Experimental and Numerical Analysis of Coffee Husks Biomass Gasification in a Fluidized Bed Reactor

AbstractA two-dimensional computational model was developed in order to describe the biomass gasification process in a fluidized bed reactor using coffee husks within the commercial CFD code FLUENT. Both, gas phase and solid phase, were described using and eulerian-eulerian approach exchanging mass, energy and momentum. Results from the numerical model were later compared with experimental data. The study was conducted in a pilot thermal gasification plant, installed at Portalegre's Industrial Park based on the fluidized bed technology, with a processing capacity of 70kg/h, and operating at around 800°C. The gasification tests were performed continuously for several days in order to optimize the heat value and composition of produced syngas. The simulated syngas composition is in good agreement with the experimental ones although slight deviation was shown especially on CO and H2. This was mainly due to kinetics were taken from literature and, and there for may differ greatly from one source to another. Also devolatilization was assumed instantaneous and no particular attention was paid to char conversion

Numerical and experimental analysis of municipal solid wastes gasification process

As the quantity of municipal solid waste (MSW) increases with economic growth, problems arise in regard to sustainable management solutions. Thermal treatment presents a valid option for reducing the amounts of post-recycling waste to be landfilled. Incineration technology, besides reducing the total volume of waste and making use of the chemical energy in MSW for power generation, has negative environmental impact from high emission of pollutants. Recent policy to tackle climate change and resources conservation stimulated the development of renewable energy and landfill diversion technology, thereby giving gasification technology development renewed importance. In this work a two-dimensional CFD model for MSW gasification was developed and an Eulerian-Eulerian approach was used to describe the transport of mass, momentum and energy for the solid and gas phases. This model is validated using experimental data from the literature. The numerical results obtained are in good agreement with the reported experimental results

Attractiveness Of Fallen Fleshy Fruits To Ants Depends On Previous Handling By Frugivores

