Nos últimos anos a questão da expansão da matriz energética brasileira e a construção de novas grandes usinas hidrelétricas, principalmente na região amazônica, tem estado no centro dos debates sobre estratégias de crescimento econômico no Brasil. Nesse debate é possível identificar a questão das vantagens comparativas da tipologia hidrelétrica frente as outras formas de geração de energia no que tange aos benefícios econômicos e sociais à nação. No entanto, há uma controvérsia na literatura que aponta para evidências de que as tais vantagens comparativas não se concretizam no plano local, estando apenas voltadas para o plano nacional. Um dos mecanismos legais visto pelos planos governamentais como promotor de desenvolvimento local é a Compensação Financeira pela utilização de recursos hídricos. Tal mecanismo visa transferir valores aos entes federativos, principalmente às municipalidades diretamente alagadas, relativos à produção de energia elétrica. Este mecanismo pode ser interpretado sob a perspectiva teórica da economia institucional enquanto uma instituição que contem regras formais, regras informais e mecanismos de enforcements que devem garantir seu funcionamento. Nesse contexto, a pergunta que se coloca é se a Compensação Financeira está associada ao desenvolvimento dos municípios brasileiros alagados pelas hidrelétricas, ao longo da década de 2000 a 2010. Para responder essa pergunta, o presente trabalho analisou as variáveis de desenvolvimento de 600 municípios alagados que receberam valores de Compensação Financeira ao longo da década de 2000 a 2010 pagos por 119 hidrelétricas. Os resultados encontrados podem ser separados em duas escalas. Na escala Nacional foram encontradas evidências de associações negativas estatisticamente significantes em relação a 21 variáveis de desenvolvimento e valores auferidos de Compensação Financeira. Numa escala regional, foram encontradas evidências de associações negativas estatisticamente significantes para as regiões Sudeste e Centro-oeste para 30 variáveis. Não foram encontradas associações significantes para a região Sul. Para as regiões Nordeste e Norte foram encontradas associações positivas estatisticamente significantes para 14 variáveis de educação e de redução da desigualdade. Sob a perspectiva da teoria da economia institucional, é possível interpretar os resultados da escala nacional como sendo condicionados pela ausência de regras formais objetivas e respectivos mecanismos de enforcements efetivos no que tange ao tema de aplicação dos recursos de Compensação Financeira recebidos pelas municipalidades, o que pode influenciar os resultados negativos observados. Para a escala regional, mesmo as regras formais e mecanismos de enforcement sendo caracterizados como não efetivos, os resultados positivos observados podem estar associados às regras informais e outros elementos regionais que condicionam positivamente a aplicação dos recursos. Assim, conclui-se que a Compensação Financeira é um importante mecanismo de compartilhamento de benefícios com potencial de influenciar dimensões do desenvolvimento desde que sejam observadas as interfaces entre as regras formais e informais que as condicionam. Esse mecanismo necessita ser aprimorado do ponto de vista das regras formais e mecanismos de enforcements, para o tema de aplicação dos recursos. Além disso, é possível inferir que as regras informais e a dinâmica regional devem ser observadas pois também possuem influência no sentido de promover o desenvolvimento dos territórios mesmo na ausência de regras formais efetivas / The comparative advantages of hydroelectric typology has been discussed in the literature regarding the gains of the affected localities. One of the legal mechanisms seen as local development promoter is the Financial Compensation (FC). The question that arises is if the CF is associated to the development of brazilian municipalities flooded by hydroelectric power plants. Using a Spearman correlation analysis the results show that, in 2000-2010 decade, there is a negative association between the amount paid by the CF and development variables for 600 municipalities flooded in Brazil in a national scale. In regional scale, only the North and Northeast region had positive associations. The CF is an important mechanism, which needs to be improved from the point of view of formal rules and enforcements. It is possible to infer that the informal rules and the regional dynamics can also influence development in the absence of effective formal rules.

