Bootstrapping the Chiral Anomaly at Large NcN_c

The bootstrap approach (demanding consistency conditions to scattering amplitudes) has shown to be quite powerful to tightly constrain gauge theories at large $N_c$. We extend previous analysis to scattering amplitudes involving pions and external gauge bosons. These amplitudes allow us to access the chiral anomaly and connect low-energy physical quantities to UV properties of the theory. In particular, we are able to obtain an analytic bound on the chiral anomaly coefficient as a function of the pion dipole polarizabilities. This bound can be useful for holographic models whose dual UV completions are not known, and provide a consistency condition to lattice simulations.Comment: 20 pages, 1 figure. v2: bound on the anomaly generalised and typos correcte

Coaxing HIS Data from Mandli Pavement Scans

The Kentucky Transportation Cabinet (KYTC) Division of Planning’s Highway Information Systems (HIS) database provides geometric information about horizontal and vertical curves, but its accuracy is unknown. An updated method of pavement analysis collects data by scanning the pavement as a van equipped with Mandli software drives the area of interest. The scans provide detailed information that can be used to calculate roadway geometry characteristics (e.g., curve radius, cross slope/superelevation, and grade). This study evaluated the ability of the Mandli data to support curve advisory calculations and find a way to utilize Mandli data to improve the existing HIS database. To this end, the report includes a literature review to determine applicability of data, a series of data validation steps to define Mandli’s accuracy, and an evaluation of tools that convert Mandli into usable HIS data. The data attributes of focus are horizontal curve radius, grade, and cross slope. Horizontal curve radii values were evaluated using University of Nevada Reno’s ArcMAP plugin, Florida DOT’s curvature extension tool, and the University of Kentucky’s Curvature Automatic Tool (UKCAT). These tools were tested for usability, efficiency, and accuracy. Vertical curve attributes, including grade and cross slope, were evaluated by comparing Mandli data to manual field measurements, design plans, and other data collection methods. After data collection and analysis, researchers outline a newly developed method for converting Mandli data into a usable form and implementing it in HIS

Giant Light-Emission Enhancement in Lead Halide Perovskites by Surface Oxygen Passivation.

Surface condition plays an important role in the optical performance of semiconductor materials. As new types of semiconductors, the emerging metal-halide perovskites are promising for next-generation optoelectronic devices. We discover significantly improved light-emission efficiencies in lead halide perovskites due to surface oxygen passivation. The enhancement manifests close to 3 orders of magnitude as the perovskite dimensions decrease to the nanoscale, improving external quantum efficiencies from <0.02% to over 12%. Along with about a 4-fold increase in spontaneous carrier recombination lifetimes, we show that oxygen exposure enhances light emission by reducing the nonradiative recombination channel. Supported by X-ray surface characterization and theoretical modeling, we propose that excess lead atoms on the perovskite surface create deep-level trap states that can be passivated by oxygen adsorption

Perfecting one-loop BCJ numerators in SYM and supergravity

We take a major step towards computing $D$-dimensional one-loop amplitudes in general gauge theories, compatible with the principles of unitarity and the color-kinematics duality. For $n$-point amplitudes with either supersymmetry multiplets or generic non-supersymmetric matter in the loop, simple all-multiplicity expressions are obtained for the maximal cuts of kinematic numerators of $n$-gon diagrams. At $n=6,7$ points with maximal supersymmetry, we extend the cubic-diagram numerators to encode all contact terms, and thus solve the long-standing problem of \emph{simultaneously} realizing the following properties: color-kinematics duality, manifest locality, optimal power counting of loop momenta, quadratic rather than linearized Feynman propagators, compatibility with double copy as well as all graph symmetries. Color-kinematics dual representations with similar properties are presented in the half-maximally supersymmetric case at $n=4,5$ points. The resulting gauge-theory integrands and their supergravity counterparts obtained from the double copy are checked to reproduce the expected ultraviolet divergences.Comment: 55 pages; Dedicated to the memory of Lars Brin

