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Articles 7771 - 7800 of 10558
Full-Text Articles in Entire DC Network
Structural Health Monitoring And Damage Detection Using An Intelligent Parameter Varying (Ipv) Technique, Soheil Saadat, Mohammad N. Noori, Gregory D. Buckner, Tadatoshi Furukawa, Yoshiyuki Suzuki
Structural Health Monitoring And Damage Detection Using An Intelligent Parameter Varying (Ipv) Technique, Soheil Saadat, Mohammad N. Noori, Gregory D. Buckner, Tadatoshi Furukawa, Yoshiyuki Suzuki
Office of the Dean (CENG) Scholarship
Most structural health monitoring and damage detection strategies utilize dynamic response information to identify the existence, location, and magnitude of damage. Traditional model-based techniques seek to identify parametric changes in a linear dynamic model, while non-model-based techniques focus on changes in the temporal and frequency characteristics of the system response. Because restoring forces in base-excited structures can exhibit highly non-linear characteristics, non-linear model-based approaches may be better suited for reliable health monitoring and damage detection. This paper presents the application of a novel intelligent parameter varying (IPV) modeling and system identification technique, developed by the authors, to detect damage in …
Structural Analysis Of Sign Bridge Structures And Luminaire Supports, Christopher Foley, Raymond Fournelle, Scott J. Ginal, John L. Peronto
Structural Analysis Of Sign Bridge Structures And Luminaire Supports, Christopher Foley, Raymond Fournelle, Scott J. Ginal, John L. Peronto
Transportation Reports with the Wisconsin Department of Transportation
The Wisconsin Department of Transportation has experienced failures of a high-mast luminaire (HML) support structure and a full-span overhead sign support structure. Furthermore, cracking has been found in many sign support structures composed of welded round hollow structural shapes (HSS). The purpose of the research conducted was to provide fatigue life estimates for these structures, which could then shed light onto the causes of the cracking found and the failures experienced. The analytical and experimental effort conducted was also used to establish rational inspection intervals for these structures and recommend changes (as required) to the procedures for design of high-mast …
Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant
Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant
Theses and Dissertations
Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …
Modeling A Field Application Of In Situ Bioremediation Of Perchlorate-Contaminated Groundwater Using Horizontal Flow Treatment Wells (Hftws), Peter G. Chosa
Modeling A Field Application Of In Situ Bioremediation Of Perchlorate-Contaminated Groundwater Using Horizontal Flow Treatment Wells (Hftws), Peter G. Chosa
Theses and Dissertations
Perchlorate contaminated groundwater is rapidly becoming a significant environmental remediation issue for the Department of Defense. In this study, an existing numerical model that simulates the operation of a Horizontal Flow Treatment Well (HFTW) system to effect the in situ biodegradation of perchlorate through the addition of an electron donor is modified to include a submodel that describes bioclogging. Bioclogging restricts flow out of the HFTW due to the accumulation of biomass directly adjacent to the well. The modified model is then applied to an existing perchlorate contaminated site that will be used for an evaluation of the HFTW technology. …
Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe
Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe
Theses and Dissertations
This study utilized a three-dimensional numerical model to evaluate the potential application of HFTWs to manage MTBE-contaminated groundwater. HFTWs consist of two dual-screened treatment wells. One well operates in an upflow mode, with MTBE-contaminated water extracted from an aquifer through a screen in the deep portion of an aquifer and injected into the aquifer through a shallow well screen, while the adjacent well operates in a downflow mode, extracting water from the shallow zone of the aquifer and injecting it into the deep zone. As the MTBE-contaminated water flows through the wells, an electron acceptor and/or another electron donor is …
Making The Business Case For Sustainable Design In The Department Of Defense, David M. Warnke
Making The Business Case For Sustainable Design In The Department Of Defense, David M. Warnke
Theses and Dissertations
Buildings are one of the largest consumers of natural resources, a major source of ecological pollution, and occasionally toxic to human health. Sustainable design is the common term associated with buildings which, during their construction, use, and eventual disposal, seek to minimize their negative impact on the environment and human health. The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system helps to assess a building's sustainability level. In the Federal Government's push to set the example for the rest of the nation, nearly every Federal Agency has chosen to adopt the LEED assessment tool. Each …
Effect Of Supplementary Cementitious Materials On The Compressive Strength And Durability Of Short-Term Cured Concrete, H. Toutanji, Norbert Delatte, S. Aggoun, R. Duval, A. Danson
Effect Of Supplementary Cementitious Materials On The Compressive Strength And Durability Of Short-Term Cured Concrete, H. Toutanji, Norbert Delatte, S. Aggoun, R. Duval, A. Danson
Civil and Environmental Engineering Faculty Publications
