Ce travail est présenté en 2 parties. La première partie aborde la synthèse stéréocontrôlée de 2 séries de carbonucléosides de structures méthylènecyclopropane. Les molécules cibles sont des analogues de l’entécavir, une prodrogue utilisée en trithérapie pour lutter contre le VHB. Les synthèses des carbonucléosides cibles de la série I utilisent un chiron commun, un alcool obtenu par désymétrisation enzymatique d’un diol méso. La transformation chimique de cet intermédiaire clé permet d’obtenir le carbonucléoside (+)-17 en 8 étapes mettant en œuvre comme étapes cruciales un réarrangement de Curtius et la construction de la base uracile avec un rendement global de 23%. Le carbonucléoside appartenant à la série II, a été synthétisé en 10 étapes mettant en jeu une réaction de Mitsunobu, une acylation chimique et contrairement à l’approche précédente, la désymétrisation enzymatique d’un diol méso n’a pas permis d’obtenir le carbonucléoside cible énantiopure. La seconde partie est consacrée à l’activation et l’homolyse des alcoxyamines pour une application en théranostique. La synthèse de l’alcoxyamine modèle présente un groupement vinyl pyridine et un nitroxyde SG1. L’activation est réalisée par protonation, oxydation, méthylation et benzylation de la partie pyridyle et met en évidence l’importance de la polarité. Elle a permis d’obtenir des espèces hautement labiles qui libèrent un radical alkyle et le nitroxyde SG1, avec notamment des valeurs de la constante de dissociation kd plus élevées et donc des énergies d’activation Ea plus faibles par rapport à l’alcoxyamine non activée. / This work is presented in 2 parts. The first part is dedicated to the stereocontrolled synthesis of 2 series of carbonucleosides of methylenecyclopropane structure. The target molecules are analogs of entecavir, a prodrug used in triple therapy to fight against HBV. The syntheses of the carbonucleosides targets of the series I use a common chiron, an alcohol obtained by enzymatic desymmetrization of meso-diol. For example, the chemical transformation of this key intermediate allows to obtain carbonucleoside (+)-16 in 8 steps as crucial steps involving a Curtius rearrangement and the construction of the uracil base with 23% overall yield. The carbonucleoside belonging to the series II was first synthesized in 10 steps involving a reaction of Mitsunobu, a chemical acylation. Howerer the enzymatic desymmetrization of a meso-diol did not get the target carbonucleoside in an enantiopur form. The second part is dedicated to the activation and the homolysis of the alcoxyamines for a theranostic application. The synthesis of the model alcoxyamine is made from vinyl pyridine and nitroxide SG1. Activation is carried out by protonation, oxidation, methylation and benzylation of the pyridyl part and highlights the importance of polarity. It allowed getting highly labile species that release an alkyl radical and nitroxide SG1, with notably higher kd dissociation constant values and therefore activation energies Ea lower compared to the alcoxyamine not enabled.

