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3,854 full-text articles. Page 81 of 157.

Local Heating With Lithographically Fabricated Plasmonic Titanium Nitride Nanoparticles, Urcan Guler, Justus Ndukaife, Gururaj Naik, Agbai Nnanna, Alexander Kildishev, V. Shalaev, Alexandra Boltasseva 2015 Purdue University, Birck Nanotechnology Center

Local Heating With Lithographically Fabricated Plasmonic Titanium Nitride Nanoparticles, Urcan Guler, Justus Ndukaife, Gururaj Naik, Agbai Nnanna, Alexander Kildishev, V. Shalaev, Alexandra Boltasseva

U. Guler

Titanium nitride is considered a promising alternative plasmonic material and is known to exhibit localized surface plasmon resonances within the near-infrared biological transparency window. Here, local heating efficiencies of disk-shaped nanoparticles made of titanium nitride and gold are compared in the visible and near-infrared regions numerically and experimentally with samples fabricated using e-beam lithography. Results show that plasmonic titanium nitride nanodisks are efficient local heat sources and outperform gold nanodisks in the biological transparency window, dispensing the need for complex particle geometries.


Nanoenhanced Additive Manufacturing: Additive Introduction Onto Halloysite Nanotubes And Into 3d Printing Filament For Tailored Material Characteristics, James Connor Nicholson 2015 Louisiana Tech University

Nanoenhanced Additive Manufacturing: Additive Introduction Onto Halloysite Nanotubes And Into 3d Printing Filament For Tailored Material Characteristics, James Connor Nicholson

Doctoral Dissertations

With the rapid advancement of additive manufacturing technologies in recent years on both the microscale and the macroscale, research must be done to test the limits of currently available technologies. On the microscale, halloysite nanotubes have proven to be a viable platform for reinforcement of polymers and time release of loaded chemicals, as well as a substrate material for the deposition of nanoparticles. The range of materials are limited due to polarity conflicts, and often lead to wet chemical processes that use more toxic alternatives. Three-dimensional (3D) printing and macroscale additive manufacturing techniques can be used to generate custom structures, …


Traction-Separation Relationships For Hydrogen-Induced Grain Boundary Embrittlement In Nickel Via Molecular Dynamics Simulations, Wesley Allen Barrows 2015 University of Arkansas, Fayetteville

Traction-Separation Relationships For Hydrogen-Induced Grain Boundary Embrittlement In Nickel Via Molecular Dynamics Simulations, Wesley Allen Barrows

Graduate Theses and Dissertations

The deleterious effects of atomic and molecular hydrogen on the mechanical properties of metals have long been observed. Although several theories exist describing the mechanisms by which hydrogen negatively influences the failure of materials, a consensus has yet to be reached regarding the exact mechanism or combination of mechanisms. Two mechanisms have gained support in explaining hydrogen’s degradative role in non-hydride forming metals: hydrogen-enhanced localized plasticity and hydrogen-enhanced decohesion. Yet, the interplay between these mechanisms and microstructure in metallic materials has not been explained. Accordingly, for this thesis, the three main objectives are: (i) to develop a numerical methodology to …


Nanoformulation For Anticancer Drug Delivery: Enhanced Pharmacokinetics And Circulation, Gaurav Parekh 2015 Louisiana Tech University

Nanoformulation For Anticancer Drug Delivery: Enhanced Pharmacokinetics And Circulation, Gaurav Parekh

Doctoral Dissertations

In this study, we have explored the application of the Layer-by-Layer (LbL) assembly technique for improving injectable drug delivery systems of low soluble anticancer drugs (e.g. Camptothecin (CPT), Paclitaxel (PTX) or Doxorubicin (DOX)). For this study, a polyelectrolyte shell encapsulates different types of drug nanocores (e.g. soft core, nanomicelle or solid lipid nanocores).The low soluble drugs tend to crystallize and precipitate in an aqueous medium. This is the reason they cannot be injected and may have low concentrations and low circulation time in the blood. Even though these drugs when present in the cancer microenvironment have high anti-tumor inhibition, the …