This research focuses on studying the effect different supplementary cementitious materials (silica fume, fly ash, slag, and their combinations) on strength and durability of concrete cured for a short period of time—14 days. This work primarily deals with the characteristics of these materials, including strength, durability, and resistance to wet and dry and freeze and thaw environments. Over 16 mixes were made and compared to the control mix. Each of these mixes was either differing in the percentages of the additives or was combinations of two or more additives. All specimens were moist cured for 14 days before testing or …
Analysis Of Inconsistencies Related To Design Speed, Operating Speed, And Speed Limits, Nikiforos Stamatiadis, Huafeng Gong
Analysis Of Inconsistencies Related To Design Speed, Operating Speed, And Speed Limits, Nikiforos Stamatiadis, Huafeng Gong
Kentucky Transportation Center Research Report
The objective of this research was to examine the relationship among design speeds, operating speeds and speed limits and address safety and operational concerns regarding the presence of disparities among these speed metrics. Roadway sections were selected throughout Kentucky based on the relationship between design speed and posted speed limit (greater or lower) and on the number of lanes (2 or 4). Speed data and roadway geometry data were collected along these sites to allow for the development of the appropriate models. The general conclusion for 2-lane highways is that the operating speed is different than the design speed indicating …
Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li
Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li
Dissertations
An intercity travel decision includes a complex set of subdecisions, such as when to travel, where to travel, which mode to choose, and others. The main focus of this dissertation is to examine trip frequency and mode choice of intercity non-business travel.
The objective of this study is to understand intercity travel behavior using disaggregate models. The proposed conceptual framework for intercity travel behavior leads to a nested logit/continuous choice model that is rigorously linked to the utility maximization theory. Compared to a traditional intercity travel demand model, the proposed model is utility consistent in that trip generation and mode …
The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu
The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu
Dissertations
CSO discharges have long been recognized as a significant source of water pollution. While many sources of water pollution have been controlled over the past 20 years, CSOs continue to be a main environmental concern in several areas, especially in old cities. In the past, most CSO research focused on the CSO control processes, including floatables and suspended solids removal. Few studies have been conducted in the area of the impacts of CSO discharge on the receiving water quality. To achieve this purpose, a powerful water-modeling tool, WASP 6.1, is utilized in this study. The Lower Hudson River is selected …
A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar
A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar
Dissertations
Existing adaptive traffic control strategies lack an effective evaluation procedure to check the performance of the control plan after implementation. In the absence of an effective evaluation procedure, errors introduced in the system such as inaccurate estimates of arrival flows, are carried forward in time and reduce the efficiency of the traffic flow algorithms as they assess prevalent traffic conditions. It is evident that the feed-forward nature of these systems cannot accurately update the estimated quantities, especially during oversaturated conditions.
This research is an attempt to develop a conceptual framework for the application of feedback control within the basic operation …
Land For Maine's Future Program: Increasing The Return On A Sound Public Investment, Richard Barringer, Hugh Coxe, Jack Kartez, Catherine Reilly, Jonathan Rubin
Land For Maine's Future Program: Increasing The Return On A Sound Public Investment, Richard Barringer, Hugh Coxe, Jack Kartez, Catherine Reilly, Jonathan Rubin
Economics and Finance
Maine is nowhere a more special place than in the quality of its landscape and the traditions of its land use. Among the mo st privately-owned of all the states, Maine’s natural diversity and beauty combine with its traditions of resource stewardship, open access, and appreciation of nature to distinguish it in the public mind and national imagination. In recent decades, however, these traditions have come under assault from the forces of economic and social change; and the people of Maine have responded. In 1986, Governor Joseph Brennan’s Special Commission on Outdoor Recreation recognized the growing threats to Maine’s natur …
A Multi-Objective Decision-Making Framework For Transportation Investments, Mashrur Chowdhury, Pulin Tan
A Multi-Objective Decision-Making Framework For Transportation Investments, Mashrur Chowdhury, Pulin Tan
Publications
This paper presents a framework based on multi-objective optimization that can be used to generate and analyze the most desirable transportation investment options based on their objectives and constraints. The framework, which is based on the surrogate worth trade-off analysis, could be applied to both discrete or continuous decision-problem scenarios. In a discrete problem, a predefined set of alternatives is available, whereas continuous problems are not characterized by a predefined set of alternatives. This framework was applied with the data generated for a Capital Beltway Corridor investment study. The multi-objective decision-making framework was found to be adaptable to this typical …