Cette thèse porte sur l'étude de dégradation atmosphérique de quelques composés organiques volatils oxygénés par les principaux oxydants atmosphériques OH, Cl, et NO3. Ce travail, comporte, d'une part la détermination des spectres d'absorption UV-Visible des composés hydroxycarbonylés (Hydroxyacétone (HAC), 4-hydroxy-2-butanone (4HB), 3-hydroxy-2-butanone (3HB) et 3-methyl-3-hydoxy-2-butanone (3H3M2B) et d'autre part les mesures cinétiques de la réaction du composé HAC avec le chlore atomique et le radical nitrate. Les réactions entre 4HB et 3H2B avec les radicaux OH et le chlore atomique ont aussi été étudié. Les mesures d'absorption ont été réalisées dans la gamme de température 250 et 363 K à l'aide d'une lampe D2 couplé à un monochromateur. Les valeurs de section obtenues sont utilisées pour calculer la constante de photolyse et d'estimer les durées de vie dans la troposphère des composés étudiés. Les résultats suggèrent que la photolyse pourrait être un processus important pour ces espèces dans la troposphère. Les résultats des études cinétiques, montrent une légère variation des constantes de vitesse avec la température. Nous avons aussi étudié les composés dicétones : 2,4-pentanedione et 2,3-pentanedione. Cette étude porte sur la détermination des spectres d'absorption UV-Visible des composés dicétones et l'étude cinétique de leur réaction avec les radicaux OH en fonction de température. Pour les deux composés une variation de température de plus de 60 % est observée. Les calculs théoriques ont été effectués avec deux programmes différents. Avec logiciel Gaussian 03 nous avons réalisé une optimisation de la géométrie des minima, complexes et états de transition au niveau B3LYP/6-311G++(2d, pd). La méthode composite de haut niveau CBS-QB3 a été utilisée. Et avec le logiciel ChemRate pour les calculs cinétique, et la détermination des constantes de vitesse en phase gazeuse de la réaction étudié en fonction de la température. Les calculs des niveaux d'énergies montrent l'existence d'une étape réactionnelle où il se produit d'un complexe intermédiaire suivi d'une abstraction d'un atome d'hydrogène. / This thesis focuses on the study of atmospheric degradation of some Oxygenated Volatile Organic Compounds by major atmospheric oxidants OH, Cl, and NO3. This work comprises firstly determining the spectra of UV-Visible absorption hydroxycarbonyl compounds (hydroxyacetone (HAC), 4-hydroxy-2-butanone (4HB), 3-hydroxy-2-butanone (3HB) and 3-methyl-3-hydoxy-2-butanone (3H3M2B) and secondly measures the kinetics of the reaction of the compound HAC with the atomic chlorine and nitrate radical.Reactions between 4HB and 3H2B with OH radicals and atomic chlorine were also studied.The UV absorption cross-sections of hydroxyacetone, 3-hydroxy 2-butanone, 4-hydroxy 2-butanone and 3-hydroxy 3-methyl 2-butanone have been measured. The experiments have been carried out between 250 and 363 K using a D2 lamp coupled to a monochromator. This work provides the first UV cross-section measurements for 3-hydroxy 2-butanone, 4-hydroxy 2-butanone and 3-hydroxy 3-methyl 2-butanone. The obtained cross-section values are used to calculate the photolysis rates and to estimate the tropospheric lifetimes of the studied compounds. The results suggest that photolysis could be an important removal process for these species in the troposphere. The results of kinetic studies show a slight variation of the rate constants with temperature.We also studied the diketones compounds: 2,4-pentanedione and 2,3-pentanedione. This study focuses on the determination of UV-Visible absorption spectra of diketones compounds and kinetic study of their reaction with OH radicals according to temperature. For both compounds a temperature variation of more than 60% is observed.The theoretical calculations were performed with two different programs: With Gaussian 03 software we performed a geometry optimization minima complex and transition states at B3LYP/6-311G + + level (2d, pd). The high-level composite method CBS-QB3 was used. And with the software ChemRate for kinetic calculations and the determination of rate constants for gas phase reaction according to the studied temperature. Calculations of energy levels show the existence of a reaction step where there is an intermediate complex followed by abstraction of a hydrogen atom.

