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Development Of 3d Thermal Models To Analyze Building Power Loss, Mark Leggiero 2019 University of North Georgia

Development Of 3d Thermal Models To Analyze Building Power Loss, Mark Leggiero

Georgia Undergraduate Research Conference (GURC)

Radiative heat loss from external surfaces is a large component in overall building heat loss, and efficient methods of measuring total radiative heat loss from buildings need to be further developed. 3D thermal model analysis of such facilities can aid substantially in understanding heat loss. High-overlap radiometric images can be obtained using small aerial drones outfitted with an infrared camera, and photogrammetry algorithms can generate 3D thermal models which contain the composited radiometric data of such images. Multiple 3D models have been produced (in the OBJ file format) of buildings in the University of North Georgia’s Dahlonega campus. Current ...


Simphysics, Taylor Woods, Maidel Fletes, Mary Elizabeth Harrell, Paul Halford 2019 Columbus State University

Simphysics, Taylor Woods, Maidel Fletes, Mary Elizabeth Harrell, Paul Halford

Georgia Undergraduate Research Conference (GURC)

Understanding and interpreting relationships and functional trends with 2-D graphs are foundational skills in STEM fields, in other sciences and in all disciplines that utilize data analysis. Introductory physics courses regularly start with the topic of kinematics which heavily utilizes 2-D graphs that describe motion. This is why difficulties that students face in understanding 2-D graphs surface early on in physics. Yet, for this same reason kinematics can be used as a great opportunity to teach graphing skills in general. The primary goal of this project is to develop an interactive intelligent tutoring system (PhysicsSim) that makes use of kinematics ...


From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen 2019 University of Illinois at Urbana-Champaign

From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen

Faculty Journal Articles

The flow of granular materials and metallic glasses is governed by strongly correlated, avalanche-like deformation. Recent comparisons focused on the scaling regimes of the small avalanches, where strong similarities were found in the two systems. Here, we investigate the regime of large avalanches by computing the temporal profile or “shape” of each one, i.e., the time derivative of the stress-time series during each avalanche. We then compare the experimental statistics and dynamics of these shapes in granular media and bulk metallic glasses. We complement the experiments with a mean-field model that predicts a critical size beyond which avalanches turn ...


P-13 Astronomy From Ripples In Spacetime, Tiffany Summerscales 2019 Andrews University

P-13 Astronomy From Ripples In Spacetime, Tiffany Summerscales

Celebration of Research and Creative Scholarship

The LIGO and Virgo detectors have made a total of 11 confirmed measurements of gravitational waves, the faint ripples in the fabric of spacetime predicted by Einstein’s theory of general relativity. Ten of these gravitational wave events were caused by the inspiral, collision, and merging of a pair of black holes and the remaining event by a pair of neutron stars. These measurements have helped us learn about the objects that produced the gravitational waves. Regular candidate detections are now shared in real time with both astronomers and the public.


Visualization And Quantitation Of Radioiodine Distribution In Silver Zeolite Cartridges, Daniel DiMarco 2019 Louisiana State University

Visualization And Quantitation Of Radioiodine Distribution In Silver Zeolite Cartridges, Daniel Dimarco

LSU Master's Theses

Iodine 131 is a major fission product released during a nuclear incident. This isotope provides a serious health hazard for humans and the environment, therefore nuclear power plants must monitor releases using air sampling. The air sampling is accomplished using air filter cartridges using silver zeolite as a filter media. During an emergency situation, silver zeolite is useful for its affinity to I-131 without adsorbing other radioactive gases. After leaving the plume, these cartridges are counted in a low background area. This measurement does not take into account the distribution of radioiodine in the cartridge. This study explores two methods ...


