The thesis is a summary and discussion of eight papers. During the last decades, precipitation has become increasingly acidic due to the extensive use of fossil fuels. In areas of poorly buffered bedrocks, e.g. Scandinavia, northeastern United States, this phenomenon has resulted in elevated amounts of Al(III) being leached into streams and lakes. Recent findings reveal that these elevated Al-concentrations could cause fish death and decreasing forest production. In the present thesis, the importance of taking naturally occurring substances into consideration when discussing Al(III) in natural waters, is emphasized. On the basis of a chemical characterization of relevant ligand classes in a natural water, the complex formation between Al^+, hydroxide ions and the inorganic ligand carbonic acid, the low-molecular weight organic ligand citric acid and the high-molecular weight model substances gallic acid, 1,2-dihydroxynaphtha-lene-4-sulfonate, 1,2-naphthoquinone-4-sulfonate, pyrocatechol and salicylic acid were investigated. The investigations were performed as series of Potentiometrie titrations and data were processed by means of the least-squares computer program LETAGROPVRID using a technique called pqr-analysis, permitting an unbiased search for complex model (and corresponding equilibrium constants) to be made. In most systems studied, the complexation at high ligand excesses can be described by a series of mononuclear complexes AIL-AIL^. Tentatively, the whole series consists of octahedrally coordinated (water and ligand oxygens) AI(III). At lower ligand excesses, the significance and in some cases even predominance of ternary mono- and polynuclear hydroxo complexes is demonstrated. In two of the systems, binary aluminium hydroxo species are evaluated. The potential importance of the substances with respect to Al-com-plexation in natural waters are indicated in a number of model calculations. The solubility of the clay mineral kaolinite is calculated as a function of -lg[H+] and ligand concentration. It is shown that citric acid, gallic acid, 1,2-dihydroxynaphthalene-4-sulfonate, pyrocatechol and salicylic acid contribute quite significant to the total solubilities, even at very low concentrations. As a complement and background to the equilibrium studies, the corrosion rate for one of the naturally occurring Al-bearing minerals, corundum, is reported. In this investigation, performed with a leach-ant solution of ground-water composition, an experimental technique was employed which made it possible to divide the corrosion into chemical and mechanical losses. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1983</p> / digitalisering@umu

Copper is an essential trace element for living organisms and has both known and additional suspected roles in human health and disease. The current understanding of copper metabolism is substantial but incomplete, particularly in regard to storage and exchange at the subcellular level, although available evidence indicates exchangeable intracellular copper is in the monovalent oxidation state. Selective fluorescent probes with sufficient sensitivity to detect Cu(I) availability at physiologically relevant levels and at subcellular resolution would be valuable tools for studying copper metabolism. As a contribution toward this goal, this work describes the development of Cu(I)-selective fluorescent probes with greatly improved aqueous solubility, contrast ratio, and fluorescence quantum yield. This work also describes the development of water-soluble, 1:1-binding chelators that form colorless, air-stable copper(I)-complexes. By acting as copper(I) buffering agents and affinity standards, these compounds can serve a complementary role to fluorescent probes in the study of copper biochemistry.

