Function in Systemic Linguistics

Christopher S. Butler 한국언어학회 1985 언어 Vol.10 No.1

Electronic structure design for nanoporous, electrically conductive zeolitic imidazolate frameworks

Butler, Keith T.,Worrall, Stephen D.,Molloy, Christopher D.,Hendon, Christopher H.,Attfield, Martin P.,Dryfe, Robert A. W.,Walsh, Aron Royal Society of Chemistry 2017 Journal of Materials Chemistry C Vol.5 No.31

<▼1><P>Electronic structure calculations are used to develop design rules for enhanced electrical conductivity in zeolitic imidazolate frameworks.</P></▼1><▼2><P>Electronic structure calculations are used to develop design rules for enhanced electrical conductivity in zeolitic imidazolate frameworks. The electrical resistivity of Co<SUP>2+</SUP> based zeolitic imidazolate frameworks has previously been found to be ∼1000 times lower than that of Zn<SUP>2+</SUP> based materials. The electrical conductivity of the frameworks can also be tuned by ligand molecule selection. Using density functional theory calculations, this controllable electrical conductivity is explained in terms of tuneable conduction band edge character, with calculations revealing the improved hybridisation and extended band character of the Co<SUP>2+</SUP> frameworks. The improvements in the methylimidazolate frameworks are understood in terms of improved frontier orbital matching between metal and ligand. The modular tuneability and previously demonstrated facile synthesis provides a route to rational design of stable framework materials for electronic applications. By outlining these design principles we provide a route to the future development of stable, electrically conductive zeolitic imidazolate frameworks.</P></▼2>

Superpower Dispute Initiation: An Empirical Model of Strategic Behavior

Christopher K. Butler 한국외국어대학교 국제지역연구센터 2011 International Area Studies Review Vol.14 No.3

A method is presented for empirically modeling simultaneous decisions using the estimation technique of bivariate probit. This technique is used to examine the directed dispute-initiation behavior of the superpowers during the Cold War. Power-transition concepts of satisfaction and rates of capability change can be used to explain directed dispute-initiation behavior. In particular, the international influence of the rival translates into a superpower’’s dissatisfaction, making dispute initiation by that superpower more likely, ceteris paribus. Additionally, a rapid strengthening of the challenger, ceteris paribus, increases the likelihood of dispute initiation in either direction. Changes in the hegemon’’s capabilities, though consistent with power-transition theory, have no effect on dispute-initiation behavior. These effects hold even while controlling for various domestic conditions in each country.

Sexual violence by government security forces: Are levels of sexual violence in peacetime predictive of those in civil conflict?

Christopher K. Butler,Jessica L. Jones 한국외국어대학교 국제지역연구센터 2016 International Area Studies Review Vol.19 No.3

Are levels of sexual violence committed by government security forces in a country prior to conflict predictive of levels of sexual violence in that country during conflict? Most of the scholarship on sexual violence focuses on the phenomenon during armed conflict, and in general the assumption made by these scholars is that conflict exacerbates the sexual violence problem. Cross-sectional analysis appears to support this assertion; however, we argue that the comparison group used by cross-sectional analyses is inappropriate for answering the question of whether conflict impacts the amount of sexual violence in a country. Instead, we propose that the appropriate comparison is between peacetime levels of sexual violence and conflict levels of sexual violence for the same country. To test this relationship, we employ data on sexual violence committed by government security forces in a sample of 170 countries for the time period 1999–2011, using a measure similar to that from Butler, Gluch, and Mitchell. Then, we use a variety of descriptive and inferential statistical tests to examine the relationship between conflict from the UCDP/PRIO Armed Conflict Dataset and the level of sexual violence in a country. We find that for cases with variation in conflict across our time period, pre-conflict levels of sexual violence are predictive of conflict levels but, contrary to the common assumption, the prediction is no change in the level of sexual violence for most cases.

