Engineering Commons^™

Radionuclide Leaching From Residual Soils: Screening Study, Mark W. Fitch, Ellen England

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Four soil samples, collected from a National Priorities Listed site contaminated with uranium, thorium, and radium, were leached for two, seven, and 30 days. The nonleached soils, leached soils, and leachates were analyzed using gamma spectroscopy, alpha spectroscopy, and delayed neutron activation. Unleached and leached soils had low radionuclide activities, and four different leaching solutions had no significant observable effect upon the resulting leachate activity. Three of the soils produced leachates with uranium activities below the expected primary drinking water standard of 30 µg/L for uranium, but the leachate from the fourth soil had an unacceptably high concentration of uranium …

Forensic Investigation Of Failed Mast Arms Of Traffic Signal Supported Structures, Genda Chen, Michael G. Barker, D. Scott Mackenzie, Christopher W. Ramsay, Joe Alderson, Lokeswarappa R. Dharani, Jiaqing Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Missouri, 11 traffic signal mast arms fractured at the arm-post weld connection in 7 years. To reduce this fatigue failure, the Missouri Department of Transportation developed a fatigue-resistant weld profile that increases the weld leg and reduces the slope of the weld at the toe. This study investigated causes of the failed arms, compared performance of new and old weld profiles, and suggested retrofitting measures for further investigation. The scope included a metallurgical investigation of one failed field mast arm, laboratory fatigue testing of five prototype mast arms (two new and three old profiles), and laboratory failure analysis of …

Biotransformation Of Various Substituted Aromatic Compounds To Chiral Dihydrodihydroxy Derivatives, Henning Raschke, Michael Meier, Roland Hany, Markus D. Muller, Jan Roelof Van Der Meer, Hans-Peter E. Kohler, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The biotransformation of four different classes of aromatic compounds by the Escherichia coli strain DH5α(pTCB 144), which contained the chlorobenzene dioxygenase (CDO) from Pseudomonas sp. strain P51, was examined. CDO oxidized biphenyl as well as monochlorobiphenyls to the corresponding cis-2,3-dihydro-2,3-dihydroxy derivatives, whereby oxidation occurred on the unsubstituted ring. No higher substituted biphenyls were oxidized. The absolute configurations of several monosubstituted cis-benzene dihydrodiols formed by CDO were determined. All had an S configuration at the carbon atom in meta position to the substituent on the benzene nucleus. with one exception, the enantiomeric excess of several 1,4-disubstituted cis-benzene dihydrodiols formed by CDO …

Fatigue Assessment Of Traffic Signal Mast Arms Based On Field Test Data Under Natural Wind Gusts, Genda Chen, Jingning Wu, Jiaqing Yu, Lokeswarappa R. Dharani, Michael G. Barker

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In recent years, several states including Missouri, Wyoming, California, and Texas experienced fracture failures of traffic signal mast arms. Almost all the failures are associated with the propagation of defects or cracks. It is therefore imperative to evaluate existing mast arms using a simple yet accurate procedure. A statistical methodology is proposed to predict the fatigue life of signal mast arm structures on the basis of field-measured strain data. The annual occurrence of various stress levels is determined using the historical wind speed data in the vicinity of a mast arm structure and the strain readings of the structure under …

Experimental Characterization Of Metallic Dampers For Seismic Retrofit Of Highway Bridges, Genda Chen, Eric R. Bothe, Jeffrey Ger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The seismic effectiveness of metallic dampers as vibration isolators and energy dissipation devices as well as the dynamic performance of high rocker bearings are investigated experimentally. The scope of the study includes optimizing the metallic dampers for maximum dissipation of energy, characterizing full-scale metallic dampers, and understanding the seismic behavior of a small-scale bridge with dampers. Three full-scale dampers, two of straight and one of linearly tapered rods, were fabricated and tested under a progressive cyclic load. Test results consistently show that the tangential stiffness of the metallic dampers does not degrade significantly as the number of loading cycles increases …

Using Flash Animations And 3d Rendering To Increase The Effectiveness Of Instructional Software, Timothy A. Philpot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Animation and three-dimensional rendering software offers exciting new capabilities that can enhance engineering instructional material. Using these software tools, instructional media can escape the static two-dimensional confines of the printed page or the classroom blackboard. This work-in-progress describes a project to develop instructional material for a Mechanics of Materials course. The paper presents examples of instructional animations, discusses software development tools used to create the animations and discusses early student reaction to the multimedia presentations

