Digital Commons Network^™

Hydrothermal Fluids And Petroleum In Surface Sediments Of Guaymas Basin, Gulf Of California: A Case Study, J. M. Gieskes, B. R. Simoneit, T. Brown, Timothy J. Shaw, Y. C. Wang, A. Magenheim

Faculty Publications

No abstract provided.

Psychology Among The Saints: The Development Of Behavioral Science At Brigham Young University, Bruce L. Brown, Mark K. Allen

Faculty Publications

There was a strong interest in psychology at Brigham Young University at the turn of the century; the third president was a psychologist and a number of distinguished psychologists regularly visited the campus. An outstanding young scholar who was destined to become the only Mormon president of the American Psychological Association started a vigorous academic psychology program in those early years, but he left the university because of a controversy over his teachings. Psychology at Brigham Young University developed little from that time until the 1940s. The 1950s were a time of rapid growth and development, expansion of the faculty, …

Quasilinear Evolution Equations In Nonclassical Diffusion, Kenneth Kuttler, Elias Aifantis

Faculty Publications

After describing the motivation leading to some nonclassical diffusion equations, we formulate a general abstract nonlinear evolution equation and establish existence of solutions. Then we return to the original equation and discuss particular initial-boundary value problems.

An Economic Explanation Of Punitive Damages, David D. Friedman

Faculty Publications

No abstract provided.

Involutions On Banach Spaces And Reflexivity, S J. Dilworth

Faculty Publications

No abstract provided.

Interpolation Of Besov-Spaces, Ronald A. Devore, Vasil A. Popova

Faculty Publications

We investigate Besov spaces and their connection with dyadic spline approximation in Lp(Omega), 0 < p (less than or equal to) infinity. Our main results are: the determination of the interpolation spaces between a pair of Besov spaces; an atomic decomposition for functions in a Besov space; the characterization of the class of functions which have certain prescribed degree of approximation by dyadic splines.

A Field Method For Assessing Borehole Friction For Directional Well Casing, Eric E. Maidla, Andrew K. Wojtanowicz

Faculty Publications

A field procedure to evaluate the borehole friction factor between a pipe string and a borehole was developed. The primary concern of this research was to investigate and mathematically describe the drag associated with casing runs in directional wells through the use of the two-dimensional approach. The borehole friction factor was found, through an iterative procedure, by matching the calculated hook load to the measured one at the surface. The borehole friction factor was calculated as the unique value for the match. This study shows the necessary precision requirements for the hook load measurement instrumentation and presents three different types …

The Twentieth Fermat Number Is Composite, Jeff Young, Duncan A. Buell

Faculty Publications

The twentieth Fermat number, F₂₀ = 2^{2^20} +1, has been proven composite by machine computation.

The Maturation Of Public Relations Degree Programs--Ten Years In Retrospect: Struggles; Experiences And Analyses Of A Communication-Based Pr Program., Jon Hall, Pamela Edwards

Faculty Publications

This paper reviews the historical experience of a new public relations program housed in a speech communication department (rather than in a journalism department; which is traditional); discusses some of the internal and external struggles experienced in the implementation and administration of the program; and reports on the placement of its graduates. The program; at the University of Northern Iowa's (UNI) department of Communication and Theatre Arts; was implemented in 1978 after five years of planning. The program received support from the administration but faced problems because of its phenomenal growth. The paper describes this support and a number of …

A Two-Dimensional Mathematical Model Of A Porous Lead Dioxide Electrode In A Lead-Acid Cell, E. C. Dimpault-Darcy, T. V. Nguyen, Ralph E. White

Faculty Publications

A two-dimensional mathematical model is presented for a lead dioxide electrode in a lead-acid cell. It is used to simulate the time dependent behavior of the electrode during discharge. The model contains six dependent variables: the concentration of the acid electrolyte, the porosity, the electrical potentials of the solid and solution phases, and the two directional components of the current density in the electrolyte. The effect of the electrode grid was included by varying the conductivity of the solid. Parameters such as electrode conductivity, electrode dimensions, and temperature are investigated to understand their effects on electrode discharge performance.

Secondary Current Distributions Using Topaz2d And Linear Kinetics, E. C. Dimpault-Darcy, Ralph E. White

Faculty Publications

Secondary current density distributions are of interest
to cell designers. The purpose of this note is to illustrate
how to use an existing numerical method to determine
these distributions for cells that contain conducting and
nonconducting bodies between the main anode and cathode.

A Mathematical Model For Predicting Cyclic Voltammograms Of Electronically Conductive Polypyrrole, Taewhan Yeu, Trung V. Nguyen, Ralph E. White

Faculty Publications

Polypyrrole is an attractive polymer for use as a high energy density secondary battery because of its potential as an inexpensive, lightweight, and noncorrosive electrode material. A mathematical model to simulate cyclic voltammograms for polypyrrole is presented here. The model is for a conductive porous electrode film on a rotating disk electrode (RDE) and is used to predict the spatial and time dependence of concentration, overpotential, and stored charge profiles within a polypyrrole film. The model includes both faradaic and capacitive charge components in the total current density expression.

