Materials Science and Engineering Commons^™

Fabrication Of Dielectric Elastomers With Improved Electromechanical Properties Using Silicone Rubber And Walnut Polyphenols Modified Dielectric Particles, Liang Jiang, Yuhao Wang, Shipeng Wen, Yanfen Zhou, Qingdao University, Stephen Jerrams

Articles

In this work, polyphenolic extract from walnut green husks (denoted as walnut polyphenols), which is an abun-dant agroindustrial residue/waste, was used to modify barium titanate (BT) particles in the preparation of sili-cone rubber (SR) based dielectric elastomer (DE) composites with enhanced electromechanical performance.By employing walnut polyphenols modification, the dispersibility of BT particles in the SR matrix and the com-patibility between BT and SR were greatly improved, which resulted in enhanced mechanical performance ofthe DE composites. Dielectric property measurement showed that DE composites containing walnut polyphenolsmodified BT particles (WNBT) had higher dielectric constants and lower dielectric losses than that of DEs …

Enhanced Fatigue And Durability Of Carbon Black/Natural Rubber Composites Reinforced With Graphene Oxide And Carbon Nanotubes, Hao Guo, Stephen Jerrams, Zongchao Xu, Yanfen Shou, Liang Jiang, Liqun Zhang, Li Liu, Shipeng Wen

Articles

Graphene oxide (GO) sheets and carbon nanotubes (CNTs) are of nanometer size and offer large shape factors which are beneficial in reducing crack propagation rates of composites when used in carbon black (CB) reinforced natural rubber (NR), thereby prolonging the service lives of rubber composites. In this research, CNT-CB/NR and GO-CB/NR composites were prepared by partially replacing CB with one-dimensional CNTs and two-dimensional flaky graphene oxide GO, respectively. The results showed that the complex filler dispersion in NR matrices was improved due to the isolation effect between the different fillers. The strain-induced crystallization (SIC) ability of CB/NR was effectively enhanced …

The Fabrication And Properties Of Magnetorheological Elastomers Employing Bio-Inspired Dopamine Modified Carbonyl Iron Particles, Yanfen Zhou, Lele Li, Wenyue Li, Shipeng Wen, Liang Jiang, Stephen Jerrams, Jianwei Ma, Shaojuan Chen

Articles

To obtain magnetorheological elastomers (MREs) with improved mechanical properties and exhibiting an enhanced magnetorheological (MR) effect, bio-inspired dopamine modification has been used to improve the functionality at the surface of carbonyl iron (CI) particles. Various techniques including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to confirm that a polydopamine (PDA) layer of about 27.5 nm had been successfully deposited on the surface of the carbonyl iron particles prior to their inclusion in the MRE composites. The magnetic properties of PDA modified CI particles were shown to be almost the same as those …

Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

Articles

The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process …

Aging Response On The Stress Corrosion Cracking Behavior Of Wrought Precipitation-Hardened Magnesium Alloy, G. R. Argade, S. K. Panigrahi, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Constant immersion testing and slow strain rate testing (SSRT) are conducted on wrought magnesium alloy in a 3.5 wt.% NaCl solution. After solution annealing (SA) at 525 °C for 8 h, the alloy was isothermally aged at 210 °C for 15 h, 48 h, and 144 h to obtain underaged (UA), peak-aged (PA), and overaged (OA) microstructures, respectively. After 32 days of constant exposure in chloride solution, the SA and UA samples showed the lowest (~ 0.10 mg cm−2 day−1) and the highest (~ 0.20 mg cm−2 day−1) weight loss, respectively. SSRT was carried out at an initial strain rate …

Electron Tunneling And X-Ray Photoelectron Spectoscopy Studies Of The Superconductiong Properties Of Nitrogen-Doped Niobium Resonator Cavities, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Iavarone

Physics Faculty Publications

We use scanning tunneling microscopy (STM) and spectroscopy (STS), and x-ray photoelectron spectroscopy (XPS) to investigate the effect of nitrogen doping on the surface electronic and chemical structures of cutouts from superconducting Nb radio-frequency cavities. The goal of this work is to get insights into the fundamental physics and materials mechanisms behind the striking decrease of the surface resistance with the radio-frequency magnetic field, which has been observed on N-doped Nb cavities. Our XPS measurements reveal significantly more oxidized Nb 3d states and a thinner metallic suboxide layer on the N-doped Nb surfaces, which is also confirmed by tunneling spectroscopy …

Potential Of Module Arrangements To Enhance Convective Cooling In Solar Photovoltaic Arrays, B. Stanislawski, Fabien Margairaz, Raúl Bayoán Cal, Marc Calaf

