942 research outputs found

    On the impact of electrolyte temperature on contact glow discharge electrolysis

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    This study aims at disclosing the effect of small temperature drops (10-15 degrees C) of the electrolyte on Contact Glow Discharge Electrolysis (CGDE). In our experiments, we measure the temperature change of electrolyte and electrode as well as the change in current following on from the addition of, first, frozen and, second, boiling KOH aqueous solution (0.1 M). Quite surprisingly, only the addition of frozen KOH aqueous solution has a significant impact on current (+130%), caused by the decrease in electrolyte temperature (-11 degrees C). In contrast, the addition of boiling KOH aqueous solution has a negligible effect on current. A very similar behavior is recorded when frozen or boiling type III deionized water is used: the addition of ice has an even stronger impact on current (+145 %) and on electrolyte temperature (-14 degrees C), while adding boiling water has no measurable effect. Thus, we here demonstrated that electrolyte temperature is critical for managing the responsiveness of the CGDE system. Our results pave the way toward temperature controlled CGDE, a powerful tool for a greener and a more efficient environmental chemistry

    Drinking patterns of adolescents who develop alcohol use disorders: results from the Victorian adolescent health cohort study

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    Objective: We identify drinking styles that place teensat greatest risk of later alcohol use disorders (AUD).Design: Population-based cohort study.Setting: Victoria, Australia.Participants: A representative sample of 1943adolescents living in Victoria in 1992.Outcome measures: Teen drinking was assessed at6 monthly intervals (5 waves) between mean ages 14.9and 17.4 years and summarised across waves as none,one, or two or more waves of: (1) frequent drinking(3+ days in the past week), (2) loss of control overdrinking (difficulty stopping, amnesia), (3) bingedrinking (5+ standard drinks in a day) and (4) heavybinge drinking (20+ and 11+ standard drinks in a dayfor males and females, respectively). Young AdultAlcohol Use Disorder (AUD) was assessed at 3 yearlyintervals (3 waves) across the 20s (mean ages 20.7through 29.1 years).Results: We show that patterns of teen drinkingcharacterised by loss of control increase risk for AUDacross young adulthood: loss of control over drinking(one wave OR 1.4, 95% CI 1.1 to 1.8; two or morewaves OR 1.9, CI 1.4 to 2.7); binge drinking (one waveOR 1.7, CI 1.3 to 2.3; two or more waves OR 2.0, CI1.5 to 2.6), and heavy binge drinking (one wave OR2.0, CI 1.4 to 2.8; two or more waves OR 2.3, CI 1.6 to3.4). This is not so for frequent drinking, which wasunrelated to later AUD. Although drinking was morecommon in males, there was no evidence of sexdifferences in risk relationships.Conclusions: Our results extend previous work byshowing that patterns of drinking that represent loss ofcontrol over alcohol consumption (however expressed)are important targets for intervention. In addition tocurrent policies that may reduce overall consumption,emphasising prevention of more extreme teenagebouts of alcohol consumption appears warranted

    The GAPS Programme with HARPS-N at TNG. III: The retrograde orbit of HAT-P-18b

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    The measurement of the Rossiter-McLaughlin effect for transiting exoplanets places constraints on the orientation of the orbital axis with respect to the stellar spin axis, which can shed light on the mechanisms shaping the orbital configuration of planetary systems. Here we present the interesting case of the Saturn-mass planet HAT-P-18b, which orbits one of the coolest stars for which the Rossiter-McLaughlin effect has been measured so far. We acquired a spectroscopic time-series, spanning a full transit, with the HARPS-N spectrograph mounted at the TNG telescope. The very precise radial velocity measurements delivered by the HARPS-N pipeline were used to measure the Rossiter-McLaughlin effect. Complementary new photometric observations of another full transit were also analysed to obtain an independent determination of the star and planet parameters. We find that HAT-P-18b lies on a counter-rotating orbit, the sky-projected angle between the stellar spin axis and the planet orbital axis being lambda=132 +/- 15 deg. By joint modelling of the radial velocity and photometric data we obtain new determinations of the star (M_star = 0.770 +/- 0.027 M_Sun; R_star= 0.717 +/- 0.026 R_Sun; Vsin(I_star) = 1.58 +/- 0.18 km/s) and planet (M_pl = 0.196 +/- 0.008 M_J; R_pl = 0.947 +/- 0.044 R_J) parameters. Our spectra provide for the host star an effective temperature T_eff = 4870 +/- 50 K, a surface gravity of log(g_star) = 4.57 +/- 0.07 cm/s, and an iron abundance of [Fe/H] = 0.10 +/- 0.06. HAT-P-18b is one of the few planets known to transit a star with T_eff < 6250 K on a retrograde orbit. Objects such as HAT-P-18b (low planet mass and/or relatively long orbital period) most likely have a weak tidal coupling with their parent stars, therefore their orbits preserve any original misalignment. As such, they are ideal targets to study the causes of orbital evolution in cool main-sequence stars.Comment: 5 pages, 2 figure

