Engineering Commons^™

Phase Space Analysis Of Nonlinear Wave Propagation In A Bistable Mechanical Metamaterial With A Defect, Mohammed A. Mohammed, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

We study the dynamics of solitary waves traveling in a one-dimensional chain of bistable elements in the presence of a local inhomogeneity (“defect”). Numerical simulations reveal that depending upon its initial speed, an incoming solitary wave can get transmitted, captured, or reflected upon interaction with the defect. The dynamics are dominated by energy exchange between the wave and a breather mode localized at the defect. We derive a reduced-order two degree of freedom Hamiltonian model for wave-breather interaction and analyze it using dynamical systems techniques. Lobe dynamics analysis reveals the fine structure of phase space that leads to the complicated …

Long-Distance Propagation Of 162 Mhz Shipping Information Links Associated With Sporadic E, Alex T. Chartier, Thomas R. Hanley, Daniel J. Emmons

Faculty Publications

This is a study of anomalous long-distance (>1000 km) radio propagation that was identified in United States Coast Guard monitors of automatic identification system (AIS) shipping transmissions at 162 MHz. Our results indicate this long-distance propagation is caused by dense sporadic E layers in the daytime ionosphere, which were observed by nearby ionosondes at the same time. This finding is surprising because it indicates these sporadic E layers may be far more dense than previously thought.

Exploring The Biomedical Applications Of Polyurethane-Based Foams, Films, And Hydrogels, Anand Utpal Vakil

Dissertations - ALL

Shape memory polymers (SMPs) are a class of smart materials that can be temporarily stored in a deformed shape and can actively recover their original shape upon exposure to an external stimulus, such as heat, magnetic field, moisture, pH, light, or electric field. The ability of SMPs to change shape when required can be used for a wide range of applications, especially in the case of minimally invasive biomedical applications. In this work, polyurethane-based SMPs were explored for their use in tissue engineering, drug delivery, and wound healing applications.

In the second chapter, low density porous foams with tunable degradability …

Phytoextraction Of Lead (Pb) Contaminated Soil By Switchgrass (Panicum Virgatum L): Impact Of Bap And Nta Applications, Genna Hart, Austin Gilly, Marina Koether, Thomas Mcelroy, Sigurdur Greipsson

Faculty Articles

The accumulation of Pb deposits in soil is a growing global concern. Soil remediation options include phytoextraction that involves the use of plants and associated soil microorganism. Switchgrass (Panicum virgatum L.), a second-generation bioenergy crop was used in this study due to its ability to produce high biomass and grow in metal polluted soils. Plants were grown in Pb-contaminated soil (5,802.5 mg kg−1) in an environmentally controlled greenhouse. Plants were treated with exogenous application of the plant growth regulator (PGR) benzylaminopurine (BAP) or complete foliar nutrient solution (Triple-12®) twice a week until harvested. Plants also received the soil fungicide propiconazole …

A Machine Learning Approach To Robotic Additive Manufacturing Of Uv-Curable Polymers Using Direct Ink Writing, Luis A. Velazquez

LSU Master's Theses

This thesis presents the design and implementation of a robotic additive manufacturing system that uses ultraviolet (UV)-curable thermoset polymers. Its design considers future applications involving free-standing 3D printing by means of partial UV curing and the fabrication of samples that are reinforced with fillers or fibers to manufacture complex-shape objects.

The proposed setup integrates a custom-built extruder with a UR5e collaborative manipulator. The capabilities of the system were demonstrated using Anycubic resin formulations containing fumed silica (FS) at varying weight fractions from 2.8 to 8 wt%. To fully cure the specimens after fabrication, a UV chamber was used. Then, measurements …

Sodium Alginate, Nanoclay And Curcumin Based Food Packaging Material For Intelligent Food Packaging Applications, Kalpani Y. Perera, Máille Hopkins, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

