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Full-Text Articles in Physical Sciences and Mathematics

H2 Separation Using Defect-Free, Inorganic Composite Membranes, Miao Yu, H. Funke, R. Noble, J. Falconer Jun 2015

H2 Separation Using Defect-Free, Inorganic Composite Membranes, Miao Yu, H. Funke, R. Noble, J. Falconer

Miao Yu

No abstract provided.


Adsorption Characteristics Of Diclofenac And Sulfamethoxazole To Graphene Oxide In Aqueous Solution, S.-W. Nam, C. Jung, H. Li, Miao Yu, Joseph Flora, L. Boateng, N. Her, K.-D. Zoh, Yeomin Yoon Jun 2015

Adsorption Characteristics Of Diclofenac And Sulfamethoxazole To Graphene Oxide In Aqueous Solution, S.-W. Nam, C. Jung, H. Li, Miao Yu, Joseph Flora, L. Boateng, N. Her, K.-D. Zoh, Yeomin Yoon

Miao Yu

No abstract provided.


Tuning The Underwater Oleophobicity Of Graphene Oxide Coatings Via Uv Irradiation, H. Li, Yi Huang, Y. Mao, W. Xu, Harry Ploehn, Miao Yu Jun 2015

Tuning The Underwater Oleophobicity Of Graphene Oxide Coatings Via Uv Irradiation, H. Li, Yi Huang, Y. Mao, W. Xu, Harry Ploehn, Miao Yu

Miao Yu

Ultraviolet (UV) irradiation was utilized to gradually modify the chemistry and structure of graphene oxide (GO) flakes, as confirmed by XPS and AFM. Ultrathin GO coatings/membranes, made of UV-irradiated flakes, showed tunable underwater oleophobicity. UV-treated, superoleophobic GO membranes exhibited excellent antifouling capability for oil/water separation.


Ultra-Thin Microporous–Mesoporous Metal Oxide Films Prepared By Molecular Layer Deposition (Mld), X. Liang, Miao Yu, J. Li, Y.-B. Jiang, A. Weimer Jun 2015

Ultra-Thin Microporous–Mesoporous Metal Oxide Films Prepared By Molecular Layer Deposition (Mld), X. Liang, Miao Yu, J. Li, Y.-B. Jiang, A. Weimer

Miao Yu

No abstract provided.


Propagating Lyapunov Functions To Prove Noise-Induced Stabilization, Tiffany Kolba, Avanti Athreya, Jonathan Mattingly Jun 2015

Propagating Lyapunov Functions To Prove Noise-Induced Stabilization, Tiffany Kolba, Avanti Athreya, Jonathan Mattingly

Tiffany N Kolba

No abstract provided.


Semiparametric Causal Inference In Matched Cohort Studies, Edward Kennedy, Arvid Sjolander, Dylan Small Jun 2015

Semiparametric Causal Inference In Matched Cohort Studies, Edward Kennedy, Arvid Sjolander, Dylan Small

Edward H. Kennedy

Odds ratios can be estimated in case-control studies using standard logistic regression, ignoring the outcome-dependent sampling. In this paper we discuss an analogous result for treatment effects on the treated in matched cohort studies. Specifically, in studies where a sample of treated subjects is observed along with a separate sample of possibly matched controls, we show that efficient and doubly robust estimators of effects on the treated are computationally equivalent to standard estimators, which ignore the matching and exposure-based sampling. This is not the case for general average effects. We also show that matched cohort studies are often more efficient …


Biological, Clinical, And Forensic Analysis Using Comprehensive Two-Dimensional Gas Chromatography, Nicholas Snow Jun 2015

Biological, Clinical, And Forensic Analysis Using Comprehensive Two-Dimensional Gas Chromatography, Nicholas Snow

Nicholas A Snow

No abstract provided.


Simultaneous Determination Of Pramoxine Hcl And Benzalkonium Chloride In Wound Care Solutions By Hplc, Panagiotis Tavlarakis, Jonine Greyling, Nicholas Snow Jun 2015

Simultaneous Determination Of Pramoxine Hcl And Benzalkonium Chloride In Wound Care Solutions By Hplc, Panagiotis Tavlarakis, Jonine Greyling, Nicholas Snow

Nicholas A Snow

No abstract provided.


