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Articles 31 - 46 of 46
Full-Text Articles in Engineering
Behavior Of Non-Ductile Slender Reinforced Concrete Columns Retrofit By Cfrp Under Cyclic Loading, Wisam Amer Aules
Behavior Of Non-Ductile Slender Reinforced Concrete Columns Retrofit By Cfrp Under Cyclic Loading, Wisam Amer Aules
Dissertations and Theses
In the Middle East region and many countries in the world, older reinforced concrete (RC) columns are deemed to be weak in seismic resistance because of their low amount of reinforcement, low grades of concrete, and large spacing between the transverse reinforcement. The capacity of older RC columns that are also slender is further reduced due to the secondary moments. Appropriate retrofit techniques can improve the capacity and behavior of concrete members. In this study, externally bonded Carbon Fiber Reinforced Polymer (CFRP) retrofit technique was implemented to improve the behavior of RC columns tested under constant axial load and cyclic …
Seismic Behavior Of Screen Grid Core Insulated Concrete Form Walls, Anwer Sabah Mohammed Mohammed
Seismic Behavior Of Screen Grid Core Insulated Concrete Form Walls, Anwer Sabah Mohammed Mohammed
Dissertations and Theses
The use of the insulated concrete form (ICF) walls in residential buildings has increased over the past few decades. Much research has been conducted to evaluate the lateral strength of these walls by applying monotonic and cyclic loadings. In the current study, full-scale shake table experiments were employed to evaluate the in-plane behavior of four screen grid insulated concrete form (SGICF) walls. The first two wall specimens utilized dry fit insulated form blocks made from recycled expanded polystyrene granules that were bonded together with cement. When stacked, the cavities in the blocks formed a grid of cores that are evenly …
Hydrological Drought Persistence And Recovery Over The Conus: A Multi-Stage Framework Considering Water Quantity And Quality, Behzad Ahmadi, Ali Ahmadalipour, Hamid Moradkhani
Hydrological Drought Persistence And Recovery Over The Conus: A Multi-Stage Framework Considering Water Quantity And Quality, Behzad Ahmadi, Ali Ahmadalipour, Hamid Moradkhani
Civil and Environmental Engineering Faculty Publications and Presentations
Hydrological droughts have considerable negative impacts on water quantity and quality, and understanding their regional characteristics is of crucial importance. This study presents a multi-stage framework to detect and characterize hydrological droughts considering both streamflow and water quality changes. Hydrological droughts are categorized into three stages of growth, persistence, retreat, and water quality variables (i.e., water temperature, dissolved oxygen concentration, and turbidity) are utilized to further investigate drought recovery. The framework is applied to 400 streamflow gauges across the Contiguous United States (CONUS) over the study period of 1950–2016. The method is illustrated for the 2012 US drought, which affected …
Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle
Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle
Civil and Environmental Engineering Faculty Publications and Presentations
Ecosystem water-use efficiency (WUE) is defined as the ratio of carbon gain (i.e., gross primary productivity; GPP) to water consumption (i.e., evapotranspiration; ET). WUE is markedly influential on carbon and water cycles, both of which are fundamental for ecosystem state, climate and the environment. Drought can affect WUE, subsequently disturbing the composition and functionality of terrestrial ecosystems. In this study, the impacts of drought on WUE and its components (i.e., GPP and ET) are assessed across the Contiguous US (CONUS) at fine spatial and temporal resolutions. Soil moisture simulations from land surface modeling are utilized to detect and characterize agricultural …
Webinar: Rethinking Streets For Bikes: An Evidence Based Guide Of Bike-Friendly Street Retrofits, Marc Schlossberg, Roger Lindgren
Webinar: Rethinking Streets For Bikes: An Evidence Based Guide Of Bike-Friendly Street Retrofits, Marc Schlossberg, Roger Lindgren
TREC Webinar Series
There is a growing demand for better infrastructure and fewer barriers to biking and other forms of space-efficient micromobility. Tackling daily trips by bike is easier on the environment, healthier for users and non-users alike, uses precious urbanized public and private land more efficiently, costs taxpayers less to build and maintain infrastructure, and when routes are safe and comfortable, moving by bike is also fun! Complete Streets policies are being adopted across the country, and there is an active conversation around the safety imperative of a Complete Streets approach. Yet, local officials often need both design guidance and the …
