Lic.-avh. (sammanfattning) Stockholm : Kungliga Tekniska högskolan, 2007. / Härtill 3 uppsatser.

A programme analysis of the compulsory courses at the bachelor level of the KTH Royal Institute of Technology study programme Engineering Chemistry was conducted in order to evaluate how sustainable development is integrated and progressed as well as the attitudes toward sustainable development from the faculty. The analysis built on governing documents as well as interviews with examiners and students. To evaluate the results of this data corpus, thematic analysis was applied, which resulted in themes of environmental focus, poor progression, vague learning objectives and student-teacher disconnect. However, the sustainable development content within the courses appeared to be majorly integrated. In order to use these results for an evaluation of sustainable development the CDIO standard framework was applied, in combination with an unpublished framework by Anders Rosén.  This resulted in the programme being evaluated to be at level 2 in the sustainable development standard, with high proximity level 3. This evaluation culminated in a development project, where suggestions mainly focused on increasing content pertaining to skills for sustainable development, covering more than environmental sustainability as well as increasing integration and progression throughout the programme. / En programanalys av de obligatoriska kandidatkurserna på civilingenjörsprogrammet Teknisk kemi på KTH genomfördes för att utvärdera hur hållbar utveckling integreras och huruvida det finns en etablerad progression samt lärarkårens attituder gentemot ämnet. Analysen tog empiri från styrdokument samt intervjuer med examinatorer och studenter. För att utvärdera resultaten av denna data tillämpades innehålls respektive tematisk analys, vilket resulterade i teman: fokus på miljö, svag progression, vaga lärandemål och skilda uppfattningar mellan lärare och studenter. Integrationen framstod som väl utförd genom programmet enligt lärarkåren. För att kunna bruka dessa resultat i utvärderingen av hållbar utveckling tillämpades CDIO:s standarder i kombination med fyr-aspekt ramverket. Detta gav programmet en nivå av 2 i standarden för hållbar utveckling, med en hög närhet till nivå 3. Utvärderingen resulterade i ett utvecklingsprojekt, resulterande i förslag med huvudsakligt fokus på att öka innehållet av färdigheter för hållbar utveckling, bredda från enbart miljömässig hållbarhet samt öka integration och progression genom hela kandidaten.

Desde a década de 80 o ensino de ciências sofreu diversas transformações. Se antes se buscava formar tecnicistas, hoje se busca formar cidadãos conscientes e críticos capazes de compreender e atuar no mundo em que vivem. Mas ainda hoje as disciplinas de ciências, como a química, são vistas como enfadonhas, difíceis e distantes da realidade, sendo necessário buscar métodos que possam alterar este quadro, como o caso do uso do humor no ensino, que apesar de ser visto com desconfiança, por razões históricas, têm apresentado bons resultados na literatura. Neste trabalho analisa-se o uso de recursos humorísticos, como tirinhas, músicas, vídeos e anedotas, no ensino de química, em uma turma de 1º ano do Ensino Médio, desde o preparo das aulas até as atividades avaliativas, através de uma pesquisa de natureza qualitativa com estratégia da pesquisa-ação. Os dados foram coletados mediante uso de questionários, entrevistas e observações e submetidos a uma análise de conteúdo. Os resultados indicam que os alunos veem, na disciplina, potencial de se relacionar com o cotidiano, mas ainda assim a julgam com estereótipos tradicionalistas, e com isso anseiam por aulas que sejam diferentes das habituais. Dessa maneira, o uso dos recursos mencionados mostrou-se eficiente por dinamizar as aulas, promover interações sociais, despertar o interesse dos alunos, contextualizar o conteúdo exposto e trazer impactos positivos na memória dos estudantes. Por outro lado foi preciso cautela com o conteúdo humorístico utilizado, a frequência de utilização dos recursos e o controle da sala de aula. Foi possível também acompanhar a identificação de um perfil docente. E por fim destacar a importância da pesquisa-ação para aproximar a pesquisa e a sala de aula. / From the 80s to the present day science education has undergone several transformations. If before it was sought to form tecnicists today seeks to educate aware and critics citizens, who can understand and act in the world in which they live. But even science subjects such as chemistry, are seen as boring, difficult and far from reality, being necessary to find out methods that can change this situation, as the case of the use of humor in teaching, that despite being viewed with suspicion, for historical reasons, have shown good results in the literature. In this work we analyze the use of humorous resources, like strips, songs, videos and anecdotes, in teaching chemistry in a class of 1st year of high school, from the preparation of classes until the evaluation activities, through a survey qualitative research with action research strategy. Data were collected by use of questionnaires, interviews and observations and subjected to content analysis. The results indicate that students see the potential to relate chemistry to the everyday, but still judge it under traditionalists stereotypes, and thus crave for classes that are different from the usual. Thus, the use of resources was efficient for streamline classes, promote social interactions, arouse the interest of students, contextualize content exposed and have a positive impact in the minds of students. On the other hand, it was necessary caution with humorous content used, the frequency of use of resources and control of the classroom. It can also track the identification of a teacher profile. Finally highlight the importance of action research to approach the research and the classroom.

