Effects of thallus disturbance on abundance and biomass of soft-bottom species in Kongsfjorden in summer 2013

The effects of biotic disturbances, like seaweed whiplash, on the diversity of benthic communities are well documented for temperate coastal systems, yet missing for Arctic benthos. In Arctic soft-bottom habitats, kelp thalli occur either continuously (e.g. trapped by sediment) or sporadically (by drifting on the sediment) after detachment from rocky shores. To explore whether a kelp thallus can disturb the structure and diversity of a coastal Arctic soft-bottom assemblage, we continuously fixed a single thallus of the kelp Saccharina latissima to or sporadically (i.e. biweekly) moved it on the sediment and compared treatment effects to unmanipulated plots (= controls). On 6 September 2013 (i.e. after 73 days of manipulation), one sediment core was taken from each of the 30 plots (n = 10), from which the number of individuals of each of the 45 encountered animal species were recorded. The continuous presence of an experimentally fixed kelp thallus significantly reduced the number of individuals on average by 27 %. This disturbance effect was even stronger, on average 49 %, where a kelp thallus was biweekly moved on the sediment. Likewise, taxon richness was lowered by an average of 19 and 36 % where a S. latissima thallus was continuously or sporadically present, respectively. While the composition of taxa was also significantly different among all treatment groups, evenness and biomass were unaffected by kelp treatments. We conclude that the presence and already movements of a single kelp thallus can promote small scale patchiness in near-shore soft-bottom assemblage structure and diversity and exemplify a significant connection between rocky and sedimentary coastal habitats.

Fast pyrolysis of biomass in a circulating fluidised bed reactor

The objective of this work was to design, construct, test and operate a novel circulating fluid bed fast pyrolysis reactor system for production of liquids from biomass. The novelty lies in incorporating an integral char combustor to provide autothermal operation. A reactor design methodology was devised which correlated input parameters to process variables, namely temperature, heat transfer and gas/vapour residence time, for both the char combustor and biomass pyrolyser. From this methodology a CFB reactor was designed with integral char combustion for 10 kg/h biomass throughput. A full-scale cold model of the CFB unit was constructed and tested to derive suitable hydrodynamic relationships and performance constraints. Early difficulties encountered with poor solids circulation and inefficient product recovery were overcome by a series of modifications. A total of 11 runs in a pyrolysis mode were carried out with a maximum total liquids yield of 61.50% wt on a maf biomass basis, obtained at 500°C and with 0.46 s gas/vapour residence time. This could be improved by improved vapour recovery by direct quenching up to an anticipated 75 % wt on a moisture-and-ash-free biomass basis. The reactor provides a very high specific throughput of 1.12 - 1.48 kg/hm2 and the lowest gas-to-feed ratio of 1.3 - 1.9 kg gas/kg feed compared to other fast pyrolysis processes based on pneumatic reactors and has a good scale-up potential. These features should provide significant capital cost reduction. Results to date suggest that the process is limited by the extent of char combustion. Future work will address resizing of the char combustor to increase overall system capacity, improvement in solid separation and substantially better liquid recovery. Extended testing will provide better evaluation of steady state operation and provide data for process simulation and reactor modeling.

Effect of the temperature on the composition of lignin pyrolysis products

The temperature dependence of the pyrolysis products of two types of lignin (Alcell lignin and Asian lignin) was investigated using pyrolysis-gas chromatography-mass spectrometry (PyGC-MS). About 50 compounds were identified and quantified for each type of lignin over a temperature range of 400-800C. The maximum yield of phenolic compounds was obtained at 600C for both lignins, which was 17.2% for Alcell lignin and 15.5% for Asian lignin. Most of the phenolic compounds had an individual yield of less than 1%; however, for Alcell lignin, 5-hydroxyvanillin was the highest yield at 4.29 wt%on dry ash-free lignin, and for Asian lignin, 2-methoxy-4-vinylphenol was the highest yield at 4.15 wt % on dry ash-free lignin.

Genetic and environmentally derived variation in the cell wall composition of miscanthus and implications for thermo-chemical conversion

Fifteen Miscanthus genotypes grown in five locations across Europe were analysed to investigate the influence of genetic and environmental factors on cell wall composition. Chemometric techniques combining near infrared reflectance spectroscopy and conventional chemical analyses were used to construct calibration models for determination of acid detergent lignin, acid detergent fibre, and neutral detergent fibre from sample spectra. The developed equations were shown to predict cell wall components with a good degree of accuracy and significant genetic and environmental variation was identified. The influence of nitrogen and potassium fertiliser on the dry matter yield and cell wall composition of M. x giganteus was investigated. A detrimental affect on feedstock quality was observed to result from application of these inputs which resulted in an overall reduction in concentrations of cell wall components and increased accumulation of ash within the biomass. Pyrolysis-gas chromatography-mass spectrometry and thermo-gravimetric analysis indicates that genotypes other than the commercially cultivated M. x giganteus have potential for use in energy conversion processes and in the bio-refining. The yields and quality parameters of the pyrolysis liquids produced from Miscanthus compared favourably with that produced from SRC willow and produced a more stable pyrolysis liquid with a higher lower heating value. Overall, genotype had a more significant effect on cell wall composition than environment. This indicates good potential for dissection of this trait by QTL analysis and also for plant breeding to produce new genotypes with improved feedstock characteristics for energy conversion.

