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F-Temper Vs O-Temper Brazing Of 3003 Aluminum Return Bends, Mieka R. Clark

Dissertations, Master's Theses and Master's Reports

As-extruded (F-temper) 3003 return bends can provide cost savings over annealed (O-temper) return bends in aluminum heat exchangers. To assess if F-temper return bends are an alternative to the baseline O-temper bends, the grain structure, bending performance, and melting behavior were assessed through:

• Quantifying the effect of dispersoids on recrystallization
• Tracking bending behavior through grain morphology and surface texture
• Measuring the number and volume fraction of the α-Al(Mn,Fe)Si intermetallic
• Inducing incipient melting through high temperature thermal exposure.

When homogenized at 620°C and 630°C, the F-temper bends had no orange peel texture, the grain size was equivalent to the annealed product, …

Machine Learning For Electronic Structure Prediction, Shashank Pathrudkar

Dissertations, Master's Theses and Master's Reports

Kohn-Sham density functional theory is the work horse of computational material science research. The core of Kohn-Sham density functional theory, the Kohn-Sham equations, output charge density, energy levels and wavefunctions. In principle, the electron density can be used to obtain several other properties of interest including total potential energy of the system, atomic forces, binding energies and electric constants. In this work we present machine learning models designed to bypass the Kohn-Sham equations by directly predicting electron density. Two distinct models were developed: one tailored to predict electron density for quasi one-dimensional materials under strain, while the other is applicable …

Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang

Journal of Marine Science and Technology–Taiwan

This study aims to investigate the determinants that underlie psychographic segmentation in the domain of autonomous ferries (AFs) by using the theory of planned behaviour (TPB) as a guiding theoretical construct. The paper focuses on Indonesian individuals who had previously utilised conventional ferry services. TPB was applied as a catalyst to identify possible market segmentation among potential AF passengers. In this study, cluster analysis is used to differentiate passengers by their perception of using AFs. The results identified three market segments through cluster analysis based on passengers’ perceptions of using AFs: Resource-Limited, Resource-Capable, and Value-Optimistic. Among these segments, the Resource-Capable …

Sales Forecasting For Retail Business Using Xgboost Algorithm And Timesfm, Prathana Dankorpho

Chulalongkorn University Theses and Dissertations (Chula ETD)

The retail industry is continuously evolving with the expansion of sales channels and the diversification of product assortments. However, current forecasting methods, relying on simplistic statistical models, frequently encounter difficulties in adjusting to the dynamic environment. This limitation leads to challenges in accurately predicting sales. Consequently, there is a critical need to improve the accuracy and frequency of sales predictions to enable timely decision-making for business strategies. Through a comprehensive analysis of datasets from 2019 to 2023, this study illustrates the advantages of integrating XGBoost and TimesFM to gain deeper insights into sales patterns. Results demonstrate a significant enhancement in …

Optimizing Large Language Models And Multimodal Approaches For Biomedical Publication And Satellite Imagery, Youngsun Jang

Electronic Theses and Dissertations

This dissertation comprises two main sections: the first focuses on natural language processing (NLP) for extracting key information from scientific literature using large language models (LLMs), and the second addresses remote sensing for detecting natural disasters, such as floods, from satellite imagery using a multimodal approach. The first section investigates methods to enhance Transformer-based models in classifying and extracting information from biomedical scientific publications. Key contributions include the development of a custom dataset for classification and Question and Answering (Q&A) tasks, fine-tuning Transformer models like the Bidirectional Encoder Representations from Transformers (BERT) and addressing multi-span answer issues with the TAg-based …

Silence Is Not Golden: Exploring The Trade-Offs Between Transparency And Burden In Dirs Reporting, Katie Nelson

Murray State Theses and Dissertations

This study explores the United States federal government's Disaster Information Reporting System (DIRS), which is an instrument that is used during emergencies to gather information on what five communication avenues are not actively working at the time of the emergency or during the recovery process. The synthesis provides a framework for characteristics that cite the necessities for this study on DIRS. Examining DIRS will help us understand its strengths, limitations, and potential improvements. Evaluating the details of historical and global research on emergency communications are gathered. The analysis provides insights into DIRS's past, present, and future. Bring to light future …

A Mixed Methods Approach To Evaluation And Modeling Of Ergonomic Stressors Due To Mass Decedent Handling, Vaishakhi Suresh

Graduate Theses, Dissertations, and Problem Reports (ETD)

