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2023

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Full-Text Articles in Engineering

Systematic Comparison Of Nonviral Gene Delivery Strategies For Efficient Co-Expression Of Two Transgenes In Human Mesenchymal Stem Cells, Tyler Kozisek, Luke Samuelson, Andrew Hamann, Angela K. Pannier Dec 2023

Systematic Comparison Of Nonviral Gene Delivery Strategies For Efficient Co-Expression Of Two Transgenes In Human Mesenchymal Stem Cells, Tyler Kozisek, Luke Samuelson, Andrew Hamann, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background Human mesenchymal stem cells (hMSCs) are being researched for cell-based therapies due to a host of unique properties, however, genetic modification of hMSCs, accomplished through nonviral gene delivery, could greatly advance their therapeutic potential. Furthermore, expression of multiple transgenes in hMSCs could greatly advance their clinical significance for treatment of multifaceted diseases, as individual transgenes could be expressed that target separate pathogenic drivers of complex diseases. Expressing multiple transgenes can be accomplished by delivering multiple DNA vectors encoding for each transgene, or by delivering a single poly-cistronic vector that encodes for each transgene and accomplishes expression through either use …


Exploring Regular And Turbulent Flow States In Active Nematic Channel Flow Via Exact Coherent Structures And Their Invariant Manifolds, Caleb G. Wagner, Rumayel H. Pallock, Jae Sung Park, Michael M. Norton, Piyush Grover Dec 2023

Exploring Regular And Turbulent Flow States In Active Nematic Channel Flow Via Exact Coherent Structures And Their Invariant Manifolds, Caleb G. Wagner, Rumayel H. Pallock, Jae Sung Park, Michael M. Norton, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

This work is a unified study of stable and unstable steady states of 2D active nematic channel flow using the framework of Exact Coherent Structures (ECSs). ECSs are stationary, periodic, quasiperiodic, or traveling wave solutions of the governing equations that, together with their invariant manifolds, organize the dynamics of nonlinear continuum systems. We extend our earlier work on ECSs in the preturbulent regime by performing a comprehensive study of stable and unstable ECSs for a wide range of activity values spanning the preturbulent and turbulent regimes. In the weakly turbulent regime, we compute more than 200 unstable ECSs that coexist …


Effect Of A Geothermal Heat Pump System On Cooling Residential Buildings In A Hot, Dry Climate, Rania Rushdy Moussa, Ayman H. Mahmoud Dec 2023

Effect Of A Geothermal Heat Pump System On Cooling Residential Buildings In A Hot, Dry Climate, Rania Rushdy Moussa, Ayman H. Mahmoud

Architectural Engineering

ABSTRACT In the last century, electricity demand has doubled due to urban expansion, which has contributed to the formation of more urban heat islands (UHI) and the appearance of environmental hazards such as the global climate change phenomenon. Since residential buildings are considered the main electricity consumer sector in Egypt, they consume up to 42% of total energy consumption, which contributes to increasing temperatures and constitutes UHI in cities. In this context, the research aims to examine the effectiveness of using the closed vertical loop geothermal system (GSHPCV) for cooling residential buildings in a hot, dry climate, such as Cairo, …


Energy Harvesting Sensors And Their Role In Fostering Sustainable Air Quality Monitoring, Tomas Valentin, Li Geng Dec 2023

Energy Harvesting Sensors And Their Role In Fostering Sustainable Air Quality Monitoring, Tomas Valentin, Li Geng

Publications and Research

This research presents a comprehensive investigation into Energy Harvesting Sensors and their role in fostering sustainable air quality monitoring. The primary objective is to explore the viability of energy harvesting technologies in energizing sensor networks devoted to the real-time collection of air quality data, emphasizing the reduction of environmental impact and maintenance demands. The study delves into the integration of energy harvesting mechanisms, including solar and piezoelectric kinetic energy, to power advanced sensor nodes capable of detecting pollutants, particulate matter, and gas concentrations. The findings of this research highlight the significant benefits of energy harvesting sensors, including enhanced sustainability, long-term …


Exploring 21st Century Learning In Virginia Secondary School Technology And Engineering Classrooms: A Hermeneutic Phenomenological Study, George Nicholas Cornwell Dec 2023

Exploring 21st Century Learning In Virginia Secondary School Technology And Engineering Classrooms: A Hermeneutic Phenomenological Study, George Nicholas Cornwell