Desde a década de 80 o ensino de ciências sofreu diversas transformações. Se antes se buscava formar tecnicistas, hoje se busca formar cidadãos conscientes e críticos capazes de compreender e atuar no mundo em que vivem. Mas ainda hoje as disciplinas de ciências, como a química, são vistas como enfadonhas, difíceis e distantes da realidade, sendo necessário buscar métodos que possam alterar este quadro, como o caso do uso do humor no ensino, que apesar de ser visto com desconfiança, por razões históricas, têm apresentado bons resultados na literatura. Neste trabalho analisa-se o uso de recursos humorísticos, como tirinhas, músicas, vídeos e anedotas, no ensino de química, em uma turma de 1º ano do Ensino Médio, desde o preparo das aulas até as atividades avaliativas, através de uma pesquisa de natureza qualitativa com estratégia da pesquisa-ação. Os dados foram coletados mediante uso de questionários, entrevistas e observações e submetidos a uma análise de conteúdo. Os resultados indicam que os alunos veem, na disciplina, potencial de se relacionar com o cotidiano, mas ainda assim a julgam com estereótipos tradicionalistas, e com isso anseiam por aulas que sejam diferentes das habituais. Dessa maneira, o uso dos recursos mencionados mostrou-se eficiente por dinamizar as aulas, promover interações sociais, despertar o interesse dos alunos, contextualizar o conteúdo exposto e trazer impactos positivos na memória dos estudantes. Por outro lado foi preciso cautela com o conteúdo humorístico utilizado, a frequência de utilização dos recursos e o controle da sala de aula. Foi possível também acompanhar a identificação de um perfil docente. E por fim destacar a importância da pesquisa-ação para aproximar a pesquisa e a sala de aula. / From the 80s to the present day science education has undergone several transformations. If before it was sought to form tecnicists today seeks to educate aware and critics citizens, who can understand and act in the world in which they live. But even science subjects such as chemistry, are seen as boring, difficult and far from reality, being necessary to find out methods that can change this situation, as the case of the use of humor in teaching, that despite being viewed with suspicion, for historical reasons, have shown good results in the literature. In this work we analyze the use of humorous resources, like strips, songs, videos and anecdotes, in teaching chemistry in a class of 1st year of high school, from the preparation of classes until the evaluation activities, through a survey qualitative research with action research strategy. Data were collected by use of questionnaires, interviews and observations and subjected to content analysis. The results indicate that students see the potential to relate chemistry to the everyday, but still judge it under traditionalists stereotypes, and thus crave for classes that are different from the usual. Thus, the use of resources was efficient for streamline classes, promote social interactions, arouse the interest of students, contextualize content exposed and have a positive impact in the minds of students. On the other hand, it was necessary caution with humorous content used, the frequency of use of resources and control of the classroom. It can also track the identification of a teacher profile. Finally highlight the importance of action research to approach the research and the classroom.

