1,252 research outputs found
Iterative adaption of the bidimensional wall of the French T2 wind tunnel around a C5 axisymmetrical model: Infinite variation of the Mach number at zero incidence and a test at increased incidence
The top and bottom two-dimensional walls of the T2 wind tunnel are adapted through an iterative process. The adaptation calculation takes into account the flow three-dimensionally. This method makes it possible to start with any shape of walls. The tests were performed with a C5 axisymmetric model at ambient temperature. Comparisons are made with the results of a true three-dimensional adaptation
Resolving Star Formation on Sub-Kiloparsec Scales in the High-Redshift Galaxy SDP.11 Using Gravitational Lensing
We investigate the properties of the interstellar medium, star formation, and
the current-day stellar population in the strongly-lensed star-forming galaxy
H-ATLAS J091043.1-000321 (SDP.11), at z = 1.7830, using new Herschel and ALMA
observations of far-infrared fine-structure lines of carbon, oxygen and
nitrogen. We report detections of the [O III] 52 um, [N III] 57 um, and [O I]
63 um lines from Herschel/PACS, and present high-resolution imaging of the [C
II] 158 um line, and underlying continuum, using ALMA. We resolve the [C II]
line emission into two spatially-offset Einstein rings, tracing the red- and
blue-velocity components of the line, in the ALMA/Band-9 observations at 0.2"
resolution. The values seen in the [C II]/FIR ratio map, as low as ~ 0.02% at
the peak of the dust continuum, are similar to those of local ULIRGs,
suggesting an intense starburst in this source. This is consistent with the
high intrinsic FIR luminosity (~ 3 x 10^12 Lo), ~ 16 Myr gas depletion
timescale, and < 8 Myr timescale since the last starburst episode, estimated
from the hardness of the UV radiation field. By applying gravitational lensing
models to the visibilities in the uv-plane, we find that the lensing
magnification factor varies by a factor of two across SDP.11, affecting the
observed line profiles. After correcting for the effects of differential
lensing, a symmetric line profile is recovered, suggesting that the starburst
present here may not be the result of a major merger, as is the case for local
ULIRGs, but instead could be powered by star-formation activity spread across a
3-5 kpc rotating disk.Comment: 17 pages, 8 figures, 3 tables, accepted for publication in the
Astrophysical Journa
Hand-in-hand in the golden years: Cognitive interdependence, partner involvement in retirement planning, and the transition into retirement
This research examined the influence of cognitive interdependence—a mental state reflecting a collective representation of the self-in-relationship—on the anticipation for and experiences with the transition into retirement. Among soon-to-be retirees (Study 1), greater cognitive interdependence was associated with seeing partners as more instrumental to one’s goals both pre- and post-retirement, anticipating greater goal alignment post-retirement, and having directly involved partners in retirement planning to a greater extent than those relatively lower in cognitive interdependence. Among recent retirees (Study 2), retrospective cognitive interdependence was associated with post-retirement goal alignment and goal instrumentality, and the extent to which they believed they had directly involved their partners in retirement planning. However, it was post-retirement goal alignment that was associated with greater ease of retirement and subjective well-being. Finally, soon-to-be retirees relatively high in cognitive interdependence responded to concerns about their retirement (i.e., goal discordance and high retirement ambivalence) by wanting to involve their partners in their retirement plans to a greater extent (Study 3). These studies highlight the importance of romantic partners across the lifespan, and how partners might influence retirement planning, the transition to retirement, and well-being among recent retirees
Morphometric analysis of the submarine arc volcano Monowai (Tofua – Kermadec Arc) to decipher tectono-magmatic interactions
Morphometric analysis of multibeam bathymetry and backscatter data is applied to Monowai, a submarine volcano of the active Tofua–Kermadec Arc to map and document the structure and evolution of the volcanic centre. Low rates of erosion and sedimentation, and pervasive tectonic and magmatic processes, allow quantification through detailed structural analysis and measurement of deformation. The Slope, Aspect, Curvature, Rugosity, and Hydrology (flow) tools of ArcGIS provide a robust structural interpretation and the development of a model of Monowai evolution.A nested caldera structure with a volume of ~ 31 km3 and a stratovolcano of ~ 18 km3 dominate the magmatic constructs. The outer caldera is elongate along 125°, and the inner caldera along 135°. Numerous parasitic cones and fissure ridges are also observed, oriented at 039° and 041°, respectively. Northeast trending faults (with a regional average strike of 031°) are widespread within this part of the backarc, forming a nascent rift graben to the west of the Monowai caldera complex. The distribution of throw varies spatially, reaching a maximum total along-rift of 320 m and across rift of 120 m, with greater throw values measured in the west.Elongation directions of the two nested calderas are near-perpendicular to the trends of faults and fissure ridges. The inner caldera is more orthogonal to the magmatic constructs (fissure ridges and aligned vent cones) and the outer caldera is approximately orthogonal to the regional fault fabric, suggesting a strong interaction between magmatic and tectonic processes, and the directions of the horizontal principal stress. We present a detailed morphometric analysis of these relationships and the data are used to interpret the spatial and temporal evolution of the tectono-magmatic system at Monowai, and classify the type of rifting as transtensional. Similar analysis is possible elsewhere in the Kermadec backarc and within other regions of submarine volcanism