Rhizosphere Competitiveness Of Trichloroethylene-Degrading, Poplar-Colonizing Recombinant Bacteria, Hojae Shim, Sadhana Chauhan, Doohyun Ryoo, Kally Bowers, Stuart M. Thomas, Keith A. Canada, Thomas K. Wood, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Indigenous bacteria from poplar tree (Populus canadensis var. eugenei `Imperial Carolina') and southern California shrub rhizospheres, as well as two tree-colonizing Rhizobium strains (ATCC 10320 and ATCC 35645), were engineered to express constitutively and stably toluene o-monooxygenase (TOM) from Burkholderia cepacia G4 by integrating the tom locus into the chromosome. The poplar and Rhizobium recombinant bacteria degraded trichloroethylene at a rate of 0.8 to 2.1 nmol/min/mg of protein and were competitive against the unengineered hosts in wheat and barley rhizospheres for 1 month (colonization occurred at a level of 1.0 × 10⁵ to 23 × 10^{5 …}

Mechanism Of Interaction Of Asphalt Cement With Crumb Rubber Modifier, Magdy Abdelrahman, Samuel Carpenter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The nature of the interaction process between asphalt cement and crumb rubber modifier (CRM) has not been fully understood. Two main types of mechanisms that affect the produced binder properties are reported: particle swelling and degradation (devulcanization and depolymerization). These mechanisms occur as the binder is subjected to different combinations of interaction time and temperature. Insight into the mechanisms by which the interaction between the two materials takes place through monitoring the changes in the rheological parameters of the binder is provided. The effects of the interaction process variables, time and temperature, are explained. The effect of CRM properties, including …

Making Concrete Less Abstract, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

CE 3 13 is a second level properties of concrete lecture course. In an effort to make it appear less abstract to the students, over the course of several semesters several learning strategies were tried, including journaling, muddiest point, entering the academy, role playing, bookends-on-a-lecture, and hands-on lab projects. Most recently, an emphasis on short writing-to-learn papers, a problems-based stance, and an integrated lab project was used. Student evaluations indicated that the lab projects and the increased writing was of significant benefit in promotion of learning.

A New Chip-Set For Astra Digital Radio, Werner Bradinal, Christoph Moeller, Timothy A. Philpot, Mike Rose

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This chip-set provides the channel and source decoding functions for ASTRA Digital Radio (ADR) receivers. An overview of the system is given together with a summary of the main features of the ICs. The chip-set offers a flexible, but optimum solution to meet the requirements for low cost consumer sets.

Estimation Of Resilient Modulus Of Fine-Grained Subgrade Soils, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Determination Of Aashto Layer Coefficients For Granular Materials By Use Of Resilient Modulus, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The layer coefficients a₂ or a₃ for an unbound granular base or subbase material are found from a relationship with resilient modulus, E_b. The resilient modulus for a given material can be found by test using the "theta model" or by use of an estimation regression equation. E_b is a function of several factors, as discussed below.

Relative Durability Of Shale -- A Suggested Rating System, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The inability to predict the degradation tendencies of shale has resulted in numerous failures of projects where shale was used as a construction material. Because shale does not fit neatly into either a soil category or a rock category, the tests that are commonly used to classify soil or rock are in many instances not totally suitable for classifying shale as to its long-term behavior properties. Thus, special classification tests of shale types has become necessary. The durability or shale relates to how well it can withstand its changing environment and still retain its initial properties. Strength, expansion characteristics, and …

Repetitive Load Deformation Of Cohesionless Soil, Rodney Lentz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Sld Potamology Study (S-9), Jerome A. Westphal, Samuel P. Clemence

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Foreword

In this report, the authors discuss factors which relate to flow characteristics of the Middle Mississippi River and its major tributaries. The variety of ways in which man and nature interact to affect the hydrologic regime of the study area are almost infinite. Furthermore, the intensity and direction of man's activity is non-uniform with respect to both time and space. Therefore, on the scale of the study area, the authors assert that 1) it is difficult to verify associations between specific human actions and river responses and 2) at this time, it is impossible to do so in a …

Missouri River Computerized Data Bank, Glendon Taylor Stevens

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This report explains the results of "The Missouri River Computerized Data Bank." It contains all known data collected on the Missouri River beginning in the mid-1930's.

It should be noted that only 10% of the included data has been verified, i.e. has been checked against the source document. A bounds check was performed by the computer on each piece of data for upper and lower limits established for each type of data. Any potential user of these data should be aware of this fact and that, on the average, 1 piece of data out of 200 may be in error. …