Engineering Commons^™

Analysis Of The Interfacial Reaction Between Bulk Metallic Glass Coated Copper, Nickel, And Titanium With Lead-Free Solders, Andromeda Dwi Laksono, Yee-Wen Yen, Rifqi Aulia Tanjung, Teodoro A. Amatosa, Ruki Harwahyu

Makara Journal of Technology

Bulk metallic glass (BMG) has good mechanical strength, high hardness, wear resistance, and corrosion resistance with promising application in various industries. However, for the industrial production of BMG, the main issue is how to overcome limitations of joining with other materials. The present study focuses on solder processing at low operating temperature to avoid exceeding the recrystallization temperature. A feasible joining process for BMG was developed using lead-free solders. The BMG surface is pre-plated with copper, nickel, or titanium as a wetting layer. The reaction temperature is set between the glass transition temperature of BMG and the melting point of …

Design Of Ac Microgrid Topology With Photovoltaic Uncertainties In A Rural Village, Vannak Vai

Makara Journal of Technology

Energy needs are increasing day by day, especially for developing countries, due to population growth and changing lifestyles. A suitable microgrid topology with renewable energy integration is considered to fulfill the people and society’s needs. This paper focuses on the design of AC microgrid topology for a nonelectrified village with the integration of PV uncertainties in both sitting and sizing. The development of an optimal algorithm based on the conductor use minimization and unbalanced load improvement is proposed. The shortest path is proposed to search for the minimum conductor use. Then, the algorithm for improving the unbalanced load with two …

Mean-Shift Object Tracking Algorithm With Systematic Sampling Technique, Yoanes Bandung, Aris Ardiansyah

Makara Journal of Technology

Mean shift is a fast object tracking algorithm that only considers pixels in an object area, hence its relatively small computational load. This algorithm is suitable for use in real-time conditions in terms of execution time. The use of histograms causes this algorithm to be relatively resistant to rotation and changes in object size. However, its resistance to lighting changes is not optimal. This study aims to improve the performance of the algorithm under lighting changes and reduce its processing time. The proposed technique involves the use of sampling techniques to reduce the number of iterations, optimization of candidate search …

Analysis Of Correlation And Mapping Of Chlorophyll-A Concentrations And Sea Surface Temperatures In Coastal Areas Based On Terra Modis Satellite Image Data, Hendrata Wibisana, Bangun Muljo Sukotjo, Umboro Lasminto

Makara Journal of Technology

Ecosystems in aquatic environments are distinct from ecosystems on land. Changes that occur in ecosystems in aquatic environments affect the lives of biota in these waters, including the fish used as a food source in fishing communities in coastal areas. This study aims to determine the role of remote sensing in mapping and analyzing the relationship between the parameters of sea surface temperature and chlorophyll-a concentrations on the coast. The correlation of sea surface temperature with chlorophyll-a concentrations is modeled via linear regression. An analysis of variance test is performed to establish the suitability of the temperature data for the …

The Role Of Rejuvenators In Embedded Damage Healing For Asphalt Pavement, Shi Xu, Xueyan Liu, Amir Tabakovic, P Lin, Y Zhang, S Nahar, B J. Lommerts, Erik Schlangen

Articles

Rejuvenator encapsulation technique showed great potential for extrinsic asphalt pavement damage healing. Once the capsules are embedded within asphalt pavement, the healing is activated on-demand via progressing microcrack. When the microcrack encounters the capsule, the fracture energy at the tip opens the capsule and releases the rejuvenator. Then the released rejuvenator wets the crack surfaces, diffuses into and softens the aged bitumen, allowing two broken edges to come in the contact, preventing further asphalt pavement deterioration. The quality and speed of the damage repair process strongly depend on the quality of rejuvenator, thus it is important to choose a proper …

Corrosion Rate Prediction In Frp-Concrete Repair, Mohammad A. Khawaja

USF Tampa Graduate Theses and Dissertations

Research has proven that wrapping structural elements with fiber-reinforced polymers (FRPs) slows down chloride-induced corrosion rate but does not stop it. Although FRP has been used for corrosion repair for over 40 years, predictive corrosion rate models for FRP-concrete systems are limited in literature. This dissertation presents an oxygen diffusion-based predictive framework to estimate corrosion rate in FRP-concrete systems.