The high ozone depletion and global warming potentials of fluorocarbon refrigerants have resulted in prohibitions and restrictions in many markets. Hydrocarbon refrigerants have low environmental impacts and are successfully used in domestic refrigerators and car air conditioners but replacing fluorocarbons in centrifugal chillers for air conditioning applications is unknown. Hydrocarbon replacements need a heat transfer correlation for refrigerant in flooded evaporators and predictions for operating conditions, capacity and performance. Safety precautions for large quantities of hydrocarbon refrigerants are needed and control of overpressure in plantrooms requires accurate prediction. Reliable correlations exist for forced convection in a single phase flow, condensation outside tubes and evaporation off sprayed tubes. For flooded evaporators this thesis proposes a new correlation for forced convection boiling of any refrigerant. An enhancement factor is combined with a modified Chen coefficient using recent pool boiling and forced convection correlations outside tubes. This correlates within typically a factor of two to known boiling literature measurements for CFC-113, CFC-11, HCFC-123, HFC-134a and HC-601. The operating conditions, capacity and performance of replacement hydrocarbons in centrifugal chillers were predicted using fluorocarbon performance as a model. With the new heat transfer correlation hydrocarbon predictions for flooded evaporators were made. For any fluorocarbon refrigerant there exists a replacement mixture of hydrocarbons which with a rotor speed increase about 40% gives the same cooling capacity in the same centrifugal chiller under the same operating conditions. For example replacing HCFC-123 in a flooded evaporator with HC-601/602 [90.4/9.6] and increasing the rotor speed by 43% will increase the coefficient of performance by 4.5% at the same cooling capacity. The maximum plantroom overpressure considered was from leakage and ignition of a uniform air/refrigerant mixture with maximum laminar burning velocity. Flow was modelled using a turbulence viscosity due to Launder and Spalding and turbulent deflagration using a reaction progress variable after Zimont. These partial differential equations were solved approximately for two and three dimensional geometries using finite volume methods from the Fluent program suite. Simple overpressure predictions from maximum flame area approximations agreed with Fluent results within 13.7% promising safe plantroom design without months of computer calculation.

Uranium mining activities have the potential to impact aquatic systems through mine drainage (runoff) and the release of treated effluent into nearby watersheds. Such anthropogenic exposure can lead to elevated concentrations of metals and major ions, which may impact aquatic biota. Previous studies have looked at the effects of water quality on aquatic biota within flooded pit lakes and natural lakes that have been exposed to various mechanisms of mining exposure. However, the literature often only examines the effects of a limited number of contaminants on a limited number of species. Researchers have rarely looked at the effects of multiple contaminants on species composition, biodiversity and ecosystem function in aquatic systems. This study uses a multivariate approach to look for relationships between water quality (24 variables), plankton species composition and abundance, biodiversity (richness and evenness) and ecosystem function among lakes exposed to mining activities (n = 18) and non-exposed reference lakes (n = 8). Lake water quality data was used to cluster lakes into groups. Lake groups were then overlain onto multivariate ordinations derived from species composition-abundance data to determine if species composition was related to water quality. Ecosystem function variables included planktonic phosphorus cycling and planktonic respiration. The classified lake groups clustered well on ordinations derived from species composition-abundance data suggesting that relationships exist between water quality and plankton species composition. However, ecosystem function was similar among the majority of lakes and flooded pits despite differences in species richness, species composition and species abundance. Only a small number of aquatic systems had ecosystem function properties that were different from the majority of lakes and pits. These systems had the greatest concentrations of contaminants and had very low biodiversity (richness and evenness) compared to the other systems. Despite having differences in plankton species composition and species richness, all lake groups were functionally similar. This suggests that functional redundancy in species composition may be present in the majority of lakes and pits in such a way that ecosystem function is maintained.

Uranium mining activities have the potential to impact aquatic systems through mine drainage (runoff) and the release of treated effluent into nearby watersheds. Such anthropogenic exposure can lead to elevated concentrations of metals and major ions, which may impact aquatic biota. Previous studies have looked at the effects of water quality on aquatic biota within flooded pit lakes and natural lakes that have been exposed to various mechanisms of mining exposure. However, the literature often only examines the effects of a limited number of contaminants on a limited number of species. Researchers have rarely looked at the effects of multiple contaminants on species composition, biodiversity and ecosystem function in aquatic systems. This study uses a multivariate approach to look for relationships between water quality (24 variables), plankton species composition and abundance, biodiversity (richness and evenness) and ecosystem function among lakes exposed to mining activities (n = 18) and non-exposed reference lakes (n = 8). Lake water quality data was used to cluster lakes into groups. Lake groups were then overlain onto multivariate ordinations derived from species composition-abundance data to determine if species composition was related to water quality. Ecosystem function variables included planktonic phosphorus cycling and planktonic respiration. The classified lake groups clustered well on ordinations derived from species composition-abundance data suggesting that relationships exist between water quality and plankton species composition. However, ecosystem function was similar among the majority of lakes and flooded pits despite differences in species richness, species composition and species abundance. Only a small number of aquatic systems had ecosystem function properties that were different from the majority of lakes and pits. These systems had the greatest concentrations of contaminants and had very low biodiversity (richness and evenness) compared to the other systems. Despite having differences in plankton species composition and species richness, all lake groups were functionally similar. This suggests that functional redundancy in species composition may be present in the majority of lakes and pits in such a way that ecosystem function is maintained.