Safety of guidewire-based measurement of fractional flow reserve and the index of microvascular resistance using intravenous adenosine in patients with acute or recent myocardial infarction

Aims: Coronary guidewire-based diagnostic assessments with hyperemia may cause iatrogenic complications. We assessed the safety of guidewire-based measurement of coronary physiology, using intravenous adenosine, in patients with an acute coronary syndrome. Methods: We prospectively enrolled invasively managed STEMI and NSTEMI patients in two simultaneously conducted studies in 6 centers (NCT01764334; NCT02072850). All of the participants underwent a diagnostic coronary guidewire study using intravenous adenosine (140 μg/kg/min) infusion for 1–2 min. The patients were prospectively assessed for the occurrence of serious adverse events (SAEs) and symptoms and invasively measured hemodynamics were also recorded. Results: 648 patients (n = 298 STEMI patients in 1 hospital; mean time to reperfusion 253 min; n = 350 NSTEMI in 6 hospitals; median time to angiography from index chest pain episode 3 (2, 5) days) were included between March 2011 and May 2013. Two NSTEMI patients (0.03% overall) experienced a coronary dissection related to the guidewire. No guidewire dissections occurred in the STEMI patients. Chest symptoms were reported in the majority (86%) of patient's symptoms during the adenosine infusion. No serious adverse events occurred during infusion of adenosine and all of the symptoms resolved after the infusion ceased. Conclusions: In this multicenter analysis, guidewire-based measurement of FFR and IMR using intravenous adenosine was safe in patients following STEMI or NSTEMI. Self-limiting symptoms were common but not associated with serious adverse events. Finally, coronary dissection in STEMI and NSTEMI patients was noted to be a rare phenomenon

An MBR Membrane Housing Design Sustainable Treatment of Domestic Wastewater

ME450 Capstone Design and Manufacturing Experience: Winter 2008Anaerobic membrane housing design for use in wastewater treatment.Professor Lutgarde Raskin Mrs. Tanna Borrellhttp://deepblue.lib.umich.edu/bitstream/2027.42/58674/1/me450w08project27_report.pd

Potential Effect of Cable Median Barriers on Commercial Vehicle Crossover Crashes

In 2016, commercial motor vehicles (CMVs) were involved in 4,079 fatal crashes in the U.S., representing 11.8 percent of all fatal crashes. State of Kentucky crash data for 2015-2016 show that per capita crash rates and increases in crash-related fatalities exceeded the national average. Crossover crashes occur when a vehicle leaves its intended path and veers into the path of oncoming traffic, typically resulting in head-on or sideswipe opposite direction crashes. Cable median barriers are a countermeasure which can potentially be used to mitigate crossover crashes. This research investigated the potential effectiveness of cable median barriers on CMV crashes. Analysis relied on an expert panel approach that evaluated the potential effects of cable barriers on altering the crash severity for fatal and incapacitating injuries (K and A in the KABCO severity index) and developed safety performance functions (SPFs) that resulted in crash prediction models that can be used to develop crash modification factors (CMFs) for estimating how the presence of cable median barriers can potentially affect crash occurrence and severity. The expert panel analysis concluded that safety gains are possible by installing cable median barriers and that their effectiveness is greater for fatalities. The average score of over 2 from the panel (on a scale from 0-5) indicates a moderate effect on crash outcomes. SPFs developed also supported the overall expert panel assessment. Analysis found that CMV crash outcomes benefit from installing cable median barriers, although only interstate routes were examined. The results indicate that CMV crashes will indeed be mitigated by installing cable median barriers. Both analyses supported this finding, and the overall conclusion is one of a positive impact. Benefits may be greater on divided roadways, since installations on two-lane roads may be more problematic due to space limitations. Additional research is recommended to evaluate this finding in light of which vehicle is the errant vehicle, since there could be significant implications for assessing the effectiveness of the cable median barrier if the CMV is the crossing-over vehicle