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Articles 5941 - 5970 of 39790

Full-Text Articles in Civil and Environmental Engineering

2022 Fall Engr333 Poster, Section A, Dat Cao, Izuchi Ebeku, Samuel Hoover, Sawyer Masselink, Ian Vanderkooi, Matthew Carlson, Jacob Heeres, Anthony Nykamp, Jacob Vanwyngarden, Nate Anderson, Anna Giboney, Gia Mien Le, Jonathan Washburn, Jess Camp, Ryan Macintyre, Aubree Peters, Alin Stoica, Drew Stoneburner, Claire Sheppard, Alayna Spiering, Reid Veneman, James Viel Dec 2022

2022 Fall Engr333 Poster, Section A, Dat Cao, Izuchi Ebeku, Samuel Hoover, Sawyer Masselink, Ian Vanderkooi, Matthew Carlson, Jacob Heeres, Anthony Nykamp, Jacob Vanwyngarden, Nate Anderson, Anna Giboney, Gia Mien Le, Jonathan Washburn, Jess Camp, Ryan Macintyre, Aubree Peters, Alin Stoica, Drew Stoneburner, Claire Sheppard, Alayna Spiering, Reid Veneman, James Viel

ENGR 333

In 2017 President Michael K. Le Roy signed Second Nature’s President Climate Commitment. This commitment outlines that Calvin’s governing body will ensure Calvin University is a carbon neutral educational institution by 2057. In June of 2022, Calvin University’s presidential seat was passed from Dr. Michael K. Le Roy to Dr. Wiebe Boer. In his short time as the president of Calvin University, Dr. Boer has put many projects into motion to help Calvin achieve its goal of becoming carbon neutral by 2057. This past fall Dr. Boer tasked the ENGR 333 class with answering the following question: What would it …


Utilizing Simulated Vehicle Trajectory Data From Connected Vehicles To Characterize Performance Measures On An Arterial After An Impactful Incident, Norris Kamugisha Novat Baraba Dec 2022

Utilizing Simulated Vehicle Trajectory Data From Connected Vehicles To Characterize Performance Measures On An Arterial After An Impactful Incident, Norris Kamugisha Novat Baraba

ETD Archive

Traffic incidents are unforeseen events known to affect traffic flow because they reduce the capacity of an arterial corridor segment and normally generate a temporary bottleneck. Identification of retiming requirements to enhance traffic signal operations when an incident occurs depends on operations-oriented traffic signal performance measurements. When effective and real-time traffic signal performance metrics are employed at traffic control centers, delays, fuel use, and air pollution may all be decreased. The majority of currently available traffic signal performance evaluations are based on high-resolution traffic signal controller event data, which gives data on an intersection-by-intersection basis but requires a substantial upfront …


Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez Dec 2022

Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez

Graduate Theses and Dissertations

Weathering steel enhances corrosion-resistant steel features over conventional steel when a patina properly forms on the weathering steel surface. Weathering steel is a low carbon steel of less than 0.3% carbon by weight and has a chemical composition including other alloying elements such as nickel, copper, and chromium that develops a patina. The patina is a dense protective oxide film layer that develops on the steel member surface. The patina defends the steel from corrosion by preventing moisture, oxygen, and contaminant penetration. However, long periods of moisture and deicing chemicals applied during wet wintry conditions hinder proper patina formation. Without …


Improving Building Cfd Peak Pressure Computation Using Les With A Focus On Inflow Turbulence Methods And Grid Spacing Size., Zahra Mansouri Dec 2022

Improving Building Cfd Peak Pressure Computation Using Les With A Focus On Inflow Turbulence Methods And Grid Spacing Size., Zahra Mansouri

Graduate Theses and Dissertations

Structural failures by extreme winds often leads to economic losses and even deaths. Proper design of buildings requires accurate estimation of wind loads to prevent structural damage. Using routine guidelines generally leads to the underestimation of buildings’ peak pressures, in which most failures occur. To estimate wind loads more accurately three different methods (i.e., field measurement, wind tunnel (WT), and computational fluid dynamics (CFD)) are in use. A well-validated CFD provides more flow field details at lower costs compared to field measurements and WT. As strong winds are extremely turbulent, the effects of turbulence in wind should be incorporated into …


