Two and three-phase flow processes involving gas, liquid and solid, are common in nature and industry, and include some of the most complex and poorly-understood transport problems. In this research hydrodynamics, heat and mass transfer processes in complex two and three-phase flows were investigated. The interfacial surface area concentration in a short vertical column subject to the through flow of fiber-liquid-gas slurry was experimentally measured using the gas absorption technique. The experimental data were statistically analyzed for parametric effects, and were empirically correlated. The absorption of a gaseous species by a slurry droplet with internal circulation and containing reactive micro-particles was simulated, and parametrically studied. The micro-particles were found to enhance the absorption rate. The absorption rate was sensitive to droplet recirculation, and shrinkage of particles with time resulted in declining absorption rates. The transport of soot particles, suspended in laminar hot gas flowing in a tube, was modeled and parametrically studied. Due to coupled thermal radiation and thermophoresis, a radially-nonuniform temperature profile develops, leading to sharp, non-uniform radial soot-concentration profiles. The assumption of monodisperse particles leads to over-prediction of thermophoresis. The transport and removal of particles suspended in bubbles rising in a stagnant liquid pool were modeled based on a Eulerian – Monte Carlo method. The bubble hydrodynamics were treated in Eulerian frame, using the Volume-of-Fluid (VOF) technique, while particle equations of motion were numerically solved in Lagrangian frame. The bubbles undergo shape change, and have complex internal circulation, all of which influence the particle removal. Model predictions were also compared with experimental data. Using a resemblance between two-phase flow in microchannels, and in large channels at microgravity, a simple Weber number-based two-phase flow regime map was developed for microchannels. Based on the available air-water experimental data, a criterion for the prediction of conditions that lead to flow regime transition out of the stratified-wavy flow pattern in horizontal annular channels was proposed. The thermocapillary effects on liquid-vapor interface shape during heterogeneous bubble ebullition in microchannels were analytically studied.

A Pipeline Analytical Program and Dredging Knowledge{Base Expert{System (DKBES) determines a pipeline dredge's production and resulting cost and schedule. Pipeline dredge engineering presents a complex and dynamic process necessary to maintain navigable waterways. Dredge engineers use pipeline engineering and slurry transport principles to determine the production rate of a pipeline dredge system. Engineers then use cost engineering factors to determine the expense of the dredge project. Previous work in engineering incorporated an object{oriented expert{system to determine cost and scheduling of mid{rise building construction where data objects represent the fundamental elements of the construction process within the program execution. A previously developed dredge cost estimating spreadsheet program which uses hydraulic engineering and slurry transport principles determines the performance metrics of a dredge pump and pipeline system. This study focuses on combining hydraulic analysis with the functionality of an expert{system to determine the performance metrics of a dredge pump and pipeline system and its resulting schedule. Field data from the U.S. Army Corps of Engineers pipeline dredge, Goetz, and several contract daily dredge reports show how accurately the DKBES can predict pipeline dredge production. Real{time dredge instrumentation data from the Goetz compares the accuracy of the Pipeline Analytical Program to actual dredge operation. Comparison of the Pipeline Analytical Program to pipeline daily dredge reports shows how accurately the Pipeline Analytical Program can predict a dredge project's schedule over several months. Both of these comparisons determine the accuracy and validity of the Pipeline Analytical Program and DKBES as they calculate the performance metrics of the pipeline dredge project. The results of the study determined that the Pipeline Analytical Program compared closely to the Goetz eld data where only pump and pipeline hydraulics a ected the dredge production. Results from the dredge projects determined the Pipeline Analytical Program underestimated actual long{term dredge production. Study results identi ed key similarities and di erences between the DKBES and spreadsheet program in terms of cost and scheduling. The study then draws conclusions based on these ndings and o ers recommendations for further use.

From the Proceedings of the 1973 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 4-5, 1973, Tucson, Arizona / Groundwater modeling is used to theoretically relate mining pumpage of the Navajo Sandstone to declines in the potentiometric surface at Navajo and Hopi Indian community, domestic, and stock usage locations. The shallow wells on top of Black Mesa are shown to be part of a perched water table condition which is dependent upon the hydraulic conductivity of an aquatard known as the Mancos Shale. The isolation of the aquatard allows the shallow wells to be treated as a problem separate from that of the artesian and recharge areas. Computer modeling of the groundwater system is concerned only with those Indian wells which directly tap the Navajo Sandstone in either artesian or free water table areas. The computer simulation developed is a modified version of the basic artesian aquifer routine used by the Illinois State Water Survey. Computer results correspond with the low percentage of storage withdrawal calculated for the artesian area under Black Mesa.

No description available.

