Bibliografie tematiche / Competitive sorption and desorption

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Letteratura scientifica selezionata sul tema "Competitive sorption and desorption"

Autore: Grafiati

Pubblicato: 25 gennaio 2025

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Articoli di riviste sul tema "Competitive sorption and desorption"

Kim, J. H., W. S. Shin, Y. H. Kim, S. J. Choi, Y. W. Jeon e D. I. Song. "Sequential sorption and desorption of chlorinated phenols in organoclays". Water Science and Technology 47, n. 9 (1 maggio 2003): 59–64. http://dx.doi.org/10.2166/wst.2003.0492.

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Effect of pH on the sorption and desorption of the chlorinated phenols (2-chlorophenol and 2,4-dichlorophenol) in HDTMA-montmorillonite organoclays was investigated using sequential batch experiments. 2,4-dichlorophenol exhibited higher affinity in both sorption and desorption than 2-chlorophenol at pH 4.85 and 9.15. For both chlorophenols, the protonated speciation (at pH 4.85) exhibited a higher affinity in both sorption and desorption than the predominant deprotonated speciation (about 80% and 95% of 2-chlorophenate and 2,4-dichlophenate anions at pH 9.15, respectively). Desorption of chlorinated phenols was strongly dependent on the current pH regardless of their speciation during the previous sorption stage. No appreciable desorption resistance of the chlorinated phenols was observed in organoclays after sequential desorptions. Affinity of both chlorophenols in bisolute competitive sorption and desorption was reduced compared to that in a single-solute system due to the competition between solutes. The ideal adsorbed solution theory coupled with the single-solute Freundlich model successfully predicted the bisolute competitive sorption and desorption equilibria.

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Zemanová, V., L. Trakal, P. Ochecová, J. Száková e D. Pavlíková. "A model experiment: competitive sorption of Cd, Cu, Pb and Zn by three different soils". Soil and Water Research 9, No. 3 (6 agosto 2014): 97–103. http://dx.doi.org/10.17221/50/2013-swr.

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The aim of this study was to evaluate and compare the competitive and individual sorption of Cd, Cu, Pb and Zn on three natural soils: a Gleyic Fluvisol (content of Cd 30, Cu 25, Pb 2297 and Zn 3718 mg/kg), a Gleyic Cambisol (content of Cd 5, Cu 29, Pb 1158 and Zn 180 mg/kg) and a Chernozem (content of Cd 0.4, Cu 36, Pb 75 and Zn 67 mg/kg). For evaluation of the sorption and desorption, the Freundlich isotherms were used. The results of the model experiment confirmed that the sorption from single-metal solution was more effective than sorption under multi-metal conditions, due to competitive effects. In all tested soils sorption of Cd, Cu and Zn decreased with the rate of other competitive metals; the Pb sorption was not affected by other competitive metals in solutions. Moreover, during multi-metal sorption, Zn was significantly desorbed in Cambisol. In general, sorptions of Cu, Pb and Zn were greater in uncontaminated soil compared to contaminated soils. Clear trend of impact of the contamination on Cd sorption was not observed. The results showed the sorption decreasing in order Chernozem > Fluvisol > Cambisol. The sorption was the greatest in uncontaminated soil with low mobility of studied metals.

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Kastelan-Macan, Marija, e Mira Petrovic. "The role of fulvic acids in phosphorus sorption and release from mineral particles". Water Science and Technology 34, n. 7-8 (1 ottobre 1996): 259–65. http://dx.doi.org/10.2166/wst.1996.0630.

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The competitive sorption of phosphates and marine fulvic acids on mineral particles (sand, calcite, bentonite and hematite) has been studied under simulated estuarine conditions. Afterwards, the release and desorption of bound phosphates by solutions containing dissolved fulvic acids was determined. It was found out that due to the favorable sorption of fulvic acids onto minerals studied binding of phosphate was significantly decreased. Desorption experiments showed that fulvic acids, present at high concentration level, similar to that in interstitial water of an oxygenated sediment, increase phosphate desorption by 10-20%.

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Kim, Ji-Hoon, Won Sik Shin, Dong-Ik Song e Sang June Choi. "Sequential competitive sorption and desorption of chlorophenols in organoclay". Korean Journal of Chemical Engineering 23, n. 1 (gennaio 2006): 63–70. http://dx.doi.org/10.1007/bf02705693.

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Ma, Rui, Tian C. Zhang, Shannon L. Bartelt-Hunt, Bill Kranz, Daniel Snow, Terry Mader, Charles Shapiro et al. "Sorption and Desorption of Testosterone to Agricultural Soils: Inhibition Effects and Competitive Sorption". Proceedings of the Water Environment Federation 2009, n. 14 (1 gennaio 2009): 2624–33. http://dx.doi.org/10.2175/193864709793955050.

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Zhang, Hua, e H. Magdi Selim. "COMPETITIVE SORPTION-DESORPTION KINETICS OF ARSENATE AND PHOSPHATE IN SOILS". Soil Science 173, n. 1 (gennaio 2008): 3–12. http://dx.doi.org/10.1097/ss.0b013e31815ce750.

