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Articles 5821 - 5850 of 16795

Full-Text Articles in Materials Science and Engineering

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu May 2020

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …


Thiol-Induced Degradation Of Hydrogels Utilizing Multiresponsive Dithiomaleimides Crosslinkers, Kundu Thapa May 2020

Thiol-Induced Degradation Of Hydrogels Utilizing Multiresponsive Dithiomaleimides Crosslinkers, Kundu Thapa

Honors Theses

Hydrogels are hydrophilic, three-dimensional materials used as platforms for various biomedical applications such as drug delivery, biosensors, or as scaffolds in tissue engineering. The ability to degrade on demand in response to biological cues is particularly attractive whether dealing with microgels or if one aims to release an active ingredient from a scaffolding material. For instance, many cancer-remediation drug delivery platforms leverage the high concentration of glutathione, a thiol-containing tripeptide, found in cancerous cells. In this work, poly(ethylene glycol) acrylate hydrogels were fabricated using dithiomaleimide (DTM) moieties. DTMs are known to undergo thiol-exchange reactions favoring the dissolution of the hydrogel …


Monolithic Chalcogenide Optical Nanocomposites Enable Infrared System Innovation: Gradient Refractive Index Optics, Myungkoo Kang, Laura Sisken, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Claudia Goncalves, Cesar Blanco, Peter Wachtel, J. David Musgraves, Alexej V. Pogrebnyakov, Erwan Baleine, Clara Rivero-Baleine, Theresa S. Mayer, Carlo G. Pantano, Kathleen A. Richardson May 2020

Monolithic Chalcogenide Optical Nanocomposites Enable Infrared System Innovation: Gradient Refractive Index Optics, Myungkoo Kang, Laura Sisken, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Claudia Goncalves, Cesar Blanco, Peter Wachtel, J. David Musgraves, Alexej V. Pogrebnyakov, Erwan Baleine, Clara Rivero-Baleine, Theresa S. Mayer, Carlo G. Pantano, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

The size and weight of conventional imaging systems is defined by costly non-planar lenses and the complex lens assemblies required to minimize optical aberrations. The ability to engineer gradient refractive index (GRIN) optics has the potential to overcome constraints of traditional homogeneous lenses by reducing the number of components in optical systems. Here, an innovative strategy to realize this goal based on monolithic GRIN media created in Ge-As-Se-Pb chalcogenide infrared nanocomposites is presented. A gradient heat treatment to spatially modulate the volume fraction of high refractive index Pb-rich nanocrystals within a glass matrix is utilized, providing a GRIN profile while …


Spherical Cavity Expansion Approach For The Study Of Rigid-Penetrator’S Impact Problems, Mario Buchely, Alejandro Marañon May 2020

Spherical Cavity Expansion Approach For The Study Of Rigid-Penetrator’S Impact Problems, Mario Buchely, Alejandro Marañon

Materials Science and Engineering Faculty Research & Creative Works

In recent years, Spherical Cavity Expansion (SCE) theory has been extensively utilized to model dynamic deformation processes related to indentation and penetration problems in many fields. In this review, the SCE theory is introduced by explaining the different mathematical features of this theory, its solution, and a potential application to model the penetration of a rigid penetrator into a deformable target. First, a chronologically literature review of the most common models used to study this kind of penetration problems is introduced, focusing on the SCE theory. Then, the engineering model of penetration is presented using the SCE approach. The model …


Size-Dependent Inhibitory Effects Of Antibiotic Nanocarriers On Filamentation Of E. Coli, Preeyaporn Songkiatisak, Feng Ding, Pavan Kumar Cherukuri, Xiao-Hong Nancy Xu May 2020