Les composites de type Cf/C sont utilisés en tant que pièces structurales dans les propulseurs spatiaux du fait de leurs excellentes propriétés mécaniques dans le domaine des très hautes températures. Néanmoins, l’atmosphère oxydante et corrosive créée lors du décollage des lanceurs et les hauts flux gazeux dégradent ces matériaux. Afin d’améliorer les performances de ces matériaux vis-à-vis de l’oxydation/corrosion, une protection composée de céramiques ultra-réfractaires (dites UHTC) peut être appliquée. Pour une efficacité de protection optimale, des phases UHTC ont été introduites en tant que constituants de la matrice. Dans ces travaux de thèse, la matrice a été réalisée par l’intermédiaire d’un procédé d’élaboration en phase liquide combinant : (i) l’introduction de poudres et (ii) la densification par infiltration réactive d’un métal fondu. La composition de la matrice appartient au système (B;C;Si;Zr). La caractérisation des matériaux après élaboration a permis de comprendre les mécanismes d’infiltration et les réactions permettant de mieux contrôler la composition chimique et la répartition des phases. Des essais sous torche oxyacétylénique ont été utilisés pour se placer dans des conditions proches de l’application visée. La caractérisation post-test des matériaux a permis d’évaluer l’efficacité de la protection dans le cas d’une utilisation unique et également d’une possible réutilisation. Les résultats en oxydation/corrosion ont permis de classer les matériaux en fonction de leur efficacité de protection. / Since many decades, Carbon/Carbon composites are used as structural parts in rocket engines due to their excellent thermomechanical properties. However, under highly oxidizing/corrosive atmosphere and high gas flow rates, carbon suffers from severe oxidation. To improve oxidation resistance of these composites, Ultra High Temperature Ceramics (UHTC) can be used as a protection. To protect the whole composite, the introduction of UHTC as a matrix has been done using a liquid phase process combining: (i) slurry infiltration process and (ii) reactive melt infiltration. Matrix constituents belong to the (B;C;Si;Zr) system. Material characterisation allowed a better understanding of the infiltration mechanisms and of the phase distribution and composition in respect to the processing conditions. To select the best composition, oxyacetylene torch testing has been done to recreate spacecraft launch environmental conditions. Post-test characterisation has been done to evaluate protection efficiency of each matrix composition for single use and possible reuse. Finally, advantages and drawbacks assessment of each composition allowed to highlight the most protective composition and phase distribution.

