Nanoscience and Nanotechnology Commons^™

Synthesis Of Graphene And Graphene-Based Composite Membrane, Yuanjun Fan

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

Vibration membrane equipped for earphone requires high performance in both mechanical properties and electronic properties. With extraordinary properties on both, graphene and graphene-based composite materials appear as a promising candidate for this application. Chemical vapor deposition (CVD) is believed to be the most convenient way to synthesize a large area (on scale of square centimeters) as well as a homogeneous thickness for the membrane. The thesis focuses on applying control variable experiment method to analyze different effects on mechanical property of the two CVD setting parameters: cooling rate, and hydrocarbon precursor. For isolating the specimens efficiently, a modified electrochemical method …

Design And Simulation Of A Miniature Cylindrical Mirror Auger Electron Energy Analyzer With Secondary Electron Noise Suppression, Jay A. Bieber

USF Tampa Graduate Theses and Dissertations

In the nanoscale metrology industry, there is a need for low-cost instruments, which have the ability to probe the structrure and elemental composition of thin films. This dissertation, describes the research performed to design and simulate a miniature Cylindrical Mirror Analyzer, (CMA), and Auger Electron Spectrometer, (AES). The CMA includes an integrated coaxial thermionic electron source. Electron optics simulations were performed using the Finite Element Method, (FEM), software COMSOL. To address the large Secondary Electron, (SE), noise, inherent in AES spectra, this research also included experiments to create structures in materials, which were intended to suppress SE backgound noise in …

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes. …

Mechanistic Modeling Of Nanoparticle-Stabilized Supercritical Co2 Foams And Its Implication In Field-Scale Eor Applications, Doris Patricia Ortiz Maestre

LSU Master's Theses

Previous experimental studies show that nanoparticle-stabilized supercritical CO₂ foams (or, NP CO₂ foams) can be applied as an alternative to surfactant foams, in order to reduce CO₂ mobility in gas injection enhanced oil recovery (EOR). These nanoparticles, if chosen correctly, can be an effective foam stabilizer attached at the fluid interface in a wide range of physicochemical conditions.

By using NP CO₂ foam experiments available in the literature, this study performs two tasks: (i) presenting how a mechanistic foam model can be used to fit experimental data and determine required model parameters, and (ii) investigating the …

The Relationship Between Total Neuropathy Score-Reduced, Neuropathy Symptoms And Function., Ashraf Abulhaija

USF Tampa Graduate Theses and Dissertations

Chemotherapy Induced Peripheral Neuropathy (CIPN) is a common problem among cancer patients who receive a wide range of chemotherapy. This problem causes a decline in quality of life and increased disabilities. CIPN assessment instruments are either subjective, objective, or a combination of both. So far, there is no agreement on the best way for assessment. The goal of this study was to explore the relationships among subjective and objective CIPN assessment instruments. Specifically, this study aimed to 1) evaluate the relationship between the Total Neuropathy Score-reduced (mainly objective) and patients’ function, as measured by the interference scale of the Chemotherapy-Induced …

Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee

Mechanical Engineering Research Theses and Dissertations

Solid‐state nanopore sensors have been used to measure the size of a nanoparticle by applying a resistive pulse sensing technique. Previously, the size distribution of the population pool could be investigated utilizing data from a single translocation, however, the accuracy of the distribution is limited due to the lack of repeated data. In this study, we characterized polystyrene nanobeads utilizing single particle recapture techniques, which provide a better statistical estimate of the size distribution than that of single sampling techniques. The pulses and translocation times of two different sized nanobeads (80 nm and 125 nm in diameter) were acquired repeatedly …

Method For Single Crystal Growth Of Photovoltaic Perovskite Material And Devices, Jinsong Huang, Qingfeng Dong

Department of Mechanical and Materials Engineering: Faculty Publications

Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container , also including at least one small perovskite single crystal , and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows , in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate . For example , a top portion of the substrate external to the solution may be cooled .

