Flow field computations for blunt bodies in planetary environments

Numerical analysis on flow distribution around hypersonic blunt body in planetary atmospher

Reactive self-heating model of aluminum spherical nanoparticles

Aluminum-oxygen reaction is important in many highly energetic, high pressure generating systems. Recent experiments with nanostructured thermites suggest that oxidation of aluminum nanoparticles occurs in a few microseconds. Such rapid reaction cannot be explained by a conventional diffusion-based mechanism. We present a rapid oxidation model of a spherical aluminum nanoparticle, using Cabrera-Mott moving boundary mechanism, and taking self-heating into account. In our model, electric potential solves the nonlinear Poisson equation. In contrast with the Coulomb potential, a "double-layer" type solution for the potential and self-heating leads to enhanced oxidation rates. At maximal reaction temperature of 2000 C, our model predicts overall oxidation time scale in microseconds range, in agreement with experimental evidence.Comment: submitte

Alternative Solutions for Government Intervention in Climate Crisis Markets: Price Gouging and the Pandemic Egg Market Case Study

The cost of a thing is the amount of what I will call life which is required to be exchanged for it, immediately or in the long run. The incredible, edible egg. Fires in California, hurricanes along the Gulf, a worldwide pandemic—it is evident that the year 2020 was defined by great crises, most of which were direct results of or exacerbated by climate change. The effects of these crises on broader American society, in particular that of the COVID-19 pandemic, are just beginning to be realized. Nearly every aspect of American life has been impacted by the pandemic and by the corresponding responses of state and federal governments. Rapid price increases are a common thread linking environmental catastrophes of various causes. Environmental catastrophes, like hurricanes, droughts, and pandemics, all can create scarcity, causing prices to rise. Depending on the magnitude, these price increases may be characterized as “price gouging.” Price gouging as a practice, and crisis price increases more broadly, can take many forms, have varying causes, and are not infrequently the subject of litigation and academic controversy. The 2020 pandemic-induced price increases were unique in their sheer breadth: commodities from thermometers to toilet paper experienced nationwide price shocks, due to increased demand, challenges to supply chains, or both. The strain that the pandemic placed on the food supply was particularly unprecedented. Animal protein markets experienced never-before-seen challenges to their supply chains, while simultaneously dealing with skyrocketing demand. Of these commodities, the egg market experienced the most dramatic shift in price, with a consumer price index increase of 16.1% in April. The next highest increase was 4.3%, for the commodity category of meat, poultry, and fish. These commodity prices eventually leveled out, and by July even egg prices had returned to relative stability. Even so, four state attorneys general brought actions against egg suppliers for price gouging through the spring and summer of 2020. In addition, calls for federal price gouging legislation have been renewed along bipartisan lines, despite overwhelming distaste among neoclassical economists for the kind of price ceilings these laws create. Traditional economic critiques, however, have largely ignored the broader ethical, political, and moral concerns of politicians and voters that keep restrictions on price gouging popular. These concerns ensure that anti-price gouging laws are an indefinite fixture in American law. Litigation under anti-price gouging laws, however, is not the only option that federal and state governments have to prevent or mitigate crisis price increases. This Note uses the egg market as a case study to present four policy alternatives that state and federal governments may consider in addressing crisis price increases, rather than resorting to anti-price gouging litigation. Part I narrows the scope of discussion and defines price gouging, a term that can be emotionally charged. Part II tells the story of the 2020 egg market, which is both an intrinsically valuable case study and a useful model to frame policy alternatives. Part III examines the theoretical underpinnings of price gouging to develop a dichotomous framework with which to evaluate policy alternatives. Part IV presents and analyzes the four policy alternatives using this framework. The goal of this Note is to describe and analyze alternatives to litigation that will better resolve the concerns that anti-price gouging laws attempt to address

Venture: The Frontiers of Free Methodism

https://place.asburyseminary.edu/freemethodistbooks/1014/thumbnail.jp

The Effects of Common Core State Standards in Mathematics on Inclusive Environments

