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Articles 241 - 270 of 331

Full-Text Articles in Civil and Environmental Engineering

Recruiting, Retaining, And Promoting For Careers At Transportation Agencies, Christofer Harper, Susan Bogus, Raghava Kommalapati, Doeun Choe Dec 2018

Recruiting, Retaining, And Promoting For Careers At Transportation Agencies, Christofer Harper, Susan Bogus, Raghava Kommalapati, Doeun Choe

Publications

State transportation agencies currently face complex challenges in recruiting and retaining the workforce necessary to function effectively. The situation exacerbates due to the number of employees from different generations that have to coexist with varying values, expectations, and principles. These agencies are primarily comprised of two generational groups: the baby-boomers, who are approaching retirement and occupy many managerial positions; and the millennials, who are demonstrating their interest in technology and demanding dynamism in their careers. This multiplicity of interest represents a challenge for human resources (HR) in addressing workforce issues and providing the necessary means to recruit and retain qualified …

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Research Incentive Programs For Closures Of Public And Private Grade Crossings, Julius Codjoe Dec 2018

Research Incentive Programs For Closures Of Public And Private Grade Crossings, Julius Codjoe

Publications

Vehicle-train crashes that occur at highway-rail crossings result in injuries, fatalities, and damage to equipment. In order to reduce the number of vehicle-train crashes, Federal Railroad Administration requires states which have challenges with crossing safety, including Louisiana, to develop a State Action Plan to improve grade crossing safety. Consequently, identification of specific solutions for improving safety at crossings was included in the 2015 Louisiana Transportation Plan as one of its objectives. This study seeks to identify and evaluate current and new incentive programs that encourage closure of at-grade railroad crossings to reduce the number of potential vehicle-train collision points, and …

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Development Of Statewide Annual Average Daily Traffic Estimation Model From Short-Term Counts: A Comparative Study For South Carolina, Sakib Mahmud Khan, Sababa Islam, Md Zadid Khan, Mashrur Chowdhury, Nathan Huynh, Mohammad Torkjazi Nov 2018

Development Of Statewide Annual Average Daily Traffic Estimation Model From Short-Term Counts: A Comparative Study For South Carolina, Sakib Mahmud Khan, Sababa Islam, Md Zadid Khan, Mashrur Chowdhury, Nathan Huynh, Mohammad Torkjazi

Publications

Annual Average Daily Traffic (AADT) is an important parameter for traffic engineering analysis. Departments of Transportation continually collect traffic count using both permanent count stations (i.e., Automatic Traffic Recorders or ATRs) and temporary short-term count stations. In South Carolina, 87% of the ATRs are located on interstates and arterial highways. For most secondary highways (i.e., collectors and local roads), AADT is estimated based on short-term counts. This paper develops AADT estimation models for different roadway functional classes with two machine learning techniques: Support Vector Regression (SVR) and Artificial Neural Network (ANN). The models predict AADT from short-term counts. The results …

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Self-Healing Microcapsules As Concrete Aggregates For Corrosion Inhibition In Reinforced Concrete, Homero Castaneda, Marwa Hassan, Miladin Radovic, Jose Milla Nov 2018

Self-Healing Microcapsules As Concrete Aggregates For Corrosion Inhibition In Reinforced Concrete, Homero Castaneda, Marwa Hassan, Miladin Radovic, Jose Milla

Publications

Reinforced Concrete (RC) structures are vital to the US’s civil infrastructure for their strength and versatility. Unfortunately, RC elements deteriorate rapidly when exposed to corrosive environments. One possible solution is to extend the life of RC elements and systems using microencapsulated corrosion inhibitors to reduce the rebar corrosion rate. The capsules house an anodic corrosion inhibitor agent including calcium nitrate (CN) and triethanolamine (TEA). The integration of such microencapsulated materials will enhance the durability and extend the useful life by controlling the corrosion precursors and the corrosion process during damage evolution. Therefore, this work aims to develop and characterize the …

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Development, Training, Education, And Implementation Of Low-Cost Sensing Technologies For Bridge Structural Health Monitoring (Shm), Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Roya Nasimi Nov 2018

