Digital Commons Network^™

Enabling Robust Distributed Real-Time Hybrid Simulation Method And Expanding Its Applications In Floating Wind Turbine Systems, Mehmet Cinar

Masters Theses

Real-time hybrid simulation (RTHS), which integrates physical experiment and numerical simulation, plays an essential role in understanding the time-dependent behavior of structures when subject to hazardous loadings. On the other hand, RTHS might not yield accurate results for complex structural systems due to experimental and computational limitations. Distributed real-time hybrid simulation (dRTHS), which takes the advantage of distributed laboratory facilities using network communications, was proposed and proven to address some limitations in RTHS. During dRTHS, Internet delay due to the network communication is added to the actuator delay in RTHS, which may cause inaccurate results or even unstable tests. To …

The Passive Effects Of Full-Gateway, In-Street Signs On Vehicular Speed, De'lon Dixon

Masters Theses

Reducing motorist’s speed when approaching crosswalks is an important goal in reducing the number of collision between motorist and pedestrian in crosswalks. The current study addresses this goal. The effect of gateway installation of in-street signs (one in-street sign installed between the two travel lanes in each direction and one on both edges of the roadway in each direction) on vehicle speed was evaluated on nine roads. The results demonstrated that the Gateway in-street sign treatment produced large speed reductions as vehicles approached the crosswalk and at the crosswalk. The average speed reduction was 3.8 mph at the crosswalk and …

Evaluation Of Bike Boxes And Protected Intersections With Bicycle Signal Treatments For Improving Safety And Multimodal Mobility At Urban Signalized Intersections, Odai Al Houz

Masters Theses

With the dramatic increase of non-motorized transportation users, more people are concerned about the non-motorized traffic safety. Unfortunately, bicyclist and pedestrian are prone to more severe injuries when involved in a crash. For bicycle crashes, failing to yield/disregarding traffic control device, and lack of non-motorized facilities were identified to be the main causes of bicycle crashes in urban intersections. This research investigated the effectiveness of two bicycle crash countermeasures with bicycle signal treatments at urban signalized intersections. The two countermeasures are the bike boxes and the protected intersections. The bicycle signal treatments are the leading bicycle interval and the exclusive …

Establishing Delay-Based Criteria For Installing Traffic Signals At Two-Lane Roundabouts, Oluwaseun Ayomide Adegbaju

Masters Theses

A roundabout is a circular intersection where drivers travel counterclockwise around a center island in the United States. Roundabouts can be more beneficial than the conventional intersections because they increase the capacity of the intersection and reduce delays and crashes at the intersection. However, the performance of roundabouts can be severely affected by unbalanced traffic flows among the approaches. While the resulting delays can be mitigated by installing traffic signals, there is a lack of clear criteria on when to install a traffic signal at a roundabout. This research focuses on establishing criteria for installing traffic signals at two-lane roundabouts …

Evaluating The Toxicity And Formation Of Halobenzoquinones In Point-Of-Use Chlorinated Drinking Water, Stephanie Hung

Masters Theses

Chlorine has effectively reduced the prevalence of waterborne diseases, however there are secondary consequences to this public health advancement. Disinfection byproducts (DBPs) are chemicals formed when chlorine reacts with natural organic matter (NOM) in water. A new class of DBPs, halobenzoquinones (HBQs), has recently been identified and data suggests it could be potentially carcinogenic and up to 1000 times more toxic than some regulated DBPs. So far, in vitro studies have assessed HBQ toxicity without taking into account its transformation in cell media into potentially less toxic compounds. This study evaluated the toxic effects of one HBQ, 2,6-DCBQ, and its …

Evaluating The Impact Of Double-Parked Freight Deliveries On Signalized Arterial Control Delay Using Analytical Models And Simulation, Aaron J. Keegan

Masters Theses

Freight deliveries on signalized urban streets are known to cause lane blockages during delivery. Traffic congestion associated with urban freight deliveries has gained increasing attention recently as traffic engineers and planners are tasked with finding solutions to manage increasing demand more sustainably with limited road capacity. The goal of this research is to evaluate two models for quantifying the capacity and signalized control delay effects of a lane-blocking freight delivery on an urban arterial. The two methods are: an All-or-Nothing model similar to methodology used in the Highway Capacity Manual 6^th Edition, and a Detailed model consistent with kinematic …

