The masonry still one of the widespread construction system for low-rise residential buildings even for countries prone to seismic risk. Seismic design methods yet in use are based on idea that controlling forces is better way to control earthquake induced damages. In recent decades, however, was highlighted as the differences in strength between two levels of damage is low, and therefore as the damage is better correlated to the displacement. Also, in recent years, has arose a widespread expectation for being able to control the damage based on the probability of occurrence of an earthquake or being able to base the design on different performance levels ("performance-based design"). In this context, the design of masonry buildings needs to develop these design methods. The results of experimental tests performed at the University of Padua in the recent years on different masonry systems both reinforced and unreinforced with different horizontal and vertical joints typologies, which were aimed to characterization under combined in-plane vertical and horizontal cyclic loading, were used to make different strategies of finite element modeling that reproduce and extend the experimental results using parametric analyses. These analyses allow a comparison and a validation of an analytical model which was then developed. This model is able to reproduce the envelope curves of the cyclic shear-compression tests and it is able to interpret the performances of panels linking them with limit states resulting from integration of cross-section equilibrium equations. Finally, it was applied a model able to reproduce the hysteretic behavior of masonry and were carried out dynamic analyses using the input data derived from the envelope curves. The data thus collected can be used as database and as input for displacement-based design methods.

Motivated by the potential vulnerability of their road infrastructure, many national authorities and local Departments of Transportation are incorporating seismic risk assessment in their management systems. This Dissertation aims to develop methods and tools for seismic risk analysis that can be used in a Bridge Management System (BMS); helping bridge owners to assess the costs of repair, retrofit and replacement of the bridges under their responsibility. More specifically, these tools are designed to offer estimates of: (1) the seismic risk to single components of bridges and their expected performance after an earthquake. (2) the impact a priori (i.e. before an earthquake) of a given earthquake on the operation of a road network, in terms of connectivity between different locations. (3) the damage a posteriori (i.e. after an earthquake) to road network operation, based on prior knowledge of network vulnerability and on the observed damage to a small number of single bridges. The effectiveness of these methods is tested and validated in a specific case study, the bridge stock of the Autonomous Province of Trento (APT) in Italy. To address the first point, I will first introduce the fragility curve method for risk assessment of individual bridges. The Hazus model is chosen as the most appropriate and is applied to the bridges of the APT stock. Once the fragility curves for all the bridges have been generated, a risk analysis is performed for three earthquake scenarios (with return periods of 72, 475 and 2475 years) and four condition states (operational, damage, life safety and collapse limit state). Next, I will extend the results of the component level analysis to the network level: the APT road network is modeled in the form of a graph and the problem of connectivity between two locations is analyzed. A shortest path algorithm is introduced and implemented to identify the best path between any two given places. Correlation in capacity and demand among bridges is not considered at this stage. After reiterating the fundamentals of probability theory, the theory of Bayesian Networks is introduced. The Bayesian Network approach is used to incorporate mutual correlation in capacity and demand, in risk assessment of a bridge stock. The concept is first formulated and illustrated on a simple case (the ‘twin bridge problem’), then extended to the general case of a full stock. I will show how the same framework can be used in post-earthquake assessment problems, where the evidence of the state of one or more bridges affects the prediction of the performance of another bridge. The outcomes and the limits of this work are discussed at the end of the Thesis.