Bionanocomposite food packaging contains materials of biological origin which display high-performance activity when compared to biopolymers and are eco-friendly alternatives to conventional packaging materials. Intelligent packaging monitors the condition of the food or environment surrounding the food and communicates changes to the consumer. This study aimed to develop a bionanocomposite intelligent packaging material by utilising sodium alginate, nanoclay and curcumin. Sodium alginate (2 W/V% SA) film incorporated with 0.3 W/V% curcumin (Cur), glycerol, and nanoclay (NC) in various concentrations (0, 0.5, 1 and 2 W/V %) was prepared using the solvent casting method. The influences of nanoclay and curcumin on …

Statistical Models Of Traffic Injury Severities: The Effects Of Driver Nationality And The Time-Of-Day On Pedestrian Injuries, Asim Alogaili

USF Tampa Graduate Theses and Dissertations

Roadway accidents have long been a major cause of casualties among all roadway users including drivers and pedestrians. Researchers have used various advanced methodologies to precisely identify affecting factors to help policy makers implement safety measures that effectively mitigate such losses. For a variety of reasons such factors, especially those related to roadway users, are subject to constant changes over time. This work investigates, in depth, the effect of multiple variables on the injury severity levels of both drivers and pedestrians using the most recent and advanced methodological approaches.

First, the dissertation starts by investigating factors that significantly contribute to …

Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosanalginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.

Towards More Task-Generalized And Explainable Ai Through Psychometrics, Alec Braynen

USF Tampa Graduate Theses and Dissertations

In this work, we propose that adopting the methods, principles, and guidelines of the field of psychometrics can help the Artificial Intelligence (AI) community to build more task-generalizable and explainable AI. Three arguments are presented and explored. These arguments are that psychometrics can help by providing 1) a framework for formulating better datasets, 2) psychometric AI data that can lead to models of generalization in AI, and 3) explainable AI through more informative evaluations.

A review of psychometrics and psychological generalization is performed, along with an overview of evaluation, generalization, and explainability in AI. Various ideas are presented throughout for …

Feedforward Control Of Thermal History In Laser Powder Bed Fusion: Toward Physics-Based Optimization Of Processing Parameters, Alex Riensche, Benjamin D. Bevans, Ziyad M. Smoqi, Reza Yavari, Ajay Krishnan, Josie Gilligan, Nicholas Piercy, Kevin D. Cole, Prahalada K. Rao

Department of Mechanical and Materials Engineering: Faculty Publications

We developed and applied a model-driven feedforward control approach to mitigate thermal-induced flaw formation in laser powder bed fusion (LPBF) additive manufacturing process. The key idea was to avert heat buildup in a LPBF part before it is printed by adapting process parameters layer-by-layer based on insights from a physics-based thermal simulation model. The motivation being to replace cumbersome empirical build-and-test parameter optimization with a physics-guided strategy. The approach consisted of three steps: prediction, analysis, and correction. First, the temperature distribution of a part was predicted rapidly using a graph theory-based computational thermal model. Second, the model-derived thermal trends were …

Comparison Study Of Consumer’S Perception Toward Urban Air Mobility In The United States And Rest Of The World Using Social Media Information, S M Toki Tahmid

USF Tampa Graduate Theses and Dissertations

Urban Air Mobility (UAM) is a wide concept that will enable access to on-demand air mobility, cargo delivery, medical applications, and emergency services that is run through a connected and integrated transportation system. This study aims to investigate social media data to compare the major topics discussed in the United States and rest of the world and perform a sentiment analysis to see if the comments are positive, negative, or neutral. Twitter was the primary source of information that was used in this thesis, as it is a place where people interact, create, and share information and ideas online. In …

A Machine Learning Approach Towards Analyzing Impact Of Surface Weather On Expect Departure Clearance Times In Aviation, Dothag Truong, Shlok Misra, Godfrey V. D'Souza

Publications

Commercial air travel in the United States has grown significantly in the past decade. While the reasons for air traffic delays can vary, the weather is the largest cause of flight cancellations and delays in the United States. Air Traffic Control centers utilize Traffic Management Initiatives such as Ground Stops and Expect Departure Clearance Times (EDCT) to manage traffic into and out of affected airports. Airline dispatchers and pilots monitor EDCTs to adjust flight blocks and flight schedules to reduce the impact on the airline’s operating network. The use of time-series data mining can be used to assess and quantify …

