This research developed a three-step demineralization process for removing scale-forming compounds from brine solutions produced during nanofiltration (NF) of potable water. The process is designed to remove compounds that would produce scale and membrane fouling during further treatment via NF or reverse osmosis (RO). Jar tests were performed to determine the most suitable dosages and mixing times for each reagent. The first step in the demineralization process employs ferric chloride for removing phosphonate scale inhibitors via co-precipitation with ferric hydroxide. The second step of the process increases the solution pH value to promote carbonate mineral precipitation. The third step involves barium sulfate precipitation promoted by barite seed crystals. Saturation indices for precipitation of mineral solids were simulated using the PHREEQC thermodynamic modeling program. Water recovery from the treated brines was modeled using the ROSA package for simulating permeate and concentrate compositions for NF processes. The three-step demineralization process allowed the recovery rate for the brine solution to be as high as the initial feed water, and achieved a total water recovery of > 97%.

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Maintaining proper waterflood conformance is a critical component of waterflood management. Most methods used to control waterflood conformance have proven to be only marginally effective. A unique technique has been developed for creating a durable reservoir flow restriction that diverts injected water into unswept reservoir sections. Placement of the restriction is based in the location of the thermal front between the injector and producers. A thermally activated nano-sized particle system-BRIGHTWATER - was developed that gives us this restriction. A sector model of ACG field has been developed to study applicability of BRIGHTWATER injection in ACG field. A decrease in oil production and increase in water production were seen in wells after production started. The water cuts were high for South flank wells. From the simulation it was seen that there were unswept zones. So this new technology was decided to apply in this thesis work. Several runs were conducted to study effect of BRIGHTWATER concentration, crosslinker concentration, injection rate and pressure, injection temperature, injection times and injection well locations. Results are given in tables and figures and briefly discussed. Also the best and the worst cases are chosen from the results, and analyzed in detail. Finally, economical analysis is given. It has been observed that injecting the polymer in slug form is better than continuous injection. Injecting polymer in early times may give better results. Injection of polymer with 3 slug sizes between 6 month injection periods seems more beneficial. According to the simulation results optimum polymer injection temperature was 780 F. Good results were obtained when polymer was injected at 65000, 75000 and 85000 bbl/day injection rates. Oil recoveries obtained during simulation were in the range of 1.4% to 3.8 % which gives additional recovery of 11 to 31 MMSTB of oil. BRIGHTWATER injection has been found to be applicable to ACG field.

The aim of the present thesis is to give a review of the ringing recoveries of the Long - eared owl (Asio otus) in the territory of the former Czechoslovakia and the Czech Republic. The bird ringing data used in this thesis come from the archive of the National Museum in Prague. The parts of the thesis are as follows:1) history of the ringing in the Czech Republic; 2) bird adaptation on the flight and migration; 3) control of the migration; 4) the data of the Long- eared owls ringed as the young birds in the nest (pulli); 5) the data of the Long - eared owls ringed as adults (ad), that were caught and checked during their wintering in the Czech Republic; 6) the recoveries of the Long- eared owls ringed by various European Bird Ringing Centres and found in the Czech Republic; 7) cause of the mortality of the Long eared owl;8) census of the Long - eared owl recoveries in the Czech Republic from 1934 till 2011 (appendix). Key words: Migration, the Long-eared Owl, Ringing, Ringing Recoveries, Mortality