With the advancement and accessibility of local probing techniques that can operate at the submicron scale it has become possible to analyse the local corrosion properties of industrially important metallic materials and relate these properties to microstructure characteristics of the same materials. In this doctoral study the focus has been on copper-zinc samples, both as industrial brass alloys and as micro-patterned copper-zinc samples. They have been exposed to dilute chloride solutions and to an atmosphere that mimics indoor conditions that cause corrosion. The main goal has been to investigate micro-galvanic effects caused by surface heterogeneities in the copper-zinc samples, and the corrosion inhibition ability of a self-assembled octadecanethiol (ODT, CH3(CH2)17SH) monolayer when applied to these heterogeneous samples. The local chemistry, local electrochemistry, and local surface chemistry in the presence of the copper-zinc galvanic couplings have been elucidated, and their importance has been investigated for corrosion initiation, propagation, termination, and inhibition. A broad spectrum of local probe techniques has been utilised. They include optical microscopy (ex situ and in situ), electrochemical techniques, scanning electron microscopy with energy dispersive spectroscopy, atomic force microscopy, scanning Kelvin probe force microscopy and confocal Raman spectroscopy. In addition, infrared reflection absorption spectroscopy (in situ) and vibrational sum frequency spectroscopy have been employed to analyse the formation of corrosion products and monitor the corrosion kinetics.    A characteristic selective zinc dissolution process was triggered in non-metallic inclusions when a brass alloy was exposed to 1 mM NaCl. Disc-like corrosion areas spread radially outwards from the inclusions, the shape and termination of which was attributed to accessibility to chloride ions. An ODT-layer deposited on brass retarded access to chloride ions at the brass surface and slowed down the radial corrosion process. Instead a delayed formation of filiform-like corrosion was observed.    Upon exposure of the copper-zinc patterned sample to humidified air containing formic acid, micro-galvanic effects were induced by the copper patches on zinc that accelerated the zinc dissolution in the thin aqueous adlayer with concomitant precipitation of zinc formate. The micro-galvanic effects not only resulted in accelerated corrosion rates for zinc, but also in broadening of shapes and atomic structures for the corrosion products formed. Crystalline zinc oxide and zinc formate were observed on the copper-zinc patterned samples, whereas amorphous zinc oxide and zinc formate were formed on the bare zinc surface. Micro-galvanic effects occurred in the two-phase Cu40Zn (Cu with 40 wt% Zn) brass alloy as well, induced by more zinc-rich beta-phase grains surrounded by an alpha matrix with lower zinc-content.    The application of a self-assembled monolayer of ODT for corrosion inhibition of pure zinc and the patterned copper-zinc samples was also explored. In situ infrared reflection absorption spectroscopy analyses showed that ODT initially reduced the rate of zinc formate formation on pure zinc and on the copper-zinc micro-patterned sample. However, the inhibition efficiency was slightly reduced with exposure time due to local removal of ODT on pure zinc and on the micro-patterned samples. This caused micro-galvanic effects that resulted in increased rates of zinc formate formation on the ODT-covered samples – even higher than on the uncovered samples. When applied to the single-phase Cu20Zn alloy, ODT resulted in a corrosion inhibition that was comparable to that of pure copper, a metal for which ODT has shown very good corrosion inhibition. On double-phase Cu40Zn local galvanic effects resulted in less efficient corrosion inhibition and more abundant corrosion products than on Cu20Zn. Based on vibrational sum frequency spectroscopy, the ODT-layer retained its well-ordered molecular structure throughout the exposure to both Cu20Zn and Cu40Zn.    In all, the inhibiting action of the ODT-layer was attributed to the transport hindrance of corrosion promoters (O2, H2O, and HCOOH) to the brass surface. This result suggests that ODT can function as a temporary corrosion inhibitor for brass exposed to benign indoor environments. / Med utvecklingen av och tillgången till lokala analysmetoder som kan ge information med en lateral upplösning på mindre än en mikrometer har det blivit möjligt att analysera lokala korrosionsegenskaper hos industriellt viktiga metalliska material och relatera dessa egenskaper till mikrostrukturen hos samma material. I doktorsavhandlingen har denna möjlighet utnyttjats för koppar-zinkprover, dels som industriella mässingslegeringar dels som mikro-mönstrade koppar-zinkprover, som exponerats för utspädda kloridlösningar samt för en atmosfär som kan efterlikna den atmosfäriska korrosionen inomhus. Det huvudsakliga målet har varit att undersöka dels mikro-galvaniska korrosionseffekter som orsakas av heterogeniteter på koppar-zinkytorna dels korrosionsförmågan