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Polylactide (PLA) is an eco-friendly biodegradable thermoplastic with excellent processability, demanding less energy to be produced compared to the petroleum-based polymers. However, PLA has drawbacks that impose some restrictions of uses use such as poor toughness property. Blending PLA with other polymers is a more practical and economic way to improve its toughness. The present study assessed the effect of the addition of the pre-crosslinked powdered nitrile rubber (NBR) containing calcium carbonate (CaCO3) and extruder screw rotation on the mechanical, rheological, morphological and thermal properties of polylactide (PLA) by using a Central Composite Rotatable Design (CCRD) analysis, which provides statistical support for the experimental data. The results showed that NBR/CaCO3 can be used as toughness modifier for PLA. This property improved due to the increase in energy expended to deform the material and generate cracks, as showed in the impact and morphological analyzes. Despite this improvement, the presence of CaCO3 caused a slight decline in the thermal resistance of the composites. The influence of rubber (NBR/CaCO3) content in PLA matrix on rheological properties, such as elongation viscosity, melt strength and drawability was also investigated. The results showed that the composition PLA/NBR/CaCO3 with higher NBR/CaCO3 content can be used in thermoforming applications.

Rice husk (RH) residue was submitted to a sequence of experimental procedures, specifically to investigate the reaction time influence of NaOH pretreatment on the extraction of silica, hemicellulose, and lignin components. In order to follow the extraction of each non-cellulosic components of rice husk, techniques such as Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and scanning electron microscopy were performed on untreated RH and samples collected from the NaOH reaction media at several different reaction times, as well as the sample after alkaline-peroxide treatment. Under the process parameters used in the present study, the results showed that a great part of hemicellulose and silica contents was removed during the first 30 min of reaction time in NaOH pretreatment. Although there is evidence that NaOH pretreatment also removed some lignin content, the complete delignification process was more effective just after alkaline-peroxide reaction, which produced material rich in type I cellulose.

In the last few years some farmers of soybeans have been testing a sowing technique called "Cross Sowing". The adoption of cross-sowing in soybean cultivation may represent a viable alternative for producers. The objective of this study was to analyze the cross-sowing system in the soybean crop, verifying the degree of technology adopted by the producers and the results achieved by the adoption of the technique in the production areas. The methodology used was the Literature Review, performing a detailed analysis on the importance of the soybean crop for Brazilian agribusiness, as well as its growth and development in the agricultural production environment for a better understanding of the cross sowing system. In view of these considerations, it is worth noting that the cross-sowing system is a promising technique. However, new experiments should be conducted verifying the real answers of this new arrangement of plants, taking into account the particularities of each producer., Nos últimos anos alguns produtores de soja vêm testando uma técnica de semeadura denominada “Semeadura Cruzada”. A adoção da semeadura cruzada na cultura da soja pode representar uma alternativa viável para os produtores. O presente trabalho objetivou-se analisar o sistema de semeadura cruzada na cultura da soja, verificando o grau de tecnologia adotada pelos produtores e os resultados alcançados pela adoção da técnica nas áreas de produção. A metodologia utilizada foi a Revisão de Literatura, realizando uma análise detalhada sobre a importância da cultura da soja para o agronegócio brasileiro, bem como seu crescimento e desenvolvimento no ambiente de produção agrícola para melhor compreensão do sistema de semeadura cruzada. Diante destas considerações, destaca-se que o sistema de semeadura cruzada é uma técnica promissora. Entretanto, novos experimentos devem ser conduzidos verificando as reais respostas deste novo arranjo de plantas, atendendo as particularidades de cada produtor.

Apple stem grooving virus (ASGV, genus Capillovirus) is disseminated worldwide, usually causing a latent infection in most commercial apple cultivars. However, infected scions grafted onto sensitive material display reduction of yield, loss of fruit quality and tree decline. In Brazil ASGV is associated with severe phloem necrosis, xylem pitting and decline of apple trees on Maruba-kaido (Malus prunifolia cv. Ringo) rootstocks usually in a complex with other latent viruses. Two Brazilian ASGV isolates from a mixed infection causing differing reactions on apple cv. Fuji on Maruba-kaido rootstocks, i.e., normal growth vs. tree decline, have been completely sequenced. The differing intensity of symptoms they co-induced on several woody indicator species/cultivars are indicative of biological differences between the two inocula. Their nucleotide sequences are 92.2% identical and display between 79.2% and 97.1% identity with other ASGV isolates available in GenBank. The two isolates (M219-3 and M220) shared 92.3% deduced amino acid (daa) sequence identity for ORF1, 95.3% for ORF2 and 93.3% for the CP gene. A high degree of daa identity, 95.8% and 96.6%, was ob- served between the CPs of M219 ? 3 and M220, respectively, with the Brazilian isolate UV01. Potential recombination events and phy logenetic relationships to major parents were investigated in isolates M219 ? 3and M220. Keywords ASGV . Apple virus . Phylogenetic analysis . Recombination

