Technical Note: Combining undisturbed soil monoliths for hydrological indoor experiments

An important decision in soil hydrological research is whether to conduct experiments outdoors or indoors. Both approaches have their advantages and trade-offs. Using undisturbed soil monoliths combines some of the advantages of outdoor and indoor experiments; however, there are often size limitations. Acquiring large monoliths necessitates heavy machinery, which is time-, cost-, and labor-intensive. Small- to medium-sized soil blocks, however, can be obtained using less demanding methods. A promising approach is the combination of smaller blocks to form a single large monolith, thereby optimizing cost and labor efficiency as well as representativity and upscaling potential. To this end, we compared the runoff properties of medium-sized (1×0.5×0.35 m) grassland soil monoliths cut in half and recombined with uncut blocks. We conducted artificial runoff experiments and analyzed the chemical composition and amount of outflow from four flow pathways (surface runoff, subsurface interflow, percolating water, lateral flow). Furthermore, we studied surface runoff velocity parameters using a salt tracer. Our results suggest that the effects of the recombination procedure are negligible compared to the variation in the data caused by the inherent soil heterogeneity. We propose that the benefits of combining soil monoliths outweigh the potential disadvantages.</p

Analytical sun synchronous low-thrust manoeuvres

Article describes analytical sun synchronous low-thrust manoeuvres

Origin and history of Phoxinus (Cyprinidae) introductions in the Douro basin (Iberian Peninsula): an update inferred from genetic data

The number of non-native freshwater fishes in the Iberian Peninsula has been greatly increasing. In this study, individuals of the genus Phoxinus were detected in 18 out of 138 stream sites sampled across the Douro Basin in 2017 and 2018. A total of 26 individuals were barcoded using partial cytochrome c oxidase subunit I (COI) and cytochrome b (cytb) genes for species identification and determination of geographical origin. Molecular data provided the first record of a second Phoxinus species in western Douro (Portugal, Iberian Peninsula), with haplotypes closely matching those found in the Charente River (southern France). This species is suspected to be a recent introduction associated with the use of minnows as live bait by freshwater anglers, which was facilitated by human movements between France and Portugal. Individuals from watercourses in eastern Douro (Spain) were genetically assigned to Phoxinus bigerri, an introduced species previously known for that region, which confirms reports of introduction events from Ebro to Douro Basin probably also related to freshwater angling and facilitated by geographic proximity. The potential ecological impacts of this genus in the region are unknown and need further investigation.We acknowledge Fernando Teixeira, Fernando Miranda, Mario Ferreira, Sara Carona, Jose Pedro RamiAo and Francisco Carvalho for the valuable assistance during fieldwork. We specially thank Maria Filomena MagalhAes for previous fruitful discussions and logistic support. We are grateful to Matthias F. Geiger and Andrea Corral Lou for facilitating genetic data and coordinates of sampling sites. Finally, we appreciate the comments of the three anonymous reviewers that improved the quality of the manuscript. AFF and AGR were supported by the project FRESHING founded by the Portuguese Foundation for Science and Technology (FCT) and COMPETE (PTDC/AAGMAA/2261/2014 - POCI-01-0145-FEDER-356016824). FMSM was supported by the FCT PhD grant SFRH/BD/104703/2014. This study was conducted as part of the projects FRESHING and FRESHCO. The latter is also supported by FCT and COMPETE (PTDC/AGR-FOR/1627/2014 - 04/SAICT/2015) and UID/AGR/04033/2019. Logistic support was also facilitated by the ENVMETAGEN - Capacity Building at InBIO for Research and Innovation Using Environmental Metagenomics project at CIBIO laboratories (668981; EUH2020-WIDESPREAD-2014-2)

Study of Inclusive J/psi Production in Two-Photon Collisions at LEP II with the DELPHI Detector

Inclusive J/psi production in photon-photon collisions has been observed at LEP II beam energies. A clear signal from the reaction gamma gamma -> J/psi+X is seen. The number of observed N(J/psi -> mu+mu-) events is 36 +/- 7 for an integrated luminosity of 617 pb^{-1}, yielding a cross-section of sigma(J/psi+X) = 45 +/- 9 (stat) +/- 17 (syst) pb. Based on a study of the event shapes of different types of gamma gamma processes in the PYTHIA program, we conclude that (74 +/- 22)% of the observed J/psi events are due to `resolved' photons, the dominant contribution of which is most probably due to the gluon content of the photon.Comment: 13 pages, 8 figures, Accepted by Phys. Lett.

Energy dependence of Cronin momentum in saturation model for p+Ap+A and A+AA+A collisions

We calculate $\sqrt{s}$ dependence of Cronin momentum for $p+A$ and $A+A$ collisions in saturation model. We show that this dependence is consistent with expectation from formula which was obtained using simple dimentional consideration. This can be used to test validity of saturation model (and distinguish among its variants) and measure $x$ dependence of saturation momentum from experimental data.Comment: LaTeX2e, 12 pages, 8 figure

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Inclusive b decays to wrong sign charmed mesons

The production of wrong sign charmed mesons b → D (s)X, D (s) = (D 0, D +, D s), is studied using the data collected by the DELPHI experiment in the years 1994 and 1995. Charmed mesons in Z → bb events are exclusively reconstructed by searching for the decays D 0 → K -π +, D + → K -π +π + and D s + φπ + → K +K -π +. The wrong sign contribution is extracted by using two discriminant variables: the charge of the b-quark at decay time, estimated from the charges of identified particles, and the momentum of the charmed meson in the rest frame of the b-hadron. The inclusive branching fractions of b-hadrons into wrong sign charm mesons are measured to be: B(b → D 0X) + B(b → D -X) = (9.3 ± 1.7(stat) ± 1.3(syst) ± 0.4(B))%, B(b → D s -X) = (10.1 ± 0.4(B))%, B(b → D s -X) = (10.1 ± 1.0(stat) ± 0.6(syst) ± 2.8(B))% where the first error is statistical, the second and third errors are systematic. © 2003 Published by Elsevier Science B.V.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe