Experiments were conducted to investigate the punching shear behaviour of thick slabs with identical spans and depths, subjected to monotonic point load conditions. Variables included: reinforcement ratio, column size, and reinforcement size. Analytical studies conducted as part of this thesis indicate that the current CSA A23.3 and the ACI 318 can be unconservative for thick slabs with low reinforcement ratios. The new fib Model Code provisions for punching offer an effective method for determining the full load-rotation behaviour of a slab up to failure, including accurate failure predictions. A summary of the background of current design procedures and standards will be presented, and a comparison between the different design equations and theories will be given. Based on the findings of this project, it is proposed that the provisions accepted by the fib Model Code should be considered for implementation in the CSA and ACI standards.

Experiments were conducted to investigate the punching shear behaviour of thick slabs with identical spans and depths, subjected to monotonic point load conditions. Variables included: reinforcement ratio, column size, and reinforcement size. Analytical studies conducted as part of this thesis indicate that the current CSA A23.3 and the ACI 318 can be unconservative for thick slabs with low reinforcement ratios. The new fib Model Code provisions for punching offer an effective method for determining the full load-rotation behaviour of a slab up to failure, including accurate failure predictions. A summary of the background of current design procedures and standards will be presented, and a comparison between the different design equations and theories will be given. Based on the findings of this project, it is proposed that the provisions accepted by the fib Model Code should be considered for implementation in the CSA and ACI standards.

The application of static shape control was investigated in this thesis particularly for a composite plate configuration using piezoelectric actuators. A new electro-mechanically coupled mathematical model was developed for the analysis and is based on a third order displacement field coupled with a layerwise electric potential concept. This formulation, TODL, is then implemented into a finite element program. The mathematical model represents an improvement over existing formulations used to model intelligent structures using piezoelectric materials as actuators and sensors. The reason is TODL does not only account for the electro-mechanical coupling within the adaptive material, it also accounts for the full structural coupling in the entire structure due to the piezoelectric material being attached to the host structure. The other significant improvement of TODL is that it is applicable to structures which are relatively thick whereas existing models are based on thin beam / plate theories. Consequently, transverse shearing effects are automatically accounted for in TODL and unlike first order shear deformation theories, shear correction factors are not required. The second major section of this thesis uses the TODL formulation in static shape control. Shape control is defined here as the determination of shape control parameters, including actuation voltage and actuator orientation configuration, such that the structure that is activated using these parameters will conform as close as possible to the desired shape. Several shape control strategies and consequently algorithms were developed here. Initial investigations in shape control has revealed many interesting issues which have been used in later investigations to improve shape controllability and also led to the development of improved algorithms. For instance, the use of discrete actuator patches has led to greater shape controllability and the use of slopes and curvatures as additional control criteria have resulted in significant reduction in internal stresses. The significance of optimizing actuator orientation and its relation to piezoelectric anisotropy in improving shape controllability has also been presented. Thus the major facets of shape control has been brought together and the algorithms developed here represent a comprehensive strategy to perform static shape control.

