Thesis (M. Sc.)--University of Hong Kong, 2001. / Also available in print.

Thesis (M. Sc.)--University of Hong Kong, 2001.

Soil stabilization is a common technique to increase the strength and durability and also to reduce the swell-shrink behavior of foundation soil or subgrade soil in pavement. Nowadays, several nontraditional stabilizers (e.g., Polymer, Enzyme, Ionic stabilizer etc.) are available in market whose behavior is not fully understood for wide range of soil types. In the present study two types of soils i.e., Carbondale soil ‘clay with high plasticity (CH)’ and Galatia soil ‘silt with low plasticity (ML)’ has been used. A commercially available liquid polymer “Soiltac” was selected as a stabilizer and mixed with both the soils at various percentages i.e., 0.0%, 0.5%, 1.0%, 1.5% and 3.0% by dry weight of soil to study the effect of polymer on geotechnical properties of soil. Particle size distribution, liquid limit, plastic limit, specific gravity and standard Proctor tests were conducted to identify the basic index properties of the soil. Unconfined Compressive Strength (UCS) tests were conducted after 3 days, 7 days and 28 days of curing period for CH soil. For ML soil, UCS tests were carried out after 7 days and 28 days of curing period. In addition, California Bearing Ratio (CBR) tests were conducted for CH soil at unsoaked and soaked (soaked for 96 hours) conditions. With the addition of stabilizer, no significant changes in UCS values were obtained for ML soil. For CH soil, UCS values increases upto 1.5% stabilizer dose and then decreases with 3.0% of stabilizer. Also, for CH soil, UCS value increases with the increase in curing period. For CH soil, the unsoaked CBR value increases upto 1.5% stabilizer dose and then decreases with 3.0% of stabilizer but no significant improvement in soaked CBR values were found.

Orientador: Tsunao Matsumoto. / Banca: Milton Dall'Aglio Sobrinho / Banca: Luís Fernando Rossi Léo / Resumo: Umas das formas de garantir a disposição final adequada das águas residuárias é submetê-las ao tratamento através das lagoas de estabilização. Um dos fatores consideráveis para estas unidades de tratamento são as características hidrodinâmicas presentes no processo. Um das lagoas de estabilização é a influência dos ventos na massa líquida. O presente projeto de pesquisa avaliou a influência do vento no comportamento da circulação da massa líquida da Lagoa Facultativa 2 da Estação de Tratamento de Esgotos (ETE) da cidade de Álvares Florence - SP, por meio de flutuadores de diferentes dimensões (15, 21 e 35 cm). Foram confeccionados 9 flutuadores, 3 grupos com 3 flutuadores (um de cada dimensão) e lançados nas 3 entradas existentes na lagoa. A pesquisa foi dividida em duas etapas: na primeira etapa foram averiguados o tempo de percurso dos flutuadores ao longo de uma célula da lagoa facultativa 2 e o efeito de borda. Na segunda etapa foi verificada a influência dos ventos na movimentação da massa líquida e as condições de mistura proporcionadas por esta influência por meio dos flutuadores e análises de DQO. O método dos flutuadores para verificação da influência do vento e a circulação de uma lagoa facultativa mostrou-se como uma alternativa efetiva e simples quando comparado ao método com traçadores / Abstract: One of the ways to ensure the proper disposal of wastewater is subject them to treatment by stabilization ponds. One of the significant factors for these treatment units are the hydrodynamic characteristics present in the process. Wind is external physical aspects that affect the hydrodynamic behavior of the stabilization ponds due to their influence on the circulation of the liquid mass. This research project evaluated the influence of wind on the behavior of the liquid mass flow of the facultative pond 2 of Sewage Treatment Plant in the city of Álvares Florence - SP, by means of floats of different sizes (15, 21 and 35 cm). Nine floats were made, three groups with three floats (one of each size) and released in three entries in the pond. The research was divided into two stages: the first step, were checked the travel time of the floats along of the facultative pond 2 and edge effect. In the second step was verified the influence of wind on movement of the liquid mass and mixing conditions provided by this influence by means of floats and COD analysis. The method for verification of the floats of the wind influence and the movement of a facultative pond proved to be a simple and effective alternative when compared with the tracer method / Mestre

