Polyurethane and the analogous ‘polyurethane-urea’ are high performance polymeric materials having remarkable properties such as high stiffness, abrasion and tear strengths. In many studies, the low strength rubbers have been blended with various types of polyurethanes for new and improved materials. However, until now, the reported heterogeneous blends offer only a narrow temperature range of application due to the high temperature softening of their polyurethane (-urea) phase. In addition, the conventional solution-or melt-blending methods are time and energy intensive, which tend to forfeit the economical realization of the reported blends. In contrast to earlier studies, a simplified reactive blending process is suggested to synthesize polyurethane-urea via a prepolymer route during blending with rubbers to obtain novel elastomeric materials having extended performance characteristics. The reactive blending process is opted to prepare blends based on nitrile butadiene rubber (NBR) and in-situ synthesized polyurethane-urea (PUU). The blending is carried out in an internal mixer at a preset temperature of 100°C. The critical temperatures of the reactive blending process are determined from the chemo-rheological analysis of a premix, composed of a 4,4′-diphenylmethane diisocyanate (MDI)/polyether (PTMEG) based prepolymer admixed with 1,3-phenylene diamine (mPD). The prepared NBR/PUU blends exhibit highly improved mechanical properties. Contrary to previous reports, the reinforced dynamic-mechanical responses of the novel blends remain stable till very high temperatures (≥180°C). The influence of diamine type on the in-situ synthesized polyurethane-urea and the performance of prepared blends are investigated. Four different diamines, namely 1,3-Phenylene diamine, 1,4-Bis(aminomethyl)benzene, 4,4′-Methylene-bis(2-chloroaniline) and 4,4ʹ-(1,3-Phenylenediisopropylidene)bisaniline, are selected to chain extend the prepolymer to PUU during blending with NBR. The chemical and domain structure of the PUUs are found to greatly influence the reinforced tensile and dynamic-mechanical responses of the NBR/PUU 70/30 blends. The PUU (based on MDI/PTMEG prepolymer and mPD) is blended with polar (CR, XNBR) and nonpolar (NR, EPDM, sSBR) rubbers. PUU compatibilizes with all the rubbers irrespective of their polarity and reinforces their tensile and dynamic-mechanical characteristics. The use of blends in industrial applications, for example, in a truck tire tread compound and as a roller covering material, is examined. In a simplified tire tread formulation, the carbon black for NR-CB composite is partially replaced with an equivalent quantity of PUU for NR/PUU-CB composite of similar hardness. The dynamic mechanical investigations reveal that the energy dissipation and strain dependent softening is high in NR-CB as compared to the NR/PUU-CB composite. In another application, NBR/PUU blend is successfully tested as a rubber roller covering material. The tested blend-covered roller retains its structural integrity and develops less heat build-up as compared to the silica filled NBR-covered roller. This shows a substantial suitability of the blend-covered rollers for film, printing and textile processing machinery. These novel blends are considered to be the promising new materials for many commercial applications including wheels, rubber rollers, belts or pump impellers.