Doctoral Dissertations and Projects

The purpose of this phenomenological study was to examine how integrative STEM teachers utilize the Standards for Technological and Engineering Literacy (STEL) to foster and assess 21st-century learning in technology and engineering classes at multiple Virginia public secondary schools. The theory guiding this study was Kolb’s experiential learning theory, which integrates nine learning theories into an innovative cyclical learning process that is like the engineering design loop. This hermeneutic phenomenology included 15 Virginia technology and engineering schoolteachers (Grades 6-12) who purposefully taught multiple academic disciplines and utilized the eight practices of the STEL in the context of their curriculum to …


Industrial Design, Husnain Khan Dec 2023

Industrial Design, Husnain Khan

Publications and Research

Universal design is important because it helps with diverse disabilities. What is universal design and why do we need it? People design buildings, products or environments to make them accessible to people in need. Also, it minimizes the need for assistive technology, results in products compatible with assistive technology, and makes products more usable by everyone. Where can universal design be found? It's practical everywhere you go, such as public transport, parks, shops and services, and sidewalks. Universal design is affected by Several categories: people with disabilities, who are perhaps the most visible group affected by universal design, and parents …


The Utilization Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Soil Properties: Green Media, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr. Dec 2023

The Utilization Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Soil Properties: Green Media, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr.

Publications and Research

The utilization of repurposed whole textiles to modify the mechanical and hydrogeological soil properties investigates the impact of adding repurposed textiles to lightweight engineered soil, documenting changes in unit weight, water content, and hydraulic conductivity. This study builds upon prior findings, which demonstrated significant alterations in hydrogeological properties when incorporating textile fabric (3% by weight at an aspect ratio of 1:1). Functioning as reinforcement, these fibers enhance the soil's strength, stability, and structural integrity—especially advantageous in erosion-prone areas, regions susceptible to landslides, or locations requiring heightened load-bearing capacity. The outcomes of this parametric study lead to green roof farms playing …


Data Science And The Ethics Of Private Information, Faria R. Promi Dec 2023

Data Science And The Ethics Of Private Information, Faria R. Promi

Publications and Research

This research focuses on the moral questions linked to modern data technologies like Big Data and the Internet of Things. These technologies can be, but they are also about privacy and keeping data secure. We've looked at what experts say about these concerns and discovered that most agree we need to safeguard people's privacy and data. Our research encourages everyone to use these technologies, finding a balance between technological progress and responsible, ethical behavior. This way, we can enjoy the benefits of these technologies while also respecting individuals' privacy and data rights. The study reviews what experts have said about …


Economy Of Scale Of Energy Intensity In Aquifer Storage And Recovery (Asr), Alyson Haley Rapp Dec 2023

Economy Of Scale Of Energy Intensity In Aquifer Storage And Recovery (Asr), Alyson Haley Rapp

Theses and Dissertations

More water utilities are adopting Aquifer Storage and Recovery (ASR) to balance long-term water supply and demand. Due to large implementation and operation costs, ASR projects need to be optimized, particularly for energy use, which is a major operating expense. This study examines the relationships among energy use, recharge, and recovery at two ASR projects in the western United States. The major finding is an economy of scale for recovery processes, but not for gravity-fed recharge processes. The economy of scale found is as follows: the energy intensity recovered decreases with volume. This suggests it is more energy-efficient to recover …


Analysis And Simulation Of Nuclear Thermal Energy Storage Systems For Increasing Grid Stability, Jaron Wallace Dec 2023

Analysis And Simulation Of Nuclear Thermal Energy Storage Systems For Increasing Grid Stability, Jaron Wallace

Theses and Dissertations

With the growing capacity of renewable energy production sources, nuclear energy, once a mainstay of power generation, faces challenges due to its limited adaptability to fluctuating energy demands. This inherent rigidity makes it less desirable than the more flexible renewable sources. However, integrating thermal energy storage (TES) systems offers a promising avenue, enabling nuclear power plants (NPPs) to enhance their operational flexibility and remain competitive in an evolving renewable market. A comprehensive ranking methodology has been introduced, delineating the criteria and processes to determine the most synergistic TES/NPP design couplings. This methodology considers the unique characteristics of both current and …


Strengthening Of Mechanical Properties And Electrical Conductivity Study On 6061 Al Alloy After Ecap Process, Nour Eldeen Megahed, A.M. El-Kassas, Maher Rashad Dec 2023

Strengthening Of Mechanical Properties And Electrical Conductivity Study On 6061 Al Alloy After Ecap Process, Nour Eldeen Megahed, A.M. El-Kassas, Maher Rashad