Broadband High Efficiency Fractal-Like And Diverse Geometry Silicon Nanowire Arrays For Photovoltaic Applications, Omar Hassan Al-Zoubi 2015 University of Arkansas, Fayetteville

Broadband High Efficiency Fractal-Like And Diverse Geometry Silicon Nanowire Arrays For Photovoltaic Applications, Omar Hassan Al-Zoubi

Graduate Theses and Dissertations

Solar energy has many advantages over conventional sources of energy. It is abundant, clean and sustainable. One way to convert solar energy directly into electrical energy is by using the photovoltaic solar cells (PVSC). Despite PVSC are becoming economically competitive, they still have high cost and low light to electricity conversion efficiency. Therefore, increasing the efficiency and reducing the cost are key elements for producing economically more competitive PVSC that would have significant impact on energy market and saving environment. A significant percentage of the PVSC cost is due to the materials cost. For that, thin films PVSC have been …


Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta 2015 Old Dominion University

Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta

Mechanical & Aerospace Engineering Theses & Dissertations

The atomic force microscope (AFM) is a probe-based microscope that uses nanoscale and structural imaging where high resolution is desired. AFM has also been used in mechanical, electrical, and thermal engineering applications. This unique technique provides vital local material properties like the modulus of elasticity, hardness, surface potential, Hamaker constant, and the surface charge density from force versus displacement curve. Therefore, AFM was used to measure both the diameter and mechanical properties of the collagen nanostraws in human costal cartilage. Human costal cartilage forms a bridge between the sternum and bony ribs. The chest wall of some humans is deformed …


Fabrication Of Sub-10 Nm Metallic Structures Via Nanomasking Technique For Plasmonic Enhancement Applications, Stephen Joseph Bauman 2015 University of Arkansas, Fayetteville

Fabrication Of Sub-10 Nm Metallic Structures Via Nanomasking Technique For Plasmonic Enhancement Applications, Stephen Joseph Bauman

Graduate Theses and Dissertations

One area of nanoscience that has become popular in recent years is the study of optics at the nanoscale. Due to enhanced fabrication techniques, new geometries and improved dimensional resolutions have been allowing the creation of nanostructures for use in this area. Nanoscale geometries cause unique optical effects such as enhancement of the signal’s electric field strength at the surface of a substrate. Specifically, structures separated by nanogaps (10 nm and smaller) have been shown to exhibit strong field enhancement within the gaps. This has opened up the potential for surface enhanced spectroscopies, enhanced absorption for photovoltaics, and improved sensing …


Engineering The Ground State Of Complex Oxides, Derek Joseph Meyers 2015 University of Arkansas, Fayetteville

Engineering The Ground State Of Complex Oxides, Derek Joseph Meyers

Graduate Theses and Dissertations

Transition metal oxides featuring strong electron-electron interactions have been at the forefront of condensed matter physics research in the past few decades due to the myriad of novel and exciting phases derived from their competing interactions. Beyond their numerous intriguing properties displayed in the bulk they have also shown to be quite susceptible to externally applied perturbation in various forms. The dominant theme of this work is the exploration of three emerging methods for engineering the ground states of these materials to access both their applicability and their deficiencies.

The first of the three methods involves a relatively new set …


Fabrication And Material Characterization Of Copper And Copper-Cnt Micropillars, Siavash Ghanbari, Jeff Darabi 2015 Southern Illinois University Edwardsville

Fabrication And Material Characterization Of Copper And Copper-Cnt Micropillars, Siavash Ghanbari, Jeff Darabi

SIUE Faculty Research, Scholarship, and Creative Activity

In this work, copper micropillars and copper-carbon nanotube (CNT) composite micropillars were fabricated by incorporating an electrodeposition technique with a xurography process. In order to disperse carbon nanotubes in copper-CNT micropillars, various amounts of CNTs were added to the electroplating bath. Surface morphology and phase characterization of copper micropillars and copper-CNT composite micropillars were analyzed by optical microscopy and X-ray diffraction. In addition, the corrosion resistance (Rp) of a bare copper substrate, copper micropillars, and optimum copper-CNT micropillars were studied by electrochemical impedance spectroscopy (EIS) technique in a 3.5 wt. % sodium chloride. Experimental results yielded a corrosion …


