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Wyszukujesz frazę "carbon dynamics" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Comparison of soil CO2 efflux rates in Larix leptolepis, Pinus densiflora and P. rigitaeda plantations in southern Korea
Autorzy:
Kim, C.
Jeong, J.
Powiązania:
https://bibliotekanauki.pl/articles/41331.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
soil
carbon dioxide
efflux system
Larix leptolepis
Pinus densiflora
Pinus rigida
carbon cycling
carbon dynamics
root decomposition
soil respiration
plantation
Korea
Opis:
This study compared soil CO2 efflux rates in three adjacent coniferous plantations consisting of larch (Larix leptolepis Gordon), red pine (Pinus densiflora S. et Z.) and rigitaeda pine (P. rigitaeda: P. rigida Mill × P. taeda L.) species planted in the same year (1963). Soil CO2 efflux, litter fall carbon (C) and root decomposition rates were measured with soil environmental factors for two years. The mean annual soil CO2 efflux rates (g CO2 m−2 hour−1) were the highest in rigitaeda pine (0.30), followed by red pine (0.27) and larch (0.24) plantations. An exponential regression of the CO2 efflux rates against their corresponding soil temperatures showed a significant (P < 0.05) relationship (red pine R2 = 0.69; rigitaeda pine R2 = 0.67; larch R2 = 0.63). The soil CO2 efflux rates were negatively correlated with soil pH, but the soil water and soil organic C content were not significantly correlated with the CO2 efflux rates. Soil CO2-C efflux rates were correlated by litter fall C inputs in the larch and red pine plantations, and the decomposition rates of 5–10 mm diameter roots in the larch plantation. This result is useful in understanding potential responses of soil CO2 efflux rates with changes in stand and soil environmental factors induced by different tree species.
Źródło:
Dendrobiology; 2016, 76
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Species diversity and litter dynamics in secondary mixed deciduous forest, Thung Salaeng Lung National Park, Northern, Thailand
Autorzy:
Podong, C.
Poolsiri, R.
Katzensteiner, K.
Pengthamkeerati, P.
Thongdeenok, P.
Powiązania:
https://bibliotekanauki.pl/articles/38576.pdf
Data publikacji:
2013
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
species diversity
species composition
carbon
nitrogen
litter dynamics
secondary mixed deciduous forest
shifting cultivation
Thung Salaeng Lung National Park
Thailand
Opis:
This study present species composition and potential of litter on carbon and nitrogen return in secondary mixed deciduous forest after shifting cultivation. The dominant species of trees were Haldina cordifolia, Albizia odoratissima and Lagerstroemia duperreana. The Important Value Index (IVI) values of trees were 132.91, 17.78 and 14.22, respectively. The pattern for the decomposition coefficients (k) was highest in the wet period (May–September) and lowest in the dry period (October–April). The carbon and nitrogen return patterns increased in the dry period (October– April) and decreased in the wet period (May–September). Carbon and nitrogen loss in the decomposing litter continually decreased during the decomposition process from the initial levels, with a final relatively rapid release in the wet period. Results from this study was understanding of community composition, litterfall production and litter decomposition for understanding potential of secondary mixed deciduous forest for balancing carbon for mitigating greenhouse gas effect in the local area.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2013, 55, 4
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD modelling of CO2 capture in a packed bed by chemical absorption
Autorzy:
Asendrych, D.
Niegodajew, P.
Drobniak, S.
Powiązania:
https://bibliotekanauki.pl/articles/185228.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon dioxide
carbon capture and storage (CCS)
2-phase flow
chemical absorption
computational fluid dynamics (CFD)
dwutlenek węgla
wychwytywanie i składowania dwutlenku węgla (CCS)
strumień 2-fazowy
absorpcja chemiczna
dynamika płynów (CFD)
Opis:
The paper deals with numerical modelling of carbon dioxide capture by amine solvent from flue gases in post-combustion technology. A complex flow system including a countercurrent two-phase flow in a porous region, chemical reaction and heat transfer is considered to resolve CO2 absorption. In order to approach the hydrodynamics of the process a two-fluid Eulerian model was applied. At the present stage of model development only the first part of the cycle, i.e. CO2 absorption was included. A series of parametric simulations has shown that carbon dioxide capture efficiency is mostly influenced by the ratio of liquid (aqueous amine solution) to gas (flue gases) mass fluxes. Good consistency of numerical results with experimental data acquired at a small-scale laboratory CO2 capture installation (at the Institute for Chemical Processing of Coal, Zabrze, Poland) has proved the reliability of the model.