Development, Training, Education, And Implementation Of Low-Cost Sensing Technologies For Bridge Structural Health Monitoring (Shm), Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Roya Nasimi

Publications

Transportation infrastructure needs continuous monitoring. However, traditional inspections cost money and are conducted visually. New technologies for bridge monitoring are expensive and complex. This project involved developing cost-effective sensor technologies that can be applied towards the maintenance of railroad bridges by recording reference-free transverse displacement. More specifically, this project developed new applications of new technologies (Arduino, wireless smart sensors, drones, Hololens) and promoted workforce development with an emphasis on outreach of high-school students. This project was carried out in three main phases: (1) development and validation of technologies, (2) education and outreach to students, and (3) outreach to industry consisting …

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Sustainability-Based Long-Term Management Of Bridges Under Multi-Hazard Exposure, Mohamed Soliman Nov 2018

Sustainability-Based Long-Term Management Of Bridges Under Multi-Hazard Exposure, Mohamed Soliman

Publications

Bridges are under deterioration due to various mechanical and environmental stressors. Hydraulic-related hazards (e.g., flood and scour), aggressive environmental conditions, and seismic events (e.g., earthquake) are recognized as the most significant threats to the safety of bridges. In traditional risk assessment methods for structures susceptible to damage due to floods and other natural hazards (e.g., corrosion and seismic events), future hazard predictions are conducted using historic return periods and climate records. However, recent increase in flood intensity in central-southern states indicate that future hazard occurrence rate may not necessarily follow past trends. Accordingly, current design, assessment, and management methodologies should …

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Erosion Rate Equations For Coarse- Grained Materials Using A Small Flume Testing, Ghada Ellithy, Johannes L. Wibowo, Maureen K. Corcoran Nov 2018

Erosion Rate Equations For Coarse- Grained Materials Using A Small Flume Testing, Ghada Ellithy, Johannes L. Wibowo, Maureen K. Corcoran

Publications

Erosion rate of soils during a levee or dam overtopping event is a major component in risk assessment evaluation of breach time and consequently in determining the downstream consequences. There is uncertainty in estimation of the erosion rate especially for coarsegrained materials that comprise the outer shell layer of dams as well as homogenous levees that are constructed of such materials. In this paper, erosion rate results are presented on three soil mixes that share the same median grain size D50 of 2 mm, the fines content varies between zero and 20%, and the gravel content between zero and 30%. …

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Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp Oct 2018

Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp

Publications

The landscape of water in Utah is changing due to population growth, conversion of agricultural land to urban development, and increasing awareness of water scarcity. At the same time, Utah is experiencing a growing number of urban and small farms, but knowledge of water use in this sector is limited. Better understanding of what occurs at the field level on urban and small farms can aid state water use estimates and conservation efforts, and assist farmers in moving towards wiser water management. For the 2015 growing season, we performed irrigation evaluations for 24 urban and small farms in Cache Valley, …

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Prediction And Rehabilitation Of Highway Embankment Slope Failures In Changing Climate, Navid Jafari, Anand Puppala Oct 2018

Prediction And Rehabilitation Of Highway Embankment Slope Failures In Changing Climate, Navid Jafari, Anand Puppala

Publications

Highway slopes constructed with clayey soil are prone to desiccation cracks due to wetting and drying weather cycle, which allows greater moisture infiltration into the embankment from precipitation. Fissures formed due to extended wetting and drying cycles allow water to seep deeper into the soil than surficial wetting and increase the water content. This increases the moisture content in the soil and results in reduction in shear strength to the fully softened strength. On the other hand, development of desiccation cracks and reduction of the soil matric suction ultimately result in higher hydraulic conductivity value which causes development of higher …

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Enhancing The Durability And The Service Life Of Asphalt Pavements Through Innovative Light-Induced Self-Healing Materials, Marwa Hassan Oct 2018

Enhancing The Durability And The Service Life Of Asphalt Pavements Through Innovative Light-Induced Self-Healing Materials, Marwa Hassan

