Maturity curve of sweet sorghum in function of total soluble solids concentration

Sweet sorghum (Sorghum bicolor (L.) Moench) has been standing out as a source of feedstock for ethanol production in Brazil from January to April (period characterized as off-season of sugarcane). The aim of this study was to construct a maturity curve of two sweet sorghum cultivars, BRS 508 and BRS 511, in order to identify the ideal point of harvest for each material and estimate the maximum of total soluble solids (TSS) reached by the cultivars. For this purpose, an experiment was carried out at Embrapa Agrossilvipastoril, located in Sinop-MT. The seeds of each cultivar were mechanically sown in contiguous lines, spaced 0.7m, aiming to establish a population 140,000 plants ha -1 . Fifteen days after flowering (DAF), plants were harvested weekly during nine weeks (71 DAF), aiming to evaluate TSS of each cultiva r along this period of time. The TSS was measured by digital refractometer ( o Brix scale) using syrup from stems of each cultivar by an electric milling. The maturity curves of each cultivar were constructed by values of TSS measured during nine weeks and the regression equations were obtained for each cultivar. In order to estimate the optimal harvest moment, the maximum point was calculated by derivation of the original equation. By deriving such equations, it was possible to estimate the number of DAF of each cultivar in order to know the highest TSS concentrations, whic h can be considered as the point of maximum maturity. In addition, the maximum TSS concentrations were estimated for each cultivar. The results showed that the cultivar BRS 508 obtained maximum concentration of 20.4 °Brix at 51 DAF. On the other hand, the cultivar BRS 511 presented a TSS peak value of 17.6 °Brix at 50 DAF. It was noted that BRS 508 obtained a higher content of TSS than BRS 511, with a magnitude approximately of 2 °Brix. However, the maturity cycles of both cultivars were similar, 50 and 51 DAF (around 130 days after sowing). After this period, the TSS concentrations tended to decrease for both genotypes, decreasing, consequently, the yield of ethanol per volume of syrup. The next stage of this work will be the evaluation of TSS and the volume of syrup produced, such characteristics are better correlated to the ethanol production and will help in the identification of the cultivar with better performance

Comportamento de híbridos de sorgo granífero cultivados na segunda safra no município de SINOP-MT.

O sorgo é uma gramínea de clima tropical de dias curtos, metabolismo C4, com eficiente mecanismo morfofisiológico, possuindo características de resistência ao déficit hídrico e habilidade de se manter dormente no período de seca (SANTOS, 2003; MAGALHAES; DURÃES, 2003). Tais características fazem com que esta cultura seja opção para cultivo em segunda safra, principalmente em períodos e regiões cujo cultivo de milho seja de risco pela possibilidade de restrições hídricas para fechamento do ciclo da planta. O levantamento da área plantada com sorgo na Safra 2013/14 é de 731 mil ha com produtividade de grãos de 2.587 kg ha-1 (CONAB, 2015). Maiores produtividades são alcançadas em lavouras que, seguindo planejamento adequado de plantio, utilizam sementes de cultivares recomendados para sua região de plantio. O melhoramento genético de plantas desenvolve variedades adaptadas a diferentes regiões e condições de cultivo, tornando importante que o produtor identifique aquelas que melhor se modele a sua realidade. Para tal, estudos de comportamento produtivo de genótipos no intuito de seleção daqueles com maior potencial produtivo e retorno econômico são recomendados antes do plantio de grandes áreas. Neste intuito, o presente trabalho avaliou o comportamento produtivo de híbridos de sorgo granífero cultivados em segunda safra, no município de Sinop, região norte de Mato Grosso.Editado por Aisy B. Baldoni, Fabiana A. de Rezende, José Ângelo N. de Menezes Júnior, Luciano B. Lopes, Sílvia de C. C. Botelho

Nitric Acid Functionalization of Petroleum Coke to Access Inherent Sulfur

Sulfonated carbon-based catalysts have been identified as promising solid acid catalysts, and petroleum coke (petcoke), a byproduct of the oil industry, is a potential feedstock for these catalysts. In this study, sulfur-containing (6.5 wt%) petcoke was used as a precursor for these catalysts through direct functionalization (i.e., without an activation step) with nitric acid to access the inherent sulfur. Catalysts were also prepared using sulfuric acid and a mixture of nitric and sulfuric acid (1:3 vol ratio). Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and titration were used to identify and quantify the acid sites. The activities of the prepared catalysts were determined for the esterification of octanoic acid with methanol. Petcoke had few −SO3H groups, and correspondingly no catalytic activity for the reaction. All acid treatments increased the number of −SO3H groups and promoted esterification. Treatment with nitric acid alone resulted in the oxidation of the inherent sulfur in petcoke to produce ~0.7 mmol/g of strong acid sites and a total acidity of 5.3 mmol/g. The acidity (strong acid and total) was lower with sulfuric acid treatment but this sample was more active for the esterification reaction (TOF of 31 h−1 compared to 7 h−1 with nitric acid treatment)

Influence of Reprocessing in the formation of functional groups during low density polyethylene aging

In recent years, the interest in polymer recycling has increased. However, in every reprocessing step the material undergoes shear stress and is affected by temperature and oxygen. The aim of this paper is to investigate the influence of multiple extrusion in the generation of functional groups, namely hydroperoxide, carbonyl, and transvinylene. Low density polyethylene was reprocessed three times in a single screw extruder. In each recycling step hot pressed films were prepared. These films were submitted to a heat treatment in an oven with air circulation and renovation to proceed with aging tests at different times and temperatures. The results obtained showed that all functional groups had their concentration increased with the increase in number of reprocessing, the aging time and temperature of the heat treatment. The factorial design was applied to verify the influence of these parameters. All the parameters had significant effects, since their regression coefficients had the same order of magnitude, with the most influential parameter being the aging temperature, followed by the aging time and number of extrusions. Most of the interactions were influential, indicating that the formation of functional groups depends upon their interaction, and not only on their isolated effects

High levels of serum mannose-binding lectin are associated with the severity of clinical signs of leptospirosis

The clinical heterogeneity observed in leptospirosis may be associated with host factors or bacteria virulence. Human serum mannose-binding lectin (MBL) recognizes many pathogens, and low levels of this lectin are associated with susceptibility to infection. MBL is also implicated in the modulation of the inflammatory process. We determined the levels of serum MBL during leptospirosis infection. A double-antibody sandwich ELISA was used to detect the immunoreactive serum MBL. The ELISA plates were coated with monoclonal antibody to MBL and bound MBL or recombinant human MBL were detected by rabbit anti-human MBL serum. HRPO-conjugated goat anti-rabbit antibody was used for detection of the reaction. Two groups of patients seen at referral hospitals in Recife, PE, Brazil, were divided according to the year of infection, 2001 (N = 61) or 2002 (N = 57) and compared in terms of disease severity and levels of serum MBL. A group of healthy volunteers (N = 97) matched by age, gender, and ethnic background was used as control. Patients infected in 2001 had more severe outcomes than those infected in 2002, including jaundice, hemorrhage, respiratory alteration, and renal complication (P = 0.0009; chi-square test). The frequency of patients producing serum MBL >1000 ng/mL was higher in the 2001 group than in the 2002 and control groups (P < 0.01), suggesting an association of MBL level with disease severity. The involvement of MBL and genetic variation of the MBL2 gene should be further evaluated to establish the role of this lectin in the pathogenesis of leptospirosis