Water chemistry, carbonate system parameters, and macro-organism biomass of vent and off-vent sites in the Columbretes Islands Marine Reserve

Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallow water (less than or equal to 5 m depth) and therefore are not representative of the broad range of continental shelf habitats. Here, we show that a decrease from pH 8.1 to 7.9 observed in a CO2 vent system at 40 m depth leads to a dramatic shift in highly diverse and structurally complex habitats. Forests of the kelp Laminaria rodriguezii usually found at larger depths (greater than 65 m) replace the otherwise dominant habitats (i.e. coralligenous outcrops and rhodolith beds), which are mainly characterized by calcifying organisms. Only the aragonite-calcifying algae are able to survive in acidified waters, while high-magnesium-calcite organisms are almost completely absent. Although a long-term survey of the venting area would be necessary to fully understand the effects of the variability of pH and other carbonate parameters over the structure and functioning of the investigated mesophotic habitats, our results suggest that in addition of significant changes at species level, moderate ocean acidification may entail major shifts in the distribution and dominance of key benthic ecosystems at regional scale, which could have broad ecological and socio-economic implications.

Potencial antifúngico, antioxidante e inibidor da produção de aflatoxina por extratos fenólicos de Chlorella sp. e Spirulina platensis

A contaminação fúngica acarreta alterações na qualidade nutricional e no valor econômico de produtos alimentícios podendo causar danos patológicos em plantas, animais e humanos. A identificação da atividade antioxidante, antifúngica e antimicotoxinas, em extratos de microalgas com propriedade de inibir a multiplicação de fungos e subseqüente produção de micotoxinas abre a perspectiva de empregar substâncias mais eficientes e com maior ação específica contra estes microorganismos. Entre os compostos com propriedades inibidoras de radicais livres, de crescimento fúngico e produção de micotoxinas, destacam-se os compostos fenólicos, que podem inibir a atividade metabólica microbiana, dificultando a atividade de enzimas. Neste estudo foram avaliados o poder de inibição de multiplicação fúngica de Rhizopus oryzae e Aspergillus flavus pelos extratos fenólicos de Chlorella sp. e Spirulina platensis, bem como sua atividade antioxidante, e a atividade antimicotoxinas da última microalga contra Aspergillus flavus. O conteúdo de fenóis totais foi em média 1000 µgfenóis/g Spirulina platensis e 600 µgfenóis/g Chlorella sp., sendo que o acido gálico e o cafeíco foram identificados como compostos majoritários na Spirulina platensis. As determinações de glicosamina (parede celular) e ergosterol (membrana celular) mostraram-se bons indicativos do desenvolvimento microbiano permitindo uma boa estimativa da inibição dele. O extrato fenólico de Spirulina platensis apresentou capacidade de inibir cerca de 50% a formação da parede e da membrana celular para ambos os fungos estudados e de 100% a produção de aflatoxina B1 até o 10º dia de cultivo do Aspergillus flavus. Além disso, o extrato metanólico de Spirulina platensis inativou 53,5% o DPPH reativo, limitou o escurecimento enzimático ocasionado pela peroxidase em 55% e inibiu a peroxidação lipídica em 46% após 14 dias de armazenamento sob luz. Estes resultados mostram que a ação antifúngica, antimicotoxinas e antioxidante está naturalmente presente em alguns tecidos microbianos e que encontrar a forma de extraí-los e aplicá-los como conservantes alimentícios é muito promissor para substituição aos antifúngicos e outros conservantes químicos.

Influência da adição de cinza do bagaço de cana calcinada em sistemas de pastas para cimentação de poços petrolíferos

Cementing operation is one of the most important stages in the oil well drilling processes and has main function to form hydraulic seal between the various permeable zones traversed by the well. However, several problems may occur with the cement sheath, either during primary cementing or during the well production period. Cements low resistance can cause fissures in the cement sheath and compromise the mechanical integrity of the annular, resulting in contamination of groundwater and producing zones. Several researches show that biomass ash, in particular, those generated by the sugarcane industry have pozzolanic activity and can be added in the composition of the cementing slurries in diverse applications, providing improvements in mechanical properties, revenue and cement durability. Due to the importance of a low cost additive that increases the mechanical properties in a well cementing operations, this study aimed to potentiate the use of sugarcane bagasse ash as pozzolanic material, evaluate the mechanisms of action of this one on cement pastes properties and apply this material in systems slurries aimed to cementing a well with 800 m depth and geothermal gradient of 1.7 °F/100 ft, as much primary cementing operations as squeeze. To do this, the ash beneficiation methods were realized through the processes of grinding, sifting and reburning (calcination) and then characterization by X-ray fluorescence, XRD, TG / DTG, specific surface area, particle size distribution by laser diffraction and mass specific. Moreover, the ash pozzolanic activity added to the cement at concentrations of 0%, 20% and 40% BWOC was evaluated by pozzolanic activity index with lime and with Portland cement. The evaluation of the pozzolanic activity by XRD, TG / DTG and compressive strength confirmed the ash reactivity and indicated that the addition of 20% in the composition of cement slurries produces improvement 34% in the mechanical properties of the slurry cured. Cement slurries properties evaluated by rheological measurements, fluid loss, free fluid, slurry sedimentation, thickening time and sonic strength (UCA) were satisfactory and showed the viability of using the sugarcane ash in cement slurries composition for well cementing

