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Articles 5251 - 5280 of 6119

Full-Text Articles in Civil and Environmental Engineering

Shear Wave Velocity Profiles At Sites Liquefied By The 1999 Kocaeli, Turkey Earthquake, Brady R. Cox May 2001

Shear Wave Velocity Profiles At Sites Liquefied By The 1999 Kocaeli, Turkey Earthquake, Brady R. Cox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents shear wave velocity profiles for 15 sites liquefied by the 1999 Kocaeli, Turkey earthquake. These profiles are used in order to evaluate each liquefaction site by the simplified shear wave velocity procedure. This procedure allowed for the identification of a potentially liquefiable region within the subsurface at each site. Locating this region at each site allowed for the separation of soils that were too stiff to liquefy from soils that were soft enough to liquefy. Once these soft regions had been identified, they were evaluated to separate granular soils expected to liquefy, from fine-grained soils expected not …


Adsorption Of Inorganic And Organic Ligands Onto Aluminum Hydroxide And Its Effect In Water Treatment, Peter Pommerenk Apr 2001

Adsorption Of Inorganic And Organic Ligands Onto Aluminum Hydroxide And Its Effect In Water Treatment, Peter Pommerenk

Civil & Environmental Engineering Theses & Dissertations

The inorganic anions fluoride, sulfate, and orthophosphate are ubiquitous substances in aqueous environments. These chemicals are also applied in drinking water treatment processes where fluoridation, coagulation with sulfate-based metal salts, or the use of passivating corrosion inhibitors or sequestering agents is practiced. If these ions are present at elevated levels in raw waters or added in the treatment train at points other than directly before entering a finished water reservoir, they can exert a negative influence on the removal of particles and natural organic matter.

Although the water chemistry of these inorganic ions seems to be well understood, their potential …


A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen Mar 2001

A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen

Theses and Dissertations

The amount of municipal solid waste discarded to landfills is continually increasing even with extensive recycling efforts. The need to understand the behavior of waste in landfills is increased due to the decreasing number of active landfills, communities' concern to the potential hazards associated with landfills, and companies or installations with landfills on-site need to understand landfill behavior comply with new legislation concerning design and detecting hazardous material movement of-site. This research is focused on increasing the understanding of landfill behavior by examining the effects of temperature in a landfill system. A system dynamics approach was used in this research …


Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson Mar 2001

Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson

Theses and Dissertations

The purpose of this study is to determine and explore the fundamental processes associated with biodegradation of chlorinated ethenes in iron-reducing conditions of a constructed wetland and to evaluate the impacts of changing conditions (both natural and engineer-controlled) on the system. The modeler uses a system dynamics approach to construct a model that represents behavior in the iron-reducing environment. The model incorporates hematite, a form of oxidized iron (Fe3+), as the electron acceptor in microbial biodegradation in the system. Vinyl chloride, cis-dichloroethene, and trans-dichloroethene are known to anaerobically degrade to carbon dioxide in the presence of oxidized iron. …


Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker Mar 2001

Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker

Theses and Dissertations

Subsurface contamination by industrial chemicals is one of the most prevalent and costly environmental problems facing the United States government. This contamination problem must be managed to protect human health and the environment. Two basic strategies are used to deal with subsurface contamination: source removal and contaminant containment. While much cost and performance data are available for individual technologies associated with each of these strategies, there have been very few studies that have examined the benefits of implementing source removal technologies in order to reduce contaminant containment (and hopefully total) costs. This study examines the tradeoff between extent of source …


Chromate Content Bias As A Function Of Particle Size In Aircraft Primer Paint Overspray, David B. Novy Mar 2001

Chromate Content Bias As A Function Of Particle Size In Aircraft Primer Paint Overspray, David B. Novy

Theses and Dissertations

Spray painting operations using chromate-containing primer paints produce particles which may expose workers to strontium chromate. Chromate contains hexavalent chromium (Cr(VI)) which is a confirmed human carcinogen. It is suspected that the smaller particles contain disproportionately less Cr(VI) than larger particles. In order to determine if a bias in chromate content exists, paint particles were collected and separated based on particle size and the Cr(VI) concentration was determined. Aviation primer paint from the DeSoto and Deft companies was sprayed in a booth and seven-stage cascade impactors were used to separate particles.