The Common Core State Standards for Mathematics (CCSSM) require students with learning disabilities in mathematics to use a range of cognitive, skills, and foundational numerical competencies to learn and understand complex standards. Students with learning disabilities in mathematics experience deficits in cognitive processes skills and foundational numerical competencies which have emerged as underlying barriers associated with mastering CCSSM. Examining the impact of high-stakes assessments on readiness for college and careers and student achievement may provide evidence that deficits in cognitive processing skills and numerical competencies can impact achievement levels. Using the cognitive theoretical frameworks of Bandura and Gagné, along with the concepts of cognitive learning, instructional interventions, and inclusion, the relationship between students\u27 scores in the algebraic foundations (AF) intervention inclusion method and the regular algebra (RA) nonintervention inclusion method, as measured on the end of the year assessments were examined in this study. An ANCOVA design was used to test the statistical significance of the relationship between the two intervention methods and the use of cognitive and numerical competencies for the two groups and to analyze the disparity in achievement scores between the AF intervention inclusion method and RA nonintervention inclusion method. The results revealed a statistically significant relationship between cognitive processing skills and foundational numerical competencies as measured on the final exam for both methods. The intended audience include academic communities using evidence-based inventions to improve college and career readiness results, leading to positive social change

Quitting the Boss? The Role of Manager Influence Tactics and Employee Emotional Engagement in Voluntary Turnover

Employees commonly cite their managers’ behavior as the primary reason for quitting their jobs. We sought to extend turnover research by investigating whether two commonly used influence tactics by managers affect their employees’ voluntary turnover and whether employees’ emotional engagement and job satisfaction mediate this relationship. We tested our hypotheses using survey data collected at two time points from a sample of financial services directors and objective lagged turnover data. Using multilevel path modeling, we found that managers’ use of pressure and inspirational appeals had opposite effects on employee voluntary turnover and that employees’ emotional engagement was a significant and unique mediating mechanism even when job satisfaction, the traditional attitudinal predictor of turnover, was also included in the path model. Our findings contribute to turnover research by demonstrating a relationship between specific managerial behaviors and employee turnover and shed light on a key mediating mechanism that explains these effects

Microbial gene abundance and expression patterns across a river to ocean salinity gradient

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 10 (2015): e0140578, doi: 10.1371/journal.pone.0140578.Microbial communities mediate the biogeochemical cycles that drive ecosystems, and it is important to understand how these communities are affected by changing environmental conditions, especially in complex coastal zones. As fresh and marine waters mix in estuaries and river plumes, the salinity, temperature, and nutrient gradients that are generated strongly influence bacterioplankton community structure, yet, a parallel change in functional diversity has not been described. Metagenomic and metatranscriptomic analyses were conducted on five water samples spanning the salinity gradient of the Columbia River coastal margin, including river, estuary, plume, and ocean, in August 2010. Samples were pre-filtered through 3 μm filters and collected on 0.2 μm filters, thus results were focused on changes among free-living microbial communities. Results from metagenomic 16S rRNA sequences showed taxonomically distinct bacterial communities in river, estuary, and coastal ocean. Despite the strong salinity gradient observed over sampling locations (0 to 33), the functional gene profiles in the metagenomes were very similar from river to ocean with an average similarity of 82%. The metatranscriptomes, however, had an average similarity of 31%. Although differences were few among the metagenomes, we observed a change from river to ocean in the abundance of genes encoding for catabolic pathways, osmoregulators, and metal transporters. Additionally, genes specifying both bacterial oxygenic and anoxygenic photosynthesis were abundant and expressed in the estuary and plume. Denitrification genes were found throughout the Columbia River coastal margin, and most highly expressed in the estuary. Across a river to ocean gradient, the free-living microbial community followed three different patterns of diversity: 1) the taxonomy of the community changed strongly with salinity, 2) metabolic potential was highly similar across samples, with few differences in functional gene abundance from river to ocean, and 3) gene expression was highly variable and generally was independent of changes in salinity.This study was carried out within the context of the Science and Technology Center for Coastal Margin Observation & Prediction (CMOP) supported by the National Science Foundation, grant number OCE-0424602 to Antonio Baptista (http://www.stccmop.org)