Nos últimos anos alguns produtores de soja vêm testando uma técnica de semeadura denominada “Semeadura Cruzada”. A adoção da semeadura cruzada na cultura da soja pode representar uma alternativa viável para os produtores. O presente trabalho objetivou-se analisar o sistema de semeadura cruzada na cultura da soja, verificando o grau de tecnologia adotada pelos produtores e os resultados alcançados pela adoção da técnica nas áreas de produção. A metodologia utilizada foi a Revisão de Literatura, realizando uma análise detalhada sobre a importância da cultura da soja para o agronegócio brasileiro, bem como seu crescimento e desenvolvimento no ambiente de produção agrícola para melhor compreensão do sistema de semeadura cruzada. Diante destas considerações, destaca-se que o sistema de semeadura cruzada é uma técnica promissora. Entretanto, novos experimentos devem ser conduzidos verificando as reais respostas deste novo arranjo de plantas, atendendo as particularidades de cada produtor., Revista de Ciências Agrárias, vol. 41 n.º 2 (2018)

A análise de ressonância magnética nuclear, RMN, de alta resolução no estado sólido permitiu um estudo detalhado da dinâmica molecular de fibras naturais, entre elas duas obtidas a partir do tronco de bananeira e outra, da fruta do coco. Utilizou-se a técnica de relaxação nuclear para avaliar os domínios relacionados às diferentes mobilidades dos componentes dessas fibras, tais como celulose, hemicelulose e lignina. Também foram realizados testes para a quantificação do teor de lignina por método químico. A partir dos tempos de relaxação e da curva de domínios, foi possível verificar que as fibras com alto teor de lignina possuem tempos maiores de relaxação, pois esse componente da fibra apresenta uma estrutura, mais rígida, de anéis aromáticos. High-resolution nuclear magnetic resonance analysis, NMR, in the solid-state permitted a detailed molecular dynamic study of natural fibers, including two obtained from the banana tree stems and from coconut fruits. The nuclear relaxation technique was applied to evaluate the domains associated with different mobilities of the fiber components, such as cellulose, hemicellulose and lignin. Experiments were also done to quantify the lignin content using a chemical method. From the relaxation times and the domain curves, fibers with higher lignin content were found to have higher relaxation times, because they present a more rigid structure with aromatic groups.

The paper investigates the stress state at the bi-material interface crack-tip by the Photoelastic and Isopachic methods and the Finite Element Analysis (FEA). The principal stresses at the bi-material interface crack-tip are theoretically determined using the combination photoelastic and isopachic fringes. The size and the shape of crack-tip isochro-matic and isopachic fringes, at a bi-material interface under static load, are studied. When the crack-tip, which is perpendicular to interface, is placed at the interface of the bi-material, the isochromatic and the isopachic fringes depend on the properties of the two materials. Thus, the isochromatic and the isopachic fringes are divided into two branches, which present a jump of values at the interface. The size of the two branches mainly depends on the elastic modulus and the Poisson’s ratio of the two materials. From the combination of the isochromatic and the isopachic fringes, the principal stresses σ1 and σ2 can be estimated and the contour curves around the crack-tip can be plotted. For the FEA analysis, the program ANSYS 11.0 was used. The bi-material cracked plates were made from Lexan (BCBA) and Plexiglas (PMMA).

Brazil has a remarkable position in the use of renewable energy. The potential of natural resources in Brazil has motivated the use of these renewable resources to make technologies more sustainable. From the large variety of commercially available High Density Polyethylene (HDPE) from different sources, two were chosen for investigation: one produced from sugarcane ethanol, and the other one, a conventional polyethylene, produced from fossil resources. In the preparation of the composites, sponge-gourds also called Luffa cylindrica were selectec. The main application of this product is as bath sponge, whose production generates scraps that are generally burnt. In this work, the composites were prepared by blending the sponge scrap at different proportions (10, 20, 30 and 40% wt/wt) with high density polyethylene (HDPE) from renewable source by extrusion. The melt flow index analysis of the composites was determined and specimens were obtained by injection molding for the assessment of mechanical properties such as tensile (elasticity modulus), flexural and Izod impact strengths. The microstructure of the impact fractured surface of the specimen also was determined. The results showed that the addition of sponge scrap affects positively all the properties studied as compared to HDPE. The results of tensile strength, elasticity modulus and flexural strength were similar to those observed in the literature for composites of HDPE from fossil source. The microstructure corroborates the results of mechanical properties. It was shown that the sponge scrap has potential to be applied as cellulosic filler for renewable polyethylene, providing a totally renewable material with good mechanical properties.

Traffic congestion with frequent “stop & go” situations causes substantial pollutant emissions. Black carbon (BC) is a good indicator of combustion-related air pollution and results in negative health effects. Both BC and CO2 emissions are also known to contribute significantly to global warming. Current traffic control systems are designed to improve traffic flow and reduce congestion. The CARBOTRAF system combines real-time monitoring of traffic and air pollution with simulation models for emission and local air quality prediction in order to deliver on-line recommendations for alternative adaptive traffic management. The aim of introducing a CARBOTRAF system is to reduce BC and CO2 emissions and improve air quality by optimizing the traffic flows. The system is implemented and evaluated in two pilot cities, Graz and Glasgow. Model simulations link traffic states to emission and air quality levels. A chain of models combines micro-scale traffic simulations, traffic volumes, emission models and air quality simulations. This process is completed for several ITS scenarios and a range of traffic boundary conditions. The real-time DSS system uses all these model simulations to select optimal traffic and air quality scenarios. Traffic and BC concentrations are simultaneously monitored. In this paper the effects of ITS measures on air quality are analysed with a focus on BC.