[pt] Este trabalho apresenta a análise numérica de vasos de pressão cilíndricos modelados por cascas e placas axissimétricas submetidas a carregamento de pressão interna uniformemente distribuída, utilizando-se a técnica de elementos finitos. São consideradas análises de junções entre superfícies com diferentes espessuras, tais como paredes finas (razão entre o raio e a espessura superior a 10) e moderadamente espessas (razão entre o raio e a espessura inferior a 5). Os campos de deslocamento considerados são os referentes aos elementos planos axissimétricos. A partir deste modelo são avaliadas as tensões na transição entre as superfícies e os resultados comparados com soluções analíticas simplificadas. Conclui-se que a solução analítica aproximada é aceitável para uma grande faixa de valores envolvendo placas e cascas de espessuras moderadamente espessas, enquanto que, para paredes finas, a análise por elementos finitos é necessária para verificação do comportamento das tensões na junção. Testes numéricos utilizando o programa ANSYS são apresentados para demonstrar o desempenho de análises lineares axissimétricas, empregando elementos quadráticos em comparação com as soluções analíticas e avaliando também as limitações do modelo analítico na região da descontinuidade geométrica do modelo proposto. / [en] This work presents the numerical analysis of cylindrical pressure vessels, modeled using axisymmetric shells and plates elements under internal pressure loads. The numerical analysis considers surface joints for various surface thickness ratios, from thin (ratio between radius and thickness greater than 10) to thick (ratio between radius and thickness less than 5) shells. Element displacement fields of axisymmetric plane elements are used to evaluate the stress state at the surfaces junctions, and the obtained results are compared to simplified analytical solutions. It is concluded that analytical approximate results present an acceptable solution for a large range of plates to shells geometries up to moderately thick shells, whereas for thin shells the finite element solution is necessary to be considered in order to accurately verify the stresses at plate to shell junction. Numerical tests applying ANSYS program are presented to demonstrate the performance of linear axisymmetric analysis applying quadratic elements in comparison to the analytical solutions also evaluating the limitations of the analytical model in the region of the geometric discontinuity of the proposed model.

Features typical for karst, such as fast groundwater flow and existence of open conduits were observed in various parts of Bohemian Cretaceous Basin (BCB). So far, vertical and areal extent of karst rocks is not known. In case of concerning conduits in quartz sandstones the observation of their evolution in profiles perpendicular to flow is missing. The thesis deals with above mentioned issues. Concerning potential to karstification it is limited to Jizera facial area of BCB. For this purpose, leaching of samples in hydrochloric acid were carried out. The hydrochloric acid was used as an accelerated simulation of natural processes of dissolution of rock by acidic solutions. The reaction of samples on leaching in acid, disintegration and content of the CaCO3 component were evaluated. CaCO3 content was determined also by calcimetry. Rocks which disintegrated can be a suitable for the evolution of karst conduits. According to the lithostratigraphic sections, the examined profiles belong to the TUR5 and TUR6 units - thus these units contain rocks suitable for the evolution of karst conduits. In Předměřice site about 23 % of samples disintegrated, in Kosmonosy site 8 % and in Turnov site 36 % disintegrated. Thus about 1/10 to 1/3 of tested profiles is prone to karstification and evolution of karst...

Research questions: This research was focused on exploring the impact of communication technologies on rural populations in the Congo. In particular, this research posed two questions: 1. Do mobile phones produce development in rural areas of the Congo? 2. Do mobile phones improve the living conditions of people? The questions helped examine ways in which mobile phones were or were not engendering development among these populations. Methods: The research was undertaken using four methods: 1. Phenomenology, 2. Sen's capability approach, 3. Participatory method, and 4. Ecological method. Phenomenology aimed to cater to the experiences and meanings of mobile phone uses. Sen's capability approach allowed the interviews to be focused on the basic needs of the poor. Participatory method provided a greater participation of respondents in discussion groups, and ecological method helped achieve a higher inclusion of key players in the targeted area. Major findings: The major findings of this study included: 1. Much of the literature on mobile phones and development was not representative or inclusive of key players and their day-to-day lives. 2. Studies have tended to present snapshots or single-focused accounts of mobile phone and development. 3. Authors of mobile phone research have tended to see rural populations with an urban-led bias, leaving aside the actual characteristics of rural areas. 4. Mobile phones were not limited to a person and her properties, but rather mobile phones were owned and shared by the community. 5. Participants expressed a need for technical skills and means to be available to the community and their members. 6. Households were not separated, but rather they were connected to allow people take care of one another. 7. People were connected through collective solidarities in order to come to the aid of those with special needs. 8. Literature and mobile phone sponsors or companies were disseminating mobile phones with an extractive and commercial tendency, focused principally on fees of batteries, chargers, and prepaid cards. Major contributions: The major contributions of this research revolved around the focus on: 1. technology to enhance the needed technical skills among concerned populations. 2. shared ownership of mobile phones to cater to both users and non-users of mobile phones among concerned populations. 3. connected households to capitalize on the dynamics of family among concerned populations. 4. collective solidarities to accommodate the processes of aiding one another among concerned populations. 5. capabilities, from a commercial or extractive aspect to capabilities to enhance the capabilities of people to afford mobile phones fees. 6. capabilities, from a corporate or business aspect to capabilities to enhance the capabilities of people who did not and could not own a business. 7. human basic needs to enhance the capabilities of mobile phone users with regard to human basic needs. 8. outliers or the marginalized to attend to those left out among concerned populations. 9. mobile phone-centric libraries to enhance the storage and retrieval of needed information among concerned populations.