Orientador: Cesar Costapinto Santana / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-30T12:54:54Z (GMT). No. of bitstreams: 1 Veredas, Vinicius de_D.pdf: 13205142 bytes, checksum: 97c5009c255088bef6fcdc1fd92294c3 (MD5) Previous issue date: 2005 / Doutorado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química

Metallic glasses possess attractive properties, such as high strength, good corrosion resistance, and superior soft magnetic performance. They also serve as precursors for synthesizing nanocrystalline materials. In addition, a new class of composites having crystalline phases embedded in amorphous matrix is evolving based on selective crystallization of metallic glasses. Therefore, crystallization of metallic glasses and its effects on properties has been a subject of interest. Previous investigations from our research group related to laser assisted crystallization of Fe-Si-B metallic glass (an excellent soft magnetic material by itself) showed a further improvement in soft magnetic performance. However, a fundamental understanding of crystallization and mechanical performance of laser treated metallic glass was essential from application point of view. In light of this, the current work employed an integrated experimental and computational approach to understand crystallization and its effects on tensile behavior of laser treated Fe-Si-B metallic glass. The time temperature cycles during laser treatments were predicted using a finite element thermal model. Structural changes in laser treated Fe-Si-B metallic glass including crystallization and phase evolution were investigated with the aid of X-ray diffraction, differential scanning calorimetry, resistivity measurements, and transmission electron microscopy. The mechanical behavior was evaluated by uniaxial tensile tests with an InstronTM universal testing machine. Fracture surfaces of the metallic glass were observed using scanning electron microscopy and site specific transmission electron microscopy. Fe-Si-B metallic glass samples treated with lower laser fluence (<0.49 J/mm2) underwent structural relaxation while higher laser flounces led to partial crystallization. The crystallization temperature experienced an upward shift due to rapid heating rates of the order of 104 K/s during laser treatments. The heating cycle was followed by termination of laser upon treatment attainment of peak temperature and rapid cooling of the similar order. Such dynamic effects resulted in premature arrest of the crystallite growth leading to formation of fine crystallites/grain (~32 nm) of α-(Fe,Si) as the major component and Fe2B as the minor component. The structural relaxation, crystallization fractions of 5.6–8.6 Vol% with α-(Fe,Si) as the main component, and crystallite/grain size of the order of 12 nm obtained in laser fluence range of 0.39-0.49 J/mm2 had minimal/no influence on tensile behavior of the laser treated Fe-Si-B metallic glass foils. An increase in laser fluence led to progressive increase in crystallization fractions with considerable amounts of Fe2B (2-6 Vol%) and increase in grain size to ~30 nm. Such a microstructural evolution severely reduced the strength of Fe-Si-B metallic glass. Moreover, there was a transition in fracture surface morphology of laser treated Fe-Si-B metallic glass from vein pattern to chevron pattern. Tensile loading lacked any marked influence on the crystallization behavior of as-cast and structurally relaxed laser-treated metallic glass foils. However, a significant crystallite/grain growth/coarsening of the order of two and half times was observed in the fractured region compared to the region around it for the laser-treated partially crystallized metallic glass foils. The simultaneous effects of stress generation and temperature rise during tensile loading were considered to play a key role in crystallite/grain growth/coarsening.

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuators / Der Download des Gesamtbandes wird erst nach der Konferenz ab 15. Oktober 2020 möglich sein.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuators

Polyurethane and the analogous ‘polyurethane-urea’ are high performance polymeric materials having remarkable properties such as high stiffness, abrasion and tear strengths. In many studies, the low strength rubbers have been blended with various types of polyurethanes for new and improved materials. However, until now, the reported heterogeneous blends offer only a narrow temperature range of application due to the high temperature softening of their polyurethane (-urea) phase. In addition, the conventional solution-or melt-blending methods are time and energy intensive, which tend to forfeit the economical realization of the reported blends. In contrast to earlier studies, a simplified reactive blending process is suggested to synthesize polyurethane-urea via a prepolymer route during blending with rubbers to obtain novel elastomeric materials having extended performance characteristics. The reactive blending process is opted to prepare blends based on nitrile butadiene rubber (NBR) and in-situ synthesized polyurethane-urea (PUU). The blending is carried out in an internal mixer at a preset temperature of 100°C. The critical temperatures of the reactive blending process are determined from the chemo-rheological analysis of a premix, composed of a 4,4′-diphenylmethane diisocyanate (MDI)/polyether (PTMEG) based prepolymer admixed with 1,3-phenylene diamine (mPD). The prepared NBR/PUU blends exhibit highly improved mechanical properties. Contrary