2022 Fall Engr333 Project Section B Final Report, Nicholas Paternoster, Nick Grossman, Jared Ruba, Zac Runhaar, Caleb Styf, Anne Ghata, Micah Lee, Thomas Noble, Liam Austin, Kai Barboza, Mark Bekhet, Jordan Tuter, Jacob Tanis, Sara Vansolkema, Aidan Bakker, Ben Casey, Sarah Mccarthy, Elise Miera, Christine Vanoyen Dec 2022

2022 Fall Engr333 Project Section B Final Report, Nicholas Paternoster, Nick Grossman, Jared Ruba, Zac Runhaar, Caleb Styf, Anne Ghata, Micah Lee, Thomas Noble, Liam Austin, Kai Barboza, Mark Bekhet, Jordan Tuter, Jacob Tanis, Sara Vansolkema, Aidan Bakker, Ben Casey, Sarah Mccarthy, Elise Miera, Christine Vanoyen

ENGR 333

Sustainability is a multi-faceted grand challenge. One of today’s largest challenges is related to sustainability: CO2 emissions from energy consumption. Calvin University purchases natural gas for the energy services it provides; however, it is a major contributor to the amount of CO2 emitted into the atmosphere. The ENGR 333 section B class was tasked with the question: What would it take to eliminate Calvin’s natural gas-related net CO2 emissions? After many hours of research and calculations, the ENGR 333 section B class answered this question with recommendations such as implementing ground source heat pumps, console heat pumps, air source heat …


Performance Evaluation Of The Modified Moisture Barrier In Stabilizing Shallow Slope Failures, Muhasina Manjur Dola Dec 2022

Performance Evaluation Of The Modified Moisture Barrier In Stabilizing Shallow Slope Failures, Muhasina Manjur Dola

Civil Engineering Dissertations - Archive

Each year significant number of highway slope failures are reported in the United States, especially in states like Texas where expansive clayey soil is prevalent. Slopes constructed over expansive clay often experience recurring shallow failures following their construction which poses maintenance problems to the Texas Department of Transportation (TxDOT). These shallow slope failures can be primarily attributed to the considerable volume change that expansive clay soil undergoes from seasonal climatic variation. Furthermore, under unsaturated conditions during dry periods, high matric suction (i.e., negative porewater pressure) exists in soil slopes. The existence of matric suction contributes to the shear strength of …


Development Of A Decesion Tree To Rehabilitate Or Replace The St. Francis Bridge Over Ih-30, Md Farhan Abir Dec 2022

Development Of A Decesion Tree To Rehabilitate Or Replace The St. Francis Bridge Over Ih-30, Md Farhan Abir

Civil Engineering Theses - Archive

ABSTRACT: The ASCE infrastructure report card indicated that about 42% of the nation’s bridges are over 50 years old, and 7.5% of the bridges are structurally deficient. The 61-year-old St. Francis bridge over IH-30 is one of the Texas Department of Transportation (TxDOT) bridges that exhibit significant deterioration in the superstructure, including potholes and delamination in the deck. The bridge was load posted to 28,000 lb. limit and has substandard vertical and horizontal clearances to the bottom chord of the beams and supporting piers, respectively, which creates a high risk for vehicle impact. In 2017, an over-height truck struck the …


Study Of The Impact Of Atmospheric Variability On Subsurface Methane Emissions: Application To Leak Detection And Quantification For Underground Natural Gas Pipeline Leaks, Shanru Tian Dec 2022

Study Of The Impact Of Atmospheric Variability On Subsurface Methane Emissions: Application To Leak Detection And Quantification For Underground Natural Gas Pipeline Leaks, Shanru Tian

Civil Engineering Dissertations - Archive

Natural gas (NG), taken as a bridging fuel for achieving a low-carbon future, has rapidly grown to be a significant component of the global energy system and requires extensive pipeline infrastructures, most of them buried underground. Fugitive methane (CH4) emissions from NG pipeline leaks pose environmental, safety, and economic threats to the public. An effective leak detection and quantification (LDAQ) survey method is critical to identifying a leak and assessing the size when it has occurred, thus initiating appropriate response actions to repair it and accounting for the environmental risks accurately. However, gaps exist between LDAQ survey methods, and the …


Investigation Of Models To Predict The Remaining Useful Life Of Prestressed Concrete Cylinder Pipe, Ahmad Mahmoud Jibreen Dec 2022

