Les arbres irriguent leurs organes par un système microfluidique complexe qui permet le transfert d’eau sous des pressions hydrostatiques négatives allant de -0.1 à -13 MPa. Dans ces conditions de métastabilité, les arbres vivent avec le risque d’une vaporisation soudaine de leur sève, qui conduit à l’embolie. Après cavitation, la poche de gaz créée croît ensuite par différence de pression et diffuse dans les vaisseaux du xylème à travers des membranes poreuses appelées “ponctuations”. Ces membranes permettent d’assurer le transfert hydrique vasculaire et de lutter contre la propagation de l’embolie gazeuse pouvant conduire à un état létal de la plante. Pour comprendre les mécanismes d’embolie d’air dans le xylème, nous avons pu étudier la structure des ponctuations du peuplier et caractériser par microscopie à force atomique (AFM) leurs propriétés mécaniques. Nous avons fait des expériences de nano-indentation et de flexion sur des échantillons secs et saturés en eau. Les premières expériences semblent montrer que les propriétés mécaniques sont peu affectées par la sorption d’eau (le module d’Young de la membrane primaire est E 0:40 GPa). Nous avons pu établir que le module des ponctuations était inférieur à celui de la paroi vaisseaux du xylème (E 8 GPa). Des expériences de micromoulages ont montré que les membranes des ponctuations se déforment sous l’effet d’une différence de pression. En tenant compte de la présence des parois secondaires, l’analyse par éléments finis de la déformation des ponctuations permet de calculer le module d’Young des membranes qui est identique à celui déterminé en AFM. Nous avons pu mettre en évidence que les mâchoires constituées par les parois secondaires limitent la déformation de la membrane au niveau de l’encastrement près du bord. Des expériences d’injection d’air ont permis de déterminer la pression critique (Pc = 1:8 MPa) et les diamètres critiques des pores présents sur les valves capillaires (dpore 160 nm). La taille des pores estimée est cohérente avec les données de la littérature. Nous avons proposé une première modélisation de la propagation d’une embolie sur la base de l’écoulement de Darcy dans la membrane. L’ensemble des résultats semble montrer que la diffusion de gaz est rendu possible par l’effet conjoint de la déformation de la membrane qui génère l’ouverture des pores diminuant ainsi la pression critique de passage du gaz et de la rupture des ponts capillaires présents dans les pores de la membrane. / The xylem vessels of trees constitute a model natural microfluidic system. In this work, we have studied the mechanism of air flow in the Populus xylem. The vessel microstructure was characterized by optical microscopy, transmission electronic microscopy (TEM), and atomic force microscopy (AFM) at different length scales. The xylem vessels have length ≈ 15 cm and diameter ≈ 20 μm. Flow from one vessel to the next occurs through ∼ 10 2 pits, which are grouped together at the ends of the vessels. The pits contain a thin, porous pit membrane with a thickness of 310 nm. We have measured the Young’s moduli of the vessel wall and of the pits (both water-saturated and after drying) by specific nanoindentation and nanoflexion experiments with AFM. We found that both the dried and water-saturated pit membranes have Young’s modulus around 0.4 MPa, in agreement with values obtained by micromolding of pits deformed by an applied pressure difference. Air injection experiments reveal that air flows through the xylem vessels when the differential pressure across a sample is larger than a critical value ∆P c ≈ 1.8 MPa. In order to model the air flow rate for ∆P ≥ ∆P c , we assumed the pit membrane to be a porous medium that is strained by the applied pressure difference. Water menisci in the pit pores play the role of capillary valves, which open at ∆P = ∆P c . From the point of view of the plant physiology, this work presents a basic understanding of the physics of bordered pits.

