Materials Science and Engineering Commons^™

Distributed Modeling Approach For Electrical And Thermal Analysis Of High-Frequency Transistors, Amirreza Ghadimi Avval

Graduate Theses and Dissertations

The research conducted in this dissertation is focused on developing modeling approaches for analyzing high-frequency transistors and present solutions for optimizing the device output power and gain. First, a literature review of different transistor types utilized in high-frequency regions is conducted and gallium nitride high electron mobility transistor is identified as the promising device for these bands. Different structural configurations and operating modes of these transistors are explained, and their applications are discussed. Equivalent circuit models and physics-based models are also introduced and their limitations for analyzing the small-signal and large-signal behavior of these devices are explained. Next, a model …

Direct Torque Control For Silicon Carbide Motor Drives, Mohammad Hazzaz Mahmud

Graduate Theses and Dissertations

Direct torque control (DTC) is an extensively used control method for motor drives due to its unique advantages, e.g., the fast dynamic response and the robustness against motor parameters variations, uncertainties, and external disturbances. Using higher switching frequency is generally required by DTC to reduce the torque ripples and decrease stator current total harmonic distortion (THD), which however can lower the drive efficiency. Through the use of the emerging silicon carbide (SiC) devices, which have lower switching losses compared to their silicon counterparts, it is feasible to achieve high efficiency and low torque ripple simultaneously for DTC drives.

To overcome …

Facile Fabrication And Characterization Of Kraft Lignin@Fe3o4 Nanocomposites Using Ph Driven Precipitation: Effects On Increasing Lignin Content, Frankie A. Petrie, Justin M. Gorham, Robert T. Busch, Serhiy O. Leontsev, Esteban E. Ureña-Benavides, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

This work offers a facile fabrication method for lignin nanocomposites through the assembly of kraft lignin onto magnetic nanoparticles (Fe3O4) based on pH-driven precipitation, without needing organic solvents or lignin functionalization. Kraft lignin@Fe3O4 multicore nanocomposites fabrication proceeded using a simple, pH-driven precipitation technique. An alkaline solution for kraft lignin (pH 12) was rapidly injected into an aqueous-based Fe3O4 nanoparticle colloidal suspension (pH 7) under constant mixing conditions, allowing the fabrication of lignin magnetic nanocomposites. The effects of increasing lignin to initial Fe3O4 mass content (g/g), increasing in ratio from 1:1 to 20:1, are discussed with a complete chemical, structural, and …

Synthesis And Electrochemical Study Of Cuau Nanodendrites For Co2 Reduction, Dylan Siltamaki, Shuai Chen, Farnood Rahmati, Jacek Lipkowski, Ai-Cheng Chen

Journal of Electrochemistry

The conversion of carbon dioxide (CO₂) to carbon monoxide (CO) and other value-added products is an interesting approach for carbon-containing fuel synthesis using renewable and clean energy. The electrochemical reduction of CO₂ is one of the promising strategies for the storage of intermittent renewable energy resources. The development of electrocatalysts with high activity and stability is vital in the electrochemical CO₂ reduction process. In this study, copper and gold alloyed (CuAu) electrodes with nanodendritic structures were synthesized using a facile electrodeposition method. The CuAu nanodendrites with the atomic ratio of Cu to Au being approximately 1:1 …

Recent Advances In Glycerol Electrooxidation On Pt And Pd: From Reaction Mechanisms To Catalytic Materials, Wei-Yi Zhang, Xian-Yin Ma, Shou-Zhong Zou, Wen-Bin Cai

Journal of Electrochemistry

The conversion of glycerol to value-added products has received considerable attention recently because the booming biodiesel industry produces a large amount of glycerol as a byproduct. Among various means, electrocatalytic oxidation of glycerol is appealing owing to its environmental friendliness and high efficiency. However, electrooxidation of glycerol is very complex, involving multiple electron and proton transfer processes with many reaction pathways. How to rationally design catalysts with high selectivity toward targeted products is an overarching challenge, and of both fundamental and practical significance. In this minireview we aim to provide an overview of recent advancements in electrooxidation of glycerol focusing …

Design And Fabrication Of The Electrolytic Cell With Silicon-Based Boron-Doped Diamond Electrode And Its Feasibility ForIn-Situ Nuclear Magnetic Resonance Study, Hao Peng, Hui-Jun Sun, Zhi-You Zhou, Lin-Fan Shen, Long Huang, Shuo-Hui Cao, Shi-Gang Sun

