Physical Sciences and Mathematics Commons^™

Electron Drift Velocities In Xenon, H. L. Brooks, M. C. Cornell, John L. Fletcher, Ian M. Littlewood, Kaare J. Nygaard

Psychological Science Faculty Research & Creative Works

The electron drift velocity has been measured in xenon over the range of reduced field strength 1 Td

Isotope Effect In Electron-Capture Differential Cross Sections At Intermediate Energies, Eduard P. Rille, Ronald E. Olson, Jerry Peacher, D. M. Blankenship, Thomas J. Kvale, E. Redd, John T. Park

Physics Faculty Research & Creative Works

The isotope dependence in the angular distribution of electron-capture cross sections for protons and deuterons with equal velocity (E=40 keV/u) colliding with atomic hydrogen or deuterium targets is predicted theoretically and observed experimentally. A projectile-dependent effect is observed at small scattering angles. No target dependence was detected in the differential cross sections. A scaling relationship is determined which permits the prediction of differential cross sections for hydrogen-isotope projectiles.

Electron Capture And Ionisation In H⁺, He2++Li Collisions, Ronald E. Olson

Physics Faculty Research & Creative Works

Single electron capture and ionization cross sections have been calculated for H++Li and He2++Li collisions at energies ranging from 50 to 400 keV amu-1. Double electrons capture cross sections are presented for the He2++Li system. The classical-trajectory Monte Carlo method and the independent-electron model were used to calculate the cross sections. In the energy range investigated, the ionization process is dominated by electron removal of the valence Li(2s) electron, whereas the single and double electron capture processes are the result of capture from the K shell of the lithium atom.

On The Ising Model For Amorphous Ferromagnets, Harry A. Brown

Physics Faculty Research & Creative Works

A calculation is made of the effect on the critical temperature of a ferromagnet whose exchange integrals are taken to be random variables. The Bethe-Peierls-Weiss approximation is used to find the partition function, Z, for an Ising system and then a configuration average is taken to find (InZ), from which the resulting decrease in the critical temperature can be found. Other results are discussed, and comparisons made with the present result.

Nonlinear Anelasticity Of Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

An approximate solution of the equation of motion of a nonlinear anelastic reed at or near resonance is presented. The steady state solution reproduces the well-known nonlinear resonances. The solution also predicts the existence of auto modulations, i.e., self-excited modulations of the amplitude and phase at constant power of excitation of the reed. Numerical examples of such auto modulations are presented for an antisymmetric deformation potential. Experimental studies of finite amplitude oscillations of a magnesium reed vibrating at 72 and 431 Hz at room temperature confirm the existence of auto modulations. The experimental results can be semi quantitatively described in …

Angular Scattering In Slow Multiple-Charged Ion, Atom Collisions, Ronald E. Olson, M. Kimura

Physics Faculty Research & Creative Works

The C6++H system is used to illustrate the importance of large-angle scattering in collisions between slow multiply charged ions and atoms. A quantum mechanical description based on a diabatic formalism of the collision system is used to obtain differential cross sections for electron capture in the relative velocity range nu =1*107 to 3*107 cm s-1 (Ecm approximately=48 to 430 eV). The threshold for angular scattering is at E theta approximately=0.2 keV deg which correlates with the curve crossing between initial and final molecular states located at Rx approximately=8a0. The centre-of-mass acceptance angles required to observe fixed fractions of the total …

Elastic Differential Cross Sections For Small-Angle Scattering Of 25-, 50-, And 100-Kev Protons By Helium Atoms, Jerry Peacher, Thomas J. Kvale, E. Redd, Paul J. Martin, D. M. Blankenship, Eduard P. Rille, V. C. Sutcliffe, John T. Park

Physics Faculty Research & Creative Works

The first measurements of elastic differential cross sections have been carried out for 25-, 50-, and 100-keV protons scattered through very small angles by helium atoms. The University of Missouri Rolla energy-loss spectrometer provided the required high angular resolution and also separated the elastically scattered ions from the inelastically scattered ions. The data are compared to our Born, Glauber, and classical calculations as well as a four-state calculation. All of the measured elastic differential cross sections are more sharply peaked than theory for the smallest scattering angles. At the larger scattering angles all of the measured elastic differential cross sections …

Selective Deposition Of Sio2 Thin Films In Acid Baths, M. A. Smith, L. L. Levenson

