Abstract In this study, green high-density polyethylene (GHDPE) composites with 5, 10 and 15% natural powdered cork (CP) with and without 5% maleic anhydride (PE-g-MA) were developed in order to evaluate the potential of these materials for civil construction applications. The composites were produced in a co-rotating twin-screw extruder and injection molded. An impedance tube was used to determine the acoustic behavior of the composites, which were then used as ceiling tiles in prototypes of provisional constructions in order to study ascertain their performance with respect to thermal comfort in the City of Teresina, PI - Brazil. Our data indicates that composites sound absorption coefficient values are good between 500 and 1200 Hz, especially for those with a higher percentage of cork, with the lowest absorption rate observed for composites containing PE-g-MA. The composites used in the prototypes provided a decrease in the internal temperature of the built structure.

Abstract The present study evaluated the effect of the taper angle of different internal conical connection implants and cyclic loading on the implant-abutment bacterial seal. A total of 96 implant-abutment sets were divided into eight groups. Four groups of different taper degrees with cyclic mechanical loading of 500,000 cycles per sample, with a 120-N load at 2 Hz before analysis [16DC (16-degree, cycled), 11.5DC (11.5-degree, cycled), 3DC (3- degree, cycled) and 4DC (4- degree, cycled)] were compared to four control groups without cyclic loading [16D (16-degree), 11.5D (11.5-degree), 3D (3-degree), and 4D (4-degree)]. Microbiological analysis was performed by immersing all samples in a suspension containing Escherichia coli and incubating them at 37°C. After 14 days, the presence of bacterial seals was evaluated. Fisher-Freeman-Halton exact tests and binomial tests were performed (5% significance level). The groups showed significant differences in bacterial seal, and mechanical load cycling improved the bacterial seal in the 3DC group. In all other groups, no significant differences in bacterial seal were found between cycled and uncycled samples. To conclude, the internal conical connection with a 3-degree taper angle showed better results than the other connection with different angles when subjected to load cycling. However, none of the angles tested were fully effective in sealing the implant-abutment interface.

The present work investigates the aquatic biodegradation of poly(3-hydroxybutyrate) (PHB)/nanoclay bionanocomposites containing PP-g-MA as compatibilizing agent. Both pristine and organically modified (Cloisite20A®) montmorillonite clay were used as fillers in different content (1 and 3 wt%). The bionanocomposites were prepared by melt intercalation in a single screw extruder. There after films (50x50x0.5mm) were prepared by compression and assessed by X-ray diffraction. Aquatic biodegradation of the films was appraised by visual inspection, optical microscopy, counting and identification of bacteria. Results proposed that the water of the Parnaíba River in the city of Teresina (Piauí, Brazil) has microorganisms (Pseudomonas putida and Pseudomonas aeruginosa) capable of degrading these bionanocomposite films, particularly the films with 3 wt% organoclay. Our data indicated the bacteria Pseudomonas aeruginosa degraded dexterously all the films. This work collaborates with the preservation of the environment and expands the use of bionanocomposites in expendable items with the development of films with properties favorable to biodegradation in aquatic environments. It is believed that PHB/clay/PP-g-MA films emerge as a promising alternative for the packaging industry.

Resumo Estimamos um VAR estrutural (SVAR) baseado em Blanchard e Perotti (2002) com dados atualizados do governo central de Gobetti e Orair (2017) para estimar multiplicadores fiscais. O resultado sugere um multiplicador maior na amostra completa (1997-2018) em relação à amostra pré-crise (até 2014) para benefícios sociais e investimentos públicos. Nosso primeiro exercício avalia a reorientação da política fiscal para os subsídios entre 2011 e 2014, com base nos multiplicadores estimados a partir do SVAR. O PIB no cenário em que os subsídios são destinados aos investimentos públicos estaria 2.7% acima do PIB verdadeiro em 2014. O segundo exercício projeta que, caso os investimentos públicos mantivessem a mesma taxa média de crescimento de 2006-2010 durante a crise, o produto estaria 6% acima do PIB observado em 2017. Além disso, o PIB estaria 2.53% abaixo do verdadeiro se os benefícios sociais não tivessem crescido em 2016 e 2017.