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Souza, Matheus Fonseca de, Emanuelle Mercês Barros Soares, Ivo Ribeiro da Silva, Roberto Ferreira Novais e Mailson Félix de Oliveira Silva. "Competitive sorption and desorption of phosphate and citrate in clayey and sandy loam soils". Revista Brasileira de Ciência do Solo 38, n. 4 (agosto 2014): 1153–61. http://dx.doi.org/10.1590/s0100-06832014000400011.

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The increase of organic acids in soils can reduce phosphorus sorption. The objective of the study was to evaluate the competitive sorption of P and citrate in clayey and sandy loam soils, using a stirred-flow system. Three experiments were performed with soil samples (0-20 cm layer) of clayey (RYL-cl) and sandy loam (RYL-sl) Red Yellow Latosols (Oxisols). In the first study, the treatments were arranged in a 2 × 5 factorial design, with two soil types and five combinations of phosphorus and citrate application (only P; P + citrate; and citrate applied 7, 22, 52 min before P); in the second, the treatments were arranged in a 2 × 2 factorial design, corresponding to two soils and two forms of P and citrate application (only citrate and citrate + P); and in the third study, the treatments in a 2 × 2 × 6 factorial design consisted of two soils, two extractors (citrate and water) and six incubation times. In the RYL-cl and RYL-sl, P sorption was highest (44 and 25 % of P application, respectively), in the absence of citrate application. Under citrate application, P sorption was reduced in all treatments. The combined application of citrate and P reduced P sorption to 25.8 % of the initially applied P in RYL-cl and to 16.7 % in RYL-sl, in comparison to P without citrate. Citrate sorption in RYL-cl and RYL-sl was highest in the absence of P application, corresponding to 32.0 and 30.2 % of the citrate applied, respectively. With P application, citrate sorption was reduced to 26.4 and 19.7 % of the initially applied citrate in RYL-cl and RYL-sl, respectively. Phosphorus desorption was greater when citrate was used. Phosphorus desorption with citrate and water was higher in the beginning (until 24 h of incubation of P) in RYL-cl and RYL-sl, indicating a rapid initial phase, followed by a slow release phase. This suggests that according to the contact time of P with the soil colloids, the previously adsorbed P can be released to the soil solution in the presence of competing ligands such as citrate. In conclusion, a soil management with continuous input of organic acids is desirable, in view of their potential to compete for P sorption sites, especially in rather weathered soils.

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Nastasovic, Aleksandra, Slobodan Jovanovic, Antonije Onjia, Zvjezdana Sandic, Ljiljana Malovic, Dragica Jakovljevic e Zorica Vukovic. "The application of macroporous copolymers in the sorption of heavy and precious metals from aqueous solutions". Chemical Industry 60, n. 11-12 (2006): 306–10. http://dx.doi.org/10.2298/hemind0612306n.

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Macroporous crosslinked poly(GMA-co-EGDMA) was synthesized by the suspension copolymerisation and functionalized by the ring-opening reaction of the pendant epoxy groups with ethylene diamine. The porosity parameters (specific pore volume, specific surface area, and pore diameter, which corresponds to half of the pore volume) for the initial and amino-functionalized copolymer samples were calculated from the cumulative pore volume distribution curves obtained by mercury porosimetry. The selectivity, sorption capacity and sorption rate of amino-functionalized poly(GMA-co-EGDMA)-en were determined under static conditions. The sorption of Cu(ll) and Ag(l) ions on poly(GMA-co-EGDMA)-en was very rapid (ti/2 value about 1 min). Slower sorption was observed for Au(lll) ions with a ti/2 value of 6.5 minutes. The different rates of Au(lll), Cu(ll) and Ag(l) sorption could be applied for gold, copper and silver ion separation from mixed solutions. The sorption of Ni(ll) and Cu(ll) ions from galvanic solution under competitive conditions was also fast, with ti/2 values of 0.5 and 2 min, respectively. However, Zn(ll) sorption was considerably slower (a ti/2 of 10 min). Similar results were obtained for galvanic solution under dynamic conditions, i.e., the metal sorption capacities of poly(GMA-co-EGDMA)-en decreased in the order: Ni(ll) > Cu(ll) >> Zn(ll). The reusability of amino-functionalized poly(GMA-co-EGDMA) for Cu(ll) sorption was tested in four sorption/desorption cycles. Regeneration experiments were performed with 0.1 and 1 M H2SO4 showed a Cu(ll) capacity loss of 50 % in the first sorption/desorption cycle. The sorption capacity increased when additional neutralization with 0.1 and 1 M NaOH was performed after each sorption/desorption cycle.

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Campillo-Cora, Claudia, Manuel Conde-Cid, Manuel Arias-Estévez, David Fernández-Calviño e Flora Alonso-Vega. "Specific Adsorption of Heavy Metals in Soils: Individual and Competitive Experiments". Agronomy 10, n. 8 (1 agosto 2020): 1113. http://dx.doi.org/10.3390/agronomy10081113.