Physics Faculty Research & Creative Works

We report observation of deposition of SiO₂ thin films on a variety of surfaces in nitric acid and hydrochloric acid solutions. Scanning electron microscopy shows that the films are composed of closely packed spheres 1000 Å in diameter. Chemical identification is made with Auger electron spectroscopy. The films are generally between 1000 and 2000 Å thick and are possibly hydrated. Deposition occurs in either acid for molarities in the 1-8 M range and at temperatures between 80 and 100 °C. The effects for molarities greater than 8 M and temperatures greater than 100 °C have not been investigated. Materials …

Monte Carlo Studies Of Water Monolayer Clusters On Substrates: Hexagonal Agi, Richard C. Ward, Jon M. Holdman, Barbara N. Hale

Physics Faculty Research & Creative Works

A Monte Carlo procedure is used to study the stability and structure of small water clusters adsorbed on model basal and prism faces of hexagonal AgI. Effective pair potentials for the H₂O-AgI interaction [B. N. Hale and J. Kiefer, J. Chem. Phys. 73, 923 (1980)] and the revised central force potentials for the H₂O-H₂O interaction [F. H. Stillinger and A. Rahman, J. Chem. Phys. 68, 666 (1978)] are used to determine average internal cluster binding energy and average cluster-substrate binding energy for water clusters containing 6, 24, and 44 water molecules at temperatures 240, …

Binary Collision Dynamics And Numerical Evaluation Of Dilute Gas Transport Properties For Potentials With Multiple Extrema, James C. Rainwater, Paul M. Holland, Louis Biolsi

Chemistry Faculty Research & Creative Works

Prediction of gaseous transport properties requires calculation of Chapman-Enskog collision integrals which depend on all possible binary collision trajectories. The interparticle potential is required as input, and for a variety of applications involving monatomic gases the Hulburt-Hirschfelder potential is useful since it is determined entirely from spectroscopic information and can accomodate the long-range maxima and minima found in many systems. Hulburt-Hirschfelder potentials are classified into five distinct types according to their qualitative binary collision dynamics, which in general can be quite complex and can exhibit “double orbiting”, i.e., a pair of orbiting impact parameters for a single energy of collision. …

The Subjective Nature Of Programming Complexity, Daniel G. Mcnicholl, Kenneth I. Magel

Computer Science Faculty Research & Creative Works

One of the more difficult problems confronting software engineers today is the construction of accurate predictive models of the software development process, [21,[8] and [93. It has long been recognized that one of the most essential elements of any successful model of this process is a quantification of the complexity of software systems. During the past several years a great deal of work has been performed by researchers such as Halstead [3], McCab [5], and others in an attempt to develop metrics which adequately capture the complexity of software systems. Yet one very important aspect of software development complexity seems …

Structural And Magnetic Properties Of Y(Al₁₋ₓfeₓ)₁₂, Ying-Chang Yang, Gary J. Long, William Joseph James, R. Yeh

Chemistry Faculty Research & Creative Works

In order to investigate the magnetic behavior of 3d atoms in the ThMn₁₂‐type structure, the structured and magnetic properties of Y(Al_1-xFe_x)₁₂ were studied by Mössbauer spectroscopy and magnetization measurements. The Y(Al_1-xFe_x)₁₂ intermetallic compounds crystallize in the ThMn₁₂‐type structure for x in the range of 0.3-0.5. The results can be explained on the basis of the preferential atomic ordering observed in the ternary compounds. The compounds are ferromagnetic with Curie temperatures of 130, 170, and 280 K, respectively, for x values of 0.3, 0.4, and 0.5.

A Theory Of Small Program Complexity, Kenneth I. Magel

Computer Science Faculty Research & Creative Works

Small programs are those which are written and understood by one. person. Large software systems usually consist of many small programs. The complexity of a small program is a prediction of how difficult it would be for someone to understand the program. This complexity depends of three factors: (1) the size and interelationships of the program itself; (2) the size and interelationships of the internal model of the program's purpose held by the person trying to understand the program; and (3) the complexity of the mapping between the model and the program. A theory of small program complexity based on …

Stochastic Modeling Of Individual Resource Consumption During The Programming Phase Of Software Development, Daniel G. Mcnicholl, Kenneth Magel

Computer Science Technical Reports

In the past several years there has been a considerable amount of research effort devoted to developing models of individual resource consumption during the software development process. Since many conditions affect individual resource consumption during the software development process, including several which are difficult if not impossible to quantify, it is our contention that a stochastic model is more appropriate than a deterministic model.