Neste trabalho foram determinadas as condições para a soldagem de chapas grossas de aço carbono ASTM A36 com aço baixo-liga temperado e revenido ASTM A514 Grau Q empregando-se o processo arame tubular. Para tanto foram soldadas diversas peças de testes com o intuito de se avaliar as condições mais adequadas de preparação e soldagem de juntas dissimilares destes materiais. A preparação foi realizada por meio de corte térmico. A temperatura de preaquecimento foi determinada através de modelos matemáticos, pelas recomendações das normas AWS D1.1 e DIN EN 1011-2 sendo posteriormente avaliada por intermédio do teste de soldabilidade tipo CTS Controlled Thermal Severity. Os parâmetros de soldagem foram determinados a partir da qualificação de um procedimento de soldagem, conforme a norma AWS D1.1. Foram avaliadas as consequências do emprego do tratamento térmico de alívio de tensões após soldagem (TTAT), pelos testes de dureza Vickers e impacto Charpy. A caracterização microestrutural foi realizada por meio de microscopia óptica e microscopia eletrônica de varredura. A caracterização das superfícies oxicortadas evidenciou os efeitos da descarbonetação e também da carbonetação. A temperatura de pré-aquecimento de 160°C determinada por meio da metodologia recomendada pelas normas AWS D1.1 e DIN EN 1011-2 mostrou-se satisfatória nos testes de soldabilidade. Foi possível a qualificação do procedimento de soldagem (EPS) com requisitos de impacto na condição \"como soldado\", porém na condição \"após TTAT\", os baixos valores de tenacidade obtidos no metal de solda, inferiores a 27J, não permitiram a qualificação de uma EPS com requisitos de impacto. Foi observada a ausência de trincas intergranulares tanto na zona afetada pelo calor quanto no metal de base ASTM A514, porém foi revelada a presença de microfases frágeis no metal de solda na condição \"como soldado\", especificamente na região da raiz, intensificadas pelo efeito da diluição. O aumento do teor de carbono na raiz, a presença de microfases frágeis, a grande fração de grãos colunares e de ferrita proeutetóide combinados com a baixa fração de ferrita acicular no metal de solda contribuíram para os baixos valores de tenacidade encontrados na condição \"como soldado\". Após o TTAT observou-se uma queda acentuada da tenacidade, inferior a 27J, do metal de solda devido à fragilização provocada pela precipitação e coalescimento de carbonetos de ferro. / In this work it was determined the conditions for welding thick plate of ASTM A36 carbon steel with quenched and tempered low-alloy steel ASTM A514 Grade Q employing the Flux Cored Arc Welding (FCAW) process. For that several coupons of tests were welded in order to evaluate the most appropriate conditions for preparation and welding of these dissimilar materials. The preparation was carried out by means of thermal cutting. The preheat temperature was determined by mathematical models, the recommendations of standards AWS D1.1 and DIN EN 1011-2 being further evaluated using the CTS type weldability test - Controlled Thermal Severity. The welding parameters were determined by qualifying a welding procedure (WPS), according to AWS D1.1. The effects of post weld heat treatment (PWHT) were evaluated by Vickers hardness tests and Charpy. Microstructural characterization was performed by optical microscopy and scanning electron microscopy. The characterization of oxi-fuel cut surfaces showed the effects of decarburization and also carburization. The preheating temperature of 160 °C determined by calculation and the methodology recommended by the standards was satisfactory in weldability tests. It was possible qualification of welding procedure (WPS) with impact requirements in the condition \"as welded\" but the condition \"after PWHT\" low toughness values obtained in the weld metal, less than 27J, did not allow to qualify a WPS with toughness requirements. The absence of intergranular cracking was observed in both the heat affected zone as the base metal ASTM A514, but the presence of fragile microphase in the weld metal was revealed in the weld metal in the condition \"as welded\" specifically in the root region, intensified by the effect of dilution. The carbon increase at root, the presence of fragile microphase, the large fraction of columnar grains and proeutectoid ferrite combined with the low fraction of acicular ferrite in the weld metal contributed to the low toughness values found in the condition \"as welded \". After PWHT there was a sharp drop in toughness, less than 27J, in the weld metal due to embrittlement caused by precipitation and coarsening of iron carbides.