SANTANA, José Ernandes Oliveira de. Matemática aplicada à química. 2016. 89 f. Dissertação (Mestrado Profissional em Matemática) - Departamento de Matemática, Universidade Federal do Ceará, Fortaleza, 2016 / Submitted by Rocilda Sales (rocilda@ufc.br) on 2017-03-09T13:21:15Z No. of bitstreams: 1 2016_dis_ jeosantana.pdf: 932381 bytes, checksum: 836a9ac0e75762271815e633c828df8d (MD5) / Approved for entry into archive by Rocilda Sales (rocilda@ufc.br) on 2017-03-09T13:22:36Z (GMT) No. of bitstreams: 1 2016_dis_ jeosantana.pdf: 932381 bytes, checksum: 836a9ac0e75762271815e633c828df8d (MD5) / Made available in DSpace on 2017-03-09T13:22:36Z (GMT). No. of bitstreams: 1 2016_dis_ jeosantana.pdf: 932381 bytes, checksum: 836a9ac0e75762271815e633c828df8d (MD5) Previous issue date: 2016 / The work is divided into three chapters. Chapter 01: Basic Applied Mathematics to Chemistry; Chapter 02: Math Middle Applied Learning Chemistry; Chapter 03: Mathematics higher education Applied to Chemistry. The first chapter consists of we use mathematics subjects in primary education as a direct and inverse proportion, weighted arithmetic average percentage to solve chemical calculation problems. For the understanding of this chapter it is necessary to have full control of all the mathematics of elementary school which will be a prerequisite also for chapters two and three. In the second chapter we focus on the application of logarithms and linear systems for specific troubleshooting as calculation of pH and balancing chemical equations respectively. For that we must to be skilled in handing properties of logarithms and solving linear equations and interpretation of solutions. The third chapter is the applicability of differential and integral calculus in calculating the concentrations, time and rate of chemical reactions. This is a subject more difficult to understand, giving that requires a chapter of the domain derivatives and integrals a theoretical review was made of both mathematics and chemistry before each application to facilitate a better understanding of this work. / O presente trabalho divide-se em três capítulos. Capítulo 01: Matemática básica aplicada à química; capítulo 02: Matemática do Ensino médio aplicada à química; capítulo 03: Matemática ao ensino superior aplicada à Química> O primeiro capítulo consiste em usarmos assuntos de matemática no ensino fundamental como proporção direta e inversa, média aritmética ponderada, porcentagem para resolvermos problemas de cálculo químico. Para o entendimento desse capítulo é necessário que se tenha pleno domínio de toda a matemática do ensino fundamental que será pré-requisito também para os capítulos dois e três. No segundo capítulo nos concentramos na aplicação dos logaritmos e de sistemas lineares para solução de problemas específicos como cálculo do pH e balanceamento das equações químicas respectivamente. Para isso temos que estar hábeis no trato das propriedades dos logaritmos e na solução de equações lineares bem como na interpretação das soluções. No terceiro capítulo faz-se a aplicabilidade do cálculo diferencial e integral no cálculo das concentrações, do tempo e da velocidade das reações químicas. Trata-se de um assunto de mais difícil compreensão, tendo em vista que requer domínio do capítulo de derivadas e integrais. Foi realizada uma revisão teórica tanto de matemática quanto de química precedendo cada aplicação para facilitar um melhor entendimento deste trabalho.

La synthèse de modèles du site actif de l'hydrogénase à fer, responsable de la catalyse réversible de la réduction des protons en dihydrogène, est un enjeu crucial dans l'optique d'une meilleure compréhension du fonctionnement du système enzymatique et du développement de nouveaux types de catalyseurs à base de clusters fer-soufre. Durant cette thèse ont été abordés les aspects synthétiques (ligands soufrés et complexes fer-carbonyle) aussi bien que les études spectroscopiques et électrochimiques.

