Desenvolvimento de um ambiente para projeto de controladores fuzzy para dispositivos móveis

Fuzzy intelligent systems are present in a variety of equipment ranging from household appliances to Fuzzy intelligent systems are present in a variety of equipment ranging from household appliances to small devices such as digital cameras and cell phones being used primarily for dealing with the uncertainties in the modeling of real systems. However, commercial implementations of Fuzzy systems are not general purpose and do not have portability to different hardware platforms. Thinking about these issues this work presents the implementation of an open source development environment that consists of a desktop system capable of generate Graphically a general purpose Fuzzy controller and export these parameters for an embedded system with a Fuzzy controller written in Java Platform Micro Edition To (J2ME), whose modular design makes it portable to any mobile device that supports J2ME. Thus, the proposed development platform is capable of generating all the parameters of a Fuzzy controller and export it in XML file, and the code responsible for the control logic that is embedded in the mobile device is able to read this file and start the controller. All the parameters of a Fuzzy controller are configurable using the desktop system, since the membership functions and rule base, even the universe of discourse of the linguistic terms of output variables. This system generates Fuzzy controllers for the interpolation model of Takagi-Sugeno. As the validation process and testing of the proposed solution the Fuzzy controller was embedded on the mobile device Sun SPOT ® and used to control a plant-level Quanser®, and to compare the Fuzzy controller generated by the system with other types of controllers was implemented and embedded in sun spot a PID controller to control the same level plant of Quanser®

Método dinâmico aplicado para antenas cilíndricas

Nowadays there has been a major breakthrough in the aerospace area, with regard to rocket launches to research, experiments, telemetry system, remote sensing, radar system (tracking and monitoring), satellite communications system and insertion of satellites in orbit. This work aims at the application of a circular cylindrical microstrip antenna, ring type, and other cylindrical rectangular in structure of a rocket or missile to obtain telemetry data, operating in the range of 2 to 4 GHz, in S-band. Throughout this was developed just the theoretical analysis of the Transverse transmission line method which is a method of rigorous analysis in spectral domain, for use in rockets and missiles. This analyzes the spread in the direction "ρ" , transverse to dielectric interfaces "z" and "φ", for cylindrical coordinates, thus taking the general equations of electromagnetic fields in function of e [1]. It is worth mentioning that in order to obtain results, simulations and analysis of the structure under study was used HFSS program (High Frequency Structural Simulator) that uses the finite element method. With the theory developed computational resources were used to obtain the numerical calculations, using Fortran Power Station, Scilab and Wolfram Mathematica ®. The prototype was built using, as a substrate, the ULTRALAM ® 3850, of Rogers Corporation, and an aluminum plate as a cylindrical structure used to support. The agreement between the measured and simulated results validate the established processes. Conclusions and suggestions are presented for continuing this work

Ambiente de desenvolvimentoweb multiplataforma configurável para robótica educacional

We propose an online configurable multiplatform development environment specifically developed for educational robotics applications. The environment, which appears as an extension of RoboEduc software, allows the programming of several programmable robots to be performed using the R-Educ language. We make it possible for the user to program in the language R-Educ and then translate the code to a language previously registered, compiled and then sent or executed by the robot. To develop this work, we conducted a bibliographic research about the main programming languages used in robotics, as well as their definitions and paradigms, from which it was possible to define a set of patterns considered important for the creation of this environment. Then, in the software development phase, we implemented the development environment, bearing in mind the requirements and functionality defined in the design phase. Finally, to validate the platform, we conducted some trials of programming languages and verificate if the complete cycle was satisfied - registration of language, programming in R-Educ, compilation for the registered language, compilation to the machine code and send the code for the robot

Análise tribológica de um sistema de acionamento alternativo de pigs para a indústria do petróleo

