Digital Commons Network^™

Transition From Quantum To Quasi-Classical Behaviour Of The Binary Encounter Peak In Collisions Of 0.6 To 3.6 Mev Amu“¹ I23+ And Xe21+ With He And Ar, J. L. Shinpaughfg, W. Wolff, H. E. Wolff, U. Ramm, O. Jagutzki, H. Schmidt-Böcking, J. Wangt, Ronald E. Olson

Physics Faculty Research & Creative Works

Double differentia] cross sections are reported for the production of binary encounter electrons in collisions of 0.6 MeV amu^-1 I²³⁺ and 1.4, 2.4, and 3.6 MeV amu^-1 Xe²¹⁺ projectiles incident on He and Ar targets. Electron energy spectra were measured between 0: and 45: in the case of the two lower projectile energies, and between 17.5° and 60- for the two higher projectile energies. The data are compared with quantum mechanical impulse approximation and classical trajectory Monte Carlo calculations. While the quantum model calculation predicts a rapid disappearance of diffraction effects in the binary encounter peak …

The Missouri Miner, September 08, 1993

The Missouri Miner Newspaper

No abstract provided.

Transition Mechanisms Of Two Interacting Dx Centers In N-Type Algaas Using Reverse-Bias Deep Level Transient Spectroscopy And Temperature-Dependent Pulse-Width Reverse-Bias Deep Level Transient Spectroscopy Methods, C. W. Wang, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

The reverse-bias pulsed deep level transient spectroscopy (RDLTS) and a new temperature-dependent pulse-width RDLTS (TDP RDLTS) technique are reported to study the electric-field effect on carrier emission rates and the direct interaction between double DX centers recently detected in the Se:Al_0.6Ga_0.4As N confinement layer of the AlGaAs/GaAs single-quantum-well laser diodes. Traditional RDLTS measurements, with constant pulse width t_p, prove that the two DX centers, Et₁ and Et₂, have strong direct emission interaction. Furthermore, the new TDP-RDLTS technique enables one to evaluate this direct transition time constant. Possible mechanisms for this interstate …

Identification Of Variegated Coloring In Skin Tumors: Neural Network Vs. Rule-Based Induction Methods, Ajaya Durg, William V. Stoecker, J. P. Cookson, Scott E. Umbaugh, Randy Hays Moss

Chemistry Faculty Research & Creative Works

The use of neural networks for automatic identification of variegated coloring, which is believed to be one of the most predictive features for malignant melanoma, is described. The Nestor development system (NDS) was chosen for neural network implementation. At the heart of NDS is a three-layer neural network called a restricted Coulomb energy (RCE) network. The learning scheme and the database for detection of variegated coloring are discussed. Results are reported

An Overview Of Some Of The Large Scale Mechanisms Of Salt Dissolution In Western Canada, Neil Lennart Anderson, Ralph W. Knapp

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Well log and seismic data indicate that the bedded rock salts of the Devonian Prairie Formation were widely distributed and uniformly deposited in the Lloydminster area, Western Canada; however, as a result of extensive leaching, the distribution of these salts is not now what it once was. The Lloydminster area is now bisected by the north-south trending main dissolutional edge of the Prairie salt. Thick salt (up to 150 m) is preserved to the west of this edge; to the east the salt is mostly absent. The paper presents an overview of the envisioned principal mechanisms of salt dissolution. The …

The Missouri Miner, September 01, 1993

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, August 25, 1993

The Missouri Miner Newspaper

No abstract provided.

Dependence Of Binary Encounter Electron Production On The Charge State Of The Recoil Ion, Jee-Ching Wang, Ronald E. Olson, H. Wolf, J. Shinpaugh, W. Wolff, H. Schmidt Böcking

Chemical and Biochemical Engineering Faculty Research & Creative Works

We study the dependence of the production of binary encounter electrons on the charge state of recoil ions for 2.4 MeV u^-l Xe²¹⁺ on He and Ar. Doubly differential cross sections of electron emission are calculated with the ncrMC method. We find that the contributions to the binary electron cross section from various recoil ion charge states reach a maximum near Ar⁵⁺ for the Ar target. In the case of the He target; double ionization dominates over single ionization for alt ejected electron energies above 100 eV. However, an unexpected local drop of double ionization in the …