to previous reports, the reinforced dynamic-mechanical responses of the novel blends remain stable till very high temperatures (≥180°C). The influence of diamine type on the in-situ synthesized polyurethane-urea and the performance of prepared blends are investigated. Four different diamines, namely 1,3-Phenylene diamine, 1,4-Bis(aminomethyl)benzene, 4,4′-Methylene-bis(2-chloroaniline) and 4,4ʹ-(1,3-Phenylenediisopropylidene)bisaniline, are selected to chain extend the prepolymer to PUU during blending with NBR. The chemical and domain structure of the PUUs are found to greatly influence the reinforced tensile and dynamic-mechanical responses of the NBR/PUU 70/30 blends. The PUU (based on MDI/PTMEG prepolymer and mPD) is blended with polar (CR, XNBR) and nonpolar (NR, EPDM, sSBR) rubbers. PUU compatibilizes with all the rubbers irrespective of their polarity and reinforces their tensile and dynamic-mechanical characteristics. The use of blends in industrial applications, for example, in a truck tire tread compound and as a roller covering material, is examined. In a simplified tire tread formulation, the carbon black for NR-CB composite is partially replaced with an equivalent quantity of PUU for NR/PUU-CB composite of similar hardness. The dynamic mechanical investigations reveal that the energy dissipation and strain dependent softening is high in NR-CB as compared to the NR/PUU-CB composite. In another application, NBR/PUU blend is successfully tested as a rubber roller covering material. The tested blend-covered roller retains its structural integrity and develops less heat build-up as compared to the silica filled NBR-covered roller. This shows a substantial suitability of the blend-covered rollers for film, printing and textile processing machinery. These novel blends are considered to be the promising new materials for many commercial applications including wheels, rubber rollers, belts or pump impellers.

In dieser Arbeit wurde eine neue fehleranalytische Methode zur industriellen Anwendung an neuen Technologien der Aufbau- und Verbindungstechnik entwickelt. Das Verfahren basiert auf der Wechselwirkung von thermischen Wellen und Defekten. Die Besonderheit ist dabei die Zerstörungsfreiheit, die Geschwindigkeit, das Auflösungsvermögen und die durch neueste IR-Detektoren erreichte Temperaturempfindlichkeit. Es wurden grundlegende Studien bezüglich Auflösung und parasitären Effekten bei der Anwendung unter industriellen Randbedingungen durchgeführt. Dabei wurde eine systematische Vorgehensweise bezüglich der Komplexität gewählt. Dies ermöglicht nun u.a. eine Vorhersage der zu erwartenden Prüfdauer zur Auflösung vergrabener Defekte, der Begrenzung der maximalen Anregungsimpulsbreite (bei gegebener Defekttiefe) und die quantitative Ermittlung des Einflusses einer Lackschicht. Methodisch kamen grundsätzlich Simulationen und vergleichende Experimente zum Einsatz. Es wurden spezielle Proben zur Isolierung und Klärung parasitärer Effekte verwendet. Letztlich konnte das Messsystem erfolgreich an industriellen Problemstellung demonstriert werden. Das entwickelte Messsystem zeichnet sich durch hohe Flexibilität aus. Verschiedene problemangepasste Anregungsquellen (interne und externe Anregung durch zahlreiche physikalische Effekte) kommen zum Einsatz. Das Messsystem besteht aus vier Hauptmodulen, der Differenzbild-Methode, der Impulsthermografie, und zwei Varianten der LockIn-Thermografie. Zusammen ist das System in der Lage, Voids, Delaminationen und Risse in verschiedenen Bereichen auch der modernen AVT sicher zu erkennen. Es werden dabei Temperaturauflösugnen bis zu 5 mK und laterale Auflösungen bis 17 µm erreicht. Diese Arbeit legt einen Grundstein für die Anwendung der thermischen Fehleranalytik in der Industrie, indem hier die Grenzen der IR-Messtechnik aufgezeigt und charakterisiert werden. / In this work a new failure analytical method for the industrial application of new technologies in electronic packaging has been developed. The developed method is based on the interaction of the thermal waves and defects. The special fature is non-destructive, speed, resolution and high temperature sensitivity due to latest IR-detectors. It fundamental studies regarding resolution and parasitic effects in the application were carried out cinsidering industrial conditions. Here, a systematic approach regarding the complexity has been selected. This now enables a prediction of the expected test period for detecting buried defects, limits for excitation pulse width (for a given defect depth) and the quantitative determination of the influence of parasitic paints. Methodically always simulations and comparative experiments were used. Simple samples for the isolation and purification of parasitic effects has been used. Finally, the measurement system has been successfully demonstrated on an industrial applications. The developed measurement system is characterized by high flexibility. Different problem-adapted excitation sources (internal and external excitation by numerous physical effects) are used. The measurement system currently consists of four main modules, the difference image method, the pulse thermography, and two variants of LockIn-thermography. Together, the system is capable of detecting voids, delaminations and cracks in various fields of electronic packageing. It will reach temperature resolutions up to 5 mK and lateral resolutions down to 17 µm. This work stes a foundation for the application of thermal failure analysis for industry by showing and charcterization the limits of IR imaging.

