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Full-Text Articles in Engineering
Advanced Techniques For Carbon Nanotube Templated Microfabrication, Jason Matthew Lund
Advanced Techniques For Carbon Nanotube Templated Microfabrication, Jason Matthew Lund
Theses and Dissertations
Carbon nanotube templated microfabrication (CNT-M) is a term describing a grouping of processes where carbon nanotubes (CNTs) serve a structural role in the fabrication of a material or device. In its basic form, CNT-M is comprised of two steps: produce a template made from carbon nanotubes and infiltrate the porous template with an additional material. Vertically aligned carbon nanotube (VACNT) templates can be grown to heights ranging from microns to millimeters and lithographically patterned to a desired form. Deposition of an existing thin film material onto a CNT template will coat all template surfaces and can produce a near solid …
Effects Of Infiltration Temperature, Time, And Gas Flow Rate On Material Properties Of Carbon Infiltration Carbon Nanotubes, Shane Dirk Sypherd
Effects Of Infiltration Temperature, Time, And Gas Flow Rate On Material Properties Of Carbon Infiltration Carbon Nanotubes, Shane Dirk Sypherd
Theses and Dissertations
This work characterizes the material properties of carbon infiltrated carbon nanotube (CI- CNT) structures. The impacts of temperature, time, and hydrogen flow rates on the material prop- erties of modulus of elasticity and strength are examined and compared. Carbon infiltration levels are assessed through the use of SEM images to determine which parameters give the highest level of infiltration. Through the use of SEM, carbon capping is observed on samples infiltrated for longer times at 900 and 950◦ C, suggesting that the samples are not being infiltrated during the entire desired infiltration period at these temperatures. The highest material properties …
Enzymatic Biofuel Cells In A Sandwich Geometry With Compressed Carbon Nanotubes/Enzyme Electrodes & Hybrid Patch Applications, Biao Leng
Dissertations
Enzymatic biofuel cells (EBFCs) convert the chemical energy of biofuels, such as glucose and methanol, into electrical energy by employing enzymes as catalysts. In contrast to conventional fuel cells, EBFCs have a simple membrane-free fuel cell design due to the high catalytic specificity of the enzymes, but the power densities obtained are lower. Although the primary goal of research on EBFCs has been to develop a sustainable power source that can be directly implanted in the human body to power bio-devices, other applications such as the use of a flexible film or fuel cell patch as a wearable power source …
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Theses and Dissertations
This work deals with the amplitude-frequency and amplitude-voltage responses of parametric and primary resonances of electrostatically actuated double-walled carbon nanotubes (DWCNTs). Nonlinear forces acting on the DWCNT are intertube van der Waals and electrostatic forces. Soft AC excitation and small viscous damping are assumed. In coaxial vibration, the outer and inner carbon nanotubes move together (in-phase), maintaining their geometric concentricity; while in noncoaxial vibration, the CNTs move in opposite direction (out-of-phase). Modal coordinate transformation is formulated. The Harmonic Balance Method (HBM) is used to find the free response solutions of the DWCNT. The Reduced Order Model (ROM) method is also …
Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani
Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani
Electronic Theses and Dissertations
Recently, Carbon Nanotubes (CNTs) are drawing considerable attention of researchers for reinforcing cementitious materials due to their excellent mechanical properties and high aspect ratio (length-to-diameter ratio). However, CNTs might not disperse well within the cement matrix, resulting in little improvement or even degradation of concrete properties. The uncertainty in producing the consistent results in different studies might be attributed to multiple interactions between the experimental variables affecting the nanotube dispersion and the final properties of CNT-cement nanocomposites. Therefore, this research mainly focused on proposing equations that can reliably capture these interactions in order to correlate CNT dispersion with the mechanical …
Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel
Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel
Theses and Dissertations
In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their …
Degradation Of Emerging Contaminants By Advanced Oxidation Using Multi-Walled Carbon Nanotubes And Continuous Ozone Injection, Emily N. Miller
Degradation Of Emerging Contaminants By Advanced Oxidation Using Multi-Walled Carbon Nanotubes And Continuous Ozone Injection, Emily N. Miller
Master's Theses
With a growing population and continuous accumulation of pollutants, water resources worldwide are quickly being depleted. Drastic improvements need to be made in both water conservation and treatment. Advanced oxidation processes (AOPs) have been developed to go above and beyond the capabilities of traditional wastewater treatment facilities to eliminate emerging contaminants from our water systems. AOPs increase the generation of hydroxyl radicals (•OH) in oxidation reactions, which are less selective and more reactive than other oxidants, such as ozone, so they are more effective at degrading persistent compounds. This study explored an AOP that utilizes ozonated multi-walled carbon nanotubes (MWCNTs) …
Efficient Methods For Robust Circuit Design And Performance Optimization For Carbon Nanotube Field Effect Transistors, Muhammad Ali
Efficient Methods For Robust Circuit Design And Performance Optimization For Carbon Nanotube Field Effect Transistors, Muhammad Ali
Dissertations and Theses
Carbon nanotube field-effect transistors (CNFETs) are considered to be promising candidate beyond the conventional CMOSFET due to their higher current drive capability, ballistic transport, lesser power delay product and higher thermal stability. CNFETs show great potential to build digital systems on advanced technology nodes with big benefits in terms of power, performance and area (PPA). Hence, there is a great need to develop proven models and CAD tools for performance evaluation of CNFET-based circuits. CNFETs specific parameters, such as number of tubes, pitch (spacing between the tubes) and diameter of CNTs determine current driving capability, speed, power consumption and area …