SMULKIŲJŲ ŽINDUOLIŲ RŪŠINĖ SUDĖTIS IR MIGRACIJA NEMUNO DELTOS REGIONINIO PARKO UŽLIEJAMOSE PIEVOSE Agnė Janonytė Nemuno deltos regioninis parkas – vienintelis gamtinis kompleksas Lietuvoje ir visame Baltijos jūros regione, pasižymintis didele biotopų įvairove gana nedidelėje teritorijoje. Europinės svarbos buveinės – tai šiame parke esančios užliejamos pievos, turinčios unikalių biotos ir kraštovaizdžio elementų. Per Nemuno deltą eina Arktikos-Europos-Rytų Afrikos paukščių migracijos kelias, todėl didelė paukščių įvairovė patraukia ornitologų dėmesį, o smulkieji žinduoliai šiame regione mažai ištirti. Tyrimai buvo vykdomi nuo 2004 m. iki 2006 m. Rusnės saloje ir Žalgirių miške. Iš viso sugautas 621 individas, priklausantis 10 rūšių. Absoliutus dominantas buvo pelkinis pelėnas (M. oeconomus) kuris sudarė 55% visų individų. 2006 m. pelkinių pelėnų (M. oeconomus) bendras vados dydis buvo didesnis neužliejamose pievose – 6.20±0.38 (3–10) embrionai, palyginus su užliejamomis – 5.87±1.10 (2–11) embrionai. Jis priklausė nuo sezono. Pavasarį (gegužės mėn.) buvo didesnis užliejamose pievose, nei neužliejamose, atitinkamai: 10.0±1.0 ir 7.75±0.63 embrionai. Kiekvienais metais dalis Rusnės salos pievų užliejamos, o vandeniui atslūgus rekolonizuojamos. Rekolonizacija – laipsniškas procesas. Be to, smulkieji žinduoliai pasižymi skirtingomis šlapios pievos rekolonizacijos strategijomis. Pirmieji į šlapią pievą migruoja pelkiniai pelėnai (M. oeconomus) – tipiški drėgnų pievų gyventojai... [toliau žr. visą tekstą] / THE SPECIFIC STRUCTURE AND MIGRATION OF SMALL MAMMALS IN THE FLOODED MEADOWS OF THE NEMUNAS DELTA Agnė Janonytė The Nemunas Delta Regional Park (W. Lithuania) is characterized by exceptional habitat diversity. Flooded meadows on Rusnė Island border with non-flooded meadows and are separated by channels and dikes. Birds are well known in the area, as the site is enlisted as a habitat of the European importance and Ramsar site, but small mammals were scarcely investigated to date. Small mammals were trapped from June 2004 to October 2006. The total catch in both flooded and non-flooded meadows was 621 specimens. They belong to 10 species. The absolute dominant was root vole (M. oeconomus), with the share of 55% in the whole area. For the first time in Lithuania, the data on breeding of M. oeconomus were collected (32 cases). We found litter size differences according to the season and habitat. Totally, litter size of M. oeconomus in flooded meadows was 5.87±1.10 (2–11), while that in non-flooded meadows – 6.20±0.38 (3–10) embryo. In May, litter size was higher in flooded meadows – 10.0±1.0 vs. 7.75±0.63 embryo. Each year a part of the meadows is flooded and re-colonized. Migration is an inevitable process in small mammal ecology. Recolonization was found to be a progressive process, resulting in heterogeneous distribution of small mammals in the floodplain. From summer to autumn densities increased and specimens could be observed on larger distances from the non-flooded areas... [to full text]

The high ozone depletion and global warming potentials of fluorocarbon refrigerants have resulted in prohibitions and restrictions in many markets. Hydrocarbon refrigerants have low environmental impacts and are successfully used in domestic refrigerators and car air conditioners but replacing fluorocarbons in centrifugal chillers for air conditioning applications is unknown. Hydrocarbon replacements need a heat transfer correlation for refrigerant in flooded evaporators and predictions for operating conditions, capacity and performance. Safety precautions for large quantities of hydrocarbon refrigerants are needed and control of overpressure in plantrooms requires accurate prediction. Reliable correlations exist for forced convection in a single phase flow, condensation outside tubes and evaporation off sprayed tubes. For flooded evaporators this thesis proposes a new correlation for forced convection boiling of any refrigerant. An enhancement factor is combined with a modified Chen coefficient using recent pool boiling and forced convection correlations outside tubes. This correlates within typically a factor of two to known boiling literature measurements for CFC-113, CFC-11, HCFC-123, HFC-134a and HC-601. The operating conditions, capacity and performance of replacement hydrocarbons in centrifugal chillers were predicted using fluorocarbon performance as a model. With the new heat transfer correlation hydrocarbon predictions for flooded evaporators were made. For any fluorocarbon refrigerant there exists a replacement mixture of hydrocarbons which with a rotor speed increase about 40% gives the same cooling capacity in the same centrifugal chiller under the same operating conditions. For example replacing