hos självorganiserande monolager av oktadekantiol (ODT, CH3(CH2)17SH) vid adsorption på dessa heterogena ytor. På så vis har den lokala kemin, ytkemin och elektrokemin kunnat klarläggas i närvaro av galvaniska effekter, och dess betydelse har undersökts för korrosionsprocessens initiering, propagering, terminering och inhibering. Ett brett spektrum av lokala analysmetoder har utnyttjats. De innefattar ljusoptisk mikroskopi (ex situ och in situ), elektrokemiska metoder, svepelektronmikroskopi med energidispersiv röntgen-spektroskopi, atomkraftsmikroskopi för mikro-kartering och Voltapotentialmätningar samt konfokal Raman-spektroskopi. Dessutom har infrarödreflektions absorptionsspektroskopi (in situ) och vibrationssummafrekvens spektroskopi (engelska: vibrational sum frequency generation) använts.    När en mässingslegering exponerades för 1 mM NaCl observerades en selektiv utlösning av zink med karakteristiskt utseende som växte radiellt från icke-metalliska inneslutningar för att bilda cirkulärt formade korrosionsområden. Formen och termineringen av denna korrosionsprocess bestäms av tillgången på kloridjoner. När ett monolager av ODT adsorberades på mässingslegeringen hämmades tillgången av kloridjoner på mässingsytan och den radiella korrosionsprocessen stannade upp. Istället iakttogs en fördröjd bildning av s.k. filiform korrosion.    Vid exponering av mikro-mönstrade koppar-zinkprover för befuktad luft med låga tillsatser av myrsyra inducerades mikro-galvaniska effekter i gränsen mellan koppar och zink som accelererade utlösningen av zink i den adsorberade fuktfilmen på provet, under samtidig utfällning av zinkformat. De mikro-galvaniska effekterna resulterade inte bara i förhöjda korrosionshastigheter jämfört med de på ren zink, utan även i andra faser hos bildade korrosionsprodukter. På de mikro-mönstrade koppar-zinkproverna bildades kristallint zinkoxid och zinkformat, under det att amorft zinkoxid och zinkhydroxyformat bildades på ren zink. Mikrogalvaniska effekter observerades även i den tvåfasiga mässingslegeringen Cu40Zn (Cu med 40 vikt-% Zn) orsakade av kontakten mellan den mer zinkrika beta-fasen och den omgivande alfa-fasen med lägre zinkhalt.    Appliceringen av ett självorganiserat monolager av ODT för korrosionsinhibering av ren zink och koppar-zinkprover har också undersöks. In situ infrarödreflektions absorptionsspektroskopi visade att adsorberat ODT initialt hämmade bildningen av zinkformat på ren zink och på de mikro-mönstrade koppar-zinkproverna. Med tiden minskade ODTs korrosionsinhiberings-förmåga på grund av att ODTs vidhäftning lokalt försvann. De mikro-galvaniska effekter som därigenom uppstod resulterade i bildandet av zinkformat som med tiden blev snabbare på de ODT-belagda proverna än på motsvarande prover utan ODT. När ODT applicerades på den enfasiga mässingslegeringen Cu20Zn resulterade detta i en korrosionsinhibering som var jämförbar med den på ren koppar, en metall på vilken ODT tidigare visat mycket bra korrosionsskydd. På den tvåfasiga mässingslegeringen Cu40Zn ledde lokala galvaniska effekter till en mindre effektiv korrosions-inhibering och en rikligare mängd korrosionsprodukter än på Cu20Zn. Baserat på vibrationssummafrekvens spektroskopi behöll ODT-lagret dess välordnade struktur under hela exponeringen på både Cu20Zn och Cu40Zn.    ODTs korrosionsinhibering tillskrivs främst transport-hämningen av korrosionsstimulatorer (O2, H2O och HCOOH) till mässingsytan och antyder att ODT kan fungera som en temporär korrosionsinhibitor för mässing i milda inomhusmiljöer. / <p>QC 20140915</p>

The main objective of nanotechnology is to build self-powered nanosystems that are ultrasmall in size, exhibit super sensitivity, extraordinary multi functionality, and extremely low power consumption. As we all know that 21st century has brought two most important challenges for us. One is energy shortage and the other is global warming. Now to overcome these challenges, it is highly desirable to develop nanotechnology that harvests energy from the environment to fabricate self-power and low-carbon nanodevices. Therefore a self-power nanosystem that harvests its operating energy from the environment is an attractive proposition. This is also feasible for nanodevices owing to their extremely low power consumption. One advantageous approach towards harvesting energy from the environment is the utilization of semiconducting piezoelectric materials, which facilitate the conversion of mechanical energy into electrical energy. Among many piezoelectric materials ZnO has the rare attribute of possessing both piezoelectric and semiconducting properties. But most applications of ZnO utilize either the semiconducting or piezoelectric property, and now it’s time to fully employ the coupled semiconducting-piezoelectric properties to form  the basis for electromechanically coupled nanodevices. Since wurtzite zinc oxide (ZnO) is structurally noncentral symmetric and has the highest piezoelectric tensor among tetrahedrally bonded semiconductors, therefore it becomes a promising candidate for energy harvesting applications. ZnO is relatively