In order to test our hypothesis we conducted an experiment based upon several student programming assignments. Data from this experiment is used to demonstrate that the two parameter Log-Normal distribution is appropriate for describing the probabilistic …

The Lebesgue Integral As The Almost Sure Limit Of Random Riemann Sums, John C. Keffer, Caslav V. Stanojevic

Mathematics and Statistics Faculty Research & Creative Works

A method is given for generating random intermediate points for a sequence of partitions. For the corresponding random Riemann sums it is shown that they converge almost surely to the Lebesgue integral. © 1982 American Mathematical Society.

Tauberian Conditions For V-Convergence Of Fourier Series, Caslav V. Stanojevic

Mathematics and Statistics Faculty Research & Creative Works

It is proved that Fourier series with asymptotically even coefficients and satisfying (formula present here), for some 1 < p < 2, con­verge in L1-norm if and only if (formula present here), where En(t) =Σk=0neiktRecent results of Stanojevic [1], Bojanic and Stanojevic [2], and Goldberg and Stanojevic [3] are special cases of some corollaries to the main theorem. © 1982 American Mathematical Society.

A Note On Fixed-Point Theorems, Troy L. Hicks, M. D. Humphries

Mathematics and Statistics Faculty Research & Creative Works

In an earlier note, S. P. Singh gave an extension of a theorem of Brosowski in a normed linear space setting. Variants of this theorem are considered in the context of strictly convex, reflexive, and inner product spaces. © 1982.

Conjugate Type Boundary Value Problems For Functional-Differential Equations, P. W. Eloe, L. J. Grimm

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

A Class Of L¹-Convergence, R. Bojan1c, C. V. Stanojevic

Mathematics and Statistics Faculty Research & Creative Works

It is proved that if the Fourier coefficients (an) of /E L!(0, ir) satisfy (*)L" kp\Aan\p = o(l), for some 1

< 2, then \\sn- f\\ = o(l), if and only if a" lg n * o(l). For cosine trigonometric series with coefficients of bounded variation and satisfying (*) it is proved that a necessary and sufficient condition for the series to be a Fourier series is (an) E 6, where G is the Garrett-Stanojevic [4] class. © 1982 American Mathematical Society.

A Study Of The Critical Cluster Size For Water Monolayer Clusters On A Model Agi Basal Substrate, Richard C. Ward, Barbara N. Hale, Sergio Terrazas

Physics Faculty Research & Creative Works

We present a formalism and estimate a critical cluster size for water monolayer formation on a (rigid) model AgI basal substrate. The formalism is modified from that developed for vapor clusters [B. N. Hale and R. C. Ward, J. Stat. Phys. 28, 487 (1982)] and uses a Metropolis Monte Carlo method developed by Squire and Hoover [J. Chem. Phys. 50, 701 (1969)] to determine (Helmholtz) free energy differences for clusters containing n and n-1 molecules. Calculations for clusters of n=1, 2, 3, 4, 6, and 24 water molecules on a model AgI basal face at 265 K are …

Current Concepts Of Cerebrovascular Disease - Stroke: Stroke And Drug Abuse, L. R. Caplan, D. (Daniel) B. Hier, G. Banks

Chemistry Faculty Research & Creative Works

This Review Summarizes Available Information Concerning Cerebral Vascular Complications of the Most Commonly Abused Substances and Discusses Possible Mechanisms of Vascular Injury and Cerebral Damage. Although Alcohol is Frequently Abused and May Have Important Cerebrovascular Effects, its Consideration is Beyond the Scope of This Review.

Preparation Of Cationic Polymer Surfaces By Grafting Polymerization, H. Yasuda, B. Sherry, M. A. Ei‐Nokaly, Stig Friberg

Chemistry Faculty Research & Creative Works

A cationic polymer surface with extensive capacity for adsorption of anionic surfactants was prepared by graft polymerization of vinyl pyridine onto a plasma‐treated polypropylene surface. The nitrogen was quaternized in order to obtain the cationic sites. The concentration dependence of adsorption from high eletrolyte solution of the anionic surfactant was similar to the one a solid surface from solutions with no added electrolyte. The hydrophobic contribution to the adsorption was experienced at surfactant concentrations far below its critical micellization. Copyright © 1982 John Wiley & Sons, Inc.

