1,113 research outputs found
Crack Initiation and Growth Behavior at Corrosion Pit in 7075-T6 High Strength Aluminum Alloy
Research on fatigue crack formation from two types corrosion pits tangent to a circular hole in a 7075-T6 aluminum alloy subjected to uni-axial loads (R = 0.5, lambda = 0) in both an air and saltwater environment provides a method for exploring crack initiation and initial growth rates. This work focuses on a fracture mechanics approach to explore the transition from corrosion pit to crack growth. Specimens with a cylinder shaped through-pit tangent to a circular hole have a closed form solution to predict this delta K that closely resembles the finite element solutions. Specimens with a semi-circular corner-pit tangent to hole lack a closed form solution and finite element modeling was used to determine delta K of these specimens. Optical and electron microscopy provided an accurate way to measure and observe the crack growth rate (da/dN) and the cycles until initiation of the fatigue cracks. This research shows that corner-pit specimens initially have a slower crack growth rate than through-pit specimens due to the propagation of a quarter-circular crack front through the thickness of the sample. After initial crack growth, both corner-pit and through-pit samples have the same growth rate as their machine notched counterparts exposed air and saltwater environments
Direct detection and quantification of microRNAs
The recent discovery of the potent regulatory nature of microRNAs (miRNAs), a relatively new class of approximately 22 nucleotide RNAs, has made them a primary focus in todayâs biochemical and medical research. The relationship between miRNA expression patterns and the onset of cancer, as well as other diseases, has glimpsed the potential of miRNAs as disease biomarkers or drug targets, making them a primary research focus. Their promising future in medicine is hinged upon improving our scientific understanding of their intricate regulatory mechanisms. In the realm of analytical chemistry, the main challenge associated with miRNA is its detection. Their extremely small size and low cellular concentration poses many challenges for achieving reliable results. Current reviews in this area have focused on adaptations to microarray, PCR, and Northern blotting procedures to make them suitable for miRNA detection. While these are extremely powerful methods and accepted as the current standards, they are typically very laborious, semi-quantitative, and often require expensive imaging equipment and/or radioactive/toxic labels. This review aims to highlight emerging techniques in miRNA detection and quantification that exhibit superior flexibility and adaptability as well as matched or increased sensitivity in comparison to the current standards. Specifically, this review will cover colorimetric, fluorescence, bioluminescence, enzyme, and electrochemical based methods, which drastically reduce procedural complexity and overall expense of operation thereby increasing the accessibility of this field of research. The methods are presented and discussed as to their improvements over current standard methods as well as their potential complications preventing acceptance as standard procedures. These new methods have addressed the many of the problems associated with miRNA detection through the employment of enzyme-based signal amplification, enhanced hybridization conditions using PNA capture probes, highly sensitive and flexible forms of spectroscopy, and extremely responsive electrocatalytic nanosystems, among other approaches
Adoption of the 2006 Field Triage Decision Scheme for Injured Patients
Background: When emergency medical services (EMS) providers respond to the scene of an injury, they must decide where to transport the injured patients for further evaluation and treatment. This is done through a process known as âfield triageâ, whereby a patientâs injuries are matched to the most appropriate hospital. In 2005-2006 the National Expert Panel on Field Triage, convened by the Centers for Disease Control and Prevention and the National Highway Traffic Safety Administration, revised the 1999 American College of Surgeons Committee on Trauma Field Triage Decision Scheme. This revision, the 2006 Field Triage Decision Scheme, was published in 2006.Methods: State Public Health departmentsâ and EMSâ external websites were evaluated to ascertain the current status of implementation of the 2006 Field Triage Decision Scheme.Results: Information regarding field triage was located for 41 states. In nine states no information regarding field triage was available on their websites. Of the 41 states where information was located, seven were classified as âfull adoptersâ of the 2006 Field Triage Decision Scheme; nine were considered âpartial adoptersâ; 17 states were found to be using a full version or modification of the 1999 Field Triage Decision Scheme; and eight states were considered to be using a different protocol or scheme for field triage.Conclusion: Many states have adopted the 2006 Decision Scheme (full or partial). Further investigation is needed to determine the reasons why some states do not adopt the guidelines. [West J Emerg Med. 2011;12(3):275-283.
