Effects of mould flux contaminant on scale-steel adhesion and hydraulic descaling of scale formed on slabs were investigated. In this investigation, stainless steel type 304 (austenitic with 18% Cr and 8% Ni) and specific mould fluxes were used when growing the scale on contaminated samples under simulated industrial reheating conditions, with subsequent high pressure water hydraulic descaling. The basic hypothesis was that the steel-scale adhesion depends on the microstructure of different phases present in the scale, the segregation of specific elements at the interface and the interfacial morphology of the scale after reheating. It was found that mould flux contaminant decreases scale-steel adhesion and therefore improved the descaling effectiveness significantly compared to non contaminated stainless steel. The descaling effectiveness of contaminated and uncontaminated slab was dependent to the presence of metal free paths (chromite layers along the austenite grains boundaries) and the presence of unoxidized metal in the scale due to nickel enrichment at the interface. Compared to the uncontaminated samples, the descaling of contaminated samples was efficient which could be due to the fact that some mechanisms which increase scale– steel adhesion (notably nickel enrichment at the interface) were considerably reduced. For all contaminated samples, the descaling effectiveness after visual observation were close to 100% and it was found that mould flux type 832 ( low basicity) gave a high descaling efficiency with better steel surface quality after descaling compared to mould fluxes type 810 and RF1. / Dissertation (MSc)--University of Pretoria, 2009. / Materials Science and Metallurgical Engineering / unrestricted

No description available.

Using experimentally measured temperature-process-dependent model parameters, the failure analysis and life prediction were conducted for Atmospheric Plasma Sprayed Thermal Barrier Coatings (APS-TBCs) and electron beam physical vapor deposition thermal barrier coatings (EB-PVD TBCs) with Pt-modified -NiAl bond coats deposited on Ni-base single crystal superalloys. For APS-TBC system, a residual stress model for the top coat of APS-TBC was proposed and then applied to life prediction. The capability of the life model was demonstrated using temperature-dependent model parameters. Using existing life data, a comparison of fitting approaches of life model parameters was performed. The role of the residual stresses distributed at each individual coating layer was explored and their interplay on the coating’s delamination was analyzed. For EB-PVD TBCs, based on failure mechanism analysis, two newly analytical stress models from the valley position of top coat and ridge of bond coat were proposed describing stress levels generated as consequence of the coefficient of thermal expansion (CTE) mismatch between each layers. The thermal stress within TGO was evaluated based on composite material theory, where effective parameters were calculated. The lifetime prediction of EB-PVD TBCs was conducted given that the failure analysis and life model were applied to two failure modes A and B identified experimentally for thermal cyclic process. The global wavelength related to interface rumpling and its radius curvature were identified as essential parameters in life evaluation, and the life results for failure mode A were verified by existing burner rig test data. For failure mode B, the crack growth rate along the topcoat/TGO interface was calculated using the experimentally measured average interfacial fracture toughness.

La famille des élastomères silicones LSR (Liquid Silicone Rubber) de haute technicité est identifiée comme celle possédant les plus forts arguments de développement au cours des prochaines décennies en raison de leurs propriétés spécifiques et de leurs facilités de mise en forme en grande série. Notamment, le moulage par injection du LSR sur d’autres matières telles que les thermoplastiques ou les métaux est aujourd’hui possible, ce qui ouvre la possibilité d’obtenir des composants multi-matières, multi-couleurs et de nouvelles fonctionnalités. Cette thèse se concentre sur la transformation des élastomères silicones LSR dans le but de mieux appréhender les phénomènes impliqués, afin d’améliorer les procédés d’élaboration et d’optimiser les conditions de transformation des composants élastométriques mono ou bi-matières à géométrie et propriété fonctionnelle bien définie. Les comportements rhéologique, cinétique et thermique des élastomères silicones ont été étudiés et caractérisés sous des conditions réelles de mise en œuvre par différentes méthodes associées. Un modèle thermo-rhéo-cinétique a été développé et ensuite implémenté dans un code de calcul de remplissage Cadmould® pour simuler le moulage par injection des élastomères silicones LSR ou encore le surmoulage de thermoplastiques. Pour la validation