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2021

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Articles 901 - 930 of 1621

Full-Text Articles in Civil and Environmental Engineering

Flexural Strengthening Of Two-Way Slabs Using Cfrp External Laminates, Shams Abbas Naqvi May 2021

Flexural Strengthening Of Two-Way Slabs Using Cfrp External Laminates, Shams Abbas Naqvi

Civil Engineering Theses - Archive

Deterioration of reinforced concrete structures with time is a common phenomenon, which often leads to reduction in the load carrying capacity. To meet the coding requirements, strengthening of these structures is of utmost importance. Composite materials, such as Carbon Fiber Reinforced Polymers (CFRP), have shown effective results in external strengthening of these structures. However, premature delamination of CFRPs can decrease their efficiency. Recently, pre-saturated CFRP (PS-CFRP), a new type of CFRP pre-impregnated with epoxy resin, was introduced. Previous research has shown that PS-CFRP has shown improved results as compared to regular CFRP (R-CFRP) for strengthening beams and columns. However, no …


Investigating Topologic And Geometric Properties Of Synthetic And Natural River Networks Under Changing Climate, Shiblu Sarker May 2021

Investigating Topologic And Geometric Properties Of Synthetic And Natural River Networks Under Changing Climate, Shiblu Sarker

Electronic Theses and Dissertations, 2020-2023

River networks are important landscape features that collect and transport water, sediment and nutrients from regions of higher elevation to lower elevations. These networks have been studied for several decades from a range of geomorphological and hydrological perspectives. Investigating the geometric and topological properties of river networks is important for developing predictive models describing the network dynamics under changing climate as well as for quantifying the physical processes operating upon them. Although these networks have been characterized for a wide range of geomorphic properties, topological properties, and in particular, spectral properties of river networks received limited attention. In this dissertation, …


Valorization Of Secondary Agriculture Residues, Narendra Kumar May 2021

Valorization Of Secondary Agriculture Residues, Narendra Kumar

Doctoral Dissertations

Secondary agriculture residues have the potential to be major contributors as resources for energy and sustainably sourced materials production. Separating secondary agricultural residues, which have already been transported to processing centers, into individual biomass components could convert these wastes into bioproducts. Many types of pretreatments to achieve this separation involve chemicals that are hazardous for the environment. Several deep eutectic solvents (DES) that are biocompatible have been investigated for their ability to deconstruct rice hulls and sugarcane bagasse. Mass yield, enzymatic hydrolysis of the pretreated biomass, fiber analysis, and Fourier transform infrared spectroscopy have confirmed that the DES formic acid:choline …


Evaluation Of Recycled Plastic Pins As Shear Keys In Mse Wall Base, Prabesh Bhandari May 2021

Evaluation Of Recycled Plastic Pins As Shear Keys In Mse Wall Base, Prabesh Bhandari

Civil Engineering Dissertations - Archive

Mechanically Stabilized Earth (MSE) walls have been widely used as retaining structures due to their flexible nature, a better tolerance against differential settlement, and many other factors. However, external stability problems of MSE walls have been an issue in North Texas over decades. Lateral displacement of the wall occurs, giving rise to sliding failure, when there is insufficient shear strength at the wall base to produce adequate frictional resistance. Such failures can cause significant maintenance, repair, and cost implications for the state department of transportation. Furthermore, MSE walls also undergo global failure due to weak soil conditions along with high …


Meta-Network Analysis Of Complex Construction Systems: Improving Project Efficiency Using Novel Computer-Based Analytic Methodology, Ethan Cummiskey May 2021

Meta-Network Analysis Of Complex Construction Systems: Improving Project Efficiency Using Novel Computer-Based Analytic Methodology, Ethan Cummiskey

Honors Scholar Theses

The objective of this study is to build upon the framework of a meta-network approach to assessing vulnerabilities in construction projects. By viewing these complex environments as configurations of various nodes and links, it is possible to show the relationship between each entity in the project and the overall completion that is achieved from these connections. To expand upon previous studies, the vulnerabilities measured from this approach will be used to optimize the current network to eliminate any shortcoming in the project model. By investigating the congruence of different agents on the project, resources and informational nodes can be supplied …