Many studies and post-earthquake investigations have recognized that masonry infill walls play a major role in the seismic response of structures. Although their effect may be beneficial in some situations, the walls are also susceptible to high levels of damage, including collapse that can be life-threatening because of the heavy debris. Despite the critical importance of infill walls for life safety, infill walls are often neglected in numerical models and analyses implemented by designers because they are traditionally considered to be non-structural elements. Moreover, the majority of experimental studies and numerical models include only the in-plane behaviour of the panels: indeed, until recently, only sophisticated micro-models incorporated the out-of-plane response of unreinforced masonry infill walls. Recently, however, researchers have started to advance proposals for simplified macro-models that are capable of modelling in-plane/out-of-plane interaction, paving the way for the consideration of the associated issues in design practice. However, very few studies have applied these models to the dynamic seismic response history analysis of realistic structures. In this context, this thesis focuses on the numerical modelling of unreinforced masonry (URM) infill walls, with particular attention to the combined in-plane/out-of-plane response of panels in reinforced concrete (RC) frame buildings during seismic events. In the first part of this research, existing studies for URM masonry infill walls are reviewed, with an emphasis on the out-of-plane response of the panels. Significant experimental tests, modeling strategies and post-earthquake surveys are presented, stressing the parameters that influence the behaviour of the infills. An in-depth description is dedicated to the infill wall macro-model that is adopted for the analyses performed in this work, emphasizing its capabilities and limitations. This model consists of a single diagonal formed by two beam elements representing the wall; lumped modal mass is concentrated at the midpoint node of the diagonal. In-plane axial force and out-of-plane bending of the equivalent element interact by means of two fibre sections located adjacent to the central node. User defined domains limit axial/bending strengths and in-plane/out-of-plane ultimate displacements of the wall. When the response of an element exceeds these domains, the model simulates the collapse of this infill wall by removing it from the analysis. Next, the numerical model is calibrated in the OpenSees software framework by comparing existing experimental results with numerical outputs. The laboratory tests comprise in-plane cyclic and out-of-plane quasi-static results on 1-bay and 1-storey frame specimens with two different types of clay URM infill walls that are frequently found in Italian and other Mediterranean countries. The calibrated model is then applied to the static pushover analysis of a set of planar frames, while the wall elements are simultaneously loaded in both orthogonal directions. The nucleus of present study is the application of the calibrated model to the dynamic response history analysis of planar RC frames. Frame dimensions, number of stories, design and infill configurations are selected to be representative of the Italian building stock. Acceleration time histories consist of a suite of a bidirectional ground motions that are scaled to be compatible with Eurocode 8 elastic spectra. Cracking and collapse of the infill walls are monitored during the analysis. The infill walls reach their ultimate displacement capacity by a combination of in-plane and out-of-plane displacements, with the out-of-plane component usually playing the dominant role. The intensity of seismic load that is required to fail the infill walls, as well as the patterns of failure, are shown to be consistent with observed damage to URM infill walls in similar buildings during recent earthquakes. This research suggests that simplified macro-elements are suitable for design-oriented models of URM infill walls in RC framed structures, capturing the critical interaction between in-plane and out-of-plane response of the infill walls but without making the models excessively complex.

This thesis work aims to successively analyze and develop "ex novo" problems concerning the use of finite elements for the analysis of issues characterized by high plasticity, geometrical and material nonlinearity, large displacements and rotations; all combined with the effect of temperature on the material mechanical properties. The ultimate objective of the work is the analysis and development of nonlinear Finite Elements devoted to the modelling of steel structures at ambient and elevated temperature. Three different experiences will be analyzed in this elaborate; each of them characterised by specific issues that may be involved in the analysis via finite element method of steel structures at ambient and elevated temperature. At the same time innovative aspects that are related, for example, to the particular typology of the analyzed case study (first case) or in the methodology used in the treatment of the problem (second and third case) are investigated. The thesis structure chronologically retraces this path and the results and the experience gained from each of them were exploited to ultimately implement a thermomechanical finite element that is expression of all the tackled problems. The thesis consists of a collection of three papers that have been published or submitted on each of the investigated topics. In detail: - In the first paper, a commercial finite-element code, of the type "multipurpose", such as ANSYS has been used for the analysis of innovative cold-formed, laterallyrestrained steel rectangular hollow flange beams subjected to monotonic bending test. The numerical analysis has been carried out by means of the direct comparison with experimental tests