Work-related injuries, illnesses, and musculoskeletal disorders (MSDs) significantly impact the U.S. healthcare industry, leading to lost working days, high medical costs, and increased turnover rates among healthcare workers (HCWs). Increased physical and mental health risks due to the handling of deceased during COVID-19 pandemic has exacerbated these issues. While the ergonomic risks of patient handling are well-studied, limited research exists on the ergonomic risks of manual handling of the deceased. Therefore, the primary objective of this study was to explore the challenges associated with decedent handling so that effective safety interventions to reduce the risk of injury and mental distress …

4d Epr Oximetry Imaging For 4d Bioprinting And Tissue Engineering, Sajad Sarvari

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bioprinting, akin to 3D printing, employs cell-laden hydrogels such as GelMA (Gelatine Methacrylate) and Alginate instead of plastic or resin to create biological structures. The printing process followed by subsequent tissue maturation is known as 4D bioprinting, where the fourth dimension is time. Ensuring adequate and consistent oxygen, O2, supply within 3D bioprint volume over the entire maturation period process is crucial, as even transient hypoxia can impact cellular behavior and phenotypes. However, printing of fully developed vasculature remains an unresolved technical challenge. Several approaches to chemically (peroxides) or biologically (photosynthesis) generate oxygen during bioprint maturation have been proposed. However, …

Responsive District Heating For A Sustainable Power Grid, Robin Zou, Sarah Robson, Denise A. Mckahn, Judith Cardell

Engineering: Faculty Publications

The electrification of energy use for building heating-cooling and transportation sectors increases stress on an already strained electric power grid. Shifting energy end-use to electricity presupposes that electricity generation is relatively clean in terms of greenhouse gas (GHG) emissions. With the legacy power system and significant operational constraints on the power grid though, the majority of electricity generation is now, and will continue for many years, to be predominantly powered from fossil fuel combustion. The continuing need to decrease carbon and other GHGs raises the need to find clean energy sources outside of the electric power grid.

One clean energy …

Constructing And Probing A Fortified Network, Maxim Davis

Williams Honors College, Honors Research Projects

Computer networking is extremely valuable and is essential to modern infrastructure and life. Due to this fact, network security is also extremely vital and is also constantly under attack due to how precious information is in the modern world. In order to set up network security and harden systems from attack, many organizations establish guidelines, standards and techniques to defend against such threats. There is also the major issue of needing to constantly test these different standards and procedures regarding network security as if these security measures are not tested, the danger of potential threats is exponential. This project seeks …

Self-Watering Plant Device, Nick Sabetta

Williams Honors College, Honors Research Projects

Many homeowners enjoy having plants around their homes. However, life can quickly become busy and stressful. This often makes it difficult to keep with their house plants. The goal of this project is to design a device that will be able to help take care of house plants. The device will be able to water the plant when the soil moisture is detected. The device will also monitor the air temperature as well as the sunlight levels that the plant is receiving. All of the collected data will then be sent via Bluetooth to a smartphone. The app will alert …

Thermal Performance Of A Pump-Assisted Capillary Cooler, Danny J. Lohan, Bhaskarjyoti Sarma, Shailesh N. Joshi, Ercan M. Dede, Anali Soto, Srivathsan Sudhakar, Justin A. Weibel

CTRC Research Publications

The heat transfer and hydraulic performance of a flat evaporator, pump-assisted capillary loop cooler is evaluated for a 1 cm² heat source. The cooler consists of a copper manifold that houses a compensation chamber that feeds liquid to a sintered, flat evaporator wick below via a micro-tube array. Liquid evaporates from the copper wick as it is attached to the heater through a copper base plate. The custom cooler design offers separate flow routes for liquid and vapor phases during steady operation and thereby maintaining the pressure balance of the flow loop. The cooler performance is evaluated using de-ionized …

Assessing Industry-Critical Skill Development In Engineering Technology Capstone Courses, Rustin Webster, Matthew Turner

School of Engineering Technology Faculty Publications

To meet industrial expectations, engineering and engineering technology (ET) graduates are expected to possess the critical competencies of design, problem-solving, communication, and teamwork. However, industry stakeholders and academic studies routinely identify these as skills gaps: areas graduates need to develop to a higher standard or are currently lacking when entering the work force. To address this issue, many undergraduate programs in the United States have implemented a comprehensive and integrative experience at the end of an academic program, often called a capstone course(s). The rate of adoption has grown such that approximately three-quarters of all undergraduate and graduate institutions include …