Calcitriol (1alpha,25-(OH)2 D3, 1,25D) is known for its calcium regulatory function, but also for being a powerful inhibitor of cell growth in a variety of normal and neoplastic cells. As such, it is a lead structure in the development of new cancer drugs. The goal of our project is to identify analogues of calcitriol which bind tightly to the vitamin D receptor (VDR) yet do not exhibit unwanted hypercalcemic effects. The development of novel analogues using conventional chemistry and dynamic chemistry was investigated. First, the numerous building blocks required for the exploration of the different libraries were created through the use of conventional techniques. We then developed different synthetic schemes based primarily on thiol alkylation and amide couplings, enabling rapid parallel synthesis of potential 1,25D analogues. Preliminary investigations allowed us to implement with our collaborators a set of biological assays to evaluate our compounds. Although some analogues appeared to bind to the VDR, it was found that none of the 8 analogues tested in the preliminary studies seemed to be vitamin D receptor (VDR) agonists. In a second part, our research focused on the study of dynamic combinatorial chemistry as a tool for the synthesis of 1,25D analogues. Our first dynamically-generated libraries were created via thioester exchange. It was found that the rate of thioester exchange was dependent on the nature of the thiols involved and the acyl portion of the thioesters. Aliphatic acid thioesters exchanged more slowly than aromatic acid thioesters. The use of branched (alpha-substituted) thiols also slowed the rate compared to primary ones. However, the use of large concentration of aliphatic or aromatic thiols could accelerate the thioester exchange. When thioesters were placed in presence of protein targets in a dynamic system, their inherent electrophilic nature rendered them prone to chemical decomposition (hydrolysis and acylation of protein nucleophilic residues) at basic pHs. Nonetheless, we created thioester libraries of up to 40 members from as few as 7 building blocks under near neutral conditions. We showed that these dynamic libraries ere influenced by the presence of proteins. We have not been able to confirm if thioester libraries were influenced exclusively by the VDR via its binding site. Some of our observations challenged the viability of the thioester exchange as a reversible process in the context of VD3 analogue synthesis. Finally, we created dithiol building blocks, amenable to disulfide exchange in dynamic libraries. Chemically stable, these disulfide entities easily generated libraries of at least 30 members from as few as 7 building blocks. Our preliminary disulfide libraries seemed uninfluenced by VDR's presence. These results still allowed us to understand better the characteristics and limitations of dynamic systems applied to the development of novel vitamin D analogues. / Calcitriol (1alpha,25-dihydroxyvitamine D3, 1,25D) est connu pour sa fonction dans la régulation du métabolisme du calcium, mais aussi comme étant un puissant inhibiteur de la prolifération cellulaire dans un éventail de cellules normales et néoplastiques. Comme tel, il représente le point de départ pour le développement de nouvelles molécules anticancéreuses. Le but de notre projet est d'identifier des analogues du calcitriol capables de se lier au récepteur de la vitamine D (RVD) sans causer d'hypercalcémie. Le développement de nouveaux analogues de la vitamine D3 a été exploré en utilisant la chimie conventionelle et la chimie dynamique. Dans un premier temps, de nombreux synthons nécessaires à la création des différentes librairies ont été fabriqués par des techniques de synthèse traditionnelles. Ensuite, des routes de synthèse basées sur l'alkylation de thiols et la formation d'amides ont été élaborées, permettant une synthèse en parallèle efficace d'analogues de la vitamine D. En collaboration avec nos partenaires, des études préliminaires ont permis d'établir la validité d'une série de tests pour évaluer l'activité biologique de nos analogues sur le récepteur de la vitamine D. Bien que plusieurs composés semblent se lier au récepteur, aucun des 8 analogues évalués de façon préliminaire n'ont révélé une activité agoniste du RVD. Dans un deuxième temps, nous avons axé notre recherche sur l'étude de la chimie combinatoire dynamique (CCD) comme outil pour la création et l'évaluation d'analogues de la vitamine D. La CCD est basée sur le fait qu'une protéine peut influencer la composition de bibliothèques dynamiques en favorisant la création de ses propres ligands, et ce, proportionnellement à leur constante d'affinité. Les premières bibliothèques dynamiques furent créées à partir d'échanges entre thioesters. Il a été évalué qualitativement que la vitesse de ce processus est dépendante de la nature des thiols impliqués ainsi que de la nature de la portion acyl des thioesters. L'échange des thioesters d'acides aliphatiques est plus lent que celui des thioesters d'acides aromatiques. Aussi, plus les thiols sont encombrés stériquement, plus le processus est lent. Toutefois, l'utilisation de grandes concentrations de thiols aromatiques et aliphatiques peut accélérer le processus d'échange. Lorsque des thioesters sont utilisés en présence de protéines à pH basique, leur caractère électrophilique les rend propices à la dégradation chimique par hydrolyse ou par acylation des fonctionnalités nucléophiles des protéines. Néanmoins, à pH neutre, des bibliothèques de thioesters possédant plus de 40 composantes furent facilement réalisées à partir de seulement 7 synthons. Il a pu être démontré que la composition de ces bibliothèques est influencée par la présence de protéines. Cependant, nous n'avons pas été en mesure de confirmer si le RVD a véritablement influencé la nature des bibliothèques de thioesters grâce à son site de liaison. Certaines de nos observations mettent en doute l'utilisation de la transthioestérification comme processus dynamique viable pour la création d'analogues de la vitamine D en présence de protéines.Finalement, des synthons dithiols furent créés et leur combinaison a permis la formation de bibliothèques dynamiques de plus de 30 composés, grâce à l'échange de disulfures. Les études préliminaires ont montré que les bibliothèques de disulfures ne semblent pas être influencées par la présence du RDV. Ces résultats ont permis de connaître les caractéristiques et les limites de ces systèmes dynamiques appliqués au développement de nouveaux analogues de la vitamine D.

