2,740 research outputs found
Influence of the external pressure on the quantum correlations of molecular magnets
The study of quantum correlations in solid state systems is a large avenue
for research and their detection and manipulation are an actual challenge to
overcome. In this context, we show by using first-principles calculations on
the prototype material KNaCuSiO that the degree of quantum
correlations in this spin cluster system can be managed by external hydrostatic
pressure. Our results open the doors for research in detection and manipulation
of quantum correlations in magnetic systems with promising applications in
quantum information science
Seed germination of six Iberian endemic species – a contribution to enhance plant conservation
Biodiversity has been degraded all around the world due to anthropogenic factors. To counteract this
worldwide tendency, ecological restoration programs are expanding. In these programs, the use of
native herbaceous species, particularly those endemic or threatened, can be promoted by seeding
them but germination requirements for most of these species are unknown. Our research meant to fill
this gap of information for six Iberian endemic species suitable to use in restoration actions - Digitalis
thapsi, Ferula communis subsp. catalaunica, Linaria amethystea subsp. amethystea, Pterocephalidium
diandrum, Sanguisorba hybrida, and Silene scabriflora subsp. scabriflora. Their seed germination behaviour
was analysed to establish germination protocols for conservation actions. Three germination conditions
were used to simulate different sown seasons. Seeds of all species were tested without pretreatment
and subjected to a cold stratification. Seeds of S. hybrida and P. diandrum were additionally
tested with a scarification treatment. All species reached their better germination performance under
autumn conditions (15/10 C; 8/16 hours). In conclusion, for all the six Iberian endemic species tested,
germination speed and percentage were suitable for their use in native plants reinforcement
Best Pratice Guide to Manage Vegetation and Promote Biodiversity in Linear Infrastructures
The present guide is based on the experience acquired in the framework of the LIFE LINES project (LIFE14 NAT/PT/001081) and intends to compile and disseminate the recommendable procedures for the management of biodiversity, particularly of plant diversity, in the marginal areas of linear infrastructures, primarily focusing on the national roads, decommissioned railways now used for recreation purposes (ecotrails) and power lines of very high voltage. The guide includes technical information for those in charge of the management of roads, trails and power lines (concession holders, municipalities), for environmental consultancy (Agência Portuguesa do Ambiente, Instituto de Conservação da Natureza e Florestas), and for landscape and agroforestry technicians, as well as for the general public
Electrochemical response of Ti joints vacuum brazed with TiCuNi, AgCu, and Ag fillers
The properties of the joints are dictated by the nature, distribution, and morphology of the phases formed at the interface. The mechanical properties of brazed joints are well documented in the literature, contrarily to their electrochemical behaviour. Thus, the main objective of this study was to understand the influence of the phases formed at the interface on the corrosion behaviour of commercially pure Ti brazed joints, produced by using TiCuNi, eutectic AgCu, and Ag filler foils. The electrochemical behaviour of the Ti joints was accessed by open circuit potential and potentiodynamic polarization tests in phosphate buffer saline solution electrolyte at body temperature. Results showed that Ag-based fillers induced susceptibility to micro-galvanic corrosion between the Ag-rich and Ti phases formed at the interface and commercially pure Ti base metal. However, no significant differences were observed between the joint system and the base material when brazing with TiCuNi filler.This work was supported by Portuguese FCT, under the reference project UIDB/04436/2020 and M-ERA-NET/0001/2015 project. The authors would also like to acknowledge A. I. COSTA for her help on the experimental studies
Gastric and Enteric Metastization of Invasive Lobular Breast Carcinoma
O carcinoma lobular invasivo (CLI) representa 5-15% dos casos de cancro invasivo da mama, diferindo do carcinoma ductal invasivo(CDI), o tumor invasivo mais frequente da mama, quer na forma de apresentação clínica, quer nos aspectos imagiológicos e histológicos,
assim como no padrão de metastização. O objectivo deste artigo passa pelo relato clínico de um padrão atípico de metastização de cancro da mama. Mulher de 80 anos, que apresentava queixas de dor abdominal, com 6 meses de evolução, de carácter generalizado,
com maior intensidade nos quadrantes direitos, associada a episódios de sub-oclusão. O exame objectivo revelou volumosa hérnia incisional paramediana direita sem sinais de sofrimento e uma lesão ulcerada da mama esquerda nunca antes revelada pela doente.
Realizou uma mamografia que mostrou uma lesão T4 e a biópsia da mesma revelou Carcinoma Ductal Invasivo. Por apresentar anemia
microcítica hipocrómica de 7 g/dL realizou também uma Endoscopia Digestiva Alta que demonstrou uma úlcera da pequena
curvatura gástrica cuja biópsia revelou um carcinoma difuso. Optou-se pela intervenção cirúrgica com ideação paliativa. Foi efectuada mastectomia simples esquerda e correcção de hérnia incisional com enterectomia segmentar. Os resultados histológicos das peças operatórias foram surpreendentes: Carcinoma lobular invasivo da mama e metástase do mesmo no segmento de intestino ressecado.
