The aeronautical sector has been, in the last decade, one of those that most invested in more efficient and ecological solutions in order to reduce significantly greenhouse gas and pollutant emissions. The introduction of biofuels in fuel mixtures for aircraft engines is a promising alternative in this sector. The main objective of this experimental study is understanding the influence of crossflow variation on droplet deformation and consequent impact outcomes. An experimental facility was developed and validated to study the impact of single droplets onto a dry, smooth aluminium impact surface under the influence of several crossflow velocities. Different crossflow velocities of 4,5,6,7 and 8m/s were tested. A combination of conventional jet fuel and a biofuel was considered to understand the behavior of jet fuel and biofuel mixtures, and three fluids were used: 100% jet fuel, 75% jet fuel/25% biofuel and 50% jet fuel/50% biofuel. Several parameters, including velocity components, impact angle and eccentricity, were analysed for the different crossflow velocities, and the spread and splash regimes were also defined for the different fluids. The results display that, for each crossflow velocity, an increase in the droplet impact velocity causes a shift from the spread to the splash regime. The presence of a crossflow induces deformation on the droplet, altering its outcome. Ellipsoidal droplets promote the occurrence of spreading, whereas splashing tends to occur for spherical forms, corresponding to higher and lower eccentricity values, respectively. A substantial increase in the crossflow velocity leads to aerodynamic breakup of the droplet.

This study examines the burning characteristics and disruptive burning phenomena of single droplets of aluminum nanoparticles (n-Al) stably suspended in a biofuel (HVO). The biofuel used in the present work is a promising alternative fuel already tested in the aviation sector to reduce greenhouse gas and pollutant emissions. Experiments were conducted with two particle sizes (40nm and 70nm) and two particle concentrations (0.5 wt.% and 1.0 wt.%) to study its influence when added to the biofuel. The effect of size and concentration of the aluminum nanoparticles was studied at 1100 °C in a drop tube furnace. This experimental facility allows the study of combustion characteristics of falling droplets, ensuring there is no influence of the supporting fiber on the burning rate and disruptive burning phenomena occurrence. A CMOS high - speed camera coupled with a high magnification lens was used to evaluate the droplet size, burning rate, and micro-explosions. Based on this procedure, pure biofuel droplets were compared with those of biofuel blended with nanoparticles. The results suggest that the combustion characteristics of pure HVO can be enhanced with the addition of aluminum nanoparticles. Furthermore, by decreasing the particle size, a slight increase in the burning rate of nanofuels was noticed. Additionally, an increase in the particle concentration leads to a pronounced increase in the burning rate. The particle concentration also influences the delay and intensity of micro-explosions, disruptive burning phenomena detected at the end of the droplet lifetime.

The combustion of wood pellets in a fixed bed combustor of a 20 kW capacity domestic pellet boiler was tested according to several factors including Power, Excess Air (EA), Primary/Secondary air Split Ratio (SR) and Grate Area (GA). The Taguchi method was applied to program the experimental design. Several parameters were measured, including gas emissions (CO), fuel bed temperature (measured at 4 different heights), and efficiency. The experimental results show that the lower CO emission and the higher efficiency were obtained at medium thermal loads and the highest temperature on the fuel bed was obtained at about ¼ of its height (15 mm). The results obtained from the analysis of variance (ANOVA) show that the SR and the Power are the most important factors contributing to the CO reduction and also increase the fuel bed temperature.

