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Articles 14191 - 14220 of 198032

Full-Text Articles in Engineering

Photodegradation Of Malachite Green Using 2d G-C3n5 Nanosheet: A Promising Metal Free Catalyst, Sonali Biswal, Swayam Aryam Behera, Asima Subhadarshini, P. Ganga Raju Achary, Binita Nanda Jan 2025

Photodegradation Of Malachite Green Using 2d G-C3n5 Nanosheet: A Promising Metal Free Catalyst, Sonali Biswal, Swayam Aryam Behera, Asima Subhadarshini, P. Ganga Raju Achary, Binita Nanda

Journal of Metals, Materials and Minerals

Environmental issues have become more serious these days due to the growth of modern industries. The paper and textile industries, in particular, were heavily dependent on the printing and discharge of dye, which constantly leaked into the water ecology and constituted a serious risk to public health. Organic wastewater treatment and remediation for its associated risks have received a lot of attention lately. This work explored the potential of the g-C3N5 nanostructure as a novel photocatalyst for malachite green degradation in aqueous solution while exposed to visible light. The nanocomposite was fabricated through an ultrasonicate-assisted technique. A number of analysis …


Regulating Copx/Co Heterostructures For Enhanced Electrocatalytic Activity Toward Hydrazine Oxidation Reaction, Qinquan Lin, Rui Zhang, Changli Yan, Qizhao Hu, Shangbin Sang, Qiumei Wu, Kaiyu Liu, Hongtao Liu Jan 2025

Regulating Copx/Co Heterostructures For Enhanced Electrocatalytic Activity Toward Hydrazine Oxidation Reaction, Qinquan Lin, Rui Zhang, Changli Yan, Qizhao Hu, Shangbin Sang, Qiumei Wu, Kaiyu Liu, Hongtao Liu

Journal of Metals, Materials and Minerals

Hydrazine hydrate (N2H4∙H2O) is considered an ideal fuel for fuel cells. Constructing a cobalt phosphide/cobalt (CoPx/Co) heterostructure can achieve efficient electrocatalytic activity for hydrazine oxidation reaction. Traditional strategies for constructing CoPx/Co heterostructures took less consideration on the exposure of the active sites. In this study, 3D nanoflower-like nano CoPx/Co heterostructures with highly exposed active sites were obtained on a nickel foam (NF) through a dual-component phosphating strategy, i.e., regulating the relative content of Co and Co(OH)2 with cathodic current density and utilizing the differences in their phosphating behaviors. The potential at 100 mA∙cm‒2 and Tafel slope of the optimized CoPx/Co(375)@NF …


Facile Synthesis Of Bamno3-Zro2 Composite: A Step Towards The Photocatalytic Degradation Of Organic Dye, Kirttimayee Mohanta, Swayam Aryam Behera, Binita Nanda, P. Ganga Raju Achary Jan 2025

Facile Synthesis Of Bamno3-Zro2 Composite: A Step Towards The Photocatalytic Degradation Of Organic Dye, Kirttimayee Mohanta, Swayam Aryam Behera, Binita Nanda, P. Ganga Raju Achary

Journal of Metals, Materials and Minerals

Environmental contamination by synthetic dyes, particularly Methylene Blue (MB), presents a significant threat to aquatic ecosystems and human health due to their chemical stability and toxicity. This study investigates the photocatalytic degradation of MB using a BaMnO3:ZrO2 composite synthesized in a 1:2 ratio via a straightforward wet-chemical method. Structural and optical characterizations were performed using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS). The composite exhibited a reduced bandgap of 2.88 eV and uniform nanoscale morphology, both favorable for visible-light-driven photocatalysis. Under visible-light irradiation, the catalyst achieved 89% degradation efficiency within …


The Effects Of Graphene Nanoplatelets And Microcrystalline Cellulose On The Mechanical Properties Of Fiberglass And Carbon Fiber Composites, Duangjai Srisamut, Nathawat Poopakdee, Warut Thammawichai Jan 2025

The Effects Of Graphene Nanoplatelets And Microcrystalline Cellulose On The Mechanical Properties Of Fiberglass And Carbon Fiber Composites, Duangjai Srisamut, Nathawat Poopakdee, Warut Thammawichai

