Physical Sciences and Mathematics Commons^™

Sulfur Dioxide Uptake And Oxidation In Sea-Salt Aerosol, William Hoppel, Louise Pasternack, Peter F. Caffrey, Glendon Frick, James Fitzgerald, Dean A. Hegg, Song Gao, John Ambrusko, Thomas Albrechcinski

Chemistry and Physics Faculty Articles

Measurements of SO₂ and O₃ uptake by sea-salt and NaCl aerosol were made in a 600 m³environmental chamber by measuring the rate of SO₂ and O₃ depletion during nebulization of seawater and NaCl solutions. The experiments were carried out with starting relative humidity between 80% and 92%, with SO₂ concentrations between 35 and 60 ppb, and ozone concentrations between O and 110 ppb. For NaCl, no SO₂ or O₃uptake was observed. For sea-salt aerosol, uptake in the range of 0.21 and 1.2 millimoles of S per liter of (nebulized) seawater …

Particle Formation And Growth From Ozonolysis Of Α-Pinene, William Hoppel, James Fitzgerald, Glendon Frick, Peter F. Caffrey, Louise Pasternack, Dean A. Hegg, Song Gao, W. Richard Leaitch, Nicole Shantz, Chris Cantrell, Thomas Albrechcinski, John Ambrusko, William Sullivan

Chemistry and Physics Faculty Articles

Observations of particle nucleation and growth during ozonolysis of α-pinene were carried out in Calspan's 600 m³ environmental chamber utilizing relatively low concentrations of α-pinene (15 ppb) and ozone (100 ppb). Model simulations with a comprehensive sectional aerosol model which incorporated the relevant gas-phase chemistry show that the observed evolution of the size distribution could be simulated within the accuracy of the experiment by assuming only one condensable product produced with a molar yield of 5% to 6% and a saturation vapor pressure (SVP) of about 0.01 ppb or less. While only one component was required to simulate the …

In-Cloud Oxidation Of So2 By O3 And H2o2: Cloud Chamber Measurements And Modeling Of Particle Growth, Peter F. Caffrey, William Hoppel, Glendon Frick, Louise Pasternack, James Fitzgerald, Dean A. Hegg, Song Gao, W. R. Leaitch, Nicole Shantz, Thomas Albrechcinski, John Ambrusko

Chemistry and Physics Faculty Articles

Controlled cloud chamber experiments were conducted to measure particle growth resulting from the oxidation of SO₂ by O₃ and H₂O₂ in cloud droplets formed on sulfuric acid seed aerosol. Clouds were formed in a 590 m³ environmental chamber with total liquid water contents ranging from 0.3–0.6 g m⁻³ and reactant gas concentrations <10 ppbv for SO₂ and H₂O₂ and <70 ppbv for O₃. Aerosol growth was measured by comparison of differential mobility analyzer size distributions before and after each 3–4 min cloud cycle. Predictions of aerosol growth were then made with a full microphysical cloud …

Experimental And Modeling Studies Of Secondary Organic Aerosol Formation And Some Applications To The Marine Boundary Layer, Song Gao, Dean A. Hegg, Glendon Frick, Peter F. Caffrey, Louise Pasternack, Chris Cantrell, William Sullivan, John Ambrusko, Thomas Albrechcinski, Thomas W. Kirchstetter

Chemistry and Physics Faculty Articles

A series of controlled experiments were carried out in the Calspan Corporation's 600 m³environmental chamber to study some secondary organic aerosol formation processes. Three precursor-ozone systems were studied: cyclopentene-ozone, cyclohexene-ozone, and α-pineneozone. Additionally, SO₂ was added to the initial gas mixture in several instances and was likely present at trace levels in the ostensibly organic-only experiments. It was found that all three systems readily formed new submicron aerosols at very low reactant levels. The chemical composition of formed aerosols was consistent with some previous studies, but the yields of organic products were found to be lower in …

Finiteness Notions In Fuzzy Sets, Lawrence Stout

Scholarship

Finite sets are one of the most fundamental mathematical structures. In the absence of the axiom of choice there are many different inequivalent definitions of finite even in classical logic. When we allow incomplete existence as in fuzzy sets the situation gets even more complicated. This paper gives nine distinct definitions of finite in a fuzzy context together with examples showing how the properties of the underlying lattice of truth values impact the meanings of finite.

