Explaining Demand for Higher Education

Recognizing the crucial role of higher education for the development of nations and individuals, many countries have recently established ambitious targets for the percentage of graduates in their population by 2020. In peripheral European Union countries, however, such objectives may be difficult to attain. In fact, both the current stringent fiscal consolidation processes and the overall depressed economic environment may exert negative effects upon domestic demand for higher education. Such uncertain context increases the need for efficient policies and henceforth the value of obtaining reliable information on the variables that are more likely to influence demand. In this study, we employ the partial least squares methodology, which allows modeling with many variables, even with relatively few observations, to identify the most relevant determinants of demand for higher education. We focus in the case of Portugal, a country where applications for higher education are centralized and thus provides a long and reliable set of data on aggregate demand. The results of our empirical analysis suggest that the most relevant determinants of demand are institutional and/or policy dependent and, therefore, may be controlled by decision makers and managed to support national strategic objectives. These results, obtained for Portugal, are also useful particularly for other southern European Union countries, which share some of the Portuguese economic, social, demographic and cultural characteristics

Explaning Demand for Higher Education

Recognising the crucial role of higher education for the development of nations and individuals, many countries have recently established ambitious targets for the percentage of graduates in their population by 2020. In peripheral European Union countries, however, such objectives may be difficult to attain. In fact, both the current stringent fiscal consolidation processes and the overall depressed economic environment may exert negative effects upon domestic demand for higher education. Such uncertain context increases the need for efficient policies and henceforth the value of obtaining reliable information on the variables that are more likely to influence demand. In this study, we employ the partial least squares methodology, which allows modelling with many variables, even with relatively few observations, to identify the most relevant determinants of demand for higher education. We focus in the case of Portugal, a country where applications for higher education are centralised and thus provides a long and reliable set of data on aggregate demand. The results of our empirical analysis suggest that the most relevant determinants of demand are institutional and/or policy dependent and, therefore, may be controlled by decision makers and managed to support national strategic objectives. These results, obtained for Portugal, are also useful particularly for other southern European Union countries, which share some of the Portuguese economic, social, demographic and cultural characteristics

Preparação e caracterização de fibras e nanotubos de BiFeO3 e FeNbO4

Mestrado em Engenharia FísicaEsta dissertação teve como objetivo a produção e caracterização física de fibras e nanotubos de BiFeO3 e FeNbO4. Para o desenvolvimento destes materiais utilizou-se a técnica de fusão com laser (LFZ), o método sol-gel (Pechini) e o método de poros absorventes. As amostras obtidas foram sujeitas a uma caracterização estrutural por difração de raios-X e espetroscopia de Raman, morfológica por microscopia electrónica de varrimento e elétrica por medidas de constante dielétrica. Os resultados obtidos com a técnica de difração de raios-X mostraram que o gel com tratamento a 750 ºC é polifásico. Para conseguir produzir nanotubos escolheu-se o LaCoO3 como material alternativo. Usando a técnica de fusão de zona com laser (LFZ) obtiveram-se fibras de BiFeO3, FeNbO4 e compósitos de BiFeO3+FeNbO4. Com esta técnica foram crescidas fibras a várias velocidades (5, 10, 25, 50, 100 e 200 mm/h), tendo os resultados obtidos com a difração de raios-X evidenciado que todas as amostras obtidas são polifásicas, sendo a amostra de 10 mm/h para o BiFeO3 e a de 5 mm/h para o FeNbO4 as que apresentam melhores propriedades. As amostras de 5 mm/h de todos os compósitos são aquelas que possuem menor quantidade de segundas fases e portanto foram alvo de estudo mais aprofundado. A caracterização dielétrica permitiu verificar que todas as amostras apresentam fenómenos de relaxação dielétrica. Verifica-se também que para o BiFeO3 a constante dielétrica é superior na amostra crescida à velocidade de 10 mm/h, para o FeNbO4 é superior na amostra crescida a 5 mm/h e nos compósitos a amostra com 75% de BiFeO3 e 25% de FeNbO4 apresenta um comportamento diferente das restantes, eventualmente devido à sua microestrutura singular.In this work, BiFeO3 and FeNbO4 fibers and nanotubes were prepared and characterized. The samples were obtained using three different preparation techniques: laser floating zone technique (LFZ), sol-gel method (Pechini) and the wetting pore method. Structural characterization of the samples was made using the X-ray diffraction (XRD) and Raman spectroscopy techniques, morphologic characterization by scanning electron microscopy (SEM) and electrical characterization by impedance spectroscopy. The XRD patterns showed that the BiFeO3 gel heat-treatment at 750 °C is polycrystalline. To produce nanotubes, by the wetting pore method, LaCoO3 was used as an alternative material. With the LFZ technique, BiFeO3 and FeNbO4 fibers and BiFeO3 + FeNbO4 composites were prepared. The fibers were grown at various pulling speeds (5, 10, 25, 50, 100 and 200 mm/h), and the XRD patterns demonstrated that all samples are polycrystalline. The BiFeO3 samples growth at 10 mm/h and the FeNbO4 samples growth at 5 mm/h were chosen to be analysed electrically. The composite samples growth at 5 mm/h are those having the least amount of secondary phases, and therefore were subjected to further studies. The dielectric characterization shown that all the samples have a dielectric relaxation phenomenon, thermally activated. It was also verifyed that for the BiFeO3 sample the dielectric constant is higher for the growth speed of 10 mm/h and for the FeNbO4 is higher for the grown speed of 5 mm/h. The composite sample 75% BiFeO3-25% FeNbO4 (% wt) behaves differently from the others, possibly due to its unique microstructure