A operação e gerência de empreendimentos mineiros são tarefas normalmente difíceis e complexas. Para otimizar toda a operação, os engenheiros precisam lidar com muitos aspectos técnicos e restrições, como a modelagem geológica, estimativa de reservas, determinação da necessidade de blendagem, projeto das cavas ótimas e operacionais, custos operacionais, questões ambientais, entre outros. Nesse sentido, o posicionamento de infraestruturas de superfície é um dos pontos críticos dentro do planejamento de mina. Aproximar as estruturas da cava, com o intuito de reduzir custos operacionais, pode interferir em eventuais expansões da cava em novos e favoráveis cenários. Nesses casos, impactos no valor presente líquido (VPL) do projeto são inevitáveis e precisam ser tratados tecnicamente, avaliando um grande número de cenários alternativos para delinear uma estratégia que incremente a lucratividade do projeto. O objetivo deste estudo é avaliar, por meio de comparações de VPL entre diferentes cenários de múltiplas restrições de superfície, sob incerteza geológica, a possibilidade de mover pilhas de estéril e outras infraestruturas de suas atuais posições e/ou definir prioridades e mensurar o impacto que cada restrição representa na lucratividade do projeto. A metodologia foi aplicada a uma mina de fosfato para ilustrar como determinar a melhor alternativa em uma perspectiva de planejamento de mina de longo prazo. Utilizando o método de cavas híbridas, aplicado ao modelo de teores simulados, foi possível identificar zonas de probabilidade de ocorrência dentro da cava matemática, o que forneceu informações cruciais para auxiliar na tomada de decisão a respeito da necessidade de relocação de estruturas. / The operation and management of mining enterprises are usually difficult and complex tasks. To optimize the entire operation the engineers must deal with several technical aspects and constraints, such as orebody modelling, reserves estimation, determination of blending necessity, optimum and operational pit designs, operational costs, environmental issues, among others. In this sense, locating surface infrastructures is one of the most critical mine planning concerns. Approximating these structures to the pit, in order to reduce the operational costs, might interfere with future pit expansions in new favorable scenarios. In such cases, impacts on project’s net present value (NPV) are inevitable and must be deal technically, evaluating several alternative scenarios to delineate a strategy to maximize profitability. The aim of this study is to evaluate, through NPV comparisons considering different scenarios with multiple constraints, under geological uncertainty, the possibility of moving waste piles and infrastructure buildings from their current position and/or defining priorities to after measuring the impact that each constraint represents on the project´s profitability. The methodology will be applied to a phosphate mine, to determine the best alternative from a long-term mine planning perspective. Using the hybrid pits method, applied to a simulated grades model, allowed the identification os occurrence probability zones within mathematical pit, providing critical data to support decision making regarding infrastructure relocation.

I monitored the chemical parameters of surface waters in wetlands and watercourses in the vicinity of Lake Medard (newly filled residual pit after brown coal mining). The characteristics of surface waters were described by means of their physical, chemical and biological indicators. The values obtained were compared with normal surface waters in the Czech Republic. I also assessed water quality and determined eutrophication. The chemical composition was compared in space and time. The most important finding is the high variability of waters in a relatively small area. Another is that the examined surface waters do not usually exhibit the typical characteristics of acid mine waters. The locations of interest are characterized by high levels of dissolved solids in water. High concentrations of sulphates are the most problematic of the found anions. In the case of cations, the following dissolved metals had high concentrations: Na, Ca, Mg, Zn, Mn and Fe.

