Temat: carbon distribution - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Characterization of soil aggregate stability using low intensity ultrasonic vibrations
Autorzy:: Schomakers, J.
Mentler, A.
Steurer, T.
Klik, A.
Mayer, H.
Powiązania:: https://bibliotekanauki.pl/articles/24235.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: soil aggregate
stability
low intensity vibration
ultrasonic vibration
cavitation limit
carbon distribution
tillage
ultrasonic dispersion
ultrasonic method
Źródło:: International Agrophysics; 2011, 25, 2
0236-8722
Pojawia się w:: International Agrophysics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Changes in soil organic matter, bulk density and tensile strength of aggregates after percolation in soils after conservation and conventional tillage
Autorzy:: Urbanek, E.
Horn, R.
Powiązania:: https://bibliotekanauki.pl/articles/25884.pdf
Data publikacji:: 2006
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: organic matter
carbon distribution
aggregate strength
bulk density
tillage
tensile strength
arable soil
conventional tillage
soil
percolation process
soil aggregate
soil conservation
aggregate
Źródło:: International Agrophysics; 2006, 20, 3
0236-8722
Pojawia się w:: International Agrophysics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Distribution of bacteria, organic carbon and amino acids in the southern part of Drake Passage and in Bransfield Strait during the BIOMASS - SIBEX (December1983 —January 1984)
Autorzy:: Zdanowski, Marek K.
Powiązania:: https://bibliotekanauki.pl/articles/2057351.pdf
Data publikacji:: 1985
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: Antarctic
bacteria
organic carbon
amino acids
distribution
Źródło:: Polish Polar Research; 1985, 6, 1-2; 43-63
0138-0338
2081-8262
Pojawia się w:: Polish Polar Research
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Improving the carbon dioxide uptake efficiency of activated carbons using a secondary activation with potassium hydroxide
Autorzy:: Zgrzebnicki, M.
Michalczyszyn, E.
Wrobel, R. J.
Powiązania:: https://bibliotekanauki.pl/articles/778515.pdf
Data publikacji:: 2018
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:: activated carbon
activation
pore size distribution
DFT
Opis:: Secondary activation of commercial activated carbon (AC) ORGANOSORB 10-CO was carried out at 600, 700 and 800°C with mass ratios of potassium to AC (K/AC) in range 1–3. Crucial samples have shown following CO₂ uptakes and SSA – 3.90 mmol/g and 1225 m²/g, 4.54 mmol/g and 1546 m²/g, 4.28 and 1717 m²/g for pristine material and samples obtained at 700°C with K/AC = 2 and at 800°C with K/AC = 3 respectively. Last sample also indicated significant mesopore volume increase in diameter range 2–5 nm, from 0.11 to 0.24 cm3/g. CO₂ uptake increase was explained by formation of micropores up to diameter of 0.8 nm, which distribution was established from CO₂ sorption using DFT. Surface chemistry of all samples has not changed during modification, what was proven by XPS. Moreover, deeper incorporation of potassium ions into graphite at higher temperatures was observed as confirmed with EDS, XPS and XRD.
Źródło:: Polish Journal of Chemical Technology; 2018, 20, 3; 87-94
1509-8117
1899-4741
Pojawia się w:: Polish Journal of Chemical Technology
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Soil aggregate size distribution and total organic carbon in intra-aggregate fractions as affected by addition of biochar and organic amendments
Autorzy:: Odugbenro, George O.
