The good properties and high productivity obtained through injection molding have enabled the use of composites reinforced with short carbon fibers for the production of automobile components. Their low strength and stiffness, however, have limited the use of these materials in some applications. The incorporation of inorganic nanoparticles such as alumina (Al2O3) is a proposed solution to this problem. There is evidence that nanoparticles promote better interfacial interaction between the polymer and short carbon fibers, improving the mechanical performance of composites. The aim of this work was to develop polypropylene (PP) composites reinforced with alumina nanoparticles and short carbon fibers for the automotive industry. The composites were processed in a twin-screw extruder. The response surface methodology was used to define the content of nanoparticles in the composites and to evaluate the effect of the incorporation of the alumina and polypropylene-grafted maleic anhydride (PP-g-MA) on the properties obtained. The hybrid composite that showed the best tensile properties was used as a matrix for reinforcement with different levels of short carbon fiber. The tensile properties were determined by the standard techniques. The results showed that the materials obtained can be used in applications that require low density along with high productivity, rigidity and resistance. components stiffness however Al2O3 AlO Al O (Al2O3 problem PP (PP industry twinscrew twin screw extruder polypropylenegrafted grafted PPgMA g MA (PP-g-MA fiber techniques resistance Al2O (Al2O

Abstract Maintenance of snakes at Butantan Institute started in the last century, intending to produce a different antivenom serum to reduce death caused by snakebites. Through a successful campaign coordinated by Vital Brazil, farmers sent venomous snakes to Butantan Institute by the railway lines with no cost. From 1908 to 1962, the snakes were kept in an outdoor serpentarium, where venom extraction was performed every 15 days. During this period, the snake average survival was 15 days. In 1963, the snakes were transferred to an adapted building, currently called Laboratory of Herpetology (LH), to be maintained in an intensive system. Although the periodicity of venom extraction remained the same, animal average survival increased to two months. With the severe serum crisis in 1983, the Ministry of Health financed remodeling for the three public antivenom producers, and with this support, the LH could be improved. Air conditioning and exhausting systems were installed in the rooms, besides the settlement of critical hygienic-sanitary managements to increase the welfare of snakes. In the early 1990s, snake survival was ten months. Over the years to the present day, several improvements have been made in the intensive serpentarium, as the establishment of two quarantines, feeding with thawed rodents, an interval of two months between venom extraction routines, and monitoring of snake health through laboratory tests. With these new protocols, average snake survival increased significantly, being eight years for the genus Bothrops, ten years for genus Crotalus and Lachesis, and four years for the genus Micrurus. Aiming the production of venoms of good quality, respect for good management practices is essential for the maintenance of snakes in captivity. New techniques and efficient management must always be sought to improve animal welfare, the quality of the venom produced, and the safety of those working directly with the venomous snakes.

RESUMO A incorporação de resíduos e a redução do teor de agregados minerais em formulações de concreto são ações que contribuem para a preservação ambiental. O objetivo desse estudo é desenvolver e avaliar as propriedades e a porosidade de concretos formulados com resíduos, provenientes de cabos usados em linhas de amarração de plataformas de petróleo. Com essa finalidade, os resíduos foram caracterizados utilizando técnicas tradicionalmente utilizadas em materiais. Corpos de prova de concretos de traço padrão 1,0: 2,3: 2,7: 0,55 (cimento: areia: brita: água) (NBR 5738) foram preparados e usados como referência. Para avaliar o efeito da incorporação dos resíduos no desempenho dos concretos, corpos de prova com teores de substituição parcial de 5% e 10% do agregado miúdo por resíduos foram preparados, e submetidos a ensaios de resistência à compressão axial (NBR 5739) e de absorção de água (NBR 778). A porosidade dos concretos foi determinada a partir de imagens obtidas em escâner comercial. Os resultados mostraram que os resíduos eram constituídos por poli (tereftalato de etileno), PET. O concreto formulado com teor de substituição de agregado miúdo por 5% de PET apresentou leve tendência ao aumento da resistência. A substituição de 10% do agregado por PET, entretanto, reduziu a resistência do concreto. Os valores de porosidade do concreto de referência e do formulado com substituição de 5% de agregado por PET apresentaram relação condizente com os valores de resistência à compressão. A metodologia adotada se mostrou satisfatória para a determinação de poros do tipo vazios de ar presentes na estrutura do concreto. As curvas de resistência versus porosidade baseadas nos modelos de Powers e Riyshkevitch demonstraram que essa metodologia pode ser utilizada para determinar a resistência à compressão de concretos com porosidade menor que 20%. O concreto formulado substituindo o agregado miúdo por 5% de PET apresenta resistência compatível com a do material de referência.