Convergence Properties Of Harmonic Measure Distributions For Planar Domains, Maria Snpes Jun 2015

Convergence Properties Of Harmonic Measure Distributions For Planar Domains, Maria Snpes

Maria Snipes

We establish sufficient conditions under which the harmonic measure distribution functionshn of a sequence of domains Dn converge pointwise to the distribution function h of the limiting domain D, at all points of continuity of h. In the case of a model example, we establish this convergence of the distribution functions. Here, the value of the function h(r) gives the harmonic measure of the part of the boundary of the domain that lies within distance r of a fixed basepoint in the domain, thus relating the geometry of the domain to the …


Realizing Step Functions As Harmonic Measure Distributions Of Planar Domains, Maria Snpes Jun 2015

Realizing Step Functions As Harmonic Measure Distributions Of Planar Domains, Maria Snpes

Maria Snipes

No abstract provided.


Converting Glx2-1 Into An Active Glyoxalase Ii, Pattraranee Limphong, Nicole Adams, Matthew Rouhier, Ross Mckinney, Melissa Naylor, Brian Bennett, Christopher Makaroff, Michael Crowder Jun 2015

Converting Glx2-1 Into An Active Glyoxalase Ii, Pattraranee Limphong, Nicole Adams, Matthew Rouhier, Ross Mckinney, Melissa Naylor, Brian Bennett, Christopher Makaroff, Michael Crowder

Matthew F Rouhier

Arabidopsis thaliana glyoxalase 2-1 (GLX2-1) exhibits extensive sequence similarity with GLX2 enzymes but is catalytically inactive with SLG, the GLX2 substrate. In an effort to identify residues essential for GLX2 activity, amino acid residues were altered at positions 219, 246, 248, 325, and 328 in GLX2-1 to be the same as those in catalytically active human GLX2. The resulting enzymes were overexpressed, purified, and characterized using metal analyses, fluorescence spectroscopy, and steady-state kinetics to evaluate how these residues affect metal binding, structure, and catalysis. The R246H/N248Y double mutant exhibited low level S-lactoylglutathione hydrolase activity, while the R246H/N248Y/Q325R/R328K mutant exhibited a …


Embedding Modal Nonmonotonic Logics Into Default Logic, Robert Milnikel Jun 2015

Embedding Modal Nonmonotonic Logics Into Default Logic, Robert Milnikel

Robert Milnikel

We present a straightforward embedding of modal nonmonotonic logics into default logic.


Derivability In Certain Subsystems Of The Logic Of Proofs Is -Complete, Robert Milnikel Jun 2015

Derivability In Certain Subsystems Of The Logic Of Proofs Is -Complete, Robert Milnikel

Robert Milnikel

The Logic of Proofs realizes the modalities from traditional modal logics with proof polynomials , so an expression □F becomes t:F where t is a proof polynomial representing a proof of or evidence for F. The pioneering work on explicating the modal logic S4 is due to S. Artemov and was extended to several subsystems by V. Brezhnev. In 2000, R. Kuznets presented a algorithm for deducibility in these logics; in the present paper we will show that the deducibility problem is-complete. (The analogous problem for traditional modal logics is PSPACE-complete.) Both Kuznets’s work and the present results make assumptions …


Skeptical Reasoning In Fc-Normal Logic Programs Is Π^1_1-Complete, Robert Milnikel Jun 2015

Skeptical Reasoning In Fc-Normal Logic Programs Is Π^1_1-Complete, Robert Milnikel

Robert Milnikel

FC-normal logic programs are a generalization by Marek, Nerode, and Remmel of Reiter's normal default theories. They have the property that, unlike most logic programs, they are guaranteed to have simple stable models. In this paper it is shown that the problem of skeptical reasoning in FC-normal programs is Π^1_1-complete, the same complexity as for logic programs without the restriction of FC-normality. FC-normal programs are defined in such a way as to make testing a program for FC-normality very difficult in general. A large subclass of FC-normal programs, locally FC-normal programs, is defined, shown to be recursive, and shown to …