Les quatre chapitres de cette thèse analysent la manière selon laquelle les différents aspects du droit de la faillite influencent les résultats économiques d’une procédure de faillite notamment le degré de recouvrement de la dette des créanciers. Le premier chapitre montre que les lois sur les faillites présentent des conditions différentes de vote de créanciers en fonction de leur origine légale telle que : l’origine anglaise, l’origine française, l’origine allemande et celle nordique. Le second chapitre soutient que l’utilisation nationale de la procédure de réorganisation est favorisée par des processus moins stricts d’acceptation. Le troisième chapitre montre que les systèmes Est-Européens de faillite offrent une protection plus forte des créances garanties que dans le cas de créances publiques. Une concentration plus élevée de la dette diminue les taux de recouvrement en cas de la procédure de liquidation. Les estimations confirment l'existence de deux effets d'interaction entre les classes de créanciers Est-Européens: l'effet d'entraînement et l'effet de rivalité. Le dernier chapitre propose un modèle théorique qui prédit que les débiteurs ont des fortes incitations à proposer aux créanciers de plans de réorganisation avec un partage sous-Optimal de coûts quelque soit l'orientation de l'environnement juridique de la faillite y compris une orientation pro-Créancier ou une orientation pro-Débiteur. / This thesis analyzes the influence of various aspects of bankruptcy law on the economic outcomes of bankruptcy proceedings, mainly the amounts of the debt recovered by claimants. First, we show that bankruptcy laws settle different voting conditions of creditors according to their legal origin, i.e. English origin, French origin, German origin, and Nordic origin. Second, the national use of reorganization procedures seems to be favoured by less strict approval processes. Third, we find that the Hungarian, the Polish, and the Romanian bankruptcy systems provide stronger protection of the private secured claims than the public ones. A higher concentration of the claims also decreases the total recovery rates produced by the liquidation procedure. Our estimations confirm the existence of two interaction effects between the claimants, i.e. the ripple effects and the rivalry effects. Fourth, we developed a theoretical model that predicts that debtors have strong incentives to submit reorganization plans with suboptimal cost sharing regardless of the orientation of the bankruptcy environment, i.e. creditor-Friendly or debtor-Friendly.

This study described an alternative approach for flotation circuit optimization using a mathematical programming technique. Mathematical formulation resulted in mixed integer nonlinear programming problem. Experimental method was used to determine operating conditions of flotation circuit such as flotation circuit stream grades. These conditions were used as the basis for solving optimization problem formulated. The results of the optimization problem were obtaining by setting up the problem in MATLAB optimization toolbox. Performance of flotation circuit in terms of recovery with respect to operating conditions such as residence, number of cells and rate constant has been presented. Stage recoveries were presented as well as overall recovery of the entire flotation circuit. Optimization strategy used superstructure to compare and analyse different alternatives flotation circuits configurations on the basis of stage recoveries. Five circuit alternatives were evaluated are best performing were identified. The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS) software for analysing data derived from mathematical formulation developed for three stages of flotation circuit. Statistically, alternatives A and B can be considered as the most efficient alternatives for the Rougher recovery since they have the same highest means relative to others. Alternative B has the highest mean of 0.995 followed by Alternative A with a mean of 0.991, the least being alternatives D, C and E, respectively. These results imply that Alternative B could be the most efficient alternatives for overall circuit recovery against all other alternatives. One of the key findings were that recovery rate at the rougher stage is higher than the one at the cleaner stage. This results also showed flotation circuits with recycle streams yield comparatively good performance in terms of recovery at rougher stage as compared to circuit without recycle stream. / Civil and Chemical Engineering / M. Tech. (Chemical Engineering)

The oxidative dissolution of chalcopyrite in ferric media often produces incomplete copper recoveries. The incomplete recoveries have been attributed to inhibition caused by the formation of a metal deficient sulphide and the deposition of elemental sulphur and jarosite. Although these phases have been qualitatively identified on the surface of chalcopyrite, none have been quantitatively identified. The aim of the project was to quantitatively analyse the surface before and after oxidative dissolution, with X-ray photoelectron spectroscopy (XPS), and to use the phases identified as the basis for mechanisms of dissolution and inhibition. / XPS analysis was performed on chalcopyrite massive fractured under anaerobic atmosphere and chalcopyrite massive and concentrate oxidised in 0.1 M ferric sulphate (pH 1.9) and 0.2 M ferric chloride (pH 1.6) at 50, 65 and 80ºC. Quantitative XPS analysis of the chalcopyrite surfaces required the development of programs that accounted for the observed XPS spectra. The output of these programs was used to construct profiles of the chalcopyrite surfaces and the deposited phases. These surface profiles were correlated with copper recoveries determined for chalcopyrite concentrate dissolution under the same conditions. / The surface of chalcopyrite before oxidative dissolution reconstructs to form a `pyritic' disulphide phase. This phase is oxidised in ferric media to form thiosulphate via the incorporation of oxygen atoms from the hydration sphere. The thiosulphate reacts in the oxidising conditions of low pH to form elemental sulphur, sulphite and sulphate. The sulphate complexes with ferric to produce hydronium jarosite. This reaction occurs at the surface during the initial stages of dissolution and in the bulk solution during the latter stages. This precipitation of hydronium jarosite during the latter stages of dissolution corresponds to inhibition of the dissolution reaction. It is therefore concluded hydronium jarosite is responsible for inhibiting the oxidative dissolution of chalcopyrite in ferric media. / The identification of hydronium jarosite as the inhibiting phase is consistent with the industrial practice of removing `excess' iron from the ferric solution before oxidative dissolution. However, additional iron and sulphate are generated at the chalcopyrite surface during oxidative dissolution. These high iron and sulphate concentrations combine with the low pH and high temperatures favoured for the oxidative dissolution of chalcopyrite to produce ideal conditions for jarosite precipitation. Therefore, pH must be lowered further to prevent jarosite precipitation and enhance copper recoveries from chalcopyrite in ferric media.

