1,432 research outputs found
Acoustic vibration test detects intermittent electrical discontinuities
Nondestructive test method detects faulty electrical connections in inaccessible or hidden portions of electronic harness assemblies and connectors. Method employs readily available commercial equipment
How long is a hillslope?
Hillslope length is a fundamental attribute of landscapes, intrinsically linked to drainage density, landslide hazard, biogeochemical cycling and hillslope sediment transport. Existing methods to estimate catchment average hillslope lengths include inversion of drainage density or identification of a break in slopeāarea scaling, where the hillslope domain transitions into the fluvial domain. Here we implement a technique which models flow from point sources on hilltops across pixels in a digital elevation model (DEM), based on flow directions calculated using pixel aspect, until reaching the channel network, defined using recently developed channel extraction algorithms. Through comparisons between these measurement techniques, we show that estimating hillslope length from plots of topographic slope versus drainage area, or by inverting measures of drainage density, systematically underestimates hillslope length. In addition, hillslope lengths estimated by slopeāarea scaling breaks show large variations between catchments of similar morphology and area. We then use hillslope lengthārelief structure of landscapes to explore nature of sediment flux operating on a landscape. Distinct topographic forms are predicted for end-member sediment flux laws which constrain sediment transport on hillslopes as being linearly or nonlinearly dependent on hillslope gradient. Because our method extracts hillslope profiles originating from every ridgetop pixel in a DEM, we show that the resulting population of hillslope lengthārelief measurements can be used to differentiate between linear and nonlinear sediment transport laws in soil mantled landscapes. We find that across a broad range of sites across the continental United States, topography is consistent with a sediment flux law in which transport is nonlinearly proportional to topographic gradient
The Mechanisms of Moral Disengagement in George W. Bushās āWar on Terrorismā Rhetoric.
Despite considerable literature on the Bush administrationās war on terrorism rhetoric, little attention has been paid to its discourse of moral disengagement, leaving an important and still relevant gap that this paper aims to address. Rather than approaching this gap in terms of an archival historical analysis that is disconnected from the present, it proposes an exploratory revisit of the rhetoric that the benefits of hindsight might enrich and, we argue, aid in understanding connections to the current post-invasion turmoil and the gradual ISIS takeover. Having subjected nineteen presidential speeches to qualitative content analysis, we identified a number of moral disengagement mechanisms: moral justification, advantageous comparisons, and attribution of blame, dehumanisation of the enemy, the use of sanitizing language, diffusion of responsibility and minimization of harm. We also identified novel themes relating to American excellence/patriotism, religious ideals and fear- arousing appeals, offering original contributions to the existing literature and advancing our understanding of dynamic, real-world, and highest stakes moral disengagement whose parallels can be identified in todayās political discourses. The detailed analysis unveils the apparent paradox of propagating moral disengagement through a thread of arguments that interweave diversity with uniformity, complexity with simplicity, in effect alerting the reader to the processes of moral desensitisation that the past, current and future āwarmongeringā political discourses may often rely upon
The minimum energy expenditure shortest path method
This article discusses the addition of an energy parameter to the shortest path execution process; namely, the energy expenditure by a character during execution of the path. Given a simple environment in which a character has the ability to perform actions related to locomotion, such as walking and stair stepping, current techniques execute the shortest path based on the length of the extracted root trajectory. However, actual humans acting in constrained environments do not plan only according to shortest path criterion, they conceptually measure the path that minimizes the amount of energy expenditure. On this basis, it seems that virtual characters should also execute their paths according to the minimization of actual energy expenditure as well. In this article, a simple method that uses a formula for computing vanadium dioxide () levels, which is a proxy for the energy expenditure by humans during various activities, is presented. The presented solution could be beneficial in any situation requiring a sophisticated perspective of the path-execution process. Moreover, it can be implemented in almost every path-planning method that has the ability to measure stepping actions or other actions of a virtual character
Between a rock and a hard place of geopolitically sensitive threats ā critical incidents and decision inertia
While the SAFE-T model of decision making emphasizes naturalistic decision making, its potential for cross-comparative analysis of incidents with global implications remains underutilized, which the current paper aims to address. To this end, it draws upon open-source reports from unclassified American, British and Russian intelligence reports to explore the management of three types of 10 high-profile geopolitically sensitive threats from across the globe (verifying potential terrorist identity, hostage rescue and national/international security). Defining features of such incidents include decision makersā ability to prospectively model competing scenarios in which they must select between options and where every outcome looks aversive and high risk (ādamned if you do or damned if you donāt decisionsā). A frequent consequence of such calculations is ādecision inertiaā (a failure to execute an important, irrevocable decision resulting in non-optimal consequences), or āimplementation failureā (a failure to make a choice). Combining the benefit of the theoretical framework and hindsight knowledge of the analyzed incidents, the paper facilitates theoretical understanding of decision inertia and failures to act. Encouraging the consideration of multiple scenario endings contingent on a wide spectrum of factors and unique cultural-historical context, it also helps identify past decision errors in order to inform assessment and management of similar geopolitical threats in the future
Sub-kiloparsec Imaging of Cool Molecular Gas in Two Strongly Lensed Dusty, Star-Forming Galaxies
We present spatially-resolved imaging obtained with the Australia Telescope
Compact Array (ATCA) of three CO lines in two high-redshift gravitationally
lensed dusty star-forming galaxies, discovered by the South Pole Telescope.
