Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Subsurface drainage (2)
- 3D printing (1)
- Academic (1)
- Additive manufacturing (1)
- Agriculture (1)
-
- Anaerobic digestion (1)
- Analytic hierarchy process (1)
- Audio signal processing (1)
- Bayesian statistics (1)
- Braided tube (1)
- Bridge (1)
- Bridge Inspection (1)
- Bridges (1)
- CFD (1)
- COD (1)
- Carbon dioxide (1)
- Clay (1)
- Clay barrier (1)
- Community energy (1)
- Computational fluid dynamic (1)
- Concrete (1)
- Connected vehicles (1)
- Construction heavy equipment (1)
- Controlled drainage (1)
- Crop (1)
- Curve Calculation (1)
- Curve Identification (1)
- DEM (1)
- Damage Quantification (1)
- Delaware basin (1)
Articles 31 - 60 of 62
Full-Text Articles in Engineering
Improving Safety Under Reduced Visibility Based On Multiple Countermeasures And Approaches Including Connected Vehicles, Yina Wu
Electronic Theses and Dissertations
The effect of low visibility on both crash occurrence and severity is a major concern in the traffic safety field. Different approaches were utilized in this research to analyze the effects of fog on traffic safety and evaluate the effectiveness of different fog countermeasures. First, a "Crash Risk Increase Indicator (CRII)" was proposed to explore the differences of crash risk between fog and clear conditions. A binary logistic regression model was applied to link the increase of crash risk with traffic flow characteristics. Second, a new algorithm was proposed to evaluate the rear-end crash risk under fog conditions. Logistic and …
Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik
Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik
Electronic Theses and Dissertations
Stadiums, pedestrian bridges, dance floors, and concert halls are distinct from other civil engineering structures due to several challenges in their design and dynamic behavior. These challenges originate from the flexible inherent nature of these structures coupled with human interactions in the form of loading. The investigations in past literature on this topic clearly state that the design of flexible structures can be improved with better load modeling strategies acquired with reliable load quantification, a deeper understanding of structural response, generation of simple and efficient human-structure interaction models and new measurement and assessment criteria for acceptable vibration levels. In contribution …
Assessing Interactions Between Estuary Water Quality And Terrestrial Land Cover In Hurricane Events With Multi-Sensor Remote Sensing, Chandan Mostafiz
Assessing Interactions Between Estuary Water Quality And Terrestrial Land Cover In Hurricane Events With Multi-Sensor Remote Sensing, Chandan Mostafiz
Electronic Theses and Dissertations
Estuaries are environmentally, ecologically and environmentally important places as they act as a meeting place for land, freshwater and marine ecosystems. They are also called nurseries of the sea as they often provide nesting and feeding habitats for many aquatic plants and animals. These estuaries also withstand the worst of some natural disasters, especially hurricanes. The estuaries as well as the harbored ecosystems undergo significant changes in terms of water quality, vegetation cover etc. and these components are interrelated. When hurricane makes landfall it is necessary to assess the damages as quickly as possible as restoration and recovery processes are …
Evaluating Filter Materials For E. Coli Removal From Stormwater, Ghaem Hooshyari
Evaluating Filter Materials For E. Coli Removal From Stormwater, Ghaem Hooshyari
Electronic Theses and Dissertations
Stormwater runoff from agricultural and urban areas carries a wide range of pollutants and pathogens that can negatively affect surface water bodies and cause significant risks to the ecosystem and public health. Bacteria is one of the pollutants carried by stormwater, and Escherichia coli (E. coli) is commonly used as a microbial pollution indicator of surface water. The aim of this research was to investigate the removal of E. coli from stormwater using low-cost filter materials. Two industrial byproducts (steel slag and steel chips) and two natural minerals (zeolite and limestone) with three different sizes (0.5-1 mm, 1-2 mm, and …
The Effectiveness Of Child Restraint And Bicycle Helmet Policies To Improve Road Safety, Claudia Bustamante
The Effectiveness Of Child Restraint And Bicycle Helmet Policies To Improve Road Safety, Claudia Bustamante
Electronic Theses and Dissertations