Implicit Methods On Parallel Processors, Larry Reeves

Computer Science Technical Reports

Since most partial differential equations (PDEs) do not have exact solutions, they are usually solved by some type of numerical method. Since a numerical method is commonly built from finite difference approximations derived from Taylor series expansions, such a development is derived. Stability and convergence of these methods is defined and the rate of convergence is defined and shown for a few simple methods. Of particular importance is the difference between implicit and explicit methods. Finally, the current applications and adaptations of implicit methods on parallel processors are examined and their strengths and weaknesses discussed.

Ccfss Technical Bulletin August 1993, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Formal Model And Specification Of Deadlock, Pei-Yu Li, Bruce M. Mcmillin

Computer Science Technical Reports

In this paper, we present a formal model of deadlock in a distributed system and develop the deadlock specification in terms of time-dependent predicates. Primitive activities of processes in the distributed system are specified by the predicates so that system behaviors can be described by logic operations. With the formal model, we have an insight into the definition of deadlock in local views. A rigorous proof to show the equivalence of local-time and global-time deadlock specifications is presented. The local-time deadlock specification, which defines the timing of dependence between deadlocked processes, will be useful in the correctness verification of distributed …

Ccfss News August 1993, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Missouri S&T Magazine, August 1993, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Symmetrically H-Bridged Dimer Of 2-Carboxylatobenzenediazonium. The 1:1 Complex Between 2-Carboxybenzenediazonium Chloride And Benzenediazonium-2-Carboxylate, Christopher J. Horan, Paul E. Haney, Charles Leslie Barnes, Rainer Glaser

Chemistry Faculty Research & Creative Works

The two zwitterions in the H-bridged dimer of 2-carboxylatobenzenediazonim (1) are linked by a crystallographically symmetric O⋯Hctdot;O hydrogen bond with an O⋯O distance of 2.436 (3) Å. Comparison of the (1) with the other benzenediazonium salts shows that the phenyl ring distortions in (1) are determined primarily by the diazonium substituent with only modest additional effects by the carboxylato group. Intramolecular neighboring goup interactions between the N₂ group and the orthoCOO(H) group are indicated and are discussed. The terminal N atom of the diazonium group is bent away from the neighboring carboxylato group. The N₂ and the …

Temperature And Supersaturation Dependent Nucleation Rates Of Heterogeneous Water By Molecular Cluster Model Calculation, Chen K. Lutrus, Donald E. Hagen, Sung-Ho Suck Salk

Physics Faculty Research & Creative Works

A statistical mechanical method to evaluate the energy of formation of water clusters attached to a foreign particle surface is described, with the binding energy being evaluated on a molecular level, using semiempirical modified neglect of diatomic overlap (MNDO) theory. The model is applied to water nucleation on a silicon oxide surface. The binding energy contribution, which represents the energy of formation at T=0 K, is found to slightly (but not negligibly in the thermal sense) increase with the number of hydrogen bonds between the water cluster and the condensation nucleus whose surface is made of silicon oxide. An analytic …

An Energy Approach To Seismic Analysis And Design Of Secondary System, Genda Chen, Tsuteh Soong

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The dynamic analysis and design of secondary systems have been extensively studied over the last two decades, resulting in a better understanding of their general dynamic characteristics. One of the current challenges for researchers is to develop simple yet accurate procedures incorporating these research results and transfer them into the development of practical design and performance evaluation procedures. This is the basic thrust of this report.

Statistical energy analysis has been proven to be a powerful tool in the dynamic analysis of complex systems involving interaction effect between acoustic field and structure. In this report, such a tool is systematically …

An Algorithm For Automated Printed Circuit Board Layout And Routing Evaluation, Todd H. Hubing, Thomas Van Doren, James L. Drewniak, Puneet Grover, R. Lee Hill

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm has been developed to evaluate printed circuit boards that are designed using automated board layout and routing software. The algorithm analyzes aspects of component placement and trace routing while searching for violations of basic EMC design principles. The algorithm is implemented in code designed to work with a widely used board layout and routing program. This code can help novice and experienced circuit board designers to avoid mistakes that may result in serious electromagnetic compatibility problems.

