On the Possibility to Run an Internal Combustion Engine on Acetylene and Alcohol

Abstract It is well known that acetylene is a high flammable and explosive compound. In comparison with commercial liquid fuels, very wide flammability limits and a low Octane Number have relegated the acetylene into the "iperdetonat" fuels category. Thus, it is impossible to run an internal combustion engine on acetylene without a detonation phenomena control system. The current paper deals with a theoretical and experimental analysis of an internal combustion engine running on acetylene and alcohol. A standard 8 kW spark ignition engine with carburettor was modified with electronic injection control system (ECU) and two standard commercial injectors: one for the acetylene and one for the alcohol. The two injectors were installed using a modified engine intake system. The ECU is able to manage two fuels: acetylene and alcohol. Moreover, an optimization method base on Genetic Algorithms and Neural Networks was used to cerate engine parameters map. Thus, Running an ICE on acetylene and alcohol it is possible to achieve acceptable engine performance and very low pollutant emissions

Analysis of Reforming Gas Combustion in Internal Combustion Engine

Abstract The present paper deals with the study of the combustion of reforming gas in a small size Internal Combustion Engine. Therefore, mathematical models of both reforming process and internal combustion engine were implemented. In particular, steams reforming of glycerol to produce synthesis gas and spark ignition four strokes ICE were studied. The reforming process mathematical model was verified using experimental data. Synthesis gas was used to feed the ICE with different syngas and engine configuration. On the basis of the comparison with the experimental results, it is possible to state that the mathematical model is validated. Engine performance and pollutant emission evaluation was carried out using the integrated mathematical models with reference to the engine running on standard commercial fuel. The results highlight a reduction in engine performance and, at the same time a reduction of pollutant emissions in terms of CO and CO 2

Experimental Analysis of a Plume Dispersion Around Obstacles

Abstract Nowadays, transport and deposition of aerosol particles (PM 2.5 , PM 10 , TSP) caused by industrial plants, environmental applications and transports, are of great concern to public health. Despite the establishment by the European Union of emission standards (European directive 2008/50/CE e.g) to control the limits of particulates in the air, the emissions by industrial plants are still not accurately monitored. In particular, the interaction between plume dispersion and obstacles, such as buildings, is not currently well studied. A lot of theoretical researches were carried out in this field with a lack of experimental data comparison. This paper focuses on a laboratory work made to better explain the interaction of a continuous plume released from a point source and various obstacles. First of all a vertical pipe was reproduced, a continuous aerosol emitter was characterized in terms of a specified and controlled mass flow and the ratio between smoke emission and the total suspended particulates thanks to use of the certified gravimetric calculation of PM 10 . The experimental campaigns were conducted by means of a wind tunnel all the data collected were validated. The characterization of plume was made by the use of several sensors and calculation of velocity in several points of the field. Moreover, the plume dispersion was studied also by using digital image analysis. It was then investigated downwind the influence of obstacles of various shapes and distances from source in terms of aerosol concentration in several points

Theoretical and Experimental Study of Gaussian Plume Model in Small Scale System

Abstract Atmospheric dispersion pollution modelling is of great and actual concern in the scientific international community. Many dispersion models have been developed and used to estimate the downwind ambient concentration of air pollutants from sources such as industrial plants, vehicular traffic or accidental chemical release. Among them, Gaussian model is perhaps the most commonly used model type. It is often used to predict the dispersion of air pollution plumes originated from ground-level or elevated sources. In this research an experimental campaign was carried out in the wind tunnel of the Industrial Engineering Department of University of Catania. It was tested an emission plume of particulate matters and the concentrations of PM 10 were evaluated in several points downwind beyond the emitter. Both the wind velocity and PM 10 mass flow were varied in order to test the differences in terms of PM10 concentrations in the sampling points. A Gaussian plume mathematical model was developed according the boundaries conditions of the experimental campaign. The results of the model were compared with experimental ones in order to identify the limits and the advantages of this model in such a small scale system

O ensino da leitura e da escrita no 1º ano de escolaridade: os resultados dos alunos em leitura

