ORCID Profile
0000-0003-0215-8701
Current Organisation
Universidade do Porto Faculdade de Engenharia
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Publisher: Universitat Politecnica de Valencia
Date: 04-04-2023
DOI: 10.4995/VITRUVIOIJATS.2023.18832
Abstract: The use of recovered materials in building construction is one of the most effective strategies for reducing the environmental impacts of the construction sector. Innovative technologies such as 3D construction printing can be applied in combination with recycling strategies in order to optimise their performances also from an environmental point of view. In fact, several studies have proposed the processing of waste material into printable material. At the same time, performance studies must be conducted on the building components produced by these methods. This study proposes a methodological approach to design a 3D printable building component made with recycled materials considering the improvement of thermal performances. In particular, the approach is based on three steps: reuse strategy conception target performance definition, modelling and iterative simulation 3D printing setting. The methodological approach has been applied to a 3D printable block using as printable material a cement-based mortar with recycled aggregates and recycled insulating material. As a result, the component’s shape (interlocking and inspired by honeycombs) can be customised to achieve the required thermal performance by using recycled materials in the printing process.
Publisher: MDPI AG
Date: 20-12-2022
DOI: 10.3390/S23010023
Abstract: The use of simpler and less bulky equipment, with a reliable performance and at relative low cost is increasingly important when assembling sensing configurations for a wide variety of applications. Based on this concept, this paper proposes a simple, efficient and relative low-cost fiber Bragg grating (FBG) interrogation solution using ultra-short FBGs (USFBGs) as edge filters. USFBGs with different lengths and reflection bandwidths were produced in silica optical fiber and in poly(methyl methacrylate) (PMMA) microstructured polymer optical fiber (mPOF), and by adjusting specific inscription parameters and the diffraction pattern, these gratings can present self-apodization and unique spectral characteristics suitable for filtering operations. In addition to being a cost-effective edge filter solution, USFBGs and standard uniform FBGs in silica fiber have similar thermal sensitivities, which results in a straightforward operation without complex equipment or calculations. This FBG interrogation configuration is also quite promising for dynamic measurements, and due to its multiplexing capabilities multiple USFBGs can be inscribed in the same optical fiber, allowing to incorporate several filters with identical or different spectral characteristics at specific wavelength regions in the same fiber, thus showing great potential to create and develop new sensing configurations.
Publisher: Universitat Politecnica de Valencia
Date: 04-04-2023
DOI: 10.4995/VITRUVIO-IJATS.2023.18832
Abstract: The use of recovered materials in building construction is one of the most effective strategies for reducing the environmental impacts of the construction sector. Innovative technologies such as 3D construction printing can be applied in combination with recycling strategies in order to optimise their performances also from an environmental point of view. In fact, several studies have proposed the processing of waste material into printable material. At the same time, performance studies must be conducted on the building components produced by these methods. This study proposes a methodological approach to design a 3D printable building component made with recycled materials considering the improvement of thermal performances. In particular, the approach is based on three steps: reuse strategy conception target performance definition, modelling and iterative simulation 3D printing setting. The methodological approach has been applied to a 3D printable block using as printable material a cement-based mortar with recycled aggregates and recycled insulating material. As a result, the component’s shape (interlocking and inspired by honeycombs) can be customised to achieve the required thermal performance by using recycled materials in the printing process.
Publisher: EDP Sciences
Date: 02-2020
DOI: 10.1051/0004-6361/201936742
Abstract: Accurate and precise measurement of the masses of galaxy clusters is key to deriving robust constraints on cosmological parameters. However, increasing evidence from observations confirms that X-ray masses obtained under the assumption of hydrostatic equilibrium might be underestimated, as previously predicted by cosmological simulations. We analyze more than 300 simulated massive clusters from the Three Hundred Project, and investigate the connection between mass bias and several diagnostics extracted from synthetic X-ray images of these simulated clusters. We find that the azimuthal scatter measured in 12 sectors of the X-ray flux maps is a statistically significant indication of the presence of an intrinsic (i.e., 3D) clumpy gas distribution. We verify that a robust correction to the hydrostatic mass bias can be inferred when estimates of the gas inhomogeneity from X-ray maps (such as the azimuthal scatter or the gas ellipticity) are combined with the asymptotic external slope of the gas density or pressure profiles, which can be respectively derived from X-ray and millimeter (Sunyaev-Zeldovich effect) observations. We also obtain that mass measurements based on either gas density and temperature or gas density and pressure result in similar distributions of the mass bias. In both cases, we provide corrections that help reduce both the dispersion and skewness of the mass bias distribution. These are effective even when irregular clusters are included leading to interesting implications for the modeling and correction of hydrostatic mass bias in cosmological analyses of current and future X-ray and SZ cluster surveys.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2023
Location: Portugal
No related grants have been discovered for Humberto Varum.