Les spécialistes de la gestion de projet sont partagés entre ceux qui défendent l’importance des pratiques de la GRH dans le succès global des projets et ceux qui demeurent sceptiques quant à l’existence d’une telle relation. Notre étude a pour objectif d’enrichir ce débat en tentant de confirmer ou infirmer l’existence d’une relation entre la GRH et le succès des projets dans les pays en voie de développement (PVD). La réalisation d’une étude dans les PVD, où les conditions (économiques, sociologiques, politiques, et cultuelles) sont différentes des pays industrialisés, permettra de savoir si la relation entre la GRH et le succès de projet varie en fonction des pays où le projet est implanté. Le choix de ce sujet de recherche est d’autant plus justifié que les études portant sur les facteurs de succès des projets dans les PVD, et en particulier sur la relation entre la GRH et le résultat de projets dans ses pays, sont plutôt rares. Nos résultats ont révélé que, bien que la GRH ait une relation significative avec le succès des projets dans les PVD, elle présente la corrélation la moins forte avec ce succès par rapport aux autres facteurs de succès étudiés. Ce résultat surprenant peut être expliqué essentiellement par les caractéristiques des PVD qui affectent la gestion de projet et la gestion des ressources humaines dans cette catégorie de pays. Il pourrait s’expliquer également par les caractéristiques spécifiques à la GRH dans le contexte de projet. Afin de mieux comprendre la relation entre les pratiques de GRH et le succès des projets dans les PVD, les recherches futures devraient accorder une attention particulière aux caractéristiques de la GRH propres au contexte de projet en général et au contexte de projet dans les PVD en particulier. / The specialists in the project management are divided between those who defend the importance of human resources practices in the project success and those who remain sceptics about the existence of such a relationship. Our study aims to enrich this debate and try to confirm or invalidate the existence of a relationship between the human resources management (HRM) and the project success. The realization of a study in the developing countries where the economical, social, cultural and legal conditions are different from the industrialized countries will make it possible to verify whether the relationship between the HRM and the project success would vary or not according to the countries where the project is established. Our results revealed that although the HRM has a significant relationship to the project success in the developing countries, it has the least strong correlation with this success. This surprising result can be explained essentially by the characteristics of the developing countries which affect the project management and the human resource management. This result could be also explained by the characteristics relating to the HRM in the project context. In order to better understand the relationship between the HR practices and the project success in the developing countries, future research should pay attention to the characteristics of the HRM in the project context, particularly in the developing countries.

Metallhalogenid-Perowskite (MHP) haben sich als hervorragende Materialklasse im Bereich der Optoelektronik erwiesen, obwohl die Degradation der häufig verwendeten organischen Komponenten ihre Langzeitstabilität begrenzt. Um schnell stabile Alternativen zu finden, ist eine Parallelisierung des Prozesses der Materialentwicklung durch kombinatorische Synthese und Hochdurchsatzanalyse erforderlich. In dieser Arbeit wird dies durch die Entwicklung, Implementierung und Validierung zweier komplementärer Methoden für die kombinatorische Synthese realisiert. Zum einen wurde die lösungsmittelbasierte Methode des kombinatorischen Tintenstrahldrucks weiterentwickelt, indem ein neuer Algorithmus für eine verbesserte Tintenmischung bereitgestellt und validiert wurde. Zum anderen wurde die Synthese von CsyPb1-y(BrxI1-x)2-y-Doppelgradientenschichten durch Co-Verdampfung erreicht. Kombinatorische Bibliotheken, die durch diese beiden Methoden hergestellt wurden, wurden für die Hochdurchsatzuntersuchung der strukturellen und optischen Eigenschaften der anorganischen CsyPb1-y(BrxI1-x)2-y-MHP verwendet. Dies ermöglichte die schnelle Erstellung vollständiger Phasendiagramme für Dünnfilme des CsPb(BrxI1-x)3-Mischkristalls, die zeigen, dass die Zugabe von Br die halbleitende Perowskitphase stabilisiert und niedrigere Verarbeitungstemperaturen