Journal of Electrochemistry

In-situ EC-NMR technique can be used to monitor the electrochemical reaction process in real-time and to explain the reaction mechanism at the molecular level, which is a promising and non-destructive online detection technology. This article for the first time reports the design and production of in-situEC-NMR three-electrode single-chamber electrolytic cell using silicon-based boron-doped diamond (Si/BDD) as the working electrode. Research shows that the geometric size of Si/BDD electrode being 12.5 mm 1.2 mm 0.5 mm in the NMR detection zone is small and the thickness of the electrode material is thin, which accounts for the less hindrance …

Progress Of Lithium-Ion Transport Mechanism In Solid-State Electrolytes, Bing-Kai Zhang, Lu-Yi Yang, Shun-Ning Li, Feng Pan

Journal of Electrochemistry

Inorganic crystalline solid electrolytes exhibit exceptional room-temperature ionic conductivities, giving them the potential to enable all-solid-state lithium (Li) - ion batteries. Developing new high-performance electrolytes is one of the most critical challenges to realize solid-state batteries, which requires understanding how chemistry facilitates fast ionic conduction and what the Li-ion migration mechanism is in inorganic solid electrolytes. In this review, we aim to summarize recent fundamental research progress in Li-ion transport, including crystal structure, behavior of ion migration (i.e., single-ion jump and multi-ions cooperative migration), and the relationship between ion migration and microstructure.
Generally, ion transport in crystalline structure can be …

Preparation Of Co1-XS-Mns@Cnts/Cnfs For Electrocatalytic Oxygen Reduction Reaction, Fang-Yan Liu, Qian Zhang, Yue-Kun Li, Feng Huang, Meng-Ye Wang

Journal of Electrochemistry

As an important cathode reaction in fuel cells and metal-air batteries, oxygen reduction reaction (ORR) is a complex reaction of slow kinetics, which severely limits performances of fuel cells and metal-air batteries. Therefore, it is of key importance to find an efficient and stable electrocatalyst to promote ORR. Carbon-based materials, which possess high conductivity, good stability and large specific surface area, are usually used in electrocatalytic ORR. However, pure carbon-based materials exhibit low efficiency. Coupling carbon-based materials with manganese (Mn) and cobalt (Co) transition metals containing 3d orbitals is an effective way to improve electrocatalytic performance. Herein, carbon nanofibers containing …

Research And Application Of Copper Electroplating In Interconnection Of Printed Circuit Board, Chong Wang, Chuan Peng, Jing Xiang, Yuan-Ming Chen, Wei He, Xin-Hong Su, Yu-Yao Luo

Journal of Electrochemistry

Copper electroplating is the key technology for manufacturing of integrated circuit, packaging substrate, printed circuit board, and other electronic interconnection components. However, the electrochemistry and mechanism of deposition growth have not been fully elucidated, and the development of additives and bath maintenance are inseparable from a large number of experiments. This article reviews recent fundamental research and application progress in copper electroplating for printed circuit board industry, and these works are mainly dedicated by the research group of Printed Circuit and Printed Electronics from University of Electronic Science and Technology of China. First of all, a brief history of copper …

Corrosion Propagation Of Stainless Steel Reinforced Concrete, Nelly Sofía Orozco Martínez

USF Tampa Graduate Theses and Dissertations

Structural durability is a growing concern in global infrastructure. The infrastructure report card released by the American Society of Civil Engineers (ASCE) indicates that approximately 9.1% of the total bridges in the United States were structurally deficient in 2016. In addition, it suggests that about 40% of the total bridges in the country are now 50 years or older. This issue becomes even more critical in structures exposed to aggressive environments such as marine structures. Thus, federal and regional efforts are now being directed towards infrastructural durability improvement to improve the long-term cost-efficiency of civil infrastructure.

Corrosion prevention strategies may …

Atomistic Thermo-Mechanical Description Of The Deformation Behavior, Scaling Laws, And Constitutive Modeling Of Nanoporous Gold, Mohammed Hassan Yousef Saffarini

LSU Doctoral Dissertations

Metallic foams, or nanoporous (NP) metals as it is widely referred to in literature, with ligament sizes up to a few tens of nm show exceptional mechanical properties such as high strength and stiffness per weight ratio under different loading scenarios due to their high surface area to solid volume ratio. Therefore, they can be utilized in a wide range of applications making them of great interest to researchers. While their elasticity and yield strength have been the subject of several studies, very limited attention was given to the effect of size, strain rate, and temperature on the material plastic …

Mechanical Failure Of Metal/Ceramic Interfacial Regions Under Shear And Tensile Loading, Xiaoman Zhang

