Physical Sciences and Mathematics Commons^™

Exact Topological Density In The Lattice Skyrme Model, Alec Schramm, Benjamin Svetitsky

Alec J Schramm

We propose using the Skyrme model on a lattice as an effective field theory of meson–baryon interactions. To this end we construct a local topological density that involves the volumes of tetrahedra in the target space S3 and we make use of Coxeter’s formula for the Schla¨fli function to implement it. We calculate the mean-square radius of a skyrmion in the three-dimensional Skyrme model, and find some surprises.

Modelling X-Ray Variability In The Structured Atmospheres Of Hot Stars., L. M. Oskinova, R. Ignace, J. C. Brown, J. P. Cassinelli

Richard Ignace

We describe X-ray production in the atmospheres of hot, early-type stars in the framework of a "stochastic shock model". The extended envelope of a star is assumed to possess numerous X-ray emitting "hot" zones that are produced by shocks and embedded in the ambient "cold" medium in dynamical equilibrium. It is shown that the apparent lack of X-ray variability on short (similar to hours) timescales do not contradict a shock model for X-ray production. The character of the X-ray variability is found to depend on the frequency with which hot zones are generated, the cool wind opacity to X-rays, and …

Dobór Systemu Oczyszczania Gazów Odlotowych Ze Spalania Odpadów Niebezpiecznych, Robert Oleniacz

Robert Oleniacz

The flue gas cleaning system is usually one of the most costly elements of the installation to the incineration of hazardous waste. Adapting the system to the actual needs could therefore bring obvious economic benefits.

The paper presents the method of the preselection of the configuration of the cleaning system based on knowledge of the level of concentration of selected components of the raw exhaust gas (sulfur dioxide, hydrogen chloride, hydrogen fluoride, total dust, mercury, cadmium and thallium, and other heavy metals). Twelve examples of flue-gas cleaning systems were proposed and extreme concentration values of the substances in the raw …

Niezorganizowana Emisja Zanieczyszczeń Powietrza Z Hal Ciągłego Odlewania Stali, Marian Mazur, Marek Bogacki, Robert Oleniacz, Agnieszka Łopata

Robert Oleniacz

Air pollutant emissions occurring in an uncontrolled way do not be subject to the regular verification just like it takes place in case of the controlled sources, for which the routine measurements are carried out. In the paper a methodology and the results of some research were presented. The research consisted in determination the quantity of dust and gaseous pollutants emitted from the halls in which technological processes connected with the steel continuous casting were being run. Stocktaking of all the uncontrolled emission sources were carried out and the technological operations predominating in the level of the particle matter and …

Study Of The Effective Transverse Momentum Of Partons In The Proton Using Prompt Photons In Photoproduction At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci

Faculty Publications

The photoproduction of prompt photons, together with an accompanying jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. A study of the effective transverse momentum, (kT), of partons in the proton, as modelled within the framework of the PYTHIA Monte Carlo, gives a value of (kT) = 1.69 ± 0.18 -0.20+0.18 GeV for the γp centre-of-mass energy range 134 < W < 251 GeV. This result is in agreement with the previously observed trend in hadron-hadron scattering for (kT) to rise with interaction energy. © 2001 Elsevier Science B.V.

Complex Effects Arising In Smoke Plume Simulations Due To Inclusion Of Direct Emissions Of Oxygenated Organic Species From Biomass Combustion, Sherri A. Mason, Richard J. Field, Robert J. Yokelson, Michael A. Kochivar, Mark R. Tinsley, Darold E. Ward, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

Oxygenated volatile organic species (oxygenates), including HCOOH, H₂CO, CH₃OH, HOCH₂CHO (hydroxyacetaldehyde), CH₃COOH, and C₆H₅OH, have recently been identified by Fourier transform infrared measurements as a significant component of the direct emissions from biomass combustion. These oxygenates have not generally been included in the hydrocarbon-based initial emission profiles used in previous photochemical simulations of biomass combustion smoke plumes. We explore the effects of oxygenates on this photochemistry by using an established initial emission hydrocarbon profile and comparing simulation results obtained both with and without addition of the above six …

The Indian “Problem” In Washington And Oregon: Exploring Connections Between Natural Resources And Indian Policy, Kevin Bourgault, Stefanie Wickstrom, Rex Wirth

Political Science Faculty Scholarship

Relationships between indigenous Americans and non-indigenous settlers of the western United States were determined in great part by the presence or absence of natural resources for which the groups competed. This paper is a study of the shifting patterns of inter-ethnic relations and governmental policies towards Indians and resources in Washington and Oregon from the 1850s to the present. We explore the connections between natural resource endowments on aboriginal lands, beliefs about indigenous peoples, and changing governmental policies affecting indigenous American communities in the two states. As philosophies guiding natural resource management have evolved over the course of the 20th …

Interfering Solutions Of A Nonhomogeneous Hamiltonian System, Gregory S. Spradlin

Publications

A Hamiltonian system is studied which has a term approaching a constant at an exponential rate at infinity. A minimax argument is used to show that the equation has a positive homoclinic solution. The proof employs the interaction between translated solutions of the corresponding homogeneous equation. What distinguishes this result from its few predecessors is that the equation has a nonhomogeneous nonlinearity.