- / Criticality-based maintenance (CBM) is a prioritized approach to the maintenance of (industrial) process equipment. CBM requires personnel with a thorough knowledge of the process/equipment under scrutiny. In this paper a criticality assessment system that is implemented by a local company (which represents the expertise and knowledge of the company experts) is reviewed and fuzzy logic theory is applied to improve the system's capability and reliability. The quality of the fuzzy system is evaluated based on several case studies. The results show that the fuzzy logic based system does not only what the conventional system does, but also outperforms in terms of reliability and has a unique ranking capability.

De nombreux travaux dans la littérature se sont concentrés sur la modélisation vibro-acoustique de coques cylindriques raidies immergées, du fait des nombreuses applications industrielles, en particulier dans le domaine aéronautique ou naval. Cependant, peu d'entre elles prennent en compte des structures internes non-axisymétriques telles que des supports moteurs, des planchers ou des carlingages, qui peuvent avoir une influence importante sur le comportement vibro-acoustique du système. C'est pourquoi une méthode de sous-structuration baptisée CTF est présentée dans cette thèse. Elle est développée dans le cas général de deux structures minces couplées le long d'une ligne. Un ensemble de fonctions orthonormées, baptisées fonctions de condensation, est défini afin d'approximer les forces et déplacements à la jonction entre les sous-systèmes. Des fonctions de transfert condensées sont définies pour chaque sous-système découplé. L'utilisation du principe de superposition, de l'équilibre des forces et de la continuité des déplacements permet de déduire le comportement des sous-systèmes couplés. La méthode est d'abord développée et validée dans le cas de plaques, puis ensuite appliquée au cas d'une coque cylindrique raidie immergée couplée à des structures internes non-axisymétriques. Le système est dans ce cas décomposé en 3 familles de sous-systèmes : la coque cylindrique immergée décrite par une méthode semi-analytique basée sur la résolution des équations de Flügge dans le domaine des nombres d’onde, les structures internes axisymétriques (raidisseurs, cloisons) décrites par éléments finis axisymétriques et les structures non-axisymétriques décrites pas des modèles éléments finis. La méthode CTF est appliquée à différents cas tests afin de montrer l'influence des structures internes non-axisymétriques sur le comportement vibro-acoustique d'une coque cylindrique pour différents types d'excitations pertinents dans le domaine naval : une force ponctuelle, une onde plane acoustique et un champ de pression aléatoire (tel qu'un champ acoustique diffus ou une couche limite turbulente). / Many works can be found in the literature concerning the vibroacoustic modelling of submerged stiffened cylindrical shells, because of high interest in the industrial domain, in particular for aeronautical or naval applications. However, only a few of them take into account non-axisymmetric internal frames, as for instance engine foundations or floor partitions, that can play a role on the vibroacoustic behavior of the system. That is why a substructuring approach called the Condensed Transfer Function (CTF) approach is proposed in the first part of this thesis. The aim is to take advantage of both analytical models and element-based models, in order to be able to deal with the geometrical complexity, and to calculate at higher frequencies than with element-based methods only. The substructuring method is developed in the general