A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel Mar 2001

A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel

Theses and Dissertations

Groundwater contamination by chlorinated ethenes is a widespread environmental problem. Conventional remediation technologies have shortcomings that have prompted further research into the development of novel treatment technologies. A palladium/ alumina catalyst in the presence of dissolved molecular hydrogen (referred to hereafter as a PD/H2 system) has been demonstrated to rapidly destroy chlorinated ethene contaminated groundwater. First-order kinetics have been used to model chlorinated ethene destruction in a PD/H2 reactor. However, catalyst deactivation and regeneration are important processes that also need to be modeled in order to better understand their effect on treatment efficiency. This study presents a model …


Decision Analysis Methodology To Evaluate Integrated Solid Waste Management Alternatives For A Remote Alaskan Air Station, Mark J. Shoviak Mar 2001

Decision Analysis Methodology To Evaluate Integrated Solid Waste Management Alternatives For A Remote Alaskan Air Station, Mark J. Shoviak

Theses and Dissertations

Eareckson Air Station (AS), a remote U.S. Air Force installation, faces the complex decision of selecting a new municipal solid waste (MSW) management strategy to replace its current non-compliant system. This research effort applies value-focused thinking and multiattribute preference theory to decision analysis techniques to produce a multiple-objective decision analysis model that captures all of the site's MSW goals, objectives, and concerns in order to facilitate the evaluation of MSW management strategies available. The model ranks 40 specific MSW management alternatives, which were developed in accordance with the decision-maker's assumptions and constraints, based on how well they meet Eareckson's overall …


Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young Mar 2001

Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young

Theses and Dissertations

Chlorinated ethenes are among the most prevalent groundwater contaminants at hazardous waste sites nationwide. In an attempt to manage the risks posed by these contaminants, while controlling costs, monitored natural attenuation (MNA) is being considered as a remediation strategy at many sites. MNA relies on naturally occurring physical, chemical, and biological processes in the subsurface to reduce the risk posed by the contamination. The implementation of MNA, however, requires a detailed understanding of these processes, and how they impact contamination at a particular site. One way to gain this understanding is through contaminant fate and transport modeling. In this study, …


Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts Mar 2001

Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts

Theses and Dissertations

The purpose of this study is to gain understanding of the dynamics of the processes that degrade Perchloroethene (PCE) to ethene, within the confines of the methanogenic zone of a constructed wetland. A system dynamics modeling approach is used. This model is focused on determining conditions that will enhance contaminant degradation. The chemical and biological processes within the methanogenic zone of a wetland system are extremely complex and dynamic processes. The model is broken up into three simultaneous processes: dechlorination, methanogenesis, and fermentation. The system behavior of the methanogenic zone can be adequately described by the classical formulations of representative …


Assessing The Economic Impact Of Aircraft Noise On Communities, Ithan B. Zimmer Jan 2001

Assessing The Economic Impact Of Aircraft Noise On Communities, Ithan B. Zimmer

Dissertations

The impact of aircraft noise on communities is complex and multi-dimensional. This matter cannot be resolved without careful analysis of a complex array of related problems and issues including the environment, the economy, and quality-of-life concerns of people living in proximity to airports or aircraft routes. The effects of community noise are widespread and varied. Impacts can include sleep and speech interference, activity interference, general annoyance, and property value decrease. In order to improve public policy and provide a foundation for additional research, it is imperative to establish the extent of a problem. Dollars are often the least common denominator …


Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu Jan 2001

Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu

Theses

In an effort to improve tools in ecological risk assessment (ERA), an ERA software tool was developed and applied. Based on a preliminary evaluation of existing ecorisk models, the relative deficiencies were identified and included the need for a user-friendly interface, an interactive database management system (DBMS), and a comprehensive evaluation of exposure pathways. In this research, Visual Basic (VB) 6.0 and Microsoft SQL server were selected for developing the Windows-based interface and local DBMS, respectively. For the exposure estimate, Yuma and Aberdeen Proving Grounds were identified as baseline ecosystems. Terrestrial and aquatic plant and animal receptor selection was based …


Optimization Of Nitrogen Removal In Sequencing Batch Reactor, Suppakit Poonyachat Jan 2001

Optimization Of Nitrogen Removal In Sequencing Batch Reactor, Suppakit Poonyachat

Theses

Operating parameters for sequencing batch reactor have the influenceon each substrate concentration. Concentration profile changes as operationparameters are changed. The study was conducted to model the variationin effluent concentration from sequencing batch reactor. MLVSS and cycletime are the parameters that were varied. Concentration in Fill, React,and Settle Period were calculated by using kinetic equations.