Magnetic Ordering In An Organic Polymer, Andrzej Rajca, Jirawat Wongsriratanakul, Suchada Rajca

Andrzej Rajca Publications

We describe preparation and magnetic properties of an organic p-conjugated polymer with very large magnetic moment and magnetic order at low temperatures. The polymer is designed with a large density of cross-links and alternating connectivity of radical modules with unequal spin quantum numbers (S), macrocyclic S = 2 and, cross-linking S = ½ modules, which permits large net S values for either ferromagnetic or antiferromagnetic exchange couplings between the modules. In the highly cross-linked polymer, an effective magnetic moment corresponding to an average S of about 5000 and slow reorientation of the magnetization by a small magnetic field …

No Planet For Hd 166435, Didier Queloz, Gregory W. Henry, Jean-Pierre Sivan, Sallie L. Baliunas, Jean-Luc Beuzit, Robert A. Donahue, Michel Mayor, Dominique Naef, Christian Perrier, Stephane Udry

Information Systems and Engineering Management Research Publications

The G0 V star HD 166435 has been observed by the fiber-fed spectrograph ELODIE as one of the targets in the large extra-solar planet survey that we are conducting at the Observatory of Haute-Provence. We detected coherent, low-amplitude, radial-velocity variations with a period of 3.7987 days, suggesting a possible close-in planetary companion. Subsequently, we initiated a series of high-precision photometric observations to search for possible planetary transits and an additional series of Ca II H and K observations to measure the level of surface magnetic activity and to look for possible rotational modulation. Surprisingly, we found the star to be …

Micromagnetics Simulation Of Deep-Submicron Supermalloy Disks, Scott L. Whittenburg, Ngocnga Dao, R. P. Cowburn

Chemistry and Biochemistry Faculty Publications

The results of recent micromagnetic simulations of deep submicron supermalloy disks are presented. A recent experimental measurement of the hysteresis and magnetic domain structure in supermalloy disks with diameters ranging from 55 to 500 nm and thickness ranging from 6 to 15 nm has been reported. Our micromagnetic simulations show remarkable agreement with the experimental hysteresis loops. The simulation results show that for thin or small diameter disks a single magnetic domain exists with all spins aligned. The hysteresis loop represents free rotation of these spins. For larger diameter disks or as the thickness increases the hysteresis loops change shape …

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

We examined stainless samples that were exposed to LBE in experiments conducted by the Russians, under contract to Los Alamos. We examined both corroded and uncorroded samples using the Scanning Electron Microscope (SEM), the Energy Dispersive X-Ray (EDAX) Spectroscopy, and the X-ray Photoelectron Spectrometer (XPS). We found that the surface of the corroded sample is covered by oxygen-containing compounds, presumably mostly iron oxide. In samples exposed for shorter times or lower temperatures, we found that some areas were covered by an oxide layer, and some areas was uncovered. We found that the level of Cr in the uncovered area is …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report August 16,2001- November 15, 2001, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application.

Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 8/16/01- 11/15/01, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

The AAA program is developing technology for the transmutation of nuclear waste to address many of the long-term disposal issues. An integral part of this program is the proposed chemical separations scheme.

Two activities are proposed in this Phase I task: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 8/16/01- 11/15/01, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible. The process involves evacuation of the furnace. The evacuation of the furnace also evacuates quartz rods used as fuel pin molds. Once evacuated the open ends of the molds are lowered into the melt; the casting furnace is then rapidly pressurized, forcing the molten metal up into the evacuated molds where solidification occurs.

This process works well …

Exchange Bias In Fef20-Copt Heterosystems With Perpendicular Anisotropy, Christian Binek

Christian Binek Publications

The previous exchange bias effect is measured in heterosystems with perpendicular anisotropy consisting of Co/Pt multilayers on top of the (0 0 1) face of a previous FeF2 single crystal. The resulting previous exchange field HE exhibits a strong dependence on temperature and the axial freezing field, HF. Within the framework of an Ising-type model, the HE vs. T as well as the HE vs. HF data are explained in terms of the microscopic spin structure at the interface.