A busca por membranas com propriedades adequadas a separação de gases em escala industrial tem levado a modificação e sIntese de polImeros de engenharia, com objetivo de obter membranas com propriedades adequadas. Uma das modificaçoes que tem se apresentado promissora é a inserção de grupos sulfônicos em polImeros comerciais. Espera-se que o polImero sulfonado apresente um aumento na permeação de gases polares, em relação a gases apolares, devido a sua estrutura mais polar e flexIvel. Neste contexto, o objetivo do presente trabalho é a sIntese e caracterização de membranas de poli(éter imida) sulfonada para a permeação de gases. Um planejamento experimental foi desenvolvido, em diferentes condiçoes reacionais de temperatura, tempo e excesso de um dos reagentes (ácido acético), para a sIntese de poli(éter imida) sulfonada (SPEI). Através deste planejamento, constatou-se que as variáveis que mais influenciam o grau de sulfonação são a temperatura e o tempo. O polImero com o maior grau de sulfonação, determinado por capacidade de troca iônica (IEC= 92 mEq H+/g), foi utilizado para o preparo da membrana de SPEI, obtida pela técnica de inversão de fase por evaporação do solvente, utilizando-se clorofórmio como solvente. Este filme foi caracterizado a partir das seguintes análises: espectroscopia de infravermelho (FTIR), calorimetria diferencial de varredura (DSC), análise termogravimétrica (TGA) e microscopia eletrônica de varredura (MEV), a fim de avaliar a influência da inserção do grupo sulfônico na matriz polimérica. O espectro de infravermelho de SPEI apresentou bandas relacionadas as vibraçoes assimétricas em 1240 cm-1 (ligação O=S=O), ligação simétrica em 1171 cm-1 (O=S=O) e ligação S-O entre 1010-1024 cm-1. Isto indica a presença de grupos sulfônicos. A análise de DSC foi realizada entre 150-250C. Nesta faixa, não foram observadas alteraçoes na temperatura de transição vItrea (Tg) do polImero modificado (217C). Acredita-se que a decomposição do grupo sulfona aconteça antes da temperatura atingir o Tg do polImero. Esta suposição é confirmada na análise de TGA. As imagens de MEV mostraram que foram obtidos filmes livres de poros e defeitos. A membrana da SPEI foi utilizada no ensaio de permeaçao dos gases 02, N2 e C02, a fim de determinar a permeabilidade e seletividade da membrana. As permeabilidades encontradas para o gas oxigênio foram de 0,76 barrer para a PEI e 0,46 barrer para a SPEI. A seletividade do dióxido de carbono em relaçao ao oxigênio aumentou de 3,5, na membrana de PEI, para 4,83, na membrana de SPEI. Em relaçao ao nitrogênio, as permeabilidades medidas foram 0,064 barrer e 0,043 barrer, para a PEI e para a SPEI, respectivamente, enquanto a seletividade em relaçao ao C02 aumentou de 41,1 para 55,5. Estes resultados indicam que o efeito de sorçao predominou devido ao aumento das interaçöes moleculares, reduzindo assim o volume livre, o que tornou a membrana sulfonada mais compacta, com permeabilidade menor e maior seletividade. Estes resultados corroboram com a premissa de que a sulfonaçao é um processo promissor para o desenvolvimento de membranas mais eficientes. / The search for membranes with suitable properties for gas separation in industrial scale has led to the modification and synthesis of engineering polymers with the purpose of obtaining membranes with superior properties. 