biosafe and biocompatible as well, so it can be used at large scale without any harm to the living environment. The synthesis of another transition metal oxide known as Co3O4 is also important due to its potential usage in the material science, physics and chemistry fields. Co3O4 has been studied extensively due to low cost, low toxicity, the most naturally abundant, high surface area, good redox, easily tunable surface and structural properties. These significant properties enable Co3O4 fruitful for developing variety of nanodevices. Co3O4 nanostructures have been focused considerably in the past decade due to their high electro-chemical performance, which is essential for developing highly sensitive sensor devices. I started my work with the synthesis of ZnO nanostructures with a focus to improve the amount of harvested energy by utilizing oxygen plasma treatment. Then I grow ZnO nanorods on different flexible substrates, in order to observe the effect of substrate on the amount of harvested energy. After that I worked on understanding the mechanism and causes of variation in the resulting output potential generated from ZnO nanorods. My next target belongs to an innovative approach in which AFM tip decorated with ZnO nanorods was utilized to improve the output energy. Then I investigated Co3O4 nanostructures though the effect of anions and utilized one of the nanostructure to develop a fast and reliable pH sensor. Finally to take the advantage of higher degree of redox chemistry of NiCo0O4 compared to the single phase of nickel oxide and cobalt oxide, a sensitive glucose sensor is developed by immobilizing glucose oxidase. However, there were problems with the mechanical robustness, lifetime, output stability and environmental adaptability of such devices, therefore more work is going on to find out new ways and means in order to improve the performance of fabricated nanogenerators and sensors.

Myopia is a refractive defect of the eye in which collimated light produces images focused in front of the retina. Myopia can be artificially induced in animal models by form deprivation (form deprivation myopia, FDM) or by application of negative lenses (lens induced myopia, LIM). In this study myopia was induced using diffusers. The project had two main aims: 1. To determine if there is an interaction between the GABAergic system and dopaminergic system in the retina in terms of myopia? 2. To determine if there is an interaction between the GABAergic system and cholinergic system in the retina in terms of myopia? Firstly, an experiment focusing on the interaction between dopaminergic receptors antagonists and GABAC receptor antagonist was developed. Comparison of the different drug treated eye with the control was found and the effects of combination injections were compared to individual drug injections. Use of different blockers for various subtype of receptors simplified the understandings the underlying pharmacological interventions for GABAC receptor antagonist TPMPA. The D1 subtype of receptors was found to be involved in transmission of signals from GABAC receptors. Our results showed that D1 receptor antagonist SCH-23390 antagonizes the actions of TPMPA. In addition to this it was also found that possibly 5HT receptor may also play an important role in modulation of signaling from GABA receptor to dopaminergic receptors in the retina. These results were consistent with the drug combination effects for agonists. GABA A/C receptor agonist muscimol negativate the efficacy of D1 receptor agonist SKF-38393 but the activity of D2/4 receptor agonist quinpirole was not affected by muscimol. Although dopaminergic receptors are found to interact with GABAergic signaling, but an alternative interaction with anticholinergic (most widely studied antimyopic agents) could not be ruled out. This problem led to a follow-up experiment, in which GABA receptors intervention in anticholinergic agents was studied. The GABAergic receptor agonist muscimol when injected with anticholinergics (atropine and pirenzepine) showed a moderate interaction. As muscimol interacted with atropine to a lesser extent a more specific M1/5 receptor antagonist pirenzepine (earlier found to inhibit myopia) was used under these circumstances. The second aim to study the interaction between muscimol and pirenzepine showed more interaction with GABAA/C receptor agonist. There were data suggesting that there is a muscarinic and GABAergic interaction in retina, such that each modulation of each receptor had an effect on FDM. However, a drug combination treatment helped in understanding the underlying mechanism. Several previous studies have indicated that there exist a strong interaction between excitatory neurotransmitter acetylcholine and inhibitory transmitter GABA in retina. The results of this study indicate a similar finding. Thus results of this study may be summarized as: 1. D1 antagonists and not D2 antagonists blocks the antimyopic effects of GABAC antagonist TPMPA 2. GABA A/C agonist muscimol partially blocks the antimyopic activity of anticholinergics (e.g. atropine and pirenzepine).