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The partitioning between the soil solid phase and the soil solution determines the mobility of pollutants like heavy metals. If nonspecific sorption takes place, the reactions are easily reversible and heavy metals are released to soil solution increasing the probability of leaching through soil profile. Mobility and leaching are also favoured if other metals are in the system and competition for specific adsorption sites takes place. In this study, desorption equilibrium experiments were conducted after adsorption ones. The specific adsorption was evaluated through the amounts of the still adsorbed Cu, Pb, Cr, Ni and Zn after desorption experiments in ten different soils. In addition, competition adsorption and desorption binary experiments were conducted for evaluating the metal competition in three of the soils. Pb and Cu are the metals adsorbed and retained in higher amounts in all the studied soils. In slightly neutral soils, Cr is retained in lesser amounts while in acidic soils Zn is the metal less retained. Results showed that despite the high and variable amounts of organic matter in the soils, soil pH is the most important variable in neutral soils. In acidic soils, soil properties different than pH play important roles and specific sorption of Pb is related to the cationic exchange capacity of the soils while that of Zn to the clay content. Instead, the release of Cu during desorption experiments is probably due to the more soluble organic fraction of the soils. The individual retention of Cu, Zn, Ni and Pb is higher than when they are in competition, except if Cr is present. In this case, the amount of those four metals and that of Cr increased. Therefore, the presence of Cr together with cationic heavy metals favoured the adsorption of those metals in multi-metal polluted areas. Specific adsorption is also important during competition as soil affinities increase during competition experiments.

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Nikiforova, T. E., V. A. Kozlov e M. K. Islyaikin. "Regularities and mechanism of heavy metal cations sorption and (or) proton desorption by chitosan from aqueous solutions". Canadian Journal of Chemistry 97, n. 8 (agosto 2019): 621–28. http://dx.doi.org/10.1139/cjc-2018-0384.

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The sorption process of heavy metal ions from aqueous solutions using chitosan flakes and chitosan beads was studied. Chitosan gel beads were prepared using covalent crosslinking of chitosan chains by epichlorohydrin with ionic gelation by sodium tripolyphosphate. The capability of chitosan beads to absorb the heavy metal ions from aqueous solutions was studied, and the physicochemical characteristics of the sorbent were evaluated using SEM and FTIR on the model solution treatment. It was found that competitive proton sorption takes place in acidic media, which results in a transformation of amino groups into inactive ammonium-salt form and decreases in heavy metal sorption onto chitosan from aqueous acidic media. Batch adsorption experiments were performed to examine the influence of various factors such as the initial concentration of metal salts, pH, and agitation duration on the process. It was established that metal ion sorption is pH dependent and has an optimum effect at a pH of 6.0. Following the Langmuir equation, the maximum sorption of Cu2+ions is estimated to be 1,6 mol/kg of modified chitosan. The kinetic study revealed that the adsorption kinetics are well-fitted to the kinetic equation of pseudo second order. Thus, sorption of heavy metal ions by chitosan is considered to be a competitive process that occurs on amino groups of the sorbent with equivalent coordinated participation of metal cations, protons, and anions.

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Tesi sul tema "Competitive sorption and desorption"

Gao, Chan. "Devenir des substances per et poly-fluoroalkylées (PFAS) dans les estuaires : focus sur les interactions avec les sédiments en suspension". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0409.

