Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 10171 - 10200 of 39816

Full-Text Articles in Civil and Environmental Engineering

Arsenic Release From Surface Soils Induced By Stormwater Bioretention, Kaisa H. Patterson May 2020

Arsenic Release From Surface Soils Induced By Stormwater Bioretention, Kaisa H. Patterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Arsenic is a naturally occurring element known for its chronic and acute toxicity. The solubility of arsenic is highly dependent on environmental conditions. The soils of Cache Valley, UT, contain naturally occurring arsenic.

Bioretention systems rely on a combined plant-soil system to remove pollutants carried by stormwater, typically nitrogen, phosphorus, dissolved organic carbon, and select metals. Phosphate from stormwater potentially increases arsenic mobility, which makes stormwater pollutant loading an important factor for evaluating risks associated with stormwater bioretention. Pollutant removal in these systems occurs through sorption of contaminants onto the soils, physical filtration by the soil media, and uptake by …


Nonpoint Source Pollution Control Using A Multi-Objective Optimization Tool For Best Management Practices Selection And Spatial Placement In The Lower Bear River Watershed, Utah, Ali A. Salha May 2020

Nonpoint Source Pollution Control Using A Multi-Objective Optimization Tool For Best Management Practices Selection And Spatial Placement In The Lower Bear River Watershed, Utah, Ali A. Salha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation presents a set of approaches to help address water quality problems related to total phosphorus loads in water bodies. Water quality degradation is caused by many nonpoint sources such as agricultural runoff, fertilizers applications, and bank erosion. Three studies present methodologies for water quality protection from degradation in watersheds. The first study demonstrates the application of a watershed simulation tool that can quantify flows in the watershed, the amount of released pollutants and identify the areas contributing to the pollutants’ release in the watershed. The second study presents a simple combination tool that can pair potential management practices …


Experimental Static And Cyclic Behavior Of Hybrid Non-Metallic Bridge Decks Reinforced With Discrete Gfrp Rebar And Gfrp Macrofiber, Jared W. Mcrory May 2020

Experimental Static And Cyclic Behavior Of Hybrid Non-Metallic Bridge Decks Reinforced With Discrete Gfrp Rebar And Gfrp Macrofiber, Jared W. Mcrory

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bridge deck corrosion is a major expense in the U.S. every year. The increased use of deicing salts in cold weather climates has led to corrosion of the steel reinforcement in bridge decks, which leads to spalling and delamination of the concrete cover. This results in costly rehabilitations or repairs, and more sustainable bridge deck solutions must be provided to prevent this cycle.

As a part of this research project, a corrosion-resistant, hybrid reinforcement strategy that is shown to be cost neutral with epoxy coated rebar is proposed. The hybrid reinforcement strategy, consisting of discrete Glass Fiber Reinforced Polymer (GFRP) …


Estimation Of Interior And Contents Damage Due To Wind Driven Rain Ingress Into Mid/High-Rise Buildings, Zhuoxuan Wei May 2020

Estimation Of Interior And Contents Damage Due To Wind Driven Rain Ingress Into Mid/High-Rise Buildings, Zhuoxuan Wei

Theses and Dissertations

Hurricanes can lead to the loss of millions of dollars and the death of hundreds of people. The increasing concentration of people in coastal cities, exacerbates this problem and results in greater hurricane damage to residential buildings. In particular, recent hurricanes in Florida have shown the vulnerability of mid/high-rise buildings (MHRB) to hurricane-induced water ingress. However, few damage models are able to produce realistic estimates of interior damage. To accurately estimate the interior and contents damage of mid/high-rise buildings due to water ingress during hurricanes, this thesis proposes a new physics-based methodology, which extends the results of previous work on …


Quantitative Resistance Assessment Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon Apr 2020

Quantitative Resistance Assessment Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The blast resistance of a typical reinforced concrete bridge pier column design was modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. While varying concrete strength, amount of longitudinal reinforcing steel, and gravity load, the effect of applying an externally bonded steel fiber reinforced polymer (SFRP) wrapping was assessed. The presented approach uniquely quantifies column blast resistance in terms of charge weight. It was found that blast capacity was roughly linearly related to concrete strength and steel reinforcement ratio, the former of which is most influential. It was further found that a single layer of …