Journal of Metals, Materials and Minerals

This study investigated how graphene nanoplatelets (GNP) and microcrystalline cellulose (MCC) affect the mechanical properties of epoxy (EP), carbon fiber (CF), and fiberglass (FG) composites. The tensile and flexural properties of GNP-EP and MCC-EP of  varying reinforcement concentrations were examined. Results indicated significant improvements on tensile and flexural properties by GNP and MCC. At 0.1 wt% GNP, tensile and flexural strengths increased by 10% and 21%, while 2.0 wt% improved flexural modulus by 65%. Similarly, 2.0 wt% MCC improved tensile strength, modulus, and flexural modulus by 11%, 11%, and 46%, respectively, and a 26% increase in flexural strength at 1.0 …


Synthesis Temperature-Driven Enhancements In Bioi Photocatalysis: A Hydrothermal Approach, Sorawit Thueanbangyang, Kittiyaporn Singsumphan, Varunya Atimayulerd, Chutima Nakmuk, Cheewita Suwanchawalit, Montri Aiempanakit Jan 2025

Synthesis Temperature-Driven Enhancements In Bioi Photocatalysis: A Hydrothermal Approach, Sorawit Thueanbangyang, Kittiyaporn Singsumphan, Varunya Atimayulerd, Chutima Nakmuk, Cheewita Suwanchawalit, Montri Aiempanakit

Journal of Metals, Materials and Minerals

Bismuth oxyiodide (BiOI) is a promising photocatalyst for visible-light-driven environmental remediation. However, its photocatalytic efficiency is highly dependent on synthesis conditions, particularly hydrothermal temperature, which governs its structural, optical, and electronic properties. In this study, BiOI was synthesized via a hydrothermal method at temperatures of 120℃, 150℃, 180℃, and 210℃ to investigate the effect of temperature on its photocatalytic performance systematically. Comprehensive characterizations, including X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence and photocatalytic degradation studies, were conducted to analyze crystallinity, morphology, band structure and charge transfer properties. The results …


Bagasse Lignin For Single-Used Food Packaging Applications: Uv-Barrier, Antioxidant, Migration And Cytotoxicity, Pawarisa Wijaranakul, Bongkot Hararak, Wanwitoo Wanmoolee, Prapudsorn Wannid, Weerawan Laosiripojana Jan 2025

Bagasse Lignin For Single-Used Food Packaging Applications: Uv-Barrier, Antioxidant, Migration And Cytotoxicity, Pawarisa Wijaranakul, Bongkot Hararak, Wanwitoo Wanmoolee, Prapudsorn Wannid, Weerawan Laosiripojana

Journal of Metals, Materials and Minerals

This study examined PLA biocomposite films made from organosolv lignin extracted from Thai agro-waste, specifically sugarcane bagasse (BG), to assess their suitability for food packaging, focusing on their physical, thermal, optical, UV-shielding, antioxidant, and migration properties. Extracted BG-lignin exhibited free radical scavenging ability with an EC50 value of 400 µg/ml, reducing DPPH absorbance by 50%. PLA composite films with BG-lignin dosage from 0.1 to 1.0 wt.% were successfully fabricated via conventional blown film extrusion. Addition of BG-lignin at 0.5 wt.% and 1.0 wt.% to PLA films decreased UV transmittance from 90% to 30% and 12%, respectively, without compromising optical clarity. …


Coating Of Zinc Substrates With Fluorosilane Molecules Using A Water-Treatment Technique As A Pre-Coating Procedure For The Creation Of Superhydrophobic Surfaces, Renz Ronald R. Prieto, Marvin U. Herrera Jan 2025

Coating Of Zinc Substrates With Fluorosilane Molecules Using A Water-Treatment Technique As A Pre-Coating Procedure For The Creation Of Superhydrophobic Surfaces, Renz Ronald R. Prieto, Marvin U. Herrera

Journal of Metals, Materials and Minerals

Superhydrophobic surfaces were successfully created when zinc substrates were coated with molecules with low surface energy through grafting of fluorosilane molecules. The zinc substrate underwent water-treatment technique as a pre-coating procedure to enhance the reaction sites for the grafting of fluorosilane molecules. The water contact angle of the samples went as high as 161.1° ± 0.8°. At lower fluorosilane-ethanol soaking times, water contact angles have lower values while at higher soaking time, it has higher water contact angle values. At 240 min fluorosilane-ethanol soaking time, optimum value of water contact angle was achieved. Fluorosilane molecules are widely distributed through the …