La production de quinoa dans l'altiplano sud de la Bolivie : entre crises et innovations

N° ISBN - 978-2-7380-1284-5International audienceThe production of quinoa in the Bolivian Altiplano: between crisis and innovations. The Bolivian Altiplano has become the biggest exporter of quinoa (Chenopodium quinoa Willd.) in the world. In the last forty years, communities have evolved from subsistence agriculture to a commercial production for exportation. The producers have carried out technical innovations, by entering mechanization into their production system, as well as social innovations, both at the activities and migration to ensure their production system. But the success of this region in getting into the globalization should not hide changes and possible blockades that question the durability of the new production system and at the same time land conflicts become common. In a context of a growing market, the producers of quinoa start wondering about the way to restructure and reinvent, by innovative actions, their production system, but also their social organization which is driven by exogenous and uncertain factors such as market or climatic change. This innovative phase is necessary to perpetuate production and ensure incomes for the population. It demands cooperation between different actors which have sometimes divergent interests. This communication offers an overview of the main problems which appeared when the production system changed from a home consumption into an exportation production system. It analyses the interactions between the producers of quinoa and their environment from the point of view of social and technical innovation

The influence of leisure activities on the health and welfare of older people living in nursing home

Background: Leisure activities, often left in the background throughout life, play an important role for older persons. They are activities that they like to accomplish, according to individual preferences that make it easier to maintain an active life, on a physical, mental and social level, improving their health. Objectives: I) Identify the leisure habits of older people living in nursing homes; II) Describe the nursing homes’offer of leisure activities; III) Identify relationships between leisure activities and the seniors’health condition. Methods: A cross-sectional descriptive correlational study, in 12 nursing homes in the north of Portugal with a sample of 1,131 seniors. We performed a descriptive and inferential statistical data analysis using SPSS/PC for Windows, version 22. Results: Participants were mostly female, widows, with an average age of 84 years. The most common leisure activity is watching TV. Impaired sight and illiteracy are the most frequent causes of elderly people’s non-adherence to leisure activities. Leisure activities: card/board games, crafts and reading are associated with better cognitive performance; sightseeing and reading are associated with greater independence in self-care; watching television is associated with greater compromise of bodily processes and greater dependence on self-care; performing manual work is associated with less depression; walking is associated with a lower compromise of bodily processes and lower risk of falling. Conclusions: Leisure habits are important in maintaining the health of older people living in nursing homes.info:eu-repo/semantics/publishedVersio

Direct Color Sensor, Optical Amplifier and Demux Device Integrated on a Single Monolithic SiC Photodetector

A pi'n/pin a-SiC:H voltage and optical bias controlled device is presented and its behavior as image and color sensor, optical amplifier and demux device is discussed. The design and the light source properties are correlated with the sensor output characteristics. Different readout techniques are used. When a low power monochromatic scanner readout the generated carriers the transducer recognizes a color pattern projected on it acting as a direct color and image sensor. Scan speeds up to 10(4) lines per second are achieved without degradation in the resolution. If the photocurrent generated by different monochromatic pulsed channels is readout directly, the information is demultiplexed. Results show that it is possible to decode the information from three simultaneous color channels without bit errors at bit rates per channel higher than 4000 bps. Finally, when triggered by light of appropriated wavelength, it can amplify or suppress the generated photocurrent working as an optical amplifier (C) 2009 Published by Elsevier Ltd

Novel structure for large area image sensing

This work presents preliminary results in the study of a novel structure for a laser scanned photodiode (LSP) type of image sensor. In order to increase the signal output, a stacked p-i-n-p-i-n structure with an intermediate light-blocking layer is used. The image and the scanning beam are incident through opposite sides of the sensor and their absorption is kept in separate junctions by an intermediate light-blocking layer. As in the usual LSP structure the scanning beam-induced photocurrent is dependent on the local illumination conditions of the image. The main difference between the two structures arises from the fact that in this new structure the image and the scanner have different optical paths leading to an increase in the photocurrent when the scanning beam is incident on a region illuminated on the image side of the sensor, while a decreasing in the photocurrent was observed in the single junction LSP. The results show that the structure can be successfully used as an image sensor even though some optimization is needed to enhance the performance of the device

Optical Transducers Based on Amorphous Si/SiC Photodiodes

Amorphous Si/SiC photodiodes working as photo-sensing or wavelength sensitive devices have been widely studied. In this paper single and stacked a-SiC:H p-i-n devices, in different geometries and configurations, are reviewed. Several readout techniques, depending on the desired applications (image sensor, color sensor, wavelength division multiplexer/demultiplexer device) are proposed. Physical models are presented and supported by electrical and numerical simulations of the output characteristics of the sensors