Functionalization And Characterization Of Chemical Vapor Deposited Graphene Sheets Towards Application In Chemical Vapor Sensing,
2018
Wright State University
Functionalization And Characterization Of Chemical Vapor Deposited Graphene Sheets Towards Application In Chemical Vapor Sensing, Nicholas Alexander Engel
Browse all Theses and Dissertations
Chemical/biological sensors serve many purposes in protecting machinery, the environment, and human life/wellness. Graphene, a two-dimensional (2-D) material made up of carbon atoms in a honeycomb-like lattice, is promising for applications to chemical/biological sensing due to its unique properties. Functionalization of graphene by surface decorating with nanoparticles and increasing interior adsorption sites can tailor its catalytic activity and electrical properties, and hence, important for detecting and distinguishing trace hazardous gases. This research introduces two different approaches to functionalize graphene towards enhanced sensitivity and selectivity of graphene-based sensors. The morphologies, structures, and electrical properties of the functionalized graphene are systematically characterized. …
Magneto-Optical Properties Of Thin Permalloy Films: A Study Of The Magneto-Optical Generation Of Light Carrying Angular Momentum,
2018
University of Kentucky
Magneto-Optical Properties Of Thin Permalloy Films: A Study Of The Magneto-Optical Generation Of Light Carrying Angular Momentum, Patrick D. Montgomery
Theses and Dissertations--Electrical and Computer Engineering
Magneto-optical materials such as permalloy can be used to create artificial spin- ice (ASI) lattices with antiferromagnetic ordering. Magneto-optical materials used to create diffraction lattices are known to exhibit magnetic scattering at the half- order Bragg peak while in the ground state. The significant drawbacks of studying the magneto-optical generation of OAM using x-rays are cost, time, and access to proper equipment. In this work, it is shown that the possibility of studying OAM and magneto-optical materials in the spectrum of visible light at or around 2 eV is viable. Using spectroscopic ellipsometry it is possible to detect a change …
Multifunctional Operational
Component For Robotic Devices,
2018
University of Nebraska-Lincoln
Multifunctional Operational Component For Robotic Devices, Shane M. Farritor, Amy Lehman, Mark Rentschler
Department of Mechanical and Materials Engineering: Faculty Publications
The various embodiments disclosed herein relate to modular medical devices, including various devices with detachable modular components and various devices with pivotally attached modular components. Additional embodiments relate to procedures in which various of the devices are used cooperatively. Certain embodiments of the medical devices are robotic in vivo devices.
Scaffold Structural Microenvironmental Cues To
Guide Tissue Regeneration In Bone
Tissue Applications,
2018
Sichuan University
Scaffold Structural Microenvironmental Cues To Guide Tissue Regeneration In Bone Tissue Applications, Xuening Chen, Hongyuan Fan, Xiaowei Deng, Lina Wu, Tao Yi, Linxia Gu, Changchun Zhou, Yujiang Fan, Xingdong Zhang
Department of Mechanical and Materials Engineering: Faculty Publications
In the process of bone regeneration, new bone formation is largely affected by physico-chemical cues in the surrounding microenvironment. Tissue cells reside in a complex scaffold physiological microenvironment. The scaffold should provide certain circumstance full of structural cues to enhance multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and subsequent new bone formation. This article reviewed advances in fabrication technology that enable the creation of biomaterials with well-defined pore structure and surface topography, which can be sensed by host tissue cells (esp., stem cells) and subsequently determine cell fates during differentiation. Three important cues, including scaffold …
Complementary Microscopy Techniques Applied For Characterizing The Localized Nanoscale Structure Of Poly (Vinylidene Fluoride),
2018
University of Nebraska-Lincoln
Complementary Microscopy Techniques Applied For Characterizing The Localized Nanoscale Structure Of Poly (Vinylidene Fluoride), Wen Qian, Shuo Sun, Charles Nguyen, Wenlong Li, Stephen Ducharme, Joesph A. Turner
Department of Mechanical and Materials Engineering: Faculty Publications