Investigation Of Models To Predict The Remaining Useful Life Of Prestressed Concrete Cylinder Pipe, Ahmad Mahmoud Jibreen

Civil Engineering Dissertations - Archive

The water distribution system in the United States consists of 2.2 million miles of pipelines with water main breaks that the American Society of Civil Engineers (ASCE) 2021 Report Card estimated results in six billion gallons of drinking water lost daily. Detecting the state of pipeline deterioration should always be a top priority in the water pipeline industry This dissertation statistically evaluates data from more than 70,000 electromagnetic inspections that have been performed since the installation of these pipes in 1971. The scope of this dissertation is related to performance and degradation of prestressed concrete cylinder pipe (PCCP) which is …


Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson Dec 2022

Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson

All Theses

The United States Air Force (USAF) has the unique capability of being able to interdict superior airpower anywhere, at any time. However, superior airpower is only as effective as the amount of time an aircraft can spend in a particular area. The closer an aircraft can get to the mission need, the more time that can be spent in the air, or the less time that must be spent moving in and out of the operational area. Through the use of skilled and experienced men and women, the USAF is able to apply expedient and unsurfaced airfield paving techniques that …


Mysteerio: Multi-Regional Environmentally Extended Input-Output Model For United States, Yash Srivastava Dec 2022

Mysteerio: Multi-Regional Environmentally Extended Input-Output Model For United States, Yash Srivastava

All Theses

This research work titled My State Environmentally Extended Regional Input-Output (MYSTEERIO) is based on the concept of multi-regional environmentally extended input-output (MREEIO), which is a combination of lifecycle thinking and economics principles. Numerous studies have highlighted the advantages of using this methodology to determine the environmental impacts associated with economic activities for a region. However, no prior attempt has been made to conduct a state-level analysis for the US. This research work thus tries to estimate the impacts embodied due to the consumption of goods and services at the state level by using the MREEIO principles. Extensive coverage of the …


Performance Based Design And Machine Learning In Structural Fire Engineering: A Case For Masonry, Deanna Craig Dec 2022

Performance Based Design And Machine Learning In Structural Fire Engineering: A Case For Masonry, Deanna Craig

All Theses

The volatile and extreme nature of fire makes structural fire engineering unique in that the load actions dictating design are intense but not geographically or seasonally bound. Simply, fire can break out anywhere, at any time, and for any number of reasons. Despite the apparent need, fire design of structures still relies on expensive fire tests, complex finite element simulations, and outdated procedures with little room for innovation. This thesis will make a case for adopting the principles of performance-based design and machine learning in structural fire engineering to simplify the process and promote the consideration of fire in all …


Microcosm Evaluation Of Natural And Biologically-Enhanced Abiotic Transformation Of Chlorinated Ethenes In Low Permeability Formations, Hao Wang Dec 2022

Microcosm Evaluation Of Natural And Biologically-Enhanced Abiotic Transformation Of Chlorinated Ethenes In Low Permeability Formations, Hao Wang

All Dissertations

Trichloroethene (TCE) is one of the most commonly found hazardous compounds at Superfund sites, especially in groundwater. Its volatility and toxicity pose a threat to drinking water safety and human health. In the past decades, research on the fate of TCE in the environment has shifted to contamination of low-permeability formations, for example fractured bedrock aquifers. TCE back-diffusion from low permeability zones and management of persistent TCE groundwater plumes caused by this long-term source zone pose major challenges for remediation.

Monitored natural attenuation (MNA) is a cost-effective remediation strategy that has gradually gained acceptance by regulators. Compared to extensive active …


Finite Element Approach On Minimization Of Cracks At I-Girder Ends Induced By Prestress, Sangit Rauniyar Dec 2022

Finite Element Approach On Minimization Of Cracks At I-Girder Ends Induced By Prestress, Sangit Rauniyar

Civil Engineering Dissertations - Archive

Prestressed I-girders are one of the very commonly and widely used girders for bridges. It is produced at precast plant and transported to bridge site. To produce a prestressed I-girder, strands are first pulled and concrete is poured in I-girder’s formwork. Once the concrete reaches a desired strength, strands are released which induce prestress in I-girder. There are mainly two types of design for I-girders-one that requires debonding of strands at the end of I-girders and another that requires harping of strands at the end of I-girders. The debonding and harping of strands are done to reduce tension at the …


