1,056 research outputs found
Discrimination of Disposable Vapes from Batteries Using the Magnetic Polarizability Tensor
Disposable vapes pose an environmental and fire hazard to waste streams when disposed of incorrectly. The lithium battery inside disposable vapes can produce an exothermic reaction when the lithium inside the battery is inadvertently exposed to air and moisture. New sensing technologies may be needed to screen waste streams for these vape hazards and this paper considers the potential of inductive techniques based on the magnetic polarisability tensor (MPT) representation. The MPT can be described by three complex components based on a target regardless of orientation. In this paper, the rank 2 MPT is measured and calculated for 10 vapes and 37 batteries for 28 logarithmically spaced frequencies from 119 Hz to 95.4 KHz. The 168 features of each object are reduced down to 2 features using principal component analysis (PCA) and linear discriminant analysis. The reduction of the features allows for the visualisation and grouping of the objects. Three clear groups of objects can be seen when the maximum feature scales the measurement and a two-component PCA transform is applied. The first group is the vapes, which are grouped away from the other batteries. The second is the batteries, which are grouped by size. Finally, zinc batteries are grouped away from the rest due to their case material.<br/
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Using a runway paradigm to assess the relative strength of rats' motivations for enrichment objects
Laboratory animals should be provided with enrichment objects in their cages; however, it is first necessary to
test whether the proposed enrichment objects provide benefits that increase the animalsâ welfare. The two main
paradigms currently used to assess proposed enrichment objects are the choice test, which is limited to determining
relative frequency of choice, and consumer demand studies, which can indicate the strength of a preference but are complex to design. Here, we propose a third methodology: a runway paradigm, which can be used to assess the strength of an animalâs motivation for enrichment objects, is simpler to use than consumer demand studies, and is faster to complete than typical choice tests. Time spent with objects in a standard choice test was used to rank several enrichment objects in order to compare with the ranking found in our runway paradigm. The rats ran significantly more times, ran faster, and interacted longer with objects with which they had previously spent the most time. It was concluded that this simple methodology is suitable for measuring ratsâ motivation to reach enrichment objects. This can be used to assess the preference for different types of enrichment objects or to measure reward system processes
Probing the atmosphere of the bulge G5III star OGLE-2002-BUL-069 by analysis of microlense H alpha line
We discuss high-resolution, time-resolved spectra of the caustic exit of the
binary microlensing event OGLE 2002-BUL-69 obtained with UVES on the VLT. The
source star is a G5III giant in the Galactic Bulge. During such events, the
source star is highly magnified, and a strong differential magnification around
the caustic resolves its surface. Using an appropriate model stellar atmosphere
generated by the NextGEN code we obtained a model light curve for the caustic
exit and compared it with a dense set of photometric observations obtained by
the PLANET microlensing follow up network. We further compared predicted
variations in the H alpha equivalent width with those measured from our
spectra. While the model and observations agree in the gross features, there
are discrepancies suggesting shortcomings in the model, particularly for the H
alpha line core, where we have detected amplified emission from the stellar
chromosphere as the source star's trailing limb exited the caustic. This
achievement became possible by the provision of the OGLE-III Early Warning
System, a network of small telescopes capable of nearly-continuous
round-the-clock photometric monitoring, on-line data reduction, daily
near-real-time modelling in order to predict caustic crossing parameters, and a
fast and efficient response of a 8m-class telescope to a
``Target-Of-Opportunity'' observation request.Comment: 4 pages Latex, 3 figures, accepted for publication to astronomy and
astrophysics letter
Rate-dependency of action potential duration and refractoriness in isolated myocytes from the rabbit AV node and atrium