The dissertation has three main components. First, a core framework that is referred to as Khawaja-Sen-Bhethanabotla (KSB) model. In the KSB model, statistical methods were used to extend experimental data on oxygen permeation coefficients. These data were for one and two …

Removal Of Heavy Metals Using Novel Adsorbent Materials, Lesley Joseph

Theses and Dissertations

Heavy metal contamination is a growing concern throughout the world, particularly as industrial and urban activities have increased. Inadequate water and wastewater treatment, coupled with increased industrial activity, have led to increased heavy metal contamination in rivers, lakes, and other water sources in developing countries. To address these concerns, a significant amount of research has been conducted on various novel adsorbents to evaluate their ability to remove heavy metals. Thus, in this study, MIL-100(Fe) and MIL-101(Cr) are fabricated and investigated to determine their ability to remove copper (Cu2+), cadmium (Cd2+), and lead (Pb2+) from aqueous solution. The experimental data fit …

Fate Of Nitrogen And Effectiveness Of Evaporation On Managing Leachate In Collection And Storage Ponds: A Case Study At The Three Rivers Solid Waste Authority Regional Landfill, Kaitlen Rose Drafts

Theses and Dissertations

Treatment of leachate from municipal solid waste (MSW) landfills can be complex and difficult, due to the variety of contaminants present. The purpose of this work was to evaluate the fate of nitrogen and effectiveness of leachate evaporation in a leachate storage and collection pond at the Three Rivers Solid Waste Authority (TRSWA) MSW landfill in Jackson, South Carolina. This was accomplished by determining the fate of nitrogen species in the pond, exploring effect of the site’s Lilypad droplet sprayer system on ammonia-nitrogen, and exploring potential to reduce overall quantity of leachate to be treated through evaporation from the pond. …

Impact Of Particle Surface Charge Heterogeneity On Deposition Onto Flat Surfaces And Transport In Porous Media, Thompson Delon

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

Biological and non-biological natural colloids are anisotropic and ubiquitously exist in groundwater. Previously in colloid transport modelling, colloids are assumed to be homogenous for simplification, whether in shape or surface charge. More research has been done to incorporate surface heterogeneity in the transport experiment, i.e., surface charge heterogeneity on collector in column experiment. However, few studies have been done on surface heterogeneity on colloids themselves.

In this dissertation, Janus particles with different surface charge was developed to model surface heterogeneity on colloids. The interaction energy between Janus particle and flat surfaces was analyzed through DLVO simulation. It was discovered that …

Rehabilitation Of Timber Piles Using Fiber Reinforced Polymers Analyzed With Acoustic Emission, Rebekah Marie Krol

Theses and Dissertations

Assessing the current state of infrastructure and implementing strengthening or rehabilitation methods on old or damaged members is important to ensure safety and longevity of structures. Non-destructive testing is an important tool for localizing and characterizing damage in structures, especially structures that are more susceptible to damage because of age or environment. In addition to locating inadequate members, it is essential to have a repair technique in place so that the structure can continue to be used in a safe manner.

This study aims to review the use of acoustic emission for evaluating damage obtained in timber piles subjected to …

Physical Modeling Of Backward Erosion Piping Phenomenon In A Geotechnical Centrifuge, William Fernando Ovalle Villamil

Theses and Dissertations

Backward erosion piping is a mechanism of internal erosion that has been widely recognized as a potential hazard for water-retaining structures, such as dams and levees, that are founded on granular materials. Backward erosion piping initiates toward the downstream zone of the structure by the concentration of flow at an exit point acting as drainage, which leads to a localized loosening of the soil and eventually to a continuous migration of grains from the foundation following a piping path pattern. Such piping path extends backward toward the impoundment once a certain critical hydraulic condition is met, resulting in the loss …

Stability Of Low Crested And Submerged Breakwaters: A Reanalysis And Model Development, Christopher P. Burgess

Civil & Environmental Engineering Theses & Dissertations

Low-crested and submerged structures (LCS) play an integral part in the stabilization of shorelines for recreational purposes, yet there are a plethora of empirical models and gaps in the understanding of their stability and damage progression. The objectives were: i) to evaluate the present formulae, ii) explore variable importance, iii) formulate a stability model, iv) extend the current datasets and v) explore a new model for LCS. The literature points to an increasing understanding of the initiation of damage of LCS and recent exploration of the shear stress-induced erosion (van Rijn, 2019). Assessment of two existing models (Kramer, 2006 and …