ABSTRACTA prerequisite step towards building a self-heating (SH) model for sulphide materials is the determination of physico-chemical parameters such as the specific heat capacity (Cp), and the energy of activation (Ea). The specific heat capacity of one copper and three nickel concentrates was determined over the temperature range 50 to 80oC in the presence of 6% moisture using the self-heating (SH) apparatus and confirmed by Drop Calorimetry. The Cp values from both techniques were comparable. The Cp values were similar for all concentrates increasing from 0.4 to 1.4 Jg-1K-1 as temperature increased from 50 to 80oC. From the Cp values, the enthalpy change (ΔH), the entropy change (ΔS) and the Gibbs free energy change (ΔG) for self-heating, were determined. The ΔG was negative, demonstrating that self-heating of the concentrates was spontaneous.Using the self-heating apparatus the, activation energy (Ea) was determined for the Ni-and Cu-concentrates and for pairs of sulphide minerals. The Ea ranged from 22 to 30 kJ.mol-1, implying a common reaction. Further support for a common reaction is the strong positive correlation between Ea and ln(QA/Cp) where Q (J.kg-1) is the heat of reaction causing self-heating and A the Arrhenius pre-exponential factor (s-1). Comparing to literature, the Ea values correspond to partial oxidation of hydrogen sulphide, supporting the contention that H2S may be an intermediate product in the self-heating of sulphide minerals. A positive relationship between Ea and the rest potential difference (ΔV) for the sulphide pairs and a negative relationship between Cp and ΔV were demonstrated which support a connection between self-heating and the galvanic effect. / RESUMÉLa réalisation d'un modèle mathématique de l'auto-échauffement des concentrés sulfurés de nickel et de cuivre et des mélanges des minerais sulfurés, enjoint à la détermination des paramètres physico-chimiques tels que les capacités de chaleur spécifiques (Cp), et les énergies d'activation (Ea). Les capacités de chaleur spécifiques d'un concentré de cuivre et de trois concentrés de nickel contenant 6% d'humidité, ont été déterminées par utilisation d'un instrument de mesure de vitesse d'auto – échauffement et validées par la calorimétrie de chute dans l'intervalle de températures allant de 50 à 80oC. Les Cp (0.4 à 1.4 Jg-1K-1) obtenues sont similaires pour tous les échantillons. A partir des valeurs des Cp, les variations de l'enthalpie (ΔH), l'entropie (ΔS) et de l'énergie libre de Gibbs (ΔG) de l'auto échauffement ont été déterminées. La valeur négative de ΔG confirme le caractère spontané de l'auto échauffement des minerais sulfurés.Les énergies d'activation (Ea) pour l'auto-échauffement des concentrés de nickel et cuivre et des paires de minerais sulfurés étaient déterminées en faisant usage de l'appareil d'auto-échauffement. Les Ea ainsi obtenues oscillent entre 22 et 30 kJ.mol-1 : Ce qui est suggestif d'une rèaction chimique commune gouvernant l'auto-échauffement de ces matériaux. Ce fait est corroboré par la forte corrélation obtenue entre Ea et ln(QA/Cp) (Q (J.kg-1) est la chaleur de la rèaction chimique responsable de l'auto-échauffement et A (s-1) la constante d'Arrhenius).Ensuite celles-ci sont similaires à celle de l'oxydation partielle du H2S. Il se pourrait, ce faisant, que H2S soit un composé intermediaire lors de l'auto–échauffement des sulfures.Enfin, la corrélation positive entre Ea et la difference de potential (ΔV) dans les paires de minerais sulfurés et celle negative entre Cp et ΔV sont une preuve qu'il existe bel et bien une connection entre l'auto-échauffement et l'effet galvanique.

