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Full-Text Articles in Physics

Finite-Strain Scale-Free Phase-Field Approach To Multivariant Martensitic Phase Transformations With Stress-Dependent Effective Thresholds, Hamed Babaei, Valery I. Levitas Nov 2020

Finite-Strain Scale-Free Phase-Field Approach To Multivariant Martensitic Phase Transformations With Stress-Dependent Effective Thresholds, Hamed Babaei, Valery I. Levitas

Aerospace Engineering Publications

A scale-free phase-field model for martensitic phase transformations (PTs) at finite strains is developed as an essential generalization of small-strain models in Levitas et al. (2004) and Idesman et al. (2005). The theory includes finite elastic and transformational strains and rotations as well as anisotropic and different elastic properties of phases. The gradient energy term is excluded, and the model is applicable for any scale greater than 100 nm. The model tracks finite-width interfaces between austenite and the mixture of martensitic variants only; volume fractions of martensitic variants are the internal variables rather than order parameters. The concept of the ...


Substitutional And Interstitial Doping In Laco5 System For The Development Of Hard Magnetic Properties: A First Principles Study, Huseyin Ucar, Renu Choudhary, Durga Paudyal Sep 2020

Substitutional And Interstitial Doping In Laco5 System For The Development Of Hard Magnetic Properties: A First Principles Study, Huseyin Ucar, Renu Choudhary, Durga Paudyal

Ames Laboratory Accepted Manuscripts

We investigate here the changes in the electronic structure at the transition metal sites of the RE-TM5 structure (RE = Rare Earth, TM = Transition Metal) while doping the interstitial sites with nitrogen. LaCo5 compound is taken as the baseline compound owing to its critically needed intrinsic magnetic properties such as magneto-crystalline anisotropy energy (MAE) of ≈5 meV/fu [1] due to the contributions from the cobalt network. In addition, because of the lack of 4f electrons in lanthanum, complications originating from the treatment of the 4f localized electrons are absent in this compound; making it an ideal reference material to all ...


High Layer Uniformity Of 2-D Materials Surprisingly From Broad Features In Surface Electron Diffraction, Shen Chen, Michael Horn Von Hoegen, Patricia A. Thiel, Adam Kaminski, Benjamin Schrunk, Thanassis Speliotis, Edward Henry Conrad, Michael C. Tringides Sep 2020

High Layer Uniformity Of 2-D Materials Surprisingly From Broad Features In Surface Electron Diffraction, Shen Chen, Michael Horn Von Hoegen, Patricia A. Thiel, Adam Kaminski, Benjamin Schrunk, Thanassis Speliotis, Edward Henry Conrad, Michael C. Tringides

Chemistry Publications

Paradoxically a very broad diffraction background, named the Bell-Shaped-Component (BSC), has been established as a feature of graphene growth. Although the BSC has been present in the earlier literature it has been ignored. Recent diffraction studies as a function of electron energy have shown that the BSC is not related to scattering interference. The BSC is a very strong effect, but its origin is still unclear. Here, additional experiments are carried out as a function of temperature while monitoring changes in the intensity of different spots over the range that single-layer-graphene (SLG) grows. Quantitative fitting of the profiles shows that ...


Elmer Fem-Dakota: A Unified Open-Source Computational Framework For Electromagnetics And Data Analytics, Anjali Sandip Aug 2020

Elmer Fem-Dakota: A Unified Open-Source Computational Framework For Electromagnetics And Data Analytics, Anjali Sandip

Mechanical Engineering Faculty Publications

Open-source electromagnetic design software, Elmer FEM, was interfaced with data analytics toolkit, Dakota. Furthermore, the coupled software was validated against a benchmark test. The interface developed provides a unified open-source computational framework for electromagnetics and data analytics. Its key features include uncertainty quantification, surrogate modelling and parameter studies. This framework enables a richer understanding of model predictions to better design electric machines in a time sensitive manner.


A Hybrid Achromatic Metalens, Fatih Balli, Mansoor A. Sultan, Sarah K. Lami, J. Todd Hastings Aug 2020

A Hybrid Achromatic Metalens, Fatih Balli, Mansoor A. Sultan, Sarah K. Lami, J. Todd Hastings

Electrical and Computer Engineering Faculty Publications

Metalenses, ultra-thin optical elements that focus light using subwavelength structures, have been the subject of a number of recent investigations. Compared to their refractive counterparts, metalenses offer reduced size and weight, and new functionality such as polarization control. However, metalenses that correct chromatic aberration also suffer from markedly reduced focusing efficiency. Here we introduce a Hybrid Achromatic Metalens (HAML) that overcomes this trade-off and offers improved focusing efficiency over a broad wavelength range from 1000-1800 nm. HAMLs can be designed by combining recursive ray-tracing and simulated phase libraries rather than computationally intensive global search algorithms. Moreover, HAMLs can be fabricated ...


