Composite Experimental and Numerical Modeling of Arced Labyrinth Weirs

Arced labyrinth weirs are a viable option for existing spillway retrofit due to their increased flow capacity. This study supplies additional arced labyrinth weir hydraulic design empirical data and uses this data to validate a numerical model (utilized Flow-3D) of the same experimental setup. The dimensionless discharge coefficient relationship is presented for the physical model, potential errors due to physical model crest referencing are discussed, and the relative and absolute errors along with a grid convergence study are given for the numerical model

The Page curve from the entanglement membrane

We study entanglement dynamics in toy models of black hole information built out of chaotic many-body quantum systems, by utilising a coarse-grained description of entanglement dynamics in such systems known as the `entanglement membrane'. We show that in these models the Page curve associated to the entropy of Hawking radiation arises from a transition in the entanglement membrane around the Page time, in an analogous manner to the change in quantum extremal surfaces that leads to the Page curve in semi-classical gravity. We also use the entanglement membrane prescription to study the Hayden-Preskill protocol, and demonstrate how information initially encoded in the black hole is rapidly transferred to the radiation around the Page time. Our results relate recent developments in black hole information to generic features of entanglement dynamics in chaotic many-body quantum systems.Comment: 22 pages + appendices, lots of figure

MapX: an In-Situ Mapping X-Ray Fluorescence Instrument for Detection of Biosignatures and Habitable Planetary Environments

The search for evidence of life or its processes on other worlds takes on two major themes: the detection of biosignatures indicating extinct or extant life, or the determination that an environment either has or once had the potential to harbor living organisms. In situ elemental imaging is useful in either case, since features on the mm to m scale reveal geological processes which may indicate past or present habitability. Further, biomineralization can leave traces in the morphology and element distribution of surfaces. The Mapping X-ray Fluorescence Spectrometer (MapX) is an in-situ instrument designed to identify these features on planetary surfaces [1]. Progress on instrument development, data analysis methods, and element quantification are presented

To Be Young, Black, and In the Academy: A Collection of Lessons

Literacy, a foundational tool that unlocks opportunities, can be viewed in both narrow and confining lenses. We, doctoral students at Michigan State University, center our own experiences in order to redefine such narratives of what literacy means, can mean, and should mean for students of color throughout the African Diaspora. We explore methods to disrupt, experiences to resist, and questions to challenge the ways that students and educators engage with various concepts of literacy. Though we come from various backgrounds, this manuscript seeks to push forward a dialogue that allows for the multiple literacies that Black children have, language and otherwise, to be seen as an asset rather than a deficit. It is incumbent upon educators to explore, accept, and learn from Black children in pursuit of allowing various literacies to be accepted, explored, and appreciated. Our work is part of a larger conversation that continues a legacy of struggle to ensure that the education Black children receive is one that is liberatory rather than shackling

Nonmethane hydrocarbon measurements in the North Atlantic Flight Corridor during the Subsonic Assessment Ozone and Nitrogen Oxide Experiment

Mixing ratios of nonmethane hydrocarbons (NMHCs) were not enhanced in whole air samples collected within the North Atlantic Flight Corridor (NAFC) during the fall of 1997. The investigation was conducted aboard NASA's DC-8 research aircraft, as part of the Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (SONEX). NMHC enhancements were not detected within the general organized tracking system of the NAFC, nor during two tail chases of the DC-8's own exhaust. Because positive evidence of aircraft emissions was demonstrated by enhancements in both nitrogen oxides and condensation nuclei during SONEX, the NMHC results suggest that the commercial air traffic fleet operating in the North Atlantic region does not contribute at all or contributes negligibly to NMHCs in the NAFC. Copyright 2000 by the American Geophysical Union

Surface ozone in the Colorado northern Front Range and the influence of oil and gas development during FRAPPE/DISCOVER-AQ in summer 2014