Analyzing the effect of legislation in children's safety when they travel as motor-vehicle passengers and bicycle riders can allow us to evaluate the effectiveness in transportation policies. The Child Restraint Laws (CRL) and Bicycle Helmet Laws (BHL) were studied by analyzing the nationwide Fatality Analysis Reporting System (FARS) to estimate the fatality reduction as well as drivers' decisions to use Child Restraint Systems (CRS) and bicycle helmets respectively. Differences in legislation could have different effects on traffic fatalities. Therefore, this study presents multiple methodologies to study these effects. In the evaluation of traffic safety issues, several proven statistical models have …
Physical Hydrogeological Modeling Of Florida's Sinkhole Hazard, Adam Perez
Physical Hydrogeological Modeling Of Florida's Sinkhole Hazard, Adam Perez
Electronic Theses and Dissertations
Sinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole states. The scope of this study is to develop a physical model to simulate sinkholes (referred to as a sinkhole simulator), which can assess the qualitative …
Glulam Timber Bridges For Local Roads, Zachary Charles Carnahan
Glulam Timber Bridges For Local Roads, Zachary Charles Carnahan
Electronic Theses and Dissertations
The most common type of bridges on South Dakota (SD) local roads are prestressed precast double-tee bridges. Currently, there is only one double-tee girder manufacturer in South Dakota (SD). In an attempt to provide more bridge type selection options for local governments, a study was performed at South Dakota State University to investigate the feasibility and performance of new types of single-span bridges suitable for local loads with low traffic. In one part of the study, Mingo (2016) developed a fully precast bridge incorporating full-depth deck-panels and prestressed inverted bulb-tee girders. The study presented in this thesis was performed to …
Extreme Weather Disaster Resilient Port And Waterway Infrastructure For Sustainable Global Supply Chain, Quang Van Nguyen
Extreme Weather Disaster Resilient Port And Waterway Infrastructure For Sustainable Global Supply Chain, Quang Van Nguyen
Electronic Theses and Dissertations
Global supply chain is largely dependent on seaports and marine terminals. Ports serve international cargo traffic for imports and exports. About 90% of the world’s goods are transported by sea and over 70% as containerized cargo ships. Coastal hurricanes/cyclones and rainfall flood disasters cause major disruptions for sea shipping traffic, disruptions of port infrastructure, and adverse impacts on coastal communities each year. Additionally, these weather related disasters threaten millions of people, damage infrastructure, and cost billions of dollars in global supply chain disruptions. Sustainable global supply chains, port infrastructure, and coastal community impact by these extreme weather disasters are the …
Integrating The Macroscopic And Microscopic Traffic Safety Analysis Using Hierarchical Models, Qing Cai
Integrating The Macroscopic And Microscopic Traffic Safety Analysis Using Hierarchical Models, Qing Cai
Electronic Theses and Dissertations
Crash frequency analysis is a crucial tool to investigate traffic safety problems. With the objective of revealing hazardous factors which would affect crash occurrence, crash frequency analysis has been undertaken at the macroscopic and microscopic levels. At the macroscopic level, crashes from a spatial aggregation (such as traffic analysis zone or county) are considered to quantify the impacts of socioeconomic and demographic characteristics, transportation demand and network attributes so as to provide countermeasures from a planning perspective. On the other hand, the microscopic crashes on a segment or intersection are analyzed to identify the influence of geometric design, lighting and …
Analysis Of Pedestrian Safety Using Micro-Simulation And Driving Simulator, Jiawei Wu
Analysis Of Pedestrian Safety Using Micro-Simulation And Driving Simulator, Jiawei Wu
Electronic Theses and Dissertations
In recent years, traffic agencies have begun to place emphasis on the importance of pedestrian safety. In the United States, nearly 70,000 pedestrians were reported injured in 2015. Although the number only account for 3% of all the people injured in traffic crashes, the number of pedestrian fatalities is still around 15% of total traffic fatalities. Furthermore, the state of Florida has consistently ranked as one of the worst states in terms of pedestrian crashes, injuries and fatalities. Therefore, it is befitting to focus on the pedestrian safety. This dissertation mainly focused on pedestrian safety at both midblock crossings and …
