1,060 research outputs found
Usage and control of solid-state lighting for plant growth
The work begins with an introductory part in which the basic aspects related to the photosynthetic radiation, the photobiology of plants and the technology of light-emitting diodes (LEDs) are overviewed. It is followed by a review of related research works that have been conducted during the last two decades, and by the main design issues of LED luminaires for plant growth. The following part of the work reports the experimental growth tests performed. The effects of the radiation emitted by spectrally tailored LED luminaires on plant growth have been investigated. A total of four growth tests using lettuce and radish cultivars were performed. Two basic approaches were used to investigate the effects and the future possibilities of the usage of solid-state lighting (SSL) in plant growth. The first approach evaluates the growth development of lettuce plants in real greenhouse conditions using LEDs as supplementary light sources to natural daylight. In the second approach the evaluation was carried out with a total absence of natural daylight by growing lettuce and radish plants in phytotron-chamber conditions. The effects of SSL treatments on the growth development and quality of crops were compared with reference lighting systems composed of conventional and well-established light-source technologies, such as fluorescent and high-pressure sodium lamps. During the process of the investigation, the need to coherently quantify and evaluate the spectral quality of the radiation in terms of its photosynthetic appetence arose. Different metrics are still been used indiscriminately to quantify radiation used by plants to perform photosynthesis. Therefore, the existing metrics are discussed and a new proposal for coherent systematization is presented. The proposed system is referred to phyllophotometric and it is developed using the average photosynthetic spectral quantum yield response curve of plants. The results of the growth tests showed that the usage of SSL in plant growth offers an unprecedented possibility to optimise the morphogenesis, the photosynthesis and the nutritional quality of crops. This can be done by controlling the quantity and the spectral composition of the radiation provided, areas where LED-based luminaires excel. These possibilities can contribute to respond to the increasing demand for high-quality horticultural products by the consumers and to the conservation of global natural environment and resources
Information profiles for DNA pattern discovery
Finite-context modeling is a powerful tool for compressing and hence for
representing DNA sequences. We describe an algorithm to detect genomic
regularities, within a blind discovery strategy. The algorithm uses information
profiles built using suitable combinations of finite-context models. We used
the genome of the fission yeast Schizosaccharomyces pombe strain 972 h- for
illustration, unveilling locations of low information content, which are
usually associated with DNA regions of potential biological interest.Comment: Full version of DCC 2014 paper "Information profiles for DNA pattern
discovery
RPG method improving business games
The business game methodology is applied for the best universities in the world and has been improved itself throughout the years. Using simulated backgrounds, the players live some experiences that could live in their professional future and take decisions to have success in the game. As all research stream, business game’s evolution not only has to prove your methods and benefits, but also has to know your criticisms. This paper studies these criticisms about the teaching model, specifically the fact that a round of decisions forces the student to take a decision, without he or she realized the real necessity of it. A business game literature review is needed so, and also about some parallel themes that could increase the knowledge and identify news alternatives for the criticisms, mainly about the role-playing-games method characteristics, proposing a new direction for the following researches focusing the improvement of the learning based in games
Regional impacts of infrastructural programmes: ex-post assessment methodologies revisited
This communication inserts in the scope of the increasing planning concerns with the economic evaluation of public investments, within a regional perspective in order to fukfill efficiency criteria.The research reported here settles, on the one hand, in a revision of recent literature about this issue and, on the other, in a case study applied to the Portuguese Northern Region.The study develops through the following steps: (i) ex-post analysis of the aggregated impact of public investments in infrastructures and public works, (ii) evaluation of the degree of attainment of the ex-ante settled goals of efficiency, economic growth and inter-regional fairness, (iii) development of an integrated set of decision-support tools concerning the aggregated ex-post evaluation of these kinds of investments.It is expected that this assessment of the impact of past public investments allows to take implications for the future, in order to improve regional policies of integrated, balanced and efficient development through: (i) the definition of transparency and efficiency criteria in the application of the public money, (ii) the redesign of future policies for public investments, and (iii) the support to a more balanced inter-regional development
The morphological sense of commerce: theoretical review and lessons learned in four Portuguese medium sized cities
Shopping has been considered the principal wealth-generator of post-modern societies. Yet,two elements continually elude current theories and practices about the role of commerce on a widerperspective. Rarely is it considered an active agent in the structuring of the city and, furthermore, moststudies have solely focused on the geographical, economic and social dimensions of shopping, neglectingits morphological dimension. Only in the last 10 years have authors addressed this perspective, althoughsporadically and presenting focused views, resulting in a lack of knowledge and, ultimately, in the lack ofproper public policies. This paper aims to address the structuring nature of commerce and the influenceof its morphological component. For that it combines knowledge from various fields of research and alarge array of morphological variables at various resolution levels. Using as test-beds four Portuguesemedium-sized cities, GIS-models containing commercial, morphological, structural and temporalvariables were produced, explored and compared. Findings include i) the definition of commercial /morphological indicators, that can constitute values of reference or comparison for commercial policiesand other planning studies; ii) the evidence that morphological, rather than statistical similaritiesgenerate, on the micro-scale, more commercial similarities; and iii) the main bridging aspects betweencommercial activity and the form and structure of cities
