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.

RESUMO A busca por materiais na construção civil ecoeficientes pode ser realizada adicionando ou substituindo as matérias-primas por resíduos gerados em outros setores industriais. Muitos destes resíduos são classificados como perigosos, sendo que a inertização dos compostos que conferem periculosidade pode ser realizada através da estabilização por solidificação (E/S) que ocasiona o encapsulamento e a fixação química de substâncias tóxicas. No entanto, no Brasil não há uma norma regulamentada ou mesmo uma recomendação técnica, que seja específica para produtos E/S utilizados como componentes de construção. Neste contexto, o presente estudo teve como objetivo avaliar a lixiviação do cromo em matriz de concreto de cimento Portland pelos métodos de imersão e irrigação, com vistas ao emprego destes métodos na avaliação ambiental de materiais e componentes da construção civil. Para isso, foram confeccionados corpos de prova de 25x200x400 mm com e sem adição de 2% de Cr2O3 (óxido de cromo) em relação a massa do cimento Portland, os quais foram submetidos a testes de lixiviação por imersão e irrigação. Os resultados obtidos permitiram verificar o encapsulamento do cromo no concreto e que os testes de lixiviação propostos em monólitos de concreto, durante a fase de uso, mostraram-se aplicáveis em 28 dias.

ABSTRACT The search for materials in eco-efficient civil construction can be carried out by adding or replacing raw materials with waste generated in other industrial sectors. Many of these residues are classified as hazardous, and the inertization of compounds that confer dangerousness can be performed through stabilization by solidification (S/S) that causes the encapsulation and chemical fixation of toxic substances. However, in Brazil there is no regulated standard or even a technical recommendation, which is specific for S/S products used as building components. In this context, the present study aimed to evaluate the leaching of chromium in Portland cement concrete matrix by immersion and irrigation methods, with a view to the use of these methods in the environmental assessment of materials and components of civil construction. For this, specimens of 25x200x400 mm were made with and without the addition of 2% Cr2O3 (chromium oxide) in relation to the Portland cement mass, which were subjected to immersion and irrigation leaching tests. The results obtained allowed to verify the encapsulation of chromium in the concrete and that the leaching tests proposed in concrete monoliths, during the use phase, proved to be applicable in 28 days.

RESUMO Este trabalho consiste na avaliação do comportamento mecânico, em especial da vida de fadiga, de algumas misturas asfálticas tradicionalmente utilizadas no estado de Goiás, Brasil. Para a preparação das amostras, a granulometria dos agregados foi definida por meio da metodologia Bailey e em seguida verificada pela Fração do Agregado Dominante (FAD). Além dos ensaios de fadiga, outros ensaios laboratoriais foram realizados para avaliação do comportamento mecânico das misturas. Os resultados obtidos nesta pesquisa indicaram que somente a seleção granulométrica a partir da metodologia Bailey não foi suficiente para que as mistura estudadas apresentassem melhorias quanto à deformação permanente, sendo necessário, portanto, a análise da porosidade FAD bem como da realização de ensaios mecânicos como o ensaio uniaxial de carga repetida para determinação do Flow Number. As misturas estudadas apresentaram bom comportamento quanto à fadiga se enquadrando na Classe 4 da metodologia utilizada no software brasileiro de dimensionamento de pavimentos (MeDiNA). Assim, constata-se que quanto à fadiga, as misturas estudadas podem ser consideradas satisfatórias. No entanto, em termos de deformação permanente elas não apresentaram o desempenho necessário, sendo que a adequação granulométrica baseada apenas na metodologia Bailey não foi suficiente para melhorar o Flow Number. A partir desses resultados, recomenda-se que a faixa indicada para o FAD seja atendida e que outros tipos de ligantes asfálticos sejam incorporados nessas misturas para obter melhor desempenho.

ABSTRACT This paper consists in the evaluation of asphalt mixtures regarding their mechanical behavior, especially the fatigue life of some asphalt mixtures traditionally used in the state of Goiás, Brazil. For sample preparation, the grain size distribution of the aggregates was defined using the Bailey methodology and then checked by the Dominant Aggregate Size Range (DASR). Besides the fatigue tests, other laboratory tests were performed to evaluate the mechanical behavior of the mixtures. The results obtained in this research were able to demonstrate that only the particle size selection from the Bailey methodology was not enough for a given mixture to present improvements in terms of permanent deformation. Therefore, analysis of the DASR porosity as well as mechanical tests such as the uniaxial repeated load test for determination of the Flow Number were necessary. The studied mixtures presented good fatigue behaviour and fit in Class 4 of the methodology used in the Brazilian design software (MeDiNA). Thus, this study points that for fatigue performance, the studied mixtures can be considered satisfactorily. However, in terms of permanent deformation they do not showed the necessary behavior, and the grain size adjustment based only at the Bailey method was not enough to improve the Flow Number. From these results, it is recommended that the DARS porosity range must be considered and other types of asphalt binders be incorporated into these mixtures to achieve their best performance.

Concrete with cactus is a new type of concrete with high fluidity, strength, and durability with more remarkable advantages. The present paper discusses the role of Euphorbia tortilis cactus (ETC) to achieve the strength, durability, and corrosion resistance properties of concrete specimens. In this work, M20 (2900psi) concrete was designed as per Indian standards, and cactus were used as an additive. ETC extracts from Tamilnadu (India) were replaced with water (1%, 3%, 5%, 7%, 9%) by weight. The performance of cactus concrete was analyzed through destructive and non-destructive tests to investigate strength properties. In addition to that, specific tests such as sorptivity, permeability, half-cell potential test, etc. have been performed further for durability and corrosion resistance. ETC concrete improves the fluidity, thereby enhancing the workability of the mixture. Concrete was analyzed through Scanning Electron Microscopy (SEM) to identify the particle distribution. Experimental investigation shows that the strength properties of concrete have been enhanced by 29% due to Polysaccharides at optimum level. However, durability is achieved at a high, which stimulates the effective filling of voids in concrete. It shows that better performance of concrete gives at optimum dosage. On Euphorbia tortilis cactus concrete, no literature has been discovered.

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.