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Optimization Of Cardiac Pacing Stimulation By Current Configuration –A Theoretical, Numerical And Experimental Study., Flavio H. Fenton, Hila Dvir, Neil Hardy 2017 Georgia Institute of Technology

Optimization Of Cardiac Pacing Stimulation By Current Configuration –A Theoretical, Numerical And Experimental Study., Flavio H. Fenton, Hila Dvir, Neil Hardy

Biology and Medicine Through Mathematics Conference

No abstract provided.


Using An Atomic Molecular Optics Laboratory For Undergraduate Research And Mentoring Of Physics Students In Georgia, Matthew P. Dallas 2017 Georgia College and State University

Using An Atomic Molecular Optics Laboratory For Undergraduate Research And Mentoring Of Physics Students In Georgia, Matthew P. Dallas

Georgia College Student Research Events

Using an Atomic Molecular Optics Laboratory for Undergraduate Research and Mentoring of Physics Students in Georgia

An Atomic and Molecular Optical (AMO) Physics research lab is an excellent tool to train and mentor undergraduate students in advanced laboratory techniques. Students gain valuable basic experience in experimental designs, data acquisition techniques, working with high precision optical equipment, building electronics, and working in the machine shop. The current project is building and testing an enclosure for the diode laser to reduce sound and vibrational interference. In addition, we are developing and evaluating a new, more compact laser cavity which is 3d printed ...


Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman 2017 Georgia College and State University

Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman

Georgia College Student Research Events

Cryptography has been around since the dawn of human civilization to send private messages for commercial, military, and political purposes. Some of the most important ciphers are the Vigenère cipher, the enigma, and the more modern RSA. Because of the development of the internet, private encryption has also become increasingly more important. The weakest link of encryption is the key creation and key distribution. A key is needed to encrypt and decipher codes and is needed by both the user and sender. A solution to this problem is the generation of quantum key distributions. In our experiment, we are now ...


3d Printing Plastic Scintillators, Madison Durrance, Nicolas Merino, Emily Vanderwolf 2017 Georgia College and State University

3d Printing Plastic Scintillators, Madison Durrance, Nicolas Merino, Emily Vanderwolf

Georgia College Student Research Events

Scintillation is the production of visible light in a transparent material when exposed to either an electron, ion, or some other high energy particle. There are many ways to manufacture scintillators, but unfortunately many of these methods involve the costly machining of crystal materials. We plan to reduce this cost by attempting to manufacture plastic scintillators using a 3D printer. The most difficult challenge has been making transparent prints. We have had success with PET filament, the same plastic used in soda bottles. Upon successful clear prints, we intend to use recycled bottles to manufacture our own doped fiber. Organic ...


Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das 2017 University of Nebraska-Lincoln

Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das

Theses, Dissertations, and Student Research: Department of Physics and Astronomy

No abstract provided.


Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, María E. Dávila, JR Dennison 2017 Instituto de Ciencia de Materiales de Madrid

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, María E. Dávila, Jr Dennison

Presentations

An unexpected behavior of the Secondary Emission Yield (SEY) on coatings composed by a mixture of conductor and dielectric microparticles was reported and modeled in [1]. As a follow up, we measured for a fixed primary energy the dynamic evolution of the SEY in similar samples and proposed a charging-roughness coupled model to simulate the experimental results. Two different coatings were selected: 1) TMM and Al microparticles (type 1), and 2) zeolites and gold nanoparticles (type 2). Pulsed and continuous tests were used to obtain the SEY as a function of the primary energy.

In both types of samples extremely ...


Temperature Of The Plasmasphere From Van Allen Probes Hope, Kevin J. Genestreti, Jerry Goldstein, Grace D. Corley, William Farner, Lynn M. Kistler, Brian A. Larsen, Christopher G. Mouikis, Chae Ramnarace, Ruth M. Skoug, Niescja E. Turner 2017 Trinity University

Temperature Of The Plasmasphere From Van Allen Probes Hope, Kevin J. Genestreti, Jerry Goldstein, Grace D. Corley, William Farner, Lynn M. Kistler, Brian A. Larsen, Christopher G. Mouikis, Chae Ramnarace, Ruth M. Skoug, Niescja E. Turner

Niescja E. Turner

We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one-dimensional E→×B→ drifting Maxwellian and that the potential field and motion of the spacecraft may be accounted for in the simplest possible manner, i.e., by a linear shift of coordinates. The ...


Antitumor Activity Of Selected Derivatives Of Pyrazole- Benzenesulfonamides From Dilithiated C(Α), N-Phenylhydrazones And Lithiated Methyl 2-(Aminosulfonyl)Benzoate, N. Dwight Camper [deceased], James M. Gum, Darby E. Lyles, William T. Pennington, Charles F. Beam, Clyde R. Metz 2017 Clemson University

Antitumor Activity Of Selected Derivatives Of Pyrazole- Benzenesulfonamides From Dilithiated C(Α), N-Phenylhydrazones And Lithiated Methyl 2-(Aminosulfonyl)Benzoate, N. Dwight Camper [Deceased], James M. Gum, Darby E. Lyles, William T. Pennington, Charles F. Beam, Clyde R. Metz

Journal of the South Carolina Academy of Science

Several pyrazole-benzenesulfonamides were subjected to biological evaluation involving tumor formation on potato discs caused by Agrobacterium tumefaciens. This assay led to some excellent and promising initial results with three of the pyrazole compounds showing increased tumor inhibition when compared to a recognized standard, camptothecin. The select pyrazole-benzenesulfonamides were prepared by condensation-cyclization of several dilithiated C(α),N-phenylhydrazones with lithiated methyl 2-aminosulfonyl-benzoate.


Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson 2017 University of Windsor

Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson

Physics Publications

The absolute concentration of zinc in human fingernail clippings tested ex vivo was determined by 1064 nm laser-induced breakdown spectroscopy and confirmed by speciated isotope dilution mass spectrometry. A nail testing protocol that sampled across the nail (perpendicular to the direction of growth) was developed and validated by scanning electron microscopy energy dispersive x-ray spectroscopy. Using this protocol, a partial least squares regression model predicted the zinc concentration in five subjects’ fingernails to within 7 ppm on average. The variation of the zinc concentration with depth into the nail as determined by laser-induced breakdown spectroscopy was studied and found to ...


Design And Characterization Of A Time-Of-Flight Mass Spectrometer For Composition Measurements In The Upper Atmosphere, E. Addison Everett 2017 Utah State University

Design And Characterization Of A Time-Of-Flight Mass Spectrometer For Composition Measurements In The Upper Atmosphere, E. Addison Everett

All Graduate Theses and Dissertations

In-situ composition measurements of the mesosphere/lower thermosphere (MLT) are challenging; this region is only accessible via high-speed sounding rockets, ambient pressures extend into the 10-3 Torr range, and particles of interest range in mass from electrons to meteoric smoke and dust particles. Time-of-flight mass spectrometers (TOF-MS) are capable of making fast, accurate measurements over a wide mass range. However, since they rely on pressure-sensitive microchannel plate (MCP) detectors and high voltages, they have rarely been applied at these altitudes. A new TOF-MS for making in-situ composition measurements in the MLT has been developed at the Space Dynamics Laboratory ...


Variable "Be" Stars In The Perseus Constellation, Peter Barsevskis 2017 Thompson Rivers University

Variable "Be" Stars In The Perseus Constellation, Peter Barsevskis

Proceedings of the Annual Thompson Rivers University Undergraduate Research and Innovation Conference

Over four nights between September 26th and October 23rd, the young star cluster “h Persei” was observed with a CCD camera attached to a Celestron telescope. The two stars, Oo 1278 and Oo 1282, are the primary focus of this research project. The apparent magnitudes for these two stars were plotted against time to create light curves to study the variability. Oo 1282 was found to be a variable star as its differential magnitude varies with time. Fourier Analysis found three frequencies for a multiperiodic trend of the differential magnitude for Oo 1282, but there was insufficient data to carry ...


Implementation And Characterization Of A Magneto-Optical Trap, Michael Anthony Highman 2017 Otterbein University

Implementation And Characterization Of A Magneto-Optical Trap, Michael Anthony Highman

Honors Thesis Projects

Rydberg atoms are those which have their valence electron excited to high principal quantum number n. Atoms in the Rydberg state are the research focus of the experiment from which this paper derives. Rydberg atoms are fragile, and thermal collisions are enough to ionize and destroy the Rydberg state. A magneto-optical trap (MOT) serves the purpose of "ultra-cooling" atoms to temperatures around 140 micro-Kelvin and dramatically reduces the impact of thermal collisions. This paper details the theory and equipment necessary to realize a MOT of rubidium-85. It will then discuss the characterization of the MOT we implemented by a technique ...


Tio2 Coating Method For Nanocellulose Aerogel, Byron Fritch 2017 University of Northern Iowa

Tio2 Coating Method For Nanocellulose Aerogel, Byron Fritch

Research in the Capitol

Titanium dioxide has been shown to be an effective catalyst for splitting water into hydrogen and oxygen gas. By increasing the surface area of the titanium dioxide catalyst, the rate of water splitting may increase. A possible method to increase the splitting of water uses a high surface area composite material formed by coating nanocellulose aerogels with titanium dioxide. Different coating methods were studied using titanium isopropoxide as the titanium dioxide source to create such composites. It was found that the most consistent titanium dioxide coatings were formed during a 12 hour titanium isopropoxide vapor bath. Other coating methods collapsed ...


How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner 2017 Wright State University - Main Campus

How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner

Naum I. Gershenzon

Description of the transitional process from a static to a dynamic frictional regime is a fundamental problem of modern physics. Previously, we developed a model based on the well-known Frenkel-Kontorova model to describe dry macroscopic friction. Here, this model has been modified to include the effect of dissipation in derived relations between the kinematic and dynamic parameters of a transition process. The main (somewhat counterintuitive) result is a demonstration that the rupture (i.e., detachment front) velocity of the slip pulse which arises during the transition does not depend on friction. The only parameter (besides the elastic and plastic properties ...


