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2019

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Articles 1411 - 1440 of 1769

Full-Text Articles in Civil and Environmental Engineering

Use Of Ponded And Fresh Ashes From China For The Production Of Portland/Calcium Sulfoaluminate Clinkers, Tristana Y. Duvallet, Robert B. Jewell, Anne E. Oberlink, Thomas L. Robl, David Harris Jan 2019

Use Of Ponded And Fresh Ashes From China For The Production Of Portland/Calcium Sulfoaluminate Clinkers, Tristana Y. Duvallet, Robert B. Jewell, Anne E. Oberlink, Thomas L. Robl, David Harris

Coal Combustion and Gasification Products Journal Archive

This article summarizes the use of two fly ashes in the synthesis of Portland/calcium sulfoaluminate (OPC/CSA or A/CSA) clinkers. They are from the Shentou second power plant located in the Shanxi Province and from the Zhungeer power plant located in Inner Mongolia, China. The Zhungeer ash was collected dry, and the Shentou ash is from a pond. Their chemical compositions differ highly, especially the SiO2 and Al2O3 contents. The high contents of silica and alumina make both ashes candidates as a partial or total substitute for bauxite, an expensive source of alumina, in the production of OPC/CSA clinkers. These particular …

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The Use Of 3-D Highway Differential Geometry In Crash Prediction Modeling, Kiriakos Amiridis Jan 2019

The Use Of 3-D Highway Differential Geometry In Crash Prediction Modeling, Kiriakos Amiridis

Theses and Dissertations--Civil Engineering

The objective of this research is to evaluate and introduce a new methodology regarding rural highway safety. Current practices rely on crash prediction models that utilize specific explanatory variables, whereas the depository of knowledge for past research is the Highway Safety Manual (HSM). Most of the prediction models in the HSM identify the effect of individual geometric elements on crash occurrence and consider their combination in a multiplicative manner, where each effect is multiplied with others to determine their combined influence. The concepts of 3-dimesnional (3-D) representation of the roadway surface have also been explored in the past aiming to …

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Image-Based Roadway Assessment Using Convolutional Neural Networks, Weilian Song Jan 2019

Image-Based Roadway Assessment Using Convolutional Neural Networks, Weilian Song

Theses and Dissertations--Computer Science

Road crashes are one of the main causes of death in the United States. To reduce the number of accidents, roadway assessment programs take a proactive approach, collecting data and identifying high-risk roads before crashes occur. However, the cost of data acquisition and manual annotation has restricted the effect of these programs. In this thesis, we propose methods to automate the task of roadway safety assessment using deep learning. Specifically, we trained convolutional neural networks on publicly available roadway images to predict safety-related metrics: the star rating score and free-flow speed. Inference speeds for our methods are mere milliseconds, enabling …

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Quantifying The Impact Of Transportation Network Companies (Tncs) On Traffic Congestion In San Francisco, Sneha Roy Jan 2019

Quantifying The Impact Of Transportation Network Companies (Tncs) On Traffic Congestion In San Francisco, Sneha Roy

Theses and Dissertations--Civil Engineering

This research investigates whether Transportation Network Companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion by complementing transit and reducing car ownership in major cities. The objective of this research study is to answer the question: are TNCs are correlated to traffic congestion in the city of San Francisco? If found to be so, do they increase or decrease traffic congestion for the case of San Francisco? If and how TNC pickups and drop-offs impact traffic congestion within San Francisco? And finally, how does the magnitude of this measured command of TNCs on …

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Analysis Of The Pile Load Tests At The Us 68/Ky 80 Bridge Over Kentucky Lake, Edward Lawson Jan 2019

Analysis Of The Pile Load Tests At The Us 68/Ky 80 Bridge Over Kentucky Lake, Edward Lawson

Theses and Dissertations--Civil Engineering

Large diameter piles are widely used as foundations to support buildings, bridges, and other structures. As a result, it is critical for the field to have an optimized approach for quality control and efficiency purposes to measure the suggested number of load tests and the required measured capacities driven piles. In this thesis, an analysis of a load test program designed for proposed bridge replacements at Kentucky Lake is performed. It includes a detailed site exploration study with in-situ and laboratory testing. The pile load test program included monitoring of a steel H-pile and steel open ended pipe pile during …

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Investigation Of Atmospheric Effects On Vapor Intrusion Processes Using Modelling Approaches, Elham Shirazi Jan 2019