Computational Prediction Of Conductivities Of Disk-Shaped Particulate Composites, Jian Qiu

Electronic Theses and Dissertations

The effective conductivities are determined for randomly oriented disk-shaped particles using an efficient computational algorithm based on the finite element method. The pairwise intersection criteria of disks are developed using a set of vector operations. An element partition scheme has been implemented to connect the elements on different disks across the lines of intersection. The computed conductivity is expressed as a function of the density and the size of the circular disks or elliptical plates. It is further expressed in a power-law form with the key parameters determined from curve fittings. The particle number and the trial number of simulations …

Rapid Characterization Of Local Shape Memory Properties Through Indentation, Peizhen Li, Haluk E. Karaca, Yang-Tse Cheng

Mechanical Engineering Faculty Publications

Shape memory alloys (SMAs) have the ability to show large recoverable shape changes upon temperature, stress or magnetic field cycling. Their shape memory, material and magnetic properties (e.g. transformation temperatures, strain, saturation magnetization and strength) determine their prospects for applications from small-scale microelectromechanical systems to large scale aerospace and biomedical systems. It should be noted that properties of SMAs are highly temperature dependent. Generally, the conventional mechanical characterization methods (e.g, tension, compression, and torsion) are used on bulk samples of SMAs to determine those properties. In this article, it will be shown that indentation technique can be used as an …

Oct-Based Three Dimensional Modeling Of Stent Deployment, Pengfei Dong, David Prabhu, David L. Wilson, Hiram G. Bezerra, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Stent deployment has been widely used to treat narrowed coronary artery. Its acute outcome in terms of stent under expansion and malapposition depends on the extent and shape of calcifications. However, no clear understanding as to how to quantify or categorize the impact of calcification. We have conducted ex vivo stenting characterized by the optical coherence tomography (OCT). The goal of this work is to capture the ex vivo stent deployment and quantify the effect of calcium morphology on the stenting. A three dimensional model of calcified plaque was reconstructed from ex vivo OCT images. The crimping, balloon expansion and …

Incorporation Of Catalytic Modalities For Forming Of A Catalytic Cascade, Albert T. Perry Iii

Nanoscience and Microsystems ETDs

This dissertation investigates the novel incorporation of inorganic and enzymatic catalysts. There is little literature on inorganic catalysts operating at biologically relevant pHs and as such a significant amount of this dissertation focuses on determination of catalyst activity. Mn amino-anitpyrene (MnAAPyr), Pt, Pt alloys, Mn-N-C and Pd catalysts on 3D graphene supports(3D-GNS), were explored for activity towards glycerol intermediates: oxalic acid, mesoxalic acid, glyoxalic acid, and formic acid. MnAAPyr was designed to mimic the reaction center of oxalate decarboxylase and oxalate oxidaze, the natural catalyst towards oxalic acid. It showed high activity towards oxalic acid, with onset potentials of 0.714±0.002V …

Floating-Gate Transistor Photodetector, Jinsong Huang, Yongbo Yuan

Department of Mechanical and Materials Engineering: Faculty Publications

A field effect transistor photodetector that can operate in room temperature includes a source electrode , a drain electrode , a channel to allow an electric current to flow between the drain and source electrodes , and a gate electrode to receive a bias voltage for controlling the current in the channel . The photodetector includes a light - absorbing mate rial that absorbs light and traps electric charges . The light absorbing material is configured to generate one or more charges upon absorbing light having a wavelength within a specified range and to hold the one or more charges …

Advances In Diamond Nanofabrication For Ultrasensitive Devices, Stefania Castelletto, Lorenzo Rosa, Jonathan Blackledge, Mohammed Zaher Al Abri, Albert Boretti

Articles

This paper reviews some of the major recent advances in single-crystal diamond nanofabrication and its impact in nano- and micromechanical, nanophotonics and optomechanical components. These constituents of integrated devices incorporating specific dopants in the material provide the capacity to enhance the sensitivity in detecting mass and forces as well as magnetic field down to quantum mechanical limits and will lead pioneering innovations in ultrasensitive sensing and precision measurements in the realm of the medical sciences, quantum sciences and related technologies.

