559 research outputs found
The Structure and Functions of the Federal Reserve System of the United States Today
An overview of the history of the Federal Reserve system from its creation in 1913 to the late 1930s, and a description of its structure as of the late 1930s.https://digitalcommons.wofford.edu/collegebooks/1010/thumbnail.jp
Bennachie and me : a site-specific, promenade, interactive community drama project, devised and performed in the North-East of Scotland
This work was supported by the AHRC (grants AH/P009654 and AH/K007750/1) and Heritage Lottery Fund (grant SH-16-04399, awarded to the Bailies of Bennachie).Peer reviewe
A Functional Analysis of Non-Presidential Primary Debates
Despite the fact that political debates are increasingly common at all levels of government, relatively little work investigates the content of non-presidential debates (and work on primary debates is even less common). This study breaks new ground by analyzing four non-presidential primary debates. Two Democratic gubernatorial debates, one Republican U.S. Senate debate, and one Republican U.S. House debate were content analyzed using the framework of the functional theory of political campaign discourse. Overall, these debates were mainly positive, with 71% acclaims, 22% attacks, and 7% defenses. The Democratic (and gubernatorial) debates had more attacks and defenses and fewer defenses than the Republican (congressional) debates. Overall, these campaign messages focused more on policy (60%) than character (40%). The Democratic (gubernatorial) debates emphasized policy even more (65% to 55%), and character less (35% to 45%), than the Republican (congressional) debates
Mapping the surface composition of Europa with SUDA
To assess the potential habitability of Jupiter's moon Europa, it is important to understand its chemical composition (Hand et al., 2007). Young terrain features on Europa's surface likely consist of material up-welled from the liquid water source below (Wilson et al., 1997; Pappalardo et al., 1998; McCord et al., 1999; Figueredo and Greeley, 2004; Mével and Mercier, 2007), encoding relevant compositional information. A major science objective of NASA's Europa Clipper mission is to characterize the composition of young terrain features using data acquired on close flybys. The Surface Dust Analyzer (SUDA) is an in situ instrument that collects and analyzes the composition of individual grains (Kempf et al., 2012), which are ejected from Europa's surface by a continuous bombardment of interplanetary impactors (Krüger et al., 1999, 2003; Goode et al., 2021). By applying a dynamical model of these particles, we compute the probability of SUDA's detections originating from a given feature along the flyby trajectory based on Monte Carlo (MC) simulations. The time-of-flight (TOF) mass spectra that characterize the chemical composition of individual grains, results in a time series of various compositional types along the flyby. We present here a method to analyze a time series of compositional spectra recorded by SUDA that provides a robust estimate for the abundance of compositional types on the surface, spatially resolved for features along the ground track of the flyby. By demonstrating the association of compositional detections with geological sites of origin, data collected by SUDA can be used to infer the compositional ground truth for terrain features on Europa
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Trajectory Measurements on the Colorado Dust Accelerator Using a Dual Dust Coordinate Sensor
The Dust Coordinate Sensor (DCS) is a dual detector instrument located on the beamline of the 3 MV hypervelocity dust accelerator at the University of Colorado Institute for Modeling Plasma, Atmospheres and Cosmic Dust (IMPACT). This instrument non-destructively measures the three-dimensional trajectories of charged, hypervelocity (3-8 km/s), micron-sized dust particles in flight by utilizing the image charge induced on grids of wire electrodes. Where previous peak detection was typically limited to dust particles carrying charges >∼ 100 fC, new signal processing techniques developed for DCS allow for effective trajectory measurements on particles carrying charges as small as 6 fC. The new signal processing also reduces false signal detections by > 90%. The position measurements are matched by timestamp to the charge and velocity for each launched dust particle. Verification of the system was performed with independent impact location measurements on a target placed in the beamline. These measurements agree to within 1 mm^2 of the predicted locations using DCS trajectories. This study demonstrates the capability of the instrument including new processing methods. Precise trajectory measurement along the beamline enables new options for instrument calibration, scientific experiments, and improvement of the accelerator performance
Newspaper Coverage of the 2008 General Election Presidential Campaigns
News coverage of political campaigns is very important to the political campaign process. Some voters pay little attention to debates or other sources of information about the candidates and their policies. The news is one important source of this information. Newspapers can also supplement and reinforce the information possessed by voters who do attend to campaign messages. This study content analyzed news coverage of the 2008 general election presidential campaign (New York Times, Washington Post, USA Today). Horse race coverage was most common topic (45%), followed by themes about character (32%), and policy (23%). The tone of newspaper coverage was more positive (51%) than negative (39%; 9% of themes reported the candidates‘ defenses)
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Annihilators of Irreducible Representations of the Lie Superalgebra of Contact Vector Fields on the Superline
The superline has one even and one odd coordinate. We consider the Lie superalgebra of contact vector fields on the superline. Its tensor density modules are a one-parameter family of deformations of the natural action on the ring of polynomials on the superline. They are parameterized by a complex number, and they are irreducible when this parameter is not zero. In this dissertation, we describe the annihilating ideals of these representations in the universal enveloping algebra of this Lie superalgebra by providing their generators. We also describe the intersection of all such ideals: the annihilator of the direct sum of the tensor density modules. The annihilating ideal of an irreducible non-zero left module is called a primitive ideal, and the space of all such ideals in the universal enveloping algebra is its primitive spectrum. The primitive spectrum is endowed with the Jacobson topology, which induces a topology on the annihilators of the tensor density modules. We conclude our discussion with a description of the annihilators as a topological space
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Investigating Europa's Surface Composition with the Surface Dust Analyzer
In the search for life beyond Earth, Jupiter's moon Europa is one of the most compelling places in the solar system to explore. Following the strategy of examining extended regions of liquid water, it is essential to investigate the composition of Europa's vast subsurface ocean in detail. NASA's Europa Clipper mission will provide such an opportunity with its suite of nine instruments, including the Surface Dust Analyzer (SUDA).
SUDA is the state-of-the-art dust impact mass spectrometer with the capability to analyze the composition of individual dust and ice grains from Europa's surface. This is possible due to the presence of impact-generated ejecta clouds surrounding airless bodies in the solar system. Samples collected from Europa's ejecta cloud by SUDA on multiple close flybys over the moon will reveal the chemical nature of various geological features that hold information regarding the history and processes of material exchange between the ocean and surface. In this thesis, I develop models that analyze series of detections that SUDA will acquire during the Clipper mission to characterize compositional abundances for geological features and regions on Europa's surface.
The models I developed have been implemented in the mission design for Europa Clipper, which will be the first time a dust analyzer will be used to map the composition of a moon's surface. Instruments like SUDA have the advantage of detailed in situ chemical analysis with the added benefit of mapping detections to the surface, making them "hybrid remote sensing" instruments. This work shifts the paradigm for how such instruments can be used to explore bodies in the solar system on future missions.</p
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