2,727 research outputs found
Bottleneck prediction and data-driven discrete-event simulation for a balanced manufacturing line
Bottleneck identification is a relevant tool for continuous optimization of production lines. In this work, we implement a data-driven discrete-event simulator (DDS) based on experimental distributions, obtained from real historical data. The DDS allows to analyse the behavior of a balanced manufacturing line at Bosch Thermotechnology, under different hypotheses. It shows that some scenarios perceived as likely to increase output may actually decrease production metrics, reveals the importance of line injection rates, and leads to the need for adequate real time bottleneck forecasting tools, which allow shift managers intervention in a useful time frame. Eleven prediction models are tested, where a random forest and a multi-layer perceptron attain the best performances (above 95% in all metrics). This data flow is operationalized through a micro-services pipeline which is briefly discussed.publishe
The use of simulation in self-perception of learning in occupational therapy students
This study aimed to assess the self-perception of students’ learning in Occupational Therapy undergraduate students of School of Health of the Polytechnic of Porto after exposure to a simulated situation of an information collection interview for an occupational profile.info:eu-repo/semantics/publishedVersio
Application of lean approaches and techniques in an automotive company
In this paper are applied lean approaches and techniques in an industrial environment at Preh Portugal, Lda., a Company involved in the automotive sector located in Trofa, Portugal. This work makes use of the action-research methodology, aiming to diagnose the production system and to implement lean production procedures in order to optimize the Mizusumashi that supplies several production sections, about plastic Injection, cutting and painting. The results obtained enabled to obtain significant improvements on this Company at several factory management and operational levels.This work was supported by FCT “Fundação para a Ciência e a Tecnologia” under the program: PEst20152020.info:eu-repo/semantics/publishedVersio
Assessment of the geological heritage of Cape Mondego Natural Monument (Central Portugal)
In the western coast of Portugal, Cape Mondego is a well-known set of outcrops due to its international stratigraphic relevance given by the establishment of two stratotypes: the Global Boundary Stratotype Section and Point (GSSP) for the base of the Bajocian Stage and the Auxiliary Stratotype Section and Point (ASSP) for the base of the Bathonian Stage.
The remarkable geodiversity of these Jurassic outcrops justifies the implementation of strategies in order to conserve and promote the geosites, which include a rich palaeontological record of macrofossils, microfossils and dinosaur footprints.
Based on the exceptional quality of the geological record, on its international importance and on its high scientific and educational values, this area was classified in 2007 as Natural Monument. However, no geosite systematic inventory was ever done.
In this work, a systematic identification, characterization and assessment of geosites was done in the Natural Monument. Based on fieldwork and published data, a first set of 32 potential geosites was identified taking into account their scientific, educational and touristic values. After the application of three criteria (representativeness, singularity and proximity) this group of 32 potential geosites was reduced to 12. These 12 geosites were assessed resulting on the establishment of a medium to high ranks for both educational and geotouristic potential uses. Based on this assessment, some valuing strategies were proposed, aiming at the sustainable use and the promotion of the Natural Monument geosites, within the scope of both educational and geotouristic activities addressed to secondary school students and the general public
Dyeing of PA6.6 fibers - Effect of solvent and temperature on thermal properties
Dyeing fibers at low temperatures has many advantages such as savings in energy and avoiding alterations to the physical properties of the fibers being dyed or other fibers also present in blends, The problem of low temperature dyeing in synthetic fibers is that it difficults the dye diffusion into the fiber. In the case of polyamide 6.6 microfibers, by using benzyl alcohol as an auxiliary dyeing, it was shown that good diffusion was obtained for the dye exhaustion with metal complex dyes at temperatures more than 30°C below the normal dyeing temperature for the dye exhaustion with metal complex dyes. Using thermal analysis methods these results were shown to be caused by the lowering of the T g of the fiber when in the presence of benzyl alcohol.Fundação para a Ciência e a Tecnologia (FCT
Processamento de imagem digital com MatLab : uma aplicação em ambiente industrial
Fundação para a Ciência e a Tecnologia (FCT
Frequency of micronuclei and of other nuclear abnormalities in erythrocytes of the grey mullet from the Mondego, Douro and Ave estuaries—Portugal
Fish are bioindicators of water pollution, and an
increased rate of their erythrocyte nuclear morphological abnormalities
(ENMAs)—and particularly of erythrocyte
micronuclei (EMN)—is used as a genotoxicity biomarker.
Despite the potential value of ENMAs andMN, there is scarce
information about fish captured in Iberian estuaries. This is the
case of the Portuguese estuaries of the Mondego, Douro and
Ave, suffering from different levels of environmental stress
and where chemical surveys have been disclosing significant
amounts of certain pollutants. So, the aim of this study was to
evaluate genotoxicants impacts and infer about the exposure
at those ecosystems, using the greymullet (Mugil cephalus) as
bioindicator and considering the type and frequency of nuclear
abnormalities of erythrocytes as proxies of genotoxicity.
Sampling of mullets was done throughout the year in the
important Mondego, Douro and Ave River estuaries (centre
and north-western Portugal). The fish (total n=242) were
caught in campaigns made in spring–summer and autumn–
winter, using nets or fishing rods. The sampled mullets were
comparable between locations in terms of the basic biometric
parameters. Blood smears were stained with Diff-Quik to assess
the frequencies of six types of ENMAs and MN (given per
1,000 erythrocytes). Some basic water physicochemical parameters
were recorded to search for fluctuations matching the
ENMAs. Overall, the most frequent nucleus abnormality was
the polymorphic type, sequentially followed by the blebbed/
lobed/notched, segmented, kidney shaped, vacuolated,MNand
binucleated. The total average frequency of the ENMAs ranged
from 73‰in the Mondego to 108‰in the Ave. The polymorphic
type was typically ≥50 % of the total ENMAs, averaging
about 51‰, when considering all three estuaries. The most
serious lesion—the MN—in fish from Mondego and Douro
had a similar frequency (≈0.38‰), which was significantly
lower than that in the Ave (0.75‰). No significant seasonal
differences existed as to the MN rates and seasonal differences
existed almost only in the Douro, with the higher values in AW.
In general, the pattern of ENMAs frequencies was unrelated
with the water physicochemical parameters. Considering the
data for both the total ENMAs and for each specific abnormality,
and bearing in mind that values of MN in fish erythrocytes
>0.3‰ usually reflect pollution by genotoxicants, it is suggested
that mullets were likely being chronically exposed to
such compounds, even in the allegedly less polluted ecosystem
(Mondego). Moreover, data supported the following pollution exposure gradient: Mondego<Douro<Ave. The scenario and
inferences nicely agree with the published data from chemical
monitoring.This work was partially supported by the European
Regional Development Fund (ERDF) funds through the Competitiveness
and Trade Expansion Program (COMPETE), and by National Funds
provided by Fundação para a Ciência e a Tecnologia (FCT), via the
research projects PTDC/MAR/70436/2006, PEst-C/MAR/LA0015/
2011, PEst-C/MAR/LA0015/2013, and also by the PhD grant
SFRH/BD/25746/2005
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