Physical Sciences and Mathematics Commons^™

Probing For Life In The Ocean Crust With The Lexen Program, H. Johnson, J. Baross, T. Bjorkland, W. Brazelton, J. Huber, M. Pruis, Susan Lang, F. Mccrosky, M. Mehta, D. Butterfield, A. Bowen, J. Howland, W. Martin, K. Roe, C. Channing, P. Kalk, C. Kammerer, R. Light, V. Miller, M. Mccarthy, B. Moore, M. Sharma, J. Voit

Susan Q. Lang

No abstract provided.

Stable Isotope Analysis Of Organic Carbon In Small (Μg C) Samples And Dissolved Organic Matter Using A Gasbench Preparation Device, Susan Lang, S. Bernasconi, G. Früh-Green

Susan Q. Lang

No abstract provided.

Sources And Cycling Of Carbon In Continental, Serpentinite-Hosted Alkaline Springs In The Voltri Massif, Italy, E. Schwarzenbach, Susan Lang, G. Früh-Green, M. Lilley, S. Bernasconi, S. Méhay

Susan Q. Lang

No abstract provided.

Purification Of Fire Derived Markers For Μg Scale Isotope Analysis (Δ13c, Δ14c) Using High Performance Liquid Chromatography (Hplc), M. Gierga, M. Schneider, D. Wiedemeier, Susan Lang, R. Smittenberg, I. Hajdas, S. Bernasconi, M. Schmidt

Susan Q. Lang

No abstract provided.

A Method To Measure The Isotopic (13C) Composition Of Dissolved Organic Carbon Using A High Temperature Combustion Instrument, Susan Lang, M. Lilley, J. Hedges

Susan Q. Lang

No abstract provided.

Dissolved Organic Carbon In Ridge-Axis And Ridge-Flank Hydrothermal Systems, Susan Lang, D. Butterfield, M. Lilley, H. Johnson, J. Hedges

Susan Q. Lang

No abstract provided.

Sources Of Organic Nitrogen At The Serpentinite-Hosted Lost City Hydrothermal Field, Susan Lang, G. Früh-Green, S. Bernasconi, D. Butterfield

Susan Q. Lang

No abstract provided.

Accelerating Diffraction-Free Beams In Photonic Lattices, K. Makris, I. Kaminer, Ramy El-Ganainy, N. Efremidis, Zhigang Chen, M. Segev, Demetrios Christodoulides

Ramy El-Ganainy

We study nondiffracting accelerating paraxial optical beams in periodic potentials, in both the linear and the nonlinear domains. In particular, we show that only a unique class of z-dependent lattices can support a true accelerating diffractionless beam. Accelerating lattice solitons, autofocusing beams and accelerating bullets in optical lattices are systematically examined.

On-Chip Multi 4-Port Optical Circulators, Ramy El-Ganainy, Miguel Levy

Ramy El-Ganainy

We present a new geometry for on-chip optical circulators based on waveguide arrays. The optical array is engineered to mimic the Fock space representation of a noninteracting two-site Bose–Hubbard Hamiltonian. By introducing a carefully tailored magnetooptic nonreciprocity to these structures, the array operates in the perfect transfer and surface Bloch oscillation modes in the forward and backward propagation directions, respectively. We show that an array made of ð2N þ 1Þ waveguide channels can function as N 4-port optical circulators with very large isolation ratios and low forward losses. Numerical analysis using beam propagation method indicates a large bandwidth of operation.

Light Transport In Pt-Invariant Photonic Structures With Hidden Symmetries, M. H. Teimourpour, Ramy El-Ganainy, A. Eisfeld, A. Szameit, Demetrios N. Christodoulides

Ramy El-Ganainy

We introduce a recursive bosonic quantization technique for generating classical PT photonic structures that possess hidden symmetries and higher order exceptional points. We study light transport in these geometries and we demonstrate that perfect state transfer is possible only for certain initial conditions. Moreover, we show that for the same propagation direction, left and right coherent transports are not symmetric with field amplitudes following two different trajectories. A general scheme for identifying the conservation laws in such PT-symmetric photonic networks is also presented.

