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Auswahl der wissenschaftlichen Literatur zum Thema „Boranes – Absorption et adsorption“
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Zeitschriftenartikel zum Thema "Boranes – Absorption et adsorption"
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Kukulka, Wojciech, Krzysztof Cendrowski, Beata Michalkiewicz und Ewa Mijowska. „Correction: MOF-5 derived carbon as material for CO2 adsorption“. RSC Advances 9, Nr. 59 (2019): 34349. http://dx.doi.org/10.1039/c9ra90077b.
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Li, Yu, Chong Meng, Meng Wang, Bing Chuan Cheng und Chang Zhi Zhou. „Regulation of the Absorption of Cu with Various of Pollutants in Sediment through Fractional Factorial Design“. Advanced Materials Research 742 (August 2013): 363–66. http://dx.doi.org/10.4028/www.scientific.net/amr.742.363.
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The resolution IV fractional factorial design was used to study the adsorption regularity of Cu coexisted with various pollutions (Zn, Pb, Cd, Ni, atrazine, malathine, et al.) onto the sediment. The study found that the main effect and the second-order interaction effect of ten pollutions concentration had significant influence on the adsorption of Cu on the sediment. The concentration of Cu was the critical factor to the promotion of the absorption capacity of Cu in sediment, the second-order effect played the critical role in restraining the absorption of Cu. The main effect of Cd, and the second-order interaction effect include Cd, had greatly inhibited the absorption of Cu in sediment, and the contribution was over 30%, which meant there was prominent antagonism between Cu and Cd. Fractional factorial design can provide a theoretical basis for the reveal of the adsorption mechanism between the different contaminants in the water environment pollution.
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Sadeghi, A. A., A. Nikkhah und P. Shawrang. „The effect of thermally activated natural zeolite on colostral IgGl, IgM and Aga absorption in newborn Holstein calves“. Proceedings of the British Society of Animal Science 2005 (2005): 210. http://dx.doi.org/10.1017/s1752756200011212.
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Neonatal calves are born with no immunoglobulins (Igs) in the blood stream and rely on Ig from colostrum through passive immunity transfer. Unfortunately, transfer of passive immunity to neonatal calves is too often inadequate, resulting in excessive rates of morbidity and mortality. Natural zeolite is characterized by framework of linked tetra hydration enclosing open cavities in the form of channels, and cages with ion exchanger and adsorption capacity. In literature, there were reported that thermally activated natural zeolite (T-zeolite) could increase colostral IgG absorption and decrease susceptibility of neonates to infections (Sadeghi et al., 2004; Stojic et al., 1995). To our knowledge, little information is available concerning the effect of thermally activated natural zeolite on colostral IgG1, IgM and IgA absorption in neonates. Our experiment was designed to investigate the effect of thermally activated natural zeolite on colostral IgG1, IgM and IgA absorption in newborn Holstein calves.
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Cao, Weijie, Tomoki Uchiyama, Kentaro Yamamoto, Toshiyuki Matsunaga, Toshiharu Teranishi, Ryota Sato, Hideto Imai, Yoshiharu Sakurai, Yoichiro Tsuji und Yoshiharu Uchimoto. „Operando X-Ray Absorption Spectroscopic Study on Influence of Specific Adsorption of Sulfo Group in Perfluorosulfonic Acid Ionomer Towards ORR Activity of Pt/C Catalyst“. ECS Meeting Abstracts MA2022-02, Nr. 42 (09.10.2022): 1559. http://dx.doi.org/10.1149/ma2022-02421559mtgabs.
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Polymer electrolyte fuel cells (PEFCs) are clean energy devices with polymer electrolytes and are expected to play an important role in the development of a global renewable energy system and a pure hydrogen energy society in the future. PEFCs have already been applied for small-scale energy systems such as fuel cell vehicles (FCVs). Pt-based catalysts are basically used due to the relatively inefficient reaction kinetics and catalyst degradation under strong acidic conditions during the oxygen reduction reaction (ORR). However, there are still many difficulties in realizing acceptable cost-effective FCVs. It is known that the ORR activity of Pt-based catalysts is reduced by specific adsorption of anionic species. Perfluorosulfonic acid ionomers such as Nafion® are commonly included in the catalyst layers of PEFCs to provide protonic pathways for promoting the ORR1. However, direct observation of anion adsorption on practical Pt nanoparticle/C catalysts for perfluorosulfonic acid ionomers using X-ray absorption spectroscopy (XAS) still has less report. In this study, to achieve specific adsorption over a higher potential range that is at least equal to the ORR active potential (around 0.90 V vs. RHE), operando XAS measurements were performed; the electronic status and local structural change of Pt atoms induced by the specific adsorption of anions at any potential were observed2. Pt/C (29.1 wt.%; TEC10V30E) catalyst supported was purchased from TKK. Nafion® solution was employed to prepare Pt/C catalyst ink with I/C ranging from 0.0 to 1.0. And the amount of Pt/C was adjusted to form a 20 µgcarbon cm-2 catalyst layer after dropping 10 μL on a glassy carbon RDE. The electrochemical cell was constructed using a model electrode fabricated in the working electrode, a Pt mesh for the counter electrode, a reversible hydrogen electrode for the reference electrode, and 0.1 M HClO4 aq for the electrolyte. operando XAS measurement of Pt L-edge was carried out in SPring-8 (Japan). The specific activity decreased as the I/C ratio increased from 0.0 to 0.20. We utilized many methods to evaluate the adsorption species separately, including the measurements of ECSA and oxygen coverage, CO stripping voltammetry, operando X-ray absorption fine structure, and analysis of 5d orbital vacancy. The ECSA and oxygen coverage did not change with increasing ionomer content, indicating that the Pt/C catalyst activity was affected by other adsorption species. A comparison of the CO displacement charge and 5d orbital vacancies of the Pt/C catalysts with I/C = 0.0 and 1.0 suggests that the ionomer-specific adsorption increases when the I/C ratio of the Pt/C catalyst is 1.0; active sites on the surface of the Pt/C catalyst are occupied, resulting in lower catalyst activity. Acknowledgment This work was supported by the project (JPNP20003) and a NEDO FC-Platform project commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References: [1] Subbaraman, R.; Strmcnik, D.; Markovic, N. M.; et al. J. Chem. Phys. Phys. Chem. 2010, 11, 13, 2825-2833. [2] Liu, C.; Uchiyama, T.; Uchimoto, Y.; et al. ACS Appl. Energy Mater. 2021, 4 (2), 1143-1149. Figure 1
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Espinosa-Garza, Gerardo, Imelda de Jesús Loera-Hernández und Edgardo Jorge Escalante Vázquez. „Elimination of Hg (II) in Water by Adsorption through Banana“. Key Engineering Materials 931 (09.09.2022): 139–49. http://dx.doi.org/10.4028/p-7t5808.