Maximum Coverage Capacitated Facility Location Problem With Range Constrained Drones, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi
Maximum Coverage Capacitated Facility Location Problem With Range Constrained Drones, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi
Civil and Environmental Engineering Faculty Publications and Presentations
Given a set of demand and potential facility locations and a set of fully available charged drones, an agency seeks to locate a pre-specified number of capacitated facilities and assign drones to the located facilities to serve the demands. The facilities serve as drone launching sites for distributing the resources. Each drone makes several one-to-one trips from the facility location to the demand points and back until the battery range is met. The planning period is short-term and therefore the recharging of drone batteries is not considered. This paper presents an integer linear programming formulation with the objective of maximizing …
Webinar: Modeling Freeway Traffic In A Mixed Environment: Connected And Human-Driven Vehicles, Xianfeng Terry Yang
Webinar: Modeling Freeway Traffic In A Mixed Environment: Connected And Human-Driven Vehicles, Xianfeng Terry Yang
TREC Webinar Series
Although connected vehicles (CVs) will soon go beyond testbeds, CVs and human-driven vehicles (HVs) will co-exist over a long period. Hence, it is critical to consider the interactions between these two types of vehicles in traffic flow modeling. In this study, we aim to develop a macroscopic model to understand how CVs would impact HVs in the traffic stream. Grounded on the second-order traffic flow model, we study the relationships among flow, density, and speed by two sets of formulations for the groups of CVs and HVs, respectively. A set of friction factors, which indicate CVs' impact to HVs, are …
From Drought To Food-Energy-Water-Security Nexus: An Assessment Of Food Insecurity In The Middle East, Maysoun Ayad Hameed
From Drought To Food-Energy-Water-Security Nexus: An Assessment Of Food Insecurity In The Middle East, Maysoun Ayad Hameed
Dissertations and Theses
Drought is an extreme climate phenomenon that happens slowly and periodically threatens the environmental and socio-economic sectors. Developing countries have experienced crucial conditions in meeting the needs for food, energy, and water security. Natural disasters contribute as risky sources of food insecurity and vulnerability in the Middle East. This dissertation presents a country-level review and quantitative assessment of the current issues associated with the Food-Energy-Water-Security (FEWS) Nexus in the Middle East. In this study, sixteen countries in the Middle East are chosen, namely, Arabian Peninsula, Iran, Syria, Lebanon, Israel, Palestine, Egypt, and Turkey. The most recent datasets are used to …
Modeling Changes In Public Transit And Private-For-Hire Usage When Implementing A Spatial Tax, Ty Lazarchik
Modeling Changes In Public Transit And Private-For-Hire Usage When Implementing A Spatial Tax, Ty Lazarchik
REU Final Reports
Private-for-Hire (PfH) transportation options, such as Uber, Lyft, and taxicabs, are consistently growing in popularity. With this expanded utilization, cities are struggling to maintain usage of their public transit systems. While PfH transportation has been heavily researched, there is a need to further study how its effects on transit usage may be minimized. In this paper, previous work in traffic modeling and analysis of transit and PfH differences are expanded to develop an agent-based decision model in order to simulate and analyze the effectiveness of implementing a location-based tax in and around the city center of Portland, Oregon. The results …
A Bayesian Nonparametric Multiple Testing Procedure For Comparing Several Treatments Against A Control, Luis Gutiérrez, Andrés Barrientos, Jorge González, Daniel Taylor-Rodríguez
A Bayesian Nonparametric Multiple Testing Procedure For Comparing Several Treatments Against A Control, Luis Gutiérrez, Andrés Barrientos, Jorge González, Daniel Taylor-Rodríguez
Mathematics and Statistics Faculty Publications and Presentations
We propose a Bayesian nonparametric strategy to test for differences between a control group and several treatment regimes. Most of the existing tests for this type of comparison are based on the differences between location parameters. In contrast, our approach identifies differences across the entire distribution, avoids strong modeling assumptions over the distributions for each treatment, and accounts for multiple testing through the prior distribution on the space of hypotheses. The proposal is compared to other commonly used hypothesis testing procedures under simulated scenarios. Two real applications are also analyzed with the proposed methodology.