Exceptional Points And Lasing Self-Termination In Photonic Molecules, Ramy El-Ganainy, M. Khajavikhan, Li Ge

Ramy El-Ganainy

We investigate the rich physics of photonic molecule lasers using a non-Hermitian dimer model.We show that several interesting features, predicted recently using a rigorous steady-state ab initio laser theory (SALT), can be captured by this toy model. In particular, we demonstrate the central role played by exceptional points (EPs) in both pump-selective lasing and laser self-termination phenomena. Due to its transparent mathematical structure, our model provides a lucid understanding for how different physical parameters (optical loss, modal coupling between microcavities, and pump profiles) affect the lasing action. Interestingly, our analysis also confirms that, for frequency mismatched cavities, operation in the …

On-Chip Non-Reciprocal Optical Devices Based On Quantum Inspired Photonic Lattices, Ramy El-Ganainy, A. Eisfeld, Miquel Levy, Demetrios N. Christodoulides

Ramy El-Ganainy

We propose integrated optical structures that can be used as isolators and polarization splitters based on engineered photonic lattices. Starting from optical waveguide arrays that mimic Fock space (quantum state with a well-defined particle number) representation of a non-interacting two-site Bose Hubbard Hamiltonian, we show that introducing magneto-optic nonreciprocity to these structures leads to a superior optical isolation performance. In the forward propagation direction, an input TM polarized beam experiences a perfect state transfer between the input and output waveguide channels while surface Bloch oscillations block the backward transmission between the same ports. Our analysis indicates a large isolation ratio …

Supersymmetric Mode Converters, Matthias Heinrich, Mohammad-Ali Miri, Simon Stützer, Ramy El-Ganainy, Stefan Nolte, Alexander Szameit, Demetrios N. Christodoulides

Ramy El-Ganainy

Originally developed in the context of quantum field theory, the concept of supersymmetry can be used to systematically design a new class of optical structures. In this work, we demonstrate how key features arising from optical supersymmetry can be exploited to control the flow of light for mode division multiplexing applications. Superpartner configurations are experimentally realized in coupled optical networks, and the corresponding light dynamics in such systems are directly observed. We show that supersymmetry can be judiciously utilized to remove the fundamental mode of a multimode optical structure, while establishing global phase matching conditions for the remaining set of …

Enhancing Optical Isolator Performance In Nonreciprocal Waveguide Arrays, Miguel Levy, Turhan Carroll, Ramy El-Ganainy

Ramy El-Ganainy

We investigate the operation of optical isolators based on magneto-optics waveguide arrays beyond the coupled mode analysis. Semi-vectorial beam propagation simulations demonstrate that evanescent tail coupling and the effects of radiation are responsible for degrading the device’s performance. Our analysis suggests that these effects can be mitigated when the array size is scaled up. In addition, we propose the use of radiation blockers in order to offset some of these effects, and we show that they provide a dramatic improvement in performance. Finally, we also study the robustness of the system with respect to fabrication tolerances using the coupled mode …

Observation Of Accelerating Wannier-Stark Beams In Optically Induced Photonic Lattices, Xinyuan Qi, Konstantinos Makris, Ramy El-Ganainy, Peng Zhang, Jintao Bai, Demetrios Christodoulides, Zhigang Chen

Ramy El-Ganainy

We generate optical beams analogous to the Wannier–Stark states in semiconductor superlattices and observe that the two main lobes of the WS beams self-bend (accelerate) along two opposite trajectories in a uniform one-dimensional photonic lattice. Such self-accelerating features exist only in the presence of the lattice and are not observed in a homogenous medium. Under the action of nonlinearity, however, the beam structure and acceleration cannot be preserved. Our experimental observations are in qualitative agreement with theoretical predictions.

Identifying The Experimental And Theoretical Effective Characteristics Of Nonaligned Anisotropic Metamaterials, Michael R. Benson

Theses and Dissertations

Previous research into anisotropic materials has assumed certain properties in order to make the underlying mathematics tractable. One of the assumptions is the alignment of the optical axes with the laboratory frame of reference, such as split-ring resonators lying at on the material plane. This assumption does not hold true for many metamaterials, such as tilted nanorods. Techniques such as ellipsometry are needed to analyze the effective characteristics of these highly anisotropic structures. In this research, tilted nanorods are analyzed using generalized ellipsometry to extract the indices of the optical axes. The underlying physics of ellipsometry is then used to …

Coupling Nuclear Induced Phonon Propagation With Conversion Electron Mössbauer Spectroscopy, Michael J. Parker

