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Materials Science and Engineering

West Virginia University

2020

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Effects Of Oxygen Modification On The Structural And Magnetic Properties Of Highly Epitaxial La0.7sr0.3mno3 (Lsmo) Thin Films, Shalini Kumari, Navid Mottaghi, Chih-Yeh Huang, Robbyn Trappen, Ghadendra Bhandari, Saeed Yousefi, Guerau Cabrera, Mohindar S. Seehra, Mikel B. Holcomb Jan 2020

Effects Of Oxygen Modification On The Structural And Magnetic Properties Of Highly Epitaxial La0.7sr0.3mno3 (Lsmo) Thin Films, Shalini Kumari, Navid Mottaghi, Chih-Yeh Huang, Robbyn Trappen, Ghadendra Bhandari, Saeed Yousefi, Guerau Cabrera, Mohindar S. Seehra, Mikel B. Holcomb

Faculty & Staff Scholarship

La0.7Sr0.3MnO3, a strong semi-metallic ferromagnet having robust spin polarization and magnetic transition temperature (TC) well above 300 K, has attracted significant attention as a possible candidate for a wide range of memory, spintronic, and multifunctional devices. Since varying the oxygen partial pressure during growth is likely to change the structural and other physical functionalities of La0.7Sr0.3MnO3 (LSMO) films, here we report detailed investigations on structure, along with magnetic behavior of LSMO films with same thickness (~30 nm) but synthesized at various oxygen partial pressures: 10, 30, 50, 100, 150, 200 and 250 mTorr. The observation of only ( …

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Modulation Of Semiconductor Photoconversion With Surface Modification And Plasmon, Joeseph Martin Bright Jan 2020

Modulation Of Semiconductor Photoconversion With Surface Modification And Plasmon, Joeseph Martin Bright

Graduate Theses, Dissertations, and Problem Reports

Semiconductor devices are the basis of modern technology. Semiconductor-based photoconversion devices that convert light into electrical signals have shown potential for light energy harvesting and conversion, environmental remediation, and sensors for detection of light, chemicals, and biological substances. Despite this potential for use in many applications, semiconductor photoconversion devices need further improvement in the photoconversion performance. This photoconversion improvement may be manifested as increased photoconversion efficiencies for light harvesting devices for power generation such as photovoltaics and photoelectrochemical (PEC) cells or improved photoconversion modulation to increase the sensitivity of semiconductor photoconversion-based sensors. In addition, alternative semiconductor materials to semiconductors that …

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Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil Jan 2020

Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil

Graduate Theses, Dissertations, and Problem Reports

The life-cycle performance, durability, and aging characteristics of Fiber Reinforced Polymer (FRP or Structural Composites) have been of keen interest to the engineers engaged in the FRP design, construction, and manufacturing. Unlike conventional construction materials such as steel and concrete, the design guidelines to account for the aging of FRP are somewhat scattered or not available in an approved or consistent format. Loss of strength over time or aging of any structural material should be of concern to engineers as the in-service lifespan of many engineering structures is expected to exceed 100 years. Use of durability strength-reduction factors or factors …

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Doping With Rare Earth Elements And Resultant Nano-Inclusions On The Electrical And Thermal Properties Of The Mis-Fit Layered Thermoelectric Oxide, Geoffroy Gauneau Jan 2020

Doping With Rare Earth Elements And Resultant Nano-Inclusions On The Electrical And Thermal Properties Of The Mis-Fit Layered Thermoelectric Oxide, Geoffroy Gauneau

Graduate Theses, Dissertations, and Problem Reports

Thermoelectric generators produce electricity by directly converting temperature differences into electrical energy through Seebeck effect. Thermoelectric generators possess many unique features, such as having no moving part and being very reliable with a relatively long lifespan once built. They are solid-state waste heat harvesters. With various waste heat available throughout many industries, thermoelectric generators could offer economically competitive renewable energy. The current state of the art thermoelectric materials includes materials with relatively toxic elements and must work under vacuum, making them quite expensive to produce. Among the various thermoelectric materials, ceramic oxides have been proved to be more chemically stable …

