We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate ...the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a Fe/H-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.
► The control problem of a solar power plant with DCS (ACUREX) is discussed. ► A new practical NMPC to regulate the temperature of solar power plants is presented. ► Stability and robustness are ...guaranteed by a Lyapunov function approach. ► The proposed NMPC algorithm has a low computational cost. ► Case studies show the system performance with different model uncertainties.
This paper presents the application of a Nonlinear Model Predictive Controller (NMPC) to a distributed solar collector field. The control technique is basically similar to Dynamic Matrix Control (DMC) but in the proposed approach a nonlinear model of the process is directly used without linearization of the process model involved in the control strategy. Moreover, a modified Practical Nonlinear Model Predictive Controller (PNMPC) algorithm adapted to solar plant is developed in this work. To include robustness of stability against uncertainties in the NMPC algorithm, a candidate Lyapunov function is included in the cost function. The main purpose of the controller is to manipulate the oil flow rate to maintain the field outlet temperature in the desired reference value and attenuate the disturbances effects. The simulated process used is a distributed parameter model, while for the prediction a lumped parameter model with time delay was considered.
ABSTRACT Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an ...orbiting planet. However, as abundance measurement techniques have progressed, there has been little standardization between individual methods and their comparisons. As a result, different stellar abundance procedures determine measurements that vary beyond the quoted error for the same elements within the same stars. The purpose of this paper is to better understand the systematic variations between methods and offer recommendations for producing more accurate results in the future. We invited a number of participants from around the world (Australia, Portugal, Sweden, Switzerland, and the United States) to calculate 10 element abundances (C, O, Na, Mg, Al, Si, Fe, Ni, Ba, and Eu) using the same stellar spectra for four stars (HD 361, HD 10700, HD 121504, and HD 202206). Each group produced measurements for each star using (1) their own autonomous techniques, (2) standardized stellar parameters, (3) a standardized line list, and (4) both standardized parameters and a line list. We present the resulting stellar parameters, absolute abundances, and a metric of data similarity that quantifies the homogeneity of the data. We conclude that standardization of some kind, particularly stellar parameters, improves the consistency between methods. However, because results did not converge as more free parameters were standardized, it is clear there are inherent issues within the techniques that need to be reconciled. Therefore, we encourage more conversation and transparency within the community such that stellar abundance determinations can be reproducible as well as accurate and precise.
Objective
To assess whether weekend admissions to hospital and/or already being an inpatient on weekend days were associated with any additional mortality risk.
Design
Retrospective observational ...survivorship study. We analysed all admissions to the English National Health Service (NHS) during the financial year 2009/10, following up all patients for 30 days after admission and accounting for risk of death associated with diagnosis, co-morbidities, admission history, age, sex, ethnicity, deprivation, seasonality, day of admission and hospital trust, including day of death as a time dependent covariate. The principal analysis was based on time to in-hospital death.
Participants
National Health Service Hospitals in England.
Main Outcome Measures
30 day mortality (in or out of hospital).
Results
There were 14,217,640 admissions included in the principal analysis, with 187,337 in-hospital deaths reported within 30 days of admission. Admission on weekend days was associated with a considerable increase in risk of subsequent death compared with admission on weekdays, hazard ratio for Sunday versus Wednesday 1.16 (95% CI 1.14 to 1.18; P < .0001), and for Saturday versus Wednesday 1.11 (95% CI 1.09 to 1.13; P < .0001). Hospital stays on weekend days were associated with a lower risk of death than midweek days, hazard ratio for being in hospital on Sunday versus Wednesday 0.92 (95% CI 0.91 to 0.94; P < .0001), and for Saturday versus Wednesday 0.95 (95% CI 0.93 to 0.96; P < .0001). Similar findings were observed on a smaller US data set.
Conclusions
Admission at the weekend is associated with increased risk of subsequent death within 30 days of admission. The likelihood of death actually occurring is less on a weekend day than on a mid-week day.
A cosmic ray muon detection system is proposed for stability monitoring in the field of civil engineering, in particular for the static monitoring of historical buildings, where conservation ...constraints are severe and the time evolution of the deformation phenomena under study may be of the order of months or years. The stability monitoring of the wooden vaulted roof of the Palazzo della Loggia, located in the town of Brescia, Italy, has been considered as a case study. The feasibility, as well as the performance and limitations of a stability monitoring system based on cosmic ray tracking have been studied by Monte Carlo simulations. A study of possible systematic uncertainties is presented along with a realistic design for the construction of a measurement system prototype.
A characterization of radiophotoluminescence (RPL) dosimeters at high doses of X-ray radiation for applications in high-radiation areas is presented. Commercial FD-7 silver-doped phosphate glasses ...(<inline-formula> <tex-math notation="LaTeX">1.5\times 8.5 </tex-math></inline-formula> mm) in use at CERN for passive dosimetry are irradiated using commercial X-ray tubes. A 1.5-mm-thick aluminum filter is used to harden the X-ray spectrum and improve dose homogeneity. Two irradiation campaigns are presented, targeting doses ranging from about 1.3 kGy to 0.46 MGy and dose rates from about 0.6 to 6.3 kGy/h, respectively. Monte Carlo (MC) simulations performed with PHITS allowed the determination of a factor to convert the dose to water, into the average absorbed dose to RPL material. The found conversion factor is validated by the achieved measurements. The results evidence a satisfactory agreement between the absorbed doses delivered with X-rays and the readout results, based on Co-60 gamma calibration.
Silverside fish inhabit marine coastal waters, coastal lagoons, and estuarine regions in southern South America. Although silversides are not fully adapted to freshwater, they can tolerate a wide ...range of salinity variations. MicroRNAs (miRNAs) are a class of ∼22 nucleotide noncoding RNAs, which are crucial regulators of gene expression at post-transcriptional level. Current data indicate that miRNAs biogenesis is altered by situations of environmental stress, thereby altering the expression of target mRNAs. Foremost, the silversides were acutely exposed to 30 g.L
−1
of salt to reveal in which tissue miR-429 could be differentially expressed. Thus, fish were acclimated to freshwater (0 g.L
−1
) and to brackish water (10 g.L
−1
), and then exposed to opposite salinity treatment. Here, we reveal that miR-429, a gill-enriched miRNA, emerges as a prime osmoregulator in silversides. Taken together, our findings suggest that miR-429 is an endogenous regulator of osmotic stress, which may be developed as a biomarker to assist silverside aquaculture.
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