Improving the Graphical User Interface (GUI) for the Dynamic Feedback Signal Set (DyFSS): Increasing Accessibility for the Neurodiverse
Peripheral biofeedback is an explicit learning tool
that allows for real-time evaluation and control of physiological
proxies by means of computerized signals. Its integration into
health practice allows users to calibrate self-awareness and self regulation
then apply these skills to everyday life. People with
neurodevelopmental differences encounter limitations when
using commercially available clinical biofeedback due to
variation in their autonomic response. Principles of Universal
Design dictate that biofeedback inputs and displays allow
effective access and benefit for as many individuals as possible.
Our Dynamic Feedback Signal Set (DyFSS, nonprovisional
patent-in-process) algorithm adjusts signal processing by
dynamically weighting feedback signals to the best abilities of the
user, increasing the efficacy of biofeedback for the neurodiverse.
The software includes an interactive graphical tutorial and quiz,
a variety of graphical user interfaces to honor individual
preferences and abilities, and a game that can be played by blind
and hard of hearing individuals alike
Origins Space Telescope: predictions for far-IR spectroscopic surveys
We illustrate the extraordinary potential of the (far-IR) Origins Survey
Spectrometer (OSS) on board the Origins Space Telescope (OST) to address a
variety of open issues on the co-evolution of galaxies and AGNs. We present
predictions for blind surveys, each of 1000 h, with different mapped areas (a
shallow survey covering an area of 10 deg and a deep survey of 1
deg) and two different concepts of the OST/OSS: with a 5.9 m telescope
(Concept 2, our reference configuration) and with a 9.1 m telescope (Concept 1,
previous configuration). In 1000 h, surveys with the reference concept will
detect from to lines from
- star-forming galaxies and from
to lines from - AGNs. The shallow survey will detect
substantially more sources than the deep one; the advantage of the latter in
pushing detections to lower luminosities/higher redshifts turns out to be quite
limited. The OST/OSS will reach, in the same observing time, line fluxes more
than one order of magnitude fainter than the SPICA/SMI and will cover a much
broader redshift range. In particular it will detect tens of thousands of
galaxies at , beyond the reach of that instrument. The polycyclic
aromatic hydrocarbons lines are potentially bright enough to allow the
detection of hundreds of thousands of star-forming galaxies up to ,
i.e. all the way through the re-ionization epoch. The proposed surveys will
allow us to explore the galaxy-AGN co-evolution up to with very
good statistics. OST Concept 1 does not offer significant advantages for the
scientific goals presented here.Comment: 24 pages, 20 figures, 2 tables, accepted for publication in PAS
The lattice stiffening transition in UO2 single crystals
The effective Debye temperatures (ΞDE) of the surface region of UO2 single crystals, prepared by the hydrothermal synthesis technique, were obtained from temperature-dependent x-ray photoemission in the temperature range of 300 Kâ623 K. A lattice stiffening transition, characterized by different regions of different effective Debye temperature, 500 ± 59 K below 475 K and 165 ± 21 K above 475 K is identified. A comparison of the temperature dependence of the effective UO2 Debye temperature, with the changes in the lattice expansion coefficient for UO2, support strong lattice-phonon interaction arising from the JahnâTeller distortion
MOST Observations of the Flare Star AD Leo
We present continuous, high-precision photometric monitoring data with 1
minute cadence of the dM3e flare star AD Leo with the {\it MOST} satellite. We
observed 19 flares in 5.8 days, and find a flare frequency distribution that is
similar to previous studies. The light curve reveals a sinusoidal modulation
with period of days that we attribute to the rotation of
a stellar spot rotating into and out of view. We see no correlation between the
occurrence of flares and rotational phase, indicating that there may be many
spots distributed at different longitudes, or possibly that the modulation is
caused by varying surface coverage of a large polar spot that is viewed nearly
pole-on. The data show no correlation between flare energy and the time since
the previous flare. We use these results to reject a simple model in which all
magnetic energy is stored in one active region and released only during flares.Comment: 20 Pages, 8 Figures, PASP Accepte
Ethics Recommendations for Crisis Translation Settings
This document is a summary public version of the Ethics Recommendations for Crisis
Translation Settings produced by some of the INTERACT project team. INTERACT is the
International Network in Crisis Translation, a project funded by the European Unionâs Horizon
2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement
No. 734211. Further information about the project as a whole is available at:
https://sites.google.com/view/crisistranslation/hom
CHILES: HI morphology and galaxy environment at z=0.12 and z=0.17
We present a study of 16 HI-detected galaxies found in 178 hours of
observations from Epoch 1 of the COSMOS HI Large Extragalactic Survey (CHILES).