Źródło:
Chemical and Process Engineering; 2013, 34, 2; 269-282
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of addition of carbon nanotubes on rheological properties of selected liquid lubricants - a computer simulation study
Autorzy:
Chopra, Anjali
Winczewski, Szymon
Powiązania:
https://bibliotekanauki.pl/articles/1954594.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska
Tematy:
nanotechnology
tribology
lubricants
rheology
propylene glycol
carbon nanotubes
non-equilibrium molecular dynamics
nanotechnologia
tribologia
smary
reologia
glikol propylenowy
nanorurki
nierównowagowa dynamika molekularna
Opis:
This work is motivated by the improvement of anti-friction properties of lubricants by addition of CNTs proved experimentally in literature. In particular, a methodology is developed to compute the shear viscosity of liquid lubricants (Propylene Glycol) based on Molecular Dynamics simulation. Non-Equilibrium molecular dynamics (NEMD) approach is used with a reactive force field ReaxFF implemented in LAMMPS. The simulations are performed using the canonical (NVT) ensemble with the so-called SLLOD algorithm. Couette flow is imposed on the system by using Lees-Edwards periodic boundary conditions. Suitable parameters such as simulation time and imposed shear velocity are obtained. Using these parameters, the influence of addition of 27 wt% CNTs to Propylene Glycol on its viscosity is analyzed. Results show that 3.2 million time-steps with a 0.1 fs time-step size is not sufficient for the system to reach equilibrium state for such calculations. With the available computational resources, a shear velocity of 5 × 10−5 Å/fs was observed to give viscosity value with approximately 43% error as compared to the experimental value. Moreover, the lubricant exhibited a shear thinning behaviour with increasing shear rates. CNTs enhanced the lubricant's viscosity by 100-190% depending upon the averaging method used for calculation.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2020, 24, 4; 345-388
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Brachiopods and their response to the Early-Middle Frasnian biogeochemical perturbations on the South Polish carbonate shelf
Autorzy:
Balinski, A
Powiązania:
https://bibliotekanauki.pl/articles/20277.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopod
brachiopod response
paleontology
Early-Middle Frasnian
Frasnian
biogeochemical perturbation
Southern Poland
Polska
carbonate shelf
Brachiopoda
Flabellulirostrum
Thomasaria
carbon isotope
diversity dynamics
Opis:
The brachiopod faunas from deposits recording the Early–Middle Frasnian transition of Poland are poorly known. The present report describes these faunas that were recovered from Wietrznia and Kostomłoty (Holy Cross Mountains) and Dębnik (Silesian−Cracow Upland) regions positioned on the southern Polish carbonate shelf. The brachiopod distribution was analysed relative to a significant δ¹³C excursion, referred recently to as Palmatolepis punctata Event. The sporadic occurrence of brachiopods at Dębnik makes it difficult to analyse the biotic response to this geochemical anomaly. However, higher brachiopod frequency in the topmost part of the section coincides with a gradual decrease of δ¹³C down to the Frasnian background values. At two studied sections at Wietrznia the greatest taxonomic diversity and abundance of brachiopods (Flabellulirostrum–Coeloterorhynchus assemblage) are confined to the Palmatolepis transitans Zone. In the following Pa. punctata Zone brachiopods are rare (Biernatella lentiformis assemblage) or absent, which suggests a serious deterioration of the environmental conditions linked probably with periods of benthic anoxia−dysoxia and oligotrophic conditions in the basin. In two Kostomłoty sections brachiopods faunas of this age are members of the mostly monospecific rhynchonellid−dominated Phlogoiderhynchus polonicus assemblage which inhabited deeper−water environments characteristic of intrashelf oxygen−depleted basins of ŁysogóryKostomłoty region. In some horizons large shells of P. polonicus were frequently colonised by discinoid Romerella? sp. Among 28 species described in this report new forms include: Flabellulirostrum kielcensis sp. nov., F. rackii sp. nov., and Thomasaria ventosa sp. nov.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 4; 647-678
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faunal dynamics across the Silurian-Devonian positive isotope excursions (delta13C, delta18O) in Podolia, Ukraine: Comparative analysis of the Ireviken and Klonk events
Autorzy:
Racki, G.
Balinski, A.
Wrona, R.
Malkowski, K.
Drygant, D.
Szaniawski, H.
Powiązania:
https://bibliotekanauki.pl/articles/20924.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fauna dynamics
Silurian
Devonian
isotope excursion
Podolia
Ukraine
comparative analysis
Ireviken event
Klonk event
Brachiopoda
Conodonta
Chitinozoa
carbon isotope
oxygen isotope
geochemistry
Opis:
Two global isotopic events, the early Sheinwoodian (early Wenlock) and that at the Silurian–Devonian transition, have been comprehensively studied in representative carbonate successions at Kytayhorod and Dnistrove, respectively, in Podolia, Ukraine, to compare geochemistry and biotic changes related correspondingly to the Ireviken and Klonk events. These two large−scale isotope excursions reveal different regional ecosystem tendencies. The well−defined increasing trend across the Llandovery–Wenlock boundary in siliciclastic input, redox states and, supposedly, bioproductivity, was without strict correlative relations to the major ¹³C enrichment event. The environmental and biotic evolution was forced by eustatic sea−level fluctuations and two−step climate change toward a glaciation episode, but strongly modified by regional epeirogeny movements due to location near the mobile Teisseyre−Törnquist Fault Zone. Thus, the global early Sheinwoodian biogeochemical perturbation was of minor depositional significance in this epeiric sea, as in many other Laurussian domains. Conversely, the Podolian sedimentary record of the Klonk Event exhibits temporal links to the abrupt δ¹³C anomaly, overprinted by a tectonically driven deepening pulse in the crucial S–D boundary interval. This carbon cycling turnover was reflected in the regional carbonate crisis and cooling episodes, paired with a tendency towards eutrophication and recurrent oxygen deficiency, but also with major storms and possible upwelling. Faunal responses in both Podolian sections follow some characters of the Silurian pattern worldwide, as manifested by conodont changeover prior to the major early Sheinwoodian isotopic/climatic anomaly. This contrasts with the relative brachiopod and chitinozoan resistances in the course of the Ireviken Event. Also, during the Klonk Event, a moderate faunal turnover, both in benthic and pelagic groups, occurred only near the very beginning of the prolonged ¹³C−enriched timespan across the system boundary, possibly due to progressive dysoxia and temperature drop. The characters point to a peculiarity of the Klonk Event by comparison with the Silurian global events, and some similarity already to the succeeding Devonian transgressive/anoxic episodes.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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