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Banana peel is a low-cost resource that can be used in a wide range of chemical and industrial processes. The novelty of this research is the use of dehydrated and sieved banana peel to remove mercury from water. The main objective of this research is to evaluate the capacity of the banana peel as an adsorbent capable of removing mercury from contaminated water. It has been shown to be an efficient, low-cost, and environmentally friendly process because banana peel is an environmental waste. To determine the ability of the banana peel to adsorb mercury, the following variables were considered: Hg concentration in water (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 ppb), particle size of the banana peel (100, 150, 200, 250 and 300 microns), quantity of banana peel per 125 ml of solution contaminated with Hg (2 and 5 grams), the contact time was (20, 40 and 60 minutes); it was not necessary to modify the pH of the solutions to obtain high % of mercury removal. The minerals and fatty acids present in the banana peel were also analyzed to improve the interpretation of the adsorption results. A higher adsorption capacity of mercury was perceived with a banana peel sieved at 150 microns; the results are consistent with other research works such as Cd (II) adsorption according to Azarpira et al. [1] where absorption is improved by decreasing the particle size of the filter material. The effectiveness of bioadsorption depends on the initial concentration of mercury ions and the filter material, the particle size of the filter material, the contact time between the mercury ions and the filter material and the pH (although in this project it is not this variable has been intervened). This study demonstrates that the banana peel used as an adsorbent is very efficient and inexpensive for removing mercury from wastewater. It became possible to demonstrate that the amount of Hg adsorbed per unit mass of absorbent increases with increasing initial Hg concentration in contaminated water, as in other metals [1]. The results of this study have confirmed the viability of using banana peel as an effective alternative for removing mercury from mercury-contaminated waters. Future studies will help to evaluate the economic use of this bioadsorbent and the identification of the main active elements it possesses in mercury adsorption. This study will allow a deeper understanding of the mercury absorption process and will verify the potential possibilities of methods to improve the adsorption process.
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Motakef kazemi, Negar. „Zinc based metal–organic framework for nickel adsorption in water and wastewater samples by ultrasound assisted-dispersive-micro solid phase extraction coupled to electrothermal atomic absorption spectrometry“. Analytical Methods in Environmental Chemistry Journal 3, Nr. 04 (29.12.2020): 5–16. http://dx.doi.org/10.24200/amecj.v3.i04.123.
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In this research, Zn2(BDC)2(DABCO) metal–organic framework (MOF) as a solid phase was used for separation and preconcentration toxic nickel ions (Ni) from water samples by ultrasound assisted-dispersive-micro solid phase extraction coupled to electrothermal atomic absorption spectrometry (USA-D-μ-SPE/ET-AAS). The MOF nanostructure was characterized by field emission-scanning electron microscope (FE-SEM) and transmission electron microscopey (TEM) for presentation of morphology and size of MOF synthesis. By procedure, 25 mg of Zn2(BDC)2(DABCO) as MOF adsorbent was added to 25 mL of water samples and then, Ni ions chemically adsorbed based on dative bonding of nitrogen in DABCO (1,4-diazabicyclo [2.2. 2]octane); N2(C2H4)3) at pH=8. The adsorbent was separated from liquid phase by syringe cellulose acetate filters (SCAF, 0.2 μm) and Ni ions back extracted from MOF adsorbent before determined by ET-AAS. The maximum recovery of MOF for nickel ions as a physically and chemically adsorption was obtained 34.6% and 98.8% at pH=3 and 8, respectively.
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Doan, Huong, Ricardo Sgarbi, Quentin Labarde und Marian Chatenet. „The Positive Effects of Carbon-Coating Layers on Protecting the Nanoparticle Towards Poisoning Ions or Gases“. ECS Meeting Abstracts MA2023-02, Nr. 41 (22.12.2023): 2030. http://dx.doi.org/10.1149/ma2023-02412030mtgabs.
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Recently, the research that explores the positive effects of carbon-coating nanoparticles to fight the severe oxidation/corrosion in Alkaline fuel cell (AFC), Proton-exchange membrane fuel cell (PEMFC) or water electrolyzer is well-recognized, since the carbon layers can extend the catalyst’s durability towards hydrogen oxidation/evolution reactions (HOR, HER) and oxygen evolution/reduction reactions (OER, ORR). Especially for the reactions in alkaline pH, with the graphite coating, the Ni nanoparticles in both HOR and HER can resist passivation and hydride poisoning. [1,2] Similarly, in the same alkaline conditions, the amorphous carbon coating slows down the degradation of Pd catalysts.[3] Moreover, the coating can block big ions such as halide, thus benefiting Pt group metals from resisting halide adsorption, that eventually prevents the dissolution of metal.[4,5] In this work, we examined the gas poisoning effects on coated catalysts. For example, we synthesized carbon-coated Pd-Ni nanoparticles, supported on Vulcan carbon and studied its electrochemical response in 0.1M KOH at room temperature and its tolerance towards CO gas. As a result, Pd-Ni coated had better resistance to passivation compared to the non-coated Pd-Ni catalyst. It also showed that the thickness of the carbon coating layers was sufficient to block the CO absorption in RDE condition initially (Figure 1, black solid line). Only after 150 cycles of accelerated stress test in Ar (AST-Ar, using potential stepping between 0.1 and 1.23 V vs. RHE with a pulse of 3 s at each potential in Ar-saturated electrolyte, 6s/cycles), the passivation that occurred at high potential could cause a small portion of Pd to be “exposed” and adsorb CO (Figure 1, red solid line). After another 150 cycles of AST-Ar (AST 300), more Pd was exposed to CO adsorption but not fully. This proves the carbon-coating layers can protect the nanoparticles from poison contaminant gas such as NOx, SOx, CO, or the COx-like species. Both AFC and PEMFC systems can benefit from this type of catalyst to operate extensively without losing catalytic activity to passivation or pollution issues. References [1] Gao, Y. et al. ACS Appl. Mater. Interfaces 2020, 12 (28), 31575–31581. [2] Doan, H. et al. J. Electrochem. Soc. 2021 168 084501 [3]Sgarbi, R., Doan, H. et al. Electrocatalysis 2022. [4] Lin, G. et al. J. Electrochem. Soc. 2016, 163 (1), A5049–A5056. [5] Mukerjee, S., Doan ,H. et al. - US Patent 10,784,518, 2020 Figure 1
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Rakhtshah, Jamshid. „Separation and determination of cadmium in water samples based on functionalized carbon nanotube by syringe filter membrane- micro solid-phase extraction“. Analytical Methods in Environmental Chemistry Journal 4, Nr. 01 (28.03.2021): 5–15. http://dx.doi.org/10.24200/amecj.v4.i01.132.