Tese de Doutoramento em Psicologia Aplicada, Área de especialidade Psicologia EducacionalO presente estudo teve como objetivo caracterizar as práticas de ensino da linguagem escrita em Portugal e perceber o seu impacto na aquisição da leitura no final do 1º ano de escolaridade. A primeira etapa deste estudo correspondeu a um estudo descritivo e comparativo com o realizado por Fijalkow (2003) em França. A partir da resposta a um questionário de 883 professores foi possível verificar que os professores dos dois países se aproximam no que diz respeito aos aspetos metodológicos do ensino da leitura e à avaliação da leitura e da escrita dos alunos. Contudo, os professores portugueses dizem utilizar com maior frequência do que os professores franceses, atividades a partir de livros infantis, outros materiais para além do manual e diferentes propostas de escrita. Na segunda etapa deste estudo, o questionário utilizado foi validado através da sua estrutura fatorial e foram utilizados os fatores revelados para a realização de uma análise hierárquica de clusters. Esta análise revelou três grupos de professores: a) um grupo de professores que centra as suas práticas no ensino do código da linguagem escrita (unidades curtas); b) um grupo que realça a construção de significado na interação com o material escrito (unidades longas); c) e um grupo de professores que reúne nas suas práticas características de ambos os grupos referidos anteriormente (unidades diversificadas). A terceira etapa realizada diz respeito à validação das respostas do questionário através da observação de sala de aula. Foram selecionados 5% dos professores de cada um dos três grupos constituídos (N=42). Cada professor foi observado duas vezes durante 60 minutos em situações escolhidas por si como situações privilegiadas para o ensino da linguagem escrita. Através da utilização de uma grelha de observação que divide as atividades desenvolvidas em atividades que remetem para o código ou para o significado, foi possível confirmar as respostas ao questionário para 55% dos professores participantes. No sentido de perceber o impacto das práticas dos professores na aquisição da leitura dos alunos foram selecionados os professores cujas observações foram coincidentes com as respostas ao questionário e avaliados os seus alunos com recurso a três provas de leitura: leitura de palavras isoladas, decisão lexical e compreensão. Participaram 461 alunos distribuídos pelos três grupos referidos anteriormente. Através da realização de uma MANCOVA, controlando a escolaridade das mães dos alunos, verificou-se que os alunos do grupo unidades diversificadas obtêm melhores resultados em todas as provas do que os alunos dos outros dois grupos. Foi ainda possível constatar que não existiram diferenças de desempenho entre os alunos do grupo unidades curtas e os alunos do grupo unidades longas.ABSTRACT: The present study aimed to characterize the teaching practices of written language and understand its impact on reading acquisition by the end of 1st grade. The first step of this study was a descriptive and comparative study to the one conducted by Fijalkow (2003) in France. Based on questionnaire answers of 883 teachers, we found that teachers from both countries have similar approaches regarding methodological aspects of teaching of reading and students’ assessment of reading and writing abilities. However, Portuguese teachers stated that they use more frequently activities from children's literature, other materials besides the manual and different writing proposals than French teachers. In the second step of the study, the questionnaire was validated through its factorial structure and the factors disclosed were used to perform a hierarchical cluster analysis. This analysis revealed three groups of teachers: a) a group of teachers who focus its practices in teaching the code of written language (short units), b) a group that emphasizes the construction of meaning in interaction with the written material (long units), c) and a group of teachers who gathered in their practices characteristics of both groups mentioned above (diversified units). The third step concerns the validation of the questionnaire answers through classroom observation. 5% of the teachers in each of the three groups were selected (N=42). Each teacher was observed twice during 60 minutes in situations identified by them as privileged situations for teaching written language. Using an observation grid which divides the activities conducted in code-activities or the meaning-activities it was possible to confirm questionnaire answers for 55% of the participating teachers. In order to understand the impact of teachers’ practices in students reading acquisition, teachers whose observations were coincident with the questionnaire answers were selected and their students were evaluated using three reading tests: single words reading, lexical decision task and comprehension task. Participants were 461 students distributed through the three groups previously mentioned. By conducting a MANCOVA, controlling mothers’ education level, we concluded that students in the diversified unit group obtain better results in all reading tests than students from the other groups. It was also possible to confirm that there were no differences in performance between students of the short units group and students of the long units group.Tese de Doutoramento em Psicologia Aplicada, Área de especialidade Psicologia EducacionalApoio financeiro da Fundação para a Ciência e Tecnologia (SFRH/BD/64630/2009