Bulletin of the American Physical Society
Fall 2011 Meeting of the APS Prairie Section
Volume 56, Number 13
Thursday–Saturday, November 10–12, 2011; Cedar Falls, Iowa
Session E1: Poster Session II (12:302:00PM) 
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Chair: Andrew Stollenwerk, University of Northern Iowa Room: UNI Center for Enery and Environmental Education Rotunda 

E1.00001: Elastic Pore Structure in Activated Carbon M.J. Connolly, Carlos Wexler Adsorbent materials such as activated carbon and MetalOrganic Frameworks (MOFs) have received significant attention as a potential storage material for hydrogen and natural gas. Typically the adsorbent material is assumed to consist of rigid slit or cylindricalshaped pores. Recent work, for MOFs in particular, revealed the importance of the mechanical response of the adsorbent in the presence of an adsorbate. In the absence of an adsorbate the pore structure is defined by the size, shape and intermolecular interactions of the constituent parts of the solid. Here, we demonstrate the flexibility of pore walls in activated carbon and the effect this has on the pore structure of the bulk samples. The interaction is modeled as a competition between Van der Waals interactions between neighboring walls and a resistance to bending due to the rigidity of graphene. Minimal energy configurations were calculated analytically for a simplified potential and numerically for a more realistic potential. The pore structures are discussed in the context of pore measurements on activated carbon samples. [Preview Abstract] 

E1.00002: Nanoscale Surface Modification of Layered Materials Aaron O'Shea A scanning electron microscope can magnify a sample many times greater than a standard microscope, down to nanoscale dimensions. It can also be used to form patterns on the surfaces of certain materials, a technique used to create microchips. We have developed a technique that simplifies and expedites this process using an unmodified scanning electron microscope. Using this technique, we are able to alter the surface chemistry in a controlled pattern on a special class of materials called transition metal dichalcogenides. These materials have many useful applications: industrial lubricants; high strength nanocomposites; advanced solar cells; and next generation electronics. Altering the surface chemistry of these materials at the nanoscale results in unusual quantum behavior, which is useful in nanotechnology. [Preview Abstract] 

E1.00003: The Multispace with its Multistructure as a Unified Field Theory Florentin Smarandache Let S$_{1}$, S$_{2}$, ..., S$_{n}$ be n structures on respectively the sets M$_{1}$, M$_{2}$, ..., M$_{n}$, where n $\ge $ 2 (n may even be infinite). The structures S$_{i}$, i = 1, 2, {\ldots}, n, may not necessarily be distinct two by two; each structure S$_{i}$ may be or not n$_{i}$concentric, for n$_{i} \quad \ge $ 1. And the sets M$_{i}$, i = 1, 2, {\ldots}, n, may not necessarily be disjoint, also some sets M$_{i }$ may be equal to or included in other sets M$_{j}$, j = 1, 2, {\ldots}, n. We defined the \textbf{multispace} M as a union of the previous sets: M = M$_{1} \quad \cup $ M$_{2} \quad \cup $ {\ldots} $\cup $ M$_{n}$, hence we have n (different or not, overlapping or not) structures on M. A multispace is a space with many structures that may overlap, or some structures may include others or may be equal, or the structures may interact and influence each other as in our everyday life. Therefore for a unified field theory we build a multispace M with a multistructure as a union of a gravitational space, electromagnetic space, weak interactions space, and strong interactions space. Then we construct a corresponding physical model. [Preview Abstract] 

E1.00004: Data analysis for the chaotic waterwheel George Rutherford, Benjamin Rogers, Richard Martin The Malkus waterwheel is a simple mechanical system whose behavior is approximated by the Lorenz equations. The ISU waterwheel consists of a circular disk on which are mounted 36 cylindrical cells. The wheel is tilted, and water enters the cells symmetrically at the top of the wheel. Each cell has a hole in the bottom to allow water to escape, and friction is provided by inductive braking. The wheel can exhibit quasiuniform rotation, periodic reversals, and chaotic reversals. The experimental data from our laboratory show good agreement with numerical simulations of the idealized model equations, although some significant differences remain. For example, at large values of the brake strength, the simulations show periodic motion, while the experimental data appear chaotic. This poster will describe the use of the 01 test for chaos to determine the nature (periodic or chaotic) for data over a range of brake strength values. This analysis contends that the experimental data at large damping values is indeed chaotic, in opposition to the numerical simulation prediction. We also report preliminary results of a novel method for determining the location of fixed points from the phase portraits of the experimental data. [Preview Abstract] 