Size-Dependent Inhibitory Effects Of Antibiotic Nanocarriers On Filamentation Of E. Coli, Preeyaporn Songkiatisak, Feng Ding, Pavan Kumar Cherukuri, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Multidrug membrane transporters exist in both prokaryotic and eukaryotic cells and cause multidrug resistance (MDR), which results in an urgent need for new and more effective therapeutic agents. In this study, we used three different sized antibiotic nanocarriers to study their mode of action and their size-dependent inhibitory effects against Escherichia coli (E. coli). Antibiotic nanocarriers (AgMUNH–Oflx NPs) with 8.6 × 102, 9.4 × 103 and 6.5 × 105 Oflx molecules per nanoparticle (NP) were prepared by functionalizing Ag NPs (2.4 ± 0.7, 13.0 ± 3.1 and 92.6 ± 4.4 nm) with a monolayer …


In-Service Performance Evaluation Of Concrete Sloped End Treatments In Iowa, Jessica Lingenfelter May 2020

In-Service Performance Evaluation Of Concrete Sloped End Treatments In Iowa, Jessica Lingenfelter

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Sloped end treatments were historically developed as low-cost, low-maintenance end treatments for rigid features like concrete barriers and bridge rails. Crash testing indicated that sloped end treatments are associated with significant instability for impacting vehicles. However, the in-service performance of these features has not been evaluated. An in-service performance evaluation (ISPE) was performed to evaluate vehicle crashes with sloped end treatments in Iowa between 2008 and 2017. Researchers generated a geographic inventory of sloped end treatment locations, reviewed crash narratives and scene diagrams for crashes near these sloped end treatments, and calculated an estimated crash rate and crash cost for …


Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh May 2020

Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh

Electronic Theses and Dissertations

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder …


Selective Laser Melting 17-4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson May 2020

Selective Laser Melting 17-4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson

Electronic Theses and Dissertations

Fatigue failure is the leading source of loss in industry. In order for new means of manufacturing to move towards mainstream use a complete understanding of material and mechanical behavior must be gained. This endeavor seeks to aide in that task by observing the fatigue behavior of selective laser melting (SLM) additive manufacturing (AM) specimens and the effect of differing thermal treatment conditions for an optimized AM process. Stainless steel 17-4 PH specimens were fabricated using SLM AM and thermally treated to three conditions: as-built, solutionized and hardened, and direct hardened. These specimens were characterized for material (powder quality, density, …


Investigation On The Morphology Of Charge-Transfer Complexes In Low Density Polyethylene, Wade Korf May 2020

Investigation On The Morphology Of Charge-Transfer Complexes In Low Density Polyethylene, Wade Korf

Master's Theses

Fillers are used ubiquitously throughout the fields of polymer and material science to overcome many inherent limitations to polymeric materials (i.e. poor stiffness or strength) and to expand their potential applications. There is a need to develop controllable particle architectures to better understand fundamental structure-property relationships in particle reinforced polymer composites. Charge-transfer complexes (CTCs) can assemble in situ into various needle and dendritic shapes via simple fabrication processes and at low loading levels. In this study, the effect of tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) CTC crystallites of various shapes and sizes on composite mechanical properties was investigated in an LDPE …


Effects Of Polytetrafluoroethylenemicro–Particles On Mechanical Andtribological Properties Of Glass Fiberreinforced Polyoxymethylene, Kunnan Singh Jasbir Singh May 2020

Effects Of Polytetrafluoroethylenemicro–Particles On Mechanical Andtribological Properties Of Glass Fiberreinforced Polyoxymethylene, Kunnan Singh Jasbir Singh

Student Works (2020-2029)

Reinforcing polyoxymethylene (POM) with glass fibers (GF) enhances its mechanical properties, but at the expense of tribological performance. Formation of a transfer film to facilitate tribo–contact is compromised due to the abrasiveness of GF. As a solid lubricant, for example, polytetrafluoroethylene (PTFE) significantly improves friction and wear resistance. The effects of chemically etched PTFE micro–particles on the fiber– matrix interface of POM/GF/PTFE composites have not been systematically characterized. This research investigated the effects of PTFE micro–particles on mechanical and tribological properties of POM/GF/PTFE composites. Since PTFE is immiscible with most polymers, the surface was etched using sodium naphthalene salt dissolved …