0ne of the modifications that have been considered promising is the insertion of sulfonic groups in commercial polymers. Due to its structure more polar and flexible, it is expected that the sulfonated polymer present an increase in polar gas permeation in relation to nonpolar gases. In this context, the objective of this work is the synthesis and characterization of membranes of poly (ether imide) sulfonated for the permeation of gases. An experimental design was developed in different reaction conditions of temperature, time and an excess of one of the reagents (acetic acid), for the synthesis of poly (ether imide) sulfonated, SPEI. Through this planning, it was found that the variables that most influenced the degree of sulfonation are temperature and time. The polymer with the highest degree of sulfonation, by ion exchange capacity (IEC = 92 mEq H+ I g), was used to prepare SPEI membrane obtained by the technique of solvent evaporation, using chloroform. This film was characterized from the following analysis: infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to evaluate the influence of insertion of the sulfonic group in the polymer matrix. The infrared spectrum showed bands of SPEI related to asymmetric vibrations at 1240cm- 1 (S = 0 = 0), in symmetric stretch at 1171 cm-1 (0 = S = 0) and S0 stretch between 1010-1024cm-1. This indicates the presence of sulfonic groups. The DSC analysis was carried out between 150-250C. In this range, there are no significant changes in glass transition temperature of the modified polymer (217C). It is believed that the decomposition of the sulfone group occurs before the temperature reaches the Tg of the polymer. This assumption is confirmed in the TGA analysis. The images of SEM showed that films were obtained free of pores and defects. The membrane SPEI obtained by the technique of solvent evaporation, was used for testing permeation of gases 02, N2 and C02 in order to determine the permeability and selectivity of the membrane. The permeabilities found for oxygen were 0.76 barrer for PEI and 0.46 barrer for SPEI. The selectivity of carbon dioxide relative to oxygen increased from 3.5 to 4.83. Regarding nitrogen, the permeability measurements were 0.064 barrer and 0.043 barrer for the PEI and the SPEI, respectively, while the selectivity relative to C02 increased from 41.1 to 55.5. These results indicate that the predominant effect of sorption due to increased molecular interactions, thus reducing the free volume, made the membrane sulfonated more compact with lower permeability and higher selectivity. These results agree with the premise that the sulfonation is a promising process for the development of more efficient membranes.