As evidências mostram uma redução ou eliminação significativa na quantidade de bactérias viáveis sob selantes e restaurações e consequente diminuição na progressão da cárie quando as bactérias se encontram separadas do meio bucal. O objetivo deste ensaio clínico controlado randomizado foi avaliar a eficácia de duas estratégias de tratamentos: 1) selamento de lesões de cárie oclusal e 2) tratamento restaurador convencional com remoção total da dentina cariada em dentes permanentes. A amostra foi constituída de 52 dentes com lesões de cárie na superfície oclusal (pré-molares e/ou molares) de 47 pacientes com idade entre 8 a 43 anos. Todas as lesões de cárie apresentaram necessidade de tratamento restaurador de acordo com os seguintes critérios: presença de cavidade e impossibilidade de controle do biofilme. A profundidade máxima das lesões foi até a metade externa de dentina avaliada através de radiografias interproximais. Os dentes foram divididos aleatoriamente em um grupo teste - tratamento selante, ou grupo controle - tratamento restaurador convencional. Dados iniciais referentes à experiência de cárie (CPOD) e índice de sangramento gengival (ISG) foram avaliados. Radiografias interproximais foram realizadas após 12 meses para avaliar a integridade das restaurações e a zona radiolúcida (ZR) sob os selantes/restaurações. Os desfechos analisados foram o desempenho clínico dos tratamentos selante e restauração e a prevalência de regressão, inativação e progressão da cárie com exames radiográficos. A presença de dentina terciária também foi observada. Os dados foram avaliados por meio do teste exato de Fisher. Um total de 26 selantes e 26 restaurações foram realizadas. Não houve diferença entre os grupos quanto às características iniciais - idade, sexo, CPOD e ISG. Após um ano, foram avaliados 49 dentes, apresentando taxas de sucesso de 95,8% e 100% nos grupos selante e restauração convencional, respectivamente (p>0,05). Houve uma falha em um dos tratamentos (perda total no grupo selante) observada durante o estudo. A avaliação radiográfica (progressão, inativação, regressão e presença de dentina terciária) não demonstrou diferença entre os grupos. Nenhum dos dentes apresentou progressão de cárie; a regressão foi observada em apenas um caso (grupo do selante) e a presença de dentina terciária foi encontrada em 12,5% da amostra (5 selantes e 1 restauração). Selantes podem ser utilizados como tratamento terapêutico para lesões de cárie incipientes em dentes permanentes, uma vez que impedem a progressão das lesões de cárie, preservando a estrutura do dente, quando comparado ao tratamento restaurador convencional. / There is a significant decrease in the number of viable microorganisms under sealants and restorations and a consequent decrease in caries progression when bacteria are separated from the oral environment. The aim of this randomized controlled clinical trial was to evaluate the efficacy of two treatments strategies: 1) sealing of carious lesions and 2) operative restorative treatment of occlusal carious lesions in permanent teeth. The sample consisted of 52 carious posterior teeth (premolars and molars) from 47 patients aged 8 - 43 years. In all lesions restorative treatment was necessary according to the following current strategies: presence of cavity and impossibility to perform biofilm control. The maximum depth of lesions was halfway through the dentine assessed by bitewing radiograph. The teeth were randomly assigned to test group – sealant treatment or control group - conventional restorative treatment. Baseline caries experience (DMFT) and gingival bleeding index (GBI) was assessed. Bitewing radiographs were performed after 12 months to evaluate the integrity of the restorations and the radiolucent zone (ZR) beneath the sealants/restorations. Outcomes were defined as clinical performance of sealant and restoration and the prevalence of regression, inactivation and progression of carious lesion by radiographic examinations. Presence of tertiary dentine was also evaluated. The data were submitted to Fisher`s exact test. A total of 26 sealants and 26 restorations were performed. There were no differences between the two groups regarding baseline characteristics – age, gender, DMFT and GBI. After one year, 49 evaluations had been performed, showing 95.8% and 100% of success rates in test and control group respectively (p>0.05). There was one therapeutic failure (total loss in the sealant group) observed during the study. No difference in the radiographic evaluation (progression, inactivation, regression and tertiary dentin deposition) was observed between the groups (p>0.05). No teeth showed caries progression; regression was observed in only one case (sealant group) and tertiary dentin was founded in 12.5% of the sample (5 sealants and 1 restoration). Sealants can be used as a therapeutic treatment for incipient carious lesions in permanent teeth, since they prevent the progression of carious lesions, while preserving tooth structure when compared to conventional restorative treatment.