Software For Optimizing International Water Resources Management, Richard C. Peralta, S. Wu
Software For Optimizing International Water Resources Management, Richard C. Peralta, S. Wu
Civil and Environmental Engineering Faculty Publications
The Simulation/Optimization MOdeling System (SOMOS) has modules adapted for a range of international water resource management needs. The SOMOA module is best for field groundwater and conjunctive water management situations. It employs several analytical simulation models and several optimization methods to give appropriate optimal guidance for situations having sparse data. SOMOA requires understanding of the limitations of common analytical equations. It does not require experience in finite difference or element numerical modeling. SOMOS also has modules ideal for situations in which there is sufficient data for numerical modeling or aquifer and stream-aquifer systems. Emphasized here are SOMOA and its applications …
Nitrification Investigation And Modeling In The Chloraminated Drinking Water Distribution System, Suibing Liu
Nitrification Investigation And Modeling In The Chloraminated Drinking Water Distribution System, Suibing Liu
Electronic Theses and Dissertations
This dissertation consists of five papers concerning nitrification in chloraminated drinking water distribution systems in a one and a half year field study. Seven finished waters were produced from different treatment processes and distributed to eighteen pilot distribution systems (PDSs) that were made pipes taken from actual distribution systems. Unlined cast iron (UCI), galvanized steel (G), lined cast iron (LCI), and PVC pipes were used to build the PDSs. All finished waters were stabilized and chloraminated before entering the PDSs. This dissertation consists of five major parts. (1) System variations of nitrates, nitrites, DO, pH, alkalinity, temperature, chloramine residuals and …
Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao
Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao
Electronic Theses and Dissertations
Five articles describing the impact of surface characteristics, and development of mass transfer models for diffusion controlled membrane applications are published in this dissertation. Article 1 (Chapter 3) describes the impact of membrane surface characteristics and NOM on membrane performance for varying pretreatment and membranes during a field study. Surface charge, hydrophobicity and roughness varied significantly among the four membranes used in the study. Membrane surface characteristics, NOM and SUVA measurements were used to describe mass transfer in a low pressure RO integrated membrane system. Inorganic and organic solute and water mass transfer coefficients were systematically investigated for dependence on …
Community Design Of A Light-Rail Transit Oriented Development Using Casewise Visual Evaluation (Cave), Keiron Bailey, Ted H. Grossardt
Community Design Of A Light-Rail Transit Oriented Development Using Casewise Visual Evaluation (Cave), Keiron Bailey, Ted H. Grossardt
Kentucky Transportation Center Faculty and Researcher Publications
The Transit Authority of River City (TARC) is in the preliminary engineering phases of developing a light-rail transit system running from downtown Louisville, Kentucky to the city’s southern suburbs, a distance of approximately 15 miles. In collaboration with the research team, TARC wished to test an innovative methodology for improving community participation in the design of a light rail transit-oriented development for the Smoketown/Shelby Park area. The Smoketown/Shelby Park neighborhood is a low-income area located to the south of the University of Louisville Medical Center. A suitable site for the station has been identified by TARC and its design partners, …
Undergraduate Summer Research In Structural Engineering, Norbert J. Delatte
Undergraduate Summer Research In Structural Engineering, Norbert J. Delatte
Civil and Environmental Engineering Faculty Publications
For the last seven years, a summer Research Experiences for Undergraduates site in structural engineering, funded by the National Science Foundation, has operated at the University of Alabama at Birmingham. During this time, 33 students from 22 colleges and universities have participated in the site. Participants are recruited nationally and have come from as far away as California and Puerto Rico. The program is intended to provide students interested in graduate studies with an introduction to research methods, and to provide students who will not continue their studies past a bachelor of science in civil engineering with a better understanding …
Coatings For Corrosion Protection: Offshore Oil And Gas Operation Facilities, Marine Pipeline And Ship Structures
United States Department of Transportation: Publications
This workshop on Coatings for Corrosion Protection: Offshore Oil and Gas Operation Facilities, Marine Pipelines, Ship Structures, and Port Facilities was held on April 14-16, 2004 in Biloxi, Mississippi. This workshop of 150 attendees drew participation by internationally recognized marine coating experts, material specialists, inspection specialists, coating manufacturers, maintenance engineers, and designers. The workshop was crafted to include multiple viewpoints: industrial, academic, environmental, regulatory, standardization, and certification.
