ABSTRACT When the only information available is the issue parameters, and the intended outwards, machine learning techniques like ANN (Artificial Neural Networks) and ANFIS (Adaptive neuro-fuzzy inference system) been proven to address the complex problems without duplicating the phenomena under investigation. The main prompting characteristics are the height-to-the-thicknesses ratio of prisms and the strength under compression of prisms and mortar were analyzed. As inputs, the prototypes are used as blocks and mortars. Both prototypes were accomplished and evaluated. Thirty-six data sets were gathered for testing in addition to verified technical and subsequently comparison with other empirical computation methods served to validate. The outwards show that the suggested prototypes have good forecast capabilities with negligible error rates. To assess and compare the structural behavior of structural completion of AAC block with the other types. At last, both the machine learning tools are good application and dependability.

ABSTRACT Knowledge of the physical and mechanical properties of wood is crucial for the safety and efficiency of structural design. In addition to promoting diversification and supply in the timber market, determining these properties for different types of native woods can contribute to reduce the concentrated overexploitation of tropical woods. Among the woods available for construction purposes in the Tocantina region of Maranhão State is tuturubá (Pouteria oblanceolata Pires). In this context, the present study aimed to evaluate the physical and mechanical properties of tuturubá wood for its use in building structures. The characterizations carried out were: moisture content, apparent density, compressive strength parallel and perpendicular to the grain, shear strength parallel to the grain, flexural strength, modulus of elasticity in compression parallel to the grain and three-point bending test. For the average moisture content, a percentage value of 13.88% was checked, and for the average apparent density, a value of 992.04 kg.m-3 was obtained. For the compressive strength parallel to the grain, an average value of 60.03 MPa was determined, while the characteristic value was 56.86 MPa. The compressive modulus of elasticity parallel to the grain determined was equal to 22761 MPa. The average values for compressive strength perpendicular to the grain and shear strength parallel to the grain were 10.74 MPa and 10.47 MPa, respectively. For flexural strength, average and characteristic values were 154.82 and 128.37 MPa, respectively. For the flexural modulus of elasticity, an average value of 21026 MPa was determined. The results allowed tuturubá wood to be classified in mechanical resistance class D50. Compared to other commercially available wood species, tuturubá has better mechanical properties than pequiá (Cary-ocar villosum) and tauari (Couratari oblongifolia) woods. This physical-mechanical characterization high-lights the potential of tuturubá wood for use in building structures.

RESUMO O conhecimento das propriedades físicas e mecânicas da madeira é crucial para a segurança e eficácia do dimensionamento das estruturas. Além de favorecer a diversificação e abastecimento do mercado madeireiro, a determinação de tais propriedades, para diferentes espécies nativas, pode contribuir para a redução da exploração concentrada de madeiras tropicais. Entre as madeiras disponíveis para a construção civil na Região Tocantina do Maranhão encontra-se o tuturubá (Pouteria oblanceolata Pires). Neste contexto, este estudo teve como objetivo determinar as propriedades físicas e mecânicas da madeira de tuturubá, visando o seu uso em estruturas de edificações. Foram determinados: o teor de umidade, a densidade aparente, as resistências à compressão paralela e perpendicular às fibras, a resistência ao cisalhamento paralelo às fibras, a resistência à flexão e os módulos de elasticidade à compressão paralela às fibras e à flexão. Obteve-se um teor de umidade médio de 13,88%, uma densidade aparente média de 992,04 kg.m-3, o valor médio da resistência à compressão paralela às fibras igual a 60,03 MPa e o valor característico de 56,86 MPa, sendo o módulo de elasticidade à compressão paralela às fibras de 22761 MPa. A resistência média à compressão perpendicular às fibras foi de 10,74 MPa e a resistência média ao cisalhamento paralelo às fibras foi igual a 10,47 MPa. A resistência à flexão média foi de 154,82 MPa e o valor característico igual a 128,37 MPa, enquanto o valor médio do módulo de elasticidade à flexão foi de 21026 MPa. Os resultados permitiram classificar a madeira de tuturubá como pertencente à classe de resistência mecânica D50. Comparativamente com outras espécies disponíveis no mercado madeireiro, a madeira de tuturubá apresentou propriedades mecânicas superiores às madeiras de pequiá (Caryocar villosum) e tauari (Couratari oblongifolia). Esta caracterização físico-mecânica evidencia o potencial da madeira de tuturubá para utilização em estruturas de edificações.