on real scale specimens; that has allowed the detection of some phenomenological problems that have been included in the model calibration. From a numerical point of view, this work has at first allowed to deeply investigate the plastic problem by means, for example, the appropriate identification of the constitutive laws for the material, the correct choice of hardening law and yield surface, and their impact on the model. The local buckling problem typical of these profiles has been evaluated, through the use of shell elements. Furthermore, the effect of the global and local imperfections, which have been introduced in the model with different amplitudes, has been deeply investigated by evaluating their effect on the ultimate load. The calibration of the model finally allowed to perform a series of parametric analyses in order to extend the results to an extended range of profiles, characterized by different slenderness. - In the second paper, the thermal problem has been introduced with the support of a finite element software, designed specifically for thermomechanical analysis (SAFIR). The case study is, in this case, based on a multi-storey steel-concrete composite open car park subjected to localized fire of vehicles. With this study, not only the plastic problem has been analyzed but also phenomena such as the effect of high geometrical nonlinearity and large displacements on the structure in addition to the temperature effect on materials mechanical properties. The case study has been used to evaluate the assumptions and the issues that arise when developing an innovative integrated modelling methodology between a computational fluid dynamics (CFD) software applied to compartment fires and a finite element (FE) software applied to structural systems. Particular emphasis has been given to the weak coupling approach developed between the CFD code fire dynamics simulator (FDS) and the FE software SAFIR. - In the third and last paper all the experiences obtained from the previous works have been focused on the implementation, inside the MATLAB environment, of a thermomechanical beam finite element based on the co-rotational beam theory for the analysis of two-dimensional frames heated under high temperature and subjected to plastic deformation and to the effect of geometrical nonlinearity. The finite element is mainly aimed at the study of steel structures, with double-symmetrical profiles such as IPE or HE cross sections, and could then be used as a modelling tool for typical frames subjected to thermal actions. The element implements both Euler-Bernoulli and Timoshenko beam theories and can analyse slender to moderately stocky structures. A co-rotational formulation was used for describing the beam kinematic. The degradation of the steel mechanical properties at high temperature according to the Eurocode 1993-1-2 was considered by integrating the material constitutive law based on a predetermined temperature field in the cross section. An improved displacement predictor for estimating the displacement field at the beginning of each time step was successfully implemented and allowed to significantly decrease the computational time. Furthermore, advanced path-following methods that detect secondary equilibrium paths owing to instability occurrence were implemented in order to analyse the elasticplastic post-buckling behaviour of compressed steel elements at high temperature without the need of introducing geometrical imperfections. In order to show the potential of the developed finite element by highlighting the practical implications, a parametric analysis was performed to show whether the element could reproduce the EN1993-1-2 buckling curve. Validation against experimental and numerical data obtained with commercial software like ABAQUS and SAFIR is thoroughly shown in the paper.

The average age of strategic constructions in the Western world is becoming higher and higher. Many of these structures need inspection, maintenance or replacement, resulting in significant costs. The accurate estimate of structural condition can make operators optimize the allocation of resources. Nowadays, the progress of technology and machine learning has made structural health monitoring appealing to the agencies that manage important structures. This has encouraged the research community in the study of new structural health monitoring methods. In spite of this, the use of monitoring data is often disregarded by practitioners, who still prefer to gather more information and then act based on experience. Similarly, unlike the design of civil structures, the design of structural health monitoring systems is carried out based on heuristics rather than on rigorous evaluations of the expected monitoring system effectiveness. In this doctoral thesis, I apply expected utility theory for the development of decision support systems to be used in structural health monitoring and I develop a procedure for the design of structural health monitoring systems that follows the scheme of semi-probabilistic structural design. The use of monitoring data in a decision support system that implements expected utility theory financially optimizes the management of civil structures. The proposed monitoring system design method enables practitioners to design monitoring systems using their experience and guarantees that the installation of a monitoring solution is financially convenient. I present the mathematical formulation for monitoring-based decision support systems and monitoring system design. Then, I propose the numerical algorithms for the development of monitoring-based decision support systems and solutions for monitoring data analysis. Finally, the proposed methods are applied to three case studies, which enabled me to discuss the application in real life and the hypotheses. The applications show also the feasibility of the proposed approaches and test the numerical algorithms.