Publications

The objective of this study was to evaluate the efficiency of a new generation of Ultraviolet (UV) light-induced selfhealing polymers in enhancing the durability and self-healing properties of asphalt mixtures. Self-healing polymers were successfully synthesized in the laboratory and were characterized using Fourier Transform Infrared Spectroscopy (FTIR). In addition, Thermogravimetric Analysis (TGA) results showed that the synthesized polymers achieved the required thermal stability to resist asphalt mixture production processes. Viscosity results showed that addition of 5% Recycled Asphalt Shingle (RAS) and/or 20% Reclaimed Asphalt Pavement (RAP) caused an increase in the viscosity of the binder blends. However, a reduction in …

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Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials, Gabriel Andres Arce Amador, Tyson Rupnow, Marwa Hassan Oct 2018

Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials, Gabriel Andres Arce Amador, Tyson Rupnow, Marwa Hassan

Publications

The project objective is to develop cost-effective Engineered Cementitious Composites (ECC) with locally available ingredients in Region 6 to address the deficiencies observed in ordinary concrete materials. The study explored the utilization of two types of river sands (coarse and fine), two types of PVA fibers (long and short), four levels of cement replacement with Class F fly ash, and the implementation of recycled crumb rubber in the performance of ECC materials. A total of 24 mix designs were prepared and evaluated in compression, tension, and bending to assess its mechanical properties. Furthermore, the cracking characteristics of the materials produced …

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Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley Oct 2018

Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley

Publications

External sulfate attack is a complex phenomenon and is manifested in the form of large expansion, cracking, and spalling depending on the exposure solution and material constituent properties. Several models were developed in the past to demonstrate sulfate attack mechanisms that account for the diffusion of sulfate ions into the porous concrete and the successive deformation triggered by the chemical reaction and precipitation of expansive agents. However, none of these models accounts for the effect of the migration of solvent water from the low solute concentration solution to high solute concentration solution driven by the osmotic pressure. Osmotic pressure is …

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In-Situ Mechanical Characterization For Compacted Aggregates, Douglas Cortes, Paola Bandini Oct 2018

In-Situ Mechanical Characterization For Compacted Aggregates, Douglas Cortes, Paola Bandini

Publications

The evaluation of compacted unbound aggregate layers is perhaps the most common undertaking in transportation-related projects. The assessment of compaction compliance in engineered fills, subgrades, subbases, and bases in roadways and railways is central to ensure longevity of ground transportation infrastructure. In many cases, premature failures in roadways that originate in the unbound aggregate layers can be traced back to inadequate compaction. These failures are preventable, provided the problem areas can be identified by a suitable field test during construction. The most widely used method for compaction assessment during construction is the nuclear density gauge (NDG) test. While the device …

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Bridge Inspecting With Unmanned Aerial Vehicles R&D, Paul Darby, Vijaya Gopu Oct 2018

Bridge Inspecting With Unmanned Aerial Vehicles R&D, Paul Darby, Vijaya Gopu

Publications

The project achieves through research including literature, on site interviews, and experimentation: 1) a recommendation for a UAV-based system to practically assist in routine bridge inspection work in the State of Louisiana, 2) the identification and description of advantages, disadvantages, and limitations in the use of UAVs for routing bridge inspection work in Louisiana, and 3) provided recommendations for future work. The Yuneec H520 aircraft and its E90 camera are recommended, as is the need for a boat to be included as part of the system. The recommended system has advantages in reaching portions of the bridge that are difficult …

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Use Of Rice Hull Ash (Rha) As A Sustainable Source Of Construction Material, Zahid Hossain, Ashraf Elsayed Oct 2018

Use Of Rice Hull Ash (Rha) As A Sustainable Source Of Construction Material, Zahid Hossain, Ashraf Elsayed

Publications

With the imminent shortage of natural resources, the need to find sustainable development is the highest in recent history. Therefore, this study examines the potential uses of Rice Hull Ash (RHA) as a sustainable cementitious material (SCM) in preparation of concrete. This study also assesses the use of RHA as an alternative of commonly used polymers in preparing high-grade asphalt binders. RHA is a potential sustainable solution because it is currently being treated as an agricultural waste material, yet its high silica content makes it a potential construction material. Three different sizes of RHA (600 µm, 150 µm, and 44 …