A Mathematical Model For The Electrodeposition Of Alloys On A Rotating Disk Electrode, Shiuan Chen, Ken-Ming Yin, Ralph E. White

Faculty Publications

A general multiple electrode reaction model for electrodeposition of alloys on a rotating disk electrode is presented. Included in the model are mass transport equations with the effect of ionic migration, Butler-Volmer kinetic rate expressions, and the mole fractions of the individual components in the solid state. The model shows that the effect of ionic migration is important and that plating variables such as applied potential, pH, and bulk concentration can be included. Two examples (Ni-P and Ru-Ni-P) are used to illustrate the predictions of the model.

Electrodeposition Of Copper-Nickel Alloys From Citrate Solutions On A Rotating Disk Electrode, Ramona Y. Ying, Patrick K. Ng, Z. Mao, Ralph E. White

Faculty Publications

A mathematical model is developed to simulate the electrodeposition of Cu-Ni alloy from citrate solutions onto a rotating disk electrode under potentiostatic control. The model includes the influence of diffusion, ionic migration, forced convection, and homogeneous equilibria. The three major electrochemical reactions treated in the model are copper deposition, nickel deposition, and hydrogen evolution. Using experimental parameters when available, the model was fitted and tested against experimentally-obtained results for different bath compositions and operating conditions. The model agreed reasonably well with the experimental results particularly in the codeposition region, –1.0 to –1.2V vs. SCE, where hydrogen evolution is not the …

Nonlocal Symmetries And Backlund Transformations For The Self-Dual Yang-Mills System, C. J. Papachristou, Kent B. Harrison

Faculty Publications

The observation is made that generalized evolutionary isovectors of the self-dual Yang–Mills equation, obtained by "verticalization'' of the geometrical isovectors derived in a previous paper [J. Math. Phys. 28, 1261 (1987)], generate Bäcklund transformations for the self-dual system. In particular, new Bäcklund transformations are obtained by "verticalizing'' the generators of point transformations on the solution manifold. A geometric ansatz for the derivation of such (generally nonlocal) symmetries is proposed.

Quantum Electrodynamics Based On Self-Fields, Without Second Quantization: A Nonrelativisitc Calculation Of G – 2, A. O. Barut, Jonathan P. Dowling, Jean F. Van Huele

Faculty Publications

Using a formulation of quantum electrodynamics that is not second quantized, but rather based on self-fields, we compute the anomalous magnetic moment of the electron to first order in the fine structure constant α. In the nonrelativistic (NR) case and in the dipole approximation, our result is a_e≡(g—2)/2=(4Λ/3m)(α/2π), where Λ is a positive photon energy cutoff and m the electron mass. A reasonable choice of cutoff, Λ/m=¾, yields the correct sign and magnitude for g—2 namely, a_e=+α/2π. . In our formulation the sign of a₃ is correctly positive, …

Digital Neural Networks, Tony R. Martinez

Faculty Publications

Demands for applications requiring massive parallelism in symbolic environments have given rebirth to research in models labeled as neural networks. These models are made up of many simple nodes which are highly interconnected such that computation takes place as data flows amongst the nodes of the network. To present, most models have proposed nodes based on simple analog functions, where inputs are multiplied by weights and summed, the total then optionally being transformed by an arbitrary function at the node. Learning in these systems is accomplished by adjusting the weights on the input lines. This paper discusses the use of …

Comparison Of Effective Medium Procedures For Optical Modeling Of Laminar Structures, David D. Allred, Robert F. Edgerton

Faculty Publications

This study addresses the question, "How can the optical properties of matter in ultrathin amorphous nonmetallic films in multilayers best be determined from reflectance (R) and transmission (T) measurements?" A blue shift in the band gap of plasma CVD a-Si:H/a-SiNx:H multilayers was reported several years ago. It was suggested that the shift in the band gap, Eg, Relative to bulk a-Si:H as given by the Tauç plot was due to quantum confinement effects. The purpose of this study is to evaluate the usefulness of various effective media theories (EMT) for determining the optical constants of materials in a multilayer and …

On The Thermodynamics Of Quantum-Electrodynamic Frequency Shifts, G. W. Ford, J. T. Lewis, R. F. O'Connell

Faculty Publications

A paper by Barton (ibid., vol.20, p.879, 1987) comments on some of Ford et al.'s recent work in this general area and takes issue with some of their conclusions. Ford et al. point out that Barton's reinterpretation of his own previous work actually serves to support their conclusions. In particular, he is making extensive use of thermodynamic concepts (free energy, thermodynamic perturbation theory, . . .) which were introduced for the first time into this area in the papers by Ford et al.

Normal-Metal Aharonov-Bohm Effect In The Presence Of A Transverse Electric Field, S. Washburn, H. Schmid, D. Kern, Richard A. Webb

Faculty Publications

The effects of transverse electric fields on the conductance fluctuations in an Sb loop have been studied. We show that the electric field can be used to tune the position (or phase) of Aharonov-Bohm oscillations as well as to alter the aperiodic conductance fluctuation patterns. We disucss two mechanisms which might cause the observed dependence of the fluctuation pattern on transverse electric field. The first is the electrostatic Aharonov-Bohm effect, and the second is the spatial shifting of the electron trajectories by the electric field.

