O ensino e aprendizagem do gráfico da função quadrática com e sem auxílio do Software Winplot

RESUMO: A utilização adequada das TIC no ensino da Matemática, nos dias de hoje é considerada por alguns como justificada e inevitável, esperando que a sua utilização melhore o ensino e a aprendizagem da Matemática. Nesta investigação, pretende-se testar o Software Winplot), no ensino e aprendizagem do gráfico da função quadrática com alunos do 10ºano, da Escola do segundo ciclo do Ensino Secundário nº9099, de modo a verificar se melhora o ensino e na aprendizagem desta temática.Para a nossa investigação Seleccionámos dois grupos de alunos do 10º ano que funcionaram como grupo de controlo e grupo experimental; depois de ambos os grupos terem realizado dois pré-testes, o grupo experimental realizou as aprendizagens no laboratório de informática com auxílio do Software Winplot, ao longo de 8 semanas, durante o 2º trimestre do ano lectivo de 2009/2010. O grupo de controlo realizou as aprendizagens, ao mesmo tempo que o grupo experimental, na sala normal de aulas sem auxílio do Software Winplot.Ao compararmos os dois grupos, o teste T de pares para amostras independentes, mostra-nos que estatisticamente não há diferenças significativas entre os dois grupos, porque os níveis de significância são maiores que p=0,05, desta feita podemos dizer que o grupo experimental, não obteve melhores resultados que o grupo de controlo, logo o Software Winplot não resultou o efeito desejado nas aprendizagens com alunos da 10ºano da Escola do segundo ciclo do ensino Secundário nº9099, sita no município de Viana (Luanda/Angola). ABSTRACT:The appropriate use of ICTs in teaching mathematics, today is considered by somo to be justified and inevitable, hoping that their use will improve the teaching and learning of mathematics.In this investigation, we intend to test the Software Winplot, teaching and learning of the graph of quadratic functions with students of grade 10, attending the second cycle of secondary School nº9099 in order to verify that improves teaching and learning of this subject.For our research selected two groups of students in 10th grade who acted as the controlo group and experimental group, after both group had undergone two pre-test, the experimental group performed the learning in the computer lab with the aid of Software Winplot, over 8 weeks during the second quarter of the academic year 2009/2010. Thr control gropu performed the learning, while the experimental group, in rregular class room without help of the Software Winplot.Comparing the two groups, the t test for independent samples pairs, shows us that there is no statistically significant differences between the two groups, because the significance levels are greater than p=0,05, this time we can say that experimental group, not yielded better results than the control group, so the Software did not result the desired effect on the learning with students from 10th grade of the School of the second cycle of Secondary nº9099, located in Viana (Luanda/Angola).

Fatores influenciadores da gestão da qualidade e independência do auditor: um estudo de caso

Dissertação apresentada ao Instituto Superior de Contabilidade para obtenção do Grau de Mestre em Auditoria Orientada por: Doutora Alcina Dias

João Romano Torres e Cia: hermenêutica social de uma editora

Em 29 de Outubro de 1885 era publicado o primeiro número d’O Recreio, Publicação Semanal, Litteraria e Charadistica, criado e dirigido por Ignacio Moreira. No número 26, de 9 de Agosto de 1886, na primeira página, sob o título “Expediente”, dá-se conta aos leitores e aos colaboradores que “d’este numero em deante toda a correspondencia deve ser dirigida a João Romano Torres, rua Nova de S. Mamede, aos Caldas, 26, 3.º - Lisboa” (p. 201). Para João Romano Torres, que acabara de adquirir a publicação, trata-se de um acto refundacional, que significará para o editor o início de um percurso editorial através do qual se dará origem a uma editora cuja actividade chegará ao último quartel do século seguinte, estabelecendo um catálogo que a tornou reconhecível e reconhecida no espaço do livro em Portugal. Desta editora se falará aqui apenas de um período situado entre o ano de 1885 e o fim da primeira década de 1900. ABSTRACT - On the 29th October 1885, the first issue of O Recreio, Publicação Semanal, Litteraria e Charadística (proposed English translation: The Playground, Weekly, Literary and Charades Publication) was published, created and headed by Ignacio Moreira. On the 26th issue, issued on the 9th August 1886, in the front page, under the headline “Dispatch”, it is imparted with readers and collaborators that “from this issue forward, all correspondence should be addressed to João Romano Torres, Nova de S. Mamede street, at Caldas, 26, 3rd - Lisbon” (p. 201). For João Romano Torres, who had just acquired the publication, this was a re-foundational act, which will represent for this publisher the beginning of a publishing trajectory through which a new publishing house will emerge, whose activity will reach the final quarter of the next century, establishing a catalogue which made it recognizable and recognized in the book field in Portugal. This publishing house will be addressed here regarding only the period spanning from the year 1885 to the end of the first decade of the 1900s.