A busca de uma melhor compreensão dos ciclos químicos que ocorrem na atmosfera de Titan, um dos satélites naturais de Saturno, tem posto em relevância a importância de reações químicas envolvendo nitrogênio atômico e hidrocarbonetos, principalmente o radical metila. Além desta ênfase astroquìmica, essa reação tem também um papel importante no estudo da decomposição de metano em plasma pós-descarga de nitrogênio e no entendimento de processos de combustão. Neste trabalho, dando continuidade a estudos teóricos envolvendo reações de espécies atômicas com hidrocarbonetos realizados por este grupo e utilizando o estado da arte em termos de cálculos de estrutura eletrônica, realizou-se uma ampla investigação da superfície tripleto de energia potencial 3[H3, C, N] com ênfase nos aspectos estruturais, energéticos e espectroscópicos dos pontos estacionários e na cinética global da reação. Nesta superfície de energia potencial, foram caracterizados 7 pontos estacionários, sendo 3 estados de transição e 4 mínimos. No melhor nível de cálculo, CCSD(T)/CBS, o mínimo global corresponde à formação do radical metilnitreno, 71,01 kcal/mol mais estável do que o canal de entrada N(4S) + CH3 (2A2\"). Entretanto, via caminhos distintos, a reação prossegue formando H2CN + H como o principal produto, resultado esse que não confirma uma suposição anterior de que HCN seria o produto principal. No aspecto cinético, verificou-se que a etapa determinante da reação é regida pelo canal de entrada bimolecular, sem barreira, e que o valor para a constante de velocidade global, na melhor descrição deste trabalho, de 1,93 x 10-10 cm3 molécula?1 s-1, é bem superior à de estudo teórico anterior. Além da boa concordância com dados experimentais, nossos resultados também mostram um aumento da constante de velocidade com a temperatura, o que não foi previsto nesse estudo anterior. / The search for a better understanding of chemical cycles in Titan´s atmosphere, one of Saturn´s largest natural satellite, has emphasized the importance of chemical reactions between atomic nitrogen and hydrocarbons, especially methyl radical. Besides this astrochemical relevance, this reaction also plays a key role in the study of methane decomposition in after-glow nitrogen plasma, and in combustion processes. In this work, as another step towards theoretical studies of reactions involving atomic species with hydrocarbons carried out by this group, and using state-of-the-art electronic structure calculations, a wide investigation of the triplet potential energy surface 3[H3, C, N] was made with emphasis on structural, energetic, and spectroscopic aspects of the stationary points, and on the global kinetic description of the reaction. In this potential energy surface, 7 stationary points were characterized: 3 transition states and 4 minima. In our best description, CCSD(T)/CBS, the global minimum corresponds to the formation of the methylnitrene radical, 71.01 kcal/mol more stable than the entrance channel N(4S) + CH3 (2A2\"). However, by different paths, the reaction proceeds leading to the formation of H2CN + H as the major product, a result that does not confirm a previous supposition that HCN would be the major product. Kinetically, we have shown that the rate determining step is the barrierless bimolecular collision of CH3 and N(4S), and that the global rate constant, in the best estimate of this work, 1.93 x 10-10 cm3 molecule-1 s-1, is well superior to that of a previous theoretical study. Besides the good agreement with the experimental data, our results also show an increase of the rate constant with the temperature, a result not predicted by that previous study.

The number of monoclonal antibodies approved for therapeutic use has increased rapidlyover the last decade. As a consequence, precise and robust kinetic characterization techniquesare crucial in order to select the best suitable candidates. A kinetic characterization methodwas developed in Gyrolab with automated sample transfers. The characterization wasperformed in solution in a mixing CD, containing an integrated nanoliter mixing chamberwith affinity binding columns. Association rate constants were determined for four anti-TSHantibodies with values ranging from 3x105 M-1s-1 to 10x105 M-1s-1. The antibodies wereranked according to kass. Reproducibility