Selfsame Epoxide-Amine Microparticle Systems: Investigation Of Crosslink Density, John J. Peyrefitte May 2020

Selfsame Epoxide-Amine Microparticle Systems: Investigation Of Crosslink Density, John J. Peyrefitte

Honors Theses

Epoxide-amine matrix materials containing microparticles with the same chemical composition provide a model system to study interphase formation in highly crosslinked epoxide-amine matrix materials. The epoxide monomer was varied between three different monomer systems to study the model system’s relationship with crosslink density. The same amine monomer, cure procedure, and stoichiometric ratio of epoxide and amine groups were used to prepare each type of microparticle and matrix material. The differences in the epoxide monomer structure affected the crosslink density of the unmodified matrix material, which was concluded to influence the effect of microparticle presence on crosslink density. For the unmodified …


Chemical And Electronic Surface Structure Of Chalcopyrite-Based Thin Films For Solar Water Splitting, James C. Carter May 2020

Chemical And Electronic Surface Structure Of Chalcopyrite-Based Thin Films For Solar Water Splitting, James C. Carter

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, various thin film solar devices have reached markedly high efficiencies on both the laboratory and large area scale. To further evaluate their potential, and help drive device optimization of efficient solar devices, a detailed understanding of the chemical and electronic structure of the surfaces and interfaces is required. It is these interfaces that play a pivotal role in dictating aspects of device performance. Chalcopyrite-based materials, such as Cu(In,Ga)S2 (CIGS) are regarded as one of the most promising absorber materials for use in highly efficient solar devices. In the context of photoelectrochemical (PEC) hydrogen generation, the tunability of …


Antibacterial And Anticancer Activity Of Hydrothermally-Synthesized Zinc Oxide Nanomaterials Using Natural Extracts Of Neem, Pepper And Turmeric As Solvent Media, C. Abinaya, R. Manjula Devi, P. Suresh, N. Balasubramanian, N. Muthaiya, N. D. Kannan, J. Annaraj, V. Shanmugaiah, Joshua Pearce, P. Shanmugapriya, J. Mayandi Apr 2020

Antibacterial And Anticancer Activity Of Hydrothermally-Synthesized Zinc Oxide Nanomaterials Using Natural Extracts Of Neem, Pepper And Turmeric As Solvent Media, C. Abinaya, R. Manjula Devi, P. Suresh, N. Balasubramanian, N. Muthaiya, N. D. Kannan, J. Annaraj, V. Shanmugaiah, Joshua Pearce, P. Shanmugapriya, J. Mayandi

Michigan Tech Publications, Part 1

A novel and simple wet chemical hydrothermal synthesis method was employed in the preparation of zinc oxide (ZnO) nanoparticles using neem (N), pepper (P) and turmeric (T) extracts as solvent media. The structural and optical properties as well as the antibacterial and anticancer properties of all the samples (ZnO, N/ZnO, P/ZnO, T/ZnO and NPT/ZnO) were characterized and analyzed. Solvent media was found to have an effect on both the size and the morphology of the nanoparticles, which in turn effected their optical and cytotoxic properties. The colony forming unit (CFU) assays were done for E. coli, S. aureus and S. …


Development Of A Novel Vehicle Guidance System: Vehicle Risk Mitigation And Control, Michael Sweigard Apr 2020

Development Of A Novel Vehicle Guidance System: Vehicle Risk Mitigation And Control, Michael Sweigard

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Over a half of fatal vehicular crashes occur due to vehicles leaving their designated travel lane and entering other lanes or leaving the roadway. Lane departure accidents also result in billions of dollars in cost to society. Recent vehicle technology research into driver assistance and vehicle autonomy has developed to assume various driving tasks. However, these systems are do not work for all roads and travel conditions. The purpose of this research study was to begin the development a novel vehicle guidance approach, specifically studying how the vehicle interacts with the system to detect departures and control the vehicle