Surface Modification Of Noble Metal Nanostructures Toward Biomedical Applications, Samir V. Jenkins 2015 University of Arkansas, Fayetteville

Surface Modification Of Noble Metal Nanostructures Toward Biomedical Applications, Samir V. Jenkins

Graduate Theses and Dissertations

Noble metal nanostructures have seen a steady increase in biomedical application over the last several decades; new diagnostic and therapeutic modalities are under intense investigation. Many of these applications are possible because of post-synthetic modifications to the particle surface. These modifications take a variety of forms and can significantly affect the pharmacokinetics of these particles. In this work, various surface modifications were investigated. Particle agglomeration, which occurs when particle surfaces remain in contact, can significantly affect the toxicity and efficacy of a nanomedicine. Darkfield microscopy and single-particle ICP-MS were developed as complementary methods to detect agglomeration in blood, with the …


Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu 2015 University of Arkansas, Fayetteville

Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu

Graduate Theses and Dissertations

Pd and its alloys are alternatives of Pt as promising catalysts and electrocatalysts for many reactions. Size controlled synthesis of nanoparticles remains a major research subject, since smaller size particles show better catalytic performance. In this work, we developed a modified chemical wet method to prepare Pd and Pd-Cu nanostructures with uniform small size. Different sizes and shapes of Pd nanostructures were successfully synthesized by using the two reducing agents (i.e., L-ascorbyl-6-palmitate or phenylphosphinic acid). The reducing agents play a role to control the final morphologies and sizes of particles. The use of L-ascorbyl-6-palmitate favors to form irregular branch shapes …


Development And Characterization Of Intermediate-Band Quantum Wire Solar Cells, Colin Stuart Furrow 2015 University of Arkansas, Fayetteville

Development And Characterization Of Intermediate-Band Quantum Wire Solar Cells, Colin Stuart Furrow

Graduate Theses and Dissertations

The effects of a quantum wire intermediate band, grown by molecular beam epitaxy, on the optical and electrical properties of solar cells are reported. To investigate the behavior of the intermediate band, the quantum wires were remotely doped at three different doping concentrations, the number of quantum wire layers was varied from three to twenty, and the solar cell structure was optimized. For all the structures, current-voltage and external quantum efficiency measurements were performed to examine the effect of absorption and power conversion of the intermediate band solar cell (IBSC). Time-resolved photoluminescence measurements showed that δ-doping can increase the lifetime …


Energy Harvesting-Aware Design For Wireless Nanonetworks, Shahram Mohrehkesh 2015 Old Dominion University

Energy Harvesting-Aware Design For Wireless Nanonetworks, Shahram Mohrehkesh

Computer Science Theses & Dissertations

Nanotechnology advancement promises to enable a new era of computing and communication devices by shifting micro scale chip design to nano scale chip design. Nanonetworks are envisioned as artifacts of nanotechnology in the domain of networking and communication. These networks will consist of nodes of nanometer to micrometer in size, with a communication range up to 1 meter. These nodes could be used in various biomedical, industrial, and environmental monitoring applications, where a nanoscale level of sensing, monitoring, control and communication is required. The special characteristics of nanonetworks require the revisiting of network design. More specifically, nanoscale limitations, new paradigms …


High Density, Vertically-Aligned Carbon Nanotube Membranes, Miao Yu, H. Funke, J. Falconer, R. Noble 2015 University of South Carolina - Columbia

High Density, Vertically-Aligned Carbon Nanotube Membranes, Miao Yu, H. Funke, J. Falconer, R. Noble

Miao Yu

No abstract provided.


Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook 2015 California Polytechnic State University - San Luis Obispo

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …


Non-Wetting Surface-Driven High-Aspect-Ratio Crystalline Grain Growth For Efficient Hybrid Perovskite Solar Cells, Cheng Bi, Qi Wang, Yongbo Yuan, Zhengguo Xiao, Jinsong Huang 2015 University of Nebraska-Lincoln

Non-Wetting Surface-Driven High-Aspect-Ratio Crystalline Grain Growth For Efficient Hybrid Perovskite Solar Cells, Cheng Bi, Qi Wang, Yongbo Yuan, Zhengguo Xiao, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3–7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level in …


Computer Simulations Of Propulsion Of Self-Propelled Flexible Nanobody, Ye Luo 2015 Western Michigan University

Computer Simulations Of Propulsion Of Self-Propelled Flexible Nanobody, Ye Luo

Masters Theses

Swimming bodies such as flagellum and fishes are found everywhere in liquid environment. The research of simulation of swimmers is one of the most important branches among the field of biophysics. This study focus on the direct computer simulation of self-propelled flexible nanobody in fluid field. Two new objectives is studied based on the previous research of Tai-hsien Wu and Dewei ai (2014)[1]. ln Wu's article, the front end of micro swimming body is fixed and the migration of swimmers is neglected. For a further study, one of new targets is to release the head in 3-D simulation fluid area. …


Studies Of Periodic And Quasiperiodic Gold Nanohole Arrays And Their Applications, Zhaoliang Yang 2015 The University of Western Ontario

Studies Of Periodic And Quasiperiodic Gold Nanohole Arrays And Their Applications, Zhaoliang Yang

Electronic Thesis and Dissertation Repository

Wavelength to refractive index sensitivity and resonance wavelength position are two very important performance characteristics for nanohole array based surface plasmon resonance sensors while these characteristics are mostly researched on periodic nanohole arrays, instead of quasiperiodic nanohole arrays. This thesis deduces theoretical equations about the wavelength to refractive index sensitivity and resonance wavelength position of quasiperiodic nanohole arrays. Theoretical analysis shows that wavelength to refractive index sensitivity is not associated with geometry pattern, hole size or pitch but with the wavelength. A novel surface plasmon resonance platform is built by transferring gold films patterned with quasiperiodic nanohole arrays to the …


Measuring The Effectiveness Of Photoresponsive Nanocomposite Coatings On Aircraft Windshields To Mitigate Laser Intensity, Ryan S. Phillips, Hubert K. Bilan, Zachary X. Widel, Randal J. DeMik, Samantha J. Brain, Matthew Moy, Charles Crowder, Stanley L. Harriman, James T. O'Malley III, Joseph E. Burlas, Steven F. Emmert, Jason J. Keleher 2015 Lewis University

Measuring The Effectiveness Of Photoresponsive Nanocomposite Coatings On Aircraft Windshields To Mitigate Laser Intensity, Ryan S. Phillips, Hubert K. Bilan, Zachary X. Widel, Randal J. Demik, Samantha J. Brain, Matthew Moy, Charles Crowder, Stanley L. Harriman, James T. O'Malley Iii, Joseph E. Burlas, Steven F. Emmert, Jason J. Keleher

Journal of Aviation Technology and Engineering

In 2004, pilots reported 46 laser illumination events to the Federal Aviation Administration (FAA), with the number increasing to approximately 3,600 in 2011. Since that time, the number of reported laser incidents has ranged from 3,500 to 4,000. Previous studies indicate the potential for flight crewmember distraction from bright laser light being introduced to the cockpit. Compositional variations of the photoresponsive nanocomposite coatings were applied to an aircraft windscreen using a modified liquid dispersion/heating curing process. The attenuating effects of the deposited films on laser light intensity were evaluated using an optical power meter and the resultant laser intensity data …


Alloy Solute Interactions At Grain Boundaries And Nanoscale Interfaces In Copper, Luke Prestowitz 2015 University at Albany, State University of New York

Alloy Solute Interactions At Grain Boundaries And Nanoscale Interfaces In Copper, Luke Prestowitz

Nanoscale Science & Engineering (discontinued with class year 2014)

To study grain boundary solute interactions we have developed recipes for co-electrodeposition of dilute copper alloys including Cu(Ni) and Cu(Co). Secondary Ion Mass Spectrometry (SIMS) was used to analyze the incorporation of solute into the copper film. In addition to the co-electrodeposition process we also used a drive-in diffusion model for Au, Ag, Co, and Ni. Atomic imaging in a scanning transmission electron microscope (STEM) was used to visualize and investigate solute at grain boundaries and interfaces in polygranular copper films. By understanding these interactions and pathways of alloying solutes in copper microstructures, we can more accurately predict alloying behavior …


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