E1.00005: rGRWf Theory of QM is Nonlocal Christopher Godfrey The rGRWf model (Tumulka 2006) is a proposed solution of the measurement problem of quantum mechanics involving a stochastic nonlinear wave equation embedded in a relativistic framework. Its primary feature is a mechanism that suppresses superpositions of macroscopically different states for macroscopic systems. The authors have claimed that the theory is local even though it is based on a nonlocal ``ontology.'' We give an argument which demonstrates several manifestly nonlocal characteristics of the rGRWf theory and discuss the general implications for nonlinear collapse theories. [Preview Abstract] 

E1.00006: Individualbased Modeling of a \textit{Pseudomonas aeruginosa} Biofilm with Glucose Substrate Matthew J. Steffens, Barbara J. Clement, Christopher D. Wentworth Individualbased modeling is a technique for simulating the spatially explicit dynamics of a community of individuals that can each be in a different state. In this investigation we use IBM to simulate growth of a simple biofilm system: \textit{Pseudomonas aeruginosa} with a glucose substrate. The recently published IBM framework for microbial communities, iDynoMiCS, is used together with growth parameters from a recent kinetics study of this system to explore patterns of films over a 24 hour growth period for a twodimensional and a 12 hour growth period for a threedimensional model. [Preview Abstract] 

E1.00007: Defining the Velocity Field of Root Cells in \textit{Arabidopsis} Seedlings Using Open Source Image Processing Tools Amy E. Craig, Brad R. Higgins, Tracy Guy, Tessa Durham Brooks, Christopher D. Wentworth The velocity field for cells in a growing root is a function of a cell's position with respect to the root apex and time. For many species of plant this function has the same general sigmoid shape described by a modified logistics curve. In this investigation we obtain microscopic images of \textit{Arabidopsis} seedling roots over a 20 minute period of time, measure the velocity field for root cells using an application developed with the open source mathematics application Octave, and test whether the velocity field can be described by the modified logistics function. We find support for describing the velocity field by the modified logistics function. [Preview Abstract] 

E1.00008: Measurement of Lightning Generated XRays Emily Bell, Zach Monti, Nick Olson, Brittany Shannon, Adam Keller, Christopher Fasano Lightning is a dramatic process that demands study and explanation. The mechanisms that cause lightning and the mechanisms by which lightning proceeds are complex and still areas of active study. In particular, understanding how lightning generates Xrays provides an interesting avenue of investigation. We report on our effort to build a prototype detector package to measure the energy spectrum of XRays produced by natural lightning while recording electric field strength and meteorological data. Knowing and understanding this energy spectrum along with electric field strength and meteorological data will play an important role in understanding the process by which lightning is produced and proceeds and it will allow testing of a variety of models that have been suggested for producing lightning and for producing Xrays. [Preview Abstract] 

E1.00009: Magnetic Behavior Of MnIntercalated $TaS_2$ Zach Griffith, Stroh Leslie, P.M. Shand, Tim Kidd, Laura Strauss In this project, the magnetic properties of manganeseintercalated tantalum disulfide ($MnTaS_2$) grown in nanotube form were investigated. Two samples were studied; one with 15\% Mn and the other with 23\% Mn . These samples were investigated thoroughly by dc magnetization and ac susceptibility measurements. For $Mn_{.23}TaS_2$, a sharp upturn in the dc magnetization and ac susceptibility at $\sim$ 100 K heralded a ferromagnetic transition, which is similar to the behavior exhibited by bulk crystals with a similar concentration of Mn. Ac susceptibility measurements with and without an applied dc magnetic field in the vicinity of the transition temperature confirmed ferromagnetic critical behavior in this sample. In the $Mn_{.15}TaS_2$ sample, a spinglasslike transition was observed at $\sim$ 10 K, consistent with a disordered distribution of the intercalated Mn ions. The outofphase ac susceptibility, which is very sensitive to phase transitions, was nonzero at temperatures substantially above that of the spinglasslike transition. This suggested the presence of strong magnetic correlations far above the transition likely resulting in shortrange ordering. Significant deviation from the CurieWeiss law supports the presence of shortrange ordering far above the transition temperature. The anisotropic nature of the $TaS_2Mn_{0.15}$ nanotubes may have contributed to the unusual behavior, but more research in this area is needed. [Preview Abstract] 
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