A …


Syntheses And Properties Of Ta5+ Doped Li7La3Zr2O12, Feng-Feng Peng, Shi-You Li, Tong-Tong Geng, Chun-Lei Li, Shuang-Wei Zeng Apr 2020

Syntheses And Properties Of Ta5+ Doped Li7La3Zr2O12, Feng-Feng Peng, Shi-You Li, Tong-Tong Geng, Chun-Lei Li, Shuang-Wei Zeng

Journal of Electrochemistry

The tantalum ion (Ta 5+) doped garnet-type inorganic solid electrolyte Ta-LLZO was prepared by solid state reaction, and the effect of doping amount on the properties of the materials was investigated. The materials were characterized by X-ray diffraction (XRD), field emission electron scanning microscopy (FESEM) and electrochemical impedance spectroscopy (EIS). And the cycle stability was tested by assembly of LiFePO4//LLZTO//Li all solid lithium battery. The results show that with the increase of Ta 5+ doping amount, the material appeared to form a single cubic phase structure. When the Ta 5+ doping content became 14.09wt.%, x=0.3, the …


Preparation And Characterization Of Cathode Supported Solid Oxide Fuel Cell, Xiao-Nan Bao, Guang-Jun Zhang, Shao-Rong Wang Apr 2020

Preparation And Characterization Of Cathode Supported Solid Oxide Fuel Cell, Xiao-Nan Bao, Guang-Jun Zhang, Shao-Rong Wang

Journal of Electrochemistry

A site deficient (La0.8Sr0.2)0.95MnO3 (LSM95) powder was synthesized by solid state reaction as a cathode material. The commercial Zr0.9Sc0.1SO1.95 (SSZ) was selected as an electrolyte material and La0.8Sr0.2Cr0.5Mn0.5O3- (LSCrM) was synthesized by sol-gel method as an anode material. Accordingly, single cells of LSCrM-CeO2|SSZ|3YSZ-LSM95 were prepared by tape casting, sintering and impregnation. The single cell test results for LSCrM-CeO2|SSZ|3YSZ-LSM95 with 0.11 g·cm -2 CeO2 and using CH4 as a fuel showed the power …


Research Progress Of Fuel Electrode In Oxide-Ion Conducting Solid Oxide Electrolysers, Ling-Ting Ye, Kui Xie Apr 2020

Research Progress Of Fuel Electrode In Oxide-Ion Conducting Solid Oxide Electrolysers, Ling-Ting Ye, Kui Xie

Journal of Electrochemistry

Solid oxide electrolysers are now attracting much more attentions because they can efficiently produce fuels by electrolyzing H2O/CO2. In this paper, a comprehensive introduction to the recent progress in the development of fuel electrode (cathode) materials is provided. The advantages, disadvantages and development trend towards various cathode materials are pointed out. The key scientific and technological problems in this field are emphasized.


Perovskite Catalysts For Fuel Reforming In Sofc:A Review And Perspective, Tong Wei, Jian Li, Li-Chao Jia, Bo Chi, Jian Pu Apr 2020

Perovskite Catalysts For Fuel Reforming In Sofc:A Review And Perspective, Tong Wei, Jian Li, Li-Chao Jia, Bo Chi, Jian Pu

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) is a generating device by electrochemical reaction to transfer the chemical energy of fossil fuels (coal, oil and gas, etc.), the biomass fuel or other hydrocarbon fuels directly into electricity with higher energy conversion efficiency and lower pollution, which is recognized to be efficient green energy technology in the 21st century. However, when hydrocarbons are directly used as fuel, carbon deposition is easy to occur in nickel-based anode, thus, losing electrochemical catalytic activity. Fuel pre-reforming on the outside of the anode is an effective solution, which strongly relies on highly efficient and stable reforming catalysts. …


