Engineering Commons^™

Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation, Mujan N. Seif, Thomas John Balk, Matthew J. Beck

Chemical and Materials Engineering Faculty Publications

Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no …

Radial Basis Densities And The Density Functional-Based Atom-In-Molecule: Designing Charge-Transfer Potentials, Godwin Amo-Kwao

Nanoscience and Microsystems ETDs

Classical potentials that are capable of describing charge transfer and charge polarization in complex systems are of central importance for classical atomistic simulation of biomolecules and materials. Current potentials—regardless of the system—do not generalize well, and, with the exception of highly-specialized empirical potentials tuned for specific systems, cannot describe chemical bond formation and breaking. The charge-transfer embedded atom method (CT-EAM), a formal, DFT-based extension to the original EAM for metals, has been developed to address these issues by modeling charge distortion and charge transfer in interacting systems using pseudoatom building blocks instead of the electron densities of isolated atoms. CT-EAM …

Data Analysis To Evaluate The Performance Of Breathing Masks Used For Filtering Nano-Level Particles At Manufacturing Sites, Gracia M. Dardano

Honors College Theses

The work performed in this research aims to evaluate the performance of commercially available breathing masks in filtering airborne nanoparticles at manufacturing sites. Nanoparticles are found virtually anywhere, from dust in a worksite to a simple sneeze. Therefore, they pose a substantial threat to human health as their velocity and volatility are high. This research analyzes if current efforts of breathing masks to hinder nanoparticles are effective, especially at manufacturing sites. Data has been collected in order to analyze the behavior of nanoparticles and to measure nanoparticle levels at manufacturing sites and its working environment. Data is statistical in nature …

Grow Local Manufacturing Along Us/Mexico Border Region For An Integrated Supply Chain In The Post Covid-19 Era, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications

The current coronavirus disease pandemic, plus the strong movement of manufacturing reshoring, provide a unique opportunity for many US regions to grow local manufacturers. This technical note attempts to review the current situation and trend in US manufacturing. We then discuss challenges and necessary steps, such as asset mapping, required to grow local suppliers. Suggestions are then made to support growing local suppliers along the US/Mexico border region.

Constructing A Complete Landslide Inventory Dataset For The 2018 Monsoon Disaster In Kerala, India, For Land Use Change Analysis, Lina Hao, Rajaneesh A., Cees Van Westen, Sajinkumar K. S., Tapas Ranjan Martha, Pankaj Jaiswal, Brian G. Mcadoo

Michigan Tech Publications, Part 1

Event-based landslide inventories are important for analyzing the relationship between the intensity of the trigger (e.g., rainfall, earthquake) and the density of the landslides in a particular area as a basis for the estimation of the landslide probability and the conversion of susceptibility maps into hazard maps required for risk assessment. They are also crucial for the establishment of local rainfall thresholds that are the basis of early warning systems and for evaluating which land use and land cover changes are related to landslide occurrence. The completeness and accuracy of event-based landslide inventories are crucial aspects to derive reliable results …

Potential Of Hemp (Cannabis Sativa L.) For Paired Phytoremediation And Bioenergy Production, Hanah T. Rheay, Emmanuel C. Omondi, Catherine E. Brewer

Agricultural and Environmental Sciences Faculty Research

Hemp (Cannabis sativa L.) is a multi-use crop that has been investigated for its potential use in phytoremediation of heavy metals, radionuclides, and organic contaminants, and as a feedstock for bioenergy production. A review of research literature indicates that hemp is a suitable crop for phytoremediation, and a competitive option for bioenergy. Coupling phytoremediation and bioenergy production from a single hemp crop is a potential solution to overcoming the economic constraints of phytoremediation projects. The current challenge is ensuring that the extracted contaminants are not introduced into the consumer marketplace. After several decades of limited research on hemp in the …

Annual Simulation Of Photovoltaic Retrofits Within Existing Parabolic Trough Concentrating Solar Powerplants, Nipun Goel, Hannah O'Hern, Matthew Orosz, Todd Otanicar

