Digital Commons Network^™

A Review Of Proton Exchange Membrane Degradation Pathways, Mechanisms, And Mitigation Strategies In A Fuel Cell, Dharmjeet Madhav, Junru Wang, Rajesh Keloth, Jorben Mus, Frank Buysschaert, Veerle Vandeginste

Department of Chemical and Biomolecular Engineering: Faculty Publications

Proton exchange membrane fuel cells (PEMFCs) have the potential to tackle major challenges associated with fossil fuel-sourced energy consumption. Nafion, a perfluorosulfonic acid (PFSA) membrane that has high proton conductivity and good chemical stability, is a standard proton exchange membrane (PEM) used in PEMFCs. However, PEM degradation is one of the significant issues in the long-term operation of PEMFCs. Membrane degradation can lead to a decrease in the performance and the lifespan of PEMFCs. The membrane can degrade through chemical, mechanical, and thermal pathways. This paper reviews the different causes of all three routes of PFSA degradation, underlying mechanisms, their …

Hydraulic Borehole Mining (Hbm) Technology Employed In Lignite Mining – Technical, Economic And Market Aspects, Bartłomiej Jura, Piotr Krawczyk, Jacek Skiba, Natalia Howaniec

Journal of Sustainable Mining

The results of a cost-effectiveness and economic efficiency assessment of the Hydraulic Borehole Mining (HBM) technology applied to lignite mining are presented. The Dynamic Generation Cost, the Net Present Value, and the Internal Rate of Return were calculated for the extraction of lignite at a rate of about 3.44 million Mg/year from a mining parcel of 1 2.5 km, taking into account CAPEX and OPEX. The cost of mining 1 Mg of lignite using the HBM technology was reported to be lower than its market prices before the energy crisis in Europe caused by the war in Ukraine. The values …

The Santa Clara, 2024-02-16, Santa Clara University

The Santa Clara

No abstract provided.

Copper−Cystine Biohybrid-Embedded Nanofiber Aerogels Show Antibacterial And Angiogenic Properties, Anik Karan, Navatha S. Polavaram, Margarita Darder, Yajuan Su, Syed Muntazir Andrabi, S M Shatil Shahriar, Johnson V. John, Zeyu Luo, Mark A. Decoster, Yu Shrike Zhang, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Copper−cystine-based high aspect ratio structures (CuHARS) possess exceptional physical and chemical properties and exhibit remarkable biodegradability in human physiological conditions. Extensive testing has confirmed the biocompatibility and biodegradability of CuHARS under diverse biological conditions, making them a viable source of essential Cu²⁺. These ions are vital for catalyzing the production of nitric oxide (NO) from the decomposition of Snitrosothiols (RSNOs) found in human blood. The ability of CuHARS to act as a Cu²⁺ donor under specific concentrations has been demonstrated in this study, resulting in the generation of elevated levels of NO. Consequently, this dual function makes …

Development Of Inorganically Cross-Linked Sulfonated Polyacrylamide Preformed Particle Gels For Conformance Control: Impact Of Anionic Groups, Reem Elaf, Ahmed Hamza, Hassan Nimir, Mohammed Saad, Ibnelwaleed A. Hussein, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Modern oil and gas extraction faces challenges, notably from the surplus of produced water, hampering hydrocarbon recovery and raising environmental and economic concerns. A promising solution is the injection of preformed particle gels (PPGs) into the reservoir's fractures and high permeability zones, facilitating production processes. This study introduces a novel class of inorganically cross-linked PPGs with exceptionally high swelling capacities, comprising sulfonated polyacrylamide cross-linked with aluminum attached to acetate, nitrate, sulfate, and lactate anions individually. These PPGs function as superabsorbents, capable of absorbing water at a ratio of 100-700 times their dry weight while maintaining adequate gel strength up to …

Blood Lead, Cadmium And Hair Mercury Concentrations And Association With Soil, Dust And Occupational Factors In E-Waste Recycling Workers In Bangladesh, Sarker Masud Parvez, Farjana Jahan, Jaynal Abedin, Mahbubur Rahman, Shaikh Sharif Hasan, Nafisa Islam, Nirupam Aich, Mohammad Moniruzzaman, Zahir Islam, Masatake Fujimura, Rubhana Raqib, Luke D. Knibbs, Peter D. Sly

Department of Civil and Environmental Engineering: Faculty Publications

Background: Electronic waste (e-waste) recycling activities release toxic metals, which pose substantial hazard to the environment and human health. We evaluated metal concentrations in biological and environmental samples, and examined the associations between biological lead (Pb), cadmium (Cd), and mercury (Hg) with soil and dust metals, and other possible determinants, among populations exposed and non-exposed to e-waste in Bangladesh.