Compilation and validation of SAR and optical data products for a complete and global map of inland/ocean water tailored to the climate modeling community
Accurate maps of surface water extent are of paramount importance for water management, satellite data processing and climate modeling. Several maps of water bodies based on remote sensing data have been released during the last decade. Nonetheless, none has a truly (90°N/90°S) global coverage while being thoroughly validated. This paper describes a global, spatially-complete (void-free) and accurate mask of inland/ocean water for the 2000–2012 period, built in the framework of the European Space Agency (ESA) Climate Change Initiative (CCI). This map results from the synergistic combination of multiple individual SAR and optical water body and auxiliary datasets. A key aspect of this work is the original and rigorous stratified random sampling designed for the quality assessment of binary classifications where one class is marginally distributed. Input and consolidated products were assessed qualitatively and quantitatively against a reference validation database of 2110 samples spread throughout the globe. Using all samples, overall accuracy was always very high among all products, between 98% and 100%. The CCI global map of open water bodies provided the best water class representation (F-score of 89%) compared to its constitutive inputs. When focusing on the challenging areas for water bodies’ mapping, such as shorelines, lakes and river banks, all products yielded substantially lower accuracy figures with overall accuracies ranging between 74% and 89%. The inland water area of the CCI global map of open water bodies was estimated to be 3.17 million km2 ± 0.24 million km2. The dataset is freely available through the ESA CCI Land Cover viewer
Radial Growth of Qilian Juniper on the Northeast Tibetan Plateau and Potential Climate Associations
There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110–2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes
Who will I be when I retire? The role of organizational commitment, group memberships and retirement transition framing on older worker’s anticipated identity change in retirement
Retirement is an eagerly awaited life transition for many older workers, but some may anticipate their exit from the workforce will result in loss of meaningful work-based activities and social interactions. For older workers more committed to their organization, retirement might represent a threat to maintaining a consistent, positive identity. Across three pre-registered studies of US adults aged 49 to 75, we investigated the relationship between organizational commitment and anticipated identity changes in retirement. Studies 1 and 2 (N = 1059) found that older workers largely anticipated positive changes to their identity in retirement. In Study 2, we divided older workers into two conditions and used a framing manipulation to present retirement as either a ‘role exit’ or a ‘role entry’. In the ‘role exit’ condition, older workers less committed to their organization anticipated more positive changes when they held more group memberships compared to those with fewer group memberships. Those in the ‘role entry’ condition anticipated significantly more positive changes to their identity in retirement than those in the ‘role exit’ condition, but did not anticipate more positive changes based on organizational commitment or group memberships. More group memberships, but not lower organizational commitment, was associated with more positive anticipation of identity changes in retirement. Study 3 (N = 215) surveyed older adults after they had retired, finding that identity changes experienced post-retirement were less positive than those anticipated by older workers. We discuss the theoretical and applied implications of these findings for older workers’ retirement decisions and wellbeing
A Cabled Acoustic Telemetry System for Detecting and Tracking Juvenile Salmon: Part 2. Three-Dimensional Tracking and Passage Outcomes
In Part 1 of this paper, we presented the engineering design and instrumentation of the Juvenile Salmon Acoustic Telemetry System (JSATS) cabled system, a nonproprietary sensing technology developed by the U.S. Army Corps of Engineers, Portland District (Oregon, USA) to meet the needs for monitoring the survival of juvenile salmonids through the hydroelectric facilities within the Federal Columbia River Power System. Here in Part 2, we describe how the JSATS cabled system was employed as a reference sensor network for detecting and tracking juvenile salmon. Time-of-arrival data for valid detections on four hydrophones were used to solve for the three-dimensional (3D) position of fish surgically implanted with JSATS acoustic transmitters. Validation tests demonstrated high accuracy of 3D tracking up to 100 m upstream from the John Day Dam spillway. The along-dam component, used for assigning the route of fish passage, had the highest accuracy; the median errors ranged from 0.02 to 0.22 m, and root mean square errors ranged from 0.07 to 0.56 m at distances up to 100 m. For the 2008 case study at John Day Dam, the range for 3D tracking was more than 100 m upstream of the dam face where hydrophones were deployed, and detection and tracking probabilities of fish tagged with JSATS acoustic transmitters were higher than 98%. JSATS cabled systems have been successfully deployed on several major dams to acquire information for salmon protection and for development of more “fish-friendly” hydroelectric facilities
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