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2020

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Articles 61 - 90 of 166

Full-Text Articles in Nanoscience and Nanotechnology

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman May 2020

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman

Macalester Journal of Physics and Astronomy

Glancing angle deposition (GLAD) is a process in which thin films are deposited onto a substrate with obliquely incident vapor together with precisely controlled azimuthal substrate rotation. Ballistic shadowing effects due to the oblique incidence produce nanoscale structures, and a variety of feature shapes, including tilted columns, helices, and vertical columns can be achieved by varying the azimuthal rotation during the deposition process. Due to this control of morphology and the compatibility of the process with a wide variety of materials, GLAD films have found applications in a variety of fields including sensing, photonics, photovoltaics, and catalysis, where they are …

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The Artificial Leaf: An Investigation Into The Sociotechnical Integration Of New Solar Energy Innovations, Alexandra K. Treml, Jamie M. Mears May 2020

The Artificial Leaf: An Investigation Into The Sociotechnical Integration Of New Solar Energy Innovations, Alexandra K. Treml, Jamie M. Mears

Senior Honors Projects, 2020-current

Increasing global demand, combined with the volatility of fossil fuels, has called for a large-scale increase in renewable energy production. Photovoltaics hold significant potential, but by nature, solar energy is intermittent and lacks dispatchability. Researchers around the world are working to create innovative solutions that utilize semiconductors found in solar cell technologies in new ways. This project harnesses photoelectrochemical water-splitting, which uses light energy to dissociate water molecules into hydrogen and oxygen. When the water-splitting device is submerged in saltwater and illuminated by sunlight, oxygen and hydrogen gas are produced on opposite surfaces, and can be either released or stored …

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Probing Nanoelectroporation And Resealing Of The Cell Membrane By The Entry Of Ca2+ And Ba2+ Ions, Wenfei Bo, Mantas Silkunas, Uma Mangalanathan, Vitalij Novickij, Maura Casciola, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Andrei G. Pakhomov May 2020

Probing Nanoelectroporation And Resealing Of The Cell Membrane By The Entry Of Ca2+ And Ba2+ Ions, Wenfei Bo, Mantas Silkunas, Uma Mangalanathan, Vitalij Novickij, Maura Casciola, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Andrei G. Pakhomov

Bioelectrics Publications

The principal bioeffect of the nanosecond pulsed electric field (nsPEF) is a lasting cell membrane permeabilization, which is often attributed to the formation of nanometer-sized pores. Such pores may be too small for detection by the uptake of fluorescent dyes. We tested if Ca2+, Cd2+, Zn2+, and Ba2+ ions can be used as nanoporation markers. Time-lapse imaging was performed in CHO, BPAE, and HEK cells loaded with Fluo-4, Calbryte, or Fluo-8 dyes. Ca2+ and Ba2+ did not change fluorescence in intact cells, whereas their entry after nsPEF increased fluorescence within <1 ms. The threshold for one 300-ns pulse was at 1.5–2 kV/cm, much lower than >7 …

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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 …

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Characterization Of Avidin And Case9 Single Protein Molecules By A Solid-State Nanopore Device, Haopeng Li May 2020

Characterization Of Avidin And Case9 Single Protein Molecules By A Solid-State Nanopore Device, Haopeng Li

Graduate Theses and Dissertations

The shape and charge of a protein play significant roles in protein dynamics in the biological system of humans and animals. Characterizing and quantifying the shape and charge of a protein at the single-molecule level remains a challenge. Solid-state nanopores made of silicon nitride (SiNx) have emerged as novel platforms for biosensing such as diagnostics for single-molecule detection and DNA sequencing. SSN detection is based on measuring the variations in ionic conductance as charged biomolecules translocate through nanometer-sized channels driven by an external voltage applied across the membrane. In this paper, we observe the translocation of asymmetric cylindrical structure CRISPR-Cas9 …

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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 …

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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 …

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Quantifying Wicking In Functionlized Surfaces, Maureen Winter, Ryan Regan, Alfred Tsubaki, Craig Zuhlke, Dennis Alexander, George Gogos Apr 2020