It is analyzed through the concepts of tribology and mechanical contact and damage the suggestion of implementing a backup system for traction and passage of Pipeline Inspection Gauge (Pig) from the inside of pipelines. In order to verify the integrity of the pipelines, it is suggested the possibility of displacement of such equipment by pulling wires with steel wires. The physical and mechanical characteristics of this method were verified by accelerated tests in the laboratory in a tribological pair, wire versus a curve 90. It also considered the main mechanisms of wear of a sliding system with and without lubricant, in the absence and presence of contaminants. To try this, It was constructed a test bench able to reproduce a slip system, work on mode back-and-forth ("reciprocation"). It was used two kinds of wires, a galvanized steel and other stainless steel and the results achieved using the two kinds of steel cables were compared. For result comparative means, it was used steel cables with and without coating of Poly Vinyl Chloride (PVC). The wires and the curves of the products were characterized using metallographic analysis, microhardness Vickers tests, X-ray diffraction (XRD), X-Ray Refraction (XRF) and tensile tests. After the experiments were analyzed some parameters that have been measurable, it demonstrates to the impracticality of this proposed method, since the friction force and the concept of alternating request at the contact between the strands of wire and the inner curves that are part ducts caused severe wear. These types of wear are likely to cause possible failures in future products and cause fluid leaks

Performance comparativa entre R290/R600a (50:50) e R134a para drop-in em refrigerador doméstico

This research this based on the seminar on Use of Natural Fluids in Refrigeration and Air-Conditioning Systems conducted in 2007 in Sao Paulo. The event was inserted in the National Plan for Elimination of CFCs, coordinated by the Ministry of Environment and implemented by the United Nations Development Programme (UNDP). The objective of this research is analyze the performance of the hydrocarbons application as zeotropic mixtures in domestic refrigerator and validate the application of technical standards for pull down and cycling (on-off) tests to the mixture R290/R600a (50:50) in domestic refrigerator. It was first developed an computational analysis of R290/R600a (50:50) compared to R134a and other mass fractions of the hydrocarbons mixtures in the standard ASHRAE refrigeration cycle in order to compare the operational characteristics and thermodynamic properties of fluids based on the software REFPROP 6.0. The characteristics of the Lorenz cycle is presented as an application directed to zeotropic mixtures. Standardized pull down and cycling (on-off) tests were conducted to evaluate the performance of the hydrocarbons mixture R290/R600a (50:50) as a drop-in alternative to R134a in domestic refrigerator of 219 L. The results showed that the use of R290/R600a (50:50) with a charge of refrigerant reduced at 53% compared to R134a presents reduced energy performance than R134a. The COP obtained with hydrocarbon mixture was about 13% lower compared to R134a. Pull down times in the refrigerator compartments for fluids analyzed were quite close, having been found a 4,7% reduction in pull down time for the R290/R600a compared to R134a, in the freezer compartment. The data indicated a higher consumption of electric current from the refrigerator when operating with the R290/R600a. The values were higher than about 3% compared to R134a. The charge of 40 g of R290/R600a proved very low for the equipment analyzed

Análise de desempenho de um refrigerador de pequeno porte com drop in de refrigerantes hidrocarbonetos

From what was stated in the Montreal Protocol, the researchers and refrigeration industry seek substitutes for synthetic refrigerants -chlorofluorocarbons (CFCs) and HCFCs (HCFC) - that contribute to the depletion of the ozone layer. The phase-out of these substances was started using as one of the replacement alternatives the synthetic fluids based on hydro fluorocarbons (HFCs) that have zero potential depletion of the ozone layer. However, contribute to the process of global warming. HFC refrigerants are greenhouse gases and are part of the group of gases whose emissions must be reduced as the Kyoto Protocol says. The hydrocarbons (HC's), for not contribute to the depletion of the ozone layer, because they have very low global warming potential, and are found abundantly in nature, has been presented as an alternative, and therefore, are being used in new home refrigeration equipment in several countries. In Brazil, due to incipient production of domestic refrigerators using HC's, the transition refrigerants remain on the scene for some years. This dissertation deals with an experimental evaluation of the conduct of a drinking fountain designed to work with HFC (R-134a), operating with a mixture of HC's or isobutane (R-600a) without any modification to the system or the lubricating oil. In the refrigeration laboratory of Federal University of Rio Grande do Norte were installed, in a drinking fountain, temperature and pressure sensors at strategic points in the refrigeration cycle, connected to an acquisition system of computerized data, to enable the mapping and thermodynamics analysis of the device operating with R-134a or with a mixture of HC's or with R-600a. The refrigerator-test operating with the natural fluids (mixture of HC's or R-600a) had a coefficient of performance (COP) lower than the R-134a

