Algorithms for Visualizing Phylogenetic Networks

We study the problem of visualizing phylogenetic networks, which are extensions of the Tree of Life in biology. We use a space filling visualization method, called DAGmaps, in order to obtain clear visualizations using limited space. In this paper, we restrict our attention to galled trees and galled networks and present linear time algorithms for visualizing them as DAGmaps.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Energy potential of native shrub species in northern Spain

This paper we present an energy review of the waste generated by shrub species in soils of low fertility for use as fuel in a power plant. The residues analysed belong to the species: Rhamus alaternus, Ulex europaeus, Prunus spinosa, Smilax aspera, Erica sp., Rubus ulmifolius, and Pteridium aquilinum. Gross calorific value (GCV), net calorific value (NCV), density, elementary chemical analysis, moisture content, percentage of ash, productivity, energy density and FVI (fuel value index) have been measured. These parameters have been determined for three levels of moisture (maximum, medium and minimum). At medium moisture level, the residues of U. europaeus are those that reach the greatest FVI, 20,000. In the other extreme is the P. aquilinum with an FVI of 403. The average productivity of waste, in t ha 1, of each species has been determined in order to know how much energy is stored per hectare. U. europaeus and P. spinosa are the species which accumulate more energy per hectare, with similar values of around 81 MJ ha 1 yr 1 and installed power of 2.59Wha 1. The energy recovery of the waste in a thermal power plant would generate an annual revenue of 14.6 MV, taking into account that 40% of the forest land covered by shrub in Cantabria is used for this purpose

Effect of biomass leaching on H2 production, ash and tar behavior during high temperature steam gasification (HTSG) process

The effect of biomass water leaching on H 2 production, as well as, prediction of ash thermal behavior and formation of biomass tar during high temperature steam gasification (HTSG) of olive kernel is the main aim of the present work. Within this study raw olive kernel samples (OK 1 , OK 2 ) and a pre-treated one by water leaching (LOK 2 ) were examined with regard to their ash fouling propensity and tar concentration in the gaseous phase. Two temperatures (T = 850 and 950 °C) and a constant steam to biomass ratio (S/B = 1.28) were chosen in order to perform the steam gasification experiments. Results indicated that considering the samples' ash thermal behavior, it seemed that water leaching improved the fusibility behavior of olive kernel; however, it proved that water leaching does not favour tar steam reforming, while at the same time decreases the H 2 yield in gas product under air gasification conditions, due to possible loss of the catalytic effect of ash with water leaching. © 2009

Atmospheric fluidized bed gasification of untreated and leached olive residue, and co-gasification of olive residue, reed, pine pellets and Douglas fir wood chips

The fluidized bed gasification of untreated and pre-treated olive residue and pre-treated olive residue mixed with reed, pine pellets and Douglas fir wood chips is studied. Leaching is used as a pre-treatment process targeted on the elimination of alkali metals such as K and Na as well as chlorine to reduce/eliminate the ash-related problems during gasification. The leaching pre-treatment process could affect the producer gas composition toward the lower or higher yield of CO and H-2 of the producer gas depending on the moisture content of parent fuels. The lower total tar yield of the producer gas in the case of leached olive residue was observed compared to untreated olive residue. At the same time, there are present wider varieties of different tar components in the producer gas of the leached olive residue compared to the untreated one. The distinctions in tar composition and content between the leached and untreated olive residue are attributed to the alkali and alkali earth metal and chorine chemistry affected by leaching pre-treatment. The addition of woody fuels and reed at elevated proportions resulted in the lower LHV value compared to the leached olive residue. The tar content of the producer gas is seen to increase adding reed and woody fuels to the leached olive residue, i.e. the producer gas contained additional variety of tar components whereas phenol becomes one of the key components determining the total tar content, apart from benzene, toluene and naphthalene. This is seen to be due to the higher cellulose, hemicelluloses, lignin as well as higher chlorine content of the reed and woody fuels compared to the leached olive residue. The olive residue is seen to be better fuel for gasification compared with woody fuels and reed. Even more, we believe that the leached olive residue is better compared to all other tested fuel/mixtures in this study. It is seen that the proportions of different fuels in the mixture play role in the composition of the producer gas.</p