Interaction with MgO-minerals is one mechanism suspected to reduce selectivity in flotation of pentlandite from ultramafic ore. Understanding the surface chemistry of the minerals involved will lead to improved flotation conditions that maximize flotation selectivity. The first part of the thesis compares isoelectric point (i.e.p.) and point of zero charge (p.z.c.) determined using Mular-Roberts [M-R] titration technique of MgO-minerals chlorite, serpentine and talc. The M-R technique was unsuccessful with talc, attributed to Mg2+ acting as potential determining ion. For serpentine and chlorite, respectively, p.z.c. was pH 4.3 and 4.6 and i.e.p. pH 3.2 and <3. Dispersion index (DI) for chlorite suggested that aggregation/dispersion is controlled by both; serpentine remained dispersed, possibly due to hydration effects.The second part determines surface properties of pentlandite and serpentine isolated from an ultramafic ore. Zeta potential measurements were made on minerals alone and as mixtures with either indifferent electrolyte or supernatant derived from an ore suspension as background. Individual mineral results anticipated interaction due to electrostatic attraction. This was confirmed in the mixed mineral case, with Mg(OH)2 precipitate interaction as an additional factor. Scanning electron microscopy validated the findings.Aggregation/dispersion was determined by turbidimetry using a light scattering technique and optical microscopy. The effect of selected factors on aggregation/dispersion of pentlandite and serpentine was investigated by a design of experiment (DOE). Concentration of carboxymethyl cellulose, CMC, and the interaction between CMC and pH were the important factors. Contact angle measurements explored effects of several factors on pentlandite hydrophobicity and, using a DOE, small-scale flotation was used to investigate effects on pentlandite floatability. The pH was the most important factor, acidic pH increasing both hydrophobicity and floatability. Copper activation enhanced both properties, as well; magnesium affected hydrophobicity at alkaline pH, but it did not show significant effect on floatability; serpentine was detrimental to the process; and CMC was capable of partially restoring the hydrophobicity and floatability of pentlandite depressed with serpentine. / L'interaction de la pentlandite avec des minéraux d'oxide de magnésium (MgO-) est soupçonnée d'être à l'origine de la sélectivité réduite de la pentlandite dans les procédés de flottation de minerais ultrabasiques. Une meilleure compréhension de la chimie de surface des minéraux impliqués devrait mener à l'amélioration des conditions de flottation qui en maximisent la sélectivité. La première partie de la thèse compare le point isoélectrique (p.i.e) et le point de charge nulle (p.c.n), déterminés à l'aide de la technique de titrage Mular-Roberts [M-R], de minéraux d'oxide de magnésium tels que la chlorite, la serpentine et le talc. Dans le cas du talc, la technique M-R a échoué, probablement dû aux ions Mg2+ qui jouent le rôle d'ions déterminateurs de potentiel. Dans le cas de la serpentine et de la chlorite, les p.c.n. ont été déterminés à pH 4,3 et 4,6 respectivement et les p.i.e à pH 3,2 et <3 respectivement. Des tests de décantations ont suggéré que l'agrégation/dispersion observée pour la chlorite était contrôlée à la fois par le p.c.n et le p.i.e ; la serpentine au contraire est restée dispersée, possiblement dû à des effets d'hydratation. La deuxième partie détermine les propriétés de surface de la pentlandite et de la serpentine isolées à partir d'un minerai ultrabasique. Des mesures du potentiel zêta ont été effectuées sur les minéraux seuls et mélangés en présence d'un électrolyte, indifférent dans un cas et surnageant dans l'autre cas, préparé à partir d'une suspension de minerai utilisée comme milieu d'étude. Les résultats relatifs aux minéraux individuels et en particulier les forces d'attraction électrostatique observables ont permis d'anticiper leur interaction. Cette hypothèse a été confirmée dans le cas des minéraux mélangés, étant après avoir pris en compte l'interaction de précipités de Mg(OH)2 comme facteur additionnel. Des observations au microscope électronique à balayage ont permis de valider les résultats. L'agrégation/dispersion a été déterminée par décantation en utilisant des techniques de lumière diffuse et de microscopie optique. L'effet de certains facteurs sur l'agrégation/dispersion de la pentlandite et de la serpentine a été étudié sur la base d'un plan d'expériences (PE). Entre autres, la concentration en carboxymethyl cellulose (CMC) et l'interaction entre le CMC et le pH ont été considérés comme des facteurs importants. Des mesures d'angle de contact ont permis d'explorer l'hydrophobicité de la pentlandite et, à l'aide d'un PE, une étude de flottation à petite échelle a été réalisée pour investiguer la flottabilité de la pentlandite. Les résultats ont montrés que le pH était le facteur le plus important, un pH acide ayant pour effet d'augmenter à la fois l'hydrophobicité et la flottabilité. L'ajout de cuivre a également permis de renforcer ces deux propriétés par un effet d'activation; la présence de magnésium au contraire a affecté l'hydrophobicité de la pentlandite à pH alcalin mais n'a pas eu d'effet significatif sur ses propriétés de flottabilité; la présence de serpentine s'est trouvée être préjudiciable au procédé mais l'utilisation de CMC a pu être utilisée afin de restaurer partiellement l'hydrophobicité et la flottabilité de la pentlandite diminuées par la présence de la serpentine.