Remoção de hidrocarbonetos do gás natural visando o ajuste do índice de metano

The use of the natural gas is growing year after year in the whole world and also in Brazil. It is verified that in the last five years the profile of natural gas consumption reached a great advance and investments had been carried through in this area. In the oil industry, the use of the natural gas for fuel in the drive of engines is usual for a long date. It is also used to put into motion equipment, or still, to generate electric power. Such engines are based on the motor cycle of combustion Otto, who requires a natural gas with well definite specification, conferring characteristic anti-detonating necessary to the equipment performance for projects based on this cycle. In this work, process routes and thermodynamic conditions had been selected and evaluated. Based on simulation assays carried out in commercial simulators the content of the methane index of the effluent gas were evaluated at various ranges of pressure, temperature, flowrate, molecular weight and chemical nature and composition of the absorbent. As final result, it was established a route based on process efficiency, optimized consumption of energy and absorbent. Thereby, it serves as base for the compact equipment conception to be used in locu into the industry for the removal of hydrocarbon from the natural gas produced

Modelagem e simulação de um separador bifásico com inversão de fases induzida

The present work has the main goal to study the modeling and simulation of a biphasic separator with induced phase inversion, the MDIF, with the utilization of the finite differences method for the resolution of the partial differencial equations which describe the transport of contaminant s mass fraction inside the equipment s settling chamber. With this aim, was developed the deterministic differential model AMADDA, wich was admensionalizated and then semidiscretizated with the method of lines. The integration of the resultant system of ordinary differential equations was realized by means of a modified algorithm of the Adam-Bashfort- Moulton method, and the sthocastic optimization routine of Basin-Hopping was used in the model s parameter estimation procedure . With the aim to establish a comparative referential for the results obtained with the model AMADDA, were used experimental data presented in previous works of the MDIF s research group. The experimental data and those obtained with the model was assessed regarding its normality by means of the Shapiro-Wilk s test, and validated against the experimental results with the Student s t test and the Kruskal-Wallis s test, depending on the result. The results showed satisfactory performance of the model AMADDA in the evaluation of the MDIF s separation efficiency, being possible to determinate that at 1% significance level the calculated results are equivalent to those determinated experimentally in the reference works

Viabilidade técnica de uma rota não convencional para a produção de leite de cabra em pó em cooperativas do Rio Grande do Norte

Nowadays, Brazil has both the greatest goat herd and the greatest goat milk production of South America. The state of Rio Grande do Norte, located in northeast of Brazil, has an average year production of three thousand cubic meters of goat milk in natura. Part of this milk production is homemade and it comes from small farms, which unite in rural cooperatives created to encourage the production and implementation of industrial processes for preservation and processing of milk. Results presented by literature and obtained from preliminary essays in this thesis show that non conventional dryer of spouted bed with inert particles is able to produce powder milk from in natura milk (cattle or goat), with the same quality of spray dryer, however, operating at low cost. The method of drying in spouted bed consists of injecting milk emulsion on the bed of inert particles gushed by hot air. This emulsion covers the particles with a thin film, which dries and is reduced to powder during the circulation of inerts inside the bed. The powder is dragged by exhaustion air and separated in the cyclone. The friction among particles resulted from the particles circulation, encourages high taxes of shear in the thin film of emulsion, breaking the cohesive forces and making this process possible. Studying the drying process and the powder goat milk production in one unit of spouted bed with inert particles, seeing the development of a low cost technological route for powder milk production is the aim of this thesis. The powder milk produced by this route must attend the local demand of food industries which need an intermediate product to be used as a food ingredient (ice-cream, milk candy). In order to reach this aim, this thesis approaches the aspects related to physical, thermodynamics and physic-chemicals characteristics of goat milk, whose complete data are still inexistent in the literature. The properties of materials are of great importance to the project of any process which involves the operations of transportation of movement, heat and mass quantity, such as the dryers which operate in fluid dynamically active regime, like the spouted bed. It was obtained new data related to the goat milk properties in function of concentration of solids and temperature. It is also important to mention the study developed about the kinetic of solids retention in the bed of inert particles during the drying of goat milk. It was found more adequate processes conditions to the proposed technological route to be implemented in small and micro-industries, with simplifications in the system of milk injection as well as in the form of operation of the dryer. Important data were obtained for a posterior stage of this research which involves the v modeling, simulation, control and optimization of the process. The results obtained in this thesis, in relation to process performance as well as to the quality of produced powder milk validate the proposal of using the spouted bed dryer in the production of powder goat milk

