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Full-Text Articles in Engineering
Lead Binding To Metal Oxide And Organic Phases Of Natural Aquatic Biofilms, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Lead Binding To Metal Oxide And Organic Phases Of Natural Aquatic Biofilms, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Civil and Environmental Engineering
The role of the composition of surface-coating materials in controlling trace metal adsorption in aquatic environments was investigated using natural biofilms that developed on glass slides in three New York State lakes and a water-supply well. Adsorption isotherms were obtained for Pb binding to each of the biofilms in solutions with defined Pb speciation at 25°C and pH 6.0, with Pb concentrations ranging from 0.2 to 2.0 μM. Adsorption isotherms for Pb binding to laboratory-derived metal oxides and surrogate organic materials were determined under the same conditions. These isotherms, combined with characterization of natural biofilm composition, were used to estimate …
Capacity‐Demand‐Diagram Methods Based On Inelastic Design Spectrum, Anil K. Chopra, Rakesh K. Goel
Capacity‐Demand‐Diagram Methods Based On Inelastic Design Spectrum, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
An improved capacity‐demand‐diagram method that uses the well‐known constant‐ductility design spectrum for the demand diagram is developed and illustrated by examples. This method estimates the deformation of inelastic SDF systems consistent with the selected inelastic design spectrum, while retaining the attraction of graphical implementation of the ATC‐40 Nonlinear Static Procedure. One version of the improved method is graphically similar to ATC‐40 Procedure A whereas the second version is graphically similar to ATC‐40 Procedure B. However, the improved procedures differ from ATC‐40 procedures in one important sense. The demand diagram used is different: the constant‐ductility demand diagram for inelastic systems …
Closure To Period Formulas For Concrete Shear Wall Buildings, Anil K. Chopra, Rakesh K. Goel
Closure To Period Formulas For Concrete Shear Wall Buildings, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
No abstract provided.
Environmental Applications Of Gps, Samuel A. Vigil, Dora Zueck
Environmental Applications Of Gps, Samuel A. Vigil, Dora Zueck
Civil and Environmental Engineering
The use of the Global Positioning System (GPS) has revolutionized air travel, ocean navigation, land navigation, and the collection of environmental data. Although a basic civilian GPS receiver can be purchased for as little as $100, the receiver is only the tip of a 12 billion dollar iceberg! This paper will discuss the history and basic operation of the Global Positioning System, a satellite-based precision positioning and timing service developed and operated by the Department of Defense. It will also describe the accuracy limitations of the civil GPS service and how accuracy can be enhanced by the use of differential …
Early Experimentation With Civil Engineering Materials, James L. Hanson
Early Experimentation With Civil Engineering Materials, James L. Hanson
Civil and Environmental Engineering
A new project-based teaching method emphasizing laboratory experimentation is being used at Lawrence Technological University. It has excited and energized the students about civil engineering applications. Engineering concepts are introduced early in the students’ academic careers using civil engineering materials. Laboratory activities related to a Civil Engineering Materials course are being used for outreach, recruitment, and an intensive laboratory experience. A departmental effort has included supporting an outreach program and expanding a freshman CE Materials course. This new teaching method has affected and complemented university recruitment and retention efforts. The course introduces incoming students to engineering analysis and the basic …
Application Of Noise Control In Environmental Engineering Education, Harold M. Cota, Kristy Grace
Application Of Noise Control In Environmental Engineering Education, Harold M. Cota, Kristy Grace
Civil and Environmental Engineering
Noise control is both a factor in the health and safety of those in the workplace and in the annoyance and interference of the quality of life at home. This falls squarely in the realm of the Environmental Engineering Profession. Noise, its effects and control, is an important element of a few Graduate Environmental Engineering Programs, but it does not have a role in most undergraduate programs. One objective of this paper is to demonstrate that noise is an issue needing to be addressed in Environmental Engineering Programs and to suggest that making it a requirement at the undergraduate level …
Possible Explanations Of Phase Transitions In Highway Traffic, C.F. Daganzo, M.J. Cassidy, Robert L. Bertini
Possible Explanations Of Phase Transitions In Highway Traffic, C.F. Daganzo, M.J. Cassidy, Robert L. Bertini
Civil and Environmental Engineering
It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. The evidence suggests that bottlenecks cause these transitions in a predictable way, and does not suggest that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. It is also shown that many of the complicated instability phenomena observed at all locations can be explained qualitatively in terms of a simple Markovian theory specific to traffic that does not necessarily …
Seismic Control Of Asymmetric Structures, Rakesh K. Goel
Seismic Control Of Asymmetric Structures, Rakesh K. Goel
Civil and Environmental Engineering
No abstract provided.
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
The ATC-40 and FEMA-274 documents contain simplified nonlinear analysis procedures to determine the displacement demand imposed on a building expected to deform inelastically. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion of these results to the capacity diagram are based only on the fundamental vibration mode of the elastic system. The earthquake-induced deformation of an inelastic SDF system is estimated by an iterative method requiring analysis of a sequence of equivalent linear systems, thus avoiding the dynamic analysis of the inelastic SDF system. …
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Capacity-Demand-Diagram Methods For Estimating Seismic Deformation Of Inelastic Structures: Sdf Systems, Anil K. Chopra, Rakesh K. Goel
Civil and Environmental Engineering
The ATC-40 and FEMA-274 documents contain simplified nonlinear analysis procedures to determine the displacement demand imposed on a building expected to deform inelastically. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion of these results to the capacity diagram are based only on the fundamental vibration mode of the elastic system. The earthquake-induced deformation of an inelastic SDF system is estimated by an iterative method requiring analysis of a sequence of equivalent linear systems, thus avoiding the dynamic analysis of the inelastic SDF system. …
Some Traffic Features At Freeway Bottlenecks, Michael J. Cassidy, Robert L. Bertini
Some Traffic Features At Freeway Bottlenecks, Michael J. Cassidy, Robert L. Bertini
Civil and Environmental Engineering
Observations from two freeway bottlenecks in and near Toronto, Canada indicate that the average rate vehicles discharge from a queue can be 10% lower than the flow measured prior to the queue's formation. Absent any influences from downstream, the queue discharge flows exhibited nearly stationary patterns that alternated between higher and lower rates. These alternating flow patterns were especially evident at one of the two sites, although the feature occurred at both sites during periods that immediately followed the onset of upstream queuing; i.e. a queue's formation was always accompanied by a relatively low discharge rate followed later by a …
Production Of Biogenic Mn Oxides By Leptothrix Discophora Ss-1 In A Chemically Defined Growth Medium And Evaluation Of Their Pb Adsorption Characteristics, Yarrow M. Nelson, Leonard W. Lion, William C. Ghiorse, Michael L. Shuler
Production Of Biogenic Mn Oxides By Leptothrix Discophora Ss-1 In A Chemically Defined Growth Medium And Evaluation Of Their Pb Adsorption Characteristics, Yarrow M. Nelson, Leonard W. Lion, William C. Ghiorse, Michael L. Shuler
Civil and Environmental Engineering
Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the addition of ≥0.1 μM FeSO4. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and …