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Development Of A Self-Healing And Rejuvenating Mechanisms For Asphalt Mixtures Containing Recycled Asphalt Shingle, Marwa Hassan Oct 2018

Development Of A Self-Healing And Rejuvenating Mechanisms For Asphalt Mixtures Containing Recycled Asphalt Shingle, Marwa Hassan

Publications

The objective of this study was to test the hypothesis that hollow-fibers encapsulating a rejuvenator product could improve both self-healing, rejuvenation, and mechanical properties of asphalt mixtures. Hollow-fibers containing a rejuvenating product were synthesized via a wet spinning procedure with sodium-alginate polymer as the encapsulating material. An optimization of the production parameters for the synthesis of fibers was performed to develop fibers suitable for high-temperature and shear stress environment typical of asphalt mixture production. A self-healing experiment was conducted to evaluate the healing/rejuvenation capabilities of sodium-alginate fibers in asphalt mixtures with varying types of binders and recycled materials. Based on …

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Development Of Environmentally-Friendly Stabilization Methods For Transportation Infrastructure Based On Geopolymers, Miladin Radovic, Anand Puppala Oct 2018

Development Of Environmentally-Friendly Stabilization Methods For Transportation Infrastructure Based On Geopolymers, Miladin Radovic, Anand Puppala

Publications

Geopolymers (GPs) have received much attention as an eco-friendly and sustainable alternative to conventional chemical additives, since they can be processed at room temperatures from aqueous solutions by utilizing waste materials (e.g. fly ash) or abundant natural sources (e.g. clay). A collaborative research study is carried out by teams from Texas A&M University (TAMU) and University of Texas at Arlington (UTA) to investigate the effectiveness of GPs for stabilizing base and subgrade materials by considering the strength and shrink-swell characteristics. Two types of clay, obtained from the North Dallas area, were mixed with a potassium-based GP synthesized from metakaolin and …

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Sustainable And Equitable Financing For Pedestrian Infrastructure Maintenance, Gregory Rowangould Oct 2018

Sustainable And Equitable Financing For Pedestrian Infrastructure Maintenance, Gregory Rowangould

Publications

In many communities, pedestrian infrastructure is discontinuous, inaccessible to those with physical disabilities, and poorly maintained. Correcting these problems would be a first step in providing infrastructure to achieve the active travel and related transportation goals of many communities. One nearly universal challenge to maintaining sidewalks in a state of good repair and addressing environmental justice concerns is an adequate, sustainable, and equitable source of funding. Municipal governments across the country maintain and repair their streets and roadways; however, most require residents to maintain and repair public sidewalks adjacent to their property. These policies are difficult to enforce and may …

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Bridge Deck Overlays Using Ultra-High Performance Concrete, Craig Newtson, Brad Weldon Oct 2018

Bridge Deck Overlays Using Ultra-High Performance Concrete, Craig Newtson, Brad Weldon

Publications

This study investigated the use of a locally produced ultra-high performance concrete (UHPC) as an alternative to typical overlay materials. Several bond strength tests including slant-shear, splitting tension, and direct tension tests were performed to assess the bond strength between UHPC and normal strength concrete (NSC) substrate with varying surface textures. Tests were also conducted to assess the early-age and longer-term shrinkage behavior and coefficient of thermal expansion of the UHPC as well as rapid chloride permeability testing. Good bond between UHPC and NSC substrate was observed even with inadequate surface texture. Combined shrinkage and thermal effects were investigated for …

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Does Length Of Ride, Gender Or Nationality Affect Willingness To Ride In A Driverless Ambulance?, Stephen Rice, Scott R. Winter, Rian Mehta, Joseph R. Keebler, Bradley S. Baugh, Emily C. Anania, Mattie N. Milner Oct 2018

Does Length Of Ride, Gender Or Nationality Affect Willingness To Ride In A Driverless Ambulance?, Stephen Rice, Scott R. Winter, Rian Mehta, Joseph R. Keebler, Bradley S. Baugh, Emily C. Anania, Mattie N. Milner