Interactions between ants and vertebrate-dispersed fleshy fruits are common on the floor of tropical forests. These interactions are considered beneficial to seeds if ants clean the seed (which may prevent fungal contamination and/or increase germination success) or act as secondary fine-scale dispersers (depositing the seed in nearby nutrient-enriched nest sites). Benefits to seeds, however, may be constrained by limited ant access to fruits. Here, we experimentally tested whether ant access to fallen fleshy fruits of Psychotria suterella (Rubiaceae) can be affected by previous handling (including ingestion) by birds. We found that mandibulated fruits and fruits embedded in feces are more prone to be visited by ants compared to entirely intact fruits. Moreover, the number of ant species per station was higher for vertebrate-handled fruit categories. We suggest that ongoing vertebrate loss in tropical forests may affect this highly opportunistic and potentially mutualistic interaction.2018589Banks-Leite, C., Ewers, R.M., Metzger, J.P., Edge effects as the principal cause of area effects on birds in fragmented secondary forest (2010) Oikos, 119, pp. 918-926Beattie, A.J., (1985) The Evolutionary Ecology of Ant-Plant Mutualisms, , Cambridge University Press, CambridgeBieber, A.G.D., (2012) A Fragmentacao Florestal e A Interacao Entre Formigas e Diasporos Carnosos Na Floresta Atlantica, , PhD thesis. Universidade Estadual de Campinas, CampinasBöhning-Gaese, K., Gaese, B.H., Rabemanantsoa, S.B., Importance of primary and secondary seed dispersal in the Malagasy tree Commiphora guillaumini (1999) Ecology, 80, pp. 821-832Bolton, B., Alpert, G., Ward, P.S., Naskrecki, P., (2007) Bolton's Catalogue of Ants of the World, pp. 1758-2005. , CD-ROM. Harvard University Press, Cambridge, MassachusettsChristianini, A.V., Mayhe-Nunes, A.J., Oliveira, P.S., The role of ants in the removal of non-myrmecochorous diaspores and seed germination in a Neotropical savanna (2007) Journal of Tropical Ecology, 23, pp. 343-351Christianini, A.V., Oliveira, P.S., Birds and ants provide complementary seed dispersal in a Neotropical savanna (2010) Journal of Ecology, 98, pp. 573-582Cordeiro, N.J., Howe, H., Forest fragmentation severs mutualism between seed dispersers and an endemic African tree (2003) Proceedings of the National Academy of Sciences of the USA, 100, pp. 14052-14056Denslow, J.S., Moermond, T.C., The effect of accessibility on rates of fruit removal from tropical shrubs: An experimental study (1982) Oecologia, 54, pp. 170-176Galetti, M., Pizo, M.A., Morellato, L.P.C., Diversity of functional traits of fleshy fruits in a species-rich Atlantic rain forest (2011) Biota Neotropica, 11, pp. 181-193Kaspari, M., Removal of seeds from neotropical frugivore droppings: Ant responses to seed number (1993) Oecologia, 95, pp. 81-88Leal, I.R., Oliveira, P.S., Interactions between fungusgrowing ants (Attini), fruits and seeds in cerrado vegetation in Southeast Brazil (1998) Biotropica, 30, pp. 170-178Levey, D.J., Byrne, M.M., Complex ant-plant interactions: Rain forest ants as secondary dispersers and postdispersal seed predators (1993) Ecology, 74, pp. 1802-1812Lista de Especies da Flora Do Brasil, , http://floradobrasil.jbrj.gov.br/2012, Online Accessed on 20 August 2012Martinez-Mota, R., Serio-Silva, J.C., Rico-Gray, V., The role of canopy ants in removing Ficus perforata seeds from howler monkey (Alouatta palliata mexicana) feces at Los Tuxtlas (2004) Mexico. Biotropica, 36, pp. 429-432Munoz, M.C., Kattan, G.H., Diets of Cracidae: How much do we know? (2007) Ornitologia Neotropical, 18, pp. 21-36Oliveira, P.S., Galetti, M., Pedroni, F., Morellato, L.P.C., Seed cleaning by Mycocepurus goeldii ants (Attini) facilitates germination in Hymenaea courbaril (Caesalpiniaceae) (1995) Biotropica, 27, pp. 518-522Passos, L., Oliveira, P.S., Ants affect the distribution and performance of Clusia criuva seedlings, a primarily bird-dispersed rainforest tree (2002) Journal of Ecology, 90, pp. 517-528Passos, L., Oliveira, P.S., Interactions between ants, fruits, and seeds in a restinga forest in south-eastern Brazil (2003) Journal of Tropical Ecology, 19, pp. 261-270Passos, L., Oliveira, P.S., Interaction between ants and fruits of Guapira opposita (Nyctaginaceae) in a Brazilian sandy plain rainforest: Ant effects on seeds and seedlings (2004) Oecologia, 139, pp. 376-382Pizo, M.A., Guimaraes, P.R., Oliveira, P.S., Seed removal by ants from faeces produced by different vertebrate species (2005) Ecoscience, 12, pp. 136-140Pizo, M.A., Oliveira, P.S., The use of fruits and seeds by ants in the Atlantic forest of southeast Brazil (2000) Biotropica, 32, pp. 851-861Pizo, M.A., Oliveira, P.S., Size and lipid content of nonmyrmecochorous diaspores: Effects on the interaction with litter-foraging ants in the Atlantic rain forest of Brazil (2001) Plant Ecology, 157, pp. 37-52Rico-Gray, V., Oliveira, P.S., (2007) The Ecology and Evolution of Ant-Plant Interactions, , University of Chicago Press Chicago, IllinoisRoberts, J.T., Heithaus, E.R., Ants rearrange the vertebrate-generated seed shadow of a neotropical fig tree (1986) Ecology, 67, pp. 1046-1051Sallabanks, R., Courtney, S.P., Frugivory, seed predation, and insect-vertebrate interactions (1992) Annual Review of Entomology, 37, pp. 377-400Sheridan, S.L., Iversen, K.A., Itagaki, H., The role of chemical defenses in seed-carrying behavior by ants: A behavioral, physiological, and morphological study (1996) Journal of Insect Physiology, 42, pp. 149-159Silva, J.M.C., Tabarelli, M., Tree species impoverishment and the future flora of the Atlantic forest of northeast Brazil (2000) Nature, 404, pp. 72-74Silvius, K.M., Fragoso, J.M.V., Pulp handling by vertebrate seed dispersers increases palm seed predation by bruchid beetles in the northern Amazon (2002) Journal of Ecology, 90, pp. 1024-1032Snow, D.W., Tropical frugivorous birds and their food plants: A world survey (1981) Biotropica, 13, pp. 1-14Sokal, R.R., Rohlf, F.J., (1995) Biometry. 3rd Edition, , W. H. Freeman and Company New York New YorkTerborgh, J., Lopez, L., Nunez, V.P., Rao, M., Shahabuddin, G., Orihuela, G., Riveros, M., Balbas, L., Ecological meltdown in predator-free forest fragments (2001) Science, 294, pp. 1923-192

Does Inundation Risk Affect Leaf-cutting Ant Distribution? A Study Along A Topographic Gradient Of A Costa Rican Tropical Wet Forest