Liu, Zhihua
Sun, Yankun
Powiązania:: https://bibliotekanauki.pl/articles/2088216.pdf
Data publikacji:: 2020
Wydawca:: Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:: biochar
aggregate stability
aggregate size distribution
microbial biomass carbon
total organic carbon
Opis:: A two-year field trial on maize (Zea mays L.) production was established to determine the influence of biochar, maize straw, and poultry manure on soil aggregate stability, aggregate size distribution, total organic carbon (TOC), and soil microbial biomass carbon (MBC). Seven treatments with four replications, namely CK, control; S, 12.5 Mg ha-1 straw; B1, 12.5 Mg ha-1 biochar; B2, 25 Mg ha-1 biochar; SB1, straw + 12.5 Mg ha-1 biochar; SB2, straw + 25 Mg ha-1 biochar; and M, 25 Mg ha-1 manure were tested at four soil depths (0–10, 10–20, 20–30, and 30–40 cm). Aggregates were grouped into large macro-aggregates (5–2 mm), small macro-aggregates (2–0.25 mm), micro-aggregates (0.25–0.053 mm) and silt + clay (<0.053 mm). Biochar, straw, and manure applications all had significant effects (p < 0.05) on aggregate stability, with B2 at 20 cm soil depth showing the greatest increase (62.1%). SB1 of small macro-aggregate fraction showed the highest aggregate proportion (50.59% ± 10.48) at the 20–30 cm soil depth. The highest TOC was observed in SB2 (40.9 g kg-1) of large macro-aggregate at 10–20 cm soil depth. Treatment effects on soil MBC was high, with B1 showing the greatest value (600.0 µg g-1) at the 20–30 cm soil depth. Our results showed that application of biochar, straw, and manure to soil increased aggregate stability, TOC as well as MBC.
Źródło:: Polish Journal of Soil Science; 2020, 53, 1; 41-54
0079-2985
Pojawia się w:: Polish Journal of Soil Science
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Gases in the near-surface zone of the reclaimed Barycz municipal waste landfill – a case study from southern Poland
Autorzy:: Kopera, Paulina A.
Sechman, Henryk
Twaróg, Anna
Powiązania:: https://bibliotekanauki.pl/articles/27310119.pdf
Data publikacji:: 2023
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:: landfill
emission
surface distribution
methane
carbon dioxide
biogas
hydrocarbons
Opis:: The formation of biogas at municipal landfills and the significant emission of greenhouse gases from these facilities into the environment were the main reasons for analyzing the molecular composition of soil gas in the near-surface zone at the reclaimed part of the Barycz municipal waste landfill. The relations between the studied components (methane, carbon dioxide, light hydrocarbons and non-hydrocarbon components) and impact of the magnitude of recorded concentrations of methane and carbon dioxide on their emission to the atmosphere were evaluated. Two profiles were determined, along which 41 soil and landfill gas samples were taken at 20-meter intervals. At the same time, emissions were measured at each sampling point using a static chamber with a portable fluxometer. Chromatographic analysis showed that the concentrations of methane and carbon dioxide fluctuated in the ranges: 2.1 ppm – 76 vol% and 0.04 ppm – 11 vol%, respectively. Relatively high concentrations of these gases were determined at many of the measurement points, and this was particularly evident at the A-A’ profile, indicating stronger biochemical processes in this part of the landfill, or lateral migration of methane from the neighbouring stage II of the landfill, where biogas extraction is currently taking place. In addition, significant correlations between methane, carbon dioxide, and oxygen were demonstrated, indicating ongoing methane fermentation processes. Based on the study, it can be concluded that the southern part of the A-A’ profile is an optimal place to locate a degassing well from which biogas production could be used. However, the research is only preliminary and, it will be necessary to extend the soil gas tests before the final decision on the location of the well is made. Moreover, it has been shown that the concentrations of methane and carbon dioxide measured at points located outside the landfill were low. This means that generated biogas probably does not migrate beyond the boundaries of reclaimed waste landfill, but this will need to be confirmed by performing additional soil gas tests inside and outside the landfill area. The preliminary assessment of the effectiveness of the reclamation carried out was confirmed by the negligible values of the measured methane and carbon dioxide emissions on the surface.
Źródło:: Geology, Geophysics and Environment; 2023, 49, 2; 101--121
2299-8004
2353-0790
Pojawia się w:: Geology, Geophysics and Environment
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Recent alterations of aerosol concentration, mercury distribution and organic matter deposition in the Arctic
Autorzy:: Pempkowiak, J.
Zielinski, T.
Petelski, T.
Zaborska, A.
Beldowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/11960.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: aerosol concentration
mercury distribution
organic matter
organic carbon
deposition
Arctic
Opis:: Material fluxes in the Arctic and Antarctic have been, in several respects, strongly affected recently. For example, atmospheric turbidity conditions are frequently subject to strong changes due to haze and dust transport episodes, which can cause considerable perturbations in the radiation balance of the atmosphere beyond regional scale. This, directly or indirectly, contributes to the increased mercury deposition and organic matter fluxes to sediments. The results show that local emissions are not always the most important factors influencing the composition of aerosol in the atmosphere of the west Spitsbergen region. The direct radiative impact of polar aerosols on the surface and at the top of the atmosphere (TOA) need to be studied more closely through both theoretical studies on the aerosol radiative properties and measurements of the surface reflectance characteristics. Mercury dissolved/solid partitioning, both in the unconsolidated, fluffy layer of suspended matter covering the sediments, and the uppermost sediment layer, indicate that the influence of the athmospheric mercury deposition event (AMDE) can prolong well into summer (July/August), and can provide a pathway to the food chain for mercury contained in sediments. Since terrigenous supplies of organic carbon to the Barents Sea are minor (∼5%) compared to the marine supply, modern sediment deposits in this region sequester on average 6.0 g/m2year organic carbon, or 5.8% of the annual integrated pelagic primary production. This burial fraction exceeds, by a factor of 3, the burial fraction derived for the Holocene.
Źródło:: Papers on Global Change; 2011, 18
2300-8121
1730-802X
Pojawia się w:: Papers on Global Change
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Impact of wood-derived biochar on the hydraulic characteristics of compacted soils: Its influence on simulated farmland carbon sequestration
Autorzy:: Ahmed, A.
Kurian, J.
Satyanarayana, S.
Raghavan, V.
Powiązania:: https://bibliotekanauki.pl/articles/2083067.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: soil biochar mixture
water retention
pore-size
distribution
hydraulic conductivity
carbon sequestration
Opis:: The addition of biochar is often proposed to increase agricultural soil quality and crop yield, while at the same time sequestering carbon from the atmosphere to help mitigate global climate change. In this research, the pore-size distribution, and saturated hydraulic conductivity of sandy loam and clay loam soils amended with varying dosages (0-10% dry basis) and two different particle sizes (0.5-420 μm (PS1) or 421-841 μm (PS2)) of wood-derived biochar were investigated under compacted conditions (5, 10, or 15 standard Proctor rammer blows (5B, 10B, or 15B, respectively)). In the 5B compacted SL (SL-5B) soil, the volume of the soil fissures and transmission pores decreased, while the volume of the storage pores (SP) increased with increasing wood-derived biochar dosage. 23.1±0.9% of the volume of the 5B compacted clay loam (CL-5B) are storage pores, this value increased to 27.4±2.0% upon amendment with 10% PS1. The saturated hydraulic conductivity of the sandy loam-5B soil amended with 10% PS1 decreased from 6.8±0.3 to 0.80±0.03 mm h-1. The sandy loam farmland C emissions decreased by 0.071 tC ha-1 y-1, whereas CL farmland C emissions decreased by 0.091 tC ha-1 y-1.
Źródło:: International Agrophysics; 2021, 35, 2; 167-177
0236-8722
Pojawia się w:: International Agrophysics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: New observations on rhynchonelloid brachiopod Dzieduszyckia from the Famennian of Morocco
Autorzy:: Balinski, A
Biernat, G.
Powiązania:: https://bibliotekanauki.pl/articles/21704.pdf
Data publikacji:: 2003
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:: Dziaduszyckia
Famennian
fossil
brachiopod
Halorellidae
rhynchonellid brachiopod
Morocco
distribution
Brachiopoda
paleontology
carbon isotope
Opis:: The genus Dzieduszyckia is especially well represented and diverse in the Famennian strata of the Middle Atlas, Morocco. In this paper we re−study and re−illustrate the rich collection of Dzieduszyckia from Morocco, described by Henri and Genevive Termier, and originally referred to Halorella or Eoperegrinella. New data on the internal shell structure of D. crassicostata, D. intermedia, and D. tenuicostata indicate great intraspecific variability in morphology. The structure of crura of three studied species demonstrates that subfamily Dzieduszyckiinae is better placed within the family Halorellidae, instead of Peregrinellidae. Type specimens (lectotypes) of the three species were also selected. An analysis of the stable isotopes of carbon and oxygen of the shell material of Dzieduszyckia and carbonate sediment was used to investigate the presumed chemosynthetic nature of its paleoenvironments. The analyses of the Moroccan and Polish material do not show any signature of unusual environmental conditions: they fall in the range of the mean values of δ¹³C for the Late Devonian.