Submitted by Morgana Andrade (morgana.andrade@ufes.br) on 2016-06-30T18:24:36Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Emanuel Maretto Effgen.pdf: 1064710 bytes, checksum: 9bafee2156d00099d000b0c4a1fea7a1 (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-07-04T12:56:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Emanuel Maretto Effgen.pdf: 1064710 bytes, checksum: 9bafee2156d00099d000b0c4a1fea7a1 (MD5) / Made available in DSpace on 2016-07-04T12:56:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Emanuel Maretto Effgen.pdf: 1064710 bytes, checksum: 9bafee2156d00099d000b0c4a1fea7a1 (MD5) / No estado do Espírito Santo, estima-se que existem pouco mais de 226 mil cabeça de suínos, gerando cerca de 730.000 m³ de dejetos ricos em nutriente anualmente. Dessa forma, partindo do pressuposto que a aplicação da Água Residuária de Suinocultura (ARS) pode promover alterações nos teores de potássio do solo, promovendo incremento desse nutriente, bem como propiciar aumento da produção de massa seca do Panicum maximum cv. Mombaça, sem que haja desbalanceamento nutricional da planta, objetivou-se avaliar os teores de potássio no solo e na planta, bem como a produção de massa seca do Capim Mombaça (Panicum maximum cv. Mombaça) decorrentes de diferentes doses de ARS em comparação com a adução mineral. Esta pesquisa foi realizada em uma propriedade rural, localizada no município de Jerônimo Monteiro – ES. Para o K e a relação K/CTC, utilizou-se o esquema de parcelas subsubdivididas com três repetições. As parcelas receberam cinco tratamentos sendo: adubação mineral (200 kg ha-1 K) via Cloreto de Potásio; e doses de ARS 50, 100, 150 e 200, equivalentes a 100, 200, 300 e 400 kg ha-1 K, calculados a partir da recomendação agronômica. Nas subparcelas, teve-se às profundidades do solo, sendo: 0 a 10; 10 a 20; 20 a 40 e 40 a 60 centímetros. Nas subsubparcelas, a situação representada pelo tempo antes da aplicação da ARS foi denominada AAARS, e dez dias após cada aplicação da ARS, denominada DAARS. Para a Massa Seca e o teor de K na planta, teve-se um esquema de parcelas subdivididas com três repetições. As parcelas receberam os tratamentos: adubação mineral e doses de ARS 50, 100, 150 e 200% da dosagem recomendada de potássio. As subparcelas foram os períodos de avaliação das aplicações da ARS aos dias 10, 130, 210 e 270 decorridos do início do experimento. Depois dos resultados obtidos, procedeu-se a análise estatística por meio de análise de variância adotando 5% significância F, sendo realizado o contraste entre os valores médios obtidos para adubação mineral e a ARS ao nível de 5 % de probabilidade, pelo teste de Tukey. Posteriormente, para as variáveis quantitativas foi realizada a análise de regressão a 5% de significância, sendo os modelos foram escolhidos pela utilização o teste t de Student, e pelos coeficientes de determinação R2, utilizando-se o software SAEG. Verificou-se que, mesmo com a aplicação de doses de K superior à recomendação agronômica através da ARS, ocorreu a redução linear dos teores de K no perfil solo, assim como ocorre o acréscimo linear desses teores com o aumento da dose. A aplicação ARS mostrou-se mais eficiente para incrementar K no solo, quando comparada à Adubação Mineral. A dose que se mostrou mais eficiente na manutenção dos teores K no solo é ARS 150 %. A maior produção de biomassa deu-se na dose 50%, todavia culminando com os menores teores de K na planta do capim Mombaça, e os maiores teores na planta foram obtidos nas maiores doses de ARS. Verifica-se que os atributos químicos do solo são influenciados pela aplicação de ARS, o que denota a necessidade de periodicidade na avaliação desses atributos em áreas com aplicação contínua de ARS. / In Espírito Santo state, it is estimated that there are just over 226 000 head of pigs, therefore, these generate about 730.000m³ nutrient-rich waste annually. Thus, assuming that the application of the swine wastewater can promote changes in the potassium soil, promoting increment this nutrient as well as provide increased dry matter yield of Panicum maximum cv. Mombasa, without nutritional unbalance the plant, it was aimed to evaluate the levels of potassium in the soil and plant, and the dry mass of Mombasa Grass (Panicum maximum cv. Mombasa) resulting from different doses of ARS compared to mineral adduction. This research was conducted in a rural property located in the municipality of Jeronimo Monteiro - ES. For K and K/CEC was used a scheme split-split-plot portion with three replications. The plots received five treatments being: mineral fertilizer (200 kg ha-1 K) via potassium chloride; ARS and doses of 50, 100, 150 and 200, corresponding to 100, 200, 300 and 400 kg ha-1 K, calculated from the agronomic recommendation. Subplots, it was taken to the depths of the soil, being: 0-10; 10 to 20; 20 to 40 and 40 to 60 centimeters. In the sub-subplots, the situation represented by time before the application of ARS was named AAARS, and ten days after each application of ARS, called DAARS. For Dry mass and K content in the plant, had become a split plot arrangement with three replications. The plots received treatments: mineral fertilizer and doses of ARS 50, 100, 150 and 200% of the recommended dosage of potassium. The subplots periods of evaluation of the applications of ARS 10 days, 130, 210 and 270 elapsed from the beginning of the experiment. After the results, it was proceeded to statistical analysis using analysis of variance adopting 5% significance F, the contrast between the mean values obtained for mineral fertilizer and the ARS at 5% probability being performed by Tukey test. Subsequently, for quantitative variables regression analysis the 5% significance level was conducted, and the models were chosen by using the Student t test, and the coefficient of determination R2, using the SAEG software. It was found that, even with the application of higher doses of K recommendation the agronomic via ARS occurred linear reducing of the content K in the soil profile as well as linear increase these levels with increasing dose occurs. The ARS application was more efficient to increase soil K compared to mineral fertilization. The more effective dose in maintaining levels of K in the soil was ARS 150%.The highest biomass yield was given at a dose 50%, however culminating with the lowest levels of K in the plant grass Mombasa, and the highest levels in the plant were obtained at higher doses of ARS. It appears that the soil chemical properties are influenced by the application of ARS, which indicates the need for periodicity in the evaluation of these attributes in areas with continuous application of ARS.

Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.

Lightweight chamotte products are popular building material. There are many types of lightweight chamotte on the market, but the most popular lightening options are organic ingredients. This brings some problems to the production of these products. This thesis deals with the burning of various types of lighters from shards of fireclay materials. In the theoretical part are summarized raw materials, which are necessary for production of lightweight chamotte. The results of the published research studies on the topic of lightening of organic lightening products are being described here. The practical part deals with properties of products made of clay or kaolin with the addition of a certain amount of lighter. These added lighters are spruce sawdust, beech sawdust, peat, bran, paper slurry and anthracite. All these lighters are direct. For comparison, the cenospheres, which represent indirect lightweights, were also included in the research. For all specimens, the temperature interval of burnout of specimens, refractoriness, classification temperature, bulk density, thermal conductivity coefficient and other properties were defined.