ermöglicht. Darüber hinaus wurden CsyPb1-y(BrxI1-x)2-y-Bibliotheken mit automatisierten, kontaktlosen optischen Raster-Messungen untersucht, die eine schnelle Sichtung von über 3400 Zusammensetzungen ermöglichten. Dies ermöglichte die Bewertung des photovoltaischen Potenzials von CsyPb1-y(BrxI1-x)2-y über einen sehr breiten Bereich von Zusammensetzungen. Das höchste Wirkungsgradpotenzial wurde für stöchiometrische Zusammensetzungen gefunden, wobei ein Überschuss an Pb oder Cs zu erhöhten Verlusten durch nichtstrahlende Rekombination führt. Diese Ergebnisse liefern wichtige Erkenntnisse für die weitere Entwicklung von anorganischen MHP-Bauelementen. / To keep up with the increasing need for specialized materials, a parallelization of the materials discovery process is needed through combinatorial synthesis and high-throughput analysis. The acceleration of materials discovery is especially of interest in the area of optoelectronics where metal halide perovskites (MHPs) have proven to be an excellent material class and have achieved impressive performance in photovoltaic devices among other applications. However, the degradation of the frequently employed organic components contributes to limiting the long-term stability of MHP devices. In this work, accelerated materials discovery is addressed through the development, implementation, and validation of two complementary methods for combinatorial synthesis. Firstly, the solution-based method of combinatorial inkjet printing was further developed by providing and validating a new algorithm for improved ink mixing. Secondly, the vapor-based synthesis of double-gradient CsyPb1-y(BrxI1-x)2-y was achieved by co-evaporation. Combinatorial libraries created by both methods were used for the high-throughput investigation of the structural and optical properties of the inorganic CsyPb1-y(BrxI1-x)2-y MHPs. This enabled the fast construction of complete phase diagrams for thin-films of the CsPb(BrxI1-x)3 solid solution which show that the addition of Br stabilizes the semiconducting perovskite phase and allows for lower processing temperatures. Additionally, CsyPb1-y(BrxI1-x)2-y libraries were investigated by automized, contact-less, optical mapping measurements, enabling the rapid screening of over 3400 compositions. This enabled the assessment of the photovoltaic potential of CsyPb1-y(BrxI1-x)2-y over a very broad compositional range. The maximum efficiency potential was found for stoichiometric compositions, with excess of Pb or Cs causing increased losses by non-radiative recombination. These results provide vital knowledge for further development of inorganic MHP devices.

Le projet s’inscrit dans le développement de sources lasers RGB miniaturisées pour l’affichage et la vidéoprojection, la conversion de fréquence dans les cellules solaires.Les verres fluorés ZLAG (ZrF4-LaF3-AlF3-GaF3) codopés terres rares ont été considérés. Ce verre possède une faible énergie de phonon, une forte solubilité des terres rares et peut être fabriqué en couche mince par la technique PVD. Il est de plus le précurseur de vitrocéramiques transparentes. On a observé dans les verres massifs et les guides d’onde des émissions bleue, orange et rouge avec un codopage Pr3+-Yb3+, bleue et rouge avec un co-dopage Tm3+-Yb3+. L’émission RGB dans les verres tri-dopés Tm3+-Er3+-Yb3+ semble prometteuse. Par ailleurs, la vitro-céramisation a permis d’augmenter de plus de 30% les sections efficaces d’absorption des ions Pr3+ et Yb3+.Une efficacité de transfert de 92% a été obtenue dans les verres co-dopés 0,5Pr3+-10Yb3+ pour le processus de conversion d’un photon bleu en deux photons IR. / The project joins in the development of miniaturized laser sources RGB for display and videoprojection, frequency conversion in solar cells.Fluoride glasses ZLAG ( ZrF4-LaF3-AlF3-GaF3) co-doped with rare earths were studied. This glass has a low phonon energy, a strong solubility of the rare earth ions and can be fabricated as thin films by PVD. It is also the precursor of transparent glass-ceramics. Similar emissions in both co-doped bulk and waveguides have been observed ; blue, orange, red emission for Pr3+-Yb3+ and blue, red emission for Tm3+-Yb3+. The RGB emission in bulk Tm3+-Er3+-Yb3+ tri-doped glass seems promising. Furthermore, the absorption cross section of Pr3+ and Yb3+ ions has been increased by 30% with the ceraming process.An energy transfer efficiency (ETE) of 92% has been obtained for co-doped glass with 0,5Pr3+-10Yb3+ for the conversion process of a blue photon into two infrared one.