case of thin mechanical structures coupled along curves. A set of orthonormal functions called condensation functions, which depend on the curvilinear abscissa along the coupling line, is considered. This set is then used as a basis for approximating and decomposing the displacements and the applied forces at the line junctions. Thanks to the definition and calculation of condensed transfer functions for each uncoupled subsystem and by using the superposition principle for passive linear systems, the behavior of the coupled subsystems can be obtained. The method is first developed and validated for plates and convergence criteria are defined in relation with the size of the basis of condensation functions. The CTF method is then applied to the case of a submerged stiffened cylindrical shell with non-axisymmetric internal frames. The system is partitioned in 3 types of subsystems: the submerged shell, the axisymmetric frames (stiffeners, bulkheads) and the non-axisymmetric frames. The submerged shell is described by a semi-analytical method based on the Flügge equations in the spectral domain. The axisymmetric frames are described by axisymmetric Finite Element models and the non-axisymmetric frames by Finite Element models. The CTF method is applied to different test cases in order to highlight the influence of non-axisymmetric internal frames on the vibroacoustic behavior of a submerged stiffened cylindrical shell, for different excitations particularly relevant in the naval domain: a point force, an acoustic plane wave, and a random pressure field (such as a diffuse sound field or a turbulent boundary layer for instance).

A Proteína Verde Fluorescente recombinante, GFPuv, é um sistema marcador atrativo pois, sua presença pode ser visualizada através da intensidade de fluorescência emitida, sem o uso de substratos ou meios complexos. Sendo uma molécula estável à presença de substâncias orgânicas, temperaturas acima de 70&#176;C e ampla faixa de pH, é um potencial Indicador Biológico (IH) para diversas aplicações. A estabilidade térmica da GFPuv, foi avaliada pela medida da perda de intensidade de fluorescência, expressa em valores D (min), tempo de exposição necessário para redução de 90% da intensidade de fluorescência inicial da GFPuv. GFPuv (3,5-9,0 &#181;g/mL), expressa por E. coli e isolada por extração de Partição em Três Fases (TPP) e purificação por Cromatografia de Interação Hidrofóbica (IDC), foi diluída nas soluções parenterais preparadas em tampão (10 mM cada: Tris-EDTA, pH 8; Fosfato, pH 6 e 7, e Acetato, pH 5) e em água para injeção, WFI; pH = 6,70&#177;0,40), e expostas a temperaturas de 25&#176;C e ao intervalo entre 80&#176;C e 100&#176;C. A 95&#176;C, os valores D para a GFPuv em soluções de 1,5% a 50% de glicose variaram de: (i) 1,63 (&#177;0,23) min em acetato pH 5; (ii) 2,64 &#177; 0,26 min em WFI; (iii) 2,50 &#177; 0,18 min em fosfato pH 6; (iv) 3,24 &#177; 0,28 min em fosfato pH 7 e, (v) 2,89 &#177; 0,44 min em Tris-EDTA pH 8. Cloreto de sódio associado aos tampões proporcionou influência positiva na estabilidade da GFPuv, sendo que em soluções de Tris-EDTA, a adição de 15-20% de NaCl dobrou a estabilidade térmica da GFPuv (valores D de 65,79 min e 18,12 min a 80 &#176;C e 85&#176;C) em relação à solução sem cloreto de sódio. Nos processos de esterilização por óxido de etileno (45&#176;C-60&#176;C), a GFPuv pode ser utilizada como IB para monitorar a distribuição de gás dentro da câmara, pois, apresentou variação na concentração remanescente de até 80%, após processamento, estabelecendo áreas distintas dentro da câmara. No tratamento em autoclave, a GFPuv em solução apresentou resistência