Materials Science and Engineering Commons^™

Ltspice Modeling For Gan-Git Hemt Including Cryogenic Temperature, Md Maksudul Hossain, Yuqi Wei, H. Alan Mantooth

Electrical Engineering Faculty Publications and Presentations

Highly efficient electrically driven avionics have led to a renewed interest in cryogenic propulsion systems with the goal of reducing carbon emission footprint. Although cryogenic converters promise better efficiency and improved power density, the successful design is incumbent upon the appropriate switching device selection and simulation-based analyses prior to initial prototyping. In this work, a datasheet-driven compact model for a gallium nitride (GaN) Gate Injection Transistor (GIT) has been proposed and implemented in LTspice, a versatile, high performance, and free circuit simulator in order to investigate the merit of the chosen device in a power electronic system.

Calculation Of Elastic Constants Of Bulk Metallic Glasses From Indentation Tests, Zhitong Xu, Ming Liu, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

One of the challenges in the applications of instrumented indentation is to simultaneously measure elastic modulus and Poisson’s ratio of homogeneous, isotropic materials. This work proposes empirical equations for simultaneous calculation of elastic modulus and Poisson’s ratio of bulk metallic glasses (BMGs) from the ratio of the short diagonal length to the long diagonal length and the area of the Knoop imprint. The parameters pre- sented in the empirical equations are determined first by Knoop microhardness tests of 24 BMGs, whose elastic moduli and Poisson’s ratios are measured by resonant ultrasound spectroscopy. These empirical equations are further validated by the …

“Zero” Porosity High Loading Nmc622 Positive Electrodes For Li-Ion Batteries, Haidar Y. Alolaywi, Kubra Uzun, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

LiNi0.6 Mn0.2Co0.2 O 2 (NMC622) is a widely used positive electrode material for lithium-ion batteries, including electric vehicles. In this work, we investigated the effects of porosity, ranging from “zero” to the typical 35%, on the electrochemical behavior of high- loading NMC622 electrodes. Although it is well known that the energy density of the electrode increases with increasing areal capacity and decreasing porosity, NMC-positive electrodes with exceedingly low porosity (e.g., near zero) and high loading (e.g., 4 mAh cm−2 ) have not been investigated. Here, we report an intriguing observation that the “zero porosity” NMC electrode can have higher capacity …

Schaeffler Icvd Coating Machine, Louis Mcgrath

Williams Honors College, Honors Research Projects

Chemical Vapor Deposition (CVD) is mutual technology used to deposit thin film through a gaseous phase by vaporizing the solid materials. This conventional process usually requires high thermal stability of the materials, which is not applicable for most of the polymeric materials. Therefore, a novel process, initiated Chemical Vapor Deposition (iCVD) is developed by introducing the gaseous monument and initiator to form the thin film in-situ. By adjusting the free-radical polymerization in the vapor phase, a variety of thin and uniform polymer films can be achieved. Depending on the chemistry, iCVD has many categories. This report explains the design …

Causational Analysis And Rectification Of Issues Concerning Scale Formation On Hot-Rolled Straight Bar Product And Its Effects On Ultrasonic Testing, Riley Mattix

Williams Honors College, Honors Research Projects

At Charter Steel's NDT Processing Plant located in Cleveland, Ohio, a concern has arisen regarding the recently implemented bar straightening and UT (Ultrasonic Testing) equipment. A substantial amount of mill scale, which is typically removed during the straightening process, is persisting on the bar’s surface throughout most of the NDT procedure. This lingering scale has been observed to flake off once inside the UT equipment, introducing unwanted noise and phantom peaks into the UT readings. Additionally, thick mill scale has been identified as a source of background interference in the received data. In contrast, bars that have been subjected to …

Gan Hemt And Air Core Magnetics Based Power Converters Evaluations At Cryogenic Temperature, Yuqi Wei, Md Maksudul Hossain, H. Alan Mantooth