Sulfur-Doped Carbon Dots Derived From Caffeine: A Highly Efficient Photocatalyst For Organic Dye Degradation, Ganyaporn Wongwaen, Koranut Dechsri, Praneet Opanasopit, Montri Aiempanakit, Cheewita Suwanchawalit Jan 2025

Sulfur-Doped Carbon Dots Derived From Caffeine: A Highly Efficient Photocatalyst For Organic Dye Degradation, Ganyaporn Wongwaen, Koranut Dechsri, Praneet Opanasopit, Montri Aiempanakit, Cheewita Suwanchawalit

Journal of Metals, Materials and Minerals

Sulfur-doped carbon dots (S-doped CDs) were synthesized via a solvothermal method using caffeine as a carbon precursor and sodium sulfide as a sulfur source. Characterization using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet -visible (UV-Vis) spectroscopy, and photoluminescence spectroscopy (PL) confirmed successful sulfur incorporation. TEM revealed a uniform size distribution and graphitic structures, while UV-Vis analysis showed a reduction in the bandgap from 3.29 eV to 3.10 eV, improving light absorption and charge carrier separation. The photocatalytic activity of S-doped CDs was evaluated for indigo carmine (IC) dye degradation under UV irradiation, where 2S-CDs …


Impacts Of Calcination Temperature On The Crystallography, Granulometry And Impedance Of Licomno4, Chee Wayne Tan, Zul Hilmi Che Daud, Zainab Asus, Mohd Hasbullah Idris, Izhari Izmi Mazali, Mohd Kameil Abdul Hamid Jan 2025

Impacts Of Calcination Temperature On The Crystallography, Granulometry And Impedance Of Licomno4, Chee Wayne Tan, Zul Hilmi Che Daud, Zainab Asus, Mohd Hasbullah Idris, Izhari Izmi Mazali, Mohd Kameil Abdul Hamid

Journal of Metals, Materials and Minerals

Spinel structured lithium cobalt manganese oxide (LiCoMnO4) which exhibit reduction potential surpassing 5.0 V (vs. Li0 | Li+) was identified to be one of the prospective cathode candidates for next generation lithium-ion electrochemical systems. This article highlights the significance of calcination temperature on the crystallography of the resultant electroceramic compound as well as the corresponding response on the granulometry and impedance of LiCoMnO4. LiCoMnO4 compounds synthesised via sol-gel reaction in the first instance were converted into xerogel and subsequently subjected to facile one-step calcination protocol. Crystallography of the post-calcinated compounds were characterised via powder x-ray diffraction (XRD) technique. Temperature ranging …


Effect Of Lanthanum Doping On Phase Transition, Piezoelectric And Energy Storage Properties Of Lead-Free 0.93(Bi0.5na0.5)Tio3‒0.07batio3 Ceramics, Pathit Premwichit, Songphop Jaila, Sasiporn Prasertpalichat Jan 2025

Effect Of Lanthanum Doping On Phase Transition, Piezoelectric And Energy Storage Properties Of Lead-Free 0.93(Bi0.5na0.5)Tio3‒0.07batio3 Ceramics, Pathit Premwichit, Songphop Jaila, Sasiporn Prasertpalichat

Journal of Metals, Materials and Minerals

In this study, lead-free (Bi0.465Na0.465Ba0.07)(1–x)LaxTiO3 (x=0.0‒0.04) ceramics were synthesized using a conventional solid-state reaction method. All samples showed a single-phase perovskite structure with pseudocubic symmetry. The dense microstructure revealed a decrease in average grain size as x increased. La3+ addition stabilized polar nanoregions (PNRs), shifting the ferroelectric to relaxor phase transition temperature (TF₋R=104℃ for x=0.0) to below room temperatures as La3+ content increased. This resulted in a transition from a rectangular to a relaxor-like thin P–E loop (x≥0.01), indicating a shift from ferro-electric (FE) to relaxor ferroelectric (RFE), which …


Aluminium Oxide Particles-Containing Organogels For Cleaning Of Optical Glass Surfaces, Galina Vladimirovna Lyamina, Oksana Valerievna Dubinina, Alfa Edison I Lela Jan 2025

