O milho é o principal alimento energético utilizado nas rações de frangos de corte e de aves em geral na maioria dos países. Os principais componentes do grão de milho são o endosperma, rico em amido, mas também contendo proteínas, e o gérmen, rico em lipídios e proteínas; além desses componentes, o pericarpo e a ponta do grão são ricos em materiais fibrosos, hemicelulose e celulose. Nas rações à base de milho, este cereal é maior fornecedor de energia disponível para as aves e, como a energia representa o maior custo das rações, existe um interesse imediato de se utilizarem valores precisos de energia metabolizável na sua formulação. Entretanto, existem tipos bastante distintos de grãos de milho sendo produzidos, especialmente quanto à textura do endosperma, representados por grãos dentados, com maior proporção de endosperma farináceo, grãos semi-dentados e grãos duros, com maior proporção de endosperma vítreo. As variações no valor nutricional, principalmente valor energético, dos diferentes tipos normalmente não são exploradas na indústria de rações. Na literatura, existem indicações de que milho de densidade alta segregado em mesa densimétrica contém maior valor de energia metabolizável do que a fração correspondente de baixa densidade, mas os motivos não são esclarecidos. Com base nesses fatos, foi desenvolvido este projeto em que foram produzidos, sob condições de cultivo semelhante, três híbridos de milho de grãos duros, semiduros e dentados. Foi feita colheita manual e debulha mecanizada, sendo o milho de grãos semiduros foi usado como padrão e os grãos duros e dentados foram segregados em mesa densimétrica para separar 25% do total como densidade alta e 25% como densidade baixa. Espigas dos três materiais foram colhidas inteiras e foram separadas em base, meio e ponta par caracterização dos grãos. Nas diferentes frações obtidas foram feitas determinações de energia bruta e composição bromatológica e determinações físicas do peso específico, peso hectolítrico, peso de mil grãos, peso relativos das partes (endosperma, gérmen, pericarpo mais ponta), forma (altura, largura e profundidade) e vitreosidade do endosperma. Os milhos duro, semiduro e dentado e as frações de alta e baixa densidade dos milhos duro e dentado foram utilizados em um ensaio de metabolismo com frangos de corte de 20 a 29 dias de idade, com 9 repetições, para determinação da energia metabolizável aparente corrigida para o balanço de nitrogênio EMAn). Na análise estatística do ensaio de metabolismo foi feita análise de variância e comparação de médias por contrastes ortogonais; para as demais variáveis foram aplicadas técnicas de análise multivariada de agrupamentos, de componentes principais e de correlações simples. O peso hectolítrico dos diferentes tipos de milho refletiu adequadamente seu peso específico, variando de 683 a 768 g/L para o milho dentado e de 778 a 802 g/L para o milho duro, sendo o semiduro intermediário. A EMAn variou de 3,109 a 3,194 kcal/g para o milho dentado e de 3,141 a 3,211 kcal/g para o milho duro. Considerando-se todas as características avaliadas, ficaram evidentes os agrupamentos para as diferentes frações dentro de cada um dos tipos, duro e dentado, e dentro de cada tipo os agrupamentos entre grãos de alta densidade com os da base e meio da espiga e os grãos de baixa densidade com os da ponta da espiga. Também, o peso específico, peso hectolítrico, vitreosidade, porcentagem de gérmen e porcentagem de lipídios foram mais determinantes para os grãos duros do que para os dentados, com maior impacto sobre a EMAn. / Corn is the main energy feed used in broiler and other poultry rations in most countries. The main components of corn are the endosperm, rich in starch, but also containing proteins, and the germ, rich in lipids and proteins; besides these components, the pericarp and the tip of the grain are rich in fibrous materials, hemicellulose and cellulose. In corn-based diets, this cereal is the largest supplier of available energy to poultry, and since energy represents the highest cost in the feed, there is an immediate interest in using precise values of metabolizable energy in their formulation. However, there are different types of corn grains being produced, especially in regard to the texture of the endosperm, represented by dent grains, with a higher proportion of farinaceous endosperm, semi-dent grains and flint grains, with a higher proportion of vitreous endosperm. Variations in nutritional value, mainly energy value, of the different types of corn are not usually exploited in the feed industry. In the literature, there are indications that high density corn segregated in densimetric table contains higher