scholarly journals Spatial variations in the growth rate of Hylocomium splendens and the thickness of the organic layer on a north-facing slope in Interior Alaska

Polar Science ◽  
2021 ◽  
pp. 100654
Author(s):  
Jumpei Toriyama ◽  
Tomoaki Morishita ◽  
Yojiro Matsuura ◽  
Kyotaro Noguchi
Keyword(s):  
Growth Rate ◽  
Spatial Variations ◽  
Organic Layer ◽  
Hylocomium Splendens ◽  
Interior Alaska

Layer Cross-Fading at Organic/Organic Interfaces in OVPD-Processed Red Phosphorescent Organic Light Emitting Diodes as a New Concept to Increase Current and Luminous Efficacy

2009 ◽  
Vol 1154 ◽  
Author(s):  
Florian Lindla ◽  
Manuel Boesing ◽  
Christoph Zimmermann ◽  
Frank Jessen ◽  
Philipp van Gemmern ◽  
...  
Keyword(s):  
Growth Rate ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Organic Layer ◽  
Driving Voltage ◽  
Emission Layer ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Organic Light

AbstractThe current and luminous efficacy of a red phosphorescent organic light emitting diode (OLED) with sharp interfaces between each of the organic layers can be increased from 18.8 cd/A and 14.1 lm/W (at 1,000 cd/m2) to 36.5 cd/A (+94%, 18% EQE) and 33.7 lm/W (+139%) by the introduction of a layer cross-fading zone at the hole transport layer (HTL) to emission layer (EL) interface. Layer cross-fading describes a procedure of linearly decreasing the fraction in growth rate of an organic layer during deposition over a certain thickness while simultaneously increasing the fraction in growth rate of the following layer. For OLED processing and layer cross-fading organic vapor phase deposition (OVPD) is used. The typical observation of a roll-off in current efficacy of phosphorescent OLED to higher luminance can be reduced significantly. An interpenetrating network of a prevailing hole and a prevailing electron conducting material is created in the cross-fading zone. This broadens the recombination zone and furthermore lowers the driving voltage. The concept of layer cross-fading to increase the efficacies is suggested to be useful in multi-colored OLED stacks as well.

scholarly journals Modeling the impediment of methane ebullition bubbles by seasonal lake ice

2014 ◽  
Vol 11 (23) ◽  
pp. 6791-6811 ◽  
Author(s):  
S. Greene ◽  
K. M. Walter Anthony ◽  
D. Archer ◽  
A. Sepulveda-Jauregui ◽  
K. Martinez-Cruz
Keyword(s):  
Growth Rate ◽  
Lake Water ◽  
Ice Cover ◽  
Controlling Factors ◽  
Ch4 Emission ◽  
Lake Ice ◽  
Ch4 Emissions ◽  
Interior Alaska ◽  
Methane Ebullition ◽  
Significant Flux

Abstract. Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominates annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.

scholarly journals Modeling the impediment of methane ebullition bubbles by seasonal lake ice

2014 ◽  
Vol 11 (7) ◽  
pp. 10863-10916 ◽  
Author(s):  
S. Greene ◽  
K. M. Walter Anthony ◽  
D. Archer ◽  
A. Sepulveda-Jauregui ◽  
K. Martinez-Cruz
Keyword(s):  
Growth Rate ◽  
Lake Water ◽  
Ice Cover ◽  
Controlling Factors ◽  
Ch4 Emission ◽  
Lake Ice ◽  
Ch4 Emissions ◽  
Interior Alaska ◽  
Methane Ebullition ◽  
Significant Flux

Abstract. Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominates annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.

