Wei Chen, L Douglas Smoot, Thomas H. Fletcher, Richard D. Boardman Jan 1996

A Computational Method For Determining Global Fuel-No Rate Expressions. Part 1, Wei Chen, L Douglas Smoot, Thomas H. Fletcher, Richard D. Boardman

Faculty Publications

Global chemical reaction rates used in the modeling of NOx formation in comprehensive combustion codes have traditionally been obtained through correlation of experimental data. In this paper, a computational approach for obtaining global rates is presented. Several premixed flames were simulated, and sensitivity analysis of species concentration profiles was used to suggest global pathways in fuel-nitrogen conversion to NO. Based on these analyses, the global reaction rates were formulated. The predicted species concentration profiles and their derivatives were then used in the determination of the global rate constants. The correlation of rate constants for the two fuel-NO global rates …


Effects Of Pyrolysis Heating Rate On Intrinsic Reactivities Of Coal Chars, Thomas K. Gale, Calvin H. Bartholomew, Thomas H. Fletcher Jan 1996

Effects Of Pyrolysis Heating Rate On Intrinsic Reactivities Of Coal Chars, Thomas K. Gale, Calvin H. Bartholomew, Thomas H. Fletcher

Faculty Publications

The main objective of this work was to determine the effects of pyrolysis heating rate on intrinsic O2 reactivity of coal chars. Relationships of intrinsic reactivity to other pyrolysis conditions and char physical and chemical structure were also investigated, and empirical correlations were obtained. Two different entrained flow reactors (a flat flame methane/air burner and a drop tube reactor) were used to prepare chars under a variety of different pyrolysis conditions at maximum particle temperatures and heating rates of 840-1627 K and 104 to 2x105 K/s, respectively. Intrinsic reactivities of a lignite and two bituminous coal chars …


Conversion Of Coal Tar To Soot During Coal Pyrolysis In A Post-Flame Environment, Thomas H. Fletcher, Jinliang Ma, Brent W. Webb Jan 1996

Conversion Of Coal Tar To Soot During Coal Pyrolysis In A Post-Flame Environment, Thomas H. Fletcher, Jinliang Ma, Brent W. Webb

Faculty Publications

Coal pyrolysis experiments were performed in the postflame region of a CH4/H2/air flat-flame burner operating under fuel-rich conditions, where the temperature and gas compositions were similar to those in the near-burner region of a large-scale coal-fired furnace. Volatiles released from the coal particles formed a cloud of soot particles at high temperatures in the absence of oxygen. The soot particles in the cloud were collected at different residence times using a water-cooled, nitrogen-quenched suction probe. Test variables included the reaction temperature and coal type. Soot yields in terms of weight percentage of dry ash-free coal were measured based on bulk …


Chemical Structure Of Coal Tar During Devolatilization, Thomas H. Fletcher, Mathew Watt Jan 1996

Chemical Structure Of Coal Tar During Devolatilization, Thomas H. Fletcher, Mathew Watt

Faculty Publications

Three coals of different rank were pyrolyzed in a drop-tube reactor at a maximum temperature of 900 K and a residence time of 160 ms. The coal and char were analyzed with solid-state 13C NMR. The tar was dissolved in deuterated methylene chloride. It was found that the tar was only partially soluble in CD2Cl2. The nonsoluble tar portion was analyzed in the same manner as the coal and char, while the soluble tar portion was analyzed using a recently developed high-resolution 13CNMRtechnique developed for liquid phases. The tar structure was found to be significantly …


Chen, W., L. D. Smoot, S. C. Hill, And T. H. Fletcher, “Global Rate Expression For Nitric Oxide Reburning. Part 2,” Energy And Fuels, 10, 1046-1052 (1996)., Wei Chen, L Douglas Smoot, Scott C. Hill, Thomas H. Fletcher Jan 1996

Chen, W., L. D. Smoot, S. C. Hill, And T. H. Fletcher, “Global Rate Expression For Nitric Oxide Reburning. Part 2,” Energy And Fuels, 10, 1046-1052 (1996)., Wei Chen, L Douglas Smoot, Scott C. Hill, Thomas H. Fletcher

Faculty Publications

An investigation of a global reburning-NO reaction, sum(CiHj) + NO => HCN + . . ., which is a reduction pathway of nitric oxide (NO) by reaction with gaseous hydrocarbons, was conducted. The global reburning-NO rate expression was deduced from a combination of elemental reactions. The global rate expression and its rate constants were then determined by correlating predicted species profiles from simple hydrocarbon flames. This global reburning-NO rate constant can be expressed as 2.7x106 exp(-18,800/RT) (gmol/cm3 s). This expression and constants are applicable to atmospheric pressure with an equivalence ratio range of 1.0-2.08 …