6,712 research outputs found
Determining the grain geometry from ultrasonic measurements of large-grained temperate ice cores
Ice shelf collapse significantly contributes to the global rise of sea levels. This intricate process of fracturing, though not yet fully understood, is intertwined with the mechanical attributes of ice. Among the critical physical attributes related to its mechanical characteristics is the crystal orientation fabric (COF), which encapsulates the dimensions, orientations, and inclinations of the constituent crystal grains within the ice structure. The acquisition of such granular information necessitates the extraction of ice cores from the ice sheets or shelves, followed by their transportation to a controlled laboratory environment. After this, these cores are sectioned into submillimetre slices and examined using polarised light microscopy (PLM). However, this procedure destroys the ice core specimens and only permits the acquisition of two-dimensional images, imparting only a partial depiction of the three-dimensional COF.The principal objective of this work is to explore the possibility of involving ultrasound technology to discern the crystal grains' COF and their geometries. This novel approach does not harm the sample material during the examination
Millisecond accuracy video display using OpenGL under Linux
To measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Scaling Behavior Of Atomic Trajectories In Confined Fluids
We study the dependence of D, a quantity that has previously been associated with the fractal dimension of an atomic trajectory, on the scale on which it is measured. Single-particle and relative trajectories are generated by molecular-dynamics simulations of Lennard-Jones atoms permanently trapped in a spherical pore. Transient trapping is studied with a generalized Langevin model of dynamics. Confinement of trajectories allows D to exceed 2; in the case of permanent trapping, D diverges
Understanding Innovations in Journalistic Practice: A Field Experiment Examining Motivations for Fact-Checking
© 2016 International Communication Association. Why has fact-checking spread so quickly within U.S. political journalism? In the first field experiment conducted among reporters, we varied journalist exposure to messages that highlight either audience demand for fact-checking or the prestige it enjoys within the profession. Our results indicate that messages promoting the high status and journalistic values of fact-checking increased the prevalence of fact-checking coverage, while messages about audience demand were somewhat less successful. These findings suggest that political fact-checking is driven primarily by professional motives within journalism, a finding that helps us understand the process by which the practice spreads within the press as well as the factors that influence the behavior of journalists
Tarnished Plant Bugs in Cotton (Research Information Sheet #101)
This publication describes tarnished plant bugs and includes information on damage, biology, varietal susceptibility, monitoring, insecticide resistance and efficacy.https://digitalcommons.lsu.edu/agcenter_researchinfosheets/1010/thumbnail.jp
Measuring Ages and Elemental Abundances from Unresolved Stellar Populations: Fe, Mg, C, N, and Ca
We present a method for determining mean light-weighted ages and abundances
of Fe, Mg, C, N, and Ca, from medium resolution spectroscopy of unresolved
stellar populations. The method, pioneered by Schiavon (2007), is implemented
in a publicly available code called EZ_Ages. The method and error estimation
are described, and the results tested for accuracy and consistency, by
application to integrated spectra of well-known Galactic globular and open
clusters. Ages and abundances from integrated light analysis agree with studies
of resolved stars to within +/-0.1 dex for most clusters, and to within +/-0.2
dex for nearly all cases. The results are robust to the choice of Lick indices
used in the fitting to within +/-0.1 dex, except for a few systematic
deviations which are clearly categorized. The realism of our error estimates is
checked through comparison with detailed Monte Carlo simulations. Finally, we
apply EZ_Ages to the sample of galaxies presented in Thomas et al. (2005) and
compare our derived values of age, [Fe/H], and [alpha/Fe] to their analysis. We
find that [alpha/Fe] is very consistent between the two analyses, that ages are
consistent for old (Age > 10 Gyr) populations, but show modest systematic
differences at younger ages, and that [Fe/H] is fairly consistent, with small
systematic differences related to the age systematics. Overall, EZ_Ages
provides accurate estimates of fundamental parameters from medium resolution
spectra of unresolved stellar populations in the old and intermediate-age
regime, for the first time allowing quantitative estimates of the abundances of
C, N, and Ca in these unresolved systems. The EZ_Ages code can be downloaded at
http://www.ucolick.org/~graves/EZ_Ages.htmlComment: Accepted to ApJ
Synthesis And Characterization Of (pyNO−)2GaCl: A Redox-Active Gallium Complex
We report the synthesis of a gallium complex incorporating redox-active pyridyl nitroxide ligands. The (pyNO−)2GaCl complex was prepared in 85% yield via a salt metathesis route and was characterized by 1H and 13C NMR spectroscopies, X-ray diffraction, and theory. UV–Vis absorption spectroscopy and electrochemistry were used to access the optical and electrochemical properties of the complex, respectively. Our discussion focuses primarily on a comparison of the gallium complex to the corresponding aluminum derivative and shows that although the complexes are very similar, small differences in the electronic structure of the complexes can be correlated to the identity of the metal
Telemeter transmission at 219.5 megacycles from two rocket-powered models at Mach numbers up to 15.7
Exploring the healthcare experiences and support needs of chestfeeding or breastfeeding for trans and non-binary parents based in the United Kingdom
Background: Trans and/or non-binary parents experience structural exclusion in family healthcare and there is a need for specialist training for healthcare professionals so that they are able to create a gender inclusive environment.
Aim: As part of a continued effort to address health inequity this study explores the body experiences of infant feeding within trans and non binary communities.
Method: Semi structured interviews were conducted with seven trans or non-binary parents, based in the United Kingdom, who have experienced chestfeeding or breastfeeding.
Results: A reflexive thematic analysis was utlitised to identify three main themes which centered around baby, body and support in health care settings. Parents were informed of the benefits of their milk and were strongly motivated by their child’s needs. However, body feeding was emotionally and physically challenging.
Conclusion: Person-centered care with consistent attention to language is required when supporting lactation
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