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You searched for subject:(Porous compound). Showing records 1 – 2 of 2 total matches.

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1. Kenfack Tsobnang, Patrice. Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons.

Degree: Docteur es, Chimie, 2014, Université de Lorraine; Université de Yaoundé I

Ce travail réalisé dans le cadre de l’initiative africaine de l’IUCr porte sur l’étude structurale par diffraction des rayons X de quelques architectures élaborées par association, via des interactions faibles, des anions {[M(C2O4)3]3-,M = Cr, Fe} et des cations complexes à base de la 2-picolylamine (amp) métaux de transition (Co2+, Cu2+ et Mn2+). L’architecture à base de l’ion Co2+ est bidimensionnelle et présente des feuillets ondulés constitués de chaines bimétalliques de chiralité différente où les deux ions complexes ([Cr(C2O4)3]3- et [Co(amp)3]3+ ) sont connectés par des liaisons hydrogène. Ces feuillets hébergent des molécules d’eau qui forment des clusters dodécamèriques aux caractéristiques nouvelles. Le composé déshydraté se réhydrate rapidement dans l’air ambiant et les deux états possèdent des couleurs différentes. Plusieurs cycles de déshydratation-réhydratation n’altèrent pas la qualité cristalline du composé. L’architecture à base des ions Cu2+ possède également des feuillets mais présente une ondulation plus forte que celle de l’architecture au cobalt. Ces couches sont constituées de chaines formées de cations dimériques [Cu2(amp)4Cl]3+ et d’anions {[M(C2O4)3]3-,M = Cr, Fe}. Les deux composés sont iso-structuraux et leur architecture présente des canaux monodimensionnels qui contiennent des molécules d’eau qui forment des clusters hexamèriques. Le composé subit des transitions de phase entre la basse température (100K) et la température de déshydratation (341K) avec une perte de la symétrie. Le composé se réhydrate plus difficilement que celui à base de l’ion cobalt(III). L’ion Mn2+ ne donne pas l’architecture escomptée mais un polymère de coordination nouveau

This work, realized under the IUCr initiative, framework involves the structural study via X-ray diffraction, of some heteromolecular architectures formed by the association through non-covalent bonds, between the tris (oxalato) chromate (III) and tris (oxalato) ferrate (III) anions {[M(C2O4)3]3-, M = Cr, Fe} and the cationic complex of the 2-picolylamine (amp) and transition metal (Co2 +, Cu2 + and Mn2 +). Co2 + ion builds two-dimensional corrugated layers made of bimetallic chiral chains where the two different complex ions ([Cr(C2O4)3]3- and [Co(amp)3]3 +) are connected by hydrogen bonds. These layers, connected by weak hydrogen interactions, host between them, water molecules which build dodecameric clusters having new characteristics. The dehydrated compound has different structure and color and is able to quickly reabsorb water molecules from surrounding to regenerate the initial compound despite that it has no pores. Several cycles of this process do not seriously affect the crystalline quality of this compound. The compound obtained with the Cu2 + ion also has a two-dimensional framework. Their layers are formed between the dimeric cation [Cu2 (amp) 4Cl]3 + and the anion {[M(C2O4)3]3-,M = Cr, Fe}. Both compounds are iso-structural; their frameworks are formed via π - - - π interactions and build 1D channels which contain water…

Advisors/Committee Members: Lecomte, Claude (thesis director), Lambi, John Ngolui (thesis director).

Subjects/Keywords: Chimie supramoléculaire; Ingénierie cristalline; Liaison non-Covalente; Oxalate; 2-Picolylamine; Composés poreux; Diffraction des rayons X; Cluster d’eau; Déshydratation; Réhydratation; Supramolecular chemistry; Crystal Engineering; Non-Covalent bond; Oxalate; 2-Picolylamine; Porous compound; Water cluster; Dehydration; Rehydration; X-Ray diffraction; 547.122 6; 661.8

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kenfack Tsobnang, P. (2014). Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons. (Doctoral Dissertation). Université de Lorraine; Université de Yaoundé I. Retrieved from http://www.theses.fr/2014LORR0243

Chicago Manual of Style (16th Edition):

Kenfack Tsobnang, Patrice. “Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons.” 2014. Doctoral Dissertation, Université de Lorraine; Université de Yaoundé I. Accessed October 15, 2019. http://www.theses.fr/2014LORR0243.

MLA Handbook (7th Edition):

Kenfack Tsobnang, Patrice. “Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons.” 2014. Web. 15 Oct 2019.

Vancouver:

Kenfack Tsobnang P. Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons. [Internet] [Doctoral dissertation]. Université de Lorraine; Université de Yaoundé I; 2014. [cited 2019 Oct 15]. Available from: http://www.theses.fr/2014LORR0243.