Electromagnetic Interference Reduction Of High-Speed Digital And Analog Circuits Using Engineered Electromagnetic Bandgap Structures, Brandon Ramos Aug 2020

Electromagnetic Interference Reduction Of High-Speed Digital And Analog Circuits Using Engineered Electromagnetic Bandgap Structures, Brandon Ramos

Undergraduate Research Journal

In this paper, we will discuss the concerns of a microstrip two patch antenna system. Coupling of the two-port system can be miniaturized using Electromagnetic Bandgap Structures (EBG) or Defected Ground Structures (DGS) centered between the two patch antennas half a wavelength in size. Different miniaturization methods were used in the design of the antenna system to change the properties of the signal. Changing via locations that are not found on EBG strips themselves, rather found on interleaved ledges between EBG strips allowed for further change in shifting the signals frequency.


Designing A Reactor Chamber For Hot Electron Chemistry On Bimetallic Plasmonic Nanoparticles, Bryn Merrill, Bingjie Zhang, Jerry Larue Aug 2020

Designing A Reactor Chamber For Hot Electron Chemistry On Bimetallic Plasmonic Nanoparticles, Bryn Merrill, Bingjie Zhang, Jerry Larue

SURF Posters and Papers

Catalysis provides pathways for efficient and selective chemical reactions by lowering the energy barriers for desired products. Gold nanoparticles (AuNPs) show excellent promise as plasmonic catalysts. Plasmonic materials have localized surface plasmon resonances, oscillations of the electron bath at the surface of a nanoparticle, that generate energetically intense electric fields which rapidly decay into energetically excited electrons. The excited electrons have the potential to destabilize atoms strongly bound to the catalysts through occupation of antibonding orbitals. Tuning the antibonding orbitals to make them accessible for occupancy by electrons is achieved by coating the AuNP in a thin layer of another ...


Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight Aug 2020

Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight

Theses, Dissertations, and Student Research from Electrical & Computer Engineering

In this dissertation, optical Hall effect (OHE) measurements are used to determine the free charge carrier properties of important two-dimensional materials and monoclinic oxides. Two-dimensional material systems have proven useful in high-frequency electronic devices due to their unique properties, such as high mobility, which arise from their two-dimensional nature. Monoclinic oxides exhibit many desirable characteristics, for example low-crystal symmetry which could lead to anisotropic carrier properties. Here, single-crystal monoclinic gallium oxide, an AlInN/GaN-based high-electron-mobility transistor (HEMT) structure, and epitaxial graphene are studied as examples. To characterize these material systems, the OHE measurement technique is employed. The OHE is a ...


Adaptive Spline Fitting With Particle Swarm Optimization, Soumya Mohanty, Ethan Fahnestock Aug 2020

Adaptive Spline Fitting With Particle Swarm Optimization, Soumya Mohanty, Ethan Fahnestock

Physics and Astronomy Faculty Publications and Presentations

In fitting data with a spline, finding the optimal placement of knots can significantly improve the quality of the fit. However, the challenging high-dimensional and non-convex optimization problem associated with completely free knot placement has been a major roadblock in using this approach. We present a method that uses particle swarm optimization (PSO) combined with model selection to address this challenge. The problem of overfitting due to knot clustering that accompanies free knot placement is mitigated in this method by explicit regularization, resulting in a significantly improved performance on highly noisy data. The principal design choices available in the method ...


Cooking Systems Using Aluminum Foam, Ryan Tetsuo Mizukami Aug 2020

Cooking Systems Using Aluminum Foam, Ryan Tetsuo Mizukami

Physics

In developing countries, the use of wood burning fires for cooking is cause for illness and death. With this in mind, research was conducted to develop a solar cooking device capable of cooking of soup within 15 mins in order to reduce the negative impacts of cooking with wood. Current methods of solar-based cooking, such as solar concentrators and solar tube ovens, are impractical. A small solar panel is a cost-effective way to produce energy but will not produce enough power to cook within a reasonable amount of time. Even if it is assumed that all of the energy produced ...


