Articles publicats (Química, Física i Ciències Ambientals i del Sòl)

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    El «trigo de los santos» de Guara: trigo robado en el santuario de san Cosme y san Damián petrificado milagrosamente.
    (Sociedad de Amigos del Museo de Ciencias Naturales de la Universidad de Zaragoza, 2021-12-01) Astudillo, Heracli
    Es mostren, s'analitzen i es contextualitzen una serie de 11 relats populars de tipus llegendari, creats per a explicar l'origen i justificar la presència sobrenatural d'unes pedretes minúscules amb forma de gra de blat 'el trigo de los santos' en diversos camins que conduien fins al santuari dels sants Cosme i Damià, a la serra de Guara (Osca). Relats apareguts en diversos documents publicats des del 1750 fins el 2013.
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    Open Access
    Friction-velocity estimates using the trace of a scalar and the mean wind speed
    (Springer, 2020-04-20) Castellví Sentís, Francesc; Suvocarev, Kosana; Reba, Michele; Runkle, Benjamin Reade Kreps
    A semi-empirical approach based on surface-renewal theory for estimating the friction velocity is tested for measurements taken in the inertial sublayer. For unstable cases, the input requirements are the mean wind speed and the high-frequency trace (10 or 20 Hz) of the air or sonic temperature. The method has been extended to traces of water vapour (H2O) and carbon dioxide (CO2) concentrations. For stable cases, the stability parameter must also be considered. The method's performance, taking the direct friction velocity measured by sonic anemometry as a reference, was tested over a growing cotton field that included bare soil with some crop residues at the beginning of the season. In general, the proposed friction-velocity estimates are reliable. For unstable cases, the method shows the potential to outperform the wind log-law computation. Discarding cases with low wind speeds (e.g., < 0.3 m s-1 and mean wind shear < 1 Hz), the proposed approach may be recommended as an alternative method to estimate the friction velocity. There is the potential, based on the input requirements, that the proposed formulation may offer significant advantages in the estimation of the friction velocity in some marine environments.
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    Open Access
    Surface renewal measurements of H, λE and CO2 fluxes over two different agricultural systems
    (Elsevier, 2019-10-16) Suvocarev, Kosana; Castellví Sentís, Francesc; Reba, Michele; Runkle, Benjamin Reade Kreps
    The importance of understanding turbulent scalar exchange over agricultural landscapes motivated this study of the surface renewal (SR) method for deployment in place of or alongside eddy covariance (EC) instrumentation. High-frequency (20 Hz) scalar data were used with turbulence and similarity parameters for SR measurements of turbulent sensible heat (H), latent heat (λE), and CO2 (Fc) flux. The eddy covariance method was used to provide a reference data set to compare the performance of SR to EC flux measurements when the SR input requirements were determined with either: (1) fast-response (SR1) or (2) slow-response (SR2) wind velocities. We test SR1 and SR2 over two agricultural crops, cotton and rice, that are suitable for adaptive ('climate-smart') management solutions which rely on decisions informed by extensive micrometeorological measurements. One advantage that the SR method provides is its simplicity of deployment and maintenance, requiring less energy and resources than typical EC networks. Regardless of the crop and scalar eddy flux, both SR flux methods agreed well with the EC flux measurements; coefficients of determination (R2) and slopes (s) of linear regression analysis ranges were [0.88, 0.98] and [1.01, 1.22], respectively. It was concluded that when EC measurements are unavailable, SR may be used as an alternative for additional climate-smart agriculture research efforts and this method may allow for higher spatial monitoring resolution because of the possibility to avoid the use of sonic anemometry.
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    Open Access
    Cambios en la presencia de especies de oribátidos (Acarina, Oribatida) asociados a la fertilización con purín porcino en clima Mediterráneo seco
    (Asociación Interprofesional para el Desarrollo Agrario, 2024-03-13) Cugno, Haydée; Bosch-Serra, Àngela D. ; Orobitg, Jordi ; Yagüe Carrasco, María Rosa; Domingo-Olivé, Francesc
    In rainfed agricultural systems, the sustainability of fertilization practices with products of organic origin needs indicators that guarantee their suitability. Oribatid mites, because of their growth characteristics and their function as organic matter transformers, are potential biological indicators. A study on the presence of oribatid mite species in a fertilization experiment (a treatment with pig slurry at a dose of 161 kg N·ha-1 and a control) was carried out. Under a dry Mediterranean climate, the experiment was established twelve years ago. It included a rotation of wheat-barley under rainfed conditions. During the barley's cropping season (October, March and June), three soil samples were taken for the identi- fication of the number of individuals for the different oribatid species present. Four species were found, but there were no significant differences in diversity or dominance between treatments. However, a significantly higher abundance of oribatids was found in plots with slurry application, linked to a signi- ficant increment of Oribatula (Zygoribatula) excavata. The higher presence of this species, with no de- triment to the rest, can be considered a positive indicator regarding the sustainability of this fertilization practice. In other words, it endorses the absence of negative impacts on soil health when the applied slurry rate was below the limit for N of organic origin established in N vulnerable zones.
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    Open Access
    Coherent states for generalized uncertainty relations as Tsallis probability amplitudes: New route to nonextensive thermostatistics
    (American Physical Society, 2023) Jizba, P.; Lambiase, G.; Luciano, Giuseppe Gaetano; Petruzziello, L.
    We study coherent states associated with a generalized uncertainty principle (GUP). We separately analyze the cases of positive and negative deformation parameter 𝛽, showing that the ensuing probability distribution is a Tsallis distribution whose nonextensivity parameter 𝑞 is monotonically related to 𝛽. Moreover, for 𝛽<0 (corresponding to 𝑞<1), we reformulate the GUP in terms of a one-parameter class of Tsallis entropy-power-based uncertainty relations, which are again saturated by the GUP coherent states. We argue that this combination of coherent states with Tsallis entropy offers a natural conceptual framework allowing one to study the quasiclassical regime of GUP in terms of nonextensive thermodynamics. We substantiate our claim by discussing the generalization of Verlinde’s entropic force and ensuing implications in the late-inflation epoch. The corresponding dependence of the 𝛽 parameter on cosmological time is derived for the reheating epoch. The obtained 𝛽 is consistent with values predicted by both string-theory models and the naturalness principle. Further salient issues, including the derivation of new 𝛽-dependent expressions for the lowest possible value of the spin and Immirzi parameter in loop quantum gravity and the connection of our proposal with the Magueijo-Smolin doubly special relativity are also discussed. This article provides a more extended and comprehensive treatment of our recent article [Phys. Rev. D 105, L121501 (2022)].