Wrong-Way Driving: A Regional Approach To A Regional Problem, Md. Omar Faruk
Wrong-Way Driving: A Regional Approach To A Regional Problem, Md. Omar Faruk
Electronic Theses and Dissertations
Wrong-way driving (WWD) has been problematic on United States highways for decades despite its rare occurrence. Since WWD crashes are rare, recent researchers have studied WWD non-crash events such as WWD 911 calls and WWD citations to understand the overall nature and trend of WWD. This paper demonstrates the regional nature of the WWD problem and proposes regional transportation systems management and operations (Regional TSM&O) solutions to combat this problem. Specifically, it was found that 11% of all WWD multi-data events (e.g., multiple 911 calls for the same WWD event) traveled from one county to another. Additionally, 30% of all …
Rehabilitation Of Longitudinal Joints In Double-Tee Girder Bridges, Lucas Michael Bohn
Rehabilitation Of Longitudinal Joints In Double-Tee Girder Bridges, Lucas Michael Bohn
Electronic Theses and Dissertations
Prefabricated bridge elements have become an essential part of accelerated bridge construction (ABC), which is an emerging technology to expedite bridge construction. Among several bridge girder types, precast double-tee girders are common on county bridges in South Dakota because of the ease of construction, the reduced construction time, and the potentially lower overall cost. However, the longitudinal joints of these bridges are rapidly deteriorating with many needing replacement before the expected 75- year service life. Research was conducted at South Dakota State University (SDSU) to develop, construct, and evaluate the performance of rehabilitation methods on this type of bridge. Current …
Biological Nutrient Removal (Bnr) Process Optimization And Recovery Of Embedded Energy Using Biodiesel By-Product, Sultan Salamah
Biological Nutrient Removal (Bnr) Process Optimization And Recovery Of Embedded Energy Using Biodiesel By-Product, Sultan Salamah
Electronic Theses and Dissertations
Enhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the biological nutrient removal (BNR) system that can be fermented to provide the desired VFAs. Glycerol (biodiesel by-product) offers a solution to reduce carbon …
Polyurethane Fiber Reinforced Polymer Strengthening Of Shear Deficient Reinforced Concrete Beams, Yasir Al-Lebban
Polyurethane Fiber Reinforced Polymer Strengthening Of Shear Deficient Reinforced Concrete Beams, Yasir Al-Lebban
Electronic Theses and Dissertations
The use of externally-bonded fiber-reinforced polymer (FRP) composites has been established as an effective means for the strengthening of shear-deficient reinforced concrete (RC) flexural members. Epoxy-based wet layup systems were predominantly employed in previous studies. In this study, carbon FRP pre-impregnated with polyurethane resin is utilized in strengthening shear-deficient RC beams and compared to an epoxy resin. Fourteen small-scale (96 in span, 6 in width, and 12 in height) and five large-scale (132 in span, 12 in width, and 17 in height) flexural specimens were tested, considering FRP system type (polyurethane versus epoxy), size effect, shear span-to-depth ratio, FRP configuration …
Effect Of Load Path And Failure Modes On Seismic Response Of Regular Bridges., Haider Darwash
Effect Of Load Path And Failure Modes On Seismic Response Of Regular Bridges., Haider Darwash
Electronic Theses and Dissertations
Bridges are essential infrastructure constituents that have been studied for centuries. Typically, seismic bridge design and assessment utilize simplified modeling and analysis techniques based on one-dimensional spine elements and zero-length springs/hinges. The geometry of the elements and calibration of parameters are based on assumptions for the lateral load path and failure modes, e.g., sacrificial backwall and shear keys, neglecting wing walls, and strength based on backfill alone. These assumptions have led to observations of underestimated resistance, overestimated displacement demands, and unpredicted damage and failure mode. The focus of the study is on ordinary standard bridges with continuous reinforced concrete box …
Annual Water Balance Model Based On Generalized Proportionality Relationship And Its Applications, Yin Tang