Quantifying Wicking In Functionlized Surfaces, Maureen Winter, Ryan Regan, Alfred Tsubaki, Craig Zuhlke, Dennis Alexander, George Gogos

UCARE: Research Products

Wicking remains the enigmatic key factor in many research areas. From boiling in power plants, to anti-icing on plane wings, to medical instruments, to heat pipes, efficiency and safety depend on how quickly a surface becomes wet. Yet wicking remains difficult to quantify and define as a property of the surface. This experiment strives to measure the wicking property by examining the rate that a liquid can be pulled out of a container. A superhydrophilic surface is placed in contact with the liquid at the bottom of a tube so that the volume flow rate across the surface can be …

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Hybrid Electro-Plasmonic Stimulation Of Primary Neurons, Ratka Damnjanovic Apr 2020

Hybrid Electro-Plasmonic Stimulation Of Primary Neurons, Ratka Damnjanovic

USF Tampa Graduate Theses and Dissertations

Biomedical prosthetics utilizing electrical stimulation have limited, effective spatial resolution due to spread of electrical currents to surrounding tissue, causing nonselective stimulation. So, precise spatial resolution is not possible for traditional neural prosthetic devices, such as cochlear implants. More recently, alternative methods utilize optical stimulation, mainly infrared, sometimes paired with nanotechnology for stimulating action potentials, which has its own drawbacks, as it may heat surrounding tissue. Recently, we employed plasmonic stimulation methods utilizing gold nanoparticle-coated nanoelectrodes to convert visible light pulses into localized surface plasmon resonance transduction for stimulation of electrically excitable cells, which had limited success. Here, we report …

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Enhanced Carrier Transport By Transition Metal Doping In Ws2 Field Effect Transistors, Maomao Liu, Sichen Wei, Simran Shahi, Hemendra Nath Jaiswal, Paolo Paletti, Sara Fathipour, Maja Remskar, Jun Jiao, Wansik Hwang, Fei Yao, Huamin Li Apr 2020

Enhanced Carrier Transport By Transition Metal Doping In Ws2 Field Effect Transistors, Maomao Liu, Sichen Wei, Simran Shahi, Hemendra Nath Jaiswal, Paolo Paletti, Sara Fathipour, Maja Remskar, Jun Jiao, Wansik Hwang, Fei Yao, Huamin Li

Physics Faculty Publications and Presentations

High contact resistance is one of the primary concerns for electronic device applications of two-dimensional (2D) layered semiconductors. Here, we explore the enhanced carrier transport through metal–semiconductor interfaces in WS2 field effect transistors (FETs) by introducing a typical transition metal, Cu, with two different doping strategies: (i) a “generalized” Cu doping by using randomly distributed Cu atoms along the channel and (ii) a “localized” Cu doping by adapting an ultrathin Cu layer at the metal–semiconductor interface. Compared to the pristine WS2 FETs, both the generalized Cu atomic dopant and localized Cu contact decoration can provide a Schottky-to-Ohmic contact …

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Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan Apr 2020

Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan

Student Works (2020-2029)

The present research is aimed to investigate the effect of varying the carbonate to phosphate (CO32−/ PO43‒) molar ratios from 0.5 to 5 on the physical and mechanical properties of carbonated hydroxyapatite (CHA) synthesized by a wet chemical method. The sintering was performed under dry carbon dioxide atmosphere at 900 °C to maintain the B-type CHA structure. It was found that increases in CO32−/ PO43‒ ratio was accompanied by an increase in the c/a lattice ratio. The diffraction peaks of the synthesized 0.5-5 CHA powders exhibited a single phase material except for 5CHA which revealed the some minor calcite or …

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Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns Apr 2020

Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns

University Honors Theses

The application of silicon nanoparticles varies from energy storage materials, to drug-delivery, and molecular recognition. Various chemical and physical properties of the Si nanoparticles arise from their morphology. This paper aims to reveal the morphology of Si nanoparticles following magnesiothermic reduction of silica (SiO2) nanoparticles. Two sets of SiO2 nanoparticles were used, commercially available NanoXact nanoparticles and laboratory-synthesized Stöber nanoparticles. A Zeiss Sigma VP FEG SEM was used to examine the morphology. Following the magnesiothermic reduction, the nanoparticles were etched with HF. Ten sets of images were taken of both Stöber and NanoXact nanoparticles: 1,2: the SiO …