ABSTRACT In recent years, the high consumption of non-renewable natural resources and energy associated with the generation of solid waste has encouraged the development of sustainable materials for civil construction. In this context, some studies on the use of polymeric residues in the formulation of concrete-based materials have been published. These residues can minimize the use of mineral aggregates, in addition to providing some desired properties to the materials obtained. Porosity is one of the most important parameters of the concrete microstructure, as it is intrinsically related to some properties of this material, such as compressive strength. The objective of this work is to evaluate the properties and porosity of a concrete formulated with different contents of poly(ethylene terephthalate) (PET) obtained from mooring cables of discarded oil platforms. The characterization of the polyester waste by different techniques showed that residue from mooringropes is comprised of PET. The mechanical evaluation of the concretes was performed by compression strength tests. The results showed that the addition of 5 % PET to the concrete formulations has a tendency to improve the mechanical strength of the materials. The porosity of each concrete sample was determined from images acquired from commercial scanner. Empirical equations were applied to relate the porosity data obtained to the compressive strength of the samples. The curves obtained matching with the inverse relationship between these two parameters.

Abstract The aim of this work was to investigate the effects of mercerization on the structure of castor oil cake (CC) and on the tensile properties of LDPE/PHB/CC composites. To achieve this goal, the fibers were treated with NaOH solutions (5 and 10 wt%). Characterization techniques such as: scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to investigate the structure of modified fibers. The composites were processed in a Haake mixer. Tensile tests of the composites were performed according to ASTM D638 standard. The analyzes revealed that mercerization promoted a partial conversion of cellulose I into cellulose II. Mercerization performed with 5% NaOH solution improved the tensile properties of the LDPE/PHB/CC composites, which were superior to those obtained with the 10% NaOH solution. This result suggests that the higher concentration of NaOH compromises the integrity of the fibers, deteriorating the mechanical properties.

RESUMO O crescente desperdício de materiais plásticos no meio ambiente juntamente com a preocupação com a futura escassez do petróleo tem aumentado o interesse por polímeros biodegradáveis, como o amido. Nos últimos anos, o amido tem sido utilizado em misturas com diferentes polímeros sintéticos. Essas misturas têm sido compatibilizadas por meio do uso de agentes compatibilizantes do tipo copolímeros. O presente trabalho tem como objetivo avaliar a influência da adição do copolímero graftizado (PP-g-MA) nas propriedades mecânicas, térmicas e morfológicas de misturas de polipropileno (PP) e amido termoplástico (TPS). O TPS foi obtido em uma extrusora monorosca com 20 % (m/m) de glicerol, usado como plastificante. Posteriormente, misturas PP/TPS 80:20 % (m/m) foram processadas em uma extrusora de rosca dupla corotacional, na presença de 3, 5 e 7% (m/m) do PP-g-MA. A morfologia das misturas foi avaliada através de microscopia eletrônica de varredura. Os resultados mostraram uma redução significativa da fase dispersa de amido, com a adição do compatibilizante. As misturas processadas em presença do PP-g-MA apresentaram uma distribuição mais homogênea da fase de amido na matriz de PP. Os resultados dos ensaios de resistência à tração mostraram que o módulo do PP sofre um ligeiro aumento, com a adição do amido e do compatibilizante. A resistência das misturas no ponto de escoamento apresentou valores similares aos do PP. Apesar disso, a deformação na ruptura diminui drasticamente com a incorporação do amido. A adição de amido ao polipropileno, entretanto, aumenta significativamente a resistência ao impacto do polímero sintético. Com a adição de PP-g-MA à mistura PP/TPS, a resistência ao impacto sofre uma queda, que pode ser atribuída a redução da fase de amido na mistura. A estabilidade térmica das misturas PP/TPS sofre um ligeiro aumento com a incorporação do agente compatibilizante. Os materiais obtidos podem ser utilizados em substituição ao PP.