Ecosystem Services (ESs) are the goods and services supplied by ecosystems. In order to fully understand their contribution to human wellbeing, there is a need to identify them, assess their supply, recognise areas where they appear together repeatedly and analyse the interactions that may exist among them. Most of these tasks are also specifically required by the European Biodiversity Strategy for 2020, which asks Member States, by 2014, to identify key ESs and to spatially assess their supply and demand (European Commission, 2011). Nevertheless, these are difficult tasks and to date they have been only partly performed: existing studies in fact have typically focused on a small sub-set of ESs and made use of information that poorly reflects the actual variability of the ESs distribution across a region. The present research aims to fill these gaps, by developing methods involving a wide set of ESs and providing a detailed ESs assessment, based on spatial and statistical analyses. The methods have been tested on an Alpine region of Italy, Trentino. The Alps present a heterogeneous landscape, resulting from the combination of natural and urbanized environments, that allows the supply of a wide range of ESs. The research has four specific objectives. The first objective focuses on the selection and the representation over specific spatial units of the real supply of multiple ESs. Operatively, 51 experts from the local administrative offices and research institutes have been involved in the selection of the most important ESs and spatial indicators for the case study. The experts identified 25 ESs and 57 representative spatial indicators (1 to 5 indicators for each service), and provided data for indicators mapping. To consider the heterogeneity of the ESs supply across the region, indicators were mapped over 20 different spatial units, including: land cover classes, cadastral parcels, fishing zones and catchments.The second objective is to develop and test a statistical method for identifying key indicators that are spatially-explicit and able to measure the biophysical, socio-cultural and economic values of ESs (both in terms of stock and flow). Spearman pairwise correlation analysis was performed among the indicators of the same service in order to identify the highly correlated ones, hence deemed to provide redundant information. Key indicators were selected among the lowly correlated ones. 35 indicators were selected for the case study (out of the 57 initial indicators). The analysis showed that there is a minimum number of key indicators for each ES. Accordingly, three general rules were identified for the selection: (i) if the supply of an ES is regulated, both its biophysical-stock and biophysical-flow indicators must be selected, (ii) if multiple stock (flow) biophysical indicators for a single ES are mapped over different spatial units, all stock (flow) indicators must be maintained, (iii) socio-cultural or economic indicators are always selected as key indicators. The third objective is to develop and test a statistical method for defining bundles of ESs, as sets of spatially correlated services. Principal Component Analysis was used to summarize the information of the 35 indicators, while hierarchical clustering was applied to identify 11 ESs clusters. Clusters were turned into bundles by analyzing the spatial variability of the services due to biophysical (e.g. morphological conditions) and human (e.g. land use) factors. The results of the analysis show that in Trentino multiple ESs can be grouped in a few number of bundles with a complex shape. In particular, areas with poor ESs supply are grouped in one single bundle and the largest bundle follows the spatial distribution of a single land cover class: i.e. forest.The fourth objective is to develop a method to study interactions among ESs, by combining statistical and spatial analyses. In fact, the supply of a given ES is correlated with the supply of other ESs and it is affected by multiple external factors. Correlations may be positive when an increase in the supply of one service corresponds to higher supplies of other services (i.e. synergies), or negative when an increase in the supply of one service corresponds to lower supplies of other services (i.e. tradeoffs). The degree of interactions among 35 key indicators is determined by performing a Spearman pairwise correlation analysis. The latter enabled to identify six patterns of ESs interactions, one pattern of tradeoffs and five of synergies. The analysis showed that the local land use management has not compromised the capacity of ecosystems to provide regulating services while supplying the provisioning ones. The external factors causing the variability of the services across the region were identified and explained by means of spatial and Spearman correlation analyses among the ESs principal components. Principal components were turned into drivers of change by analyzing the spatial variability of the ESs due to biophysical (e.g. forest density) and human (e.g. land use) factors. Land use management was found as the external factor that causes the greatest variability of the ESs distribution across the region. Within forest areas, forest management activities that involve loss of vegetation were found as the main drivers of ESs change. This research aimed to consider a wide set of ESs and information able to reflect the actual variability of the services distribution across a region. It proposed a scientifically sound methodology to deal with the main issues of the ESs spatial assessment, that may reveal efficiently applicable in other geographical areas where ESs are heterogeneously supplied.

Industrial process plants and power plants are crucial components of modern infrastructures, playing a pivotal role in sustaining communities through the provision of essential goods and services. These facilities contain critical equipment and structures vulnerable to damage or failure when exposed to seismic excitations without protection measures. Robust seismic protection ensures the preservation of structural integrity and functionality, guaranteeing the uninterrupted delivery of vital services like electricity generation, water treatment, and manufacturing. Consequently, seismic protection measures for these plants enhance overall community resilience and safety, mitigating potential disruptions and harm in the face of earthquakes. Based on these insights, a novel seismic protection system, known as metafoundation (MF), is revisited and enhanced. Geared towards offering cost-effective, modular, and multidirectional protection to critical infrastructure components, the investigation delves into the exploration and implementation of novel nonlinearities