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Surface Treatment For Mitigation Of Hydrogen Absorption And Penetration Into Aisi 4340 Steel, G. Zheng, Branko N. Popov, Ralph E. White Jan 1993

Surface Treatment For Mitigation Of Hydrogen Absorption And Penetration Into Aisi 4340 Steel, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The effectiveness of underpotential deposition of Pb onto a membrane made of AISI 4340 steel on the reduction of the hydrogen evolution reaction on the membrane and the degree of hydrogen ingress into the membrane was determined. In the presence of a monolayer coverage of Pb on the membrane surface, the hydrogen evolution currents were reduced by a factor of two compared with the values obtained on bare steel, and the steady-state hydrogen permeation flux through the steel membranes was reduced by 71%.

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Impedance Spectroscopy As A Nondestructive Health Interrogation Tool For Lithium-Bcx Cells, Branko N. Popov, W. Zhang, E. C. Darcy, Ralph E. White Jan 1993

Impedance Spectroscopy As A Nondestructive Health Interrogation Tool For Lithium-Bcx Cells, Branko N. Popov, W. Zhang, E. C. Darcy, Ralph E. White

Faculty Publications

The objective of this investigation was to study the growth of thick passivating layers on the Li anode in Li/BCX(Li/SOCl2 + BrCl) cells which were stored for a period of 3 years. Impedance spectroscopy and equivalent circuit models were used to determine characterizing parameters for these cells. The equivalent circuit used for virgin cells includes a faradic contribution and diffusion of the electroactive species. The equivalent circuit for batteries stored 1 or 2 years includes the impedance of a metal/passive film interface, the resistance of the film, and the impedance of the passivating film/electrolyte interface. The equivalent circuit used …

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Using Electrochemical Impedance Spectroscopy As A Tool For Organic Coating Solute Saturation Monitoring, Branko N. Popov, Mohammed A. Alwohaibi, Ralph E. White Jan 1993

Using Electrochemical Impedance Spectroscopy As A Tool For Organic Coating Solute Saturation Monitoring, Branko N. Popov, Mohammed A. Alwohaibi, Ralph E. White

Faculty Publications

Electrochemical impedance spectroscopy (EIS) has been used to study the solute uptake for epoxy/phenolic (E/p) andepoxy/amine (E/a) thick-coated mild steel samples immersed for 160 days in 3.5 weight percent NaCl solution exposed to air. Samples with thicknesses of approximately 200 µm with an exposed surface area of 22.6 cm2 were used to follow solute saturation of the organic coating. Good agreement was obtained between the calculated and measured coating capacitance when, according to the diffusion equation, the coating capacitance was plotted against exposure time.

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Galvanostatic Pulse And Pulse Reverse Plating Of Nickel-Iron Alloys From Electrolytes Containing Organic Compounds On A Rotating Disk Electrode, Branko N. Popov, Ken-Ming Yin, Ralph E. White Jan 1993

Galvanostatic Pulse And Pulse Reverse Plating Of Nickel-Iron Alloys From Electrolytes Containing Organic Compounds On A Rotating Disk Electrode, Branko N. Popov, Ken-Ming Yin, Ralph E. White

Faculty Publications

Linear sweep voltammetry, galvanostatic pulse, and pulse reverse techniques were used to study the plating of nickel-iron alloys in the presence of organic additives. The effects of pulse current densities, ip, reverse current densities, ir, rotation speed of disk electrode, and the presence of organic additives on deposition of nickel-iron alloys are evaluated. The observed phenomena can be explained by the concentration depletion of reactants (or products), and the surface coverage of the additives on the electrode. A new formulation of the plating bath is defined.