ABSTRACT Turbochargers have proven to be essential in the automotive field as they are machines responsible for increasing power, reducing fuel consumption, and generating less carbon dioxide in an internal combustion engine. This article presents the development of a mathematical model based on a plenum to obtain the dynamic characteristics of the mass flow generated by a turbocharger. To comply with the proposal, it was based on the theoretical-practical knowledge of the laws and concepts that make up a turbocharger, resulting in the simulation of a mathematical model using the Simulink tool. For the development of the mathematical model, theoretical and test data in stable and dynamic regimes were used, as well as the behavior of the plenum subjected to the compression system. This proposed model will contribute to the scientific community by obtaining the characteristics between the compression ratio and the compressor mass flow of a turbocharger and will also contribute to the field of detection and diagnosis of targeted failures in vehicle turbochargers.

RESUMEN Los turbocargadores en la actualidad han demostrado ser imprescindibles en el campo automotriz por ser máquinas que se encargan de aumentar la potencia, reducir el consumo de combustible y generar menos dióxido de carbono en un motor de combustión interna. En este artículo se presenta el desarrollo de un modelo matemático en base a un plenum, con el propósito de obtener las características dinámicas del flujo másico que genera un turbocargador. Para cumplir con lo propuesto se fundamentó en el conocimiento teórico-práctico de las leyes y conceptos que conforman un turbocargador, dando como resultado la simulación de un modelo matemático utilizando la herramienta Simulink. Para el desarrollo del modelo matemático se utilizaron datos teóricos y de pruebas en régimen estable y dinámico, así como el comportamiento del plenum sometido al sistema de compresión. Este modelo planteado contribuirá a la comunidad científica a través de la obtención de las características entre la relación de compresión y el flujo de masa del compresor de un turbocargador, también, aportará en el futuro al campo de la detección y diagnósticos de fallos orientados a los turbocargadores vehiculares.

abstract Proper curing of concrete is one of the most important processes in the post-concreting period so that concrete can achieve the desired mechanical strength and durability. However, part of the construction works perform this procedure for inadequate periods or often do not perform it; as a result, surface characteristics are commonly affected, resulting in increased porosity and, consequently, increased permeability, cracking and carbonation. Materials that have water retention capacity and subsequent gradual release may be effective as internal curing agents. Superabsorbent polymers (PSA) are already used and widely studied for this purpose, but usually with commercial origin. The objective of this research is to evaluate different water absorption methods in industrial waste of superabsorbent polymer and cellulosic fiber (PSAR) for later use as an internal curing agent in Portland cement matrices. PSAR was homogenized by a process at two different times. The material in its natural state and homogenized had its absorption capacity evaluated using two methods: ISO 17190:2001 and sieve method. For the sieve method, the influence of hydration time on absorption was analyzed. The ISO 17190:2001 method did not show representativeness in the results due to the high absorption variation. The sieve method was more representative and demonstrated efficiency in the homogenization processes, reducing the coefficient of variation by up to 43%. The material with the highest potential for use was PSAR60, with an absorption value of 68.26 g of water per g of PSAR, since the absorption test showed the highest homogeneity and, from this absorption, no longer had significant variations.