Annual Water Balance Model Based On Generalized Proportionality Relationship And Its Applications, Yin Tang
Electronic Theses and Dissertations
The main goal of this dissertation research is to derive a type of conceptual models for annual water balance at the watershed scale. The proportionality relationship from the Soil Conservation Service Curve Number method was generalized to annual scale for deriving annual water balance model. As a result, a one-parameter Budyko equation was derived based on one-stage partitioning; and a four-parameter Budyko equation was derived based on two-stage partitioning. The derived equations balance model parsimony and representation of dominant hydrologic processes, and provide a new framework to disentangle the roles of climate variability, vegetation, soil and topography on long-term water …
A Comprehensive Assessment Of Vehicle-To-Grid Systems And Their Impact To The Sustainability Of Current Energy And Water Nexus, Yang Zhao
Electronic Theses and Dissertations
This dissertation aims to explore the feasibility of incorporating electric vehicles into the electric power grid and develop a comprehensive assessment framework to predict and evaluate the life cycle environmental, economic and social impact of the integration of Vehicle-to-Grid systems and the transportation-water-energy nexus. Based on the fact that electric vehicles of different classes have been widely adopted by both fleet operators and individual car owners, the following questions are investigated: 1. Will the life cycle environmental impacts due to vehicle operation be reduced? 2. Will the implementation of Vehicle-to-Grid systems bring environmental and economic benefits? 3. Will there be …
Development And Application Of Microelectrodes To Study In Situ Disinfectant Loss And Corrosion On Metal Surface, Xiangmeng Ma
Development And Application Of Microelectrodes To Study In Situ Disinfectant Loss And Corrosion On Metal Surface, Xiangmeng Ma
Electronic Theses and Dissertations
The primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing to the brass in free chlorine solution, reflecting oxygen could be a major part of the corrosion initiation process. While cement showed less reactive characteristics to disinfectants and oxygen compared …
Reducing Sulfuric Acid Pretreatment In A Nanofiltration Process Treating Surficial Groundwater, Carlyn Higgins
Reducing Sulfuric Acid Pretreatment In A Nanofiltration Process Treating Surficial Groundwater, Carlyn Higgins
Electronic Theses and Dissertations
Nanofiltration (NF) is a pressure driven membrane process employed in drinking water treatment that requires pretreatment for reliable operation. The objective of this research was to determine if NF membranes can proficiently operate with a decreased or eliminated dose of sulfuric acid pretreatment. When used as pretreatment, sulfuric acid prevents calcium carbonate scaling on NF membranes, yet is costly, hazardous, and imparts high sulfate concentrations to NF feed and concentrate streams. To conduct this research, a 0.324 million gallon per day (MGD) NF pilot plant was operated for 3,855 run-hours at a flux rate of 15 gallons per square foot-day. …
Pedestrian Safety Analysis Through Effective Exposure Measures And Examination Of Injury Severity, Md Imran Shah
Pedestrian Safety Analysis Through Effective Exposure Measures And Examination Of Injury Severity, Md Imran Shah
Electronic Theses and Dissertations
Pedestrians are considered the most vulnerable road users who are directly exposed to traffic crashes. In 2014, there were 4,884 pedestrians killed and 65,000 injured in the United States. Pedestrian safety is a growing concern in the development of sustainable transportation system. But often it is found that safety analysis suffers from lack of accurate pedestrian trip information. In such cases, determining effective exposure measures is the most appropriate safety analysis approach. Also it is very important to clearly understand the relationship between pedestrian injury severity and the factors contributing to higher injury severity. Accurate safety analysis can play a …
Identification, Calculation And Warning Of Horizontal Curves For Low-Volume Two-Lane Roadways Using Smartphone Sensors, Shaohu Zhang
Identification, Calculation And Warning Of Horizontal Curves For Low-Volume Two-Lane Roadways Using Smartphone Sensors, Shaohu Zhang
Electronic Theses and Dissertations
