Search results for "Fluctuations"

A 5500-year oxygen isotope record of high arctic environmental change from southern Spitsbergen

2017

The oxygen isotope composition of chironomid head capsules in a sediment core spanning the past 5500 years from Lake Svartvatnet in southern Spitsbergen was used to reconstruct the oxygen isotope composition of lake water (δ18Olw) and local precipitation. The δ18Olw values display shifts from the baseline variability consistent with the timing of recognized historical climatic episodes, such as the Roman Warm Period, the Dark Ages Cold Period and the ‘Little Ice Age’. The highest values of the record, ca. 3‰ above modern δ18Olw values, occur at ca. 1900–1800 cal. yr BP. Three negative excursions increasing in intensity toward the present, at 3400–3200, 1250–1100, and 350–50 cal. yr BP, are…

Dimensionality of the Superconductivity in the Transition Metal Pnictide WP

2020

We report theoretical and experimental results on the transition metal pnictide WP. The theoretical outcomes based on tight-binding calculations and density functional theory indicate that WP is a three-dimensional superconductor with an anisotropic electronic structure and nonsymmorphic symmetries. On the other hand, magnetoresistance experimental data and the analysis of superconducting fluctuations of the conductivity in external magnetic field indicate a weakly anisotropic three-dimensional superconducting phase.

Estudio de las fluctuaciones del nivel del agua en la laguna de Gallocanta (Aragón, España) mediante imágenes satelitales de Sentinel-2

2021

[EN] This study has been monitored for five years by Sentinel-2 satellite images, at different seasons of the year, of the fluctuations in the water level of the Gallocanta Lake (between the provinces of Teruel and Zaragoza, Spain) considered a hypersaline and endorheic wetland, which has characteristics that make it unique in the geographical area in which it is located, as well as for the operation of the system. Rainfall in the area has a wide variation giving the maximums in the moths of May and June and the minimums in January and February, with considerable fluctuations in the water level from the almost total drying of the lagoon to the filling with a depth of approximately 3 meters.

Understanding the fluctuations of perceived authenticity in cultural tourism : an investigation of Bali and Alsace contexts

2022

The marketing of cultural tourism faces a dilemma between maximizing the economic return and nurturing the culture’s social functions. It needs to attract segments driven by cultural motifs, through a differentiation based on authenticity. Perceived authenticity changes over a time, but how it does remains elusive to researchers. This research investigated fluctuations of existential authenticity in cultural tourists in Bali. Participants were purposively and conveniently-sampled among visitors of cultural attractions. It comprised two stages: qualitative for building the model, and quantitative fortesting the variables. The first employed Grounded Theory interviewing 24 visitors, found the…

Magnetically excited breather modes in an overlap-geometry Josephson tunnel junction

2022

A scheme for the controlled generation of single traveling sine- Gordon breathers in a long Josephson junction is described. In the presence of dissipation, a direct current source, and thermal fluctuations, the theoretical analysis shows that, through the nonlinear supratransmission effect, tailored magnetic pulses at the junction’s edge can effectively yield breather modes only.

Critical Phenomena and Diffusion in Complex Systems

2008

Regional climate model simulations for Europe at 6 and 0.2 k BP: sensitivity to changes in anthropogenic deforestation

2014

International audience; This study aims to evaluate the direct effects of anthropogenic deforestation on simulated climate at two contrasting periods in the Holocene, ∼ 6 and ∼ 0.2 k BP in Eu-rope. We apply the Rossby Centre regional climate model RCA3, a regional climate model with 50 km spatial resolution, for both time periods, considering three alternative descriptions of the past vegetation: (i) potential natural vegetation (V) simulated by the dynamic vegetation model LPJ-GUESS, (ii) potential vegetation with anthro-pogenic land use (deforestation) from the HYDE3.1 (History Database of the Global Environment) scenario (V + H3.1), and (iii) potential vegetation with anthropogenic land …

Debating Sound Money in Early Modern Europe: From Dualist to Metallic Monetary Systems

2019

International audience; In this paper, we present the monetary debates in Europe from the XVIth to the XVIIIth centuries from the viewpoint of the problem of good and sound money. The framework of the paper is built on a typology of monetary systems, by which a dualist system is distinguished from a metallic one. Under the dualist system, the value in units of account of the specie in circulation was defined by monetary proclamations (Einaudi locates this era from Charlemagne to the French Revolution). Metallist proponents aimed at preventing any kind of manipulations with a radical transformation of the system of payment, which gave birth to a metallic monetary system from the very end of …

Mediterranean Climate and Eutrophication of Reservoirs: Limnological Skills to Improve Management

2011

Sicily is the largest Mediterranean island and one of the most densely populated areas in the region. To counteract the periodic oscillation in water availability and fulfill drinking and agriculture needs, about 30 dam-reservoirs, impounding in total 750 106 m3, were built in the last 60 years. However, the inherent features of the Mediterranean climate and the total lack of awareness from local authorities have contributed to a progressive increase in the trophic state of these human-made lakes. In particular, the water is stored during the winter rainy season and then it is intensively used in the dry summer. These operational procedures, in particular the time separation between filling…

Kirkwood-Buff integrals from molecular simulation

2019

The Kirkwood-Buff (KB) theory provides a rigorous framework to predict thermodynamic properties of isotropic liquids from the microscopic structure. Several thermodynamic quantities relate to KB integrals, such as partial molar volumes. KB integrals are expressed as integrals of RDFs over volume but can also be obtained from density fluctuations in the grand-canonical ensemble. Various methods have been proposed to estimate KB integrals from molecular simulation. In this work, we review the available methods to compute KB integrals from molecular simulations of finite systems, and particular attention is paid to finite-size effects. We also review various applications of KB integrals comput…