Concepção e estudo de um biofiltro para tratamento de compostos orgânicos voláteis COVs

In the last decade, biological purification of gaseous waste has become an important alternative to many conventional methods of exhaust air treatment. More recently, biofiltration has proved to be an effective and inexpensive method for the treatment of air contaminated with volatile organic compounds (VOCs). A biofilter consists in a reactor packed with a porous solid bed material, where the microorganisms are fixed. During the biofiltration process, polluted air is transported through the biofilter medium where the contaminant is degraded. Within the biofilm, the pollutants in the waste gases are energy and carbon sources for microbial metabolism and are transformed into CO2, water and biomass. The bed material should be characterized by satisfactory mechanical and physical properties as structure, void fraction, specific area and flow resistance. The aim of this research was the biofilter construction and study of the biological degradation of ethanol and toluene, as well as the modeling of the process. Luffa cylindrica is a brazilian fiber that was used as the filtering material of the present work. The parameters and conditions studied were: composition of nutrients solution; effect of microflorae strains, namely Pseudomanas putida and Rhodococcus rhodochrous; waste gas composition; air flow rate; and inlet load of VOCs. The biofilter operated in diffusion regime and the best results for remotion capacity were obtained when a microorganisms consortion of Pseudomanas putida and Rhodococcus rhodochrous,were used, with a gas flow rate of 1 m3.h-1 and molar ratio nitrogene/phosphore N/P=2 in the nutrients solution. The maximum remotion capacity for ethanol was around 90 g.m-3.h-1 and 50 g.m-3.h-1 to toluene. It was proved that toluene has inhibitory effect on the ethanol remotion When the two VOCs were present in the same waste gas, there was a decrease of 40% in ethanol remotion capacity. Luffa cylindrica does not present considerable pressure drop. Ottengraf and van Lith models were used to represent the results obtained for ethanol and toluene, respectively. The application of the transient model indicated a satisfactory approximation between the experimental results obtained for ethanol and toluene vapors biofiltration and the ones predicted it

A natureza como símbolo do Narcisismo Noailliano

Dans ce travail de recherche nous nous proposons d étudier l oeuvre d Anna de Noailles, poétesse et romancière française qui a publié ses premières poésies à la fin du XIXème siècle. Notre corpus est constitué de trois poèmes du recueil L Ombre des Jours, publié en 1902, à savoir : Jeunesse, Le Répit et Renaissance. Initialement, nous avons traité la mise en contexte sociale et culturelle de la fin du XIXème et du début du XXème siècle. Ensuite, nous avons abordé l espace interne de l oeuvre noaillienne qui se manifeste à travers des paysages de la nature. Nous avons remarqué que dans celle-ci, il y a une identification avec le moi lyrique. Enfin, nous avons analysé les trois poèmes de notre corpus. Nous soulignons que le manque de critiques et de recherche sur l oeuvre noailliene en France et l absence de recherche sur la poétesse dans le milieu académique brésilien nous ont motivée à réaliser cette étude. Ce travail a comme objectif mettre en évidence la richesse de la poétique d Anna de Noailles. Dans notre étude sur l oeuvre l ombre des jours, nous nous sommes apperçue que l auteur possède son propre style, elle ne cherchait pas à imiter un modèle littéraire particulier à ses contemporains. Dans son esthétique, nous avons remarqué le refuge dans la nature, dans le passé et aussi une forte évocation sensorielle. L univers lyrique de l oeuvre noaillienne est representé à travers des paysages bucoliques qui évoquent des saisons. Malgré ce retour à la nature, nous avons découvert des éléments que caractérisent la poésie moderne, comme la luminosité, la quête de l expansion, la superposition des images, entre autres. L espace de l ombre des jours est grandiloquent, la poétesse mentionne fréquemment son désir d expansion et pour cette raison, nous trouvons dans les poèmes des lieux ouverts, où le contact direct avec la lumière, l air et l eau devient possible. Dans l Ombre des Jours, il est rare qu une référence à un lieu clos soit traitée; si la poétesse le fait, c est pour exprimer la suspension de la passion

A constituição de identidades de mulheres : práticas discursivas e relações de poder