LSU Doctoral Dissertations

Quantitative assessment of the adhesion strength of ceramic hard coatings on substrates is a subject of great technological importance as well as current scientific relevance. Achievement of reliable and quantitative measurements of interfacial strength has proven difficult over the past two decades. In this dissertation, how the deformation and fracture behavior of ceramic/metal/substrate interfacial regions under shear and tensile loading is influenced by the structure and chemical composition of the interfacial region were observed and discussed. Interfacial shear failure experiments were carried out on focused ion beam fabricated micro pillars containing interfacial regions of ceramic/metal/substrate systems. Detailed characterization was carried …

The Effect Of Room-Temperature Aging On Enthalpy And Dielectric Property Of Carbon-Fiber/Epoxy Composite Prepreg And The Mechanical Property Of Manufactured Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Relebohile George Qhobosheane, Vamsee Vadlamudi

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

Fiber-based reinforced plastics are widely used materials in different industries - e.g., Automotive, Aerospace, Defense- because of their various advantages. The most reliable raw materials for manufacturing fiber-based composites are pre-impregnated reinforcing fiber (prepreg). However, the limitation of using prepreg lies in its instability at room temperature. Prepregs have a specific out-life which sometimes makes the manufacturing process difficult. The objective of this study is to find out a way to investigate the room temperature aging effect on prepreg by analyzing the enthalpy and dielectric properties. In this study, differential scanning calorimetry (DSC) was used to measure the reaction enthalpy …

Role Of Lithium Doping In P2-Na0.67Ni0.33Mn0.67O2 For Sodium-Ion Batteries, Yingying Xie, Eric Gabriel, Haoyu Zhu, Julie Pipkin, Malia Dustin, Hui Xiong

Materials Science and Engineering Faculty Publications and Presentations

P2-structured Na_0.67Ni_0.33Mn_0.67O₂ (PNNMO) is a promising Na-ion battery cathode material, but its rapid capacity decay during cycling remains a hurdle. Li doping in layered transition-metal oxide (TMO) cathode materials is known to enhance their electrochemical properties. Nevertheless, the influence of Li at different locations in the structure has not been investigated. Here, the crystallographic role and electrochemical impact of lithium on different sites in PNNMO is investigated in Li_xNa_0.67–yNi_0.33Mn_0.67O_2+δ (0.00 ≤ x ≤ 0.2, y = 0, 0.1). Lithium occupancy on prismatic Na …

Experimental Investigation Of The Performance Of A Hybrid Self-Healing System In Porous Asphalt Under Fatigue Loadings, Shi Xu, Liu Xueyan, Amir Tabakovic, Erik Schlangen

Articles

Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO2 emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with …

The Role Of Scenography In The Narration Of The Inner Space Of Contemporary Museums Through Employment The Space Staging, Shamael M. W. Al-Dabbagh, Dania Saleh Yaheia Al-Jaboury

Al-Esraa University College Journal for Engineering Sciences

In the recent period, several design mechanisms have emerged related to the design of internal spaces in architecture, specifically the museum spaces and associated with exhibitions, and the most important of these scenographic mechanisms are clearly and significantly adopted in the field of theater to design the stage and the scene that embodies the narrative vision and the idea of the theater director and scenographic designer to express what the text wants from Anecdotal expressing the objectives of the product of the text, therefore the research aimed to delve into the effect of the scenography mechanism on the contemporary architectural …

Evaluating The Performance Of The Jadriya Water Project For Water Treatment, Rana Mohammed Rasheed

Al-Esraa University College Journal for Engineering Sciences

For the purpose of evaluating the performance of the Al-Jadriya water project, water samples were taken before and after the sedimentation basins to find out the efficiency of the sedimentation ponds, as well as water samples were taken before and after the filtration basins, to know the efficiency of the filtration basins by conducting the following tests on them (Turbidity, TDS, TC, pH) to ensure that these ponds work properly. It was found that the efficiency rate of sedimentation ponds was 83%, which indicates the inefficiency of these ponds, as well as the inefficiency of the fast and slow mixing …

Possible Developments Of The Industrialization Of Appropriate Building Subsystem For Iraq, Wisam William Saleem Al-Ayoubi

Al-Esraa University College Journal for Engineering Sciences

Industrialization of building has developed very rapidly in industrialized countries as well as in many other parts of the world to fulfill the need for housing and public buildings after the Second World War. Prefabricated building is defined as a type of building that consists of several elements or modular units prepared in advance and assembled on-site. The term prefabricated indicates that these building elements are manufactured in the workshop or factory and then combined with other elements. Iraq has witnessed vital development in the construction industry sector. The study investigates the appropriate technology for Iraq, considering resources, economy, labor, …