Maintaining Deck Profile In Steel I-Girder Bridges During Deck Placement, Ali Naif Inceefe

Masters Theses

Conventional steel I-girder highway bridges utilize cast-in-place concrete deck. Maintaining the deck profile as per project specifications might be a challenging task. Deformation of girders and formwork used for deck placement need to be controlled during deck placement. Differential deflection between girders, exterior girder web out-of-plane deformation, exterior girder warping, or a combination thereof could impact the deck profile. These deformations challenge maintaining deck profile and need to be considered as a part of constructability evaluation. Determining deck profile due to potential girder deformations is necessary before deck placement so that the remedial actions can be implemented when deck finish …

All-Red Clearance Intervals For Use In The Left-Turn Application Of Flashing Yellow Arrows, Francis Tainter

Masters Theses

With the advancement of implementation for a novel traffic control device, the Flashing Yellow Arrow (FYA), agencies across the country have continually sought strategies to improve intersection operations and safety, specifically with respect to the left-turn application. More so, permissive left-turn intervals have been communicated to drivers using several traffic signal indications; however, most frequently these phases are represented through the circular green (CG) ball and more recently, the FYA. Previous research in this area determined that the FYA indication produced the most effective communication of permissive left-turns. Further, this previous research led to the inclusion of the FYA in …

Impact Of S-Curve On Speed In A Modern Roundabout, Akshaey Sabhanayagam

Masters Theses

According to the US Department of Transportation, around 20 people die on a daily basis in a signalized intersection, with most of these resulting from angle or head-on collisions. The US-DoT’s Federal Highway Administration (FHWA) has identified modern roundabout intersections to be substantially safer than signalized intersections, due in part to the reduction in conflict points from 32 in a traditional signalized intersection to 8 in a modern roundabout. Despite the increased adoption of modern roundabouts across the US, there are a number of specific design elements for which the direct impact they have on operational and safety related performance …

Reward Allocation For Maximizing Energy Savings In A Transportation System, Adewale O. Oduwole

Masters Theses

Transportation has a major impact on our society and environment, contributing 70% of U.S petroleum use, 28% of U.S. greenhouse gas (GHG) emissions, over 34,000 fatalities and 2.2 million injuries in 2013. Punitive approaches to used to tackle environmental issues in the transportation sector, such as congestion pricing have been well documented, although the use of incentives or rewards lags behind in comparison. In addition to the use of more fuel-efficient, alternate energy vehicles and various other energy reduction strategies; energy consumption can be lowered through incentivizing alternative modes of transportation. This paper focused on modifying travelers’ behavior by providing …

Driver Understanding Of The Flashing Yellow Arrow And Dynamic No Turn On Red Sign For Right Turn Applications, Elizabeth Casola

Masters Theses

Since their introduction to the 2009 Edition of the Manual on Uniform Traffic Control Devices, flashing yellow arrows (FYA) have had significant success in communicating the permissive turn message. While widely used for the permissive left turn maneuver, agencies recently have been utilizing flashing yellow arrows for the use with right turn applications as drivers interact with crossing pedestrians. As pedestrian conflicts are a concern during the permissive green phase, there is additional worry for the potential interaction between a pedestrian and vehicle turning right on red. This research explores the existing driver comprehension of permissive right turns during both …

Modeling Root Causes Of Construction Site Fatalities Using Social Network Analysis, Seifeldeen Omar Eteifa

Masters Theses

In spite of the continuing decrease in accident rates in the US Construction industry, accidents are one of the key factors constraining construction industry in terms of cost and time. Fatality rates in the US are more than other developed countries. Research into accident causation included accident occurrence mechanisms, different levels and types of accident causes as and best practices for accident prevention. These efforts, however, did not focus particularly on fatal accidents and did not prioritize the relationships amongst root causes for accidents. Accordingly, this research’s goal is to quantitatively analyze relationships between fatal accident root causes as well …

