528 research outputs found
The winter floods of 2015/2016 in the UK - a review
A remarkably persistent and exceptionally mild cyclonic episode beginning in early-November 2015 and lasting around fourteen weeks brought severe, extensive and protracted flooding which impacted most damagingly on northern Britain, Northern Ireland and parts of Wales. Many existing rainfall and seasonal temperature records were eclipsed during this period and, most notably, maximum recorded river flows were exceeded over a substantial proportion of the country. At the national scale, previous maximum daily and monthly outflows were clearly eclipsed and four relatively discrete episodes of extreme runoff can be recognised. In many areas, the magnitude, persistence and repetitive nature of the flooding had major adverse impacts on communities, infrastructure, agriculture and a host of other sectors of the economy.
The extent and duration of the flooding has very few close parallels in the historical record and, overall, it was a hydrometeorological episode which ranks alongside the 1975/1976 drought and 1947 floods as the most extreme broad-scale events captured in observational records during the last 100 years at least. The truly exceptional runoff patterns experienced in 1947 and 1976 had a major impact on flood and drought management strategies but occurred before the exacerbating impact of climate change was generally recognised. The 2015/2016 flooding, together with the impact of other protracted flood events in the 21st century thus far, has underlined the need to adapt engineering design and flood management strategies to accommodate the recent extension in the range of recorded runoff variability
Non-locality and quasiclassical reality in Kent's formulation of relativistic quantum theory
We report Adrian Kent's proposed framework for a realist, one-world,
Lorentz-invariant formulation of quantum theory. The idea is to postulate a
final boundary condition: in effect, a late-time distribution of mass-energy
recording how photons scattered off macroscopic objects. Nature selects this
final boundary condition with the orthodox late-time Born probability; and this
defines the probability space of events, to give a realist quantum theory. We
emphasize two topics. First, we consider this formulation's verdicts about
traditional locality conditions, such as Outcome Independence and Parameter
Independence. Second, we discuss a possible amendment to Kent's proposal that,
roughly speaking, allows for the emergence of a quasiclassical history even
when mass-energy is shielded or delayed from appearing in the final boundary
condition.Comment: 14 pages, 7 figures, submitted to Journal of Physics: Conference
Serie
Drift-induced deceleration of Solar Energetic Particles
We investigate the deceleration of Solar Energetic Particles (SEPs) during their propagation from the Sun through interplanetary space, in the presence of weak to strong scattering in a Parker spiral configuration, using relativistic full orbit test particle simulations. The calculations retain all three spatial variables describing particles’ trajectories, allowing to model any transport across the magnetic field. Large energy change is shown to occur for protons, due to the combined effect of standard adiabatic deceleration and a significant contribution from particle drift in the direction opposite to that of the solar wind electric field. The latter drift-induced deceleration is found to have a stronger effect for SEP energies than for galactic cosmic rays. The kinetic energy of protons injected at 1 MeV is found to be reduced by between 35 and 90% after four days, and for protons injected at 100 MeV by between 20 and 55%. The overall degree of deceleration is a weak function of the scattering mean free path, showing that, although adiabatic deceleration plays a role, a large contribution is due to particle drift. Current SEP transport models are found to account for drift-induced deceleration in an approximate way and their accuracy will need to be assessed in future work
Who Am I: Farmington Honors Journal, Volume 5, Spring 2023
Hello everyone,
Thank you for taking the time to look at the work of some of the wonderful students here at the University of Maine at Farmington. These pieces showcase both personal works, as well as works for specific classes. There was a recurring theme of identity throughout many of the submissions seen here in this journal, so to play off of last year\u27s Why Am I?, the 2023 Honors Journal brings you Who I Am. I hope you enjoy these pieces as much as I have.