Electrical Engineering Faculty Publications and Presentations

Cryogenic power electronics is both advantageous and indispensable in many applications, like deep space probe, military electric vehicle, magnetic resonance imaging etc. Among different semiconductors, the gallium nitride (GaN) high electron mobility transistor (HEMT) is the most promising candidate for cryogenic applications with significant conduction loss and switching loss reductions. Moreover, there is no carrier freeze out effect for the GaN HEMTs, which is applicable in extreme low temperature operating conditions. In this work, the efficiency of GaN HEMTs based power converters with different power levels (from several Watts to several kiloWatts) are evaluated at cryogenic temperature. Three different commercial …

The Impact Of Modern Buildings On Traditional Urban Environments And Urban Identity, Ann S. Ibrahim

Al-Esraa University College Journal for Engineering Sciences

Contemporary cities face significant challenges in integrating modern buildings into traditional urban environments while preserving urban identity. This study focuses on the relationship between modern architecture and urban heritage. The research problem revolves around how modern buildings affect urban identity in traditional areas, and whether they can interact positively with the urban context without distorting its traditional character.

The study aims to analyze this impact by examining a range of global examples using architectural indicators such as visual integration, spatial integration, material harmony, urban scale, accessibility, and environmental impact. A three-point scale (weak, partial, excellent) was applied to assess each …

Transitioning To A Lower Global Warming Refrigerant, A Performance Study Of R-513a And Hfc-134a In Commercial Chillers, Hossein Abedsoltan, Mark B. Shiflett

Chemical and Biochemical Engineering Faculty Research & Creative Works

The performance of R-513A and HFC-134a refrigerants is compared in two identical chillers operating at the University of Kansas. R-513A is a more environmentally friendly refrigerant due to its lower global warming potential that can be used as a retrofit replacement for HFC-134a in chillers. This study investigates the performance comparison of transitioning from HFC-134a to R-513A. The chillers have been in operation for two years, and cooling capacity, coefficient of performance, and other operating parameters are compared under similar cooling conditions. Cooling capacities ranged from 100 to 500 kW for both chillers. Overall, the energy consumption and coefficient of …

Economic Profitability Of Sustainable Buildings Industry, Mohanad Ibrahim Altuma, Hanadi Abdulridha Lateef, Ayad Abdulkhaleq Al-Yousuf

Al-Esraa University College Journal for Engineering Sciences

The increasing global awareness of the Earth's deteriorating condition and the unpredictable effects of climate change has given rise to worldwide phenomena that impact several elements like the economy, agricultural security, water availability, and energy supplies. Buildings contribute significantly to the generation of greenhouse gases, as well as the disposal of pollutants and energy consumption. Therefore, they play a crucial role in addressing environmental issues.

Although sustainable buildings are widely acknowledged as a potential advancement, professionals in the property market still believe that the upfront costs of creating sustainable buildings are significantly higher than those of conventional buildings. This view …

Designing A Visual Control Framework Based On Feature Point Analysis To Guide Robots In Uncharted Areas, Isam Sadiq Rasham Al-Ghadhbawi

Al-Esraa University College Journal for Engineering Sciences

Image processing may be made more accurate and efficient with the use of optical processing technologies. In order to make better design judgments early in the package design process, visual packaging art simulation aims to swiftly develop realistic packaging effects. Conventional simulation techniques frequently yield findings that are neither realistic or detailed, and they also take a lot of time and human resources. Optical processing-based machine vision technology can fully utilize computer vision and image processing techniques to simulate package designs accurately and efficiently. This research proposes a foundation for machine vision technologies based on image optical processing. Real package …

Machine-Learning-Assisted Design Of Deep Eutectic Solvents Based On Uncovered Hydrogen Bond Patterns, Usman Lame Abbas, Yuxuan Zhang, Joseph Tapia, Md Selim, Jin Chen, Jian Shi, Qing Shao