Construction And Electrochemical Performance Of Garnet-Type Solid Electrolyte/Al-Li Alloy Interface, Jia-Lin Ma, Hong-Chun Wang, Zheng-Liang Gong, Yong Yang Apr 2020

Construction And Electrochemical Performance Of Garnet-Type Solid Electrolyte/Al-Li Alloy Interface, Jia-Lin Ma, Hong-Chun Wang, Zheng-Liang Gong, Yong Yang

Journal of Electrochemistry

Garnet-type solid electrolyte is a newly developed Li ion conductor and promising in the application of all-solid-state batteries. However, Garnet is incompatible with Li anode, which restricts the application of Garnet-type solid batteries. In order to improve the contact between Garnet-type solid electrolyte and Li electrode, a composite anode which contains Al-Li alloy (Al4Li9) was prepared as an electrode. Al-Li alloy has many advantages such as easy preparation, low cost, simple post-treatment and high capacity. Garnet-type Li6.5La3Zr1.75W0.25O12 (LLZWO) was synthesized via solid-state reaction. Garnet solid electrolyte has …


Evaluation And Update Of Mash Test Vehicles, Kellon B. Ronspies Apr 2020

Evaluation And Update Of Mash Test Vehicles, Kellon B. Ronspies

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The Manual for Assessing Safety Hardware (MASH) requires full-scale crash testing of roadside features using worst practical impact conditions. Vehicle selection for full-scale crash testing is intended to be representative of the contemporary passenger vehicle fleet. Researchers at the Midwest Roadside Safety Facility (MwRSF) investigated attributes of passenger vehicle sales to determine if the vehicle selection criteria shown in MASH should be revised to accommodate changes in the vehicle fleet. A methodology was considered to affordably re-analyze the vehicle fleet when necessary to ensure MASH vehicle selection criteria are reflective of vehicles currently on roadways.

Representative vehicles were documented using …


Direct Carbon Solid Oxide Fuel Cells, Jiang Liu, Xiao-Min Yan Apr 2020

Direct Carbon Solid Oxide Fuel Cells, Jiang Liu, Xiao-Min Yan

Journal of Electrochemistry

Carbon is richly reserved in coal, biomasses, and many other nature resources. It is usually used as an energy source through oxygen oxidation reaction. The oxidation is generally realized through combustion which causes serious air pollution. Besides, the conversion efficiency of generating electricity through the combustion process is limited by Carnot efficiency. A direct carbon solid oxide fuel cell (DC-SOFC) is a solid oxide fuel cell (SOFC) directly operated with solid carbon as the fuel. It can convert the chemical energy of carbon into electricity with high efficiency. The concentration of produced CO2 from a DC-SOFC is so high …


Research Progress In Ethane Dehydrogenation To Cogenerate Power And Value-Added Chemicals In Solid Oxide Fuel Cells, Yun Fan, Qi Wang, Jun Li, Jing-Li Luo, Xian-Zhu Fu Apr 2020

Research Progress In Ethane Dehydrogenation To Cogenerate Power And Value-Added Chemicals In Solid Oxide Fuel Cells, Yun Fan, Qi Wang, Jun Li, Jing-Li Luo, Xian-Zhu Fu

Journal of Electrochemistry

Increasing supplies of methane/shale gas have promoted global development of higher value chemicals such as ethylene production by ethane, which dramatically changes the markets of petrochemical industry. Clean and efficient transformation of ethane into higher value chemicals has far-reaching significance. Ethylene production through ethane steam cracking is a relatively matured technology for industrial production. However, the process consumes large amounts of energy and the presence of carbon deposition becomes a serious problem which is difficult to be solved. The cogenerated energy-chemicals solid oxide fuel cells have been widely studied because fuel gas can be converted into high-value chemicals via spontaneous …