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Les substances per et poly-fluoroalkylées (PFAS) constituent un vaste groupe hétérogène de micropolluants émergents. Du fait de leur structure physico-chimique très stable, les PFAS sont persistantes et largement répandues dans l'environnement et posent de nombreux problèmes environnementaux. Ces dernières années, le devenir des PFAS a fait l'objet d'une attention croissante. Dans le cycle des PFAS, l'air, l'eau, le sol et les sédiments sont différents compartiments impliqués. À l'exutoire des grands bassins versants et à l’interface terre-mer, les estuaires sont considérés comme la principale voie d’entrée des PFAS vers le milieu océanique, puits ultime des PFAS. Les conditions estuariennes complexes affectent le comportement des PFAS dans les sédiments et déterminent le sort final des PFAS. Les estuaires jouent par ailleurs un rôle écologique majeur et sont soumis à une forte pression chimique, générant des risques environnementaux. Il est donc important d'étudier le devenir des PFAS dans les estuaires.Les sédiments estuariens constituent un réservoir important pour les PFAS, où la sorption et la désorption se produisent et contrôlent la distribution des PFAS. Les conditions géochimiques jouent un rôle essentiel dans ce processus. D'une part, les flux fluviaux apportent d'énormes quantités de particules en suspension qui absorbent les PFAS et se déposent finalement dans les sédiments estuariens. D'autre part, au cours des cycles de marée, les particules sont remises en suspension, transportées et remises en place, désorbant ou réabsorbant les PFAS. La distribution des PFAS entre les particules et l'eau est la clé de l'étude du devenir des PFAS dans les estuaires. Les conditions contrastées de salinité et de turbidité des estuaires peuvent influencer la distribution des PFAS entre les particules et l'eau en facilitant ou en entravant la sorption/désorption, ce qui complique l'interaction entre les sédiments et l'eau pour les PFAS. Il est donc très important de réaliser des études approfondies sur la distribution des PFAS entre les particules et l'eau dans les conditions estuariennes.Ces travaux sont divisés en deux parties : 1) détermination des cinétiques d'adsorption et de désorption des PFAS seuls ou mélange (compétition) sur un substrat modèle, la kaolinite et 2) étudier l'influence de la salinité et de la turbidité sur la distribution particules-eau des PFAS en conditions estuariennes. Ces travaux fournissent des éléments importants pour paramétrer les modèles de devenir des PFAS et estimer les bilans de masse à l'interface terre-mer
To understand the fate of legacy and emerging PFAS at the land-sea interface, this work focused on the interactions with estuarine sediments. More precisely, we mainly studied the influence of co-existing PFAS, salinity (S) and suspended particulate matter (SPM) on the sediment-water partitioning of PFAS. First, to investigate the effect of coexisting PFAS on their adsorption and desorption, competitive adsorption and desorption experiments were conducted using single and mixed PFAS solutions at low concentrations, using kaolinite as model sorbent. Selected PFAS include eight perfluoroalkyl carboxylates (PFCAs), two perfluoroalkyl sulfonic acids (PFSAs) and one zwitterionic PFAS (8:2 fluorotelomer sulfonamide alkylbetaine (8:2 FTAB)), which were studied in three single-solute solutions and two mixture solutions. A pseudo-second-order kinetic model was used to fit in the adsorption and desorption kinetics data correctly. Their sorption and desorption on kaolinite were quite fast, with equilibrium reached within 2h. Sorption processes appeared to be influenced by the PFAS molecular structure: sorption increased and desorption decreased with increasing fluoroalkyl chain length, characterized by the increase of log Kd. Besides, PFSAs (i.e, PFHxS and PFOS) had greater sorption and weaker desorption than PFCAs (i.e, PFHpA and PFNA) with similar fluoroalkyl chain. The zwitterionic 8:2 FTAB showed stronger sorption and smaller desorption than anions (i.e., PFOS or PFNA) with a similar fluoroalkyl chain. Sorption and desorption data obtained for single and multi-solute experiments indicated that there was no significant statistical difference between such conditions. Thus, the influence of competitive adsorption and desorption was negligible at low concentrations. To study the influence of salinity and SPM on the sorption of PFAS, we used a sediment sample collected in the fluvial sector of the Garonne-Gironde system. We performed sorption kinetics and sorption isotherms tests for the same PFAS, under 35 combination of salinity and turbidity. Based on response surface methodology (RSM) modelling approach, results indicated the sorption kinetics of PFAS onto sediment can be described by pseudo-second-order model and 24h is the equilibrium time for targeted PFAS. Besides, PFAS sorption can be well fitted by linear model and Freundlich model, the linear sorption range for PFAS studied was in the range of 0.12 to 1.31 nM (equilibrium concentration). Moreover, based on RSM modelling approach, we found that Kd varied between 0.62 and 55271 L/kg and that both S and SPM were significant factors, i.e. the Kd of PFAS was positively related to S due to salting-out effect while it was negatively related to SPM concentration. Moreover, SPM had a stronger effect than salinity (S) for PFHxA and PFHpA, whereas S was the more dominant factor for most other compounds. For PFUnDA and 8:2 FTAB, S and SPM displayed nearly equivalent weights as drivers of Kd. In addition, a negative interaction between both factors was observed, i.e. if SPM increases, the effect of S on Kd is weaker. Overall, this work provides original results to model the sorption of legacy and emerging PFAS on estuarine sediments based on RSM modelling approach. It provides a new perspective to investigate the fate of PFAS at the land-sea interface

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Coover, James Brigham. "Phosphorus sorption and desorption in ephemeral gully erosion". Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/17865.

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Master of Science
Department of Agronomy
Nathan O. Nelson
Phosphorus (P) is an essential nutrient in crop production, but P inputs to surface waters have resulted in impairments such as eutrophication and algae blooms. Non-point sources such as agricultural fields are a main contributor of P. Kansas, being a high agricultural dependent state, has frequent fresh water body impairments. Multiple erosion and transport processes contribute to P loss. While P loss from sheet and rill erosion has been studied extensively, P loss from ephemeral gully erosion is largely unknown. The objective of this study is to understand the effects ephemeral gullies have on the transport and transformation of P. Three fields in McPherson County with well-defined ephemeral gullies were studied. Soil samples were taken in field locations that are effected by ephemeral gullies at the 0 to 2, 2 to 5, 5 to 15, and 15 to 30 cm depths. Samples were analyzed for total P, anion exchange phosphorus (AEP) (labile P), ammonium-oxalate extractable Fe, Al, and P (Fe[subscript]ox, Al[subscript]ox, P[subscript]ox), Mehlich 3 extractable Fe, Al, Ca, and P (Fe[subscript]M3, Al[subscript]M3, Ca[subscript]M3, P[subscript]M3), equilibrium phosphorus concentration at zero net sorption (EPC[subscript]0), 1:1 soil to water pH, and texture. Soil testing showed that P quantities tend to be much higher in surface soils eroded by sheet and rill erosion and lower in subsoil soil that is eroded by ephemeral gullies. The quantity of sorptive elements such as Fe and Al, were not significantly different throughout the tested area except in areas of changing soil texture. EPC[subscript]0 testing showed it was likely that P desorbs from the surface erosion of sheet and rill and is adsorbing onto the subsoil eroded from ephemeral gullies. Sediment eroded by ephemeral gullies has a P buffering capacity greater than the sediment eroded by sheet and rill, and a small quantity of ephemeral gully subsoil will have a large effect on the dissolved P concentration of runoff. Sediment, total P loss and expected dissolved P in runoff was surveyed and modeled for two of the fields. Ephemeral gullies contributed to a majority of sediment and total P loss. The addition of ephemeral gully sediment to the erosional mix of sheet and rill sediment caused the dissolved P concentration to decrease from 0.0204 to 0.0034 mg L[superscript]-1 in one field and from 0.0136 to 0.0126 mg L[superscript]-1 in another. The results of this study show that best management practices (BMPs) such as grass waterways could cause the losses of total P to decrease as much as 2 to 12 times in fields with ephemeral gullies. However, reducing ephemeral gully erosion will likely increase dissolved P concentrations up to 600% more in runoff. Therefore, BMPs need to be combined to fully control P loss from agricultural fields.

