Active Shooter Events: The Guardian Plan

The decision on how to protect the children and youth while at schools is a serious conversation with varying agreements on the best practices. Some feel that school personnel should not be trained nor expected to be able to react to an armed person while others believe that training of school personnel and allowing them to be armed will deter armed assailants in schools. Ultimately, each school board and district leadership need to choose an emergency safety plan that fits their community. The number of school shootings has brought emergency safety discussions to the forefront again. One school district, highlighted in this article, chose the implementation of a plan called the Guardian Plan

HRXRD study of the theoretical densities of novel reactive sintered boride candidate neutron shielding materials

Reactive Sintered Borides (RSBs) are novel borocarbide materials derived from FeCr-based cemented tungsten (FeCr-cWCs) show considerable promise as compact radiation armour for proposed spherical tokamak,[1],[2],[3],[4],[5]. Six candidate compositions (four RSBs, two cWCs) were evaluated by high-resolution X-ray diffraction (XRD), inductively coupled plasma (ICP), energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) to determine the atomic composition, phase presence, and theoretical density. RSB compositions were evaluated with initial boron contents equivalent to 25 at% 30 at%. All RSB compositions showed delamination and carbon enrichment in the bulk relative to the surface, consistent with non-optimal binder removal and insufficient sintering time. Phase abundance within RSBs derived from powder XRD was dominated by iron tungsten borides (FeWB/FeW2B2), tungsten borides (W2B5/WB) and iron borides. The most optimal RSB composition (B5T522W) with respect to physical properties and highest ρ/ρtheo had ρtheo = 12.59 ± 0.01 g cm-3 for ρ/ρtheo = 99.3% and had the weigh-in and post-sintered W : B : Fe abundance closest to 1 : 1 : 1. This work indicates that despite their novelty, RSB materials can be optimized and in principle be processed using existing cWC processing routes

A Numerical Treatment of Melt/Solid Segregation: Size of the Eucrite Parent Body and Stability of the Terrestrial Low-Velocity Zone

Crystal sinking to form cumulates and melt percolation toward segregation in magma pools can be treated with modifications of Stokes' and Darcy's laws, respectively. The velocity of crystals and melt depends, among other things, on the force of gravity (g) driving the separations and the cooling time of the environment. The increase of g promotes more efficient differentiation, whereas the increase of cooling rate limits the extent to which crystals and liquid can separate. The rate at which separation occurs is strongly dependent on the proportion of liquid that is present. As a result, cumulate formation is a process with a negative feedback; the more densely aggregated the crystals become, the slower the process can proceed. In contrast, melt accumulation is a process with a positive feedback; partial accumulation of melt leads to more rapid accumulation of subsequent melt. This positive feedback can cause melt accumulation to run rapidly to completion once a critical stability limit is passed. The observation of cumulates and segregated melts among the eucrite meteorites is used as a basis for calculating the g (and planet size) required to perform these differentiations. The eucrite parent body was probably at least 10-100 km in radius. The earth's low velocity zone (LVZ) is shown to be unstable with respect to draining itself of excess melt if the melt forms an interconnecting network. A geologically persistent LVZ with a homogeneous distribution of melt can be maintained with melt fractions only on the order of 0.1% or less

Resource Allocation Contests: Experimental Evidence

Across many forms of rent seeking contests, the impact of risk aversion on equilibrium play is indeterminate. We design an experiment to compare individuals’ decisions across three contests which are isomorphic under risk-neutrality, but are typically not isomorphic under other risk preferences. The pattern of individual play across our contests is not consistent with a Bayes-Nash equilibrium for any distribution of risk preferences. We show that replacing the Bayes-Nash equilibrium concept with the quantal response equilibrium, along with heterogeneous risk preferences can produce equilibrium patterns of play that are very similar to the patterns we observe.rent seeking, experiments, risk aversion, game theory

Rapidly self-deoxygenating controlled radical polymerization in water via in situ disproportionation of Cu(i)

Rapidly self-deoxygenating Cu-RDRP in aqueous media is investigated. The disproportionation of Cu(I)/Me6Tren in water towards Cu(II) and highly reactive Cu(0) leads to O2-free reaction environments within the first seconds of the reaction, even when the reaction takes place in the open-air. By leveraging this significantly fast O2-reducing activity of the disproportionation reaction, a range of well-defined water-soluble polymers with narrow dispersity are attained in a few minutes or less. This methodology provides the ability to prepare block copolymers via sequential monomer addition with little evidence for chain termination over the lifetime of the polymerization and allows for the synthesis of star-shaped polymers with the use of multi-functional initiators. The mechanism of self-deoxygenation is elucidated with the use of various characterization tools, and the species that participate in the rapid oxygen consumption is identified and discussed in detail

GENTRIFICATION MOVES TO THE GLOBAL SOUTH: AN ANALYSIS OF THE PROGRAMA DE RESCATE, A NEOLIBERAL URBAN POLICY IN MÉXICO CITY\u27S CENTRO HISTÓRICO

This dissertation argues that urban neoliberal programs currently formulating in the Global South are unprecedented in historical México as well as in examined practices of gentrification and globalization. In this dissertation I specifically focus on the Programa de Rescate – an urban policy being amassed in México City’s Centro Histórico as a nexus of processes of gentrification, neoliberalization, and globalization. This work re-theorizes how gentrification functions when it is implemented in the Global South – as the neoliberalization of space

Hierarchical strategies for efficient fault recovery on the reconfigurable PAnDA device

A novel hierarchical fault-tolerance methodology for reconfigurable devices is presented. A bespoke multi-reconfigurable FPGA architecture, the programmable analogue and digital array (PAnDA), is introduced allowing fine-grained reconfiguration beyond any other FPGA architecture currently in existence. Fault blind circuit repair strategies, which require no specific information of the nature or location of faults, are developed, exploiting architectural features of PAnDA. Two fault recovery techniques, stochastic and deterministic strategies, are proposed and results of each, as well as a comparison of the two, are presented. Both approaches are based on creating algorithms performing fine-grained hierarchical partial reconfiguration on faulty circuits in order to repair them. While the stochastic approach provides insights into feasibility of the method, the deterministic approach aims to generate optimal repair strategies for generic faults induced into a specific circuit. It is shown that both techniques successfully repair the benchmark circuits used after random faults are induced in random circuit locations, and the deterministic strategies are shown to operate efficiently and effectively after optimisation for a specific use case. The methods are shown to be generally applicable to any circuit on PAnDA, and to be straightforwardly customisable for any FPGA fabric providing some regularity and symmetry in its structure

Managerial Power and Rent Extraction in the Design of Executive Compensation

This paper develops an account of the role and significance of managerial power and rent extraction in executive compensation. Under the optimal contracting approach to executive compensation, which has dominated academic re-search on the subject, pay arrangements are set by a board of directors that aims to maximize shareholder value. In contrast, the managerial power approach suggests that boards do not operate at arm's length in devising executive compensation arrangements; rather, executives have power to influence their own pay, and they use that power to extract rents. Furthermore, the desire to camouflage rent extraction might lead to the use of inefficient pay arrangements that provide suboptimal incentives and thereby hurt shareholder value. The authors show that the processes that produce compensation arrangements, and the various market forces and constraints that act on these processes, leave managers with considerable power to shape their own pay arrangements. Examining the large body of empirical work on executive compensation, the authors show that managerial power and the desire to camouflage rents can explain significant features of the executive compensation landscape, including ones that have long been viewed as puzzling or problematic from the optimal contracting perspective. The authors conclude that the role managerial power plays in the design of executive compensation is significant and should be taken into account in any examination of executive pay arrangements or of corporate governance generally.