Investigate An Appropriate Spatial Resolution For Large-Scaled Pedestrian Travel Demand Model, Qin Zhang, Kelly Clifton, Rolf Moeckel
Investigate An Appropriate Spatial Resolution For Large-Scaled Pedestrian Travel Demand Model, Qin Zhang, Kelly Clifton, Rolf Moeckel
Civil and Environmental Engineering Faculty Publications and Presentations
An appropriate spatial resolution plays a significant role in any travel demand models. It directly impacts the level of detail of model input data, outcomes, and sensitivities (Castiglione et al., 2014; Moeckel and Donnelly, 2015). Compared to motorized or bicycle travel, pedestrian trips occur over a shorter travel distance and they are sensitive to environmental conditions at a much finer grain. Thus, it is important for models to set an appropriate spatial resolution to capture variations in walking conditions, leading to better representation of pedestrian demand over space (Gehrke and Clifton, 2014).
The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors
The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors
Civil and Environmental Engineering Faculty Publications and Presentations
Scientists and engineers have observed for some time that tidal amplitudes at many locations are shifting considerably due to non-astronomical factors. Here we review comprehensively these important changes in tidal properties, many of which remain poorly understood. Over long geological time-scales, tectonic processes drive variations in basin size, depth, and shape, and hence the resonant properties of ocean basins. On shorter geological time-scales, changes in oceanic tidal properties are dominated by variations in water depth. A growing number of studies have identified widespread, sometimes regionally-coherent, positive and negative trends in tidal constituents and levels during the 19th, 20th and early …
Observational Method And Coding Framework For Analyzing The Functionality Of Unprotected Bicycle Lanes, Cat Silva, Kelly Clifton, Rolf Moeckel
Observational Method And Coding Framework For Analyzing The Functionality Of Unprotected Bicycle Lanes, Cat Silva, Kelly Clifton, Rolf Moeckel
Civil and Environmental Engineering Faculty Publications and Presentations
This research evaluates how well unprotected bicycle lanes function as dedicated travel lanes for bicyclists. Two types of bicycle lanes are included in this study, including on-street bicycle lanes demarcated with painted lines on the vehicular roadway and bicycle lanes at-grade with, and immediately adjacent to, the pedestrian sidewalk. Specifically, the research is focused on how people behave and interact on street segments with these facilities in place. To assess how, and how well, these types of bicycle lanes function for the bicyclists using them, an observational method is deployed to record, document, and analyze people’s behavior and interactions. A …
Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth
Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth
Civil and Environmental Engineering Faculty Publications and Presentations
Wind-induced sea level blowouts, measured as negative storm surge or extreme low water (ELW), produce public safety hazards and impose economic costs (e.g., to shipping). In this paper, we use a regional hydrodynamic numerical model to test the effect of historical environmental change and the time scale, direction, and magnitude of wind forcing on negative and positive surge events in the New York Harbor (NYH). Environmental sensitivity experiments show that dredging of shipping channels is an important factor affecting blowouts while changing ice cover and removal of other roughness elements are unimportant in NYH. Continuously measured water level records since …
Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield
Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield
Civil and Environmental Engineering Faculty Publications and Presentations
Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the …
Evaluation Of Shared Space To Reduce Traffic Congestion, Kimley Frosch, David Martinelli, Avinash Unnikrishnan
Evaluation Of Shared Space To Reduce Traffic Congestion, Kimley Frosch, David Martinelli, Avinash Unnikrishnan
Civil and Environmental Engineering Faculty Publications and Presentations
Pedestrian and vehicle interactions often lead to conflicts that bring about safety, traffic congestion, and priority or right of way issues. Common methods used in the past to combat said issues have largely relied on the principle of separating the motions of pedestrians and vehicles by means of bridges, tunnels, signals, and access restrictions. A different approach known as shared space aims to solve the same problems with a less structured and defined environment which instead places more reliance on human interaction and perception. Although it has been used in multiple scenarios across Europe with success, instances of shared spaces …