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Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt: Effects Of Partial Pressure Of Carbon Dioxide And Temperature, Bhasker B. Dave, Ralph E. White, Supramaniam Srinivasan, A. John Appleby Jan 1993

Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt: Effects Of Partial Pressure Of Carbon Dioxide And Temperature, Bhasker B. Dave, Ralph E. White, Supramaniam Srinivasan, A. John Appleby

Faculty Publications

Effects of partial pressure of carbon dioxide and temperature on oxygen reduction kinetics on a gold electrode in a lithium carbonate melt were examined using electrochemical impedance spectroscopic (EIS) and linear sweep voltammetric techniques. The impedance spectra were analyzed by a complex nonlinear least squares method, using the Randles-Ershler equivalent circuit model, to determine the electrode-kinetic and the mass-transfer parameters such as the charge-transfer resistance and the Warburg coefficient. The cyclic voltammetric measurements indicated that the oxygen reduction process in lithium carbonate melt is "reversible" up to 200 mV/s. The product DC0 determined by cyclic voltammetry agreed well …

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Thermal Analysis Of Spirally Wound Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White Jan 1993

Thermal Analysis Of Spirally Wound Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White

Faculty Publications

A thermal analysis of Li/BCX and high rate Li/SOCl2 cells is presented. The thermal model developed was used to study the effect of ambient temperature of discharge (0–40°C) on Li/BCX cells discharged at the same rate. The model predictions show that ambient temperature of discharge was critical in thermal management of the cell. For forced convection cooled cells, the model predicted that ambient temperature near room temperature (25°C) was required to achieve the lowest maximum temperature rise in the cell. Inclusion of the effects of reaction products to the model predictions showed that a constant composition assumption may be …

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Criminal Justice Reforms In The United States, Paul Marcus Jan 1993

Criminal Justice Reforms In The United States, Paul Marcus

Faculty Publications

No abstract provided.

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Book Review Of Liberalism And Republicanism In The Historical Imagination, Cynthia V. Ward Jan 1993

Book Review Of Liberalism And Republicanism In The Historical Imagination, Cynthia V. Ward

Faculty Publications

No abstract provided.

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Revelation And Inspiration: Method For A New Approach, Fernando L. Canale Jan 1993

Revelation And Inspiration: Method For A New Approach, Fernando L. Canale

Faculty Publications

No abstract provided.

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Toward A Theological Encounter: Jewish Understanding Of Christianity, By Leon Klenicki, Jacques R. Doukhan Jan 1993

Toward A Theological Encounter: Jewish Understanding Of Christianity, By Leon Klenicki, Jacques R. Doukhan

Faculty Publications

No abstract provided.

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"Accidental" Shootings As Fourth Amendment Seizures, Kathryn R. Urbonya Jan 1993

"Accidental" Shootings As Fourth Amendment Seizures, Kathryn R. Urbonya

Faculty Publications

No abstract provided.

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An Overview Of Acerc Research In Fuel Characterization And Reaction Mechanisms, Ronald J. Pugmire, Thomas H. Fletcher Jan 1993

An Overview Of Acerc Research In Fuel Characterization And Reaction Mechanisms, Ronald J. Pugmire, Thomas H. Fletcher

Faculty Publications

A major objective of the Advanced Combustion Engineering Research Center is the development and verification of data on fuel characterization and reaction mechanisms and rates that can be incorporated into submodels for use in the comprehensive combustion codes. As technology has advanced, the levels of analytical sophistication has also advanced, making it possible to augment the existing body of information with new data. From this new data it is possible to draw new insights regarding the complex nature of coal and the various processes associated with combustion. The ACERC program has made it possible to bring different disciplines together to …

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Overview Of Acerc Comprehensive Model Development, Thomas H. Fletcher, Scott C. Hill Jan 1993

Overview Of Acerc Comprehensive Model Development, Thomas H. Fletcher, Scott C. Hill

Faculty Publications

A major objective of the Advanced Combustion Engineering Research Center (ACERC) is the development of comprehensive combustion models to help in the solution of critical national combustion problems. Computer models incorporate research and technology results from center projects and from external research programs. The synergistic integration of scientific knowledge that is expected from the NSF engineering research centers is demonstrated to a great extent at ACERC by the development of these software tools. The transfer of technology from ACERC to industry is also accomplished in part by the implementation of the models at industrial firms. The effort to develop such …

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Measurement Accuracy Of The Glottal Enterprises Pneumotachograph System, Christopher Dromey, Ronald C. Scherer, Chen-Geng Guo Jan 1993

Measurement Accuracy Of The Glottal Enterprises Pneumotachograph System, Christopher Dromey, Ronald C. Scherer, Chen-Geng Guo

Faculty Publications

No abstract provided.