[Truncated abstract] To date, many subsurface contaminant modelling studies have focused on increasing model complexity and measurement requirements to improve model accuracy and widen model application. However, due to the highly complex and heterogeneous nature of flow in the subsurface, the greater benefit in model development may lie in decreasing complexity by identifying key processes and parameters, simplifying the relationships that exist between them, and incorporating these relationships into simple models that recognise or quantify the inherent complexity and uncertainty. To address this need, this study aims to identify and isolate the key processes and parameters that control dense nonaqueous phase liquid (DNAPL) and aqueous phase migration through single, onedimensional fractures. This is a theoretical representation which allows the study of processes through conceptual and mathematical models. Fracture systems typically consist of multiple two-dimensional fractures in a three-dimensional network; however, these systems are computationally and conceptually demanding to investigate and were outside of the scope of this study. This work initially focuses on DNAPL migration in single, one-dimensional fractures. The similitude techniques of dimensional and inspectional analysis are performed to simplify the system and to develop breakthrough time scale factors. This approach relies heavily on the limitations of the equation used for the analysis and on the difficulty in representing variable aperture scenarios. The complexity of the conceptual model is then increased by embedding the fracture in a two-dimensional, porous matrix. ... These tools can be readily applied by the field investigator or computer modeller to make order-of-magnitude estimates of breakthrough times, reduce or target measurement requirements, and lessen the need to employ numerical multiphase flow models. To determine the implications of the results found in the one-dimensional studies to applications at the field scale, the complexity of the conceptual model was increased to a single, two-dimensional, planar fracture embedded in a three-dimensional porous matrix. The focus of this study was not DNAPL breakthrough times but the relative importance and interaction of different mass transport processes and parameters on plume migration and evolution. Observations clearly show that estimates of the size, location and concentration of the plume is highly dependent on the geologic media, the temporal and spatial location and resolution of measurements, and on the history, mass and location of the DNAPL source. In addition, the processes controlling mass transport (especially matrix diffusion and back diffusion) act in combination at the field scale in ways not always expected from an analysis of processes acting individually at smaller spatial and temporal scales. Serious concerns over the application of the common '1% Rule of Thumb' to predict DNAPL presence and the use of remediation efforts that rely largely on natural attenuation are raised. These findings have major implications for the field worker and computer modeller, and any characterisation, monitoring or remediation program development needs to be sensitive to these findings.

Thesis (Ph.D.); Submitted to the University of California, Berkeley, CA (US); 18 Dec 2003. / Published through the Information Bridge: DOE Scientific and Technical Information. "LBNL--54280" Garcia, Julio Enrique. USDOE Director. Office of Science. Basic Energy Sciences (US) 12/18/2003. Report is also available in paper and microfiche from NTIS.