Electroactive Nanoporous Metal Oxides and Chalcogenides by Chemical Design

Hendon, Christopher H.,Butler, Keith T.,Ganose, Alex M.,Romá,n-Leshkov, Yuriy,Scanlon, David O.,Ozin, Geoffrey A.,Walsh, Aron American Chemical Society 2017 Chemistry of materials Vol.29 No.8

<P/><P>The archetypal silica- and aluminosilicate-based zeolite-type materials are renowned for wide-ranging applications in heterogeneous catalysis, gas-separation and ion-exchange. Their compositional space can be expanded to include nanoporous metal chalcogenides, exemplified by germanium and tin sulfides and selenides. By comparison with the properties of bulk metal dichalcogenides and their 2D derivatives, these open-framework analogues may be viewed as three-dimensional semiconductors filled with nanometer voids. Applications exist in a range of molecule size and shape discriminating devices. However, what is the electronic structure of nanoporous metal chalcogenides? Herein, materials modeling is used to describe the properties of a homologous series of nanoporous metal chalcogenides denoted np-MX<SUB>2</SUB>, where M = Si, Ge, Sn, Pb, and X = O, S, Se, Te, with Sodalite, LTA and aluminum chromium phosphate-1 structure types. Depending on the choice of metal and anion their properties can be tuned from insulators to semiconductors to metals with additional modification achieved through doping, solid solutions, and inclusion (with fullerene, quantum dots, and hole transport materials). These systems form the basis of a new branch of semiconductor nanochemistry in three dimensions.</P>

Absorbate-Induced Piezochromism in a Porous Molecular Crystal

Hendon, Christopher H.,Wittering, Kate E.,Chen, Teng-Hao,Kaveevivitchai, Watchareeya,Popov, Ilya,Butler, Keith T.,Wilson, Chick C.,Cruickshank, Dyanne L.,Miljanić,, Ognjen Š,.,Walsh, Aron American Chemical Society 2015 Nano letters Vol.15 No.3

<P/><P>Atmospherically stable porous frameworks and materials are interesting for heterogeneous solid–gas applications. One motivation is the direct and selective uptake of pollutant/hazardous gases, where the material produces a measurable response in the presence of the analyte. In this report, we present a combined experimental and theoretical rationalization for the piezochromic response of a robust and porous molecular crystal built from an extensively fluorinated trispyrazole. The electronic response of the material is directly determined by analyte uptake, which provokes a subtle lattice contraction and an observable bathochromic shift in the optical absorption onset. Selectivity for fluorinated absorbates is demonstrated, and toluene is also found to crystallize within the pore. Furthermore, we demonstrate the application of electronic structure calculations to predict a physicochemical response, providing the foundations for the design of electronically tunable porous solids with the chemical properties required for development of novel gas-uptake media.</P>

The Influence of Health Perception on Shoulder Outcome Measure Scores

Richard E. Hardy,Engin Sungur,Christopher Butler,Jefferson C. Brand 대한견주관절학회 2019 대한견주관절의학회지 Vol.22 No.4

Background: Patient reported outcome measures assess clinical progress from the patient’s perspective. This study explored the relationship between shoulder outcome measures (The Disability of the Arm, Shoulder and Hand [DASH], American Shoulder and Elbow Surgeons Standard Shoulder Assessment score [ASES], and Constant score) by comparing the best possible scores obtained in an asymptomatic population compared to overall perception of health, as measured by the SF-36 outcome measure. Methods: Volunteers (age range, 20–69 years) with asymptomatic shoulders and no history of shoulder pain, injury, surgery, imaging, or pathology (bilaterally) were included. The DASH and ASES measures were completed by 111 volunteers (72 female, 39 male), of which 92 completed the Constant score (56 female, 36 male). The SF-36 was completed by all volunteers (level of evidence: IV case series). Results: The mean (x) score for ASES measure on the right shoulder was higher for the left-hand dominant side (x=100.00 vs. 95.02, p-value<0.001); no other significant differences. Better SF-36 scores were associated with better DASH scores. Our prediction models suggest that perception of overall health affects the DASH scores. Sex affected all three shoulder measures scores. Conclusions: Comparing scores of shoulder outcome measures to the highest possible score is not the most informative way to interpret patient progress. Variables such as health status, sex, and hand dominance need to be considered. Furthermore, it is possible to use these variables to predict scores of outcome measures, which facilitates the healthcare provider to deliver individualized care to their patients.