1,155 research outputs found
Governing the COVID-19 Pandemic in the Middle East and North Africa: Containment Measures as a Public Good
What determined how governments in the Middle East and North Africa reacted to the global covid-19 pandemic? We develop a theoretical argument based on the political costs of different policy options and assess its empirical relevance. Distinguishing between the immediate costs associated with decisive action and the potential costs of uncontrolled spread that are likely to accrue over the long term, we argue that leaders who have fewer incentives to provide public goods to stay in power will lock down later than their more constrained counterparts. We find empirical support for this argument in statistical analyses covering the 1 January - 30 November 2020 period using the Oxford covid-19 Government Response Tracker (OxCGRT) and our own original data on the timing of mosque closures and strict lockdowns across the region. We also illustrate our argument with a description of the response to the pandemic in Egypt
Session 2-3-G: Starving to Gamble: Hunger and gambling-related craving interact to heighten persistent play among problem gamblers
Describes how hunger and gambling-related cravings relate to problem gambling
Patch Plate Materials Compatibility Assessment
Lunar dust proved to be a greater problem during the Apollo missions than was originally anticipated. The highly angular, charged dust particles stuck to seals, radiators, and visors; clogged mechanisms; and abraded space suits. As reported by Apollo 12 astronaut Pete Conrad "We must have had more than a hundred hours suited work with the same equipment, and the wear was not as bad on the training suits as it is on these flight suits in just the eight hours we were out.". Dust clinging to surfaces was also transport-ed into habitable spaces leading to lung and eye irritation of the astronauts. The Apollo astronauts were on the Lunar surface less than 24 hours and experienced many dust related problems. With the Artemis program, we are planning longer stays on the surface, with more activities that have the potential to put the astronauts and equipment in contact with greater quantities of Lunar dust. The success of these missions will depend on our understanding of material interactions with Lunar dust and the development of ways to mitigate dust effects in cases where exposure to dust will lead to failure of components, unacceptable loss of power or thermal control, unacceptable loss of visibility, or health issues. Through the Lunar Surface In-novation Initiative (LSII), we are initiating a Patch Plate Materials Compatibility Assessment project. The overall goal of the three year project is to develop passive approaches to mitigate Lunar dust adhesion to surfaces for technologies that are currently at TRL levels 2-3 to bring them to TRL level 5 through ground-based assessment, culminating in a demonstration flight experiment on a Commercial Lunar Payload Services (CLPS) lander in 2022-2023. This paper discusses the detailed technical objectives and approach for this project. References: Gaier, J.R. "The Effects of Lunar Dust on EVA Systems During the Apollo Missions," NASA/TM-2005-213610/REV1, (2005), Apollo 12 Technical Crew Debriefing, December 1, 1969, pp. 10-54
Governing the covid-19 pandemic in the Middle East and North Africa: Containment measures as a public good
What determined how governments in the Middle East and North Africa reacted to the global COVID-19 pandemic? We develop a theoretical argument based on the political costs of different policy options and assess its empirical relevance. Distinguishing between the immediate costs associated with decisive action and the potential costs of uncontrolled spread that are likely to accrue over the long term, we argue that leaders who have fewer incentives to provide public goods to stay in power will lock down later than their more constrained counterparts. We find empirical support for this argument in statistical analyses covering the 1 January – 30 November 2020 period using the Oxford covid-19 Government Response Tracker (OxCGRT) and our own original data on the timing of mosque closures and strict lockdowns across the region. We also illustrate our argument with a description of the response to the pandemic in Egypt.Institutions, Decisions and Collective Behaviou
Insect Residue Contamination on Wing Leading Edge Surfaces: A Materials Investigation for Mitigation
Flight tests have shown that residue from insect strikes on aircraft wing leading edge surfaces may induce localized transition of laminar to turbulent flow. The highest density of insect populations have been observed between ground level and 153 m during light winds (2.6 -- 5.1 m/s), high humidity, and temperatures from 21 -- 29 C. At a critical residue height, dependent on the airfoil and Reynolds number, boundary layer transition from laminar to turbulent results in increased drag and fuel consumption. Although this represents a minimal increase in fuel burn for conventional transport aircraft, future aircraft designs will rely on maintaining laminar flow across a larger portion of wing surfaces to reduce fuel burn during cruise. Thus, insect residue adhesion mitigation is most critical during takeoff and initial climb to maintain laminar flow in fuel-efficient aircraft configurations. Several exterior treatments investigated to mitigate insect residue buildup (e.g., paper, scrapers, surfactants, flexible surfaces) have shown potential; however, implementation has proven to be impractical. Current research is focused on evaluation of wing leading edge surface coatings that may reduce insect residue adhesion. Initial work under NASA's Environmentally Responsible Aviation Program focused on evaluation of several commercially available products (commercial off-the-shelf, COTS), polymers, and substituted alkoxy silanes that were applied to aluminum (Al) substrates. Surface energies of these coatings were determined from contact angle data and were correlated to residual insect excrescence on coated aluminum substrates using a custom-built "bug gun." Quantification of insect excrescence surface coverage was evaluated by a series of digital photographic image processing techniques
Dying at Home Due to Coronavirus Disease 2019
Background. Coronavirus disease 2019 (COVID-19) is a leading cause of US deaths and when severe requires admission to a
hospital; however, 9% of US COVID-19 deaths before 2022 occurred at home.