HCFC-123 in a flooded evaporator with HC-601/602 [90.4/9.6] and increasing the rotor speed by 43% will increase the coefficient of performance by 4.5% at the same cooling capacity. The maximum plantroom overpressure considered was from leakage and ignition of a uniform air/refrigerant mixture with maximum laminar burning velocity. Flow was modelled using a turbulence viscosity due to Launder and Spalding and turbulent deflagration using a reaction progress variable after Zimont. These partial differential equations were solved approximately for two and three dimensional geometries using finite volume methods from the Fluent program suite. Simple overpressure predictions from maximum flame area approximations agreed with Fluent results within 13.7% promising safe plantroom design without months of computer calculation.

This work consisted in the analysis of the off-line coupling of hydrological and hydraulic models from observed rainfall data and in the TRMM satellite precipitation intensity estimates in the Paraíba do Meio watershed (AL/PE), with the final objective the mapping of flooded areas and risk analysis of Atalaia-AL city, when considering the flood event occurred in 2010. The main computational programs used were: HEC-HMS in hydrological modeling and HEC-RAS in hydraulic modeling, in addition to their respective extensions integrated with ArcMap in the preprocessing stage, HEC-GeoHMS and HEC-GeoRAS. The results showed that the rainfall intensity data estimated by the TRMM satellite presented a good correlation with the rainfall data series, presenting values of 0.90 ("TRMM" x Postos) and 0.94 ("TRMM + Postos" x Postos). The hydrological model presented a good representation in relation to flood events in the Paraíba do Meio watershed, from data the flood occurred in 2000 and the flood of 2010. The validation of the model presented satisfactory results in the Atalaia post (39870000) in relation to the corrected satellite series ("TRMM + Postos"), evidencing with a Nash Sutcliffe coefficient - COE of 0.91. The hydraulic modeling was calibrated based on the Manning coefficient (n) adjustment for the banks and bottom of the channel, based on the ENGEMAP field markings and the peak flow recorded during the 2010 event by the fluviometric Atalaia post (39870000), already the model validation was done from the calibrated Manning coefficient (n) and the hydrograph generated in the hydrological simulation based on the corrected satellite series TRMM ("TRMM + Postos"). Thus, the mapping of the flooded areas made based on the 2010 flood data allowed a Risk Analysis in Atalaia city, based on the threat and vulnerability of the resident population in the riverine region to the occurrence of floods. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho consistiu na análise do acoplamento “off-line” de modelos hidrológico e hidráulico a partir de dados de precipitação observada e nas estimativas de intensidade de precipitação do satélite TRMM em relação à bacia hidrográfica do rio Paraíba do Meio (AL/PE), tendo como objetivo final o mapeamento das áreas inundáveis e análise de risco do município de Atalaia-AL, ao considerar o evento de cheia ocorrido em 2010. Os principais programas computacionais empregados foram: o HEC-HMS na modelagem hidrológica e o HEC-RAS na modelagem hidráulica, além de suas respectivas extensões integradas ao ArcMap na etapa do pré-processamento, HEC-GeoHMS e HEC-GeoRAS. Os resultados mostraram que as intensidades pluviométricas estimadas pelo satélite TRMM apresentaram boa correlação com a série de dados dos pluviômetros, com valores de 0,90 (“TRMM” x Postos) e de 0,94 (“TRMM+Postos” x Postos). O modelo hidrológico demonstrou uma boa representatividade em relação a eventos de cheia na bacia, a partir de dados da cheia ocorrida em 2000 e da cheia de 2010. A validação do modelo hidrológico demonstrou resultados satisfatórios no posto Atalaia (39870000) para a série corrigida do satélite (“TRMM+Postos”), exibindo um coeficiente de eficiência de Nash Sutcliffe – COE – de 0,91. A modelagem hidráulica teve sua calibração baseada no ajuste do coeficiente de Manning (n) para as margens e fundo do canal, com base nas marcas de cheia levantadas em campo pela ENGEMAP e pela vazão de pico registrada no posto Atalaia (39870000) durante o evento de 2010, já a validação do modelo partiu do coeficiente de Manning (n) calibrado e do hidrograma gerado na simulação hidrológica a partir da série corrigida do satélite TRMM (“TRMM+Postos”). Por fim, o mapeamento das áreas inundadas, permitiu uma Análise de Risco no município de Atalaia baseada na análise da vulnerabilidade social e das ameaças às quais a população residente às margens do rio está exposta diante da ocorrência de eventos de inundação.