Depuis quelques temps, les enjeux énergétiques ne cessent d’apparaître en tête de liste des préoccupations actuelles pour l’avenir. La fin annoncée des énergies fossiles, à l’origine de 80% de celle que nous consommons aujourd’hui, s’accompagne naturellement par la recherche d’alternatives pour subvenir aux besoins futurs. L’intégration d’une dimension environnementale pour la mise en œuvre d’un développement durable met clairement en avant les atouts des énergies dites renouvelables qui concernent de nos jours moins de 15% de la production mondiale. Le travail proposé ici s’inscrit dans ce cadre de recherche et de proposition de sources d’énergies primaires renouvelables avec l’étude de valorisation de déchets contenant de la biomasse et plus particulièrement du cas du revêtement de sol stratifié. Parmi les diverses voies de valorisation actuelles, l’incinération avec l’ensemble des autres déchets reste le plus usité. L’inconvénient majeur réside dans la nécessité de traitement des fumées qui s’avère relativement coûteux. Il semblerait donc judicieux d’envisager une autre issue de valorisation. Le procédé proposé fait apparaître les trois étapes suivantes : une étape de prétraitement par pyrolyse à basse température (275°C) assurant une séparation des éléments azotés (précurseurs susceptibles de conduire à la formation de polluants) en altérant au minimum le matériau en vue d’une récupération maximale d’énergie lors de l’étape suivante ; une étape de valorisation énergétique, qui constitue le centre du procédé, par une pyrolyse à haute température (1000°C). L’énergie est obtenue par l’intermédiaire du gaz de synthèse ; et une étape de valorisation matière sous deux aspects avec l’obtention de produits à valeur ajoutée (panneaux de particules et charbons actifs) dont l’entrée dans le bilan économique global d’une installation industrielle pourrait s’avérer intéressante / Since a few years, energy challenges are appearing at the top of the list of the current concerns for the future. The forecasted end of fossil fuels, at the origin of 80% of currently consumed energy, is obviously accompanied by research about alternatives to provide for the future needs. The integration of an environmental care concerning the implementation of a sustainable development puts clearly ahead the assets of renewable energies which constitutes nowadays less than 15% of the worldwide production. Work suggested here deals with this scope of research and proposal for renewable primary energy sources with the recovery study of waste containing biomass and more precisely the case of laminated flooring. Among the various current recovering ways, incineration with the whole waste remains the most used one. The main drawback deals with the need for smoke treatment, the cost of which can be really high. It would thus seem to be judicious to look for another recovering issue. The suggested process is divided in the three following steps: - A pretreatment step through low temperature pyrolysis (275°C) making it possible a nitrogenous components separation of the elements (precursor able to form pollutants species) in deteriorating the fuel the less as possible to provide a maximum energy recovery in the following stage.- An energy recovery step, which constitutes the main goal of the process, through a high temperature pyrolysis (1000°C). Energy is recovered via syngas.- A material recovery step through two aspects in order to produce added-value material (particle boards and activated carbon), the consideration of which in the global economic assessment of an industrial installation could be interesting

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