A Study Of Numerically Efficient Algorithms For Power System Dynamic Analysis, J. G. Chen, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the multirate method is introduced to analyze power system behavior including linear and nonlinear systems with widely varying time constants. The development and study of time domain simulation techniques and error detection are discussed. The results, both in terms of accuracy and computation time, are compared to traditional simulation methods in a small nonlinear power system example

Parallel Genetic Algorithm For The Dag Vertex Splitting Problem, Matthias Mayer

Computer Science Technical Reports

Directed Acyclic Graphs (DGAs) are often used to model circuits and networks. The path length in such DAGs represents circuit or network delays. In the vertex splitting problem, the objective is to determine a minimum number of vertices from the graph to split such that the resulting graph has no path of length greater than a given maximum delay δ. The problem has been proven to be NP-hard. A sequential Genetic Algorithm has been developed to solve the DAG Vertex Splitting Problem. Unlike a standard Genetic Algorithm, this approach uses a variable chromosome length to represent the vertices that split …

Method For Stripping Metals In Solvent Extraction, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Aqueous solutions containing metal cations, that may include cations of both desired metal and impurity or secondary metal, are treated with an organic liquid extractant suitable for the extraction of cations of the desired metal, cations of at least one secondary metal being co-extracted. After phase disengagement, the loaded organic phase containing cations of either a desired metal or desired metal together with at least one secondary metal is contacted with a solid metal or solid metal alloy capable of reducing in the organic phase cations of either a desired metal or a secondary metal from a higher to a …

Parallel Algorithm Fundamentals And Analysis, Bruce M. Mcmillin, Hanan Lutfiyya, Grace Tsai, Jun-Lin Liu

Computer Science Technical Reports

This session explores, through the use of formal methods, the “intuition” used in creating a parallel algorithm design and realizing this design on distributed memory hardware. The algorithm class NC and the LSTM machine are used to show why some algorithms realize their promise of speedup better than others and the algorithm class NP is used to show why other algorithms will never be good for parallelization. Performance and correctness through cooperative axiomatic reasoning and temporal reasoning provide an additional basis for understanding parallel algorithm design and specification. Finally, the realities of algorithm design are presented through partitioning and mapping …

Parallel Algorithm Fundamentals And Analysis, Bruce M. Mcmillin, Hanan Lutfiyya, Grace Tsai, Jun-Lin Liu

Computer Science Technical Reports

This session explores, through the use of formal methods, the “intuition” used in creating a parallel algorithm design and realizing this design on distributed memory hardware. The algorithm class NG and the LSTM machine are used to show why some algorithms realize their promise of speedup better than others and the algorithm class NP is used to show why other algorithms will never be good for parallelization. The realities of algorithm design are presented through partitioning and mapping issues and models. Finally, correctness through cooperative axiomatic reasoning provides an additional basis for understanding parallel algorithm design and specification and is …

X.500 Directory Service Support For Electronic Mail, Mihai G. Sirbu, Fikret ErçAl

Computer Science Technical Reports

One of the difficult problems on the Internet is finding the electronic mail addresses of users. In practice, there are some indirect ways of finding these addresses such as the finger program in UNIX, but almost all of these methods require the user to know the exact host name of the destination. What is most desirable is an automated mechanism which provides the e-mail addresses of users if some minimal information about the destination site is known.

This thesis describes the design of such a directory service support system, based on the X.500 Series of CCITT Recommendation, for the elm …

Genetic Algorithm With 3-Parent Uniform Crossover, L. Vincent Edmondson, Billy E. Gillett

Computer Science Technical Reports

A new genetic algorithm which uses a 3-parent uniform crossover operator is developed and analyzed. Uniform crossover operators are shown to be based on the premise that all bit-level genetic information should be passed from parents to children. The 3-parent uniform crossover operator is shown to adhere to this premise. The 3-parent uniform crossover operator is shown to be better than the 2-parent uniform crossover operator on the De Jong test functions.