Aluminium Oxide Particles-Containing Organogels For Cleaning Of Optical Glass Surfaces, Galina Vladimirovna Lyamina, Oksana Valerievna Dubinina, Alfa Edison I Lela

Journal of Metals, Materials and Minerals

Hypothesis:  Some types of cleaning methods are not very effective and can actually increase damage to the optical parts being cleaned. As an alternative to these methods, we propose the use of gel-like substances to remove contaminants from optical surfaces. We have developed a method for cleaning optical glass surfaces that uses organogels, which are based on copolymers of methyl methacrylate and methacrylic acid. These organogels are loaded with polyethylene glycol, and aluminum oxide particles (Al2O3), which help to effectively remove contaminants without causing damage to the surface.   Experiments:  Al2O3 nanoparticles prepared by a Nano Spray Dryer were added to …


Predicting Complex Di-Alkylation Kinetics Using Machine Learning, Colin Bailey, Thomas Roper Jan 2025

Predicting Complex Di-Alkylation Kinetics Using Machine Learning, Colin Bailey, Thomas Roper

Graduate Research Posters

Background: Predicting reaction kinetics for complex chemical systems often presents significant challenges due to intricate reaction pathways, multiple product formations, and competing side reactions. Additionally, the transient nature of reaction intermediates and limited experimental data complicate efforts to capture system dynamics accurately. These complexities necessitate advanced modeling approaches and precise experimental techniques to reliably describe and predict chemical behavior.

Methods: This work investigates the kinetics of di-alkylation of 4-Hydroxybenzoic Acid (4-HBA) using multiple machine learning algorithms, including Random Forest Regression, Gradient Boosting, Lasso, Ridge, and XGBoost. By leveraging reaction conditions, such as temperature, sulfuric acid equivalents, and initial concentrations of …


Enhancing Trust In Ai For Healthcare: A Quantative Evaluation Of Explainable Methods In Clinical Decision Support Systems, Abdul Aziz Noor Jan 2025

Enhancing Trust In Ai For Healthcare: A Quantative Evaluation Of Explainable Methods In Clinical Decision Support Systems, Abdul Aziz Noor

Masters

The integration of Artificial Intelligence (AI) into healthcare has revolutionized Clinical Decision Support Systems (CDSS) by enabling sophisticated predictive capabilities. However, the opaque nature of many machine learning models, commonly referred to as "black-box" systems, poses significant challenges to their adoption in critical clinical settings where transparency, interpretability, and trust are paramount. This thesis addresses these challenges by developing a rigorous, mathematically grounded framework to evaluate Explainable AI (XAI) methods and enhance their integration into CDSS.


Mechanistic Scale-Up Of Gas-Solid Fluidized Beds Via Local Hydrodynamic Similarity, Faraj M. Zaid, Thaar M. Aljuwaya, Muthanna H. Al-Dahhan Jan 2025

Mechanistic Scale-Up Of Gas-Solid Fluidized Beds Via Local Hydrodynamic Similarity, Faraj M. Zaid, Thaar M. Aljuwaya, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study presents a detailed experimental evaluation of a newly developed mechanistic scale-up methodology for gas-solid fluidized beds. Traditional scale-up approaches typically rely on matching global dimensionless groups, which often fail to ensure local hydrodynamic similarity. In contrast, the new mechanistic method aims to achieve scale-up by matching the radial profiles of gas holdup between geometrically similar beds at corresponding dimensionless axial positions (z/Dc). This approach is based on the premise that when gas holdup profiles align, other key hydrodynamic parameters—such as solids holdup and particle velocity—also become similar. To validate this methodology, experiments were conducted in two …


Food Waste Crisis In The United States Of America: The Known, The Overlooked And The Undisclosed, Sagarika Srivastava, David J. Tonjes Jan 2025

Food Waste Crisis In The United States Of America: The Known, The Overlooked And The Undisclosed, Sagarika Srivastava, David J. Tonjes

Technology & Society Faculty Publications

With a loss of 1,250 calories per day per person or 140 kg/p/yr, the United States (U.S.) has a large problem with food waste. The later a product is wasted in the supply chain, the greater its environmental cost. Many food waste mitigation efforts focus on the retail and consumer stages, but there is also considerable food waste in the production phase, which includes growing, harvesting, transportation, storage and processing. The study is conducted in two steps: a bibliometric analysis of 218 articles on food waste in the U.S., followed by an investigation of options to meet food waste recovery …


