4,651 research outputs found
Robust Gravitational Wave Burst Detection and Source Localization in a Network of Interferometers Using Cross Wigner Spectra
We discuss a fast cross-Wigner transform based technique for detecting
gravitational wave bursts, and estimating the direction of arrival, using a
network of (three) non co-located interferometric detectors. The performances
of the detector as a function of signal strength and source location, and the
accuracy of the direction of arrival estimation are investigated by numerical
simulations.Comment: accepted in Class. Quantum Gravit
Insights on the use of wind speed vertical extrapolation methods
The present work aims to study the influence of
using different methods for wind speed extrapolation in energy
production calculations. A dataset of 21 meteorological masts
from several landscape characteristics and locations, with at least
one year of 10-minute wind speed/direction data, was used as the
basis for calculations. Both the power law through estimation of
wind shear coefficients, and the logarithmic-based profile using
WAsP, were used as mathematical models for predicting wind
shear. Wind speed extrapolation was performed either from the
top-most height, using a distance method that incorporated all
measurement heights, or using the function for wind shear
coefficient prediction. It was found that using the logarithmicbased
profile was the less reliable of all studied methods. The
study showed that the most accurate method was the power law
with wind shear coefficients estimated from the two upper
heights closest to the extrapolation height, by wind direction
sector of 30º, and the wind speeds extrapolation from the topmost
height of the two. It is suggested that the use of this method
reduces uncertainty in AEP estimates.info:eu-repo/semantics/publishedVersio
Competitiveness of the tourism sector in Portugal: the case of Baixo Mondego and Baixo Vouga
Our main objective is to analyze how a great, diverse tourism offer in a quite limited geographic area, corresponding to the Baixo Mondego and Baixo Vouga, can make it more competitive. We propose to identify the territorial factors that can increase competitiveness of the tourism sector, both regionally and nationally. We intend to identify the region‟s most valued aspects by visitors, as well as its least praised ones; additionally, we will pinpoint existing and potential outbound travel markets, and identify those that are characterized by higher levels of wealth and touristic demand. A quantitative approach will be complemented by a qualitative analysis, based on interviews of entrepreneurial, academic and institutional entities. Deeper knowledge of the regional tourism sector will allow us to contribute to the adaptation of tourism oriented policies and strategies that would promote the role of tourism in the regional economical development. An economic impact analysis will assess the contribution of tourism activity on the region
ER Stress and Iron Homeostasis: A New Frontier for the UPR
The C282Y mutation of HFE accounts for the majority of cases of the iron overload disease Hereditary Hemochromatosis (HH).
The conformational changes introduced by this mutation impair the HFE association with β2-microglobulin
(β2m) and the cell surface expression of the protein: with two major consequences. From a functional perspective,
the ability of HFE to bind to transferrin receptors 1 and 2 is lost in the C282Y mutant, thus affecting hepcidin regulation. Also due to the faulty
assembly with β2m, HFE-C282Y molecules remain in the endoplasmic reticulum (ER) as aggregates that undergo
proteasomal degradation and activate an Unfolded Protein Response (UPR). UPR activation, regardless of the ER stress stimuli, was shown
to reshape the expression profile of iron-related genes and to decrease MHC-I cell surface expression. The possibility of a HFE-C282Y-mediated
interplay between the UPR and iron homeostasis influencing disease progression and the clinical heterogeneity among C282Y carriers is
discussed. The responsiveness of the ER chaperone calreticulin to both ER and iron-induced oxidative stresses, and its correlation with HH
patients' phenotype, reinforce the interest of dissecting the UPR signaling/iron metabolism crosstalk and points to the potential
clinical value of use of pharmacological chaperones in HFE-HH
Standardization and optimization of an automotive components production line