abstract: Gnamma pit is an Australian aboriginal term for weathering pit. A mix of weathering and aeolian processes controls the formation of gnamma pits. There is a potential to utilize gnamma as an indicator of paleowind intensity because gnamma growth is promoted by the removal of particles from gnamma pits by wind, a process referred to as deflation. Wind tunnel tests determining the wind velocity threshold of deflation over a range of pit dimensions and particles sizes are conducted. Computational fluid dynamics (CFD) modeling utilizing the Re-Normalisation Group (RNG) K-Epsilon turbulence closure is used to investigate the distribution of wall shear stress and turbulent kinetic energy. An empirical equation is proposed to estimate shear stress as a function of the wind velocity and pit depth dimensions. With this equation and Shields Diagram, the wind velocity threshold for evacuating particles in the pit can be estimated by measuring the pit depth ratio and particle size. It is expected that the pit would continue to grow until this threshold is reached. The wind speed deflation threshold is smaller in the wind tunnel than predicted by the CFD and Shields diagram model. This discrepancy may be explained by the large turbulent kinetic energy in the gnamma pit as predicted by the CFD model as compared to the flat bed experiments used to define the Shields diagram. An empirical regression equation of the wind tunnel data is developed to estimate paleowind maximums. / Dissertation/Thesis / Masters Thesis Geography 2015

abstract: Previous research has indicated that certain breeds of dogs stay longer in shelters than others; however exactly how breed perception and identification influences potential adopters' decisions remains unclear. Current dog breed identification practices in animal shelters are often based upon information supplied by the relinquishing owner, or staff determination based on the dog's phenotype. However discrepancies have been found between breed identification as typically assessed by welfare agencies and the outcome of DNA analysis. In Study 1, the perceived behavioral and adoptability characteristics of a pit-bull-type dog were compared with those of a Labrador Retriever and Border Collie. How the addition of a human handler influenced those perceptions was also assessed. In Study 2, lengths of stay and perceived attractiveness of dogs that were labeled as pit bull breeds to dogs that were phenotypically similar but were labeled as another breed at an animal shelter were compared. The latter dogs were called "lookalikes." In Study 3, perceived attractiveness in video recordings of pit-bull-type dogs and lookalikes with and without breed labels were compared. Lastly, data from an animal shelter that ceased applying breed labeling on kennels was analyzed, and lengths of stay and outcomes for all dog breeds, including pit bulls, before and after the change in labeling practice were compared. In total, these findings suggest that breed labeling influences potential adopters' perceptions and decision-making. Given the inherent complexity of breed assignment based on morphology coupled with negative breed perceptions, removing breed labels is a relatively low-cost strategy that will likely improve outcomes for dogs in animal shelters. / Dissertation/Thesis / Masters Thesis Psychology 2015

Orientador: Renato Herman Sundfeld / Banca: Alma Blasida Concepción Elizaur Benetez Catirse / Banca: Cléa Adas Saliba Garbin / Resumo: O objetivo dessa dissertação foi analisar e mensurar a penetração (tags) de materiais adesivos no esmalte dental, que foi condicionado com ácido fosfórico ou que recebeu a aplicação de um adesivo autocondicionante, previamente a realização do selamento das fóssulas e fissuras. Foram formados 6 grupos de estudo com 6 espécimes cada; os dos Grupos I, III e V receberam a aplicação do condicionamento com ácido fosfórico a 35%, pelo tempo de 30 segundos e os dos grupos II, IV e VI a aplicação do adesivo autocondicionante Adper Prompt L Pop, previamente a realização do selamento oclusal com os materiais Climpro (Grupos I e II), Vitroseal (Grupos IIII e IV), e Fugi II (Grupos V e VI). Após foram seccionados no sentido vestíbulo-lingual, lixados até a espessura de 100 um, descalcificados e analisados em microscopia óptica comum em aumento de 400 X. Os espécimes pertencentes aos grupos I, III e