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Uygur, Veli. "Zn sorption/desorption chemistry in calcareous soils from Turkey". Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388131.

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Whitehead, Thomas William 1951. "Sorption and desorption of volatile alkyl halides in a desert soil". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191936.

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A series of twelve laboratory column experiments were conducted to determine equilibrium partitioning coefficients (K ) and kinetic rate coefficients for sorption of four hydrophobic pollutants on a low organic carbon natural soil. K 's for trichloroethene (ICE), tetrachloroethene (PCE), 1,1,1-trichloroethane (TCA), and 1,1,2,2-tetrachloroethane (PCA), were 0.17, 0.44, 0.06, and 0.05, respectively; about as expected based on empirical carbon-based partitioning equations found in the literature. Tailing of the breakthrough curves could be accounted for with a two-site non-equilibrium solute transport model. Rates were fast compared to pore water velocities normally encountered in an alluvial aquifer, but kinetic effects were observed at pore water velocities likely to be encountered during pumping, such as for site cleanup. Desorption was faster than adsorption, with forward rates of about 10⁻⁴ to 10⁻⁵ s⁻¹ and reverse rates about 10⁻³ to 10⁻⁴ s⁻¹. The two-site model indicated that slower sites constituted roughly half the total number of sites.

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Garman, Stephanie Michelle. "Desorption Kinetics of Lead from Goethite: Effect of Mixing and Sorption Period". Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/41240.

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In natural systems, the solution concentration and hence, potential bioavailability of trace metals is primarily controlled by adsorption-desorption reactions at the mineral-water interface. While many studies have been conducted to understand the adsorption of trace metals to soil minerals, less is known about long-term adsorption/desorption processes. In this study, we examined the influence of mixing and sorption period on the desorption of lead from goethite. Lead sorption was rapid and essentially complete in 1 h, with no change in the quantity of lead adsorbed over the 6 month sorption period. Desorption of lead was slower than the adsorption reaction and was best modeled by two first order equations. At all sorption densities, the desorption of lead followed the order Short-term (24 h) > Long-term non-stirred (6 months) > Long-term stirred (6 months). However, statistical analysis indicated that these differences were not statistically significant. Furthermore, the desorption rate coefficients were very similar for all the experiments indicating that there was no significant residence time effect in this study. However, a sample from a previous study that was allowed to age 5 years and then analyzed by the desorption procedure did have statistically significant differences between the long-term (5 years) and the short-term (5 months). These results suggest that longer adsorption periods, perhaps a number of years, may be necessary to determine if residence time effects are an artifact of the experimental conditions or truly the length of the adsorption period.
Master of Science

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Mower, Matthew Bywater. "Competitive desorption of carbon tetrachloride + water from mesoporous silica particles". Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Summer2005/m%5Fmower%5F081205.pdf.

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Mikutta, Christian. "Controls of the phosphate sorption and desorption kinetics of organic matter goethite associations". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979599083.

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Shi, Zhenqing. "Kinetics of trace metals sorption on and desorption from soils developing predictive models /". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 3.09 Mb., 309 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3205426.

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Davis, James Hal 1956, e James Hal 1956 Davis. "Sorption and desorption of benzene and para-xylene on an unsaturated desert soil". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/291366.

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A series of bench-scale experiments was carried out to determine the rate and efficiency with which benzene and p-xylene, components of gasoline, could be removed from an unsaturated soil by air stripping. Glass columns, 30 cm in length, were packed with soil and wetted to volumetric moisture contents of 10 and 18 percent. Air saturated with one of the volatile organic compounds (VOCs) was used to load the column. Clean air was used to strip the contaminant from the soil. Benzene and p-xylene concentrations in the soil water and air were reduced four orders of magnitude after a few hours (2-8) of stripping. Benzene was removed faster than p-xylene. Air flow was the rate-limiting step early in the stripping, however slow desorption from the soil became rate-limiting as the stripping progressed. As moisture content increased the rate of removal of both contaminants decreased.

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Wang, Guohui. "Sorption, desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials". kostenfrei, 2008. http://d-nb.info/988782308/34.

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Libri sul tema "Competitive sorption and desorption"

Selim, Hussein Magd Eldin. Sorption-desorption and transport of TNT and RDX in soils. [Hanover, N.H.]: U.S. Army Corps of Engineers, Cold Regions Research & Engineering Laboratory, 1994.

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Ticknor, K. V. Sorption/desorption experiments on Chalk River sand and potential buffer materials. Pinawa, Man: Whiteshell Laboratories, 1997.

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Grathwohl, Peter. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4615-5683-1.