A busca de uma melhor compreensão dos ciclos químicos que ocorrem na atmosfera de Titan, um dos satélites naturais de Saturno, tem posto em relevância a importância de reações químicas envolvendo nitrogênio atômico e hidrocarbonetos, principalmente o radical metila. Além desta ênfase astroquìmica, essa reação tem também um papel importante no estudo da decomposição de metano em plasma pós-descarga de nitrogênio e no entendimento de processos de combustão. Neste trabalho, dando continuidade a estudos teóricos envolvendo reações de espécies atômicas com hidrocarbonetos realizados por este grupo e utilizando o estado da arte em termos de cálculos de estrutura eletrônica, realizou-se uma ampla investigação da superfície tripleto de energia potencial 3[H3, C, N] com ênfase nos aspectos estruturais, energéticos e espectroscópicos dos pontos estacionários e na cinética global da reação. Nesta superfície de energia potencial, foram caracterizados 7 pontos estacionários, sendo 3 estados de transição e 4 mínimos. No melhor nível de cálculo, CCSD(T)/CBS, o mínimo global corresponde à formação do radical metilnitreno, 71,01 kcal/mol mais estável do que o canal de entrada N(4S) + CH3 (2A2\"). Entretanto, via caminhos distintos, a reação prossegue formando H2CN + H como o principal produto, resultado esse que não confirma uma suposição anterior de que HCN seria o produto principal. No aspecto cinético, verificou-se que a etapa determinante da reação é regida pelo canal de entrada bimolecular, sem barreira, e que o valor para a constante de velocidade global, na melhor descrição deste trabalho, de 1,93 x 10-10 cm3 molécula?1 s-1, é bem superior à de estudo teórico anterior. Além da boa concordância com dados experimentais, nossos resultados também mostram um aumento da constante de velocidade com a temperatura, o que não foi previsto nesse estudo anterior. / The search for a better understanding of chemical cycles in Titan´s atmosphere, one of Saturn´s largest natural satellite, has emphasized the importance of chemical reactions between atomic nitrogen and hydrocarbons, especially methyl radical. Besides this astrochemical relevance, this reaction also plays a key role in the study of methane decomposition in after-glow nitrogen plasma, and in combustion processes. In this work, as another step towards theoretical studies of reactions involving atomic species with hydrocarbons carried out by this group, and using state-of-the-art electronic structure calculations, a wide investigation of the triplet potential energy surface 3[H3, C, N] was made with emphasis on structural, energetic, and spectroscopic aspects of the stationary points, and on the global kinetic description of the reaction. In this potential energy surface, 7 stationary points were characterized: 3 transition states and 4 minima. In our best description, CCSD(T)/CBS, the global minimum corresponds to the formation of the methylnitrene radical, 71.01 kcal/mol more stable than the entrance channel N(4S) + CH3 (2A2\"). However, by different paths, the reaction proceeds leading to the formation of H2CN + H as the major product, a result that does not confirm a previous supposition that HCN would be the major product. Kinetically, we have shown that the rate determining step is the barrierless bimolecular collision of CH3 and N(4S), and that the global rate constant, in the best estimate of this work, 1.93 x 10-10 cm3 molecule-1 s-1, is well superior to that of a previous theoretical study. Besides the good agreement with the experimental data, our results also show an increase of the rate constant with the temperature, a result not predicted by that previous study.