V apresentaram uma penetração significativamente superior do material selador no esmalte dental oclusal, do que os dos Grupos II, IV e VI que receberam o adesivo autocondicionante Adper Prompt L Pop. O selante resinoso de fóssulas e fissuras Climpro e o modificado por resina Vitroseal Alfa (Grupos I e III) apresentaram penetração semelhante entre si e superior ao material ionomérico modificado por resina Fuji II LC (Grupo V). A aplicação do adesivo autocondicionante Adper Prompt L Pop (Grupos II, IV e VI), previamente a aplicação dos materiais seladores, demonstrou níveis de penetração significativamente semelhantes entre si, evidenciada pela formação de prolongamentos resinosos (tags) curtos e não uniformes ao longo da interface esmalte/adesivo. / Abstract: The aim of this dissertation was to show an scientific article, analysing and measuring the penetration of adhesives materials (tags) on dental enamel, that was etched with phosphoric acid or recived a self-etching aplication, before pit and fissures sealing. Just 6 study groups was formed with 6 especimens each one; the especimens of Goups I, III and V recived phocphoric acid etching aplication (35%), during 30 seconds and the especimens of Groups II, IV and VI recived the Adper Prompt L Pop self-etching aplication, before occlusal sealing with Climpro (Gourps I and II), Vitroseal (Groups III and IV) and Fugi II (Groups V and VI) materials. After, the tooth were cuted on vestibular and lingual direction, polished until 100 micrometers of density, descalcificed and analysed on common optic microscopy with 400x amplification. The especimens of Groups I, III and V showed a higher significantly penetration of sealed material on occlusal dental enamel than especimens of Groups II, IV and VI that recived the Adper Prompt L Pop self-etching adhesive. The Climpro resin sealant of pit and fissures and the Vitroseal Alfa sealant modificated by resin (Groups I and III) showed similar penetration among themselves and higher penetration of Fuji II LC ionomeric material modificated by resin (Group V). The aplication of Adper Prompt L Pop selfetching adhesive (Groups II, IV and VI), before sealed materials aplication, demonstred similar singnificantly penetration levels among themselves, evidenced by formation of short and not regular resin prolongations (tags) along adhesive/enamel interface. / Mestre

Made available in DSpace on 2014-06-11T19:27:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-14Bitstream added on 2014-06-13T20:17:07Z : No. of bitstreams: 1 santos_kt_me_araca.pdf: 239170 bytes, checksum: b24c0fe420996ac1d95a647a4cd46f52 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo dessa dissertação foi analisar e mensurar a penetração (tags) de materiais adesivos no esmalte dental, que foi condicionado com ácido fosfórico ou que recebeu a aplicação de um adesivo autocondicionante, previamente a realização do selamento das fóssulas e fissuras. Foram formados 6 grupos de estudo com 6 espécimes cada; os dos Grupos I, III e V receberam a aplicação do condicionamento com ácido fosfórico a 35%, pelo tempo de 30 segundos e os dos grupos II, IV e VI a aplicação do adesivo autocondicionante Adper Prompt L Pop, previamente a realização do selamento oclusal com os materiais Climpro (Grupos I e II), Vitroseal (Grupos IIII e IV), e Fugi II (Grupos V e VI). Após foram seccionados no sentido vestíbulo-lingual, lixados até a espessura de 100 um, descalcificados e analisados em microscopia óptica comum em aumento de 400 X. Os espécimes pertencentes aos grupos I, III e V apresentaram uma penetração significativamente superior do material selador no esmalte dental oclusal, do que os dos Grupos II, IV e VI que receberam o adesivo autocondicionante Adper Prompt L Pop. O selante resinoso de fóssulas e fissuras Climpro e o modificado por resina Vitroseal Alfa (Grupos I e III) apresentaram penetração semelhante entre si e superior ao material ionomérico modificado por resina Fuji II LC (Grupo V). A aplicação do adesivo autocondicionante Adper Prompt L Pop (Grupos II, IV e VI), previamente a aplicação dos materiais seladores, demonstrou níveis de penetração significativamente semelhantes entre si, evidenciada pela formação de prolongamentos resinosos (tags) curtos e não uniformes ao longo da interface esmalte/adesivo. / The aim of this dissertation was to show an scientific article, analysing and