A compostagem dos resíduos orgânicos com a posterior incorporação dos compostos no solo é um processo eficaz para a melhoria das características do solo no modo de produção biológico. Para avaliar o efeito da composição de diferentes resíduos vegetais na evolução das características físico-químicas e das emissões gasosas durante o processo, procedeu-se à compostagem de resíduos de diferentes brássicas, de castanha e de jatropha. Estes foram compostados com adição de relva e palha em 15 compostores com a capacidade de 135 L. Os 15 compostores foram dispostos aleatoriamente, com cada um dos 5 tratamentos (testemunha, brócolo, couve-penca, castanha e jatropha), cada tratamento foi repetido em três compostores. Avaliaram-se as principais características físico-químicas (temperatura, teor de matéria seca, pH, condutividade elétrica, emissões de C-CO2, N-N2O, C-CH4 e C/N), bem como os teores de nutrientes de fitoquímicos. As elevadas temperaturas atingidas nos primeiros dois dias de compostagem estiveram associadas à rápida decomposição da matéria orgânica. Considerando a baixa C/N inicial, sugere-se cuidado ao adicionar materiais ricos em N como relva. As maiores emissões de C-CO2 foram registadas durante a fase termófila, mostrando uma relação direta com os picos de temperatura. No entanto, estas emissões ocorreram, embora em menor quantidade, durante todo o processo de compostagem. As emissões de C-CH4 ocorreram apenas nos dois primeiros dias de compostagem e as emissões de N-N2O foram registadas no início da compostagem e na fase de maturação. No final do ensaio a decomposição da matéria orgânica ainda não estava totalmente concluída uma vez que ainda ocorriam emissões de C-CO2 e de N-N2O. Relativamente aos glucosinolatos estes desapareceram logo após o arranque do ensaio, os compostos fenólicos totais tenderam a aumentar e os taninos tenderam a diminuir ao longo do processo de compostagem. Este estudo sugere que os resíduos de brássicas, castanha e jatropha poderão ser utilizados como materiais compostados para incorporação no solo, no entanto deverá haver o cuidado na mistura destes com outros materiais, de forma a originar um produto final estável rico em compostos húmicos. Relativamente ao uso de compostados de brássicas ricos em glucosinolatos, neste ensaio não se evidenciou qualquer resistência dos glucosinolatos à degradação durante a compostagem e consequentemente, capacidade fitopatogénica dos compostos finais.

A total of 70 Nellore bulls (18 ± 3 months of age) were used to determine the effects of crude glycerine (CG) replacing starch- v. fibre-based energy ingredients in low (LC; 0·40 concentrate) or high concentrate (HC; 0·60 concentrate) ? on a dry matter (DM) basis ? on DM intake (DMI), methane emissions and growth. Ten bulls were slaughtered (reference group) to obtain the carcass gain (CrG). The 60 remaining bulls (374 ± 24·5 kg) were allocated to a 2 × 3 factorial arrangement (two concentrate levels, LC or HC; and three feeding regimes, FR). The FR were: CO ? without CG and maize as an ingredient of concentrate; CGM ? inclusion of CG (0·10 of DM) replacing maize in the concentrate; and CGSH ? inclusion of CG (0·10 of DM) replacing soybean hulls (SH) in the concentrate. Bulls fed LC or HC had similar DMI (kg/d) and growth. The DMI and average daily gain (ADG) were similar among FR. Concentrate level and FR tended to interact for methane emissions (g) per kg DMI. Bulls fed CGM had a greater G : F (g CrG/kg DMI) than those fed CO or CGSH diets. Increasing dietary concentrate (0·40?0·60) did not affect intake, methane emissions, or growth. Inclusion of CG in diets to replace SH in LC diets tended to decrease methane emissions from animals. When CG replaces SH in the diets, CrG and G:F (g CrG/kg DMI) are decreased compared with bulls fed CGM.

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2017-09-05T18:31:56Z No. of bitstreams: 2 Giuseppe Eugênio Peruzo Iacono.pdf: 2577047 bytes, checksum: bb62d55c3be7ddb1b3582f74cf39b66b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)

The Municipal Solid Waste (MSW) increasing in the world is a direct consequence of population and consumption growth. Each year more and more MSW is generated, which needs to be correctly collected and transported. This MSW management stage addresses the collection and transportation of waste from cities to a landfill and is one of the steps that most damage the environment through greenhouse gas (GHG) emissions. This study made a historical analysis of the MSW management in the Novo Hamburgo city located in the Rio Grande do Sul state and proposed a new route for MSW collection vehicle trucks using different scenarios. For this, the Network Analyst tool was used within a Geographic Information System software to identify the most efficient routes for MSW collecting vehicles. Based on this information, the financial costs and GHG emissions to carry out the MSW collection were estimated. The results showed that to mitigate the gases emitted by MSW collection trucks in one year, it would be necessary to plant more than 285 thousand Atlantic Forest native trees accordingly to the routing scenario choose, this gives an average area equivalent to 15,900 soccer fields, without taking into account the transportation of this MSW to the Minas do Leão landfill, which is located more than 100 km away from the Nova Hamburgo center and would considerably increase this value. Therefore, the MSW management historical analysis and the definition of more efficient MSW collection routes will bring to the city better public cleaning services and environmental impacts mitigation.