Ac Susceptibility Studies Of Discontinuous Co80fe20al2o3 Multilayers, Christian Binek

Christian Binek Publications

Discontinuous metal–insulator multilayers [Co80Fe20(t)/Al2O3(3 nm)]10 are prepared by ion-beam sputtering and investigated by SQUID magnetometry and previous AC susceptometry. For 1.0less-than-or-equals, slanttless-than-or-equals, slant1.6 nm, two coexisting subsystems of dipolar coupled nanoparticles are encountered. While a spin-glass-like freezing particulate fraction dominates at t=1.0 nm, a percolating dipolar ferromagnetic fraction becomes increasingly important at higher nominal thickness of t.

Entropy Splitting For High Order Numerical Simulation Of Vortex Sound At Low Mach Numbers, Bernhard Müller, H. C. Yee

United States National Aeronautics and Space Administration: Publications

Several recent developments in efficient, stable, highly parallelizable high order non-dissipative spatial schemes with characteristic based filters that exhibit low dissipation for long time linear and nonlinear wave propagations are utilized for computational aeroacoustics (CAA). For stability consideration, the Euler equations are split into a conservative and a symmetric non-conservative portion. Due to the large disparity of acoustic and stagnation quantities in low Mach number aeroacoustics, the split Euler equations are formulated in perturbation form to minimize numerical cancellation errors. Spurious oscillations are suppressed by a characteristic-based filter. The method has been applied to accurately simulate the sound emitted by …

Quantum Anomaly In Molecular Physics, Horacio E. Camblong

Physics and Astronomy

The interaction of an electron with a polar molecule is shown to be the simplest realization of a quantum anomaly in a physical system. The existence of a critical dipole moment for electron capture and formation of anions, which has been confirmed experimentally and numerically, is derived. This phenomenon is a manifestation of the anomaly associated with quantum symmetry breaking of the classical scale invariance exhibited by the point-dipole interaction. Finally, analysis of symmetry breaking for this system is implemented within two different models: point dipole subject to an anomaly and finite dipole subject to explicit symmetry breaking.

Anomaly Induced Qcd Potential And Quark Decoupling, Joseph Schechter, Stephen D.H. Hsu, Francesco Sannino

Physics - All Scholarship

We explore the anomaly induced effective QCD meson potential in the framework of the effective Lagrangian approach. We suggest a decoupling procedure, when a flavored quark becomes massive, which mimics the one employed by Seiberg for supersymmetric gauge theories. It is seen that, after decoupling, the QCD potential naturally converts to the one with one less flavor. We study the N_c and N_f dependence of the \eta^{\prime} mass.

Ethnomathematics: Challenging Traditional Notions Of Mathematical Authority, Christopher D. Goff

College of the Pacific Faculty Presentations

No abstract provided.

Monte Carlo Simulation Of Homogeneous Binary Vapor–Liquid Nucleation: Mutual Enhancement Of Nucleation In A Partially Miscible System, S. Yoo, K.J. Oh, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Gibbs free energy of ij-cluster formation ΔG_ij is obtained via the relation n_ij=Ne^{-ΔG_ij /k_BT}, where N is the number of molecules in the system, T is temperature, and kB is the Boltzmann constant. The saddle point on the free energy surface ΔG_ij versus i and j provides a measure of the activation barrier to nucleation ΔG *. A statistical mechanical formula of ΔG_ij is derived based on the physical-cluster theory of nucleation, and from which a molecular interpretation of ΔG_{ij …}

Differential Responses Of Coyotes To Novel Stimuli In Familiar And Unfamiliar Settings, Charles E. Harris, Frederick F. Knowlton

United States Department of Agriculture Wildlife Services: Staff Publications

We studied behavioral responses of captive and wild coyotes (Canis latrans) toward novel objects and artificial scent stations to determine how they might respond to novel stimuli used in coyote management and research. When captive coyotes encountered novel stimuli in unfamiliar surroundings they showed little avoidance, while the same stimuli caused avoidance and neophobic reactions among coyotes when encountered in familiar surroundings. In the field phase of the study, radio-collared coyotes in southern Texas were intensively monitored in order to relate space-use patterns to the locations where these coyotes were exposed to artificial scent stations. Coyotes were more …

The Demographic Response Of Bank-Dwelling Beavers To Flow Regulation: A Comparison On The Green And Yampa Rivers, Stewart W. Breck, Kenneth R. Wilson, Douglas C. Anderson

