Materials Science and Engineering Commons^™

Overlooked Ionic Contribution Of A Chiral Dopant In Cholesteric Liquid Crystals, Hassanein Shaban, Po-Chang Wu, Yi-Fei Jia, Wei Lee

Basic Science Engineering

This study focuses on the ionic contribution by a chiral dopant added into a nematic host for preparing cholesteric liquid crystals (CLCs). Chiral structures were designated by individually incorporating two enantiomers, R5011 and S5011, into the nematic E44 to construct right- and left-handed CLCs, respectively. Characterized by the space-charge polarization, the dielectric spectra of the CLCs were investigated in the low-frequency regime, where f ≤ 1 kHz. The role of the individual chiral dopant, R5011 or S5011, at concentrations of 0–4.0 wt.% in altering the ionic properties of the CLC material was analyzed by deducing the electrical conductivity, ion density, …

Characterization Of Wood Plastic Composites Made Of Rice Straw And Recycled Low-Density Polyethylene, Waleed Mohamed Hassona Dr., Ahmed Elkassas, Nader Zaafarani

Journal of Engineering Research

In this work, the physical and mechanical properties of a fabricated wood-plastic composite (WPC) in accordance with the internationally recognized standard are investigated. The wood-plastic composite is made from recycled low-density polyethylene and mechanically processed rice straw fibers by using a specially designed extrusion machine. From the physical test, it was found that the newly developed WPC has low water absorption and thickness swelling compared to the standard limits. The mechanical tests revealed an improvement of the modulus of rupture and modulus of elasticity by the increase of fiber content to 65%. The highest recorded values of the modulus of …

Optimizing The Physical Properties Of Biochar For Co2 Adsorption Using Resonant Vibrations, Amirhosein Riahi, Richard Ladouceur

Mining Engineering

Among various Carbon Capture and Sequestration (CCS) technologies, significant emphasis has been placed on biochar as an effective post-combustion CO2 capture method. Biochar demonstrates potential as a technically effective method for stabilizing carbon. However, the efficacy of CCS based on adsorption phenomenon depends on factors such as the CO2 uptake of the adsorbent, kinetic rates, and cyclic adsorption. The study shows that Low-Frequency High Amplitude (LFHA) resonant vibratory mixing improves the physical characteristics and adsorption properties of hemp biochar. According to the results of an analysis of variance (ANOVA), increasing both the mass of biochar and the intensity of resonant …

Synergistic Approaches For Microstructural Refinement, Enhanced Mechanical And Wear Behaviour In Additively Manufactured 17-4 Ph Stainless Steel, Pradeep Kumar S

Theses and Dissertations

The surface and microstructural characteristics of additively manufactured parts play a significant role under mechanical loading. Due to its high strength, tailorable mechanical properties by heat treatment, and ease of printability, the 17-4 precipitation hardened (PH) stainless steel is gaining attention in the additive manufacturing (AM) field.

Selective Laser Melting (SLM), one of the laser-based powder bed fusion (L-PBF) processes, is capable of making fully dense metallic parts with high geometrical fidelity and greater design flexibility at high resolution. The main factors limiting the adoption of SLM are poor surface roughness, anisotropic microstructure, and the formation of micro-pores in the …

Mechanical Properties Of Polymer Matrix Nanocomposites Reinforced With Varying Carbon Nanotube Geometries, Ethan Gaigalas, Zoe Kelemen

College of Engineering Summer Undergraduate Research Program

This study serves as part of an introduction to nanocomposite research at California Polytechnic State University, San Luis Obispo, and attempts to form an observational comparison between the performance of various CNT-Epoxy nanocomposites under drop weight testing. As a continuation of research on CNT-Epoxy nanocomposites, this study specifies three geometries of Multi-walled carbon nanotubes: straight (MWSCNTs), helical (MWHCNTs), and OH-functionalized straight (FMWSCNTs); and it compares their impact resistances to neat epoxy samples. Based on the total number of failed samples under a normalized impact energy of 0.335J/mm, it is observed that FMWSCNTs increase the impact resistance of Epoxy panels at …

Deep-Learning Based Microstructure Reconstruction And Generation, Cameron J. Maloney, Lucas Taliaferro

College of Engineering Summer Undergraduate Research Program

Characterizing the microstructural behavior of materials is crucial for understanding their properties and performance. Traditional imaging methods, such as optical microscopy and electron microscopy, are effective but costly and time-consuming. Computational approaches can reduce costs and time while expanding the accessibility of microstructural analysis through the generation of new microstructure images. Traditional computational approaches, namely descriptor-based approaches, are slow but effective in low-data scenarios. Modern approaches use machine learning (ML), which is faster but often requires a lot of data to approach the performance of descriptor-based methods. This research leverages a special data-efficient Generative Adversarial Network (GAN) architecture to artificially …

The Undergraduate Engineering Mental Health Help-Seeking Instrument (Ue-Mh-Hsi): Development And Validity Evidence, Joseph H. Hammer, Courtney J. Wright, Melanie E. Miller, Sarah A. Wilson

Chemical and Materials Engineering Faculty Publications

Background: Undergraduate engineering students experiencing distress are less likely than peers to ask for professional help. A population-specific instrument to facilitate the identification of factors that influence mental healthcare utilization could guide development and testing of interventions to increase help seeking.