Supported by the concepts and definitions of Standard Work methodology, which underpins Lean Thinking philosophy and Kaizen, the study described in this article was developed at a company in the automotive sector, more specifically directed at a production line manufacturing components for air-conditioning systems. The main objectives were to standardize operations, decrease or eliminate the number of activities those are not generating added-value, enhance productivity and associate continuous improvement actions to the processes at hand in order to eliminate waste. After the implementation of a few simple changes - the standardization of operations, adjustments and allocations of workstations – one was able to tailor the production objectives and cycle times to the line’s capacity. The productivity and efficiency of both machines and workers was also increased. Due to the elimination of waste and generation of value, from the customer’s perspective, one was able to raise the OEE (Overall Equipment Effectiveness) general average by 16%, from 70% to 86%.info:eu-repo/semantics/publishedVersio
Implementing autonomous maintenance in an automotive components manufacturer
The automotive sector constitutes one of the most demanding activities in the global market, since it requires a constant increase in productivity, both in the automobile industry as well as in the companies whose manufacture its components. This sector is currently set within an economic framework where there is a relentless search for costs reduction and an increase in productivity with minimal investment. In order to meet these requirements, companies have sought to optimise their products and processes to ensure higher profits. This study was developed with the purpose of enhancing procedures in the maintenance sector regarding a company which supplies air-conditioning tubes to the automotive sector. The main objective was to increase its machines and equipment availability through the implementation of autonomous maintenance. Due to the undertaken improvements, there was a 10% increase in the monthly indicator of equipment availability on line AA3 at the company where the study was carried out. This, in turn, resulted in an increase of 8% in OEE (Overall Equipment Effectiveness) during the same time period, which was chiefly due to a reduction both in machine breakdown rates, as well as in the MTTR (Mean Time To Repair) on the same line.info:eu-repo/semantics/publishedVersio
Fluorescence of a benzothienopyridopyrimidone in solution and in lipid vesicles
Fluorescence properties of a biologically active benzothienopyridopyrimidone in solution and in lipid vesicles are reported. Assays at different pH values (0.5–10) allowed the determination of pKa = 2.0, showing that this compound may be useful as a pH indicator for pH ≤ 4. In lipid vesicles,
benzothienopyridopyrimidone locates in a water-rich environment, indicating that it can be carried in the hydrophilic region of liposomes for drug delivery applications.Fundação para a Ciência e a Tecnologia (FCT
Testes de conforto térmico aplicados a uma malha multifuncional desenvolvida com novos materiais
Os produtores europeus, os engenheiros têxteis e os designers devem, no desenvolvimento de novas peças de vestuário, terem em consideração as novas exigências dos consumidores em relação ao conforto.
Uma grande variedade de áreas de investigação foram, nos últimos tempos, criadas e desenvolvidas permitindo atingir as exigências relacionadas com o conforto, nomeadamente, considerando os aspectos funcionais e estéticos, entre outros. O conforto térmico humano é, de certa forma, um dos componentes mais importantes a considerar, podendo ser definido como a principal troca de calor e massa e calor do corpo humano com o meio ambiente, através da roupa.
Um dos objectivos deste trabalho foi, através do trabalho de uma equipa multidisciplinar, desenvolver uma malha funcional de forma a permitir o conforto termo-fisiológico a quem a utilizar. O presente trabalho permite assim investigar as várias etapas relacionadas com o estudo do conforto no desenvolvimento de novas peças de vestuário: o desenvolvimento de novas malhas, a execução de testes num manequim térmico; a simulação numérica do corpo humano com e sem roupa e o desenvolvimento de testes subjectivos de conforto térmico.
A nova malha produzida foi caracterizada e testada em laboratório, em termos de quantidade de vapor de água e da permeabilidade ao ar e outros parâmetros físicos. A malha produzida foi aplicada como forro de botas de caminhada e para o fabrico de t-shirts. Os protótipos das botas de caminhada foram avaliados de forma subjectiva através de questionários. Um manequim térmico foi utilizado para medir o isolamento térmico das t-shirts e a distribuição de temperatura na pele.
Juntamente com este trabalho experimental, um modelo de termo regulação do corpo humano foi desenvolvido para validar os dados experimentais obtidos. Alguns dos resultados são apresentados e discutidos
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