Investigation Of Atmospheric Effects On Vapor Intrusion Processes Using Modelling Approaches, Elham Shirazi

Theses and Dissertations--Civil Engineering

Most people in the United States (US) spend considerable amount of time indoors—about 90% of their time as compared to outdoors, which makes the US population vulnerable to adverse health effects of indoor air contaminants. Volatile organic compound (VOC) concentrations are well-known to be higher in indoor air than outdoor air. One source of VOC concentrations in indoor air that has gained considerable attention in public health and environmental regulatory communities is vapor intrusion. Vapor intrusion is the process by which subsurface vapors enter indoor spaces from contaminated soil and groundwater. It has been documented to cause indoor air contamination …

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Applied Fluid Mechanics Lab Manual, Habib Ahmari, Shah Md Imran Kabir Jan 2019

Applied Fluid Mechanics Lab Manual, Habib Ahmari, Shah Md Imran Kabir

Civil Engineering Faculty Publications - Archive

This lab manual provides students with the theory, practical applications, objectives, and laboratory procedure of ten experiments. The manual also includes educational videos showing how student should run each experiment and a workbook for organizing data collected in the lab and preparing result tables and charts.

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Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung Jan 2019

Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

In order to study the intensity of chemical weathering during the formation of sedimentary strata in the site profile, the evolution of climatic environment in the region where the site profile is located was revealed. The rubidium (Rb) and strontium (Sr) values in the rubidium (Rb) and strontium (Sr) were tested and analysed. The Rb/Sr ratio has become an ideal alternative indicator in the study of regional environmental evolution. The Rb value in the strata section of Zhongba site is low, and the average value (calculated based on 202 sample values) is only 80 g/g. The Sr value was higher, …

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Evaluate Probe Speed Data Quality To Improve Transportation Modeling, Fahmida Rahman Jan 2019

Evaluate Probe Speed Data Quality To Improve Transportation Modeling, Fahmida Rahman

Theses and Dissertations--Civil Engineering

Probe speed data are widely used to calculate performance measures for quantifying state-wide traffic conditions. Estimation of the accurate performance measures requires adequate speed data observations. However, probe vehicles reporting the speed data may not be available all the time on each road segment. Agencies need to develop a good understanding of the adequacy of these reported data before using them in different transportation applications. This study attempts to systematically assess the quality of the probe data by proposing a method, which determines the minimum sample rate for checking data adequacy. The minimum sample rate is defined as the minimum …

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E-Construction Technologies For Efficient Highway Construction Inspections, Dhaivat Patel Jan 2019

E-Construction Technologies For Efficient Highway Construction Inspections, Dhaivat Patel

Theses and Dissertations--Civil Engineering

Over recent years, organizations such as the Federal Highway Administration and Departments of Transportation across the United States have showed interest in automating highway construction processes. The addition of e-Construction and other advanced technologies can significantly improve the efficiency and safety of highway paving operations, specifically paving inspections. Activities such as collecting load tickets, tracking pavement lay-down temperatures, and monitoring roller movement are antiquated practices that DOT inspectors perform during paving operations. E-Ticketing, Paver Mounted Thermal Profiling, and Intelligent Compaction were proposed to automate paving inspections and were recently tested in two resurfacing pilot projects in the state of Kentucky. …

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Patellar Tendon Morphology In Trans-Tibial Amputees Utilizing A Prosthesis With A Patellar-Tendonbearing Feature, Kai-Yu Ho, Michelle Harty, Jessica Kellogg, Kelly Teter, Szu-Ping Lee, Yu-Jen Chang, Gregory Bashford Jan 2019

Patellar Tendon Morphology In Trans-Tibial Amputees Utilizing A Prosthesis With A Patellar-Tendonbearing Feature, Kai-Yu Ho, Michelle Harty, Jessica Kellogg, Kelly Teter, Szu-Ping Lee, Yu-Jen Chang, Gregory Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A patellar-tendon-bearing (PTB) bar is a common design feature used in the socket of trans-tibial prostheses to place load on the pressure-tolerant tissue. As the patellar tendon in the residual limb is subjected to the perpendicular compressive force not commonly experienced in normal tendons, it is possible for tendon degeneration to occur over time. The purpose of this study was to compare patellar tendon morphology and neovascularity between the residual and intact limbs in trans-tibial amputees and healthy controls. Fifteen unilateral trans-tibial amputees who utilized a prosthesis with a PTB feature and 15 age- and sex- matched controls participated. Sonography …

