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Full-Text Articles in Engineering

Version Control Software And Its Possible Impact On Students Academic Integrity, David Mcquaid Jan 2023

Version Control Software And Its Possible Impact On Students Academic Integrity, David Mcquaid

HECA Research Conference

Ensuring that students treat their work with integrity has become increasingly difficult in recent years. The advent of Generative AI, Essay Mills, coupled with old fashioned plagiarism and a shift to “online” learning has created a huge shift in the domain of education. Unfortunately, this has manifested as Academic misconduct in many cases and indeed, it could be speculated, that many cases of misconduct are not recognised or discovered. This presentation discusses how version control can be used as a tool to avoid plagiarism.


Revised Avenues Of Assessment In Higher Education In The Presence Of Ai Generative Contents, Muhammad Iqbal Jan 2023

Revised Avenues Of Assessment In Higher Education In The Presence Of Ai Generative Contents, Muhammad Iqbal

HECA Research Conference

This study explores the impact of Generative Artificial Intelligence (AI) tools on academic assessments, focusing on their efficacy in generating unique content across various domains. Dr. Muhammad Iqbal from CCT College Dublin emphasizes the increasing prevalence of AI generative tools and their potential influence on learning quality in academia. The study addresses concerns related to assessment standards in higher education and proposes the evaluation of AI-generated content reliability.


Sedimentological And Geochemical Characterization Of A Varved Sediment Record From The Northern Neotropics, Edward Duarte, Jonathan Obrist-Farner, Susan R.H. Zimmerman, Erik T. Brown, Robert Brown Jan 2023

Sedimentological And Geochemical Characterization Of A Varved Sediment Record From The Northern Neotropics, Edward Duarte, Jonathan Obrist-Farner, Susan R.H. Zimmerman, Erik T. Brown, Robert Brown

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Annually resolved sedimentological records (including annual varves) can be used to develop precise chronologies for key climatic and tectonic events. Varved records, however, are most common in high latitude lakes, resulting in a spatial bias with respect to annually resolved records in tropical regions. Here we report on the sedimentology of two sediment cores from Lake Izabal, eastern Guatemala, that contain a well-preserved thinly laminated section spanning ca. 2200 years of the mid-Holocene. We integrate radiocarbon age-depth modeling, sedimentological observations, laminae counting, µX-ray fluorescence scanning, and multivariate statistical analyses to constrain the nature and chronology of the laminations. Our sedimentological …


Laboratory Investigation Of Regained Rock Permeability Using High Viscosity Friction Reducer In Comparison To Linear Guar Fracture Fluids, Ghith Biheri, Abdulmohsin Imqam Jan 2023

Laboratory Investigation Of Regained Rock Permeability Using High Viscosity Friction Reducer In Comparison To Linear Guar Fracture Fluids, Ghith Biheri, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing is a method employed for extracting oil and gas from unconventional reservoirs by pumping a mixture of water, sand, and additives into the reservoirs to fracture oil formations. A high viscosity friction reducer (HVFR) based on polyacrylamide is a popular chemical that has been employed recently during hydraulic fracturing treatments to help transport proppant and to reduce friction. However, the use of HVFRs at high concentrations, especially in regions with high concentration levels of total dissolved solids (TDS), has raised concerns over the possibility of formation damage. In this research, a new type of HVFR was investigated for …


Microcrystalline Dolomite In A Middle Permian Volcanic Lake: Insights On Primary Dolomite Formation In A Non-Evaporitic Environment, Xin Jiao, Yi Qun Liu, Wan Yang, Hong Li, Zi Yuan Meng, Min Ru Zhao, Zhe Xuan Li Jan 2023

Microcrystalline Dolomite In A Middle Permian Volcanic Lake: Insights On Primary Dolomite Formation In A Non-Evaporitic Environment, Xin Jiao, Yi Qun Liu, Wan Yang, Hong Li, Zi Yuan Meng, Min Ru Zhao, Zhe Xuan Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lacustrine dolomite nucleation commonly occurs in modern and Neogene evaporitic alkaline lakes. As a result, ancient lacustrine microcrystalline dolomite has been conventionally interpreted to be formed in evaporitic environments. This study, however, suggests a non-evaporitic origin of dolomite precipitated in a volcanic–hydrothermal lake, where hydrothermal and volcanic processes interacted. The dolomite occurs in lacustrine fine-grained sedimentary rocks in the middle Permian Lucaogou Formation in the Santanghu intracontinental rift basin, north-west China. Dolostones are composed mainly of nano-sized to micron-sized dolomite with a euhedral to subhedral shape and a low degree of cation ordering, and are interlaminated and intercalated with tuffaceous …