Development Of Cracking Resistance Prediction Model Of Long-Term Aged Asphalt Mixtures, Peyman Barghabany

LSU Doctoral Dissertations

With the increasing complexity of asphalt mixture composition, the current volumetric-based Superpave mixture design would not be sufficient to address durability concerns. To address this limitation, performance-based testing is introduced to supplement conventional volumetric mixture design in assessing the cracking resistance of asphalt mixtures. To perform cracking tests, samples need to be aged to represent the most embrittlement case. The current AASHTO standard for asphalt mixture long-term aging (LTA) is a 5-day oven-aging at 85°C. Quality control/assurance practices require samples to be long-term aged prior to a cracking test which is a time-consuming process. Therefore, it would be beneficial to …

Stream Power Analysis Of The Mid-Barataria Conveyance Channel Model, Jack Graham

LSU Master's Theses

Louisiana’s coast is disappearing at an alarming rate. Erosion, subsidence, sea level rise, and the devastating impacts from hurricanes have contributed to the loss of thousands of square miles of land that was once a thriving ecosystem. The Louisiana government is taking action to help protect and restore these coastal habitats, which are a home to some two million people and numerous species of animals, birds, and fish. The Mid-Barataria Sediment Diversion is a new type of project to help create land in Barataria Basin. Conceptually, the diversion is designed to use the available sediment and stream power provided by …

Advanced Concrete Composites For Improved Performance: A Bibliometric Survey, Dhruv Patel, Aryan Tiwari, Nishnat Nikhare, Rohit Shinde, Ashutosh Dubey, Manan Shah, Shalaka Hire, Sayali Sandbhor

Library Philosophy and Practice (e-journal)

Concrete is the core component of any civil engineering construction. Conventional concrete can be modified depending upon the needs and requirements of the construction. Such concrete is called advanced concrete and this report aims to study advanced concrete and its composites. The main objective of this report is to perform a bibliographic survey on the latest research literature available under the domain of advanced concrete composites for improved performance. Timespan considered for the survey is from the year 2015 to 2020. The bibliographic survey consists of literature from online platforms such as the Web of Science (WoS) and Scopus database. …

Non-Newtonian Model Development For Post-Wildfire Flood Risk Management, Ian Eli Floyd

LSU Doctoral Dissertations

Wildfire effected regions of the western U.S. frequently produce non-Newtonian floods (or floods that have a non-linear relationship between stress and deformation) in response to moderate to severe precipitation events. This research presents the development, evaluation, and demonstration of a post-wildfire hydrodynamic one-dimensional and two-dimensional diffusive wave and shallow-water numerical modeling approach that can be used to predict post-wildfire downstream runout of debris flows and floodplain inundation conditions. While researchers have developed a variety of Non-Newtonian approaches to simulate debris flows and mudflows, there has been very limited application to post-wildfire flooding. This can make it difficult to understand the …

Analysis Of Tensegrity Structures Using Abaqus, Kayla M. Allen

Honors College Theses

This project involves modeling and analysis of a tensegrity structure using the finite element approach utilizing the Abaqus software package. A tensegrity structure is a special type of assembly consisting of a series of straight solid members, arranged in various geometrical configurations in three-dimensional space and held together by series of cables. The developed finite element models for several tensegrity structures are included in this thesis report to better describe the project.

Evaluation Of Compatibility Between Asphalt Binders And Mineral Aggregates, Tandra Bagchi

Student Theses and Dissertations

One of the major problems of asphalt concrete pavements faced by most state Departments of Transportations (DOTs) and other highway agencies is moisture damage. Poor compatibility between asphalt binders and aggregates is the main reason behind such kind of distresses. This study aims to conduct compatibility analyses of selected asphalt binders and aggregates used in Arkansas. Asphalt binders used in this study include two Performance Grade (PG) binders (PG 64-22) from two different sources along with their modified counterparts. Additionally, four different types of aggregates are being evaluated in the laboratory. The Sessile Drop method has been followed to determine …

Feasibility Of Using A High-Power Electromagnetic Energy Harvester To Power Structural Health Monitoring Sensors And Systems In Transportation Infrastructures, Mohsen Amjadian, Anil K. Agrawal, Hani Nassif