Integer Squares With Constant Second Difference, Duncan A. Buell

Faculty Publications

The problem addressed is this: Do there exist nonconsecutive integers n₀, n₁, n₂, . . ., such that the second differences of the squares of the n_i are constant? Specifically, can that constant be equal to 2? A complete characterization of sequences of length four can be given. The question of whether or not sequences of length five exist is still open but the existence or nonexistence of such sequences can be described in a more algorithmic way than the simple statement of the problem.

Moment Method Analysis Of The Electric Field Under Ehv Transmission Lines, T. L. Simpson, Charles W. Brice

Faculty Publications

The charge moment method is applied to the analysis of electric fields under EHV transmission lines over irregular terrain.

Observation Of An Oxygen Isotope Effect In Yba2Cu3O7, Kevin J. Leary, Hans Conrad Zur Loye, Steven W. Keller, Tanya A. Faltens, William K. Ham, James N. Michaels, Angelica M. Stacy

Faculty Publications

A small decrease in T_c of 0.3 K to 0.5 K is observed when as much as 90% of the ¹⁶O in YBa₂Cu₃O₇ is substituted with¹⁸O. This result is consistent with our observation that there is an oxygen isotope effect in La_1.85Sr_0.15CuO₄, but in contrast with previous reports that there is no isotope effect for YBa₂Cu₃O₇. This new result suggests that phonons play an important role in the electron-pairing mechanism in YBa₂Cu₃O₇.

Sequentially Compact, Franklin-Rajagopalan Spaces, Peter J. Nyikos, J. E. Vaughan

Faculty Publications

No abstract provided.

Observation Of An Isotope Shift In The Superconducting Transition Temperature Of La1.85Sr0.15Cuo4, Tanya A. Faltens, William K. Ham, Steven W. Keller, Kevin J. Leary, James N. Michaels, Angelica M. Stacy, Hans Conrad Zur Loye, Donald E. Morris, T W. Barbee Iii, Marvin L. Cohen, Cohen S. Hoen, A Zettl

Faculty Publications

An oxygen isotope shift is observed in superconducting La_1.85Sr_0.15CuO₄ when ¹⁸O is substituted partially for ¹⁶O; the superconducting transition temperature T_c is lowered by 0.3 to 1.0 K in different samples. We examine these results using conventioanl phonon-mediated BCS theory and conclude that, for La_1.85Sr_0.15CuO₄, phonons play an important role in the pairing mechanism.

Research On Effective Schools: Implications For Less Developed Countries, Elchanan Cohn, Richard A. Rossmiller

Faculty Publications

No abstract provided.

Giovanni Maria Artusi's L'Artusi Overo Delle Imperfettioni Della Moderna Musica (1600): A Translation And Commentary, Malcolm Litchfield

Faculty Publications

Giovanni Maria Artusi is well known for his conservative role in the debate between advocates of the prima and seconda pratiche. Contemporary authors marvel at Artusi's audacity in criticizing the genius of Monteverdi. Though often viewed as a pedant, Artusi was a significant Italian theorist who understood ancient Greek theory and had innovative ideas for applying this ancient knowledge to modern practice.

L' Artusi, overo Delle imperfettioni deIla moderna musica was written to illuminate and correct errors Artusi found in contemporary scholarship (chiefly in Bottrigari's work) and composition (specifically, certain liberties in Monteverdi's madrigals). Artusi effectively argues for a universal …

Can Programmers Reuse Software?, Scott N. Woodfield, David W. Embley, Del T. Scott

Faculty Publications

An experiment asked programmers untrained in reuse to evaluate component reusability. They did poorly. Are reusability's promises hollow? Or are there some answers?

Surface Conductance Of A Copper Wire In A Fluid At High Pressure, Daniel L. Decker

Faculty Publications

The three-dimensional flow of heat in a wire carrying a current and immersed in a liquid is solved in detail. Using this exact result the surface conductance of copper in petroleum ether has been measured as a function of pressure to 40 kbars. The measured surface conductance for copper in a fluid is very small, justifying approximations which yield results that are in agreement with a simplified one-dimensional heat-flow problem. Surprisingly, even at 40 kbars pressure a very large fraction of the joule heating within a wire with a length-to-diameter ratio of ~100 is dissipated through the ends of the …

Superconductivity At 155 K, David D. Allred, S. R. Ovshinsky, R. T. Young, G. Demaggio, G. A. Van Der Leeden

Faculty Publications

Transition to a superconducting zero-resistance state at 155 K is observed for the first time in bulk material. A new five-element compound has been synthesized with nominal composition Y1Ba2Cu3F2Oy. Fluorine plays a critical role in achieving this effect. X-ray diffraction and electron microprobe analysis indicate that the samples are multiphasic. Evidence is presented that the samples contain superconducting phases with onset temperatures considerably above 155 K. Magnetic measurements suggest a flux-trapping effect below 260 K, and diamagnetic deviations from Curie-Weiss behavior in the range from 250 K≤T≤100 K indicate that Meissner effect in a small superconducting volume fraction.