measuring the penetration of adhesives materials (tags) on dental enamel, that was etched with phosphoric acid or recived a self-etching aplication, before pit and fissures sealing. Just 6 study groups was formed with 6 especimens each one; the especimens of Goups I, III and V recived phocphoric acid etching aplication (35%), during 30 seconds and the especimens of Groups II, IV and VI recived the Adper Prompt L Pop self-etching aplication, before occlusal sealing with Climpro (Gourps I and II), Vitroseal (Groups III and IV) and Fugi II (Groups V and VI) materials. After, the tooth were cuted on vestibular and lingual direction, polished until 100 micrometers of density, descalcificed and analysed on common optic microscopy with 400x amplification. The especimens of Groups I, III and V showed a higher significantly penetration of sealed material on occlusal dental enamel than especimens of Groups II, IV and VI that recived the Adper Prompt L Pop self-etching adhesive. The Climpro resin sealant of pit and fissures and the Vitroseal Alfa sealant modificated by resin (Groups I and III) showed similar penetration among themselves and higher penetration of Fuji II LC ionomeric material modificated by resin (Group V). The aplication of Adper Prompt L Pop selfetching adhesive (Groups II, IV and VI), before sealed materials aplication, demonstred similar singnificantly penetration levels among themselves, evidenced by formation of short and not regular resin prolongations (tags) along adhesive/enamel interface.

Made available in DSpace on 2014-06-11T19:27:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T19:35:55Z : No. of bitstreams: 1 oliveira_dc_me_araca.pdf: 770246 bytes, checksum: afb5979626e6e6f01c61959aab800ef5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A aplicação de selantes de fossas e fissuras e aplicação tópica de flúor são amplamente utilizados em procedimentos preventivos de cárie dentária, a eficácia desses materiais na prevenção de cárie dentária tem sido provada por revisões de literatura. O objetivo desse estudo foi comparar o efeito preventivo do selante de fossas e fissuras à base de ionômero de vidro (SIV) com o verniz fluoretado (VF) em molares permanentes de crianças com e sem experiência de cárie. Participaram do presente estudo 80 crianças, de ambos os gêneros, na faixa etária de 6 a 8 anos de idade, com os quatro primeiros molares permanentes recém irrompidos. Foram divididas em 2 grupos, sendo o grupo 1 formado por 53 crianças sem experiência de cárie e o grupo 2 formado por 27 crianças com experiência de cárie dentária. Em cada criança de um lado da cavidade bucal, os dois primeiros molares permanentes foram selados com um selante de ionômero de vidro (Fuji Triage), e nos outros dois primeiros molares permanentes do lado oposto, foi aplicado um verniz fluoretado (Duraflur). Para avaliar a eficácia dos materiais na prevenção da cárie dentária foi utilizado o método clínico visual, e a retenção do selante foi realizada aplicando-se os critérios de presença, parcial presença e ausência, estabelecidos por Simonsen. Os pacientes foram avaliados clinicamente após 6, 12 e 18 meses. Dos 320 primeiros molares que iniciaram o estudo, foram avaliados 319, 304, 299 aos 6, 12 e 18 respectivamente. Quanto ao efeito preventivo, mantiveram-se hígidos 307 (96%), 279 (92%) e 271 (91%) dentes, respectivamente nos períodos de análise. A lesão cariosa ocorreu em 12 (4%), 25 (8%) e 28 (9%) dentes respectivamente, sendo que em todos os períodos analisados, sua ocorrência prevaleceu no grupo de crianças com experiência de cárie dentária, sendo este... / Application of pit and fissure sealants and topical fluoride are widely used procedures in the prevention of decay, and their effectiveness in caries prevention has been proved by systematic reviews. The purpose of this clinical study was to compare the effectiveness of a glass ionomer sealant (GIS) with a fluoride varnish (FV) in the prevention of dental decay on first permanent molars of children with and without caries experience. The trial targeted eighty children aged 6 to 8 years, with all four newly erupted permanent first molars present. They were divided into 2 groups, with group 1 consisted of 53 children without caries experience and group 2 consists of 27 children with dental caries experience. In every child on one side of the oral cavity, the two first