Materials Science and Engineering Commons^™

Turbulence Numerical Simulation Of Flow Characteristics Of Laval Nozzle Top Blow Jet, Ai Liang Chen, Yao Liu, Zi Biao Wang, Huan Wu Zhan, Xue Xian Jiang, Feng Long Sun, Jiann Yang Hwang, Xi Jun Zhang

Michigan Tech Publications

The turbulent characteristics of the top-blown Laval nozzle and the influence of pressure and Mach number were studied through numerical simulation. With 2.72% error between the results and the empirical formula, the results are reliable. Nozzle fluid is influenced by pipe structure, causing pressure and density to drop as speed increases. Differences in pressure and velocity between the jet and surrounding gas lead to jet velocity attenuation, flow expansion, deflection, and eddy currents. The optimal top blowing pressure is 0.6 MPa, and the center velocity and width of the jet are 345 m/s and 0.124 m, respectively, at 20De (De …

Underlying Mechanisms Of The Effect Of Microfines Of Manufactured Sand On Non-Linear Structural Build-Up Of Cement Paste, Jiang Zhu, Jiaping Liu, Kamal H. Khayat, Xin Cheng, Wei Zhao, Zhen Li, Xin Shu, Yongbo Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The rheological properties of cement-based materials made with manufactured sand vary with the content and physio-chemical properties of microfines in the sand. However, the evaluation of rheological properties regarding the structural build-up at early-age hydration remains challenging for the cementitious materials prepared with different manufactured sands, due to complicated underlying structuration mechanisms. This paper studies the effect of disparate microfines of different manufactured sands on the non-linear growth of static yield stress of cement pastes at rest. The paste mixtures were prepared with 0.40 and 0.275 water-to-cement mass ratio (W/C) and had a fixed mini-slump flow of 240 ± 5 …

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs

Senior Honors Papers / Undergraduate Theses

The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …

Understanding Firn Dynamics: Modeling And Microstructure From East Antarctica, Ilyse Horlings

Dartmouth College Ph.D Dissertations

Glacier ice is formed from the accumulation of snow and its compaction through a transitional material called firn. Firn dynamics are fundamentally influenced by climatic factors, such as temperature and snow accumulation rate, and so are crucial for understanding a number of cryospheric applications. For example, ice-sheet mass loss contributions to sea-level rise from repeat satellite-altimetry observations depend on calculating firn density and its evolution. Past atmospheric gases in ice core bubbles are often younger than the surrounding ice, and their exact age depends on how firn closes off interconnected pores to become impermeable. Models often estimate bulk properties, such …

Effects Of High Temperature Compaction On 3d Printed Carbon Fiber Reinforced Polymer Composites, John D. Barber

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this dissertation was to study the effects of hot temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM), carbon fiber reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect upon the mechanical behavior and the material crystalline composition. Treated, carbon fiber reinforced PA6 samples were analyzed using differential scanning calorimetry, x-ray diffraction, thermogravimetric analysis, scanning electron microscopy, double cantilever beam testing and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190°C combined with 80 psi pressure resulted …

Bismuth Cuprates Produced By Solar Energy Showing Anomalous Resistance, Dilbara Dj. Gulamova, Sirojiddin Z. Mirzaev, Sirojiddin Kh. Bobokulov, Timur I. Gulamov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to obtain bismuth superconducting cuprates with higher superconducting properties. The advantages of superconducting materials in power engineering, disadvantages of synthesis based on solid-phase and melt principles, and the prospect of using nontrivial methods to obtain high critical parameters are presented. The advantages of synthesis under the influence of concentrated solar energy are shown. In order to obtain a superconductor with high critical properties, a massive, long-term stable bismuth cuprate was synthesized using solar technology. It pushes out an external magnetic field and has a nanostructured layered microstructure with caverns containing submicron-sized particles. The phase …

