The role of spatial and temporal radiation deposition in inertial fusion chambers: the case of HiPER¿

The first wall armour for the reactor chamber of HiPER will have to face short energy pulses of 5 to 20 MJ mostly in the form of x-rays and charged particles at a repetition rate of 5–10 Hz. Armour material and chamber dimensions have to be chosen to avoid/minimize damage to the chamber, ensuring the proper functioning of the facility during its planned lifetime. The maximum energy fluence that the armour can withstand without risk of failure, is determined by temporal and spatial deposition of the radiation energy inside the material. In this paper, simulations on the thermal effect of the radiation–armour interaction are carried out with an increasing definition of the temporal and spatial deposition of energy to prove their influence on the final results. These calculations will lead us to present the first values of the thermo-mechanical behaviour of the tungsten armour designed for the HiPER project under a shock ignition target of 48 MJ. The results will show that only the crossing of the plasticity limit in the first few micrometres might be a threat after thousands of shots for the survivability of the armour

Electrical compatibility of transmission fluids in electric vehicles

The in electrical vehicles, where the electric motor is inside the transmissielectrical compatibility of the automatic transmission fluids (ATFs) is very important on and in contact with the ATF. This work studies the influence of factors like temperature, time, and air exposition on the oxidation of three ATFs and their changes in electrical conductivity. The results showed that the higher content of additive the lower variations of electrical conductivity with the oxidation; the measurements of electrical conductivity are better than FT-IR ones for monitoring oil thermo-oxidative degradation at initial periods; the conventional ATFs could maintain good electrical compatibility in electrified drivelines, although their materials compatibility and copper corrosion protection of electrical components should be also tested

Effectiveness and safety of mechanical thrombectomy for acute ischaemic stroke in Latin American countries: A systematic review

YesTo describe the use, effectiveness, and safety outcomes of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in Latin American countries. Studies reporting MT outcomes for AIS in Latin America were identified in CINAHL, MEDLINE, Web of Science, SciELO, EMBASE, and LILACS databases. Synthesis was conducted according to effectiveness (recanalization rates) and safety measures (mortality and functional independence at 90 days). Seventeen studies were included, mainly from public and university hospitals. MT utilization varied from 2.6% to 50.1%, while successful recanalization ranged from 63% to 95%. Functional independence 90 days after stroke (a modified Rankin scale score of 0 to 2) was achieved in less than 40% across most studies. Mortality rates were below 30%; studies with posterior circulation strokes reported higher mortality rates. The randomized trial reported better health outcomes for functional independence among patients in the MT group (OR 2.28; 95% CI, 1.41 - 3.69), favoring MT over standard care. The included studies had great methodological heterogeneity due to differences in study design, the MT time window, and stroke location. The only randomized trial showed improved functional independence and lower mortality rates with MT than with standard care. The rest of the studies reported similar findings to available literature. Efforts to improve stroke care are reflected in improved patient outcomes in the region. Future studies should consider standard time window criteria and reduce the risk of bias by including representative samples and comparison groups

A Hot Uranus Orbiting the Super Metal-rich Star HD77338 and the Metallicity - Mass Connection

We announce the discovery of a low-mass planet orbiting the super metal-rich K0V star HD77338 as part of our on-going Calan-Hertfordshire Extrasolar Planet Search. The best fit planet solution has an orbital period of 5.7361\pm0.0015 days and with a radial velocity semi-amplitude of only 5.96\pm1.74 m/s, we find a minimum mass of 15.9+4.7-5.3 Me. The best fit eccentricity from this solution is 0.09+0.25-0.09, and we find agreement for this data set using a Bayesian analysis and a periodogram analysis. We measure a metallicity for the star of +0.35\pm0.06 dex, whereas another recent work (Trevisan et al. 2011) finds +0.47\pm0.05 dex. Thus HD77338b is one of the most metal-rich planet host stars known and the most metal-rich star hosting a sub-Neptune mass planet. We searched for a transit signature of HD77338b but none was detected. We also highlight an emerging trend where metallicity and mass seem to correlate at very low masses, a discovery that would be in agreement with the core accretion model of planet formation. The trend appears to show that for Neptune-mass planets and below, higher masses are preferred when the host star is more metal-rich. Also a lower boundary is apparent in the super metal-rich regime where there are no very low-mass planets yet discovered in comparison to the sub-solar metallicity regime. A Monte Carlo analysis shows that this, low-mass planet desert, is statistically significant with the current sample of 36 planets at around the 4.5\sigma\ level. In addition, results from Kepler strengthen the claim for this paucity of the lowest-mass planets in super metal-rich systems. Finally, this discovery adds to the growing population of low-mass planets around low-mass and metal-rich stars and shows that very low-mass planets can now be discovered with a relatively small number of data points using stable instrumentation.Comment: 25 pages, 15 figures, 5 tables, accepted for publication in Ap