Sequent Calculi For Skeptical Reasoning In Predicate Default Logic And Other Nonmonotonic Logics, Robert Milnikel Jun 2015

Sequent Calculi For Skeptical Reasoning In Predicate Default Logic And Other Nonmonotonic Logics, Robert Milnikel

Robert Milnikel

Sequent calculi for skeptical consequence in predicate default logic, predicate stable model logic programming, and infinite autoepistemic theories are presented and proved sound and complete. While skeptical consequence is decidable in the finite propositional case of all three formalisms, the move to predicate or infinite theories increases the complexity of skeptical reasoning to being Π 1 1 -complete. This implies the need for sequent rules with countably many premises, and such rules are employed.


The Complexity Of Predicate Default Logic Over A Countable Domain, Robert Milnikel Jun 2015

The Complexity Of Predicate Default Logic Over A Countable Domain, Robert Milnikel

Robert Milnikel

Lifschitz introduced the notion of defining extensions of predicate default theories not as absolute, but relative to a specified domain. We look specifically at default theories over a countable domain and show the set of default theories which possess an ω-extension is Σ21-complete. That the set is in Σ21 is shown by writing a nearly circumscriptive formula whose ω-models correspond to the ω-extensions of a given default theory; similarly, Σ21-hardness is established by a method for translating formulas into default theories in such a way that ω-models of the circumscriptive formula correspond to ω-extensions of the default theory. (That the …


Conditions Equivalent To The Existence Of Odd Perfect Numbers, Judy Holdener Jun 2015

Conditions Equivalent To The Existence Of Odd Perfect Numbers, Judy Holdener

Judy Holdener

No abstract provided.


A Cryptographic Scavenger Hunt, Judy Holdener Jun 2015

A Cryptographic Scavenger Hunt, Judy Holdener

Judy Holdener

In this article, the authors present a mathematical scavenger hunt designed to motivate and excite students learning RSA cryptography in an introductory number theory course. The hunt relies on the RSA cryptosystem, in which Maple is used to encipher and decipher secret information contained within the clues.


Generalized Thue-Morse Sequences And The Von Koch Curve, Judy Holdener Jun 2015

Generalized Thue-Morse Sequences And The Von Koch Curve, Judy Holdener

Judy Holdener

: In a recent paper, Ma and Holdener used turtle geometry and polygon maps to show that the Thue-Morse sequence encodes the von Koch curve. In the final paragraph of this same paper, they ask whether or not there exist certain generalized Thue-Morse sequences that also encode the curve. Here we answer this question in the affirmative, providing an infinite family of words that generate generalized Thue-Morse sequences encoding the von Koch curve.


When Thue-Morse Meets Koch, Judy Holdener Jun 2015

When Thue-Morse Meets Koch, Judy Holdener

Judy Holdener

In this paper, we reveal a remarkable connection between the Thue-Morse sequence and the Koch snow°ake. Using turtle geometry and polygon maps, we realize the Thue-Morse sequence as the limit of polygonal curves in the plane. We then prove that a sequence of such curves converges to the Koch snow°ake in the Hausdor® metric. In the ¯nal section we consider generalized Thue-Morse sequences and provide a characterization of those that encode curves converging to the Koch snow°ake.


Parametric Plots: A Creative Outlet, Judy Holdener Jun 2015

Parametric Plots: A Creative Outlet, Judy Holdener

Judy Holdener

No abstract provided.


Product-Free Sets In The Card Game Set, Judy Holdener Jun 2015

Product-Free Sets In The Card Game Set, Judy Holdener

Judy Holdener

The card game SET has attracted the attention of math and game enthusiasts alike. In this article, I present a first semester Abstract Algebra project that guides the students through an algebraic formulation of the game. There are many interesting mathematical questions that one can ask about the game, and I illustrate how the project can be used to get students working on such questions. In this way, the project can also serve as an opportunity for undergraduate research.


Art And Design In Mathematic, Judy Holdener Jun 2015

Art And Design In Mathematic, Judy Holdener

Judy Holdener

No abstract provided.