Developing Arduino Coding Curriculum, Tyler Brown, Riley Bucheitte, Timothy Kidd Jul 2020

Developing Arduino Coding Curriculum, Tyler Brown, Riley Bucheitte, Timothy Kidd

Summer Undergraduate Research Program (SURP)

No abstract provided.


Eusectra: European Nuclear Security Training Centre Providing Hands-On Training And Education In Nuclear Security And Safeguards, Willem Janssens, Veronique Berthou, Abbas Kamel, Jean Galy, Klaus Luetzenkirchen, Klaus Mayer, Stefan Nonneman Jul 2020

Eusectra: European Nuclear Security Training Centre Providing Hands-On Training And Education In Nuclear Security And Safeguards, Willem Janssens, Veronique Berthou, Abbas Kamel, Jean Galy, Klaus Luetzenkirchen, Klaus Mayer, Stefan Nonneman

International Journal of Nuclear Security

The European Nuclear Security Training Centre (EUSECTRA) inaugurated under this global name about 10 years ago and operated by the European Commission Joint Research Centre (JRC), located both on the Karlsruhe (Germany) and Ispra (Italy) sites, includes a large variety of capacity building and professional development activities which span from the hands-on training for nuclear security and safeguards actors (e.g. respectively border guards or customs and nuclear inspectors) to educational efforts in both nuclear security and safeguards. Whereas the first ones, which gave rise to the new name, focus mainly on detection, on-site assistance, crime-scene management, technical reach-back and ...


Generation Of Correlated Dual Frequency Combs With Pm Fiber Lasers For High-Precision Metrology, Hanieh Afkhamiardakani Jul 2020

Generation Of Correlated Dual Frequency Combs With Pm Fiber Lasers For High-Precision Metrology, Hanieh Afkhamiardakani

Optical Science and Engineering ETDs

Intracavity Phase Interferometry (IPI) using two correlated, counter-propagating frequency combs (pulse trains) in mode-locked lasers has evolved into a powerful technique for high-precision metrology. In this method a physical parameter to be measured imparts a phase shift onto a pulse circulating in the laser cavity. Inside a laser cavity, that phase shift becomes a frequency shift (phase shift/round-trip time) applied to the whole frequency comb created by this pulse as it exits the cavity at each round-trip. This frequency shift is measured by interfering this comb with a reference comb created by a reference pulse circulating in the same ...


Reynolds-Stress Modeling Of Cluster-Induced Turbulence In Particle-Laden Vertical Channel Flow, Michael C. Baker, Rodney O. Fox, Bo Kong, Jesse Capecelatro, Olivier Desjardins Jul 2020

Reynolds-Stress Modeling Of Cluster-Induced Turbulence In Particle-Laden Vertical Channel Flow, Michael C. Baker, Rodney O. Fox, Bo Kong, Jesse Capecelatro, Olivier Desjardins

Chemical and Biological Engineering Publications

Particle-laden flow in a vertical channel was simulated using a Reynolds-averaged Navier-Stokes two-fluid model including a Reynolds-stress model (RSM). Two sets of cases varying the overall mass loading were done using particle sizes corresponding to either a large or small Stokes number. Primary and turbulent statistics extracted from counterpart Eulerian-Lagrangian and Eulerian-Eulerian anisotropic-Gaussian simulations were used to inform parameters and closures applied in the RSM. While the behavior at the center of the channel compared well with the other simulations, including the transition from fully developed turbulent flow to relaminarization to cluster-induced turbulence as the mass loading increased, the behavior ...


Search For Encapsulation Of Platinum, Silver, And Gold At The Surface Of Graphite, Ann Lii-Rosales, Yong Han, Dapeng Jing, Michael C. Tringides, Patricia A. Thiel Jul 2020

Search For Encapsulation Of Platinum, Silver, And Gold At The Surface Of Graphite, Ann Lii-Rosales, Yong Han, Dapeng Jing, Michael C. Tringides, Patricia A. Thiel

Chemistry Publications

Using scanning tunneling microscopy, we show that Pt clusters can be encapsulated beneath the surface of graphite, whereas Ag and Au cannot. This is in complete agreement with independent predictions from density functional theory, which show that surface intercalation of single metal atoms is favorable for Pt, but unfavorable for Ag and Au. This supports the validity of using single-metal-atom energetics for predicting encapsulation of metal nanoparticles at the graphite surface. We also demonstrate that the optimal temperature for encapsulation scales with the cohesive energy of the metal.


