Some considerations about the contribution of roller shutters positions to noise insulation of façades

This paper describes an experimental study on the evaluation of the influence of roller shutters positions on noise insulation of façades. The study is based on the results of a set of tests carried out in laboratory, and in situ using the 1st, 2nd, 3rd and 4th floors of a selected new housing building which is typical of Portuguese cooperative construction. For the purpose a specific type of window was considered. The window system (glazing and frame, plus the roller shutter) was firstly characterized in laboratory. In situ, the tests were performed in 2 different rooms having different window dimensions. The measurements were done in accordance with what is prescribed by international standards, using a loudspeaker as noise source. The considered shutters positions were: totally opened, half closed, partially closed (shutter extended) and completely closed (shutter fully extended). Additionally, in situ measurements with the window open were also done. The results have shown that the façade transmission loss curve related to each shutter position at the same storey and between different floor levels differs with some significance. Other interesting and important conclusions were extracted from the study done, namely: i) the important influence of shutter position when the window is open; the discrepancy between laboratory and in situ sound insulation performance; the low influence of flanking transmission regarding façades performance, which is due to its weak sound insulation when compared to those of the adjoining elements; and, finally, the evolution of sound insulation in frequency domain for the set of combinations window open and closed versus shutter positions.Fundação para a Ciência e a Tecnologia (FCT

New frontiers in remediation of (micro)plastics

Plastic pollution is increasing daily, raising social, environ- mental, and economic concerns. Along with the reduction policies on plastic use and consumption, and improvement of waste management systems, it is of utmost importance to develop and implement remediation and emission control measures. Focused on the most recent literature, this article provides a critical overview and in-depth discussion on breakthrough technological and biotechnological research that may sustain an effective and efficient (micro)plastic remedia- tion in the near future.publishe

Testing strong line metallicity diagnostics at z~2

High-z galaxy gas-phase metallicities are usually determined through observations of strong optical emission lines with calibrations tied to the local universe. Recent debate has questioned if these calibrations are valid in the high-z universe. We investigate this by analysing a sample of 16 galaxies at z~2 available in the literature, and for which the metallicity can be robustly determined using oxygen auroral lines. The sample spans a redshift range of 1.4 < z < 3.6, has metallicities of 7.4-8.4 in 12+log(O/H) and stellar masses 10^7.5-10^11 Msun. We test commonly used strong line diagnostics (R23, O3, O2, O32, N2, O3N2 and Ne3O2 ) as prescribed by four different sets of empirical calibrations, as well as one fully theoretical calibration. We find that none of the strong line diagnostics (or calibration set) tested perform consistently better than the others. Amongst the line ratios tested, R23 and O3 deliver the best results, with accuracies as good as 0.01-0.04 dex and dispersions of ~0.2 dex in two of the calibrations tested. Generally, line ratios involving nitrogen predict higher values of metallicity, while results with O32 and Ne3O2 show large dispersions. The theoretical calibration yields an accuracy of 0.06 dex, comparable to the best strong line methods. We conclude that, within the metallicity range tested in this work, the locally calibrated diagnostics can still be reliably applied at z~2.Comment: 12 pages, 8 Figures, accepted for publication in MNRA

Case study : comparison between the acoustic performance of a mixed building technology building and a conventional building

The objective of this work is to compare the acoustical performance of MBT (Mixed Building Technology) constructions and conventional buildings. The sound insulation performance of a MBT construction was assessed by tests done in situ. The results were compared with similar data from earlier measurements undertaken by the Building Physics Laboratory of the University of Minho in Portugal, and from simplified prediction methods. The building where this comparison was done is a 3-storey building. The first 2 storeys were refurbished using conventional construction methods, but the 3rd storey was built using MBT methods, characterised by using lightweight materials, with high thermal insulation, and large fenestration areas. Based on the work undertaken, some conclusions and proposals for further work are presented.(undefined

The Use of Intravascular Ultrasound in Portugal: Japan Is a Long Way Away

info:eu-repo/semantics/publishedVersio

Optimal solution of a diffusion equation with a discrete source term

In this paper we study the numerical behavior of a diffusion equation with a discrete control source term. The equation is discretized in space by finite differences and in time by an implicit scheme. The control variables are calculated in order to minimize an objective function, taking into account some restrictions. We define two strategies to obtain the optimal solution and present some numerical results in a context of a model that describes the oxygen concentration in a single chamber microbial fuel cell