Źródło:: Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:: Acta Palaeontologica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: Influence of glueline parameters on the mechanical behaviour of CFRP reinforced wood - numerical analysis
Wpływ parametrów spoiny klejowej na pracę drewna wzmocnionego taśmą CFRP - analiza numeryczna
Autorzy:: Burawska, I.
Tarasovs, S.
Powiązania:: https://bibliotekanauki.pl/articles/8182.pdf
Data publikacji:: 2014
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:: glue line
mechanical parameter
mechanical behaviour
CFRP tape zob.carbon fibre reinforced polymer
carbon fibre reinforced polymer
wood
numerical analysis
stress distribution
reinforcement
Źródło:: Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2014, 87
1898-5912
Pojawia się w:: Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 11.

Tytuł:: Carbon isotope distribution along pine needles [Pinus nigra Arnold]
Autorzy:: Barszczowska, L
Jedrysek, M.O.
Powiązania:: https://bibliotekanauki.pl/articles/57836.pdf
Data publikacji:: 2005
Wydawca:: Polskie Towarzystwo Botaniczne
Tematy:: Croatia
pine
inhomogeneity
needle
growth
distribution
kinetic isotope effect
black pine
Spain
Pinus nigra
carbon isotope
Opis:: In this paper we show spatial carbon isotope variations in black pine (Pinus nigra Arnold) needles, collected in spring 2001 and autumn 2003, from trees at the coast of south-western Croatia island (Žirje) and southern Spain (Benalmadena near Malaga), respectively. Needles were segmented perpendicularly to the longer axis (base, middle and top) and each segment was analysed separately. d13C values in needles from Croatia varied between -26.65‰ to -24.43‰ (2 months old needles) and from -28.25‰ to -25.21‰ (1 year old needles), while d13C values in needles from Spain varied from -27.58‰ to -25.27‰. The difference between d13Cb (base) and d13Ct (top) in the same needle (D13Cb-t) varied from 1.85 to 2.05‰ (in young needles from Croatia), from 0,02 to 1,80‰ (young needles from Spain), and 1.16 to 2.32‰, (in old needles from Croatia). The average D13Cb-t values were 0.78‰ and 1.73‰ in Spain and Croatia, respectively. In each needle the base of the needle was always 13C-enriched as compared to the top of the same needle. This evidences that carbon isotopes are not retranslocated after its fixation into the leaf structure (after the growth process is over). Temperature variation was most probably negligible for the discovered intraneedle carbon isotope distribution. Although, the intraneedle carbon isotope inhomogeneity can be partly the result of seasonal variation in d13C of atmospheric CO2, most probably the remarkably high D13Cb-t values, and regular pattern, are predominantly resulting from isotopic and chemical composition of primary and secondary products contained in the growin part of needle and kinetic isotope fractionation during decomposition of storage materials at the base.
Źródło:: Acta Societatis Botanicorum Poloniae; 2005, 74, 2
0001-6977
2083-9480
Pojawia się w:: Acta Societatis Botanicorum Poloniae
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 12.

Tytuł:: Distribution and origin of gaseous hydrocarbons and carbon dioxide in the Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)
Autorzy:: Kotarba, M. J.
Sechman, H.
Dzieniewicz, M.
