750 research outputs found
Transient High Strain Rate During Localized Viscous Creep in the Dry Lower Continental Crust (Lofoten, Norway)
6 months embargo, already passed by the time of deposit
On Ultrasmall Silicate Grains in the Diffuse Interstellar Medium
The abundance of both amorphous and crystalline silicates in very small
grains is limited by the fact that the 10 micron silicate emission feature is
not detected in the diffuse ISM. On the basis of the observed IR emission
spectrum for the diffuse ISM, the observed ultraviolet extinction curve, and
the 10 micron silicate absorption profile, we obtain upper limits on the
abundances of ultrasmall (a < 15 Angstrom) amorphous and crystalline silicate
grains.
Contrary to previous work, as much as ~20% of interstellar Si could be in a <
15 Angstrom silicate grains without violating observational constraints. Not
more than ~5% of the Si can be in crystalline silicates (of any size).Comment: Submitted to ApJ Letters, 11 pages, 4 figures, Late
An International Perspective on Changes in Work Due to COVID-19
The very nature and format of work, along with its social and psychological dynamics, the labor market, and economic conditions within which it is embedded have undergone a large change in the months since COVID-19 was declared a global pandemic (Kniffin et al., 2020; Rudolph et al., 2021). No country has been spared the spread of disease and nowhere are workers free from the impact and aftermath of COVID-19. Industrial and organizational psychology (I-O) faculty and practitioners have been keenly observing, tracking, and studying the changing nature of work, but few have been doing so from a cross-cultural and international lens. Given the global nature of the pandemic, here we take a deliberate global, international perspective to understanding the disruption and opportunities for the world of work. An international perspective is imperative to developing a complete and holistic understanding of (a) work psychology in the face of pandemics, (b) the consequent challenges faced by workers and organizations, (c) the future of work post-COVID-19, and (d) how I-O can meaningfully contribute to ease work-oriented disruptions and better prepare for similar future challenges. We apply a cross-cultural and international lens to focus on four areas where scholarship and practice in I-O could help in matters related to employment and the workplace: (a) informal workers, workers in poverty, and precarious work around the world; (b) technology, human resources; (HR) practices, and the digital divide; (c) the intersection of culture, work, health, and well-being; and (d) learning from crises and crisis management during a global pandemic
RDF Querying
Reactive Web systems, Web services, and Web-based publish/
subscribe systems communicate events as XML messages, and in
many cases require composite event detection: it is not sufficient to react
to single event messages, but events have to be considered in relation to
other events that are received over time.
Emphasizing language design and formal semantics, we describe the
rule-based query language XChangeEQ for detecting composite events.
XChangeEQ is designed to completely cover and integrate the four complementary
querying dimensions: event data, event composition, temporal
relationships, and event accumulation. Semantics are provided as
model and fixpoint theories; while this is an established approach for rule
languages, it has not been applied for event queries before
Atmospheric Chemistry in Giant Planets, Brown Dwarfs, and Low-Mass Dwarf Stars II. Sulfur and Phosphorus
Thermochemical equilibrium and kinetic calculations are used to model sulfur
and phosphorus chemistry in giant planets, brown dwarfs, and extrasolar giant
planets (EGPs). The chemical behavior of individual S- and P-bearing gases and
condensates is determined as a function of pressure, temperature, and
metallicity. The results are independent of particular model atmospheres and,
in principle, the equilibrium composition along the pressure-temperature
profile of any object can be determined. Hydrogen sulfide (H2S) is the dominant
S-bearing gas throughout substellar atmospheres and approximately represents
the atmospheric sulfur inventory. Silicon sulfide (SiS) is a potential tracer
of weather in substellar atmospheres. Disequilibrium abundances of phosphine
(PH3) approximately representative of the total atmospheric phosphorus
inventory are expected to be mixed upward into the observable atmospheres of
giant planets and T dwarfs. In hotter objects, several P-bearing gases (e.g.,
P2, PH3, PH2, PH, HCP) become increasingly important at high temperatures.Comment: 38 pages, 8 figures, accepted for Astrophysical Journa
A Cryogenic Silicon Interferometer for Gravitational-wave Detection
The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of the existing LIGO observatory facilities, we have designed a new instrument that will have 5 times the range of Advanced LIGO, or greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby universe, as well as observing the universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGOâs first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
Extinction curves expected in young galaxies
We investigate the extinction curves of young galaxies in which dust is
supplied from Type II supernovae (SNe II) and/or pair instability supernovae
(PISNe). We adopt Nozawa et al. (2003) for compositions and size distribution
of grains formed in SNe II and PISNe. We find that the extinction curve is
quite sensitive to internal metal mixing in supernovae (SNe). The extinction
curves predicted from the mixed SNe are dominated by SiO2 and is characterised
by steep rise from infrared to ultraviolet (UV). The dust from unmixed SNe
shows shallower extinction curve, because of the contribution from large-sized
(~ 0.1 um) Si grains. However, the progenitor mass is important in unmixed SNe
II: If the progenitor mass is smaller than ~ 20 Msun, the extinction curve is
flat in UV; otherwise, the extinction curve rises toward the short wavelength.
The extinction curve observed in a high-redshift quasar (z=6.2) favours the
dust production by unmixed SNe II. We also provide some useful observational
quantities, so that our model might be compared with future high-z extinction
curves.Comment: 11 pages, 6 figures, Accepted for publication in MNRA
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