The submerged entry nozzle (SEN) is used to transport the molten steel from a tundish to a mould. The main purpose of its usage is to prevent oxygen and nitrogen pick-up by molten steel from the gas. Furthermore, to achieve the desired flow conditions in the mould. Therefore, the SEN can be considered as a vital factor for a stable casting process and the steel quality. In addition, the steelmaking processes occur at high temperatures around 1873 K, so the interaction between the refractory materials of the SEN and molten steel is unavoidable. Therefore, the knowledge of the SEN behaviors during preheating and casting processes is necessary for the design of the steelmaking processes  The internal surfaces of modern SENs are coated with a glass/silicon powder layer to prevent the SEN graphite oxidation during preheating. The effects of the interaction between the coating layer and the SEN base refractory materials on clogging were studied. A large number of accretion samples formed inside alumina-graphite clogged SENs were examined using FEG-SEM-EDS and Feature analysis. The internal coated SENs were used for continuous casting of stainless steel grades alloyed with Rare Earth Metals (REM). The post-mortem study results clearly revealed the formation of a multi-layer accretion. A harmful effect of the SENs decarburization on the accretion thickness was also indicated. In addition, the results indicated a penetration of the formed alkaline-rich glaze into the alumina-graphite base refractory. More specifically, the alkaline-rich glaze reacts with graphite to form a carbon monoxide gas. Thereafter, dissociation of CO at the interface between SEN and molten metal takes place. This leads to reoxidation of dissolved alloying elements such as REM (Rare Earth Metal). This reoxidation forms the “In Situ” REM oxides at the interface between the SEN and the REM alloyed molten steel. Also, the interaction of the penetrated glaze with alumina in the SEN base refractory materials leads to the formation of a high-viscous alumina-rich glaze during the SEN preheating process. This, in turn, creates a very uneven surface at the SEN internal surface. Furthermore, these uneven areas react with dissolved REM in molten steel to form REM aluminates, REM silicates and REM alumina-silicates. The formation of the large “in-situ” REM oxides and the reaction of the REM alloying elements with the previously mentioned SEN´s uneven areas may provide a large REM-rich surface in contact with the primary inclusions in molten steel. This may facilitate the attraction and agglomeration of the primary REM oxide inclusions on the SEN internal surface and thereafter the clogging. The study revealed the disadvantages of the glass/silicon powder coating applications and the SEN decarburization. The decarburization behaviors of Al2O3-C, ZrO2-C and MgO-C refractory materials from a commercial Submerged Entry Nozzle (SEN), were also investigated for different gas atmospheres consisting of CO2, O2 and Ar. The gas ratio values were kept the same as it is in a propane combustion flue gas at different Air-Fuel-Ratio (AFR) values for both Air-Fuel and Oxygen-Fuel combustion systems. Laboratory experiments were carried out under nonisothermal conditions followed by isothermal heating. The decarburization ratio (α) values of all three refractory types were determined by measuring the real time weight losses of the samples. The results showed the higher decarburization ratio (α) values increasing for MgO-C refractory when changing the Air-Fuel combustion to Oxygen-Fuel combustion at the same AFR value. It substantiates the SEN preheating advantage at higher temperatures for shorter holding times compared to heating at lower temperatures during longer holding times for Al2O3-C samples. Diffusion models were proposed for estimation of the decarburization rate of an Al2O3-C refractory in the SEN. Two different methods were studied to prevent the SEN decarburization during preheating: The effect of an ZrSi2 antioxidant and the coexistence of an antioxidant additive and a (4B2O3 ·BaO) glass powder on carbon oxidation