ABSTRACT ASTM Mar-M247 is one of the superalloys used to manufacture gas turbine blades in power stations. This paper studies the microstructure across welded joints of a turbine blade made of a high-strength material (Mar-M247 alloy) employing AWS ERNiCrMo-3 as a filler alloy. This process was carried out using gas tungsten arc welding (GTAW). The dendritic and interdendritic structures were observed in the fusion zone. The results also showed the presence of epitaxial growth at the interface between the weld metal and the base alloy without solidification cracks. Al and Co concentrations gradually decrease towards the weld metal zone during the solidification process, while Cr content increases towards the fusion zone. Vickers hardness revealed that the hardness in the heat-affected zone (HAZ) is higher than that of the base metal and the weld metal zone, the average in the HAZ is 340HV, while in the base metal and the fusion zone is 322HV, 284HV respectively. Coarse grains in the HAZ were found with an agglomeration of carbides at the grain boundaries due to the input heat of the welding process.

ABSTRACT Coffee grounds (SCG) and rice husk ash (RHA) are used in this study as raw materials to obtain lightweight aggregates (LWAs), replacing clay. The waste generated during the processing of coffee and rice is commonly disposed of in landfills and rubbish dumps, aggravating environmental impacts. Combined with the scarcity of natural resources and the sustainable management of this waste, its properties favour the development of LWAs. However, research into their use is scarce and superficial. The aim of this research is to evaluate the application of SCG and RHA as raw materials in the production of a new sustainable LWA. The starting materials were benefited and then characterized by laser granulometry, X-ray fluorescence and diffraction, and scanning electron microscopy. The mixtures were then formulated according to the Riley diagram. The specimens developed were then dried and sintered at temperatures of 1100 to 1250 °C. A total of 20 different specimens were produced, with clay substitution ranging from 15% to 62%, 12 of which have at least one engineering application. The manufactured aggregates had a bloating index (BI ) of –79.90% to –7.80%, loss of mass (LOI ) of 15% to 53%, particle density ( ρd ) of 0.88 to 2.23 g/cm3, water absorption (WA24H) of 0.1% to 61.7% and crushing strength (S ) of 0.81 to 29.32 MPa, as well as being assessed for mineralogy and microstructure. In general, the main properties of LWAs were affected by the firing method and the proportions of starting materials. The results show that the production of sustainable LWAs from SCG and RHA is feasible, with the appropriate indices being achieved for application in engineering works and services.

ABSTRACT Concrete may develop micro cracks and contains pores, both of which are extremely undesirable since they allow water and other harmful chemicals to enter the material easily. The Bacterial Self Compacting (BSCC), which continually deposits calcite in concrete, is one efficient method for sealing fissures. Microbiologically Induced Calcite Precipitation, or MICP, is the term used to describe this occurrence. The urease enzyme assists bacteria in the deposition of calcium carbonate (CaCO3). Because it is bio-based, environmentally safe, and long-lasting, the bacterial remediation method outperforms other methods. The high pH of concrete and the mechanical forces that occur during mixing require bacteria to provide resistance. The MICP-induced concrete has become a significant topic of study for high performance building. The utilization of bacteria for the production of bacterial SCC has received very little attention in India, and the durability properties of these mixtures have also received inadequate attention. Bacterial Self-Compacting Concrete (BSCC) of M60 grade, with bacteria as admixture along with flyash and silica fume. This research is to know about the workability, mechanical properties, durability and micro analysis of bacterial self-compacting concrete. The test results shows the bacteria of size 106 shows the best results in bacterial self-compacting concrete.

ABSTRACT This study is aimed at analyzing the mechanical behavior of low-density polyethylene (LDPE) plastic bags exposed for three years to air, immersed in polluted and tap water, buried in soil, and exposed on the soil surface. The pH and conductivity analyses for polluted water resources, clean water and soil extract were performed. Semi-quantitative chemical analysis of soil using X-ray fluorescence spectrometry (XRF) was performed. For the mechanical assay, a 100 kN load cell was used subjected to a traction with obtaining strain curve x deformation. The aqueous soil extract is rich mainly in nitrate, sulfate, and calcium. The polluted water in which the bags were immersed had a high concentration of chlorides, and contained nitrate, sodium, and calcium. Finally, tap water contained mostly sulfate, sodium, calcium, and chloride ions. However, the chloride content of polluted water is ten times the content of tap water. The tensile strength and elongation of degraded samples are lower than the reference, confirming the process of degradation. An exception was the deformation of plastic bag buried in soil which was the highest.