Calibration Of A Low-Cost Air Quality Sensor Package Integrated Into The New York State Mesonet, Ellie Hojeily Jan 2025

Calibration Of A Low-Cost Air Quality Sensor Package Integrated Into The New York State Mesonet, Ellie Hojeily

Electronic Theses & Dissertations (2024 - present)

The University at Albany designed and manufactured 59 low-cost air quality sensor packages to continuously measure PM₂.₅, CO, O₃, NO₂, and NO at 38 New York State Mesonet (NYSM) sites located in the New York City Metropolitan Area. Prior to use for monitoring, low-cost sensors require calibration to correct for environmental sensitivities. Calibration models can be developed using data collected from co-location periods in which low-cost sensors are installed at sites with Federal Reference Methods and/or Federal Equivalent Methods instruments. In this study, packages were periodically co-located (calibrated) for 18 to 162 days at the New York State Department of …


Mobile Air Quality Assessment Using Public Transportation: A Community-Focused Study In The Capital Region, Allen Pronith Reddy Yeddula Jan 2025

Mobile Air Quality Assessment Using Public Transportation: A Community-Focused Study In The Capital Region, Allen Pronith Reddy Yeddula

Electronic Theses & Dissertations (2024 - present)

The monitoring of air quality plays a crucial role in establishment of concentrations of air pollutants over space and time in relation to human health, urban planning, and environmental conservation. This research offers a new strategy of monitoring the air quality in the Capital Region of New York State utilizing public transit buses as air quality moving sampling platforms. To assess the level of pollutants, a Capital District Transportation Authority (CDTA) bus network was used across the urban, suburban, and rural areas thus filling a research gap where public transit has most of the time been disregarded as a mobile …


Advancing 4h-Silicon Carbide Power Mosfets Through Three-Dimensional Technology Computer Aided Design Optimization, Skylar A. Deboer Jan 2025

Advancing 4h-Silicon Carbide Power Mosfets Through Three-Dimensional Technology Computer Aided Design Optimization, Skylar A. Deboer

Electronic Theses & Dissertations (2024 - present)

This research contributes to the advancement of 1.2 kV 4H-Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) through the development and implementation of sophisticated three-dimensional Technology Computer-Aided Design (3D TCAD) methodologies. These advanced simulation techniques enable comprehensive evaluation of innovative unit cell architectures that remain inaccessible to conventional two-dimensional (2D) TCAD approaches. By leveraging these 3D simulation capabilities, this work facilitates significant improvements in both the performance and reliability of next-generation wide-bandgap power devices.

Power devices convert electrical energy between different forms throughout the power grid making them essential in applications ranging from personal electronics, electric vehicles, renewable energy systems, industrial …


Development Of 2d Microfluidics Surface With Low-Frequency Electric Fields For Cell Separation Applications, Madushan Wickramasinghe, Dharmakeerthi Nawarathna Jan 2025

Development Of 2d Microfluidics Surface With Low-Frequency Electric Fields For Cell Separation Applications, Madushan Wickramasinghe, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Cell separation techniques are widely used in many biomedical and clinical applications for the development of screening, diagnosis and therapeutic tests. Current 3D microfluidics-based cell separation methods have limited applications in part due to low throughput and technical complexity. To address these critical needs, we have developed a 2D microfluidics surface which is the miniaturized version of a 3D microfluids cell separation device. Using low-frequency electric fields (1–10 Vpp and 1 kHz–20 MHz), we have first studied dielectrophoresis, AC electro-osmosis and capillary flow within a sessile drop, and finally utilized the results to develop the 2D cell separation surface. Our …


Flux-Weakening Control Methods For Permanent Magnet Synchronous Machines In Electric Vehicles At High Speed, Samer Alwaqfi, Mohamad Alzayed, Hicham Chaoui Jan 2025

Flux-Weakening Control Methods For Permanent Magnet Synchronous Machines In Electric Vehicles At High Speed, Samer Alwaqfi, Mohamad Alzayed, Hicham Chaoui