The results can show that these parameters have effects on the concentrationprofile. The increase of MLVSS can lower the concentration of BOD andammonium concentration in React period. Increasing MLVSS can show thatmore substrate utilization and nitrification process occur more rapidly.Concentration of nitrate at the end of …


Webquests As An Integrative Experience In Introductory Environmental Engineering, Mary P. Cardenas Jan 2001

Webquests As An Integrative Experience In Introductory Environmental Engineering, Mary P. Cardenas

All HMC Faculty Publications and Research

An Integrative Experience was developed as part of an introductory environmental engineering course at Harvey Mudd College. The Integrative Experience was developed to help the college students consider the relationship of science and technology with contemporary society. Junior and senior students enrolled in the course designed WebQuests for middle school students. The WebQuests involved the integration of an environmental issue, problem, or technology and societal effects. WebQuests were designed for a middle school audience in order to expand the amount of engineering outreach that is done at the K-12 level. The HMC students chose WebQuests topics including nuclear and alternative …


Estimation Of Reference Crop Evapotranspiration Using Fuzzy State Models, Lameck O. Odhiambo, R. E. Yoder, D. C. Yoder Jan 2001

Estimation Of Reference Crop Evapotranspiration Using Fuzzy State Models, Lameck O. Odhiambo, R. E. Yoder, D. C. Yoder

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Daily evapotranspiration (ET) rates are needed for irrigation scheduling. Owing to the difficulty of obtaining accurate field measurements, ET rates are commonly estimated from weather parameters. A few empirical or semi–empirical methods have been developed for assessing daily reference crop ET, which is converted to actual crop ET using crop coefficients. The FAO Penman–Monteith method, which is now accepted as the standard method for the computation of daily reference ET, is sophisticated. It requires several input parameters, some of which have no actual measurements but are estimated from measured weather parameters. In this study, we examined the suitability of fuzzy …


Optimization Of Fuzzy Evapotranspiration Model Through Neural Training With Input–Output Examples, Lameck O. Odhiambo, R. E. Yoder, D. C. Yoder, J. W. Hines Jan 2001

Optimization Of Fuzzy Evapotranspiration Model Through Neural Training With Input–Output Examples, Lameck O. Odhiambo, R. E. Yoder, D. C. Yoder, J. W. Hines

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In a previous study, we demonstrated that fuzzy evapotranspiration (ET) models can achieve accurate estimation of daily ET comparable to the FAO Penman–Monteith equation, and showed the advantages of the fuzzy approach over other methods. The estimation accuracy of the fuzzy models, however, depended on the shape of the membership functions and the control rules built by trial–and–error methods. This paper shows how the trial and error drawback is eliminated with the application of a fuzzy–neural system, which combines the advantages of fuzzy logic (FL) and artificial neural networks (ANN). The strategy consisted of fusing the FL and ANN on …


Studies On The Pollution Parameters Of Leachate From Ampang Landfill, Syed Fatimah Kamal Batcha Jan 2001

Studies On The Pollution Parameters Of Leachate From Ampang Landfill, Syed Fatimah Kamal Batcha

Student Works (2000-2009)

ln the first part of the study, the characteristics of the leachate from Ampang landfill, collected before and after the landfill closure was analysed. In general, the characteristics of the Ampang landfill leachate was found to be typical of other landfill leachates in the Klang Valley. The analysis reveals that the Ampang landfill leachate during its active life had high contents of sodium, potassium, chloride and ferum, with concentrations of 687 ppm, 785 ppm, 2500 ppm and 45 ppm respectively. Generally and as expected, the leachate collected before the landfiII closure was found to be more concentrated and contains more …


Assessing Methodologies For Identification Of Significant Impacts In The Iso 14001 Ems (Environmental Management Systems), Ann Wye-Wye Wang Jan 2001

Assessing Methodologies For Identification Of Significant Impacts In The Iso 14001 Ems (Environmental Management Systems), Ann Wye-Wye Wang

Student Works (2000-2009)

ISO 14001 is a voluntary environmental management system specification standard in the ISO 14000 series. It contains those elements that must be satisfied by an organisation seeking registration or certification to the standard. Identification of significant environmental impacts is one of the requirements as stated in clause 4.3.1 of MS ISO 14001 EMS - specification with guidance for use, and is an important step in the implementation of ISO 14001 standard. A study on the methodologies for identification of significant environmental impacts in the ISO 14001 EMS (Environmental Management Systems) was carried out. Three methods that have been developed are …


Development Of A Physico-Chemical Wastewater Treatment Strategy For A Chemical Plant, T. Alagarajah K. Thavarajah Jan 2001

Development Of A Physico-Chemical Wastewater Treatment Strategy For A Chemical Plant, T. Alagarajah K. Thavarajah

Student Works (2000-2009)