L'amélioration de la qualité nutritionnelle des produits carnés cuits nécessite une meilleure compréhension des changements physicochimiques des protéines induits au chauffage. Ce travail porte sur l'analyse des mécanismes à l'origine des changements d'état des protéines afin de développer un modèle stoechio-cinétique de prédiction de l'effet de la composition et de la température sur ces changements. Un modèle expérimental, représentant l'environnement physicochimique du tissu musculaire (pH et force ionique), a permis de quantifier l'incidence spécifique de la chaleur, de la composition en fibres, en oxydants (fer, peroxyde d'hydrogène et vitamine C) et en antioxydants (enzymatiques, vitaminique et peptidique) sur l'oxydation, la dénaturation thermique et l'agrégation des protéines. Le modèle stoechio-cinétique est constitué de 43 réactions, représentant l'ensemble des phénomènes mis en jeu dans le modèle expérimental : chimie de Fenton, attaques radicalaires des acides aminés et dénaturation thermique. La résolution du système d'équations différentielles permet de calculer les concentrations des composés au cours du chauffage ; 3 constantes de vitesse inconnues ont été ajustées à partir des cinétiques expérimentales. Les résultats expérimentaux montrent : (1) un effet synergique des oxydants et du chauffage sur les oxydations, (2) une incidence négligeable des oxydants sur la dénaturation thermique et l'agrégation, (3) une sensibilité accrue des protéines de fibres α-white aux oxydations et à la dénaturation thermique par rapport à celles de fibres β-red et (4) un important effet de la nature des oxydants et des antioxydants sur les taux d'oxydation. Les prédictions du modèle stoechio-cinétique permettent de reproduire les tendances expérimentales. En partant de cette base, les modèles expérimentaux et mathématiques pourront être complexifiés progressivement pour avoir un outil prédictif de la qualité nutritionnelle des viandes cuites. / Improving the nutritional quality of cooked meat products needs a better understanding of protein physicochemical changes induced by heating. This study aims to analyse the mechanisms responsible to protein state changes, in the goal to develop a predictive stoichio-kinetic model of effect of composition and temperature on these changes. An experimental model which represent the physicochemical environment of meat tissue (pH and ionic strength) allowed to quantify the specific effect of heating, composition in fibres, in oxidants (iron, hydrogen peroxide and vitamin C) and in antioxidants (enzymes, vitamins and peptides) on oxidations, thermal denaturation (hydrophobicity) and aggregation of proteins. The stoichio-kinetic model is composed of 43 reactions which represent all phenomenon involved in the experimental model : Fenton chemistry, radical attack on amino acids and thermal denaturation. A system of differential equation solver allows to determine the concentration of compounds during heating ; 3 unknown rate constants were adjusted with experimental kinetics. Experimental results show : (1) a synergistic effect of oxidants and heating on protein oxidation, (2) a negligible impact of oxidants on thermal denaturation and aggregation (3) a significant higher sensitivity to oxidation and thermal denaturation of protein from α-white than those from β-red, (4) an important effect of the composition in oxidants and antioxidants on the protein oxidation levels. Stoichio-kinetic model predictions reproduce experimental tendencies. From this base, experimental and stoichio-kinetic models could be progressively complexified to obtain a predictive tool of nutritional quality of meat.

This thesis is concerned about ion-molecular reactions at low temperatures, which are important the fully understand the chemical evolution in interstellar medium. For realization of experimental part of thesis has been used the apparatus of 22-pole radiofrequency ion trap, which allows study the rate constant of reactions at temperatures 10 - 100 K. Thesis contains measuring results of reaction NH+ + H → N+ + H2, which follows the previous study of reaction N+ + H2 → NH+ + H on the same apparatus, description of the apparatus and the general introduction.