Smart Mobility Sensing Of Origin-Destination Pairs Using Computer Vision, Seyed Sina Shid Moosavi Jan 2023

Smart Mobility Sensing Of Origin-Destination Pairs Using Computer Vision, Seyed Sina Shid Moosavi

Electronic Theses and Dissertations, 2020-2023

The measurement of the origin-destination (OD) flow of individual passengers within the public transportation system plays a vital role in understanding resident mobility and facilitating route planning. Particularly in resource-limited communities, where access to advanced technologies like smart card systems may not be available, bus transportation systems play a crucial role in daily life. Traditional methods, such as driver logs, are not only time-consuming but also difficult to provide precise measurements of individualized OD pairs. Therefore, the primary objective of this study is to propose an automatic passenger sensing system (software) capable of accurately measuring OD pairs for individual passengers …


Structural Transformations In Photo-Thermo-Refractive Glass For Hologram Recording, Roberto Alejandro Alvarez Aguirre Jan 2023

Structural Transformations In Photo-Thermo-Refractive Glass For Hologram Recording, Roberto Alejandro Alvarez Aguirre

Electronic Theses and Dissertations, 2020-2023

This dissertation focuses on the structural transformations in photo-thermo-refractive (PTR) glass that enable recording phase holograms for efficient transformation of optical beams and high resolution spectroscopy. PTR glass is a multicomponent silicate matrix doped with Ce, Ag, Sn and Sb. It is a holographic phase medium with the ability of permanent refractive index change after UV exposure and thermal development above 500°C due to the precipitation of a NaF crystalline phase. Electronic processes are studied by analyzing the structure of absorption and luminescence bands of PTR glass matrix and its dopants. We analyze the structural transformations in PTR glass from …


Development,Validation, And Integration Of Ai-Driven Computer Vision System And Digital-Twin System For Traffic Safety Dignostics, Ou Zheng Jan 2023

Development,Validation, And Integration Of Ai-Driven Computer Vision System And Digital-Twin System For Traffic Safety Dignostics, Ou Zheng

Electronic Theses and Dissertations, 2020-2023

The use of data and deep learning algorithms in transportation research have become increasingly popular in recent years. Many studies rely on real-world data. Collecting accurate traffic data is crucial for analyzing traffic safety. Still, traditional traffic data collection methods that rely on loop detectors and radar sensors are limited to collect macro-level data, and it may fail to monitor complex driver behaviors like lane changing and interactions between road users. With the development of new technologies like in-vehicle cameras, Unmanned Aerial Vehicle (UAV), and surveillance cameras, vehicle trajectory data can be collected from the recorded videos for more comprehensive …


Active Photonic Integrated Devices And Circuits On Thin-Film Lithium Niobate Platform, Ehsan Ordouie Jan 2023

Active Photonic Integrated Devices And Circuits On Thin-Film Lithium Niobate Platform, Ehsan Ordouie

Electronic Theses and Dissertations, 2020-2023

This thesis delves into innovative active photonic integrated devices and circuits on the thin-film lithium niobate (TFLN) platform, focusing on their applications and potential future advancements. We introduce a new family of electrooptic modulators (EOMs), the Four-Phase Electrooptic Modulators (FEOMs), which are fabricated using the TFLN platform. These devices effectively mitigate bandwidth and dynamic-range constraints in optical communication systems by reducing dispersion penalties and common-mode noises. Their functionality is demonstrated in a photonic time-stretch system. A dual-polarization variant further exemplifies the mitigation of both dispersion penalties and common-mode noises in long-haul communication links, marking significant strides towards the practical implementation …


Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung Jan 2023

Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung

Electronic Theses and Dissertations, 2020-2023

The endothelium composes the inner lining of blood vessels, the heart, and lymphatic vessels. Within the cardiovascular system, it is an extremely important structure, aiding in the regulation of blood pressure with the vascular tone, recruiting immune response, regulating the transfer of material in and out of the bloodstream, and the creation of new blood vessels through angiogenesis. The endothelium is composed entirely of endothelial cells. These cells lay in a flat squamous formation and are in direct contact with blood and aid in the regulation and transfer of material in and out of the bloodstream via active and passive …


Nanostructured Alloy Thin Film Fabrication And Application For Zinc-Air Battery And Lithium-Ion Battery, Guanzhi Wang Jan 2023