This research investigates the discursive constitution of identities; in spe-cial, it aim to problematize women identities constitution, pointing discursive prac-tices and power relations which involve them. The interviewed subjects had been adult women who had resumed their school trajectory, after certain period without frequenting educational establishments. Aware of that those identities can be per-ceived through the observations of the discursive practices, we question: which discursive practices and power relations involve and constitute those women? Which identity positionings they take through the discursive practices and power relations that include them and that are identified in their stories? Which linguistic marks characterize, in the speech of those women, forms of resistance in the con-stitution of identities? We intend to investigate the constitution of woman identities in the contemporanity; pointing discursive practices and power relations which in-volve women that converge to their identity constitution; exploring in the linguistic materiality effects of senses that emanate of the discursive practices and power relations which involve the collaborators in the identity constitution in private and public spaces. Research corpus is composed by stories of life granted by three women, collected through semidirected interview between 2004 and 2005. To ana-lyze the data, we base in authors as Pêcheux (1993; 2002), Foucault (1979; 1988; etc.), Butler (2003), Scott (1992; 1995), Hall (2000; 2004; 2005), Bauman (1999; 2005), among others that problematize questions as discourse, identity, social gender, power and its interfaces. The life stories had allowed to analyze: the gen-der identity constitution from discursive practices and relations of forces lived in the familiar scenery; assumed identity positionings from discursive practices in globalized urban contexts; power positions in the domestic and extradomestic sphere and new identity positionings

O Macrogênero drama Norte-Riograndense: uma análise de gênero e de discurso sob a perspectiva da linguística sistêmico-funcional

The focus of this qualiquantitative research is the phenomenon we are denominating Drama-of-Rio-Grande-do-Norte, which contemplates short verse texts from the oral tradition, sung and presented on stage by women in communities on the south coast of the northeastern Brazilian State, Rio Grande do Norte. This tradition harkens to the medieval romance of the Iberian Peninsula (CASCUDO, 2001; GURGEL, 1999; GALVÃO, 1993; MAGALHÃES, 1973; ROMERO,1977). The objective of this research is to: identify what characterizes the genre Drama of Rio Grande do Norte; situate this genre within a systemization of genres from the oral tradition in Rio Grande do Norte; investigate the interpersonal relationships of power and solidarity through the role of the women in the discourse, how they see themselves and others, pointing out which elements of the world they evaluate and to identify representations of the feminine in the discourse. The theory of Genre and Register of Martin and Rose (2008) and Generic Structure Potential of Hasan (1989, 1996), which has as a base the Systemic Functional Linguistics of Halliday and Matthiessen (2004), Eggins (1994) among others, offers a theoretical framework for the characterization of the genre through the identification of stages and phases configuring its typology the individual schematic structure and its topology its relation to other phenomena in the oral tradition. Other groupings were mapped of the ‗Macrogenre , from the model of Martin and Rose (2008) as a continuum on two axis: between the poles of how the genre circulates orally x in writing, and recited/individually x staged/collectively; as well as mapping the samples with relation to power using the same model, but with the poles of individual voice x collective voice on an axis between increased power and diminished power. Eleven texts described as Narratives and one Anecdote were selected for the analysis of Attitudes, and Negotiations of power. Through the quantification of semantic discursive resources in the discourse systems of Appraisal (MARTIN; WHITE, 2005) and of Negotiation (MARTIN; ROSE, 2007), as well as reflections about humor (EGGINS; SLADE, 1997) we identified the Attitudes and the Negotiations of interpersonal roles. The quantification is based on the theories of Corpus Linguistics (BERBER SARDINHA, 2010), using WordSmith Tools 5.0 (SCOTT, 2010). Our results show that the Drama-of-Rio-Grande-do-Norte is characterized as a Macrogenre in the Community of Oral Stories, in the Family of Street Theatre/Games, composed of five genre types: Narratives, Praise, Complaints, Anecdotes, and Exemplum. The Macrogenre is characterized by its being circulated orally, staged collectively and the texts analyzed configure in differing degrees of power between men and woman. In synthesis we observe that through humor, the Drama-of-Rio-Grande-do-Norte functions to offer a space for women to voice, comment, judge and orient about social conditions in their communities, such as alcoholism, domestic violence, inequalities before the law etc., as well as circulating positive appreciations of rural/coastal culture and judgments about the behavior of members of the speech community, the role of women being to establish and reinforce norms. We anticipate possible benefits of the addition of the genre analyzed in literacy projects in the schools of Rio Grande do Norte