value of metabolizable energy than the corresponding fraction of low density, but the reasons are not clear. Based on these facts, this project was developed in which three hybrids of flint, semi-dent and dent corn were produced under similar growing conditions. The corn was manually harvested and mechanically shelled, with semi-dent grain corn being used as standard, and the flint and dent grains were segregated in a densimetric table to separate 25% of the total as high density and 25% as low density. Individual ears of the three materials were collected whole and were separated in base, middle and tip for characterization of the grains. In the different fractions obtained, determinations of gross energy and bromatological composition and physical determinations of specific weight, hectoliter weight, weight of a thousand grains, relative weight of the parts (endosperm, germ, pericarp plus tip), shape (height, width and depth) and vitreousness of the endosperm. The flint, semi-dent and dent corn and the high and low density fractions of flint and dent corn were used in a metabolism assay with broiler chickens from 20 to 29 days of age, with 9 replicates, to determine the Nitrogen-corrected apparent metabolizable energy (MEn). In the statistical analysis of the metabolism assay analysis of variance was performed and comparison of means by orthogonal contrasts; for the other variables, techniques of multivariate analysis of clusters, main components and simple correlations were applied. The hectoliter weight of the different types of corn adequately reflected their specific weight, varying from 683 to 768 g/L for dent corn and from 778 to 802 g/L flint corn, the semi-dent corn being intermediate. MEn ranged from 3.109 to 3.194 kcal/g for dent corn and from 3.141 to 3.211 kcal/g for flint corn. Considering all the characteristics evaluated, it was evident the clustering of the different fractions within each corn type, flint and dent, and, within each type, the clustering between the grains with high density and those of the base and middle of the ear and the grains with low density and those of the tip of the ear. Also, the specific weight, hectoliter weight, vitreousness, percentage of germ and percentage of lipids were more determinant for the flint grains than for the dent grains, with greater impact on MEn.

O milho é o principal alimento energético utilizado nas rações de frangos de corte e de aves em geral na maioria dos países. Os principais componentes do grão de milho são o endosperma, rico em amido, mas também contendo proteínas, e o gérmen, rico em lipídios e proteínas; além desses componentes, o pericarpo e a ponta do grão são ricos em materiais fibrosos, hemicelulose e celulose. Nas rações à base de milho, este cereal é maior fornecedor de energia disponível para as aves e, como a energia representa o maior custo das rações, existe um interesse imediato de se utilizarem valores precisos de energia metabolizável na sua formulação. Entretanto, existem tipos bastante distintos de grãos de milho sendo produzidos, especialmente quanto à textura do endosperma, representados por grãos dentados, com maior proporção de endosperma farináceo, grãos semi-dentados e grãos duros, com maior proporção de endosperma vítreo. As variações no valor nutricional, principalmente valor energético, dos diferentes tipos normalmente não são exploradas na indústria de rações. Na literatura, existem indicações de que milho de densidade alta segregado em mesa densimétrica contém maior valor de energia metabolizável do que a fração correspondente de baixa densidade, mas os motivos não são esclarecidos. Com base nesses fatos, foi desenvolvido este projeto em que foram produzidos, sob condições de cultivo semelhante, três híbridos de milho de grãos duros, semiduros e dentados. Foi feita colheita manual e debulha mecanizada, sendo o milho de grãos semiduros foi usado como padrão e os grãos duros e dentados foram segregados em mesa densimétrica para separar 25% do total como densidade alta e 25% como densidade baixa. Espigas dos três materiais foram colhidas inteiras e foram separadas em base, meio e ponta par caracterização dos grãos. Nas diferentes frações obtidas foram feitas determinações de energia bruta e composição bromatológica e determinações físicas do peso específico, peso hectolítrico, peso de mil grãos, peso relativos das partes (endosperma, gérmen, pericarpo mais ponta), forma (altura, largura e profundidade) e vitreosidade do endosperma. Os milhos duro, semiduro e dentado e as frações de alta e baixa densidade dos milhos duro e dentado foram utilizados em um ensaio de metabolismo com frangos de corte de 20 a 29 dias de idade, com 