Nanostructured Alloy Thin Film Fabrication And Application For Zinc-Air Battery And Lithium-Ion Battery, Guanzhi Wang

Electronic Theses and Dissertations, 2020-2023

The depletion of unsustainable fossil fuels and growing environmental issues have given rise to scientific challenges and research interests in the development of renewable energy technologies to meet the rising global energy demand. Electrochemical energy storage and conversion technologies (ESCTs), such as lithium-ion batteries, metal-air batteries, supercapacitors, and fuel cells, etc., offer a clean and sustainable strategy for utilizing energy. As the core components, the electrode materials, including anodes, cathodes, and catalysts, play a direct decisive role in the device's performance in practical application. Therefore, the development of high-performance and low-cost electrode materials is critical for the success of these …


Inventions In The Area Of Nanotechnologies And Nanomaterials. Part I, Leonid A. Ivanov, Li Da Xu, Zhanna V. Pisarenko, Svetlana R. Muminova, Nadezda G. Miloradova Jan 2023

Inventions In The Area Of Nanotechnologies And Nanomaterials. Part I, Leonid A. Ivanov, Li Da Xu, Zhanna V. Pisarenko, Svetlana R. Muminova, Nadezda G. Miloradova

Information Technology & Decision Sciences Faculty Publications

Introduction. Advanced technologies inspire people by demonstrating the latest achievements (materials, methods, systems, technologies, devices etc.) that dramatically change the world. This, first of all, concerns nanotechnological inventions designed by scientists, engineers and specialists from different countries. Main part. The article provides an abstract overview of inventions of scientists, engineers and specialists from different countries: Germany, Russia, China, USA et al. The results of the creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials allow, when introduced to industry, achieving a significant effect in construction, housing and communal services, and related sectors of …


Electroanalytical Investigations Of Microrna-Conjugated Cerium Oxide Based Nanomaterials For Biomedical Applications, Chaimae El Ghzaoui Jan 2023

Electroanalytical Investigations Of Microrna-Conjugated Cerium Oxide Based Nanomaterials For Biomedical Applications, Chaimae El Ghzaoui

Electronic Theses and Dissertations, 2020-2023

Diabetes patients are increasingly suffering from wound-healing impairments coupled with other severe medical conditions. High levels of oxidative stress and proinflammatory cytokines are predominant pathologic characteristics of diabetic wounds. Applying microRNA (miRNA) in gene therapy often successfully treats various disorders by generating highly specific bio-responses. Studies revealed that microRNA146a (miR146a), a regulator of inflammation, is downregulated in diabetic wounds. However, miR203 is found to be highly-expressed in diabetic foot ulcers in positive correlation with disease severity. We have synthesized Cerium oxide nanoparticles (CNPs) since they are used in various biomedical applications due to their high enzyme-mimetic activities and reactive oxygen …


A Bim-Based Digital Platform For Assessing The Whole Building Circularity Indicators Of Modular Steel Projects, Yin Min Maung Jan 2023

A Bim-Based Digital Platform For Assessing The Whole Building Circularity Indicators Of Modular Steel Projects, Yin Min Maung

Chulalongkorn University Theses and Dissertations (Chula ETD)

The construction industry is undergoing a paradigm shift towards sustainable practices, one of which is circular economy (CE). Adopting the CE concept is a complex undertaking, which is characterized by a set of indicators capturing its key aspects. Various tools and techniques are employed to implement this novel concept. An essential step of CE implementation is evaluating the circularity of buildings. This research develops a BIM-based digital platform for assessing the whole building circularity indicators (WBCI) of modular steel projects. The platform is designed to assist in computing these indicators, which requires diverse data inputs and complex interrelated equations. The …


Implementing The Circular Economy Concept In Construction Supply Chain Management Of Modular Steel Projects, Thet Htar San Jan 2023

Implementing The Circular Economy Concept In Construction Supply Chain Management Of Modular Steel Projects, Thet Htar San

Chulalongkorn University Theses and Dissertations (Chula ETD)

The circular economy is a modern economic model where the value of products, materials, and resources is maintained in the economy as long as possible, whereas the generation of waste is minimized. The current linear take-make-dispose model prevalent in construction supply chain management is increasingly unsustainable, marked by significant resource wastage and environmental impacts. The conventional linear supply chain models in modular steel construction contribute to unsustainable resource utilization and environmental impacts. This research explores the transition from linear to circular supply chain models. We identify key actors, potential barriers, and opportunities for implementing circular economy practices in modular steel …