MSCAGR (Animal Science) / Department of Animal Science / The objective of the study was to determine the effects of fertilisation with bio-digester slurry and the inclusion of carbohydrate additives at ensiling on the fermentation characteristics, chemical composition, ruminal degradability, and in vitro digestibility of Napier grass silage. Napier grass planted at the School of Agriculture Experimental Farm, University of Venda in 5 m x 4 m plots replicated three times in a completely randomised design and was irrigated with either biodigester slurry or no bio-digester slurry (tap water) for a period of 12 weeks. After 12 weeks, the Napier was freshly cut and ensiled for 90 days in 1 litre glass jars in a 2 (Control - tap water and slurry irrigation) x 4 (No additive, molasses, maize meal and brown sugar) factorial arrangement. Fermentation quality and nutritive composition were determined using standard protocols. The dry matter (DM) and crude protein (CP) ruminal degradability was determined in sacco by incubating feed samples in nylon bags (external dimension: 6 × 12 cm, pore size of 46 μm) in the rumen in three Bonsmara steers fitted with rumen cannulae for 0, 6, 12, 24, 48, 72, 96 and 120 hours (h). Parameters to describe the dynamics of ruminal degradability of DM and CP were obtained by fitting the data on the exponential equation P = a + b (1 - e-ct) using the NEWAY computer program, where “a” is the rapidly degradable fraction, “b” is the slowly degradable fraction and “c” is the outflow rate. The in vitro DM and CP degradability of rumen undegradable residue collected after 12, 24 and 48 h incubation was determined by sequential digestion in pepsin (abomasal) and pancreatin (small intestine) solutions. Fertilisation with bio-digester slurry increased (P <0.05) CP content of fresh cut Napier grass pre-ensilage. Bio-digester slurry fertilisation with molasses inclusion improved (P <0.05) the silage DM content which improved (P >0.05) fermentation characteristics with pH of 4.2 and lowest NH3-N of 13.3 g/kg. Other chemical compositions and fermentation characteristics were not affected (P >0.05) due to fertilisation x additives treatment combinations. No bio-digester slurry fertilisation with maize meal inclusion increased (P <0.01) DM degradability at 0 h incubation. As time progressed to 24 h, no biodigester slurry fertilisation with no additive included reduced (P <0.01) DM degradability with no difference (P >0.05) on other treatments. Potential DM degradability (a + b) of no bio-digester slurry fertilisation with no additive inclusion silage was reduced (P <0.01). The reduction was associated with low levels (P <0.01) of slowly degradable fraction “b”. In vitro DM and CP digestibility were not affected (P >0.05) due to fertilisation x additives treatment combinations. In conclusion, bio-digester slurry application improved the quality of fresh cut Napier grass, with the combination of bio-digester slurry fertilisation and molasses addition yielding the best silage quality.

Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are ideal for conversion of coal and biomass. However, precipitated iron catalysts used in slurry-bubble column reactors suffer from high attrition resulting in difficulty separating catalysts from product and increased slurry viscosity. Thus, development of an active and selective-supported iron catalyst to manage attrition is needed. This thesis focuses on the development of a supported iron catalyst and kinetic models of FTS on the catalyst using advanced statistical methods for experimental design and analysis. A high surface area alumina, modified by the addition of approximately 2 wt% lanthanum, was impregnated with approximately 20 wt% Fe and 1% Pt in a two step procedure. Approximately 10 wt% Fe and 0.5 wt% Pt was added in each step. The catalyst had a CO uptake of 702 μmol/g, extent of reduction of 69%, and was reduced at 450°C. The catalyst was stable over H2 partial pressures of 4-10 atm, CO partial pressures of 1-4 atm, and temperatures of 220-260°C. Weisz modulus values were less than 0.15. A Langmuir-Hinshelwood type rate expression, derived from a proposed FTS mechanism, was used with D-optimal criterion to develop experiments sequentially at 220°C and 239°C. Joint likelihood confidence regions for the rate expression parameters with respect to run number indicate rapid convergence to precise-parameter estimates. Difficulty controlling the process at the designed conditions and steep gradients around the D-optimal criterion resulted in consecutive runs having the same optimal condition. In these situations another process condition was chosen to avoid consecutive replication of the same process condition. A kinetic model which incorporated temperature effects was also regressed. Likelihood and bootstrap confidence intervals suggested that the model parameters were precise. Histograms and skewness statistics calculated from Bootstrap resampling show parameter-effect nonlinearities were small.