No acervo que compõem o patrimônio cultural, há muitos utensílios, obras de arte, monumentos, etc., que são feitos de metais. Mas dentre os diversos metais existentes, o cobre possui uma posição de destaque na história, pois este foi o primeiro utilizado pela humanidade. Os metais quando expostos à atmosfera podem sofrer processos de corrosão, o que pode comprometer um artefato histórico. No cobre e suas ligas, o produto dos processos de corrosão é denominado pátina. O estudo das pátinas e das ligas que compõe a matriz, no qual a pátina se forma, é de fundamental importância para a compreensão dos processos de corrosão. Com esta informação, puderam-se determinar as melhores técnicas de conservação e restauração que devem ser aplicadas. No presente estudo utilizou-se pátinas artificiais, que já são amplamente conhecidas, e possibilitam a simulação de pátinas naturais, além de ser possível utilizá-las na recolocação de pátinas que fora removidas e/ou perdidas de peças metálicas. Em um estudo anterior foram produzidas pátinas artificiais a partir de três soluções utilizando dois procedimentos de preparação e a análise foi realizada através das técnicas: EIS (Espectroscopia por Impedância Eletroquímica), MEV (Microscopia Eletrônica de Varredura), e XRD (Difração de Raio X), que são consideradas técnicas micro-destrutivas. No presente estudo, destas mesmas pátinas, utilizou-se para análise as técnicas de PIXE (Emissão de Raio X Induzido por Partícula) e ED-XRF (Fluorescência de Raio X por Dispersão de Energia), ambas não destrutivas e, no caso de ED-XRF, mais frequentemente, possível ser utilizada in situ. Estas técnicas permitem a analise de obras de arte em atmosfera, em um arranjo externo, o que contribui para a análise de peças de diferentes formas e tamanhos. Os resultados obtidos mostraram que o PIXE possui uma melhor caracterização de elementos leve, enquanto que o ED-XRF é melhor para elemento pesados. Na comparação entre PIXE interno e externo, observou-se que a montagem externa é suficiente na análise desse tipo de material. As medidas de padrões de aço validaram a técnica PIXE para análise de alvos grossos e permitiram quantificar os elementos presentes nas amostras. Tanto PIXE, quanto ED-XRF, mostraram nas análises das amostras os elementos que estão presentes nas soluções aplicadas. Além disso, houve um aumento do enxofre em algumas amostras e pátinas, e isto pode indicar que este elemento foi agregado com o tempo nas amostras, devido à exposição à atmosfera. Em comparação ao estudo anterior, que caracterizou a composição das camadas de pátinas em amostras semelhantes, foi possível mostrar que se pode determinar e quantificar com PIXE eED-XRF os elementos presentes sem que seja necessária a retirada do material a ser analisado, principalmente se aplicadas para a análise de peças com valor histórico e cultural. O estudo utilizando as técnicas PIXE e/ou ED-XRF, juntamente com técnicas EIS, SEM e XRD, torna as respostas mais completas, mas nem sempre isso é possível em se tratando de bens do patrimônio histórico, cultural e artístico. / The collection that composes the cultural patrimony has many utensils (vessels, pottery, adornment), works of art, monuments, etc., that are made of metals. However amongst the diverse existing metals, copper possesses a position of historical prominence, since this metal was the first one to be used by humanity. Metals when displayed in the atmosphere, can suffer processes corrosion which can destroy partially or completely the historical object. In copper and its alloys, the product of the corrosion processes is called patina. Analyses of the patina and the matrix alloy material are necessary to understand the corrosion processes and its development. The analyses are also needed to study the alterations imposed on an artifact in order to develop an adequate conservation and restoration treatment techniques. In the present work well known artificial patinas were used and can simulate the natural ones besides permitting to use them in the replacement of lost patinas that have been removed and/or lost in metalic parts. A previous study was realized with artificial patinas produced from three solutions and two different procedures of application. These patinas were analyzed by different techniques such as: EIS (Electrochemical Impedance Spectroscopy), SEM (Scanning Electron Microscopy), and XRD (X-ray Diffraction), which are micro-destructive methods. In the present study, the same samples were analyzed by PIXE (Particle Induced X-ray Emission) and ED-XRF (Energy Dispersive X-ray Fluorescence) techniques, both not destructive, and in the case of ED-XRF, more frequently, it can be used in situ. These methods allow the analyses of works of art of