2,652 research outputs found
MS-077: Gladys Kennedy World War II Letters
This collection of correspondence contains letters from all fronts and from many of Gladysâ âsweethearts.â It appears that she shipped her address out in the parts she made at the Depot and would get responses from some of the soldiers and sailors. Some of the letters are from soldiers and sailors abroad from her hometown of York Springs, Pennsylvania. Collection includes paperwork from a raise received by Kennedy in 1944.https://cupola.gettysburg.edu/findingaidsall/1146/thumbnail.jp
Midcourse maneuver operations program
Midcourse Maneuver Operations Program /MMOP/ computes the required velocity change to correct a spacecraft trajectory. The program establishes the existence of maneuvers which satisfy spacecraft constraints, explores alternate trajectories in the event that some out-of-tolerance condition forces a change in plans, and codes the maneuvers into commands
Progress in the Verification and Validation Efforts for START: A Spent Fuel Routing Tool
The US Department of Energys Office of Nuclear Energy is planning for an
integrated waste management approach to transport, store, and eventually
dispose of spent nuclear fuel and other high-level radioactive waste as part of
the Integrated Waste Management program. In support of this effort, the
Stakeholder Tool for Assessing Radioactive Transportation is being developed
within the IWM program. This is a web-based decision support tool that can be
used to analyze geospatial data related to the transportation of SNF and HLW.Comment: Presented at the '2023 ANS Winter Conference and Expo
Seafloor seismicity, Antarctic ice-sounds, cetacean vocalizations and long-term ambient sound in the Indian Ocean basin
International audienceThis paper presents the results from the Deflo-hydroacoustic experiment in the Southern Indian Ocean using three autonomous underwater hydrophones, complemented by two permanent hydroacoustic stations. The array monitored for 14 months, from November 2006 to December 2007, a 3000 x 3000 km wide area, encompassing large segments of the three Indian spreading ridges that meet at the Indian Triple Junction. A catalogue of 11 105 acoustic events is derived from the recorded data, of which 55 per cent are located from three hydrophones, 38 per cent from 4, 6 per cent from five and less than 1 per cent by six hydrophones. From a comparison with land-based seismic catalogues, the smallest detected earthquakes are m(b) 2.6 in size, the range of recorded magnitudes is about twice that of land-based networks and the number of detected events is 5-16 times larger. Seismicity patterns vary between the three spreading ridges, with activity mainly focused on transform faults along the fast spreading Southeast Indian Ridge and more evenly distributed along spreading segments and transforms on the slow spreading Central and ultra-slow spreading Southwest Indian ridges; the Central Indian Ridge is the most active of the three with an average of 1.9 events/100 km/month. Along the Sunda Trench, acoustic events mostly radiate from the inner wall of the trench and show a 200-km-long seismic gap between 2 degrees S and the Equator. The array also detected more than 3600 cryogenic events, with different seasonal trends observed for events from the Antarctic margin, compared to those from drifting icebergs at lower (up to 50 degrees S) latitudes. Vocalizations of five species and subspecies of large baleen whales were also observed and exhibit clear seasonal variability. On the three autonomous hydrophones, whale vocalizations dominate sound levels in the 20-30 and 100 Hz frequency bands, whereas earthquakes and ice tremor are a dominant source of ambient sound at frequencies < 20 Hz
Alpha-decay lifetimes semiempirical relationship including shell effects
A new version of the semiempirical formula based on fission approach of alpha
decay is derived, by using the optimum values of the fitting parameters
determined for even-even nuclei, combined with hindrance factors for even-odd,
odd-even, and odd-odd nuclides. The deviations from experimental data for two
regions of nuclear chart (493 alpha emitters with Z=52-118 and 142 transuranium
nuclei including superheavies (Z=92-118), respectively) are compared with those
obtained by using the universal curve and the Viola-Seaborg semiempirical
relationship.Comment: 11 pages, 3 figures, revtex
Carinae's Dusty Homunculus Nebula from Near-Infrared to Submillimeter Wavelengths: Mass, Composition, and Evidence for Fading Opacity
Infrared observations of the dusty, massive Homunculus Nebula around the
luminous blue variable Carinae are crucial to characterize the mass-loss
history and help constrain the mechanisms leading to the Great Eruption. We
present the 2.4 - 670 m spectral energy distribution, constructed from
legacy ISO observations and new spectroscopy obtained with the {\em{Herschel
Space Observatory}}. Using radiative transfer modeling, we find that the two
best-fit dust models yield compositions which are consistent with CNO-processed
material, with iron, pyroxene and other metal-rich silicates, corundum, and
magnesium-iron sulfide in common. Spherical corundum grains are supported by
the good match to a narrow 20.2 m feature. Our preferred model contains
nitrides AlN and SiN in low abundances. Dust masses range from 0.25 to
0.44 but 45 in both cases due to an
expected high Fe gas-to-dust ratio. The bulk of dust is within a 5
7 central region. An additional compact feature is detected at 390 m.
We obtain = 2.96 10 , a 25\% decline from
an average of mid-IR photometric levels observed in 1971-1977. This indicates a
reduction in circumstellar extinction in conjunction with an increase in visual
brightness, allowing 25-40\% of optical and UV radiation to escape from the
central source. We also present an analysis of CO and CO through lines, showing that the abundances are consistent with
expectations for CNO-processed material. The [C~{\sc{ii}}] line is
detected in absorption, which we suspect originates in foreground material at
very low excitation temperatures.Comment: Accepted in Ap
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