1,568 research outputs found
Observing Gravitational Waves with a Single Detector
A major challenge of any search for gravitational waves is to distinguish
true astrophysical signals from those of terrestrial origin. Gravitational-wave
experiments therefore make use of multiple detectors, considering only those
signals which appear in coincidence in two or more instruments. It is unclear,
however, how to interpret loud gravitational-wave candidates observed when only
one detector is operational. In this paper, we demonstrate that the observed
rate of binary black hole mergers can be leveraged in order to make confident
detections of gravitational-wave signals with one detector alone. We quantify
detection confidences in terms of the probability that a signal
candidate is of astrophysical origin. We find that, at current levels of
instrumental sensitivity, loud signal candidates observed with a single
Advanced LIGO detector can be assigned . In the future,
Advanced LIGO may be able to observe single-detector events with confidences
exceeding .Comment: 8 pages, 4 figures; published in CQG; minor updates to match
published versio
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The Book of Mormon Topic Structure, Keyness Distinctions, and Collocates of Deity: Implications for Mental Health Professionals
Understanding the spiritual worldview of clients is a core element of multicultural competency for mental health professionals. One spiritual and religious population is members of The Church of Jesus Christ of Latter-day Saints and related Latter-day Saint populations. The Book of Mormon is an important sacred text of this population. A corpus linguistic examination of the Book of Mormon provides mental health professionals with an understanding of the worldview of Latter-day Saint community members, and this understanding can inform competent counseling practices. This dissertation project has two studies. The first examined the spiritually informed worldview of members of The Church of Jesus Christ of Latter-day Saints through exploration of the topical structure of the Book of Mormon sacred text. This study utilized latent Dirichlet allocation (LDA) to identify the latent topical structure of the Book of Mormon. Thirty topics were identified. Levels of topics among books, the title page, and witness statements are given. Implications of results, limitations, and suggestions for further study are discussed. The top latent topic was the establishment and collapse of the Church of Christ. The second study examined the worldview of members of The Church of Jesus Christ of Latter-day Saints through keyness and collocation analysis of the Book of Mormon as a sacred text. Keywords of the Book of Mormon were identified by using the Hebrew Bible and New Testament as reference corpuses, and the Book of Mormon was used as a reference corpus to identify biblical keywords as well. Collocates of deity within the Book of Mormon were identified and examined. Limitations and implications for research and practice are discussed. When comparing the Book of Mormon to the New Testament, the two words with the strongest keyness were “pass” and “land” and when comparing the Book of Mormon to the Hebrew Bible the two words with the strongest keyness were “yea” and “Lamanites”. Both studies expand multicultural awareness in line with CACREP Standard 2.F.2.g (CACREP, 2016). The first study examined the topic structure of the Book of Mormon and the levels of topics among the books, title page, and witness statements. The second study examined the Book of Mormon as a whole, compared to the Hebrew Bible and New Testament and in relation to deity. Both assist in accomplishing this multicultural standard. These studies support a cultural understanding of members of the Latter-day Saint community for mental health professionals and other providers
Hamster and Murine Models of Severe Destructive Lyme Arthritis
Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology
Ceramic Substrates for High-temperature Electronic Integration
One of the most attractive ways to increase power handling capacity in power modules is to increase the operating temperature using wide-band-gap semiconductors. Ceramics are ideal candidates for use as substrates in high-power high-temperature electronic devices. The present article aims to determine the most suitable ceramic material for this application
Optimal Packings of Superballs
Dense hard-particle packings are intimately related to the structure of
low-temperature phases of matter and are useful models of heterogeneous
materials and granular media. Most studies of the densest packings in three
dimensions have considered spherical shapes, and it is only more recently that
nonspherical shapes (e.g., ellipsoids) have been investigated. Superballs
(whose shapes are defined by |x1|^2p + |x2|^2p + |x3|^2p <= 1) provide a
versatile family of convex particles (p >= 0.5) with both cubic- and
octahedral-like shapes as well as concave particles (0 < p < 0.5) with
octahedral-like shapes. In this paper, we provide analytical constructions for