Slowing Down Of Spin Glass Correlation Length Growth: Simulations Meet Experiments, Qiang Zhai, V. Martin-Mayor, Deborah L. Schlagel, Gregory G. Kenning, Raymond L. Orbach 2019 University of Texas at Austin

Slowing Down Of Spin Glass Correlation Length Growth: Simulations Meet Experiments, Qiang Zhai, V. Martin-Mayor, Deborah L. Schlagel, Gregory G. Kenning, Raymond L. Orbach

Deborah L. Schlagel

The growth of the spin glass correlation length has been measured as a function of the waiting time tw on a single crystal of CuMn (6 at. %), reaching values ξ∼150 nm, larger than any other glassy correlation length measured to date. We find an aging rate dlntw/dlnξ larger than found in previous measurements, which evinces a dynamic slowing down as ξ grows. Our measured aging rate is compared with simulation results by the Janus Collaboration. After critical effects are taken into account, we find excellent agreement with the Janus data.


Complex Oscillatory Decrease With Size In Diffusivity Of {100}-Epitaxially Supported 3d Fcc Metal Nanoclusters, King C. Lai, James W. Evans 2019 Iowa State University and Ames Laboratory

Complex Oscillatory Decrease With Size In Diffusivity Of {100}-Epitaxially Supported 3d Fcc Metal Nanoclusters, King C. Lai, James W. Evans

James W. Evans

Diffusion and coalescence of supported 3D metal nanoclusters (NCs) leads to Smoluchowski Ripening (SR), a key pathway for catalyst degradation. Variation of the NC diffusion coefficient, DN, with size N (in atoms) controls SR kinetics. Traditionally, a form DN ∼ N−β was assumed consistent with mean-field analysis. However, KMC simulation of a stochastic model for diffusion of {100}-epitaxially supported fcc NCs mediated by surface diffusion reveals instead a complex oscillatory decrease of DN with N. Barriers for surface diffusion of metal atoms across and between facets, along step edges, etc., in this model are selected to accurately capture behavior ...


Effect Of Synthesized 3-Hydroxyflavone Solutions On The Performance Of Dye-Sensitized Solar Cells, Aarya Kapani, Hasitha Mahabaduge 2019 Georgia College and State University

Effect Of Synthesized 3-Hydroxyflavone Solutions On The Performance Of Dye-Sensitized Solar Cells, Aarya Kapani, Hasitha Mahabaduge

Georgia Journal of Science

We investigated the influence of synthesized dye combination 3-hydroxyflavone with potassium hydroxide and sodium hydroxide as photosynthesizers for dye-sensitized solar cells (DSSCs). DSSCs are classified as hybrid inorganic/organic photovoltaic cells that have been reported to have lower production costs and efficiency as high as 12%. Annealed titanium dioxide pastes on fluorine doped tin oxide was used as the front layer of the completed devices and the performance of 3-hydroxyflavone with potassium hydroxide and sodium hydroxide was compared with the performance of dyes extracted from berries. UV-vis spectroscopy was used to characterize the absorbance of the respective absorber dyes. 3-Hydroxyflavone ...


Topology Of Earth's Magnetic Shield: Modeled Properties And Applications, David Alan Smith 2019 Utah State University

Topology Of Earth's Magnetic Shield: Modeled Properties And Applications, David Alan Smith

David Smith

The open-closed boundary (OCB) defines the region where geomagnetic field
lines transition from being closed to open. A closed field line has both
foot points at or near Earth in opposing hemispheres. An open field line has
one foot point at Earth while the other maps to the interplanetary magnetic
field (IMF). Charged particles are able to follow these open field lines
into Earth's upper atmosphere. The altitude to which these charged particles
penetrate is a function of particle energy and latitude and is known as the
energy cutoff latitude (CL). Given sufficient energy, these charged
particles may reach ...


A Diffraction Paradox: An Unusually Broad Diffraction Background Signals Ideal Graphene, Shen Chen, Michael Horn-von Hoegen, Patricia A. Thiel, Michael C. Tringides 2019 Iowa State University and Ames Laboratory

A Diffraction Paradox: An Unusually Broad Diffraction Background Signals Ideal Graphene, Shen Chen, Michael Horn-Von Hoegen, Patricia A. Thiel, Michael C. Tringides

Patricia A. Thiel

The realization of the unusual properties of 2-d materials requires the formation of large domains of single layer thickness, extending over the mesoscale. It is found that the formation of ideal graphene on SiC, contrary to textbook diffraction , is signaled by a strong bell-shaped-component (BSC) around the (00) and G(10), but not the SiC(10) spots.The BSC is also seen for graphene on metals, because single layer uniform graphene with large lateral size can also be grown. It is only seen by electron diffraction and not with X-ray or He-scattering experiments. Most likely it originates from the spatial ...