Civil Engineering Faculty Publications

This paper investigates the feasibility of an electromagnetism energy harvester (EMEH) for scavenging electric energy from transportation infrastructures and powering of conventional sensors used for their structural health monitoring. The proposed EMEH consists of two stationary layers of three cuboidal permanent magnets (PMs), a rectangular thick aircore copper coil (COIL) attached to the free end of a flexible cantilever beam whose fixed end is firmly attached to the highway bridge oscillating in the vertical motion due to passing traffic. The proposed EMEH utilizes the concept of creating an alternating array of permanent magnets to achieve strong and focused magnetic field …

Temperature Gradient Effects On Behavior And Design Of Prestressed Concrete Girder Bridges, Ahmed Saad Elsayed Mohamed Elshoura

LSU Doctoral Dissertations

Temperature variation is an inevitable environmental loading type that affects bridges. Considering temperature effects during structural design is deemed essential for short, medium, and long span bridges. Temperature loading can be categorized into three components; uniform temperature, vertical temperature gradient, and transverse temperature gradient. Temperature variation causes additional movements, stresses, and internal forces that should be considered in the design of bridges. In this study, the temperature effects of vertical and transverse temperature gradients are investigated for continuous prestressed concrete bridges.

Thermal restraint moments induced by vertical temperature gradients on prestrssed concrete bridges are investigated by performing three-dimensional (3D) finite …

Longitudinal Trajectory Tracking Analysis For Autonomous Electric Vehicles Based On Pid Control, Hossein Amiri

USF Tampa Graduate Theses and Dissertations

The implementation of autonomous vehicles has huge potential for revolutionizing transportation as we currently know it. All use cases of autonomous vehicles require the vehicle to travel on a pre-specified path. Accurate tracking of this defined trajectory is a crucial aspect of the implementation of autonomous vehicles; a controller system is required to translate this pre- defined trajectory in the form of the throttle, brake, and steering inputs. This project covers the application of a Proportional-Integral-Derivative (PID) controller to achieve longitudinal trajectory tracking of autonomous electric vehicles with stability and accuracy in the CARLA autonomous driving simulation platform. The implemented …

Prediction Of The Effects Of Turbulence On Vehicle Hydroplaning Using A Numerical Model, Thathsarani Dilini Herath Herath Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Pneumatic hydroplaning has been identified as one of the major causes of wet weathertraffic accidents. Therefore, knowledge of potential hydroplaning speeds is crucial in designing roadways to reduce crash risks. It has been shown that the tire inflation pressure is the predominant factor affecting the hydroplaning speed while factors such as the water film thickness also contribute heavily to this phenomenon. Extensive research has been directed at the development of accurate models to predict the effects of vehicle characteristics, pavement conditions and water film thickness on hydroplaning. Current literature does not indicate any studies directed at understanding the effects of …

Feasibility Of Epoxy Bond Enhancement On High-Strength Concrete, Amanda A. Lewis

USF Tampa Graduate Theses and Dissertations

While fiber-reinforced polymer materials have many applications in various industries,when used structurally, many cases, such as flexural and shear strengthening, are considered bond critical. Interfacial bond quality between a fiber-reinforced polymer system and the substrate is dependent on two mechanisms: chemical bonding and mechanical interlock, with mechanical interlock having the greater effect on bond quality. Mechanical interlock describes the type of bond that occurs as a result of surface roughness and substrate porosity and can be significantly affected by surface preparation methods and surface moisture. This study aims to explore the possibility of enhancing bond quality between carbon-fiberreinforced polymers and …

Soil Improvement By Electro-Osmotic Consolidation: Laboratory Testing, Yenni Mariana Ramírez-Mazo, Juan Pablo Osorio, Sergio C. Agudelo-Flórez

Conference papers

Electro-osmotic consolidation is a ground improvement technique that has been successfully implemented on the field and at laboratory scale since the 30s. However, its application has been done primarily through empirical procedures and experience. The determinant variables in the effectiveness and efficiency of the improvement are numerous and require further studies. This paper presents the evaluation of the improvement process of an inorganic low plasticity clay subjected to a 150 V/m voltage during 5780 minutes. The special analysis of the strains showed differential settlements, as well as cracking at the surface and with depth. The consolidations curves obtained follow the …

A Non-Destructive Electromagnetic Sensing Technique To Determine Chloride Level In Maritime Concrete, Goran Omer Dr, Patryk Kot Dr, William Atherton Dr, Magomed Muradov Dr, Michaela Gkantou Dr, Andy Shaw Prof, Michael Riley Prof, Khalid Hashim Dr., Ahmed Al-Shamma’A

Karbala International Journal of Modern Science

Deterioration of concrete due to the corrosion of reinforcement is a serious durability problem faced by the construction industry. This study aims to develop a non-destructive and real-time technique to monitor the chloride level at an early stage to prevent the development of the reinforcement’s corrosion using electromagnetic spectroscopy. The experimental work was performed on 5 concrete specimens with different chloride levels at three different concrete depths (18, 40, and 70mm) using the sensor system (2-12GHz frequency range) and a chlorometer. The LM algorithm was selected to develop a prediction model for the detection of chloride ions. The results demonstrated …

The Prospect Of Microwave Heating: Towards A Faster And Deeper Crack Healing In Asphalt Pavement, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Microwave heating has been shown to be an effective method of heating asphalt concrete and in turn healing the damage. As such, microwave heating holds great potential in rapid (1–3 min) and effective damage healing, resulting in improvement in the service life, safety, and sustainability of asphalt pavement. This study focused on the microwave healing effect on porous asphalt concrete. Steel wool fibres were incorporated into porous asphalt to improve the microwave heating efficiency, and the optimum microwave heating time was determined. Afterwards, the microwave healing efficiency was evaluated using a semi–circular bending and healing programme. The results show that …

The Effect Of Cement And Blast Furnace Slag Characteristics On Expansion Of Heat-Cured Mortar Specimens, Jair G. Burgos

USF Tampa Graduate Theses and Dissertations

Delayed ettringite formation (DEF) is a durability issue that typically occurs in concrete exposed to high temperatures at an early age such as precast elements and massive concrete structural elements. There are many advantages to precast concrete such as its quality control, better safety control, and reusable forms, which make them cheaper than casting on site [1]. Heat curing of precast concrete is conducted to obtain high early-strength. However, in doing so, durability issues can arise in the form of internal sulfate attack also known as DEF, if the internal temperature of concrete exceeds 70°C. Past this threshold, ettringite decomposes …

Machine Learning Methods To Map Stabilizer Effectiveness Based On Common Soil Properties, Amit Gajurel, Bhaskar Chittoori, Partha Sarathi Mukherjee, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Most chemical stabilization guidelines for subgrade/base use unconfined compressive strength (UCS) of treated soils as the primary acceptance criteria for selecting optimum stabilizer in laboratory testing. Establishing optimal additive content to augment UCS involves a resource-intensive trial-and-error procedure. Also, samples collected from discrete locations for laboratory trials may not be representative of the overall site. This study aims to minimize the number of laboratory trials and help strategize sampling locations by developing spatial maps of UCS at different treatment levels for lime and cement. These spatial maps were developed using machine-learning techniques, and using a database compiled from various reported …

A Decision-Support System For The Deployment Tasking Process Of U.S. Air Force Civil Engineer Officers, Kenneth A. Neal

Theses and Dissertations

The Armed Forces frequently deploy their personnel to expeditionary locations around the world. For example, the Air Force tasks its personnel to deploy based on a six-month rotational cycle. In the current tasking process, the deployment makes its way down from combatant commanders to squadron commanders through the chain of command. The commander then has a few days to select an individual from their unit to fill the tasking. The commander may consider an individuals’ dwell time, home-station position, and upcoming significant life events; however, because commanders have little time and information, minimum requirements selection criteria often become the driving …

Investigating Manufacturer Selection Decisions For Built Infrastructure Assets Using A Technical Performance Metric, Sarah L. Brown

Theses and Dissertations

Facility and built infrastructure asset management are necessary functions of any organization that utilizes buildings to operate their businesses. However, most organizations require facility managers to ensure the successful operation of their assets without providing sufficient resources to accomplish this task. Therefore, in resource-scarce environments, facility managers require data-driven solutions to manage their assets and make the best decisions. Facility managers need novel solutions to help make asset life-cycle decisions. This research provides such a solution. Capitalizing on available data, a technical performance metric is created, allowing facility managers to calculate their assets' operational performance. This performance metric provides a …