A study was carried out to determine the physico-chemical treatment of the wastewater collected from a soap and detergent factory in Selangor, Malaysia. The study was initiated by determining the characteristics of the wastewater. Treatability studies involving coagulation and flocculation were determined by the jar test method. The parameters of interest were coagulant dosage, pH, mixing intensity, mixing time and settling time. The coagulants were restricted to alum and ferric sulfate and coagulant aids utilized were polyvinyl alcohol, sodium alginate and polycthylcninimine. An extended evaluation to determine the effect of double chemical treatment was also carried out with the most …


Comparative Performance Of Wastewater Treatment Plants In Three Rubber Glove Manufacturing Plants, Lee Kuan Loh Jan 2001

Comparative Performance Of Wastewater Treatment Plants In Three Rubber Glove Manufacturing Plants, Lee Kuan Loh

Student Works (2000-2009)

During the manufacturing of rubber gloves, water is used as wash water at different stages to clean the rubber gloves, thus generating quite a substantial amount of effluent. There are four main sources of effluent. i.e. a) from the glove formers cleaning tank, which collects the acidified water used to clean these formers, b) latex dipping tank, where it collects wash water used to cool the tank during dipping process and the sludge form the tank itself, c) leaching tank, where it collects wash water used to leach out the pollutants from the gloves and lastly d) latex compounding, containing …


Waste Management In Palm-Oleo Sdn. Bhd, Ramesh Ramasamy Jan 2001

Waste Management In Palm-Oleo Sdn. Bhd, Ramesh Ramasamy

Student Works (2000-2009)

Oleochemical industry in Malaysia has been diversifying significantly due to the availability of raw materials (palm oil) and the high demand for downstream products such as fatty acids, fatty alcohols and glycerine. The growth of oleochemical industries is further enhanced by fluctuations io petroleum price and regular animal diseases, which made tallow-based fats unreliable. Environmental awareness is growing rapidly in Malaysia. There is growing realization of the need to balance industrial and economic development with environmental preservation and protection, as well as, with efficient use of energy sources in order to achieve sustainable development. Extensive waste management studies were focused …


Performance Comparison Of A Roundabout Versus Two-Way Stop Controlled (Twsc) Intersections, Deogratias Eustace Dec 2000

Performance Comparison Of A Roundabout Versus Two-Way Stop Controlled (Twsc) Intersections, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The superior safety record of modern roundabouts is well known in Western Europe, Australia and in most British-influenced countries around the world. The experience from a single modern roundabout installed in the City of Manhattan, Kansas, some three years ago, also shares the same experience. A major study of the performance of Manhattan, Kansas, modern roundabout was conducted at Kansas State University (KSU) and was co-sponsored by Mac-Blackwell National Rural Transportation Study Center, Kansas State University, and the City of Manhattan. The study examined three intersections, one modern roundabout and two Two-Way Stop Controlled (TWSC) intersections with similar traffic conditions. …


Alternative Principal Components Regression Procedures For Dendrohydrologic Reconstructions, Hugo G. Hidalgo, Thomas C. Piechota, John A. Dracup Nov 2000

Alternative Principal Components Regression Procedures For Dendrohydrologic Reconstructions, Hugo G. Hidalgo, Thomas C. Piechota, John A. Dracup

Civil and Environmental Engineering and Construction Faculty Research

Streamflow reconstruction using tree ring information (dendrohydrology) has traditionally used principal components analysis (PCA) and stepwise regression to form a transfer function. However, PCA has several procedural choices that may result in very different reconstructions. This study assesses the different procedures in PCA-based regression and suggests alternative procedures for selection of variables and principal components. Cross-validation statistics are presented as an alternative for independently testing and identifying the optimal model. The objective is to use these statistics as a measure of the model's performance to find a conceptually acceptable model with a low prediction error and the fewest number of …


Environmental Evaluation Of Incinerators In Egypt & Waste Management Of Ash, Aya Mohamed Lamei Jul 2000

Environmental Evaluation Of Incinerators In Egypt & Waste Management Of Ash, Aya Mohamed Lamei

Archived Theses and Dissertations

No abstract provided.