Factors Influencing Mode Choice Selection And Intention Of Public Transport Users : A Comparative Study Between Thailand And Indonesia During Pandemic, Aditya Mahatidanar Hidayat Jan 2023

Factors Influencing Mode Choice Selection And Intention Of Public Transport Users : A Comparative Study Between Thailand And Indonesia During Pandemic, Aditya Mahatidanar Hidayat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The COVID-19 pandemic significantly impacted public transportation, causing a substantial decline in bus passengers. In 2021, Bangkok witnessed a 40-60% reduction compared to normal conditions, while Jakarta experienced a staggering 76% decline compared to June 2019. This study aims to assess passengers' intentions to use buses during the pandemic and analyze factors influencing mode choice. Two methodologies were employed: the Structural Equation Model (SEM) to identify factors impacting transportation intentions and the Hybrid Choice Model (HCM) to understand mode choice influencers. Data collection occurred in Bangkok and Jakarta, targeting bus users at central transportation hubs, with 392 and 387 respondents. …


The Need For International Ai Activities Monitoring, Parviz Partow-Navid, Ludwig Slusky Jan 2023

The Need For International Ai Activities Monitoring, Parviz Partow-Navid, Ludwig Slusky

Journal of International Technology and Information Management

This paper focuses primarily on the need to monitor the risks arising from the dual-use of Artificial Intelligence (AI). Dual-use AI technology capability makes it applicable for defense systems and consequently may pose significant security risks, both intentional and unintentional, with the national and international scope of effects. While domestic use of AI remains the prerogative of individual countries, the unregulated and nonmonitored use of AI with international implications presents a specific concern. An international organization tasked with monitoring potential threats of AI activities could help defuse AI-associated risks and promote global cooperation in developing and deploying AI technology. The …


Determinants Of Continuance Intention To Use Mobile Wallets Technology In The Post Pandemic Era: Moderating Role Of Perceived Trust, Shailja Tripathi Jan 2023

Determinants Of Continuance Intention To Use Mobile Wallets Technology In The Post Pandemic Era: Moderating Role Of Perceived Trust, Shailja Tripathi

Journal of International Technology and Information Management

The Covid-19 pandemic amplified the volume and importance of mobile payments using digital wallets and placed a basis for their continued adoption. The objective of the study is to formulate and test a comprehensive model by integration of the technology acceptance model (TAM) and expectation confirmation model (ECM) with the addition of three constructs, namely perceived trust, perceived risk, and subjective norm, to identify the determinants of continuance intention to use mobile wallets. Questionnaire-based survey method was used to gather the data from 550 users having experience using mobile wallets for more than six months. The data were analyzed using …


A Camera-Only Based Approach To Traffic Parameter Estimation Using Mobile Observer Methods, Temitope D. Jegede Jan 2023

A Camera-Only Based Approach To Traffic Parameter Estimation Using Mobile Observer Methods, Temitope D. Jegede

College of Graduate Studies: Theses & Dissertations

As vehicles become more modern, a large majority of vehicles on the road will have the required sensors to smoothly interact with other vehicles and infrastructure on the road. There will be many benefits of this new connectivity between vehicles on the road but one of the most profound improvements will be in the area of road accident prevention. Vehicles will be able to share information vital to road safety to oncoming vehicles and vehicles that are occluded so they do not have a direct line of sight to see a pedestrian or another vehicle on the road.

Another advantage …


Mitigation Of Aeroacoustic Noise Of A Fixed Wing Using Passive Flow Control, Cameron L. Perry Jan 2023

Mitigation Of Aeroacoustic Noise Of A Fixed Wing Using Passive Flow Control, Cameron L. Perry

College of Graduate Studies: Theses & Dissertations

As the world becomes more environmentally conscious, noise pollution is of increasing concern. In this study, shallow dimples are applied to a NACA 0012 airfoil at multiple angles of attack (AoA) with the intent of reducing aeroacoustic noise emissions. Both Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models are used for aerodynamic and aeroacoustic investigations, respectively, at a fixed Reynolds number of 4.8 x 105. Altering the dimple depth to diameter ratio (d/D) from 2.5% to 15% is first investigated, with a d/D of 5% or lower resulting in the least aerodynamic impact. The transition from …


Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins Jan 2023

Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins

College of Graduate Studies: Theses & Dissertations

Magnetorheological elastomers, or MREs, are smart composite materials with controllable physical and mechanical properties when introduced to an external stimulus of a magnetic field. The controllability of these properties is highly tunable by the selection of the elastomeric matrix, concentration of magnetically permeable particles, introduction of additives, and the alignment of the constituents during the curing process. The fabrication of MREs typically calls for a mold that is filled with an MRE mixture to create the final desired geometry after curing. These molds are frequently placed under a magnetic field which orients the micron sized magnetic particles along the magnetic …


Computational And Experimental Investigation Of Mass Reduced Aircraft Wing Ribs, Charles R. Fricks Iii Jan 2023

Computational And Experimental Investigation Of Mass Reduced Aircraft Wing Ribs, Charles R. Fricks Iii

College of Graduate Studies: Theses & Dissertations

This study seeks to develop and evaluate a novel design of mass reduced aircraft wing ribs through the topology optimization method. For comparison, the same examination is performed on ribs with normal internal geometry. The wing rib design is based on that of the Gulfstream G650 transonic jet. The rib was divided into three segments for analysis based around the positions of the two spars. Only the center section of the rib (that being between the forward and aft spars) is mass optimized, while the leading and trailing edges of the ribs (outside the spars) will be kept solid for …


Methods On Implementing Radar And Antenna Solutions To Defense And Biomedical Problems, Jalexis E. Vanga Guzman Jan 2023

Methods On Implementing Radar And Antenna Solutions To Defense And Biomedical Problems, Jalexis E. Vanga Guzman

College of Graduate Studies: Theses & Dissertations

Growing developments in antenna and radio frequency systems have created a strong incentive for researchers to study and apply electromagnetic (EM)-based solutions to modern defense and biomedical problems. The ability to transmit and receive EM waves using antenna systems has not only increased global connectivity, but also increased the need for innovation in antenna size reduction and development of radar systems.

Size reduction techniques have been extensively studied for antennas after the development of electrically small antennas (ESAs) which follow Chu’s limit. ESAs allow the implementation of antennas with much smaller foot-size than traditional full-sized designed while keeping the same …


Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi Jan 2023

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …


On The Chronological Understanding Of The Homogeneous Dielectric Barrier Discharge, Xinpei Lu, Zhi Fang, Dong Dai, Tao Shao, Feng Liu, Cheng Zhang, Dawei Liu, Lanlan Nie, Chunqi Jiang Jan 2023

On The Chronological Understanding Of The Homogeneous Dielectric Barrier Discharge, Xinpei Lu, Zhi Fang, Dong Dai, Tao Shao, Feng Liu, Cheng Zhang, Dawei Liu, Lanlan Nie, Chunqi Jiang

Bioelectrics Publications

Dielectric barrier discharges (DBD) are widely utilised non-equilibrium atmospheric pressure plasmas with a diverse range of applications, such as material processing, surface treatment, light sources, pollution control, and medicine. Over the course of several decades, extensive research has been dedicated to the generation of homogeneous DBD (H-DBD), focussing on understanding the transition from H-DBD to filamentary DBD and exploring strategies to create and sustain H-DBD. This paper first discusses the influence of various parameters on DBD, including gas flow, dielectric material, surface conductivity, and mesh electrode. Secondly, a chronological literature review is presented, highlighting the development of H-DBD and the …


Extracellular Vesticles In Acute Respiratory Distress Syndrome: Understanding Protective And Harmful Signaling For The Development Of New Therapeutics, Matthew Bavuso, Noel Miller, Joshua M. Sill, Anca Dobrian, Ruben M. L. Colunga Biancatelli Jan 2023

Extracellular Vesticles In Acute Respiratory Distress Syndrome: Understanding Protective And Harmful Signaling For The Development Of New Therapeutics, Matthew Bavuso, Noel Miller, Joshua M. Sill, Anca Dobrian, Ruben M. L. Colunga Biancatelli

Bioelectrics Publications

Acute respiratory distress syndrome (ARDS) is a severe respiratory condition characterized by increased lung permeability, hyper-inflammatory state, and fluid leak into the alveolar spaces. ARDS is a heterogeneous disease, with multiple direct and indirect causes that result in a mortality of up to 40%. Due to the ongoing Covid-19 pandemic, its incidence has increased up to ten-fold. Extracellular vesicles (EVs) are small liposome-like particles that mediate intercellular communication and play a major role in ARDS pathophysiology. Indeed, they participate in endothelial barrier dysfunction and permeability, neutrophil, and macrophage activation, and also in the development of a hypercoagulable state. A more …