Generative Spatio-Temporal And Multimodal Analysis Of Neonatal Pain, Md Sirajus Salekin

USF Tampa Graduate Theses and Dissertations

Neonates can not express their pain like an adult person. Due to the lacking of proper muscle growth and inability to express non-verbally, it is difficult to understand their emotional status. In addition, if the neonates are under any treatment or left monitored after any major surgeries (post-operative), it is more difficult to understand their pain due to the side effect of medications and the caring system (i.e. intubated, masked face, covered body with blanket, etc.). In a clinical environment, usually, bedside nurses routinely observe the neonate and measure the pain status following any standard clinical pain scale. But current …

Assessment Of Narrow-Band And Full Spectrum Gas Radiation Methods In A Real Industrial Glass Furnace Configuration, M. Galtier, W. Woelffel, F. André, V. P. Solovjov, B. W. Webb, Somesh Roy

Mechanical Engineering Faculty Research and Publications

This work is dedicated to a comparison of various methods of gaseous flame radiation in a three-dimensional configuration representative of a glass furnace studied at Saint Gobain Research Paris. For this purpose, several narrow band and full spectrum models of flame radiation are assessed against LBL calculations. Among narrow band models, the recently proposed l-distribution method is shown to be more accurate than the k-distribution method. Among global models, the RC-SLW technique provides a high accuracy and can be confidently used for radiative heat transfer calculations in three-dimensional high temperature configurations.

Residual Properties Of Silicone (Med-4719) Lead With Leads From Retrieved Devices, Anmar Salih, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Leads are designed for in vivo applications, however, for a definite period of time. In-vivo environment affects the mechanical behavior of implantable devices, therefore, there is a need to evaluate the residual properties of implantable leads used with pacemakers, defibrillator and neuro-stimulators. Silicone (MED-4719) lead is widely used in cardiac implantable electronic devices made by different manufacturers. . We collected 150 devices (with or without leads) from Anatomical Gift Program of the Wright State University. The objective of this study was to investigate the residual properties of Silicone (MED-4719) lead with different in vivo exposure time and compare the properties …

Chapter 6: Hydraulic Grade Line (Hgl) And Energy Grade Line (Egl), Donald V. Chase

Open Educational Resource: Civil Engineering Course Notes

No abstract provided.

Intelligent Control Of Groundwater In Slopes With Deep Reinforcement Learning †, Aynaz Biniyaz, Behnam Azmoon, Zhen (Leo) Liu

Michigan Tech Publications, Part 1

The occurrence of landslides has been increasing in recent years due to intense and prolonged rainfall events. Lowering the groundwater in natural and man-made slopes can help to mitigate the hazards. Subsurface drainage systems equipped with pumps have traditionally been regarded as a temporary remedy for lowering the groundwater in geosystems, whereas long-term usage of pumping-based techniques is uncommon due to the associated high operational costs in labor and energy. This study investigates the intelligent control of groundwater in slopes enabled by deep reinforcement learning (DRL), a subfield of machine learning for automated decision-making. The purpose is to develop an …

Business Benefits Associated With Improving Fatigue Regulations For Cargo Pilots, Arthur Chiari, Bruna De Gois E Silva, Nelson Christianini

Student Works

The central idea of this research is to assess business-related factors in the Pilots ́ Fatigue Regulations and evaluate if a more flexible regulation would improve productivity of airline cargo pilots in Brazil.

The results of the study have indicated that Brazilian Civil Aviation Authority (ANAC) can create a regulatory environment that may lead up to 34,28% of improved productivity of pilots ́ availability in cargo operations, which may contribute for gains up to USD $3.6 million for an airline with cargo 70 pilots flying 16.500 hours per year.

