602 research outputs found
Alternative baths for the gold electrodeposition based on 1-butyl-1-methyl-pyrrolidinium dicyanamide ionic liquid
Towards an electroless deposition of gold on metallic substrates using ionic liquids as electrolytes
Recent research has suggested a number of applications for gold in fuel cells and related hydrogen fuel processing, which include light weight corrosion resistance bipolar plates and the incorporation of gold as catalyst to provide improvements in electrode conductivity, among others. This paper reports on the electroless deposition of gold on copper substrates from a HAuCl4.3H2O solution in 1-butyl-1- methylpyrrolidinium dicyanamide (BMP-DCA), in laboratory atmospheric conditions. The electrochemical behaviour of the plating solution was studied by potential sweep techniques. Results suggest that gold ions are reduced and deposited on copper without the aid of external polarization, probably by displacement deposition involving copper dissolution, since no other oxidation reaction was identified. Preliminary studies using SEM/EDX showed that compact gold thin films, deposited on copper substrates at 333 K, present a granular nanostructured morphology
Effect of mixed convection on laminar vortex breakdown in a cylindrical enclosure with a rotating bottom plate
© 2020 Elsevier Masson SAS Vortex breakdown plays a central role in the performance of countless rotating machinery applications, many of which contain thermal gradients either inadvertently or by design. The effect of thermal gradients on vortex breakdown and further flow development in a cylindrical domain with a rotating bottom plate is examined using the Generalized Integral Transformation Technique (GITT) with a streamfunction-only formulation. A thermal gradient is imposed in the axial direction, such that the buoyancy forces oppose the base flow driven by the rotation of the lower plate, i.e. the temperature difference acts to stabilize the flow. The hybrid numerical-analytical approach is shown to accurately capture vortex breakdown phenomena for a variety of conditions involving single, double and triple recirculation bubbles. The buoyancy forces – expressed in terms of the Richardson number (Ri) – act to suppress vortex breakdown in all cases examined and led to a series of flow transitions with increasing Ri, characterized by the appearance of a stratified structure with multiple fluid layers. These flow transitions have a significant impact on the overall performance of the system. The torque coefficient decreases with Ri, compared to the base (isothermal) case following an empirical power law relationship, which is independent of Reynolds number, aspect ratio or number of fluid layers present. Flow stratification suppresses the transport of angular momentum; azimuthal velocity is shown to decline exponentially in the regions where layering occurs, accompanied by a sharp reduction in the Nusselt number, as fluid layers act to insulate the upper plate
Helical tomotherapy versus 3D conformal radiotherapy in dosimetric planning for patients with localized prostate cancer
Radiotherapy is one of the therapeutics selected for localized prostate cancer, in cases where the tumour is confined to the
prostate, penetrates the prostatic capsule or has reached the seminal vesicles (T1 to T3 stages). The radiation therapy can be
administered through various modalities, being historically used the 3D conformal radiotherapy (3DCRT). Other modality of radiation administration is the intensity modulated radiotherapy (IMRT), that allows an increase of the total dose through modulation of the treatment beams, enabling a reduction in toxicity. One way to
administer IMRT is through helical tomotherapy (TH). With this study we intent to analyze the advantages of helical
tomotherapy when compared with 3DCRT, by evaluating the doses in the organs at risk (OAR) and planning target volumes (PTV)
Next-generation sequencing as a promising approach for assessing the entomological origin of honey
Honey is a food widely consumed worldwide and much appreciated for its nutritional and organoleptic properties as well as for its beneficial health effects. However, honey is also considered one of the foods most prone to be adulterated either by the admixing of honey with lower quality, by the addition of sugars, or by mislabeling of botanical and geographical origins, among other possible frauds.1 Therefore, typically, honey authentication has focused mainly on the development of techniques targeting these types of frauds. Recently, increased attention has been paid to honey’s entomological origin since it also relates with geographical origin whose label non-compliances are difficult to detect. Moreover, in the current context where native honeybees are increasingly threatened by introgression, due to the use of exotic queens, preservation of honeybee subspecies in their native ranges, to which they are better adapted, is perceived as of high importance. In this sense, valorisation of the honey produced by native subspecies has been suggested as a possible approach to generate higher income for beekeepers, contributing to the development of rural regions and of sustainable beekeeping based on conservation strategiesThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020),