Mansoura Engineering Journal

The investigation centered around the analysis of enhanced mechanical properties and electrical conductivity in an industrial aluminum alloy that underwent a transformation into an ultra-fine-grained (UFG) state. The aforementioned transformation was successfully accomplished by utilizing a singular iteration of the Equal Channel Angular Pressing (ECAP) method. The study involved conducting evaluations through hardness and compression tests, measuring electrical conductivity, and analyzing microstructures using OM and SEM. After annealing for three hours at a temperature of 4150C, it is experimentally explored how the electrical conductivity and material properties of AA-6061 The mechanical properties of the material are influenced by the level …


Classification Of Kidney Masses Using Convolution Neural Network, Nada M. Yakout, Eman Abdelhalim, Abdalla Abdelhalim, Hossam El-Din Moustafa Dec 2023

Classification Of Kidney Masses Using Convolution Neural Network, Nada M. Yakout, Eman Abdelhalim, Abdalla Abdelhalim, Hossam El-Din Moustafa

Mansoura Engineering Journal

Classification of tumors among kidney masses (KM) through deep neural networks is one of the most important applications for detecting the disease at an early stage. It can increase patient survival rates, prevent mass growth, and prevent complications. Preoperative multi-phase abdominal Contrast Enhancement Computed Tomography (CE-CT) is widely used to detect lesions of kidney masses in order to avoid unneeded biopsy or surgery. However, decisions about treatment are difficult because of inter-observer variability caused by minute variations in the imaging characteristics of mass sub-types. In this study, we offer a comprehensive deep learning model using a Convolutional Neural Networks(CNN) for …


An Image Processing Technique For Studying The Flame Structure Using Single Shots Of Oh-Plif Diagnostics, Hazem M. Al-Bulqini, El-Shafie B. Zeidan, Farouk M. Okasha, Mohy S. Mansour Dec 2023

An Image Processing Technique For Studying The Flame Structure Using Single Shots Of Oh-Plif Diagnostics, Hazem M. Al-Bulqini, El-Shafie B. Zeidan, Farouk M. Okasha, Mohy S. Mansour

Mansoura Engineering Journal

Laser diagnostic techniques have played a crucial role in enhancing our understanding of combustion processes. Among these techniques, Planar Laser-Induced Fluorescence (PLIF) utilizing OH radicals has proven to be a powerful tool for investigating reaction zones, flame curvature, and flame surface density in diverse flame modes including premixed, non-premixed, and partially premixed flames. However, to fully harness the potential of experimental measurements and laser diagnostics in studying combustion processes, a comprehensive grasp of image processing techniques and tools is essential for effectively analyzing captured images and extracting valuable information. In this study, we present a detailed algorithm that facilitates the …


Using Jtag For External Scrubbing On The Amd Versal Acap, Michael L. Bjerregaard Dec 2023

Using Jtag For External Scrubbing On The Amd Versal Acap, Michael L. Bjerregaard

Theses and Dissertations

The Versal Adaptive Compute Acceleration Platform (Versal ACAP) is a system-on-chip (SoC) developed by AMD Xilinx. To help protect the programmable logic from soft errors, the configuration needs to be constantly checked and repaired through a process called scrubbing. This thesis provides a methodology for scrubbing the configuration over JTAG. The scrubber uses two platform device image (PDI) files, one to read the configuration and one to send corrected frames. The methodology is characterized to determine the time it takes to completely scrub the configuration. The designed scrubber was able to scrub the VM1802 in 11.5 seconds, or 41.6 Mbits/second, …


Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros Dec 2023

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …


Comparative Evaluation Of Propulsive Power Transmission Technologies For High-Speed Vertical Takeoff And Landing (Hsvtol) Cargo Aircraft, Xinyu Yang Dec 2023

Comparative Evaluation Of Propulsive Power Transmission Technologies For High-Speed Vertical Takeoff And Landing (Hsvtol) Cargo Aircraft, Xinyu Yang

Doctoral Dissertations and Master's Theses

Designing High-Speed Vertical Takeoff and Landing (HSVTOL) cargo aircraft capable of both low downwash velocity hovering and high subsonic speed cruising presents a significant engineering challenge. This challenge, stemming from conflicting design requirements, has been substantially influenced by recent technological advancements, which have offered greater flexibility in rotor placement. Consequently, this has led to the emergence of innovative mission-specific designs that hold the potential to outperform traditional concepts. The central objective of this study is to evaluate the benefits of modern technologies for VTOL cargo aircraft and assess their performance relative to baseline VTOL aircraft. The results of this comparative …