and mechanisms to finite locally resonant MFs in order to obtain further improvements. The thesis commences by elucidating the principles of periodic lattices and lattice-based acoustic metamaterials, the foundational concept of finite locally resonant MFs, using both analytical and numerical met-hodologies, followed by some experimental validation. Theoretical exploration encompasses one-dimensional linear and nonlinear metamaterials featuring local resonance properties, via resonators. By incorporating nonlinear mechanisms, such as the Bouc-Wen and Duffing oscillators, the study delves into unique nonlinear wave dynamics and evolving dispersion characteristics. Notably, the focus intensifies on bistable Duffing oscillators as the primary cell spring, and the reliability of numerical simulations is confirmed through experimental validation. Transitioning from theoretical frameworks to practical applications, the finite lattices has been analysed. The effectiveness of MFs under seismic loading relies significantly on the seismic input. Consequently, both natural and synthetic three-directional accelerograms — where the former were generated through a physics-based ground motion model — were utilized for performance assessment and, crucially, for optimization purposes. The inherent locally resonant property of MFs necessitates careful tuning of resonator parameters, as mistuning can lead to notable performance degradation. Optimization strategies encompassed frequency domain and time domain approaches for linear and nonlinear MFs, respectively. In the frequency domain, the Power Spectrum Density (PSD) functions of ground motions were considered alongside the transfer function of MF-superstructure coupled systems to quantify responses. The optimization was achieved through solving the multi-variable, multiobjective optimization problem, facilitated by a specialized algorithm based on sensitivity analysis. In the time domain, conversely, optimization focused on energy dissipation through time history analyses. To streamline computational efficiency, experimental design methods and Kriging models were employed. The pursuit of enhanced performance and novelty, required intricate nonlinear mechanisms in conjunction with MFs to be considered. The columns of MF were substituted with bistable ones. In another application instead, to enhance vertical seismic protection, unit cells featuring vertical quasi-zero-stiffness mechanisms were interconnected in series with locally resonant unit cells. Moreover, to improve performance and minimize MFs’ voluminous size —needed for low-frequency attenuation — the incorporation of novel inerters to resonators was considered. The implemented strategies based on 3D modelled MFs, were applied to a storage tank of a process plant and two in-design stage Small Modular Reactor (SMR) buildings. Detailed time history analyses revealed that MFs can effectively meet targeted performance objectives of the coupled systems. This includes achieving performance levels comparable to conventional isolation solutions for horizontal seismic excitation, while also safeguarding the superstructure against vertical actions and resultant rocking motions. Finally, it was shown that MFs offer a viable solution aligned with the primary development objective of SMRs, facilitating modular standardization for deployment in beyond-design earthquake locations without additional resistance of the superstructure.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Arquitetura e Urbanismo, Florianópolis, 2010 / Made available in DSpace on 2012-10-25T03:58:56Z (GMT). No. of bitstreams: 1 288600.pdf: 5581071 bytes, checksum: f92c8313a885b5c980479451f674c164 (MD5) / Esta pesquisa apresenta um estudo de caso sobre as técnicas de intervenção aplicadas nas esquadrias de madeira e nos revestimentos argamassados da fachada principal de três edificações históricas erigidas no final do séc. XIX e início do XX, no estado do Paraná, sob o enfoque tecnológico e dos critérios de conservação patrimoniais: Paço Municipal e Palacete Leão Júnior em Curitiba e Alfândega do Porto, em Paranaguá. O estudo desenvolvido visa identificar os principais fenômenos patológicos presentes antes da última intervenção ocorrida em cada edificação, suas principais causas e técnicas utilizadas no seu tratamento, efetivando-se análises: de conformidade com os princípios das Cartas Patrimoniais e de durabilidade obtida com o emprego de cada uma das técnicas de intervenção. Serão comparadas as análises de conformidade e de durabilidade em relação aos resultados obtidos pelas técnicas empregadas verificando-se, também, a correlação entre o uso dos critérios das Cartas Patrimoniais e de técnicas adequadas com a durabilidade e sua contribuição para a preservação da edificação histórica. Por meio do aprendizado decorrente desta pesquisa serão elaboradas algumas instruções e recomendações com o intuito de prevenir a deterioração das esquadrias de madeira e revestimentos argamassados da fachada das construções analisadas e de outras com materiais e período arquitetônico semelhantes aos estudados neste trabalho. / This research presents a case study on the architectural intervention techniques applied to the wooden frames and the mortar covering/coating of the main facade of three historic buildings erected in the late nineteenth and early twentieth centuries, in Paraná, according to the technology standpoint and the heritage conservation policy/criteria. In the state capital are going to be analyzed the buildings of the Paço Municipal and the Palacete Leão Júnior, and in Paranaguá, the Alfândega do Porto. The aim of this study is to identify the main pathological phenomena present before the last intervention carried out in each building, its main causes, and techniques used in their treatment. Also, the aim is to analyze if these techniques are in accordance with the principles established in the International Charters for the Conservation and Restoration of Monuments and the durability achieved through the use of these intervention techniques. The analysis are going to be compared according to the results obtained by the techniques applied, verifying the correlation between the use of the criteria in the International Charters for the Conservation and Restoration of Monuments and of techniques appropriate with the durability and its contribution to the preservation of the historic building. Through the learning arising from this research some guidelines and recommendations are going to be developed, in order to prevent the deterioration of the wooden frames and the mortar covering/coating of the facades analyzed, and also, of other facades with materials and architectural period similar to those studied in this research.

