Search results for "Plateau"

Motion, relaxation dynamics, and diffusion processes in two-dimensional colloidal crystals confined between walls

2012

The dynamical behavior of single-component two-dimensional colloidal crystals confined in a slit geometry is studied by Langevin dynamics simulation of a simple model. The colloids are modeled as pointlike particles, interacting with the repulsive part of the Lennard-Jones potential, and the fluid molecules in the colloidal suspension are not explicitly considered. Considering a crystalline strip of triangular lattice structure with n=30 rows, the (one-dimensional) walls confining the strip are chosen as two rigidly fixed crystalline rows at each side, commensurate with the lattice structure and, thus, stabilizing long-range order. The case when the spacing between the walls is incommensura…

Features and ecological significance of benchmark soils of the Moldavian plateau, Romania

2016

Features and ecological significance of benchmark soils of the Moldavian plateau, Romania

A TWO-COMPONENT MANTLE EXTENDING FROM MT ETNA TO HYBLEAN PLATEAU (EASTERN SICILY) AS INFERRED BY AN INTEGRATED APPROACH WITH NOBLE GASES, TRACE ELEME…

2012

A new species of Anthemis sect. Hiorthia (Asteraceae) from SE Sicily

2013

A new species of Anthemis sect. Hiorthia (Asteraceae) is described from Sicily. This taxon, named A. piagnattiorum, is confined to a restricted area of the Hyblaean territory (SE Sicily), in the Natural Reserve of Cava Grande (Cassibile, Siracuse), where it takes shelter on carbonate rocky habitat and participates, with other Sicilian endemic taxa, to the composition of a termophilous chasmophytic community (Putorio calabricae–Micromerietum microphyllae).

Stone lines and heaps on south-western Niger plateaus as remains of ancient agricultural land

2011

Les plateaux de la rive occidentale du fleuve Niger sont recouverts de lignes et de tas de pierres sèches alors que ces surfaces tabulaires sont aujourd'hui dépourvues de toutes cultures. Le sol du plateau est constitué d'un horizon argilo-sableux visible uniquement dans la zone où ces structures sont présentes. Elles témoigneraient d'un épierrage pour faciliter le travail agricole du sol. Les matériaux extraits ont été disposés en ligne puis en tas si la quantité de blocs était trop élevée. Ce parcellaire pourrait être contemporain de l'activité métallurgique située au pied des plateaux et datée de la deuxième moitié du premier millénaire.

Neoendemic ground beetles and private tree haplotypes: two independent proxies attest a moderate last glacial maximum summer temperature depression o…

2011

Abstract Previous findings regarding the Last Glacial Maximum LGM summer temperature depression (maxΔT in July) on the Tibetan Plateau varied over a large range (between 0 and 9 °C). Geologic proxies usually provided higher values than palynological data. Because of this wide temperature range, it was hitherto impossible to reconstruct the glacial environment of the Tibetan Plateau. Here, we present for the first time data indicating that local neoendemics of modern species groups are promising proxies for assessing the LGM temperature depression in Tibet. We used biogeographical and phylogenetic data from small, wingless edaphous ground beetles of the genus Trechus , and from private junip…

Structural heteropolysaccharides as air-tight sealants of the human pleura

2018

Pulmonary "air leaks," typically the result of pleural injury caused by lung surgery or chest trauma, result in the accumulation of air in the pleural space (pneumothorax). Air leaks are a major source of morbidity and prolonged hospitalization after pulmonary surgery. Previous work has demonstrated structural heteropolysaccharide (pectin) binding to the mouse pleural glycocalyx. The similar lectin-binding characteristics and ultrastructural features of the human and mouse pleural glycocalyx suggested the potential application of these polymers in humans. To investigate the utility of pectin-based polymers, we developed a simulacrum using freshly obtained human pleura. Pressure-decay leak t…

Entre Voge et le Plateau de Langres, le Nord de la Haute-Saône

1994

National audience; Cet ensemble géographique qui correspond à la Voge et à la partie occidentale de la dépression périvosgienne, à l'amont du confluent de la Saône avec la Lanterne, est une zone de transition entre les plateaux de Haute-Saône et les modestes reliefs de Lorraine du sud autrefois baptisés "Monts Faucilles". Cette transition s'exprime dans la structure géologique, la topographie, les paysages végétaux, l'habitat et les activités économiques.

A two-component mantle source feeding Mt. Etna magmatism; insights from the geochemistry of primitive magmas.

2014

The major elements, trace elements and Sr and Nd isotopes of selected Etnean primitive rocks (b15 ky BP) were studied in order to characterize their mantle source. The noble-gas geochemistry of fluid inclusions in minerals fromthe same lavaswas also investigated. Themajor element compositions ofwhole rocks and minerals showed that these products are among the most primitive atMt. Etna, comprising 6.3–17.5 wt.% MgO. The variable LREE (Light Rare Earth Elements) enrichment relative to MORB (Mid-Ocean Ridge Basalt) (Lan/Ybn = 11–26), togetherwith the patterns of certain trace-element ratios (i.e., Ce/Yb versus Zr/Nb and Th/Y versus La/Yb), can be attributed to varying degrees of melting of a c…

Optical measurements of an acylated azacrown at the air-water interface

1991

In this study, a cyclame derivative bearing four aliphatic chain substituents shows, like many amphiphiles, solid-condensed as well as liquid-expanded phases. In contrast to the classical amphiphiles, the onset of its phase transition is characterized by a bump-like shape whose amplitude is a function of the compression speed. Ellipsometry which is very sensitive to the monolayer physical state changes, and fluorescence microscopy which has contributed significantly to the understanding of the phenomena occurring in the phase transition region have been used to investigate the monolayer behavior of this compound. This study shows that in the liquid-expanded state, the film is homogeneous an…