ABSTRACT Despite the increasing use of plaster as a construction material, due to its numerous advantages when compared to cement, its use is still restricted, because of its low mechanical resistance and high solubility in water. In this context, research has been carried out related to the addition of nanomaterials to improve the mechanical and physical properties of plaster in civil construction. A highly available, low-cost nanomaterial with excellent properties is nanotalc. In this work, nanocomposites with dimensions of 40 × 40 × 160 mm were produced with ultrafine micronized nanotalc replacing plaster in proportions of 0%; 0.5%; 1%; 1.5% and 2%. The physical and mechanical properties of the nanocomposites were evaluated according to standards. The nanocomposites produced with 1% nanotalc showed satisfactory results for physical and mechanical properties, with an increase of 1.8% in apparent density and 24.12% in compressive strength, and a decrease in water absorption of 6.23%, compared to the composite without the incorporation of nanotalc. The production of nanocomposites with the incorporation of 1% nanotalc is viable and shown to be promising, presenting potential for application as linings and internal partitions, since they showed low water absorption due to the hydrophobicity of nanotalc.

ABSTRACT Given the difficulty in machining of hardened steels and the complex geometries commonly observed in injection molds, besides the necessary surface quality to produce plastic parts without defects, an adequate milling strategy must be chosen, which consists in defining not only the cutting parameters and the tool, but also its trajectory. Thus, the present work focuses on investigating the influence of two different cutting strategies in milling process on the surface quality of a convex (constant curvature) surface on two types of material. The quality was evaluated through distinct roughness parameters, which were correlated to the perceived gloss and analyzed in combination with the characteristics of each material, such as hardness and microstructure. From the results obtained after the finishing operation, it was possible to verify the positive influence of the parallel tool path, which led to the lowest values of average Sa and maximum Sz roughness in both steels, VH13IM and VTMPlus, in comparison to the zig-zag tool path. The combination of low roughness values with a homogeneous topographic profile of the surface led to a higher gloss level and mirror effect.

RESUMO Dada a dificuldade em se usinar aços endurecidos e a complexidade das geometrias comumente observadas em moldes de injeção, além da qualidade da superfície necessária para a geração de peças plásticas sem defeitos, uma estratégia adequada de fresamento deve ser escolhida, o que implica na definição não apenas dos parâmetros de corte e da ferramenta, mas também de sua trajetória. Assim, o presente trabalho tem como foco a investigação da influência de duas diferentes estratégias de corte no fresamento sobre a qualidade de uma superfície convexa (de curvatura constante) em dois tipos de materiais. A qualidade foi avaliada a partir de diferentes parâmetros de rugosidade, os quais foram correlacionados com o brilho percebido e analisados juntamente às características de cada material, como dureza e microestrutura. A partir dos resultados encontrados na etapa final de acabamento, foi possível constatar a influência positiva da estratégia de corte em paralelo na obtenção dos menores valores de rugosidade média Sa e máxima Sz em ambos os aços estudados, VH13IM e VTMPlus, em comparação com a estratégia zig-zag. O conjunto de baixos valores de rugosidade com um perfil topográfico homogêneo da superfície levou a um maior brilho e grau de espelhamento.