different forms and sizes in the atmosphere, in an external arrangement. The results have shown that PIXE has a better characterization of light elements, whereas the ED-XRF is better for heavy elements. The comparison of internal and external PIXE measurements showed that the PIXE external setup is enough for the analysis of this type of material. The PIXE results of steel standards had validated the technique PIXE for analysis of thick targets and had allowed the quantification of the elements presents in the samples. PIXE and ED-XRF analyses had shown the principal elements present in the samples and in the solutions. Moreover, it was possible detect an increase of sulphur in some samples and patinas, indicating that this element is being absorbed by the samples due to the exposition to the atmosphere. This work also shows that it is possible to determine and quantify with PIXE and ED-XRF the elements present in the samples, without any extraction of material and it is important mainly if applied to the analysis of historical and cultural objects. A study using suitable combination of techniques, as used in the previous study (EIS, SEM e XRD) coupled to PIXE and/or ED-XRF techniques can give a complete characterization of the corrosion compounds, but sometimes the complete combination of techniques is impossible if dealing with artistic and cultural historic objects.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-05-04T19:29:57Z No. of bitstreams: 2 Dissertação - Régina Vaz da Costa Fernandes - 2017.pdf: 17164598 bytes, checksum: 7d27b7e5b1088e664e3f5df03d3efdba (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-05T13:01:51Z (GMT) No. of bitstreams: 2 Dissertação - Régina Vaz da Costa Fernandes - 2017.pdf: 17164598 bytes, checksum: 7d27b7e5b1088e664e3f5df03d3efdba (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-05T13:01:51Z (GMT). No. of bitstreams: 2 Dissertação - Régina Vaz da Costa Fernandes - 2017.pdf: 17164598 bytes, checksum: 7d27b7e5b1088e664e3f5df03d3efdba (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-16 / The State of Goiás, in the region dominated by the Cerrado Biome, has undergone an intense occupation, structuring of development policies and government investments since the 1930s. Since then, public policies have prioritized the internalization of Brazil, with the construction of Goiânia (1930s) and Brasilia (1960s) increased the production and flow of agricultural products in the region. In this context, the municipality of Catalão did not escape this process of expansion of the agricultural frontier, and with this the region suffered and undergoes still profound transformations, mainly of socio-environmental nature. The present study has as main theme the Revegetation Program carried out in the area of the Ribeirão Samambaia Basin, in the municipality of Catalão (GO), from 2003 to 2015, whose objective is to analyze the effectiveness of this Program in order to diagnose possible mitigating actions in the Riparian areas of the watercourses that make up the catchment area. The interest for the discussion of the theme arose due to the fact that, in the municipality of Catalão (GO), the use and occupation of the soil, due to the socioeconomic transformations have influenced the recent urban growth and expansion, subjecting the Ribeirão Basin Samambaia to the alterations resulting from the parceling of the soil and the creation of infrastructures, leading the urban meshwork over these areas with consequent population densities, resulting in the suppression of the primary vegetation remnants, including the riparian environments along the banks of the courses. water. Through field research, in the Ribeirão Samambaia Basin area, it is noted that there has been an increasing process of environmental degradation and the consequent restructuring of landscapes. For the accomplishment of the research, procedures were adopted that obeyed the sequence: theoretical, field and laboratory research. The present work studies the Cerrado Biome and its main characteristics, being of fundamental importance for the balance of the other Biomes. The Cerrado Biome undergoes profound environmental transformations, mainly in the phytophysiognomies of forest formations, especially the Matas de Galerias. In this context, in the area of the Ribeirão Samambaia Hydrographic Basin, Catalão (GO), there is intense land use and occupation, where soil has been gradually modified, both by urban and rural activities, through the practices used to modernize Field and consequent planting in large areas and urban growth. The water basin is mainly responsible for the public water supply of the city of Catalão, which is under the responsibility of the Superintendency of Water and