Radiation-Balanced Fiber Lasers And Amplifiers, Esmaeil Mobini Souchelmaei Mr Jul 2020

Radiation-Balanced Fiber Lasers And Amplifiers, Esmaeil Mobini Souchelmaei Mr

Optical Science and Engineering ETDs

Over the past decades, high-power fiber lasers and amplifiers have been extensively under research to achieve higher output powers. However, temperature rise in the core of fiber lasers and amplifiers has been a big issue in power-scaling. Radiation-balancing is a viable technique introduced for effective heat mitigation in lasers and amplifiers by S. Bowman in 1995. Radiation-balancing relies on solid-state laser cooling as a self-cooling mechanism to mitigate the generated heat in lasers and amplifiers. To implement the mentioned idea in fiber lasers and amplifiers, a set of issues should be scrutinized; (i) the amenability of silica glass (as the ...


Van Der Waals Epitaxy Of Ultrathin Early Transition Metal (Ti & V) (Di)Selenides: Charge And Magnetic Order In The Ultrathin Limit, Manuel Bonilla Lopez Jun 2020

Van Der Waals Epitaxy Of Ultrathin Early Transition Metal (Ti & V) (Di)Selenides: Charge And Magnetic Order In The Ultrathin Limit, Manuel Bonilla Lopez

Graduate Theses and Dissertations

Since the isolation of graphene in 2004, two-dimensional (2D) layered materials, specially the transition metal dichalcogenides (TMDs), have attracted immense interest from theoreticians and experimentalist due to the diversity of properties presented in this family of materials. The main reason for the interest in such materials has been the observation of emergent properties as a consequence of the reduced dimensions, i.e. the monolayer regime. Initially the monolayer regime was obtained via the scotch-tape method. The implementation of exfoliation techniques was successful since layered 2D materials are composed of stacked layers held together by weak van der Walls forces that ...


Demonstration Of A Distributed Bragg Reflector For Polyvinylcarbazole And Cadmium Sulfide Layers: Modeling And Comparison To Experimental Results, Javier E. Hasbun, L. Ajith Desilva Jun 2020

Demonstration Of A Distributed Bragg Reflector For Polyvinylcarbazole And Cadmium Sulfide Layers: Modeling And Comparison To Experimental Results, Javier E. Hasbun, L. Ajith Desilva

Georgia Journal of Science

Light wave propagation in a periodically stratified medium has many applications in physics, mathematics, and engineering. The subject is of interest to students, teachers, and researchers, as it presents a great opportunity to focus on principles of optics and to understand the basics of mathematical modeling. A complete theory of wave propagation can be derived using Born’s optics theory. We employed that theory to determine the reflectivity of a one-dimensional distributed Bragg reflector (DBR) and do simulations using MATLAB. A DBR is a photonic crystal consisting of alternating layers of materials with different refractive indices. In this study, we ...


Unprecedented Generation Of 3d Heterostructures By Mechanochemical Disassembly And Re-Ordering Of Incommensurate Metal Chalcogenides, Oleksandr Dolotko, Ihor Hlova, Arjun K. Pathak, Yaroslav Mudryk, Vitalij K. Pecharsky, Prashant Singh, Duane D. Johnson, Brett W. Boote, Jingzhe Li, Emily A. Smith, Scott L. Carnahan, Aaron J. Rossini, Lin Zhou, Ely M. Eastman, Viktor P. Balema Jun 2020

Unprecedented Generation Of 3d Heterostructures By Mechanochemical Disassembly And Re-Ordering Of Incommensurate Metal Chalcogenides, Oleksandr Dolotko, Ihor Hlova, Arjun K. Pathak, Yaroslav Mudryk, Vitalij K. Pecharsky, Prashant Singh, Duane D. Johnson, Brett W. Boote, Jingzhe Li, Emily A. Smith, Scott L. Carnahan, Aaron J. Rossini, Lin Zhou, Ely M. Eastman, Viktor P. Balema

Materials Science and Engineering Publications

Three-dimensional heterostructures are usually created either by assembling two-dimensional building blocks into hierarchical architectures or using stepwise chemical processes that sequentially deposit individual monolayers. Both approaches suffer from a number of issues, including lack of suitable precursors, limited reproducibility, and poor scalability of the preparation protocols. Therefore, development of alternative methods that enable preparation of heterostructured materials is desired. We create heterostructures with incommensurate arrangements of well-defined building blocks using a synthetic approach that comprises mechanical disassembly and simultaneous reordering of layered transition-metal dichalcogenides, MX2, and non-layered monochalcogenides, REX, where M = Ta, Nb, RE = Sm, La, and X = S, Se ...


