348 research outputs found
Evaluation of Salt Removal from Azulejo Tiles and Mortars using Electrodesalination
12ª Conferência Internacional, realizada no Porto, de 12-15 de abril de 2011.info:eu-repo/semantics/publishedVersio
Three ways to solve the orbit of KIC11558725: a 10 day beaming sdB+WD binary with a pulsating subdwarf
The recently discovered subdwarf B (sdB) pulsator KIC11558725 features a rich
g-mode frequency spectrum, with a few low-amplitude p-modes at short periods,
and is a promising target for a seismic study aiming to constrain the internal
structure of this star, and of sdB stars in general.
We have obtained ground-based spectroscopic Balmer-line radial-velocity
measurements of KIC11558725, spanning the 2010 and 2011 observing seasons. From
these data we have discovered that KIC11558725 is a binary with period P=10.05
d, and that the radial-velocity amplitude of the sdB star is 58 km/s.
Consequently the companion of the sdB star has a minimum mass of 0.63 M\odot,
and is therefore most likely an unseen white dwarf.
We analyse the near-continuous 2010-2011 Kepler light curve to reveal orbital
Doppler-beaming light variations at the 238 ppm level, which is consistent with
the observed spectroscopic orbital radial-velocity amplitude of the subdwarf.
We use the strongest 70 pulsation frequencies in the Kepler light curve of the
subdwarf as clocks to derive a third consistent measurement of the orbital
radial-velocity amplitude, from the orbital light-travel delay.
We use our high signal-to-noise average spectra to study the atmospheric
parameters of the sdB star, deriving Teff = 27 910K and log g = 5.41 dex, and
find that carbon, nitrogen and oxygen are underabundant relative to the solar
mixture.
Furthermore, we extract more than 160 significant frequencies from the Kepler
light curve. We investigate the pulsation frequencies for expected period
spacings and rotational splittings. We find period-spacing sequences of
spherical-harmonic degrees \ell=1 and \ell=2, and we associate a large fraction
of the g-modes in KIC11558725 with these sequences. From frequency splittings
we conclude that the subdwarf is rotating subsynchronously with respect to the
orbit
Micro-scale Modelling of the Urban Wind Speed for Air Pollution Applications
Modelling wind speeds in urban areas have many applications e.g. in relation to assessment of wind energy, modelling air pollution, and building design and engineering. Models for extrapolating the urban wind speed exist, but little attention has been paid to the
influence of the upwind terrain and the foundations for the extrapolation schemes. To analyse the influence of the upwind terrain and the foundations for the extrapolation of the urban wind speed, measurements from six urban and non-urban stations were explored, and a model for the urban wind speed with and without upwind influence was developed and validated. The agreement
between the wind directions at the stations is found to be good, and the influence of atmospheric stability, horizontal temperature gradients, land-sea breeze, temperature, global radiation and Monin-Obukhov Length is found to be small, although future work should explore if this is valid for other urban areas. Moreover, the model is found to perform reasonably well, but the upwind
influence is overestimated. Areas of model improvement are thus identified. The upwind terrain thus influences the modelling of the urban wind speed to a large extent, and the fundamental assumptions for the extrapolation scheme are fulfilled for this specific case
Developing the Improving Post-event Analysis and Communication Together (IMPACT) Tool to Involve Patients and Families in Post-Event Analysis
The analysis of harmful errors is typically led by a team within the hospital and includes clinicians and staff who were involved at the time of the event. However, the patient and family are often left out of this process and are not asked to participate in the investigation. Because little guidance is available for facilitating patient input, an interprofessional team convened to develop a semi-structured tool to be used in eliciting patient feedback. Some 72 persons who had experienced adverse events were interviewed. Using a thematic analysis approach, the team learned that 51% of the interviewees preferred to participate in event analysis directly through an interview and 47% recommended that patients and families should be offered the opportunity to provide their views immediately (within 24-48 hours of the event). The resulting tool, IMPACT, incorporates a conversational flow of questions that allows patients to tell their story, focus their attention on specific causative factors, and give recommendations to improve healthcare in their institutions or to prevent further harm
Phosphorus Recovery from a Water Reservoir–Potential of Nanofiltration Coupled to Electrodialytic Process
Analysis of the impact of inhomogeneous emissions in the Operational Street Pollution Model (OSPM)
Semi-parameterized street canyon models, as e.g. the Operational Street
Pollution Model (OSPM<sup>®</sup>), have been
frequently applied for the last two decades to analyse levels and
consequences of air pollution in streets. These models are popular due to
their speed and low input requirements. One often-used simplification is the
assumption that emissions are homogeneously distributed in the entire length
and width of the street canyon. It is thus the aim of the present study to
analyse the impact of this assumption by implementing an inhomogeneous
emission geometry scheme in OSPM. The homogeneous and the inhomogeneous
emission geometry schemes are validated against two real-world cases:
Hornsgatan, Stockholm, a sloping street canyon; and Jagtvej, Copenhagen;
where the morning rush hour has more traffic on one lane compared to the
other. The two cases are supplemented with a theoretical calculation of the
impact of street aspect (height / width) ratio and emission inhomogeneity
on the concentrations resulting from inhomogeneous emissions. The results
show an improved performance for the inhomogeneous emission geometry over the
homogeneous emission geometry. Moreover, it is shown that the impact of
inhomogeneous emissions is largest for near-parallel wind directions and for
high aspect ratio canyons. The results from the real-world cases are however
confounded by challenges estimating the emissions accurately
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