The California Planet Survey. I. Four New Giant Exoplanets

We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne spectroscopy. Their orbital parameters span wide ranges of planetary minimum mass (M sin i = 0.38-1.9 M(Jup)), orbital period (P = 2.87-11.5 yr), semimajor axis (a = 2.1-5.2 AU), and eccentricity (e = 0.02-0.41). HD 34445 b (P = 2.87 yr, M sin i = 0.79 MJup, e = 0.27) is a massive planet orbiting an old, G-type star. We announce a planet, HD 126614 Ab, and an M dwarf, HD 126614 B, orbiting the metal-rich star HD 126614 (which we now refer to as HD 126614 A). The planet, HD 126614 Ab, has minimum mass M sin i = 0.38 MJup and orbits the stellar primary with period P = 3.41 yr and orbital separation a = 2.3 AU. The faint M dwarf companion, HD 126614 B, is separated from the stellar primary by 489 mas (33 AU) and was discovered with direct observations using adaptive optics and the PHARO camera at Palomar Observatory. The stellar primary in this new system, HD 126614 A, has the highest measured metallicity ([ Fe/ H] = + 0.56) of any known planet-bearing star. HD 13931 b (P = 11.5 yr, M sin i = 1.88 MJup, e = 0.02) is a Jupiter analog orbiting a near solar twin. Gl 179 b (P = 6.3 yr, M sin i = 0.82 M(Jup), e = 0.21) is a massive planet orbiting a faint M dwarf. The high metallicity of Gl 179 is consistent with the planet-metallicity correlation among M dwarfs, as documented recently by Johnson & Apps.NSF AST-0702821NASA NNX06AH52GMcDonald Observator

The Cosmic Telescope that Lenses the Sunburst Arc, PSZ1 G311.65-18.48: Strong Gravitational Lensing model and Source Plane Analysis

We present a strong lensing analysis of the cluster PSZ1 G311.65-18.48, based on Hubble Space Telescope imaging, archival VLT/MUSE spectroscopy, and Chandra X-ray data. This cool-core cluster (z=0.443) lenses the brightest lensed galaxy known, dubbed the "Sunburst Arc" (z=2.3703), a Lyman continuum (LyC) emitting galaxy multiply-imaged 12 times. We identify in this field 14 additional strongly-lensed galaxies to constrain a strong lens model, and report secure spectroscopic redshifts of four. We measure a projected cluster core mass of M(<250 kpc)=2.93+0.01/-0.02x10^14M_sun. The two least-magnified but complete images of the Sunburst Arc's source galaxy are magnified by ~13x, while the LyC clump is magnified by ~4-80x. We present time delay predictions and conclusive evidence that a discrepant clump in the Sunburst Arc, previously claimed to be a transient, is not variable, thus strengthening the hypothesis that it results from an exceptionally high magnification. A source plane reconstruction and analysis of the Sunburst Arc finds its physical size to be 1x2 kpc, and that it is resolved in three distinct directions in the source plane, 0, 40, and 75 degrees (east of North). We place an upper limit of r <~ 50 pc on the source plane size of unresolved clumps, and r<~ 32 pc for the LyC clump. Finally, we report that the Sunburst Arc is likely in a system of two or more galaxies separated by <~6 kpc in projection. Their interaction may drive star formation and could play a role in the mechanism responsible for the leaking LyC radiation.Comment: 31 pages, 14 figures, 4 tables. Submitted to Ap

Neutrino Physics from Charged Higgs and Slepton Associated Production in AMSB

In the Minimal Supersymmetric Standard Model with bilinear R-Parity violation, terms that violate R-Parity and lepton number are introduced in the superpotential, and sneutrino vacuum expectation values are induced. As a result, neutrino masses and mixing angles are generated via a low energy see-saw mechanism. We show that this model embedded into an anomaly mediated supersymmetry breaking scenario is testable at a linear collider using charged Higgs boson production in association with a stau. This is possible in regions of parameter space where the charged Higgs and stau have similar mass, producing an enhancement of the charged scalar mixing angles. We show that the bilinear parameter and the sneutrino vev can be determined from charged scalar observables, and estimate the precision of this determination.Comment: 21 pages, including 8 figure