On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Aly Mousaad Aly, Faiaz Khaled May 2021

On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Aly Mousaad Aly, Faiaz Khaled

Faculty Publications

Large-eddy simulation (LES) has proven to offer superior accuracy in regards to predicting surface pressures compared to the Reynolds-averaged Navier Stokes (RANS) models. However, the primary impediment is the high computational cost associated with LES. The authors attempt to investigate the computational cost and accuracy by employing different sub-grid scale (SGS) models in LES and hybrid RANS-LES models. One of the prerequisites of accurate pressure estimations is to ensure a horizontally homogeneous empty computational domain. This study aims to compare the computational competence qualitatively and quantitatively using an empty domain in regards to the ability to maintain horizontal homogeneity. The …


Analysis, Modeling, And Simulation (Ams) Case Studies Of Connected And Automated Vehicle (Cav) Implementations Specific To The South Central Region, Christopher Melson, Jiaqi Ma May 2021

Analysis, Modeling, And Simulation (Ams) Case Studies Of Connected And Automated Vehicle (Cav) Implementations Specific To The South Central Region, Christopher Melson, Jiaqi Ma

Data

Connected and automated vehicles (CAVs) offer potentially transformative and far-reaching impacts to the transportation system. However, realized benefits will be directly tied to how well agencies prepare for these technologies. This report documents efforts that support CAV preparatory actions in Louisiana and includes: (1) conducting a stakeholder survey to inform engagement activities to develop strategic partnerships in CAV deployment and (2) conducting crash analyses for deployment scenarios of CAV-based queue warning systems (QWSs).

An electronic survey was developed and disseminated to 273 Louisiana organizations. The purpose of the survey was to engage these organizations under the context of CAV planning …


Risk And Safety Associated With Hazardous Materials Transport In Rural And Native American Communities: A Case Study Of Thurston County, Nebraska, Sydney James May 2021

Risk And Safety Associated With Hazardous Materials Transport In Rural And Native American Communities: A Case Study Of Thurston County, Nebraska, Sydney James

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

Rural counties and Native American Reservations often lack the resources and planning to respond to a hazardous material release which can cause catastrophic results. Many rural counties and Native American Reservations do not have close access to a fire department or medical facility, which would increase response times during a time of crisis. Jurisdiction issues further complicate the matter since Native American Reservations are sovereign nations,.

Thurston County, home to two Native American Reservations, served as a case study to perform a safety analysis for vehicles transporting hazardous material. Stakeholders within the county from tribal, county, and state levels were …


Analysis Of Shear-Strength In Weathered Shale Strata Along A Highway Slope Failure Site In Northwest Arkansas, Olivia Overton May 2021

Analysis Of Shear-Strength In Weathered Shale Strata Along A Highway Slope Failure Site In Northwest Arkansas, Olivia Overton

Civil Engineering Undergraduate Honors Theses

Slope failures cost millions of dollars per year to repair and can be deadly. Accurate modeling of slope conditions, including soil parameters, water table locations, and depth to bedrock, are essential to determining the overall stability of a slope. This project is a continuation of the work completed in 2019 by a former University of Arkansas researcher, Vanessa LeBow. LeBow RocScience used Slide2 modeling software to model two highway embankment slopes in Northwest Arkansas that experienced slope movement to determine whether increased use of geophysical data could increase the accuracy of slope stability models. A parametric study of shear strengths …


Modeling And Monitoring Of Water Quantity And Quality In Permeable Pavement Systems Using Geophysical Equipment, Abby Klimowicz May 2021

Modeling And Monitoring Of Water Quantity And Quality In Permeable Pavement Systems Using Geophysical Equipment, Abby Klimowicz

Honors Scholar Theses

Permeable pavements are a type of low impact development (LID) that reduces runoff by increasing the permeability of developed surfaces. Less runoff helps protect the surrounding ecosystems from erosion and pollution. Without pools of accumulating runoff, the potential for the development of ice on roads and parking lots is also decreased. However, sufficient research on the movement of water and the ions dissolved in it through the permeable pavement system has not been completed. In this study, geophysical equipment was used to observe how moisture, measured as volumetric water content (VWC), and ions, approximated by electrical conductivity, pass through constructed …