Validation Of Passive Air Sampling Monitors Onboard United States Navy Submarines, Larry A. Mcfarland Jul 2000

Validation Of Passive Air Sampling Monitors Onboard United States Navy Submarines, Larry A. Mcfarland

Community & Environmental Health Theses & Dissertations

An operating submarine creates a unique air quality mixture of compounds that result from a combination of human metabolism, construction materials, materials brought onboard and compounds created through the interaction of ship systems. A comprehensive study of submarine atmospheres is ongoing during deployments of U.S. Navy nuclear submarines. As part of the overall effort, a paired air sampling comparison field validation was conducted to compare the air sampling effectiveness of passive diffusive monitors compared to more traditional active air sampling methods when sampling for acrolein, formaldehyde and ozone in the enclosed submarine atmosphere. Acrolein monitors containing 2-hydroxymethylpiperidine (HMP) impregnated glass …


Towards Quantification Of Active Sand Volume In The Nearshore Profile, Sukru Serkan Ozger Apr 2000

Towards Quantification Of Active Sand Volume In The Nearshore Profile, Sukru Serkan Ozger

Civil & Environmental Engineering Theses & Dissertations

An active sand volume concept is introduced for the first time in this study. The significance of this new concept and its possible practical uses for Coastal Engineering are discussed. A theory is proposed towards quantification of the active sand volume across a beach profile and the circumstances under which it should be defined are determined.

Next, a 12-year nearshore bathymetric data set surveyed at the Field Research Facility of the Army Corps of Engineers at Duck, NC is used to determine the hypothetical quantity of active volume. Statistical analysis of elevations at digitized cross-shore distances is performed and a …


A Buffered Advection/Dispersion Lake Water Quality Transport Framework For Modeling Lake Gaston Pipeline Intake Water Withdrawal, Lloyd Ashton Gatling Apr 2000

A Buffered Advection/Dispersion Lake Water Quality Transport Framework For Modeling Lake Gaston Pipeline Intake Water Withdrawal, Lloyd Ashton Gatling

Civil & Environmental Engineering Theses & Dissertations

Water quality response to reservoir water withdrawal is investigated in Pea Hill Arm of Lake Gaston, a non-tidal reservoir tributary, where the point of water withdrawal is in an upstream tributary and influences the direction of tributary flow causing longitudinal velocity null flow conditions to occur. The study also focuses on control of withdrawal rate and timing to optimize both quality of water remaining in the tributary and quantity of water that can be safely withdrawn.

Research was conducted assuming steady state conditions and later under spatial and temporal variability experienced in the reservoir with main lake pool elevation fluctuations …


In Situ Treatment Of Chlorinated Ethene-Contaminated Groundwater Using Horizontal Flow Treatment Wells, Derek R. Ferland Mar 2000

In Situ Treatment Of Chlorinated Ethene-Contaminated Groundwater Using Horizontal Flow Treatment Wells, Derek R. Ferland

Theses and Dissertations

The limitations of conventional containment technologies for groundwater contaminated with chlorinated solvents have motivated development of innovative technologies to achieve national groundwater remediation objectives. One inn9vative technology that is currently under development involves metal reductants or catalysts to chemically destroy the dissolved chlorinated solvent. Models are important tools that can be used to help transition this technology to the field. Model studies can be used to gain understanding about the technology, help determine when the prospective technology might work for a given site, and design full-scale field applications.


Modeling The Effect Of Nonlinear And Rate-Limited Sorption On The Natural Attenuation Of Chlorinated Ethenes, Peter P. Feng Mar 2000

Modeling The Effect Of Nonlinear And Rate-Limited Sorption On The Natural Attenuation Of Chlorinated Ethenes, Peter P. Feng

Theses and Dissertations

Chlorinated solvents like tetrachloroethene (PCE) and trichloroethene (TCE) are the most common detected groundwater contaminants at Department of Defense installations in the United States. Unfortunately, technologies conventionally used to remediate chlorinated solvent-contaminated groundwater often fall short of achieving regulatory goals. Natural attenuation of chlorinated solvents offers an alternative remediation strategy that may achieve goals. However, the processes involved with natural attenuation are not fully understood, and this lack of understanding has hindered acceptance of natural attenuation by regulatory agencies. This study involved use of a numerical model that incorporated the physical, chemical, and biological processes thought to be relevant to …


Use Of Genetic Algorithms To Characterize Groundwater Contamination Source Areas, Chaz M. Williamson Mar 2000

Use Of Genetic Algorithms To Characterize Groundwater Contamination Source Areas, Chaz M. Williamson

Theses and Dissertations

In this work, genetic algorithms (GAs) were used to help interpret tracer breakthrough curves from partitioning interwell tracer tests (PITTs) conducted at Hill AFB, Utah by researchers from the University of Florida. Two transport models were developed to simulate tracer transport in the test cells. One model assumed the cell consisted of multiple layers, and that transport in each layer could he described by the one-dimensional advective/dispersive equation. The second model also assumed multiple layers, and modeled transport in the individual layers as advective transport through 100 tubes. Transport times were represented by a stochastic (lognormal) distribution. The model solutions …