Phenotypic Evaluation of Mother Trees and their Effects on Seed Emergence and Growth Dynamics of African Locust Bean Seedlings in Nursery

This study was carried out in order to identify the most productive in term of seeds between African locust bean trees aged 10-29 years, 30-50 years and 51 years and older. It aims also to identify which one can guarantee better emergence and growth of young P.B seedlings in the nursery. These plants were chosen according to the availability of fruit and their accessibility. For the emergence and growth tests, a complete randomized block design with three replicates, each with three treatments was installed. The SPSS v21 software was used for statistical analysis, with a significance level of 5%.The results show that the dendrometry and productivity parameters are better when the plants are at least 30 years old (DBH > 44 cm). Indeed, seeds from trees aged 30 - 50 years significantly improved seed emergence by giving a rate of 70.33%±7.23. Plants growth was not significantly affected by trees age

La fiabilité de l'échantillonnage et de l'analyse du mercure et de l'arsenic dans l'industrie pétrochimique et pétrolière

Mercury (Hg) and arsenic (As) are naturally occurring and problematic compounds in natural gas and crude oil. They are present at concentration levels varying by several orders of magnitude. In addition to health and environmental problems, Hg catalyses the corrosion of aluminium components, with potentially dramatic consequences in processing plants. For As, high concentrations can cause catalyst poisoning and can also induce toxic solid deposition in surface processes or in pipes. A reliable assessment of the concentrations of these two critical elements in hydrocarbon streams is still necessary to anticipate problems and possibly design a treatment unit.The determination and speciation of these two trace elements from deep reservoirs is a very different approach from that applied in clean rooms. The question of the reliability and representativeness of the sampling carried out on site is predominant compared to the analysis and speciation of mercury and arsenic. Sampling and analysis of trace elements in natural gas and oil are full of potential artefacts. In industry, when looking at routine trace element measurements, it is not uncommon to be wrong by several orders of magnitude. This is due to poor consideration of artefacts, including the risk of false positives due to contamination or false negatives due to the delayed breakthrough effect of trace compounds in a well test.The main objectives of this thesis are to track down potential artefacts during sampling and analysis of mercury and arsenic and to propose improvements during these two steps in order to reliably and representatively assess Hg and As concentrations in petroleum fluids.Le mercure (Hg) et l'arsenic (As) sont des composés naturels et problématiques présents dans le gaz naturel et le pétrole brut. Ils sont présents à des niveaux de concentration variant de plusieurs ordres de grandeur. Outre les problèmes de santé et d'environnement, le Hg catalyse la corrosion des composants en aluminium, avec des conséquences potentiellement dramatiques dans les usines de traitement. En ce qui concerne l'As, des concentrations importantes peuvent provoquer un empoisonnement des catalyseurs et peuvent également induire un dépôt solide toxique dans les procédés de surfaces ou dans les canalisations. Une évaluation fiable des concentrations de ces deux éléments critiques dans les flux d'hydrocarbures reste nécessaire pour anticiper les problèmes et éventuellement concevoir une unité de traitement. La détermination et la spéciation de ces deux éléments traces provenant de réservoirs profonds est une approche très différente de celle appliquée en salle blanche. Le questionnement sur la fiabilité et la représentativité de l'échantillonnage réalisé sur site est prédominant par rapport à l'analyse et la spéciation du mercure et de l'arsenic. L'échantillonnage et l'analyse des éléments traces dans le gaz naturel et le pétrole sont pleins d'artefacts potentiels. L'objectif principal de cette thèse est de traquer les artefacts potentiels durant l'échantillonnage et l'analyse du mercure et de l'arsenic dans des fluides pétroliers