United States Department of Agriculture Wildlife Services: Staff Publications

We assessed the effects of flow regulation on the demography of beavers (Castor canadensis) by comparing the density, home-range size, and body size of bank-dwelling beavers on two sixth-order alluvial river systems, the flow-regulated Green River and the free-flowing Yampa River, from 1997 to 2000. Flow regulation on the Green River has altered fluvial geomorphic processes, influencing the availability of willow and cottonwood, which, in turn, has influenced the demography of beavers. Beaver density was higher on the Green River (0.5–0.6 colonies per kilometer of river) than on the Yampa River (0.35 colonies per kilometer of river). Adult …

The Vacuum Buffer, Voicu Popescu

Link Foundation Modeling, Simulation and Training Fellowship Reports

Image-based rendering (IBR) techniques have the potential of alleviating some of the bottlenecks of traditional geometry-based rendering such as modeling difficulty and prohibitive cost of photorealism. One of the most appealing IBR approaches uses images enhanced with per-pixel depth and creates new views by 3D warping (IBRW). Modeling a scene with depth images lets one automatically capture intricate details, which are hard to model conventionally. Also, rendering from such representations has the potential of being efficient since it seems that the number of samples that need to be warped is independent of the scene complexity and is just a fraction …

Characterization Of The Native Cr2O3 Oxide Surface Of Cro2, Ruihua Cheng, B. Xu, C.N. Borca, Andrei Sokolov, C.S. Yang, Lu Yuan, Sy_Hwang Liou, Bernard Doudin, Peter A. Dowben

Peter Dowben Publications

Using photoemission and inverse photoemission, we have been able to characterize the Cr₂O₃ oxide surface of CrO₂ thin films. The Cr₂O₃ surface oxide exhibits a band gap of about 3 eV, although the bulk CrO₂ is conducting. The thickness of this insulating Cr₂O₃ layer is twice the photoelectron escape depth which is about 2 nm thick. The effective Cr₂O₃ surface layer Debye temperature, describing motion normal to the surface, is about 370 K. From a comparison of CrO₂ films grown by different techniques, with different …

The Formation Of Vortex Loops (Strings) In Continuous Phase Transitions, Mark Bowick, Angelo Cacciuto, Alex Travesset

Physics - All Scholarship

The formation of vortex loops (global cosmic strings) in an O(2) linear sigma model in three spatial dimensions is analyzed numerically. For over-damped Langevin dynamics we find that defect production is suppressed by an interaction between correlated domains that reduces the effective spatial variation of the phase of the order field. The degree of suppression is sensitive to the quench rate. A detailed description of the numerical methods used to analyze the model is also reported.

Transverse Magnetism Of The Diluted Antiferromagnet Fe1-Xmgxbr2 (X=0.15), Christian Binek

Christian Binek Publications

Neutron diffraction and magnetization measurements of the diluted crystal Fe1−xMgxBr2 (xnot, vert, similar0.15) were performed. Successive phase transitions at zero applied field at TN1not, vert, similar12 K and TN2not, vert, similar10 K were found. A previous transverse term ferromagnetic moment was detected just below TN2.

Comments On “Errors In The Estimate Of The Fractal Correlation Dimension Of Raindrop Spatial Distribution”, A. R. Jameson, Alexander Kostinski

Department of Physics Publications

No abstract provided.

Synthesis Of A New Hollandite-Type Manganese Oxide With Framework And Interstitial Cr(Iii), Stanton Ching, Peter F. Driscoll, Katarzyna S. Krukowska, Michael R. Marvel, Steven L. Suib

Chemistry Faculty Publications

Hollandite with Cr(III) in both tunnel and framework sites has been prepared hydrothermally from layered manganese oxide precursors.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 3, November 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Bronx River Restoration: Report And Assessment, Nicole Marshall

Student Theses 2001-2013

No abstract provided.

Energetic Particles And Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, G. Qin, Vyacheslav S. Lukin , '00, C. D. Cothran, Michael R. Brown, W. H. Matthaeus

Physics & Astronomy Faculty Works

Results from the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] indicate that formation and partial merging of two spheromak plasmas can be described well by a magnetohydrodynamic (MHD) picture in which there is substantial evolution towards force free states within each vessel, while reconnection activity, also described reasonably well by MHD, occurs in the region of interaction. MHD simulations [V. S. Lukin , Phys. Plasmas 8, 1600 (2001)] support and provide further detail to this interpretation. In the present study, test particle equations are integrated using MHD data from SSX simulations to further understand the …