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Stochastic Cost-Optimization And Risk Assessment Of In Situ Chemical Oxidation For Dense Non-Aqueous Phase Liquid (Dnapl) Source Remediation, Ungtae Kim, Jack C. Parker, Robert C. Borden Jan 2019

Stochastic Cost-Optimization And Risk Assessment Of In Situ Chemical Oxidation For Dense Non-Aqueous Phase Liquid (Dnapl) Source Remediation, Ungtae Kim, Jack C. Parker, Robert C. Borden

Civil and Environmental Engineering Faculty Publications

This study involved development of a computer program to determine optimal design variables for in situ chemical oxidation (ISCO) of dense nonaqueous phase liquid (DNAPL) sites to meet site-wide remediation objectives with minimum life-cycle remediation cost while taking uncertainty in site characterization data and model predictions into consideration. A physically-based ISCO performance model computes field-scale DNAPL dissolution, instantaneous reaction of oxidant with contaminant and with readily oxidizable natural oxidant demand (NOD), second-order kinetic reactions for slowly oxidizable NOD, and time to reach ISCO termination criteria. Remediation cost is computed by coupling the performance model with a cost module. ISCO termination …

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Conceptual Groundwater Remedial Alternatives At Coal Combustion Residuals Sites†, Herwig Goldemund, Jeffrey M. Ahrens Jan 2019

Conceptual Groundwater Remedial Alternatives At Coal Combustion Residuals Sites†, Herwig Goldemund, Jeffrey M. Ahrens

Coal Combustion and Gasification Products Journal Archive

Groundwater below many basins that have been used to store coal combustion residuals (CCRs) may have concentrations of certain inorganic constituents in excess of applicable regulatory standards. Given that many inorganic CCR constituents are also naturally occurring in the aquifer matrix, their detection may not always be indicative of a release from the CCR unit. Inorganics may be present at elevated levels in groundwater due to natural or background conditions, or due to changes to the aquifer geochemistry resulting from the presence of the CCR basin, which then mobilizes these naturally occurring constituents beneath the CCR unit. Care must be …

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Fly Ash Composites, A Step Toward Pond Ash Composites, Kunigal N. Shivakumar, Wade H. Brown, Kazi A. Imran Jan 2019

Fly Ash Composites, A Step Toward Pond Ash Composites, Kunigal N. Shivakumar, Wade H. Brown, Kazi A. Imran

Coal Combustion and Gasification Products Journal Archive

The study demonstrated that ash composites made from polyurethane and fly ash are able to reduce leaching of coal ash inorganics to less than one-third of the U.S. Environmental Protection Agency’s maximum containment limit even after being exposed to an accelerated water circulation system for 14 months. Even if these ash blocks are broken, the composite is safe. The concept of encapsulation of fly ash into ash composite by using a polar polymer to bind the fine inorganic particles, as nature has done in the original unburned coal, makes the ash composite safe. The ash composites have compression and f …

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In Situ Characterization Of Mixture Of Fly Ash And Fluidized Gas Desulfurization By-Product At Tennessee Valley Authority’S Gallatin Ash Stacking Facility†, David J. White, Pavana Vennapusa, Brendan Fitzpatrick, Jason F. Hill, Nicholas Mcclung Jan 2019

In Situ Characterization Of Mixture Of Fly Ash And Fluidized Gas Desulfurization By-Product At Tennessee Valley Authority’S Gallatin Ash Stacking Facility†, David J. White, Pavana Vennapusa, Brendan Fitzpatrick, Jason F. Hill, Nicholas Mcclung

Coal Combustion and Gasification Products Journal Archive

This article presents the results of field and laboratory testing performed on a new coal combustion product (CCP) derived from a mixture of fly ash and dry fluidized gas desulfurization by-product at the Tennessee Valley Authority’s Gallatin Fossil Plant in Gallatin, TN. Field testing included geospatial mapping using a vibratory smooth drum roller instrumented with a validated intelligent compaction (VIC) system and by field testing to characterize elastic modulus, shallow shear wave velocity, moisture content, dry density, and shear strength properties. Field testing was performed in areas where the CCP had been placed several days before testing and in areas …