des modèles choisis et des paramètres identifiés, les essais d’injection sur l’outillage industrielle instrumenté ont été réalisés et confrontés à des résultats numériques obtenus. Enfin, la caractérisation de l’adhésion et l’adhérence interfaciale entre les thermoplastiques et les élastomères silicones a été réalisé sous différentes sollicitations complexes. De plus, l’évolution d’adhérence interfaciale des assemblages collés au cours de la vulcanisation des élastomères silicones a été caractérisée par l’essai de traction en utilisant un rhéomètre rotatif sous différentes modes de chauffage. / The family of high technology silicone elastomers LSR (Liquid Silicone Rubber) is identified as having the strongest arguments for development in the coming decades due to their unique properties and easy forming in large series. In particular, the injection molding of LSR on other materials such as thermoplastics or metals is possible today, which opens the possibility of obtaining multi-material, multi-color and new features components. The work presented in this thesis focuses on the transformation of silicone elastomers in order to better understand the phenomena involved, as to improve production processes and optimize processing conditions for mono or bi-material components in geometry and property functional well defined. The rheological, curing kinetic and thermal behaviors of silicone elastomers have been studied and characterized under real conditions of production by different methods combined. A thermo-rheo-kinetic model was then developed and implemented in commercial computer software Cadmould® to simulate the injection molding process of LSR or the overmolding process of LSR on to thermoplastics. For the validation of the models chosen and the parameters identified, the injection molding tests on industrial instrumented tools were performed and compared to numerical results. Finally, the characterization of interfacial adhesion between the thermoplastic and silicone elastomers was carried out under various adhesion tests. Moreover, the evolution of interfacial adhesion in thermoplastic/silicone components during the vulcanization of silicone elastomers has been characterized by the tensile test using a rotating rheometer in different heating cycles

Polyethylene composites which contain low concentrations of metal-oxide nanoparticles e.g. ZnO and MgO are emerging materials for the use in insulations of extruded high-voltage direct-current (HVDC) cables. The challenge in the development of the composites with ultra-low electrical conductivity is to synthesize uniform and high-purity metal-oxide nanoparticles, which are functionalized with hydrophobic groups in order to make them compatible with polyethylene. The thesis reports different approaches to prepare this new generation of insulation materials. Different reaction parameters/conditions – zinc salt precursor, precursor concentrations and reaction temperature – were varied in order to tailor the size and morphology of the ZnO nanoparticles. It was shown that different particle sizes and particle morphologies could be obtained by using different zinc salt precursors (acetate, nitrate, chloride or sulphate). It was shown that 60 °C was a suitable reaction temperature in order to yield particles with different morphologies ranging from nano-prisms to flower-shaped superstructures. For removal of reaction residuals from the particles surfaces, a novel cleaning method based on ultrasonication was developed, which was more efficient than traditional water-replacement cleaning. After cleaning, the presence of one atomic layer of zinc-hydroxy-salt complex (ZHS) on the nanoparticle surfaces was suggested by thermogravimetry and infrared spectroscopy. A method involving three steps – silane coating, heat treatment and silica layer etching – was used to remove the last trace of the ZHS species from the nanoparticle surface while preserving its clean and active hydroxylated surface. The surface chemistry of these nanoparticles was further tailored from hydroxyl groups to hydrophobic alkyl groups with different lengths by reactions involving methyltrimethoxysilane (C1), octyltriethoxysilane (C8) and octadecyltrimethoxysilane (C18). MgO nanoparticles were prepared by aqueous precipitation of Mg(OH)2 followed by a partial transformation to MgO nanoparticles via heat treatment at 400 °C. The surface regions of the MgO nanoparticles convert into a hydroxide phase in humid media. A novel method to obtain large surface area MgO nanoparticles with a remarkable inertness to humidity was also presented. The method involved three steps:  (a) thermal decomposition of Mg(OH)2 at 400 °C; (b) silicone oxide coating of the nanoparticles to prevent inter-particle sintering and (c) a high temperature heat treatment at 1000 °C. These MgO nanoparticles showed essentially no sign of formed hydroxide phase even after