Final Report - Uav-Enabled Measurement For Spatial Magnetic Field Of Smart Rocks In Bridge Scour Monitoring, Genda Chen, Haibin Zhang, Zhaochao Li Apr 2020

Final Report - Uav-Enabled Measurement For Spatial Magnetic Field Of Smart Rocks In Bridge Scour Monitoring, Genda Chen, Haibin Zhang, Zhaochao Li

Project SN-1

This project proposed an unmanned aerial vehicle (UAV)-based method to measure the change in magnetic field as a result of the movement of a smart rock to monitor the maximum depth of bridge scour. A high resolution 3-axis magnetometer and global positioning system (GPS) unit were installed on the UAV to obtain the magnetic field intensity and its corresponding coordinate. The optimization algorithm for the localization of smart rock was demonstrated and adopted. The impact factors on accurate smart rock positioning were experimentally investigated. Utilizing finite element method, the influence of steel reinforcing bars on the distribution of ambient magnetic …


Final Report - In-Line Long Period Grating And Brillouin Scattering Fiber Optic Sensors For Strain, Temperature, Chloride Concentration, And Steel Mass Loss Measurement In Bridge Applications, Genda Chen, Chuanrai Guo Apr 2020

Final Report - In-Line Long Period Grating And Brillouin Scattering Fiber Optic Sensors For Strain, Temperature, Chloride Concentration, And Steel Mass Loss Measurement In Bridge Applications, Genda Chen, Chuanrai Guo

Project SN-3

This project developed an in-line grating and scattering fiber optic sensing system for strain, temperature, and steel mass loss measurement in bridge applications. Long period fiber gratings (LPFG) sensors are responsive to thermal and mechanical deformation, and the refractive index change of their surrounding medium. Brillouin scattering sensors are responsive to temperature and strain along an optical fiber. A CO2 laser aided fiber grating system was assembled for LPFG fabrication. To enable mass loss measurement, a low pressure chemical vapor deposition (LPCVD) system was built to synthesize a graphene/silver nanowire composite film as flexible transparent electrode for the electroplating of …


Chehalis River And Tributary Water Quality And Hydrodynamic Modeling: Model Setup, Calibration Analysis For 2013-2015, Tel Jensen Apr 2020

Chehalis River And Tributary Water Quality And Hydrodynamic Modeling: Model Setup, Calibration Analysis For 2013-2015, Tel Jensen

Dissertations and Theses

The Chehalis River is located in southwest Washington State. Its headwaters are in the Willapa Hills, and it drains parts of the Doty Hills, the western foothills of the Cascade Mountains, and the southern Olympic Mountains. The Chehalis River is over 125 miles long and its basin is over 2000 square miles spanning parts of seven counties and diverse land uses.

CE-QUAL-W2 is a widely used two-dimensional (vertical and longitudinal) hydrodynamic and water quality model developed by the US Army Corp of Engineers and the Water Quality Research Group at Portland State University. Version 4.2 includes the ability to run …


Resilience Engineering: Theory And Practice, Michaela Jones Apr 2020

Resilience Engineering: Theory And Practice, Michaela Jones

Civil Engineering ETDs

Civil and environmental engineering works at the interface of humans and the natural environment, making the environment hospitable for people and limiting adverse anthropogenic impacts on the ecosystem. Such socioecological systems are often complex and highly interconnected, and traditional engineering interventions focused on optimizing system elements result in unanticipated consequences. Resilience engineering utilizes a holistic methodology grounded in systems analysis and adaptation. This work broadly explores the concept of resilience engineering and contextualizes the approach using the case study of the Rio Chama. The resilience of the watershed is characterized in terms of its response to both traditional and resilience …


Investigation Of Activated Carbon And Protein Polysaccharide Amendments In Capping Applications For Sediment Remediation, Mehdi Begag Apr 2020

