697 research outputs found
Being at the edge of Place
This paper by Professor Edward Casey, Stony Brook University, is based on a lecture he gave at the University of Southern Denmark on September 9, 2010. As such it works as a draft of Professor Casey’s current research and is not a complete and finished research article
Gravitational Microlensing Event Statistics for the Zwicky Transient Facility
Microlensing surveys have discovered thousands of events with almost all
events discovered within the Galactic bulge or toward the Magellanic clouds.
The Zwicky Transient Facility (ZTF), while not designed to be a microlensing
campaign, is an optical time-domain survey that observes the entire northern
sky every few nights including the Galactic plane. ZTF observes
stars in g-band and r-band and can significantly contribute to the observed
microlensing population. We predict that ZTF will observe 1100
microlensing events in three years of observing within degrees
latitude of the Galactic plane, with 500 events in the outer Galaxy
(). This yield increases to 1400 (800) events
by combining every three ZTF exposures, 1800 (900) events if ZTF
observes for a total of five years, and 2400 (1300) events for a
five year survey with post-processing image stacking. Using the microlensing
modeling software PopSyCLE, we compare the microlensing populations in the
Galactic bulge and the outer Galaxy. We also present an analysis of the
microlensing event ZTF18abhxjmj to demonstrate how to leverage these population
statistics in event modeling. ZTF will constrain Galactic structure, stellar
populations, and primordial black holes through photometric microlensing.Comment: 19 pages, 13 figures, 5 tables, accepted to ApJ (6/4/2020),
microlensing simulation catalogs available at
https://portal.nersc.gov/project/uLens/Galactic_Microlensing_Distribution
Recent Radiation Test Results for Power MOSFETs
Single-event effect (SEE) and total ionizing dose (TID) test results are presented for various hardened and commercial power metal-oxide-semiconductor field effect transistors (MOSFETs), including vertical planar, trench, superjunction, and lateral process designs
A novel application of satellite radar data: measuring carbon sequestration and detecting degradation in a community forestry project in Mozambique
Background: It is essential that systems for measuring changes in carbon stocks for Reducing Emissions from Deforestation and Forest Degradation (REDD) projects are accurate, reliable and low cost. Widely used systems involving classifying optical satell
Recent Radiation Test Results for Trench Power MOSFETs
Single-event effect (SEE) radiation test results are presented for various trench-gate power MOSFETs. The heavy-ion response of the first (and only) radiation-hardened trench-gate power MOSFET is evaluated: the manufacturer SEE response curve is verified and importantly, no localized dosing effects are measured, distinguishing it from other, non-hardened trench-gate power MOSFETs. Evaluations are made of n-type commercial and both n- and p-type automotive grade trench-gate device using ions comparable to of those on the low linear energy transfer (LET) side of the iron knee of the galactic cosmic ray spectrum, to explore suitability of these parts for missions with higher risk tolerance and shorter duration, such as CubeSats. Part-to-part variability of SEE threshold suggests testing with larger sample sizes and applying more aggressive derating to avoid on-orbit failures. The n-type devices yielded expected localized dosing effects including when irradiated in an unbiased (0-V) configuration, adding to the challenge of inserting these parts into space flight missions
What do experienced water managers think of water resources of our nation and its management infrastructure?
This article represents the second report by an ASCE Task Committee Infrastructure Impacts of Landscape-driven Weather Change under the ASCE Watershed Management Technical Committee and the ASCE Hydroclimate Technical Committee. Herein, the \u27infrastructure impacts are referred to as infrastructure-sensitive changes in weather and climate patterns (extremes and non-extremes) that are modulated, among other factors, by changes in landscape, land use and land cover change. In this first report, the article argued for explicitly considering the well-established feedbacks triggered by infrastructure systems to the land-atmosphere system via landscape change. In this report by the ASCE Task Committee (TC), we present the results of this ASCE TC\u27s survey of a cross section of experienced water managers using a set of carefully crafted questions. These questions covered water resources management, infrastructure resiliency and recommendations for inclusion in education and curriculum. We describe here the specifics of the survey and the results obtained in the form of statistical averages on the \u27perception\u27 of these managers. Finally, we discuss what these \u27perception\u27 averages may indicate to the ASCE TC and community as a whole for stewardship of the civil engineering profession. The survey and the responses gathered are not exhaustive nor do they represent the ASCE-endorsed viewpoint. However, the survey provides a critical first step to developing the framework of a research and education plan for ASCE. Given the Water Resources Reform and Development Act passed in 2014, we must now take into account the perceived concerns of the water management community. © 2015 Hossain et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The Size Evolution of High Redshift Galaxies
Hubble Space Telescope images of high-redshift galaxies selected via color
and photometric redshifts are used to examine the size and axial-ratio
distribution of galaxies as a function of redshift at lookback times t > 8 Gyr.
These parameters are measured at rest-frame UV wavelengths (1200-2000
Angstroms) on images with a rest-frame resolution of less than 0.8 kpc. Galaxy
radii are found to scale with redshift approximately as the inverse of the
Hubble parameter H(z). This is in accord with the theoretical expectation that
the typical sizes of the luminous parts of galaxies should track the expected
evolution in the virial radius of dark-matter halos. The mean ratio of
semi-major to semi-minor axis for a bright well-resolved sample of galaxies at
z ~ 4 is b/a = 0.65, suggesting that these Lyman break galaxies are not drawn
from a spheroidal population. However the median concentration index of this
sample is C = 3.5, which is closer to the typical concentration indices, C ~ 4,
of nearby elliptical galaxies than to the values, C<2 for local disk galaxies
of type Sb and later.Comment: 5 pages, including 3 figures; uses emulateapj style; accepted by ApJL
for publication in a special issue of early GOODS result
Lymphocytic Choriomeningitis in Michigan
We summarize the first reported case of acquired lymphocytic choriomeningitis virus (LCMV) infection in Michigan to be investigated by public health authorities and provide evidence of the focal nature of LCMV infection in domestic rodents. Results of serologic and virologic testing in rodents contrasted, and negative serologic test results should be confirmed by tissue testing
Sex Differences in Response to Smoking Cessation Resources Offered in the Emergency Department (ED)
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