Household Income And Air Pollution At Public Schools In The United States, Katyland Facas, Kristina Wagstrom May 2021

Household Income And Air Pollution At Public Schools In The United States, Katyland Facas, Kristina Wagstrom

Honors Scholar Theses

Poor air quality at schools may negatively impact students’ academic performance.1 2 3 In this study we look at the relationship between ambient, outdoor air quality and student socioeconomic status at United States public schools. We used free and reduced lunch eligibility, as part of the USDA’s National School Lunch Program, as an indicator of household income. We focus on nitrogen dioxide (NO2), ozone (O3), and particulate matter smaller than 2.5 microns (PM2.5). We used ambient pollutant concentration estimates at census block group resolution (Kim et al.) as the outdoor air pollution concentration at each school.4 We found a positive …


Project Management Research Support, Bryan Gibson, Jeff Jasper, Robin Baskette, Christopher Van Dyke, Doug Kreis May 2021

Project Management Research Support, Bryan Gibson, Jeff Jasper, Robin Baskette, Christopher Van Dyke, Doug Kreis

Kentucky Transportation Center Research Report

Like many state transportation agencies, the Kentucky Transportation Cabinet (KYTC) faces unprecedented challenges related to project development and management. Staff losses due to attrition and retirements have resulted in the loss of institutional knowledge. Early- to mid-career project managers (PMs) shoulder more responsibilities than ever while being expected to deliver over 600 successful projects each year. To improve the efficiency of project management, PMs must be able to access effective project management concepts, tools, and strategies which are field validated. Recognizing the importance of strengthening its project management capabilities, the Cabinet asked the Kentucky Transportation Center (KTC) to provide ongoing …


Evaluation Of Conventional Energy Conservation Strategies And Active Thermal Insulation Wall System And Economic Analyses., Li Liu May 2021

Evaluation Of Conventional Energy Conservation Strategies And Active Thermal Insulation Wall System And Economic Analyses., Li Liu

Electronic Theses and Dissertations

For the past few decades, the importance and the technology of building energy conservation is increasing. In support of this research into energy efficiency, the Department of Energy has developed simulation models of sixteen buildings representing most commercial buildings in the US. In this research, four of these sixteen prototype models were used in energy conservation analyses variety of energy conservation strategies in the seven US Climate Zones. To estimate the effectiveness of several common energy conservation measures on yearly building energy use, holistic analyses were conducted using software that accounts for the interactions of the building systems, occupants and …


A Spatial Analysis Of Supply-Demand Of Public Transportation In Jefferson County, Kentucky., Nastaran Abdoli May 2021

A Spatial Analysis Of Supply-Demand Of Public Transportation In Jefferson County, Kentucky., Nastaran Abdoli

Electronic Theses and Dissertations

Public transportation is important as it serves individuals, especially the transit-dependent population, by providing a basic mobility service to these people and all others who rely on public transportation. This research utilized estimating public transportation demand and supply to analyze the spatial patterns of public transportation in Jefferson County, Kentucky. The study focuses on the transit-dependent population, and it considers indicators of age, poverty status, vehicle ownership, and foreign-born population with less than five years residency in the United States. This study conducted a public transit supply-demand analysis to identify areas with imbalanced supply and demand in Jefferson County at …


Cross Domain Iw Threats To Sof Maritime Missions: Implications For U.S. Sof, Gary C. Kessler, Diane M. Zorri May 2021

Cross Domain Iw Threats To Sof Maritime Missions: Implications For U.S. Sof, Gary C. Kessler, Diane M. Zorri

Publications

As cyber vulnerabilities proliferate with the expansion of connected devices, wherein security is often forsaken for ease of use, Special Operations Forces (SOF) cannot escape the obvious, massive risk that they are assuming by incorporating emerging technologies into their toolkits. This is especially true in the maritime sector where SOF operates nearshore in littoral zones. As SOF—in support to the U.S. Navy— increasingly operate in these contested maritime environments, they will gradually encounter more hostile actors looking to exploit digital vulnerabilities. As such, this monograph comes at a perfect time as the world becomes more interconnected but also more vulnerable.


Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis May 2021

Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis

Biological and Agricultural Engineering Undergraduate Honors Theses

Residential adoption of low-impact development (LID) technology can positively impact downstream watershed hydrology by reducing total volumetric discharge from the residential site. This reduction can provide economic, environmental, and social benefits for the residents as well as the community at large. Additionally, homeowners are often affected by stormwater related issues, like flooding or washout, that could be easily mitigated with a sustainably engineered LID structure or network. Engineering for sustainability often includes the blending of several objectives to provide greater overall benefit. This thesis compares the outflow characteristics of three low-maintenance residential LID design scenarios differing in rain garden soil …


Developing Lrfd Side Shear And End Bearing Resistance Factors For Design Of Axially Loaded Drilled Shafts In Soil Containing Caliche Layers Using The Monte Carlo Approach, Visar Farhangi May 2021

Developing Lrfd Side Shear And End Bearing Resistance Factors For Design Of Axially Loaded Drilled Shafts In Soil Containing Caliche Layers Using The Monte Carlo Approach, Visar Farhangi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Conventional design and construction procedures of the drilled shafts (bored piles) are mainly developed for homogenous soils in the absence of highly cemented layers. However, the presence of competent and cementitious layers such as caliche deposits in soil profile can affect the resistance and settlement of pile foundations. This study concerns with the uncertainties on the resistance estimation of axially loaded drilled shafts in interaction with caliche layers The prime objective is to calibrate the side shear and end bearing resistance factors of axially loaded drilled shafts based on the soil characteristics of Nevada. The load-settlement responses of axially loaded …


Behavior Of Aged Reinforced Concrete Columns Under High Sustained Concentric And Eccentric Loads, Wenchen Ma May 2021

Behavior Of Aged Reinforced Concrete Columns Under High Sustained Concentric And Eccentric Loads, Wenchen Ma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Columns are critical components resisting the collapse of a reinforced concrete (RC) frame structure subjected to high sustained loads. Research on columns under sustained high stresses is very limited. At material level, past creep tests were focused either on concrete with ages less than 90 days or under a sustained stress less than 70% of short-time strength. At structural component scale, virtually no experimental data can be found for the response of axially loaded RC columns subjected to high sustained loads exceeding 75% of column short-time strength with loading age greater than 200 days. Even if a few experiments were …


Investigation Of Bench-Scale Packed Bioreactor For Perchlorate Reduction In The Presence Of Co-Contaminants And High Salinity, Julia Ribeiro Rabello May 2021

Investigation Of Bench-Scale Packed Bioreactor For Perchlorate Reduction In The Presence Of Co-Contaminants And High Salinity, Julia Ribeiro Rabello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Perchlorate (ClO4-), commonly found as a salt, is naturally occurring in nature and is found in natural nitrate deposits (such as the Chilean nitrate). Perchlorate anion is considered an inhibitor of iodine by the thyroid gland, reducing the production of thyroid hormones. The latest action by the USEPA was to not determine a national drinking water standard for perchlorate. However, the states still have their own regulations on perchlorate concentration in drinking water. Contaminated sites with high concentrations of perchlorate (ppm levels) are associated with historic perchlorate manufacture and use, while those with low concentrations (ppb levels) are found in …


On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Faiaz Khaled, Aly Mousaad Aly May 2021

On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Faiaz Khaled, Aly Mousaad Aly

Faculty Publications

No abstract provided.