Methods: A total of 199 e-waste workers and 104 non-exposed individuals were recruited. We measured blood Pb (BPb) and Cd (BCd) concentrations and total Hg (THg) from hair samples. Data were collected on occupational, and behavioral factors. We fitted …

Shaping Aam Educational Methods: A Comparison Of Traditional And Compressed Class Schedules In Uas Classes., Collin D. Mcdonald, Daniel Siao, Kevin Corns

National Training Aircraft Symposium (NTAS)

Advanced Air Mobility (AAM) is a paradigm shift in the versatility of the aviation industry. The obvious benefits of this platform will revolutionize a variety of aspects of the industry. One of the aspects in which the Federal Aviation Administration (FAA) has recommended research is the effectiveness of the traditional educational methods. Spurred by the COVID-19 pandemic, online teaching methodologies have become widely accepted in aviation. In addition, the format of traditional, instructor-led courses have also changed. Compressed schedules (accelerated courses) have become an additional option in some programs.

To better understand if there are statistically significant differences in testing …

Mmwave Rat Optimization: Mac Layer Initial Access Design And Transport Layer Integration, Suresh Srinivasan

Dissertations and Theses

MmWave Radio Access Technology (RAT) is a promising technology for wireless communication due its large bandwidth and is already being deployed in 5G cellular and emerging WiFi technologies. MmWave systems use highly directional beams with narrow beamwidths to overcome the high path loss associated with their frequency bands. A mmWave radio can be used either in a standalone mode (where all radios use the same technology) or simultaneously with other technologies such as LTE and low frequency WiFi in a communication mode commonly referred to as integrated mode. This thesis proposes two methods to optimize mmWave RAT performance in both …

Material Order: A Discovery Group And Shared Catalogue For Materials Collections, Mark Pompelia, Margot Mcilwain Nishimura

Faculty & Librarian Work

Material Order is an academic consortium of material sample collections for art, architecture, and design disciplines. Founded by the Graduate School of Design at Harvard University and Fleet Library at Rhode Island School of Design and since comprising several more institutions in the US, it provides a community-based approach to management and open access utilizing and developing standards and best practices. Now in its twelfth year and reaching a level of maturation, Material Order offers research and pedagogical value to current and potential members and the larger design communities.

Experimental Thermal Conductivity Studies Of Agar-Based Aqueous Suspensions With Lignin Magnetic Nanocomposites, Bishal Gautam, Saja M. Nabat Al-Ajrash, Mohammad Jahid Hasan, Abhishek Saini, Sarah J. Watzman, Esteban Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

Nanoparticle additives increase the thermal conductivity of conventional heat transfer fluids at low concentrations, which leads to improved heat transfer fluids and processes. This study investigates lignin-coated magnetic nanocomposites (lignin@Fe₃O₄) as a novel bio-based magnetic nanoparticle additive to enhance the thermal conductivity of aqueous-based fluids. Kraft lignin was used to encapsulate the Fe₃O₄ nanoparticles to prevent agglomeration and oxidation of the magnetic nanoparticles. Lignin@Fe₃O₄ nanoparticles were prepared using a pH-driven co-precipitation method with a 3:1 lignin to magnetite ratio and characterized by X-ray diffraction, FT-IR, thermogravimetric analysis, and transmission electron …

Rab7 Deficiency Impairs Pulmonary Artery Endothelial Function And Promotes Pulmonary Hypertension, Bryce Piper, Srimathi Bogamuwa, Tanvir Hossain, Daniela Farkas, Lorena Rosas, Adam C. Green, Geoffrey Newcomb, Nuo Sun, Jose A. Ovando-Ricardez, Jeffrey C. Horowitz, Aneel R. Bhagwani, Hu Yang, Tatiana V. Kudryashova, Mauricio Rojas

Chemical and Biochemical Engineering Faculty Research & Creative Works

Pulmonary arterial hypertension (PAH) is a devastating and progressive disease with limited treatment options. Endothelial dysfunction plays a central role in the development and progression of PAH, yet the underlying mechanisms are incompletely understood. The endosome-lysosome system is important to maintain cellular health, and the small GTPase RAB7 regulates many functions of this system. Here, we explored the role of RAB7 in endothelial cell (EC) function and lung vascular homeostasis. We found reduced expression of RAB7 in ECs from patients with PAH. Endothelial haploinsufficiency of RAB7 caused spontaneous pulmonary hypertension (PH) in mice. Silencing of RAB7 in ECs induced broad …