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Oxygen Transport Kinetics Of Surface Modified Mixed Conductor (La0.60sr0.40)0.95co0.20fe0.80o3-X As Solid Oxide Fuel Cell Cathode, Manuel Serrano Laguna Jan 2020

Oxygen Transport Kinetics Of Surface Modified Mixed Conductor (La0.60sr0.40)0.95co0.20fe0.80o3-X As Solid Oxide Fuel Cell Cathode, Manuel Serrano Laguna

Graduate Theses, Dissertations, and Problem Reports

The oxygen transport kinetics of the electrodes of Solid Oxide Fuel Cells (SOFC) are critical properties to achieve higher efficiencies in the cell. (La0.60Sr0.40)0.95Co0.20Fe0.80O3-x (LSCF) is a mixed ion-electron conductor material that is expected to be optimized and utilized as the cathode of the SOFC’s. The reason for LSCF to be considered as the next cathode material for SOFC is due to its high ionic and electronic conductivities, and high oxygen transport kinetics. Additionally, to the excellent properties that this material offers, it has been seen that the kinetic properties of the material can be further optimized by adding a …

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Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves Jan 2020

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …

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Paper-Based Point-Of-Care Tools For Blood Testing, Xuefei Gao Jan 2020

Paper-Based Point-Of-Care Tools For Blood Testing, Xuefei Gao

Graduate Theses, Dissertations, and Problem Reports

Early detection of malignant disease is crucial for timely diagnosis and effective medical intervention, which significantly increases survival rates and reduce financial burden on patients. Biomarkers are becoming increasingly important in detection of malignant diseases, because they can be employed for indicating diseases, predicting risks and monitoring the progression of diseases. In addition, biomarkers show up at early stages of diseases in human tissues and fluids (e.g., blood, urine and saliva), which shows great promise for early disease detection. In this dissertation, paper-based lateral flow strips (PLFSs) have been developed for the detection of disease biomarkers, including protein biomarkers and …

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Plasmon-Enhanced Optical Probes For Sensing Of Drug Metabolite, Jennifer Boryczka Jan 2020

Plasmon-Enhanced Optical Probes For Sensing Of Drug Metabolite, Jennifer Boryczka

Graduate Theses, Dissertations, and Problem Reports

An Au@SiO2 core-shell nanostar structure was synthesized along with CuInS2 quantum dots. The quantum dots display near-infrared fluorescence. In this work, the nanostar structure was functionalized with antibodies and then was utilized as a SERS probe for drug metabolite detection. Drugs are an illicit substance that police, medics, and hospitals need to know if an individual is under the influence of but that individual will not always be willing or able to provide that information. A sensor based on this new probe has been developed for detection of drug metabolites in buffer.

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Comprehensively Improved Electrochemical Performance Of Lithium-Sulfur Batteries By “Chemical Anchors” And Lithium Anode Modification, Zhipeng Zeng Jan 2020

Comprehensively Improved Electrochemical Performance Of Lithium-Sulfur Batteries By “Chemical Anchors” And Lithium Anode Modification, Zhipeng Zeng

Graduate Theses, Dissertations, and Problem Reports

Lithium-sulfur battery is considered to be one of the most promising contenders for the next generation high-energy storages due to their high theoretical energy density (~2600 W h kg-1). However, a series of issues, especially for the dissolution of lithium polysulfides (LiPSs) with their “shuttle effect” and dendrite formation on the lithium anode, greatly limit their widely commercial applications. Starting from a brief overview of conventional methods to solve these problems, the achievements spotlighted in this research work mainly focus on the structure design of cathode materials by employing “chemical anchors” to effectively suppress the diffusion of LiPSs, …

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