Sequential Probability Ratio Tests For The Shape Parameter Of A Nonhomogeneous Poisson Process, Lee J. Bain, Max Engelhardt

Mathematics and Statistics Faculty Research & Creative Works

Sequential probability ratio tests for the shape parameter of one or more nonhomogeneous Poisson processes, with power intensity functions, are provided. The tests can be performed when the scale parameter is an unknown nuisance parameter; the effective loss of not knowing the scale parameter is one observation per process. The resulting tests can be expressed in terms of the maximum likelihood estimators of the shape parameters for the usual fixed sample procedure. A further advantage of the present approach is that the scale parameters for different processes, in the multiple sample procedures, need not be equal. Approximations for the operating …

An Approximation Theory For Conjugate Surfaces And Solutions Of Elliptic Multiple Integral Problems: Application To Numerical Solutions Of Generalized Laplace's Equation, John Gregory, Ralph W. Wilkerson

Computer Science Faculty Research & Creative Works

An Approximation Theory is Given for a Class of Elliptic Quadratic Forms Which Include the Study of Conjugate Surfaces for Elliptic Multiple Integral Problems. These Ideas Follow from the Quadratic Form Theory of Hestenes, Applied to Multiple Integral Problems by Dennemeyer, and Extended with Applications for Approximation Problems by Gregory. the Application of This Theory to a Variety of Approximation Problem Areas in This Setting is Given. These Include Conjugate Surfaces and Conjugate Solutions in the Calculus of Variations, Oscillation Problems for Elliptic Partial Differential Equations, Eigenvalue Problems for Compact Operators, Numerical Approximation Problems, And, Finally, the Intersection of These …

On The Curie Temperatures Of Amorphous Ferromagnets, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

A Note On The Use Of A Photoelectric Counter For Total Particle Counting, Josef Podzimek, Paul C. Yue

Physics Faculty Research & Creative Works

The ability of the Nolan-Pollak counter to function as a "total" particle counter was investigated. Comparison with the UMR Absolute Aitken Nuclei Counter operated at an expansion pressure ratio of 1.33 revealed that in mean, the N-P counter measurements (at an expansion pressure ratio of 1.21) were 30% less. This correction, however, depends on particle nature, concentration and size distribution and assumes that particle losses in the central part of the UMRAAN counter are negligible. © 1982.

Electron-Capture Collisions Of H+ With Ground- And Excited-State Na, M. Kimura, Ronald E. Olson, J. Pascale

Physics Faculty Research & Creative Works

Pseudopotential molecular-structure calculations have been used to obtain the low-lying interaction energies for NaH+. The wave functions were used to calculate accurate radial and rotational coupling matrix elements. Scattering calculations which include electron translational factors were performed using up to eight coupled channels for laboratory energies 0.1 to 10 keV. Electron capture from ground-state Na 3s yields cross sections in the 10-15-cm2 range of which the dominant products are H 2s and H 2p. Electron capture from excited Na 3p does not show an enhanced cross section relative to capture from the ground state even though the energy gap E(R=) …

Phaseautomodulation In Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

No abstract provided.

Comparison Of Several Aitken Nuclei Counters, Josef Podzimek, John C. Carstens, P. C. Yue

Physics Faculty Research & Creative Works

The basic thermodynamical processes leading to the formation of droplets in the central part of the Nolan-Pollak counter are analyzed in some detail. The comparison of the UMR-Absolute Aitken Nuclei counter with Nolan-Pollak, General Electric and Gardner counters showed consistently higher counts of the UMR-AAN counter. The mean deviations varied between 20% and 50% depending on the type of the counter, nuclei concentration and nature. Several observations are made on ultrafine particle counting. © 1981.

Biomedical Applications Of Plasma Polymerization And Plasma Treatment Of Polymer Surfaces, H. Yasuda, M. Gazicki

Chemistry Faculty Research & Creative Works

Thin polymer films obtained by plasma polymerization usually show good biocompatibility when compared to classical biomaterials such as Silastic. The thicknesses of these films (from several hundreds of Å to several μm) make them suitable for the purpose of changing the surface properties of the substrate without altering its bulk properties. Both the above features together indicate the possible Biomedical use of plasma polymerization as well as plasma treatment of polymer surfaces processes. The purpose of this review is to present the most significant efforts to develop such applications with the specification of particular fields where these efforts are directed. …