Search results for "QE"
showing 10 items of 457 documents
Paleobiology and paleobiogeography of sclerorhynchid sawfishes (Chondrichthyes, Batomorphii)
2021
Sclerorhynchid sawfishes are a monophyletic group of Cretaceous selachians. They resemble modern sawfishes in the outer morphology and by having a hypertrophic rostral cartilage armed with lateral rows of spines. Generally, sclerorhynchid sawfishes were inhabitants of warm, shallow tropical and subtropical marine environments. Teeth of the oldest sclerorhynchid sawfishes from Spain are presented. They belong to Onchopristis Stromer and come from the lower Barrernian of eastern Spain. The paleobiology and paleogeographic pattern of sclerorhynchid sawfishes is reviewed and discussed.
Os carcharhiniformes (cCondrichthyes, Neoselachii) da Bacia de Alvalade (Portugal)
2021
The uppermost Miocene, Esbarrondadoiro Formation (Alvalade basin, Portugal) yielded more than 10 thousandSelachian teeth at Santa Margarida, Esbarrondadoiro and Vale de Zebro outcrops. Forty-five taxa were identifiedbelonging to the orders Hexanchiformes, Squaliformes, Lamniformes, Carcharhiniformes, Torpediniformes and Myliobatiformes. The Carcharhiniformes make up about 40% of the selachian fauna that has been identified in the studiedarea. The different distribution of the Carcharhiniformes (as well as that of the other orders) by the three sitespoints out to distinct environments in the corresponding areas: Esbarrondadoiro indicates relatively deeper, ratherstill waters; Santa Margarida…
Nitrous oxide emission budgets and land-use-driven hotspots for organic soils in Europe
2014
Organic soils are a main source of direct emissions of nitrous oxide (N2O), an important greenhouse gas (GHG). Observed N2O emissions from organic soils are highly variable in space and time, which causes high uncertainties in national emission inventories. Those uncertainties could be reduced when relating the upscaling process to a priori-identified key drivers by using available N2O observations from plot scale in empirical approaches. We used the empirical fuzzy modelling approach MODE to identify main drivers for N2O and utilize them to predict the spatial emission pattern of European organic soils. We conducted a meta-study with a total amount of 659 annual N2O measurements, which was…
On a new robust workflow for the statistical and spatial analysis of fracture data collected with scanlines (or the importance of stationarity)
2020
Abstract. We present an innovative workflow for the statistical analysis of fracture data collected along scanlines, composed of two major stages, each one with alternative options. A prerequisite in our analysis is the assessment of stationarity of the dataset, which is motivated by statistical and geological considerations. Calculating statistics on non-stationary data can be statistically meaningless, and moreover the normalization and/or sub-setting approach that we discuss here can greatly improve our understanding of geological deformation processes. Our methodology is based on performing non-parametric statistical tests, which allow detecting important features of the spatial distrib…
The extrabasinal elements in Lower Pennsylvanian floras of the Maritime Provinces, Canada: Description of Adiantites, Pseudadiantites and Rhacopterid…
2021
Adiantites adiantoide s (Lindley and Hutton) Kidston, Pseudadiantites sessilis (Roehl) Gothan and Pseudadiantites rhomboideus (Ettingshausen) comb. nov. are figured and described as well as Rhacopteridium speciosum (Ettingshausen) Hirmer, as part of a revision of lower Pennsylvanian floras of Nova Scotia. These species show a foliar branching structure which is described as "pseudopinnate" as against the fully planated pinnate structure of the Palaeozoic fern and pteridosperm fronds. Their systematic affinity is unknown. A discussion is presented of the genera A diantites, Pseudadiantites, Aneimites , Palaeopteridium , and Triphyllopteris , and the problematic nature of the history of Adian…
Status and perspectives of atomic physics research at GSI
2003
A short overview on the results of atomic physics research at the storage ring ESR is given followed by a presentation of the envisioned atomic physics program at the planned new GSI facility. The proposed new GSI facility will provide highest intensities of relativistic beams of both stable and unstable heavy nuclei - up to a Lorentz factor of 24. At those relativistic velocities, the energies of optical transitions, such as for lasers.. are boosted into the X-ray region and the high-charge state ions generate electric and magnetic fields of exceptional strength. Together with high beam intensities a range of important experiments can be anticipated, for example electronic transitions in r…
Two-loop QED corrections to the Altarelli-Parisi splitting functions
2016
We compute the two-loop QED corrections to the Altarelli-Parisi (AP) splitting functions by using a deconstructive algorithmic Abelianization of the well-known NLO QCD corrections. We present explicit results for the full set of splitting kernels in a basis that includes the leptonic distribution functions that, starting from this order in the QED coupling, couple to the partonic densities. Finally, we perform a phenomenological analysis of the impact of these corrections in the splitting functions.
New method for calculating electromagnetic effects in semileptonic beta-decays of mesons
2020
We construct several classes of hadronic matrix elements and relate them to the low-energy constants in Chiral Perturbation Theory that describe the electromagnetic effects in the semileptonic beta decay of the pion and the kaon. We propose to calculate them using lattice QCD, and argue that such a calculation will make an immediate impact to a number of interesting topics at the precision frontier, including the outstanding anomalies in $|V_{us}|$ and the top-row Cabibbo-Kobayashi-Maskawa matrix unitarity.
Valoración patrimonial de los yacimientos del Mioceno inferior del Barranco de Campisano de la Cuenca de Ribesalbes-Alcora (Araia d'Alcora, Castelló,…
2019
En el presente trabajo se realiza una valoración patrimonial del conjunto de yacimientos del Mioceno inferior del barranco de Campisano (cuenca de Ribesalbes-Alcora). Los resultados obtenidos al calcular los parámetros según la metodología del Inventario Español de Lugares de Interés Geológico (IELIG) ponen de manifi esto el alto valor científi co y didáctico de la zona, así como un valor turístico y recreativo medio. El riesgo de degradación es medio, por lo que debería ser tenido en cuenta para la protección de los yacimientos a corto plazo. En consonancia con estos datos, se propone la consideración de los yacimientos como LIG (Lugar de Interés Geológico) y su inclusión en el IELIG. In t…
Two-dimensional apparent microfabric of the basal Late Weichselian till and associated shear zone: case study from western Latvia
2008
The examination of glacial sediments in thin sections has become a common procedure in recent years. Apparent sand grain orientation (microfabric) in thin sections is one of the key elements marking certain microstructures. In an attempt to make till micromorphology studies less subjective and investigate the orientation of sand-sized particles in tills, we have developed an image analysis procedure to measure and analyse the spatial distribution of the till microfabric. We studied 13 thin sections of the Weichselian subglacial till and basal shear zone outcropping in the Baltic Sea bluffs at the Ziemupe site in western Latvia. The results were visualized as a two-dimensional grid of rose d…