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2013 Annual Report Of Uvm Extension And The Vermont Agricultural Experiment Station, Uvm Extension And Vermont Agricultural Experiment Station

Annual Reports

2013 Annual report of outreach and research from UVM Extension and Vermont Agricultural Experiment Station.

Nonlinear Ball Chain Waveguides For Acoustic Emission And Ultrasound Sensing Of Ablation, Stephen Herbert Pearson

Graduate College Dissertations and Theses

Harsh environment acoustic emission and ultrasonic wave sensing applications often benefit from placing the sensor in a remote and more benign physical location by using waveguides to transmit elastic waves between the structural location under test and the transducer. Waveguides are normally designed to have high fidelity over broad frequency ranges to minimize distortion - often difficult to achieve in practice. This thesis reports on an examination of using nonlinear ball chain waveguides for the transmission of acoustic emission and ultrasonic waves for the monitoring of thermal protection systems undergoing severe heat loading, leading to ablation and similar processes. Experiments …

Path Integral Quantum Monte Carlo Study Of Coupling And Proximity Effects In Superfluid Helium-4, Max Graves

Graduate College Dissertations and Theses

When bulk helium-4 is cooled below T = 2.18 K, it undergoes a phase transition to a superfluid, characterized by a complex wave function with a macroscopic phase and exhibits inviscid, quantized flow. The macroscopic phase coherence can be probed in a container filled with helium-4, by reducing one or more of its dimensions until they are smaller than the coherence length, the spatial distance over which order propagates. As this dimensional reduction occurs, enhanced thermal and quantum fluctuations push the transition to the superfluid state to lower temperatures. However, this trend can be countered via the proximity effect, where …

Electron Correlation Effects In Strained Dual-Layer Graphene Systems, Peter Karl Harnish

Graduate College Dissertations and Theses

In low dimensional systems, electron correlation effects can often be enhanced. This can be vital since these effects not only play an important role in the study of many-electron physics, but are also useful in designing new materials for various applications. Since its isolation from graphite in 2004, graphene, a two dimensional sheet of carbon atoms, has drawn considerable interest due to its remarkable properties. In the past few years, research has moved on from single to bi-, dual- and multi-layer graphene systems, each displaying their own multitudes of intriguing properties. In particular, multi-layer systems that are electronically decoupled, but …

Mechanical Optimization Of Poly(Vinyl Alcohol) Cryogels To Activate Osteochondral Mechanotransduction Pathways, Meredith Ericson Koch

Graduate College Dissertations and Theses

Tissue engineering and regenerative medicine have emerged as viable approaches to repairing osteochondral tissue damage, especially with the implementation of biomaterials and mesenchymal stem cells (MSCs). Poly(vinyl alcohol) (PVA) is a synthetic and non-biodegradable polymer that has received attention as a tissue engineering scaffold and cartilage replacement due to its inherent viscoelasticity and biocompatibility. This work investigated the use of mechanical cues to trigger mechanotransduction pathways and thereby guide human MSCs towards a desired differentiation lineage.

PVA scaffolds with a range of compressive moduli (1 - 600 kPa) were fabricated by varying molecular weight, solution concentration, and freeze-thaw cycles. Mass …

Numerical Study Of Particle Bed Scour By Vortices, Daniel S. Hagan

Graduate College Dissertations and Theses

Scouring is the process of soil or sediment erosion due to flowing water, which can lead to bed degradation and compromised transportation infrastructure. In the decade before 2000, over half of the 500 bridge failures in the United States were caused by flooding or scouring. To gain a better grasp of the effects of extreme weather events, such as Tropical Storm Irene, on the scouring process, this work is focused on a first principle understanding of the mechanism(s) of scour. The field of Computational Fluid Dynamics (CFD) is particu larly well suited to this task. Utilizing a Direct Numerical Simulation …

Ofdm Coupled Compressive Sensing Algorithm For Stepped Frequency Ground Penetrating Radar, Mohamed Metwally

Graduate College Dissertations and Theses

Dating back to as far as 1940, the US road and bridge infrastructure system has garnered quite the status for strategically connecting together half a continent. As monumental as the infrastructure's status, is its rate of deterioration, with the average bridge age coming at a disconcerting 50 years. Aside from visual inspection, a battery of non-destructive tests were developed to conduct structural fault assessment and detect laminations, in order to preemptively take preventive measures.

The mainstream commercially favored test is the impulse time domain ground penetrating radar (GPR). An extremely short, high voltage pulse is used to visualize cross-sections of …

Exploring Relationships Between Building And Transportation Energy Use Of Residents In U.S. Metropolitan Regions, Timothy Pede

Graduate College Dissertations and Theses

There is much potential to decrease energy consumption in the U.S. by encouraging compact, centralized development. Although many studies have examined the extent to which built environment and demographic factors are related to household energy use, few have considered both building and transportation energy together. We hypothesized that residents living further from city centers, or urban cores, consume more energy for both purposes than their inner city counterparts, resulting in a direct relationship between building and transportation energy usage. This hypothesis was tested with two case studies.

The first focused on New York City. Annual building energy per unit of …

An Atomic Force Microscopy Nanoindentation Study Of Size Effects In Face-Centered Cubic Metal And Bimetallic Nanowires, Erin Leigh Wood

Graduate College Dissertations and Theses

The enhancement of strength of nanoscale materials such as face-centered cubic metal nanowires is well known and arises largely from processes mediated by high energy surface atoms. This leads to strong size effects in nanoscale plasticity; ,smaller is stronger. Yet, other factors, such as crystalline defects also contribute greatly to the mechanical properties. In particular, twin boundaries, which are pervasive and energetically favorable defects in face-centered cubic metal nanowires, have been shown to greatly enhance the strength, furthermore this increase in strength has been shown to be directly influenced by the twin density. However, attempts to control the …

Measurement Of Fluid And Particle Transport Through Narrow Passages, Christopher Ghazi

Graduate College Dissertations and Theses

There are many instances where fluid and particles traveling through a narrow passage, such as a crack in a window or door, have large but sometimes unseen effects on our daily lives. For instance, in the cold months of the year a pressure gradient can exists between the inside and outside of a building which causes cold, outdoor air to flow inside through any cracks; significantly decreasing heating efficiency. This inflow of atmospheric air can bring with it dangerous contaminant particles to the inside of a building. Pollution can also occur inside a structure from internal sources of contamination, such …

Local Energy Governance In Vermont: An Analysis Of Energy System Transition Strategies And Actor Capacity, Tarah Rowse

Graduate College Dissertations and Theses

While global, national, and regional efforts to address climate and energy challenges remain essential, local governments and community groups are playing an increasingly stronger and vital role. As an active state in energy system policy, planning and innovation, Vermont offers a testing ground for research into energy governance at the local level. A baseline understanding of the energy planning and energy organizing activities initiated at the local level can support efforts to foster a transition to a sustainable energy system in Vermont. Following an inductive, applied and participatory approach, and grounded in the fields of sustainability transitions, energy planning, and …

Surface Gas Permeability Of Porous Building Materials: Measurement, Analysis And Applications, David Klein Weibust Grover

Graduate College Dissertations and Theses

In many events affecting our civil infrastructure, such as contamination or weathering, it is likely that only the surfaces of the affected building materials will be available for non-destructive measurements. In this work, we describe and analyze surface gas permeability measurements on a variety of natural and engineered building materials using two types of relatively new, non-destructive surface permeameters. It is shown that the surface gas permeability measurements correlate well with each other and could provide rapid estimates of macroscopic gas permeability and degradation of materials due to weathering. It is hypothesized that surface permeability can be used to predict …

Regulation Of Β-Casein Gene Expression By Octamer Transcription Factors And Utilization Of Β-Casein Gene Promoter To Produce Recombinant Human Proinsulin In The Transgenic Milk, Xi Qian

Graduate College Dissertations and Theses

β-Casein is a major milk protein, which is synthesized in mammary alveolar secretory epithelial cells (MECs) upon the stimulation of lactogenic hormones, mainly prolactin and glucocorticoids (HP). Previous studies revealed that the proximal promoter (-258 bp to +7 bp) of the β-casein gene is sufficient for induction of the promoter activity by HP. This proximal region contains the binding sites for the signal transducer and activator of transcription 5 (STAT5), glucocorticoid receptor (GR), and octamer transcription factors (Oct). STAT5 and GR are essential downstream mediators of prolactin and glucocorticoid signaling, respectively. This study investigated the functions of Oct-1 and Oct-2 …

Understanding And Improving Microbial Biofuel Tolerance As A Result Of Efflux Pump Expression Through Genetic Engineering And Mathematical Modeling, William James Turner

Graduate College Dissertations and Theses

Recent advances in synthetic biology have enabled the construction of non-native metabolic pathways for production of next-generation biofuels in microbes. One such biofuel is the jet-fuel precursor α-pinene, which can be processed into high-energy pinene dimers. However, accumulation of toxic biofuels in the growth medium limits the possible fuel yield. Overexpression of transporter proteins such as efflux pumps can increase tolerance to biofuels by pumping them out of the cell, thus improving fuel yields. However, too many efflux pumps can compromise the cell as well, creating a trade-off between biofuel toxicity and pump toxicity. In this work we improve the …

Design And Optimization Of Uwb Antenna For Air Coupled Gpr Applications, Amr Ahmed

Graduate College Dissertations and Theses

This thesis presents a novel antenna structure that satisfies the challenging requirements of an air coupled high speed ground penetrating radar (GPR). The desired GPR system is to achieve high spatial resolution and accurate inspection results while scanning at relatively high speed for highway pavement and bridge deck inspection. This work utilizes the Ultra Wide Band (UWB) antenna design to achieve both physical and electrical requirements imposed.

The design procedure starts with a short survey to discuss typical UWB antennas used for GPR applications, and various tradeoffs of each type specifically when used for Air Coupled GPR applications. Our structure …

Segregation Of Particles Of Variable Size And Density In Falling Suspension Droplets, Melissa Kathleen Faletra

Graduate College Dissertations and Theses

The problem of the falling under gravity suspension droplet was examined for cases where the droplet contains particles with different densities and different sizes. Cases examined include droplets composed of uniform-size particles with two different densities, of uniform-density particles of two different sizes, and of a distribution of particles of different densities. The study was conducted using both simulations based on Oseenlet particle interactions and laboratory experiments. It is observed that when the particles in the suspension droplet have different sizes and densities, an interesting segregation phenomenon occurs in which lighter/smaller particles are transported downward with the droplet and preferentially …