We focus on two redshift ranges between 0.108 <= z <= 0.127 and 0.162 <= z <=
0.183 which are among the worst affected by radio frequency interference (RFI).
While this represents only 10% of the total frequency coverage and 18% of the
total expected time on source compared to what will be the full CHILES survey,
we demonstrate that our data reduction pipeline recovers high quality data even
in regions severely impacted by RFI. We report on our in-depth testing of an
automated spectral line source finder to produce HI total intensity maps which
we present side-by-side with significance maps to evaluate the reliability of
the morphology recovered by the source finder. We recommend that this become a
common place manner of presenting data from upcoming HI surveys of resolved
objects. We use the COSMOS 20k group catalogue, and we extract filamentary
structure using the topological DisPerSE algorithm to evaluate the \hi\
morphology in the context of both local and large-scale environments and we
discuss the shortcomings of both methods. Many of the detections show disturbed
HI morphologies suggesting they have undergone a recent interaction which is
not evident from deep optical imaging alone. Overall, the sample showcases the
broad range of ways in which galaxies interact with their environment. This is
a first look at the population of galaxies and their local and large-scale
environments observed in HI by CHILES at redshifts beyond the z=0.1 Universe.Comment: 23 pages, 12 figures, 1 interactive 3D figure, accepted to MNRA
The Magnetic Field of the Irregular Galaxy NGC 4214
We examine the magnetic field in NGC 4214, a nearby irregular galaxy, using
multi-wavelength radio continuum polarization data from the Very Large Array.
We find that the global radio continuum spectrum shows signs that free-free
absorption and/or synchrotron losses may be important. The 3cm radio continuum
morphology is similar to that of the Halpha, while the 20cm emission is more
diffuse. We estimate that 50% of the radio continuum emission in the center of
the galaxy is thermal. Our estimate of the magnetic field strength is \uG\ in the center and \uG\ at the edges. We find that the hot
gas, magnetic, and the gravitational pressures are all the same order of
magnitude. Inside the central star forming regions, we find that the thermal
and turbulent pressures of the HII regions dominate the pressure balance. We do
not detect any significant polarization on size scales greater than 200 pc. We
place an upper limit of 8 \uG\ on the uniform field strength in this galaxy. We
suggest that the diffuse synchrotron region, seen to the north of the main body
of emission at 20cm, is elongated due to a uniform magnetic field with a
maximum field strength of 7.6 \uG. We find that, while the shear in NGC 4214 is
comparable to that of the Milky Way, the supernova rate is half that of the
Milky Way and suggest that the star formation episode in NGC 4214 needs
additional time to build up enough turbulence to drive an
dynamo.Comment: Accepted by ApJ. Version with high resolution figures at
http://www.astro.virginia.edu/~aak8t/data/n4214/ms.pd
- âŠ