Identificação e análise de movimento humano com ultrassons

Faz-se nesta dissertação a análise do movimento humano utilizando sinais de ultrassons refletidos pelos diversos membros do corpo humano, designados por assinaturas de ultrassons. Estas assinaturas são confrontadas com os sinais gerados pelo contato dos membros inferiores do ser humano com o chão, recolhidos de forma passiva. O método seguido teve por base o estudo das assinaturas de Doppler e micro-Doppler. Estas assinaturas são obtidas através do processamento dos ecos de ultrassons recolhidos, com recurso à Short-Time Fourier Transform e apresentadas sobre a forma de espectrograma, onde se podem identificar os desvios de frequência causados pelo movimento das diferentes partes do corpo humano. É proposto um algoritmo inovador que, embora possua algumas limitações, é capaz de isolar e extrair de forma automática algumas das curvas e parâmetros característicos dos membros envolvidos no movimento humano. O algoritmo desenvolvido consegue analisar as assinaturas de micro-Doppler do movimento humano, estimando diversos parâmetros tais como o número de passadas realizadas, a cadência da passada, o comprimento da passada, a velocidade a que o ser humano se desloca e a distância percorrida. Por forma a desenvolver, no futuro, um classificador capaz de distinguir entre humanos e outros animais, são também recolhidas e analisadas assinaturas de ultrassons refletidas por dois animais quadrúpedes, um canino e um equídeo. São ainda estudadas as principais características que permitem classificar o tipo de animal que originou a assinatura de ultrassons. Com este estudo mostra-se ser possível a análise de movimento humano por ultrassons, havendo características nas assinaturas recolhidas que permitem a classificação do movimento como humano ou não humano. Do trabalho desenvolvido resultou ainda uma base de dados de assinaturas de ultrassons de humanos e animais que permitirá suportar trabalho de investigação e desenvolvimento futuro.

Polycyclic aromatic hydrocarbon levels in three pelagic fish species from Atlantic Ocean: inter-specific and inter-season comparisons and assessment of potential public health risks

The concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) were determined in three commercially valuable fish species (sardine, Sardina pilchardus; chub mackerel, Scomber japonicus; and horse mackerel, Trachurus trachurus) from the Atlantic Ocean. Specimens were collected seasonally during 2007–2009. Only low molecular weight PAHs were detected, namely, naphthalene, acenaphthene, fluorene and phenanthrene. Chub mackerel (1.80–19.90 microg/kg ww) revealed to be significantly more contaminated than horse mackerel (2.73–10.0 microg/kg ww) and sardine (2.29–14.18 microg/kg ww). Inter-specific and inter-season comparisons of PAHs bioaccumulation were statistically assessed. The more relevant statistical correlations were observed between PAH amounts and total fat content (significant positive relationships, p < 0.05), and season (sardine displayed higher amounts in autumn–winter while the mackerel species showed globally the inverse behavior). The health risks by consumption of these species were assessed and shown to present no threat to public health concerning PAH intakes.

Lipid content of frozen fish: comparison of different extraction methods and variability during freezing storage

In this work, a microwave-assisted extraction (MAE) methodology was compared with several conventional extraction methods (Soxhlet, Bligh & Dyer, modified Bligh & Dyer, Folch, modified Folch, Hara & Radin, Roese-Gottlieb) for quantification of total lipid content of three fish species: horse mackerel (Trachurus trachurus), chub mackerel (Scomber japonicus), and sardine (Sardina pilchardus). The influence of species, extraction method and frozen storage time (varying from fresh to 9 months of freezing) on total lipid content was analysed in detail. The efficiencies of methods MAE, Bligh & Dyer, Folch, modified Folch and Hara & Radin were the highest and although they were not statistically different, differences existed in terms of variability, with MAE showing the highest repeatability (CV = 0.034). Roese-Gottlieb, Soxhlet, and modified Bligh & Dyer methods were very poor in terms of efficiency as well as repeatability (CV between 0.13 and 0.18).

Analysis of polycyclic aromatic hydrocarbons in fish: optimisation and validation of microwave-assisted extraction

An accurate and sensitive method for determination of 18 polycyclic aromatic hydrocarbons (PAHs) (16 PAHs considered by USEPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) in fish samples was validated. Analysis was performed by microwave-assisted extraction and liquid chromatography with photodiode array and fluorescence detection. Response surface methodology was used to find the optimal extraction parameters. Validation of the overall methodology was performed by spiking assays at four levels and using SRM 2977. Quantification limits ranging from 0.15–27.16 ng/g wet weight were obtained. The established method was applied in edible tissues of three commonly consumed and commercially valuable fish species (sardine, chub mackerel and horse mackerel) originated from Atlantic Ocean. Variable levels of naphthalene (1.03–2.95 ng/g wet weight), fluorene (0.34–1.09 ng/g wet weight) and phenanthrene (0.34–3.54 ng/g wet weight) were detected in the analysed samples. None of the samples contained detectable amounts of benzo[a]pyrene, the marker used for evaluating the occurrence and carcinogenic effects of PAHs in food.

