48 research outputs found
Hybrid moulds : the use of combined techniques for the rapid manufacturing of injection moulds
"Virtual modeling and rapid manufacturing : advanced research in virtual and rapid prototyping : proceedings of the 2nd International Conference on Advanced Research and Rapid Prototyping, Leiria, Portugal, 28 September - 1 October, 2005 (VR@P 2005)". ISBN 0-415-39062-1Injection moulding is the major polymer processing technique. The mould is a key element of
this process and its characteristics have a key importance on the parts produced. The fabrication of products
with higher added value, especially in terms of production time and costs, is essential for the success of the
mouldmaking industry within a global competitive environment.
This paper presents the concept of hybrid mould, a recent concept for injection moulding of prototype and
short series. Direct and indirect rapid tooling technologies can be used for the fabrication of these moulds.
Hence, new design guidelines need to be defined to produce these moulds as well to assess its performance.
Epoxy tooling and selective laser sintering are the two rapid tooling technologies explored to produce inserts
for hybrid-moulds. This work studies the fabrication of hybrid-moulds through these rapid tooling technologies,
as well its mechanical and thermal behaviour.(undefined
Processo de sobremoldação de vedante numa tampa plástica
O objeto da presente patente é o processo de sobremoldação de uma tampa
Plástica com vedante incorporado, na qual é injetado o material de maior dureza sobre o
De menor dureza. Este processo de sobremoldação é aplicado somente em bi-injecção
(utilização de dois materiais ou mais), em tampas plásticas rígidas para embalagens de
Forma redonda ou outras. A solução adotada passou por proteger o vedante (3) do fluxo
(9) do material da tampa (2) de modo a evitar que este cause deformações no vedante (3)
Durante o processo de enchimento. A forma de orientação precisa do fluxo (9) do sobre o
Material de menor dureza (3) evita a deformação deste ultimo recorrendo aos diferenciais
De pressão conjugados com a velocidade. Desta forma é possível injetar sobre um
Material de menor dureza (3), um material de maior dureza (2)
Severe community-acquired pneumonia in the intensive care unit
Introduction Community-acquired pneumonia remains a common condition worldwide. It is associated with significant morbidity and mortality. The aim of this study was to evaluate conditions that could predict a poor outcome
The molecular epidemiology of HIV-1 in the Comunidad Valenciana (Spain): analysis of transmission clusters
HIV infections are still a very serious concern for public heath worldwide. We have applied molecular evolution methods to study the HIV-1 epidemics in the Comunidad Valenciana (CV, Spain) from a public health surveillance perspective. For this, we analysed 1804 HIV-1 sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2004 and 2014. These sequences were subtyped and subjected to phylogenetic analyses in order to detect transmission clusters. In addition, univariate and multinomial comparisons were performed to detect epidemiological differences between HIV-1 subtypes, and risk groups. The HIV epidemic in the CV is dominated by subtype B infections among local men who have sex with men (MSM). 270 transmission clusters were identified (>57% of the dataset), 12 of which included ≥10 patients; 11 of subtype B (9 affecting MSMs) and one (n = 21) of CRF14, affecting predominately intravenous drug users (IDUs). Dated phylogenies revealed these large clusters to have originated from the mid-80s to the early 00 s. Subtype B is more likely to form transmission clusters than non-B variants and MSMs to cluster than other risk groups. Multinomial analyses revealed an association between non-B variants, which are not established in the local population yet, and different foreign groups
Origin and Epidemiological History of HIV-1 CRF14_BG
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Users must also make clear the license terms under which the work was published. CC BY Licence: http://creativecommons.org/licenses/by/4.0/Background: CRF14_BG isolates, originally found in Spain, are characterized by CXCR4 tropism and rapid disease
progression. This study aimed to identify the origin of CRF14_BG and reconstruct its epidemiological history based on new
isolates from Portugal.Methodology/Principal Findings: C2V3C3 env gene sequences were obtained from 62 samples collected in 1993–1998
from Portuguese HIV-1 patients. Full-length genomic sequences were obtained from three patients. Viral subtypes, diversity,
divergence rate and positive selection were investigated by phylogenetic analysis. The molecular structure of the genomes
was determined by bootscanning. A relaxed molecular clock model was used to date the origin of CRF14_BG. Geno2pheno
was used to predict viral tropism. Subtype B was the most prevalent subtype (45 sequences; 73%) followed by CRF14_BG (8;
13%), G (4; 6%), F1 (2; 3%), C (2; 3%) and CRF02_AG (1; 2%). Three CRF14_BG sequences were derived from 1993 samples.
Near full-length genomic sequences were strongly related to the CRF14_BG isolates from Spain. Genetic diversity of the
Portuguese isolates was significantly higher than the Spanish isolates (0.044 vs 0.014, P,0.0001). The mean date of origin of
the CRF14_BG cluster was estimated to be 1992 (range, 1989 and 1996) based on the subtype G genomic region and 1989
(range, 1984–1993) based on the subtype B genomic region. Most CRF14_BG strains (78.9%) were predicted to be CXCR4.
Finally, up to five amino acids were under selective pressure in subtype B V3 loop whereas only one was found in the
CRF14_BG cluster.Conclusions: CRF14_BG emerged in Portugal in the early 1990 s soon after the beginning of the HIV-1 epidemics, spread to
Spain in late 1990 s as a consequence of IVDUs migration and then to the rest of Europe. CXCR4 tropism is a general
characteristic of this CRF that may have been selected for by escape from neutralizing antibody response
Selection of Air Force Pilot Candidates: A Case Study on the Predictive Accuracy of Discriminant Analysis, Logistic Regression, and Four Neural Network Types
Clinical electroencephalogram (EEG) evaluation is improved by the amplitude asymmetry index
Para o estudo da evolução do ensino e da formação em administração educacional em Portugal
Estudos sobre a evolução do ensino de disciplinas, na formação de professores em Portugal, são recentes. O controle burocrático centralizado reteve as dimensões do controle político-administrativo. De certo modo, protegeu a esfera educativa das influências modernizantes, do capitalismo industrial e das lógicas mercantis e gerencialistas. Defendeu a educação do domínio político, da intervenção de movimentos sociais, das propagandas de ideais democráticos e da cidadania. A utilização da designação "Administração educacional" ilustra as dificuldades sentidas, ao longo dos últimos anos, em termos da construção acadêmica de uma área, seja pela falta de tradição, seja pelos antecedentes históricos.In Portugal, studies about the evolution of disciplines teaching in the teachers formation are recent. The centralized bureaucratic control has held back the dimensions of politic administrative control. In a certain way, it has protected the education against the new-fashioned influences, manufacturing capitalism, and mercantile and managerial logics. This centralized bureaucratic control has also profected the education against the politic dominion, the intervention of social movements, the advertising of democratic ideals, and against the citizenship. The use of the term "Educational administration" shows the difficulties met by the searchers along the latest years, since there is no tradiction nor historic antecedence