Strong lensing allows us to probe the structure and dynamics of the molecular
gas in these two objects, at z=2.78 and z=5.66, with effective source-plane
resolution of less than 1kpc. We model the lensed emission from multiple CO
transitions and the dust continuum in a consistent manner, finding that the
cold molecular gas as traced by low-J CO always has a larger half-light radius
than the 870um dust continuum emission. This size difference leads to up to 50%
differences in the magnification factor for the cold gas compared to dust. In
the z=2.78 galaxy, these CO observations confirm that the background source is
undergoing a major merger, while the velocity field of the other source is more
complex. We use the ATCA CO observations and comparable resolution Atacama
Large Millimeter/submillimeter Array dust continuum imaging of the same objects
to constrain the CO-H_2 conversion factor with three different procedures,
finding good agreement between the methods and values consistent with those
found for rapidly star-forming systems. We discuss these galaxies in the
context of the star formation - gas mass surface density relation, noting that
the change in emitting area with observed CO transition must be accounted for
when comparing high-redshift galaxies to their lower redshift counterparts.Comment: 14 pages, 7 figures; accepted for publication in Ap
Non-spherical optically trapped probes: Design, control, and applications
In this proceedings paper we show describe how a microtool can be assembled, and tracked in three dimensions such that its full rotational and translational coordinates, q, are recovered. This allows tracking of the motion of any arbitrary point, d, on the microtool's surface. When the micro-tool is held using multiple optical traps the motion of such a point investigates the inside of an ellipsoidal volume - we term this a 'thermal ellipsoid. We demonstrate how the shape of this thermal ellipsoid may be controlled by varying the relative trapping power of the optical traps, and adjusting the angle at which the micro-tool is held relative to the focal plane. Our experimental results follow the trends derived by Simpson and Hanna
Recommended from our members
Hippocampal volume varies with educational attainment across the life-span
Socioeconomic disparitiesāand particularly differences in educational attainmentāare associated with remarkable differences in cognition and behavior across the life-span. Decreased educational attainment has been linked to increased exposure to life stressors, which in turn have been associated with structural differences in the hippocampus and the amygdala. However, the degree to which educational attainment is directly associated with anatomical differences in these structures remains unclear. Recent studies in children have found socioeconomic differences in regional brain volume in the hippocampus and amygdala across childhood and adolescence. Here we expand on this work, by investigating whether disparities in hippocampal and amygdala volume persist across the life-span. In a sample of 275 individuals from the BRAINnet Foundation database ranging in age from 17 to 87, we found that socioeconomic status (SES), as operationalized by years of educational attainment, moderates the effect of age on hippocampal volume. Specifically, hippocampal volume tended to markedly decrease with age among less educated individuals, whereas age-related reductions in hippocampal volume were less pronounced among more highly educated individuals. No such effects were found for amygdala volume. Possible mechanisms by which education may buffer age-related effects on hippocampal volume are discussed
Home blood pressure monitors owned by participants in a large decentralised clinical trial in hypertension:the Treatment In Morning versus Evening (TIME) study
Various home blood pressure monitors (HBPMs) are available to the public for purchase but only some are validated against standardised protocols. This study aimed to assess whether HBPMs owned by participants taking part in a clinical trial were validated models. The TIME study is a decentralised randomised trial investigating the effect of antihypertensive medication dosing time on cardiovascular outcomes in adults with hypertension. No HBPMs were provided to participants in this trial but patients were asked to report if they already owned one. We identified the model of HBPM reported by participants, then cross-referenced this against lists of validated HBPMs produced by dabl Educational Trust and the British and Irish Hypertension Society (BIHS). Of 21,104 participants, 10,464 (49.6%) reported their model of HBPM. 7464 (71.3%) of these participants owned a monitor that could be identified from the participantsā entry. Of these, 6066 (81.3%) participants owned a monitor listed as validated by either dabl (nā=ā5903) or BIHS (nā=ā5491). Some were listed as validated by both. 1398 (18.7%) participants owned an identifiable HBPM that lacked clear evidence of validation. 6963 (93.3%) participants owned an upper arm HBPM and 501 (6.7%) owned a wrist HBPM. Validated HBPMs had a higher median online retail price of Ā£45.00 compared to Ā£20.00 for HBPMs lacking clear evidence of validation. A significant number of participants own HBPMs lacking evidence of validation
- ā¦