The goal of this research is to test the design constraints of active dpp-bridged RuII,RhIII (dpp = 2,3-bis(2-pyridyl)pyrazine)) supramolecular photocatalysts for water reduction to H2 and provide mechanistic insights into the catalytic cycle. Two member of a new RuII,RhIII motifs with only one Rh-'Cl bond, [(bpy)2Ru(dpp)RhCl(tpy)](PF6)4 ( bpy = 2,2'-bipyridine, tpy = 2,2':6,2"-terpyridine) and [(bpy)2Ru(dpp)RhCl(tpm)](PF6)4, (tpm = tris(1-pyrazolyl)methane), and a cis-RhCl2 model system, [(bpy)2Ru(dpp)RhCl2(bpy)](PF6)3, were prepared. This new motif was to test whether two Rh-'Cl bonds on RhIII are required for the photocatalytic water reduction. 1H NMR spectroscopic analysis of complexes prepared using deuterated ligands was used to characterize these three RuII,RhIII supramolecular complexes. Electrochemical studies suggested that replacing bpy with a tridentate ligand on RhIII shifts the RhIII/II and RhII/I reduction couples positively, which can modulate the orbital energetics of the RhIII LUMO (lowest-unoccupied molecular orbital). This substitute also changes the rate of ligand dissociation following the reduction of RhIII. In tpm and bpy systems, RhII intermediate is more stable than that in the tpy system. All three complexes were good light absorbers in the visible region and weak emitters from their emissive Ru(dπ)-'dpp(π*) 3MLCT (metal-to-ligand charge transfer) excited states at room temperature. The population of a low-lying 3MMCT (metal-to-metal charge transfer) ES (excited state) from the 3MLCT ES contributed to the weak emission, indicating an important intramolecular electron transfer process from dpp' to RhIII upon photoexcitation. The lower-lying 3MMCT excited state in the tpm and tpy systems relative to the bpy system result in a higher rate constant (ket = 2.6 x 10^7 vs 1.7 x 10^7 s-1) for intramolecular electron transfer. Spectrophotochemical analysis suggested that all three complexes were photoinitiated electron collectors capable of collecting two electrons on the RhIII center to generate the RuII,RhI species in the presence of DMA (N,N-dimethylaniline). The observed H2 production from water using [(bpy)2Ru(dpp)RhCl(tpm)](PF6)4 and [(bpy)2Ru(dpp)RhCl(tpy)](PF6)4 established that two halides on RhIII are not necessary in the dpp-bridge RuII,RhIII supramolecular photocatalytic-water-reduction system. This new discovery opens a new approach to the design of different RuII,RhIII motifs for photocatalysis. The active species for water reduction is proposed to be [(bpy)2Ru(dpp)RhICl(TL)]3+ from [(bpy)2Ru(dpp)RhCl(TL)](PF6)4 (TL (terminal ligand) = tpy or tpm) and [(bpy)2Ru(dpp)Rh(bpy)]3+ from [(bpy)2Ru(dpp)RhCl2(bpy)](PF6)3 respectively. Included here is the design and study of a RuII,RhI complex, [(bpy)2Ru(dpp)RhCl(COD)](PF6)3 (COD =1,5-cyclooctadiene) to provide more insights into the photophysical and photochemical properties of polypyridyl RuII,RhI species. Electrochemical and photophysical studies revealed a dpp-based LUMO in this RuII,RhI complex, suggesting dpp reduction upon photoexcitation. Photochemical study found that [(bpy)2Ru(dpp)RhCl(COD)](PF6)3 is an active photocatalyst for water reduction and that additional reduction(s) is (are) required after the generation of the RuII,RhI active species in the RuII,RhIII supramolecular photocatalytic H2 production system. This hypothesis was supported by the electrocatalytic behaviors of the RuII,RhIII supramolecular complexes for proton reduction. Cyclic voltammetry results in the presence of an acid suggested that the protonolysis of the RuII,RhIIH and RuII,RhIH species are electrocatalytic H2-evolution pathways. The mechanism is acid-dependent and influenced by terminal ligand. The studies of electrocatalytic proton reduction on these RuII,RhIII complexes suggested several possible intermediates involved in the photocatalytic water reduction cycle. The insights gained from this research can provide guidance in designing new type of RuII,RhIII and RuII,RhI complexes with better photocatalytic and/or electrocatalytic H2 production performance. / Ph. D.