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Highly Transmissive Scalable Colored Coatings For Architectural Photovoltaic Panels, Akbar Ali Syed Apr 2020

Highly Transmissive Scalable Colored Coatings For Architectural Photovoltaic Panels, Akbar Ali Syed

Electrical & Computer Engineering Theses & Dissertations

Highly transmissive coatings were developed by fabricating thin films using SiO2 and SiO2/TiO2 core/shell nanoparticles on glass substrates and on the photovoltaic cell glass covers. This coating is to maintain an attractive color appearance of the exterior surface for architecturally integrated photovoltaics and can be coated on fabricated photovoltaic panels. The color and optical properties of the nanoparticle coating was investigated for different nanoparticle diameters of 200-400 nm for SiO2 nanoparticles and core/shell nanoparticles having SiO2/TiO2 structure with 300 ± 11 nm diameter, and SiO2/TiO2/SiO2 structure with …

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Role Of Thyroid Hormone Modulating Astrocyte Activation, Payal Ghosh Mar 2020

Role Of Thyroid Hormone Modulating Astrocyte Activation, Payal Ghosh

USF Tampa Graduate Theses and Dissertations

Astrocytes are the specialized cells in the central nervous system (CNS). They play an important role in neuronal homeostasis. When activated, astrocytes may cause neuronal inflammation and degeneration. Thyroid hormones are important in maintaining neuronal development and homeostasis. Astrocytes play a pivotal role in this process. However, the role of levothyroxine (T4) in neuroinflammation is not clear. It is hypothesized that thyroid hormone treatment will reduce the inflammatory activation in astrocytes. Available oral T4 supplementations allow accumulation of T4 in the body and cause toxicity and side effects. It is hypothesized that the encapsulation of T4 in liposomes would reduce …

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A Wirelessly Controlled Smart Bandage With 3d-Printed Miniaturized Needle Arrays, Hossein Derakhshandeh, Fariba Aghabaglou, Alec Mccarthy, Azadeh Mostafavi, Chris Wiseman, Zack Bonick, Ian Ghanavati, Seth Harris, Craig Kreikemeier-Bower, Seyed Masoud Moosavi Basri, Jordan Rosenbohm, Ruiguo Yang, Pooria Mostafalu, Dennis Orgill, Ali Tamayol Mar 2020

A Wirelessly Controlled Smart Bandage With 3d-Printed Miniaturized Needle Arrays, Hossein Derakhshandeh, Fariba Aghabaglou, Alec Mccarthy, Azadeh Mostafavi, Chris Wiseman, Zack Bonick, Ian Ghanavati, Seth Harris, Craig Kreikemeier-Bower, Seyed Masoud Moosavi Basri, Jordan Rosenbohm, Ruiguo Yang, Pooria Mostafalu, Dennis Orgill, Ali Tamayol

Department of Mechanical and Materials Engineering: Faculty Publications

PUBLIC ACCESS

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Luciferase Reporter Crc Cell Line For Bioluminescence Imaging In Orthotopic Tumor Model, Pratik Chopade Mar 2020

Luciferase Reporter Crc Cell Line For Bioluminescence Imaging In Orthotopic Tumor Model, Pratik Chopade

USF Tampa Graduate Theses and Dissertations

CRC is the second most common type of cancer in women and the third most common type of cancer in men. It accounts for 9.7% of all cancers in terms of people diagnosed. Measuring the real-time effect of chemotherapeutic drugs has been a major obstacle in developing a tumor model mouse. Tracking the regression of cancer cells after chemotherapy could be an effective way to resolve this issue. Therefore, cancer cells expressing the constitutive luciferase reporter gene can be a potential solution. The biggest advantage of the luciferase (Luc) reporter is that it is detectable at very low concentrations in …

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Identification Of Snps Associated With Multiple Antibiotic Resistance Genes In Eight Clinical Variants Of Enterococcus Faecium., Krishna S. Karia Mar 2020

Identification Of Snps Associated With Multiple Antibiotic Resistance Genes In Eight Clinical Variants Of Enterococcus Faecium., Krishna S. Karia