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Solar power for electricity production comes from either photovoltaics or concentrating solar power plants. The former has seen rapid growth and expansion due to the rapid fall in global prices, while the latter has seen moderate growth due to ability to cheaply store thermal energy for later use. Hybridization, or combining photovoltaics with concentrating solar power represents a potential way for lowering cost while enabling long term storage. Over 5 GW of capacity exist worldwide using parabolic trough style technology for concentrating solar power which presents a unique option for optimization in the form of a photovoltaic retrofit. While it …

Integrating Deep Learning And Augmented Reality To Enhance Situational Awareness In Firefighting Environments, Manish Bhattarai

Electrical and Computer Engineering ETDs

We present a new four-pronged approach to build firefighter's situational awareness for the first time in the literature. We construct a series of deep learning frameworks built on top of one another to enhance the safety, efficiency, and successful completion of rescue missions conducted by firefighters in emergency first response settings. First, we used a deep Convolutional Neural Network (CNN) system to classify and identify objects of interest from thermal imagery in real-time. Next, we extended this CNN framework for object detection, tracking, segmentation with a Mask RCNN framework, and scene description with a multimodal natural language processing(NLP) framework. Third, …

Fusion-Features And Visual-Dictionary Image Recognition Methods For Apple Classification In Smart Manufacturing, Ahsiah Ismail

Student Works (2020-2029)

Smart manufacturing enables an efficient manufacturing process to optimize production. The optimization is performed through data analytics that requires reliable and informative data as input. Therefore, in this research, two image recognition feature extraction methods namely Curvelet Wavelet-Gray Level Co-occurrence Matrix (CWGLCM) and Fuzzy-Spatial Pyramid Matching (F-SPM) are proposed to provide reliable inputs for vision-based apple classification in smart manufacturing. Feature extraction is one of the major steps that could influent the efficiency of the manufacturing process. The CW-GLCM method is a feature extraction of fusion-features with Decision Tree classifier, while the F-SPM method uses a visual-dictionary based method to …

Energy-Efficient Communications In Wireless Powered Cognitive Radio Networks Based On Game Theory, Fadhil Mukhlif Aswad Al-Obaidy

Student Works (2020-2029)

There are challenging and prevalent problems related to spectrum resources with the interference of battery-based devices in future wireless networks. To address such challenges, this thesis proposes a theoretical framework for designing and analyzing the distributed power control algorithms in modern 5G cognitive networks. Previous experiments have shown that game theory tools can be used as a suitable and efficient technique to build scalable, balanced, and energy efficient for the distributed power control schemes in order to use it practically in battery-based devices in wireless networks. In reality, the power control issue is constructed as a non-cooperative game for which …

Optimal Matching Reactance Design And Validation In Wireless Power Transfer System For Electric Vehicle Based On Sae J2954-Rp, Anfeng Huang, Dongwook Kim, Qiusen He, Hanyu Zhang, Yuyu Zhu, Hongseok Kim, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Wireless power transfer (WPT) is foreseen as a suitable technology to provide charging without cables to electric vehicles. The charging requires a specific charging profile for different type of battery. In addition, the loading condition of the charging circuit could change drastically as following the charging profile. Due to the dependencies on loading condition, the transmission efficiency of a WPT system could degrade during the charging process. Nevertheless, the sensitivity of efficiency to loading condition could be reduced with proper design of compensation network, e.g., LCC. In this paper, a SPICE-simulation based optimization flow is demonstrated for matching reactance optimization …

A Deep Neural Network-Based Estimation Of Efficiency Enhancement By An Intermediate Coil In Automotive Wireless Power Transfer System, Boogyo Sim, Daehwan Lho, Dongryul Park, Seungtaek Jeong, Seongsoo Lee, Hongseok Kim, Hyunwook Park, Hyungmin Kang, Seokwoo Hong, Joungho Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we proposed a deep neural network (DNN)-based estimation of efficiency enhancement by an intermediate (Int) coil in automotive wireless power transfer (WPT) system. The Int coil can enhance the efficiency in the WPT system with the proper resonant frequency of the Int coil. The previous study has explained the resonant frequency of the Int coil should be higher than the operating frequency. According to the resonant frequency of the Int coil, we can achieve the amount of efficiency enhancement. Therefore, the design of the Int coil is essential for optimize the efficiency enhancement of the automotive WPT …