Universite de Lille, McMaster University / The main question of this thesis is: do we have today the tools to efficiently describe the structure, the bonding and the thermodynamics of actinide systems? This broad question is answered thanks to three studies. The first two are directly applied to the plastic industry and the nuclear plant safety. The last one, more fundamental, concerns the benchmarking of newly developed theoretical approach on f-element systems. First, actinides and transition metal arene-coordinated alkyl cations have been recently proven to be efficient catalysts for ethylene polymerizations. Interestingly, thorium, uranium and zirconium alkyl cations? catalytic activity depends on the solvent. To understand these behaviors and to confirm the tendency of these complexes to engage in unusual-arene coordination, relativistic DFT calculations combined with a characterization of the interaction thanks to the ETSNOCV method are used. Second, in accident scenario along the reprocessing of spent nuclear fuel, plutonium can be released in various volatile forms (PuO2, PuO3 or PuO2(OH)2, ...). The exploration of these scenarios by the use of simulations requires, among the various parameters, the knowledge of the thermodynamic properties of the possibly formed elements. Our insilico study focusses on the determination of the enthalpies of formation of the former two species for which experimental uncertainties remain, using multi-configurational relativistic wavefunction method. The last part of the thesis focusses on the benchmark of the B2-PLYP functional for f-element systems, which turns out quite accurate with respect to the experimental data and the gold-standard CCSD(T) method. La question générale traitée dans cette thèse est de déterminer si, aujourd’hui, nous disposons d óutils théoriques efficaces pour d’ écrire la structure, la liaison et les propriétés thermodynamiques de système comprenant un actinide. Cette large question va être abordée à láide de trois études différentes. Les deux premières sont directement liées à l?industrie plastique et à la sureté nucléaire. La dernière, plus fondamentale concerne une analyse comparative d?une approche théorique nouvellement développée sur des systèmes comprenant des éléments f. Tout dábord, les cations alkyles contenant un actinide (Th, U) ou un métal de transition (Zr) coordonné à un arène se sont révélés efficaces pour la catalyse de la synthèse du polyéthylène. étonnamment, les activités catalytiques des cations alkyles dépendent du solvant. Pour comprendre cela et confirmer la tendance quónt ces complexes à se lier à l?arène, une étude en DFT dans un contexte relativiste combinée à une caractérisation de liaison avec la méthode ETS-NOCV fut faite. La deuxième étude vise à étoffer les bases de données thermodynamiques qui servent à explorer numériquement les scénarios d?accidents. Notre étude in silico porte sur la détermination des enthalpies de formation des deux espèces pour lesquelles des incertitudes expérimentales subsistent (PuO3 ou PuO2(OH)2, ...), en utilisant une méthode quantique multiconfigurationnelle et relativiste. La dernière partie de la théorie se concentre sur l?estimation de la précision de la fonctionnelle B2-PLYP pour les éléments f, qui sávère assez précise en comparaison aux données expérimentales et à la méthode de référence CCSD(T). / Thesis / Doctor of Philosophy (PhD)