Variation in postfire organic layer thickness in a black spruce forest complex in interior Alaska and its effects on soil temperature and moisture

2005 ◽  
Vol 35 (9) ◽  
pp. 2164-2177 ◽  
Author(s):  
Eric S Kasischke ◽  
Jill F Johnstone
Keyword(s):  
Soil Temperature ◽  
Fuel Consumption ◽  
Fire History ◽  
Black Spruce ◽  
Mineral Soil ◽  
Stand Age ◽  
Organic Layer ◽  
Layer Depth ◽  
Interior Alaska ◽  
Soil Temperature And Moisture

This study investigated the relationship between climate and landscape characteristics and surface fuel consumption as well as the effects of variations in postfire organic layer depth on soil temperature and moisture in a black spruce (Picea mariana (Mill.) BSP) forest complex in interior Alaska. Mineral soil moisture and temperature at the end of the growing season and organic layer depth were measured in three burns occurring in different years (1987, 1994, 1999) and in adjacent unburned stands. In unburned stands, average organic layer and humic layer depth increased with stand age. Mineral soil temperature and moisture varied as a function of the surface organic layer depth in unburned stands, indicating that as a stand matures, the moisture content of the deep duff layer is likely to increase as well. Fires reduced the depth of the surface organic layers by 5 to 24 cm. Within each burn we found that significant variations in levels of surface fuel consumption were related to several factors, including mineral soil texture, presence or absence of permafrost, and timing of the fires with respect to seasonal permafrost thaw. While seasonal weather patterns contribute to variations in fuel moisture and consumption during fires, interactions among the soil thermal regime, surface organic layer depth, and previous fire history are also important in controlling patterns of surface fuel consumption.

Spatial Variations in Growth Rate within Klebsiella pneumoniae Colonies and Biofilm

1996 ◽  
Vol 12 (3) ◽  
pp. 316-321 ◽  
Author(s):  
E.J. Wentland ◽  
P.S. Stewart ◽  
C.-T. Huang ◽  
G.A. McFeters
Keyword(s):  
Growth Rate ◽  
Klebsiella Pneumoniae ◽  
Spatial Variations

Spatial variations in immediate greenhouse gases and aerosol emissions and resulting radiative forcing from wildfires in interior Alaska

2015 ◽  
Vol 123 (3-4) ◽  
pp. 581-592
Author(s):  
Shengli Huang ◽  
Heping Liu ◽  
Devendra Dahal ◽  
Suming Jin ◽  
Shuang Li ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Radiative Forcing ◽  
Spatial Variations ◽  
Interior Alaska ◽  
Aerosol Emissions

scholarly journals Recovery of carbon pools a decade after wildfire in black spruce forests of interior Alaska: effects of soil texture and landscape position

2018 ◽  
Vol 48 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Gregory P. Houle ◽  
Evan S. Kane ◽  
Eric S. Kasischke ◽  
Carolyn M. Gibson ◽  
Merritt R. Turetsky
Keyword(s):  
Soil Texture ◽  
Black Spruce ◽  
Mineral Soil ◽  
Carbon Stocks ◽  
Parent Material ◽  
Influential Factor ◽  
Landscape Position ◽  
Organic Layer ◽  
Fire Dynamics ◽  
Interior Alaska

We measured organic-layer (OL) recovery and carbon stocks in dead woody debris a decade after wildfire in black spruce (Picea mariana (Mill.) B.S.P.) forests of interior Alaska. Previous study at these research plots has shown the strong role that landscape position plays in governing the proportion of OL consumed during fire and revegetation after fire. Here, we show that landscape position likely influences fire dynamics in these stands through changes in mineral soil texture. The content of fine-textured materials in underlying mineral soils was positively related to OL depths measured 1 and 10 years after fire, and there was an interaction between soil texture and elevation in governing OL consumption and OL recovery a decade following fire. OL depths 10 years after fire were 2 cm greater than 1 year after fire, with a range of 19 cm of accumulation to 9 cm of subsidence. Subsidence was inversely related to the percentage of fine textures within the parent material. The most influential factor determining the accumulation of OL carbon stocks a decade following wildfire was the interaction between landscape position and the presence of fine-textured soil. As such, parent material texture interacted with biological processes to govern the recovery of soil organic layers.

scholarly journals Modeling of spatial variations of growth within apical domes by means of the growth tensor. II. Growth specified on dome surface