Aviation fatigue regulations are an extremely important subject in the aviation …

Deepdemod: Bpsk Demodulation Using Deep Learning Over Software-Defined Radio, Arhum Ahmad, Satyam Agarwal, Sam Darshi, Sumit Chakravarty

Open Access Publishing Fund Collection

In wireless communication, signal demodulation under non-ideal conditions is one of the important research topic. In this paper, a novel non-coherent binary phase shift keying demodulator based on deep neural network, namely DeepDeMod, is proposed. The proposed scheme makes use of neural network to decode the symbols from the received sampled signal. The proposed scheme is developed to demodulate signal under fading channel with additive white Gaussian noise along with hardware imperfections, such as phase and frequency offset. The time varying nature of hardware imperfections and channel poses a additional challenge in signal demodulation. In order to address this issue, …

Compilation Optimizations To Enhance Resilience Of Big Data Programs And Quantum Processors, Travis D. Lecompte

LSU Doctoral Dissertations

Modern computers can experience a variety of transient errors due to the surrounding environment, known as soft faults. Although the frequency of these faults is low enough to not be noticeable on personal computers, they become a considerable concern during large-scale distributed computations or systems in more vulnerable environments like satellites. These faults occur as a bit flip of some value in a register, operation, or memory during execution. They surface as either program crashes, hangs, or silent data corruption (SDC), each of which can waste time, money, and resources. Hardware methods, such as shielding or error correcting memory (ECM), …

Enabling The Human Perception Of A Working Camera In Web Conferences Via Its Movement, Anish Shrestha

LSU Master's Theses

In recent years, video conferencing has seen a significant increase in its usage due to the COVID-19 pandemic. When casting user’s video to other participants, the videoconference applications (e.g. Zoom, FaceTime, Skype, etc.) mainly leverage 1) webcam’s LED-light indicator, 2) user’s video feedback in the software and 3) the software’s video on/off icons to remind the user whether the camera is being used. However, these methods all impose the responsibility on the user itself to check the camera status, and there have been numerous cases reported when users expose their privacy inadvertently due to not realizing that their camera is …

Sers Platform For Single Fiber Endoscopic Probes, Debsmita Biswas

LSU Doctoral Dissertations

Molecular detection techniques have huge potential in clinical environments. In addition to many other molecular detection techniques, endoscopic Raman spectroscopy has great ability in terms of minimal invasiveness and real-time spectra acquisition. However, Raman Effect is low in sensitivity, limiting the application. Surface-Enhanced Raman Scattering (SERS), addresses this limitation. SERS brings rough nano-metallic surfaces in contact with specimen molecules which enormously enhances Raman signals. This provides Raman spectroscopy with immense capabilities for diverse fields of applications.

Generally, in clinical probe applications, the spectrometer is brought near the target molecules for detection. Typically, optical fibers are used to couple spectrometers to …

Geospatial Analysis Of Impact On Evacuation Routes And Urban Areas In South Texas Due To Flood Events, Layda B. Spor Leal, Jungseok Ho, Sara E. Davila

Civil Engineering Faculty Publications

The Lower Rio Grande Valley has historically faced a variety of hurricanes and tropical storms that have led to sever flooding. As a consequence, waves of mass evacuation of the local population with the means of transportation occur frequently. While evacuation is encouraged in some cases of disaster, the routing is not always available as water takes to roads and drainage capacities are overwhelmed. In order to dissert the most appropriate evacuation routes, it is necessary to analyze the areas that will be affected in the future based on urban locations, elevation, and historical information. This project utilizes a semi-coupled …

Adiabatic Shear Banding In Nickel And Nickel-Based Superalloys: A Review, Russell A. Rowe, Paul G. Allison, Anthony N. Palazotto, Keivan Davami

Faculty Publications

This review paper discusses the formation and propagation of adiabatic shear bands in nickel-based superalloys. The formation of adiabatic shear bands (ASBs) is a unique dynamic phenomenon that typically precedes catastrophic, unpredicted failure in many metals under impact or ballistic loading. ASBs are thin regions that undergo substantial plastic shear strain and material softening due to the thermo-mechanical instability induced by the competitive work hardening and thermal softening processes. Dynamic recrystallization of the material’s microstructure in the shear region can occur and encourages shear localization and the formation of ASBs. Phase transformations are also often seen in ASBs of ferrous …