Purpose: We used mixed methods guided by the Integrated Behavioral Model (IBM) to develop and evaluate the Undergraduate Engineering Mental Health Help-Seeking Instrument (UE-MH-HSI).

Method: First, we adapted existing measures of mental health help-seeking intention and mechanisms (i.e., attitudes, perceived norm: injunctive, perceived norm: descriptive, personal agency: autonomy, personal agency: capacity). Second, we coded qualitative interviews (N = 33) …

Solubility Characterization Of Organic Molecules For Aqueous Organic Redox Flow Batteries, Anthony W. Ferrell, Harkeerith K. Vij, Seamus D. Jones

College of Engineering Summer Undergraduate Research Program

The major obstacle to renewable energy sources is a lack of long-term energy storage capabilities. Energy produced during the day dissipates, leaving insufficient electricity for at night. The goal of the project is to design an Aqueous Organic Redox Flow Battery (AORFB) to act as long-term energy storage. Work has been done using machine learning to identify suitable compounds for the batteries. In this work there was no indication as to the aqueous solubility of the molecules; this controls the device’s energy storage capabilities. We used a machine learning model to determine the aqueous solubility of slightly more than 3000 …

Computational Modeling Of High Yttrium Refractory High Entropy Alloy Microstructures, Kaleb C. Ryan, Marissa M. Baker

College of Engineering Summer Undergraduate Research Program

Refractory high entropy alloys (RHEAs) are advanced metals made up of five or more principal elements in roughly equal amounts. The microstructural effects of alloying with yttrium as a principal element for RHEAs are currently not well understood. This project compared RHEA microstructures from literature with simulations using the High Entropy Alloy Predicting Software (HEAPS), which computes 10 screening criteria to predict the microstructure of a RHEA composition. The accuracy of HEAPS predictions was assessed by comparing them with experimentally validated microstructures found in literature. A combination of criteria was found to have a 95.8% accuracy rate, and a new …

Engineering Ceramic Ductility Into Aluminum Oxide, Krish Bhuva

Holster Scholar Projects

This project explores the enhancement of ductility in Aluminum Oxide (Al₂O₃) ceramics through microstructural engineering. The goal is to combine the hardness and stability of Al₂O₃ with enhanced ductility for diverse industrial applications. Inspired by the naturally occurring Itacolumite rock, known for its complex microstructure, this research aims to replicate similar microstructural features in engineering ceramics. By doping Al₂O₃ with Titanium Dioxide (TiO₂), Boron Nitride (BN), and a pore former, while employing innovative sintering techniques, we hypothesize that these modifications will lead to a measurable increase in ductility. Despite early challenges in achieving homogeneity in sintering, promising results were observed …

Substrate Interference And Strain In The Second-Harmonic Generation From Mose2 Monolayers, Sudeep Puri, Sneha Patel, Jose Luis Cabellos, Luis Enrique Rosas-Hernandez, Kaitlin Reynolds, Hugh O.H. Churchill, Salvador Barraza-Lopez, Bernardo S. Mendoza, Hiroyuki Nakamura

Physics Faculty Publications and Presentations

Nonlinear optical materials of atomic thickness, such as non-centrosymmetric 2H transition metal dichalcogenide monolayers, have a second-order nonlinear susceptibility (χ⁽²⁾) whose intensity can be tuned by strain. However, whether χ⁽²⁾ is enhanced or reduced by tensile strain is a subject of conflicting reports. Here, we grow high-quality MoSe₂ monolayers under controlled biaxial strain created by two different substrates and study their linear and nonlinear optical responses with a combination of experimental and theoretical approaches. Up to a 15-fold overall enhancement in second-harmonic generation (SHG) intensity is observed from MoSe₂ monolayers grown on SiO₂ when …

Intrinsic Manipulation Of Microstructure And Strength Of Ice-Templated Lithium Titanate, Rohan Parai

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation focuses on developing a fabrication landscape first time ever for directionally porous lithium titanate (LTO) materials using ice-templating technique. Ice-templating, a promising fabrication technique for porous ceramics, enables the formation of sintered structures with anisotropic pores that are aligned to improve mechanical stability of materials.

