scholarly journals Model of the tokamak edge density pedestal including diffusive neutrals

2003 ◽  
Vol 10 (6) ◽  
pp. 2616-2618 ◽  
Author(s):  
K. H. Burrell
Keyword(s):  
Edge Density ◽  
Tokamak Edge

Thermal transport catastrophe and the tokamak edge density limit

2006 ◽  
Vol 13 (6) ◽  
pp. 062503 ◽  
Author(s):  
D. A. D’Ippolito ◽  
J. R. Myra
Keyword(s):  
Thermal Transport ◽  
Edge Density ◽  
Density Limit ◽  
Tokamak Edge

scholarly journals A new technique for tokamak edge density measurement based on microwave interferometer

2022 ◽  
Vol 93 (1) ◽  
pp. 013502
Author(s):  
Mariia Usoltceva ◽  
Stéphane Heuraux ◽  
Ildar Khabibullin ◽  
Helmut Faugel
Keyword(s):  
Density Measurement ◽  
New Technique ◽  
Edge Density ◽  
Tokamak Edge ◽  
A New Technique

Issues of TOKAMAK Edge Plasma Transport and Plasma-material Interactions

2015 ◽  
Vol 6 (1-2) ◽  
pp. 86-91
Author(s):  
S. I. Krasheninnikov ◽  
J. Guterl ◽  
W. Lee ◽  
R. D. Smirnov ◽  
E. D. Marenkov ◽  
...  
Keyword(s):  
Edge Plasma ◽  
Plasma Transport ◽  
Tokamak Edge ◽  
Plasma Material Interactions

Dynamics and generation mechanisms of mesoscale structures in tokamak edge plasmas

2008 ◽  
Vol 15 (5) ◽  
pp. 055909 ◽  
Author(s):  
S. I. Krasheninnikov ◽  
A. I. Smolyakov
Keyword(s):  
Mesoscale Structures ◽  
Tokamak Edge ◽  
Edge Plasmas ◽  
Generation Mechanisms

scholarly journals Landscape structure affects the sunflower visiting frequency of insect pollinators

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Károly Lajos ◽  
Ferenc Samu ◽  
Áron Domonkos Bihaly ◽  
Dávid Fülöp ◽  
Miklós Sárospataki
Keyword(s):  
Landscape Structure ◽  
Honey Bees ◽  
Agricultural Landscape ◽  
Edge Density ◽  
Wild Bees ◽  
Natural Habitats ◽  
Mass Flowering ◽  
Positive Effects ◽  
Pollinator Community ◽  
Foraging Ranges

AbstractMass-flowering crop monocultures, like sunflower, cannot harbour a permanent pollinator community. Their pollination is best secured if both managed honey bees and wild pollinators are present in the agricultural landscape. Semi-natural habitats are known to be the main foraging and nesting areas of wild pollinators, thus benefiting their populations, whereas crops flowering simultaneously may competitively dilute pollinator densities. In our study we asked how landscape structure affects major pollinator groups’ visiting frequency on 36 focal sunflower fields, hypothesising that herbaceous semi-natural (hSNH) and sunflower patches in the landscape neighbourhood will have a scale-dependent effect. We found that an increasing area and/or dispersion of hSNH areas enhanced the visitation of all pollinator groups. These positive effects were scale-dependent and corresponded well with the foraging ranges of the observed bee pollinators. In contrast, an increasing edge density of neighbouring sunflower fields resulted in considerably lower visiting frequencies of wild bees. Our results clearly indicate that the pollination of sunflower is dependent on the composition and configuration of the agricultural landscape. We conclude that an optimization of the pollination can be achieved if sufficient amount of hSNH areas with good dispersion are provided and mass flowering crops do not over-dominate the agricultural landscape.

scholarly journals Spatial-Temporal Analysis of the Forest Fragments Surrounding a Conservation Unit in the Southern Region of Brazil

2020 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Bianca Fernandes ◽  
Ligia Batista
Keyword(s):  
Nearest Neighbor ◽  
Temporal Analysis ◽  
Management Plan ◽  
Edge Density ◽  
Forest Fragments ◽  
Conservation Unit ◽  
Border Effect ◽  
Action Strategies ◽  
Landsat Satellite ◽  
High Degree

