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Ccfss News August 1995, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Diagnosing And Modeling Common-Mode Radiation From Printed Circuit Boards With Attached Cables, James L. Drewniak, Fei Sha, Todd H. Hubing, Thomas Van Doren, J. Shaw

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for diagnosing and modeling radiation from printed circuit boards with attached cables is presented through a case study of a production model electronic control unit. Procedures for determining EMI antennas, IC sources, and mechanisms by which noise is coupled from the IC source to the antenna are suggested.

Phonon And Magnetic Neutron Scattering At 41 Mev In Yba2cu3o7, Hung Fai Fong, Bernard Keimer, Pw Anderson, D. Reznik, Fatih Dogan, Ilhan A. Aksay

Materials Science and Engineering Faculty Research & Creative Works

We report inelastic neutron scattering measurements at excitation energies ħ⁢w∼41 meV in YBa₂Cu₃O₇. We separate magnetic and phonon contributions to the scattering cross section by a detailed analysis of the momentum dependence of the scattered intensity. The previously reported broad peak around q = (π/a,π/a) in the normal state can be entirely accounted for by a phonon which primarily involves vibrations of the in-plane oxygen. Magnetic scattering centered around 41 meV and q = (π/a,π/a) appears in the superconducting state only. Theoretical implications of …

Missouri S&T Magazine, Special Edition 1995, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Effect Of Micelles And Mixed Micelles On Efficiency And Selectivity Of Antibiotic-Based Capillary Electrophoretic Enantioseparations, Kimber L. Rundlett, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Vancomycin (an oligophenolic, glycopeptide, macrocyclic antibiotic) has been shown to be a superb chiral selector for anionic and neutral compounds. It was found that adding sodium dodecyl sulfate to the run buffer increased efficiency by over 1 order of magnitude, decreased analysis times, and reversed the elution order of the enantiomers. This allows for control of the retention order as well as the resolution of enantiomers in complex mixtures in a single run. A mechanism is proposed which explains all of the observed effects and is verified experimentally. Since vancomycin is present in both the micelle and in free solution, …

Matching And Indexing Techniques In Rules, Madhav Moganti

Computer Science Technical Reports

Rules are widely used in present-day intelligent systems for modeling intelligent behavior, building expert systems, database rule systems, and advanced document retrieval systems. Most rule-based system programs are extremely computation-intensive and run quite slowly. This problem may get still worse when a rulebase does not fit into primary memory completely. This article reviews currently existing rule matching and indexing techniques. This report is organized into two parts. Part I presents the well known rule matching algorithms, Rete and TREAT, along with their performance evaluations. Part II presents rule indexing techniques for large scale rulebases. Here two sources of indexing are …

Generalization Of The Schwartz-Soffer Inequality For Correlated Random Fields, Thomas Vojta, Michael Schreiber

Physics Faculty Research & Creative Works

We investigate the influence of spatial correlations between the values of the random field on the critical behavior of random-field lattice models and derive a generalized version of the Schwartz-Soffer inequality for the averages of the susceptibility and its disconnected part. At the critical point this leads to a modification of the Schwartz-Soffer exponent inequality for the critical exponents η and η^- describing the divergences of the susceptibility and its disconnected part, respectively. It now reads η_^- ≤ 2η-2y where 2y describes the divergence of the random-field correlation function in Fourier space. As an example we exactly calculate …

Binary Nucleation Kinetics. I. Self-Consistent Size Distribution, Gerald Wilemski, Barbara Ellen Wyslouzil

Physics Faculty Research & Creative Works

Using the principle of detailed balance, we derive a new self-consistency requirement, termed the kinetic product rule, relating the evaporation coefficients and equilibrium cluster distribution for a binary system. We use this result to demonstrate and resolve an inconsistency for an idealized Kelvin model of nucleation in a simple binary mixture. We next examine several common forms for the equilibrium distribution of binary clusters based on the capillarity approximation and ideal vapor behavior. We point out fundamental deficiencies for each expression. We also show that each distribution yields evaporation coefficients that formally satisfy the new kinetic product rule but are …

Binary Nucleation Kinetics. Ii. Numerical Solution Of The Birth-Death Equations, Barbara Ellen Wyslouzil, Gerald Wilemski

Physics Faculty Research & Creative Works

We numerically solve the complete set of coupled differential equations describing transient binary nucleation kinetics for vapor-to-liquid phase transitions. We investigate binary systems displaying both positive and negative deviations from ideality in the liquid phase and obtain numerical solutions over a wide range of relative rates of monomer impingement. We emphasize systems and conditions that either have been or can be investigated experimentally. In almost every case, we find behavior consistent with Stauffer's idea that the major particle flux passes through the saddle point with an orientation angle that depends on the rates of monomer impingement. When this is true, …