to Fenapícola and Capemel for supplying the Portuguese honeys, to Dr. Antonio Nanetti (CREA-AA) for the Italian honeys and to António
Pajuelo (Pajuelo Consultores Apícolas S.L.) for the Spanish honeys. D. Henriques is supported by the project BeeHappy (POCI-01-0145-FEDER-029871) funded by FEDER, COMPETE 2020-POCI and FCT and A. Quaresma by the PhD scholarship funded by the FCT
(DFA/BD/5155/2020)info:eu-repo/semantics/publishedVersio
High resolution melting analysis of a COI mini-barcode as a simple approach for the entomological authentication of honey
Honey is highly valued for its taste, aroma, content in bioactive compounds and for being a natural food. In the European Union (EU), market demand for honey is higher than the domestic production and therefore a substantial amount of honey is imported. According to a 2014 European Parliament report on fraud in the food chain, honey was ranked as the 6th food product most prone to adulterateration.1 Up until now, honey authenticity addressed mainly sugars addition and botanical origin. However, an increased attention has recently been paid to honey entomological origin as it also relates to its geographical origin since honeybees carrying mitochondrial DNA (mtDNA) of distinct ancestries can be found across Europe. While in Portugal the predominant mtDNA of the autochthonous subspecies Apis mellifera iberiensis belongs to the A-lineage, when moving towards the northeastern part of the Iberian Peninsula this lineage is gradually replaced by the M-lineage. The native distribution of the M-lineage A. m. mellifera expands from the Pyrenees to Scandinavia and from the British Isles to the Ural Mountains while the C-lineage A. m. ligustica and A. m. carnica are naturally found in the Apennine and Balkan peninsulas, respectivelyThis work was funded by the project-2022, financed by IFAP. The authors are also grateful to the
Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), to Fenapícola and Capemel for supplying the Portuguese honeys, to Dr. Antonio Nanetti (CREA-AA) for the Italian honeys and to António
Pajuelo (Pajuelo Consultores Apícolas S.L.) for the Spanish honeys. D. Henriques is supported by the project BeeHappy (POCI-01-0145-FEDER-029871) funded by FEDER, COMPETE 2020-POCI and FCT. A. R. Lopes and A. Quaresma acknowledge the PhD scholarship funded
by the FCT (SFRH/BD/143627/2019 and DFA/BD/5155/2020, respectively).info:eu-repo/semantics/publishedVersio
Acceptance of dishes based on mechanically separated meat of tambaqui (Colossoma macropomum) in a public school, Brazil.
In Brazil, due to economic and social factors, public policies are needed to grant access to quality nutrition in school. This provision should respect the local food culture; however, in the North, the region with the highest production of inland fisheries, fish consumption among students is still very low. The aim of the present study is to characterize Tambaqui (Colossoma macropomum) MSM, suggest planned school dishes based on this MSM and assesses their acceptability among students at the elementary and high school levels in northern Brazil. The study was carried out over one month and was a quantitative (hedonic scale and leftover/intake index) and qualitative research about preference. The participants were 120 elementary- and high-school students chosen randomly after they were authorized by their parents or legal guardians. Fish-based dishes were inserted in the diet of schoolchildren and their acceptability was evaluated. The children were also inquired about their fish consumption routines. The statistical analyses used were frequency tables and chi-squared independence test associated with Fisher?s exact test. Two dishes were well accepted by the students; however, the results showed that fish acceptance among younger students are higher than among adolescents. So, policies that promote fish intake and a healthy lifestyle must be stimulated since the early grades
Random array of drifting acoustic receivers (RADAR'07)
Rep 04/07 - SiPLAB
15/December/2007This report describes the complete set of data acquired
during the RADAR’07 sea trial, that took place aboard
the NRP D. Carlos from July 9 - 15, 2007, off the
west coast of Portugal, in the Set´ubal area
Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons
Single hadron azimuthal asymmetries in the cross sections of positive and negative hadron production in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle is obtained by means of a five-parameter fitting function that besides a -independent term includes four modulations predicted by theory: , , and . The amplitudes of the five terms have been first extracted for the data integrated over all kinematic variables. In further fits, the -dependence is determined as a function of one of three kinematic variables (Bjorken-, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the other two. Except the -independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties.Peer Reviewe
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