USF Tampa Graduate Theses and Dissertations

The evolution of multi drug resistant (MDR) bacteria has been well documented these last decade, suggesting that resistance to antibiotics is most commonly associated to single nucleotide polymorphism (SNPs) mutation. To this aim, several molecular methods have been performed to elucidate SNPs in the increasing number of resistant microorganisms. Early detection of MDR bacteria has become of prime necessity in order to combat the disease and ensure public health. Therefore, this research was conducted to screen for SNP mutations correlated to drug resistance in some nosocomial MDR bacteria strains donated from Moffitt Cancer Center (MCC) hospital. Blood, stool, urine, and …

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A Micro-Nano Particle System For Sustained Drug Release In Lung Cancer Therapy, Heta N. Jadhav Mar 2020

A Micro-Nano Particle System For Sustained Drug Release In Lung Cancer Therapy, Heta N. Jadhav

USF Tampa Graduate Theses and Dissertations

Lung cancer remains the leading cause of cancer-related mortality in men and women worldwide (National Comprehensive Cancer Network). Hence, developing an effective new therapy to treat lung cancer is under intense investigation. Specifically, the sustained release of a drug in lung tumors is critically important. Previous studies at the USF have shown that telmisartan exhibits synergistic properties when combined with Actinomycin-D for lung cancer treatment. The objective of this study is to develop a novel micro/nano system consisting of lipids and chitosan polymers that would be able to deliver Tel directly to the lungs and release its payloads in a …

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Role Of Serum Amyloid P Component In The Pathogenesis Of Chronic Traumatic Encephalopathy, Brittany Urban Mar 2020

Role Of Serum Amyloid P Component In The Pathogenesis Of Chronic Traumatic Encephalopathy, Brittany Urban

USF Tampa Graduate Theses and Dissertations

Serum amyloid P (SAP) component is a glycoprotein that is a major constituent of human serum. SAP has been recognized to stimulate amyloid fibrillogenesis. One way that SAP can be transported to the brain is by passing through the blood brain barrier (BBB). Traumatic brain injury (TBI) and repeated or severe non-penetrating head injury, can escalate the exposure of the brain to SAP, which in turn can contribute to neurodegeneration. TBI can lead to chronic traumatic encephalopathy (CTE) which is a neuropathological condition that has been found in people who have been exposed to repeated head injuries or impacts. In …

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Sunitinib-Loaded Mpeg-Pcl Micelles For The Treatment Of Age-Related Macular Degeneration, Jarriaun D. Streets Mar 2020

Sunitinib-Loaded Mpeg-Pcl Micelles For The Treatment Of Age-Related Macular Degeneration, Jarriaun D. Streets

USF Tampa Graduate Theses and Dissertations

Age-related Macular Degeneration, or AMD will be responsible for the vision impairment of more than 5 million late-aged adults in the next 30 years. Current treatment options include frequent intravitreal injections which report high levels of pain resulting in a low patient compliance. However, there are methods of drug delivery that can decrease the amount of intravitreal injections by sustaining drug release. Polymeric micelles, specifically MPEG-PCL have reported superb biocompatibility and more efficient ways of delivering anti-VEGF drugs such as Sunitinib to the posterior segment of the eye. In this study, the novel micellar formulation exhibited an average DLS particle …

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Synthesis Of A Targeted Ph Responsive Nanoparticle For Controlled Release Of Actinomycin D, Alejandro Jesus Gonzalez Mar 2020

Synthesis Of A Targeted Ph Responsive Nanoparticle For Controlled Release Of Actinomycin D, Alejandro Jesus Gonzalez

USF Tampa Graduate Theses and Dissertations

Out of all cancer diagnosis’s, lung cancer has the highest mortality in both sexes making it the leading cause of cancer deaths. Current therapeutic and clinical methods fail to successfully treat the disease, contributed to the development of multi-drug resistance (MDR). Hence, new therapies are needed that can exploit the tumor microenvironment (TME) to target Cancer Stem Cells (CSC). CSCs constitute a key population of the TME, promoting hypoxia, low intracellular pH, and angiogenesis. Actinomycin D (ACD) is a potent CSC inhibitor, but due to its high toxicity and lack of specificity towards cancer cells presents a need for a …