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Managing Springs Emanating From Coal Combustion Residual Disposal Impoundments, Mark L. Orzechowski, Daniel M. Tolmer Jan 2019

Managing Springs Emanating From Coal Combustion Residual Disposal Impoundments, Mark L. Orzechowski, Daniel M. Tolmer

Coal Combustion and Gasification Products Journal Archive

Affected springs emanating from coal combustion residual (CCR) disposal impoundments where “wet disposal” methods were employed is a typical issue that frequently needs to be addressed during operation and management of these facilities. Identifying potential effects on a spring is typically accomplished through regularly scheduled field reconnaissance and laboratory analyses. Analytical testing is performed to characterize the chemical constituents present in the spring water. The management approach employed for specific springs is developed on the basis of several factors, including chemical composition and flow rate of the spring water, regulatory requirements and discharge standards, available treatment technologies, facility operations, site …

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Shear Strength Of Coal Combustion Product By Vane Shear, Wesley J. Herweynen, Christopher A. Bareither, Joseph Scalia Jan 2019

Shear Strength Of Coal Combustion Product By Vane Shear, Wesley J. Herweynen, Christopher A. Bareither, Joseph Scalia

Coal Combustion and Gasification Products Journal Archive

The objective of this study was to evaluate the shear strength of a coal combustion product (CCP) by using the vane shear test. A series of small-scale vane shear (SS-VS; diameter = 12.7 mm and height = 25.4 mm) and large-scale vane shear (LS-VS; diameter = 25 mm and height = 50 mm) laboratory tests were conducted. Undrained and drained strength envelopes were determined using consolidated undrained triaxial compression tests, and drained strength was checked via consolidated drained direct shear. In addition, effects of (1) rate of vane rotation, (2) time delay between vane insertion and beginning rotation, and (3) …

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Mineralogy And Geochemistry Of Feed Coals And Combustion Residues From Tunçbilek And Seyitömer Coal-Fired Power Plants In Western Turkey, Ali Ihsan Karayigit, Ozlem Yigitler, Seda Iserli, Xavier Querol, Maria Mastalerz, Riza Gorkem Oskay, James C. Hower Jan 2019

Mineralogy And Geochemistry Of Feed Coals And Combustion Residues From Tunçbilek And Seyitömer Coal-Fired Power Plants In Western Turkey, Ali Ihsan Karayigit, Ozlem Yigitler, Seda Iserli, Xavier Querol, Maria Mastalerz, Riza Gorkem Oskay, James C. Hower

Coal Combustion and Gasification Products Journal Archive

This study focuses on the enrichment of elements in feed coal (FC) and combustion residues, namely, fly ash (FA) and bottom ash (BA) samples, picked up from the Tunçbilek and Seyitömer coal-fired power plants in western Turkey. The FCs in both plants have generally similar mineralogical compositions, although siderite and dolomite are more prominent in Tunçbilek and feldspar and pyrite are more abundant in Seyitömer. Minerals in the FA from both power plants are mainly quartz, hematite, magnetite, anhydrite, and mullite. Along with quartz, the Fe-oxides are dominant phases in the BA samples. Accessory minerals in the FCs, FAs, and …

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Phaselous Vulgaris Growth Under The Influence Of Manufactured Coal Ash Aggregates, Sangchul Hwang, Imiraily Hernandez, Isomar Latorre, Sahid Rosado Jan 2019

Phaselous Vulgaris Growth Under The Influence Of Manufactured Coal Ash Aggregates, Sangchul Hwang, Imiraily Hernandez, Isomar Latorre, Sahid Rosado

Coal Combustion and Gasification Products Journal Archive

Manufactured coal ash aggregates (MAs) are a 2:1 (w/w) solidified composite of fly and bottom ash. The current study assessed the feasibility of beneficial utilization of MAs as a subsoil substitute for open-pit restoration to phyto-viable land. A series of indoor and outdoor experiments examined Phaselous vulgaris growth under the influence of MAs in the soil environment. With the MAs layer below the topsoil, P. vulgaris showed enhanced growth with respect to shoot height, leaf number, and leaf chlorophyll intensity. Similar growth enhancement was observed when the MAs were mixed with topsoil or applied as a micronutrient source over the …

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Using The Conceptual Site Model To Efficiently And Effectively Implement Groundwater Monitoring And Corrective Action At Coal Combustion Residual Sites†, Carla Landrum, Jim Feild, Tim Glover, Alison Dunn Jan 2019