The Kelvin Equation And Self-Consistent Nucleation Theory, Gerald Wilemski

Physics Faculty Research & Creative Works

Issues of self-consistency are reviewed for several unary equilibrium size distributions based on the capillarity approximation. Some apparent difficulties of interpretation are resolved. In terms of the kinetic approach to nucleation theory, the influence of self-consistency on the nucleation rate is shown to arise entirely from differences in the dimer evaporation rates for nearly all versions of classical theory. The nucleation rate behavior of the Kelvin model is explored. In this model, the Kelvin equation is used to prescribe all cluster evaporation rates. Nucleation rates predicted by the Kelvin model are quantitatively similar to those of the self-consistent classical (SCC) …

Precision Total Pressure Measurements Of Propyne With Propane, Propene, And Propadiene, Edward A. Kyser, David B. Manley

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental total pressure measurements of propyne mixed with propane, propene, and propadiene are presented for five isotherms from 253 to 353 K. Thermodynamically consistent vapor compositions and saturated phase densities are calculated using a cubic equation of state with three isothermal pure component parameters and two binary mixture parameters. The precision vapor—liquid equilibrium cell and experimental procedure which are particularly useful for measurements involving close boiling light hydrocarbons are described, and the experimental and modeled results are presented. © 1995, American Chemical Society. All rights reserved.

Parallel Fast Multipole Algorithm Using Mpi, Daniel Okunbor, Eric Jui-Lin Lu

Computer Science Technical Reports

The simulation of many-body, many-particle system has a wide range of applications in area such as biophysics, chemistry, astrophysics, etc. It is known that the force calculation contributes ninety percent of the simulation time. This is mainly due to the fact that the total number of interactions in the force is 0( N 2 ), where N is the number of particles in the system. The fast multipole algorithm, proposed by Greengard and Rokhlin, reduces the time complexity of the force calculation to O(N). We implement the fast multipole algorithm, using MPI, based on optimal communication scheme which minimizes the …

Integration Methods For N-Body Problems, D. I. Okunbor

Computer Science Technical Reports

Particle simulation studies the time evolution of the dynamical state of a system of interacting particles by the computation of trajectories of particles based on the numerical integration of the Newton equations of motion. This approach is widely used in biomolecular modeling to study, for example, proteins; and in astrophysics to study gravitational N-body system. The dimension of this system of equations of motion is in the order of tens of thousands. To solve this system involves an enormous amount of computer time. Several techniques have been advanced to reduce the computational complexity of this problem. Some of which are: …

Design Of Automotive Structural Components Using High Strength Sheet Steels Effect Of Strain Rate On The Structural Strength Of Cold-Formed Steel Hybrid Beams, Chi-Ling Pan, Wei-Wen Yu

CCFSS Library (1939 - present)

INTRODUCTION In cold-formed steel design, local buckling is one of the major design features because of the use of large width-to-thickness ratios for compression elements. For the purpose of determining the load-carrying capacity of automotive components, the effective width approach has been used. In view of the fact that the design criteria for effective design width included in the AISI Automotive Steel Design Manual 1 are based on the test results for static loading condition, an investigation was conducted at University of Missouri-Rolla from January 1988 through December 1991 to study the validity of these effective design width formulas for …

The Missouri Miner, May 31, 1995

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, May 24, 1995

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, May 17, 1995

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, May 10, 1995

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, May 03, 1995

The Missouri Miner Newspaper

No abstract provided.

Software Testing Paradigms, A. Subramaniam, G. Zobrist

Computer Science Technical Reports

The development of software follows a series of steps adopted from the Classical Life Cycle approach. Amongst all the steps, Software testing demands a lot of attention considering the amount of effort applied in it. There are various techniques by which a software can be tested. A review of techniques available are discussed. A methodology that can be applied to software testing has also been suggested. This document can be used by a programmer to select the technique for software testing and also assists in providing a narrowed view to the vast number of techniques available for software testing.

Discovery Of Integrity Relationships In Relational Databases, D. Harrier, D. C. St. Clair

Computer Science Technical Reports

The use of database management system integrity constraints has been a powerful tool in raising the quality of data within an application subject database. Unfortunately, the successful use of integrity constraints requires that the database administrator has implemented the constraint before data are inserted into the database.