    Why are Prices Sticky? Evidence from Business Survey Data

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    This paper offers new insights on the price setting behaviour of German retail firms using a novel dataset that consists of a large panel of monthly business surveys from 1991-2006. The firm-level data allows matching changes in firms' prices to several other firm-characteristics. Moreover, information on price expectations allow analyzing the determinants of price updating. Using univariate and bivariate ordered probit specifications, empirical menu cost models are estimated relating the probability of price adjustment and price updating, respectively, to both time- and state- dependent variables. First, results suggest an important role for state-dependence; changes in the macroeconomic and institutional environment as well as firm-specific factors are significantly related to the timing of price adjustment. These findings imply that price setting models should endogenize the timing of price adjustment in order to generate realistic predictions concerning the transmission of monetary policy. Second, an analysis of price expectations yields similar results providing evidence in favour of state-dependent sticky plan models. Third, intermediate input cost changes are among the most important determinants of price adjustment suggesting that pricing models should explicitly incorporate price setting at different production stages. However, the results show that adjustment to input cost changes takes time indicating "additional stickiness" at the last stage of processing

    A subgroup analysis of the ODYSSEY APPRISE study: Safety and efficacy of alirocumab in the Italian cohort.

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    Background and aims: ODYSSEY APPRISE trial evaluated efficacy and safety of alirocumab in 994 patients with hypercholesterolemia and high CV risk in a real-life setting. The aim of the present report is to detail on the Italian cohort enrolled and treated in the trial. Methods and results: The methodology of the of the multinational, single-arm, Phase 3b open-label ODYSSEY APPRISE (Clinicaltrials.gov: NCT02476006) has been previously reported. 255 Italian patients were enrolled and treated according to the trial protocol. Overall mean exposure to alirocumab was 83.3 ± 27.7 weeks. At week 12, LDL-C decreased by 51.3 ± 23.1% and this reduction was overall maintained for the duration of the study. A similar reduction was observed in patients with and without heterozygous familial hypercholesterolemia (HeFH 50.7% ± 23.9 vs. non-FH, 53.6% ± 19.6). LDL-C was reduced below 1.8 mmol/L and/or by ≥ 50% reduction from baseline in 62% of patients overall (61% in HeFH and 67% in non-FH). Alirocumab was similarly well tolerated in the Italian cohort as in the entire study population and the more common treatment emergent adverse events (TEAEs) were influenza, myalgia and nasopharyngitis. The incidence LDL-C levels &lt;25 mg/dl and &lt;15 mg/dl, was 8.2% and 2.9% respectively. Conclusion: The efficacy and safety of alirocumab in a real-life setting, in the Italian subgroup of patients are consistent with findings in the entire study population and confirm that alirocumab is a beneficial approach to further reduce LDL-C levels in patients at high CV risk on maximally tolerated conventional lipid lowering treatment

    Determination of rotation periods in solar-like stars with irregular sampling: the Gaia case

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    We present a study on the determination of rotation periods (P) of solar-like stars from the photometric irregular time-sampling of the ESA Gaia mission, currently scheduled for launch in 2013, taking into account its dependence on ecliptic coordinates. We examine the case of solar-twins as well as thousands of synthetic time-series of solar-like stars rotating faster than the Sun. In the case of solar twins we assume that the Gaia unfiltered photometric passband G will mimic the variability of the total solar irradiance (TSI) as measured by the VIRGO experiment. For stars rotating faster than the Sun, light-curves are simulated using synthetic spectra for the quiet atmosphere, the spots, and the faculae combined by applying semi-empirical relationships relating the level of photospheric magnetic activity to the stellar rotation and the Gaia instrumental response. The capabilities of the Deeming, Lomb-Scargle, and Phase Dispersion Minimisation methods in recovering the correct rotation periods are tested and compared. The false alarm probability (FAP) is computed using Monte Carlo simulations and compared with analytical formulae. The Gaia scanning law makes the rate of correct detection of rotation periods strongly dependent on the ecliptic latitude (beta). We find that for P ~ 1 d, the rate of correct detection increases with ecliptic latitude from 20-30 per cent at beta ~ 0{\deg} to a peak of 70 per cent at beta=45{\deg}, then it abruptly falls below 10 per cent at beta > 45{\deg}. For P > 5 d, the rate of correct detection is quite low and for solar twins is only 5 per cent on average.Comment: 12 pages, 18 figures, accepted by MNRA
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