High mixing ratios of ozone (O3) in the northern Front Range (NFR) of Colorado are not limited to the urban Denver area but were also observed in rural areas where oil and gas activity is the primary source of O3 precursors. On individual days, oil and gas O3 precursors can contribute in excess of 30 ppb to O3 growth and can lead to exceedances of the EPA O3 National Ambient Air Quality Standard. Data used in this study were gathered from continuous surface O3 monitors for June–August 2013–2015 as well as additional flask measurements and mobile laboratories that were part of the FRAPPE/DISCOVER-AQ field campaign of July–August 2014. Overall observed O3 levels during the summer of 2014 were lower than in 2013, likely due to cooler and damper weather than an average summer. This study determined the median hourly surface O3 mixing ratio in the NFR on summer days with limited photochemical production to be approximately 45–55 ppb. Mobile laboratory and flask data collected on three days provide representative case studies of different O3 formation environments in and around Greeley, Colorado. Observations of several gases (including methane, ethane, CO, nitrous oxide) along with O3 are used to identify sources of O3 precursor emissions. A July 23 survey demonstrated low O3 (45–60 ppb) while August 3 and August 13 surveys recorded O3 levels of 75–80 ppb or more. August 3 exemplifies influence of moderate urban and high oil and gas O3 precursor emissions. August 13 demonstrates high oil and gas emissions, low agricultural emissions, and CO measurements that were well correlated with ethane from oil and gas, suggesting an oil and gas related activity as a NOx and O3 precursor source. Low isoprene levels indicated that they were not a significant contributor to O3 precursors measured during the case studies

Work-life Events Theory: Making Sense of Shock Events in Dual-Earner Couples

Dual-earner couples are increasingly prevalent and encounter demands arising from each partner’s commitment to various work and life domains. Unfortunately, there has been little theoretical progress in explaining how dual-earner couples navigate work-life shock events, which we define as disruptive, novel, and critical events that require investment of a couple’s resources. Drawing from identity and sensemaking theories, we develop a theory of work-life shock events to explain how dual-earner couples perceive and respond to these events. We theorize that partners initially make sense of the event as individuals and then engage in couple-level sensemaking. We argue that each individual’s shock intensity perceptions are shaped by the shock event’s characteristics and the identity factors of role salience hierarchy and future self. A subsequent couple-level process of sensemaking ensues, influenced by the salience of the originating domain and partner role, as well as relational identity factors. Couple-level shock intensity perceptions result in the couple’s decision regarding resource investment in the shock event’s originating domain. We discuss implications for future research and for organizations

Roundabout Oxford Podcast Episode 12: Podcasts and Podcasting

This time Roundabout Oxford goes meta as we talk podcasts and podcasting in our podcast! Interviews feature Blake Thompson, host of Beyond the Square and Oxford Charger podcasts; Adam Clemons and Abigail Norris-Davidson, interviewees for BBC\u27s Breaking Mississippi podcast; and Alex Langhart, head of University Health Services, What\u27s Plaguing U

MapX An In Situ, Full-frame X-Ray Spectroscopic Imager for Planetary Science and Astrobiology

Microbial life exploits micron-scale disequilibria at boundaries where valence, chemical potential, pH, Eh, etc. vary on a length scale commensurate with the organisms - 10's to 100's of microns. The detection of accumulations of the biogenic elements C,N,O,P,S at appropriate concentrations on or in a mineral/ice substrate would constitute permissive evidence of extant life, but context is also required. Does the putative biosignature exist under habitable conditions? Under what conditions of P, T, and chemical potential was the host mineralogy formed? MapX is an in situ robotic spacecraft instrument that images the biogenic elements C, N, O, P, S, as well as the cations of the rock-forming minerals (Na, Mg, Al, Si, K, Ca, Ti, Cr, Mn, Fe) and important anions such as Cl, Fl. MapX provides element maps with less than or equal to100 microns resolution over a 2.5 cm X 2.5 cm area, as well as quantitative XRF spectra from ground- or instrument-selected Regions of Interest (ROI). XRF spectra are converted to mineralogies using ground- or instrument-based algorithms. Either X-ray tube or radioisotope sources such as 244Cm (Alpha-particle and gamma- ray fluorescence) can be used. Fluoresced sample Xrays are imaged onto an X-ray sensitive CCD through an X-ray MicroPore Optic (MPO). The MapX design as well as baseline performance requirements for a MapX instrument intended for life detection / identification of habitable environments will be presented