Improving Operational Hydrologic Forecasting Via Conditional Bias-Penalized Multi-Sensor Precipitation Estimation And Multi-Model Streamflow Prediction, Ali Jozaghi May 2021

Improving Operational Hydrologic Forecasting Via Conditional Bias-Penalized Multi-Sensor Precipitation Estimation And Multi-Model Streamflow Prediction, Ali Jozaghi

Civil Engineering Dissertations - Archive

Many multivariate analysis techniques involve minimizing mean square error (MSE) or error variance under unbiasedness. In the presence of observation error, variance minimization tends to introduce negative and positive biases, or conditional bias (CB), over the upper and lower tails of the predictands, respectively. This work describes and evaluates three multivariate merging techniques, 1) adaptive conditional bias-penalized cokriging (CBPCK), 2) conditional bias-penalized Multiple Linear Regression (CBP-MLR), and 3) conditional bias-penalized Bayesian Model Averaging (CBP-BMA) which implements CBP-MLR in place of MLR. CBPCK and CBP-MLR minimize a linearly weighted sum of errors squared and the sum of the Type-II error squared, …


Feasibility Study: Alternatives To Prevent Settlements And Bumps At Bridge Approach, Seunghee Kim, Jongwan Eun, Yusuf Alhowaidi, Daniel Robertson May 2021

Feasibility Study: Alternatives To Prevent Settlements And Bumps At Bridge Approach, Seunghee Kim, Jongwan Eun, Yusuf Alhowaidi, Daniel Robertson

Nebraska Department of Transportation: Research Reports

This project aims to examine the feasibility of improving the current design practice of the approach slab foundation in Nebraska and the alternative of using geosynthetic reinforcement of soils to prevent the bump issues near the end of bridge approaches via an in-depth numerical simulation study. A large-scale pullout test is also conducted as complementary to provide input parameters for the interaction between the regional soil and selected geosynthetics. Based on the results, it is recommended that the number of grade beam piles could be reduced to 40-50 % of the total number of abutment piles while maintaining the same …


Evaluating Asct Operations For Dodge Street Corridor, Anuj Sharma, Subhadipto Poddar, Atousa Zarindast, Christopher Day May 2021

Evaluating Asct Operations For Dodge Street Corridor, Anuj Sharma, Subhadipto Poddar, Atousa Zarindast, Christopher Day

Nebraska Department of Transportation: Research Reports

As Adaptive Traffic Control (ATC) is increasingly being implemented by various traffic agencies, careful evaluation is needed of the degree to which a given ATC implementation improves traffic signal performance. The present study details the evaluation of ATC for two arterial corridors in the City of Omaha, Nebraska. Several performance measures were used across two stages of ATC implementation as well as during the unanticipated COVID-19 lockdown stage.

The average travel time and variability in travel time showed that Stage 1 of ATC implementation in Omaha did not improve traffic signal performance for the study’s main corridor, Dodge Street. This …


When It Rains, It Pours: A Case Study Of Spatio-Temporal Variations In High-Intensity Precipitation Events In Arkansas, Deanna Mantooth-Hendrix May 2021

When It Rains, It Pours: A Case Study Of Spatio-Temporal Variations In High-Intensity Precipitation Events In Arkansas, Deanna Mantooth-Hendrix

Graduate Theses and Dissertations

Climate change is having an impact on weather systems and ecosystems worldwide. Glaciers are receding, oceans are acidifying, hurricanes are stronger, and extreme precipitation is increasing in frequency. Even with the wealth of data and knowledge about the threat of climate change, some places are slow to adapt because they think that the impact to their ecosystem will not be severe. The goal of this project was to determine if climate change is having an impact on extreme precipitation in the top urban areas of Arkansas. The major concern with an increase in extreme events in urban areas is flooding. …


Urban Arterial Lane Flow Distribution: A Before And After Traffic Microsimulation Analysis On The Effect Of Implementing New Route Markings And Signage., Larry Michael Summers May 2021

Urban Arterial Lane Flow Distribution: A Before And After Traffic Microsimulation Analysis On The Effect Of Implementing New Route Markings And Signage., Larry Michael Summers

Electronic Theses and Dissertations

Urban arterials may not effectively utilize available lanes to move vehicles efficiently as drivers try to establish position along the corridor. This study evaluates lane flow distribution before and after implementing new route markings and overhead signs to utilize existing lanes better. A cellphone-based traffic data service called StreetLight gathered the traffic data used to establish the VISSIM model parameters for simulating current and projected conditions. This study shows that the lane assignment signage and route markers affected the lane flow distribution in the simulation. The simulation indicated the existing condition had average queue lengths of 320.6 meters, average travel …


