Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Adhesion (1)
- Bio-inspired (1)
- Brush block copolymers (1)
- Buckling (1)
- CNT (1)
-
- Carbon Nanotube (1)
- Complex curing reaction (1)
- Composites (1)
- Computing (1)
- Constitutive modeling (1)
- Crosslinking (1)
- Crystallizations (1)
- Density functional theory (1)
- Eigenvalue (1)
- Elastocapillarity (1)
- Elastomer (1)
- Electronic structure (1)
- FEAST (1)
- Fabrication (1)
- Film (1)
- Finite-element (1)
- Floating films (1)
- Gold nanorod composites (1)
- Granular material (1)
- High performance material (1)
- Ion Trap (1)
- Low field NMR (1)
- MCNT (1)
- Material science (1)
- Mesoscale (1)
- Publication Type
Articles 1 - 9 of 9
Full-Text Articles in Engineering Physics
Design And Fabrication Of A Trapped Ion Quantum Computing Testbed, Christopher A. Caron
Design And Fabrication Of A Trapped Ion Quantum Computing Testbed, Christopher A. Caron
Masters Theses
Here we present the design, assembly and successful ion trapping of a room-temperature ion trap system with a custom designed and fabricated surface electrode ion trap, which allows for rapid prototyping of novel trap designs such that new chips can be installed and reach UHV in under 2 days. The system has demonstrated success at trapping and maintaining both single ions and cold crystals of ions. We achieve this by fabricating our own custom surface Paul traps in the UMass Amherst cleanroom facilities, which are then argon ion milled, diced, mounted and wire bonded to an interposer which is placed …
Synthesis, Fabrication, And Assembly Of Mesoscale Polymer Filaments, Dylan M. Barber
Synthesis, Fabrication, And Assembly Of Mesoscale Polymer Filaments, Dylan M. Barber
Doctoral Dissertations
Mesoscale materials, with feature sizes in the range of one hundred nanometers to tens of micrometers, are ubiquitous in Nature. In organisms, mesoscale building blocks connect the properties of underlying molecular and nanoscructures to those of macroscale, organism-scale materials through hierarchical assemblies of recurring structural motifs. The collective action of large numbers of mesoscale features can afford stunning features like the structural color of the morpho butterfly wing, calcium ion-mediated movement in muscle, and wood structures like xylem that can support enormous external compressive loads and negative internal pressure to transport nutrients throughout an organism. In synthetic systems, the design, …
Amorphous-Crystalline Brush Block Copolymers: Phase Behavior, Rheology And Composite Design, Gayathri Kopanati
Amorphous-Crystalline Brush Block Copolymers: Phase Behavior, Rheology And Composite Design, Gayathri Kopanati
Doctoral Dissertations
Bottlebrush block copolymers are polymers with chemically distinct polymer side chains grafted onto a common backbone. The unique architecture induced properties make these materials attractive for applications such as photonic materials, stimuli responsive actuators and drug delivery vehicles to name a few. This dissertation primarily investigates the phase transitions and rheological behavior of amorphous-crystalline bottlebrush brush block copolymers and their composites. The temperature induced phase behavior is investigated using time resolved synchrotron X-ray source. Irrespective of volume fraction and backbone length, the samples display strong segregation even at high temperatures (200 °C) and there is no accessible order-disorder transition in …
Modeling Deformation Behavior And Strength Characteristics Of Sand-Silt Mixtures: A Micromechanical Approach, Mehrashk Meidani
Modeling Deformation Behavior And Strength Characteristics Of Sand-Silt Mixtures: A Micromechanical Approach, Mehrashk Meidani
Doctoral Dissertations
This dissertation is comprised of six chapters. In the first chapter the motivation of this research, which was modeling the deformation behavior and strength characteristics of soils under internal erosion, is briefly explained. In the second chapter a micromechanis-based stress-strain model developed for prediction of sand-silt mixtures behavior is presented. The components of the micromechanics-based model are described and undrained behavior of six different types of sand-silt mixtures is predicted for several samples with different fines contents. The need for a more comprehensive compression model for sand-silt mixtures is identified at the end of this chapter. This desired compression model …
Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel
Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel
Doctoral Dissertations
A uniform dispersion of reactants is necessary to achieve a complete reaction involving multi-components, especially for the crosslinking of rigid high-performance materials. In these reactions, miscibility is crucial for curing efficiency. This miscibility is typically enhanced by adding a third component, a plasticizer. For the reaction of the highly crystalline crosslinking agent hexamethylenetetramine (HMTA) with a strongly hydrogen-bonded phenol formaldehyde resin, furfural has been traditionally used as the plasticizer. However, the reason for its effectiveness is not clear. In this doctoral thesis work, miscibility and crosslinking efficiency of plasticizers in phenolic curing reactions are studied by thermal analysis and spectroscopic …
Deformation And Adhesion Of Soft Composite Systems For Bio-Inspired Adhesives And Wrinkled Surface Fabrication, Michael Imburgia
Deformation And Adhesion Of Soft Composite Systems For Bio-Inspired Adhesives And Wrinkled Surface Fabrication, Michael Imburgia
Doctoral Dissertations
The study of soft material deformation and adhesion has broad applicability to industries ranging from automobile tires to medical prosthetics and implants. When a mechanical load is imposed on a soft material system, a variety of issues can arise, including non-linear deformations at interfaces between soft and rigid components. The work presented in this dissertation embraces the occurrence of these non-linear deformations, leading to the design of functional systems that incorporate a soft elastomer layer with application to bio-inspired adhesives and wrinkled surface fabrication. Understanding the deformation of a soft elastomer layer and how the system loading and geometry influence …
Introducing The Newton-Poisson-Brillouin Model In The Quest For Plasmons In Metallic Carbon Nanotubes, Richard P. Zannoni
Introducing The Newton-Poisson-Brillouin Model In The Quest For Plasmons In Metallic Carbon Nanotubes, Richard P. Zannoni
Doctoral Dissertations
A new method is presented to model carbon nanotubes (CNT) of micron length. The Newton-Poisson-Brillouin (NPB) model uses Newtonian physics to model the interaction of a population of thermally excited quasi-particles. The NPB model is self-consistent with Poisson’s equation, and the quasi-particles are confined to the CNT’s band structure. In this work, we explore the parameter space of the model.
Studies On The Wrinkling Of Thin Polymer Films Floating On Liquid, Kamil B. Toga
Studies On The Wrinkling Of Thin Polymer Films Floating On Liquid, Kamil B. Toga
Doctoral Dissertations
This dissertation aims to broaden our understanding on wrinkling instabilities occurring on floating polymeric sheets, and tries to establish innovative methods that exploit these patterns in studies on material behavior and interfacial phenomena. We will address three major topics in this thesis including, i) characterization of the conditions required to buckle an annular disc, ii) characterization of wrinkles occurring around a droplet/bubble placed on a membrane that is kept taut at the liquid-air interface, and iii) using wrinkling patterns as a probe to understand the interfacial behavior and dynamics of ultrathin films. The first project in this thesis is about …
A Non-Linear Eigensolver-Based Alternative To Traditional Self-Consistent Electronic Structure Calculation Methods, Brendan E. Gavin
A Non-Linear Eigensolver-Based Alternative To Traditional Self-Consistent Electronic Structure Calculation Methods, Brendan E. Gavin
Masters Theses 1911 - February 2014
This thesis presents a means of enhancing the iterative calculation techniques used in electronic structure calculations, particularly Kohn-Sham DFT. Based on the subspace iteration method of the FEAST eigenvalue solving algorithm, this nonlinear FEAST algorithm (NLFEAST) improves the convergence rate of traditional iterative methods and dramatically improves their robustness. A description of the algorithm is given, along with the results of numerical experiments that demonstrate its effectiveness and offer insight into the factors that determine how well it performs.