Mechanical and Materials Engineering Faculty Publications and Presentations

When solar photovoltaic (PV) module temperatures rise during operation, commonly-installed modules experience an efficiency loss between 0.1 and 0.5% per degree above 25+C. Thus, extensive research has aimed to reduce the operating temperature of solar modules. However, many cooling solutions require additional cost or equipment that precludes their implementation in utility-scale PV plants. Based on previous studies of land-atmosphere interactions of surface thermal heterogeneity, we hypothesize that certain solar farm arrangements may enhance natural convective heat transfer between the solar modules and surrounding flow. Due to the strong non-linear relationship between module temperature and convective heat transfer, enhancing the convective …

Thei Student Applied Research Presentations Sarp 2020, Research Office, Technological And Higher Education Institute Of Hong Kong

THEi Student Applied Research Presentations (SARP)

No abstract provided.

Texture Evolution Induced By Twinning And Dynamic Recrystallization In Dilute Mg-1sn-1zn-1al Alloy During Hot Compression, Meijuan Hao, Weili Cheng, Lifei Wang, Ehsan Mostaed, Liping Bian, Hongxia Wang, Xiaofeng Niu

Michigan Tech Publications, Part 1

Texture evolution of an extruded dilute Mg-1Sn-1Zn-1Al alloy was thoroughly investigated based on the twinning and dynamic recrystallization (DRX) behavior via hot compression at a strain rate of 10 s−1 and temperature of 225°C. It was found that the types and intensities of the texture are strongly dependent on the fraction of twins and DRX modes as well as regions where sub-grain boundaries (sub-GBs) are intensively accumulated. At the initial stage of deformation, the formation of compression direction (CD)-tilted basal texture was mainly determined by the occurrence of {101¯2} extension twins. As the strain increases, the variation in the texture …

Very High Cycle Fatigue Behavior Of Laser Beam-Powder Bed Fused Inconel 718 Considering The Layer Orientation And Surface Finish Effects, Palmer Frye

UNF Graduate Theses and Dissertations

Additive Manufacturing (AM) techniques have recently gained popularity for fabrication of parts used in aerospace applications. Some of these parts may be subjected to cyclic loading at very high frequencies, leading to service life requirements exceeding ten-million cycles (>10⁷ cycles). Therefore, understanding the very high-cycle fatigue (VHCF) behavior of these AM parts is an important step in their design and qualification processes. In this thesis, both high-cycle fatigue (HCF) and VHCF behaviors of Inconel 718, a Ni-base superalloy, manufactured via a Laser Beam-Powder Bed Fusion (LB-PBF) process, are investigated. Uniaxial, fully reversed force-controlled fatigue tests were conducted utilizing …

Thermodynamic Investigations Of Pure And Blended Cement Mixtures, Jonathan Lapeyre

Doctoral Dissertations

” This research is made up of several studies. The first study focused on understanding the reaction kinetics of Ca₃SiO₅ and metakaolin (MK) mixtures compared to Ca₃SiO₅ and silica fume (SF) mixtures. It was shown that MK was a more effective additive than SF at small replacement levels (i.e. ≥ 10% by mass) while higher replacement levels of MK became a detriment due to excess (Al(OH)₄¯) ions preventing the nucleation and growth of C-S-H. In a follow-up study where the MK particle size distribution (PSD) was modified, similar effects were observed but …

From Open Access To Open Science: The Path From Scientific Reality To Open Scientific Communication, Christian Heise, Joshua M. Pearce

Michigan Tech Publications, Part 1

Although opening up of research is considered an appropriate and trend-setting model for future scientific communication, it can still be difficult to put open science into practice. How open and transparent can a scientific work be? This article investigates the potential to make all information and the whole work process of a qualification project such as a doctoral thesis comprehensively and freely accessible on the internet with an open free license both in the final form and completely traceable in development. The answer to the initial question, the self-experiment and the associated demand for openness, posed several challenges for a …

Artificial Intelligence In Plasma Electrolytic Micro-Oxidation For Surface Hardening - Insights From Scholarly Citation Networks And Patents., Priya Jadhav, Dr.Arun Bongale, Dr.Satish Kumar, Dr.Amit Kumar Tiwari

Library Philosophy and Practice (e-journal)

Objective - The purpose of this article is to analyze the top work areas and patent domains in the field of surface hardening by micro-arc oxidation. Also, it is directed on the opportunities of data analysis by different machine learning tools. Material and methods - The www.lens.org database is used to collect articles from Elsevier, Trans tech publications, Springer New York, MDPI, etc. to review the relevant articles as well as patents related to the topic. The result - A total of 1057 articles were published in 60 different journals and 756 patents in the area of research under various …