Pisa Printing Microneedles With Controllable Aqueous Dissolution Kinetics, Aaron Priester, Jimmy Yeng, Yuwei Zhang, Krista Hilmas, Risheng Wang, Anthony J. Convertine

Chemistry Faculty Research & Creative Works

This study focused on the development of high-resolution polymeric structures using polymer-induced self-assembly (PISA) printing with commercially available digital light-processing (DLP) printers. Significantly, soluble solids could be 3D-printed using this methodology with controllable aqueous dissolution rates. This was achieved using a highly branched macrochain transfer agent (macro-CTA) containing multiple covalently attached CTA groups. In this work, the use of acrylamide as the self-assembling monomer in isopropyl alcohol was explored with the addition of N-(butoxymethyl)acrylamide to modulate the aqueous dissolution kinetics. PISA-printed microneedles were observed to have feature sizes as small as 27 μm, which was close to the resolution limit …

Radiation-Induced Polymerization Of Thermo-Responsive Polymers And Comprehensive Characterization For Improved Performance, Attia Attia, Islam Mohamed Eng., Mohamed El-Deab Prof., Nabila Maziad Prof.

Petroleum Engineering and Gas

Early water breakthrough with high water cut through highly conductive thief zones is a prevalent problem in many water-flooded oil reservoirs. Smart polymers that are sensitive to temperature changes, also known as thermo-responsive polymers, e.g., polyethylene glycol (PEG) have great advantages over conventional polymers that can be exploited to solve the problem of conductive thief zones. Thus, this study aims at designing and synthesizing a thermo-responsive polymer using Gamma Ray Induced radiation with good tolerance against high temperature, and high salinity reservoir conditions with feasible and economic synthesis procedure for application in Egyptian oil reservoirs. That is a combined use …

Customer Churn Prediction Based On Sentiment Score, Shadha Al-Safi

Theses and Dissertations

In recent years, the telecommunications industry has witnessed intensified competition, wherein the expense associated with acquiring new consumers exceeds that of sustaining existing ones. Consequently, predicting customer churn prior to its occurrence has become essential. This study proposes a sentiment-based customer churn prediction model in which the sentiment of customers is predicted using Random Forest. Subsequently, the derived sentiment predictions are combined with additional features to predict customer churn. The ensemble technique is applied to predict churn, consisting of K-nearest neighbors, Support Vector Machines, Random Forest as base learners, and Multiple Layer Perceptron as a meta learner. Moreover, mutual information …

Motion Magnification-Inspired Feature Manipulation For Deepfake Detection, Aydamir Mirzayev, Hamdi Di̇bekli̇oğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Recent advances in deep learning, increased availability of large-scale datasets, and improvement of accelerated graphics processing units facilitated creation of an unprecedented amount of synthetically generated media content with impressive visual quality. Although such technology is used predominantly for entertainment, there is widespread practice of using deepfake technology for malevolent ends. This potential for malicious use necessitates the creation of detection methods capable of reliably distinguishing manipulated video content. In this work we aim to create a learning-based detection method for synthetically generated videos. To this end, we attempt to detect spatiotemporal inconsistencies by leveraging a learning-based magnification-inspired feature manipulation …

Sampling-Accelerated Prediction Of Phonon Scattering Rates For Converged Thermal Conductivity And Radiative Properties, Ziqi Guo, Zherui Han, Dudong Feng, Guang Lin, Xiulin Ruan

Purdue University Libraries Open Access Publishing Fund

The prediction of thermal conductivity and radiative properties is crucial. However, computing phonon scattering, especially for four-phonon scattering, could be prohibitively expensive, and the thermal conductivity for silicon after considering four-phonon scattering is significantly under-predicted and not converged in the literature. Here we propose a method to estimate scattering rates from a small sample of scattering processes using maximum likelihood estimation. The calculation of scattering rates and associated thermal conductivity and radiative properties are dramatically accelerated by three to four orders of magnitude. This allows us to use an unprecedented q-mesh (discretized grid in the reciprocal space) of 32 × …