How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner 2017 Wright State University - Main Campus

How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner

Gust Bambakidis

Description of the transitional process from a static to a dynamic frictional regime is a fundamental problem of modern physics. Previously, we developed a model based on the well-known Frenkel-Kontorova model to describe dry macroscopic friction. Here, this model has been modified to include the effect of dissipation in derived relations between the kinematic and dynamic parameters of a transition process. The main (somewhat counterintuitive) result is a demonstration that the rupture (i.e., detachment front) velocity of the slip pulse which arises during the transition does not depend on friction. The only parameter (besides the elastic and plastic properties ...


How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner 2017 Wright State University - Main Campus

How Does Dissipation Affect The Transition From Static To Dynamic Macroscopic Friction?, Naum I. Gershenzon, Gust Bambakidis, Thomas E. Skinner

Thomas E. Skinner

Description of the transitional process from a static to a dynamic frictional regime is a fundamental problem of modern physics. Previously, we developed a model based on the well-known Frenkel-Kontorova model to describe dry macroscopic friction. Here, this model has been modified to include the effect of dissipation in derived relations between the kinematic and dynamic parameters of a transition process. The main (somewhat counterintuitive) result is a demonstration that the rupture (i.e., detachment front) velocity of the slip pulse which arises during the transition does not depend on friction. The only parameter (besides the elastic and plastic properties ...


Half-Metallic Co-Based Quaternary Heusler Alloys For Spintronics: Defect- And Pressure-Induced Transitions And Properties, Enamullah, D. D. Johnson, K. G. Suresh, Aftab Alam 2017 Indian Institute of Technology Bombay

Half-Metallic Co-Based Quaternary Heusler Alloys For Spintronics: Defect- And Pressure-Induced Transitions And Properties, Enamullah, D. D. Johnson, K. G. Suresh, Aftab Alam

Duane D. Johnson

Heusler compounds offer potential as spintronic devices due to their spin polarization and half-metallicity properties, where electron spin-majority (minority) manifold exhibits states (band gap) at the electronic chemical potential, yielding full spin polarization in a single manifold. Yet, Heuslers often exhibit intrinsic disorder that degrades its half-metallicity and spin polarization. Using density-functional theory, we analyze the electronic and magnetic properties of equiatomic Heusler (L21) CoMnCrAl and CoFeCrGe alloys for effects of hydrostatic pressure and intrinsic disorder (thermal antisites, binary swaps, and vacancies). Under pressure, CoMnCrAl undergoes a metallic transition, while half-metallicity in CoFeCrGe is retained for a limited range. Antisite ...


Origin Of Magnetic Anisotropy In Doped Ce2co17 Alloys, Liqin Ke, D. A. Kukusta, Duane D. Johnson 2017 Ames Laboratory

Origin Of Magnetic Anisotropy In Doped Ce2co17 Alloys, Liqin Ke, D. A. Kukusta, Duane D. Johnson

Duane D. Johnson

Magnetocrystalline anisotropy (MCA) in doped Ce2Co17 and other competing structures was investigated using density functional theory. We confirmed that the MCA contribution from dumbbell Co sites is very negative. Replacing Co dumbbell atoms with a pair of Fe or Mn atoms greatly enhance the uniaxial anisotropy, which agrees quantitatively with experiment, and this enhancement arises from electronic-structure features near the Fermi level, mostly associated with dumbbell sites. With Co dumbbell atoms replaced by other elements, the variation of anisotropy is generally a collective effect and contributions from other sublattices may change significantly. Moreover, we found that Zr doping promotes the ...


Stacking 2d Materials, Michael Hernandez, John C. Mann 2017 Pepperdine University

Stacking 2d Materials, Michael Hernandez, John C. Mann

Seaver College Research And Scholarly Achievement Symposium

Monolayer Transition Metal Dichalcogenides are atomically thin semi-conductors that are considered quasi 2D materials due to their extremely small thickness. It has been observed that atomically thin crystals exhibit different physical properties than their bulk counterparts due to quantum confinement effects. We are attempting discover new physical properties by developing a technique to stack two different monolayer crystals, MoS2 and MoSe2.


Experimental Studies Of Electrical Resistivity Behavior Of Cu, Zn And Co Along Their Melting Boundaries: Implications For Heat Flux At Earth’S Inner Core Boundary, Innocent Chinweikpe Ezenwa 2017 The University of Western Ontario

Experimental Studies Of Electrical Resistivity Behavior Of Cu, Zn And Co Along Their Melting Boundaries: Implications For Heat Flux At Earth’S Inner Core Boundary, Innocent Chinweikpe Ezenwa

Electronic Thesis and Dissertation Repository

Abstract

The electrical resistivity of high purity Cu, Zn and Co has been measured at pressures (P) up to 5GPa and at temperatures (T) in the liquid phase. The electrical resistivity of solid state Nb was also measured up to 5GPa and ~1900K. All measurements were made in a large volume cubic anvil press. Using two thermocouples placed at opposite ends of the sample wire, serving as temperature probes as well as resistance leads, a four-wire technique resistivity measurement was employed along with a polarity switch. Post-experiment compositional analyses were carried out on an electron microprobe.

The expected resistivity decrease ...


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