Mat-Rix-Toe: Improving Writing Through A Game-Based Project In Linear Algebra, Adam Graham-Squire, Elin Farnell, Julianna Stockton Jun 2015

Mat-Rix-Toe: Improving Writing Through A Game-Based Project In Linear Algebra, Adam Graham-Squire, Elin Farnell, Julianna Stockton

Elin R Farnell

The Mat-Rix-Toe project utilizes a matrix-based game to deepen students’ understanding of linear algebra concepts and strengthen students’ ability to express themselves mathematically. The project was administered in three classes using slightly different approaches, each of which included some editing component to encourage the improvement of the students’ mathematical thinking and writing. Differences in the implementation of the project illustrate the benefits and drawbacks of various methods of editing in the mathematics classroom and highlight recommendations for improvements in future implementations of the project.


Economics Of Nuclear Power And Climate Change Mitigation Policies, Nico Bauer, Robert Brecha, Gunnar Luderer Jun 2015

Economics Of Nuclear Power And Climate Change Mitigation Policies, Nico Bauer, Robert Brecha, Gunnar Luderer

Robert J. Brecha

The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive …


Record Of Archaeal Activity At The Serpentinite-Hosted Lost City Hydrothermal Field, S. Méhay, G. Früh-Green, Susan Lang, S. Bernasconi, W. Brazelton, M. Schrenk, P. Schaeffer, P. Adam Jun 2015

Record Of Archaeal Activity At The Serpentinite-Hosted Lost City Hydrothermal Field, S. Méhay, G. Früh-Green, Susan Lang, S. Bernasconi, W. Brazelton, M. Schrenk, P. Schaeffer, P. Adam

Susan Q. Lang

No abstract provided.


Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation, Susan Lang, G. Früh-Green, S. Bernasconi, L. Wacker Jun 2015

Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation, Susan Lang, G. Früh-Green, S. Bernasconi, L. Wacker

Susan Q. Lang

We present a method for the isolation and off-line isotope analysis of formate and acetate in marine samples. Organic acids are separated by high performance liquid chromatography and collected in glass Exetainer® screw-capped vials that have been prespiked with an oxidant and flushed with helium. The vials are subsequently heated to convert the organic compounds to CO2 for radiocarbon and δ13C analysis. Small aliquots are sampled for measurement of δ13C by isotope ratio mass spectrometry, whereas the majority of the CO2 is saved for radiocarbon analysis by accelerator mass spectrometry using a gas ion source. Accurate δ13C and radiocarbon values …


H2/Ch4 Ratios Cannot Reliably Distinguish Abiotic Vs. Biotic Methane In Natural Hydrothermal Systems, Susan Lang, G. Früh-Green, D. Kelley, M. Lilley, G. Proskurowski, E. Reeves Jun 2015

H2/Ch4 Ratios Cannot Reliably Distinguish Abiotic Vs. Biotic Methane In Natural Hydrothermal Systems, Susan Lang, G. Früh-Green, D. Kelley, M. Lilley, G. Proskurowski, E. Reeves

Susan Q. Lang

No abstract provided.


Dissolved Organic Carbon Measurement Using A Modified High-Temperature Combustion Analyzer, M. Peterson, Susan Lang, A. Aufdenkampe, J. Hedges Jun 2015

Dissolved Organic Carbon Measurement Using A Modified High-Temperature Combustion Analyzer, M. Peterson, Susan Lang, A. Aufdenkampe, J. Hedges

Susan Q. Lang

No abstract provided.


Microbial Utilization Of Abiogenic Carbon And Hydrogen In A Serpentinite-Hosted System, Susan Lang, G. Früh-Green, S. Bernasconi, M. Lilley, G. Proskurowski, S. Méhay, D. Butterfield Jun 2015

Microbial Utilization Of Abiogenic Carbon And Hydrogen In A Serpentinite-Hosted System, Susan Lang, G. Früh-Green, S. Bernasconi, M. Lilley, G. Proskurowski, S. Méhay, D. Butterfield

Susan Q. Lang

No abstract provided.