Electrical & Computer Engineering Faculty Publications

Permanent magnet synchronous motors (PMSMs) are widely favored by manufacturers for use in electric vehicles (EVs) because of their many benefits, which include high power density at high speeds, ruggedness, potential for high efficiency, and reduced control complexity. However, since the Back Electromotive Force (EMF) increases proportionally with the motor’s rotational speed, it must be carefully controlled at high speeds. Flux-weakening (FW) control is required to avoid excessive electromagnetic flux beyond the power source and inverter’s voltage restrictions. This paper aims to compare various FW control strategies and analyze their effectiveness in maximizing the speed of PMSMs in EV applications …


Incorporating Insulin Into Alginate-Chitosan 3d-Printed Scaffolds: A Comprehensive Study On Structure, Mechanics, And Biocompatibility For Cartilage Tissue Engineering, Afsaneh Jahani, Mohammad Sagdegh Nourbakhsh, Ali Moradi, Marzieh Mohammadi, Lobat Tayebi Jan 2025

Incorporating Insulin Into Alginate-Chitosan 3d-Printed Scaffolds: A Comprehensive Study On Structure, Mechanics, And Biocompatibility For Cartilage Tissue Engineering, Afsaneh Jahani, Mohammad Sagdegh Nourbakhsh, Ali Moradi, Marzieh Mohammadi, Lobat Tayebi

Electrical & Computer Engineering Faculty Publications

Osteoarthritis is a leading cause of disability worldwide, challenging current treatments to limited cartilage self-healing capacity. Cartilage tissue engineering (CTE) integrates cells, scaffolds, and signaling molecules, with Insulin being utilized as a differentiation biomolecule due to cost-effectiveness, dose-dependent influence on chondrogenesis, suitable biological activity, and ability to activate relevant receptors. Yet, administering differentiation biomolecules through conventional scaffolds poses a persistent challenge. Alginate (Alg) is commonly employed in CTE for its biocompatibility, though it lacks sufficient mechanical properties. Chitosan (Cs), while enhancing scaffold mechanical properties, but does not independently provide optimal support for chondrogenesis. While Alg-Cs scaffolds have garnered attention, challenges …


Artificial Intelligence Event Video Collection (2025), Peaaii Umass Boston Jan 2025

Artificial Intelligence Event Video Collection (2025), Peaaii Umass Boston

Paul English Applied Artificial Intelligence (AI) Institute Publications

This submission contains a collection of recorded videos and promotional materials from artificial intelligence events organized by the Paul English Applied AI Institute (PEAAII) at the University of Massachusetts Boston in 2025. These events include AI Frontier Day, the Fall Symposium, and the AI Applications Hackathon.

The video collection highlights student research, academic collaboration, and applied learning experiences in artificial intelligence. These materials are intended to support education, increase accessibility to AI-related content, and showcase the work of students and faculty involved in PEAAII programs.


Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen Jan 2025

Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen

OES Faculty Publications

In coastal urban areas, tidal flooding brings water carrying nutrients and particles back from land to estuarine and coastal waters. A statistical model to predict nutrient loads during tidal flooding events can help estimate nutrient loading from previous and future flooding events and adapt nutrient reduction strategies. We measured concentrations of dissolved inorganic nitrogen and phosphorus in floodwater at seven sentinel sites during 15 tidal flooding events from January 2019 to September 2020. The study area was the Lafayette River watershed in Norfolk, VA, USA, which is prone to tidal flooding and is predicted to experience more frequent and intense …


Internally Stowed, Radially Deployed Radiator Panels For Passive Cubesat Thermal Control, Josh R. Cannon, Kyle N. Havey, Noah S. Housley, Rydge B. Mulford, Brian D. Iverson Jan 2025

Internally Stowed, Radially Deployed Radiator Panels For Passive Cubesat Thermal Control, Josh R. Cannon, Kyle N. Havey, Noah S. Housley, Rydge B. Mulford, Brian D. Iverson

Faculty Publications

CubeSats experience significant thermal loads due to solar irradiation and the dissipation from electrical components. The high heat dissipation per unit volume can lead to mission failure if not properly managed. Deployable radiators that are externally stowed and passively actuated in response to changes in CubeSat temperature have been explored as a viable solution. This work describes a radially deployed fin array that is stowed within the CubeSat body when the required heat dissipation is low and passively deploys when the required heat dissipation is high. Internal stowage improves thermal transport to the deployable fins and minimizes heat loss when …


Drop Dynamics During Condensation On Superhydrophobic Surfaces In Vapor Shear Flow, Shaur Humayun, R. Daniel Maynes, Julie Crockett, Brian D. Iverson Jan 2025