for non-isothermal and isothermal heating conditions in a controlled atmosphere. The coexistence of 8 wt% ZrSi2 and 15 wt% (4B2O3 ·BaO) glass powder of the total alumina-graphite refractory base materials, presented the most effective resistance to carbon oxidation. The 121% volume expansion due to the Zircon formation during heating and filling up the open pores by a (4B2O3 ·BaO) glaze during the green body sintering led to an excellent carbon oxidation resistance. The effects of the plasma spray-PVD coating of the Yttria Stabilized Zirconia (YSZ) powder on the carbon oxidation of the Al2O3-C coated samples were investigated. Trials were performed at non-isothermal heating conditions in a controlled atmosphere. Also, the applied temperature profile for the laboratory trials were defined based on the industrial preheating trials. The controlled atmospheres consisted of CO2, O2 and Ar. The thicknesses of the decarburized layers were measured and examined using light optic microscopy, FEG-SEM and EDS. A 250-290 μm YSZ coating is suggested to be an appropriate coating, as it provides both an even surface as well as prevention of the decarburization even during heating in air. In addition, the interactions between the YSZ coated alumina-graphite refractory base materials in contact with a cerium alloyed molten stainless steel were surveyed. The YSZ coating provided a total prevention of the alumina reduction by cerium. Therefore, the prevention of the first clogging product formed on the surface of the SEN refractory base materials. Therefore, the YSZ plasma-PVD coating can be recommended for coating of the hot surface of the commercial SENs. / <p>QC 20111014</p>

No description available.

Dans ce travail, de nouveaux traitements de protection, à base de couches minces dures, de type nitrures des métaux de transition, ont été développés en vue d'améliorer la tenue de service d'outils destinés à l'usinage de MDF (Medium Density Fiberboard). En raison des sollicitations sévères auxquelles l'arête est soumise, ces revêtements doivent avoir de bonnes propriétés physicochimiques, mécaniques et tribologiques. Compte tenu des travaux précédents où des résultats prometteurs avaient été obtenus en utilisant des films de CrN, nous avons voulu améliorer les principales caractéristiques de ce système binaire en lui ajoutant des éléments métalliques tels que l'Al et le V. De ce fait, des couches de CrAlN et CrVN ont été réalisées par pulvérisation dual magnétron RF. Nous nous sommes intéressés en particulier à l'effet du pourcentage d'Al et de V respectivement sur les propriétés de CrAlN et CrVN. Dans un deuxième temps, les revêtements optimaux ont été par la suite, réalisés sur des plaquettes en carbure de tungstène utilisées en usinage de trois types de MDF (Standard, Hydrofuge et Ignifugé) et en tenant compte de l'épaisseur et du profil de densité de chaque panneau. Une procédure de pré-rodage des plaquettes carbure a été mise au point et les revêtements ont été effectués à la fois sur des plaquettes pré-rodées ou non. Les résultats indiquent que l'utilisation des films minces pouvait apporter des améliorations significatives en termes de résistance à l'usure et qu'une préparation préalable par pré-rodage était fortement conseillée pour permettre une meilleure adhérence de la couche

Thin films are produced from layers of materials ranging from nanometres to micrometres in height. They are increasingly common and are being used in integrated circuit design, optical coatings, protective coatings, and environmental sensing. Thin films can be fabricated using a variety of methods involving chemical reactions or physical transport of matter. Glancing angle deposition (GLAD) thin films are produced using physical vapour deposition techniques under high vacuum conditions where exploitation of the geometric conditions between the source and the substrate causes enhanced atomic self shadowing to produce structured thin films. This work deals with the modification of these films, emph{in situ} by altering growing conditions through substrate temperatures control, or post-deposition through