Genotypic variation in growth and lead accumulation among Brassica juncea accessions.

Selecting (inter-varietal) Brassica juncea for tolerance to metal-contamination has been proposed as a strategy to develop superior genotypes for phytoextraction of lead (Pb) through selection and breeding techniques. To understand the differences among accessions of a single species to Pb accumulation, a pot experiment was conducted with three B. juncea accessions under levels of Pb added to the soil (0, 90, 180, and 540 mg kg-1). The duration of the growth period was 100 d. Pb concentration levels did not affect the flowering of B. juncea accessions. Plant height, shoot dry matter, and root dry matter were reduced linearly when soil Pb concentration increased to 540 mg kg-1. A significant interaction between Pb concentration levels and accessions was observed for Pb concentration in shoots and roots, indicating genotypic variation in Pb absorption. The concentration of Pb in shoots in accession PI 180266 was 51% higher compared to accessions PI 649105 and PI 432379 when soil Pb concentration increased to 540 mg kg-1. It can be concluded that the B. juncea accessions differed significantly in Pb uptake, and the selection of tolerant cultivars might be helpful for Pb phytoremediation of contaminated soils.

Comparison of the emissions and performance of ethanol-added diesel-biodiesel blends in a compression ignition engine with those of pure diesel.

In this study, a biodiesel was produced from blending vegetable and animal sources with diesel and diesel-ethanol using a motor-generator set to evaluate its performance and emission characteristics. Fifteen and twenty percent of animal-vegetable biodiesel were added to each diesel-ethanol blend. A motor-generator test was conducted for each mixture; each sample was subjected to resistive loads from 2 to 5 kW with six repetitions. The physicochemical properties met the national standard guidelines, while the best specific fuel consumption (SFC) was observed for the 15% biodiesel-1% ethanol (B15E1) blend at the load of 5 kW with 327.069 g kW-1 h-1, followed by diesel (334.875 g kW-1 h-1). The exhaust gas temperature behaved differently depending on the ethanol concentration; it was lower when the concentration of added ethanol was higher. The NO emissions decreased while the SO2 emissions increased as the ethanol concentration increased.

Free fatty acids esterification catalyzed by acid Faujasite type zeolite.

The catalytic activity of the protonated form of H-Y(80) zeolite (Faujasite with high Si/Al ratio) was evaluated as an acid catalyst in the esterification step pre-treatment of FFA by means of the esterification reaction of oleic acid with methanol in soybean oil. The zeolite structure was characterized by XRD and FTIR. Textural characterization was carried out by N2 physisorption. The thermal stability was evaluated by TG-DTA and the acidity measured by NH3-TPD and Pyridine-FTIR. The limitations of the use of this zeolite in a pre-treatment for biodiesel production was investigated through oleic acid esterification in soybean oil, as a model reaction, performed with different temperatures, catalyst amounts and molar ratios. The results showed that the amount of remaining FFA decreased to values well below the initial amount. Under the optimal reactional conditions, conversions to methyl esters above 95% were achieved. Results support that such reactions can be performed under H-Y(80) zeolite catalysis and can be applied in a pre-treatment esterification of feedstocks with high contents of FFA. Catalyst reuse is feasible due to its easy separation from reaction products allowing new reaction cycles, as well as the application of the H-Y(80) zeolite in biodiesel production.

Power generation and gaseous emissions performance of an internal combustion engine fed with blends of soybean and beef tallow biodiesel.

This study aimed to compare the performance of an internal combustion engine fed with blends of biodiesel produced from soybean and diesel, and blends of biodiesel produced from beef tallow and diesel. Performance was evaluated in terms of power generated at low loading conditions (0.5, 1.0 and 1.5 kW) and emission of organic and inorganic pollutants. In order to analyse inorganic gases (CO, SO2 and NOx), an automatic analyser was used and the organic emissions (benzene, toluene, ethylbenzene and xylene - BTEX) were carried out using a gas chromatograph. The results indicate that the introduction of the two biodiesels in the fuel caused a reduction in CO, SO2 and BTEX emissions. In addition, the reduction was proportional to the increase in loading regime. Beef tallow biodiesels presented better results regarding emission than soybean biodiesels. The use of pure biodiesels also presented a net reduction in pollutant gas emissions without hindering the engine generator performance.