Markey Cancer Center Faculty Publications

Non-ionic deep eutectic solvents (DESs) are non-ionic designer solvents with various applications in catalysis, extraction, carbon capture, and pharmaceuticals. However, discovering new DES candidates is challenging due to a lack of efficient tools that accurately predict DES formation. The search for DES relies heavily on intuition or trial-and-error processes, leading to low success rates or missed opportuni- ties. Recognizing that hydrogen bonds (HBs) play a central role in DES formation, we aim to identify HB features that distinguish DES from non-DES systems and use them to develop machine learning (ML) models to discover new DES systems. We first analyze the …

Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash

Graduate Theses, Dissertations, and Problem Reports (ETD)

Global demand for fertilizer production is expanding substantially to meet the food demand of an increasing world population. Anaerobic digestate (AD) of various centralized wastewater facilities contains substantial amounts of ammonium (NH₄⁺) (300-800 mg/L), potassium (K⁺) (13-120 mg/L), and phosphorus (P) (30-100 mg/L)- based nutrients. In addition to reducing energy costs and CO₂ emissions compared to conventional fertilizing raw material manufacturing, recovering nutrients from these waste streams could help mitigate problems such as eutrophication, which otherwise incurs billions of dollars losses to US economy annually. Apart from nutrients, wastewater streams also contain organic pollutants …

Data-Driven Modeling Of Oxygen Kinetics In La0.6sr0.4co0.2fe0.8o3−Δ (Lscf) For High-Temperature Reduction Of Co2 In An Electrolysis Cell, Ferron Campbell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electrolysis systems are critical to several societal applications, particularly energy storage and conversion. Developing these systems requires a detailed knowledge of the chemistry and thermodynamics of the materials used in the electrolysis cell. This work focuses on using embedded scientific machine learning as an efficient way to build an interpretable model for the reaction and transport kinetics in the LSCF electrode, whose performance directly influences the electrolysis system’s performance. The models developed in this study are trained using the publicly available machine learning package, FoKL-GP. This package incorporates a robust Gibbs sampler that employs a forward variable selection process to …

Advancing Polymer Sustainability Through Custom Interpenetrating Polymer Network Synthesis, Processing, And Design, Alexandra Maria Lehman-Chong

Theses and Dissertations

The need for improving polymer sustainability is as ubiquitous as the role of polymers in modern society. Interpenetrating polymer network (IPN) design flexibility offers opportunities for improved polymer sustainability while balancing desired polymer properties for various applications. This work investigates the structure-property-processing relationships of IPNs judiciously designed under the framework of the polymer life cycle. Sustainable polymer design was largely considered at the feedstock and manufacturing stages while considering overall polymer performance. Chemicals from bio-based feedstocks were used to design a full simultaneous polybenzoxazine-epoxy IPN, focusing on the effects of monomer and polymer structure on polymer properties. Processing-property relationships were …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Application Of Quantum Algorithms In The Synthesis Of Dynamic Objects, Noilakhon Yakubova

Chemical Technology, Control and Management

Around the world, the food industry is focusing on achieving energy and resource efficiency. One of the main challenges in the field of process automation is the creation of effective control systems using intelligent technologies to improve the quality of processes and achieve the production of high-quality products with less energy and resources. Therefore, it is necessary to work with a large amount of data. Particular attention is paid to the development of computational algorithms for automated high-speed computational analysis systems for processing this data at high speed. Therefore, the article discusses the use of quantum computing methods in controlling …

Electrochemical Performance Of Porous Ceramic Supported Tubular Solid Oxide Electrolysis Cell, Heng-Ji Wang, Wen-Guo Chen, Zhou-Yi Quan, Kai Zhao, Yi-Fei Sun, Min Chen, Ogenko Volodymyr

Journal of Electrochemistry

Solid oxide electrolysis cell (SOEC) is an efficient and clean energy conversion technology that can utilize electricity obtained from renewable resources, such as solar, wind, and geothermal energy to electrolyze water and produce hydrogen. The conversion of abundant intermittent energy to hydrogen energy would facilitate the efficient utilization of energy resources. SOEC is an all-ceramic electrochemical cell that operates in the intermediate to high temperature range of 500–750 ℃. Compared with traditional low temperature electrolysis technology (e.g., alkaline or proton exchange membrane cells operating at ~100 ℃), the high-temperature SOEC can increase the electrolysis efficiency from 80% to ~100%, providing …