“Soft” Anharmonic Vortex Glass In Ferromagnetic Superconductors, Leo Radzihovsky, A. M. Ettouhami, Karl Saunders, John Toner

Physics

Ferromagnetic order in superconductors can induce a spontaneous vortex (SV) state. For external field H = 0, rotational symmetry guarantees a vanishing tilt modulus of the SV solid, leading to drastically different behavior than that of a conventional, external-field-induced vortex solid. We show that quenched disorder and anharmoinc effects lead to elastic moduli that are wave-vector dependent out to arbitrarily long length scales, and non-Hookean elasticity. The latter implies that for weak external fields H, the magnetic induction scales universally like B(H)∼B(0)+cHα, with α≈0.72. For weak disorder, we predict the SV solid is a topologically ordered glass, in …

Multiplicity Moments In Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci

Faculty Publications

Multiplicity moments of charged particles in deep inelastic e+p scattering have been measured with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb-1. The moments for Q2 > 1000 GeV2 were studied in the current region of the Breit frame. The evolution of the moments was investigated as a function of restricted regions in polar angle and, for the first time, both in the transverse momentum and in absolute momentum of final-state particles. Analytic perturbative QCD predictions in conjunction with the hypothesis of Local Parton-Hadron Duality (LPHD) reproduce the trends of the moments in polar-angle regions, although some …

Randomized Motion Planning For Groups Of Nonholonomic Robots, Christopher M. Clark, Stephen M. Rock.

Computer Science and Software Engineering

This paper presents a technique for motion planning which is capable of planning trajectories for a large number of nonholonomic robots. The robots plan within a two dimensional environment that consists of stationary/moving obstacles, and fixed boundaries. Each robot uses randomized motion planner techniques based on Probabilistic Road Maps (PRM’s) to construct it’s own trajectory that is free of collisions with moving obstacles and other robots. The randomized motion planner allows easy integration of the robots nonholonomic constraint into the planning so that only kinematically consistent plans are constructed. It is important to include this constraint in the planning problem …

Ecosystems And Immune Systems: Hierarchical Response Provides Resilience Against Invasions, Craig R. Allen

United States Geological Survey: Staff Publications

Janssen (2001) provides the stimulus for thoughtful comparison and consideration of the ranges of responses exhibited by immune systems and ecological systems in the face of perturbations such as biological invasions. It may indeed be informative to consider the similarities of the responses to invasions exhibited by immune systems and ecological systems. Clearly, both types of systems share a general organizational structure with all other complex hierarchical systems. Their organization provides these systems with resilience. However, when describing the response of ecological-economic systems to invasions, Janssen emphasizes the human-economic response. I would like to expand on his comparison by focusing …

Infrequent Cowbird Parasitism On Common Grackles Revisited: New Records From The Northern Great Plains, Brian D. Peer, H. Jeffrey Homan, Spencer G. Sealy

United States Department of Agriculture Wildlife Services: Staff Publications

We report nine new records of Brown-headed Cowbird (Molothrus ater) parasitism on the Common Grackle (Quiscalus quiscula): six from Benson County, North Dakota, and three from Delta Marsh, Manitoba. These observations represent 30% of the total number of records of parasitism on this host. Parasitism frequencies were 0.8% of 727 nests in North Dakota, and 4.0% of 75 nests in Manitoba. The data from Manitoba, combined with previous data from this location (Neudorf and Sealy 1994), yields a parasitism frequency of 3.4% of 119 nests examined. These parasitism frequencies are the highest recorded for the Common …

Angular Distributions For Double Ionization Of Li- By An Ultrashort, Intense Laser Pulse, G. Lagmago Kamta, Anthony F. Starace

Anthony F. Starace Publications

We predict photoelectron angular distributions for double ionization of Li^- by both weak and intense ultrashort, linearly polarized laser pulses by direct numerical integration of the three-dimensional, time-dependent Schrödinger equation. Li^- is treated as a two-active electron system. Near threshold, for low intensity we recover general features of angular distributions for one-photon double ionization. For the intense field (multiphoton) case, the photoelectron angular distribution changes significantly, particularly in directions parallel and perpendicular to the laser polarization axis.

Doubly Perturbed S_3 Neutrinos And The S_{13} Mixing Parameter, Joseph Schechter, Renata Jora, M. Naeem Shahid

Physics - All Scholarship

We further study a predictive model for the masses and mixing matrix of three Majorana neutrinos. At zeroth order the model yielded degenerate neutrinos and a generalized ``tribimaximal" mixing matrix. At first order the mass splitting was incorporated and the tribimaximal mixing matrix emerged with very small corrections but with a zero value for the parameter $s_{13}$. In the present paper a different, assumed weaker, perturbation is included which gives a non zero value for $s_{13}$ and further corrections to other quantities. These corrections are worked out and their consequences discussed under the simplifying assumption that the conventional CP violation …

Remark On Pion Scattering Lengths, Joseph Schechter, Deirdre Black, Nae Woong Park

Physics - All Scholarship

First it is shown that the tree amplitude for pion pion scattering in the minimal linear sigma model has an exact expression which is proportional to a geometric series in the quantity (s-$m_\pi^2$)/($m_B^2-m_\pi^2$), where $m_B$ is the sigma mass which appears in the Lagrangian and is the only a priori unknown parameter in the model. This induces an infinite series for every predicted scattering length in which each term corresponds to a given order in the chiral perturbation theory counting. It is noted that, perhaps surprisingly, the pattern, though not the exact values, of chiral perturbation theory predictions for both …

Creating Better Governance, Denise D. Fort

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

17 pages (includes illustration).