Foram revistas as lâminas referentes à biópsia gástrica previamente realizada, tendo sido feito estudo imunohistoquímico que mostrou positividade para os receptores hormonais o que favorecia tratar-se de metástase de carcinoma lobular da mama no estômago. Como conclusão temos a referir que o CLI apresenta um padrão distinto de metastização em relação ao CDI, com diferentes órgãos-alvo, realçando o papel fundamental da suspeição clínica e de uma histologia exigente para o seu diagnóstico
Application of polyoxometalate-ionic liquids (POM-ILs) in dye-sensitized solar cells (DSSCs)
project “SunStorage- Harvesting and storage of solar energy”, with reference POCI-01-0145-FEDER-016387, and by national funds (PTDC/ QEQ-QFI/1971/2014), through FCT - Fundação para a Ciência e a Tecnologia.
H. Cruz thanks to Fundacão para a Ciência e a Tecnologia, MCTES, for the norma transitória DL 57/2016 Program Contract. L. C. Branco thanks to financial support of FCT/MCTES IF/0041/2013/CP1161/CT00).
Ana Lucia Pinto thanks to FCT/MCTES for the grant PD/BD/135087/2017Polyoxometalates (POMs) as anionic metal oxides are promising candidates for application in dye-sensitized solar cells (DSSCs) due to their peculiar properties including a reversible and multi-electron redox behavior. In this work, four polyoxometalate as ionic liquids (POM-ILs) based on the combination between phosphomolybdate anion (PMo12O40 3−) and organic cations such as [BMIM]+, [BPy]+, [HDPy]+ and [P6,6,6,14]+ were prepared and characterized. A detailed chemical structural elucidation by elemental analysis, ATR-FTIR, 1H and 31P NMR spectroscopies have been performed. These POM-ILs were tested as photosensitizers by adsorption to the photoanode (TiO2 film) for different times (15 min to 17 h). The DSSCs performance can be highly improved comparing the commercially available compound and POM-ILs. The electrodeposition process is an excellent alternative to adsorption in order to improve the overall efficiencies. In general, [BPy]3[PMo12O40] and [P6,6,6,14]3[PMo12O40] are the most promissory compounds for DSSC approaches.publishersversionpublishe
Plant communities as a tool in temporary ponds conservation in SW Portugal
Temporary ponds are seasonal wetlands
annually subjected to extreme and unstable ecological conditions, neither truly aquatic nor truly terrestrial. This habitat and its flora have been poorly studied and documented because of the ephemeral character of the flora, the changeable annual weather that has a great effect on the small, herbaceous taxa and the declining abundance of temporary ponds. The objectives of this study are:
(a)to define plant community diversity in terms of floristic composition of ephemeral wetlands in SW Portugal,
(b) to identify temporary pond types according to their vegetation composition and
(c) to identify those ponds that configure the European community priority habitat (3170* – Mediterranean temporary ponds).
Vegetation sampling was conducted in 29 ponds, identifying 168 species grouped among 15 plant communities. Soil texture, pH, organic C and N
content were measured, but only N and percent of clay appear to be related with the distribution of each community type. The results showed that ephemeral wetlands could be classified into four type: vernal pools, marshlands, deep ponds and disturbed wetlands. Vernal pools correspond to the Mediterranean temporary ponds (3170*), protected as priority hab-
itat under the EU Habitats Directive. Submersed Isoetes species (Isoetes setaceum and Isoetes velatum) represents, together with Eryngium corniculatum, the indicator species for vernal pools. We
identify also indicator plant communities of this priority habitat, namely I. setaceum and E. corniculatum–Baldellia ranunculoides plant communities. In
this region, the conservation of temporary ponds has so far been compatible with traditional agricultural activities, but today these ponds are endangered by the intensification of agriculture and the loss of traditional land use practices and by the development of tourism
Caracterização dos sistemas de produção de milho para altas produtividades.
bitstream/CNPMS-2010/22429/1/Circ-124.pd
Application of radar techniques to the verification of design plans and the detection of defects in concrete bridges
Non-destructive tests (NDT) are an essential tool used in special inspections to gather detailed information about
the condition of a bridge. The inspection of bridge decks is a critical task, and, currently, can be successfully carried
out using a wide range of NDT techniques. Nevertheless, some of these techniques are excessively expensive and time
consuming. One of these techniques, the ground penetrating radar (GPR), has been used for some decades in the
non-destructive inspection and diagnosis of concrete bridges. GPR is useful to find general information about the
true position of reinforcement and tendon ducts, and check the quality of the construction and materials. A
significant number of reinforced and prestressed concrete bridges are deteriorating at a rapid rate and need to be
repaired and strengthened. During these rehabilitation processes, designers are often faced with a lack of original
design plans and unawareness of the real position of reinforcement and tendon ducts. In this paper, three case
studies of the use of GPR techniques for the inspection of concrete bridges are presented and analysed. The main
aim of this research is to show the strong need and usefulness of these techniques, which can provide non-visible
information about structural geometry and integrity required for strengthening and rehabilitation purposes.L. T. would like to acknowledge the support from the 'Sustainable Bridges' European project, grant number FP6-PLT-01653 (www.sustainablebridges.net). F. M. F. acknowledges the partial funding of this work by the FCT through the scholarship POCTI SFRH/BPD/26706/2005
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