Using The Conceptual Site Model To Efficiently And Effectively Implement Groundwater Monitoring And Corrective Action At Coal Combustion Residual Sites†, Carla Landrum, Jim Feild, Tim Glover, Alison Dunn

Coal Combustion and Gasification Products Journal Archive

On 19 October 2015, the Disposal of Coal Combustion Residuals (CCRs) for Electric Utilities final rule (CCR Rule), issued by the U.S. Environmental Protection Agency (US EPA) under Subtitle D of the Recovery and Conservation Act (RCRA), became effective. The Groundwater Monitoring and Corrective Action subsections of the CCR Rule (40 CFR §§ 257.90–257.98) set out strict requirements for groundwater monitoring at the detection and assessment levels, followed by (if necessary) groundwater characterization in support of corrective measures assessment. Since the federal CCR Rule was implemented, the US EPA has proposed and finalized some amendments, and some states have proposed …

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The Role Of Ash Mineralogy On Breakthrough Pressure And Contact Angle: A Statistical Evaluation, Jenberu L. Feyyisa, John L. Daniels Jan 2019

The Role Of Ash Mineralogy On Breakthrough Pressure And Contact Angle: A Statistical Evaluation, Jenberu L. Feyyisa, John L. Daniels

Coal Combustion and Gasification Products Journal Archive

One method to minimize contaminant leaching from coal fly ash (CFA) involves modifying its surface to become water repellent. Five types of CFA, CFA-1, CFA-2, CFA-3, CFA-5, and CFA-6, were modified by three organosilane (OS) products at different mix ratios. Multiple breakthrough pressure (BP) experiments were conducted for different samples at different mix ratios to identify the performance of the modified surface to resist a positive water entry pressure. The contribution of oxides and minerals in CFA to form a water-repellent surface were analyzed without considering OS effects. Results showed that semi-log–transformed regression models can effectively establish the relationship between …

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South Africa’S Power Producer’S Revised Coal Ash Strategy And Implementation Progress, Kelley Reynolds-Clausen, Nico Singh Jan 2019

South Africa’S Power Producer’S Revised Coal Ash Strategy And Implementation Progress, Kelley Reynolds-Clausen, Nico Singh

Coal Combustion and Gasification Products Journal Archive

The South African electricity public utility Eskom has embarked on a process to increase utilisation of the ash produced through the electricity generation process at its coal-fired power stations. In the 2014–2015 financial year, 119.2 million tons of coal was consumed, producing 34.4 million tons (28.9%) of ash. About 7% of the Eskom ash is sold from 6 of the 13 coal-fired power stations. Many stations are currently running out of ash storage space, and expansion of the ash disposal facilities is required, which could affect security of supply because of limited ashing areas. Additionally, legislative requirements lead to extra …

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Disinfection By-Product Formation Potential Assessment For Central Florida Groundwater Supplies, Tulsi Shukla Jan 2019

Disinfection By-Product Formation Potential Assessment For Central Florida Groundwater Supplies, Tulsi Shukla

Electronic Theses and Dissertations

Disinfection of potable water supplies is a primary requirement of the United States' Environmental Protection Agency's (USEPA's) Safe Drinking Water Act. The use of chlorine as a disinfectant is widely accepted by water purveyors due to its effectiveness and low cost. However, chlorine reacts with natural organic matter present in water supplies to form suspected carcinogenic disinfection by-products (DBPs). In this work, the formation of the regulated chlorinated by-products total trihalomethanes (TTHMs) and haloacetic acids (HAA5) for eleven Central Florida wells has been investigated. Fluorescence, UV-254, dissolved organic carbon (DOC), specific UV absorbance (SUVA), chlorine decay, and TTHM and HAA5 …

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Basic Turbo Roundabouts As An Alternative To Conventional Double-Lane Roundabouts: Operational Performance Evaluation, Zuhair Elhassy Jan 2019

Basic Turbo Roundabouts As An Alternative To Conventional Double-Lane Roundabouts: Operational Performance Evaluation, Zuhair Elhassy