Poly (vinylidenefluoride) (PVDF), a well-recognized electroactive polymer, has been studied extensively over many decades. Recently, there has been increasing interest in tuning the electrical properties of PVDF from ferroelectric to piezoelectric and to pyroelectric, which can be attained via controlling the microscale structure down to the nanoscale structure [1-2]. To optimize the preparation conditions of PVDF and its copolymers, as well as to improve the performance for many applications, comprehensive analytical techniques are of great importance. In this paper, we demonstrate complementary nanoscale characterization and measurement techniques, by conducting a systematic and coordinated study involving scanning electron microscopy (SEM), high …
Tissue Stresses In Stented Coronary Arteries With Different Geometries: Effect Of The Relation Between Stent Length And Lesion Length,
2018
Jiangsu University
Tissue Stresses In Stented Coronary Arteries With Different Geometries: Effect Of The Relation Between Stent Length And Lesion Length, Xiang Shen, Song Ji, Yong-Quan Deng, Hong-Fei Zhu, Jia-Bao Jiang, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
In-stent restenosis after stent deployment remains an obstruction in the long-term benefits of stenting. This study sought to investigate the influence of the relation between stent length and lesion length on the mechanics of the arterial wall with different geometries, including straight and tapered vessels. Results showed that when the length of the stent was longer than the lesion length, the maximum stress in plaque and vessel increased as the length of stent increased. When the length of the stent was shorter than the lesion length, the vessel stress induced by stent inflation was lower; both ends of the stenosis …
Experimental Measurement Of Dolphin Thrust
Generated During A Tail Stand Using Dpiv,
2018
West Chester University
Experimental Measurement Of Dolphin Thrust Generated During A Tail Stand Using Dpiv, Frank E. Fish, Terrie M. Williams, Erica Sherman, Yae Eun Moon, Vicki Wu, Timothy Wei
Department of Mechanical and Materials Engineering: Faculty Publications
Estimation of force generated by dolphins has long been debated. The problem was that indirect estimates of force production for dolphins resulted in low values that could not be validated. Bubble digital particle image velocimetry (DPIV) measured hydrodynamic force production for swimming dolphins and demonstrated high force production. To validate the bubble DPIV and reconcile force production measurements, two bottlenose dolphins (Tursiops truncatus) performing tail stands were measured with bubble DPIV. Microbubbles were generated from a finely porous hose and compressed air source. Displacement of the bubbles by the propulsive motions of the dolphin was tracked with a …
Study Of Asymmetry Configuration Effects On Plate Heat Exchanger Performance,
2018
Faculty of Engineering
Study Of Asymmetry Configuration Effects On Plate Heat Exchanger Performance, Pearachad Chartsiriwattana
Chulalongkorn University Theses and Dissertations (Chula ETD)
Plate heat exchanger is wildly used in engineering application. Previous studies indicated that flow profile effects to plate heat exchanger overall heat transfer coefficient with various factors that manipulate flow profile. This study aims to observe the effect of manipulation flow by creating non-uniform cross-section area along with the flow by applied asymmetry configuration to plate heat exchanger. The experimental results categorize into two groups. The first group is an asymmetric configuration that enhances the overall heat transfer coefficient by 6.54% compared to symmetric configuration due to promoting heat convection. The other group is an asymmetric configuration that ineffective to …
Leaching Of A Mongolian Chalcopyrite Concentrate,
2018
Edith Cowan University
Leaching Of A Mongolian Chalcopyrite Concentrate, Nicholas J. Welham, Jadambaa Temuujin, Nader Setoudeh
Research outputs 2014 to 2021
A Mongolian chalcopyrite flotation concentrate was leached using sodium hypochlorite adjusted to different pH using hydrochloric acid. It was found that using a starting pH of below 5.0 resulted in more efficient leaching. The extent of chalcopyrite leaching was determined by the concentration of sodium hypochlorite with > 40% dissolution being achieved. The residue after leaching was found to consist primarily of unreacted chalcopyrite which would be suitable for further leaching or smelting.