Development Of A Constellation Simulator For A 5g/Iot Mission Planning System, Franco Criscola Dec 2023

Development Of A Constellation Simulator For A 5g/Iot Mission Planning System, Franco Criscola

Doctoral Dissertations and Master's Theses

The advancement of 5G and Internet-of-Things technologies has presented new challenges for telecommunications providers. One of the challenges is integrating these technologies with present networks. A solution has been found in low-Earth orbit satellite constellations. On one hand, this method increases coverage and reduces costs, but on the other it raises new problems like how to efficiently manage large constellations of spacecraft. This thesis introduces the Constellation Management System, developed in collaboration with i2Cat foundation. This novel tool is composed of two modules: the simulator and the scheduler. The former propagates satellite motion and computes visibility events to various targets …


Code To Combustion: Cnc Rotor Replication Using Cam, Luis Luna Dec 2023

Code To Combustion: Cnc Rotor Replication Using Cam, Luis Luna

Publications and Research

In the current landscape, computer-aided design (CAD) and computer numerical control (CNC) technologies have greatly enhanced manufacturing processes, allowing rapid and high-precision production. This project will focus on recreating a Wankel engine rotor, using SolidWorks for design and Mastercam for Computer-Aided Manufacturing (CAM) simulations. The process begins with SolidWorks, which is used for a template of a high-precision rotor model. Mastercam is then utilized for the CAM programming, allowing for the creation of intricate tool paths and tool usage simulations. This approach is vital for complex objects like the Wankel engine rotor, which demands high precision. The primary objective of …


An Inexpensive, 3d Printable, Arduino And Bluray-Based, Confocal Laser And Fluorescent Scanning Thermal Microscope, Justin Loose Dec 2023

An Inexpensive, 3d Printable, Arduino And Bluray-Based, Confocal Laser And Fluorescent Scanning Thermal Microscope, Justin Loose

Theses and Dissertations

The Fluorescence Scanning Thermal Microscope (FSTM v3.0), was designed to create an inexpensive, and easily manufactured, device for measuring the diffusivity of samples with microscopic locational precision. This was accomplished by using a Blu-ray device known as a PHR-803T, referred to in this work as a PHR. The optics in the PHR are nearly identical in function to conventional devices used in thermoreflectance microscopy, making the PHR extremely useful to integrate into the FSTM design. The focus of this thesis is the application of the FSTM as a confocal microscope using 3D printed components and various low-cost devices to operate …


Modeling The Influence Of Vibration On Flow Through Embedded Microchannels, Joseph S. Seamons Dec 2023

Modeling The Influence Of Vibration On Flow Through Embedded Microchannels, Joseph S. Seamons

Theses and Dissertations

The influence of vocal fold (VF) vibration on perfused flow through VF vasculature is an area of research that has previously received limited attention. The aim of the research presented in this thesis was to contribute towards an improved understanding of the effects vibration on perfusion through vasculature within the VFs. This was done using a series of computational simulations of geometric changes to, and perfusion through, microchannels embedded in VF models. A computational structural model based on synthetic VF models used in previous experimental studies was first developed. The model and its embedded microchannel were initially studied under static …


Coarsening Dynamics Of Ternary Polymer Solutions With Mobility And Viscosity Contrasts, Jan Ulric Garcia, Douglas R. Tree, Alyssa Bagoyo, Tatsuhiro Iwama, Kris T. Delaney, Glenn H. Fredrickson Dec 2023

Coarsening Dynamics Of Ternary Polymer Solutions With Mobility And Viscosity Contrasts, Jan Ulric Garcia, Douglas R. Tree, Alyssa Bagoyo, Tatsuhiro Iwama, Kris T. Delaney, Glenn H. Fredrickson

Faculty Publications

Using phase-field simulations, we investigate the bulk coarsening dynamics of ternary polymer solutions undergoing a glass transition for two models of phase separation: diffusion only and with hydrodynamics. The glass transition is incorporated in both models by imposing mobility and viscosity contrasts between the polymer-rich and polymer-poor phases of the evolving microstructure. For microstructures composed of polymer-poor clusters in a polymer-rich matrix, the mobility and viscosity contrasts significantly hinder coarsening, effectively leading to structural arrest. For microstructures composed of polymer-rich clusters in a polymer-poor matrix, the mobility and viscosity contrasts do not impede domain growth; rather, they change the transient …


