Comparison of deposited surface area of airbone ultrafine particles generated from two welding processes

This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers

Empenhamento(s) organizacional(is): Dois laços afectivos, dois instrumentais, um normativo e um de ausência

Este artigo visa testar um hexa-modelo dimensional do empenhamento organizacional sugerido em pesquisas anteriores de Rego (2002b, 2003). O modelo difere do esquema tri-dimensional mais comum (afectivo, normativo e instrumental) no que concerne a três aspectos: a) a faceta afectiva é desmembrada em duas (empenhamento afectivo; futuro comum); b) a faceta instrumental é dividida nas facetas “escassez de alternativas” e “sacrifícios elevados”; c) é sugerida uma nova dimensão, designada “ausência psicológica” e que representa o “grau zero” do empenhamento. A amostra é constituída por 366 indivíduos, com actividades profissionais bastante distintas. Análises factoriais confirmatórias sugerem que o modelo de seis dimensões se ajusta satisfatoriamente aos dados, embora os modelos de quatro e cinco dimensões denotem igualmente boas qualidades psicométricas.This study aims at testing a six-factor model of organizational commitment suggested by Rego (2002b, 2003). The model differs from the more common three-factor model in what concerns three aspects: a) affective commitment is divided in two dimensions (affective commitment; future in common); b) continuance commitment is also divided (great sacrifices; scarcity of available alternatives); c) a new dimension (psychological absence) is proposed. The sample comprises 366 individuals with several occupations. Confirmatory factor analyses show that the six-factor model fits the data well, but the models with four or five factors have also good psychometric properties

Educational technology in care management: technological profile of nurses in Portuguese hospitals

Objetivo Identificar o perfil tecnológico de enfermeiros de hospitais portugueses. Método Estudo exploratório quantitativo, realizado em dois hospitais da região norte e um da região central de Portugal. A amostra foi aleatória e contou com960 enfermeiros. Resultados Dos partícipes 420 (46,1%) utilizavam ocomputador, 196 (23,4%) referiram que têm conhecimento da utilização do computador para o ensino, 174 (21,1%)utilizaram o computador para ensino, 112 (15,1%) reconhecem que a utilização do computador pode ser um meio tecnológico para completar a formação presencial, 477 (61,6%) gostariam de receber formação sobre a utilização do computador e 382 (40,9%) referiram autoaprendizagem em informática. Em relação ao ensino a distância 706 (74,9%) relataram que não estão familiarizados e 752 (76,4%) referiram interesseem participar em formaçõesnesta modalidade. Conclusão As organizações devem estar atentas ao perfil tecnológico que se desenha neste grupo de enfermeiros e procurar formas de introduzir as tecnologias educacionais na gestão de cuidados.Objective To identify the technological profile of nurses in Portuguese hospitals. Method A quantitative exploratory study conducted in two hospitals in the northern region and one in the central region of Portugal. The sample was randomly selected and included 960 nurses. Results Of the participants, 420 (46.1%) used computers, 196 (23.4%) reported having knowledge about using computers for teaching, 174 (21.1%) used computers to teach, 112 (15.1%) recognized that using computers can be a technological means to supplement classroom training, 477 (61.6%) would like to receive training on using computers, and 382 (40.9%) reported self-learning of information technology. In relation to distance education, 706 (74.9%) reported they were familiar with it and 752 (76.4%) indicated an interest in participating in training using this modality. Conclusion Organizations should be mindful of the technological profile shown by this group of nurses and look for ways to introduce educational technologies in the management of care.Objetivo Identificar el perfil tecnológico de los enfermeros en los hospitales portugueses. Método Un estudio exploratorio cuantitativo realizado en dos hospitales en la región norte y la región central de Portugal. La muestra se seleccionó de forma aleatoria e incluyó 960 enfermeros. Resultados De los 420 participantes (46,1%) utilizan el computadora, 196 (23.4%) reportaron haber tenido conocimiento del uso de la computadora para la enseñanza, 174 (21,1%) utiliza la computadora para la enseñanza, 112 (15, 1%) reconoce que el uso de la tecnología informática puede ser un medio para complementar la formación presencial, 477 (61,6%) les gustaríarecibir capacitaciónen el uso dela computadora y 382 (40,9%) informaron de auto-aprendizaje en la computación. En relación con la educación a distancia 706 (74.9%) reportaron no están familiarizados y 752 (76,4%) indicaron su interés en participar en esta modalidad de formación. Conclusión Las organizaciones deben tener en cuenta el perfil tecnológico que señala este grupo de enfermeras y buscar maneras de introducir tecnologías de la educación en gestión de la atención

Experimental analysis of niti alloy during strain-controlled low-cycle fatigue

PTDC/CTM-CTM/29101/2017- POCI-01-0145-FEDER-029101 UIDB/EMS/00285/2020 UIDB/50025/2020-2023The interaction between the stress-induced martensitic transformation and resistivity behavior of superelastic NiTi shape memory alloy (SMA) was studied. Strain-controlled low-cycle fatigue up to 6% was monitored by in situ electrical resistivity measurements. The experimental results show that a great motion of martensite fronts results in a significant accumulation of defects, as evidenced by transmission electron microscopy (TEM), before and after the tensile cycles. This gives rise to an overall increase of the resistivity values up to the maximum deformation. Therefore, the research suggests that shape memory alloy wire has great potential as a stress sensor inside bulk materials.publishersversionpublishe

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types