térmica em solução de fosfato pH 7,0 (valor F = 2,53 min (&#177; 0,12)). Quando expressa por esporos de Bacillus subtilis, a intensidade de fluorescência emitida por esporos sobreviventes se manteve. A estabilidade térmica da GFPuv atestou sua potencialidade como indicador biológico fluorescente da garantia da eficácia de tratamento de soluções e materiais expostos ao calor. / The recombinant Green Fluorescent Protein, GFPuv is an attractive system marker due to its ability to emit fluorescence when exposed to ultraviolet light, without use of substrates or complex environment. Being a stable molecule even in the presence of organic substances, temperatures above 70&#176;C and wide range of pH, it is a potential Biological Indicator, BI, for many applications, including thermal processes. GFPuv thermal stability was evaluated by the loss of fluorescence intensity expressed in decimal reduction time (D-value, min), the exposure time required to reduce 90% of the GFPuv initial fluorescence intensity. GFPuv (3.5-9.0 &#181;g/mL), expressed by E. coli and isolated by Three Phases Partitioning, TPP extraction with Hidrophobic Interaction Chromatography, HIC, was diluted in buffered solutions (each 10 mM: Tris-EDTA, pH 8; phosphate, pH 6 and 7, and acetate, pH 5) and in water for injection, WFI; pH = 6.70 (&#177; 0.40), and exposed to temperatures of 25&#176;C and between 80&#176;C and 95&#176;C. At 95&#176;C, the D-value for GFPuv in 1.5%-50% glucose, ranged from: (i) 1.63 &#177; 0.23 min in acetate pH 5; (ii) 2.64 &#177; 0.26 min in WFI; (iii) 2.50 &#177; 0.18 min in phosphate, pH 6; (iv) 3.24 &#177; 0.28 min in phosphate, pH 7, (v) 2.89 &#177; 0.44 min in Tris-EDTA, pH 8. Sodium cloride provided a positive influence over GFPuv stability. In Tris-EDTA solutions, the addition of 15% and 20% of NaCl doubled the thermal stability of GFPuv (D = 65.79 min and D = 18.12 min at 80&#176;C, and 85&#176;C, respectively, in relation to the solutions without NaCl. For ethylene oxide sterilization processes (45&#176;C-60&#176;C), GFPuv can be used as biological indicator to monitor gas distribution into the chamber. After processing, the protein concentration varied by 80%, showing distinct areas into the chamber. In autoclave, GFPuv in solution showed thermal resistance in phosphate pH 7.0 solution (F-value = 2.53 (&#177; 0.12) min. When expressed by Bacillus subtilis spores, the fluorescence intensity was kept constant after thermal processing. The thermal stability of GFPuv provides the basis for its potential utility as a fluorescent biological indicator to assess the efficacy of the treatment of liquids and materials exposed to steam.

A Proteína Verde Fluorescente recombinante, GFPuv, é um sistema marcador atrativo pois, sua presença pode ser visualizada através da intensidade de fluorescência emitida, sem o uso de substratos ou meios complexos. Sendo uma molécula estável à presença de substâncias orgânicas, temperaturas acima de 70&#176;C e ampla faixa de pH, é um potencial Indicador Biológico (IH) para diversas aplicações. A estabilidade térmica da GFPuv, foi avaliada pela medida da perda de intensidade de fluorescência, expressa em valores D (min), tempo de exposição necessário para redução de 90% da intensidade de fluorescência inicial da GFPuv. GFPuv (3,5-9,0 &#181;g/mL), expressa por E. coli e isolada por extração de Partição em Três Fases (TPP) e purificação por Cromatografia de Interação Hidrofóbica (IDC), foi diluída nas soluções parenterais preparadas em tampão (10 mM cada: Tris-EDTA, pH 8; Fosfato, pH 6 e 7, e Acetato, pH 5) e em água para injeção, WFI; pH = 6,70&#177;0,40), e expostas a temperaturas de 25&#176;C e ao