9 repetições, para determinação da energia metabolizável aparente corrigida para o balanço de nitrogênio EMAn). Na análise estatística do ensaio de metabolismo foi feita análise de variância e comparação de médias por contrastes ortogonais; para as demais variáveis foram aplicadas técnicas de análise multivariada de agrupamentos, de componentes principais e de correlações simples. O peso hectolítrico dos diferentes tipos de milho refletiu adequadamente seu peso específico, variando de 683 a 768 g/L para o milho dentado e de 778 a 802 g/L para o milho duro, sendo o semiduro intermediário. A EMAn variou de 3,109 a 3,194 kcal/g para o milho dentado e de 3,141 a 3,211 kcal/g para o milho duro. Considerando-se todas as características avaliadas, ficaram evidentes os agrupamentos para as diferentes frações dentro de cada um dos tipos, duro e dentado, e dentro de cada tipo os agrupamentos entre grãos de alta densidade com os da base e meio da espiga e os grãos de baixa densidade com os da ponta da espiga. Também, o peso específico, peso hectolítrico, vitreosidade, porcentagem de gérmen e porcentagem de lipídios foram mais determinantes para os grãos duros do que para os dentados, com maior impacto sobre a EMAn. / Corn is the main energy feed used in broiler and other poultry rations in most countries. The main components of corn are the endosperm, rich in starch, but also containing proteins, and the germ, rich in lipids and proteins; besides these components, the pericarp and the tip of the grain are rich in fibrous materials, hemicellulose and cellulose. In corn-based diets, this cereal is the largest supplier of available energy to poultry, and since energy represents the highest cost in the feed, there is an immediate interest in using precise values of metabolizable energy in their formulation. However, there are different types of corn grains being produced, especially in regard to the texture of the endosperm, represented by dent grains, with a higher proportion of farinaceous endosperm, semi-dent grains and flint grains, with a higher proportion of vitreous endosperm. Variations in nutritional value, mainly energy value, of the different types of corn are not usually exploited in the feed industry. In the literature, there are indications that high density corn segregated in densimetric table contains higher value of metabolizable energy than the corresponding fraction of low density, but the reasons are not clear. Based on these facts, this project was developed in which three hybrids of flint, semi-dent and dent corn were produced under similar growing conditions. The corn was manually harvested and mechanically shelled, with semi-dent grain corn being used as standard, and the flint and dent grains were segregated in a densimetric table to separate 25% of the total as high density and 25% as low density. Individual ears of the three materials were collected whole and were separated in base, middle and tip for characterization of the grains. In the different fractions obtained, determinations of gross energy and bromatological composition and physical determinations of specific weight, hectoliter weight, weight of a thousand grains, relative weight of the parts (endosperm, germ, pericarp plus tip), shape (height, width and depth) and vitreousness of the endosperm. The flint, semi-dent and dent corn and the high and low density fractions of flint and dent corn were used in a metabolism assay with broiler chickens from 20 to 29 days of age, with 9 replicates, to determine the Nitrogen-corrected apparent metabolizable energy (MEn). In the statistical analysis of the metabolism assay analysis of variance was performed and comparison of means by orthogonal contrasts; for the other variables, techniques of multivariate analysis of clusters, main components and simple correlations were applied. The hectoliter weight of the different types of corn adequately reflected their specific weight, varying from 683 to 768 g/L for dent corn and from 778 to 802 g/L flint corn, the semi-dent corn being intermediate. MEn ranged from 3.109 to 3.194 kcal/g for dent corn and from 3.141 to 3.211 kcal/g for flint corn. Considering all the characteristics evaluated, it was evident the clustering of the different fractions within each corn type, flint and dent, and, within each type, the clustering between the grains with high density and those of the base and middle of the ear and the grains with low density and those of the tip of the ear. Also, the specific weight, hectoliter weight, vitreousness, percentage of germ and percentage of lipids were more determinant for the flint grains than for the dent grains, with greater impact on MEn.