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A simple and fast separation of cadmium (Cd) based on functionalized carbon nanotubes with 2,3-dimercapto-1-propanol (CNTs@DHSP) was achieved in water samples before a determination by atom trap flame atomic absorption spectrometry (AT-FAAS). In this study, Cd(II) ions were extracted by syringe filter membrane-micro solid phase extraction procedure(SFM-μ-SPE). Firstly, 20 mg of the CNTs@DHSP as solid-phase added to 20 mL of water sample in a syringe, then dispersed for 3 min after adjusting pH up to 7 and pass through SFM very slowly. After extraction, the Cd(II) ions were back-extracted from SFM/CNTs@DHSP by 1.0 mL of eluent in acidic pH. Finally, the cadmium concentration was measured by AT-FAAS. Under the optimal conditions, the linear range (2–90 µg L−1), LOD (0.75 µg L−1) and enrichment factor (19.6) were obtained (RSD<1.5%). The adsorption capacity of Cd(II) with the CNTs@DHSP was obtained about 152.6 mg g-1. The method was validated by certified reference materials (SRM, NIST) and ET-AAS in water samples.
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Kralin, Vyacheslav, Anton Orekhov, Roman Kamyshinsky, Yury Chesnokov und Polina Demina. „Abstract P-35: Cryo-Electron Tomography of Protein Conjugated Upconverting Nanophosphors“. International Journal of Biomedicine 11, Suppl_1 (01.06.2021): S27. http://dx.doi.org/10.21103/ijbm.11.suppl_1.p35.
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Background: Over the past decades, significant advances have been made in the field of creating nanobioreagents for solving modern medicine problems (Grebenik et al., JBO, 2013). However, the problem of their low accumulation rate in pathological tissue in vivo experiments still remains. First of all, it is associated with the adsorption of blood proteins on the surface of nanobioreagents and the protein layer formation, which significantly changes the surface properties, which leads to their rapid excretion by the reticuloendothelial system. In particular, it is possible to reduce the blood plasma proteins adsorption and increase the time spent in the circulatory system by forming a coating of proteins. Methods: In situ cryоelectron tomography (Cryo-ET) is the only method that allows the experimental observation of protein structures on the nanoparticle’s surface in their natural functional state. The basic principle of the method is to obtain a series of projections of a vitrified sample thin lamella at different tilt angles related to an incident electron beam. Their further processing leads to obtaining the volumetric information about the structure of the sample. The use of a cryo-focused ion beam (Cryo-FIB) in specimen thinning makes it possible to carry out experiments with thin sections of cellular structures and observe the penetration of nanoparticles into the intracellular environment. Results: Upconverting nanophosphors (AN) were used as a nanoplatform for creating a protein coating. To create a protein coating on the AN surface, they were functionalized using an amphiphilic polymer containing carboxyl groups. Then, conjugation with protein molecules from the class of immunoglobulins was carried out by the method of carbodiimide activation. At each stage of synthesis and modification, AN solutions with different size distribution were vitrified for subsequent tomography. After a series of experiments to study the morphology of nanoparticles, an experiment on their successful absorption by cells of the cancer line A549 was carried out. Conclusion: Within this work, a series of in situ Cryo-ET methods were proposed and applied for structural characterization and visualization of the processes of synthesis, modification, and engulfment of nanoparticles into cellular systems. For the first time in its native form, the engulfment of ANF into the internal environment of the A549 cancer line cells was demonstrated.
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Schmid, O., P. Artaxo, W. P. Arnott, D. Chand, L. V. Gatti, G. P. Frank, A. Hoffer, M. Schnaiter und M. O. Andreae. „Spectral light absorption by ambient aerosols influenced by biomass burning in the Amazon Basin. I: Comparison and field calibration of absorption measurement techniques“. Atmospheric Chemistry and Physics 6, Nr. 11 (21.08.2006): 3443–62. http://dx.doi.org/10.5194/acp-6-3443-2006.
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Abstract. Spectral aerosol light absorption is an important parameter for the assessment of the radiation budget of the atmosphere. Although on-line measurement techniques for aerosol light absorption, such as the Aethalometer and the Particle Soot Absorption Photometer (PSAP), have been available for two decades, they are limited in accuracy and spectral resolution because of the need to deposit the aerosol on a filter substrate before measurement. Recently, a 7-wavelength (λ) Aethalometer became commercially available, which covers the visible (VIS) to near-infrared (NIR) spectral range (λ=450–950 nm), and laboratory calibration studies improved the degree of confidence in these measurement techniques. However, the applicability of the laboratory calibration factors to ambient conditions has not been investigated thoroughly yet. As part of the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia – SMOke aerosols, Clouds, rainfall and Climate) campaign from September to November 2002 in the Amazon basin we performed an extensive field calibration of a 1-λ PSAP and a 7-λ Aethalometer utilizing a photoacoustic spectrometer (PAS, 532 nm) as reference device. Especially during the dry period of the campaign, the aerosol population was dominated by pyrogenic emissions. The most pronounced artifact of integrating-plate type attenuation techniques (e.g. Aethalometer, PSAP) is due to multiple scattering effects within the filter matrix. For the PSAP, we essentially confirmed the laboratory calibration factor by Bond et al. (1999). On the other hand, for the Aethalometer we found a multiple scattering enhancement of 5.23 (or 4.55, if corrected for aerosol scattering), which is significantly larger than the factors previously reported (~2) for laboratory calibrations. While the exact reason for this discrepancy is unknown, the available data from the present and previous studies suggest aerosol mixing (internal versus external) as a likely cause. For Amazonian aerosol, we found no absorption enhancement due to hygroscopic particle growth in the relative humidity (RH) range between 40% and 80%. However, a substantial bias in PSAP sensitivity that correlated with both RH and temperature (T) was observed for 20%<RH<30% and 24°C<T<26°C, respectively. In addition, both PSAP and Aethalometer demonstrated no sensitivity to gaseous adsorption. Although very similar in measurement principle, the PSAP and Aethalometer require markedly different correction factors, which is probably due to the different filter media used. Although on-site calibration of the PSAP and Aethalometer is advisable for best data quality, we recommend a set of "best practice" correction factors for ambient sampling based on the data from the present and previous studies. For this study, the estimated accuracies of the absorption coefficients determined by the PAS, PSAP and Aethalometer were 10, 15 and 20% (95% confidence level), respectively.