Improving The Analysis And Prediction Of Coastal Flooding During Hurricane Landfalls Through Coupled And Integrated Modeling, Md Arifur Rahman Dec 2022

Improving The Analysis And Prediction Of Coastal Flooding During Hurricane Landfalls Through Coupled And Integrated Modeling, Md Arifur Rahman

Civil Engineering Dissertations - Archive

ABSTRACT: As the intensity and frequency of landfalling tropical storms are likely on the rise in a warming climate, coastal communities are increasingly being exposed to flooding caused by storm surges compounded by heavy rainfall. Prediction and reanalysis of storm surges, especially compound flooding, rely on wind and pressure fields either from parametric tropical cyclone wind models or numerical weather model reanalysis. Both are subject to significant errors during landfall. Besides, land surface attributes and different storm structures influence the intensity and location of compound flooding in coastal areas. Therefore, this dissertation aims to improve the analysis and prediction of …


Performance Evaluation Of Recycled Plastic Pins In Two Layers To Stabilize Deep Slope Failures, Sachini Madanayake Dec 2022

Performance Evaluation Of Recycled Plastic Pins In Two Layers To Stabilize Deep Slope Failures, Sachini Madanayake

Civil Engineering Dissertations - Archive

Slope failures are a common occurrence in highway embankments throughout Texas due to the presence of high plastic clays with expansive behavior. Although shallow slope failures are prevalent, slope failures extending deeper into the slope occur due to the development of micro and macro cracks. The cracks facilitate the infiltration of rainwater deeper into the slope over time. Slope failures incur thousands of dollars’ worth of repairs every year for transportation departments across the country. Recycled Plastic Pins (RPP) have been identified as an effective, cost efficient, and sustainable solution to stabilize shallow failures. The resistance of RPP is mobilized …


Sensor Formed From Conductive Nanoparticles And A Porous Non-Conductive Substrate, Erik T. Thostenson, Thomas Schumacher Dec 2022

Sensor Formed From Conductive Nanoparticles And A Porous Non-Conductive Substrate, Erik T. Thostenson, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

In various aspects, the sensors include a substrate that is porous and non-conductive with nanoparticles deposited onto the substrate within pores of the substrate by an electrophoretic process to form a sensor element. The nanoparticles are electrically conductive. The sensor includes a detector in communication with the sensor element to measure a change in an electrical property of the sensor element. The change in the electrical property may result from alterations in quantum tunneling between nanoparticles within the sensor element, in various aspects.


Comparison Of Crop Water Use Estimation Methodologies In Irrigated Crops, Laura Christiansen Dec 2022

Comparison Of Crop Water Use Estimation Methodologies In Irrigated Crops, Laura Christiansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As increasing drought events limit water resources available for irrigation, farmers and other water users are looking for ways to monitor how much water crops use over a growing season. The amount of water used by crops over time is the evapotranspiration (ET) rate. This study compares different methods for ET estimation to recommend methods to water users based on their accuracy, efficiency, and accessibility. Each method was used to estimate ET for sprinkler-irrigated corn and alfalfa fields in Modena, UT over the 2021 growing season. The Soil Moisture based ET (SMET) method was used to estimate ET based on …


Biodegradation Of Methyl Tert-Butyl Ether And Tert-Butyl Alcohol Using Bioaugmentation With Biowish® Aqua, Elizabeth Villanueva Dec 2022

Biodegradation Of Methyl Tert-Butyl Ether And Tert-Butyl Alcohol Using Bioaugmentation With Biowish® Aqua, Elizabeth Villanueva

Master's Theses

Aqua, a commercial product manufactured by BiOWiSH® Technologies, was utilized in this research to study its effectiveness to biodegrade methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Microcosms containing varying concentrations of MTBE and TBA as well as a growth media and mineral salt solution were examined. Analytical instrumentation used in this study included the use of a gas chromatograph-mass spectrometer (GC/MS) to determine concentrations of MTBE and TBA and a spectrophotometer to extrapolate approximate active biomass concentrations in each experiment. Four different environmental conditions were tested for both MTBE and TBA. The environmental conditions tested for each contaminant included: …


Project Selection In Facility And Infrastructure Maintenance Organizations, Bayram M. Kurbanov Dec 2022