Sewer of Catalan (SAE) and Rural Communities of Area of the Ribeirão Samambaia Basin, in 2003, started a Revegetation Program, implementing vegetation recovery techniques in the basin area. Through the indicators that measure the stage of development of the seedlings, canopy formation and natural regeneration, it can be concluded that the results obtained in this study allow to demonstrate that the positive effectiveness of the Program occurred, but it was not possible to observe a well delineated planning and monitoring For this work and this compromises the continuity of the recovery process of the area. As a result, it is necessary to review the Revegetation Program implemented, seeking to renew its techniques and adapt them to the current reality that lies in the watershed areas of the Basin. The different recommendations can serve as reference for general application, taking into account the need to observe the particularities inherent to each location. / O Estado de Goiás, na região dominada pelo Bioma Cerrado, vem passando por um processo intenso de ocupação, estruturação de políticas de desenvolvimento e investimentos governamentais a partir da década de 1930. A partir de então, as políticas públicas priorizaram a vinteriorização do Brasil, com a construção de Goiânia (anos 1930) e Brasília (anos 1960) aumentou a produção e o escoamento de produtos agrícola na região. Nesse contexto, o município de Catalão não fugiu desse processo de expansão da fronteira agrícola, e com isso a região sofreu e sofre ainda profundas transformações, principalmente de cunho socioambiental. O presente estudo tem como tema principal o Programa de Revegetação realizado na área da Bacia Hidrográfica do Ribeirão Samambaia, no município de Catalão (GO), no período de 2003 a 2015, cujo objetivo é analisar a efetividade desse Programa visando diagnosticar possíveis ações mitigadoras nas áreas ripárias dos cursos d’águas que compõem a área da bacia hidrográfica. O interesse pela discussão da temática surgiu devido ao fato de que, no município de Catalão (GO), o uso e a ocupação do solo, em virtude das transformações socioeconômicas terem influenciado no crescimento e na expansão urbana recente, submetendo a Bacia Hidrográfica do Ribeirão Samambaia às alterações decorrentes do parcelamento do solo e da criação de infraestruturas, conduzindo o avanço da malha urbana sobre essas áreas com consequente adensamento populacional, tendo como consequência desse processo a supressão dos remanescentes de vegetação primárias, inclusive dos ambientes ciliares às margens dos cursos d’água. Através de pesquisa em campo, na área da Bacia Hidrográfica do Ribeirão Samambaia, nota-se que vem ocorrendo um processo crescente de degradação do ambiente e a consequente reestruturação das paisagens. Para a realização da pesquisa, adotou-se procedimentos que obedeceram a sequência: pesquisas teóricas, de campo e de laboratório. O presente trabalho estuda o Bioma Cerrado e suas principais características, sendo que exerce importância fundamental para o equilíbrio dos demais Biomas. O Bioma Cerrado sofre profundas transformações ambientais, principalmente, nas fitofisionomias de formações florestais, com destaque para as Matas de Galerias. Nesse contexto, na área da Bacia Hidrográfica do Ribeirão Samambaia, Catalão (GO), ocorre o intenso uso e ocupação da terra, onde o solo gradativamente vem sendo modificado, tanto pelas atividades urbanas como pelas rurais, através das práticas empregadas para a modernização no campo, consequente plantio em grandes extensões de áreas e pelo crescimento urbano, sendo a bacia hidrográfica a principal responsável pelo abastecimento público de água da cidade de Catalão, que sob a responsabilidade da Superintendência de Água e Esgoto de Catalão (SAE) e Comunidades Rurais da área da Bacia Hidrográfica do Ribeirão Samambaia, no ano de 2003, iniciaram um Programa de Revegetação, implementando-se técnicas de recuperação vegetacional na área da bacia. Através dos indicadores que medem o estágio de desenvolvimento das mudas, formação de dossel e regeneração natural, pode-se concluir que os resultados obtidos nesse estudo permitem demonstrar que ocorreu a efetividade positiva do Programa, mas não foi possível observar um planejamento e monitoramento bem delineado para este trabalho e isso compromete a continuidade do processo de recuperação da área. Em decorrência disso, faz-se necessário rever o Programa de Revegetação implantado, buscando renovar suas técnicas e adequá-las a realidade atual que se encontra as áreas ciliares da Bacia. As diferentes recomendações podem servir como referência para aplicação em geral, tendo-se em conta a necessidade de se observar as particularidades inerentes a cada local.