Smartphones and other portable personal devices that integrate global positioning systems, Bluetooth Low Energy, and advanced computing technologies have become more accessible due to affordable prices, product innovation, and people’s desire to be connected. As more people own these devices, there are greater opportunities for data acquisition in Intelligent Transportation Systems, and for vehicle-to-infrastructure communication. Horizontal curves are a common factor in the number of observed roadway crashes. Identifying locations and geometric characteristics of the horizontal curves plays a critical role in crash prediction and prevention, and timely curve warnings save lives. However, most states in the US face a …
Analysis Of Mechanical Properties Of Alternative Timber Beams For A Native American Earth Lodge, Freddy E. Moran
Analysis Of Mechanical Properties Of Alternative Timber Beams For A Native American Earth Lodge, Freddy E. Moran
Electronic Theses and Dissertations
To fill a gap in the literature, this thesis explored the mechanical properties for alternative roof beams of a historic Native American Hidatsa earth lodge. The research demonstrates that in those alternative beams, when Moisture Content (MC) increases, Modulus of Elasticity (E) decreases and deflection increases. The procedure included obtaining dimensions for alternative beams from scaled sketches created by ethnographers and informants who recorded an actual Hidatsa earth lodge in the early 1800s (confirmed by other sources) although no material properties studies have resulted. After calculating loads, the variations in the E were determined using an equation. Using linear analysis, …
Uav-Based Bridge Inspection And Computational Simulations, Luis Duque
Uav-Based Bridge Inspection And Computational Simulations, Luis Duque
Electronic Theses and Dissertations
The use of Unmanned Aerial Vehicles (UAV), commonly known as drones, has significantly increased in the field of civil engineering due to the poor condition of the United States’ infrastructure. The American Society of Civil Engineers (ASCE) recently reported that more than 9.1% of the United States’ bridges were structurally deficient and required attention and maintenance to ensure appropriate structural performance. Meanwhile, current practices are expensive and unsafe for bridge inspectors, requiring innovative and safer methods for the study of bridges. The goal of this paper was to identify better techniques to not only inspect, quantify, and determine the effect …
A Demonstration Study Of Drainage Water Management In Eastern South Dakota, Ashik Sahani
A Demonstration Study Of Drainage Water Management In Eastern South Dakota, Ashik Sahani
Electronic Theses and Dissertations
Subsurface drainage is a common water management practice for improving crop production in poorly drained soils; however, the practice is associated with several environmental concerns such as nutrient losses to downstream surface waters. These environmental concerns from subsurface drainage have prompted interest in drainage water management strategies such as controlled drainage. This study assessed the agronomic and environmental impacts of drainage water management in eastern South Dakota by using two demonstration plots for controlled and conventional drainage. Drain flow, nitrate and dissolved phosphorous concentration in drain water, shallow groundwater, crop yield, residual soil nitrate, soil moisture and temperature, soil penetration …
Evaluation Of Woodchip Bioreactor Denitrification Kinetics, Abdoul Aziz Kouanda
Evaluation Of Woodchip Bioreactor Denitrification Kinetics, Abdoul Aziz Kouanda
Electronic Theses and Dissertations
Agricultural subsurface drainage is a water management practice used to remove excess water in poorly drained soil. The use of fertilizers combined with subsurface drainage practice affects negatively surface water quality due to nutrient loss. Woodchip bioreactors have previously been used as a technology for removing nitrate from agricultural subsurface drainage. Understanding the mechanism that governs nitrate removal in woodchip bioreactors is crucial for field bioreactor design and application. The objective of this project is to determine woodchip bioreactor denitrification kinetics parameters under different operating conditions including hydraulic retention time, temperature and influent nitrate concentrations. Laboratory column experiments were conducted …
Effects Of Mechanical Bar Splices On Seismic Performance Of Reinforced Concrete Buildings, Abdullah Al Hashib