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Testing Glutathione-S-Transferase Mu 1 (Gstm1) In Protecting Retinal Pigment Epithelium Cells From Oxidative Stress, Inyoung C. Garner Mar 2020

Testing Glutathione-S-Transferase Mu 1 (Gstm1) In Protecting Retinal Pigment Epithelium Cells From Oxidative Stress, Inyoung C. Garner

USF Tampa Graduate Theses and Dissertations

Currently, the most widely available treatment for wet age-related macular degeneration (AMD) involves the intraocular delivery of biopharmaceuticals, such as anti-VEGF therapy. Drawbacks of this treatment includes a short-term efficacy, requiring repeated injections with additional risks, and a limited availability of options for non-responders. Furthermore, there are no treatments available for patients diagnosed with dry-AMD. The drawbacks and limitations of current therapies represent a need for more effective and permanent therapy as the prevalence of the population affected by AMD is growing. Antioxidant gene therapies are one solution to these implications, protecting the cells from oxidative stress which is one …

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Amino Acid Quantification For Dmc Biotechnologies, Russell Beckerman, Rebecca Hines, Kenya Jacob, Megan Mccabe, Ju Yun Lee Mar 2020

Amino Acid Quantification For Dmc Biotechnologies, Russell Beckerman, Rebecca Hines, Kenya Jacob, Megan Mccabe, Ju Yun Lee

ENGS 89/90 Reports

From pharmaceuticals to biofuels, fermentation bioprocessing has gained traction in many industries reaching a global market value of almost $60 billion in 2018. However, applications of bioprocessing have been limited in scope due to high capital costs, long development times, and difficulties maintaining productivity during scale-up. Furthering development and scale-up of fermentation bioprocesses require careful monitoring and control through analytical chemistry. Currently, there are no small molecule quantification techniques that are sufficiently accurate, inexpensive, and high-throughput. This investigation explores viability of a novel quantification assay for amino acids in fermentation broth leveraging molecularly imprinted polymers (MIPs) and gold nanoparticles (AuNPs).

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Laser Induced Thermal Degradation Of Carbon Fiber-Carbon Nanotube Hybrid Laminates, Joshua A. Key Mar 2020

Laser Induced Thermal Degradation Of Carbon Fiber-Carbon Nanotube Hybrid Laminates, Joshua A. Key

Theses and Dissertations

Recent advancements in fiber laser technology have increased interest in target material interactions and the development of thermal protection layers for tactical laser defense. A significant material of interest is carbon fiber reinforced polymers due to their increased use in aircraft construction. In this work, the thermal response of carbon fiber-carbon nanotube (CNT) hybrid composites exposed to average irradiances of 0.87-6.8 W/cm2 were observed using a FLIR sc6900 thermal camera. The camera had a pixel resolution of 640x512 which resulted in a spatial resolution of 0.394x0.383 mm/pixel for the front and 0.463x0.491 mm/pixel for the back. The hybrid samples …

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Electrochemical Impedance Spectroscopy For Electrocatalytic Interfaces And Reactions: Classics Never Die, Jun Huang Feb 2020

Electrochemical Impedance Spectroscopy For Electrocatalytic Interfaces And Reactions: Classics Never Die, Jun Huang

Journal of Electrochemistry

This review article recapitulates electrochemical impedance spectroscopy (EIS) studies in the field of electrocatalysis. The history of this specialized field, ranging from the beginning of the twentieth century to now, is outlined. We then chronicle milestones of the impedance theory. Special emphases are put on the Dolin-Ershler model, the prevailing model for analyzing adsorption impedance data. Afterwards, we narrow into a very specific and fundamental topic, the double-layer capacitance at platinum (Pt) single crystals. We discuss the challenges in experimentation and theoretical understanding thereof. We cast doubts into the validity of using the Dolin-Ershler model to obtain the double-layer capacitance …

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Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun Feb 2020

Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun

Journal of Electrochemistry

The performance of catalysts highly depends on their surface structure and composition. Nanocrystals bounded by high-index facets usually exhibit high catalytic activity due to their high-density low-coordinated step atoms with high reactivity. In this paper, we have reviewed the preparations of noble metals (e.g., Pt, Pd and Rh) nanocatalysts with high-index facets by electrochemical square-wave potential method developed in our group. The square-wave potential method includes a nucleation procedure to generate nuclei, followed by a square-wave potential procedure for a certain period of time for the growth of nuclei into nanocrystals. The formation mechanism of high-index facets is also discussed. …

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In-Situ Raman Spectroscopic Study Of Electrochemical Reactions At Single Crystal Surfaces, Min Su, Jin-Chao Dong, Jian-Feng Li Feb 2020

In-Situ Raman Spectroscopic Study Of Electrochemical Reactions At Single Crystal Surfaces, Min Su, Jin-Chao Dong, Jian-Feng Li

Journal of Electrochemistry

Since the 1970s, in-situ spectroscopy (Raman, infrared, etc.) has been used to systematically study the electrochemical interfacial reactions which can provide more information about surface reactions and reveal the mechanisms from microscopic view due to its excellent surface sensitivity and energy resolution. With the development of nano-technology, surface-enhanced Raman scattering effect spectroscopy has made rapid progress. Recently, the emergence of SHINERS provides a good in-situ spectroscopic technique for the study of catalytic reactions on single crystal model electrodes with deterministic surface structure. In this paper, we have summarized the application of SHINERS in the study of …

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Cycle-To-Cycle Flow Variations In A Square Duct With A Symmetrically Oscillating Constriction, Erica Sherman, Lori M. Lambert, Bethany White, Michael H. Krane, Timothy Wei Feb 2020

Cycle-To-Cycle Flow Variations In A Square Duct With A Symmetrically Oscillating Constriction, Erica Sherman, Lori M. Lambert, Bethany White, Michael H. Krane, Timothy Wei

Department of Mechanical and Materials Engineering: Faculty Publications

Spatially and temporally resolved Digital Particle Image Velocimetry (DPIV) measurements are presented of flow complexities in a nominally two-dimensional, symmetric, duct with an oscillating constriction. The motivation for this research lies in advancing the state-of-the-art in applying integral control volume analysis to modeling unsteady internal flows. The specific target is acoustic modeling of human phonation. The integral mass and momentum equations are directly coupled to the acoustic equations and provide quantitative insight into acoustic source strengths in addition to the dynamics of the fluid-structure interactions in the glottis. In this study, a square cross-section duct was constructed with symmetric, computer …

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Development Of Integrated Zinc Oxide Nanorods Coated Glass Substrate Sensing Device, Mohd Yusof Haziezol Helmi Feb 2020

Development Of Integrated Zinc Oxide Nanorods Coated Glass Substrate Sensing Device, Mohd Yusof Haziezol Helmi

Student Works (2020-2029)

A simple and practical cost-effective integrated zinc oxide (ZnO) nanorods coated glass substrate sensing device for humidity and formaldehyde vapor sensing applications is reported. The developed sensor device is composed of a commercial light-emitting diode (LED) and photodiode that correspondingly served as light source and detector which precisely positioned on a 3D printed sensor platform. A receiver circuit and Arduino platform were employed for signal amplification and processing. A uniform ZnO nanorods coating were grown on the surface of glass substrate via hydrothermal method by controlling the growth durations and coating length. A standard reference for the optimum working condition …

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In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen, Nader Shehata, Ishac Kandas, Effat Samir Feb 2020

In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen, Nader Shehata, Ishac Kandas, Effat Samir

Electrical & Computer Engineering Faculty Publications

Cerium oxide (ceria) nanoparticles (NPs) have been proved to be an efficient optical fluorescent material through generating visible emission (~530 nm) under violet excitation. This feature allowed ceria NPs to be used as an optical sensor via the fluorescence quenching Technique. In this paper, the impact of in-situ embedded gold nanoparticles (Au NPs) inside ceria nanoparticles was studied. Then, gold–ceria NPs were used for sensing dissolved oxygen (DO) in aqueous media. It was observed that both fluorescence intensity and lifetime were changed due to increased concentration of DO. Added gold was found to enhance the sensitivity of ceria to DO …

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