Enhancement Of Thermoelectric Properties Of Ald Synthesized Pbte And Pbse By Phonon Engineering, Xin Chen

Electrical & Computer Engineering Theses & Dissertations

Thermoelectrics is a green renewable energy technology that plays an important role in power generation due to its potential in generating electricity out of waste heat. The main challenge for the development of thermoelectrics is its low conversion efficiency. One key strategy to improve conversion efficiency is focused on reducing the thermal conductivity of thermoelectric materials. In this thesis, the novel phononic engineering concept was implemented by conformal ALD deposition of PbTe, PbSe thermoelectric films, and PbTe/PbSe nanolaminates on patterned silicon substrates in order to improve the thermoelectric performance of the thermoelectric films. The silicon substrates were lithographically patterned with …

Nanowire-Based Light-Emitting Diodes: A New Path Towards High-Speed Visible Light Communication, Mohsen Nami

Physics & Astronomy ETDs

Nano-scale optoelectronic devices have gained significant attention in recent years. Among these devices are semiconductor nanowires, whose dimeters range from 100 to 200 nm. Semiconductor nanowires can be utilized in many different applications including light-emitting diodes and laser diodes. Higher surface to volume ratio makes nanowire-based structures potential candidates for the next generation of photodetectors, sensors, and solar cells. Core-shell light-emitting diodes based on selective-area growth of gallium nitride (GaN) nanowires provide a wide range of advantages. Among these advantages are access to non-polar m-plane sidewalls, higher active region area compared to conventional planar structures, and reduction of threading …

Two Dimensional Layered Materials And Heterostructures, A Surface Science Investigation And Characterization, Yujing Ma

USF Tampa Graduate Theses and Dissertations

The isolation of single layers of van der Waals materials has shown that their properties can be significantly different compared to their bulk counterparts. These observations, illustrates the importance of interface interactions for determining the materials properties even in weakly interacting materials and raise the question if materials properties of single layer van der Waals materials can be controlled by appropriate hetero-interfaces. To study interface effects in monolayer systems, surface science techniques, such as photoemission spectroscopy and scanning probe microscopy/spectroscopy, are ideally suited. However, before these characterization methods can be employed, approaches for the synthesis of hetero-van der Waals systems …

Can Schools Use Nanotechnology To Prevent Cell Phones From Ringing, Sarah C. Boyer

Oklahoma Journal of Law and Technology

No abstract provided.

Theory And Applications Of Plasmonically Active Spherical And Core-Shell Nanoparticles, Mohammad Habibur Rahaman

Student Theses and Dissertations

Optical properties of metal nanoparticles and core-shell nanoparticles are related to their plasmon response. Plasmonic resonance is the collective oscillations of conduction electrons in metal. The core-shell nanoparticles represent unique geometry and plasmonic resonance can be tuned either by changing the distance between core-shell nanoparticle or by changing their core to shell ratio. This work focuses on the theoretical design of single and multiple core-shell nanoparticles for exploring the resonance properties of core-shell nanoparticles using scattering theory. The results provide new and tunable optical properties of core-shell nanoparticles that solid single or multiple metal nanoparticles can not demonstrate. We have …

Optical And Electronic Properties Of Femtosecond Laser-Induced Sulfur-Hyperdoped Silicon N+/P Photodiodes, Ting Zhang, Bohan Liu, Waseem Ahmad, Yaoyu Xuan, Xiangxiao Ying, Zhijun Liu, Zhi David Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

Impurity-mediated near-infrared (NIR) photoresponse in silicon is of great interest for photovoltaics and photodetectors. In this paper, we have fabricated a series of n⁺/p photodetectors with hyperdoped silicon prepared by ion-implantation and femtosecond pulsed laser. These devices showed a remarkable enhancement on absorption and photoresponse at NIR wavelengths. The device fabricated with implantation dose of 10¹⁴ ions/cm² has exhibited the best performance. The proposed method offers an approach to fabricate low-cost broadband silicon-based photodetectors.

Design And Validation Of A Low Cost High Speed Atomic Force Microscope, Michael Ganzer, Tien Pham

Journal of Undergraduate Research at Minnesota State University, Mankato

The Atomic Force Microscope (AFM) is an important instrument in nanoscale topography, but it is expensive and slow. The authors designed an AFM to overcome both limitations. To do this, they used an Optical Pickup Unit (OPU) from a DVD player as the laser and photodetector system to minimize cost and they did not implement a vertical control loop, which maximized potential speed. Students will be able to be use this device to make nanoscale measurements and engage in micro-engineering. To prototype this idea, the authors tested an OPU with a silicon wafer and demonstrated the ability to consistently distinguish …