Contains 2 pages of references.

Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka

Faculty Publications

Through the use of variable disulfide crosslinkers, we have created polyacrylamide gels whose shape can be altered after polymerization. N,N'-bisacryloylcystamine is incorporated as a crosslinker, along with a smaller amount of a permanent crosslinker. After polymerization, the disulfide bonds are cleaved into thiols through reduction. By reoxidizing the thiols with the gel held in a new macroscopic shape, a new set of disulfide bonds is formed, and the gel is forced to adopt the new shape. Retension of the new shape improves with greater distortion from the original shape, as well as with increased concentration of variable …

Fast Ignitor Concept With Light Ions, V. Yu. Bychenkov, W. Rozmus, Anatoly Maksimchuk, Donald Umstadter, C.E. Capjack

Donald Umstadter Publications

A short-laser-pulse driven ion flux is examined as a fast ignitor candidate for inertial confinement fusion. Ion ranges in a hot precompressed fuel are studied. The ion energy and the corresponding intensity of a short laser pulse are estimated for the optimum ion range and ion energy density flux. It is shown that a lightion beam triggered by a few-hundreds-kJ laser at intensities of ~10²¹W/cm² is relevant to the fast ignitor scenario.

Jno2 At High Solar Zenith Angles In The Lower Stratosphere, R. S. Gao, L. A. Del Negro, W. H. Swartz, R. J. Salawitch, S. A. Lloyd, M. H. Proffitt, D. W. Fahey, Stephen G. Donnelly Ph.D., J. A. Neuman, R. M. Stimpfle, T. P. Bui

Chemistry Faculty Publications

In situ measurements of NO, NO2, O3, HO2, C1O, pressure, and temperature have been made at high solar zenith angles (SZA, 70° - 93°) in the lower stratosphere. These measurements are used to derive the photolysis rate of NO2, JNO2, using a time-dependent method. The resultant JNO2 values and the results of a multiple-scattering actinic flux model show a linear relationship throughout the SZA range. The difference of the two sets of JNO2 values of about 11% suggests that the model scattering calculation is very accurate at high SZA conditions near sunrise and sunset.

Creating Better River Basin Governance: A Comment, David M. Freeman

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

3 pages.

Third Generation Seesaw Mixing With New Vector-Like Weak-Doublet Quarks, Marko Popovic

Marko B. Popovic

We present a class of models with a third generation seesaw mixing with new vectorlike weak-doublet quarks. We analyze a low-energy phenomenology and present several strong dynamics, high-energy realizations of these models. In the top-color-type scenario, named top-bottom color, we obtain an effective, composite two Higgs doublet model where the third generation isospin splitting is introduced via tilting interactions related to the broken non-Abelian gauge groups @i.e., without strong, triviality-sensitive U~1! groups#. In addition, we discuss t t ¯ production at the Next Linear Collider and suggest how one can experimentally observe and distinguish between the weak-doublet and the weak-singlet …

Water For The Environment: A Californian’S Retrospective, Thomas J. Graff

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

9 pages.

Strategies To Facilitate Changes In Water Use, Bonnie G. Colby

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

21 pages.

Contains 4 pages of references and 2 pages of endnotes.

Toward Ecologically Sustainable Water Management: The Roles Of Science And Technology, Brian D. Richter

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

5 pages.

Scientific And Social Landscapes: New Frameworks And Forums For Water Management And Sustainability, Christine Turner, Herman Karl

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

11 pages.

Contains 2 pages of references.

Clarifying State Water Rights And Adjudications, John E. Thorson

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

32 pages.

Contains references.

Clarifying State Water Rights And Adjudications, Greg Hobbs

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

14 pages.

Contains footnotes.

Transition Temperature For Weakly Interacting Homogeneous Bose Gases, Frederico F. De Souza Cruz, Marcus B. Pinto, Rudnei O. Ramos

Dartmouth Scholarship

We apply the nonperturbative optimized linear δ expansion method to the O(N) scalar field model in three dimensions to determine the transition temperature of a dilute homogeneous Bose gas. Our results show that the shift of the transition temperature ΔTc/Tc of the interacting model, compared with the ideal-gas transition temperature, really behaves as γan1/3 where a is the s-wave scattering length and n is the number density. For N=2 our calculations yield the value γ=3.059.

Agricultural Water Use Efficiency, Gordon Mccurry

Two Decades of Water Law and Policy Reform: A Retrospective and Agenda for the Future (Summer Conference, June 13-15)

3 pages (includes color illustrations).