Metodologia experimental para avaliação de custos de produção e utilização de biodiesel: estudo de caso de quatro ésteres metílicos e óleo diesel comercial / Experimental methodology for assessing the cost of biodiesel production and use biodiesel: a case study of four methyl esters and commercial diesel fuel

Considerando que o Brasil detém uma vasta gama de matérias-primas para produção de biodiesel, e também que há a possibilidade de produção em pequena escala, prima-se por estudos de cunho econômico a partir de metodologias de fácil execução. O objetivo do trabalho foi demonstrar uma metodologia e sua aplicação para avaliação dos custos inseridos dentro do processo produtivo e de utilização do biodiesel. A metodologia foi aplicada a biodieseis originários de óleo de soja, girassol, frango e sebo bovino, dos quais se avaliaram economicamente os custos fixos e variáveis para conversão química dos óleos e gorduras em ésteres metílicos, em uma planta de produção experimental. Os custos de produção para cada uma das quatro citadas são distintos em função do valor inicial por litro de cada uma. Também fora avaliado o custo específico e o consumo específico de cada um dos biodieseis, a fim de determinar a diferença em relação ao óleo diesel comercial. No estudo de caso, os resultados mostraram vantagens para o óleo diesel, tanto no custo quanto no consumo. Comparando-se os biodieseis, o de sebo bovino apresentou-se com o menor custo de produção e o menor consumo.

Considering that Brazil has a wide range of raw materials for biodiesel production, and also the possibility of small scale production, there is a demand for economic methodology studies with easy implementation. The objective of this research was to demonstrate a methodology and its application to assess the costs within the production process and the biodiesel use. The methodology was applied to biodiesels originated from soybean oil, sunflower oil, chicken oil and beef tallow, which assessed the fixed and variable costs for chemical conversion of oils and fats into methyl esters in an experimental production plant. Production costs for each of the four mentioned esters are peculiar due to the initial value of each oil per liter. Also the specific cost and specific fuel consumption were evaluated for each biodiesel to determine the difference with the commercial diesel oil. The case study showed advantages for diesel oil, both in cost and consumption. Comparing the biodiesels, the beef tallow showed the lowest production costs and lower consumption.

Light and electron microscopical data on the spores of Thelohanellus rhabdalestus n. sp. (Myxozoa: Myxosporea), a parasite of a freshwater fish from the Kwanza River, Angola.

The myxosporean Thelohanellus rhabdalestus n. sp. (Myxozoa: Bivalvulida), a parasite of the freshwater fish Rhabdalestes maunensis (Fower) collected from the Kwanza River, Angola, is described based on light and electron microscopical studies. The parasite occurs in irregular, milky-whitish, cyst-like plasmodia (up to 0.8 mm in diameter) in close contact with the liver and heart. The spores are pyriform, with slight tapering anterior and round posterior ends, and measure 16.8 ± 0.5 µm (n = 50) long, 10.2 ± 0.6 µm (n = 50) wide and 5.6 ± 0.8 µm (n = 25) thick. The spore wall is partly surrounded by a discontinuous, closely adhered, external coat of electron-dense material of variable thickness (up to c.35 nm). A single flask-shaped polar capsule [7.2 ± 0.3 µm (n = 50) long and 4.0 ± 0.4 µm (n = 50) in diameter] lies close to the apex of the spores and contains a polar filament with six or seven (rarely eight) coils oblique to its longitudinal axis. Based on morphological and ultrastructural differences, compared with other members of Thelohanellus Kudo, 1933, and judging from the host-specificity of previously described species, we consider this species new to science. This is the first reported myxosporean from the Angolan fauna.