extended exposure to humid air. The functionalized metal-oxide nanoparticles showed only a minor adsorption of phenolic antioxidant, which is important in order to obtain nanocomposites with an adequate long-term stability. Tensile testing and scanning electron microscopy revealed that the surface-modified metal-oxide nanoparticles showed improved dispersion and interfacial adhesion in the polyethylene matrix with reference to that of unmodified metal-oxide nanoparticles. The highly “efficient” interfacial surface area induced by these modified nanoparticles created the traps for charge carriers at the polymer/particle interface thus reducing the DC conductivity by more than 1 order of magnitude than that of the pristine polyethylene. / Polyetenkompositer med mycket låga halter av ZnO och MgO metalloxid nanopartiklar är en växande kategori material för användning som isolering av extruderade kablar avsedda för likriktad högspänning. En utmaning i utvecklingen av dessa material kan relateras till den praktiska kompositframställningen, vilken innefattar framställning av högrena metalloxid nanopartiklar som ytmodifieras med hydrofoba molekylstrukturer för att möjliggöra blandning med den hydrofoba polyetenplasten. Denna avhandling behandlar olika metoder för att framställa denna generation av isoleringsmaterial. Vid syntesen av de rena nanopartiklarna krävdes optimering av ett antal olika reaktionsparametrar för att uppnå tillfredställande slutresultat i form av partikelstorlekar och partikelmorfologier. Dessa inkluderade val av zinksalt, zinksaltkoncentration vid utfällning, samt reaktionstemperatur vid framställningen. Experimenten avslöjade att olika partikelstorlekar och partikelmorfologier kunde framställas som endast korrelerat mot källan av zinkjonerna, och berodde av vilka motjoner som zinkatomerna haft i zinksaltet (acetat, nitrat, klorid eller sulfat). Optimering av reaktionstemperaturen visade att ca 60 °C utgjorde en lämplig start för utvärdering av synteserna, som resulterade i olika partikelmorfologier i form av pyramidformade nanopartiklar till blomformationer. Utöver de specifika reaktionsparametrarna utvecklades även en ny ultrasonikeringsmetod för att rena ytorna hos partiklarna från motjoner relaterade till de valda specifika salterna. Metodiken som visade sig avsevärt mer effektiv än sedvanlig rening att utfällda nanopartiklar via repetitivt vattenutbyte, och skapade förutsättningar etablering av kolloidal stabilitet och fragmentering av aggregat i vattensuspensionerna. Efter ultrasonikeringsreningen beräknades de kvarvarande zinkhydroxidsalterna (ZHS) utgöra endast ett atomlager ZHS utifrån termogravimetriska data kompletterade med infraröd spektroskopi. En metod att eliminera de kvarvarande ZHS-komplexen från ytan av partiklarna tillämpades/utvecklades, inkluderade ytbeläggning av partiklarna med silan, följt av värmebehandling samt etsning av den resulterande kiseloxidytan, för att uppnå en ren hydroxylyta på partiklarna. Ytkemin hos dessa partiklar modifierades från att bestå av hydroxylgrupper till att utgöras av hydrofoba alkylgrupper med olika längder relaterade metyltrimetoxysilan (C1), oktyltrietoxysilan (C8), eller oktadekyltrimetoxysilan (C18). Även MgO nanopartiklar framställdes via vattenutfällning av Mg(OH)2 partiklar, vilka omvandlades till MgO nanopartiklar via en lågtemperatur värmebehandling vid 400°C. Ytan av dessa partiklar omvandlades dock till hydroxid i fuktig miljö. En ny metod att bibehålla den stora ytarean av MgO nanopartiklarna med anmärkningsvärd motståndskraft mot att omvandlas till hydroxid utvecklades således. Metoden består av (a) en låg temperatur omvandling av Mg(OH)2, (b) en kiseloxidytbehandling av nanopartiklarna för att undvika partikelsintring vid högre temperaturer och (c) en hög temperaturbehandling vid 1000 °C. De framställda partiklarna uppvisade ingen anmärkningsvärd känslighet mot luftfuktighet och bibehöll MgO sammansättningen efter exponering mot fukt. De modifierade metalloxid nanopartiklarna visade mycket liten adsorption av fenoliska antioxidanter, vilket medförde en långtidsstabilitet hos polyeten nanokompositerna. De ytmodifierade metalloxidpartiklarna visade även förbättrade möjligheter för dispergering och yt-kompatibilitet med/i polyetenmatrisen i jämförelse med omodifierade metalloxidpartiklar, utifrån mätningar baserade på dragprovning och svepelektronmikroskopi. Slutligen, de utvecklade ytorna på de modifierade nanopartiklarna skapade ett polymer/nanopartikel gränssnitt som kunder fungera som laddningsansamlingsområden i nanokompositerna, vilket resulterade i en storleksordning minskad ledningsförmåga hos kompositerna jämfört med den rena polyetenen. / <p>QC 20160829</p>