Feasibility Of Electric Field Assisted Clogging Reduction In Cold Gas Spraying Nozzle, Hendric Tronsson Jun 2020

Feasibility Of Electric Field Assisted Clogging Reduction In Cold Gas Spraying Nozzle, Hendric Tronsson

ENGS 88 Honors Thesis (AB Students)

The relatively novel cold spraying process expands its range of applications constantly. In order to continue this trend, this process still has various hurdles that need to be overcome such as clogging. Clogging within the cold gas spraying process causes porous coatings with less material properties and lower durability; a solution is needed in order to reduce the clogging and so expand the cold gas spraying applications. This study aimed to explore the feasibility of using an electric field to reduce clogging. To do so a simplified channel was used to simulate charged particle trajectory shifts under the influence of ...


Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin Jun 2020

Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin

Mechanical Engineering

Studies suggest that when designed and executed well, hands-on activities can enhance student understanding of key mechanics concepts. Current products are expensive and typically not designed to meet a variety of learning objectives. Through the Mechanics of Inclusion and Inclusivity in Mechanics grant, the Cal Poly Physics and Engineering Departments are seeking to incorporate new hands-on activities into their courses. Our team has designed three inexpensive ”MechaniKits” to be used in physics, statics and dynamics courses [1]. This Final Design Review outlines our findings, objectives, and final designs for this project. It also explains our manufacturing and design verification plans ...


Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey Jun 2020

Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey

Publications and Research

La(Fe,Si)13–based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)13, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in ...


First-Order Magnetic Phase Transition In Pr2in With Negligible Thermomagnetic Hysteresis, Anis Biswas, N. A. Zarkevich, Arjun Pathak, Oleksandr Dolotko, Ihor Z. Hlova, A. V. Smirnov, Yaroslav Mudryk, Duane D. Johnson, Vitalij K. Pecharsky Jun 2020

First-Order Magnetic Phase Transition In Pr2in With Negligible Thermomagnetic Hysteresis, Anis Biswas, N. A. Zarkevich, Arjun Pathak, Oleksandr Dolotko, Ihor Z. Hlova, A. V. Smirnov, Yaroslav Mudryk, Duane D. Johnson, Vitalij K. Pecharsky

Materials Science and Engineering Publications

Magnetic first-order phase transitions are key for the emergence of functionalities of fundamental and applied significance, including magnetic shape memory as well as magnetostrictive and magnetocaloric effects. Such transitions are usually associated with thermomagnetic hysteresis. We report the observation of a first-order transition in Pr2In from a paramagnetic to a ferromagnetic state at TC=57K without a detectable thermomagnetic hysteresis, which is also accompanied by a large magnetocaloric effect. The peculiar electronic structure of Pr2In exhibiting a large density of states near the Fermi energy explains the highly responsive magnetic behavior of the material. The magnetic properties of Pr2In are ...


A Study Of The Design Of Adaptive Camber Winglets, Justin J. Rosescu Jun 2020

A Study Of The Design Of Adaptive Camber Winglets, Justin J. Rosescu

Master's Theses

A numerical study was conducted to determine the effect of changing the camber of a winglet on the efficiency of a wing in two distinct flight conditions. Camber was altered via a simple plain flap deflection in the winglet, which produced a constant camber change over the winglet span. Hinge points were located at 20%, 50% and 80% of the chord and the trailing edge was deflected between -5° and +5°. Analysis was performed using a combination of three-dimensional vortex lattice method and two-dimensional panel method to obtain aerodynamic forces for the entire wing, based on different winglet camber configurations ...