Sincerely, Madisyn Smit
Time to onset of cannabidiol (CBD) treatment effect in Lennox-Gastaut syndrome: Analysis from two randomized controlled trials
OBJECTIVE: To estimate time to onset of cannabidiol (CBD) treatment effect (seizure reduction and adverse events [AEs]), we conducted post hoc analyses of data from two randomized, placebo-controlled, Phase 3 trials, GWPCARE3 (NCT02224560) and GWPCARE4 (NCT02224690), of patients with Lennox-Gastaut syndrome. METHODS: Patients received plant-derived pharmaceutical formulation of highly purified CBD (Epidiolex, 100 mg/ml oral solution) at 10 mg/kg/day (CBD10; GWPCARE3) or 20 mg/kg/day (CBD20; both trials) or placebo for 14 weeks. Treatment started at 2.5 mg/kg/day for all groups and reached 10 mg/kg/day on Day 7 and 20 mg/kg/day (CBD20 and matching placebo only) on Day 11. Percentage change from baseline in drop seizure frequency was calculated by cumulative day (i.e., including all previous days). Time to onset and resolution of AEs were evaluated. RESULTS: Overall, 235 patients received CBD (CBD10 [GWPCARE3 only], n = 67; CBD20 [pooled GWPCARE3&4], n = 168) and 161 received placebo. Mean (range) age was 15.3 years (2.6-48.0). Patients had previously discontinued a median (range) of six (0-28) antiepileptic drugs (AEDs) and were currently taking a median of three (0-5) AEDs. Differences in drop seizure reduction between placebo and CBD emerged during the titration period and became nominally significant by Day 6 (p = .008) for pooled CBD treatment groups. Separation between placebo and CBD in ≥50% responder rate emerged by Day 6. Onset of the first reported AE occurred during the titration period in 45% of patients (CBD10, 46%; CBD20, 52%; placebo, 38%). In patients with AEs, resolution occurred within 4 weeks of onset in 53% of placebo and 39% of CBD patients and by end of study in 63% of placebo and 61% of CBD patients. SIGNIFICANCE: Treatment effect (efficacy and AEs) of CBD may occur within 1 week of starting treatment. Although AEs lasted longer for CBD than placebo, most resolved within the 14-week period
Solar energetic particle transport near a heliospheric current sheet
Solar energetic particles (SEPs), a major component of space weather, propagate through the interplanetary medium strongly guided by the interplanetary magnetic field (IMF). In this work, we analyze the implications that a flat Heliospheric Current Sheet (HCS) has on proton propagation from SEP release sites to the Earth. We simulate proton propagation by integrating fully 3D trajectories near an analytically defined flat current sheet, collecting comprehensive statistics into histograms, fluence maps, and virtual observer time profiles within an energy range of 1–800 MeV. We show that protons experience significant current sheet drift to distant longitudes, causing time profiles to exhibit multiple components, which are a potential source of confusing interpretations of observations. We find that variation of the current sheet thickness within a realistic parameter range has little effect on particle propagation. We show that the IMF configuration strongly affects the deceleration of protons. We show that in our model, the presence of a flat equatorial HCS in the inner heliosphere limits the crossing of protons into the opposite hemisphere
A Performance Versus Cost Analysis of Prepreg Carbon Fibre Epoxy Energy Absorption Structures
Carbon fibre epoxy composites are sought after for their excellent specific energy absorption (SEA) but are costly. A range of prepreg carbon fibre epoxy layups were subjected to a 10 m/s impact with 4 kJ of energy. Fibre volume fraction and voidage were determined for each sample and the fracture analysed in detail. SEA ranged from 35.27 J/g to 60.25 J/g with the highest performance from 8 plies of 200gsm 2x2 twill all laid at 0 degrees. Vacuum assisted oven cure resulted in higher voidage than autoclave cure (2.52% versus 0.17%) but did not affect SEA. According to a ratio of performance to cost the highest rated samples were an 8 ply oven cure and a 3 ply autoclave cure specimen and there was little difference between them. This work has highlighted that there is enormous potential for cost reduction of prepreg carbon fibre epoxy energy absorption structures through the use of heavier areal weight fabrics and fewer plies as well as through the use of oven cured prepreg
Measurement of the antineutrino neutral-current elastic differential cross section
arXiv:1309.7257v1 [hep-ex
Torosaurus Is Not Triceratops: Ontogeny in Chasmosaurine Ceratopsids as a Case Study in Dinosaur Taxonomy
Background: In horned dinosaurs, taxonomy is complicated by the fact that the cranial ornament that distinguishes species changes with age. Based on this observation, it has been proposed that the genera Triceratops and Torosaurus are in fact synonymous, with specimens identified as Torosaurus representing the adult form of Triceratops. The hypothesis of synonymy makes three testable predictions: 1) the species in question should have similar geographic and stratigraphic distributions, 2) specimens assigned to Torosaurus should be more mature than those assigned to Triceratops, and 3) intermediates should exist that combine features of Triceratops and Torosaurus. The first condition appears to be met, but it remains unclear whether the other predictions are borne out by the fossil evidence. Methodology/Principal Findings: We assessed the relative maturity of Torosaurus and Triceratops specimens by coding skulls for characters that vary with maturity, and then using a clustering analysis to arrange them into a growth series. We found that a well-defined sequence of changes exists in horned dinosaurs: development of cranial ornament occurs in juveniles, followed by fusion of the skull roof in subadults, and finally, the epoccipitals, epijugals, and rostral fuse to the skull in adults. Using this scheme, we identified mature and immature individuals of both Torosaurus and Triceratops. Furthermore, we describe the ventral depressions on the frill of Triceratops, and show that they differ in shape and position from the parietal fenestrae of Torosaurus. Thus, we conclude that these structures are not intermediates between the soli
The Postcranial Skeleton of an Exceptionally Complete Individual of the Plated Dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A.
Copyright: © 2015 Maidment et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
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