Modern Ir-Spectroscopic Methods For The Analysis Of Hydroxybenzene-Methanal Resin Obtained On The Basis Of 2,5-Furandion, Sherali Anvarovich Umarov, Ravshan Israilovich Ismailov Ismailov

Technical science and innovation

The chemical changes occurring during the synthesis of hydroxybenzene-methanal resins obtained on the basis of 2,5-furandion under various ratios and temperature conditions were investigated using the IR spectroscopic method. Analysis of the compositional changes in the resin during the production of the thermoreactive resin revealed that the content of hydroxyl groups (~3300–3500 cm⁻¹) decreased, while the aldehyde groups (~1700–1750 cm⁻¹) increased; moreover, the presence of ether groups (~1050–1150 cm⁻¹) indicated that the process was successful. The synthesis of resins based on thermoreactive hydroxybenzene-methanal resins was carried out at high temperatures (70°C, 80°C, 95°C). During the identification of the functional groups …

Scalable Mxene-Based Textile Supercapacitors, Abaigeal Aydt

Honors Program: Senior Projects (Public)

The demand for flexible and wearable energy storage devices for portable applications has led to the exploration of textile-based supercapacitors (TSCs). TSCs will allow for the creation of a new class of energy harvesting and storing technology directly into our clothing and will require using non-toxic and/or biocompatible materials. This will result in a greener and more sustainable path to address the challenges at the nexus of energy, mobility, and sustainability. To fabricate a TSC, a yarn made of fibers, such as wool or cotton, is coated with MXene flakes; MXenes are composed of transition metal carbides, nitrides, or carbonitrides …

Recent Advances In Non-Enzymatic Electrochemical Sensors For Theophylline Detection, Gustria Ernis, Yulia M T A Putri, Muhammad Iqbal Syauqi, Prastika Krisma Jiwanti, Yeni Wahyuni Hartati, Takeshi Kondo, Qonita Kurnia Anjani, Jarnuzi Gunlazuardi

Journal of Electrochemistry

Detection of target analytes at low concentrations is significant in various fields, including pharmaceuticals, healthcare, and environmental protection. Theophylline (TP), a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma, bronchitis, and emphysema, has a narrow therapeutic window with a safe plasma concentration ranging from 55.5–111.0 μmol·L^–1 in adults. Accurate monitoring of TP levels is essential because too low or too high can cause serious side effects. In this regard, non-enzymatic electrochemical sensors offer a practical solution with rapidity, portability, and high sensitivity. This article aims to provide a comprehensive review of the recent developments …

Exploring Corona Discharge In Electrostatic Printing For Electronics And In Other Application, Zijian Weng

USF Tampa Graduate Theses and Dissertations

The field of printed electronics (PEs) is expanding rapidly, driven by increasing market demand. According to reports, the global market for PEs is expected to reach $23 billion by 2026, with a compound annual growth rate of 18.3% from 2023 to 2028. This growth necessitates the development of innovative printing technologies that can meet these demands efficiently, delivering high-quality, high-resolution PEs suitable for applications in health, environmental monitoring, sports, aerospace, and more.

Currently, PEs manufacturing relies on two main groups of printing technologies. Contact printing methods offer high-speed production but struggle with precision, while non-contact methods provide high resolution but …

Study On Dopamine Electrochemical Sensing Based On Au@Mos2, Ning An, Ni Su, Xin-Ran Li, Jian-Yu Liu, Qi-Yan Wang

Journal of Electrochemistry

Dopamine (DA) is a vital neurotransmitter, and accurate detection of its concentration is critical for both clinical diagnostics and neuroscience research. Due to its electrochemical activity, DA is commonly detected using electrochemical methods, which are favored for their simplicity, fast response time, and suitability for in vivo analysis. In this work, a highly sensitive DA electrochemical sensor was developed using an Au@MoS₂ composite, created by modifying molybdenum disulfide (MoS₂) nanosheets with gold nanoparticles through HAuCl₄ reduction, and it was aimed at enhancing DA adsorption and improving detection performance. Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), …