Cochlear Implant Wireless Power Transfer System Design For High Efficiency And Link Gain Stability Using A Proposed Stagger Tuning Method, Seokwoo Hong, Seungtaek Jeong, Seongsoo Lee, Boogyo Sim, Hongseok Kim, Hoseung Lee, Woojin Ahn, Jonghyeok Park, Seunghoom Lee, Joungho Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In recent years, wireless power transfer (WPT) technology is becoming an increasingly important part of the various applications because of its safety. Especially, medical implant devices such as a cochlear implant are one of the typical applications of the WPT technology. Because of the individual body differences, however, the coupling coefficient of the WPT system can be changed. Therefore, the coupling coefficient-insensitivity is very important design issue. In this paper, we propose a stagger tuning method of a cochlear implant WPT system. The proposed method makes the cochlear implant WPT system stable at the link gain regardless of the coupling …

Investigation Of The Hall-Petch Relationship Using Strain Gradient Plasticity Model For Finite Deformation Framework, Yooseob Song

Civil Engineering Faculty Publications

The Hall-Petch relationship in metals is investigated using the strain gradient plasticity theory within the finite deformation framework. For this purpose, the thermodynamically consistent constitutive formulation for the coupled thermomechanical gradient-enhanced plasticity model is developed. The corresponding finite element method is performed to investigate the characteristics of the Hall-Petch relationship in metals. The proposed model is established based on an extra Helmholtz-type partial differential equation, and the nonlocal quantity is calculated in a coupled method based on the equilibrium conditions. An excellent agreement between the simulation results and the test data is resulted in the Hall-Petch graph. Furthermore, it is …

Using Tandem-X To Measure Pyroclastic Flow Source Location, Thickness And Volume: Application To The 3rd June 2018 Eruption Of Fuego Volcano, Guatemala, F. Albino, J. Biggs, R. Escobar-Wolf, A. Naismith, M. Watson, J. C. Phillips, G. A. Chigna Marroquin

Michigan Tech Publications, Part 1

The estimation of the volume of volcanic flows during an ongoing eruption is challenging but this information is crucial for improving risk assessment and for forecasting future events. Although previous studies have shown the ability of TanDEM-X satellite data to derive the thickness and the volume of lava flow fields during effusive eruptions, the method has not been explored yet for pyroclastic flows. Using bi-static interferometry, we produce TanDEM-X DEM on Fuego volcano (Guatemala) to measure the significant topographic changes caused by the 3rd June 2018 eruption, which destroyed the town of San Miguel Los Lotes. We estimate the volume …

Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers, Fuqian Yang, Shanshan Wang, Yuling Zhang

Chemical and Materials Engineering Faculty Publications

The progress in the fabrication of carbon-nanotube-based structures has made it possible to use Raman spectroscopy to measure the deformation states of carbon nanotubes and abutting materials. In this work, we investigate the effects of laser power and surrounding materials on the Raman shift of carbon-nanotube (CNT) papers for the laser intensity in a range of 0.071 to 1.415 kW/mm² without action of mechanical loading. Two different configurations of the CNT papers are used in the Raman measurement; one uses a suspended CNT paper, and the other places a CNT paper on a glass or aluminum substrate. The experimental …

Evaluation Of A Bulge Reduction Technology For Corrugated Fiberboard Containers Under Static Compression, Daan Peleman, Jay Singh, Koushik Saha, S. Roy

Journal of Applied Packaging Research

This research examines the effect of top-to-bottom static compression load on the bulge of RSC containers. The study compares a control regular slotted container (RSC) constructed with corrugated fiberboard to tape-reinforced designs. The bulge reduction, achieved using various tape placements and conditioning environments, were measured. Currently, no research on the effect of reinforcement tape towards reduction in the out-of-plane displacement (bulging) of the corrugated fiberboard panels has been undertaken. Samples related to four different container designs, varying by presence, quantity and the position of the reinforcement tape on the vertical panels, were tested and analyzed. The study involved the use …

Obtaining Mechanical Shock Fragility Statistics For Simple Stochastic Cushioning Design., Shogo Horiguchi, Katsuhiko Saito