Electronic Theses and Dissertations

Conventional roundabouts have been prevalent worldwide since the emergence of modern roundabouts in 1966. An innovative design of multilane roundabouts known as turbo roundabouts, however, has been recently introduced as an alternative to conventional multilane roundabouts. Due to several reasons, there has been no general consensus on the operational performance of turbo roundabouts throughout the world. Nationwide, turbo roundabouts have yet to be part of roadway systems, but there is an ongoing project expected to be finished in early 2020. Therefore, this dissertation aims to evaluate the operational performance of a widespread variant of turbo roundabouts, namely basic turbo roundabouts, …

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Inventory Of Hazardous Materials Shipments Moving Into Fayette County, Kentucky, Candice Y. Wallace, Bryan Gibson, Steven Douglas Kreis Jan 2019

Inventory Of Hazardous Materials Shipments Moving Into Fayette County, Kentucky, Candice Y. Wallace, Bryan Gibson, Steven Douglas Kreis

Kentucky Transportation Center Research Report

Each day, significant quantities of hazardous materials are transported through Fayette County. The bulk of the materials pass through without incident, but some vehicles carrying them are involved in roadway incidents and/or accidents. However, first responders and management personnel lack clear knowledge of what hazardous material commodities are on central Kentucky’s roads. This project was designed to provide a high level analysis of hazardous material commodity flows in Fayette County.

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Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield Jan 2019

Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield

Civil and Environmental Engineering Faculty Publications and Presentations

Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the …

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Evaluation Of Shared Space To Reduce Traffic Congestion, Kimley Frosch, David Martinelli, Avinash Unnikrishnan Jan 2019

Evaluation Of Shared Space To Reduce Traffic Congestion, Kimley Frosch, David Martinelli, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

Pedestrian and vehicle interactions often lead to conflicts that bring about safety, traffic congestion, and priority or right of way issues. Common methods used in the past to combat said issues have largely relied on the principle of separating the motions of pedestrians and vehicles by means of bridges, tunnels, signals, and access restrictions. A different approach known as shared space aims to solve the same problems with a less structured and defined environment which instead places more reliance on human interaction and perception. Although it has been used in multiple scenarios across Europe with success, instances of shared spaces …

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The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors Jan 2019

The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Scientists and engineers have observed for some time that tidal amplitudes at many locations are shifting considerably due to non-astronomical factors. Here we review comprehensively these important changes in tidal properties, many of which remain poorly understood. Over long geological time-scales, tectonic processes drive variations in basin size, depth, and shape, and hence the resonant properties of ocean basins. On shorter geological time-scales, changes in oceanic tidal properties are dominated by variations in water depth. A growing number of studies have identified widespread, sometimes regionally-coherent, positive and negative trends in tidal constituents and levels during the 19th, 20th and early …

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Investigate An Appropriate Spatial Resolution For Large-Scaled Pedestrian Travel Demand Model, Qin Zhang, Kelly Clifton, Rolf Moeckel Jan 2019

Investigate An Appropriate Spatial Resolution For Large-Scaled Pedestrian Travel Demand Model, Qin Zhang, Kelly Clifton, Rolf Moeckel

Civil and Environmental Engineering Faculty Publications and Presentations

An appropriate spatial resolution plays a significant role in any travel demand models. It directly impacts the level of detail of model input data, outcomes, and sensitivities (Castiglione et al., 2014; Moeckel and Donnelly, 2015). Compared to motorized or bicycle travel, pedestrian trips occur over a shorter travel distance and they are sensitive to environmental conditions at a much finer grain. Thus, it is important for models to set an appropriate spatial resolution to capture variations in walking conditions, leading to better representation of pedestrian demand over space (Gehrke and Clifton, 2014).

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Observational Method And Coding Framework For Analyzing The Functionality Of Unprotected Bicycle Lanes, Cat Silva, Kelly Clifton, Rolf Moeckel Jan 2019

Observational Method And Coding Framework For Analyzing The Functionality Of Unprotected Bicycle Lanes, Cat Silva, Kelly Clifton, Rolf Moeckel

Civil and Environmental Engineering Faculty Publications and Presentations

This research evaluates how well unprotected bicycle lanes function as dedicated travel lanes for bicyclists. Two types of bicycle lanes are included in this study, including on-street bicycle lanes demarcated with painted lines on the vehicular roadway and bicycle lanes at-grade with, and immediately adjacent to, the pedestrian sidewalk. Specifically, the research is focused on how people behave and interact on street segments with these facilities in place. To assess how, and how well, these types of bicycle lanes function for the bicyclists using them, an observational method is deployed to record, document, and analyze people’s behavior and interactions. A …

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