In recent years, anthropogenic actions have intensified forest fragmentation, causing several damages to the landscape’s natural components, propagating the loss of biodiversity. This study aims to present an analysis of the forest fragments in a conservation unit located at southern of Brazil. The evaluation was carried out for the years 1998, 2008, and 2018, by using landscape metrics and classification of remote sensing imagery of the Landsat satellite. The following metrics were analyzed: area and edge, shape, core area, and aggregation. The results indicated an increase of 16.88% in the total area of vegetation, and the percentage of fragments increased from 16.16% to 18.89%. The number of fragments decreased, resulting in an increase of the mean area in 5.4 ha. The percentage of vegetation under border effect changed from 40.2% to 37.1%. In 1998, the average nearest neighbor distance was 155.4 m, and in 2018, 149.7 m. However, this distance is still classified as a high degree of isolation, which hinders the movement of organisms and the dispersion of species. Thus, all the analyzed metrics indicated a decrease in the fragmentation, except for the edge density metric, in which its increase of 1.86 pointed to a lower degree of conservation during the analyzed period. A study of this nature is important as it provides subsidies for future researches and can contribute to action strategies to be adopted in the management plan of the area.

Alfvén wave forces, affecting the tokamak edge plasma in the presence of impurities or dust

1997 ◽  
Vol 4 (9) ◽  
pp. 3436-3438 ◽  
Author(s):  
V. S. Tsypin ◽  
S. V. Vladimirov ◽  
A. G. Elfimov ◽  
M. Tendler ◽  
A. S. de Assis ◽  
...  
Keyword(s):  
Edge Plasma ◽  
Alfven Wave ◽  
Wave Forces ◽  
Tokamak Edge

Effects of geographic information system vector–raster–vector data conversion on landscape indices

1996 ◽  
Vol 26 (8) ◽  
pp. 1416-1425 ◽  
Author(s):  
Pete Bettinger ◽  
Gay A. Bradshaw ◽  
George W. Weaver
Keyword(s):  
Information System ◽  
Fractal Dimension ◽  
Geographic Information System ◽  
Cell Size ◽  
Grid Cell ◽  
Conversion Process ◽  
Data Conversion ◽  
Edge Density ◽  
Gis Data ◽  
Landscape Level

The effects of geographic information system (GIS) data conversion on several polygon-and landscape-level indices were evaluated by using a GIS vegetation coverage from eastern Oregon, U.S.A. A vector–raster–vector conversion process was used to examine changes in GIS data. This process is widely used for data input (digital scanning of vector maps) and somewhat less widely used for data conversion (output of GIS data to specific formats). Most measures were sensitive to the grid cell size used in the conversion process. At the polygon level, using the conversion process with grid cell sizes of 3.05, 6.10, and 10 m produced relatively small changes to the original polygons in terms of ln(polygon area), ln(polygon perimeter), and 1/(fractal dimension). When grid cell size increased to 20 and 30 m, however, polygons were significantly different (p < 0.05) according to these polygon-level indices. At the landscape level, the number of polygons, polygon size coefficient of variation (CV), and edge density increased, while mean polygon size and an interspersion and juxtaposition index (IJI) decreased. The youngest and oldest age-class polygons followed the trends of overall landscape only in terms of number of polygons, mean polygon size, CV, and IJI. One major side effect of the conversion process was that many small polygons were produced in and around narrow areas of the original polygons. An alleviation process (referred to as the dissolving process) was used to dissolve the boundaries between similarly attributed polygons. When we used the dissolving process, the rate of change for landscape-level indices slowed; although the number of polygons and CV still increased with larger grid cell sizes, the increase was less than when the dissolving process was not used. Mean polygon size, edge density, and fractal dimension decreased after use of the dissolving process. Trends for the youngest and oldest age-class polygons were similar to those for the total landscape, except that IJI was greater for these age-classes than for the total landscape.

Modeling of velocity distributions of dust in tokamak edge plasmas and dust–wall collisions

2009 ◽  
Vol 390-391 ◽  
pp. 84-87 ◽  
Author(s):  
R.D. Smirnov ◽  
S.I. Krasheninnikov ◽  
A.Yu. Pigarov ◽  
D.J. Benson ◽  
M. Rosenberg ◽  
...  
Keyword(s):  
Tokamak Edge ◽  
Edge Plasmas
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