Robotic Gutter Cleaner, Zachary Nopper

Williams Honors College, Honors Research Projects

Gutters redirect rainwater away from nearly every roof and home in America and Europe but build up debris over time and require constant maintenance. Manual gutter cleaning is unpleasant, time-consuming, and dangerous, with 80,000 injuries/year attributed to people cleaning their gutters and overreaching from ladders in the U.S. alone. This difficult situation implies that consumers would be interested in a method to make this process safer and easier. In an age of increasing automation of tasks, especially those that might be dangerous to complete, a gutter cleaning robot is a solution that could alleviate several of these problems at once. …

Assessing Co2 Capture On Amine Sorbents At Low Vacuum Swing Conditions, Brock Haas, Payton Taylor

Williams Honors College, Honors Research Projects

Carbon dioxide (CO2) emissions to Earth's atmosphere have increased rapidly in recent decades largely due to growing fossil fuel use in human-led activities The research contained in this proposal assesses a way to capture CO2 concentration in the atmosphere. The project studies the effectiveness of a vacuum swing adsorption (VSA) process for capture of CO2 from air. CO2 will first be adsorbed by introducing an amine sorbent to a CO2-rich environment for a predetermined period. The amine sorbent will be placed in a VSA unit that will operate at the desorption stage. The sorbent will then be sent to a …

Exploring Natural Raw Materials For The Development Of Hot Melt Adhesives For Linings Of Paintings, Erica Factor

Williams Honors College, Honors Research Projects

Natural raw materials will be explored for developing hot melt adhesives for the lining of paintings. The leading raw material is a natural resin called "Damar". This resin is obtained from the tree family Dipterocaupocea in India and Southeast Asia. This material has shown promising results from initial testing. Damar, with the potential for other natural raw materials, will be combined with synthetic ingredients to create sustainable formulations. The formulations will be tested on linen to replicate the application onto paintings. The sustainability, tackiness, texture, and overall performance of each formula will be considered. Once a formulation has been selected, …

Proceedings Of The Ninth Annual Indiana Stem Education Conference: Resourcing Stem Education, William S. Walker Iii, Lynn A. Bryan, S. Selcen Guzey

Indiana STEM Education Conference

The Proceedings of the Ninth Annual Indiana STEM Education Conference are edited by the Center for Advancing the Teaching and Learning of STEM (CATALYST, https://www.education.purdue.edu/catalyst/) at Purdue University. The theme for the 2024 conference is Resourcing STEM Education. This year’s Indiana STEM Education Conference provides opportunities to learn about effective STEM education strategies, curriculum, and resources to engage students in integrated STEM learning opportunities and address the recently updated Indiana Academic Standards for Science and Computer Science, Indiana Academic Standards for Mathematics, and Indiana Academic Standards for Integrated STEM (https://www.in.gov/doe/students/indiana-academic-standards/).

Kiloton Class Isru Systems For Lo2/Lch4 Propellant Production On The Mars Surface, Steven R. Oleson, Elizabeth Turnbull, Julie Kleinhenz, Wesley Johnson, Ryan Grotenrath, Nicholas Uguccini, Benjamin Abshire, Lee Mason, Thomas Packard, Anthony Colozza, John Z. Gyekenyesi, James Fittje, Stephen Hoffman, Leslie S. Gertsch

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

As part of the 2023 strategic analysis cycle to explore the trade space, the NASA Mars Architecture Team wanted to explore what it takes to produce in situ on Mars many hundreds of tons of propellants for a large all-chemical transportation system. The conceptual operations and design of the LO₂/LCH₄ in situ resource utilization (ISRU) water acquisition, propellant production and liquification system was assigned to the NASA Compass concurrent engineering team with support from various NASA ISRU, cryogenic fluid management, and surface power experts. The conceptual point design examined one case producing 300 t of LO_{2 …}

Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing treatments in unconventional infill (or "child") wells can be significantly affected by depletion from existing parent-well, resulting in asymmetrical fracture growth. These issues may lead to excessive load-water production, proppant deposition, casing deformation in the parent well, and unbalanced stimulation of infill wells. To mitigate these effects, various strategies have been proposed, including the use of far-field diverters in child wells and repressurization of parent wells. Additionally, an increasingly popular strategy involves injecting near-wellbore diverters to temporarily plug entry points into the parent wellbores during frac operations on infill wells. To achieve better application, a novel low-cost, self-degradable, …

Exploring The Diffusion Potential Of A Collaborative Mobile Platform For Disaster Management And Relief, Joao De Mendonca Salim