Dissertationen zum Thema "Boranes – Absorption et adsorption"
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Poucin, Cyprien. „Borane adsorption on MgO nanoparticles for increased catalytic activity in the cycloaddition of CO2 on epoxides“. Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS142.pdf.
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La capture et la valorisation du dioxyde de carbone sont devenus des défis majeurs pour les décennies à venir. Les technologies de capture sont déjà suffisamment matures pour être mises en œuvre à l'échelle industrielle, mais les technologies de valorisation font encore défaut. Ce travail de thèse se concentre sur le développement de nouveaux catalyseurs pour la valorisation chimique du CO2. L'introduction bibliographique souligne le potentiel des oxydes alcalino-terreux pour la capture et la valorisation du CO2 en raison de leur capacité à former facilement des carbonates, ainsi que le développement récent de la chimie des Paires de Lewis Frustrées (FLP) pour l'activation de petites molécules comme le CO2. Nous y proposons une stratégie de synthèse de nanoparticules d'oxyde de magnésium fonctionnalisées avec des ligands boranes pour créer une interaction de type FLP à la surface et augmenter l'activité catalytique des nanoparticules dans la cycloaddition du CO2 sur des époxydes. Dans la première partie de ce travail, la synthèse de nanoparticules d'oxyde de magnésium par précipitation-calcination est étudiée. Les paramètres de réaction tels que la température de calcination et les lavages post-synthèse ont un impact sur la morphologie et l'état de surface des nanoparticules. La deuxième partie de ce travail se concentre sur l'adsorption de boranes sur les nanoparticules de MgO avec et sans présence de CO2. La preuve d'une interaction MgO-CO2-BPh3 est apportée par des analyses de spectroscopie infrarouge. Une interaction unique entre MgO et le chloroborane BCl2Ph est mise en évidence par un changement de couleur visuel des nanoparticules ainsi que par spectroscopie infrarouge. La dernière partie de ce travail se concentre sur l'étude catalytique de la réaction de cycloaddition. La comparaison entre les différents catalyseurs MgO confirme l'importance des paramètres de synthèse des nanoparticules sur leur activité. L'adsorption de boranes modifie l'activité et/ou la sélectivité de MgO en fonction du solvant de réaction. L'ajout de BCl2Ph augmente l'activité du catalyseur MgO d'un facteur 10 mais réduit également sa sélectivité vers la formation du carbonate cyclique. L'impact de la température, de la concentration et de la durée de la réaction sur les performances catalytiques de ce couple nanoparticule-ligand est étudié afin de dévoiler l'origine de cette synergie inédite entre MgO et BCl2PhCarbon dioxide capture and valorisation have become major challenges for the future decades. Capture technologies are already mature enough to start being implemented at industrial scale but valorisation technologies are still lacking. This thesis work focuses on the development of new catalysts for CO2 chemical valorisation. The bibliographic introduction emphasizes the potential alkaline earth oxides for CO2 capture and valorisation due to their ability to easily form carbonates, as well as the recent development of Frustrated Lewis Pair (FLP) chemistry for the activation of small molecules like CO2. We propose a strategy to synthesize magnesium oxide nanoparticles functionalised with borane ligands to create FLP-like interaction at the surface and increase the catalytic activity of the nanoparticles in the cycloaddition of CO2 on epoxides. In the first part of this work, the synthesis of magnesium oxide nanoparticles by precipitation-calcination is studied. Reaction parameters like calcination temperature and post synthesis washings are shown to impact the nanoparticles morphology and surface state. The second part of this work focuses on borane adsorption on MgO nanoparticles with and without presence of CO2. Proof of a MgO-CO2-BPh3 interaction is found using infrared spectroscopy analyses. A unique interaction between MgO and the chloroborane BCl2Ph is evidenced by a visual colour change of the nanoparticles and by infrared spectroscopy. The last part of this work focuses on the catalytic study of the cycloaddition reaction. Comparison between the different MgO catalysts confirmes the importance of the nanoparticles synthesis parameters on their activity. Adsorption of borane modifies the MgO activity and/or selectivity depending on the reaction solvent. The addition of BCl2Ph increases the activity of the MgO catalyst by a factor 10 but also reduces the selectivity toward cyclic carbonate. Impact of temperature, concentration and reaction duration on the catalytic performances of this nanoparticle¬ ligand pair is studied to unveil the origin of this unreported synergy between MgO and BCl2Ph
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Mohd, Ali. „Adsorption et électrosorption d'herbicides et de tensioactifs sur charbons actifs en grains“. Pau, 1996. http://www.theses.fr/1996PAUU3028.
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Ce travail relatif a l'adsorption et l'electrosorption (adsorption sous potentiel impose) de polluants sur charbons actifs en grains comporte trois parties : la premiere partie a pour but d'etudier l'influence sur l'interaction adsorbat-adsorbant de la nature physique et chimique du charbon actif. Les resultats obtenus, par les methodes de titrage de boehm, de chromatographie gazeuse inverse et d'une combination de ces deux methodes, ont permis d'identifier separement l'effet sur les forces d'interaction de la porosite et des groupements fonctionnels. La deuxieme partie est consacree a l'etude de l'adsorption d'herbicides et de tensioactifs sur charbon actif en grains (cag) en regime dynamique. Les resultats obtenus montrent que la capacite et la cinetique d'adsorption en flux continu sont influencees par les proprietes de l'adsorbat et celles de l'adsorbant. Les parametres utilises sont la solubilite, la charge et la concentration pour les solutes, la porosite et les proprietes acido-basiques pour l'adsorbant. La capacite d'adsorption varie lineairement avec ln t. La derniere partie s'interesse a l'etude de l'electrosorption de deux herbicides et de trois tensioactifs. Les resultats montrent, pour les herbicides atrazine et simazine, que l'application d'un potentiel negatif au cag augmente legerement l'adsorption tandis qu'un potentiel positif diminue nettement la quantite retenue. Pour les tensioactifs anionique (abs) ou non-ionique (triton n-101), l'effet d'un potentiel applique est relativement faible et difficile a interpreter. Pour le cdbac, tensioactif cationique, l'alternance de cycles positifs et negatifs donne lieu a une electrosorption reversible et comprise entre 10 et 15%.
