851 research outputs found
Relativistic deuteron structure function at large Q^2
The deuteron deep inelastic unpolarized structure function F_2^D is
calculated using the Wilson operator product expansion method. The long
distance behaviour, related to the deuteron bound state properties, is
evaluated using the Bethe-Salpeter equation with one particle on mass shell.
The calculation of the ratio F_2^D/F_2^N is compared with other convolution
models showing important deviations in the region of large x. The implications
in the evaluation of the neutron structure function from combined data on
deuterons and protons are discussed.Comment: 7 pages, 1 ps figure, RevTeX source, 1 tar.gz file. Submited to
Physical Letter
A look into the circularity of waste water sludge in Portugal: context, constraints and opportunities
The Portuguese action plan for the circular economy, proposes under action #6, the need to increase the efficiency of water use and reuse, as well as the improvement in the valorisation of nutrients present in waste water sludge. In 2014, last data available, only 52% of the sludge was subject to valorisation, indicating a significant room for improvement. This paper aims to analyse the potential for improvement in the quantity of sludge from WW subject to valorisation. To this end, the installed capacity to valorize sludge and its location is compared with the quantity of sludge produced and its location. Preliminary results indicate a clear mismatch between the distribution of installed capacity for biological treatment of WW-sludge and the distribution of waste water sludge produced
From 1D convolutional codes to 2D convolutional codes of rate 1/n
In this paper we introduce a new type of superregular matrices that give
rise to novel constructions of two-dimensional (2D) convolutional codes with finite support. These codes are of rate 1=n and degree d with n d +1 and achieve the
maximum possible distance among all 2D convolutional codes with finite support
with the same parameters
Evaluation of a co-financing model for the mitigation of runoff negative pollution
As a result of the intense traffic, characteristic of the developed world, urban and highway runoff are responsible for negative environmental externalities that has a huge impact on the quality of life and on ecosystems. Although there is scientific and technical knowledge to control this type of pollution, the financing model seems to be one of the limitations. In this sense, and based on the Contingent Valuation Method, a research was developed to study the main factors that influence the perception of the population and to assess their availability to participate, actively and financially, in the resolution of this problem. The results of this research provide a contribution for the implementation of co-financing strategies for holistic and integrated programs that, on one hand, mitigate the negative effects of urban and highway runoff and, on the other hand, enhance the sustainable development and life quality in the urban environment
The LSTS open-source communication and autonomy software: enabling networked vehicle systems to find track, and sample dynamic features of the ocean
Peer Reviewe
Resilience and adaptation in the face of climate change: the Douro wine bio- cultural landscape
The Douro wine region is one of the most important Portuguese wine regions, and the oldest demarcated wine region in the world. The evolving and living cultural landscape resulted from a symbiotic relationship between human and nature, that has proven, through time, to be sustainable and resilient was, in 2001, recognized as a UNESCO world heritage site.
Climate change effects represent a growing/global concern, since more frequent and extreme climate events are expected, that can go beyond the natural ecosystem?s resilience, posing additional risks to vine and wine production, that may request the implementation of urgent adaptation measures. This threat has even more importance in communities that mostly depend on the wine industry, as is the case of the Douro Valley.
The evaluation of natural systems resilience to different climate change scenarios, and the how to improve this natural capital, must be a starting point for wine producers, to the local economy agents, and to society at large, before considering more structural and costly adaptation measures.
The aim of the present paper is to analyse the journey of the Douro Valley, to identify local resilience factors to climate change, and to discuss how they can contribute to mitigate the consequences or effects of future climate change scenarios.Financial support from National Funds of the FCT â Portuguese Foundation for Science and
Technology within the project UID/ECO/03182/2019, UIDB/04011/2020 and
UID/SOC/04011/2019 is acknowledged
A sustainable and symbiotic relationship between human occupation and a natural waterscape: the Afife case study, from the XIIth to the XXth century
Working Paper Series, nr. 66The waterscape defined by the Afife creek (Portugal) is a hotspot of time and cultural cross-references. In the 1200s, the presence of Benedictine monks, in the Convent of S. JoĂŁo de Cabanas, suggest the existence of a Catholic agrarian landscape. Benedictine monks ought to provide shelter, food, wool for blankets, and products for religious sacred services to pilgrims. Therefore, wheat, hay or barley, vineyards and olive trees would be cultivated. As such, the landscape should reveal the cultivation of cereals, olive trees, vineyards, and grazing lands, and mills to mow the cereals, produce olive oil, and saw the wood.
The design of the former landscape on cereals, wine, olive trees, sheep, goats and sawing industry in the area, under the Benedictine convent of S. JoĂŁo de Cabanas, together with its architectural structure, is strongly related to the XVIth century. In particular, the cross of S. Tiago de Compostela (Spain), indicating a route of pilgrimage, and the concentration of seven water mills in a 100 meters upstream distance to the convent, reveal a great presence of permanent water power.
The present irregular distribution of the remaining pine-trees, oaks, eucalyptus and acacias indicate changes in the agrarian exploitation throughout the XIXh and XXth centuries. The Ecalyptus, original from Australia and New-Zeeland, was introduced in Portugal in the 1800s, while the Acacia was introduced in the 1900s, to sustain moving sands. Their expansion in the slopes of the Afife creek suggests very recent farming abandonment (after 1940s). This paper proposes to discuss agro-forest sustainable adjustments to changing cultural-economic drivers in the long run, through a case study. The case study is the Afife waterscape transformation, located in the village of Afife in the North of Portugal. The analyses will adopt an interdisciplinary approach crossing diverse sources of information and methodologies
Verifying design plans and detecting deficiencies in concrete bridge using GPR
During the construction of concrete structures such as bridges, many deficiencies
may occur due to an incorrect application or changes in the original design plans and
construction errors. Frequently, areas with very poorly vibrated concrete, insufficiently grouted tendon ducts and incorrectly positioned reinforcement bars appear. Thus, the detection of these construction deficiencies is essential to prevent further damage to the bridge. Subsequently, a
concrete specimen was prepared aimed at simulating some of the problems that can occur during the construction. The specimen was then mapped using a GPR system to check the effectiveness of this tool to provide information about those deficiencies. The acquisition was carried out in reflection mode and the results were further processed using 3D reconstruction software in order to obtain a more realistic and comprehensible image. These measurements showed rather good results. The 3D image provided much more detailed information about the elements placed inside the specimen relatively to 2D radargrams, which are generally used for
primary target identification.Fundação para a CiĂȘncia e a Tecnologia (FCT) - POCTI SFRH/BD/6409/2001.Sustainable Bridgesâ European project FP6-PLT-0165
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