Abstract We estimated a structural VAR based on Blanchard and Perotti (2002)’s methodology with updated data of the central government from Gobetti and Orair (2017) in order to estimate fiscal multipliers. The result suggests a higher multiplier in the complete sample (1997-2018) than in the pre-crisis sample (until 2014) for social benefits and public investments. Our first exercise assesses the reorientation of fiscal policy towards subsidies between 2011 and 2014. GDP in the scenario in which subsidies are destinated to public investments would be 2.7% above the actual GDP in 2014. The second exercise projects that, if public investments had kept the same average growth rate of 2006-2010 during the crisis, GDP would be 6% above the observed GDP in 2017. Also, GDP would be 2.53% below the actual if social benefits had not grown in 2016 and 2017.

This work developed ternary films based on Poly(Lactic Acid) (PLA), Cloisite 30B (C30B) and Oregano Essential Oil (OEO) as proposal to be applied in food packaging. The films thus manufactured were unscathed, with reduced surface defects. Their thickness and moisture content varied according to the composition and content of each component in the formulation. Optical micrographs indicated a homogeneous morphology, with good distribution of clay in the matrix. FTIR data confirms the incorporation of OEO into the films. TGA analysis indicated that the thermal stability of the films was not significantly affected by the incorporation of C30B and OEO. OEO incorporation did not promote an efficient antimicrobial action which is probably due to its retention by the clay. Further studies are needed to confirm this hypothesis. The combination between C30B and OEO in the PLA polymeric matrix is a promising proposal.

Resumo O objetivo deste artigo é verificar se o STF, STJ, TRF2 e TJRJ consideraram a pandemia de Covid-19 ao julgar pedidos de reintegração de posse e imissão na posse entre 06/02/2020 e 06/02/2021, e se observaram os parâmetros internacionais sobre remoções forçadas. Após analisarmos 291 decisões, constatamos que a pandemia não foi mencionada na maioria dos casos e os parâmetros internacionais foram ignorados.

Abstract The purpose of this paper is to verify if the Supreme Court, Superior Court of Justice, Federal Court of Appeals of the 2nd Circuit and the Rio de Janeiro State Tribunal considered the Covid-19 pandemic when judging repossession and possession lawsuits between 02/06/2020 and 06/02/2021, and whether international standards on forced eviction were observed. After analyzing 291 decisions, we observed that the pandemic was not mentioned in the majority of the decisions and that international parameters were ignored.

Abstract The paper presents empirical evidence from Brazil on the bidirectional relationship between inequality and the Covid-19 crisis: Racial, regional and income inequalities have both aggravated the pandemic and been exacerbated by it. The paper provides a measure of social risk factors to Covid-19, which is positively associated with the number of Covid-19 cases across Brazilian states. This is complemented by a discussion of the country's inequalities in access to healthcare and in the incidence of comorbidities, which elucidates observed disparities in the need of a ventilator and in the number of deaths by Covid-19. Finally, our empirical analysis suggests that the substantive fiscal effort in the country and particularly the implementation of the cash relief program Auxílio Emergencial neutralized the short-term increase in wage disparities but has been insufficient to neutralize the cost of multi-dimensional structural inequalities on Brazil’s death tolls.

Resumen Este artículo presenta evidencia empírica de Brasil sobre la relación bidireccional entre desigualdad y la crisis de Covid-19: las desigualdades raciales, regionales y de ingresos han agravado y se han exacerbado a causa de la pandemia. El estudio construye una medida de factores de riesgo social que se asocia positivamente con el número de casos de Covid-19 en los estados brasileños. Esto se complementa con una discusión sobre las desigualdades en el acceso a salud y en la incidencia de comorbilidades que explica las disparidades observadas en la necesidad de un ventilador durante la pandemia y en el número de muertes. Finalmente, nuestro análisis empírico sugiere que el sustancial esfuerzo fiscal y en particular la implementación del programa Auxílio Emergencial neutralizaron el aumento a corto plazo de las disparidades salariales, pero han sido insuficientes para neutralizar el costo de las desigualdades multidimensionales en el número de muertes en Brasil.