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Caja, Monique. „Adsorption du gaz naturel sur les charbons en conditions anhydres et saturées en eau : Etude des quantités adsorbées et du fractionnement isotopique“. Aix-Marseille 2, 2000. http://www.theses.fr/2000AIX22019.
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Deyme, Michel. „Modification de la composition chimique superficielle de polymères : étude de l'adsorption du collagène aux interfaces air ou polymère/solutions aqueuses“. Paris 11, 1989. http://www.theses.fr/1989PA114804.
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Mercury, Maud Chloé. „Etude de méthodes et moyens d'adsorption/désorption pour l'analyse en ligne de traces de dioxines/furannes à l'émission de sources fixes“. Aix-Marseille 1, 2010. http://www.theses.fr/2010AIX11049.
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La gestion des déchets est un problème majeur de notre société de consommation. En 2008, la France a produit 868 millions de tonnes de déchets. Aujourd’hui, un des principaux moyens de valoriser et d’éliminer nos déchets ultimes est l’incinération. Cependant, depuis la découverte des « dioxines » issues des procédés de combustion, cette technique est devenue un sujet d’inquiétude. L’application de la réglementation fixant des seuils limites à l’émission a engendré une forte diminution des émissions des sources fixes. Toutefois, il apparaît important de connaître et maîtriser en « temps réel » les taux de dioxines émis en sortie d’incinérateur. Ces travaux s'intègrent dans une étude globale d'un dispositif de mesure en ligne, "temps réel" et directe de dioxines/furannes à l'émission de sources industrielles fixes. Ils concernent plus spécifiquement l’étude de nouveaux moyens d’adsorption sélectifs de congénères toxiques vis-à-vis des autres congénères et des composés de la matrice gazeuse des rejets, matériaux qui seront implantés dans ce dispositif en ligne. Dans un premier temps, ces travaux se sont focalisés sur l'étude, la synthèse et la caractérisation de nouveaux matériaux adsorbants sélectifs de type zéolithique. Ces matériaux ont été utilisés comme supports lors de l’adsorption de dioxines en solution (2,3-DCDD et 1,2,3,4-TCDD) et ont été comparés aux adsorbants utilisés dans la norme NF EN 1948 lors du prélèvement à l’émission. Cette étude de l’adsorption de dioxines en solution dans l’isooctane a permis d’identifier la zéolithe NaX comme la plus efficace pour le piégeage sélectif des dioxines. En parallèle, un appareillage polyvalent d’adsorption/désorption thermique en ligne de dioxines en phase, gazeuse a été conçu et mis au point. Ce dispositif est couplé à un chromatographe en phase gazeuse et à un spectromètre de masse. Il permet l’analyse en ligne de flux de gaz étalon de dioxines et l’analyse de dioxines piégées dans un tube d’adsorbants. L’ensemble de ces travaux ont permis de démontrer l’intérêt d’utiliser les zéolithes pour le piégeage sélectif des dioxines en phase gazeuse dans un pré-dispositif de terrain d’adsorption/désorption thermique en ligne de dioxines à l’émission de sources fixesWaste management is a major problem of our society where the amount of waste is still increasing. In 2008, in France, 868 million tons of waste were produced. Today, incineration is considered to be an effective method for disposing of waste. However, since the discovery dioxins generated in all waste plants, this technique becomes a topic of great concern. The authorities require a regulation of dioxin emissions lower than 0. 1 ng ITEQ. M-3 in Europe. Consequently it appears very important to measure and control in “real time” dioxin emission levels from waste incinerators. The major focus of this dissertation work centers on the development of an on-line, real time and direct monitoring technique to study stationary emission sources of dioxins/furans. It concerns the study of new classes of selective adsorbents; in relation to the complexity of the gas mixture in the incinerator’s emissions and to the possible existence of the gas phase dioxin congeners. In a first time, these works focus on study, synthesis and characterization of new selective adsorbent materials as zeolites. These materials have been used as supports for adsorption of solutions of dioxins (2,3- DCDD and 1,2,3,4-TCDD in isooctane) and they have been compared to adsorbents used in NF EN 1948 standard during emission sampling. This study shows that NaX zeolite was the best adsorbent for selective trapping on dioxins. In a second time, an analytical method for on line monitoring of gas phase dioxin at the emission of waste incinerators is designed and developed. This method is based on an adsorption/ thermal desorption device coupled to gas chromatography and mass spectrometry. The device allows the on-line analysis of the standard gas flue of dioxins and the analysis of dioxins trapped in an adsorbent tube. To conclude, these works shows the interest of use zeolites for selective trapping of gas phase dioxins in an on-line field device of adsorption/ thermal desorption of dioxins from stationary sources
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Benaïssa, Houcine. „Adsorption de propane et propylène sur corps microporeux“. Grenoble INPG, 1988. http://www.theses.fr/1988INPG0106.
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Prevision des equilibres d'adsorption de melanges gazeux a partir de la seule connaissance des equilibres des gaz purs. Etude de l'adsorption du melange propane-propylene sur la zeolite 13x et le charbon actif microporeux a 23 et 50**(o)c et de 0,2 a 101kpa
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Nanakassé, Sidiki. „Sur l'utilisation du gel de silice dans des machines frigorifiques à affinité : adsorption de l'eau et du méthanol“. Dijon, 1986. http://www.theses.fr/1986DIJOS070.
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Etude théorique de l'évolution morphologique du gel de silice (Rhône-Poulenc, Prolabo) sous l'action combinée de la température et de la vapeur d'adsorbat (eau, méthanol). Application à la réfrigération. Le système gel de silice-adsorbat (eau, méthanol) est très efficace dans le cas des faibles différences de température entre la source froide et la source chaude, et la source froide et la température de l'évaporateur; mais il est très sensible aux écarts de température au niveau de l'adsorbeur. La faible vitesse d'adsorption entraine quelques difficultés à utiliser ce système pour la mise en froid d'une charge. Par contre, il sera facilement utilisable pour la compensation des pertes thermiques.