Powiązania:: https://bibliotekanauki.pl/articles/191503.pdf
Data publikacji:: 2009
Wydawca:: Polskie Towarzystwo Geologiczne
Tematy:: near-surface geochemical survey
depth gas distribution
stable carbon isotopes
gaseous hydrocarbon origin
carbon dioxide origin
Quaternary sediments
woolly rhinoceros
Starunia palaeontological site
Ukrainian Carpathians
Opis:: Near-surface gases were investigated in Starunia, where remains of mammoth and woolly rhinoceroses were discovered at the beginning of the 20th century. Samples were collected at 30 measurement sites, from 0.8, 1.6, 2.4, 3.2 and 4.0 m depths and analysed for their molecular and isotopic compositions. Most of the methane and all higher gaseous hydrocarbons accumulated within the near-surface zone are of thermogenic origin. The distribution of thermogenic methane and higher gaseous hydrocarbons in Quaternary sediments is variable and, generally, increases with depth. Microbial methane or a mixture of microbial and thermogenic methane also occurs at the near-surface zone. The presence of hydrogen and alkenes in the near-surface gases also suggests a contribution from recent, microbial processes. Helium of crustal origin migrated through the Rinne Fault and other tectonic zones located in the study area, and was subsequently dispersed during migration through the lithologically diversified Pleistocene and Holocene sediments. The high variability of the carbon dioxide concentration and stable carbon isotope composition at various depths in the near-surface zone is caused by its polygenetic origin (thermogenic, microbial, and oxidation of hydrocarbons and Quaternary organic matter), and also by its dissolution in water and oil during migration through lithologically diversified Pleistocene and Holocene sediments. Zones of thermogenic methane occurrence within Pleistocene sediments, dominated by muds saturated with bitumen and brines, provide the most favourable environment for preservation of large extinct mammals. It is likely that during the Pleistocene winters, when thick ice and snow covered the tundra lake and swamp, zones of outflow of brines, oils, helium, and thermogenic gaseous hydrocarbons had a higher temperature, which could have resulted in melting and cracking of the ice cover and drowning of large mammals. The most favourable conditions for preservation of large, extinct mammals probably still exists in the vicinity of sampling probe sites Nos 21, 22, 23 and 36. Zones of dominance of microbial methane concentrations are less favourable sites for preservation of extinct mammals, because this methane was generated within recent swamps and also within recent descending meteoric waters which infiltrated into Pleistocene and Holocene sediments. Older Pleistocene microbial gases have already escaped to the atmosphere.
Źródło:: Annales Societatis Geologorum Poloniae; 2009, 79, No 3; 403-419
0208-9068
Pojawia się w:: Annales Societatis Geologorum Poloniae
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 13.

Tytuł:: Nanorogi węglowe - modelowanie i właściwości adsorpcyjne
Carbon Nanohorn - Modeling and Adsorption Properties
Autorzy:: Terzyk, A. P.
Furmaniak, S.
Kaneko, K.
Gauden, P. A.
Kowalczyk, P.
Itoh, T
Powiązania:: https://bibliotekanauki.pl/articles/297587.pdf
Data publikacji:: 2013
Wydawca:: Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:: nanorogi węglowe
symulacje komputerowe
krzywa dystrybucji porów
adsorpcja
rozdział
carbon nanohorn
computer simulation
pore size distribution
adsorption
separation
Opis:: Nanorogi węglowe są obecnie jedną z najbardziej interesujących form węgla. W pracy przedstawiono pierwszy atomowy model nanorogów węglowych. Omówiono wyniki symulacji komputerowych adsorpcji Ar i ich porównanie z danymi doświadczalnymi. W dalszej części skonfrontowano teoretyczne i eksperymentalne wyniki rozdziału mieszaniny CH4/CO2. Uzyskane wyniki prowadzą do wniosku, że o ile podczas określania krzywej dystrybucji średnic nanorogów za pomocą badań adsorpcji Ar nanorogi można przybliżać modelem nieskończonej rurki (część stożkowa nie gra roli), o tyle w przypadku rozdziału mieszaniny CH4/CO2 obecność części stożkowej ma kluczowe znaczenie i decyduje o przewadze nanorogów nad nanorurkami węglowymi o tej samej średnicy.