Laurentide Ice Sheet outburst floods to the Gulf of Mexico have been mainly documented based on deep-sea cores, especially the megafloods, only during the last several interglacial episodes in the late Pleistocene. The paleoclimatic significance of giant sedimentary structures developed under unconfined Froude-supercritical turbidity currents in subaqueous settings is considerably under-examined. This research extensively documents >20-km-wide and 200-m-thick Plio-Pleistocene giant sediment waves for the first time on the northern Gulf of Mexico continental slope using 3D seismic data, which show waveform morphology in unprecedented detail. The results suggest that such large-scale bedforms were formed under sheet-like unconfined Froudesupercritical turbidity currents as cyclic steps, based on numerical and morphological analyses. Paleohydraulic reconstruction (e.g., flow velocity, discharge, and unit flux), in association with other evidence like geologic age, stable isotope records, and temporal rarity, points out that the responsible Froude-supercritical turbidity currents were most likely triggered by deglacial catastrophic outburst floods during the late Pliocene to early Pleistocene. These flooding events constitute, by far, the oldest record of the glacial outburst floods during the Quaternary Ice Age. The results propose that such pervasive occurrence of large-scale sediment waves are a proxy for catastrophic megaflood events

Discharge of brine wastewater produced from industrial plants into adjacent coastal water bodies is considered as a preferable and common method currently used in many offshore industrial plants. Therefore, it is important to carefully study the behavior of jets and their environmental impacts on water bodies close to the discharge points, especially when the density is different between the jets and the receiving water. The main goal of this study is to improve the understanding of the mixing behaviour of jet trajectories for positively (offset) and negatively (inclined) buoyant jets when density is considered a significant factor, and also to examine the accuracy of some RANS turbulence models and one type of artificial neural network in predicting jet trajectory behaviours. In the first part of this study, experiments using a PIV system for offset buoyant jets were conducted in order to study the effect of the density differences (due to salinity [nonthermal] or temperature [thermal]) between the discharge and the receiving water body on the jet behavior, and the results showed that the nonthermal jets behaved differently as compared to the thermal jets, even though the densimetric Froude numbers (Frd) and density differences (∆ρ) were similar. In addition, a Reynolds-averaged Navier-Stokes (RANS) numerical model was performed using open-source CFD code (OpenFOAM) with a developed solver (modified form of the pisoFoam solver). The realizable k-ε model showed the best prediction among the models. Secondly, an extensive experimental study of an inclined dense jet for two angles (15°and 52°) was conducted to study the effect of these angles on the jets’ geometrical characteristics in the presence of a wide range of densimetric Froude numbers as well as with different discharge densities. More experimental data were obtained for these angles to be added to the previous data for the purpose of calibrating, validating, and comparing the various numerical models for future studies. The results of these experiments are used to evaluate the performance of a type of artificial neural network method called the group method of data handling (GMDH), and the GMDH results are then compared with existing analytical solutions in order to prove the accuracy of the GMDH method in simulating mixing behaviors in water bodies. Thirdly, a comprehensive study on predicting the geometrical characteristics of inclined negatively-buoyant jests using GMDH approach was conducted. The superiority of this model was demonstrated statistically by comparing to several previous analytical models. The results obtained from this study confirm that the GMDH model was highly accurate and was the best among others for predicting the geometrical characteristics of inclined negatively-buoyant jests.

In this study, the effects of submergence on local scour in a uniform cohesionless sediment bed by a plane turbulent wall jet and the resulting flow field were investigated experimentally. Here, submergence is defined as the ratio of the tailwater depth to the thickness of the jet at its origin. The main focus was to determine scour dimensions at an asymptotic state, examine whether there was similarity in the velocity profiles for the flow in the scour hole, and to determine the growth of the length scales and decay of the maximum velocity of the jet. Also examined were the relationships between the scales for the velocity field in the scour hole and the scour hole size.<p>In the experiments, the range of submergence was varied from 3-17.5, whereas the range of densimetric Froude number and the ratio of the boundary roughness to the gate opening (relative boundary roughness) were varied from 4.4-6.9 and 0.085-0.137 respectively. The velocity field in the scour hole at asymptotic state was measured using a SonTek 16-MHz MicroADV. Time development of the characteristic dimensions of the scour hole was also measured.<p>The dimensions of the scour hole were found to increase with increasing submergence for all experiments with a bed-jet flow regime. In the bed-jet flow regime, the jet remains near the bed throughout the scouring process. Further, the time development of the scour hole dimensions were observed to increase approximately linearly with the logarithm of time up to a certain time before the beginning of asymptotic state for experiments with either the bed-jet or surface-jet flow regimes.<p> The flow field results showed that the velocity profiles in the region of forward flow and the recirculating region above the jet were similar in shape up to about the location of the maximum scour depth. Relationships describing this velocity profile, including its velocity and length scales, were formulated. The decay rate of the maximum velocity, the growth of the jet half-width, and the boundary layer thickness were also studied. The decay and the growth rate of the jet length scales were found to be influenced by the submergence ratio, densimetric Froude number, and the relative boundary roughness.<p>Two distinct stages in the decay of the maximum streamwise velocity, with distance along the direction of flow, were observed for the jet flows having a bed-jet flow regime. The first stage of velocity decay was characterized by a curvilinear decay of velocity, which followed that of a wall jet on a smooth, rigid bed for streamwise distance approximately equal to 2L. For the surface-jet flow regime, the decay of velocity was observed to be similar to that of a free-jump on a smooth, rigid bed for a streamwise distance approximately equal to L. Here, L is defined as the streamwise distance measured from the end of the rigid apron to where the maximum streamwise velocity in the jet is half the velocity of the jet at the end of apron. The streamwise maximum velocity of the jet was then seen to increase in what was called the recovery zone.<p>A relationship for the streamwise decay of the maximum velocity within the scour hole is proposed. Moreover, other scales representing the flow inside the scour hole such as the streamwise distance from the end of the apron to where the streamwise maximum velocity starts to deviate from curvilinear to linear decay and the streamwise distance to where maximum streamwise velocity starts to increase are suggested. Some new results on the velocity distribution for the reverse flow for a bed-jet flow regime are also presented. Finally, some dimensionless empirical equations describing the relationship between the jet scales for the jet flow in a scour hole and the scour hole size are given.