Modeling Single Microtubules As A Colloidal System To Measure The Harmonic Interactions Between Tubulin Dimers In Bovine Brain Derived Versus Cancer Cell Derived Microtubules, Arooj Aslam May 2020

Modeling Single Microtubules As A Colloidal System To Measure The Harmonic Interactions Between Tubulin Dimers In Bovine Brain Derived Versus Cancer Cell Derived Microtubules, Arooj Aslam

Dissertations

The local properties of tubulin dimers dictate the properties of the larger microtubule assembly. In order to elucidate this connection, tubulin-tubulin interactions are be modeled as harmonic interactions to map the stiffness matrix along the length of the microtubule. The strength of the interactions are measured by imaging and tracking the movement of segments along the microtubule over time, and then performing a fourier transform to extract the natural vibrational frequencies. Using this method the first ever reported experimental phonon spectrum of the microtubule is reported. This method can also be applied to other biological materials, and opens new doors ...


Waiting-Time Paradox In 1922, Naoki Masuda, Takayuki Hiraoka May 2020

Waiting-Time Paradox In 1922, Naoki Masuda, Takayuki Hiraoka

Northeast Journal of Complex Systems (NEJCS)

We present an English translation and discussion of an essay that a Japanese physicist, Torahiko Terada, wrote in 1922. In the essay, he described the waiting-time paradox, also called the bus paradox, which is a known mathematical phenomenon in queuing theory, stochastic processes, and modern temporal network analysis. He also observed and analyzed data on Tokyo City trams to verify the relevance of the waiting-time paradox to busy passengers in Tokyo at the time. This essay seems to be one of the earliest documentations of the waiting-time paradox in a sufficiently scientific manner.


Non-Equilibrium Growth Of Metal Clusters On A Layered Material: Cu On Mos2, Dapeng Jing, Ann Lii-Rosales, King C. Lai, Qiang Li, Jaeyoun Kim, Michael C. Tringides, James W. Evans, Patricia A. Thiel May 2020

Non-Equilibrium Growth Of Metal Clusters On A Layered Material: Cu On Mos2, Dapeng Jing, Ann Lii-Rosales, King C. Lai, Qiang Li, Jaeyoun Kim, Michael C. Tringides, James W. Evans, Patricia A. Thiel

Chemistry Publications

We use a variety of experimental techniques to characterize Cu clusters on bulk MoS2 formed via physical vapor deposition of Cu in ultrahigh vacuum, at temperatures ranging from 300 K to 900 K. We find that large facetted clusters grow at elevated temperatures, using high Cu exposures. The cluster size distribution is bimodal, and under some conditions, large clusters are surrounded by a denuded zone. We propose that defect-mediated nucleation, and coarsening during deposition, are both operative in this system. At 780 K, a surprising type of facetted cluster emerges, and at 900 K this type predominates: pyramidal clusters with ...


Phantoms To Placentas: Mr Methods For Oxygen Quantification, Kelsey Meinerz May 2020

Phantoms To Placentas: Mr Methods For Oxygen Quantification, Kelsey Meinerz

Arts & Sciences Electronic Theses and Dissertations

Molecular oxygen (O2) is vital for efficient energy production and improper oxygenation is a hallmark of disease or metabolic dysfunction. In many pathologies, knowledge of tissue oxygen levels (pO2) could aid in diagnosis and treatment planning. The gold standard for pO2 measures in tissue are implantable probes, which are invasive, require surgery for placement, and are inaccessible to certain regions of the body. Methods for determining pO2 both non-invasively and quantitatively are lacking. The slight paramagnetic nature of O2 provides opportunities to non-invasively characterize pO2 in tissue via magnetic resonance (MR) techniques. As such, O2 can be treated as a ...


Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman May 2020

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman

Macalester Journal of Physics and Astronomy

Glancing angle deposition (GLAD) is a process in which thin films are deposited onto a substrate with obliquely incident vapor together with precisely controlled azimuthal substrate rotation. Ballistic shadowing effects due to the oblique incidence produce nanoscale structures, and a variety of feature shapes, including tilted columns, helices, and vertical columns can be achieved by varying the azimuthal rotation during the deposition process. Due to this control of morphology and the compatibility of the process with a wide variety of materials, GLAD films have found applications in a variety of fields including sensing, photonics, photovoltaics, and catalysis, where they are ...


Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore May 2020

Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore

Macalester Journal of Physics and Astronomy

The current energy grid in the United States is dominated by carbon intense energy generation methods that are based on production when and where it is required. However, solar and wind power have proved themselves as the most promising carbon free energy generation sources. Due to the unpredictable and uncontrollable nature of energy production from solar and wind, large scale integration of these resources into the electric grid will require robust storage capacity. In this project, we model the energy grid of the Midcontinent Independent System Operator (MISO) energy region with high concentrations of solar and wind power to analyze ...