2014 ◽  
Vol 53 (3) ◽  
pp. 301-316 ◽  
Author(s):  
Zygmunt Hejnowicz ◽  
Jerzy Nakielski ◽  
Krystyna Hejnowicz
Keyword(s):  
Growth Rate ◽  
Coordinate System ◽  
Growth Rates ◽  
Relative Rate ◽  
Spatial Variations ◽  
Curvilinear Coordinate System ◽  
Volumetric Growth ◽  
Shoot Apices ◽  
Curvilinear Coordinate ◽  
Area Growth

Variations of the elemental relative rate of growth are modeled for parabolic, elliptic and hyperbolic domes of shoot apices by using the growth tensor in a suitable curvilinear coordinate system when the mode of area growth on the dome surface is known. Variations of growth rates within the domes are obtained in forms of computer-made maps for the following variants of growth on the dome surface: (1) constant meridional growth rate, (2) isotropic area growth, (3) anisotropy of area growth which becomes more intensive with increasing distance from the vertex. In variants 1 and 2 a maximum of volumetric growth rate appears in the center of the dome. Such a distribution of growth seems to be unrealistic. However, the corresponding growth tensors are interesting because they can be used in combination with other growth tensors to get the expected minimum volumetric growth rate in the dome center.

scholarly journals Spatial variations of growth within domes having different patterns of principal growth directions

2014 ◽  
Vol 56 (4) ◽  
pp. 611-623 ◽  
Author(s):  
Jerzy Nakielski
Keyword(s):  
Growth Rate ◽  
Coordinate System ◽  
Growth Rates ◽  
Relative Rate ◽  
Spatial Variations ◽  
Coordinate Systems ◽  
Dome A ◽  
Rate Of Growth ◽  
Natural Coordinate System ◽  
Natural Coordinate

Growth rate variations for two paraboloidal domes: A and B, identical when seen from the outside but differing in the internal pattern of principal growth directions, were modeled by means of the growth tensor and a natural coordinate system. In dome A periclinal trajectories in the axial plane were given by confocal parabolas (as in a tunical dome), in dome B by parabolas converging to the vertex (as in a dome without a tunica). Accordingly, two natural coordinate systems, namely paraboloidal for A and convergent parabolic for B, were used. In both cases, the rate of growth in area on the surfaces of domes was assumed to be isotropic and identical in corresponding points. It appears that distributions of growth rates within domes A and B are similar in their peripheral and central parts and different only in their distal regions. In the latter, growth rates are relatively large; the maximum relative rate of growth in volume is around the geometric focus in dome A, and on the surface around the vertex in dome B.

The threshold energy for atom displacement in fcc metals

1990 ◽  
Vol 48 (4) ◽  
pp. 530-531
Author(s):  
Wilfried Sigle ◽  
Matthias Hohenstein ◽  
Alfred Seeger
Keyword(s):  
Growth Rate ◽  
Elevated Temperatures ◽  
Threshold Energy ◽  
Dislocation Loops ◽  
Absolute Minimum ◽  
Voltage Electron ◽  
Atom Displacement ◽  
Electron Microscopes ◽  
Fcc Metal

Prolonged electron irradiation of metals at elevated temperatures usually leads to the formation of large interstitial-type dislocation loops. The growth rate of the loops is proportional to the total cross-section for atom displacement,which is implicitly connected with the threshold energy for atom displacement, Ed . Thus, by measuring the growth rate as a function of the electron energy and the orientation of the specimen with respect to the electron beam, the anisotropy of Ed can be determined rather precisely. We have performed such experiments in situ in high-voltage electron microscopes on Ag and Au at 473K as a function of the orientation and on Au as a function of temperature at several fixed orientations.Whereas in Ag minima of Ed are found close to <100>,<110>, and <210> (13-18eV), (Fig.1) atom displacement in Au requires least energy along <100>(15-19eV) (Fig.2). Au is thus the first fcc metal in which the absolute minimum of the threshold energy has been established not to lie in or close to the <110> direction.

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