Σκοπός της μελέτης ήταν ο ποσοτικός προσδιορισμός των ιχνοστοιχείων βαρέων μετάλλων του ψευδαργύρου, καδμίου και χαλκού στο υδατοειδές υγρό ασθενών με ψευδοαποφολίδωση και η μέτρηση του δυναμικού οξειδοαναγωγής στο υδατοειδές αυτών των ασθενών. Υλικό και μέθοδοι: Δείγματα υδατοειδούς υγρού ελήφθησαν κατά την εγχείρηση καταρράκτη από 14 ασθενείς με PEX σύνδρομο (7 άνδρες και 7 γυναίκες) και 21 ασθενείς με καταρράκτη αλλά χωρίς PEX (9 άνδρες και 12 γυναίκες). Τα δείγματα διατηρήθηκαν στους -24C μέχρι την ανάλυση. Τα επίπεδα των τριών μετάλλων και στις δύο ομάδες προσδιορίστηκαν, για πρώτη φορά στην Οφθαλμολογία, με τη μέθοδο της βολταμετρίας με χρήση ηλεκτροδίων υαλώδους γραφίτη με υμένιο υδραργύρου, ενδεικτικού ηλεκτροδίου λευκόχρυσου και αναφοράς Ag/AgCl. Εφαρμόσθηκε η τεχνική της ανοδικής βολταμετρίας απογύμνωσης με τετραγωνικούς παλμούς και έγινε σύγκριση των τιμών ανάμεσα στις δύο ομάδες. Η στατιστική επεξεργασία των αποτελεσμάτων έγινε με το Mann-Whitney test (p<0.05) Στη συνέχεια, κατά τον ίδιο τρόπο, δείγματα υδατοειδούς ελήφθησαν από 13 ασθενείς με PEX (7 άνδρες/6 γυναίκες) και 22 ασθενείς χωρίς PEX (7 άνδρες/15 γυναίκες). Η μέτρηση του δυναμικού οξειδοαναγωγής γινόταν αμέσως μετά την απόκτηση του κάθε δείγματος και για το σκοπό αυτό χρησιμοποιήθηκε για πρώτη φορά στην Οφθαλμολογία, ένα μικροηλεκτρόδιο λευκοχρύσου μαζί με ένα ενσωματωμένο ηλεκτρόδιο αναφοράς Ag/AgCl/KCl. Η στατιστική ανάλυση των αποτελεσμάτων έγινε με το t-test για ανεξάρτητα δείγματα (p<0.05). Αποτελέσματα: O Cu βρέθηκε στατιστικά σημαντικά χαμηλότερος στην PEX ομάδα σε σχέση με τη φυσιολογική ομάδα (p<0.05), ενώ ο Zn και το Cd δεν παρουσίασαν καμία συσχέτιση στο υδατοειδές υγρό ασθενών με ψευδοαποφολίδωση. Το δυναμικό οξειδοαναγωγής ήταν στατιστικά σημαντικά υψηλότερο στο υδατοειδές των ασθενών με PEX σύνδρομο. Συμπεράσματα: Στην παρούσα εργασία εφαρμόζεται για πρώτη φορά, η ανοδική βολταμετρία απογύμνωσης για τον προσδιορισμό στο υδατοειδές υγρό του Zn, Cd και Cu και η μέτρηση του δυναμικού οξειδοαναγωγής στο υδατοειδές. Τόσο τα στατιστικώς σημαντικά χαμηλότερα επίπεδα Cu στο υδατοειδές ασθενών με PEX, όσο και το υψηλότερο δυναμικό οξειδοαναγωγής στο υδατοειδές αυτών των ασθενών ενισχύουν την παθογενετική θεωρία του οξειδωτικού στρες του PEX συνδρόμου. / To determine the Zn, Cd and Cu concentrations in aqueous humor of patients with PEX syndrome and to evaluate the overall oxidative status of the aqueous in this group by measuring the reduction-oxidation (redox) potential in the aqueous samples. Material and methods: Samples from aqueous humor were collected during cataract extraction from 14 patients with PEX syndrome (7 male/7 female) and 21 patients without PEX (9 male/12 female). All samples were stored in -24C until analyzed. The levels of selected trace elements in both groups were assayed for the first time in the field of Ophthalmology, with anodic stripping voltammetry, using the square wave differential pulse technique. In this analytical procedure a glassy carbon mercury film electrode, a platinum indicator and a reference Ag/AgCl electrode were used. Finally the metal levels in all samples were compared between the two groups using the Mann-Whitney test (p<0.05). Similarly, samples were collected during cataract extraction from 13 patients (7 male/6 female) with PEX syndrome and 22 normal patients (7 male/15 female). A platinum electrode together with a reference electrode Ag/AgCl/KCl was used for the first time in Ophthalmology, for the measurement of the apparent redox potential in the aqueous humor. The independent samples t-test was used to compare aqueous redox potential between the study and control group. Statistical significance was set at 0.05. Results: Cu was found significantly lower in the PEX than in the control group (p<0.05), whereas Zn and Cd had no statistical differences between the two groups. The redox potential was found significantly higher in patients with PEX syndrome than in normal patients (p<0.05). Conclusions: In the present study we represent the first successful application of ASV in eye research for the determination of aqueous Zn, Cd and Cu concentrations and the meauserment of aqueous redox potential. The significantly lower Cu concentrations and the higher redox potential in aqeous humor of PEX syndrome support the role of increased oxidative stress in the development of PEX.