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Navarro, Pedro. „Etude du comportement électrochimique des électrodes à pâte de carbone : application à l'étude des espèces adsorbées sur solide non électroactif“. Lyon 1, 1996. http://www.theses.fr/1996LYO10025.
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Ce travail a pour objectif l'etude electrochimique des electrodes a pate de carbone modifiees par l'introduction sur solide non electroactif de molecules organiques. La premiere partie est consacree a l'adsorption de molecules d'alizarine s et de pyrocatechol sur alumine. Les voltamperogrammes ont ete traces et les rendements de la reaction electrochimique ont ete evalues. Une relation lineaire entre la quantite d'electricite et la masse de molecules organiques presentes dans l'electrode a ete trouvee. Dans une seconde partie, nous decrivons l'etude des molecules organiques ayant des proprietes complexantes adsorbees sur alumine: dithizone, 8-hydroxyquinoleine et 1,10 phenanthroline. L'incorporation a ete faite en evaporant le solvant ou a ete dissous le complexant. La poudre a ete utilisee pour la preparation de l'electrode a pate de carbone. Les preconcentrations des ions metalliques dans des cellules separees ont ete realisees a circuit ouvert pendant un temps fixe, puis la determination voltamperometrique a ete effectuee. Les ions pb#2#+ et cd#2#+ ont ete determines avec l'electrode qui contient de la dithizone. Une relation lineaire est obtenue entre le courant de pic et la concentration pour le plomb. Les determinations realisees pour le cadmium sont similaires. Quelques essais ont ete effectues en utilisant le nujol comme liant, le plomb a ete determine. Dans ce cas il a ete necessaire d'activer prealablement l'electrode pour pouvoir preconcentrer cet ion. Le courant de pic est lineaire avec la concentration. Des essais similaires ont ete faits avec la 8-hydroxyquinoleine et la 1,10 phenanthroline pour etudier la reponse des ions cd#2#+, pb#2#+, hg#2#+, co#2#+ et fe#2#+
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Elayadi, Houda. „Comparaison physico-chimique et sites catalytiques entre les solides Au/CeO2 préparés par deux méthodes différentes : déposition-précipitation et imprégnation“. Littoral, 2010. http://www.theses.fr/2010DUNK0269.
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Deux catalyseurs 4%Au/CeO2 ont été préparés par deux méthodes différentes : déposition-précipitation (DP) et imprégnation (Imp). L’analyse par DRX, MEB et MET a permis de mettre en évidence la présence des nanoparticules d’or dans le solide DP et des grosses particules d’or à côté de nanoparticules pour le catalyseur Imp. Dans la suite, les deux catalyseurs ont été testés dans trois réactions : oxydation totale du propène, oxydation de CO et combustion du noir de carbone. Dans les trois réactions, le catalyseur DP a représenté une meilleure activité comparée à celle du catalyseur Imp. Cette activité a été reliée à la présence des nanoparticules d’or sur la surface du catalyseur DP, à la meilleure dispersion de ces particules et enfin à la présence d’une quantité, plus importante que dans l’imprégné, de l’or chargé positivement à côté de l’or métallique et les ions O2- du réseau de CeO2. La faible activité catalytique du catalyseur Imp a été corrélée à la présence, à côté des nanoparticules, des grosses particules d’or et à la forte teneur en chlorures dans ces catalyseurs car ces derniers sont considérés comme poison catalytique. Dans l’objectif d’étudier les propriétés oxydo-réductrices, les deux catalyseurs DP et Imp, ont subi un traitement sous vide à 400°C pendant une heure avant de faire adsorber l’air sur les deux solides et les caractériser par la technique de la RPE. Deux signaux complètement différents ont été mis en évidence: un signal avec g- < g// sur le DP et un signal M avec g- > g// sur le catalyseur Imp. Le signal obtenu sur le DP a été attribué à l’espèce O2- alors l’attribution du signal M a nécessité une étude plus approfondie. L’adsorption de l’air sur les solides x%Au/CeO2 (Imp), où 0 = x= 4, a montré, par la RPE, la présence d’un signal P à côté du signal M pour les faibles teneurs en or. Suite aux résultats obtenus par l’adsorption des molécules : O2, N2, O2+N2 ou air, (O2 puis N2) ; (N2 puis O2), NO, N2O et NO2, nous avons attribué le signal P à O2- , NO2 2- ou NO3 2- et le signal M à NO, O- ou N2O-. Les produits azotés peuvent être considérés comme des produits intermédiaires ou finaux. A partir de tous les résultats obtenus, nous avons proposé des mécanismes correspondant à ces formationsTwo 4%Au/CeO2 catalysts have been prepared by two different methods : deposition-precipitation (DP) and impregnation (Imp). From the XRD, SEM and TEM study, nanoparticles of gold have been evidenced in the DP catalyst and agglomerates nearby nanoparticles in the Imp solid. Compared to the Imp solid, the DP catalyst showed a better catalytic activity in the CO oxidation reaction, the total oxidation of propene and the combustion of carbon black (soots). This difference in the activity is related to the presence of well-dispersed gold nanoparticles on the DP solid surface and a significant quantity of Aun+ located nearby the metallic gold and the O2- ions of the ceria lattice. The weak activity of the Imp catalyst is correlated to the presence on the surface of gold agglomerates and an important amount of chloride ions. These latter species are known as inhibitor in calatysis. In order to elucidate the redox properties of both DP and Imp catalysts, the solids have been degassed and treated under vacuum at 400°C for 1h before the absorption of air. Therefore, the two catalysts have been studied with the EPR technique. Two signals completely different have been evidenced : the first one with g- < g// on DP and the other one, denoted M, with g- > g// on the Imp catalyst. The DP signal has been attributed to O2- species whereas, the attribution of M signal has needed of more detailed study. In fact, the adsorption of air on x%Au/CeO2 (Imp) solids, where 0 <(or egal) x <(or egal) 4, has shown using the EPR technique, the appearance of a new P signal nearby of the M signal for Au contents less than x = 2. 5. From EPR results obtained after absorption, on x%Au/CeO2 (Imp) solids, O2, N2, O2+N2 or air, O2 before N2 ; N2 before O2, NO, N2O and NO2, the P signal has been attributed to O2- , NO2 2- or NO3 2- and M signal M to NO, O- or N2O-. The Nox formed can be considered as intermediate or final products. From these results mechanisms corresponding to all the formed products have been proposed
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Mocho, Pierre. „Adsorption de composés organiques volatils sur charbon actif : régénération in situ du charbon par chauffage par induction électromagnétique“. Pau, 1994. http://www.theses.fr/1994PAUU3015.