Theses and Dissertations

Mössbauer spectroscopy is a very sensitive measurement technique (10^-8 eV) which prompted motivation for the experiment described in this thesis. Namely, can a sensitive detection system be developed to detect nuclear recoils on the order of 10 to 100 of eVs? The hypothesis that this thesis tests is: Nuclear induced phonon bursts caused by Rutherford scattered alphas, decayed from ²⁴¹Am, in a type-310 stainless steel material can couple with 7.3 keV conversion electron Mössbauer events at the other end of the material which will have a statistically significant effect on a Mössbauer spectrum. The phonon bursts produced by …

Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L. Vacher, Lee J. Florea

International Journal of Speleology

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20^th century; a period, up to around the turn of …

Barriers And Opportunities To Promote Rights To Sustainable Production Of Smallholders In The Context Of Climate Stresses In Central America, Raffaele Vignola

Food Systems Summit 2015

Under a systemic approach, right to food implies also considering two aspects such as the implementation of and correspondent support to sustainable agricultural production by smallholders. Given the observed and projected trends, this requires also considering how such practices can help these vulnerable producers cope with and recover from the increasing climate stresses affecting them. We here focus on these two complementary aspects for the case of coffee and basic grains smallholders: the identification of adaptive benefits of sustainable practices and the barriers and strengths of cross-scale governance to support their implementation in Central America (a highly climate-vulnerable region).

Investigating The Links Between Ozone And Organic Aerosol Chemistry In A Biomass Burning Plume From A Prescribed Fire In California Chaparral, M. J. Alvarado, C. R. Lonsdale, Robert Yokelson, Sheryl Kashi Akagi, H. Coe, J. S. Craven, E. V. Fischer, G. R. Mcmeeking, J. H. Seinfeld, T. Soni, J. W. Taylor, D. R. Weise, C. E. Wold

Chemistry and Biochemistry Faculty Publications

Within minutes after emission, complex photochemistry in biomass burning smoke plumes can cause large changes in the concentrations of ozone (O3) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O₃ and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed fire in chaparral, which was sampled over …

The Polarcat Model Intercomparison Project (Polmip): Overview And Evaluation With Observations, L K. Emmons, S R. Arnold, S A. Monks, V Huijnen, S Tilmes, K S. Law, J L. Thomas, J C. Raut, I Bouarar, S Turquety, Y Long, B Duncan, S Steenrod, S Strode, J Flemming, J Mao, J Langner, A M. Thompson, D Tarasick, E C. Apel, D R. Blake, Robert C. Cohen, Jack E. Dibb, Glenn Diskin, A Fried, S R. Hall, L Gregory Huey, Andrew Weinheimer, Armin Wisthaler, Tomas Mikoviny, J Nowak, Jeff Peischl, J M. Roberts, Thomas B. Ryerson, C Warneke, D Helmig

Earth Sciences

A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage …

Some Relations Between The Caputo Fractional Difference Operators And Integer-Order Differences, Baoguo Jia, Lynn Erbe, Allan Peterson

Department of Mathematics: Faculty Publications

In this article, we are concerned with the relationships between the sign of Caputo fractional differences and integer nabla differences. In particular, we show that if N -1 < v < N. f : Na -N + 1 -> R, va * f(t) > O, for t - Na +1 and N-1f(a) > 0, then N -1 f(t) > 0 for t- Na +1, then va* f(t) > 0, for each t - Na +1. As applications of these two results, we get that if 1 < vR, va*f(t) > 0 for t - Na +1 and f(a) > f(a-1), then f(t) is an increasing function for t- Na -1. Conversely if 0 < vR and f is an increasing function for t - Na, then va*f(t) > 0, for each t - Na +1. …

Singly-Spinning Black Rings Ind= 5 U(1)3 Supergravity, H. Lu, C. N. Pope, Justin F. Vázquez-Poritz, Zhibai Zhang

Publications and Research

We construct black ring solutions in five-dimensional U(1)3supergravity which carry three dipole charges, three electric charges and one angular momentum parameter.These solutions are written in a form that is sufficiently compact that their global and thermodynamic properties can be studied explicitly. In particular, we find that the Smarrformula is obeyed regardless of whether or not conical singularities are present, where as the first law of thermodynamics holds only in the absence of conical singularities. We also present black ring solutions with three background magnetic fields.