ABSTRACT Fly ash is used partially as a replacement to cement to make the concrete. Fly ash contains SiO2 and Al2O3, which contribute to increase the strength of concrete. In the current investigation, fly ash has been replaced with varying percentages of nanosize in concrete, and the strength of the resulting hardened concrete has been evaluated. The production of nanosized fly ash has been made by the ball milling process and the analyses has been completed using scanning electron microscope (SEM) and X-ray diffraction (XRD), in order to determine the chemical and physical composition of the nanoparticles of fly ash. The nano fly ash concrete (NFAC) have been undergone for the durability tests of acid, sulphate and chloride attack. The concrete with 23% of nano fly ash replaced with cement performs well against these adverse conditions. The comparison has been made between the conventional (CC), raw fly ash (RFAC) and NFAC. Nano fly ash makes concrete much denser and more resistant to cracking. So the durability behaviour of NFAC is much better than CC and RFAC. The percentage of reduction in strength after durability aspects is varies from 0.03% to 10.75% for the NFAC.

ABSTRACT The urine bag is a thermo-labile medical-hospital device used in clinical/surgical procedures in urine drainage and collection. As it is a thermolabile material, it is commonly sterilized by ethylene oxide, a highly toxic, mutagenic and carcinogenic cyclic ether gas. Currently, several countries require, through documents and standards, the quantification of ethylene oxide in medical and hospital devices. Thus, this work describes the development and validation of a method employed for the quantification of ethylene oxide (ETO) in urine bags. The method was developed based on the guidelines of ISO 10993-7, ANVISA and INMETRO. The work range, linearity, limits of detection and quantification, repeatability, intermediate precision and selectivity were evaluated. Statistical tools such as Levene's test, Grubbs, residual analysis, F-test of two variances, paired sample T test and ANOVA table, were also applied to evaluate the method. The linearity of the work range (10 – 400 mg.L-1) showed an adequate correlation coefficient (r > 0.9993), with a homoscedastic profile with absence of outliers while the limit of detection and quantification were 1,95 and 6,5 mg.L-1 respectively. After validation, 45 samples of urine bags of different batches were evaluated, which demonstrated levels of ETO below the limit of detection (1,95 mg.L-1). The results highlight a simple method that meets several regulations with a wide working range, high sensitivity and capability to quantify ETO not only in urine bags but also in other medical devices.

ABSTRACT The use of polymeric compounds is limited to sealing masonry in Brazil, due to the criteria of the NBR 16590 [1]. However, one must evaluate how much this material can contribute when applied to structural masonry. Thus, this study investigated the operation of a type of polymeric compound when applied in structural masonry, performing chemical and physical characterization tests and adhesion at the interface between block and binder. Besides these, we investigated the axial compressive strength of full-scale walls was investigated. One sample was made with horizontal joints filled with cementitious mortar and two containing polymeric compound, with 2 and 4 fillets for settlement the blocks. The characterization results of the binder material and interface showed that the polymeric compound has greater resilience and better adherence performance when compared to cementitious mortar. In the overall analysis of the system, it was found that masonry built with 4 fillets of polymeric composite achieved the same compressive strength of the sample built with conventional cement mortar (~ 138 kN/m at break), the sample with 2 fillets presented higher vertical deformation, 25% in relation to the others, showing the potential use of the polymeric compound in structural masonry.

RESUMO O uso dos compostos poliméricos se limita às alvenarias de vedação no Brasil, devido aos critérios da NBR 16590 [1]. No entanto, deve-se avaliar o quanto este material pode contribuir quando aplicado em alvenarias estruturais. Sendo assim, esse estudo investigou o funcionamento de um tipo de composto polimérico, quando aplicado em alvenarias estruturais, realizando ensaios de caracterização química e física do material e de aderência na interface entre bloco e o ligante. Além dessas, foram investigadas a resistência à compressão axial de paredes em escala real, sendo uma amostra executada com as juntas horizontais preenchidas por argamassa cimentícia e outras duas contendo composto polimérico, com 2 e 4 filetes para assentamento dos blocos. Os resultados de caracterização do material ligante e interface mostraram que o composto polimérico possui maior resiliência e melhor desempenho à aderência, quando comparado à argamassa cimentícia. Já na análise global do sistema, verificou-se que a alvenaria construída com 4 filetes de composto polimérico atingiu a mesma resistência à compressão da amostra construída com argamassa cimentícia convencional (~138 kN/m na ruptura), a amostra com 2 filetes apresentou maior deformação vertical, 25 % em relação as demais, mostrando o potencial de utilização do composto polimérico em alvenaria estrutural.