ABSTRACT The growing waste of plastics in the environment coupled with concerns about future oil shortages has increased interest in biodegradable polymers such as starch. In recent years, starch has been used in blends with different synthetic polymers. Such blends have been compatibilized by the use of compatibilizing agents of the copolymer type. In this study, the morphological, mechanical and thermal properties of polypropylene (PP)/thermoplastic starch (TPS) blends obtained in the presence of the compatibilizing agent (PP-g-MA) were evaluated. The thermoplastic starch was obtained in a single screw extruder with 20% (mass/mass) of glycerol used as plasticizer. PP/TPS blends were prepared by melt mixing in a co-rotating twin-screw extruder. The concentration of the compatibilizing agent was 3, 5 and 7% (mass/mass). The morphology of the blends was evaluated by scanning electron microscopy. The results showed a significant reduction of the dispersed starch phase with the addition of the PP-g-MA. The blends obtained in the presence of PP-g-MA showed a more homogeneous distribution of the starch phase in the PP matrix. The results obtained with the tensile tests showed that the elastic modulus of PP undergoes a slight increase with the addition of the starch and the compatibilizer. The tensile strength of the PP was not significantly affected. However, there was a significant decrease of the elongation at break with the incorporation of starch. The starch incorporated in the PP matrix led to a significant increase in the impact strength of the final material. However, with the addition of PP-g-MA to the PP/TPS blend, the impact strength falls. This result can be attributed to the reduction of the starch phase in the PP matrix. The thermal stability of the PP/TPS blends was slightly increased with the incorporation of the compatibilizing agent. The materials obtained can be used instead of PP.

The use of polyethylene in sliding systems for automotive industry requires adequate mechanical properties, such as high wear resistance, besides good processing properties in conventional extrusion processes. Aiming to fulfill these requirements, crosslinks were introduced in a high molecular weight polyethylene (HMWPE) grade through a process involving grafting of vinyltrimethoxysilane (VTMOS) onto the polymer chain, promoted by dicumyl peroxide (DCP). The results obtained showed that the introduction of crosslinks improved the wear resistance of HMWPE. However, the HMWPE crosslinking led to a significant decrease in the Young’s Modulus, as a result of the reduction in crystallinity or the heterogeneous structure of the crosslinked samples. The tensile strength and the thermal properties were not affected.

LDPE blends based on PHB and GG biodegradable polymers were prepared by melt mixing in a twin screw extruder. The mechanical properties of the materials were evaluated. Preliminary information about the biodegradation behavior of the specimens was obtained by visual observation of samples removed from the simulated soil in 90 days. The results indicated that LDPE/PHB blends may be used for designing LDPE based materials with increased susceptibility to degradation, if elongation at break and impact properties are not determinant factors of their performance. LDPE based materials on GG present values of flexural and mechanical strength lower than those of LDPE/PHB blends. LDPE/PHB/GG blends exhibit unsatisfactory properties. Apparently, the effect of addition of GG to LDPE on the biodegradation behavior of LDPE/GG blends was less intense than the effect caused by addition of PHB to the blends. Similar observation has occurred with the partial replacement of GG by PHB in the ternary blends.