A New Approach To Multiplanar, Real-Time Simulation Of Physiological Knee Loads And Synthetic Knee Components Augmented By Local Composition Control In Fused Filament Fabrication,
2018
University of Texas at El Paso
A New Approach To Multiplanar, Real-Time Simulation Of Physiological Knee Loads And Synthetic Knee Components Augmented By Local Composition Control In Fused Filament Fabrication, Joshua Taylor Green
Open Access Theses & Dissertations
Despite numerous advances in biomedical engineering, few developments in surgical simulation have been made outside of computational models. Cadavers remain the primary media on which surgical research and simulation is conducted. Most attempts to quantify the effects of orthopedic surgical methods fail to achieve statistical significance due to limited quantities of cadaver specimen, large variations among the cadaver population, and a lack of repeatability among measurement techniques. The general purpose of the research covered in this dissertation is to develop repeatable simulation of physiological loads and develop techniques to fabricate a synthetic-based replacement of cadaver specimens. Future work applying this …
Streamlining Alloy Design And Thermo-Mechanical Processing Parameters For High Strength Line Pipe Steels And Hot Rolled Microalloyed Steels: Process - Structure - Property Paradigm,
2018
University of Texas at El Paso
Streamlining Alloy Design And Thermo-Mechanical Processing Parameters For High Strength Line Pipe Steels And Hot Rolled Microalloyed Steels: Process - Structure - Property Paradigm, Venkata Vignesh Natarajan
Open Access Theses & Dissertations
The process parameters related to thermo-mechanical controlled processing (TMCP) of steels play a vital role in affecting the ultimate mechanical properties. We illustrate here the impact of coiling temperature, the impact of finish cooling temperature on interrupted cooling and compare with continuous cooling, and the impact of carbon and niobium on the microstructure and precipitation behavior and corresponding changes in mechanical properties, in an ultrahigh strength titanium-niobium microalloyed steel. The microstructural advancement was contemplated via transmission electron microscopy and electron backscattered diffraction (EBSD). The goal was to underscore the impact of coiling temperature on the nature and distribution of microstructural …
Heterogeneous Integration Of Metallic, Semiconducting And Dielectric Two-Dimensional Layered Material Inks For Electronics And Sensing Device Platforms,
2018
University of Texas at El Paso
Heterogeneous Integration Of Metallic, Semiconducting And Dielectric Two-Dimensional Layered Material Inks For Electronics And Sensing Device Platforms, Jay Amrish Desai
Open Access Theses & Dissertations
In monolayers of two-dimensional (2-D) layered materials, the motion of electrons is confined to a 2-D plane yielding a "zero" effective thickness with regard to the electrons. These monolayers are commonly obtained by exfoliating membranes from the bulk crystal to overcome the weak interplanar Van der Waals bonding using the so-called top-down approach. The bottom-up approach is another avenue to realize these materials, where atoms and molecules coalesce together into increasingly larger assemblies for the realization of the bulk three-dimensional (3-D) crystal. The unique properties of many of these 2-D materials make them highly sought out candidates for advancing conventional …
Effects Of Air And Other Gases In The Stabilization Process Of The Superprotonic Phase Of Cesium Dihydrogen Phosphate Within A Hermetically Sealed Chamber,
2018
University of Texas at El Paso
Effects Of Air And Other Gases In The Stabilization Process Of The Superprotonic Phase Of Cesium Dihydrogen Phosphate Within A Hermetically Sealed Chamber, Israel Martinez
Open Access Theses & Dissertations
The solid acid CsH2PO4 (CDP), exhibits a sudden increase in its proton conductivity as it’s heated above a certain temperature (around T~235oC), which makes it a very attractive candidate to be used as an electrolyte in intermediate temperature fuel cells. Unfortunately, at these temperatures the sample is not stable, as starts to dehydrate; which causes a dramatic drop in the proton conductivity over a short period of time (less than one hour). In order to inhibit, or at least delay, the dehydration process, the solid acid it’s put under a saturated water vapor atmosphere. Another method to stabilize the highly …
Implementation Of Magnesium Alloy Az91d On Wire And Arc Additive Manufacturing,
2018
University of Texas at El Paso
Implementation Of Magnesium Alloy Az91d On Wire And Arc Additive Manufacturing, David Adrian Martinez Holguin
Open Access Theses & Dissertations
