2,242 research outputs found
Magnetostratigraphy of the Miocene continental deposits of the Montes de Castejón (central Ebro basin, Spain): geochronological and paleoenvironmental implications
A detailed magnetostratigraphic study has been carried out in the early to middle Miocene distal alluvial and lacustrine sediments of the Montes de Castejón (central Ebro Basin). The study was based on the analysis of 196 magnetostratigraphic sites sampled along a stratigraphic interval of about 240 meters. Local magnetostratigraphy yielded a sequence of 12 magnetozones (6 normal and 6 reverse) which could be correlated with the Geomagnetic Polarity Time Scale (GPTS) interval C5Cr to C5AD (between 17 and 14.3 Ma.). The sampled sedimentary sequences include the boundary between two tectosedimentary units (TSU, T5 and T6) already defined in the Ebro Basin. The magnetostratigraphy of the Montes de Castejón allows to date the T5/T6 TSU boundary at 16.14 Ma, within chron C5Cn.1n. This magnetostratigraphy also allows us to analyse in detail as well as to discuss the variations in sedimentation rates through space and time between different lacustrine environments: Outer carbonate lacustrine fringes and distal alluvial plains (Montes de Castejón sections) show higher sedimentation rates than offshore lacustrine areas (San Caprasio section, 50 km east of Montes de Castejón)
Transfinite order dimension
We give two different transfinite extensions of the covering dimension based on the Borst's order of certain families of boundaries of basic open sets. We compare them and we study their main properties
Dimension, inverse limits and GF-spaces
In this paper we characterize (covering) dimension in
metrizable spaces in terms of fractal structures. We will also
study dimension for compact metric spaces, giving a theorem relating dimension and a certain class of inverse limits, similar to
that of Freudenthal
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Special Economic Zones, Global Value Chains, and the Degree of Economic Linkages in the Dominican Republic
The Dominican Republic is often considered an example of the successful implementation of Special Economic Zones (henceforth SEZs) in the Western hemisphere. The zones fueled economic growth during the 1980s and 1990s and, while they experienced a sharp decline in employment due in part to the expiry of the end of the Multi-Fiber Agreement and stronger international competition in the textile and apparel industry in 2005, signs of recovery have been observed since 2009. Surgical equipment, chemicals and plastics, and footwear have recently emerged as the new drivers of export dynamism in the zones (World Bank, 2015). The objective of this report is to inform the policy discussion around the developmental impact of SEZs in the Dominican Republic by empirically assessing i) the implications of regulatory reforms aimed at complying with WTO disciplines regarding the elimination of incentives conditioned on export performance for SEZs firms, ii) the extent to which SEZs participate in Global Value Chains, and iii) their linkages with domestic suppliers. The report is organized as follows: The second section presents the historical importance of SEZ as an engine of economic growth in the country. The third section depicts the structural shift in terms of production in SEZs and evaluates the degree of value addition taking place in the Dominican Republic. The fourth section evaluates the degree and evolution of linkages between SEZs and local firms. The fifth section shows the impact of the regulatory changes in the SEZ regimen undertaken to comply with WTO disciplines. Finally, some conclusions and policy recommendations are presented in section six
Metastable anisotropy orientation of nematic quantum Hall fluids
We analyze the experimental observation of metastable anisotropy resistance
orientation at half filled quantum Hall fluids by means of a model of a quantum
nematic liquid in an explicit symmetry breaking potential. We interpret the
observed ``rotation'' of the anisotropy axis as a process of nucleation of
nematic domains and compute the nucleation rate within this model. By comparing
with experiment, we are able to predict the critical radius of nematic bubbles,
. Each domain contains about electrons.Comment: 10 pages, 8 figures, final version as will appear in PR
Are bullying behaviors tolerated in some cultures? Evidence for a curvilinear relationship between workplace bullying and job satisfaction among Italian workers
Since the early 1990s, increasing attention has been paid to the impact of workplace bullying on employees’ well-being and job attitudes. However, the relationship between workplace bullying and job satisfaction remains unclear. This study aims to shed light on the nature of the bullying-job satisfaction relationship in the Italian context (n = 1,393 employees from different organizations). As expected, the results revealed a U-shape curvilinear relationship between workplace bullying and job satisfaction after controlling for demographic variables. In contrast to the curvilinear model, the results support a negative linear relationship between workplace bullying and psychological well-being, in which higher exposure to negative acts at work is associated with diminished well-being. In addition, gender and job position significantly predicted mental health scores where men and managers reported a better psychological well-being than women, blue-collar, and white-collar employees. Practical and theoretical implications are discussed according to these results.info:eu-repo/semantics/acceptedVersio
Magnetite: Raman study of the high-pressure and low-temperature effects
We report the results of a low-temperature (300K-15K) high-pressure (up to
22GPa) Raman study of the Verwey transition in magnetite (Fe3O4). We use
additional Raman modes observed below the Verwey transition to determine how
the transition temperature changes with the quasihydrostatic pressure. Increase
of the pressure results in the linear decrease of the Verwey transition
temperature, with no discontinuity. The corresponding pressure coefficient
dTV/dP is found to be ~ -5.2 K/GPa. Such a decrease is substantially larger
than the one predicted by the mean-field Coulomb interaction model of the
transition
Temporal aspects of genetic stratigraphic units in continental sedimentary basins: Examples from the Ebro basin, Spain
The utility of genetic stratigraphy lies with the fundamental relationship between genetic stratigraphic units and correlative intervals of geologic time. While high-resolution studies may reveal varying degrees of diachroneity that are associated with their bounding surfaces, genetic stratigraphic units are generally viewed as chronostratigraphic in nature, representing specific periods of basin fill. Despite the vast literature on basin analysis, an evaluation of the temporal character of the boundaries between genetic stratigraphic units, particularly in cases where they are conformable, has not yet been undertaken. The Cenozoic Ebro basin is a foreland basin on the north-eastern Iberian Peninsula that provides a case for assessing the temporal character of the boundaries between genetic stratigraphic units. These units are termed “tecto-sedimentary units” following the method of tecto-sedimentary analysis that is used in some continental basins. In the Ebro basin tecto-sedimentary analysis is based on direct field observations. In this work, magnetostratigraphic data from four tecto-sedimentary units (units T4 to T7) that span rocks of lower and middle Miocene age (ca. 1000 m thick) in the central and western areas of the basin are analysed. The study area contains alluvial, fluvial and lacustrine deposits that were sourced from Pyrenean and Iberian areas, whose catchments were structured during the collision of Iberia and Eurasia. New magnetostratigraphic data from this study and previously published magnetostratigraphic data enable us to determine the ages of these tecto-sedimentary unit boundaries throughout a 200-km-long, east–west transect that extends from the basin centre to the southwestern margin. The results indicate that the diachrony of the three boundaries between the Miocene tecto-sedimentary units through the central Ebro basin is less than 0.3 Ma where they are conformable. This low degree of diachroneity may be attributed to the effects of allogenic, largely tectonic processes that operate in the catchment areas and methodological inaccuracies. These results provide empirical support to the idea that genetic stratigraphic units are bounded by surfaces that exhibit low amounts of diachroneity where they are conformities
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