Physics Professor Receives $250k From Nsf To Help Advance Climate Science, 2019 Selected Works

Physics Professor Receives $250k From Nsf To Help Advance Climate Science

Frank Robinson

Sacred Heart University has received $252,060 from the National Science Foundation (NSF) to help advance climate science. This grant will help fund an undergraduate physics research program introducing juniors and seniors to cutting-edge scientific research, intended to bridge major gaps in climate modeling.


In Situ Investigation Of Magnetism In Metastable Phases Of Levitated Fe83b17 During Solidification, D. G. Quirinale, D. Messina, G. E. Rustan, Andreas Kreyssig, Ruslan Prozorov, Alan I. Goldman 2019 Iowa State University

In Situ Investigation Of Magnetism In Metastable Phases Of Levitated Fe83b17 During Solidification, D. G. Quirinale, D. Messina, G. E. Rustan, Andreas Kreyssig, Ruslan Prozorov, Alan I. Goldman

A. I. Goldman

In situ measurements of structure, density, and magnetization on samples of Fe83B17 using an electrostatic levitation furnace allow us to identify and correlate the magnetic and structural transitions in this system during its complex solidification process. In particular, we identify magnetic ordering in the metastable Fe23B6/ fcc Fe coherently grown structures and primitive tetragonal Fe3B metastable phase in addition to characterizing the equilibrium Fe2B phase. Our measurements demonstrate that the incorporation of a tunnel-diode oscillator circuit within an electrostatic levitation furnace enables investigations of the physical properties of high-temperature metastable structures.


Distinct Pressure Evolution Of Coupled Nematic And Magnetic Orders In Fese, Anna E. Böhmer, Karunakar Kothapalli, Wageesha T. Jayasekara, John M. Wilde, Bing Li, Aashish Sapkota, Benjamin G. Ueland, Pinaki Das, Yumin Xiao, Wenli Bi, Jiyong Zhao, E. Ercan Alp, Sergey L. Bud’ko, Paul C. Canfield, Alan I. Goldman, Andreas Kreyssig 2019 Ames Laboratory and Karlsruhe Institute of Technology

Distinct Pressure Evolution Of Coupled Nematic And Magnetic Orders In Fese, Anna E. Böhmer, Karunakar Kothapalli, Wageesha T. Jayasekara, John M. Wilde, Bing Li, Aashish Sapkota, Benjamin G. Ueland, Pinaki Das, Yumin Xiao, Wenli Bi, Jiyong Zhao, E. Ercan Alp, Sergey L. Bud’Ko, Paul C. Canfield, Alan I. Goldman, Andreas Kreyssig

A. I. Goldman

We present a microscopic study of nematicity and magnetism in FeSe over a wide temperature and pressure range using high-energy x-ray diffraction and time-domain Mössbauer spectroscopy. The low-temperature magnetic hyperfine field increases monotonically up to ∼ 6 GPa. The orthorhombic distortion initially decreases under increasing pressure but is stabilized at intermediate pressures by cooperative coupling to the pressure-induced magnetic order. Close to the reported maximum of the superconducting critical temperature at p = 6.8 GPa , the orthorhombic distortion suddenly disappears and a new tetragonal magnetic phase occurs. The pressure and temperature evolution of the structural and magnetic order parameters suggests that ...


Heisenberg Model Analysis On Inelastic Powder Neutron Scattering Data Using Parent And K Doped Bamn2as2 Samples, Mehmet Ramazanoglu, Aashish Sapkota, Abhishek Pandey, Jagat Lamsal, Douglas L. Abernathy, Jennifer L. Niedziela, Matthew B. Stone, R. Salci, D. A. Acar, F. O. Oztirpan, Şener Ozonder, Andreas Kreyssig, Alan I. Goldman, David C. Johnston, Robert J. McQueeney 2019 Istanbul Technical University