intervalo entre 80&#176;C e 100&#176;C. A 95&#176;C, os valores D para a GFPuv em soluções de 1,5% a 50% de glicose variaram de: (i) 1,63 (&#177;0,23) min em acetato pH 5; (ii) 2,64 &#177; 0,26 min em WFI; (iii) 2,50 &#177; 0,18 min em fosfato pH 6; (iv) 3,24 &#177; 0,28 min em fosfato pH 7 e, (v) 2,89 &#177; 0,44 min em Tris-EDTA pH 8. Cloreto de sódio associado aos tampões proporcionou influência positiva na estabilidade da GFPuv, sendo que em soluções de Tris-EDTA, a adição de 15-20% de NaCl dobrou a estabilidade térmica da GFPuv (valores D de 65,79 min e 18,12 min a 80 &#176;C e 85&#176;C) em relação à solução sem cloreto de sódio. Nos processos de esterilização por óxido de etileno (45&#176;C-60&#176;C), a GFPuv pode ser utilizada como IB para monitorar a distribuição de gás dentro da câmara, pois, apresentou variação na concentração remanescente de até 80%, após processamento, estabelecendo áreas distintas dentro da câmara. No tratamento em autoclave, a GFPuv em solução apresentou resistência térmica em solução de fosfato pH 7,0 (valor F = 2,53 min (&#177; 0,12)). Quando expressa por esporos de Bacillus subtilis, a intensidade de fluorescência emitida por esporos sobreviventes se manteve. A estabilidade térmica da GFPuv atestou sua potencialidade como indicador biológico fluorescente da garantia da eficácia de tratamento de soluções e materiais expostos ao calor. / The recombinant Green Fluorescent Protein, GFPuv is an attractive system marker due to its ability to emit fluorescence when exposed to ultraviolet light, without use of substrates or complex environment. Being a stable molecule even in the presence of organic substances, temperatures above 70&#176;C and wide range of pH, it is a potential Biological Indicator, BI, for many applications, including thermal processes. GFPuv thermal stability was evaluated by the loss of fluorescence intensity expressed in decimal reduction time (D-value, min), the exposure time required to reduce 90% of the GFPuv initial fluorescence intensity. GFPuv (3.5-9.0 &#181;g/mL), expressed by E. coli and isolated by Three Phases Partitioning, TPP extraction with Hidrophobic Interaction Chromatography, HIC, was diluted in buffered solutions (each 10 mM: Tris-EDTA, pH 8; phosphate, pH 6 and 7, and acetate, pH 5) and in water for injection, WFI; pH = 6.70 (&#177; 0.40), and exposed to temperatures of 25&#176;C and between 80&#176;C and 95&#176;C. At 95&#176;C, the D-value for GFPuv in 1.5%-50% glucose, ranged from: (i) 1.63 &#177; 0.23 min in acetate pH 5; (ii) 2.64 &#177; 0.26 min in WFI; (iii) 2.50 &#177; 0.18 min in phosphate, pH 6; (iv) 3.24 &#177; 0.28 min in phosphate, pH 7, (v) 2.89 &#177; 0.44 min in Tris-EDTA, pH 8. Sodium cloride provided a positive influence over GFPuv stability. In Tris-EDTA solutions, the addition of 15% and 20% of NaCl doubled the thermal stability of GFPuv (D = 65.79 min and D = 18.12 min at 80&#176;C, and 85&#176;C, respectively, in relation to the solutions without NaCl. For ethylene oxide sterilization processes (45&#176;C-60&#176;C), GFPuv can be used as biological indicator to monitor gas distribution into the chamber. After processing, the protein concentration varied by 80%, showing distinct areas into the chamber. In autoclave, GFPuv in solution showed thermal resistance in phosphate pH 7.0 solution (F-value = 2.53 (&#177; 0.12) min. When expressed by Bacillus subtilis spores, the fluorescence intensity was kept constant after thermal processing. The thermal stability of GFPuv provides the basis for its potential utility as a fluorescent biological indicator to assess the efficacy of the treatment of liquids and materials exposed to steam.