Capacity degradation of Li4Ti5O12 during long-term cycling in terms of composition and structure

2020 ◽  
Vol 49 (29) ◽  
pp. 10003-10010 ◽  
Author(s):  
Xue Bai ◽  
Tao Li ◽  
Yu-Jun Bai
Keyword(s):  
Composition And Structure ◽  
Capacity Degradation ◽  
Structure Disordering

The performance decay of Li4Ti5O12 (LTO) associates with the ever-increasing residual Li+ and Ti3+ in the delithiated LTO, structure disordering, gradually reduced conductivities, and escalated polarization besides the electrolyte decomposition.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

scholarly journals Tailoring Charged Nanofiltration Membrane Based on Non-Aromatic Tris(3-aminopropyl)amine for Effective Water Softening

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 251
Author(s):  
Pengrui Jin ◽  
Michiel Robeyn ◽  
Junfeng Zheng ◽  
Shushan Yuan ◽  
Bart Van der Bruggen
Keyword(s):  
High Performance ◽  
Molecular Structures ◽  
Water Softening ◽  
Selective Layer ◽  
Long Term Stability ◽  
Composition And Structure ◽  
Amine Groups ◽  
High Rejection ◽  
Positively Charged

High-performance positively-charged nanofiltration (NF) membranes have a profound significance for water softening. In this work, a novel monomer, tris(3-aminopropyl)amine (TAEA), with one tertiary amine group and three primary amine groups, was blended with trace amounts of piperazine (PIP) in aqueous solution to fabricate a positively-charged NF membrane with tunable performance. As the molecular structures of TAEA and PIP are totally different, the chemical composition and structure of the polyamine selective layer could be tailored via varying the PIP content. The resulting optimal membrane exhibited an excellent water permeability of 10.2 LMH bar−1 and a high rejection of MgCl2 (92.4%), due to the incorporation of TAEA/PIP. In addition, this TAEA NF membrane has a superior long-term stability. Thus, this work provides a facile way to prepare a positively charged membrane with an efficient water softening ability.

scholarly journals Fire Exclusion Destroys Habitats for At-Risk Species in a British Columbia Protected Area

Fire ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 48
Author(s):  
Kira M. Hoffman ◽  
Sara B. Wickham ◽  
William S. McInnes ◽  
Brian M. Starzomski
Keyword(s):  
British Columbia ◽  
Fire History ◽  
Prescribed Burning ◽  
Douglas Fir ◽  
Conifer Encroachment ◽  
Oak Trees ◽  
Composition And Structure ◽  
Fire Exclusion ◽  
History Of

Fire exclusion and suppression has altered the composition and structure of Garry oak and associated ecosystems in British Columbia. The absence of frequent low severity ground fires has been one of the main contributors to dense patches of non-native grasses, shrubs, and encroaching Douglas-fir trees in historical Garry oak dominated meadows. This case study uses remote sensing and dendrochronology to reconstruct the stand dynamics and long-term fire history of a Garry oak meadow situated within Helliwell Provincial Park located on Hornby Island, British Columbia. The Garry oak habitat in Helliwell Park has decreased by 50% since 1950 due to conifer encroachment. Lower densities and mortalities of Garry oak trees were associated with the presence of overstory Douglas-fir trees. To slow conifer encroachment into the remaining Garry oak meadows, we recommend that mechanical thinning of Douglas-fir be followed by a prescribed burning program. Reintroducing fire to Garry oak ecosystems can restore and maintain populations of plants, mammals, and insects that rely on these fire resilient habitats.

Variations in beech bark disease and its effects on species composition and structure of northern hardwood stands in central New England

1984 ◽  
Vol 14 (4) ◽  
pp. 565-574 ◽  
Author(s):  
Mark J. Twery ◽  
William A. Patterson III
Keyword(s):  
Species Composition ◽  
New England ◽  
Beech Bark Disease ◽  
Northern Hardwood ◽  
Disease Mortality ◽  
Composition And Structure ◽  
Understory Composition ◽  
Bartlett Experimental Forest ◽  
Compositional Changes

The extent of beech bark disease was examined on 41 permanent inventory plots in western Massachusetts and on 25 plots in Bartlett Experimental Forest in New Hampshire. The amounts of disease-caused mortality and defect were correlated to differences in species composition and 12 other site variables. Stands dominated by hemlock had significantly more beech mortality than other stands. Importance of both beech and yellow birch decreased on plots with beech bark disease mortality. Hemlock benefited most from the loss of beech. Beech bark disease has not noticeably changed understory composition on these plots. In the long term, beech bark disease appears to have caused minor compositional changes on most of the areas studied.

scholarly journals Composition and structure of plankton communities in the Bering Sea

2021 ◽  
Vol 201 (1) ◽  
pp. 158-176
Author(s):  
K. M. Gorbatenko
Keyword(s):  
Deep Water ◽  
Bering Sea ◽  
Oithona Similis ◽  
Composition And Structure ◽  
Calanus Glacialis ◽  
Neocalanus Plumchrus ◽  
Calanus Marshallae ◽  
Metridia Pacifica ◽  
The Bering Sea