Keynote and topic papers were presented to establish a current information base for discussions. Six discussion groups addressed specific issues and identified, prioritized, and recommended specific research and development topics for the government …
Modeling Impacts On Populations: Fathead Minnow (Pimephales Promelas) Exposure To The Endocrine Disruptor 17Β-Trenbolone As A Case Study, David H. Miller, Gerald T. Ankley
Modeling Impacts On Populations: Fathead Minnow (Pimephales Promelas) Exposure To The Endocrine Disruptor 17Β-Trenbolone As A Case Study, David H. Miller, Gerald T. Ankley
United States Environmental Protection Agency: Publications
Evaluation of population-level impacts is critical to credible ecological risk assessments. In this study, a predictive model was developed to translate changes in fecundity of the fathead minnow (Pimephales promelas) in a short-term laboratory toxicity test to alterations in population growth rate. The model uniquely combines a Leslie population projection matrix and the logistic equation. Application of the model requires only a life table for the organism of interest, a measure of carrying capacity for the given population, and an estimation of the effect of a stressor on vital rates. The model was applied to investigate population dynamics …
Review Of Spokane River Model For Washington Department Of Ecology, Chris Berger, Robert Leslie Annear, Scott A. Wells
Review Of Spokane River Model For Washington Department Of Ecology, Chris Berger, Robert Leslie Annear, Scott A. Wells
Civil and Environmental Engineering Faculty Publications and Presentations
This memorandum discusses changes made to the Spokane River model calibration since the original calibration of the model discussed in the following reports: Annear et al. (2001), Berger at al. (2002), Slominski et al. (2002), and Berger et al. (2003). The first group of refinements was made by the Washington Department of Ecology. Additional changes were made by Portland State University (PSU) and were discussed in this report along with the results of two alternative calibrations. The last section displays the original calibration results from Berger et al. (2003) as a basis for comparison to the changes made by Ecology …
Willamette River Basin Temperature Tmdl Model: Boundary Conditions And Model Setup, Robert Leslie Annear, Michael Lee Mckillip, Sher Jamal Khan, Chris Berger, Scott A. Wells
Willamette River Basin Temperature Tmdl Model: Boundary Conditions And Model Setup, Robert Leslie Annear, Michael Lee Mckillip, Sher Jamal Khan, Chris Berger, Scott A. Wells
Civil and Environmental Engineering Faculty Publications and Presentations
The State of Oregon Department of Environmental Quality (DEQ) is developing a TMDL for temperature in the Willamette River basin shown in Figure 1. The study area included the Willamette River and all major tributaries (except the Tualatin River where a TMDL process was already concluded). A large section of the Columbia River was also modeled to provide adequate boundary representation of tidal flows in the lower Willamette River. The Willamette River below the Oregon City Falls in the Portland metropolitan area has a typical diurnal tidal range of 1 m. The development of a dynamic model of temperature and …
Sympathetic Vibration Due To Co-Ordinated Crowd Jumping, Christopher Y. Tuan
Sympathetic Vibration Due To Co-Ordinated Crowd Jumping, Christopher Y. Tuan
Civil Engineering Faculty Publications
In assembly structures or places where crowds may gather such as dance halls, theaters, gymnasia and stadia, the loading is almost entirely caused by human activities. Structural resonance or near resonance and the resulting vibrations causing discomfort of spectators have often been observed during a rock concert or a sporting event. Recent research efforts have focused on developing load models to quantify the dynamic loading effects induced by individuals and groups up to 40 people. The lack of coherence of motion from a large crowd, the so-called ‘‘group effect’’, has been quantified based on simulations. The simulation results and the …
Joint Application Of Artificial Neural Networks And Evolutionary Algorithms To Watershed Management, Misgana K. Muleta, John W. Nicklow
Joint Application Of Artificial Neural Networks And Evolutionary Algorithms To Watershed Management, Misgana K. Muleta, John W. Nicklow
Civil and Environmental Engineering
Artificial neural networks (ANNs) have become common data driven tools for modeling complex, nonlinear problems in science and engineering. Many previous applications have relied on gradient-based search techniques, such as the back propagation (BP) algorithm, for ANN training. Such techniques, however, are highly susceptible to premature convergence to local optima and require a trial-and-error process for effective design of ANN architecture and connection weights. This paper investigates the use of evolutionary programming (EP), a robust search technique, and a hybrid EP–BP training algorithm for improved ANN design. Application results indicate that the EP–BP algorithm may limit the drawbacks of using …