[pt] A tentativa é a de pensar verdade e ética no pensamento de Heidegger. A partir daí, defendemos a existência de um traço ético estrutural em toda a obra do pensador, assim como de uma investigação ética específica que pode ser encontrada em seus textos sobre o habitar. Estes, por sua vez, devem ser lidos em conjunto com os textos sobre a questão da técnica. Assim, o que a dissertação pretende estabelecer é a existência de uma preocupação ética no centro da obra heideggeriana. / [en] The attempt is to think truth and ethics in Heidegger´s thought. Starting from there, we defend the existence of a structural ethical trace in all of Heidegger´s work, as of a specific ethical investigation that can be found in his texts on dwelling. These, on their turn, must be read together with his texts about the question of tecnology. Therefore, what this work seizes to establish is the existence of an ethical concern in the centern of Heidegger´s work.

Orientador: Carlos Augusto Araujo Valadão / Banca: Valentim Arabicano Gheller / Banca: Joaquim Mansano Garcia / Banca: Renata Gebara Sampaio Dória / Banca: Paulo Aléscio Canola / Resumo: As técnicas de fertilização in vitro e transferência de embrião são amplamente utilizadas como multiplicadores genéticos em fêmeas de alto valor zootécnico. Para sua realização é mandatório o uso de anestesia epidural, porém sabe-se que a punção repetida do espaço epidural pode causar alterações inflamatórias e fibrose do canal, aos quais reduzem a eficácia da técnica. Objetivou-se, por meio deste estudo desenvolver uma técnica cirúrgica de implantação de cateter epidural com portal de acesso subcutâneo e avaliar a patência deste dispositivo para a realização de aspiração folicular em vacas, por um período de 510 dias. Para a realização deste estudo foram utilizadas doze vacas, com idade entre 3-5 anos e peso entre 308-518 kg, que foram alocadas em dois grupos, grupo A, animais da raça Nelore e B animais da raça Holandesa. Após contenção em tronco, foi realizada sedação com 0,04 mg/kg de acepromazina 1% associada a 0,01 mg/kg de xilazina 2% pela via intramuscular e bloqueio anestésico local da região sacrococcígea e sacral direita. Procedeu-se uma incisão de pele semicircular de dez centímetros (incisão-I), abrangendo o espaço sacrococcígeo e intercoccígeo. Após divulsão da tela subcutânea, a pele foi rebatida lateralmente. Através de uma agulha de Tuohy (16G) posicionada na articulação sacrococcígea ou intercoccígea, introduziu-se dez centímetros do cateter (17G) em sentido cranial, no canal epidural. Procedeu-se uma segunda incisão (incisão-II), de quatro centímetros, no te... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In vitro fertilization and embryo transfer are often used as genetic multipliers in cows of high zootechnical value. Epidural anesthesia is mandatory preceding these procedures, but repeated puncture of the epidural space may cause inflammation and fibrosis, which reduce the effectiveness of the technique in time. The objective of this study was to describe a surgical technique for implantation of an epidural catheter with subcutaneous access portal, and to evaluate the patency this device during eight follicular aspiration cycles in cows. Twelve cows, aged between 3-5 years, weighting 308-518 kg were used in this study. They were allocated in two groups, (A) Nellore and (B) Holstein. Following physical retrain in a hydraulic stock and sedation with 0.04 mg/kg of acepromazine 1% associated with 0.01 mg/Kg of xylazine 2%, administered intramuscularly, local anesthetic block of the sacrococcygeal and right sacral region was made. Then, a 10-cm semicircular followed by skin incision (I-incision), was performed over the sacrococcygeal space, after divulsion of the subcutaneous tissue. Through a Tuohy needle (16G) positioned within the sacrococcygeal joint, ten centimeters of the catheter (17G) were cranially inserted in the epidural space. A second incision (incision-II), four centimeters long, was made at the middle third of the right sacral region. The epidural catheter was transposed from the I-incision to the II-incision through the subcutaneous by using a metallic guide, and... (Complete abstract click electronic access below) / Doutor