In this study, composites based on poly(lactic acid) (PLA)/talc were prepared at different compositions by melt mixing in a twin screw extruder. The effect of a nucleating agent, talc, on the crystallization behavior, rheological and morphological properties of PLA was investigated. DSC results showed that the addition of the mineral filler in the range between 1 and 5 wt. % to the PLA matrix increases the degree of crystallinity. This finding shows that talc acted as a nucleating agent for PLA during the processing stage. The composites morphology was also studied using a scanning electron microscope (SEM). The micrographs showed that a good dispersion of talc was achieved in all compositions analyzed. The rheology of PLA/talc composites was evaluated with the dynamic mode and correlated with the aforementioned observed morphology. The results showed that the addition of the mineral filler to the PLA matrix decreased system viscosity, thus highlighting the filler's lubricant effect. As talc content increased, system's viscosity also increased, providing material with higher elastic behavior. Thermal analysis showed that the composition of 3 wt.% of talc added to polymer matrix seems to be interesting with regard to the need of articles possessing good dimension stability.

Blends of PHB and LDPE were prepared by melt mixing in a twin screw extruder. Castor oil cake (CC) was used as filler for the blends. The design of experiments (DOE) technique was used to evaluate the effect of the components proportion on the materials properties. The mechanical properties and morphology of the materials were evaluated. The LDPE Young's modulus increases but the other tensile properties and impact resistance deteriorate with the addition of PHB or CC. The tensile strength values of binary mixtures of LDPE lie in the range from 8.9 to 10 MPa. As some commercial grades of LDPE have mechanical strength in this range, it may be inferred that the addition of a certain amount of PHB or CC to LDPE may be considered as a possibility for obtaining LDPE based materials with increased susceptibility to biodegradation. The poor interfacial adhesion between the phases became visible in all samples.

Blends of PHB and LDPE were prepared by melt mixing in a twin screw extruder. Castor oil pressed cake (CC) was used as filler for the blends. The mixture design technique was used to evaluate the effect of the components proportion on the materials flexural properties. The results show that superior LDPE flexural properties may be obtained by the addition of PHB or castor oil cake to LDPE. Biodegradation was evaluated burying the samples in simulated soil for different periods of time. The ternary mixtures with higher content of PHB showed more pronounced degradation. Under the experimental conditions studied the LDPE/CC compositions presented no degradation. However, the loss of mass of the LDPE/PHB/CC ternary mixtures was higher than the loss of mass of the corresponding LDPE/PHB binary mixture. This result suggests that the castor oil cake accelerates the degradation of the LDPE/PHB mixtures.

Blends of linear low density polyethylene (LLDPE) ethylene-1-octene copolymers (EOC), with different 1-octene (OC) content, and ground rubber tire (GRT) were prepared by melt mixing in a twin screw extruder. Five different compositions of LLDPE/EOC/GRT blends were processed in the extruder to evaluate the effect of EOC addition to the LLDPE/GRT blends. The addition of EOC to LLDPE/GRT blends improves the mechanical properties. Besides, the replacement of 5% of GRT by EOC grades (OC = 20 or 30 wt %) in the 50/50 LLDPE/GRT blend, leads to a significant increase of ultimate tensile properties. The EOC comonomer content affects the properties of LLDPE/EOC and LLDPE/EOC/GRT blends. Dynamical-mechanical analyses showed that, with the addition of EOC to LLDPE/GRT blends, the Tg of GRT and the Tg of EOC are closer. This effect is more pronounced when the EOC with the highest content of comonomer (30 wt %) is added to LLDPE/GRT blend. In this case, only one peak related to the Tg of the rubber phase can be visualized in the amorphous region. These findings indicate that EOC may act as compatibilizer agent for LLDPE/GRT blends.

Neste texto pretendemos interrogar certos "consensos" que se estabelecem em torno da desvalorização do magistério, de modo que se possa ampliar o campo das lutas vinculadas à invenção de outros modos de trabalhar e viver na escola. A partir de uma perspectiva micropolítica e com base nas contribuições de Foucault e Deleuze, vimos discutindo a desvalorização do magistério em suas implicações com a institucionalização da produção de saberes e do trabalho de formação. Como conclusão, evidenciamos que, sob uma aparente convergência, residem diferentes leituras do que se passa e dos consequentes desafios cotidianos na singularização das práticas, acarretando desdobramentos e interferências nas políticas públicas.