From Architectural Design To Structural Analysis: A Data-Driven Approach To Study Building Information Modeling (Bim) Interoperability, Mohammed Aldegeily

Masters Theses

BIM has been playing an essential role in building construction projects in recent years. It was used to automate many tasks such as clash detection, 4D planning, and quantity takeoff, among others. However, the interoperability of BIM still lacks in many fields across the architecture, engineering, and construction domains. This research studies the interoperability between architectural design and structural analysis. The goal is to explore structural analysis of BIM models through data transfer processes between different software platforms via three types of paths: (1) Application Programming Interface (API); (2) “immediately connect,” which is the direct link between software programs from …

Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke

Masters Theses

"With infrastructure continuing to age, technologies are being developed to strengthen structures as a more sustainable option than replacement. The use of fiber-reinforced cementitious matrix (FRCM) strengthening systems is a promising new technology for adding flexural and shear capacity to existing reinforced concrete members. While cement based systems with carbon, PBO, and steel have all been implemented in a lab setting, there is not research data available for installation in the field. FRCM composites have advantages over more widely used fiber reinforced polymer (FRP) composites such as heat resistance and compatibility with concrete substrate. FRP systems have previously been field …

Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari

Masters Theses

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of …

Examination Of Shear Friction Design Provisions, Nikkolas J. Edgmond

Masters Theses

"This thesis reports the results of research conducted to establish a state-of-the-art database of shear-friction studies to be turned over to ACI Committee 445-0D as a living document, utilize a subset of the established database to examine the effectiveness of the ACI 318 Code (2014), PCI Design Handbook (2010), AASHTO LRFD Bridge Design Specification (2016) and CSA A23.3 Design of Concrete Structures Standard (2014) provisions to predict shear transfer strength, and examine the effective coefficient of friction (µ_e) approach allowed in the PCI Design Handbook (2010).The shear friction design concept is applicable in conditions where direct shear must …

Bioaccessibility Of Lead From Contaminated Soil Using Phosphate Treatment -- Physiologically Based Extraction Test And In Vitro Gastrointestinal Method Test, Austin Charles Doss

Masters Theses

"Phosphate treatments are used to immobilize lead in soil by forming pyromorphite. Soil from Bonne Terre, Mo was collected to study whether such treatment decreases the bioaccessibility of lead. The soil was treated using 0.5 soil wt% of phosphate. Treatments were: none, phosphoric acid, triple super phosphate, and organic bone meal. Each sample was studied after one, four, sixteen, and twenty weeks; during this time span, water was added approximating the average rainfall rate. Percolated water was collected to test the leached phosphate concentrations. Phosphate was below the detection limit in that leachate. Remediated soil samples were used in Physiologically …

Simultaneous Enhancement Of Fluidity And Thixotropy Of Vibration-Free Concrete, Piyush Rajendra Lunkad

Masters Theses

"This research articulates the development of a vibration-free concrete for slip-form paving enabling a simple and rapid construction process. To achieve this, properties such as rheology including thixotropy, shape stability, and workability loss with time are mainly investigated. Concrete mixture with high thixotropic strength and its shape holding ability, flowability, and workability retention with time is evaluated. This study consists of two phases: (1) selection of paste component from rheology of cement paste incorporating various micro- and nano- sized particles (2) study of fresh properties of concrete mixtures using the excess paste layer concept.

From the cement paste study, it …

Nonlinear Finite Element Analysis Of Concrete Columns Subjected To Complex Loading, Adam Christopher Morgan

Masters Theses

"This study details the development and implementation of a finite element model within a commercial finite element code, Abaqus CAE, for the analysis of reinforced concrete (RC) bridge columns containing interlocking spirals subjected to combined loading conditions including axial, shear, bending, and torsional loads, including the post-peak response. The model is a first of its kind attempt at simulating the response of RC columns with continuous spiral transverse reinforcement and subjected to combined loading conditions including torsion. The model is utilized to determine the quasi-static load-deformation response under various proportions of the input loads and displacements. The resulting quasi-static load-deformations, …