Investigation Of Activated Carbon And Protein Polysaccharide Amendments In Capping Applications For Sediment Remediation, Mehdi Begag

Honors Scholar Theses

Contaminated sediment is a major environmental problem in numerous sites across the US and requires costly treatment to effectively remediate the sediment and prevent contaminants from entering the water column. Capping of contaminated sediment has emerged as the preferred treatment design as it is more cost effective and effectively isolates the contaminants in-situ. Powdered Activated Carbon (PAC) is commonly introduced in capping designs due to its high sorption capacity of organic contaminants. However, its low bulk density and fine particle size result in significant carbon resuspension during cap placement. This report provides experimental and modeling results focused on the effects …


Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer Apr 2020

Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The vulnerability of soil toward erosion might be reduced by having a good vegetative cover over the soil surface, slope improvement, and improving soil properties so that it is not easily detached and transported. However, the establishment of proper vegetative cover is a long process because it takes time for seeds to germinate and attain maturity. As an alternative approach, if soil resistance was increased by increasing the shear strength of soil against erosive forces offered by eroding agents, the soil system would become capable of withstanding the detachment of its particles on the application of shear stress. To achieve …


Effects Of Cyclic Heating And Water Cooling On The Physical Characteristics Of Granite, Xiangchao Shi, Leiyu Gao, Jie Wu, Cheng Zhu, Shuai Chen, Xiao Zhuo Apr 2020

Effects Of Cyclic Heating And Water Cooling On The Physical Characteristics Of Granite, Xiangchao Shi, Leiyu Gao, Jie Wu, Cheng Zhu, Shuai Chen, Xiao Zhuo

Henry M. Rowan College of Engineering Departmental Research

This paper aims to study the effect of cyclic heating and flowing-water cooling conditions on the physical properties of granite. Ultrasonic tests, gas measured porosity, permeability, and microscope observations were conducted on granite after thermal treatment. The results showed that the velocity of P- and S-waves decreased as the number of thermal cycles increased. The porosity increased with the number of the thermal cycles attained at 600 °C, while no apparent changes were observed at 200 and 400 °C. The permeability increased with the increasing number of thermal cycles. Furthermore, microscope observations showed that degradation of the granite after thermal …


Effect Of Micropiles On Clean Sand Liquefaction Risk Based On Cpt And Spt, Visar Farhangi, Moses Karakouzian, Marten Geertsema Apr 2020

Effect Of Micropiles On Clean Sand Liquefaction Risk Based On Cpt And Spt, Visar Farhangi, Moses Karakouzian, Marten Geertsema

Civil and Environmental Engineering and Construction Faculty Research

Liquefaction is a hazardous seismic-based phenomenon, which causes an abrupt decrease in soil strength properties and can result in the massive destruction of the built environment. This research presents a novel approach to reduce the risk of soil liquefaction using jet-grouted micropiles in clean sands. The saturated soil profile of the study project mainly contains clean sands, which are suitable to more reliably employ simplified soil liquefaction analyses. The grouting is conducted using 420 micropiles to increase the existing soil properties. The effect of jet grouting on reducing the potential of liquefaction is assessed using the results of the cone …


Load Truncation Approach For Development Of Live Load Factors For Bridge Rating, Sasan Siavashi, Christopher D. Eamon Apr 2020

Load Truncation Approach For Development Of Live Load Factors For Bridge Rating, Sasan Siavashi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

Various local governments have developed state-specific vehicular live load factors for bridge rating. However, a significant computational demand is often associated with such an effort. This is due to the large size of the weigh-in-motion (WIM) databases frequently used in the procedure. In this study, a method is proposed that can significantly reduce the computational cost of the analysis, while still maintaining reasonable accuracy. The proposed approach develops approximate live load random variable statistics by truncating the WIM database based on gross vehicle weight, then a complete reliability analysis is conducted to develop new live load factors that meet AASHTO-specified …


Energy Dissipation Of Type A Piano Key Weirs, Kam R. Eslinger, Brian M. Crookston Apr 2020

Energy Dissipation Of Type A Piano Key Weirs, Kam R. Eslinger, Brian M. Crookston