Ion Exchange Method For Sulphate Removal From Treated Wastewater Of Al-Doura Refinery, Rana Mohammed Rasheed

Al-Esraa University College Journal for Engineering Sciences

The treated wastewater by the industrial Wastewater Treatment Plant (WWTP), commonly named (INGECO) in Al-Doura refinery, suffers from highly sulfate concentrations that exceed the EPA specified limits of 250 mg/L. Laboratory water quality historical data have been reviewed and analyzed to determine the annual rate, maximum, and peak sulfate concentrations, which were found to be 360 mg/L, 425 mg/L, and 550 mg/L, respectively. A field inspection was conducted to identify the reasons for the high sulfate concentrations in the wastewater of most refinery process units. It was found that the maximum required sulfate remaining concentration should not exceed 10 mg/L …

The Effect Of The Spirit Of The Place On The Formulation Of Emotion In Contemporary Arab-Islamic Architecture, Mahdi Saleh Al-Faraj, Dania Saleh Yaheia

Al-Esraa University College Journal for Engineering Sciences

Arab-Islamic architecture is characterized by both constants and variables, with spiritual aspects (content) representing the constants and physical aspects (form) representing the variables. It evolves based on changing times and needs, with compassion being a significant feature associated with its spiritual aspects. Compassion is essential for collective agreement and individual emotional connection in Arab-Islamic architecture. The present research aims to investigate the influence of the spirit of the place, as embraced by designers, on the emotional characteristics of contemporary Arab-Islamic architecture. The research problem identified is the lack of a theoretical concept regarding the impact of the spirit of the …

The Effect Of Bioenergy Systems On The Architectural Product The Effect Of Fung Shui And Biogetric To Achieve The Performance Of Architectural Space, Abdullah Saadon Al-Mamoory, Ann Samari Ibrahim

Al-Esraa University College Journal for Engineering Sciences

This research presents an analytical study exploring the vital systems of energy science and their influence on architecture by examining ancient environmental philosophies like Feng Shui in China and bio-geometry in Egypt. These philosophies serve as guiding principles for studying energy and its impact on human daily life, highlighting their effects on integrated ecosystems in the design of residential buildings at both external and internal levels. The study examines key aspects such as the influence of energy on furniture arrangement in living spaces. The primary objective is to establish a synergistic relationship between architectural design of residential spaces during occupancy …

Some Aspects Of The Suitability Of Three-Story Residential Buildings For Vertical Housing In Iraq, Wisam William Saleem Al-Ayoubi

Al-Esraa University College Journal for Engineering Sciences

This research initially aimed to examine the changes in housing since the 1930s, driven by rapid population growth and evolving lifestyles, juxtaposed with advancements in contemporary building materials that are environmentally compatible. After a comprehensive analysis of housing and living arrangements throughout history, including the evolution of open house units towards more interior-focused designs such as the Baghdadi house with its central courtyard, the study delved into the significant changes and the challenges posed by the rapid population growth. The focus of the study was on the viability of vertical housing in Iraq and the considerations related to low-rise residential …

Role Of Iconic Architecture In Sustainable Tourism Development, Basim H. H. Al-Majidi, Ann Samari Ibrahim

Al-Esraa University College Journal for Engineering Sciences

Architecture "is an expression of the way of life and the spirit of the ages and cultures in which I grew up" as the buildings speak for themselves. While tourism is a scenario "to define a city to an unfamiliar audience and acquire an identity for a citizen". Both architecture and tourism have been linked together since time immemorial. Architecture was the main aspect of attracting crowds, while tourism helped architecture survive the test of time as well as money. Both tourism and architecture operate in a symbiotic manner to break the lack of familiarity with any culture and to …

Advanced Research And Development Of Face Masks And Respirators Pre And Post The Coronavirus Disease 2019 (Covid-19) Pandemic: A Critical Review, Ebuka A. Ogbuoji, Amr M. Zaky, Isabel C. Escobar

Chemical and Materials Engineering Faculty Publications

The outbreak of the COVID-19 pandemic, in 2020, has accelerated the need for personal protective equipment (PPE) masks as one of the methods to reduce and/or eliminate transmission of the coronavirus across communities. Despite the availability of different coronavirus vaccines, it is still recommended by the Center of Disease Control and Prevention (CDC), World Health Organization (WHO), and local authorities to apply public safety measures including maintaining social distancing and wearing face masks. This includes individuals who have been fully vaccinated. Remarkable increase in scientific studies, along with manufacturing-related research and development investigations, have been performed in an attempt to …

Investigation Of Single, Binary, And Ternary Metal Oxides Of Iridium, Rhodium, And Palladium For Neural Interfacing Applications, Gregory Vincent Taylor

