Engineering Commons^™

Final State Distributions For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson

Chemical and Biochemical Engineering Faculty Research & Creative Works

Final state nim distributions are studied for electron capture from orientated circular Rydberg atoms. Strong orientation effects are found for all quantum numbers at collision speeds comparable to the electron orbital speed. Predominant population of large m states is observed when the plane of the circular orbit is nearly perpendicular to the incident direction of the projectile. The Ini distributions show structures due to quasi-Thomas scattering even at low relative collision velocities. © 1993 IOP Publishing Ltd.

Ionic Charge Dependence Of The Zero Degree Binary Encounter Peak For Partially Stripped Heavy Ions, W. Wolff, H. E. Wolff, J. L. Shinpaugh, Jee-Ching Wang, Ronald E. Olson, D. Fainstein, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report on the measurements of double differential cross sections, at zero degree, for the production of secondary electrons from the collision of 0, 6 MeV amu^-1 Cu⁵⁺, I⁷⁺, Au¹¹⁺, U¹³⁺, Cu¹⁹⁺, t²³⁺ and Au²⁹⁺ projectiles with H₂ and He. The shapes and positions of the observed binary encounter electron peaks are compared with continuum distorted wave-eikonal initial state (CDW-EIS), impulse approximation and classical trajectory Monte Carlo calculations, as well as with predictions from an adiabatic resonant tunnelling model recently proposed by Fainstein and co-workers. The …

A Kinematically Intelligent Blackboard For Computer Aided Instruction, J. Keith Nisbett, D. Watkins, Clark R. Barker

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A CAI (computer-aided instruction) package is being developed to be used as a classroom tool for the instruction of undergraduate mechanical engineering students in an introductory kinematics of mechanisms course. This graphical environment allows the instructor to emulate on the projected graphics screen everything that is currently done on the blackboard for planar mechansims. Unlike the blackboard, the software will have the intelligence to interpret the drawings in a kinematic sense so that the drawing of the linkage will behave as a linkage. The software environment involves three principal components: (1) a sketching method for defining the linkage, (2) the …

Periodic Pn Sequence Delay Estimation Using Phase Spectrum Data, Kurt Louis Kosbar, Jorge J. Zaninovich

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm for estimating the delay of a periodic pseudonoise (PN) sequence is presented. It is a rapid, block-based estimator that can be used for both linear and nonlinear codes. The algorithm exploits the periodicity of the difference between the phase spectra of the received sequence and a local reference. The estimator takes the Fourier transform of the phase spectrum difference data, and searches for the fundamental frequency. Unlike previously described methods, phase unwrapping is not required. The performance in the presence of additive white Gaussian noise (AWGN) and a continuous wave (CW) jammer is investigated using computer simulation. Comparisons …

Method Of Stemming A Blast Hole, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A method of stemming a blast hole loaded with an explosive charge. The blast hole has side walls, an outwardly opening mouth and a central axis extending longitudinally of the blast hole. The method comprises inserting a conduit having a discharge end inwardly through the mouth of the blast hole and positioning the discharge end of the conduit within the blast hole generally adjacent the explosive charge. Particulate stemming material is forced under pressure through the conduit for exit from its discharge end into the blast hole toward the explosive charge thereby to pack stemming material in the blast hole …

Two-Dimensional Simulation Of Switch-On Speeds In Hydrogenated Amorphous Silicon Thin-Film Transistors, J. S. Huang, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We report accurate two-dimensional simulations of switch-on speeds in hydrogenated amorphous silicon thin-film transistors. The trap charge density along, or transverse to, the direction of semiconductor channel is highly nonuniform and the trap filling time dominates the switching time as compared to the transit time, which is about four orders of magnitude smaller. Near both contacts, direction of the transverse current is always upwards toward the insulator-semiconductor interface due to the strong electric fields. However, at the central region of the channel, the transient current is quite complex and is discussed here. When the channel length varies from 2 to …

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

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 …

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

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

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

CCFSS Newsletters (1999 - 2008)

No abstract provided.

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

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.

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 …

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 …

Preliminary Design Guide For Cold-Formed Steel C- And Z-Members, Committee On Specifications For The Design Of Cold-Formed Steel Structural Members

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Man-Made Vibrations And Solutions, K. R. Massarsch

International Conference on Case Histories in Geotechnical Engineering

The generation and propagation of man-made vibrations in the ground is discussed. Emphasis is placed a simplified approach which is used to assess the most important factors, such as wave attenuation, refraction focusing and vibration amplification as a result of resonance. Practical guidelines are presented which can be used to predict vibrations and settlements in the ground. A semi-empirical relationship for the assessment of permissible vibration levels for buildings is proposed. Finally, a new ground vibration isolation method, the gas cushion screen is presented.

Discussions And Replies: State Of The Art Papers, Mohamad Hussein, Fred H. Held Iii, C. Mirza, T. M. Davisson

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Practical Studies Of The Seismic Response Of A Rockfill Dam And A Tailings Impoundment, W. D. Liam Finn

International Conference on Case Histories in Geotechnical Engineering

Two case studies from engineering practice are presented to demonstrate how useful a sophisticated finite element analysis can be in providing a comprehensive understanding of how dams behave during earthquakes. The first example involves determining, from the recorded performance of a rockfill dam, the volume change characteristics of the rockfill which cannot be measured directly. The second example covers the full range of current capability for analysis. It involves dynamic effective stress analysis of a tailings dam to check the triggering of liquefaction and the analysis of post-liquefaction flow deformations.

Negative Skin Friction In Piles And Design Decisions, M. T. Davisson

International Conference on Case Histories in Geotechnical Engineering

Negative skin friction behavior of pile foundations is described for conditions of pile usage in the USA. Methods of determining downdrag load and pile resistance to downdrag are explained. Other factors entering into design are discussed such as pile load testing and analysis, pile structural strength, factors of safety, pile drivability, and reduction of downdrag loads. Observations from seven unpublished negative skin friction failures are used for illustration.

Seismic Response Of The Pile Foundation Of Ohba-Ohashi Bridge, George Gazetas, Takashi Tazoh, Katsumi Shimizu, Ke Fan

International Conference on Case Histories in Geotechnical Engineering

The paper outlines the recorded response to numerous earthquakes of the pile foundation, the supporting soil, and the superstructure of the main pier of a road bridge. The records include free-field accelerograms at the ground surface and the base of the alluvial deposit, accelerograms on the footing and the superstructure, and the bending and axial strain histories at several depths along two of the sixty-four piles. Recently developed methods of seismic analysis are used in interpreting the recorded data. Extensive comparisons are made between theory and measurements. Successes and failures of the theory are discussed. Emphasis is given to the …

Conference Snapshots, Multiple People

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Past Proceedings: Third International Conference On Case Histories In Geotechnical Engineering, St. Louis (1993), Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Author Index Volume I And Ii, Multiple Authors

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Authors And Discussors Index, Multiple Authors

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Meet Our Authors, Multiple Authors

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Meeting Minutes Of The Organizing And Steering Committees, Multiple Members

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

List Of Conference Participants, Multiple Participants

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Steering Committee; Organizing Committee; Paper Review Committee, Multiple Members

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.