On the data of long-term surveys, mean biomass of plankton in the epipelagic layer of the Bering Sea is evaluated as 821.3 mg/m3 (1058.2 mg/m3 in shelf areas and 760.6 mg/m3 in the deep-water areas) and the stock as 245.1•106 t WW (64.4 • 106 t over the shelf and 180.7 • 106 t in the deep-water sea). By taxa, the average annual portions are: 55.1 % for copepods, 26.3 % for arrowworms, 10.8 % for euphausiids, 3.2 % for medusas, and 2.9 % for amphipods. The dominant species are the arrowworm Sagitta elegans (26.3 %) and the copepod Eucalanus bungii (19.7 %); other mass species are: large-sized copepods Neocalanus cristatus (10.4 %), Neocalanus plumchrus + Neocalanus flemingeri (7.8 %) and Calanus glacialis + Calanus marshallae (5.1 %), euphausiids Thysanoessa raschii (3.5 %) and Thysanoessa longipes (3.4 %), small-sized copepods Metridia pacifica (3.5 %) and Oithona similis (3.5 %), medusa Aglantha digitale (3.2 %).

scholarly journals Influence of Markets and Forest Composition on Lumber Production in Pennsylvania

2006 ◽  
Vol 23 (2) ◽  
pp. 87-93 ◽  
Author(s):  
William G. Luppold ◽  
Matthew S. Bumgardner
Keyword(s):  
Regional Differences ◽  
Forest Composition ◽  
Hardwood Lumber ◽  
Composition And Structure

Abstract In this study, we examine regional differences in the hardwood timber resources of Pennsylvania and how the combined changes in inventory volume, forest composition, and lumber prices have influenced regional lumber production. Isolation of these relationships is important because shifts in lumber production reflect changes in harvesting activity. In turn, harvesting influences long-term forest composition and structure. We define three hardwood regions in Pennsylvania based on forest composition and present a chronology of regional changes in sawtimber volumes, sawtimber composition, and lumber production. Regional changes in hardwood lumber production were found to be positively related to changes in the price of No. 1 Common lumber adjusted for changes in forest composition between 1970 and 1999. This finding supports our contention that regional changes in lumber production are influenced by a combination of changes in interspecies lumber price and changes in species availability.

Changes in the Quality of the Danube River Water in the Section Smederevo-Kladovo in the Conditions of Backwater Effects

1990 ◽  
Vol 22 (5) ◽  
pp. 181-188 ◽  
Author(s):  
M. Peršić ◽  
M. Miloradov ◽  
V. Tutundžić ◽  
Z. Čukić
Keyword(s):  
River Water ◽  
Danube River ◽  
Hydropower Plant ◽  
Biochemical Processes ◽  
The Danube River ◽  
Global View ◽  
Physico Chemical ◽  
Composition And Structure

The paper describes specific changes in the quality of the Danube river water under the conditions of backwater effects in the Hydropower Plant Djerdap I storage. The results of longterm tests in five profiles of the investigated section, at various discharges give a global view of the intensity of changes in the composition of water mass. The analysis included changes in the contents of: organic matter, oxygen regime, reduction of turbidity and changes in the composition and abundance of plankton. The specific changes in the domain of physico-chemical and biochemical processes and changes in the biological status of the watercourse (composition and structure of plankton) at varying retention times complete the picture of short-term changes in the investigated system. Presentation of some settling effects and processes in the sediment of the storage provides an idea of some long-term changes in the conditions of backwater effects of the Danube in the investigated section.

scholarly journals Modelling Post-Disturbance Successional Dynamics of the Canadian Boreal Mixedwoods

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Kobra Maleki ◽  
Mohamadou Alpha Gueye ◽  
Benoit Lafleur ◽  
Alain Leduc ◽  
Yves Bergeron
Keyword(s):  
Spruce Budworm ◽  
Eastern Canada ◽  
Species Dominance ◽  
Silvicultural Treatments ◽  
Composition And Structure ◽  
Long Time ◽  
Successional Stages ◽  
Boreal Mixedwoods ◽  
Natural Dynamics

Natural disturbances, such as fire and insect outbreaks, play important roles in natural forest dynamics, which are characterized over long time scales by changes in stand composition and structure. Individual-based forest simulators could help explain and predict the response of forest ecosystems to different disturbances, silvicultural treatments, or environmental stressors. This study evaluated the ability of the SORTIE-ND simulator to reproduce post-disturbance dynamics of the boreal mixedwoods of eastern Canada. In 1991 and 2009, we sampled all trees (including seedlings and saplings) in 431 (256 m2) plots located in the Lake Duparquet Research and Teaching Forest (western Quebec). These plots were distributed in stands originating from seven wildfires that occurred between 1760 and 1944, and which represented a chronosequence of post-disturbance stand development. We used the 1991 inventory data to parameterize the model, and simulated short- to long-term natural dynamics of post-fire stands in both the absence and presence of a spruce budworm outbreak. We compared short-term simulated stand composition and structure with those observed in 2009 using a chronosequence approach. The model successfully generated the composition and structure of empirical observations. In long-term simulations, species dominance of old-growth forests was not accurately estimated, due to possible differences in stand compositions following wildfires and to differences in stand disturbance histories. Mid- to long-term simulations showed that the secondary disturbance incurred by spruce budworm did not cause substantial changes in early successional stages while setting back the successional dynamics of middle-aged stands and accelerating the dominance of white cedar in late-successional post-fire stands. We conclude that constructing a model with appropriate information regarding stand composition and disturbance history considerably increases the strength and accuracy of the model to reproduce the natural dynamics of post-disturbance boreal mixedwoods.

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