Theses and Dissertations

In this dissertation, thin film single, binary, and ternary metal oxides of iridium (Ir), ruthenium (Ru), rhodium (Rh), and palladium (Pd) were synthesized for use as electrode/microelectrode coatings for neural interfacing applications using DC reactive magnetron sputtering. Synthesis conditions which enhanced the electrochemical properties of films as measured by cyclic voltammetry and electrochemical impedance spectroscopy in a phosphate buffered saline solution of the single metal oxides were identified to be 30 mTorr working pressure, 20% oxygen partial pressure, and cathode power densities ≤ 4.9 W/cm². These parameters were then used to develop the binary and ternary metal oxide …

Assessment Of Carbon Dioxide Emission And Its Impact On High-Rise Mixed-Use Buildings In Egypt, Ahmed Salah Hamza

Theses and Dissertations

With Egypt's vision of 2030 focusing on sustainable development with a true emphasis on Carbon Dioxide (CO₂) emission reduction in the newly built cities and high-rise buildings, efforts are exerted on various levels towards accomplishing the vision’s goals. This is achieved through multiple tools and models associated with aiding the reduction of carbon emissions, yet not a clear one was introduced for the mixed-use buildings in Egypt.

Through this work, a significant gap was identified with respect to high-rise buildings carbon emission assessment in Egypt. This was a main driving force for this work in an attempt to …

Impact Of Green And White Roofs On Air Handler Filters And Indoor Ventilation Air, Pradeep Ramasubramanian, Irvan Luhung, Serene B. Y. Lim, Stephan C. Schuster, Olyssa Starry, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Rooftop surfaces near building outdoor air intakes may contribute to the mass loading on filters and compounds emitted to ventilation air downstream of the filter. In laboratory analyses, we characterized microbial composition, primary volatile organic compound (VOC) emissions, ozone removal rates, and VOC emissions in the presence of ozone on filters collected from air handlers located on the green and white roof sections of a big-box retail store. Total DNA masses per area of filter were 26.3 ± 11.9 ng cm−2 and 6.3 ± 6.5 ng cm−2 for green and white roof filters respectively, with higher mass observed in winter …

Heated Assembly And Transfer Of Van Der Waals Heterostructures With Common Nail Polish, Kristine L. Haley, Jeffrey A. Cloninger, Kayla Cerminara, Randy M. Sterbentz, Takashi Taniguchi, Kenju Watanabe, Joshua O. Island

Physics & Astronomy Faculty Research

Recent advances in the manipulation and control of layered, two-dimensional materials has given way to the construction of heterostructures with new functionality and unprecedented electronic properties. In this study, we present a simple technique to assemble and transfer van der Waals heterostructures using common nail polish. Commercially available nail polish acts as a resilient sticky polymer, allowing for the fabrication of complex multi-material stacks without noticeable fatigue. Directly comparing four commercially available brands of nail polish, we find that one stands out in terms of stability and stacking characteristics. Using this method, we fabricate two top-gated devices and report their …

A Three-Dimensional Musculoskeletal Model Of The Dog, Heiko Stark, Martin S. Fischer, Alexander Hunt, Fletcher Young, Roger Quinn, Emanuel Andrada

Mechanical and Materials Engineering Faculty Publications and Presentations

Abstract The domestic dog is interesting to investigate because of the wide range of body size, body mass, and physique in the many breeds. In the last several years, the number of clinical and biomechanical studies on dog locomotion has increased. However, the relationship between body structure and joint load during locomotion, as well as between joint load and degenerative diseases of the locomotor system (e.g. dysplasia), are not sufficiently understood. Collecting this data through in vivo measurements/records of joint forces and loads on deep/small muscles is complex, invasive, and sometimes unethical. The use of detailed musculoskeletal models may help …

A Review On Alpha Case Formation And Modeling Of Mass Transfer During Investment Casting Of Titanium Alloys, R. Sharon Uwanyuze, Janos E. Kanyo, Sarah F. Myrick, Stefan Schafföner

Materials Science and Engineering Faculty Research & Creative Works

Titanium alloys have excellent corrosion resistance, high temperature strength, low density, and biocompatibility. Therefore, they are increasingly used for aerospace, biomedical, and chemical applications. Investment casting is a well-established process for manufacturing near-net-shape intricate parts for such applications. However, mass transfer arising from metal-mold reactions is still a major problem that drastically impairs the surface and properties of the castings. Although there have been astounding developments over the past 20 years, they remain scattered in various research papers and conference proceedings. This review summarizes the current status of the field, gaps in the scientific understanding, and the research needs for …