Biological Nitrogen And Phosphorus Removal From Wastewater Under Low Dissolved Oxygen (Ldo) Conditions, Bashar Al-Daomi Dec 2023

Biological Nitrogen And Phosphorus Removal From Wastewater Under Low Dissolved Oxygen (Ldo) Conditions, Bashar Al-Daomi

Dissertations and Theses

This study examines the complexities of the integration of different technologies for nutrient removal, investigating parameters like sludge residence time (SRT), carbon-to-nitrogen (C/N) ratio, Anaerobic/Oxic (A/O), and Anaerobic/Oxic/Anoxic (A/O/A) systems, continuous and intermittent aeration regimes, and air OFF/air ON periods ratios for efficient nitrogen and phosphorus removal.

Two continuous aeration systems were implemented: The first aimed to carry out a simultaneous nitrification and denitrification (SNdN) process for nitrogen and phosphorus removal under low dissolved oxygen (DO) and C/N ratio conditions. This system operated with 4.5-5-day total sludge age in a single-stage anaerobic/oxic (A/O)-SBR, performing stepwise DO reduction at varying DO …


Maximising Captured Power And Battery Management For Heaving Wave Energy, Omsalama Mubarak Mohamed Dec 2023

Maximising Captured Power And Battery Management For Heaving Wave Energy, Omsalama Mubarak Mohamed

Thesis/ Dissertation Defenses

Sea waves are considered the most potent energy carriers among all sources of renewable energy. This research work is concerned with developing technologies to enhance performance and improve power capturing and conversion capabilities of a single heaving wave energy converter (WEC) actuated by a PMLG (Permanent Magnet Linear Generator). The objective of this dissertation is achieved by three techniques. The first one considers maximizing conversion between the mechanical and electrical powers. It is implemented by designing intrinsic resistance using a rapid procedure involving the mechanical and electrical models of the converter and considering its operating constraints. A robust PID (proportional …


2023 Fall Engr333 Seminar Presentation File, Michael Lanning, Panashe Makuvaro, David Harris, Stuart Johnston Dec 2023

2023 Fall Engr333 Seminar Presentation File, Michael Lanning, Panashe Makuvaro, David Harris, Stuart Johnston

ENGR 333

File for student presentation on Carbon Neutrality for Calvin University, given by students in the Fall 2023 class of ENGR333.


Revising Policy And Process: A Collaborative Project Between The Society Of Chartered Surveyors Ireland (Scsi) And Tu Dublin, Roisin Murphy Dr, James Lonergan Dec 2023

Revising Policy And Process: A Collaborative Project Between The Society Of Chartered Surveyors Ireland (Scsi) And Tu Dublin, Roisin Murphy Dr, James Lonergan

Conference Papers

No abstract provided.


Experimental Investigation Of Temperature Polarisation By Capturing The Temperature Profile Development Over Dcmd Membranes, Hiras Ahamed Hijaz, Masoumeh Zargar, Abdellah Shafieian, Amir Razmjou, Mehdi Khiadani Dec 2023

Experimental Investigation Of Temperature Polarisation By Capturing The Temperature Profile Development Over Dcmd Membranes, Hiras Ahamed Hijaz, Masoumeh Zargar, Abdellah Shafieian, Amir Razmjou, Mehdi Khiadani

Research outputs 2022 to 2026

Temperature polarisation (TP) is a major drawback limiting the global acceptance of membrane distillation (MD) technology. TP is typically quantified using a dimensionless index known as Temperature Polarisation Coefficient (TPC). TPC has significant limitations, whereby it cannot be used to compare different MD configurations or design conditions, nor to analyse the TP phenomenon along the membrane. In this research, the temperature profile over and along a lengthy DCMD membrane has been measured under various operational conditions, where its impact on TP has been explored for the first time. A specialised DCMD membrane cell was manufactured to capture temperature profiles, both …


Modular Open-Source Design Of Pyrolysis Reactor Monitoring And Control Electronics, Finn K. Hafting, Daniel G. Kulas, Etienne Michels, Sarvada Chipkar, Stefan Wisniewski, David Shonnard, Joshua M. Pearce Dec 2023

Modular Open-Source Design Of Pyrolysis Reactor Monitoring And Control Electronics, Finn K. Hafting, Daniel G. Kulas, Etienne Michels, Sarvada Chipkar, Stefan Wisniewski, David Shonnard, Joshua M. Pearce