Effects Of Mechanical Bar Splices On Seismic Performance Of Reinforced Concrete Buildings, Abdullah Al Hashib
Electronic Theses and Dissertations
Mechanical bar splices, which are commonly referred to as couplers, are currently used in reinforced concrete structures to directly connect steel bars in lieu of conventional lap splicing. With proper detailing, couplers can be utilized to connect precast beams and columns to accelerate the construction. However, the experimental and analytical studies regarding their effect on the performance of RC moment-resisting frames (MRFs) are scarce. Current ACI 318 restricts the use of couplers in plastic hinge regions of special moment-resisting frames (SMRFs). Nevertheless, they can be incorporated at any location of the intermediate and ordinary MRFs. The seismic performance of RC …
Evaluating The Interactive Effects Of Traffic Volumes And Access Density On Crash Frequency, Ali Mohammed Alsubeai
Evaluating The Interactive Effects Of Traffic Volumes And Access Density On Crash Frequency, Ali Mohammed Alsubeai
Electronic Theses and Dissertations
Control of access points (e.g., driveway density) is an important consideration in roadway access management. Research has shown that by limiting the number of access points, there is a reduction in the number of conflict points along a roadway, resulting in improved safety. The effects of managing access points on crash frequency are documented as Crash Modification Factors/Functions (CMF) in the Highway Safety Manual (HSM) and the federal Highway Administration’s CMF Clearinghouse. The CMFs from the HSM indicate that the impacts of Access Density (AD) on crash frequency are a function of both AD and traffic volume (for rural roads). …
Impact Of Subsurface Drainage On Water Yield For Typical Soil And Weather In Eastern South Dakota, Govinda Karki
Impact Of Subsurface Drainage On Water Yield For Typical Soil And Weather In Eastern South Dakota, Govinda Karki
Electronic Theses and Dissertations
Subsurface drainage in agricultural land changes the field water balance by providing an alternate pathway for subsurface water. Determining the effects of subsurface drainage on downstream hydrology requires quantifying the components of the water balance. A number of studies have looked at the hydrological impacts of subsurface drainage. However, the effects are complex and difficult to generalize. The complex interaction involves the interrelation among variables such as soil type and properties, climate (rainfall and evapotranspiration), and drainage design configuration (drainage intensity and drainage coefficient), which all are local in nature. Additionally, most studies have been conducted in humid climates, whereas …
Monopile Foundation Offshore Wind Turbine Simulation And Retrofitting, William A. Schaffer
Monopile Foundation Offshore Wind Turbine Simulation And Retrofitting, William A. Schaffer
Electronic Theses and Dissertations
Offshore wind turbines (OWT) provide a renewable source of energy with great proximity to many large cities. This has caused a major increase in OWT development and implementation, primarily in Europe, but spreading throughout the world. There are a multitude of different foundation options, each with their own benefits. The most common types are: monopile, jacket, TLP, Semi-Submersible, and SPAR. The monopile foundation OWT has been proven to be the most economic selection for water depths up to approximately 25m. This thesis has analyzed strictly monopile foundations due to their previous success and popularity. Three different chapters have been created …
Mercury Cycling In Sulfur Rich Sediment From The Brunswick Estuary, Travis William Nicolette
Mercury Cycling In Sulfur Rich Sediment From The Brunswick Estuary, Travis William Nicolette
Electronic Theses and Dissertations
Mercury is potentially toxic to the environment. Mercury is absorbed into anaerobic sediments of surface waters, which may be converted to methylmercury, a toxic form of mercury that bio-accumulates in aquatic biota. Sources of mercury in the environment vary, but the production of methylmercury is common in sulfur-rich sediments containing mercury. In such environments, sulfur reducing bacteria (SRB) produce methylmercury as a by-product. The metabolic process uses energy from the reduction of sulfate to sulfide. This study focuses on determining the methylmercury production and release potential from sulfur-rich sediments extracted from different areas of the Brunswick Estuary. Previous studies note …