Geographic versus industry diversification: constraints matter

This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost consistently outperforms industry portfolios, although we cannot establish statistical significance. JEL Classification: G11, G15block-bootstrap tests, Diversification gains, EMU, geographic diversification, industry diversification

Tecnologia digital em ambiente familiar: o caso de crianças dos 0 aos 6 anos

Pretendeu-se com esta pesquisa conhecer as práticas com tecnologias de crianças até 6 anos de idade em ambiente familiar. Optei por uma metodologia qualitativa, nomeadamente a Grounded Theory, pois era minha intenção não basear-me em teorias existentes, mas sim criar novas ideias e novas teoria a partir da realidade observada. Para isso, realizei entrevistas semi-estruturadas e observações a 15 famílias portuguesas nas suas habitações. Recorri a uma amostragem teórica, ou seja, procurei realidades onde o fenómeno em estudo existia, por isso as famílias teriam de ter, pelo menos, um filho com menos de 6 anos de idade e preferencialmente um irmão mais velho. Durante a recolha de dados verifiquei que as crianças estão rodeadas de tecnologias e usam-nas, de um modo geral, quando desejam, incluindo as crianças com meio ano de idade. Elas preferem os dispositivos móveis, como o tablet e o smartphone, mas também usam o computador, a televisão e consolas de jogos. O género é decisivo nas atividades escolhidas nos dispositivos, usados geralmente sozinhos e de forma independente, levando as crianças a dominar alguns dos dispositivos melhor do que os pais e os irmão mais velhos pensam.info:eu-repo/semantics/acceptedVersio

Propriedades hidráulicas dos solos e modelação para a optimização da rega considerando a dinâmica do azoto e dos sais

Doutoramento em Engenharia dos Biossistemas - Instituto Superior de AgronomiaModeling has become an essential tool for implementing better irrigation and fertilization practices. The HYDRUS software package is currently one of the few models capable of considering multicomponent geochemistry and evaluating multiple environmental problems in an integrated way. The model was used to simulate water movement and solute transport in two complex experiments carried out under field conditions, between 2004 and 2010. The field experiments were helpful to identify the main physical and chemical processes influencing soil water flow and multicomponent solute transport in soils irrigated with saline waters. They were further useful for evaluating different irrigation water quality and fertilization scenarios while considering soil salinization/sodification risks, root nutrient uptake, nutrient leaching, and crop yield. HYDRUS proved to be a powerful tool for establishing sound irrigation policies. However, the considerable demand on input data, namely, soil hydraulic properties, has been limiting its use (and other reactive transport models). Different pedotransfer functions (PTFs) were thus established to indirectly estimate soil hydraulic properties from the soil information available in the PROPSOLO database. A set of class-PTFs were developed to estimate water retention properties after grouping data by soil texture, soil horizon, and bulk density. A different procedure was also presented to estimate water retention properties from particle size distribution using the soil texture triangle and ordinary kriging. Finally, a set of PTFs were established for Cape Verde soils. All these PTFs may have multiple applications in irrigation management and watershed modelling. However, it is still necessary to further extend those PTFs to other regions of Portugal and Cape Verde, and to gain more knowledge on the hydraulic conductivity functions of those soils so that they can be used in reactive transport modelin

Online practices of children under 6: a grounded theory study

With this research we intended to know the practices of children with technologies in home environment. We opted for Grounded Theory, because we do not intend to base ourselves on existing theories, but to create new one. Semi-structured interviews and observations to 15 families were carried out in their homes. Families would have to have, at least, one child under 6 and (preferably) an older brother. Through the collect data we verified that children are surrounded by technologies and use it when they want, including children with 1 year old. They prefer the mobile ones, such as the tablet and the smartphone, but also use the computer, the television and game consoles. Gender is decisive in the chosen activities on the devices, which are used mainly alone and independently, leading to children mastering devices better than parents think.info:eu-repo/semantics/publishedVersio

Geographic versus industry diversification: constraints matter

This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost consistently outperforms industry portfolios, although we cannot establish statistical significance

Improving ergonomic conditions and productivity: a case study in a PVD coating production area

Introduction: Due to demographic variation, fewer young workers are available and the overall number of workers will decrease. The length of absenteeism, especially due to musculoskeletal disorders (MSDs), increases with higher age (Müglich et al., 2015). According to Neumann and Dul (2010), if effectively applied in the design of operation systems, Human Factors can improve system performance while reducing health hazards for employees. The aim of this work is to evaluate “How productivity is affected after the implementation of ergonomics improvements?” The case study takes place in a PVD coating production area, where workers’ complaints due to shoulder pains were rising considerably. These complaints come mainly from the processes of loading and unloading pieces from the suspension, before and after the product entering the PVD machine, respectively. This is a repetitive job and involves two awkward postures: flexion of the arms above 60º (from now on “arms up”) about 30% of the time and the difficulty to move manually a full suspension of 6kg, on average, from the machine carpet to a table every 3 minutes and vice-versa depending if it is an unloading or a loading process

MEREC - Guarda: An Energy and Resource Efficiency Process undermined by the early stages of a democratic setting.

This article focuses on the historical background which lead to the implementation of an EUA programme in a European country; a programme designed for developing countries. To that end, we seek to discern, how 1980's Managing Energy and Resource Efficient Cities (MEREC) methodology has perpetuated in urban planning and architecture practice as well as in the discourses of its stakeholders. Guarda is a medieval border town (1050m) in the hinterland of Portugal, far away from the impact of metropolitan areas, such as Lisbon or Porto. Guarda kept a balanced urban growth over the years, but demography and key sectors of the economy changed profoundly after the Portuguese democratic revolution (1974). Serving as an early experience towards city resilience and sustained development, MEREC was a programme developed by the United States Agency for International Development (USAID). Inspired by the work of Richard Meier (1974), MEREC answered to the growing concerns triggered by the 1970s energy crisis and its consequences. Amid a rapid urbanisation and population growth, increased energy costs and pressure on natural resources, MEREC targeted cities in developing countries which could adopt preventive approaches towards resource efficiency. However, instead of concentrating its efforts on metropolitan areas, MEREC aimed at the development of secondary cities, where most of the growth had yet to come.From 1983 to 1985, MEREC established a comprehensive planning process, involving Guarda Municipality, central and regional agencies and the know-how of Portuguese universities and private consultants. MEREC identified the city's problems in water supply, urban waste, urban management, changes in local building materials used and scattered urbanisation. Several of these problems had been overcome with the project's completion, the development of Guarda's master plan, research technology, and awareness campaigns.USAID-MEREC advisors considered the results achieved in Guarda as rewarding. Architect Maria Castro (1989) points out the clarity achieved in the decision-making processes for urban planning and management during the MEREC programme. However, as she notes, discourses and institutional support changed after MEREC. MEREC’s methodology was somehow thrown away, suggesting a lack of planning culture among local political powers, unwilling to redirect resources. MEREC happened ten years after Portugal's dictatorship had ended, when the country was committed to the world as a democratic country, facing political and economical instability until its accession to the European Economic Union (EEC), as well as, undergoing deep socio-cultural transformations and striving for development. From 1986 onwards, MEREC programme was hampered by a democratic setting that aimed for development in more immediate ways, regardless of the resource-efficiency strategy proposed