Electrospun Fibers With Smart Delivery Of Therapeutic Agents, Zahra Mahdieh

Graduate Student Theses, Dissertations, & Professional Papers

Electrospinning is the most widely studied technique of producing fibers. Delivery of nanoparticles and therapeutic agents from electrospun fibers have potential uses in various fields including drug delivery, filtration, and cosmetics. However, controlling the delivery rate remains the main challenge. In the current study, core-shell structure fibers were developed with zinc oxide nanoparticles applied in the shell composition to improve the pore structure (release pathway) and mechanical stability. Fine-tuned delivery rates were achieved via loading different sizes of silver nanoparticles (Ag NP) inside the fiber core. In vitro drug release assays showed fast, slow, and intermediate delivery rates of 20 …

Hot Deformation Data For Haynes 214, Haynes 230 And Inconel 740h, Benjamin Adam, Julie Tucker, Graham Tewksbury

Mechanical and Materials Engineering Faculty Publications and Presentations

This article presents the datasets gathered for the hot processing of three Ni-based superalloys intended for A-USC application, Haynes 214, Haynes 230 and Inconel 740H. Isothermal compression tests were conducted with a Gleeble 3500 at temperatures between 1000 C and 1200 C and strain rates between 0.01/s and 1/s to a full true strain of 0.7. The obtained true stress-true strain curves were used as basis for hot processing maps, linking temperature, stress and strain rate. Subsequently, all samples were sectioned through the geometric centre to provide microstructural information, captured using EBSD, as well as EDX for the evolution of …

Synthesis And Characterization Of Novel Lithium Gallium Phosphate (Ligap2o7) For Extreme Environment Applications, Mohan Raj Rajkumar

Open Access Theses & Dissertations

In this work, we report on the synthesis, characterization, and performance of LiGaP2O7 (LGP), a novel material and fairly new to the scientific & engineering community. LiGaP2O7 materials were was synthesized using the conventional high-temperature, solid-state ceramic reaction. Calcination was done in three steps at the temperatures of 300 °C, 500 °C, and 650 °C for 8 h each to ensure a single phase. Utilizing this, different green pellets were sintered at 800 °C for varying times of 3 h, 6 h, 12 h, and 24 h. The structure, phase, and morphology were analyzed using X-ray diffraction (XRD) and scanning …

Effect Of Flow Velocity And Geometry On The Signal From A Piezoelectric Flow Rate Sensor, Jad Gerges Aboud

Open Access Theses & Dissertations

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Development Of Software Tools And Experimental In Situ Electron Spin Resonance For Characterizing The Magnetic And Electrocatalytic Properties Of Transition Metal Chalcogenide Crystals, Jose Armando Delgado

Open Access Theses & Dissertations

Studying the magnetic properties and crystal defects of transition metal chalcogenide crystals is of paramount importance for utilizing them for next generation spintronics devices and hydrogen evolution reaction catalysts. Hydrothermally grown transition metal chalcogenide nanocrystals (MoS2, Ru2S3, Rh2S3, Co2S8) were chosen as catalysts for the hydrogen evolution reaction due to their low dimensionality and previous utilization as catalysts for hydrodesulfurization. The relationship between crystal defect sites and catalytic activity must be discerned to maximize the efficiency of hydrogen production during the hydrogen evolution reaction. ESR spectroscopy was utilized as a spin sensitive technique to study the defects and local changes …

Fabrication, Development, And Characterization Of Hipco Swcnt - Alginate Hydrogel Composites For Cellular Product Applications, Fabian Armando Alvarez-Primo

Open Access Theses & Dissertations

In this study, we designed, synthesized, and characterized ultrahigh purity single-walled carbon nanotube (SWCNT)-alginate hydrogel composites. Among the parameters of importance in the formation of an alginate-based hydrogel composite with single-walled carbon nanotubes, are their varying degrees of purity, their particulate agglomeration and their dose-dependent correlation to cell viability, all of which have an impact on the resultant compositeâ??s efficiency and effectiveness towards biomedical applications. To promote their homogenous dispersion by preventing agglomeration of the SWCNT, at first, we used three different surfactants-sodium dodecyl sulfate (SDS-anionic), cetyltrimethylammonium bromide (CTAB-cationic), and Pluronic F108 (nonionic). After experimentation and corroboration through evidence obtained …

Synthesis And Characterization Of Material Systems For 3d Printed Smart Structures, Hilda Fontes

Open Access Theses & Dissertations

The silica hollow spheres have demonstrated excellent results in multiple applications such as light-weight composites, and optical applications as a glass coating. This material also exhibits excellent thermal, shock impact, and hydrophilic properties extremely useful for industrial applications. However, a controllable size of the particle is desired to further increase the number of applications of the silica hollow spheres.

This Thesis aims a method to fabricate silica hollow spheres in a single step with a controlled diameter size. A study was developed to demonstrate the particle size change when adjusting the molecular weight of the medium by using different alcohol …