Abstract: Successional state of forest and availability of pioneer plants are recognized factors affecting densities of leaf-cutting ants. However little is known about how abiotic factors can shape nest distributions. We investigated the effect of topography, soil, forest successional state and inundation risk on nest density and size of Atta cephalotes colonies along streams in a tropical wet forest in Costa Rica. In each forest type, we surveyed 12 sites, each site comprising five transects (10 × 100 m) varying in topography and proximity to streambeds. We found no difference regarding nest size or density between forest types or soil consociation. Nest density varied with topographic environment, with significantly higher nest density on slope tops (farther from streambeds) and without colonies in valley bottoms (closer to streambeds). Nests found in areas affected by the last great inundation before our study were scarcer and smaller than nests in non-flooded areas. We showed that inundation events favour an accumulation of Atta colonies towards higher sites, where they are also allowed to become larger and may survive longer. Inundation risk may be a strong force shaping the distribution of leaf-cutting ant nests in tropical floodplain forests, even concealing the relevance of successional state of forest. Copyright © Cambridge University Press 2013.3018992Adis, J., Eco-entomological observations from the Amazon: III. How do leaf-cutting ants of inundation forest survive flooding? (1982) Acta Amazonica, 12, pp. 839-840Bitancourt, A.A., Expressao mateḿatica do crescimento de formigueiros de Atta sexdens rubropilosa representado pelo aumento do ńumero de olheiros (1941) Arquivos Do Instituto Bioĺogico de Sao Paulo, 12, pp. 229-237Corella, O., (2001) Elaboracíon de un Mapa Hist́orico Del Cambio de Uso Del Suelo en la Estacíon Bioĺogica la Selva, PuertoViejo de Sarapiqú?, Heredia, , Doctoral thesis, Instituto Tecnoĺogico de Costa RicaCosarinsky, M.I., Roces, F., Neighbor leaf-cutting ants and mound-building termites: Comparative nest micromorphology (2007) Geoderma, 141 (3-4), pp. 224-234. , DOI 10.1016/j.geoderma.2007.06.006, PII S0016706107001644Denslow, J.S., Tropical rainforest gaps and tree species diversity (1987) Annual Review of Ecology and Systematics, 18, pp. 431-451Farji-Brener, A.G., Why are leaf-cutting ants more common in early secondary forests than in old-growth tropical forests? An evaluation of the palatable forage hypothesis (2001) Oikos, 92 (1), pp. 169-177(2006) World Reference Base for Soil Resources. World Soil Resources Reports, (103), 128p. , IUSS WORKING GROUP WRB FAO, RomeKleineidam, C., Roces, F., Carbon dioxide concentrations and nest ventilation in nests of the leaf-cutting ant Atta vollenweideri (2000) Insectes Sociaux, 47, pp. 241-248Laurance, W.F., Ferreira, L.V., Rankin-de Merona, J.M., Laurance, S.G., Rain forest fragmentation and the dynamics of Amazonian tree communities (1998) Ecology, 79 (6), pp. 2032-2040McDade, L.A., Bawa, K.S., Hespenheide, H.A., Hartshorn, G.S., (1994) La Selva: Ecology and Natural History of A Neotropical Rain Forest, 493p. , University of Chicago Press, ChicagoPenaloza, C., Farji-Brener, A.G., The importance of treefall gaps as foraging sites for leaf-cutting ants depends on forest age (2003) Journal of Tropical Ecology, 19 (5), pp. 603-605. , DOI 10.1017/S0266467403003675Schnitzer, S.A., Carson, W.P., Treefall gaps and the maintenance of species diversity in a tropical forest (2001) Ecology, 82 (4), pp. 913-919Silva, P.S.D., Bieber, A.G.D., Leal, R., Wirth, I.R., Tabarelli, M., Decreasing abundance of leaf-cutting ants across a chronosequence of advancing Atlantic forest regeneration (2009) Journal of Tropical Ecology, 25, pp. 223-227Sokal, R.R., Rohlf, F.J., (1995) Biometry: The Principles and Practice of Statistics in Biological Research, p. 887. , (Third edition W. H. Freeman and Co., New YorkSollins, P., Sancho, F.M., Mata, R.C., Sanford, R., Soils and soil process research (1994) La Selva: Ecology and Natural History of A Neotropical Rain Forest, pp. 34-53. , McDade, L. A., Bawa, K. S., Hespenheide, H. A. & Hartshorn, G. S. (eds. University of Chicago Press, ChicagoVan Gils, H.A.J.A., Gaigl, A., Ǵomez, L.E., The relationship between soil variables and leafcutter ant (Atta sexdens) nest distribution in the Colombian Amazon (2010) Insectes Sociaux, 57, pp. 487-49

Deconica neorhombispora (Agaricales, Strophariaceae): New combination and synonym

Based on the study of type specimens, we conclude that Psilocybe subbrunneocystidiata is a synonym of P. neorhombispora. Because of its non-bluing nature, it belongs in Deconica and is named Deconica neorhombispora, comb. nov. It is re-described, discussed and illustrated

Deconica neorhombispora (Agaricales, Strophariaceae): New combination and synonym

Based on the study of type specimens, we conclude that Psilocybe subbrunneocystidiata is a synonym of P. neorhombispora. Because of its non-bluing nature, it belongs in Deconica and is named Deconica neorhombispora, comb. nov. It is re-described, discussed and illustrated