Council of Science Editors:

Kenfack Tsobnang P. Synthèse, caractérisation et étude du comportement à la déshydratation par diffraction des rayon X sur monocristal et poudre, de quelques composés supramoléculaires à base de métallo-tectons ioniques : Synthesis, Characterization and Study of Behavior with Single Crystal and Powder X-rays Diffraction Analysis during the Dehydration Process of some Supramolecular Compounds built with Ionic Metallo-tectons. [Doctoral Dissertation]. Université de Lorraine; Université de Yaoundé I; 2014. Available from: http://www.theses.fr/2014LORR0243

2. Mongol Akhir Khan, I.A. Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis.

Degree: 2018, University Utrecht

Diffusion-dominated vapor phase transport is often excluded from quantitative assessments due to the problem of diffusive mixing of concentrations with different isotopic signatures for Compound-specific stable isotope analysis – CSIA interpretation. This thesis presents and verifies a concept for the assessment of biodegradation-induced stable isotope fractionation along a diffusive transport path of VOCs in unsaturated porous media. Reactive transport of vapor-phase VOCs in the subsurface is controlled by a multitude of interrelated factors, such as properties of the chemicals, the presence of microbial communities and the soil properties. The approach used in this thesis is to highlight and interpret the data obtained by multiple experiments and modeling scenarios. To fill the knowledge gap and to improve the understanding of dynamics of vapor-phase VOCs in the unsaturated subsurface environment, various sets of laboratory column experiments were performed. Furthermore, an approximation of Rayleigh-model was derived, which in turn allowed derivation of a stable isotope fractionation factor for diffusion and biodegradation from various depth profiles of vapor-phase VOC concentrations and the associated isotope ratios. The thesis in general consists of: laboratory experiments dealing with vapor transport, phase exchange, biodegradation, CSIA, and numerical model simulations of biodegradation using parameters derived from experiments. Biodegradation is an important removal process of gas phase VOCs in unsaturated porous media. Toluene (non-deuterated and deuterated) has been studied as a model VOC in this work to assess biodegradation by combining data on the concentration gradients in the column and batch reactors and on the associated stable isotope fractionation with numerical modeling. A conservative volatile tracer (MTBE, non-reactive with the given bacterial strain) was used to quantify physical transport mechanisms independently of biological or chemical interactions. Our results show that the presence of bacteria along with sufficient amount of VOCs, moisture, and oxygen lead to total removal of the VOCs. Hence, the unsaturated zone can be an efficient biofilter for VOCs emanating from the groundwater and helps to avoid emissions to the atmosphere even at high gas-phase diffusion rates. However, our findings are based on the key assumptions that there is no governing process for mass transfer except diffusion and the whole reactor setups represents an unsaturated zone with only gas-phase chemicals. Therefore, the results would be misleading if extrapolated to the entire vadose zone. Our results further show that biodegradation can be limited by mass transfer of contaminants to the cells and by toxicity effects due to the combination of chemicals present in the system. Advisors/Committee Members: Middelburg, Jack, Thullner, Martin.

Subjects/Keywords: Volatile organic compounds (VOC); biodegradation; reactive transport modelling; compound-specific stable isotope analysis – (CSIA); porous media; vertical flow filters; dynamic phase exchange; bioavailability; toxicity; intrinsic cellular activity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Mongol Akhir Khan, I. A. (2018). Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis. (Doctoral Dissertation). University Utrecht. Retrieved from http://dspace.library.uu.nl/handle/1874/370746 ; URN:NBN:NL:UI:10-1874-370746 ; urn:isbn:978-90-6266-510-5 ; URN:NBN:NL:UI:10-1874-370746 ; http://dspace.library.uu.nl/handle/1874/370746

Chicago Manual of Style (16th Edition):

Mongol Akhir Khan, I A. “Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis.” 2018. Doctoral Dissertation, University Utrecht. Accessed October 15, 2019. http://dspace.library.uu.nl/handle/1874/370746 ; URN:NBN:NL:UI:10-1874-370746 ; urn:isbn:978-90-6266-510-5 ; URN:NBN:NL:UI:10-1874-370746 ; http://dspace.library.uu.nl/handle/1874/370746.

MLA Handbook (7th Edition):

Mongol Akhir Khan, I A. “Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis.” 2018. Web. 15 Oct 2019.

Vancouver:

Mongol Akhir Khan IA. Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis. [Internet] [Doctoral dissertation]. University Utrecht; 2018. [cited 2019 Oct 15]. Available from: http://dspace.library.uu.nl/handle/1874/370746 ; URN:NBN:NL:UI:10-1874-370746 ; urn:isbn:978-90-6266-510-5 ; URN:NBN:NL:UI:10-1874-370746 ; http://dspace.library.uu.nl/handle/1874/370746.

Council of Science Editors:

Mongol Akhir Khan IA. Reactive transport and stable isotope fractionation of volatilized petroleum hydrocarbons in porous media : Experimental and numerical analysis. [Doctoral Dissertation]. University Utrecht; 2018. Available from: http://dspace.library.uu.nl/handle/1874/370746 ; URN:NBN:NL:UI:10-1874-370746 ; urn:isbn:978-90-6266-510-5 ; URN:NBN:NL:UI:10-1874-370746 ; http://dspace.library.uu.nl/handle/1874/370746

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