The results of this research provide a methodology for discovering previously unknown integrity relationships in a relational database. The methodology uses the principles of knowledge discovery from the artificial intelligence community, and Quinlan's ID3 machine learning algorithm as the discovery tool. Experimental results are provided that demonstrate how the methodology can be applied.

Power Bus Decoupling On Multilayer Printed Circuit Boards, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, David M. Hockanson

Electrical and Computer Engineering Faculty Research & Creative Works

Guidelines for the selection and placement of decoupling capacitors that work well for one-sided or two-sided printed circuit boards are not appropriate for multilayer boards with power and ground planes. Boards without internal planes take advantage of the power bus inductance to help decouple components at the higher frequencies. An effective decoupling strategy for multilayer boards must account for the low inductance and relatively high capacitance of the power bus.

The Effect Of Flange Restraint On Web Crippling Strength Of Cold-Formed Steel Z- And I-Sections, Darryl E. Cain, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE When considering the web crippling strength of a cold-formed steel member, the current edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members does not distinguish between the behavior of a member having its flanges attached to a support member, and a member not attached to its support. To enhance the industry and design professional's understanding of web crippling, a study was initiated at the University of Missouri-Rolla to explore the influence of flange attachment. This research consisted of web crippling tests on identical specimens. The specimens were tested where either cross sections were attached to …

A Tracking System For Generating Change Transactions For Digital Maps, K. L. Smith, R. W. Wilkerson

Computer Science Technical Reports

Making maps is a very expensive process. Data must be gathered by talcing aerial photographs, field technicians must survey the area generating control points for map adjustment, feature verification must be done by physically driving to the site being mapped, and then the map itself must be generated or edited using aerial photographs and computer equipment. Maps were originally generated primarily by hand, but in the last decade, digital maps have become the latest, most technological way to make maps. As this method of malcing maps has become more and more common, the possibility of sharing map data has become …

Observation Of Postcollision Effects In The Scattered Projectile Spectra For Ionizing Proton-Helium Collisions, Tibor Vajnai, A. D. Gaus, Joachim A. Brand, W. T. Htwe, Don H. Madison, Ronald E. Olson, Jerry Peacher, Michael Schulz

Physics Faculty Research & Creative Works

We have measured and calculated doubly differential single ionization cross sections as a function of the scattering angle and the projectile energy loss for 50 to 150 keV proton-helium collisions. These cross sections show unexpected structures as a function of both the energy loss and the scattering angle, which are interpreted as due to the postcollision interaction. Although the effects of postcollision interactions have previously been observed in electron spectra, this is the first observation of such effects for the scattered protons.

Behavior Of Cold-Formed Steel Roof Trusses, Michael M. Harper, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE To aid in adapting cold-formed steel to the residential market, a research project was initiated in 1993 at the University of Missouri-Rolla. Design issues relating to the use of cold-formed steel members and connections in residential roof truss systems were the focus of the project. The purpose of this research was to study the behavior of cold-formed steel roof truss systems and to establish appropriate design recommendations. Overall, the research findings were intended to aid the promotion of cold-formed steel as a safe, serviceable, and cost effective alternative in residential construction. The project consisted of a review of available …

From Formal Security Specifications To Executable Assertions - A Distributed Systems Preliminary Study, C. Serban, B. Mcmillin

Computer Science Technical Reports

A security policy for a distributed system can be checked for compliance at run-time, as the system executes, using assertions embedded in software. This paper presents the concept of run-time security assurance, according to a given security policy for a given distributed system, along with mechanisms for its usage. A model problem illustrates the implementation of executable security assertions and their run-time validation on histories (traces) of events.

The Missouri Miner, April 26, 1995

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, April 19, 1995

The Missouri Miner Newspaper

No abstract provided.

Target Dependence Of Binary Encounter Electron Peak Anomalies In Collisions Of Partially Stripped Heavy Ions With Molecular Hydrogen And Noble Gases, W. Wolff, J. Wang, H. E. Wolft, J. L. Shinpaugh, Ronald E. Olson, D. H. Jakubassa-Amundsen, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking

Physics Faculty Research & Creative Works

A systematic search was performed for the manifestation of quantum interference effects in the shape and angular distribution of the binary-encounter electron peak in collisions of partially stripped, or structured, heavy ions with noble gases and molecular hydrogen. The ionic species investigated were Cu5+,19+, I7+,23+, Au11+,29+ and U13+, all at the same nominal velocity equivalent to 0.6 MeV amu-1. Experimental double-differential cross sections for secondary electron emission in the binary encounter energy region are compared with a simple model based on the elastic scattering of quasi-free target electrons in the projectile field as well as with results of impulse approximation …