As progress on Additive Manufacturing (AM) techniques focusing on ceramics and polymers evolve, metals continue to be a challenging material to manipulate when fabricating products. Current methods, such as Selective Laser Sintering (SLS) and Electron Beam Melting (EBM) face many intrinsic limitations due to the nature of their processes. Material selection, elevated cost and low deposition rates are some of the barriers to consider when one of these methods is to be used for the fabrication of engineering products. The research here presented demonstrates the use of a Wire and Arc Additive Manufacturing (WAAM) system for the creation of metallic …
Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals,
2018
University of Texas at El Paso
Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez
Open Access Theses & Dissertations
Magnetism and catalytic activity of nanoscale layered two-dimensional (2D) transition metal dichalcogenides (TMDs) have gained an increasing research interest in the recent past. To broaden the current knowledge and understanding on this subject, in this work, together with my collaborators, I study the magnetic and electrocatalytic properties of hydrothermally grown pristine and transition metal doped (10% of Co, Ni, Fe and Mn) 2H-MoS2 nanosheets/nanocrystals (NCs), with the particle size of 25-30 nm. A broad range of experimental measurements such as x-ray diffraction, transmission electron microscopy, x-ray photo absorption spectroscopy, Raman spectroscopy, magnetic, catalytic and electron spin resonance have been employed …
Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study,
2018
University of Texas at El Paso
Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman
Open Access Theses & Dissertations
Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …
Tribological Characterization Of Ti-Based Alloys For Biomedical Applications In Simulated Body Fluid,
2018
University of Texas at El Paso
Tribological Characterization Of Ti-Based Alloys For Biomedical Applications In Simulated Body Fluid, Edgar Reyes
Open Access Theses & Dissertations
Tribology is a terminology introduced in the 1960's and it is a study that relates to the investigation of the damage of materials. Titanium, as a material used for a wide range of application, it has been brought to the attention of researchers some characteristics such as its much lower density if compared to steel, its capability as an alloying agent with an amount of metals to enhance physical and mechanical properties, to name just a few characteristics. This paper will discuss the performance on tribology behavior in two different Titanium alloys. These Titanium alloys are Ti-6Al-4V (Ti64), and Ti-24Nb-4Zr-8Sn …
Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications,
2018
University of Texas at El Paso
Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe
Open Access Theses & Dissertations
Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown …
Titanium Incorporated Gallium Oxide (Ga-Ti-O): Structure Property Relationship And Performance Evaluation For Extreme Environment Applications,
2018
University of Texas at El Paso
Titanium Incorporated Gallium Oxide (Ga-Ti-O): Structure Property Relationship And Performance Evaluation For Extreme Environment Applications, Sandeep Manandhar
Open Access Theses & Dissertations
The existing power generation systems, which utilize fossil fuels, are in dire need of efficient, reliable chemical sensors that can operate safely at higher temperatures. These sensors control the combustion environment and the emissions during combustion. Several sensing materials such as SnO2, ZnO, TiO2, WO3, and Ga2O3 exhibit high sensitivity to certain type of chemical molecules and in a certain range of temperatures. Among these candidate materials, β-Ga2O3 is stable at very high temperatures and has shown functionality for oxygen sensing at higher temperatures (>700°C). However, the response time and sensitivity must be significantly improved in order to derive …
Evaluation Of Large Area Additively Manufactured Fiber Reinforced Acrylonitrile Butadiene Styrene (Abs),
2018
University of Texas at El Paso
Evaluation Of Large Area Additively Manufactured Fiber Reinforced Acrylonitrile Butadiene Styrene (Abs), Kevin Schnittker
Open Access Theses & Dissertations
To enable the advancement of large-scale additive manufacturing processes, it is necessary to establish and standardize methodologies to characterize the mechanical properties of printed test coupons. Due to the large size of the print beads, conventional test standards are inadequate. The focus of this study was to determine the feasibility of using Digital image correlation (DIC) technology as a key enabler for robust data collection of strain measurements of large 3D printed parts. To incorporate the DIC measurements, a novel method was developed to prepare large 20 wt.% glass filled ABS test coupons for adequate contrast. Through this technique, Poisson's …