Publications

A Piano Key weir (PK weir) is a nonlinear, labyrinth-type weir well suited for rehabilitation projects due to a relatively small footprint and the ability to pass large discharges for lesser upstream-head values when compared with other weir types. A critical component of a hydraulic structure is the energy-dissipative properties. Currently, information and guidance is limited, with previous energy dissipation studies of PK weirs primarily of specific projects. Therefore, to document and quantify energy dissipation, four laboratory-scale Type A PK weir models with different width ratios (Wi/Wo) were studied, with 255 tests comprising this new …


Reliability-Calibrated Ann-Based Load And Resistance Factor Load Rating For Steel Girder Bridges, Francisco Garcia Apr 2020

Reliability-Calibrated Ann-Based Load And Resistance Factor Load Rating For Steel Girder Bridges, Francisco Garcia

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This research aimed to develop a supplemental ANN-based tool to support the Nebraska Department of Transportation (NDOT) in optimizing bridge management investments when choosing between refined modeling, field testing, retrofitting, or bridge replacement. ANNs require an initial investment to collect data and train a network, but offer future benefits of speed and accessibility to engineers utilizing the trained ANN in the future. As the population of rural bridges in the Midwest approaching the end of their design service lives increases, Departments of Transportation are under mounting pressure to balance safety of the traveling public with fiscal constraints. While it is …


Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, Tami M. Brown-Bandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda Apr 2020

Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, Tami M. Brown-Bandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at …


Civil Engineering And Construction News, Georgia Southern University Apr 2020

Civil Engineering And Construction News, Georgia Southern University

Civil Engineering & Construction: News & Publications (2011-2022)

  • ASCE Student Chapter Wins GeoWall Challenge


The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi Apr 2020

The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Plug-in electric vehicles (PEVs) play a significant role in the development of green cities since they generate less pollution than conventional vehicles. To promote PEV adoption and mitigate range anxiety, charging infrastructure should be deployed at strategic locations that are readily accessible to the public. Nebraska is working on the expansion of charging infrastructure around the state; however, stakeholders face several difficulties in trying to minimize irregular charging behaviors. Most electric vehicle users plug in and leave their vehicles for an extended time at public parking lots designated for PEVs. Some users even leave their vehicles for longer than 24 …


A Prescriptive Criterion For Amphibious Foundation Design, Erin Hughes Apr 2020

A Prescriptive Criterion For Amphibious Foundation Design, Erin Hughes

Master of Science in Civil Engineering Theses

Flooding is the most frequently occurring natural disaster in the United States and worldwide (FEMA, 2004). Each year, when major flooding ravishes communities, residents are put in danger and often displaced from their homes and jobs for several weeks or months, if not more. The use of amphibious structures as a flood risk mitigation technique has currently only been implemented in individual or small-scale development. Information on the structural design of such buildings is limited and most of the current knowledge regarding amphibious structures is presented in architectural applications. The primary objective of this research is to develop a prescriptive …


Sensitivity Analysis Of Data-Driven Groundwater Forecasts To Hydroclimatic Controls In Irrigated Croplands, Alessandro Amaranto, Francesca Pianosi, Dimitri Solomatine, Gerald Corzo-Perez, Francisco Munoz-Arriola Apr 2020

Sensitivity Analysis Of Data-Driven Groundwater Forecasts To Hydroclimatic Controls In Irrigated Croplands, Alessandro Amaranto, Francesca Pianosi, Dimitri Solomatine, Gerald Corzo-Perez, Francisco Munoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In the last decades, advancements in computational science have greatly expanded the use of artificial neural networks (ANNs) in hydrogeology, including applications on groundwater forecast, variable selection, extended lead-times, and regime-specific analysis. However, ANN-model performance often omits the sensitivity to ob- servational uncertainties in hydroclimate forcings. The goal of this paper is to implement a data-driven modeling framework for assessing the sensitivity of ANN-based groundwater forecasts to the uncertainties in observational inputs across space, time, and hydrological regimes. The objectives are two-folded. The first objective is to couple an ANN model with the PAWN sensitivity analysis (SA). The second objective …