Esta pesquisa foi desenvolvida na Estação de Tratamento de Esgoto de Cajati, onde o tratamento é realizado por lagoas de estabilização com sistema australiano. Em amostragens de variação nictemeral e sazonal, observou-se estratificação térmica nas duas lagoas, sendo que esta foi mais acentuada em abril. Em todos os períodos, a coluna de água esteve homogênea às 2h e 8h e estratificada às 14h e 20h. A estratificação térmica resultou na estratificação química (pH e oxigênio dissolvido), sendo que ambas as lagoas foram divididas em dois compartimentos: superior, com maiores temperaturas, pH e oxigênio dissolvido, e outro inferior, com comportamento contrário. A lagoa anaeróbia apresentou concentrações de oxigênio dissolvido de aproximadamente 10,0 mg/L, o que resulta em funcionamento inadequado também foi confirmado pelos resultados de clorofila nesta lagoa, que foram semelhantes aos da facultativa e atingiram até 3,5x\'10 POT.3\' \'mü\'g/L em abril e julho. Além disso, as concentrações de nutrientes e coliformes foram baixas no afluente bruto em relação às obtidas na literatura. Os valores de pH estiveram altos para lagoas de estabilização, com máxima de 12,17 em janeiro. Apenas em abril, o pH esteve menor (6,84-9,86), condizente com a literatura e adequado para fermentação anaeróbia. O menor pH e maiores temperaturas obtidos em abril resultaram em melhores eficiências de redução que nos outros períodos. As estimativas de vazão e carga orgânica revelaram que a ETE vem operando abaixo da carga prevista, o que pode influenciar na eficiência do sistema, pois este não terá tempo suficiente para formar comunidade microbiana estável. Não foi possível observar variabilidade vertical padrão das biomoléculas proteínas, carboidratos e lipídeos, nem ao longo do sistema. Observou-se heterogeneidade espacial e vertical entre as concentrações de nitrogênio e fósforo em todo sistema, onde alguns processos puderam ser identificados e estes foram influenciados por temperatura, pH e oxigênio dissolvido. Houve predomínio de cianobactéria (Synechocystis sp) na ETE Cajati, seguido de clorofícea (Chlorella kessleri). Em ambas as lagoas, o predomínio foi de Eubactéria com baixas concentrações de Arquéias. O efluente final esteve de acordo com os padrões de lançamento de efluentes estabelecidos na Resolução CONAMA 357/2005. / This research was developed in the Cajati wastewater treatment plant, where the treatment is carried through by stabilization ponds with australian system. In samplings of nictemeral and seasonal variation, thermal stratification in the two ponds was observed, and this was more accented in April. In all the periods, the water column was homogeneous at 2 a.m. and 8 a.m. and stratified at 2 p.m. and 8 p.m. Thermal stratification resulted in chemical stratification (pH and dissolved oxygen) and both the ponds had been divided into two compartments: superior, with higher temperatures, pH and dissolved oxygen, and another inferior, to the contrary behavior. The anaerobic pond presented concentrations of dissolved oxygen of approximately 10,0 mg/L that results in functioning inadequate confirmed by the results of chlorophyll in this pond. The anaerobic pond had been similar to the facultative one, which had reached 3,5 x \'10 POT.3\' \'mü\'g/L in April and July. Moreover, the concentrations of nutrients and coliforms had been low in the raw affluent in relation to those described in literature. The pH values had been high for stabilization ponds, with maximum of 12,17 in January. In April, pH was minor (6,84-9,86), according to literature and for anaerobic fermentation. The minor pH and greater temperature taken in April had resulted in better efficiencies of reduction that in the other periods. The estimates of outflow and organic load had disclosed that the plant is operating below the design load, which can influence the efficiency of the system, therefore it will not have enough time to form steady microbial community. Vertical and spatial variability was not observed for proteins, carbohydrates and lipids. Vertical and spatial heterogeneity was observed in nitrogen and phosphorus concentrations, where some processes could have been identified and these had been influenced by temperature, pH and dissolved oxygen. There were predominance of Cyanobacteria (Synechocystis sp) followed by Chlorophycea (Chlorella kessleri). In both ponds, there was predominance of Eubacteria with low concentrations of Archeae. The final effluent was in accordance with the established standards of discharge of effluent - Resolution CONAMA 357/2005.

A sílica obtida da queima de casca de arroz foi convertida nas fases α e β. A estabilização da fase β foi obtida pela introdução de alumínio e cálcio na rede de sílica, 10001100 °C, na proporção CaO:2Al2O3:38SiO2. Foi observado que a transição de fase α→β da cristobalita α tem sua temperatura de transição reduzida de 175°C bem como sua entalpia de transição, de 16,0 J/g para 7,0 J/g. Esse efeito é causado pela introdução de íon K+, presente na casca de arroz, na estrutura da sílica. O processamento empregado nessa conversão usa equipamentos normalmente encontrados em empresas de cerâmica tradicional moinho, atomizador, prensa e forno / Silica generated from burned rice shells has been converted to the β and &#945 phases of cristobalite. The β phase stabilization was acomplished by instilling aluminum and calcium into the silica structure, at 1000-1100 °C, in the following proportion CaO:2Al2O3:38SiO2. The phase transition α→β of the α-cristobalite has a lower transition temperature, as compared with cristobalite made from pure silica, from 270°C to 170°C. Also the transition entalphy was reduced from 16,0 J/g to 7,0 J/g. These changes were attributed to the K+ ion present in the silica structure of the burned silica. The process used in this convertion makes use of standard equipments, regularly used in ceramic producing companies mill, spray dryer, furnaces, and press.

This project deals with design of universal system for temperature stabilization using a Peltier device, controlled by microcontroller. The result of this work is an autonomous equipment with automatic tuning of regulation constants, calculation of temperature stabilization limits, possibility of setting required modes and with interface for connection to PC. The regulator stabilise temperature with an accuracy of 0,1 °C within the range of temperature from 0 to 60 °C.

Pitch and heave are limiting motions when driving at high speed on water. The installation ofa T-foil is an effective solution that reduces these motions. Commercial T-foils are available,but today none of them are non-magnetic. This thesis studies the possibility to design anon-magnetic T-foil that can carry the considerable loads that such a constructionexperiences. The T-foil is designed for vessels such as the Visby Class corvette. Vortex lattice theory is used to calculate the pressure distribution acting on the construction atdifferent load cases. Required laminate thickness is determined by iteration using a linearfinite element model of the fin. The conclusion is that it is possible to manufacture a non-magnetic T-foil of the required size.A critical area in the construction is the T-joint between the vertical strut and the horizontalfoil. Future investigations should include laboratory tests of the T-joint as well as moredetailed hydrodynamic analysis for more accurate input parameters of the T-foil. / NR 20140804

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