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Aerodynamic And Acoustic Changes Following Intensive Voice Therapy For Patients With Parkinson's Disease: A Case Study, Christopher Dromey, Lorraine O. Ramig, Ronald Scherer Jan 1993

Aerodynamic And Acoustic Changes Following Intensive Voice Therapy For Patients With Parkinson's Disease: A Case Study, Christopher Dromey, Lorraine O. Ramig, Ronald Scherer

Faculty Publications

No abstract provided.

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A Pilot Study: Comparing The Use Of Computer-Based Instruction Materials And Audio-Tape Materials In Practicing Chinese, Ka-Fai Shiu, Sharon E. Smaldino Jan 1993

A Pilot Study: Comparing The Use Of Computer-Based Instruction Materials And Audio-Tape Materials In Practicing Chinese, Ka-Fai Shiu, Sharon E. Smaldino

Faculty Publications

Computer-based and audio tape materials were compared for their effectiveness in helping students practice Chinese language lessons. Subjects were enrolled in an intensive elementary course in Mandarin Chinese. The textbook and audio tape were prepared by the Beijing Language Institute in China; and the computer-based material was developed by the author using HyperCard based on the textbook. Written and spoken components were tested; using tests developed by the instructor; a native of China. The instructional materials were used alternately in the 16-week course at the University of Northern Iowa (Cedar Falls). Students performed better in the weeks the computer-based materials …

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Legal Anthropology Comes Home: A Brief History Of The Ethnographic Study Of Law, John M. Conley, William M. O'Barr Jan 1993

Legal Anthropology Comes Home: A Brief History Of The Ethnographic Study Of Law, John M. Conley, William M. O'Barr

Faculty Publications

No abstract provided.

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Oscillator Strengths Of The Si Ii 181 Nanometer Resonance Multiplet, Scott D. Bergeson, J. E. Lawler Jan 1993

Oscillator Strengths Of The Si Ii 181 Nanometer Resonance Multiplet, Scott D. Bergeson, J. E. Lawler

Faculty Publications

We report Si II experimental log (gf)-values of –2.38(4) for the 180.801 nm line, of –2.18(4) for the 181.693 nm line, and of –3.29(5) for the 181.745 nm line, where the number in parenthesis is the uncertainty in the last digit. The overall uncertainties (~10%) include the 1 σ random uncertainty (~6%) and an estimate of the systematic uncertainty. The oscillator strengths are determined by combining branching fractions and radiative lifetimes. The branching fractions are measured using standard spectroradiometry on an optically thin source; the radiative lifetimes are measured using time-resolved laser-induced fluorescence.

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Radiative Lifetimes, Branching Ratios, And Absolute Transition Probabilities In Cr Ii And Zn Ii, Scott D. Bergeson, J. E. Lawler Jan 1993

Radiative Lifetimes, Branching Ratios, And Absolute Transition Probabilities In Cr Ii And Zn Ii, Scott D. Bergeson, J. E. Lawler

Faculty Publications

New absolute atomic transition probability measurements are reported for 12 transitions in Cr II and two transitions in Zn II. These transition probabilities are determined by combining branching ratios measured by classical techniques and radiative lifetimes measured by time-resolved laser-induced fluorescence. The measurements are compared with branching fractions, radiative lifetimes, and transition probabilities in the literature. The 206 nm resonance multiplets in Cr II and Zn II are included in this work. These multiplets are very useful in determining the distribution of the elements in the gas versus grain phases in the interstellar medium.