Cellulose And Sulfate Degradation In A Biochemical Reactor During Treatment Of Mine Drainage, Sweta Ojha

Masters Theses

"Seventy-two biochemical reactors were set up, and operated using a mixture of chip-bark, horse manure, and gravel as the biochemical treatment substrate. The simulated mine water containing sulfate (1000 mg/l) was pumped into each reactor at a flow rate of 0.5 ml/minute (approximate), giving an empty bed contact time of 8 days. The main idea is that the microorganisms present in horse manure would convert the cellulose in chip-bark into volatile fatty acids. The produced volatile fatty acid would enhance the metabolism of sulfate-reducing bacteria (SRB) initially present in horse manure, which would degrade (and eventually remove) the sulfate from …

Compressive Behavior Of Masonry Columns Confined With Steel Reinforced Grout (Srg) Composite, Sarah Elizabeth Jemison

Masters Theses

"In this study, a new type of composite comprised of steel fiber cords embedded in a natural hydraulic lime mortar matrix, known as steel reinforced grout (SRG), is explored for the use in confinement of masonry columns. An experimental study was carried out to understand the behavior of solid clay brick masonry columns confined by SRG jackets. Twenty-four confined and seven unconfined columns with a square cross-section were tested to failure under a monotonic concentric compressive load. Test parameters considered were the column corner condition, number of fiber jacket layers, and number of fiber overlapping faces. SRG confinement improved the …

Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li

Masters Theses

"The Lake Chesterfield North Dam in Wildwood city, Missouri has been leaking, more or less continuously since the dam was constructed in 1986 despite mitigation efforts in 1988, 1994, 1995, 2004, and 2005. Neither the grouting efforts in 1988, 1994, 1995, 2004 or 2005, nor the placement and rehabilitation of an impervious clay liner in 2005 has solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate.

Prior to authorizing additional mitigation work, the Lake Chesterfield Home Owners Association (LCHOA) decided to acquire geophysical data across the dry lake bed. …

Cyclic Axial Compression Behavior Of Concrete-Filled Hybrid Large Rupture Strain Frp Tubes, Monika Nain

Masters Theses

"This study introduces an experimental investigation of the behavior of concrete filled fiber reinforced polymer (FRP) tubes (CFFTs) under cyclic axial compression. The FRP used in this study were either small rupture strain FRP (SRS-FRP) or large rupture strain FRP (LRS-FRP). This paper also presents the first-ever experimental study on the behavior of concrete confined using hybrid LRS-FRP and SRS-FRP. LRS-FRP included PEN (polyethylene napthalate) and PET (polyethylene terephthalate) where both of them having ultimate axial strain larger than 5%, and low stiffness. SRP-FRP included carbon and glass FRP having small rupture strains, smaller than 2%, and high stiffness. The …

Numerical And Experimental Analysis Of Local Buckling Of Axially Loaded Steel Tubes Confined By Concrete And Frp, Nicholas Colbert

Masters Theses

“The hollow core Fiber-Reinforced-Polymer (FRP) concrete circular-steel (HC-FCS) column consists of an outer circular fiber reinforced polymer (FRP) tube, an inner thin-walled circular steel tube concentrically aligned, and a concrete shell between them. Research has been performed on the performance of the member as a whole, but to date, there has been no investigation into the behavior of the steel tube confined in the column. 17 small-scale columns were tested under axisymmetric axial compressions applied directly to the steel tube under displacement control. The conducted parametric study examined the effects of diameter-to-thickness (D/t) ratio, concrete unconfined compressive strength, FRP thickness, …

Thermal Curing Efficiency Of Geopolymer Mortars, Simon Peter Sargon

Masters Theses

”Missouri is the fourth largest coal consumer in the U.S. with coal-fired power plants generate 81.3% of the electricity in the state which generate about 2.7 million tons of coal combustion residuals (CCRs) annually. The CCR, including fly ash, disposal issue is not limited to Missouri, rather it is a national issue with CCRs being the second largest waste stream in the U.S. Ninety million tons of fly ash are stored in landfills and ash ponds annually. Hence, using this waste product effectively is necessary. One of the emerging applications of fly ash is to use it as binder in …