Search results for "E7"
showing 10 items of 152 documents
Reconstruction of Hamiltonians from given time evolutions
2010
In this paper we propose a systematic method to solve the inverse dynamical problem for a quantum system governed by the von Neumann equation: to find a class of Hamiltonians reproducing a prescribed time evolution of a pure or mixed state of the system. Our approach exploits the equivalence between an action of the group of evolution operators over the state space and an adjoint action of the unitary group over Hermitian matrices. The method is illustrated by two examples involving a pure and a mixed state.
Algebraic quantization on a group and nonabelian constraints
1989
A generalization of a previous group manifold quantization formalism is proposed. In the new version the differential structure is circumvented, so that discrete transformations in the group are allowed, and a nonabelian group replaces the ordinary (central)U(1) subgroup of the Heisenberg-Weyl-like quantum group. As an example of the former we obtain the wave functions associated with the system of two identical particles, and the latter modification is used to account for the Virasoro constraints in string theory.
ANALYSIS OF THE SEXUAL VARIABILITY IN THE SHELL OF THE SPANISH UPPER CRETACEOUS TURTLE DORTOKA VASCONICA (PAN-PLEURODIRA, DORTOKIDAE)
2021
The present study characterizes the morphological variability related to the sexual dimorphism in the shells of the Spanish Upper Cretaceous turtle Dortoka vasconica . This study is based on the material from its type locality: Lano, Burgos. Two morphotypes were identified there based on the posterior plastral area as well as two for the anterior plastral lobe. However, a correlation with the previously indicated morphotypes could not be established due to the disarticulation of the specimens and the limited information available on the sexual dimorphism of Pleurodira. The morphological variability previously identified for Dortoka vasconica is analysed here through a quantitative approa…
Rare Middle and Upper Devonian dalmanelloid (Orthida) of the Cantabrian Mountains, N Spain
2018
Rare Cantabrian Dalmanellidae ( Costisorthis lisae nov. sp.), Dicoelosiidae ( Teichertina cf. peregrina , T. cf. ?tzroyensis ), and Mystrophoridae ( Mystrophora sp., Biernatium suco i nov. sp., and Biernatium sp. 2) are described and ?gured for the ? rst time in Spain. Most of them are scarce forms that occur only in certain localities. All the species but one came from the lower part of the Portilla (province of Leon) and Candas (province of Asturias) formations, Faunal Interval 21, Polygnathus rhenanus/P. varcus conodont zone, middle Givetian. The exception is Biernatium sp. 2 that occurs in Asturias in FI 25, Pineres Fm., Palmatolepis transitans zone, lower Frasnian. Costisorthis ranges …
Promoting Food Waste Reduction at Primary Schools. A Case Study
2021
Food waste (FW) has recently attracted the interest of different institutions and has been the focus of many studies due to its important environmental, social and economic impact. This paper aims to analyze whether a didactic intervention, consisting of informing teachers and pupils and involving pupils in reducing FW, could bring about changes in the level of knowledge and attitude towards FW and in the amount of FW generated during the mid-morning break and lunch at schools. This study was conducted at a public Primary School in Valencia (Spain). Subtle changes in the level of knowledge and attitude towards FW were detected in teachers and pupils after the intervention. Around 30% of FW …
Geological context and micromammal fauna characterisation from the karstic infilling of La Pedrera (Albaida, Valencia, E Spain)
2020
La Pedrera is a new palaeontological site located south of the province of Valencia, between the Betic and Iberian Ranges, in a cavity filled with sediments inside a tufa formation. Roughly 260 fossil remains, corresponding to 14 taxa, have been recovered and studied from Unit III. Six rodents (Microtus sp., M. sp. gr. M. (Terricola) duodecimcostatus-lusitanicus, Microtus sp. gr. M. brecciensis-cabrerae, Arvicola sapidus, Eliomys quercinus, and Apodemus sp. gr. sylvaticusfl avicollis), one lagomorph (Oryctolagus cf. cuniculus), three insectivores (Soricinae indet., Crocidura sp., and Talpa cf. europaea) and four bats (Myotis blythii, Rhinolophus cf. ferrumequinum, Myotis bechsteinii, and Rh…
Fossil micromammals of the early Pliocene locality of Almenara MB: biostratigraphical and palaeoecological implications
2020
In this work, we have studied the fossil rodent, insectivore and chiropteran faunas, of a new locality from the AlmenaraCasablanca karstic complex, named ACB MB (Castellón, east Spain). We consider an early Ruscinian age for this site, close to the Miocene/Pliocene boundary, and infer warm and relatively humid conditions from the analysis of the micromammal assemblage. We remark the presence of two species of Eliomys in ACB MB, rare in localities of this age, and the lack of any gerbil remains, fossil markers of faunal interchanges between Africa and Europe in the context of the Messinian Salinity Crisis, recorded in the nearby late Miocene site of ACB M
Middle Eocene calcareous nannofossils in the Jaca transect (South-central Pyrenees Eocene Basin, Aragón river valley, Huesca)
2020
The calcareous nanoplankton is studied from the base of the turbidite systems of the Upper Hecho Group (Jaca Basin, middle Eocene of the South-central Pyrenean Basin) up to the Gracionepel instabilities, within the Larres slope Marls. This new chronostratigraphic contribution is of crucial importance for the improvement of the detailed temporal and spatial correlation framework of the genetically related depositional systems at basin scale. The calcareous nanofossil assemblage is largely dominated by Coccolithus pelagicus , C. formous as well as different species of Reticulofenestra , accompanied by occasional specimens of several species of Sphenolithus and Chiasmolithus . The results obt…
Recension of Collins, M.E., Manchester, S.R. & Wilde, W. 2012
2020
Collins, M.E., Manchester, S.R. & Wilde, W. 2012. Fossil fruits and seeds of the Middle Eocene Messel biota, Germany.Abhandlungen der Senckenberg Gessellschaft für Naturforschung, 570, 251 pp. ISBN 978-3-510-61400-4 This book presents a survey of the extensive fruit and seed collection found at the Middle Eocene Messel site. The first part of the book is dedicated to a few introductory chapters about the site, geologic setting, age control of the sedimentary sequence and taphonomy of the fossil remains. It is worth pointing out that unlike many lacustrine deposits in which fruits are preserved as impressions, most of the Messel plant macrofossils are preserved as remnants of the original pl…
Middle Triassic (Ladinian) deep-water sediments in Sicily: New findings from the Madonie Mountains
2012
A section of carbonate megabreccias grading upward to deep-water Daonella limestones is described from the locality of Sant’Otiero, near Petralia Sottana, in the Madonie Mountains (Sicily). The megabreccia mainly consists of neritic elements containing dasycladalean algae (Diplopora annulatissima Pia) along with benthic foraminifers and problematics. The overlying calcilutitic strata are characterized by lumachella intercalations containing the bivalve Daonella tyrolensis Mojsisovics suggesting an early Late Ladinian (Protrachyceras longobardicum ammonoid zone) age. We informally name the Daonella limestone as the calcare di Sant’Otiero (Sant’Otiero limestone). The Daonella limestones along…