Honors Undergraduate Theses

This thesis describes the creation of a collaborative digital platform for disaster management and relief, focusing on the case study of the city of Petrópolis natural disaster in February 2022. The frequency and intensity of natural disasters are rising, necessitating efficient and timely disaster response efforts. This thesis details the development of a software application that fosters collaboration among governmental agencies, emergency services, non-governmental organizations (NGOs), and civil society to enhance logistical planning and situational awareness during disasters. The proposed platform harnesses the power of social networking and leverages the ubiquitous presence of smartphones equipped with cameras, GPS, and sensors …

Bioprinting With Adipose Stem Cells And Hydrogel Modified With Bioactive Glass, Krishna C.R. Kolan, Apurv Saxena, Bradley A. Bromet, Lesa B. Steen, August T. Bindbeutel, Julie A. Semon, Delbert E. Day, Ming C. Leu

Biological Sciences Faculty Research & Creative Works

Bioprinting research is focused on utilizing growth factors and multiple cell types to create clinically relevant three-dimensional (3D) tissue models using hydrogels. Rheological and biological challenges are two main factors that limit the creation of extrudable bioactive hydrogels. In this study, we investigate incorporation of fast dissolving and bioactive borate glass in different weight to volume percentages (0.075 to 0.6%) to alginate-gelatin (1:1) hydrogel to improve rheological properties and enable bioprinting with bioactive glass. The addition of glass improved the stiffness of the hydrogel. Human adipose-derived mesenchymal stem cells (ASCs) were uniformly mixed in this bioink at 1 x 106 …

Flow Regimes In Bubble Columns With And Without Internals: A Review, Ayat N. Mahmood, Amer A. Abdulrahman, Laith S. Sabri, Abbas J. Sultan, Hasan Shakir Majdi, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hydrodynamics characterization in terms of flow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies. This review presents recent studies on the typical flow regimes established in bubble columns. Some effort is also provided to introduce relevant definitions pertaining to this field, namely, that of "void fraction" and related (local, chordal, cross-sectional and volumetric) variants. Experimental studies involving different parameters that affect design and operating conditions are also discussed in detail. In the second part of the review, the attention is shifted to cases with internals of various types (perforated …

Liposomes-Encapsulating Double-Stranded Nucleic Acid (Poly I:C) For Head And Neck Cancer Treatment, Vidit Singh, Anna Chernatynskaya, Lin Qi, Hsin Yin Chuang, Tristan Cole, Vimalin Mani Jeyalatha, Lavanya Bhargava, W. Andrew Yeudall, Laszlo Farkas, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Polyriboinosinic acid-polyribocytidylic acid (Poly I:C) serves as a synthetic mimic of viral double-stranded dsRNA, capable of inducing apoptosis in numerous cancer cells. Despite its potential, therapeutic benefits, the application of Poly I:C has been hindered by concerns regarding toxicity, stability, enzymatic degradation, and undue immune stimulation, leading to autoimmune disorders. To address these challenges, encapsulation of antitumor drugs within delivery systems such as cationic liposomes is often employed to enhance their efficacy while minimizing dosages. In this study, we investigated the potential of cationic liposomes to deliver Poly I:C into the Head and Neck 12 (HN12) cell line to induce …

Novel Modified Polyethersulfone High Temperature And Low Humidity Fuel Cell Membrane: Experimental And Simulation Study, Mohammed K. Al Mesfer, Muthanna H. Al-Dahhan, Mohd Danish, Mumtaj Shah

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Present Study Focuses on Synthesizing a High-Temperature Stable Membrane Working under Low Relative Humidity (RH) by Aminating the Traditional Polyethersulfone Polymer with Aniline for Fuel Cell Applications. a Condensed-Phase Optimized Molecular Potentials for Atomistic Simulation Studies Force Field-Based Molecular Dynamics Simulation Was Used to Explore the Microscopic Properties and Transport of Water and Hydronium (H3O+) Ions Across the Electrolyte at Varied Temperatures and RHs. COMSOL Calculates Oxygen and Hydrogen Concentrations after Examining the Polymer–ion Interaction with the Radial Distribution Function (RDF). the High H3O+ Diffusion Coefficient of the Aniline-Treated Membrane Shows the Benefit of the Modification. the RDF Confirmed …