ABSTRACT The choice of floor type within the animal production system is an important factor, as it is associated with a high incidence of changes in locomotion, hoof injuries and herd disposal, which has led producers to modify the type of flooring for more comfortable, durable and dry materials, such as rubber, however, the raw material makes the investment very high. Because polymeric waste is potentially recyclable and has good thermal and mechanical properties, it is feasible to develop research aimed at characterizing them in order to verify their feasibility of application as flooring for animal production installations. The present research analyzed the combination between the EVA residue and the regenerated rubber from tires, where samples were produced in 4 different concentrations: 0, 25, 50 and 75% of regenerated rubber. The samples were analyzed by scanning electron microscopy and submitted to tensile, permanent deformation under compression, abrasion and hardness tests. The sample with 75% showed greater softness and less residual deformation, which is a positive effect due to the reduction of stiffness due to the insertion of rubber in the compounds. However, due to the incompatibility of the blends and a significant decline in the mechanical properties, the sample without regenerated rubber has a greater potential for recycling and application for which the research aimed for. It is estimated that the property improvement can be achieved with the use of a compatibilizing agent that favors the adhesion between the materials.

RESUMO A escolha do tipo de piso dentro do sistema de produção animal é um fator importante, já que está associado a grande incidência de alterações na locomoção, lesões de cascos e descarte de rebanho, o que tem levado aos produtores modificar o tipo de piso por materiais mais confortáveis, duráveis e secos, como é o caso dos emborrachado, no entanto, a matéria-prima torna o investimento muito alto. Devido os resíduos poliméricos serem potencialmente recicláveis, apresentar boas propriedades térmicas e mecânicas, torna-se viável o desenvolvimento de pesquisas que visem caracteriza-los de modo a verificar sua viabilidade de aplicação como piso para instalação de produção animal. A presente pesquisa analisou a combinação entre o resíduo de EVA e a borracha regenerada oriunda de pneus, onde foram produzidas amostras em 4 diferentes concentrações: 0, 25, 50 e 75% de borracha regenerada. As amostras foram analisadas através da microscopia eletrônica de varredura e submetida a testes de tração, deformação permanente à compressão, abrasão e dureza. A amostra com 75% apresentou maior maciez e menor deformação residual, sendo este um efeito positivo devido a redução da rigidez devido a inserção de borracha aos compostos, no entanto, devido a incompatibilidade das blendas e declínio significativo das propriedades mecânicas analisadas, a amostra sem borracha regenerada apresenta melhor potencial de reciclagem e de aplicação a qual a pesquisa a destina. Estima-se que a melhoria de propriedade pode ser alcançada com uso de agente compatibilizante que favoreça a adesão entre os materiais.

ABSTRACT The application of intelligent materials in drilling fluids has greatly reduced the investment of human resources and effectively made up for the shortcomings of traditional drilling fluids, such as insufficient directivity, poor adaptive ability and difficult monitoring. Therefore, the research of intelligent drilling fluids is a valuable direction for the future oil and gas industry. In this study, the temperature-sensitive modified bentonite NIPAM-B developed by Pan Yi et al. was used as the drilling fluid base slurry, and the drilling fluid additives were optimized to complete the modulation of the intelligent drilling fluid inspection system. In addition, the rheology, filtration, shale wellbore stability and stability of the intelligent drilling fluid inspection system will be evaluated. The results show that the intelligent drilling fluid has good temperature-sensitive thickening performance, and the rheology is not affected by temperature changes, which can realize intelligent heating and thickening. In addition, compared with the original bentonite drilling fluid system, the intelligent drilling fluid has good fluid loss reduction ability and shale borehole wall protection ability, and the shale rolling recovery rate reaches more than 95 %.