In this paper we intend to discuss some consensus around devaluation of teaching in the scope of the struggles involved in other forms of living and working at school. From a micro-politics view, the contributions of Foucault and Deleuze, we also discuss the devaluation of the teaching profession in the process of knowledge and job training institutionalization.In conclusion we show that, under the apparent convergence reside different readings of what is happening and the consequent challenges in everyday practice, encouraging developments and interference in public policy.

En este texto se tiene la intención de interrogar ciertos "consensos" que se establecieron en relación a la devaluación del magisterio, de manera que se pueda ampliar el campo de las luchas relacionadas a la invención de otras formas de trabajar y vivir en la escuela. Desde una perspectiva micropolítica, a partir de aportaciones de Foucault y Deleuze, se viene discutiendo la devaluación del magisterio en su repercusión para la institucionalización de la producción de saberes y del trabajo de formación. Como conclusión se demuestra que bajo la aparente convergencia residen diferentes lecturas de lo que sucede y de los consecuentes desafíos cotidianos en la singularización de las prácticas, favoreciendo despliegues y interferencia en las políticas públicas.

Neste artigo, elegemos como eixo de discussão a comunicação na escola, em particular a que, aparentemente, não estaria em situação de trabalho - as interações realizadas na sala de professores, onde os profissionais se encontram nos intervalos. A partir do funcionamento do quadro-mural, o que se busca polemizar são as relações entre os profissionais e os sentidos do trabalho. A perspectiva é a de colocar em análise os dispositivos de comunicação, atentando para os efeitos produzidos em um regime de verdade que autoriza uma maneira de trabalhar docente que fortalece a exclusão de alunos e profissionais na sua capacidade de gestão das práticas. Iniciamos por situar o leitor na problemática e no referencial adotado, passando à polemização dos conceitos de trabalho, saúde e produção de conhecimento e trazendo o quadro-mural como analisador dos processos. Por fim, evidenciamos as derivas e outros possíveis na formação.

In this article we elected communication at school as the discussion focus, in particular the one which apparently would not be held at work situation - the teachers' room interactions, where teachers meet during the break. From the way the notice board is used we intend to engage in a controversy about the relations between the professionals and the meanings of work. The perspective is to analyze the communication devices holding attention to the produced effects in a truth regime that authorizes a way of working which increases the exclusion of students and teachers in their ability on practice management. First of all we will situate the reader in the problematic and reference adopted. Then, we will go through the controversy of work, health and knowledge production concepts, bringing the notice board as a processes analyzer. Finally, we will point out leeways and other formation possibilities.

Este trabalho visa a analisar as tecnologias de poder que têm tecido as práticas educacionais na contemporaneidade, apontando a escola contemporânea como espaço estratégico de gestão da vida. Compartilhando indagações advindas das pesquisas realizadas em escolas públicas, discute os efeitos dos novos processos de governo da vida que vêm se intensificando no cotidiano escolar, ressaltando como as artes liberais de governar a vida tecem novas práticas de normalização distintas das clássicas tecnologias disciplinares de poder. Aponta que a medicalização do aprender e a judicialização das questões escolares têm se constituído como um dispositivo biopolítico de controle dos modos de existência. Conclui indicando que as mudanças no processo educacional requerem interferências no modo de funcionamento das políticas e no regime de enunciação do que tem sido configurado como problema e desafio a ser enfrentado pela escola pública.

This work has the intend to analyse the technologies of power which have been serving as basis for educational practices of nowadays. In this context, these practices point out to a contemporary school as a strategic space of life management. Sharing questions from research conducted in public schools, discusses the effects of new government processes of life that has been intensifying in school life, emphasizing the liberal arts and to govern the lives weave new practice of standardization of different classic technologies of disciplinary power. He points out that the medicalization of learning and the judicialization of school issues have been constituted as a control device biopolitical modes of existence. Conclusion indicating that changes in the educational process require interference in the operating mode of the policies and the regime of enunciation than has been configured as a problem and challenge to be faced by the public school.