Synergy In Materials: Leveraging Phosphosilicate Waste Forms For Electrochemical Salt Waste, Jonathan S. Evarts, Brian J. Riley, Charmayne E. Lonergan, Michaella S. Harris, Jincheng Bai, Eric W. Bohannan, Iheanyichukwu Ajoku, Saehwa Chong, John S. Mccloy

Materials Science and Engineering Faculty Research & Creative Works

Waste forms containing glassy and crystalline phosphate and silicate phases were produced to immobilize salt waste simulants from pyro processing and characterized by using Raman spectroscopy, Mössbauer spectroscopy, X-ray diffraction, scanning electron microscopy, heat capacity, and chemical durability measurements. In this work, a phosphosilicate waste form is presented to leverage the benefits of both borosilicate glasses and iron phosphate glasses. To improve waste loading, prior to immobilization, salt simulants were successfully dechlorinated using ammonium dihydrogen phosphate, mixed with a borosilicate frit (5–30 wt. %) and Fe2O3, and vitrified. Additions of 2.5–15 wt. % borosilicate glass (NBS3) improved normalized release rates …

Analysis Of An Ultra-Broadband Terahertz Metamaterial Absorber, Md Ariful Islam, Md Rezwan Ahmed, Oishi Jyoti, Pritu Sarkar, Md. Samiul Habib

Mechanical Engineering Faculty Publications

This paper introduces a metamaterial absorber (MA) based on vanadium dioxide (VO2) that achieves over 90% absorption of incident terahertz (THz) waves in between 4.50 THz to 11.90 THz with an average absorption of 94.64% and a relative absorption bandwidth (RAB) of 90.18% — the highest reported absorption bandwidth for VO2-based absorbers to our knowledge. The proposed metamaterial absorber features a design with a central square surrounded by four ’T’-shaped elements on each side, symmetrically arranged on a TOPAS dielectric substrate. We perform all numerical analyses keeping the phase-changing material VO2 in the metallic state, and our simulation results show …

Enhancing Road Performance With Void Reducing Asphalt Membrane, Tim Zahrn, Todd Thomas, Randy Miller

Purdue Road School

This presentation will discuss how using the technology of a Void Reducing Asphalt membrane can improve performance of our Asphalt Pavements by creating a more durable asphalt surface that resists cracking and reduces permeability. Void Reducing Asphalt Membrane (VRAM) Specifications: VRAM reduces voids in longitudinal joints, which improves the longevity of a quality road surface. INDOT has already required VRAM on certain road designs. We will review the current specifications for VRAM and outline specifications that may update with the technology. We will also discuss the Impact of Rumble Strips on Longitudinal Joint Performance. The session will also highlight how …

Investigating Spatial Mapping Of Lipid And Protein Alterations Within Cells And Tissues Using Raman Microspectroscopy, Elnaz Sheikh

LSU Doctoral Dissertations

The progression of various diseases is associated with alterations in the microenvironment of cells, consisting of a variety of metabolites like lipids and proteins. It is well known that lipids and proteins are potential biomarkers for indicating alterations within the cell microenvironment induced by disease, and various methods are frequently used for their examination. To understand the chemical composition and spatial distribution of constituents in tissues and cells, confocal Raman spectroscopy and microscopy, as non-destructive tools, have shown potential for monitoring abnormalities at the cellular level with high resolution and can facilitate detection through targeting multiple biomarkers. The application of …

Exploring The Effect Of The Architecture Morphology On Urban Ventilation At Block Scale Using Cfd-Gis And Random Forest Combined Method, Bin Guo, Miaoyi Chen, Xiaowei Zhu, Zheng Wang, Lu Li, Lin Pei, Hailong Chen, Puhao Chen, Tengyue Guo