The impact of commercial activity on the form and structure of the city - the case of Portuguese mediumsized cities
The present document aims to sum up the first year of research in the on-going doctoral thesis, whichdwells on the balance between commercial activity and city realm. Both these entities have latelywitnessed new stages of evolution, which reflect themselves in changing variables and patterns. Initially,commerce was considered as an after-the-fact consequence of the urban form and structure preexistence,but because it has the ability to change and adapt more rapidly than the city, as well as havinglarge economic and social power, the flow of influence can be inverted. The research tends then to knowwhether the two entities are convergent or divergent in their patterns and what overlaps in theirdichotomies, bearing in mind that, although evolving separately, they must have to some degree commonvariables that can be assessed for further understanding the urban realm, finding solutions for regulatingand balancing estimated forms of distribution, proposing integrated political and technical mechanisms,and ultimately strengthening the use of commerce to reshape urban spaces. Aware that medium-sizedcities are now at the core of a network-base territory, are synonyms of equilibrium, sustainability andinnovation, and places of opportunity and (inter)national projection, the literature review focuses on fourdistinct points of view: city's, commerce's (three fronts: traditional retail, new commercial formats andweb-based), citizen's and planner's (merging the above and finding research tools). The "thesis" thatsubstantiates the research is then proposed. The last point presents the early makings of a workingmethodology, which presently is being developed
Plane contraction flows of upper convected Maxwell and phan-ThienTanner fluids as predicted by a finite-volume method
A finite-volume (FV) procedure is applied to the prediction of two-dimensional (2-D) laminar flow through a 4 : 1 planar contraction of upper convected Maxwell (UCM) and simplified Phan-Thien±Tanner (SPTT) fluids. The method incorporates
general coordinates, indirect addressing for easy mapping of complex domains, and is based on the collocated mesh
arrangement. Calculations with the UCM model at a Reynolds number of 0.01 were carried out with three consecutively refined meshes which enabled the estimation of the accuracy of the predictions of the main vortex characteristics through Richardson's extrapolation. Converged solutions with the first-order upwind differencing scheme for the convective terms
were obtained up to at least De à 8 in the finest mesh, but were limited to De 1, De 3 and De 5 for the fine, medium
and coarse meshes, respectively, when using the second-order linear upwind scheme. The predicted flow patterns for
increasing Deborah numbers with the UCM model resemble the well known lip vortex enhancement mechanism reported in the literature for constant-viscosity fluids in axisymmetric contractions and shear-thinning fluids in planar contraction, but very fine meshes were required in order to capture the described vortex activity. Predictions with the SPTT model also compared well with the behaviour reported in the literature
Incidência da deficiência da desidrogenase dos ácidos gordos de cadeia média (MCAD) em Portugal
Challenges of Portuguese urban planning instruments and practice: demonstrating a DSS integrating space syntax
Peer Reviewe
Urban form and vacant shops: can one explain the other? – a case study in Portugal
[EN] Shopping is much more than a wealth-generator in post-modern societies; it is intrinsically linked with the way people experience the city and an indivisible part of their day-to-day social experiences. Consequently, the literature has gradually recognized that commercial geographies are not just a consequence of economic market logics. It has been proven that there is a relationship between store-types and urban morphology, and that commerce is an important catalyst for urban regeneration and revitalization. Thus, the urban form can also be a cause for the lack of success of a shop. The amount of vacant shops has been signaled as an important problem in urban areas, affecting the structure and the identity of neighborhoods, and reflects the negative effects of the economic-crisis. Strategies to overcome this problem are usually economically-oriented and fail to capitalize on the new-found relationships between store-success and urban morphology. Thus this research wishes to test whether there are indeed correlations between specific morphological features and the existence of vacant shops, and consequently to propose how changes in the urban environment can contribute to overcome, and even prevent, such cases. The geographical distribution of vacant shops in a sample of Portuguese cities was set against morphological variables such as building age or centrality in the network (Space Syntax). Positive association was found, for example, between new developments and vacant shops, questioning the need for more store space in certain areas; and, particularly outside central neighborhoods, between open shops and high ‘choice’ (rather than high ‘integration’) segments.This work was supported by the Portuguese Foundation for Science and Technology under Grant SFRH / BD / 45205 /2008.Saraiva, M.; Marques, T.; Pinho, P. (2018). Urban form and vacant shops: can one explain the other? – a case study in Portugal. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 209-220. https://doi.org/10.4995/ISUF2017.2017.5141OCS20922
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