En France, les anciennes mines d'uranium et leurs eaux d'exhaure font l'objet d’une surveillance environnementale dû à la présence de stériles miniers qui peuvent modifier la chimie des eaux en augmentant leur concentration en uranium. Afin de pouvoir rejeter des eaux dans le milieu naturel dont les concentrations en U(VI) soient conformes aux normes, des stations de traitement ont été mises en place. Cependant, une future règlementation diminuera drastiquement la limite autorisée de rejet en uranium impliquant une révision des méthodes d'élimination de celui-ci. L'adsorption aqueuse est une méthode efficace et peu couteuse. Les matériaux à mésoporosité ordonnée présentent des propriétés d'adsorption intéressantes à cause de leurs propriétés texturales et leurs possibles fonctionnalisations. Plusieurs familles de matériaux mésoporeux (silices fonctionnalisées ou non, carbones, oxyde de magnésium) ont été synthétisées, caractérisées et utilisées pour adsorber U(VI). Des études en batch et en dynamique ont été réalisées à partir de solutions reconstituées et d'eaux d'exhaure issues du site de Bellezane (87) sur les différents matériaux choisis, et les mécanismes d'adsorption ont été étudiés en fonction de la spéciation aqueuse de l'uranium et de la présence d'ions compétiteurs. Les résultats ont montré que la SBA-15 greffée avec des fonctions aminopropyles, présentait les meilleures capacités d'adsorption à pH 6. Il a été montré que l'U(VI) s'adsorbait par formation de complexe de sphère interne dans la mésoporosité du matériau, et que la présence de complexes entre l'U(VI) et les carbonates dissous diminuait significativement la capacité d'adsorption du matériau en U(VI). / In France, former uranium mines and their draining effluents are kept under environmental monitoring due to the presence of mine tailings which can modify the chemistry of surface waters and increase their uranium concentration. In order to decrease the U(VI) concentration to the one set by the standards, water treatment facilities are used. However, an incoming regulation will drastically decrease the allowed U(VI) concentration in the released water, implying the changing of the current U(VI) removal methods. Aqueous adsorption is known to be an efficient and non expensive method. Ordered mesoporous materials have interesting adsorption properties due to their textural properties and their ability to be functionalized. Different types of mesoporous materials (functionalized or non functionalized silica, carbon, magnesium oxide) were synthesized, characterized, and experimented as U(VI) adsorbents. Studies made in batch and dynamic modes were achieved from reconstituted solutions and mine-water from the Bellezane's site (87), on the different materials, and adsorption mechanisms were studied in function of the aqueous uranium speciation and the presence of competitive ions. Results show that aminopropyl grafted SBA-15 displays the best adsorption capacities at pH 6. It is also shown that U(VI) adsorption proceeds through the formation of inner-sphere complex inside of the mesoporosity of the material, and that the presence of complexes involving U(VI) and dissolved carbonates significantly decrease the adsorption capacity of the material toward U(VI).

Les dérivés phosphorylés de nucléosides naturels ou d'analogues (appelés nucléotides) sont des composés primordiaux largement utilisés comme outils biologiques. Certains d'entre eux présentent également un fort potentiel thérapeutique en particulier comme agents antiviraux ou antitumoraux. La préparation des dérivés polyphosphorylés de nucléosides demeure cependant un challenge du fait de rendements de synthèse parfois faibles et des multiples étapes de purification longues et fastidieuses. Ce manuscrit relève donc de la problématique globale de synthèse de ces composés. Le premier chapitre est consacré à l’étude non exhaustive des méthodes de synthèse décrites dans la littérature pour ces dérivés, en rappelant les avantages et inconvénients de ces approches. Le deuxième chapitre rapporte la voie de synthèse en milieux aqueux de nucléotides, et de quelques analogues, que nous avons développée. Des résultats préliminaires de mécanosynthèse basée sur cette même approche sont également présentés. Enfin, le troisième chapitre porte sur deux voies de synthèse supportée de nucléotides. L’une implique la cytidine et son ancrage sur polyéthylène glycol afin de fournir les dérivés 5’-di- et triphosphate correspondants. L’autre porte sur le développement d’un support tétrapode inédit en vue de son utilisation pour la synthèse de dérivés de l'adénosine. / Phosphorylated derivatives of endogenous nucleosides or analogues (called nucleotides) are crucial compounds widely used as biological tools. Some of them also have a high therapeutic potential, in particular as antiviral or antitumor agents. However, the synthesis of polyphosphorylated derivatives of nucleosides remains a challenge due to low yields as well as long and tedious multiple purification steps. Thus, this manuscript is dealing with the overall problem of synthesis of these compounds. The first chapter is devoted to the non-exhaustive study of the synthetic methods described in the literature for such compounds, recalling the advantages and disadvantages of these approaches. In the second chapter, we report our contribution to an original synthetic pathway in aqueous media of some nucleotides and analogues. Some preliminary results of mecanosynthesis based on the same approach are also presented. Finally, the third chapter refers to supported synthesis of nucleotides with two different approaches. One involves cytidine and its anchoring on polyethylene glycol in order to provide the corresponding 5'-di- and triphosphate derivatives. The other concerns the development of a novel tetrapod support that may be valuable for the synthesis of adenosine derivatives.