An In-Situ Raman Spectroscopic Study On The Interfacial Process Of Carbonate-Based Electrolyte On Nanostructured Silver Electrode, Yu Gu, Yuan-Fei Hu, Wei-Wei Wang, En-Ming You, Shuai Tang, Jian-Jia Su, Jun Yi, Jia-Wei Yan, Zhong-Qun Tian, Bing-Wei Mao

Journal of Electrochemistry

The solid-electrolyte interphase (SEI) plays a key role in anodes for rechargeable lithium-based battery technologies. However, a thorough understanding in the mechanisms of SEI formation and evolution remains a major challenge, hindering the rapid development and wide applications of Li-based batteries. Here, we devise a borrowing surface-enhanced Raman scattering (SERS) activity strategy by utilizing a size optimized Ag nanosubstrate to in-situ monitor the formation and evolution of SEI, as well as its structure and chemistry in an ethylene carbonate-based electrolyte. To ensure a reliable in-situ SERS investigation, we designed a strict air-tight Raman cell with a three-electrode configuration. Based on …

Isolation And Characterization Of Caffeine-Degrading Bacteria From Coffee Plantation Areas In Malaysia, Elvina Clarie Dullah, Mohd Fazli Farida Asras

Makara Journal of Technology

Decaffeination by microbial degradation is currently the most optimal and low-cost approach, involving only microbial cells and/or their enzymes. The bacterium was characterized using a series of biochemical tests. Positive results were obtained from carbohydrate fermentation, citrate utilization, and catalase tests, while negative results were obtained from Voges-Proskauer (VP) and indole tests. Three different caffeine concentrations of 0.25%, 0.4%, and 2% were tested and measured through Gas Chromatography-Mass Spectrophotometry (GC-MS) analysis. The highest caffeine reduction (89.25%) was found when 0.25% caffeine was used in the media. Only a small amount of caffeine was reduced to 0.4% and 2%, with 34.78% …

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, D. Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N₂) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …

The Role Of Interactive Spaces In Enhancing Social Interaction Of Children In Orphanage Institutions, Zainab Khalid Rashad Al Khafaji, Shamael M. W. Al Dabbagh

Al-Esraa University College Journal for Engineering Sciences

The child who moves to an environment outside his family environment, suchas orphanage institutions because of the loss of one or all of his family members, itis obvious that he feels a kind of alienation and isolation from his peers and a loss ofa sense of interaction and communication with society, so it is possible to mitigatethis feeling by promoting diversity in interactive activities within the internal spacesof the orphanage institutions and at the neighborhood level, the research problemwas represented by "the lack of clarity in the nature of knowledge aboutthe role of of interactive spaces in enhancing social interaction …

Environmental Footmark And Its Effects On The Sustainability Of Towns, Ali Abdul Samea Hameed

Al-Esraa University College Journal for Engineering Sciences

The Ecological Footmark (EF) is one of the utmost recent and important criteria for assessing the capacity of the population to uphold a life sustainable way. It tests the extent which the indicators have an influence on the natural resources (NR) of the ecosystem such as forestry, water bodies, agricultural lands, pastures, CO2, and properties for construction purposes. This footmark was utilized to evaluate the use of NR to the capacity of the land for regeneration. This research paper discusses the theoretical conceptual component of the EF framework and plans regarding issues related to the environment. The environmental image (EI) …

The Effects Of Urban Fragmentation / Analysis Of The Causes And Challenges In The City Structure, Seemon Matte Abbo, Inaam Amin Albazzaz