Toward A Safer Transportation System For Senior Road Users, Saba Doulabi

LSU Doctoral Dissertations

Senior pedestrians and drivers (65 years and older) are among the most vulnerable road users. As the population of seniors rise, concerns regarding older adults' traffic safety are growing. The advantages of using autonomous vehicles, innovative vehicle technologies, and active transportation are becoming more widely recognized to improve seniors' mobility and safety. This behooves researchers to further investigate senior road users’ safety challenges and countermeasures. This study contributes to the literature by achieving two main goals. First, to explore contributing factors affecting the safety of older pedestrians and drivers in the current transportation system. Second, to examine seniors’ perceptions, preferences, …

Spam Detection Using Machine Learning And Deep Learning, Olubodunde Agboola

LSU Doctoral Dissertations

Text messages are essential these days; however, spam texts have contributed negatively to the success of this communication mode. The compromised authenticity of such messages has given rise to several security breaches. Using spam messages, malicious links have been sent to either harm the system or obtain information detrimental to the user. Spam SMS messages as well as emails have been used as media for attacks such as masquerading and smishing ( a phishing attack through text messaging), and this has threatened both the user and service providers. Therefore, given the waves of attacks, the need to identify and remove …

Local Astronaut May Command U.S.-Russian Flight (Reprint From 1972), Weatherford Daily News

Articles

EDITOR’S NOTE: this story first appeared in the November 2, 1972, edition of the Weatherford Daily News, 50 years ago today, about Lt. Gen. Thomas P. Stafford’s chance to commence a U.S.-Russian space flight.

Unless stated otherwise within this repository collection, all materials are shared under the following Creative Commons license: [Creative Commons Attribution-NonCommercial 4.0 International License].

A Field-Deployable Quartz Crystal Microbalance System For Gas Detection, Jongyoon Park

LSU Doctoral Dissertations

Quartz crystal microbalance (QCM) has been widely studied as a mass sensing technique in laboratory environments and has shown a wide range of industrial applications such as food quality control, various forms of chemical detection, and biomolecular recognition under gas phase as well as liquid phase media. The construction of multi-sensor arrays combined with special sensor coatings enables multiple analyte detections and discrimination of multi-analyte along with statistical analysis. Despite the great sensing capabilities of QCM and growing interest in practical applications beyond the laboratory setup, most QCM studies are still performed in laboratory settings with benchtop QCM instruments. Therefore, …

Interactive Industrial Energy Assessment Learning Platform Using 360-Degree Virtual Reality Contents, Laleh Ghanbari

LSU Doctoral Dissertations

The traditional passive industrial energy assessment training methods included low direct involvement of students, and they lacked an engaging learning environment. Since the main task for energy assessment is visual inspection and data collection, traditional passive training methods were not able to provide hands-on experience for the students. An active training method was needed to make the current industrial energy assessment training more efficient and effective, a method which provides the opportunity for students to have more interaction with the training environment. In this study, an interactive industrial energy assessment learning platform using 360ᵒ virtual reality contents was developed. The …

Experimental Evidence That Shear Bands In Metallic Glasses Nucleate Like Cracks, Alan A. Long, Wendelin Wright, Xiaojun Gu, Anna Thackray, Mayisha Nakib, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

Highly time-resolved mechanical measurements, modeling, and simulations show that large shear bands in bulk metallic glasses nucleate in a manner similar to cracks. When small slips reach a nucleation size, the dynamics changes and the shear band rapidly grows to span the entire sample. Smaller nucleation sizes imply lower ductility. Ductility can be increased by increasing the nucleation size relative to the maximum (“cutoff”) shear band size at the upper edge of the power law scaling range of their size distribution. This can be achieved in three ways: (1) by increasing the nucleation size beyond this cutoff size of the …