Mechanical and Materials Engineering Faculty Publications and Presentations

Urban ventilation plays a crucial role in dispersing air pollutants and mitigating the urban heat island effect. As a key factor, urban architectural morphology can significantly impact the wind field and ventilation efficiency. This study combines Computational Fluid Dynamics (CFD), Geographic Information System (GIS), and Random Forest (RF) methods to investigate the influence of architectural morphology on urban ventilation at the block scale. First, Remote Sensing (RS) and GIS were used to extract architectural morphology parameters. Second, CFD simulations, guided by in-situ observations, were conducted to model the wind field, with the Standard k-ɛ model validated as the optimal choice. …

Synthesis, Characterization And Electrical Properties Evaluation Of Zirconium Dioxide Capacitors, Thomas P. Chandy

USF Tampa Graduate Theses and Dissertations

This thesis focuses on the fabrication and comprehensive characterization of thin-film capacitors utilizing zirconium dioxide (ZrO2) as the dielectric material, placed between aluminum electrodes. The research primarily aims to examine the impact of varying ZrO2 film thickness and the effects of post-deposition annealing on the structural, morphological, and electrical properties of the capacitors. A controlled sputtering deposition technique was employed to ensure uniform film growth, maintaining consistency in thickness and material quality across all samples.

A comprehensive set of characterization techniques was employed to analyze the capacitors. Scanning electron microscope (SEM) was used to assess surface roughness, revealing fewer defects …

Impact Of Crack Location, Crack Initial Length, And Crosshead Speed On Fracture Toughness Of Polypropylene And Glass Fiber-Reinforced Polypropylene Pipes, R. Singer, A. Koriem, A. M. Ollick, M. Elhadary

Mansoura Engineering Journal

Fracture toughness (K_IC) is a critical parameter for evaluating the performance of materials, particularly in engineering applications where structural integrity is crucial. The objective of this study is to investigate the fracture toughness characteristics of polypropylene (PP) and glass fiber-reinforced polypropylene (GFPP) pipes. Specifically, evaluating the influence of crosshead speed, crack location, and initial crack length on the K_IC of these materials under both tensile loading (Mode I fracture) and bending conditions. Tensile tests were conducted on both materials using two specimen configurations and varied notch lengths to simulate Mode I fracture conditions. Additionally, three-point bending tests …

Synthesis, Characterization And Delamination Studies Of Metallic Thin Films Prepared Using Sputtering And Ebeam Evaporation Methods, Anoop Joseph

USF Tampa Graduate Theses and Dissertations

In many mechanical applications, including the manufacturing, automotive, and cutting tool sectors, metallic thin film coatings are crucial due to their tribological and protective properties. This research focuses on the development of metallic thin films of Aluminum (Al), Chromium (Cr) and Titanium (Ti) using deposition techniques like Sputtering and Electron Beam Evaporation. Metallic thin films were fabricated, with variations in thickness for each material, allowing for an in-depth study of the effects of Sputtering and Ebeam Evaporation deposition method on film characteristics. The thickness of these metallic thin films were evaluated using High-Resolution Scanning Electron Microscopy (HRSEM) and Profilometer while …

Analytical Electrochemistry Of Nickel, Platinum, And Platinum-Nickel Electrodepositions, Kyle James Troche

Nanoscience and Microsystems ETDs

Nickel and platinum electrodeposits have numerous applications in corrosion and wear-resistant coatings, electronic connectors, heat resistance, metal finishings, and catalysts. The addition of additives can vastly change the morphology of the deposition. Electrokinetic parameters can be calculated by conducting rotating disk electrode (RDE) experiments along with Koutecky-Levich analysis. Significant challenges need to be addressed to deposit uniform films of Pt-Ni alloys from a single co-deposition bath. The main challenge is platinum’s catalytic property to reduce the overpotential for the hydrogen generation reaction. An Investigation into methanol and carbon monoxide’s hydrogen generation reaction suppression was conducted. Electrodeposition of nickel, platinum, and …