A exploração de petróleo em alto mar traz consigo desafios crescentes com o aumento da lâmina d’água e do grau de agressividade dos contaminantes presentes no fluido produzido. Sendo a produção no País majoritariamente escoada do poço para as unidades de produção por dutos flexíveis, faz-se necessária a realização de estudos aprofundados da influência destas condições na vida em fadiga destes equipamentos. Tais condições quando associadas ao alagamento da região anular dos dutos flexíveis, pode favorecer a corrosão das armaduras de tração, responsáveis por conferir resistência axial ao duto. Este fato compromete a integridade da estrutura, levando a operação à uma condição não segura. Com o intuito de elevar o grau de conhecimento sobre estes mecanismos de degradação, o presente estudo tem por objetivo estabelecer uma relação entre os parâmetros construtivos e operacionais destes dutos, com o seu desempenho em campo frente a carregamentos cíclicos e na condição de anular alagado Para tal, tendo como base a literatura disponível no tema, foram selecionados parâmetros de estudo para, a partir destes, determinar fatores de redução de vida em fadiga (FRVFs). Estes fatores foram quantificados e estudados através de correlações numéricas e experimentais, sendo validadas através da realização de um ensaio em escala real de um duto flexível com anular alagado com água do mar sintética saturada com dióxido de carbono. Como resultados foram obtidos fatores de redução de vida em fadiga para as condições estudadas. Ainda, foi estabelecida uma metodologia para a determinação destes e sua utilização para o cálculo do dano acumulado de fadiga nestes dutos. / Offshore oil exploration involves growing challenges as water depth increases and aggressive oil contaminants are present in production fluid. As Brazilian production is conducted from the well to the production units mostly through flexible pipes, studies regarding the influence of this conditions on fatigue life of these structures are necessary. When the annulus is flooded with seawater the above conditions turns the environment corrosive for tensile armor wires, that are responsible to provide axial strength to the pipe. This fact compromises the integrity of the structure as a whole turning the operation unsafe. To increase the knowledge regarding these degradation mechanisms this study aims to stablish a relationship between constructive and operational parameters with field performance considering dynamic loadings and flooded annulus conditions. For such, using the literature data available it was selected some relevant parameters and from these it was determined fatigue life reduction factors (FRVFs). The FRVF was quantified and studied using numeric and experimental relations and validated through a full scale fatigue test in flooded annulus condition with synthetic seawater saturated with CO2. As a result, it was obtained the FRFV to explored conditions. Even more, it was stablished a methodology for its determination and applicability for calculation of cumulative fatigue damage in flexible pipes.