Heisenberg Model Analysis On Inelastic Powder Neutron Scattering Data Using Parent And K Doped Bamn2as2 Samples, Mehmet Ramazanoglu, Aashish Sapkota, Abhishek Pandey, Jagat Lamsal, Douglas L. Abernathy, Jennifer L. Niedziela, Matthew B. Stone, R. Salci, D. A. Acar, F. O. Oztirpan, Şener Ozonder, Andreas Kreyssig, Alan I. Goldman, David C. Johnston, Robert J. Mcqueeney

A. I. Goldman

Low temperature powder inelastic neutron scattering measurements were performed on three different powder samples; parent BaMn2As2,12.5% K-doped Ba0.875K0.125Mn2As2 and 25% K-doped Ba(0.75)K0.25Mn2As2. The Heisenberg Model involving J1‐J2‐Jz coupling constants were compared to the data by a powder integration routine using Monte Carlo integration methods. The best magnetic parameters were selected using a chi-square test where model intensities were compared to the full (q,E) dependence of magnetic scattering. A key step to this analysis is the characterization of the background which is formed mostly by phonon scattering intensities along with ...


Antiferromagnetic Stacking Of Ferromagnetic Layers And Doping-Controlled Phase Competition In Ca1−X Srx Co2−Y As2, Bing Li, Yuriy Sizyuk, Nediadath S. Sangeetha, John M. Wilde, Pinaki Das, W. Tian, David C. Johnston, Alan I. Goldman, Andreas Kreyssig, Peter P. Orth, Robert J. McQueeney, Benjamin G. Ueland 2019 Iowa State University and Ames Laboratory

Antiferromagnetic Stacking Of Ferromagnetic Layers And Doping-Controlled Phase Competition In Ca1−X Srx Co2−Y As2, Bing Li, Yuriy Sizyuk, Nediadath S. Sangeetha, John M. Wilde, Pinaki Das, W. Tian, David C. Johnston, Alan I. Goldman, Andreas Kreyssig, Peter P. Orth, Robert J. Mcqueeney, Benjamin G. Ueland

A. I. Goldman

In search of a quantum phase transition between the two-dimensional (2D) ferromagnetism of CaCo2−yAs2 and stripe-type antiferromagnetism in SrCo2 As2, we instead find evidence for 1D magnetic frustration between magnetic square Co layers. We present neutron-diffraction data for Ca1−x Srx Co2−y As2 that reveal a sequence of x -dependent magnetic transitions which involve different stacking of 2 D ferromagnetically aligned layers with different magnetic anisotropy. We explain the x-dependent changes to the magnetic order by utilizing classical analytical calculations of a 1D Heisenberg model where single-ion magnetic anisotropy and frustration of antiferromagnetic nearest- and next-nearest-layer exchange interactions ...


Crystal Growth, Microstructure, And Physical Properties Of Srmnsb2, Yong Liu, Tao Ma, Warren E. Straszheim, Farhan Islam, Brandt A. Jensen, Wei Tian, Thomas Heitmann, R. A. Rosenberg, John M. Wilde, Bing Li, Andreas Kreyssig, Alan I. Goldman, Benjamin G. Ueland, Robert J. McQueeney, David Vaknin 2019 Ames Laboratory

Crystal Growth, Microstructure, And Physical Properties Of Srmnsb2, Yong Liu, Tao Ma, Warren E. Straszheim, Farhan Islam, Brandt A. Jensen, Wei Tian, Thomas Heitmann, R. A. Rosenberg, John M. Wilde, Bing Li, Andreas Kreyssig, Alan I. Goldman, Benjamin G. Ueland, Robert J. Mcqueeney, David Vaknin

A. I. Goldman

We report on the crystal and magnetic structures and magnetic and transport properties of SrMnSb2 single crystals grown by the self-flux method. Magnetic susceptibility measurements reveal an antiferromagnetic (AFM) transition at TN=295(3) K. Above TN, the susceptibility slightly increases and forms a broad peak at T∼420 K, which is a typical feature of two-dimensional magnetic systems. Neutron diffraction measurements on single crystals confirm the previously reported C-type AFM structure below TN. Both de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects are observed in SrMnSb2 single crystals. Analysis of the oscillatory component by a Fourier transform shows ...


Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. McQueeney 2019 Iowa State University and Ames Laboratory

Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. Mcqueeney

A. I. Goldman

Whereas magnetic frustration is typically associated with local-moment magnets in special geometric arrangements, here we show that SrCo2As2 is a candidate for frustrated itinerant magnetism. Using inelastic neutron scattering (INS), we find that antiferromagnetic (AF) spin fluctuations develop in the square Co layers of SrCo2As2 below T approximate to 100 K centered at the stripe-type AF propagation vector of (1/2, 1/2), and that their development is concomitant with a suppression of the uniform magnetic susceptibility determined via magnetization measurements. We interpret this switch in spectral weight as signaling a temperature-induced crossover from an instability toward ferromagnetism ordering to ...


Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. McQueeney 2019 Iowa State University and Ames Laboratory

Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. Mcqueeney

Peter P. Orth

Whereas magnetic frustration is typically associated with local-moment magnets in special geometric arrangements, here we show that SrCo2As2 is a candidate for frustrated itinerant magnetism. Using inelastic neutron scattering (INS), we find that antiferromagnetic (AF) spin fluctuations develop in the square Co layers of SrCo2As2 below T approximate to 100 K centered at the stripe-type AF propagation vector of (1/2, 1/2), and that their development is concomitant with a suppression of the uniform magnetic susceptibility determined via magnetization measurements. We interpret this switch in spectral weight as signaling a temperature-induced crossover from an instability toward ferromagnetism ordering to ...


Skyrmions And Spirals In Mnsi Under Hydrostatic Pressure, L. J. Bannenberg, R. Sadykov, R. M. Dalgliesh, C. Goodway, Deborah L. Schlagel, Thomas A. Lograsso, P. Falus, E. Lelièvre-Berna, A. O. Leonov, C. Pappas 2019 Delft University of Technology

Skyrmions And Spirals In Mnsi Under Hydrostatic Pressure, L. J. Bannenberg, R. Sadykov, R. M. Dalgliesh, C. Goodway, Deborah L. Schlagel, Thomas A. Lograsso, P. Falus, E. Lelièvre-Berna, A. O. Leonov, C. Pappas

Thomas A. Lograsso

The archetype cubic chiral magnet MnSi is home to some of the most fascinating states in condensed matter, such as skyrmions and a non-Fermi-liquid behavior in conjunction with a topological Hall effect under hydrostatic pressure. Using small angle neutron scattering, we study the evolution of the helimagnetic, conical, and skyrmionic correlations with increasing hydrostatic pressure. We show that the helical propagation vector smoothly reorients from ⟨111⟩ to ⟨100⟩ at intermediate pressures. At higher pressures, above the critical pressure, the long-range helimagnetic order disappears at zero magnetic field. Nevertheless, skyrmion lattices and conical spirals form under magnetic fields, in a part ...


Skyrmions And Spirals In Mnsi Under Hydrostatic Pressure, L. J. Bannenberg, R. Sadykov, R. M. Dalgliesh, C. Goodway, Deborah L. Schlagel, Thomas A. Lograsso, P. Falus, E. Lelièvre-Berna, A. O. Leonov, C. Pappas 2019 Delft University of Technology

Skyrmions And Spirals In Mnsi Under Hydrostatic Pressure, L. J. Bannenberg, R. Sadykov, R. M. Dalgliesh, C. Goodway, Deborah L. Schlagel, Thomas A. Lograsso, P. Falus, E. Lelièvre-Berna, A. O. Leonov, C. Pappas

Deborah L. Schlagel

The archetype cubic chiral magnet MnSi is home to some of the most fascinating states in condensed matter, such as skyrmions and a non-Fermi-liquid behavior in conjunction with a topological Hall effect under hydrostatic pressure. Using small angle neutron scattering, we study the evolution of the helimagnetic, conical, and skyrmionic correlations with increasing hydrostatic pressure. We show that the helical propagation vector smoothly reorients from ⟨111⟩ to ⟨100⟩ at intermediate pressures. At higher pressures, above the critical pressure, the long-range helimagnetic order disappears at zero magnetic field. Nevertheless, skyrmion lattices and conical spirals form under magnetic fields, in a part ...


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