Forest resources in Graciosa Island (Azores) : biomass availability for sustainable energetic use

Dissertação de Mestrado em Ambiente, Saúde e Segurança.

The mirage of curricular autonomy

ECER 2014 "The Past, the Present and Future of Educational Research in Europe" will take place at the University of Porto from 1 - 5 September 2014.

Perceções dos turistas sobre as práticas de sustentabilidade ambiental no turismo rural : o caso de São Miguel

Dissertação de Mestrado, Gestão de Empresas (MBA), 2 de Outubro de 2015, Universidade dos Açores.

Analysis of polycyclic aromatic hydrocarbons in fish: evaluation of a quick, easy, cheap, effective, rugged, and safe extraction method

QuEChERS method was evaluated for extraction of 16 PAHs from fish samples. For a selective measurement of the compounds, extracts were analysed by LC with fluorescence detection. The overall analytical procedure was validated by systematic recovery experiments at three levels and by using the standard reference material SRM 2977 (mussel tissue). The targeted contaminants, except naphthalene and acenaphthene, were successfully extracted from SRM 2977 with recoveries ranging from 63.5–110.0% with variation coefficients not exceeding 8%. The optimum QuEChERS conditions were the following: 5 g of homogenised fish sample, 10 mL of ACN, agitation performed by vortex during 3 min. Quantification limits ranging from 0.12– 1.90 ng/g wet weight (0.30–4.70 µg/L) were obtained. The optimized methodology was applied to assess the safety concerning PAHs contents of horse mackerel (Trachurus trachurus), chub mackerel (Scomber japonicus), sardine (Sardina pilchardus) and farmed seabass (Dicentrarchus labrax). Although benzo(a)pyrene, the marker used for evaluating the carcinogenic risk of PAHs in food, was not detected in the analysed samples (89 individuals corresponding to 27 homogenized samples), the overall mean concentration ranged from 2.52 l 1.20 ng/g in horse mackerel to 14.6 ± 2.8 ng/ g in farmed seabass. Significant differences were found between the mean PAHs concentrations of the four groups.

Mercury, cadmium, lead and arsenic levels in three pelagic fish species from the Atlantic Ocean: intra- and inter-specific variability and human health risks for consumption

Three commonly consumed and commercially valuable fish species (sardine, chub and horse mackerel) were collected from the Northeast and Eastern Central Atlantic Ocean in Portuguese waters during one year. Mercury, cadmium, lead and arsenic amounts were determined in muscles using graphite furnace and cold vapour atomic absorption spectrometry. Maximum mean levels of mercury (0.1715 ± 0.0857 mg/kg, ww) and arsenic (1.139 ± 0.350 mg/kg, ww) were detected in horse mackerel. The higher mean amounts of cadmium (0.0084 ± 0.0036 mg/kg, ww) and lead (0.0379 ± 0.0303 mg/kg, ww) were determined in chub mackerel and in sardine, respectively. Intra- and inter-specific variability of metals bioaccumulation was statistically assessed and species and length revealed to be the major influencing biometric factors, in particular for mercury and arsenic. Muscles present metal concentrations below the tolerable limits considered by European Commission Regulation and Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO). However, estimation of non-carcinogenic and carcinogenic health risks by the target hazard quotient and target carcinogenic risk, established by the US Environmental Protection Agency, suggests that these species must be eaten in moderation due to possible hazard and carcinogenic risks derived from arsenic (in all analyzed species) and mercury ingestion (in horse and chub mackerel species).

A divulgação de informação financeira no relato intercalar : uma análise às entidades cotadas no PSI geral

Mestrado em Auditoria

Estudo económico das energias renováveis: o caso português

Dissertação de Mestrado apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Empreendedorismo e Internacionalização, sob orientação de Maria Clara Dias Pinto Ribeiro

BabeLO : an extensible converter of programming exercises formats

In the last two decades, there was a proliferation of programming exercise formats that hinders interoperability in automatic assessment. In the lack of a widely accepted standard, a pragmatic solution is to convert content among the existing formats. BabeLO is a programming exercise converter providing services to a network of heterogeneous e-learning systems such as contest management systems, programming exercise authoring tools, evaluation engines and repositories of learning objects. Its main feature is the use of a pivotal format to achieve greater extensibility. This approach simplifies the extension to other formats, just requiring the conversion to and from the pivotal format. This paper starts with an analysis of programming exercise formats representative of the existing diversity. This analysis sets the context for the proposed approach to exercise conversion and to the description of the pivotal data format. The abstract service definition is the basis for the design of BabeLO, its components and web service interface. This paper includes a report on the use of BabeLO in two concrete scenarios: to relocate exercises to a different repository, and to use an evaluation engine in a network of heterogeneous systems.