permanent molars were sealed with a glass ionomer sealant (Fuji Triage), and the other two first permanent molars on the opposite side, we applied a fluoride varnish (Duraflur). To assess the effectiveness of the materials in the prevention of tooth decay the clinical visual method was used, and retention of the sealant was performed by applying the criteria of complete presence, partial presence and absence, established by Simonsen’s. Patients were clinically evaluated after 6, 12 and 18 months. Of the 320 first molars that started the study 319, 304, 299 were evaluated to 6, 12 and 18 months respectively. Considering the preventive effect, 307 (96%), 279 (92%) and 271 (91%) teeth remained healthy respectively in the periods of analysis. The carious lesion occurred in 12 (4%), 25 (8%) and 28 (9%) respectively, and in all periods analyzed, their occurrence has prevailed in the group with caries experience, and this result was statistically significant. The materials used showed similar result in the periods of analysis, with no statistically significant... (Complete abstract, click electronic address below)

A operação e gerência de empreendimentos mineiros são tarefas normalmente difíceis e complexas. Para otimizar toda a operação, os engenheiros precisam lidar com muitos aspectos técnicos e restrições, como a modelagem geológica, estimativa de reservas, determinação da necessidade de blendagem, projeto das cavas ótimas e operacionais, custos operacionais, questões ambientais, entre outros. Nesse sentido, o posicionamento de infraestruturas de superfície é um dos pontos críticos dentro do planejamento de mina. Aproximar as estruturas da cava, com o intuito de reduzir custos operacionais, pode interferir em eventuais expansões da cava em novos e favoráveis cenários. Nesses casos, impactos no valor presente líquido (VPL) do projeto são inevitáveis e precisam ser tratados tecnicamente, avaliando um grande número de cenários alternativos para delinear uma estratégia que incremente a lucratividade do projeto. O objetivo deste estudo é avaliar, por meio de comparações de VPL entre diferentes cenários de múltiplas restrições de superfície, sob incerteza geológica, a possibilidade de mover pilhas de estéril e outras infraestruturas de suas atuais posições e/ou definir prioridades e mensurar o impacto que cada restrição representa na lucratividade do projeto. A metodologia foi aplicada a uma mina de fosfato para ilustrar como determinar a melhor alternativa em uma perspectiva de planejamento de mina de longo prazo. Utilizando o método de cavas híbridas, aplicado ao modelo de teores simulados, foi possível identificar zonas de probabilidade de ocorrência dentro da cava matemática, o que forneceu informações cruciais para auxiliar na tomada de decisão a respeito da necessidade de relocação de estruturas. / The operation and management of mining enterprises are usually difficult and complex tasks. To optimize the entire operation the engineers must deal with several technical aspects and constraints, such as orebody modelling, reserves estimation, determination of blending necessity, optimum and operational pit designs, operational costs, environmental issues, among others. In this sense, locating surface infrastructures is one of the most critical mine planning concerns. Approximating these structures to the pit, in order to reduce the operational costs, might interfere with future pit expansions in new favorable scenarios. In such cases, impacts on project’s net present value (NPV) are inevitable and must be deal technically, evaluating several alternative scenarios to delineate a strategy to maximize profitability. The aim of this study is to evaluate, through NPV comparisons considering different scenarios with multiple constraints, under geological uncertainty, the possibility of moving waste piles and infrastructure buildings from their current position and/or defining priorities to after measuring the impact that each constraint represents on the project´s profitability. The methodology will be applied to a phosphate mine, to determine the best alternative from a long-term mine planning perspective. Using the hybrid pits method, applied to a simulated grades model, allowed the identification os occurrence probability zones within mathematical pit, providing critical data to support decision making regarding infrastructure relocation.