101,895 research outputs found
ÆSOPUS 2.1: Low-temperature Opacities Extended to High Pressure
No full textWe address the critical need for accurate Rosseland mean gas opacities in high-pressure environments, spanning temperatures from 100 K to 32,000 K. Current opacity tables from Wichita State University and ÆSOPUS 2.0 are limited to log ( R ) ≤ 1 , where R = ρ T 6 − 3 in units of g cm − 3 ( 10 6 K ) − 3 . This is insufficient for modeling very low-mass stars, brown dwarfs, and planets with atmospheres exhibiting higher densities and pressures ( log ( R ) > 1 ). Leveraging extensive databases such as ExoMol, ExoMolOP, MoLLIST, and HITEMP, we focus on expanding the ÆSOPUS opacity calculations to cover a broad range of pressure and density conditions ( − 8 ≤ log ( R ) ≤ + 6 ). We incorporate the thermal Doppler mechanism and microturbulence velocity. Pressure-broadening effects on molecular transitions, leading to Lorentzian or Voigt profiles, are explored in the context of atmospheric profiles for exoplanets, brown dwarfs, and low-mass stars. We also delve into the impact of electron degeneracy and nonideal effects, such as ionization potential depression under high-density conditions, emphasizing its notable influence on Rosseland mean opacities at temperatures exceeding 10,000 K. As a result, this study expands the ÆSOPUS public web interface for customized gas chemical mixtures, promoting flexibility in opacity calculations based on specific research needs. Additionally, precomputed opacity tables, inclusive of condensates, are provided. We present a preliminary application to evolutionary models for very low-mass stars
Effetti della programmazione ospedaliera sulle migrazioni dei pazienti: esperienza senese
No full textConfronto tra prevalenza delle infezioni ospedaliere ed altri indicatori di processo per la Valutazione della qualità assistenziale
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Diagnostic turnaround times as a tool for assessing hospital performance: a pilot study in Italy and Germany
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Qualità in ospedale: requisiti qualitativi della cartella clinica come strumento di Valutazione dell’assistenza sanitaria
No full textStudio di prevalenza sulle infezioni tra i ricoverati nel Policlinico di Siena - Luglio 1990
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