In this study, the effects of submergence on local scour in a uniform cohesionless sediment bed by a plane turbulent wall jet and the resulting flow field were investigated experimentally. Here, submergence is defined as the ratio of the tailwater depth to the thickness of the jet at its origin. The main focus was to determine scour dimensions at an asymptotic state, examine whether there was similarity in the velocity profiles for the flow in the scour hole, and to determine the growth of the length scales and decay of the maximum velocity of the jet. Also examined were the relationships between the scales for the velocity field in the scour hole and the scour hole size.<p>In the experiments, the range of submergence was varied from 3-17.5, whereas the range of densimetric Froude number and the ratio of the boundary roughness to the gate opening (relative boundary roughness) were varied from 4.4-6.9 and 0.085-0.137 respectively. The velocity field in the scour hole at asymptotic state was measured using a SonTek 16-MHz MicroADV. Time development of the characteristic dimensions of the scour hole was also measured.<p>The dimensions of the scour hole were found to increase with increasing submergence for all experiments with a bed-jet flow regime. In the bed-jet flow regime, the jet remains near the bed throughout the scouring process. Further, the time development of the scour hole dimensions were observed to increase approximately linearly with the logarithm of time up to a certain time before the beginning of asymptotic state for experiments with either the bed-jet or surface-jet flow regimes.<p> The flow field results showed that the velocity profiles in the region of forward flow and the recirculating region above the jet were similar in shape up to about the location of the maximum scour depth. Relationships describing this velocity profile, including its velocity and length scales, were formulated. The decay rate of the maximum velocity, the growth of the jet half-width, and the boundary layer thickness were also studied. The decay and the growth rate of the jet length scales were found to be influenced by the submergence ratio, densimetric Froude number, and the relative boundary roughness.<p>Two distinct stages in the decay of the maximum streamwise velocity, with distance along the direction of flow, were observed for the jet flows having a bed-jet flow regime. The first stage of velocity decay was characterized by a curvilinear decay of velocity, which followed that of a wall jet on a smooth, rigid bed for streamwise distance approximately equal to 2L. For the surface-jet flow regime, the decay of velocity was observed to be similar to that of a free-jump on a smooth, rigid bed for a streamwise distance approximately equal to L. Here, L is defined as the streamwise distance measured from the end of the rigid apron to where the maximum streamwise velocity in the jet is half the velocity of the jet at the end of apron. The streamwise maximum velocity of the jet was then seen to increase in what was called the recovery zone.<p>A relationship for the streamwise decay of the maximum velocity within the scour hole is proposed. Moreover, other scales representing the flow inside the scour hole such as the streamwise distance from the end of the apron to where the streamwise maximum velocity starts to deviate from curvilinear to linear decay and the streamwise distance to where maximum streamwise velocity starts to increase are suggested. Some new results on the velocity distribution for the reverse flow for a bed-jet flow regime are also presented. Finally, some dimensionless empirical equations describing the relationship between the jet scales for the jet flow in a scour hole and the scour hole size are given.