Thermo-Hydro-Mechanical Characterization Of Ottawa Sand And Kaolin Clay Through Experimental Models., Mohammad Joshaghani May 2021

Thermo-Hydro-Mechanical Characterization Of Ottawa Sand And Kaolin Clay Through Experimental Models., Mohammad Joshaghani

Electronic Theses and Dissertations

Recent advances in energy geotechnics and increased utilization of ground source heat pump systems (e.g., geothermal boreholes and energy y piles) and energy geo-structures require improving the understanding of the thermo-hydro-mechanical behavior of soil. Energy geo-structures consist of above-ground facilities, buried structures, and the soil surrounding the buried structure. A buried structure transfers the energy between the ground and above-ground facilities. Energy transfer between above-ground facilities and the soil will cause temperature changes in soil and this will affect soil hydro-mechanical properties. The changes in soil temperature can also significantly alter the soil-structure interaction and its mechanical strength. Soil temperature …


Effects Of Flow Path Factors In The Permeability Of Natural And Man-Made Granular Soils Using The Kozeny-Carman Equation, Robert Davies May 2021

Effects Of Flow Path Factors In The Permeability Of Natural And Man-Made Granular Soils Using The Kozeny-Carman Equation, Robert Davies

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The research presented in this paper serves to observe how the flow path factors relate to the void ratio, the effective diameter of a soil particle, and the permeability of a given sample assuming the behavior is consistent across natural and artificial soils. The basis of the comparison is the derived Kozeny-Carman Equation for permeability with focus on the factors Cs and Cl where Cs represents the shape of the flow path and Cl represents the length of the flow path that a single water molecule must travel through a soil sample. Permeameter tests were conducted …


Evaluating The Effects Of Seismic Loading On Concrete Reinforced Versus Precast Concrete Slab Floor Systems, Mahima Maharjan May 2021

Evaluating The Effects Of Seismic Loading On Concrete Reinforced Versus Precast Concrete Slab Floor Systems, Mahima Maharjan

Honors Theses

This thesis is part of the senior design capstone project of Ole Miss Department of Civil Engineering. The seismic loadings for the commercial buildings project located in Oxford, Mississippi are evaluated to fulfill the honor thesis requirement. This thesis follows the codes from American Concrete Institute (ACI), International Building Code (IBC), and ASCE-7/SEI (Minimum Design Loads and Associated Criteria for Buildings and Other Structures/Structural Engineering Institute) to design the gravitational loadings and seismic loadings.

Furthermore, a reinforced concrete slab flooring system is replaced with a precast slab flooring system to analyze the most seismic performance effective floor system for the …


Design Of Load Bearing Wall For Low Rise Building With Partially Grouted Reinforced Masonry, Anil Bhatt May 2021

Design Of Load Bearing Wall For Low Rise Building With Partially Grouted Reinforced Masonry, Anil Bhatt

Honors Theses

The seismic and wind load acting on the 2-storeyed building of dimension 120 ft x 98 ft located in Oxford, MS, were calculated and the seismic load was considered for the design of the 120 ft long and 24 ft high load-bearing wall because it being critical. The maximum loading was computed using different load combinations. The masonry behavior and masonry specifications were considered to select the masonry unit, grout, and mortar for the load-bearing wall. The seismic design requirement for the shear and slender wall was fulfilled for the special reinforced masonry wall. The in-plane and out-of-plane loading scenarios …


Bridge Prioritization And Preservation Along Route 66, Sarah Ballard May 2021

Bridge Prioritization And Preservation Along Route 66, Sarah Ballard

Open Access Theses & Dissertations

Eligible bridges around the United States receive federal funding every year for replacement or rehabilitation. The main criterion for allocation of this funding is based on engineering aspects (e.g., life safety, condition, functionality), often leaving the historical value of the bridge at the bottom of the importance level. One of the main historical roads known in America is Route 66, also known as the â??Mother Road.â?? This route was the road to opportunity in the 1930s. Many bridges with historical significance carry the route and represent an integral part of the history of the Mother Road. This research analyzes bridges …