Journal of Applied Packaging Research

Proper cushioning to prevent product damage and over-packaging must consider the mechanical-shock fragility of the product. Furthermore, improved cushioning design can be achieved by performing stochastic cushioning design using mechanical-shock fragility statistics and transport hazard statistics. However, many samples are required to obtain mechanical-shock fragility statistics from standard testing comprising critical velocity change tests and critical-acceleration tests (the “conventional method”). In many cases, the required number of samples cannot be prepared. Thus, this research is designed to develop testing methods requiring half the number of samples of the conventional method. Thus far, "test method with one sample" has been developed …

Water Resources International Development: What On Earth Are We Doing?, Patrick Ray

All ECSTATIC Materials

Large agencies such as the World Bank, the Millennium Challenge Corporation, the United Nations, regional development banks (such as the Asian Development Bank), and philanthropic organizations (such as the Rockefeller Foundation) are actively engaged in water resources development in low-income countries. Why? And what metrics do they use to decide if the investments of hundreds of millions or billions of dollars in water infrastructure projects are justified? And what accommodations do they tend to make for risks such as climate change? And what attention do they tend to give to questions of equity? I probably have no idea. But I’ve …

Isolation Of Specific Phospholipids From Nannochloropsis Oculata Microalga For Cosmetic Applications, Ahmet Yener Manisali

USF Tampa Graduate Theses and Dissertations

Algae, photosynthetic aquatic organisms, have recently caught the attention of the food, cosmetic, pharmaceutical, and nutraceutical industries due to the variety of natural compounds in their cellular bodies such as carbohydrates, lipids, and proteins. Specifically, microalgae-derived natural compounds such as phospholipids are extensively utilized in cosmetics as part of liposome formers, emulsifiers, solubilizers, and wetting agents. Although phospholipids are currently extracted from food sources, this practice raises sustainability concerns. Hence, growing microalgae on the provision of macronutrients such as nitrates and phosphates will serve as a more sustainable source of the several specific phospholipids such as phosphatidylcholine (PC), phosphatidyl-ethanolamine (PE), …

Conversion From Metal Oxide To Mof Thin Films As A Platform Of Chemical Sensing, Meng Chen

USF Tampa Graduate Theses and Dissertations

Chemical sensor is working as a widely used device which can be applied to the detection of specific chemicals that are existing in the environment especially in gas phase. The detection of combustible and toxic chemicals can be extremely important in the field of both industrial and civil activities. The chemical sensor is commonly operating by utilizing a chemical or physical interaction between the specific chemical compound and the sensing functional unit, to obtain an electronic signal caused by the property change and realize the chemical detection. Traditional chemical gas sensors such as catalytic gas sensor, thermal conductivity gas sensor, …

Proximity-Induced Magnetization In Graphene: Towards Efficient Spin Gating, Mihovil Bosnar, Ivor Lončarić, P. Lazić, Kirill Belashchenko, Igor Žutić

Kirill Belashchenko Publications

Gate-tunable spin-dependent properties could be induced in graphene at room temperature through the magnetic proximity effect by placing it in contact with a metallic ferromagnet. Because strong chemical bonding with the metallic substrate makes gating ineffective, an intervening passivation layer is needed. Previously considered passivation layers result in a large shift of the Dirac point away from the Fermi level, so that unrealistically large gate fields are required to tune the spin polarization in graphene (Gr). We show that a monolayer of Au or Pt used as the passivation layer between Co and graphene brings the Dirac point closer to …

Identification Of Ecg Anomalies Through Deep Deterministic Learning, Uzair Iqbal

Student Works (2020-2029)

Electrocardiography (ECG) is a primary diagnostic tool for measuring the malfunctioning of the heart muscles in the context of morbidity of different cardiac diseases and arrhythmia. Different existing techniques and methods delivered accurate cardiac diseases myocardial infarction (heart stroke) and atrial fibrillation recognition. However, there are still some flaws in existing methods like recognition of special myocardial infarction situation flattened T wave in “Non-Specific ST-T Changes (nsst-t)” and reduction of computational cost in cardiac diseases recognition. Accurate recognition of cardiac diseases along with least computational complexity and feature analysis of flattened T wave in myocardial infarction remains an open job. …

Experimental Investigation Of Liquid Height Estimation And Simulation Verification Of Bolt Tension Quantification Using Surface Acoustic Waves, Hani Alhazmi

USF Tampa Graduate Theses and Dissertations

In this dissertation, two separate applications that are related to surface acoustic waves in a solid media are presented. The first study concerns simulating and validating an experimentally study for quantifying the bolt tension in the bolted joints using the surface acoustic wave. The second study experimentally investigates measuring the level of a liquid existing on a solid surface via surface acoustic waves and exploring the effect of liquid existence on the propagation of surface acoustic waves over the solid surface.