During atrial fibrillation, ventricular rate is determined by atrioventricular nodal (AVN) conduction, which in part is dependent upon the refractoriness of single AVN cells. The aims of this study were to investigate the rate-dependency of the action potential duration (APD) and effective refractory period (ERP) in single myocytes isolated from the AV node and atrium of rabbit hearts, using whole cell patch clamping, and to determine the contribution of the 4-aminopyridine (4-AP)-sensitive current, ITO1to these relationships in the two cell types. AVN cells had a more positive maximum diastolic potential (-60±1 v-71±2 mV), lower Vmax(8±2 v 144±17 V/s) and higher input resistance [420±46 v 65±7 MOHgr (mean±s.eP<0.05n=9â33)], respectively, than atrial myocytes. Stepwise increases in rate from 75 beats/min caused activation failure and Wenckebach periodicity in AVN cells (at around 400 beats/min), but 1:1 activation in atrial cells (at up to 600 beats/min). Rate reduction from 300 to 75 beats/min shortened the ERP in both cell types (from 155±7 to 135±11 ms in AVN cells [P<0.05, n=6] and from 130±8 to 106±7 ms in atrial cells [P<0.05, n=10]). Rate increase from 300 to 480 and 600 beats/min shortened ERP in atrial cells, by 12±4% (n=8) and 26±7% (n=7), respectively (P<0.05). By contrast, AVN ERP did not shorten at rates >300 beats/min. In atrial cells, rate reduction to 75 beats/min caused marked shortening of APD50(from 51±6 to 29±6 ms, P<0.05). 4-AP (1 mm) significantly prolonged atrial APD50at 75 beats/min (P<0.05, n=7), but not at 300 or 400 beats/min. In AVN cells, in contrast, there was less effect of rate change on APD, and 4-AP did not alter APD50at any rate. 4-AP also did not affect APD90or ERP in either cell type. In conclusion, a lack of ERP-shortening at high rates in rabbit single AVN cells may contribute to ventricular rate control. ITO1contributed to the APD50rate relation in atrial, but not AVN cells and did not contribute to the ERP rate relation in either cell type
Limits on Stellar and Planetary Companions in Microlensing Event OGLE-1998-BUL-14
We present the PLANET photometric data set for \ob14, a high magnification
() event alerted by the OGLE collaboration toward the
Galactic bulge in 1998. The PLANET data set consists a total of 461 I-band and
139 band points, the majority of which was taken over a three month period.
The median sampling interval during this period is about 1 hour, and the
scatter over the peak of the event is 1.5%. The excellent data
quality and high maximum magnification of this event make it a prime candidate
to search for the short duration, low amplitude perturbations that are
signatures of a planetary companion orbiting the primary lens. The observed
light curve for \ob14 is consistent with a single lens (no companion) within
photometric uncertainties. We calculate the detection efficiency of the light
curve to lensing companions as a function of the mass ratio and angular
separation of the two components. We find that companions of mass ratio are ruled out at the 95% confidence level for projected separations
between 0.4-2.4 \re, where \re is the Einstein ring radius of the primary
lens. Assuming that the primary is a G-dwarf with \re\sim3 {\rm AU} our
detection efficiency for this event is for a companion with the mass
and separation of Jupiter and for a companion with the mass and
separation of Saturn. Our efficiencies for planets like those around Upsilon
And and 14 Her are > 75%.Comment: Data available at http://www.astro.rug.nl/~planet/planetpapers.html
20 pages, 10 figures. Minor changes. ApJ, accepte
The impact of the ATLAS zero-lepton, jets and missing momentum search on a CMSSM fit
Recent ATLAS data significantly extend the exclusion limits for
supersymmetric particles. We examine the impact of such data on global fits of
the constrained minimal supersymmetric standard model (CMSSM) to indirect and
cosmological data. We calculate the likelihood map of the ATLAS search, taking
into account systematic errors on the signal and on the background. We validate
our calculation against the ATLAS determinaton of 95% confidence level
exclusion contours. A previous CMSSM global fit is then re-weighted by the
likelihood map, which takes a bite at the high probability density region of
the global fit, pushing scalar and gaugino masses up.Comment: 16 pages, 7 figures. v2 has bigger figures and fixed typos. v3 has
clarified explanation of our handling of signal systematic
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