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Llopis, José L. Survey of laboratory studies relating to the sorption/desorption of contaminants on selected well casing materials. [Washington, D.C.]: U.S. Environmental Protection Agency, Office of Research and Development, Office of Solid Waste and Emergency Response, 1992.

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Llopis, José L. Survey of laboratory studies relating to the sorption/desorption of contaminants on selected well casing materials. [Washington, D.C.]: U.S. Environmental Protection Agency, Office of Research and Development, Office of Solid Waste and Emergency Response, 1992.

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Laboratory, Occupational Medicine and Hygiene. Chlorinated hydrocarbon solvent vapours in air: Laboratory method using pumped charcoal sorption tubes, solvent desorption and gas chromatography. Bootle: Health and Safety Executive, 1990.

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Mmochi, Aviti J. Degradation and sorption/desorption of propanil in soils from Mahonda-Makoba drainage basin and Cheju rainfed rice field, Zanzibar, Tanzania. [Zanzibar]: WIOMSA, 2003.

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Canada, Atomic Energy of. Sorption/desorption studies of selenium on fracture-filling minerals under aerobic and anaerobic conditions / by K.V. Ticknor, D.R. Harris, T.T. Vandergraaf. S.l: s.n, 1988.

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Papelis, Charalambos. Evaluation of cesium, strontium, and lead sorption, desorption, and diffusion in volcanic tuffs from Frenchman Flat, Nevada Test Site: Macroscopic and spectroscopic investigations. Las Vegas, Nev: Desert Research Institute, 2003.

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Capitoli di libri sul tema "Competitive sorption and desorption"

Wutz, Max, Hermann Adam e Wilhelm Walcher. "Sorption und Desorption". In Theorie und Praxis der Vakuumtechnik, 62–75. Wiesbaden: Vieweg+Teubner Verlag, 1992. http://dx.doi.org/10.1007/978-3-322-87814-4_3.

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Wutz, Max, Hermann Adam e Wilhelm Walcher. "Sorption und Desorption". In Handbuch Vakuumtechnik, 62–75. Wiesbaden: Vieweg+Teubner Verlag, 1997. http://dx.doi.org/10.1007/978-3-322-99421-9_3.

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Wutz, Max, Hermann Adam, Wilhelm Walcher e Karl Jousten. "Sorption und Desorption". In Handbuch Vakuumtechnik, 62–75. Wiesbaden: Vieweg+Teubner Verlag, 2000. http://dx.doi.org/10.1007/978-3-322-99947-4_3.

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Wutz, Max, Hermann Adam e Wilhelm Walcher. "Sorption und Desorption". In Theorie und Praxis der Vakuumtechnik, 59–71. Wiesbaden: Vieweg+Teubner Verlag, 1988. http://dx.doi.org/10.1007/978-3-322-83543-7_3.

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Chorover, Jon, e Mark L. Brusseau. "Kinetics of Sorption—Desorption". In Kinetics of Water-Rock Interaction, 109–49. New York, NY: Springer New York, 2008. http://dx.doi.org/10.1007/978-0-387-73563-4_4.

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Gupta, Raj K., I. P. Abrol, Charles W. Finkl, M. B. Kirkham, Marta Camps Arbestain, Felipe Macías, Ward Chesworth et al. "Solute Sorption‐Desorption Kinetics". In Encyclopedia of Soil Science, 739–44. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-3995-9_569.

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Bachmaf, Samer, Britta Planer-Friedrich e Broder J. Merkel. "Uranium sorption and desorption behavior on bentonite". In Uranium, Mining and Hydrogeology, 515–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-87746-2_63.

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Nair, Vimala D., e K. Ramesh Reddy. "Phosphorus Sorption and Desorption in Wetland Soils". In Methods in Biogeochemistry of Wetlands, 667–81. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2136/sssabookser10.c34.

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Clapp, C. E., M. H. B. Hayes e U. Mingelgrin. "Measurements of Sorption-Desorption and Isotherm Analyses". In Humic Substances and Chemical Contaminants, 205–40. Madison, WI, USA: Soil Science Society of America, 2015. http://dx.doi.org/10.2136/2001.humicsubstances.c13.

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Elbana, Tamer A., Wenguang Sun, Joshua Padilla e H. Magdi Selim. "Kinetics of Vanadium Sorption/Desorption in Soils". In Vanadium in Soils and Plants, 49–71. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003173274-3.

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Atti di convegni sul tema "Competitive sorption and desorption"

Krishnadoss, Rajalakshmi, e Thomas A. Adams. "Integration of a Chemical Heat Pump with a Post- combustion Carbon Capture Sorption Unit". In Foundations of Computer-Aided Process Design, 484–89. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.128149.

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A novel process system which integrates an isopropanol-based chemical heat pump with a post-combustion carbon capture unit was proposed, designed, and analyzed. The system uses low-quality waste heat (~80�C) produced through the CO2 adsorption step of a carbon capture process and upgrades that heat to a higher temperature (~150�C) using the chemical heat pump. The chemical heat pump is powered mostly by the waste heat and requires only a small amount of electricity. The higher temperature heat produced can be used in the desorption stage of the CO2 capture process, displacing a portion of the existing fossil energy required. The energy and exergy performance characteristics of the chemical heat pump were computed using the results of a steady state simulation in a systems analysis. Using exergy cost correlations, the profitability of the chemical heat pump concept was estimated. It was found that for this particular configuration, the fossil energy load of desorption could be reduced by roughly 2.7% with very little parasitic electric load.