Development Status And Prospects Of Hydrogen Production By High Temperature Solid Oxide Electrolysis, Wen-Qiang Zhang, Bo Yu Apr 2020

Development Status And Prospects Of Hydrogen Production By High Temperature Solid Oxide Electrolysis, Wen-Qiang Zhang, Bo Yu

Journal of Electrochemistry

Solid oxide electrolysis cell is an advanced energy conversion device with high efficiency, simplicity, flexibility, and environmental friendliness. It is currently a research hotspot in the international energy field. This paper introduces and analyzes the basic principles, key materials, system components and developments of solid oxidation electrolysis cells. Furthermore, the recent research progresses, challenges and future development directions in solid oxidation electrolysis cells in the field of high-efficiency hydrogen production are summarized and outlined.


Materials, Micro-Stacks And Related Applications Of Single-Chamber Solid Oxide Fuel Cells, Zhe Lv, Bo Wei, Zhi-Hong Wang, Yan-Ting Tian Apr 2020

Materials, Micro-Stacks And Related Applications Of Single-Chamber Solid Oxide Fuel Cells, Zhe Lv, Bo Wei, Zhi-Hong Wang, Yan-Ting Tian

Journal of Electrochemistry

Single-chamber solid oxide fuel cell (SC-SOFC) is a special type of fuel cells, in which both an anode and a cathode are placed in one chamber. Its working principle relies on the selective catalytic activity of the electrodes towards fuel and oxidant in a gas mixture, leading to the generation of an electromotive force. Because of its unique principle and structure, SC-SOFC has many advantages such as sealing-free, easy stacking, quick start-up and no carbon deposition, thus, it possesses large potential in application. Herein, the principles and characteristics of SC-SOFC are introduced. Furthermore, the SC-SOFC materials, micro-stack design, degeneration mechanisms …


Recent Advances Of Co2 Electrochemical Reduction In Solid Oxide Electrolysis Cells, Yi-Hang Li, Chang-Rong Xia Apr 2020

Recent Advances Of Co2 Electrochemical Reduction In Solid Oxide Electrolysis Cells, Yi-Hang Li, Chang-Rong Xia

Journal of Electrochemistry

Solid oxide electrolysis cells (SOECs) have stimulated wide interests for their promising application in the reduction of CO2 emissions and the storage of renewable energy. Here, the advances made in the development of cathode materials including cermets and perovskite oxides in our research group, are summarized, along with the design of cell configurations. The electrochemical kinetics and performances of cathodes and cells are discussed and analyzed. It is expected that this brief review offers critical insights and useful guidelines for developing superior electrodes and SOECs in the future.


Electrochemical Performance Improvement Of Li2Mno3 Cathode Materials By Mgf2 Coating, Du-Dan Wang, Fei Wang, Huan-Huan Zhai, Yu-Peng Li, Na-Chuan Yang, Kang-Hua Chen Apr 2020

Electrochemical Performance Improvement Of Li2Mno3 Cathode Materials By Mgf2 Coating, Du-Dan Wang, Fei Wang, Huan-Huan Zhai, Yu-Peng Li, Na-Chuan Yang, Kang-Hua Chen

Journal of Electrochemistry

Cathode material Li2MnO3 has received more and more attention owing to its high theoretical capacity (459 mAh·g -1). However, the low initial coulombic efficiency and the poor cycle stability hamper its practical application in lithium-ion batteries. Herein, we investigated the crystal structure and electrochemical performance of Li2MnO3 by introducing MgF2 coating layer. The results indicated that the conversion of partial layer Li2MnO3 to spinel phase induced by MgF2 coating could reduce the initial irreversible capacity and improve the first cycle efficiency. The initial coulombic efficiencies of the 0.5wt.%, …