Drop Dynamics During Condensation On Superhydrophobic Surfaces In Vapor Shear Flow, Shaur Humayun, R. Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

Accurate models for predicting drop dynamics, such as maximum drop departure sizes, are crucial for estimating heat transfer rates during condensation on superhydrophobic (SH) surfaces. Previous studies have focused on examining the heat transfer rates for SH surfaces under the influence of gravity or vapor flowing over the surface. This study investigates the impact of surface solid fraction and texture scale on drop mobility in a condensing environment with a humid air flow. Experiments recorded condensation with varying surface feature sizes from micro- to nano scale under different flow rates. Video analysis detected the drop-size distribution and maximum drop departure …


Origami Folding Pattern Development For Gossamer 18 Structures, Larry L. Howell, Ivy Running, Carolina Wright, Robert J. Lang, Spencer Magleby Jan 2025

Origami Folding Pattern Development For Gossamer 18 Structures, Larry L. Howell, Ivy Running, Carolina Wright, Robert J. Lang, Spencer Magleby

Faculty Publications

Gossamer structures for satellites are large, thin deployable structures that are attractive for space applications because they can be stowed compactly for transportation and deployed to have large functional surface areas. Reflectarray antennas, in particular, are candidates for gossamer structures because they can be realized on thin membranes. However, the efficiency of reflectarray antennas decreases with any deviations from a flat plane, including those induced by plastically deformed creases. Rolling membranes can prevent some plastic deformation, but requires relative slipping between layers that are rolled together. In this work, we describe, analyze, and demonstrate two rolled configurations for deployable gossamer …


Secured Communication And Coexistence For Efficient Spectrum Utilization, Xue Wei Jan 2025

Secured Communication And Coexistence For Efficient Spectrum Utilization, Xue Wei

Electronic Theses & Dissertations (2024 - present)

Over the years, the demand for wireless communications has grown exponentially, resulting in a scarcity of available spectrum. This scarcity leads to the need for efficient spectrum utilization, a key factor in ensuring reliable and uninterrupted communications. One of the key challenges in achieving reliable communication is ensuring secure transmissions to protect the privacy and integrity of data for active users. Wireless communications are vulnerable to eavesdropping, interception, and unauthorized access, which can compromise the confidentiality and integrity of transmitted data. The coexistence of multiple wireless communication systems is another challenge to be addressed for passiver users. In many cases, …


Semi-Quantitative Elemental Imaging Of Corrosion Products From Bioabsorbable Mg Vascular Implants In Vivo, Weilue He, Keith W. Macrenaris, Adam Griebel, Maria P. Kwesiga, Erico Freitas, Amani Gillette, Jeremy Schaffer, Thomas V. O'Halloran, Roger J. Guillory Ii Jan 2025

Semi-Quantitative Elemental Imaging Of Corrosion Products From Bioabsorbable Mg Vascular Implants In Vivo, Weilue He, Keith W. Macrenaris, Adam Griebel, Maria P. Kwesiga, Erico Freitas, Amani Gillette, Jeremy Schaffer, Thomas V. O'Halloran, Roger J. Guillory Ii

Michigan Tech Publications

While metal materials historically have served as permanent implants and were designed to avoid degradation, next generation bioabsorbable metals for medical devices such as vascular stents are under development, which would elute metal ions and corrosion byproducts into tissues. The fate of these eluted products and their local distribution in vascular tissue largely under studied. In this study, we employ a high spatial resolution spectrometric imaging modality, laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOF-MS) to map the metal distribution, (herein refered to as laser ablation mapping, or LAM) from Mg alloys within the mouse vascular system and approximate …


Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones Jan 2025

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …


A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles Jan 2025

A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles

Faculty Publications

In multi-input systems, it is often necessary to quantify the contribution of each input to an output. Such contribution analysis is frequently performed using coherence. However, when correlation is present between inputs, existing coherence measures do not accurately quantify the contribution of individual inputs, except in special cases. Here we propose an expanded coherence framework that enables contribution analysis in any multi-input system, regardless of input correlation. We bridged the gap by defining three new coherence measures: component, excluded, and isolated coherence. Component coherence is an intermediate measure that decomposes measured output power into components attributable to inputs directly vs …