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Wolf, Jeremy, Sepideh Maaref, Benjamin Tutolo e Apostolos Kantzas. "An Experimental Study of Single Component Adsorption/Desorption Isotherms". In SPE Canadian Energy Technology Conference. SPE, 2022. http://dx.doi.org/10.2118/208920-ms.

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Abstract Within tight reservoirs, gas is stored both as free gas contained in the pores and adsorbed gas on the rock matrix. Adsorbed gas exhibits liquid-like densities resulting in significantly more gas being stored on the rock surface. By having accurate adsorption/desorption data of injected and reservoir gases, one can acquire a better understanding of the true original gas in place, as well as how to maximize production through optimal enhanced gas recovery (EGR) techniques. The aim of this research is to measure the adsorption/desorption isotherms of single-component gases on activated carbon in a series of pressure steps up to 1500 psi. The experiments are conducted at varying temperatures to establish a wide array of isotherms. Temperatures are maintained through the use of a water bath. The obtained isothermal pressure data is modeled using the Gibbs sorption isotherm and the Langmuir mathematical model, the most popular and simplistic approach. Furthermore, by plotting pressure divided by adsorption capacity as a function of pressure, Langmuir parameters are determined. From the experiments, isothermal pressure data was able to be modeled using the Gibbs sorption isotherm and the Langmuir isotherm and Langmuir parameters were determined and compared. It was observed that decreasing temperature and increasing hydrocarbon molecular weight were the main contributing factors to higher sorption capacities of the single component gases. It is important to quantify both adsorption and desorption processes because in EGR techniques such as cyclic solvent injection (CSI) injected gas is competitively adsorbing onto the rock, causing the adsorbed reservoir gas to be displaced, desorb, and subsequently be produced. Due to the aforementioned irreversibilities, by using adsorption metrics to quantify the amount of gas desorbed within the reservoir, gas production may be overestimated. To date, most adsorption/desorption experimental work has been conducted on methane, carbon dioxide, and nitrogen. This research aims to expand on previous literature by performing adsorption/desorption experiments on higher chain hydrocarbons, such as ethane and propane. By doing so, CSI EGR schemes can be more meticulously modeled as the inclusion of higher chain hydrocarbons allows for the model sorption inputs to be more representative of typical unconventional reservoir gas. This in turn will allow for more accurate production forecasting, helping minimize the financial risk of costly EGR projects.

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Safarov, Jasur, Sunil Verma, Shakhnoza Sultanova, Abhijit Tarawade e Azamat Usenov. "SORPTION AND DESORPTION OF RAW MATERIALS". In XXVII savetovanje o biotehnologiji. University of Kragujevac, Faculty of Agronomy, 2022. http://dx.doi.org/10.46793/sbt27.553s.

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The presented work is related to the study of the „water – medicinal raw materials“ system, where the influence of humidity and storage temperature on the hygroscopicity of the process was determined. Sorption isotherms help classify drying rates according to the hygroscopicity of materials to show the distribution and intensity of water compounds. Sorption isotherms make it possible to determine important information about the sorption processes of plant materials.

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Ma, Rui, e Tian C. Zhang. "Sorption and Desorption of Testosterone in Agricultural Soils". In World Environmental and Water Resources Congress 2009. Reston, VA: American Society of Civil Engineers, 2009. http://dx.doi.org/10.1061/41036(342)268.

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Luna-Flores, Mario, Mariana Gisela Peña-Juarez, Angélica Mara Bello-Ramirez, Javier Telis-Romero e Guadalupe Luna-Solano. "Moisture sorption isotherms and isosteric heat sorption of habanero pepper (Capsicum chínense) dehydrated powder". In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7637.

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Moisture sorption isotherms of the habanero pepper powder were determined using the Dynamic Vapor Sorption (DVS) method at 20, 25, 35, 45 and 55 °C in a range of water activity from 0.10 to 0.90 at which the processes of drying, packing and storage of habanero pepper are developed. The sorption capacity decreased with increasing temperature at a given water activity and the sorption isotherms showed a sigmoid form (Type II). The hysteresis phenomenon was observed in the sorption isotherms at all temperatures studied and it was more pronounced at temperatures high. The experimental sorption curves were fitting to the GAB, BET and Oswin models. It was concluded that the models that best describe the adsorption and desorption data for habanero pepper dehydrated powder were the GAB and Oswin models. The isosteric heat of water sorption was calculated with the moisture content data in equilibrium. The desorption isotherms present a higher isosteric heat in relation to the adsorption isotherms. In both, the isosteric heat decreased as the moisture content increased. Keywords: Habanero pepper dehydrated powder; Convective drying; Moisture sorption isotherms; Mathematic models

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"Mathematical modeling of sorption and desorption dynamics in adsorption systems". In Chemical technology and engineering. Lviv Polytechnic National University, 2021. http://dx.doi.org/10.23939/cte2021.01.051.