Nio@Rgo Supported Palladium And Silver Nanoparticles As Electrocatalysts For Oxygen Reduction Reaction, Shuo Yao, Tai-Zhong Huang, Rizwan Haider, Heng-Yi Fang, Jie-Mei Yu, Zhan-Kun Jiang, Dong Liang, Yue Sun, Xian-Xia Yuan Apr 2020

Nio@Rgo Supported Palladium And Silver Nanoparticles As Electrocatalysts For Oxygen Reduction Reaction, Shuo Yao, Tai-Zhong Huang, Rizwan Haider, Heng-Yi Fang, Jie-Mei Yu, Zhan-Kun Jiang, Dong Liang, Yue Sun, Xian-Xia Yuan

Journal of Electrochemistry

For pervasive applications of fuel cells, highly efficient and economical materials are required to replace Pt-based catalysts for oxygen reduction reaction (ORR). In this study, the NiO@rGO, Pd-NiO@rGO and Ag-NiO@rGO nanoparticles were synthesized, and their catalytic performances toward ORR were investigated. The results revealed that all the three materials were capable of catalyzing ORR, but both the Pd-NiO@rGO and Ag-NiO@rGO showed the better performances compared with the NiO@rGO in terms of the reaction pathway being 4-electron process, the increases of the onset potential and the intermediate yielding rate, as well as the extended stability. Moreover, the effect of Pd modification …


Designing An Adjustable And Transportable Staircase, Allison Currey Apr 2020

Designing An Adjustable And Transportable Staircase, Allison Currey

Undergraduate Honors Thesis Projects

People climb stairs every day, whether it is at work, a store, or at home; however, there are populations such as people who are elderly, with pathologies, with Parkinson’s disease, or have suffered from a stroke that see climbing the stairs as a challenging task and it decreases their mobility and quality of life. Factors such as muscle weakness, strategy, and balance have been previously investigated in these populations during stair climbing. However, few studies have researched how stair climb ability, balance, and perception of difficulty are influenced by step height. The objective of this thesis is to design a …


Faculty Instruction Face Shield Project, David Holden, John Schneiderhan Apr 2020

Faculty Instruction Face Shield Project, David Holden, John Schneiderhan

Michigan Tech 3D Designs

Early in the spring of 2020 project contributors David Holden and John Schneiderhan began test printing a variety of open source Personal Protective Equipment (PPE)/Covid related items that could help protect or prevent the spread of the emerging virus. With assistance from Pete Baril of the Western Upper Peninsula Health Department (WUPHD) approval was obtained for the face shields to be used in the health care and nursing homes in the area. With the support and approval from university and library administration efforts were coordinated with Dr. Joshua Pearce and the students from the MOST lab to concentrate on the …


On-Chip Terahertz Modulation And Emission With Integrated Graphene Junctions, Joshua O. Island, Peter Kissin, Jacob Schalch, Xiaomeng Cui, Sheikh Rubaiat Ui Haque, Alex Potts, Takashi Taniguchi, Kanji Watanabe, Richard D. Averitt, Andrea F. Young Apr 2020

On-Chip Terahertz Modulation And Emission With Integrated Graphene Junctions, Joshua O. Island, Peter Kissin, Jacob Schalch, Xiaomeng Cui, Sheikh Rubaiat Ui Haque, Alex Potts, Takashi Taniguchi, Kanji Watanabe, Richard D. Averitt, Andrea F. Young

Physics & Astronomy Faculty Research

The efficient modulation and control of ultrafast signals on-chip is of central importance in terahertz (THz) communications and a promis- ing route toward sub-diffraction limit THz spectroscopy. Two-dimensional (2D) materials may provide a platform for these endeavors. We explore this potential, integrating high-quality graphene p–n junctions within two types of planar transmission line circuits to modulate and emit picosecond pulses. In a coplanar strip line geometry, we demonstrate the electrical modulation of THz signal transmission by 95%. In a Goubau waveguide geometry, we achieve complete gate-tunable control over THz emission from a photoexcited graphene junction. These studies inform the development …