Anaerobic digestion in sustainable biomass chains

This thesis evaluates the potential contribution of anaerobic digestion (AD) to the sustainability of biomass chains. Results provide insights in the technological potential to recover energy and valuable by-products from energy crops and residues, and evaluate biomass cascades involving AD technology for their feasibility and desirability. Embedding AD in biomass chains addresses current constraints towards increased use of biomass for energy production considering land competition and environmental pollution. In this context, so far the major advantages of AD to improve energy efficiency and closing material cycles have received, thus far, limited attention. As part of the experimental research an Oxitop® protocol was refined for screening plant material suitable for anaerobic digestion based on their energy content. Environmental factors influencing the test outcome are the use of NaOH pellets for CO2 scavenging, substrate pretreatment, microbial culture, and type of buffer. The use of NaOH pellets and substrate pretreatments were most influential on the results. By means of the developed Oxitop® protocol the relationship between plant ligno-cellulosic composition and the Biochemical Methane Potential (BMP) and first-order hydrolysis constant (kh) was researched. The Acid Detergent Fibre (ADF) and the Neutral Detergent Fibre (NDF) as analyzed by the van Soest method were proposed as suitable plant characterization techniques for predicting BMP and kh, respectively. The model proposed was further used to predict the biodegradability of 114 European plant samples identifying interesting crops and crop residues suitable for anaerobic digestion. Batch experiments on digestate quality during codigestion of maize silage and manure showed an increase of 20-26% and 0-36% in solublised NH4+ and PO43-, respectively, after 2 months of digestion. The largest fraction of the inorganic nutrients was found in the liquid fraction of the digestate, i.e. 80-92% NH4+ and 65-74% PO43-. Increase in manure content in the mixture showed a positive effect in the methane production rate. Digestion time and increased proportion of maize silage in the mixture positively influenced the availability of PO43-. The added value of AD within different biomass cascades was evaluated by means of a sustainability framework developed for the purpose. The sensitivity analysis of the energy balance of an AD facility showed that the most important energy loss when a high value substrate such as energy maize is employed are heat losses induced by restricted reuse possibilities within the cascade. In contrast, when low energy substrates such as manure are used, indirect energy inputs embedded in infrastructure become significant. The developed sustainability framework was applied for the Colombian case. Results show that production of bio-ethanol from cassava is only sustainable from an energy and greenhouse gas (GHG) perspective when energy recovery from the process residues, using AD, is part of the process. The exact outcome of the evaluation largely depends on variables like substrate drying, type of fuel used, reuse possibilities for the digestate and type of applied AD system. During the study of other Colombian biofuel cascades the contribution of by-products was shown to be crucial, constituting 41-68% of the sum of all energy flows. For oil palm, sugarcane, panelacane and cassava, the estimated energy contribution of the by-products to the different biofuel systems fluctuate between 51-158, 122-290, 71-170, and 36-71 GJ.ha-1yr-1, respectively. AD had also a positive impact on nutrient recovery and water savings in the studied chains. The energy, nutrient and water benefits were set in perspective by giving an indication on the economic benefits and land savings potentially attainable under Colombian conditions. <br/

Diversity of seed mineral composition of Phaseolus vulgaris L. germplasm

A collection of 155 accessions of ancient Portuguese common beans (Phaseolus vulgaris L.) was evaluated in relation to the content of 8minerals (Zn, Cu, Fe, Mn, Ca, Mg, P and K) important for human nutrition. A high degree of variability for P, Fe, Zn, Cu, Mn and Ca was observed in the collection. Total correlation matrix analysis revealed the existence of two important sets of strong positive correlations (P 0.0001), one involving P, Fe, Zn, Cu and protein, and the other Ca and Mn. The principal component analysis showed that Zn, Fe and Cu are highly correlated to the first component (27% of variability) and Mn and Ca to the second component (22% of the variability). The high mineral variability observed in the seeds of this common bean collection could be useful for the selection of cultivars with higher nutrition value and for the improvement of seed nutrition quality traits

Combining landscape fire simulations with stand-level growth simulations to assist landowners in building wildfire-resilient landscapes