Publications

Due to the frequent lack of ambulances and personnel, the purpose of this study was to examine consumers’ willingness-to-ride in an ambulance that was either driven by a human driver or completely automated (with no human driver) based on the gender of the participant and their nationality, either Indian or American. A two-study experimental design was utilized using over 1,000 participants. In Study 1, the length of the ride and the type of driver were manipulated while in Study 2, the length of the ride was manipulated across genders and nationality. Study 2 also collected affect measures to complete a …

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Evaluation Of Seismic Performance Of Mid-Rise Reinforced Concrete Frames Subjected To Far-Field And Near-Field Ground Motions, Mokhtar Ansari, Masoud Ansari, Amir Safiey Aug 2018

Evaluation Of Seismic Performance Of Mid-Rise Reinforced Concrete Frames Subjected To Far-Field And Near-Field Ground Motions, Mokhtar Ansari, Masoud Ansari, Amir Safiey

Publications

Damages to buildings affected by a near-fault strong ground motion are largely attributed to the vertical component of the earthquake resulting in column failures, which could lead to disproportionate building catastrophic collapse in a progressive fashion. Recently, considerable interests are awakening to study effects of earthquake vertical components on structural responses. In this study, detailed modeling and time-history analyses of a 12-story code-conforming reinforced concrete moment frame building carrying the gravity loads, and exposed to once only the horizontal component of, and second time simultaneously the horizontal and vertical components of an ensemble of far-field and near-field earthquakes are conducted. …

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Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu Jun 2018

Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu

Publications

The seismic vulnerability functions for portfolio-level loss estimation are typically developed for general classes of buildings which may not be suitable to assess building-specific risks. Performance-based earthquake engineering (PBEE) provides the means to conduct building-specific seismic risk assessments. However, such assessments often rely on computationally-intensive analytical frameworks such as incremental dynamics analysis (IDA) which poses a challenge for many types of risk assessment projects. To expand its accessibility, FEMA P-58 outlines a simplified method to predict the nonlinear responses of buildings in which the scope is limited to lower levels of inter-story drifts (less than 4%). This limitation restricts its …

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Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg Jun 2018

Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg

Publications

The probability that a building is sanctioned to demolition following an earthquake depends on several geotechnical, structural, strategic and financial decision variables. This paper explores the literature on post-earthquake reparability assessment of buildings focusing on structural characteristics and evaluates their approaches for four midrise code-compliant structural systems, namely, steel moment frame, reinforced concrete moment frame, light frame wood, and steel braced frame. The structural responses are estimated using incremental dynamics analysis (IDA) in accordance with FEMA P-695 provisions and the IDA results are relayed to a building-specific loss assessment framework to estimate their seismic vulnerability in terms of monetary losses. …

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Determination Of Erosion Parameters Of Coarse-Grained Materials Using A Small Flume, Ghada S. Ellithy, Johannes L. Wibowo, Maureen K. Corcoran Jun 2018

Determination Of Erosion Parameters Of Coarse-Grained Materials Using A Small Flume, Ghada S. Ellithy, Johannes L. Wibowo, Maureen K. Corcoran

Publications

Overtopping is one of the major causes of dams and levees failure. There is uncertainty in estimation of the erosion parameters especially for coarse- grained materials that comprise the outer shell layer of dams as well as homogenous levees that are constructed of such materials. In this paper, results from a box test performed on three coarse grained materials in a 0.3-meter wide flume are discussed. The three materials share the same median grain size D50 of 2 mm, however, they vary in fines content between zero to 20%. The box measured 0.3 m wide x 0.6 m long x …

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Assessing Subjectivity In Environmental Sensor Data Post Processing Via A Controlled Experiment, Amber Spackman Jones, Jeffery S. Horsburgh, David P. Eiriksson May 2018

Assessing Subjectivity In Environmental Sensor Data Post Processing Via A Controlled Experiment, Amber Spackman Jones, Jeffery S. Horsburgh, David P. Eiriksson

Publications

Collection of high resolution, in situ data using environmental sensors is common in hydrology and other environmental science domains. Sensors are subject to drift, fouling, and other factors that can affect the quality of the measurements and their subsequent use for scientific analyses. The process by which sensor data are reviewed to verify validity often requires making edits in post processing to generate approved datasets. This quality control process involves decisions by technicians, data managers, or data users on how to handle problematic data. In this study, an experiment was designed and conducted where multiple participants performed quality control post …