Project Selection In Facility And Infrastructure Maintenance Organizations, Bayram M. Kurbanov

Theses and Dissertations

The current Air Force Civil Engineer Center (AFCEC) built infrastructure Facility Sustainment Restoration and Modernization (FSRM) portfolio management methodology results in an unbalanced project portfolio. The consequence of this unbalance is that majority of the funding goes towards buildings on the flightline and Facility Support Services activities do not get adequate funding which leads to further deterioration of those facilities. This research investigates whether decision support framework based on Value-Focused Thinking (VFT) process yields better project selection outcomes for facility and infrastructure maintenance organizations. To accomplish that, the investigation focuses on understanding current AFCEC decision support methodology, building an alternative …


Influence Of Climate And Droughts On Visibility Degradation In Saudi Arabia, Saleh Alhathloul Dec 2022

Influence Of Climate And Droughts On Visibility Degradation In Saudi Arabia, Saleh Alhathloul

All Dissertations

The spatial and temporal distribution of temperature and precipitation determines the availability of water resources for ecosystems. The hydrological cycle can be disrupted by differences in meteorological variables and the random nature of water demand. Horizontal visibility degradation is an indicator of the changes in local meteorological variables, rainfall deficits, and drought conditions. Long-term analysis of meteorological variables and visibility records helps understand the causes of visibility degradation. The first objective of this dissertation is to investigate the long-term variability of horizontal visibility along with metrological variables based on annual and seasonal time scales over Saudi Arabia. The second objective …


Comparative Analysis Of 3d Printed Bridge Construction In Louisiana, Amirhosein Jafari, Ali Kazemian, Sarah Ataei Dec 2022

Comparative Analysis Of 3d Printed Bridge Construction In Louisiana, Amirhosein Jafari, Ali Kazemian, Sarah Ataei

Data

A construction 3D printing system could result in automated infrastructure development at reduced cost and time, significantly boosting overall productivity. Although there has been a growing interest in using construction 3D printing for projects such as house construction, implementing this innovative technology for infrastructure development, particularly bridge construction, has not been investigated as extensively. This study aims to compare the environmental impact of precast and 3D concrete printing (3DCP) techniques with a pedestrian bridge case study, located in Louisiana, where the bridge elements were 3D printed off-site and then transported and assembled on the bridge site. A detailed cradle-to-site life …


Comparative Analysis Of 3d Printed Bridge Construction In Louisiana, Amirhosein Jafari, Ali Kazemian, Sarah Ataei Dec 2022

Comparative Analysis Of 3d Printed Bridge Construction In Louisiana, Amirhosein Jafari, Ali Kazemian, Sarah Ataei

Publications

A construction 3D printing system could result in automated infrastructure development at reduced cost and time, significantly boosting overall productivity. Although there has been a growing interest in using construction 3D printing for projects such as house construction, implementing this innovative technology for infrastructure development, particularly bridge construction, has not been investigated as extensively. This study aims to compare the environmental impact of precast and 3D concrete printing (3DCP) techniques with a pedestrian bridge case study, located in Louisiana, where the bridge elements were 3D printed off-site and then transported and assembled on the bridge site. A detailed cradle-to-site life …


Development Of Ultra-High Performance Engineered Geopolymer Composites (Uhp-Egcs), Hassan Noorvand, Miladin Radovic, Marwa Hassan, Svetlana Sukhishvili, Gabriel Arce, Ruwa Abufarsakh, Adriana A. Alvarado, Oscar Huang, Sang Zhen Dec 2022

Development Of Ultra-High Performance Engineered Geopolymer Composites (Uhp-Egcs), Hassan Noorvand, Miladin Radovic, Marwa Hassan, Svetlana Sukhishvili, Gabriel Arce, Ruwa Abufarsakh, Adriana A. Alvarado, Oscar Huang, Sang Zhen

Data

This study investigated the possibility of developing novel UHP-EGC materials for the repair and new construction of transportation infrastructure in Region 6 by utilizing locally available resources. To this end, the geopolymers (GPs) in this study were synthesized by activating metakaolin (MK) with potassium silicate and sodium silicate solutions. The solutions were manufactured in the laboratory by dissolving silica fume and potassium hydroxide (KOH) or sodium hydroxide (NaOH) in deionized water. MK-based GP binders, mortars, and fiber-reinforced composites were manufactured and evaluated to determine their density, compressive strength, tensile properties, and slant shear bond strength to Portland cement concrete (PCC). …


Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon Dec 2022

Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon

Architectural Engineering

Precious Plastics, a Netherlands based company, created an open source project that can be used to create different objects from recycled plastics. The San Luis Obispo area has a large amount of recyclable plastic that is being treated as trash, adding to the pollution of the ocean and the air. This project is to determine the necessary steps to create plastic building blocks, using the Precious Plastic process, as a construction material for low-income, temporary housing. This report covers the process that was used to build two of the machines that will be used to create the bricks. This requires …


Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos Dec 2022

Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos

Open Access Theses & Dissertations

An interpenetrating polymer network (IPN) for cation exchange applications was synthesized from a blend of styrene-ethylene/butylene-styrene (SEBS) and acrylonitrile butadiene styrene (ABS), which was 3D printed, grafted with crosslinked polystyrene (PS), and sulfonated. A method for styrene grafting was applied to reduce the damage to polymer phases caused by the sulfonation reaction. Styrene and divinylbenzene monomers were introduced to the IPN and induced with heat treatment to polymerize in situ. The graft copolymerization reaction was enhanced with varying quantities of benzoyl peroxide as a chemical initiator. The samples were subsequently sulfonated with chlorosulfonic acid in dichloroethane and functionalized for ion …


Spf-R Online User Guide, Eric Green, Paul Ross, Christopher Blackden, William Staats, Reginald Souleyrette Dec 2022

Spf-R Online User Guide, Eric Green, Paul Ross, Christopher Blackden, William Staats, Reginald Souleyrette

Kentucky Transportation Center Research Report

SPF-R Online greatly improves and simplifies the SPF development process. Building on the original SPF-R script, the online tool eliminates many of the technical barriers associated with the original process, allowing for a much larger audience to take advantage of SPF-R’s capabilities. Like the original SPF-R script, SPF-R Online lets users quickly explore the effect of roadway network heterogeneity on SPF development, compare CURE plots , and compare goodness-of-fit measures to decide which SPF is most appropriate for a given dataset.


Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong Dec 2022

Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong

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

Nonlinear acoustic techniques have been used to determine the nonlinear properties of materials. Existing methods either require complex equipment to measure absolute nonlinear coefficients or can only be used on laboratory-sized specimens. A recently developed thermal modulation method addresses the limitations of existing methods, but further theoretical analysis and validation are required.

In this dissertation, theoretical analyses were first conducted to study the mechanically and thermally induced acoustoelastic effect. Beginning with the wave equation, the relationship of the ultrasonic wave velocity with respect to mechanical strain and the thermal strain was derived in detail. These analyses provided theoretical support for …


The Rise Of Terrorism In Africa And What It Means For U.S. Policymakers, Bridget Mary Hughes Dec 2022

The Rise Of Terrorism In Africa And What It Means For U.S. Policymakers, Bridget Mary Hughes

Master's Theses

This thesis utilizes three case studies to measure the rise of terrorism in Africa. This qualitative data leads the reader to one ultimate question: what does the rise in terrorism in Africa mean for the United States (U.S.) and U.S. policymakers, National Security academia, students in National Security, if anything at all? The answer is: if civilian and military compounds are being targeted by these violent extremists, as these three case studies demonstrate, it is my recommendation that U.S. policymakers cease sending troops to the African theater and, instead, allocate funding to the citizens and nonprofits of the countries whom …


Effectiveness Of Suspended Lead Dampers In Steel Buildings Under Localized Lateral Impact And Vertical Pulsating Load, Herish Abdullah Hussein Dec 2022

Effectiveness Of Suspended Lead Dampers In Steel Buildings Under Localized Lateral Impact And Vertical Pulsating Load, Herish Abdullah Hussein

Civil & Environmental Engineering Theses & Dissertations

Presented herein is a study of the effectiveness of suspended lead dampers for use in steel buildings under a localized impact load and a vertical pulsating load. A series of lead spheres mounted on a string are suspended inside the building columns or damping panels to absorb the energy of vibration through a collision between the lead dampers and internal surfaces of the members. Experiments are conducted on a three-story steel building model and a cantilever member with suspended lead dampers and subjected to localized impact loading. The cantilever under impact load is analyzed with a partial differential equation of …