Biological Systems Engineering, Asmaa Abdella, Fernando Segato, Mark R. Wilkins Apr 2020

Biological Systems Engineering, Asmaa Abdella, Fernando Segato, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (kLa) for efficient xylanase production was found to be 38.6 h1. Fed batch mode and repeated batch fermentation was also performed with kLa was 38.6 h1. …


P-Y Curve Of Small-Spaced Row Piles Subjected To Lateral Loads In Marine Clay, Runze Xue, Shean Bie, Linlin Guo Apr 2020

P-Y Curve Of Small-Spaced Row Piles Subjected To Lateral Loads In Marine Clay, Runze Xue, Shean Bie, Linlin Guo

Journal of Marine Science and Technology–Taiwan

Newly proposed pile wall frame structures (PWFSs), notably with small-spaced row piles, have great potential for cofferdams of artificial islands applied for oil recovery in shallow seas. Studies have been called to analyze the bearing performance of small-spaced row piles subjected to lateral loads. A numerical investigation of laterally loaded row piles with small pile spacing was conducted to achieve a fitted algebraic expression of the P-Y curve. Significantly different from the hyperbolic P-Y curves of a single pile reported in other studies, the P-Y curve of small-spaced row piles is similar to an elastic–perfectly plastic curve, which simply depends …


Decision-Support System For Lid Footprint Planning And Urban Runoff Mitigation In The Lower Rio Grande Valley Of South Texas, Javier Guerrero, Taufiqul Alam, Ahmed Mahmoud, Kim D. Jones, Andrew Ernest Apr 2020

Decision-Support System For Lid Footprint Planning And Urban Runoff Mitigation In The Lower Rio Grande Valley Of South Texas, Javier Guerrero, Taufiqul Alam, Ahmed Mahmoud, Kim D. Jones, Andrew Ernest

Civil Engineering Faculty Publications

To address regional flooding in the United States, federal and state agencies are adopting strict drainage policies in any large-scale commercial development within the watershed boundary. The conventional approach of implementing a wet detention pond (WP) reduces the land cover and causes operation and maintenance challenges eventually. The present study developed a decision-support system (DSS) in the Lower Rio Grande Valley region of South Texas for optimal selection of Best Management Practices (BMPs) by substituting a portion of the WP footprint with three regionally promising low-impact development practices, namely, porous concrete pavement (PCP), bioretention (BR), and bioswale (BS). Source Load …


The Siltcatcher: A Sediment-Capture System For Wetland Creation And Coastal Protection In Western Lake Pontchartrain, Andrew M. Wright Apr 2020

The Siltcatcher: A Sediment-Capture System For Wetland Creation And Coastal Protection In Western Lake Pontchartrain, Andrew M. Wright

LSU Master's Theses

The West Lake Pontchartrain region faces a number of long-term environmental challenges due to anthropogenic climate disturbance and landscape modification, including sea level rise, increased storm surge risk, shoreline erosion, and wetland degradation. In response, this thesis applies recent research in the fields of landscape architecture and civil engineering to propose a dynamic, natural-systems solution for wetland creation and shoreline protection. The project envisions a series of breakwater-like structures in western Lake Pontchartrain positioned to slow water released from the nearby Bonnet Carré Spillway, causing suspended sediment to settle and create self-building and self-sustaining wetlands capable of keeping pace with …


Polyester Polymer Concrete For Bridge Deck Overlays, Robert James Stevens Apr 2020

Polyester Polymer Concrete For Bridge Deck Overlays, Robert James Stevens

Theses and Dissertations

The objectives of this research were to 1) compile a synthesis of information about polyester polymer concrete (PPC) from the literature; 2) conduct a scanning tour to observe PPC construction, inspect in-service PPC overlays, and discuss topics related to PPC; 3) revise the existing Utah Department of Transportation (UDOT) PPC specification; 4) document a PPC field demonstration project; and 5) perform laboratory characterization of the material properties of field-mixed PPC. The scope of the research included a scanning tour, field testing, and laboratory experimentation. The objectives of the scanning tour included observation of a PPC overlay placement, inspection of existing …