Methods. Death certificate data were used to examine the cumulative probability of dying at home from COVID-19 and from
any cause in North Carolina, including by race and ethnicity.
Results. Between March 1, 2020 and December 31, 2021, 22 646 COVID-19 deaths were recorded in North Carolina; of these, 1771
(7.8%) occurred at home. Cumulative risk of dying at home with COVID-19 increased from 3.3/100 000 on December 31, 2020 to 13.0/
100 000 on December 31, 2021. After standardizing each racial/ethnic group, cumulative at-home COVID-19 mortality among
Hispanic people compared to White people was 9.9/100 000 versus 2.3/100 000, respectively, at year-end 2020 (difference, 7.6/100
000; 95% confidence interval [CI], 5.6–9.6) and 19.0/100 000 versus 11.4/100 000 at year-end 2021 (difference, 7.6; 95% CI, 4.9–
10.4). At-home mortality among Black people was also elevated compared to White people (difference, 5.6/100 000; 95% CI, 3.7–
7.4) at year-end 2021. Rates of dying at home from any cause increased overall but were greatest among Hispanic people.
Conclusions. By the end of 2021, the risk of dying at home from COVID-19 increased, especially for persons of color. The risk of
dying at-home from any cause also increased for all but more so for Hispanic persons. These findings suggest perennial barriers to care
prevent those with progressive COVID-19 from accessing medical attention and the need for initiatives that extend healthcare access
for those disproportionately impacted by COVID-19 to prevent avoidable deat
Modified Surface Having Low Adhesion Properties to Mitigate Insect Residue Adhesion
A process to modify a surface to provide reduced adhesion surface properties to mitigate insect residue adhesion. The surface may include the surface of an article including an aircraft, an automobile, a marine vessel, all-terrain vehicle, wind turbine, helmet, etc. The process includes topographically and chemically modifying the surface by applying a coating comprising a particulate matter, or by applying a coating and also topographically modifying the surface by various methods, including but not limited to, lithographic patterning, laser ablation and chemical etching, physical vapor phase deposition, chemical vapor phase deposition, crystal growth, electrochemical deposition, spin casting, and film casting
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To the Editors:
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Influence of Surface Properties and Impact Conditions on Adhesion of Insect Residues
Insect residues can cause premature transition to turbulent flow on laminar flow airfoils. Engineered surfaces that mitigate the adhesion of insect residues provide, therefore, a route to more efficient aerodynamics and reduced fuel burn rates. Areal coverage and heights of residues depend not only on surface properties, but also on impact conditions. We report high speed photography of fruit fly impacts at different angles of inclination on a rigid aluminum surface, optical microscopy and profilometry, and contact angle goniometry to support the design of engineered surfaces. For the polyurethane and epoxy coatings studied, some of which exhibited superhydrophobicity, it was determined that impact angle and surface compositions play critical roles in the efficacy of these surfaces to reduce insect residue adhesion
Influence of Surface Properties and Impact Conditions on Insect Residue Adhesion
Airflow over airfoils used on current commercial aircraft transitions from laminar to turbulent at relatively low chord positions. As a result, drag increases, requiring more thrust to maintain flight. An airfoil with increased laminar flow would experience reduced drag and a lower fuel burn rate. One of the objectives of NASA's Environmentally Responsible Aviation project is to identify and demonstrate technologies that will enable more environmentally friendly commercial aircraft. While more aerodynamically efficient airfoil shapes can be designed, surface contamination from ice, dirt, pollen, runway debris, and insect residue can degrade performance
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