Abstract Polymer processing parameters may considerably affect final product characteristic as, if properly chosen, these parameters may lead to products with optimal properties. The aim of this work is to evaluate the rheological characteristics of poly(ethylene terephthalate) (PET) by torque rheometry, as well as to estimate its incipient degradation rate during processing in an internal laboratory mixer. In order to estimate the temperature coefficient of the viscosity (β), and the pseudoplasticity index (n) of PET, two sets of experiments need to be performed. In the first one, the polymer is processed at three different temperatures at a single rotor speed for 10 min, getting temperature coefficient of the viscosity equal to β = 0.053 °C-1. In the second set of experiments, the resin (PET) is processed at a single temperature at six different rotor speeds for the same time interval and the pseudoplasticity index was determined, n = 0.78. From the results obtained, it is possible to indicate the internal mixer as an equipment not only for mixing polymers or composites, but as a tool for determining important rheological variables for predicting degradative processes.

Abstract In this work, starch obtained from mango kernel seeds was applied in the preparation of films in combination with its hydrophobic derivatives. Chemical modification of starch was carried out at two different concentrations of vinyl laurate, in dimethyl sulfoxide, under basic catalysis. The degrees of substitution of the starch laurates were 2.4 and 0.3, respectively. None of the products formed films when dispersed in water. However, blends of starch/starch laurate (degree of substitution = 0.3) formed films after microfluidization of their aqueous suspensions. The blends with up to 15% wt of starch laurate (degree of substitution = 0.3) resulted in films of higher elongation at break, higher opacity and lower tensile strength and elastic modulus. The microfluidization of biopolymer suspensions was crucial to obtain films with lower water vapor permeability. X-ray diffraction results corroborated to the mechanical properties of the films, showing that the incorporation of starch laurate reduced the starch films crystallinity.

Abstract The use of polymer blends and composites based on fossil-based and bio-based polymers has become an important environmentally protective alternative for common use and disposable plastics applications such as packaging, bottles and trays. The disposal of these more degradable products, however, may also harm the environment and, therefore, recycling these systems becomes relevant. Recycling involves reprocessing which can significantly change the morphology and properties of polymeric products. Therefore, this study deals with the effects of reprocessing cycles on the properties and morphology of blends and nanocomposites based on fossil and bio-based polymers. The systems investigated were: a) neat polypropylene (PP), b) a polypropylene/poly(3-hydroxybutyrate) (PP/PHB) blend and c) PP/PHB/organoclay nanocomposite compatibilized with polypropylene-g-maleic anhydride (PP-g-MA) and erucamide. These materials were submitted to up to seven extrusion cycles in a single screw extruder operating at 60 rpm. Samples were taken after the first, third, fifth and seventh extrusion cycles and their tensile properties and morphology were determined. Scanning electron microscopy indicated that two phases were observed in the blend which showed spherical PHB domains. The addition of clay, PP-g-MA and erucamide improved the adhesion between the nanocomposites components. X-ray diffraction analysis showed that crystallinity tended to increase with the number of reprocessing cycles for all systems investigated up to the fifth cycle and then tended to decrease. A 10% crystallinity increase was observed for neat PP in the fifth cycle. In general, the tensile properties of all systems decreased with reprocessing and the highest losses were observed for the PP/PHB blend after seven processing cycles with 50% and 37% decreases in stress at break and elastic modulus, respectively. Impact strength of the PP matrix and of the PP/PHB blend tended to decrease with reprocessing, except for the nanocomposite which showed a slight increase especially after the seventh processing cycle in which an 18% increase in impact strength was observed.

ABSTRACT Two studies were carried out to evaluate the effects of levels of soybean meal produced from damaged soybean grains replacing normal soybean meal on in vitro and in situ digestibility of ruminant diets as well as on intake, digestibility, and animal performance of growing/finishing lambs. In trial 1, we evaluated the in vitro digestibility of each soybean meals (normal and damaged), as well as diets containing levels of the damaged replacing the normal (0, 333, 667 and 1,000 g.kg−1) soybean meal on kinetic parameters of in vitro cumulative gas production, in vitro dry matter and crude protein digestibility, in situ rumen-degradable protein, rumen-undegradable protein, and in vitro intestinal digestibility of rumen-undegradable protein. In trial 2, we used 48 growing/finishing lambs to evaluate the effects of damaged soybean meal levels (0, 333, 667, and 1,000 g.kg−1) replacing normal soybean meal in feedlot diets (20:80 roughage:concentrate ratio) on intake and digestibility of nutrients and on animal performance. The damaged soybean meal presented lower values for total gas production and in vitro dry matter digestibility than normal soybean meal. Higher rumen-undegradable protein was estimated for damaged soybean meal than for the normal and consequently lower rumen-degradable protein for damaged compared to normal. Because of the lower rumen-degradable protein, damaged soybean meal promoted lower in vitro ammonium nitrogen (NH3-N) concentrations than the normal in feedlot diets. In the in vivo trial, there were no effects of damaged soybean meal levels in the diets on intake and digestibility of nutrients (dry matter, organic matter, crude protein, and fiber) as well as on total weight gain, average daily gain, carcass yield, or feeding efficiency. Thus, damaged soybean meal can fully replace the normal one in lamb feedlot diets (in up to of 1,000 g.kg−1 of the normal soybean meal) without causing adverse effects on intake and digestibility of nutrients and on animal performance.