Molecular Imaging Nanoprobes And Their Applications In Atherosclerosis Diagnosis, Huari Kou, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Molecular imaging has undergone significant development in recent years for its excellent ability to image and quantify biologic processes at cellular and molecular levels. Its application is of significance in cardiovascular diseases, particularly in diagnosing them at early stages. Atherosclerosis is a complex, chronic, and progressive disease that can lead to serious consequences such as heart strokes or infarctions. Attempts have been made to detect atherosclerosis with molecular imaging modalities. Not only do imaging modalities develop rapidly, but research of relevant nanomaterials as imaging probes has also been increasingly studied in recent years. This review focuses on the latest developments …

Injectable Dendrimer Hydrogel Delivers Melphalan In Both Conjugated And Free Forms For Retinoblastoma, Remy C. Cooper, Juan Wang, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report the successful synthesis of an injectable dendrimer hydrogel (DH) carrying melphalan, a clinical drug for retinoblastoma treatment, in both conjugated and free forms. Polyamidoamine (PAMAM) dendrimer generation 5 (G5) is surface-modified with an acid-sensitive acetal-dibenzocyclooctyne linker and then undergoes azide-alkyne cycloaddition with melphalan-PEG-N3 conjugate to form G5-acetal-melphalan. During the DH gelation between G5-acetal-melphalan and PEG-diacrylate, free melphalan is added, resulting in a hydrogel (G5-acetal-melphalan-DH/melphalan) that carries the drug in both conjugated and free forms. Melphalan is slowly released from G5-acetal-melphalan-DH/melphalan, with the conjugated melphalan released more quickly at pH 5.3 due to acid-triggered acetal bond cleavage. The formulation's …

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

Chemical and Biochemical Engineering Faculty Research & Creative Works

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

A Contribution To The Exploration Of The Chemical Durability, Thermal Stability, And Structural Ability Of Glasses From The Fe2o3-K2o-Moo3-P2o5 Quaternary System, Asmae Er-Rafai, Yasmina Alaoui, Mohamed Laourayed, Mohamed Ounacer, Mouloud El Moudane, Mohammed Sajieddine, Abdelkbir Bellaouchou

Journal of Metals, Materials and Minerals

The relationships between the properties and structure of xFe2O3-(40-x)K2O-10MoO3-50P2O5 glasses have been reported in this paper. Homogeneous glasses are formed for different Fe2O3 contents. The density and molar volume evolution of these glasses shows that Fe2O3 acts as a glass former and strengthens the structural bonds of the glass. Experimental 57Fe Mössbauer spectroscopy graphs suggest the existence of divalent Iron (FeII) and trivalent Iron (FeIII). The boost in chemical durability agrees with the growth in glass transition temperature due to more powerful bonding in the structural network. P-O-Fe bonds replace P-O-P bonds when Fe2O3 is present in the phosphate network.

Photocatalytic Degradation Of Ciprofloxacin Drug Utilizing Novel Pvdf/Polyaniline/ Lanthanum Strontium Manganate@Ag Composites, Swayam Aryam Behera, Ali Amanat, P. Ganga Raju Achary

Journal of Metals, Materials and Minerals

Poly (vinylidene fluoride) (PVDF) is the first-choice ferroelectric support or membrane material. The lanthanum strontium manganite (LSMO) is a well-known electrode material in the class of the solid oxide fuel cell (SOFC) materials. A set of four polymer composites PVDF-LSMO-PANI(5.0 wt%) with different amount of silver doping were fabricated with the silver nitrate and reducing agent. The characterization of these four novel PVDF based composites were characterized by the XRD, FTIR, SEM, UV-Visible DRS. The present communication highlights: (I) the effect of PANI in the PVDF-LSMO-PANI (PLP) composites towards the photocatalytic degradation of ciprofloxacin drug. (II) the effect of Ag …

The Effect Of Two-Stage Heat Treatment On The Microstructure And Mechanical Properties Of High Chrome Austenitic Manganese Steel, Mohammad Reza Hermawan, Budi Hartono Setiamarga, Ilham Nur Hakim, Rizka Mulia Anggraeni

Journal of Metals, Materials and Minerals

In this research, heat-treatment was used to determine changes in the microstructure and mechanical characteristics of austenitic manganese steel equivalent to ASTM A128-C. Carbide formed in as-cast conditions is transformed into dispersed hardened austenite to increase the toughness of the material because it can inhibit dislocation movement. Heat treatment is carried out in two heating stages. The first stage of heating was carried out at a temperature of 625°C with a holding time varying by 2.5, 3.5, and 4.5 h, and the second stage was carried out at a temperature of 1000°C with a constant holding time of 1.5 h. …