Dans cette étude, l’intérêt est porté sur l’effet des conditions opératoires sur l’enrobage en voie sèche de grosses particules « hôtes » par de fines particules « invitées » et aussi sur la modélisation de cet enrobage selon la méthode par éléments discrets (DEM) afin de mieux comprendre les phénomènes mis en jeu. Dans ce travail, les matériaux choisis comme particules hôtes sont les Suglets® et les particules invitées sont en stéarate de magnésium (StMg). Ces deux éléments sont introduits dans un mélangeur à fort taux de cisaillement, le Cyclomix. Les propriétés du produit final, comme la coulabilité, la mouillabilité et le degré d’avancement de l’enrobage, ont été caractérisés. La variation des propriétés est étudiée en fonction de la durée de traitement dans le Cyclomix pour diverses vitesses de rotation, taux de remplissage et rapport de taille de particules hôte et invitée. La coulabilité a été améliorée avec la durée du mélange ou la vitesse de rotationLe degré d’avancement présente une tendance semblable pour différentes conditions opératoires. Sa variation est représentée par une loi exponentielle empirique en fonction du temps de mélange, paramétrée par une constante ajustable. Cette constante permet d’estimer l’efficacité de l’enrobage. La simulation des mouvements de particules dans le mélangeur par DEM a permis d’obtenir des informations sur la position, la vitesse des particules, et d’autres paramètres énergétiques. Les champs de vitesse réelle ou numérique liés aux mouvements de particules, analysés par PIV (Particule Image Velocimetry), sont analogues. La constante d’enrobage dépend de la vitesse de rotation simulée et peut être ainsi prédite par DEM. / Investigations of the effect of the operating conditions on the dry coating and the motion of particles in a high shear mixer by the DEM simulation have been done. Big Suglets® and small Magnesium Stearate materials have been chosen for the dry coating process. The treatment has been carried out in a Cyclomix, a high shear mixer, at different mixing time, rotational speeds, filling ratio of the samples and particle size ratio to observe the effect of the operating conditions on the dry coating. A conversion ratio has been introduced to quantify the degree of coating and measured. The flowability has been improved when increasing the operation time in the mixer. Higher speeds of rotation can improve the flowability more rapidly. However, the flowability doesn’t seem to be sensitive to the filling ratio. The curves of conversion ratio versus time exhibit the same kind of variations for different operating conditions. It is possible to approximate this tendency by an exponential function in which a characteristic parameter “coating rate constant” is introduced, linked to the efficiency of the dry coating process, since the conversion ratio shows a linear relation with a flowability index and the wettability angle. Simulation of the particle motion in the mixer has been carried out by a Discrete Element Method: different parameters characterizing the location, the velocities, and the attachment of the particles have been derived. The velocity fields of the real and simulated particle motions, compared by Particle Image Velocity (PIV), are quite similar, validating the DEM method and allowing the prediction of the coating process.

Shelby tube sediment samples collected from the foundations of ten (10) bridges located in the state of Georgia were tested in the laboratory to find their erosional behavior and the correlation of erosion parameters with sediment properties in order to improve the prediction of scour around bridge foundations. These sites were spatially distributed in order to fall into different major river basins and in different physiographic regions. A description of the Valley and Ridge, Blue Ridge, Piedmont, and Coastal Plain physiographic regions of Georgia is included, and the erosion parameters found from flume measurements are associated with their respective regions. Flume measurements were performed using a rectangular, tilting, recirculating flume located in the hydraulics lab in the School of Civil and Environmental Engineering at Georgia Tech. Velocities up to 1.7 m/s and bed shear stresses up to 21 Pa can be achieved in the flume. Regression analysis was performed on erosion rates as a function of applied shear stress to determine the parameters of the erosion function. The resulting parameters, the critical shear stress and the erosion rate constant, were correlated with soil properties and physiographic regions. Experimental methodology was chosen to approach this problem because the involvement of interparticle forces for fine-grained materials makes it difficult to deal with the erosion phenomenon through other means. Nevertheless, analytical description of the erosion phenomenon was included in order to provide a better understanding of it. Linear, exponential and power regression mathematical models for erosion rate were compared, and the two best-fit regression models of erosion rate as a function of shear stress are proposed to formulate a methodology intended to characterize the behavior of a soil exposed to erosive flow conditions. One of them is a linear model to calculate critical shear stresses and low erosion rates. The second model, which is exponential, has the advantage of describing the erosion rate response for a wider range of shear stress values. It is shown that one of the most relevant predictors for the critical shear stress and erosion rate constant in the regression models is the fine material content present in the sample, which is an indirect indicator of the contribution of interparticle forces to the erosion process. Applying the described methodology, a more case-specific calculation of the erosion at bridge foundations can be performed taking into account the actual material in situ.