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Mitigating The Structural Vibrations Of Wind Turbines Using Tuned Liquid Column Damper Considering Soil-Structure Interaction, Tadhg Buckley, Phoebe Watson, Paul Cahill, Vesna Jaksic, Vikram Pakrashi May 2018

Mitigating The Structural Vibrations Of Wind Turbines Using Tuned Liquid Column Damper Considering Soil-Structure Interaction, Tadhg Buckley, Phoebe Watson, Paul Cahill, Vesna Jaksic, Vikram Pakrashi

Publications

This paper considers the potential of using a Tuned Liquid Column Damper (TLCD) to reduce structural vibrations of a wind turbine tower. The effect of TLCD on wind turbine towers, including the soil-structure interactions for a monopile foundation was modelled theoretically and scaled laboratory experiments were carried out to validate these results. The tower of the turbine is represented as a Euler beam with a set of springs at the boundary to simulate the soil-structure interaction. TLCD design was carried out using such a model and the reduction in tower vibrations due to the deployment of TLCD was then examined …

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Simulation Of The Behavior Of Corrosion Damaged Reinforced Concrete Beams With/Without Cfrp Retrofit, Masoud Zabihi-Samani, Mohsenali Shayanfar, Amir Safiey, Amir Najari Apr 2018

Simulation Of The Behavior Of Corrosion Damaged Reinforced Concrete Beams With/Without Cfrp Retrofit, Masoud Zabihi-Samani, Mohsenali Shayanfar, Amir Safiey, Amir Najari

Publications

Harsh environmental conditions along with aggressive chemical agents are known as one of the main reasons behind damages observed in reinforced concrete members. Corrosion of reinforcement worldwide is one of the leading causes of damages occurred in reinforced concrete over the lifespan. There are many critical energy and transportation infrastructures located on coastal regions exposed to high humidity and chloride content where they are highly prone to reinforcement corrosion. This calls for retrofit methods, which safeguard not only the strength but also the durability of corrosion deteriorated reinforced concrete structures. Carbon fiber polymers considering their mechanical and chemical properties are …

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Fatigue Life Of Pitch- And Stall-Regulated Composite Tidal Turbine Blades, Ciaran R. Kennedy, Vesna Jaksic, Sean B. Leen, Conchúr M. Ó Brádaigh Feb 2018

Fatigue Life Of Pitch- And Stall-Regulated Composite Tidal Turbine Blades, Ciaran R. Kennedy, Vesna Jaksic, Sean B. Leen, Conchúr M. Ó Brádaigh

Publications

Tidal turbine blades are subject to harsh loading and environmental conditions, including large thrust and torsional loadings, relative to wind turbine blades, due to the high density of seawater, among other factors. The complex combination of these loadings, as well as water ingress and associated composite laminate saturation, have significant implications for blade design, affecting overall device design, stability, scalability, energy production and cost-effectiveness. This study investigates the effect of seawater ingress on composite material properties, and the associated design and life expectancy of tidal turbine blades in operating conditions. The fatigue properties of dry and water-saturated glass fibre reinforced …

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The Effects Of Isoprene And Nox On Secondary Organic Aerosols Formed Through Reversible And Irreversible Uptake To Aerosol Water, Marwa M. El-Sayed, Diana L. Ortiz-Montalvo, Christopher J. Hennigan Jan 2018

The Effects Of Isoprene And Nox On Secondary Organic Aerosols Formed Through Reversible And Irreversible Uptake To Aerosol Water, Marwa M. El-Sayed, Diana L. Ortiz-Montalvo, Christopher J. Hennigan

Publications

Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using measurements of particulate water-soluble organic carbon …

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Energising Dairy Decisions, John Upton, Philip Shine, Michael Breen, Michael D. Murphy Jan 2018

Energising Dairy Decisions, John Upton, Philip Shine, Michael Breen, Michael D. Murphy

Publications

A new tool developed by Teagasc researchers easily and quickly allows dairy farmers to see their energy usage and evaluate how renewable sources could decrease energy costs.

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