149 research outputs found

    Micro-determination of cerium

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    The compact multiple system HIP 41431

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    The nearby (50 pc) K7V dwarf HIP 41431 (EPIC 212096658) is a compact three-tier hierarchy. Three K7V stars with similar masses, from 0.61 to 0.63 solar, make a triple-lined spectroscopic system where the inner binary with a period of 2.9 d is eclipsing, and the outer companion on a 59-d orbit exerts strong dynamical influence revealed by the eclipse time variation in the Kepler photometry. Moreover, the centre of mass of the triple system moves on a 3.9-yr orbit, modulating the proper motion. The mass of the fourth star is 0.35 solar. The Kepler and ground-based photometry and radial velocities from four different spectrographs are used to adjust the spectro-photodynamical model that accounts for dynamical interaction. The mutual inclination between the two inner orbits is 2{^{circ}.}16 ± 0{^{circ}.}11, while the outer orbit is inclined to their common plane by 21°±16°. The inner orbit precesses under the influence of both outer orbits, causing observable variation of the eclipse depth. Moreover, the phase of the inner binary is strongly modulated with a 59-d period and its line of apsides precesses. The middle orbit with eccentricity e = 0.28 also precesses, causing the observed variation of its radial velocity curve. Masses and other parameters of stars in this unique hierarchy are determined. This system is dynamically stable and likely old

    CHEMICAL MODIFICATION OF CELLULOSE

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    Thermolytic degradation of cellulose is dependant on its initial DP, accessibility and on the method and temperature of the treatment. A limiting DP could be detected in the depolymerizing reaction. The deteriorating action of aggressive water could be demonstrated. Quantitative correlation was elaborated concerning the role of accessibility in the reaction between cellulose and reactive dyestuffs. The role of temperature was cleared up in the ceIlulose-caustic soda interaction. New bleaching process was elaborated with the use of singlet oxygen. Physical characteristics, amount of releasable formaldehyde and colouristic influence of resin finishing of cotton could be optimized

    Shortening the length of stay and mechanical ventilation time by using positive suggestions via MP3 players for ventilated patients

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    Long stay in intensive care unit (ICU) and prolonged ventilation are deleterious for subsequent quality of life and surcharge financial capacity. We have already demonstrated the beneficial effects of using suggestive communication on recovery time during intensive care. The aim of our present study was to prove the same effects with standardized positive suggestive message delivered by an MP3 player. Patients ventilated in ICU were randomized into a control group receiving standard ICU treatment and two groups with a standardized pre-recorded material delivered via headphones: a suggestive message about safety, self-control, and recovery for the study group and a relaxing music for the music group. Groups were similar in terms of age, gender, and mortality, but the SAPS II scores were higher in the study group than that in the controls (57.8 ± 23.6 vs. 30.1 ± 15.5 and 33.7 ± 17.4). Our post-hoc analysis results showed that the length of ICU stay (134.2 ± 73.3 vs. 314.2 ± 178.4 h) and the time spent on ventilator (85.2 ± 34.9 vs. 232.0 ± 165.6 h) were significantly shorter in the study group compared to the unified control. The advantage of the structured positive suggestive message was proven against both music and control groups

    Variability of M giant stars based on Kepler photometry: general characteristics

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    M giants are among the longest-period pulsating stars which is why their studies were traditionally restricted to analyses of low-precision visual observations, and more recently, accurate ground-based data. Here we present an overview of M giant variability on a wide range of time-scales (hours to years), based on analysis of thirteen quarters of Kepler long-cadence observations (one point per every 29.4 minutes), with a total time-span of over 1000 days. About two-thirds of the sample stars have been selected from the ASAS-North survey of the Kepler field, with the rest supplemented from a randomly chosen M giant control sample. We first describe the correction of the light curves from different quarters, which was found to be essential. We use Fourier analysis to calculate multiple frequencies for all stars in the sample. Over 50 stars show a relatively strong signal with a period equal to the Kepler-year and a characteristic phase dependence across the whole field-of-view. We interpret this as a so far unidentified systematic effect in the Kepler data. We discuss the presence of regular patterns in the distribution of multiple periodicities and amplitudes. In the period-amplitude plane we find that it is possible to distinguish between solar-like oscillations and larger amplitude pulsations which are characteristic for Mira/SR stars. This may indicate the region of the transition between two types of oscillations as we move upward along the giant branch.Comment: 12 pages, 13 figures, accepted for publication in MNRAS. The normalized light curves are available upon reques

    Characteristics of cardiorespiratory output determining factors among 11–19-year-old boys at rest and during maximal load: Its impact on systolic hypertension

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    As consequence of the expansion of sedentary lifestyle among schoolchildren the prevalence of particular symptoms related to decreased cardiorespiratory fitness increases. The purpose of this study was twofolds, on one hand to compare boys in three developmental groups: second childhood (G1), puberty (G2), young adult (G3) and on the other hand to compare groups classified on resting systolic blood pressure (RSBP) to differentiate cardiorespiratory output determining factors both at rest and at maximal load. Randomly selected apparently healthy boys were assessed, all subjects (n = 282) performed an incremental treadmill test until fatigue. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), and oxygen consumption were measured. Resting HR was higher and resting SBP and DBP were lower in the G1 as compared to G2 and G3 (p < 0.05) but not differed at maximal loads. However indicators of cardiovascular load differed between groups. The oxygen pulse and Q were the lowest in the G1 and increased significantly between groups (p < 0.05). In conclusion based on our data we can suggest that there is an observable development of hypertension associated with maturation and cardiac output determining factors

    Testing one-body density functionals on a solvable model

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    There are several physically motivated density matrix functionals in the literature, built from the knowledge of the natural orbitals and the occupation numbers of the one-body reduced density matrix. With the help of the equivalent phase-space formalism, we thoroughly test some of the most popular of those functionals on a completely solvable model.Comment: Latex, 16 pages, 4 figure
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