To form Cu interconnects, dual-damascene techniques like chemical mechanical planarization (CMP) and post-CMP became inevitable for removing the "overburden" Cu and for planarizing the wafer surface. During the CMP processing, Cu interconnects and barrier metal layers experience different electrochemical interactions depending on the slurry composition, pH, and ohmic contact with adjacent metal layers that would set corrosion process. Ruthenium as a replacement of existing diffusion barrier layer will require extensive investigation to eliminate or control the corrosion process during CMP and post CMP. Bimetallic corrosion process was investigated in the ammonium citrate (a complexing agent of Cu in CMP solutions) using micro test patterns and potentiodynamic measurements. The enhanced bimetallic corrosion of copper observed is due to noble behavior of the ruthenium metal. Cu formed Cu(II)-amine and Cu(II)-citrate complexes in alkaline and acidic solutions and a corrosion mechanism has been proposed. The currently used metallization process (PVD, CVD and ALD) require ultra-high vacuum and are expensive. A novel method of Si surface metallization process is discussed that can be achieved at room temperature and does not require ultra-high vacuum. Ruthenation of Si surface through strong Si-Ru covalent bond formation is demonstrated using different ruthenium carbonyl compounds. RBS analysis accounted for monolayer to sub-monolayer coverage of Si surface. Interaction of other metal carbonyl (like Fe, Re, and Rh) is also discussed. The silicon (111) surface modifications with vinyl terminated organic compounds were investigated to form self-assembled monolayers (SAMs) and there after these surfaces were further functionalized. Acrylonitrile and vinylbenzophenone were employed for these studies. Ketone group of vinylbenzophenone anchored to Si surface demonstrated reactivity with reducing and oxidizing agents.

Oil is a very complex chemical system, as for instance, the paraffinic type which was considered as a fluid to be evaluated in this scientific paper, trough the static interfacial tension with the surfaces of the API 5L grade B conduction pipe and the EPOXY and EPOXY M resins. The paraffinic oil produced in the 7-PIR-244D-AL well, which is located in the producing field of Pilar in the state of Alagoas, presents special characteristics concerning its flow which are different from the other oils in the Sedimentary Basin of Sergipe and Alagoas. The resin used in the experiments were the EPOXY, commercially know as DGEBA, as well as EPOXY M, which was produced from the DGEBA with the addition of a substance whose objective is to reduce the deposit of organic and/or inorganic molecules in its surfaces along the oil flow. The evaluation of the static interfacial tension between this type of paraffinic oil and the surfaces of the EPOXY (37,2 mN/m), EPOXY M (14,8 mN/m) resins and the steel pipe (4.790,2 mN/m) has produced results, the performance of this fluid compared with the EPOXY M resin was better than when compared with the EPOXY and, as a consequence, better than when compared with the metallic material of the pipe. As a result of the data got through the experiments with these materials, there was a conclusion about the possibility of practical use of the EPOXY M resin as a coating in the internal surface of the pipes that carry oil with a considerable quantity of paraffin in its composition, aiming at a better performance relating to the flow of this fluid. / O petróleo é um sistema químico bastante complexo, como por exemplo, o do tipo parafínico, o qual foi considerado como o fluido para ser avaliado nesse trabalho científico, através da tensão interfacial estática com as superfícies do tubo de condução metálico API 5L grau B e das resinas EPÓXI e EPÓXI M. O óleo parafínico produzido no poço 7-PIR-244D-AL, o qual está localizado no campo produtor de Pilar no estado de Alagoas, apresenta particularidades com relação ao escoamento, diferentes dos outros petróleos na Bacia Sedimentar de Sergipe e Alagoas. As resinas utilizadas nos experimentos foram a EPÓXI comercialmente denominada DGEBA, como também a EPÓXI M que foi produzida a partir da DEGEBA com a adição de uma substância cuja finalidade é reduzir o depósito de moléculas orgânicas e/ou inorgânicas nas suas superfícies durante o escoamento do petróleo. A avaliação da tensão interfacial estática entre este tipo de petróleo parafínico e as superfícies das resinas EPÓXI (37,2 mN/m) e EPÓXI M (14,8 mN/m) como também do tubo de aço (4.790,2 mN/m), gerou resultados; onde a performance desse fluido com relação a resina EPÓXI M foi melhor quando comparada com a EPÓXI, e conseqüentemente em relação ao material metálico do tubo. Como conseqüência dos dados obtidos através dos experimentos realizados entre estes materiais, concluiu-se a possibilidade de uso prático sobre a utilização da resina EPÓXI M como revestimento junto à superfície interna de tubulações que possuam petróleo com considerável quantidade de parafina em sua composição, objetivando um melhor desempenho quanto ao escoamento desse fluido.