Michigan Tech Publications

Industrial pilot projects often rely on proprietary and expensive electronic hardware to control and monitor experiments. This raises costs and retards innovation. Open-source hardware tools exist for implementing these processes individually; however, they are not easily integrated with other designs. The Broadly Reconfigurable and Expandable Automation Device (BREAD) is a framework that provides many open-source devices which can be connected to create more complex data acquisition and control systems. This article explores the feasibility of using BREAD plug-and-play open hardware to quickly design and test monitoring and control electronics for an industrial materials processing prototype pyrolysis reactor. Generally, pilot-scale pyrolysis …


Predictive Modeling Of Asphalt Pavement Performance Using Artificial Neural Networks, Rami Khalifah Dec 2023

Predictive Modeling Of Asphalt Pavement Performance Using Artificial Neural Networks, Rami Khalifah

Civil Engineering Theses

This thesis highlights the significance of using the Resilient Modulus (Mr) and Soil-Water Characteristic Curve (SWCC) coefficients within the scope of pavement design. It aims to demonstrate the importance of pavement quality and safety by developing a prediction model for bleeding and rutting depth in asphalt pavements using data from the Long-Term Pavement Performance (LTPP) database and the National Catalog of Natural Subgrade Properties Database. Additionally, the thesis builds predictive models using Artificial Neural Networks (ANNs), which include a single hidden layer and multiple neurons. The developed Mr and SWCC models in this thesis utilized the basic soil index properties …


Quaternary Ammonium Compounds (Qacs) In Wastewater Influent And Effluent Throughout The Covid-19 Pandemic, Anna K. Mahony, Patrick J. Mcnamara, William A. Arnold Dec 2023

Quaternary Ammonium Compounds (Qacs) In Wastewater Influent And Effluent Throughout The Covid-19 Pandemic, Anna K. Mahony, Patrick J. Mcnamara, William A. Arnold

Civil and Environmental Engineering Faculty Research and Publications

Quaternary ammonium compounds (QACs) are used in consumer and industrial products, including disinfectants. Due to the COVID-19 pandemic, disinfectant use has increased, purportedly increasing loads to wastewater treatment plants and the environment. To understand how the increased usage has affected QAC loadings to treatment plants and to determine how effectively plants remove QACs from liquid effluent that is discharged to surface and groundwaters, influent and effluent wastewater samples were collected from four treatment plants (treatment capacities < 5 MGD to > 100 MGD) for 21 months beginning in May 2020. Influent QAC concentrations were hundreds of μg/L and effluent QAC concentrations were < 1 μg/L, corresponding to an average removal of 98% from all four plants. The most prevalent QACs in influent were those used most commonly in disinfectants, specifically benzylalkyldimethylammonium compounds (BACs) and short-chain dialkyldimethylammonium compounds (DADMACs), and influent levels of these compounds were correlated with QAC sales. Prior to this study, ethylbenzylalkyldimethylammonium compounds (EtBACs) had not been studied, and they comprised 13 ± 6% of QACs in influent. While removal was high at all plants, low μg/L concentrations were still continuously discharged into the environment. For QACs with equivalent alkyl chain lengths, those with aromatic substituents (BACs and EtBACs) appear to be removed more effectively than those with only alkyl chains (DADMACs).


Experimental And Modelling Of Lightning Damage To Carbon Fibre-Reinforced Composites Under Swept Stroke, Chengzhao Kuang, Kunkun Fu, Juhyeong Lee, Huixin Zhu, Qizhen Shi, Xiaoyu Cui Dec 2023

Experimental And Modelling Of Lightning Damage To Carbon Fibre-Reinforced Composites Under Swept Stroke, Chengzhao Kuang, Kunkun Fu, Juhyeong Lee, Huixin Zhu, Qizhen Shi, Xiaoyu Cui

Mechanical and Aerospace Engineering Faculty Publications

Lightning swept stroke creates multiple lightning attachments along an aircraft in flight. This introduces distinct structural damage compared to that from a single-point lightning current injection test in laboratory. This study presents both experimental and numerical studies on lightning damage in carbon fibre-reinforced polymer (CFRP) composites under swept stroke. Coupled electrical–thermal finite element (FE) models were proposed to predict lightning damage to CFRP composites under single-point current injection and swept stroke, respectively. A lightning swept stroke testing method was proposed by embedding a copper wire inside the composites to simulate multiple lightning attachments on the composites. The FE-predicted damage from …