Integrated Petrophysical Evaluation And Rock Physics Modeling Of Broom Creek Deep Saline Aquifer For Geological Co2 Storage, Prasad Pothana, Ghoulem Ifrene, Kegang Ling

Petroleum Engineering Student Publications

Fossil fuels, such as coal and hydrocarbons, are major drivers of global warming and are primarily responsible for worldwide greenhouse gas emissions, including carbon dioxide CO₂. The storage of CO₂ in deep saline reservoirs is acknowledged as one of the top practical and promising methods to reduce CO₂ emissions and meet climate goals. The North Dakota Industrial Commission (NDIC) recently approved the fourth Class VI permit for a carbon capture and storage project in the Williston basin of North Dakota for the geological CO₂ storage in the Broom Creek formation. The current research aimed to …

A Study On The Incentives And Barriers For The Adoption Of Electric Vehicles In South Alabama, Marianne Loes, Daniela Wolter Ferreira Touma, Jennifer C. Zoghby

AMTP Proceedings 2024

ABSTRACT

Through a series of public policy incentives and consumer demand, more electric vehicles are being sold nationwide than ever before. Although electric vehicles (EVs) are being adopted nationwide by many consumers in recent years, car-buyers across South Alabama have not followed the trend. This research considers different stakeholders in the complex consumer buying process of car purchases, and it uses the extant technology adoption models to assess the public policy incentives, as well as statewide roadblocks, to EV adoption.

Systemization & Survival -- “Houston, We Have A Problem” – Business Lessons From Apollo 13, Judith Jacob Iddy, Njeru Zakayo

Markets, Globalization & Development Review

In the business world, there are different factors that determine whether a business will survive or not. Apollo 13 film perfectly demonstrates what every business undergoes throughout its lifecycle. Apollo 13 spacecraft started its journey to the moon successfully with the mission being to land on the moon. Unfortunately, within a very short period of time, Apollo 13 started to experience a series of problems that required quick actions and decisions to be made with the involvement of different sets of technical skills. Ultimately, by using the prototype and systems which NASA had established for Apollo 13, the teams managed …

The Santa Clara, 2024-02-02, Santa Clara University

The Santa Clara

No abstract provided.

Analysis Of The Impact Of Water Treatment By Liming Sedimentation And Dredging On The Content Of Heavy Metals In Fish Intended For Consumption, Asfie Maidie, Ismail Fahmy Almadi, Muchlis Efendi, Rekha Yusdha Nilawardhani, Komsanah Sukarti, Henny Pagoray

Journal of Sustainable Mining

The present study sought to determine the presence of metals and arsenic, a metalloid, among the fish of a coal mine reservoir, where the water was treated regularly through liming sedimentation combined with dredging, and the fish living in an adjoining river. The potential hazard of metals in fish as human food was analyzed. Except for selenium (an important metal to the human body), which was higher among the river fish than in the reservoir fish (P < 0.01), there were no particular patterns of other studied metals found in either habitat (P > 0.05), and apparently not related to the fish family that consumed by local people. Measurements of bioaccumulation factor (BAF) yielded scattered values from …

Beneath I-280: Excavating A Neighborhood Lost To San José Freeways, Leila Ullmann, Gordon Douglas

Mineta Transportation Institute

Throughout the 1960s and 1970s, thousands of people in San José, California were displaced from their homes as the state used eminent domain to purchase land and uproot neighborhoods for the construction of Interstate freeways. This report presents a multifaceted research and public knowledge effort that uncovers some of the communities buried beneath these freeways, in the area where I-280 and CA-87 meet today near downtown San José. The project builds primarily from previously unprocessed California Department of Transportation (CalTrans) archival documents, which this project studies for the first time. The records are rich in detail about valuation and sale …

Generalized Linear Targeting For Cislunar Flight, David Geller, Brayden Barton, David Woffinden

Space Dynamics Laboratory Publications

An important element of Artemis and NASA’s campaign to explore the Moon is the autonomous onboard two-level targeter (TLT) used during all cislunar flight phases. The function of the TLT is to autonomously recompute the burn targets for the upcoming burn (or multiple burns) in response to navigation and vehicle dispersion providing a solution that meets all trajectory constraints. Although the TLT has been utilized previously as a ground-based planning tool, and flown onboard during the Artemis I mission, it’s complexity and iterative nature make is difficult to incorporate into and support rapid analyses such as robust optimal trajectory design …