Les nanoémulsions (NEs) huile/eau peuvent être utilisées en tant que systèmes de délivrance des médicaments pour l’encapsulation des substances actives hydrophobes afin d’améliorer leur stabilité et leur biodisponibilité. Néanmoins, leur stabilisation nécessite l’utilisation de concentrations plus importantes de tensioactifs par rapport aux émulsions conventionnelles en raison de l’augmentation de la surface spécifique. La plupart des tensioactifs synthétiques couramment utilisés dans la formulation des émulsions sont potentiellement irritants, voire toxiques. Cela entrave l'application thérapeutique des NEs en particulier pour les traitements à long terme. L'objectif de cette thèse est alors de formuler des NEs pharmaceutiques huile/eau stabilisées par un biopolymère, la beta-lactoglobuline (beta-lg), à la place des tensioactifs synthétiques.Les NEs ont été préparées par homogénéisation à haute pression (HHP). La composition de la formulation et les conditions du procédé ont été optimisées afin d’obtenir des gouttelettes nanométriques dans des NEs stables. Les résultats ont montré que les NEs les plus stables, avec une taille de gouttelettes < 200 nm, ont été obtenues quand 5 m/m% de l’huile ayant la viscosité la plus faible ont été utilisés en tant que phase huileuse, 95 m/m% de la solution de beta-lg à une concentration de 1 m/m% ont été utilisés en tant que phase aqueuse et 4 cycles d’HPH de 100 MPa ont été appliqués. Cette formulation a été stable contre les phénomènes de croissance de gouttelettes pendant au moins 30 jours grâce à un film interfacial quasiment purement élastique. La gomme xanthane, un polysaccaride naturel, a été ajoutée à la formulation optimale à une concentration de 0,5 m/m% en tant qu’agent épaississant. Cela a permis d’obtenir une texture crémeuse avec un comportement rhéofluidifiant. Dans cette dernière formulation, la vitesse de migration des gouttelettes a été considérablement réduite et la stabilité des NEs a été améliorée.Les effets du procédé d’HPH sur les différents niveaux de structure de la protéine ont été évalués à l’aide de méthodes spectroscopiques, chromatographiques et électrophorétiques. L’influence de ce traitement sur ses propriétés interfaciales et émulsionnantes a également été étudiée. L’efficacité émulsionnante optimale a été obtenue quand les conditions d’HPH n’ont pas altéré la structure de la beta-lg, ni ses propriétés interfaciales. Néanmoins, un traitement d’HHP excessif (300 MPa/5 cycles) a induit des modifications structurelles, principalement une transformation des feuillets beta en structures désordonnées, une large perte dans le cœur hydrophobe, et une agrégation importante par des liaisons disulfure intermoléculaires. La beta-lg modifiée par l’HHP a montré une hydrophobie de surface plus importante conduisant à une vitesse d’adsorption à l’interface huile/eau plus élevée et une formation plus précoce d’un film interfacial. La dénaturation de la protéine par ce traitement à haute pression, qui a été effectuée avant le processus d’émulsification, n'a pas modifié de façon significative l'efficacité émulsionnante. La réduction de l’efficacité a été probablement plutôt induite par la dénaturation simultanée avec l’émulsification sous conditions d’écoulement très turbulent.L’intérêt de la formulation développée en tant que véhicule pour un modèle de substance active hydrophobe a été étudié avec l’isotrétinoïne (IT), usuellement utilisé pour le traitement de l’acné sévère. La formulation développée a permis d’encapsuler 0,033 m/m% d’IT sans aucune modification de la stabilité du système. Environ 10 % de l’IT ajoutée ont été solubilisés dans la phase aqueuse en association avec la protéine libre en excès. L’IT encapsulée dans les gouttelettes huileuses a été plus stable contre la photo-isomérisation que celle associée à la protéine libre. La formulation développée apparait prometteuse en tant que système de délivrance de l’IT pour une application cutanée. / Oil-in-water nanoemulsions can be used as drug delivery systems for the encapsulation of hydrophobic active substances in order to increase their solubility and their bioavailability. However, due to their higher specific area, their stabilization requires higher surfactant concentrations compared to conventional emulsions. Most of the synthetic surfactants commonly used in emulsion formulation are potentially irritant and even toxic, which hinders the therapeutic application of nanoemulsions especially during long-term treatment. The objective of this thesis is thus to formulate pharmaceutical oil/water nanoemulsions stabilized by a biopolymer, beta-lactoglobulin (beta-lg), instead of synthetic surfactants. Nanoemulsions were prepared by high pressure homogenization (HPH). The formulation composition and the process conditions were optimized in order to obtain nanometric droplets within stable nanoemulsions. The results showed that the most stable nanoemulsions, with droplet size