Changes in biomass, chemical composition and nutritive value of Spartina alterniflora due to organic pollution in the Itanhaém River Basin (SP, Brazil)

Foram comparados a biomassa, a composição química e o valor nutritivo da macrófita aquática emersa S. alterniflora em um rio impactado por descargas de efluentes domésticos (Rio Guaú) e em um rio bem conservado (Rio Itanhaém). Amostras de S. alterniflora, água e sedimento foram coletadas nos dois rios, em novembro de 2001. O rio Guaú apresentou as maiores concentrações de N-Total e P-Total na água (415 e 674 µg.L-1, respectivamente) e sedimento (0,25 e 0,20% de Massa Seca, respectivamente), em relação a água (NT = 105 µg.L-1; PT= 20 µg.L-1) e sedimento (NT = 0,12% MS; PT = 0,05% MS) do rio Itanhaém. A biomassa aérea (316 g MS.m-2) e subterrânea (425 g MS.m-2) de S. alterniflora no rio Guaú foram significativamente maiores do que no rio Itanhaém (146 e 115 g MS.m-2). Além disto, os valores de NT, proteínas, PT, lipídios e carboidratos solúveis foram significativamente maiores na biomassa de S. alterniflora no rio Guaú. Por outro lado, a fração de parede celular e os teores de polifenóis foram maiores na biomassa de S. alterniflora no rio Itanhaém. Concluiu-se que o lançamento de efluentes domésticos em corpos d'água pode aumentar a biomassa e alterar a composição química de S. alterniflora. A maior disponibilidade de N e P no rio Guaú, provavelmente, é a causa dos maiores valores de biomassa, NT, PT, lipídeos e carboidratos solúveis em S. alterniflora neste rio.

Ambientes de cultivo, recipientes e substratos na produção de biomassa foliar e radicular em mudas de maracujazeiro amarelo em Aquidauana - MS

The objective of the work was to evaluate the effects of environment, recipients, and substrate compositions in passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) seedlings biomass production in Pantanal region from September to November of 2006. Experimental trials were conducted in four protected environments, in two types of containers and three different substrate compositions. The environments were: A1 (greenhouse covered with low-density, 150-microns-thick polyethylene film), A2 (monofilament black screened with mesh for 50% of shade), A3 (aluminized screened with mesh for 50% of shade) and A4 (environment covered with straw of native coconut palm); the recipients were: polyethylene bags (R1) (15 x 25 cm) and polystyrene trays (R2) (with 72 cells). There substrates were: S1 (soil + organic compost + vermiculite, 1:1: 1 v/v), S2 (soil + organic compost + sawdust, 1:1: 1 v/v) and S3 (soil + organic compost + vermiculite + sawdust, 1:1: 1/2: 1/2 v/v). The experimental design was completely randomized statistical analysis in split-split-plot, with fifteen replications. The treatments in the plot were environments, in the subplots were pots, and subsubplots were substrates (4 x 2 x 3 = 24 treatments). Fresh and dry mass of aerial and root system parts were evaluated. Environments with screen showed better results for seedlings of yellow passion fruit biomass in polyethylene bags. Polyethylene bags promoted higher biomasses. The substrate with vermiculite showed better results for both types of containers. The substrate with a higher percentage of sawdust showed the worst result.

Allometric models for estimating the phytomass of a secondary Atlantic Forest area of southeastern Brazil

The purpose of this study was to develop and validate equations to estimate the aboveground phytomass of a 30 years old plot of Atlantic Forest. In two plots of 100 m², a total of 82 trees were cut down at ground level. For each tree, height and diameter were measured. Leaves and woody material were separated in order to determine their fresh weights in field conditions. Samples of each fraction were oven dried at 80 °C to constant weight to determine their dry weight. Tree data were divided into two random samples. One sample was used for the development of the regression equations, and the other for validation. The models were developed using single linear regression analysis, where the dependent variable was the dry mass, and the independent variables were height (h), diameter (d) and d²h. The validation was carried out using Pearson correlation coefficient, paired t-Student test and standard error of estimation. The best equations to estimate aboveground phytomass were: lnDW = -3.068+2.522lnd (r² = 0.91; s y/x = 0.67) and lnDW = -3.676+0.951ln d²h (r² = 0.94; s y/x = 0.56).