reactive ion etching (RIE). The first part of the thesis deals with the modification of TiO$_2$ GLAD humidity sensors using RIE with CF$_4$. The data presented demonstrates improved response times to step changes in humidity. Characterization revealed response times of better then 50~ms (instrument-limited measurement). An etch recipe for complete removal of TiO$_2$ was also demonstrated with shadow masking to transfer patterns into GLAD films. The subsequent chapter focuses on modification of thin film growth conditions by increasing adatom mobility. A radiative heating system was designed and implemented with the ability to achieve chuck temperatures of 400$^circ$C. Capping layers on top of GLAD films were grown to demonstrate effects of emph{in situ} heating, and a quantitative analysis of crack reduction with increased temperatures is presented. Lithographic pattern transfer onto a capped GLAD film was demonstrated. Opposite to the goal of the preceding chapter, the focus of the final experimental chapter was to limit adatom mobility. A LN$_2$-based cooling system was designed and implemented for the purpose of studying the growth by GLAD of lower melting point materials, which under regular growth conditions do not form well-defined structures. Chuck temperatures of $-60$$^circ$C can be achieved during deposition while still allowing substrate rotation. The growth of helical copper films was used to demonstrate the effects of emph{in situ} substrate cooling. / Micro-Electro-Mechanical Systems (MEMS) and Nanotechnology

This study focuses on preparing surface enhanced fluorescence (SEF) substrates for use in the enhancement of the emission signal of rhodamine B and fluorescein dyes. Fluorescence spectroscopy has been widely utilized owing to its high sensitivity. SEF is a process where the interactions of fluorophores with the localized surface plasmons of metal nanoparticles results in fluorescence enhancement, increased photostability and rates of system radiative decay which leads to a decreased lifetime. One of the most important factors of SEF studies is to provide a uniform distance between fluorophore and metal nanoparticle in a controlled manner / otherwise, F&ouml / rster resonance energy transfer takes place from fluorophore to metal nanoparticle and emission intensity of fluorophore is quenched. The spherical gold and silver nanoparticles were prepared using the well known and straightforward chemical reduction method, in which sodium citrate acted both as a reducing agent and a stabilizer around the formed nanoparticles. Silver and gold were chosen because of their high plasmon field enhancement. Since plasmon field strongly depends on the shape and size of the nanoparticles, the prepared nanoparticles were characterized using absorption spectroscopy and field emission scanning electron microscopy (FE-SEM). Prior to deposition of silver or gold nanoparticles on glass slides, the slides were derivatized by immersing them into an aqueous solution of 3-Aminopropylethoxysilane (APTES). Following derivatization, silver or gold nanoparticles were deposited by immersing the slides into the colloid mixture. Metal nanoparticle coated slides were characterized using absorption spectroscopy and field emission scanning electron microscopy (FE-SEM). Surface enhanced Raman scattering (SERS) measurements were carried out to observe the plasmon efficiency of the deposited nanoparticles. The SERS measurements were repeated for the duration of two weeks in order to check the stability of the plasmon efficiency. In this study, different types of materials (silica, zinc oxide, gold, stearic acid.) were employed as spacers to observe their effects on fluorescence enhancement. Physical vapor deposition (PVD) and Langmuir-Blodgett (LB) film deposition techniques were used for the formation of the spacer within the substrate. Fluorescence enhancement of rhodamine B and fluorescein was observed on the prepared SEF substrates. Obtained enhancement factors indicate that SEF substrates have the potential for sensitivity improvements of fluorescence sensing in many fields.