inférieure à 200 nm, were obtained when 5 w/w% of the oil with the lowest viscosity value was used as the oily phase, 95 w/w% of beta-lg solution at a concentration of 1 w/w% was used as the aqueous phase, and 100 MPa of homogenization pressure was applied for 4 cycles. This formulation was stable against droplet growth phenomena during 30 days at least, thanks to a quasi purely elastic interfacial film. Xanthan gum, a natural polysaccharide, was added to the optimal formulation as a texturizing agent at a concentration of 0.5 w/w%. This allowed obtaining a cream texture with a shear thinning behavior. In this formulation, the migration rate of droplets was considerably reduced and the nanoemulsions stability was enhanced.The effects of the homogenization process on the different levels of the protein structure were assessed by spectroscopic, chromatographic and electrophoretic methods. The influence of this treatment on its interfacial and emulsifying properties was also investigated. The optimal emulsifying efficiency was obtained when the homogenization conditions did alter neither the structure of beta-lg nor its interfacial properties. However, an excessive HPH treatment (300 MPa/5 cycles) introduced structural modifications, mainly from beta-sheets into random coils, wide loss in lipocalin core, and protein aggregation by intermolecular disulfide bridges. HPH modified beta-lg displayed higher surface hydrophobicity inducing a higher adsorption rate at the O/W interface and an earlier formation of an elastic interfacial film. Structural and interfacial properties modifications by HPH denaturation appeared qualitatively similar to that of the heat denaturation with, however, differences in extent. Protein denaturation by a high pressure treatment that was performed before the emulsification process did not alter significantly its emulsifying efficiency. The reduction in the efficiency was rather induced by the simultaneous denaturation with the emulsification under high turbulent flow.The efficiency of the developed formulation as a vehicle for a model hydrophobic active substance was studied using isotretinoin, usually used for the treatment of severe acne. The developed formulation was able to encapsulate 0.033 w/w of isotretinoin without any modification on the system stability. About 10 % of the added isotretinoin was solubilized in the aqueous phase associated with the free protein in excess. Isotretinoin encapsulated in the oily droplets was more stable against photo isomerization than the one associated to the excess protein in the aqueous phase. The developed formulation seems promising as a drug delivery system of isotretinoin for a dermal application.

<p>To fully realize the advantages of the two-fluid model, the interfacial area concentration (IAC) should be properly given by a constitutive model. The conventional flow-regime-based IAC correlations intrinsically cannot predict the dynamic flow structure change and would introduce a discontinuity and numerical instability to system codes. As a promising alternative, the interfacial area transport equation (IATE) is developed to model the interface structure mechanistically. Progress has been achieved for IATE modeling in bubbly, slug, and churn-turbulent flow during the past two decades. Aiming at a comprehensive flow structure predictor for all flow regimes, further development in two directions is highly desirable. First is extending the current experiment and modeling capability from churn-turbulent to annular flow. In this study, an advanced four-sensor droplet capable conductivity probe (DCCP-4) is developed to capture all interfaces in churn-turbulent and annular flow, including liquid film, liquid droplet, gas core, and gas bubble. A first of a kind experimental database in churn-turbulent, annular, and wispy annular flow with two-dimensional spatial distributions is established, which provides the experimental basis for the multi-field two-phase flow model development. The measured parameters include local time-averaged volume faction, IAC, and velocity for various fields of annular flow. In addition, a new constitutive model to quantify the interfacial area between the gas core and liquid film of annular flow is developed, which fills the last theoretical gap of interfacial area modeling. The other important direction is improving the current IATE model to fulfill the dynamic prediction of developing flow, especially the bubbly to slug transition flow. Vertical-upward air-water two-phase flow experiments are performed. The state-of-the-art IATE model is evaluated against the newly collected data at bubbly and slug flow, and the result shows unsatisfactory performance in predicting the developing flow with intensive bubble coalescence. A new bubble coalescence model is derived by using the log-normal bubble size distribution, which significantly improves the model prediction capability.</p>

No description available.