Ion Irradiation And Examination Of Additive Friction Stir Deposited 316 Stainless Steel, Priyanka Agrawa, Ching-Heng Shiau, Aishani Sharma, Zhihan Hu, Megha Dubey, Yu Lu, Lin Shao, Ramprashad Prabhakaran, Yaqiao Wu, Rajiv S. Mishra

Materials Science and Engineering Faculty Publications and Presentations

This study explored solid-state additive friction stir deposition (AFSD) as a modular manufacturing technology, with the aim of enabling a more rapid and streamlined on-site fabrication process for large meter-scale nuclear structural components with fully dense parts. Austenitic 316 stainless steel (SS) is an excellent candidate to demonstrate AFSD, as it is a commonly-used structural material for nuclear applications. The microstructural evolution and concomitant changes in mechanical properties after 5 MeV Fe⁺⁺ ion irradiation were studied comprehensively via transmission electron microscopy and nanoindentation. AFSD-processed 316 SS led to a fine-grained and ultrafine-grained microstructure that resulted in a simultaneous increase …

Computational Discovery Of Microstructured Composites With Optimal Stiffness-Toughness Trade-Offs, Beichen Li, Bolei Deng, Wan Shou, Tae-Hyun Oh, Yuanming Hu, Yiyue Luo, Liang Shi, Wojciech Matusik

Mechanical Engineering Faculty Publications and Presentations

The conflict between stiffness and toughness is a fundamental problem in engineering materials design. However, the systematic discovery of microstructured composites with optimal stiffness-toughness trade-offs has never been demonstrated, hindered by the discrepancies between simulation and reality and the lack of data-efficient exploration of the entire Pareto front. We introduce a generalizable pipeline that integrates physical experiments, numerical simulations, and artificial neural networks to address both challenges. Without any prescribed expert knowledge of material design, our approach implements a nested-loop proposal-validation workflow to bridge the simulation-to-reality gap and find microstructured composites that are stiff and tough with high sample efficiency. …

Quaternary Ammonia Compounds In Disinfectant Products: Evaluating The Potential For Promoting Antibiotic Resistance And Disrupting Wastewater Treatment Plant Performance, Zihao Lu, Anna K. Mahony, William A. Arnold, Christopher Marshall, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Quaternary ammonium compounds (QACs) are a class of compounds that were widely used as disinfectants during the COVID-19 pandemic and continue to be used as disinfecting agents. After consumer usage, QAC concentrations are diluted in wastewater as they enter wastewater treatment plants. At sub-inhibitory concentrations, QACs may have unintended repercussions, including increased antibiotic resistance and inhibition of process performance in wastewater treatment plants. This review first summarizes how QACs inhibit bacteria and then highlights the mechanisms by which QACs can promote antibiotic resistance in general. Reported environmental concentrations of QACs are compared to concentrations that are suspected to impact antibiotic …

Inhibited Surface Diffusion In Nanoporous Multi-Principal Element Alloy Thin Films Prepared By Vacuum Thermal Dealloying, Tibra Das Gupta, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Nanoporous structures with 3D interconnected networks are traditionally made by dealloy- ing a binary precursor. Certain approaches for fabricating these materials have been applied to refrac- tory multi-principal element alloys (RMPEAs), which can be suitable candidates for high-temperature applications. In this study, nanoporous refractory multi-principal element alloys (np-RMPEAs) were fabricated from magnesium-based thin films (VMoNbTaMg) that had been prepared by magnetron sputtering. Vacuum thermal dealloying (VTD), which involves sublimation of a higher vapor pres- sure element, is a novel technique for synthesizing nanoporous refractory elements that are prone to oxidation. When VMoNbTaMg was heated under vacuum, a nanoporous structure was …

Life Cycle Assessment Of Hydrothermal Carbonization: A Review Of Product Valorization Pathways, Andrea Ogunleye, Joseph Flora, Nicole Berge

Faculty Publications

Hydrothermal carbonization (HTC) has the potential to be a sustainable and environmentally beneficial approach for organic waste treatment. It is likely that HTC product use will dictate the viability of large-scale HTC facilities; therefore, understanding the viability and environmental implications associated with HTC product valorization pathways is critical. The overall goal of this review is to gain an understanding of how HTC product valorization is currently being modeled in life cycle assessment studies, and to use such information to assess current research and/or data needs associated with product valorization. To accomplish this, a review of existing HTC literature was conducted …

Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han

Michigan Tech Publications

Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction-a measure of …

Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish K. Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han

Michigan Tech Publications

Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction—a measure of …