Interactions Of Carboxylated Nanodiamonds With Mouse Macrophages Cell Line And Primary Cells, Maisoun Bani-Hani, Stephen J. Beebe, Michael W. Stacey, Christopher Osgood Jan 2023

Interactions Of Carboxylated Nanodiamonds With Mouse Macrophages Cell Line And Primary Cells, Maisoun Bani-Hani, Stephen J. Beebe, Michael W. Stacey, Christopher Osgood

Bioelectrics Publications

Nanodiamonds (ND) have attracted significant interest for their use in several biomedical applications. These applications can be very useful if the safety and compatibility of ND are proven. We assessed the effects of ND (100 nm, Carboxylated) on primary macrophages and a macrophage-like cell line and found that these particles are not toxic to these cells at lower concentrations but may interfere with cell functions and differentiation. Internalization of ND by these cells in a time- and dose-dependent manner was mostly via phagocytosis and clathrin-dependent endocytosis and localized to the cytoplasm but not into the nucleus. No significant induction of …


Evaluation Of Cold Atmospheric Plasma For The Decontamination Of Flexible Endoscopes, R. C. Hervé, Michael G. Kong, Sudhir Bhatt, Hai-Lan Chen, E. E. Comoy, J-P. Deslys, T. J. Secker, C. W. Keevil Jan 2023

Evaluation Of Cold Atmospheric Plasma For The Decontamination Of Flexible Endoscopes, R. C. Hervé, Michael G. Kong, Sudhir Bhatt, Hai-Lan Chen, E. E. Comoy, J-P. Deslys, T. J. Secker, C. W. Keevil

Bioelectrics Publications

Background: Despite adherence to standard protocols, residues including live microorganisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins notoriously difficult to eliminate.

Aim: We tested the potential of cold atmospheric plasma (CAP) for the decontamination of flexible endoscope various surfaces, measuring total proteins and prion-residual infectivity as an indicator of efficacy.

Methods: New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were then examined for the presence of residues using very sensitive fluorescence epi-microscopy. Prion residual infectivity was determined using the …


Pulsed Electric Field Ablation Of Esophageal Malignancies And Mitigating Damage To Smooth Muscle: An In Vitro Study, Emily Gudvangen, Uma Mangalanathan, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Andrei G. Pakhomov Jan 2023

Pulsed Electric Field Ablation Of Esophageal Malignancies And Mitigating Damage To Smooth Muscle: An In Vitro Study, Emily Gudvangen, Uma Mangalanathan, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Andrei G. Pakhomov

Bioelectrics Publications

Cancer ablation therapies aim to be efficient while minimizing damage to healthy tissues. Nanosecond pulsed electric field (nsPEF) is a promising ablation modality because of its selectivity against certain cell types and reduced neuromuscular effects. We compared cell killing efficiency by PEF (100 pulses, 200 ns–10 µs duration, 10 Hz) in a panel of human esophageal cells (normal and pre-malignant epithelial and smooth muscle). Normal epithelial cells were less sensitive than the pre-malignant ones to unipolar PEF (15–20% higher LD50, p < 0.05). Smooth muscle cells (SMC) oriented randomly in the electric field were more sensitive, with 30–40% lower LD50 (p < 0.01). Trains of ten, 300-ns pulses at 10 kV/cm caused twofold weaker electroporative uptake of YO-PRO-1 dye in normal epithelial cells than in either pre-malignant cells or in SMC oriented perpendicularly to the field. Aligning SMC with the field reduced the dye uptake fourfold, along with a twofold reduction in Ca2+ transients. A 300-ns pulse induced a twofold smaller transmembrane potential in cells aligned with the field, making them …


Analyzing Residential Curbside Collection For Food Waste In Humboldt County, Yvette Lindler Jan 2023

Analyzing Residential Curbside Collection For Food Waste In Humboldt County, Yvette Lindler

Cal Poly Humboldt theses and projects

The most prevalent material in the California landfill-destined solid waste stream is food. Food waste is not only an economic and social concern, but a significant environmental challenge as well. Most food waste is disposed of in landfills, where it anaerobically decomposes and releases methane, an extremely potent greenhouse gas and driver of climate change. Policies passed in California, including AB 1826 and SB 1383, aim to implement organic waste recycling programs and reduce methane emissions by diverting organic waste from landfills. The technology to process this food waste exists, but these facilities are limited or nonexistent in rural areas …