Representing Life In The Earth System With Soil Microbial Functional Traits In The Mimics Model, William R. Wieder, A. Stuart Grandy, Cynthia M. Kallenbach, P. G. Taylor, G. B. Bonan

Faculty Publications

Projecting biogeochemical responses to global environmental change requires multi-scaled perspectives that consider organismal diversity, ecosystem processes, and global fluxes. However, microbes, the drivers of soil organic matter decomposition and stabilization, remain notably absent from models used to project carbon (C) cycle–climate feedbacks. We used a microbial trait-based soil C model with two physiologically distinct microbial communities, and evaluate how this model represents soil C storage and response to perturbations. Drawing from the application of functional traits used to model other ecosystems, we incorporate copiotrophic and oligotrophic microbial functional groups in the MIcrobial-MIneral Carbon Stabilization (MIMICS) model; these functional groups are …

Instruction Re-Selection For Iterative Modulo Scheduling On High Performance Multi-Issue Dsps, Doosan Cho, Ravi Ayyagari, Gang-Ryung Uh, Yunheung Paek

Gang-Ryung Uh

An iterative modulo scheduling is very important for compilers targeting high performance multi-issue digital signal processors. This is because these processors are often severely limited by idle state functional units and thus the reduced idle units can have a positively significant impact on their performance. However, complex instructions, which are used in most recent DSPs such as mac, usually increase data dependence complexity, and such complex dependencies that exist in signal processing applications often restrict modulo scheduling freedom and therefore, become a limiting factor of the iterative modulo scheduler.

In this work, we propose a technique that efficiently reselects instructions …

Annual Brome Biocontrol After Wildfire Using A Native Fungal Seed Pathogen, Susan E. Meyer, Phil S. Allen, Julie Beckstead, Michael Gregg, Heidi Newsome, Kathleen Harcksen, Gary Kidd, Glenn Paulsen, Karen Prentice, Dana Quinney, David Wilderman, Stephanie Carlson, Suzette Clement, Duane Smith, Thom Stewart, Katie Merrill, Keith Merrill, Kedra Foote, Stephen Harrison, Kelly Bergen, Brian Connelly, Trevor Davis, Sandra Dooley, Michael Huck, Laura Street, Lauren Miller

Benjamin L. Harwood

A major problem in post-fire restoration of semi-arid shrublands dominated by annual bromes is the presence of carryover seed banks that cannot be controlled using conventional methods. These seeds can provide significant competition for seeded species in the years following treatment. We investigated the feasibility of using a naturally occurring seed pathogen, the ascomycete Pyrenophora semeniperda, as a biocontrol organism for eliminating this carryover seed bank. We carried out the necessary technology development to create and apply field inoculum to cheatgrass- or red brome-infested areas (both burned and unburned) at six sites located in three states across two years of …

Conference Participants: Thirteenth Vertebrate Pest Conference,

Benjamin L. Harwood

The Conference totalled 401 registered attendees. The wide representation from the United States and from 14 countries throughout the world contributed to the success of the Conference by providing a highly diversified group for the exchange of ideas and information.

Proceedings Tenth Vertebrate Pest Conference,

Benjamin L. Harwood

VERTEBRATE PEST COUNCIL 1982 EXECUTIVE BOARD CONFERENCE COMMITTEES SESSION CHAIRPERSONS CONFERENCE ASSISTANTS CHAIRPERSONS OF PREVIOUS CONFERENCES CONTENTS

Conference Participants -- 4th Vertebrate Pest Conference,

Benjamin L. Harwood

The Fourth Vertebrate Pest Conference was the largest ever, with 275 registered participants and an estimated additional 50 to 75 persons who attended portions of the conference but did not register. The attendance was made up of individuals having varying interests in vertebrate pest problems, including foresters, agriculturalists, conservationists, pest control operators, vector control specialists, health officials, wildlife specialists, product distributors and manufacturers, instructors and researchers from twenty nine states plus the District of Columbia. Participants from Canada, England, Germany and Japan provided an international touch which contributed greatly to the success of the conference.

The Impacts Of Climate Change Mitigation Strategies On Animal Welfare, Sara Shields, Geoffrey Orme-Evans

Sara Shields, PhD

The objective of this review is to point out that the global dialog on reducing greenhouse gas emissions in animal agriculture has, thus far, not adequately considered animal welfare in proposed climate change mitigation strategies. Many suggested approaches for reducing emissions, most of which could generally be described as calls for the intensification of production, can have substantial effects on the animals. Given the growing world-wide awareness and concern for animal welfare, many of these approaches are not socially sustainable. This review identifies the main emission abatement strategies in the climate change literature that would negatively affect animal welfare and …