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Hosseini, M., J. B. Colliat e N. Burlion. "Numerical Simulation of Sorption-Desorption Isotherme for Cement-Based Materials". In 10th International Conference on Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures. Reston, VA: American Society of Civil Engineers, 2015. http://dx.doi.org/10.1061/9780784479346.143.

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Baishibekov, A., D. Purwaningsih, G. Toilanbay e Khaldun M. Al Azzam. "Comparative Analysis of Sorbents on Chromate Ion (VI) Sorption and Desorption: Influence of Composition and pH from Ilmenite Processing Solutions". In Challenges of Science, 117–22. Institute of Metallurgy and Ore Beneficiation JSC, Satbayev University, 2024. http://dx.doi.org/10.31643/2024.17.

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In this work, the processes of sorption and desorption of chromate ions from the solution obtained as a result of the processing of high-chromium ilmenite concentrate were studied using sorbents: Amberlite IR120 (Na), Amberlite IRA-35, PuroliteA-100, LewatitMono Plus M-500. The influence of pH factor and sorption system composition on the sorption process of chromate ions (VI) was investigated. Different polymers were tested to evaluate their combined effect on the recovery of chromate ions. A correlation was found between the increase in the efficiency of the sorption process of chromate ions (98%) and a decrease in pH from pH 13.5 to pH 2.5. In addition, the sorption process was improved at higher sorbent concentrations and the desorption efficiency increased at higher molar concentrations of sodium hydroxide (NaOH). The study's results will serve for the optimization of sorption processes for the extraction of chromate ions (VI) with the participation of various polymeric sorbents in the industry.

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Yu, Hai-bin, Ye-yao Wang e Cun-yi Song. "Sorption and Desorption Behaviors of Chlorobenzene on the Sediment of Songhua River". In 2010 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE 2010). IEEE, 2010. http://dx.doi.org/10.1109/icbbe.2010.5517313.

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Fellers, Christer, e Ake Bränge. "The Impact of Water Sorption on the Compression Strength of Paper". In Papermaking Raw Materials, a cura di V. Punton. Fundamental Research Committee (FRC), Manchester, 1985. http://dx.doi.org/10.15376/frc.1985.2.529.

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The effects of preconditioning, moisture content and relative humidity during adsorption and desorption on the compression strength of paper were evaluated for a kraft liner and an NSSC-fluting over a range of moisture content from 1-23%. The method used was the STFI Short Span test. In general, the results show that compression strength decreases with increasing moisture content. More specifically, if compression strength is evaluated as a function of moisture content, the data points fall on a single curve for both adsorption and desorption . This result is independent of the moisture history of preconditioning of the sample. If compression strength is evaluated as a function of the relative humidity of the test environment, the moisture history and preconditioning both exert a large influence on the test result. This indicates that samples of unknown moisture history should be preconditioned in much drier atmospheres than previously recommended.

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Rapporti di organizzazioni sul tema "Competitive sorption and desorption"

Gordon Borwn Jr., Jeffrey Catalano, David Singer e John Zachara. Characterization of U9VI) Sorption-Desorption Processes and Model Upscaling. Office of Scientific and Technical Information (OSTI), maggio 2007. http://dx.doi.org/10.2172/911851.

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Kung, K. S., J. Chan, P. Longmire e M. Fowler. Cesium sorption and desorption on selected Los Alamos soils. Office of Scientific and Technical Information (OSTI), agosto 1995. http://dx.doi.org/10.2172/94679.

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Phil WInston. Single Component Sorption-Desorption Test Experimental Design Approach Discussions. Office of Scientific and Technical Information (OSTI), settembre 2011. http://dx.doi.org/10.2172/1027920.

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Bai, Jing, Wenming Dong e William P. Ball. Characterization of U(VI) Sorption-Desorption Processes and Model Upscaling. Office of Scientific and Technical Information (OSTI), ottobre 2006. http://dx.doi.org/10.2172/894270.

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William Tuminello, Maciej Radosz e Youqing Shen. Novel Sorption/Desorption Process for Carbon Dioxide Capture (Feasibility Study). Office of Scientific and Technical Information (OSTI), novembre 2008. http://dx.doi.org/10.2172/993828.

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Zachara, John M. Characterization of U(VI) Sorption-Desorption Processes and Model Upscaling. Office of Scientific and Technical Information (OSTI), giugno 2003. http://dx.doi.org/10.2172/835467.

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Brown, Gordon E. Characterization of U(VI) Sorption-Desorption Processes and Model Upscaling. Office of Scientific and Technical Information (OSTI), giugno 2003. http://dx.doi.org/10.2172/835468.

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Zachara, John M., Brown, Gordon, E., Peter C. Lichtner e William Ball. Characterization of U(VI) Sorption-Desorption Processes and Model Upscaling. Office of Scientific and Technical Information (OSTI), giugno 2004. http://dx.doi.org/10.2172/839157.

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Boyd, S., e W. Guerin. Influence of sorption/desorption processes on the bioavailability of organic contaminants. Office of Scientific and Technical Information (OSTI), gennaio 1990. http://dx.doi.org/10.2172/7169461.

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Trautschold, Olivia Carol. Dynamic Moisture Sorption and Desorption in Fumed Silica-filled Silicone Foam. Office of Scientific and Technical Information (OSTI), settembre 2016. http://dx.doi.org/10.2172/1321702.

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