Effect Of Source Water Blending On Copper Release In Pipe Distribution System: Thermodynamic And Empirical Models, Weizhong Xiao
Effect Of Source Water Blending On Copper Release In Pipe Distribution System: Thermodynamic And Empirical Models, Weizhong Xiao
Electronic Theses and Dissertations
This dissertation focuses on copper release in drinking water. Qualitative and quantitative assessment of Cu and Fe corrosion by process water quality was assessed over one year in a field study using finished waters produced from seven different treatment process and eighteen pilot distribution systems (PDSs) that were made from unlined cast iron and galvanized steel pipes, and lined cement and PVC pipes taken from actual distribution systems. Totally seven different waters were studied, which consisted of three source waters: groundwater, surface, and simulated brackish water designated as G1, S1, and RO. With certain pre-established blending ratios, these three waters …
Estimating Energy Savings In Compressed Air Systems, Chris Schmidt, J. Kelly Kissock
Estimating Energy Savings In Compressed Air Systems, Chris Schmidt, J. Kelly Kissock
Mechanical and Aerospace Engineering Faculty Publications
Compressed air is typically one of the most expensive utilities in an industrial facility. As a result, potential savings opportunities are aggressively sought out and identified. Once identified, projected energy savings must be calculated in order to justify the cost of implementing the savings opportunity. It is important to calculate projected energy and cost savings as accurately as possible. Unfortunately, savings are frequently overestimated because the methods used to estimate savings neglect to consider important factors such as compressor control and type, storage, and multiple compressor operation.
In this paper, a methodology is presented for modeling air compressor performance and …
Development Of A Neural Network Approach For The Assessment Of The Performance Of Traffic Sign Retroreflectivity, Nagajyothi Swargam
Development Of A Neural Network Approach For The Assessment Of The Performance Of Traffic Sign Retroreflectivity, Nagajyothi Swargam
LSU Master's Theses
The goal of the research was to develop a new predictive tool for assessing the performance of traffic sign retroreflectivity and to compare the developed tool with the existing linear regression models. Retroreflectivity decreases as sign sheeting ages. Currently Louisiana Department of Transportation and Development (LADOTD) replace signs with low reflectivity based on driver complaints. This practice might have resulted in premature sign replacement (removal of signs with several years of in-service life still remaining) or in non-replacement of signs that are not in compliance with LADOTD minimum reflectivity standards. In this study, both neural network models and regression models …
Travel Time Tomographic Imaging Of The Distribution Of The Effective Stress In Clean Sand Under A Model Footing, William M. Tanner
Travel Time Tomographic Imaging Of The Distribution Of The Effective Stress In Clean Sand Under A Model Footing, William M. Tanner
LSU Master's Theses
The use of high-speed data acquisition systems, inexpensive and reliable transducers, and better models of interpretation have combined to make elastic wave tomographic imaging of geotechnical engineering systems easier to accomplish both in the laboratory and in the field. An important application of these developments is that the evaluation of states of effective stress in soils using images of elastic wave velocity distribution. As a consequence, it is possible to experimentally estimate the state of induced and in-situ effective stresses and to compare these results with established models of stress distribution based on the theory of elasticity (e.g., Boussinesq’s solution). …
Experimental And Computational Modeling Of Granular Materials, Orlando Boscan
Experimental And Computational Modeling Of Granular Materials, Orlando Boscan
LSU Master's Theses
4-inch cubical sand specimens were been tested under drained conditions using a wide range of stress paths. The testing was performed by means of a true (cubical) triaxial device that has been conditioned for this study. This testing set-up consisted of a servo-controlled, single-boundary type apparatus, with six flexible membranes that create a center cavity surrounding the soil specimens. This thesis illustrates the functioning of the triaxial device, including detailed descriptions of the device components, sample preparation, and a practical application related to the mechanical characterization of granular materials using critical state soil mechanics. An experimental program, based on the …
Application Of Absorptive Treatments On Traffic Noise Barriers In Florida, Chin Boon Chua
Application Of Absorptive Treatments On Traffic Noise Barriers In Florida, Chin Boon Chua
Electronic Theses and Dissertations
In this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier insertion loss. The best fit equation model was then used to test against measured/model result and TNM prediction results for its …