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La première partie de la thèse a pour but de caractériser les liens entre les composés organiques volatils adsorbés et le charbon actif. La thermogravimétrie a permis de déterminer les vitesses de désorption en fonction de la température ainsi que la température à laquelle la vitesse de désorption est maximale. Une étude statistique menée sur les résultats obtenus a permis de mettre en évidence l'influence prépondérante jouée par la réfraction molaire, le moment dipolaire et la masse molaire sur les paramètres précédents. Les énergies d'interactions mises en jeu sont déterminées par calorimétrie différentielle à balayage. L'influence de la tension superficielle est mise en évidence. Les composes étudiés donnent lieu à une physisorption permettant d'envisager une régénération in situ du charbon par chauffage inductif. La deuxième partie est consacrée à l'étude de l'adsorption des composés organiques volatils sur charbon actif. L'étude en réacteur ferme fait apparaître une adsorption de type Langmuir pour les essais effectues en phase gazeuse, de type B. E. T. Pour ceux menés en phase aqueuse. L'étude en régime dynamique a montré l'intérêt des plans d'expériences pour un dimensionnement global de filtre à charbon. La dernière partie s'intéresse à la régénération de lit de charbon à l'aide de l'induction électromagnétique. L'étude révèle l'influence prépondérante de la nature du charbon sur l'efficacité du chauffage. Une autre caractéristique importante est l'augmentation des rendements avec les dimensions du lit. Enfin, un dimensionnement de filtre est proposé dans la perspective de transfert technologique du procédé.
Bücher zum Thema "Boranes – Absorption et adsorption"
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Adsorption by carbons. Amsterdam: Elsevier, 2008.
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Vandenberg, A. Modèle physique de l'infiltration, du drainage et du ruissellement dans des sols à couches multiples. [s.l: s.n.], 1989.
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Westall, John C. The use of cationic surfactants to modify aquifer materials to reduce the mobility of hydrophobic organic compounds / John C. Westall ... [et al.]. Ada, OK: U.S. Environmental Protection Agency, Robert S. Kerr Environmental Research Laboratory, 1994.
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Westall, John C. The use of cationic surfactants to modify aquifer materials to reduce the mobility of hydrophobic organic compounds / John C. Westall ... [et al.]. Ada, OK: U.S. Environmental Protection Agency, Robert S. Kerr Environmental Research Laboratory, 1994.
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International Institute of Refrigeration. Commission A3. Comparaison avec la cryogénie des procédés PSA et membranes pour la séparation des gaz industriels: Compte rendu de la réunion de la Commission A3 = Comparison between cryogenics and PSA and membrane processes for industrial gas separation : proceedings of the meeting of Commission A3, October 24-25, 1989. Paris, France: Institut international du froid, 1989.
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author, Thomas Sabu, MirMahaleh Moein MehdiPour author, Rafiei Saeedeh author, Maghsoodlou Shima author und Afzali Arezo author, Hrsg. Foundations of nanotechnology. Oakville, ON, Canada: Apple Academic Press Inc., 2014.
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1934-, Kies Constance, American Chemical Society Meeting und American Chemical Society. Division of Agricultural and Food Chemistry., Hrsg. Nutritional bioavailability of calcium. Washington, D.C: American Chemical Society, 1985.
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Applications of furrow and micro irrigation in arid and semi-arid regions. Oakville: Apple Academic Press, 2016.
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W, Shalaby Shalaby, und Burg Karen J. L, Hrsg. Absorbable biodegradable polymers: Contemporary topics. Boca Raton, FL: CRC Press, 2004.
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1947-, Ghebre-Sellassie Isaac, Hrsg. Multiparticulate oral drug delivery. New York: M. Dekker, 1994.
Den vollen Inhalt der Quelle findenKonferenzberichte zum Thema "Boranes – Absorption et adsorption"
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Suciu, Claudiu Valentin. „Thermal Effects on Nano-Energy Absorption Systems (Nano-EAS)“. In 2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2008. http://dx.doi.org/10.1115/micronano2008-70039.
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Development of intelligent and ecological energy absorption systems (EAS) is important to various fields such as automotive (vehicle suspensions, bumpers, engine mounts), construction (protections against seismic and wind-induced vibrations), and defense (parachuted objects, armors). Usual EAS use composites, shape-memory alloys and foams. Recently, liquid adsorption/desorption in/from nanoporous solids was employed to develop high-performance nano-EAS. Energy loss is based on the well-known capillary phenomenon: external work must be done to spread a non-wetting liquid on a solid surface. Nano-EAS provide considerably higher dissipated energies, about 1–10J/g at deformability of 30–70%, compared with the energy absorption of Ti-Ni alloys, about 0.01–0.05J/g at deformability of 5–8%. For water against hydrophobic nanoporous silica gel (artificial sand), the nano-EAS become ecological; they can be also made intelligent by thermo-electrical control. Relative to thermal effects, Qiao et al. have investigated, for nanoporous silica gel with insufficient coverage of the alkyl-based hydrophobic coating, the problem of hysteresis recovery by increasing the temperature in the range 20∼80°C. Energy loss capacity reduced severely after the first loading-unloading cycle, so, the hysteresis was found as irreversible. Shape of the first hysteresis, the accessible specific pore volume and the desorption pressure were almost unaffected by the temperature change. At temperature augmentation the second hysteresis was partially recovered and when the temperature exceeded 50°C the system became almost fully reusable. Water inflow was found as governed by Laplace-Washburn equation but the outflow process was perceived as thermally aided. On the other hand, Eroshenko et al. have contradictorily obtained for nanoporous silica gel with full coverage of the alkyl-based hydrophobic coating, a stable hysteresis at repeated working cycles. Adsorption pressure decreased and desorption pressure increased at temperature augmentation, this producing a reduction of the hysteresis area and damping. However, the accessible specific pore volume was found as thermally unaffected. Oppositely, both the in- and out-flows were found as governed by Laplace-Washburn equation. In this work, for nanoporous silica gels with partial and full coverage of the alkyl and fluorocarbon based hydrophobic coatings, the thermal effects on the hysteresis and damping performances are studied. Test rig used is a compression-decompression chamber introduced inside of an incubator that allows temperature adjustment in the range of −10∼50°C. Results reveal that, depending on the hydrophobic coating coverage, findings reported by Qiao et al. and Eroshenko et al. are in fact not contradictory but complementary. However, as expected, the accessible specific pore volume was found to decrease at temperature reduction. In order to explain all these apparently opposite experimental findings, a model based on the water cluster size distribution versus temperature, the pore size distribution of silica gel and the ability of water molecules to form hydrogen bonds with the uncovered hydroxyl groups on the solid surface is proposed.