Two new genetic algorithms which use 3-parent traditional crossover operators are developed and analyzed. The first uses a strategy of randomly selecting 3 of the 6 children resulting …

Design Of Automotive Structural Components Using High Strength Sheet Steels Effect Of Strain Rate On The Structural Strength And Crushing Behavior Of Cold-Formed Steel Stub Columns, Chi-Ling Pan, Wei-Wen Yu

CCFSS Library (1939 - present)

INTRODUCTION In the past, a considerable amount of theoretical and experimental research has been undertaken to study material properties and the behavior of structures under dynamic loads and impact loads. For the purpose of investigating the structural behavior and strength of cold-formed steel members under dynamic loads, a research project was conducted at the University of Missouri-Rolla from January 1988 through December 1991 to study the effect of strain rate on mechanical properties of sheet steels and the structural behavior and strength of cold-formed steel members. The test results of material properties, stub columns, and beams with evaluations were summarized …

A Neutron Diffraction And Mössbauer Effect Study Of The Magnetic Properties Of Pr₂Fe₁₇ And Pr₂Fe₁₇N₂.₆, Gary J. Long, Oran Allan Pringle, Fernande Grandjean, William B. Yelon, K. H. Buschow

Chemistry Faculty Research & Creative Works

The neutron diffraction powder patterns of Pr₂Fe₁₇ and Pr₂Fe₁₇N_2.6 have been measured at 295 K and refined within the Th₂Zn₁₇ structure type to give the structural changes which occur upon nitrogenation; changes which include a 6.4% expansion of the unit cell volume. The Mössbauer spectra of Pr ₂Fe₁₇ and Pr₂Fe₁₇N_2.6 have been measured between 85 and 295 K and analyzed with a model which is based on the Wigner-Seitz cell environment of each iron site, the basal orientation of the magnetization, and …

Long-Range Random Walks On Energetically Disordered Lattices, B. D. Bookout, Paul Ernest Parris

Physics Faculty Research & Creative Works

Although the master equation describing long-range random walks on an energetically disordered lattice is governed by a nonsymmetric transition matrix W, it may be mapped through a similarity transform onto an imaginary-time Schrödinger equation governed by a Hermitian (Hamiltonian) operator H₀ having a nondegenerate ground state. Under this mapping the diffusion constant D can be expressed in terms of the exact ground state energy of operators that are infinitesimally perturbed from H₀.

Three-Body Distorted-Wave Born Approximation For Electron-Atom Ionization, Stephenie J. Jones, Don H. Madison, Achim Franz, P. L. Altick

Physics Faculty Research & Creative Works

We report a theoretical calculation for electron-impact ionization of atoms that includes short-range electron-atom effects for wave functions that satisfy the exact asymptotic boundary conditions. Results of this theory, which we label as the three-body distorted-wave Born approximation, are compared with experiment and other theories for ionization of hydrogen and helium for incident-electron energies from 4 to 18 times the ionization energy.

Connection Between Superelastic And Inelastic Electron-Atom Collisions Involving Polarized Collision Partners, Klaus Bartschat, Don H. Madison

Physics Faculty Research & Creative Works

It is shown how the results of a recent experiment by Jiang, Zuo, Vuković, and Bederson [Phys. Rev. Lett. 68, 915 (1992)], who investigated low-energy electron scattering from laser-excited polarized sodium atoms in the initial (3p) ²P°_3/2 (F=3, M_F=3) state, can be related to the inelastic 3S→3P transition involving initially unpolarized electron and atom beams. Hence, this method can provide an independent check of the traditional electron-scattering experiment with unpolarized beams.

Operational Evaluation Of Responsiveness Properties, Grace Tsai, Matt Insall, Bruce M. Mcmillin

Computer Science Technical Reports

In this paper, a new technique for ensuring run-time satisfaction of properties-specifically responsiveness property, a subset of liveness property, in responsive systems, is presented. Since whether the run-time behavior of a system is satisfied depends on the execution (operational) environment, we develop a translation which takes into account the constraints in the operational environment, and generates histories for each process in the system. Thus, every process can utilize its history to operationally evaluate the system behavior and signal errors if its history is violated. Therefore, this technique provides software safety, handles error-detection, and ensures run-time satisfaction of responsiveness property in …