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Transition Probabilities For The 3s23p(2PO)–3s3p2(4P) Intersystem Lines Of Si Ii, Anthony G. Calamai, Peter L. Smith, Scott D. Bergeson Jan 1993

Transition Probabilities For The 3s23p(2PO)–3s3p2(4P) Intersystem Lines Of Si Ii, Anthony G. Calamai, Peter L. Smith, Scott D. Bergeson

Faculty Publications

Intensity ratios of lines of the spin-changing "intersystem" multiplet of Si II (4P → 2Po) at 234 nm have been used to determine electron densities and temperatures in a variety of astrophysical environments. However, the accuracy of these diagnostic calculations have been limited by uncertainties associated with the available atomic data. We report the first laboratory measurement, using an ion-trapping technique, of the radiative lifetimes of the three metastable levels of the 3s3p2 4P term of Si II. Our results are 104 ± 16, 406 ± 33, and 811 ± 77 µs for …

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Ti-Ii Transition Probabilities And Radiative Lifetimes In Ti+ And The Solar Titanium Abundance, A. Bizzarri, M.C.E. Huber, A. Noels, N. Grevesse, Scott D. Bergeson, P. Tsekeris, J. E. Lawler Jan 1993

Ti-Ii Transition Probabilities And Radiative Lifetimes In Ti+ And The Solar Titanium Abundance, A. Bizzarri, M.C.E. Huber, A. Noels, N. Grevesse, Scott D. Bergeson, P. Tsekeris, J. E. Lawler

Faculty Publications

Transition probabilities of 100 Ti-II emission lines, originating from 7 different atomic levels, have been determined by combining branching fractions with radiative lifetimes. The branching fractions were meaures using Fourier transform spectroscopy on a hollow cathode. The radiative lifetimes of these 7 – and 35 additional – levels were measured using time resolved laser-induced fluorescence on a slow Ti ion beam. The transition probabilities of 21 very weak lines have been used to derive a solar titanium abundance of aTi=log(NTi/NH)+12=5.04±0.04 dex, which is insensitive to the solar model. This value is in …

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Developmental Appropriateness Of Kindergarten Programs And Academic Outcomes In First Grade, Diane C. Burts, Craig H. Hart, Rosalind Charlesworth, Michele Dewolf, Jeanette Ray, Karen Manuel, Pamela O. Fleege Jan 1993

Developmental Appropriateness Of Kindergarten Programs And Academic Outcomes In First Grade, Diane C. Burts, Craig H. Hart, Rosalind Charlesworth, Michele Dewolf, Jeanette Ray, Karen Manuel, Pamela O. Fleege

Faculty Publications

This study explored the relationship between the developmental appropriateness of kindergarten classroom instruction and first-grade report card grade overall averages and average in reading, language, spelling, math, science, and social studies. the interactive roles that gender, SES, and kindergarten classroom type play in children's later achievement were also examined. The sample consisted of 166 first-grade children who had attended kindergarten classrooms with teaching practices identified as predominately developmentally appropriate or developmentally inappropriate. Findings indicated that first-graders from more appropriate kindergarten classrooms had higher reading averages than children from less appropriate kindergarten classrooms. Females had higher overall and subject area averages …

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"Good Heavens!": An Old English Euphemism?, Dallin D. Oaks Jan 1993

"Good Heavens!": An Old English Euphemism?, Dallin D. Oaks

Faculty Publications

It is commonly assumed that the expression good heavens! is a euphemistic one, originally coined to avoid a more direct reference to God. The OED, for example, seems to regard the word heavens as a "substituted expression" for God in the exclamation good heavens! While this substitution may in fact characterize how speakers use the expression now, it may not reflect the original meaning behind this expression.