The submerged entry nozzle (SEN) is used to transport the molten steel from a tundish to a mould. The main purpose of its usage is to prevent oxygen and nitrogen pick-up by molten steel from the gas. Furthermore, to achieve the desired flow conditions in the mould. Therefore, the SEN can be considered as a vital factor for a stable casting process and the steel quality. In addition, the steelmaking processes occur at high temperatures around 1873 K, so the interaction between the refractory materials of the SEN and molten steel is unavoidable. Therefore, the knowledge of the SEN behaviors during preheating and casting processes is necessary for the design of the steelmaking processes  The internal surfaces of modern SENs are coated with a glass/silicon powder layer to prevent the SEN graphite oxidation during preheating. The effects of the interaction between the coating layer and the SEN base refractory materials on clogging were studied. A large number of accretion samples formed inside alumina-graphite clogged SENs were examined using FEG-SEM-EDS and Feature analysis. The internal coated SENs were used for continuous casting of stainless steel grades alloyed with Rare Earth Metals (REM). The post-mortem study results clearly revealed the formation of a multi-layer accretion. A harmful effect of the SENs decarburization on the accretion thickness was also indicated. In addition, the results indicated a penetration of the formed alkaline-rich glaze into the alumina-graphite base refractory. More specifically, the alkaline-rich glaze reacts with graphite to form a carbon monoxide gas. Thereafter, dissociation of CO at the interface between SEN and molten metal takes place. This leads to reoxidation of dissolved alloying elements such as REM (Rare Earth Metal). This reoxidation forms the “In Situ” REM oxides at the interface between the SEN and the REM alloyed molten steel. Also, the interaction of the penetrated glaze with alumina in the SEN base refractory materials leads to the formation of a high-viscous alumina-rich glaze during the SEN preheating process. This, in turn, creates a very uneven surface at the SEN internal surface. Furthermore, these uneven areas react with dissolved REM in molten steel to form REM aluminates, REM silicates and REM alumina-silicates. The formation of the large “in-situ” REM oxides and the reaction of the REM alloying elements with the previously mentioned SEN´s uneven areas may provide a large REM-rich surface in contact with the primary inclusions in molten steel. This may facilitate the attraction and agglomeration of the primary REM oxide inclusions on the SEN internal surface and thereafter the clogging. The study revealed the disadvantages of the glass/silicon powder coating applications and the SEN decarburization. The decarburization behaviors of Al2O3-C, ZrO2-C and MgO-C refractory materials from a commercial Submerged Entry Nozzle (SEN), were also investigated for different gas atmospheres consisting of CO2, O2 and Ar. The gas ratio values were kept the same as it is in a propane combustion flue gas at different Air-Fuel-Ratio (AFR) values for both Air-Fuel and Oxygen-Fuel combustion systems. Laboratory experiments were carried out under nonisothermal conditions followed by isothermal heating. The decarburization ratio (α) values of all three refractory types were determined by measuring the real time weight losses of the samples. The results showed the higher decarburization ratio (α) values increasing for MgO-C refractory when changing the Air-Fuel combustion to Oxygen-Fuel combustion at the same AFR value. It substantiates the SEN preheating advantage at higher temperatures for shorter holding times compared to heating at lower temperatures during longer holding times for Al2O3-C samples. Diffusion models were proposed for estimation of the decarburization rate of an Al2O3-C refractory in the SEN. Two different methods were studied to prevent the SEN decarburization during preheating: The effect of an ZrSi2 antioxidant and the coexistence of an antioxidant additive and a (4B2O3 ·BaO) glass powder on carbon oxidation for non-isothermal and isothermal heating conditions in a controlled atmosphere. The coexistence of 8 wt% ZrSi2 and 15 wt% (4B2O3 ·BaO) glass powder of the total alumina-graphite refractory base materials, presented the most effective resistance to carbon oxidation. The 121% volume expansion due to the Zircon formation during heating and filling up the open pores by a (4B2O3 ·BaO) glaze during the green body sintering led to an excellent carbon oxidation resistance. The effects of the plasma spray-PVD coating of the Yttria Stabilized Zirconia (YSZ) powder on the carbon oxidation of the Al2O3-C coated samples were investigated. Trials were performed at non-isothermal heating conditions in a controlled atmosphere. Also, the applied temperature profile for the laboratory trials were defined based on the industrial preheating trials. The controlled atmospheres consisted of CO2, O2 and Ar. The thicknesses of the decarburized layers were measured and examined using light optic microscopy, FEG-SEM and EDS. A 250-290 μm YSZ coating is suggested to be an appropriate coating, as it provides both an even surface as well as prevention of the decarburization even during heating in air. In addition, the interactions between the YSZ coated alumina-graphite refractory base materials in contact with a cerium alloyed molten stainless steel were surveyed. The YSZ coating provided a total prevention of the alumina reduction by cerium. Therefore, the prevention of the first clogging product formed on the surface of the SEN refractory base materials. Therefore, the YSZ plasma-PVD coating can be recommended for coating of the hot surface of the commercial SENs.

No description available.