Quantifying bolt tension and ensuring that bolts are appropriately tightened for large-scale civil infrastructures are crucial. This study investigates …

New Metal Based Saturable Absorber For Ultrashort Pulse Generation, Muhammad Taufiq Ahmad

Student Works (2020-2029)

Cost-efficient, robust and flexible laser systems are vital for a wide-range of applications ranging from high-precision material processing to biomedicine. This thesis aims to explore pure silver and gold based saturable absorbers (SAs) as Q-switcher and mode-locker in various fibre laser cavities. The generations of Q-switched pulses in 1-,1.55-, and 2-micron regions have been successfully demonstrated using a pure gold, which was deposited using electron beam deposition onto a PVA thin-film as SA. For instance, a stable Q-switched thulium-doped fibre laser (TDFL) operating at 1949 nm was successfully demonstrated with the gold SA. The proposed laser generates Q switched pulses …

Evaluating Public Transit Accessibility In Albuquerque, New Mexico: A Fixed-Route Bus Service Analysis, Risa E. Gutierrez

Civil Engineering ETDs

This research analyzed how residential accessibility to fixed-route bus service in Albuquerque, New Mexico varies by distance, income level, and headway. A literature review investigated components of travel that might deter people from using public transit such as travel distance, sidewalk condition or availability, bus headway, lack of active travel in today’s society, personal and traffic safety, and access equity. Geographic Information System (GIS) mapping was used to determine if low-income neighborhoods have better or worse access to ABQ Ride bus stops relative to medium- or high-income neighborhoods. Residential land use was divided into three economic classes based on 2018 …

Dynamic Between Biomass, Ph And Acid Lactic By Microorganisms In Fermentation Of Fresh Milk, Emmanuel Rodriguez, Aurelio Castillo, Paul A. Valle, Yolocuauhtli Salazar

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Strain And Stress Relationships For Optical Phonon Modes In Monoclinic Crystals With Β-Ga2O3 As An Example, Rafal Korlacki, Megan Stokey, A. Mock, Sean Knight, A. Papamichail, V. Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Strain-stress relationships for physical properties are of interest for heteroepitaxial material systems, where strain and stress are inherent due to thermal expansion and lattice mismatch. We report linear perturbation theory strain and stress relationships for optical phonon modes in monoclinic crystals for strain and stress situations which maintain the monoclinic symmetry of the crystal. By using symmetry group analysis and phonon frequencies obtained under various deformation scenarios from density-functional perturbation theory calculations on β-Ga₂O₃, we obtain four strain and four stress potential parameters for each phonon mode. We demonstrate that these parameters are sufficient to …

Health Monitoring Using Deep Learning Of Acoustic And Speech Signals, Eric E. Hamke

Electrical and Computer Engineering ETDs

The focus of the research is to identify stress markers in a firefighter's speech. These markers include changes in breathing patterns and changes in the fundamental frequency of an individual’s voice. The breathing patterns are characterized using the number of breaths taken in a minute and the time spent inhaling. These measures are estimated using a Restricted Boltzmann Machine to process a firefighters’ SCBA regulator sounds, as open and closed. The classifications are then combined into continuous intervals. Observing the length of the intervals and the number of interval-starts represents time spent inhaling and the breathing rates (breaths per minute). …

Dynamic Adaptive Policy Pathways, Marjolijn Haasnoot

All ECSTATIC Materials

• Dynamic Adaptive Policy Pathways (DAPP) is a decision making approach that explicitly includes decision making over time. The essence is proactive and dynamic planning in response to how the future actually unfolds.
• DAPP explores alternative sequences of decisions (adaptation pathways) for multiple futures and illuminates the path dependency of alternative strategies. It opens the decision space and helps to overcome policy paralysis due to deep uncertainty. There are different routes that can achieve the objectives under changing conditions (like ‘different roads leading to Rome’).
• Policy actions have an uncertain design life and might fail sooner or later to continue achieving …