The work presented in this dissertation addresses advancements in tuning the porosity, strength, and microstructural characteristics of ice-templated LTO materials through adjustments of intrinsic variables, including sucrose as a water-soluble additive, variations in freezing front velocity, solute concentration, and solid loading. First, this study demonstrated that adding sucrose in LTO suspensions increased the …

Kinetic Modeling Of Dust Grain Dynamics In Electrostatic Sieving, Aaron Berkhoff, Easton Ingram, Fateme Rezaei, Jeffrey Smith, David Bayless, William Schonberg, Daoru Han

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith dust particles with applications to the concept of electrostatic sieving. the new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. a case study for a concept of electrostatic sieving was chosen to validate the new model. the simulation achieved similar performance of particle size classification as reported in the literature. the new model is computationally efficient (takes a few minutes on a PC-type laptop computer) so …

Impact Of Tib2 Source On The Microstructure And Properties Of Tib2–Sic–B4c Ceramics, Steven M. Smith, Suzana Filipovic, William G. Fahrenholtz, Gregory E. Hilmas, Carlo Baldisserri, Laura Silvestroni

Materials Science and Engineering Faculty Research & Creative Works

To date, the thermal and electrical properties of three-phase ceramics containing a boride phase, silicon carbide, and boron carbide have not been studied in detail. Further, the effect of the source of the boride powder has also not been investigated. This study produced three-phase ceramics containing titanium diboride, silicon carbide, and boron carbide using three different TiB₂ sources: commercial powder, TiB₂ synthesized by boro/carbothermal reduction, or (Ti,Cr)B₂ synthesized by boro/carbothermal reduction to address the effect of the TiB₂ source. Ceramics containing synthesized TiB₂ or (Ti,Cr)B₂ reached >99% relative density, while the ceramic produced from …

Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

To ensure consistent performance of additively manufactured metal parts, it is advantageous to identify alloys that are robust to process variations. This paper investigates the effect of steel alloy composition on mechanical property robustness in laser-directed energy deposition (L-DED). In situ blending of ultra-high-strength low-alloy steel (UHSLA) and pure iron powders produced 10 compositions containing 10–100 wt.% UHSLA. Samples were deposited using a novel configuration that enabled rapid collection of hardness data. The Vickers hardness sensitivity of each alloy was evaluated with respect to laser power and interlayer delay time. Yield strength (YS) and ultimate tensile strength (UTS) sensitivities of …

Concrete Design: Underwater Concrete Forms In A Saltwater Environment, Noah Z. Lau

Construction Management

This following project investigated the effects of salt on the concrete curing process. Concrete possesses numerous strengths, making it extremely versatile. This makes it one of the most utilized construction materials. New improved methods are constantly being developed for concrete’s application as a construction material. While concrete is a flexible material with many strengths, it is not without its flaws. Concrete, while strong in compression is weak in tension. It has long cure times and doesn’t generally handle moisture well. This paper evaluates concrete’s change in strength from letting concrete cure in a salt-based underwater environment. To determine the full …

Electronic Communication Between Co And Ru Sites Decorated On Nitrogen-Doped Carbon Nanotubes Boost The Alkaline Hydrogen Evolution Reaction, Meng-Ting Gao, Ying Wei, Xue-Meng Hu, Wenj-Jie Zhu, Qing-Qing Liu, Jin-Yuan Qiang, Wan-Wan Liu, Ying Wang, Xu Li, Jian-Feng Huang, Yong-Qiang Feng

Journal of Electrochemistry

Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction (HER) remains a significant challenge. Here, a novel and efficient cobalt (Co), ruthenium (Ru) bimetallic electrocatalyst composed of CoRu nanoalloy decorated on the N-doped carbon nanotubes (CoRu@N-CNTs), was prepared by reacting fullerenol with melamine via hydrothermal treatment and followed by pyrolysis. Benefiting from the electronic communication between Co and Ru sites, the as-obtained CoRu@N-CNTs catalyst exhibited superior electrocatalytic HER activity. To deliver a current density of 10 mA·cm^–2, it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV·dec …

Zhong-Qun Tian, Academician And Honorary Member Of Electrochemistry Committee Chinese Chemical Society, Achieved "Raman Lifetime Award", Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Optimization Of Channel Structure Of Alkaline Water Electrolyzer By Using An Expanded Mesh As A Bipolar Plate, Hai-Yan Xiong, Zhen-Xiao Zhu, Xin Gao, Chen-Ming Fan, Hui-Bao Luan, Bing Li

Journal of Electrochemistry

Alkaline water electrolysis (AWE) is the most mature technology for hydrogen production by water electrolysis. Alkaline water electrolyzer consists of multiple electrolysis cells, and a single cell consists of a diaphragm, electrodes, bipolar plates and end plates, etc. The existing industrial bipolar plate channel is concave-convex structure, which is manufactured by complicated and high-cost mold punching. This structure still results in uneven electrolyte flow and low current density in the electrolytic cell, further increasing in energy consumption and cost of AWE. Thereby, in this article, the electrochemical and flow model is firstly constructed, based on the existing industrial concave and …

2024 Tianmulake Advanced Anode Materials Innovation Forum And Sixth National Conference Of Advanced Battery Failure Analysis And Testing Technology Concluded Successfully, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.