Pavement Management System Research Output: A Scientometric Assessment, Shabir Hussain Khahro, Zubair Ahmed Memon, Nur Izzi Md. Yusoff Dr, Lillian Gungat, Muhamad Razuhanafi Mat Yazid Apr 2020

Pavement Management System Research Output: A Scientometric Assessment, Shabir Hussain Khahro, Zubair Ahmed Memon, Nur Izzi Md. Yusoff Dr, Lillian Gungat, Muhamad Razuhanafi Mat Yazid

Library Philosophy and Practice (e-journal)

Developing countries are struggling with cost management of pavement construction and rehabilitation. This case is similar to developedcountries butdeveloping countries are suffering issues of inadequate funds. Therefore, most of the countries started usage of Pavement Management Systems (PMS) to manage the decision-making process and alternate/priority assessments for pavement construction and rehabilitation. Hence, the PMS remains the topic of research interest for various researchers. This paper evaluates the scale and effectiveness of articles published by Web of Science (WoS) Group on PMS since 1990. The data has been collected from the WoS database from 1990 till 2020. The datawas processedand analyzed …


Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen Apr 2020

Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen

LSU Doctoral Dissertations

The Mississippi River Delta is threatened by a growing pressure to support large human populations in the United States both with food production, navigation systems, and urban development in the Mississippi River Basin. Nitrate-nitrogen load in the Mississippi River, up to 100 Tg N yr-1 from agricultural and urban runoff, leads to phytoplankton blooms and hypoxia across the Louisiana continental shelf, creating dead zones of low dissolved oxygen threatening a significant commercial fishery. Along the coast and river corridors, floodplain ecosystems have the capacity to retain and remove nitrate. This dissertation explores the role of productive, actively growing coastal …


Real-Time Pm10 Emission Rates From Paved Roads By Measurement Of Concentrations In The Vehicle's Wake Using On-Board Sensors Part 1. Scamper Method Characterization, Dennis R. Fitz, Kurt Bumiller, Charles Bufalino, David E. James Apr 2020

Real-Time Pm10 Emission Rates From Paved Roads By Measurement Of Concentrations In The Vehicle's Wake Using On-Board Sensors Part 1. Scamper Method Characterization, Dennis R. Fitz, Kurt Bumiller, Charles Bufalino, David E. James

Civil and Environmental Engineering and Construction Faculty Research

Based on emission factors derived from the AP-42 algorithm, particulate matter from paved roads has been estimated to be a major source of PM10 of geologic origin. This is an empirical formula based on upwind-downwind measurement of PM10 concentrations and is dependent solely on the silt loading of the pavement and the weight of vehicles. A number of upwind-downwind studies conducted in urban areas to validate this algorithm have been generally inconclusive because the PM10 concentration difference between upwind and downwind often is within the measurement uncertainty. In the approach presented here PM10 concentrations were measured directly behind a moving …


Constitutive Models For Dynamic Strain Aging In Metals: Strain Rate And Temperature Dependences On The Flow Stress, Yooseob Song, Daniel Garcia-Gonzalez, Alexis Rusinek Apr 2020

Constitutive Models For Dynamic Strain Aging In Metals: Strain Rate And Temperature Dependences On The Flow Stress, Yooseob Song, Daniel Garcia-Gonzalez, Alexis Rusinek

Civil Engineering Faculty Publications

A new constitutive model for Q235B structural steel is proposed, incorporating the effect of dynamic strain aging. Dynamic strain aging hugely affects the microstructural behavior of metallic compounds, in turn leading to significant alterations in their macroscopic mechanical response. Therefore, a constitutive model must incorporate the effect of dynamic strain aging to accurately predict thermo-mechanical deformation processes. The proposed model assumes the overall response of the material as a combination of three contributions: athermal, thermally activated, and dynamic strain aging stress components. The dynamic strain aging is approached by two alternative mathematical expressions: (i) model I: rate-independent model; (ii) model …