While in the traditional agricultural management soil attributes variability used in the crop production has not been considered, the site-specific management aims to identify this variability. The main objective of the present work was to compare the site-specific management to the traditional management in the flooded rice crop describing the techniques and identifying economical and technicals factors that provide a viability analysis. For this reason, an experiment was carried out in a commercial flooded rice field with application of site-specific management techniques. The methodology consisted in the elaboration of soil attributes, management and yield maps and the correlations among these maps were used to elaborate maps of fertilizers application variable rate. The results showed variability in the flooded rice yield. The higgest positive correlations between the rice yield and soil attributes were verified for calcium and magnesium and the higgest negative correlations were for exchangeable aluminum and aluminum saturation. The application of lime at variable rate reduced the total amount lime used when compared to the application at the fixed rate and increased the profit margin yield, providing profitability of 71% with the operation. The results showed the technical and economical viability of use site-specific management techniques in the flooded rice crop. / Enquanto que no gerenciamento agrícola tradicional a variabilidade de atributos de solo utilizados na produção vegetal não tem sido considerada, o manejo localizado visa identificar esta variabilidade. O presente trabalho objetivou comparar o manejo localizado com o manejo tradicional na cultura do arroz irrigado, descrevendo as técnicas e identificando fatores técnicos e econômicos que proporcionam uma análise de viabilidade. Por esta razão, foi conduzido um experimento em uma lavoura comercial de arroz irrigado com aplicação de técnicas de manejo localizado. A metodologia consistiu na elaboração de mapas de atributos de solo, manejo e produtividade da cultura e as correlações entre estes mapas foram utilizadas para elaborar mapas de aplicação de fertilizantes à taxa variável. Os resultados mostraram variabilidade na produtividade de arroz irrigado. As maiores correlações positivas entre produtividade de arroz e atributos de solo foram verificadas para cálcio e magnésio e as maiores correlações negativas para alumínio trocável e saturação por alumínio. A aplicação de calcário em taxa variável reduziu a quantidade de calcário necessária comparada à aplicação em taxa fixa e incrementou a margem líquida na produção, proporcionando uma lucratividade de 71% com a operação. Os resultados mostram viabilidade técnica e econômica para utilização das técnicas de manejo localizado na cultura do arroz irrigado.

Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-10Bitstream added on 2014-06-13T18:34:31Z : No. of bitstreams: 1 castro_cs_me_botfmvz.pdf: 574026 bytes, checksum: a3b5e4a6e9a6c9f9da758f541856b136 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Essa pesquisa teve por objetivo avaliar o efeito da frequência alimentar no desempenho produtivo da rã-touro (Lithobates catesbeianus) e determinar os coeficientes de disponibilidade de cálcio e fósforo e o coeficiente de digestibilidade da proteína da ração. Foram testadas três frequências de alimentação (6, 24 e 46 refeições/dia) em delineamento inteiramente casualizado com quatro repetições. Foram utilizadas rãs com peso médio de 70,59 ± 1,05 g, distribuídas em 12 baias de recria com piso alagado localizadas dentro de uma estufa. A ração foi fornecida por meio de alimentadores automáticos. Para determinação da digestibilidade da proteína e disponibilidade de cálcio e fósforo utilizou-se a sílica (SiO2) como marcador interno. O melhor crescimento foi observado com a maior frequência de alimentação aos 20, 40 e 60 dias. Ao final do experimento, as frequências de 6, 24 e 46 refeições/dia proporcionaram valores de conversão alimentar aparente de 2,31; 1,88 e 1,20, respectivamente. As diferentes frequências de alimentação não influenciaram na digestibilidade aparente da proteína e na disponibilidade aparente do cálcio e fósforo da ração fornecida para a rã-touro. Recomenda-se a alimentação de rã-touro em alta frequência (46 refeições/dia) / This study aimed to evaluate the effect of feeding frequency in the productive performance of bullfrogs (Lithobates catesbeianus) and to determine the availability coefficients of calcium and phosphorous and the digestibility coefficient of protein contained in diet. Three feeding frequencies were tested (6, 24 and 46 meals/day) in a randomized completely design, with four repetitions. Bullfrogs were used with mean weight of 70.59 ± 1.05 g, distributed in 12 frog production stalls with flooded floor. The diet was supplied through automatic feeders. For determination of protein digestibility contained in diet and calcium and phosphorous availability used the silica (SiO2) as internal marker. The best growth was obtained using the largest feeding frequency during 20, 40 and 60 days. At the end of the experiment, the frequencies of 6, 24 and 46 meals/day provided values of apparent feed conversion ranged from 2.31; 1.88 and 1.20, respectively. The different feeding frequencies didn't influence in the apparent digestibility of the protein and about the apparent availability of calcium and phosphorous contained in diet supplied for the bullfrogs. It is recommended high feeding frequency (46 meals/day) for the bullfrogs