Single Walled Carbon Nanohorn (SWNH) is one of the most interesting new forms of carbon. We present the first atomistic model of SWNH. Next we discuss the results of molecular simulations of Ar adsorption, and the comparison with experimental data. The application of SWNHs for CH4/CO2 mixture separation is also discussed. It is concluded that during calculation of the PSD curve the tip is not important. In the contrary, it plays a crucial role in the separation of considered mixture. In this way, SWNHs are more promising materials than carbon nanotubes and can be applied for CO2 capture from a biogas.
Źródło:: Inżynieria i Ochrona Środowiska; 2013, 16, 2; 217-223
1505-3695
2391-7253
Pojawia się w:: Inżynieria i Ochrona Środowiska
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 14.

Tytuł:: Analiza porowatości materiałów węglowych z jednoczesnym wykorzystaniem danych adsorpcji azotu i dwutlenku węgla
Analysis of carbon materials porosity by simultaneous use of adsorption data for nitrogen and carbon dioxide
Autorzy:: Choma, J.
Stachurska, K.
Kloske, M.
Dziura, A.
Jagiełło, J.
Jaroniec, M.
Powiązania:: https://bibliotekanauki.pl/articles/236332.pdf
Data publikacji:: 2017
Wydawca:: Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:: adsorption
active carbon
adsorption isotherm
N2
CO2
pore size distribution
adsorpcja
węgiel aktywny
izoterma adsorpcji
funkcja rozkładu objętości porów
Opis:: Knowledge of porous structure of carbons, including ultramicropores, micropores and mesopores, is of great importance in application of these materials for different purposes. Usually, their characteristics includes determination of specific surface area, pore volume and pore size distribution. The latter is often calculated on the basis of experimental nitrogen adsorption isotherm at –196 oC for relative pressures ranging from about 10–7 up to 1.0. It has been determined that experimental CO2 adsorption isotherm alone (0 oC, up to 1 atm), or together with N2 adsorption isotherm, may be applied to yield interesting results of pore size distributions. For illustration purposes, the pore size distributions were calculated for the three polymer-obtained microporous carbons and one ordered mesoporous carbon obtained by soft templating. The calculations were performed using the latest version of the SAIEUS program based on the Nonlinear Method in the Density Functional Theory (NLDFT) for the non-uniformly porous carbon materials. It has been shown that the simultaneous use of N2 and CO2 adsorption isotherms for calculation of the pore size distribution allows for a realistic assessment of carbon materials porosity.
Wiedza o strukturze porowatej węgli aktywnych, w tym o ultramikroporach, mikroporach i mezoporach, ma zasadnicze znaczenie w zastosowaniu tych materiałów do różnych celów. Zazwyczaj charakterystyka tych materiałów obejmuje wyznaczenie powierzchni właściwej, objętości porów i funkcji rozkładu objętości porów. Tę ostatnią funkcję wyznacza się na podstawie doświadczalnej izotermy adsorpcji azotu w temperaturze –196°C w przedziale ciśnień względnych od około 10–7 do około 1,0. W pracy wykazano, że interesujące wyniki dotyczące funkcji rozkładu objętości porów można otrzymać, jeśli wykorzystuje się doświadczalną izotermę adsorpcji CO2 (w temp. 0°C i ciśnieniu do 1 atm) lub jednocześnie izotermy adsorpcji N2 i CO2. W celu ilustracji rozwiązania tego problemu, w pracy obliczono funkcje rozkładu objętości porów trzech mikroporowatych węgli otrzymanych z prekursorów polimerowych oraz jednego uporządkowanego węgla mezoporowatego otrzymanego metodą miękkiego odwzorowania. Obliczenia funkcji rozkładu wykonano za pomocą najnowszej wersji programu SAIEUS, stosując metodę z teorii funkcjonału gęstości (NLDFT) w przypadku niejednorodnych, porowatych materiałów węglowych. Wykazano, że jednoczesne wykorzystanie izoterm adsorpcji N2 i CO2 do wyznaczania funkcji rozkładu porów pozwala na rzeczywistą ocenę porowatości materiałów węglowych.
Źródło:: Ochrona Środowiska; 2017, 39, 3; 4-7
1230-6169
Pojawia się w:: Ochrona Środowiska
Dostawca treści:: Biblioteka Nauki