A responsabilidade enunciativa em Itinéraire d un Voyage en Allemagne

Nossa pesquisa se circunscreve nos estudos da Análise Textual dos Discursos, proposta pelo linguista Jean-Michel Adam. Nosso foco principal está voltado para o fenômeno da Responsabilidade Enunciativa (doravante RE). Além das categorias de análise para se estudar a RE, conforme Adam (2008, 2010, 2011), também seguiremos outros estudiosos no assunto, como Oswald Ducrot (1984), os teóricos Teoria Escandinava da Polifonia Linguística, (2004), Zlatka Guentchéva (1994), Jean-Pierre Desclés (2009) e Jacqueline Authier-Revuz (1998, 2004). Utilizaremos os pressupostos apresentados por Alain Rabatel (2004, 2008, 2009, 2010), sobretudo, no que concerne às noções de locutor/enunciador, ponto de vista ou vozes que podem ser encontradas em um texto. Para tanto, analisaremos um relato de viagem, Itinéraire d un Voyage en Allemagne (doravante Itinéraire), escrito no século XIX por Nísia Floresta, uma norte-rio-grandense que fez residência na França e ficou conhecida como uma das primeiras feministas do Brasil. O relato de viagem é um gênero diferenciado para se analisar a RE, sobretudo o Itinéraire, pois nele também podemos encontrar a presença de outros gêneros, quais sejam: epistolar e autobiográfico. Assim, percorreremos, primeiramente, algumas abordagens sobre gêneros de discurso, utilizando-nos, principalmente, dos pressupostos de Mikhail Bakhtin (1992, 2003), Geneviève Bordet (2011), Jean Michel Adam (2011) e Luiz Antônio Marcuschi (2008) e, posteriormente, apresentaremos algumas características que envolvem os gêneros citados. Por fim, para análise dos dados, estamos seguindo a abordagem qualitativa de natureza interpretativista. Nossa pesquisa comprovou que o Itinéraire apresenta muitas marcas de assunção da RE, mas que, apesar de Nísia Floresta ser locutora e enunciadora, é possível encontrar marcas de não assunção da RE, ou seja, outros PDV

Equacões preditivas para as pressões respiratórias estáticas máximas de adolescentes brasileiros

Introduction: The reference values and prediction equations for maximal respiratory pressures (MRP) differ significantly between the available studies. This large discrepancy can be attributed to the different methodologies proposed. Although the importance of MRP is widely recognized, there are no Brazilian studies that provide predictive equations and reference values for PRM adolescents. Objectives: The purpose of this study was to provide normal values and propose predictive equations for maximal static respiratory pressures of Brazilian adolescents. Methods: An observational cross-sectional study, which evaluated 182 adolescents of both sexes aged between 12 and 18 years, enrolled in schools of the state and private in the city of Natal / RN. The selection of schools and participants of the study was randomly through a lottery system. The spirometric evaluation was performed through the digital spirometer One Flow FVC prior to the assessment of respiratory muscle strength. The MICs were measured with MVD digital manometer 300. Statistical analysis was performed using the SPSS 17.0 software STATISTICS, assigning the significance level of 5%. The normality of data distribution was verified using the Kolmogorov-Smirnov (KS). The descriptive analysis was expressed as mean and standard deviation. We used one-way ANOVA test to verify the difference of the averages of MRPs between age and gender and comparing the averages of MRPs between levels of physical activity. The test t'Student unpaired compared the averages of MRPs being ages and sexes. The comparison of mean values obtained in this study PRM with the values predicted using the equations mentioned above was relizada by testing paired t'Student. To verify the correlation between the PRM and the independent variables (age, weight, height) was used Pearson correlation test. Levene's test evaluated the homogeneity of variance. To obtain predictive equations analysis was used stepwise multiple linear regression. Results: There was no significant difference in mean age between the PRM. The male adolescents, regardless of age, showed superiority in MRP values when compared to the opposite sex. Weight, height and sex correlated with the PRM. Regression analysis suggested in this study, pointed out that the weight and sex had an influence in MIP and MEP only in relation to sex influenced. The mean for each PRM adolescents classified as very active were superior to those observed in adolescents classified as irregularly active. Conclusion: This study provides reference values and two models of predictive equations for maximal inspiratory and expiratory pressures, and to establish the lower limits of normality that will serve as an indispensable condition for careful evaluation of respiratory muscle strength in Brazilian adolescents