25,816 research outputs found
The Unmet Need for Care: Vulnerability Among Older Adults
In this brief, authors Rebecca Glauber and Melissa Day explore factors that exacerbate the unmet need for care among the noninstitutionalized older population and seek to determine who is likely to need care but go without. They find that unmarried individuals and those who live alone are more likely than others to need care but not receive it. These older adults are frail, have difficulty meeting their daily needs, and do not have family members or friends to whom to turn in times of need. This group of vulnerable older adults requires an array of social supports
A Volume Clearing Algorithm for Muon Tomography
The primary objective is to enhance muon-tomographic image reconstruction
capability by providing distinctive information in terms of deciding on the
properties of regions or voxels within a probed volume "V" during any point of
scanning: threat type, non-threat type, or not-sufficient data. An algorithm
(MTclear) is being developed to ray-trace muon tracks and count how many
straight tracks are passing through a voxel. If a voxel "v" has sufficient
number of straight tracks (t), then "v" is a non-threat type voxel, unless
there are sufficient number of scattering points (p) in "v" that will make it a
threat-type voxel. The algorithm also keeps track of voxels for which not
enough information is known: where p and v both fall below their respective
threshold parameters. We present preliminary results showing how the algorithm
works on data collected with a Muon Tomography station based on gas electron
multipliers operated by our group. The MTclear algorithm provides more
comprehensive information to a human operator or to a decision algorithm than
that provided by conventional muon-tomographic reconstruction algorithms, in
terms of qualitatively determining the threat possibility from a probed volume.
This is quite important because only low numbers of cosmic ray source muons are
typically available in nature for tomography, while a quick determination of
threats is essential.Comment: 3 pages, 3 figures, submitted to conf. record of 2014 IEEE Nucl. Sci.
Symposium, Seattl
An experimental investigation of the condensation of silicate grains
Amorphous magnesium silicate smoke particles were condensed from hydrogen and argon atmospheres containing Mg and Si0. A wide range of initial compositions were observed but all particles could be recrystallized into forsterite (Mg2Si04), by heating to 1000 C in vacuum. The amount of smoke formed decreased rapidly with temperatures between 300 and 800 K at reactant partial pressures of about 1 torr
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Interface temperatures in friction braking
YesResults and analysis from investigations into the behaviour of the interfacial layer (Tribolayer)
at the friction interface of a brake friction pair (resin bonded composite friction material
and cast iron rotor) are presented in which the disc/pad interface temperature has been
measured using thermocouple methods. Using a designed experiment approach, the interface
temperature is shown to be affected by factors including the number of braking applications,
the friction coefficient, sliding speed, braking load and friction material. The time-dependent
nature of the Tribo-Iayer formation and the real contact area distribution are shown to be
causes of variation in interface temperatures in friction braking. The work extends the
scientific understanding of interface contact and temperature during friction braking
Resonant tunneling in fractional quantum Hall effect: superperiods and braiding statistics
We study theoretically resonant tunneling of composite fermions through their
quasi-bound states around a fractional quantum Hall island, and find a rich set
of possible transitions of the island state as a function of the magnetic field
or the backgate voltage. These considerations have possible relevance to a
recent experimental study, and bring out many subtleties involved in deducing
fractional braiding statistics.Comment: Phys. Rev. Lett. in pres
Is simultaneous and --scaling in the quasi-elastic region accidental?
We study the and --scaling of the nuclear response at large momentum
transfer in order to understand how scaling based on very different
descriptions of the elementary interaction can occur simultaneously. We find
that the approximate validity of -scaling at low energy loss arises from
the coincidental behavior of the quasielastic and deep inelastic cross
sections.Comment: 4 pages, 3 Postscript figure
Proof-of-Concept Testing of a Sustained Vortex-Flow Configuration for Hybrid Rocket Motors
One of the drawbacks of hybrid rocket motors is the limited regression rate of the fuel grain, which impacts on the scalablility of the type. A number of methods of increasing this have been proposed and successfully tested, in particular the use of swirling oxidiser flow to create turbulence and increase the local oxidiser mass flux. However, many of these have limitations in practical motors for many applications, and a common problem is that of the swirl decaying within the motor. The proposed method described here is to use a tapering fuel-grain port to sustain the swirl. A short series of firings indicates that such a method may be effective, although the evidence is limited thus far. The majority of previous research has used gaseous oxygen, and it has been found during this test programme that using liquid nitrous oxide poses particular problems. However, solutions have been found, and are described in this paper
Initial experience using a femtosecond laser cataract surgery system at a UK National Health Service cataract surgery day care centre
© 2019 The Author(s). This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/OBJECTIVES: To describe the initial outcomes following installation of a cataract surgery laser system.SETTING: National Health Service cataract surgery day care unit in North London, UK.PARTICIPANTS: 158 eyes of 150 patients undergoing laser-assisted cataract surgery.INTERVENTIONS: Laser cataract surgery using the AMO Catalys femtosecond laser platform.PRIMARY AND SECONDARY OUTCOME MEASURES: PRIMARY OUTCOME MEASURE: intraoperative complications including anterior and posterior capsule tears.SECONDARY OUTCOME MEASURES: docking to the laser platform, successful treatment delivery, postoperative visual acuities.RESULTS: Mean case age was 67.7±10.8 years (range 29-88 years). Docking was successful in 94% (148/158 cases), and in 4% (6/148 cases) of these, the laser delivery was aborted part way during delivery due to patient movement. A total of 32 surgeons, of grades from junior trainee to consultant, performed the surgeries. Median case number per surgeon was 3 (range from 1-20). The anterior capsulotomy was complete in 99.3% of cases, there were no anterior capsule tears (0%). There were 3 cases with posterior capsule rupture requiring anterior vitrectomy, and 1 with zonular dialysis requiring anterior vitrectomy (4/148 eyes, 2.7%). These 4 cases were performed by trainee surgeons, and were either their first laser cataract surgery (2 surgeons) or their first and second laser cataract surgeries (1 surgeon).CONCLUSIONS: Despite the learning curve, docking and laser delivery were successfully performed in almost all cases, and surgical complication rates and visual outcomes were similar to those expected based on national data. Complications were predominately confined to trainee surgeons, and with the exception of intraoperative pupil constriction appeared unrelated to the laser-performed steps.Peer reviewe
On implicational bases of closure systems with unique critical sets
We show that every optimum basis of a finite closure system, in D.Maier's
sense, is also right-side optimum, which is a parameter of a minimum CNF
representation of a Horn Boolean function. New parameters for the size of the
binary part are also established. We introduce a K-basis of a general closure
system, which is a refinement of the canonical basis of Duquenne and Guigues,
and discuss a polynomial algorithm to obtain it. We study closure systems with
the unique criticals and some of its subclasses, where the K-basis is unique. A
further refinement in the form of the E-basis is possible for closure systems
without D-cycles. There is a polynomial algorithm to recognize the D-relation
from a K-basis. Thus, closure systems without D-cycles can be effectively
recognized. While E-basis achieves an optimum in one of its parts, the
optimization of the others is an NP-complete problem.Comment: Presented on International Symposium of Artificial Intelligence and
Mathematics (ISAIM-2012), Ft. Lauderdale, FL, USA Results are included into
plenary talk on conference Universal Algebra and Lattice Theory, June 2012,
Szeged, Hungary 29 pages and 2 figure
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