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Seniūnaitė, Jurgita, Rasa Vaiškūnaitė und Kristina Bazienė. „Mathematical Modelling for Copper and Lead Adsorption on Coffee Grounds“. In Environmental Engineering. VGTU Technika, 2017. http://dx.doi.org/10.3846/enviro.2017.007.
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Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.
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Li, Shidong, und Ole Torsæter. „The Impact of Nanoparticles Adsorption and Transport on Wettability Alteration of Intermediate Wet Berea Sandstone“. In SPE Middle East Unconventional Resources Conference and Exhibition. SPE, 2015. http://dx.doi.org/10.2118/spe-172943-ms.
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AbstractNanoparticles as part of nanotechnology have drawn the attention for its great potential of increasing oil recovery. From authors' previous studies (Li et al., 2013a), wettability alteration was proposed as one of the main Enhanced Oil Recovery (EOR) mechanisms for nanoparticles fluid, as adsorption of nanoparticles on pore walls leads to wettability alteration of reservoir. We conducted a series of wettability measurement experiments for aged intermediate-wet Berea sandstone, where the core plugs were treated by different concentration and type of nanoparticles fluid. Nanoparticles transport experiments also were performed for core plugs with injection of varying concentration and type of nanoparticles fluid. Pressure drop across the core plug during injection was recorded to evaluate nanoparticles adsorption and retention inside core, as well as desorption during brine postflush. Both hydrophilic silica nano-structure particles and hydrophilic silica colloidal nanoparticles were utilized in above two experiments.The results of wettability alteration experiments indicated that hydrophilic nanoparticles have ability of making intermediate-wet Berea sandstone to be more water wet, and basically the higher concentration the more water wet will be. And different type of nanoparticles has different effect on the wettability alteration process. For nanoparticles transport experiments, the results showed that the nanoparticles undergo both adsorption and desorption as well as retention during injection. Pressure drop curves showed that absorption and retention of nano-structure particles inside core was significant while colloidal nanoparticles did not adsorb much. Permeability impairment was observed during nano-structure particles fluid injection, but on the contrary colloidal nanoparticles dispersion injection made core more permeable.
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von Felten, A. „DETECTION OF LUPUS ANTICOAGULANTS BY THE “INSIDE-OUT MEMBRANE ADSORPTION TEST”: aPTT IS SHORTENED AFTER INCUBATION OF THE PLASMA WITH THE ADSORBENT“. In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644238.
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Prolongation of the aPTT in a mixture of a patient’s plasma with normal plasma is characteristic for the presence of a coagulation inhibitor. Since inhibitors directed against individual blood coagulation factors differ in their clinical significance from a lupus anticoagulant (LA), a fast and reliable distinction from each-other would be highly desirable. The test presented which is based on the absorption of antiphospholipid antibodies by use of a stable phospholipid adsorbent largely fullfills this demand.Method 1. Preparation of the LA-adsorbent (modified acc. to Steck et al., Science 168:255, 1970): Fresh human RBC (bl. gr. 0, in 0.5% EDTA) are washed (NaCl, 0.15m / phosphate buffer,0.005m, pH8.0) and lysed in phosphate buffer alone. The membranes are washed with the same buffer (centrifugations: 40’000g, lOmin, 4°C) and incubated 60 min on ice in phosphate buffer, 0.0005m. After centrifugation, the sediment is resuspended in an equal volume of buffer (0.0005m, with merthiolate 0.1%), homogenized and centrifuged in portions of lml; the supernatant is carefully removed. The adsorbent, stored at 4°C in capped tubes, is stable for at least three months.2. Performance of test: To 600ul of patient’s plasma mixed with 600ul normal plasma (citrated), 12ul of heparin (501U/ml) are added. 600ul of the mixture are given to the LA-adsorbent, vorte-xed, incubated (room temp., 30min) and centrifuged (40’000g). From the supernatant as well as the not adsorbed portion of the plasma mixture, heparin is eliminated by adding ECTEOLA-cellulose. After centrifugation, aPTT is determined in both supernatant samples. Results The test is positive, i.e. LA is present, if aPTT is shortened by at least 5 sec after treatment with LA-adsorbent. *not diluted; other samples are mixed 1:1 with normal plasma
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Li, Jinwei, Shiyou Xu und Yong Shi. „TiO2 Nanofibers Based Dye-Sensitized Solar Cells“. In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-13027.
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Dye sensitized solar cells (DSSCs) are promising photovoltaic devices as they offer advantages such as low cost and easy for fabrication et al. The key part of the original DSSC is a sintered film of nanoparticles which has a large surface area for the absorption of dyes. It has been reported that boundaries of nanoparticles diminish the efficiency of charge transport in the nanoparticle network, and lead to charge–carrier recombination. The one dimensional morphology of the nanofiber is believed to improve electron transport efficiency without sacrificing the high specific surface area for the adsorption of dyes. In this paper, TiO2 nanofibers are used to replace TiO2 nanoparticles in the DSSC. The film of nanofibers was synthesized by electrospinning process and collected on the transparent conductive glass substrate. The precursor used for the electrospinning of the nanofiber consists of titanium (IV) isopropoxide, acetate acid, ethanol and polyvinylpyrrolidone(PVP). After the electrospinning process, nanofibers were pretreated at 120°C for 2 hours and annealed at 500°C in atmosphere for another 2 hours. Then DSSC with the film of TiO2 nanofibers were assembled and characterized through electrical measurements. Open circuit voltage of 0.7V and short circuit current densities of 0.45mA/cm2 were achieved.