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants persistants retrouvés majoritairement dans l’environnement, qui sont reconnus comme hautement toxiques pour les organismes vivants. Les nombreux travaux réalisés sur les mécanismes contrôlant l’évolution des HAP dans le sol et dans la rhizosphère ont mis en exergue le rôle majeur de la biodégradation par les microorganismes et de la sorption aux constituants du sol. Néanmoins, un manque d’informations persiste concernant le devenir de ces HAP dans le sol, et plus particulièrement leur localisation dans les compartiments du sol ainsi que la nature et le comportement des composés issus de leur dégradation. La thèse avait donc comme principaux objectifs : (a) la localisation des HAP et des produits dérivés dans les compartiments du sol (matières organiques, phases minérales, microorganismes et plante), et (b) la quantification et l’identification des composés organiques formant les résidus liés du sol. Pour cela, nous avons couplé deux approches:(i) le suivi d’un HAP modèle marqué, le 13C-phénanthrène (13C-PHE), dans un sol artificiellement contaminé planté et non planté pour notamment déterminer par IRMS et NanoSIMS la distribution du C issu du PHE dans les compartiments et pour identifier les composés dérivés du 13C-PHE par 13C-RMN et TD/pyGCMS. (ii) le suivi d’une contamination ancienne et récente en HAP dans un sol historiquement contaminé pour étudier l’influence des matières organiques et des phases minérales (séparées par un fractionnement densimétrique) dans la rétention des HAP. Plus de 40% du C issu du 13C-PHE est retenu dans le sol après 14 jours de croissance du ray-grass. L’enrichissement en 13C observé dans la plante est du même ordre que celui du sol (E13C ≈ 0.04 % at.) démontrant une incorporation homogène du 13C-PHE entre la plante et le sol. Cet enrichissement global dans la plante est confirmé par les images NanoSIMS réalisées sur les racines. Des hotspots en 13C ont également été observés dans la rhizosphère, et à partir de leur taille, leur forme et leur composition élémentaire en C, N et S ils ont été identifiés comme étant des bactéries, ce qui met en avant leur rôle dans la dynamique des HAP du sol. Dans le sol industriel, la majorité des HAP est retrouvée dans les MO non complexées aux minéraux. En revanche, les HAP fraîchement ajoutés se sont significativement liés aux associations organo-minérales composées de quartz, de feldspaths et de phyllosilicates / Polycyclic aromatic hydrocarbons (PAHs) are major persistent pollutants in the environment that are recognized as highly toxic to living organisms. Numerous studies were carried out on the fate of PAHs in soil and in plant rhizosphere and highlighted the major contribution of biodegradation processes and of the sorption to soil constituents. However, a lack of knowledge remains about the fate of PAHs in the soil and especially their location in soil compartments as well as the nature and the behavior of degradation products. The main objectives of the thesis were: (a) to localize PAHs and their derived products within soil compartments (organic matter, minerals, microorganisms and plant), and (b) to quantify and identify the organic compounds forming bound residues. For this purpose, we used two approaches: (i) the monitoring of a labeled PAH, the 13C-phenanthrene (13C-PHE), in a spiked soil planted or not to determine by IRMS and NanoSIMS the 13C-distribution into compartments and to identify derived compounds of 13C-PHE by 13C-RMN et TD/pyGCMS. (ii) the distribution and localization of aged and freshly spiked PAH contamination in a brownfield soil to study the impact of organic matter and minerals (using soil densimetric fractionation) in the PAH retention. More than 40% of C from 13C-PHE remained in the soil after 14 days of ryegrass growth. The 13C-enrichment in plant tissue was similarly to the soil enrichment (E13C ≈ 0.04 at.%) indicating uniform uptake of 13C-PHE between the soil and plant. NanoSIMS images acquired for roots confirmed this global enrichment in the plant. 13C-Hospots were also observed in the rhizosphere, and on the basis on their size, their shape and their elemental composition in C, N and S, they were identified as bacteria, which emphasize their contribution to the fate of PAHs in soil. In the industrial soil, most of the PAHs were found attached to the free OM. However, the freshly spiked PAHs in the soil were significantly associated with organo-mineral associations containing quartz, feldspars and phyllosilicates

The main goal of this study is to define the technique to be used to assess the aggradation (by bed load) and degradation (of sediments) of the recessed as well as non-recessed stilling basins of rectangular cross section; when the hydraulic jump occurs in the stilling basin where the submergence coefficient equals 1,05. It consists of two parts, theoretical and experimental. The theoretical part summarizes the related theory on a hydraulic jump, design of a stilling basin, an incipient motion of sediment, an assessment of silting and scouring of the stilling basin. The second part, the actual experiment, led to the determination of the critical values essential for the assessment. For the evaluation, the nondimensional shear stress and the densimetric Froude number were used.