Al-Esraa University College Journal for Engineering Sciences

Fragmentation is a fundamental term in the history of critical urban thought,yet the product of fragmentation is manifested in fragments. Urban fragmentationis used to describe the phenomenon that occurs when the urban environment isbroken up into smaller units or dispersed areas. This means that cities becomefragmented rather than cohesive and integrated. This disintegration can be the resultof various factors such as poor planning, lack of infrastructure, different land uses,and social dispersion. This research addresses the problem of urban fragmentationas one of the challenges facing the urban structure of cities, and clarifies the mostimportant factors affecting the city structure during the …

A Review: Special Types Of Concrete Used In Structures, Reem Hatem Ahmed, Mohammed Mosleh Salman

Al-Esraa University College Journal for Engineering Sciences

The term “special” possesses inherent significance and is utilized in this context to denote the distinctive attributes characteristic of concrete. The term “special” connotes enhanced strength, durability, and solidity in concrete. The production of specialized concrete involves the incorporation of distinct components via specific procedures following specific criteria. Specialized concrete is required to construct unique structures such as power plants, offshore buildings, docks, and airports. Each of these unique structures is essential for survival in harsh conditions, including sulfate, chemical, acid, and chloride attacks, as well as other surface characteristics. Concrete is a versatile material that exhibits good compressive strength …

The Role Of Young Architects As Entrepreneurship Generational Units In Shaping The Future Of Architecture, Attaa H. Al Obaidi, Anwar. S. Al-Qaraghuli

Al-Esraa University College Journal for Engineering Sciences

Youth are the pillar of nations and the secret of their renaissance, thebuilders of their civilization and the line of defense, the main participants inbasic planning processes, and the agents of change to build a world that iscompatible with the aspirations of future generations. This applies to the field ofarchitecture in terms of the importance of young architects in shaping it underthe challenges it faces, which impose interaction in a manner commensuratewith the emerging requirements and needs. This research is based on theconsideration that young architects are an integrated phenomenon thatcontributes to shaping architectural production according to the data of …

Using Artificial Intelligence To Diagnose Demented In The Elderly, Ohood Fadil Alwan

Al-Esraa University College Journal for Engineering Sciences

In addition to possible other symptoms, memory loss and impairment are the hallmarks of Demented or Alzheimer’s disease (AD). Despite the fact that dementia is incurable and has a significant negative impact on patients' lives, an early diagnosis can help start the right treatment and prevent additional brain damage. Over the years, machine learning techniques have been used to classify AD; nevertheless, the efficacy of the results depends on the use of multi-step classifiers and manually created features. Thanks to recent advances in deep learning, patterns may now be classified using neural networks' final stage. In order to diagnose dementia …

Risk Detection Of Gestational Diabetes In Early Pregnancy Depend On Artificial Neural Network, Sanaa Hammad Dhahi

Al-Esraa University College Journal for Engineering Sciences

Early prediction of gestational diabetes mellitus (GDM) risk is particularly important because it may enable more effective interventions and reduce cumulative maternal and fetal injury. The aim of this study is to develop machine learning (ML) models for early prediction of GDM using widely available variables, facilitating early intervention, and enabling the application of prediction models in settings where more complex tests are not accessible. In this paper, an artificial neural network (ANN) was used to detect the risk of gestational diabetes. A global dataset was used to collect clinical and experimental data from pregnant women and people with diabetes …

Impact Of Merging Basalt Fibers With Various Types Of Concrete And The Factors Affecting Them: A Review, Adil M. Jabbar, Lubna S. Dankha

Al-Esraa University College Journal for Engineering Sciences

This paper reviews effecting of blending basalt fibers into concreteon mechanical properties, ductility, and toughness. Based on concretecomponents, the perfect basalt fiber percentage can differ and is influencedby factors like fiber length, w/c ratio, and age. The beneficial basalt fiberspercentage is lower than that of steel fibers. Even with a low concentrationof basalt fibers, concrete tensile and flexural strength can be improved moreeffectively than a higher amount of steel fibers. As the amount of basaltfiber increases, the mix workability decreases. Additionally, the flow abilitymay drop slightly as the length of the fibers increases. Adding basalt fiber toconcrete can minimize drying …