Abstract This study aims to evaluate the effects of natural weathering in the city of Teresina, State of Piauí, Brazil, on the morphology and mechanical properties of eco-composites based on high-density green polyethylene, powdered cork and compatibilizer processed in a twin-screw extruder and injection molded. The analyses revealed that although weathering induced surface bleaching of eco-composites and cracking, these effects were not intense in the compatibilized samples. The tensile properties of the investigated materials were affected by abiotic degradation, which led to a reduction of the tensile strength and elastic deformation of the eco-composites, however, the incorporation of PEgMA was fundamental for the maintenance of mechanical performance after natural aging. In general, the results obtained were satisfactory for external applications of the compatibilized eco-composite with 15% cork in the proposed weathering range, which indicates its possible use in temporary constructions.

Abstract The rheological behavior of poly (butylene adipate-co-terephthalate) (PBAT) and its composites prepared with three different organoclays was investigated. Composites containing up to 7.5%, w/w organoclay, were prepared by two routes: (a) direct melt blending in an internal laboratory mixer with high intensity rotors and (b) concentrates (prepared in the internal mixer) with 50 %, by weight, of the organoclays diluted in a co-rotating twin screw extruder equipped with a high intensity mixing thread operating at a nominal speed of 480 rpm. The samples were characterized by both torque and parallel plate rheometry. Results indicate that nanodispersions in the clay layers were obtained during processing and that, like the pure matrix, at high shear rates, the organoclay compounds follow the power law, although with higher viscosity. It is believed that the interaction of the polymer with the organoclay is responsible for the increase in melt viscosity (observed by increases in torque and relaxation time) of the hybrid systems.

Abstract Blends of Polystyrene (PS) and Poly(ε-caprolactone) (PCL) were twin screw extruded, two PSs, with low and high melt flow rate (MFR) were used and their feasibility within PCL investigated by means of torque rheometry, mechanical tests, heat deflection temperature (HDT) and scanning electron microscopy (SEM); predictive models were utilized to evaluate interfacial adhesion in PS/PCL blends. Results show that no decreasing was verified in torque rheometry plots suggesting thermally stable blends; elastic modulus decreased and elongation at break increased in PS/PCL blends compared to neat PS. PS/PCL blends with low MFR PS and higher PCL amount are more thermodynamically stable. Higher HDT was verified in PS/PCL blends. The trends observed applying predictive models are indicative of poor adhesion between PCL and PS, agreeing with coalescence and phase segregation as verified in SEM images. PS/PCL systems with higher MFR PS presented the best results.

Polymeric syntactic foams are composites made from the mixture of Hollow Glass Microspheres (HGM) and polymer matrices. One of their main characteristics is their low density and the production of these composites using a matrix derived from renewable sources potentiates their development without neglecting sustainability. In this paper , the properties of High Density Polyethylene (HDPE)/HGM syntactic foams containing 1% and 5% w/w HGM and 5% w/w of a compatibilizer are assessed. The composites were prepared by two processing routes: single screw extruder and twin screw extruder. The morphology and mechanical properties (tensile and impact) of the syntactic foams thus manufactured were ascertained. Morphological analysis indicated that matrix/filler adhesion was poor for all samples and that the best HGM dispersions were obtained in twin screw extruded samples. Mechanical properties were affected by the processing route adopted and by the content of hollow glass microspheres added. Elastic modulus, tensile strength and strain were reduced by 20, 10 and 23%, respectively, in systems processed in a twin screw extruder. Impact strength was the exception, with an increase of more than 300%. Higher contents of hollow glass microspheres led to reductions in mechanical strength of the syntactic foams, varying from 5% for the elastic modulus to 50% for strain.