the densest known superball packings for all convex and concave cases. The
candidate maximally dense packings are certain families of Bravais lattice
packings. The maximal packing density as a function of p is nonanalytic at the
sphere-point (p = 1) and increases dramatically as p moves away from unity. The
packing characteristics determined by the broken rotational symmetry of
superballs are similar to but richer than their two-dimensional "superdisk"
counterparts, and are distinctly different from that of ellipsoid packings. Our
candidate optimal superball packings provide a starting point to quantify the
equilibrium phase behavior of superball systems, which should deepen our
understanding of the statistical thermodynamics of nonspherical-particle
systems.Comment: 28 pages, 16 figure
Effect of additive concentration during copper deposition using EnFACE electrolyte
Copper deposition from solutions using high concentration of acid, metal ions and polyethylene glycol (PEG), and bis-(3-sulphopropyl) disulphide (SPS) and chloride ions (Cl-) is well known. A recent maskless micropatterning technology, which has the potential to replace the traditional photolithographic process, called EnFACE, proposed using an acid-free, low metal ion solution which is in direct contrast to those used in standard plating technology. In this work copper has been deposited using both standard electroplating solutions and those used in the EnFACE process. In the standard electrolyte 0.63 M CuSO4 and 2.04 M H2SO4 has been used, along with Gleam additives supplied by Dow Chemicals. For the Enface electrolyte, copper deposition has been carried out without any acid, and with different concentrations of additives between 17%-200% of those recommended by suppliers. 25 μm of metal has been plated on stainless steel coupons as suggested by ASTM, peeled off and subjected to ductility and resistance measurements. Scanning electron microscopy and electron back scatter diffraction have been carried out to determine the deposit morphology. It was found that copper deposits obtained from acid-free solutions containing low concentration of metal ion and additives produced copper deposits with properties which are comparable to those obtained from standard electrolytes. The optimum additive concentration for the EnFACE electrolyte was 50% of the supplier recommended value
No peaks without valleys: The stable mass transfer channel for gravitational-wave sources in light of the neutron star-black hole mass gap
Gravitational-wave (GW) detections are starting to reveal features in the
mass distribution of double compact objects. The lower end of the black hole
(BH) mass distribution is especially interesting as few formation channels
contribute here and because it is more robust against variations in the cosmic
star formation than the high mass end. In this work we explore the stable mass
transfer channel for the formation of GW sources with a focus on the low-mass
end of the mass distribution. We conduct an extensive exploration of the
uncertain physical processes that impact this channel. We note that, for
fiducial assumptions, this channel reproduces the peak at in the GW-observed binary BH mass distribution remarkably
well, and predicts a cutoff mass that coincides with the upper edge of the
purported neutron star BH mass gap. The peak and cutoff mass are a consequence
of unique properties of this channel, namely (1) the requirement of stability
during the mass transfer phases, and (2) the complex way in which the final
compact object masses scale with the initial mass. We provide an analytical
expression for the cutoff in the primary component mass and show that this
adequately matches our numerical results. Our results imply that selection
effects resulting from the formation channel alone can provide an explanation
for the purported neutron star--BH mass gap in GW detections. This provides an
alternative to the commonly adopted view that the gap emerges during BH
formation.Comment: Accepted for publication in ApJ associated code is available at
https://github.com/LiekeVanSon/LowMBH_and_StableChanne
'Surely the most natural scenario in the world’: Representations of ‘Family’ in BBC Pre-school Television
Historically, the majority of work on British children’s television has adopted either an institutional or an audience focus, with the texts themselves often overlooked. This neglect has meant that questions of representation in British children’s television – including issues such as family, gender, class or ethnicity - have been infrequently analysed in the UK context. In this article, we adopt a primarily qualitative methodology and analyse the various textual manifestations of ‘family’, group, or community as represented in a selected number of BBC pre-school programmes. In doing so, we question the (limited amount of) international work that has examined representations of the family in children’s television, and argue that nuclear family structures do not predominate in this sphere
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