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Chemical Structural Features Of Pyridine Extracts Of The Argonne Premium Coals Using 13c Nmr Spectroscopy, Thomas H. Fletcher, S Bai, Ronald J. Pugmire, Steven Wood, David M. Grant Jan 1993

Chemical Structural Features Of Pyridine Extracts Of The Argonne Premium Coals Using 13c Nmr Spectroscopy, Thomas H. Fletcher, S Bai, Ronald J. Pugmire, Steven Wood, David M. Grant

Faculty Publications

Soxhlet extractions were performed on the eight Argonne Premium coals using pyridine purged with argon and followed by a novel washing procedure to remove the pyridine. Mass closure (extracts plus residues) on duplicate experiments accounted for 94-96% of the original coal, repeatable to within 2%. Chemical structural features determined from 13C NMR analyses of the extracts and residues showed more attachments per aromatic cluster for the residues, indicating a greater degree of covalent bonding in the residue than in the extract. 1H NMR analysis of the extracts showed a gradual increase in the hydrogen aromaticity with rank, along …

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“The Proverbs,” In 1 Kings To Malachi, Dana M. Pike Jan 1993

“The Proverbs,” In 1 Kings To Malachi, Dana M. Pike

Faculty Publications

The book of Proverbs is found in that portion of the Old Testament known as the Writings (material not included in the Law or the Prophets), and is categorized as Wisdom Literature. It is a compilation of instructions and sayings that has as its aim the social, moral, and ultimately, spiritual betterment of people. As an anthology, Proverbs is designed for consultation and study in measured doses.

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The Making Of Social Policy In Britain 1830-1990, L. Margaret Barnett Dec 1992

The Making Of Social Policy In Britain 1830-1990, L. Margaret Barnett

Faculty Publications

No abstract provided.

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Photopolymer-Based Stratified Volume Holographic Optical Elements, Gregory P. Nordin, A. R. Tanguay Dec 1992

Photopolymer-Based Stratified Volume Holographic Optical Elements, Gregory P. Nordin, A. R. Tanguay

Faculty Publications

We report the implementation of stratified volume holographic optical elements (SVHOE's) using DuPont's Omnidex holographic photopolymer material and an in situ exposure technique for simultaneous multilayer grating recording. Experimental measurement of the +1-order angular sensitivity of a seven-layer SVHOE structure shows remarkable agreement with both theory and numerical simulation for incidence angles near the Bragg angle. For SVHOE's having modulation layers that individually operate in the Bragg or transition diffraction regimes, the envelope of the SVHOE angular sensitivity is experimentally shown to approximate closely that of a single modulation layer.

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Diffraction Properties Of Stratified Volume Holographic Optical Elements, Gregory P. Nordin, R. V. Johnson, A. R. Tanguay Dec 1992

Diffraction Properties Of Stratified Volume Holographic Optical Elements, Gregory P. Nordin, R. V. Johnson, A. R. Tanguay

Faculty Publications

We present a unified treatment of the diffraction properties of stratified volume holographic optical elements (SVHOE's). We show that the relative phasing of the diffraction orders as they propagate from layer to layer gives rise to a unique notched diffraction response of the +1 order (for the case of Bragg incidence) as a function of the normalized buffer-layer thickness, the grating spatial frequency, and the readout wavelength. For certain combinations of these parameters Bragg diffraction behavior characteristic of volume holographic optical elements (VHOE's) is observed, whereas for other combinations pure Raman-Nath behavior periodically recurs. By using these same relative-phasing arguments, …

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Conventionalism And Contractarianism, Noel B. Reynolds Nov 1992

Conventionalism And Contractarianism, Noel B. Reynolds

Faculty Publications

In this paper Noel B. Reynolds’s theory of law as convention is compared to the public choice contractarian theory of James M. Buchanan. While there are numerous similarities, major differences emerge. Only conventionalism can produce legal and political authority and norms to guide the use of that authority in maintaining the rule of law. The concept of constructive unanimity is introduced to overcome the ultimate failure of contractarianism to legitimate the authority of law.

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Labeling Graphs With A Condition At Distance 2, Jerrold R. Griggs, Roger K. Yeh Nov 1992

Labeling Graphs With A Condition At Distance 2, Jerrold R. Griggs, Roger K. Yeh

Faculty Publications

No abstract provided.

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