The wildfire regime in Portugal has been responsible for millions of hectares of burnt area, and Alvares parish is no exception. In 2017, a severe wildfire burnt 60% of its area. Land abandonment has been increasing since the mid 20th century, and a large fraction of the forest area belongs to quasi-absent landowners. This has given rise to large, almost unbroken expanses of undermanaged forests that, in combination with rugged topography, originates a landscape prone to large, intense wildfires. Thus, a change in landscape composition and structure capable of reducing flammability and promoting fuel discontinuity is urgently needed. A fire spread simulator and a forest growth simulator were combined to show the impact of improving management at landscape level. It was assumed that the probability of large wildfires may be reduced by setting aside forest area for the implementation of a fuel break network (FBN) and increasing the area under sustainable forest management. Three levels of management intensity were simulated by restricting the area of Quasi-absent non-industrial owners to 34.5%, 20.1%, and 8.5% of the Alvares forest area, in favor of increasing the area of active and semi-active non-industrial owners (current, moderate, and high management scenarios). Different FBN extents, representing four levels of network implementation priority were combined with the management levels, resulting in 12 scenarios. To evaluate the impact of fire, simulations assuming no-fire, no-FBN, and current management intensity were performed, whereas the impact of operation costs was assessed assuming reduced costs for silvicultural operations. Per hectare simulations were then scaled up to the parish level and volume harvested and net present values were used to compare the management improvement scenarios. Results showed that fire has major repercussions on forest income, but these impacts can be minimized. Intensifying forest management and implementing the first priority FBN segments originated substantial improvements in financial outcome from timber production, close to those obtained for the full FBN implementation. Results also evidenced contrasting contributions from industrial and non-industrial owners with the later evidencing unbalanced cash-flows derailing the possibility for interesting forest incomes. The coupling of fire and forest growth simulations can be an interesting approach to assess the impact of different management and policy scenarios and inform policiesinfo:eu-repo/semantics/publishedVersio

Cultivo de Calophyllum braziliense em várzea e terraço fluvial e seleção de espécies para a conversão agroflorestal.

O cultivo agroflorestal de Guanandi - Calophyllum braziliense nas várzeas e terraços fluviais do Vale do Paraíba é sustentável e representa baixo impacto ambiental na principal bacia hidrográfica da região Sudeste do Brasil. Este estudo de caso contém informações do Projeto desenvolvido na centenária Fazenda Coruputuba, em Pindamonhangaba, SP. Aborda aspectos ecofisiológicos do gênero Calophyllum que torna o guanandi apto ao cultivo sob inundação e contém uma seleção de espécies adaptadas aos dois ambientes: várzea inundável e terraço fluvial

Scintillation efficiency of liquid xenon for nuclear recoils with the energy down to 5 keV

The scintillation efficiency of liquid xenon for nuclear recoils has been measured to be nearly constant in the recoil energy range from 140 keV down to 5 keV. The average ratio of the efficiency for recoils to that for gamma-rays is found to be 0.19+-0.02.Comment: 13 pages, 5 figure

Analysis Of The Ergosterol Biosynthesis Pathway Cloning, Molecular Characterization And Phylogeny Of Lanosterol 14 α-demethylase (erg11) Gene Of Moniliophthora Perniciosa

The phytopathogenic fungus Moniliophthora perniciosa (Stahel) Aime & Philips-Mora, causal agent of witches’ broom disease of cocoa, causes countless damage to cocoa production in Brazil. Molecular studies have attempted to identify genes that play important roles in fungal survival and virulence. In this study, sequences deposited in the M. perniciosa Genome Sequencing Project database were analyzed to identify potential biological targets. For the first time, the ergosterol biosynthetic pathway in M. perniciosa was studied and the lanosterol 14α-demethylase gene (ERG11) that encodes the main enzyme of this pathway and is a target for fungicides was cloned, characterized molecularly and its phylogeny analyzed.ERG11 genomic DNA and cDNA were characterized and sequence analysis of the ERG11 protein identified highly conserved domains typical of this enzyme, such as SRS1, SRS4, EXXR and the heme-binding region (HBR). 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The in vitro bioactivity of two novel hydrophilic, partially degradable bone cements

Composite bone cements were prepared with bioactive glasses (MgO–SiO2–3CaO Æ P2O5) of different reactivities. The matrix of these so-called hydrophilic, partially degradable and bioactive cements was composed of a starch/cellulose acetate blend and poly(2-hydroxyethyl methacrylate). The addition of 30 wt.% of glasses to this system made them bioactive in acellular medium: a dense apatite layer formed on the surface after 7 days of immersion in simulated body fluid. This was demonstrated both by microscopic and infrared spectroscopic techniques. The composition of the glass and, consequently, its structure was found to have important effects on the rate of the apatite formation. The combination of reactivity obtained by one formulation with the hydrophilic and degradable character of these cements makes them a very promising alternative to conventional acrylic bone cements, by allowing a better stabilization of the implant and a stronger adhesion to the bone