A discussion concerning active infrared thermography in the evaluation of buildings air infiltration

[EN] The EU is strongly committed to energy saving in buildings. Air leaks through the building envelope represent a significant percentage of buildings energy consumption. Locating and minimizing air leaks is thus necessary to optimize energy efficiency. This work presents the results of an experimental campaign that aimed to promote a discussion concerning the opportunities and constraints of using active IRT to detect air leakage points. The potential of active IRT was evaluated both in a qualitative approach, by comparing the thermograms with the ones obtained with passive IRT, and in a quantitative one, by testing methods of numerically interpret the thermograms. The results allowed concluding that active IRT increases the thermal contrast and the affected area, proving that active IRT combined with pressure differences is an effective methodology for detecting air infiltrations. In the quantitative approach different numerical methods can be used. Their selection depends on the aims of the study, as they can highlight different perspectives of the phenomenon. (C) 2018 Elsevier B.V. All rights reserved.This work was financially supported by: Project POCI-01-0145-FEDER-007457 - CONSTRUCT - Institute of R&D In Structures and Construction funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI) - and by national funds through FCT - Fundacao para a Ciencia e a Tecnologia.Lerma Elvira, C.; Barreira, E.; Almeida, R. (2018). A discussion concerning active infrared thermography in the evaluation of buildings air infiltration. Energy and Buildings. 168:56-66. https://doi.org/10.1016/j.enbuild.2018.02.050S566616

Time-metric equivalence and dimension change under time reparameterizations

We study the behavior of dynamical systems under time reparameterizations, which is important not only to characterize chaos in relativistic systems but also to probe the invariance of dynamical quantities. We first show that time transformations are locally equivalent to metric transformations, a result that leads to a transformation rule for all Lyapunov exponents on arbitrary Riemannian phase spaces. We then show that time transformations preserve the spectrum of generalized dimensions D_q except for the information dimension D_1, which, interestingly, transforms in a nontrivial way despite previous assertions of invariance. The discontinuous behavior at q=1 can be used to constrain and extend the formulation of the Kaplan-Yorke conjecture

Four-year monthly sediment deposition on turbid southwestern Atlantic coral reefs, with a comparison of benthic assemblages

A sedimentação é freqüentemente relacionada a estresse em recifes de coral. Os recifes do Atlântico sul ocidental possuem grande sedimentação, entretanto carecem de séries temporais das taxas de deposição de sedimento. Foram avaliadas estas taxas e a composição carbonática do sedimento, além da cobertura de corais e zoantídeos em seis recifes brasileiros durante quatro anos consecutivos. A deposição variou de zero a 233 mg cm-2 dia-1, com picos entre agosto e dezembro e médias anuais variando de nove a 104 mg cm-2 dia-1. As taxas de deposição apresentaram correlação com o vento, indicando que a ressuspensão deve ser o fator preponderante. A contribuição do carbonato variou de 38% a 90%, com dois locais apresentando diferenciação sazonal. As comunidades bênticas foram similares entre locais, entretanto as análises sugerem freqüencias diferenciadas para cada local. Não houve correlação significativa entre sedimentação e a comunidade bêntica. Entretanto, maior cobertura de Palythoa caribaeorum normalmente ocorreu em áreas de maior sedimentação. Nossos resultados não corroboraram resultados prévios sugerindo que 10 mg cm-2 dia-1 seria "limite crítico para sobrevivência" dos corais. Recifes brasileiros podem estar associados a ambientes de alta deposição de sedimento com elevadas frações carbonáticas, o que não impede o desenvolvimento das comunidades recifais do Atlântico sul ocidental.High sedimentation is often related to stress in coral reef communities. Most southwestern Atlantic reefs are characterized by high sedimentation. However, there are no temporal series of sediment deposition rates. We evaluated sediment deposition, the sediment carbonate composition and coral and zoanthid covers on six reefs in Brazil over four-years. Sediment deposition rates varied from near zero to 233 mg cm-2 day-1, with peaks between August and December, and yearly averages ranging from nine to 104 mg cm-2 day-1. Deposition rates presented site-specific correlations with wind, indicating that resuspension must be a major factor. The presence of carbonates varied from 38% to 90%, with two sites showing seasonal differences. Benthic communities were fairly similar among sites, but the analyses suggested particular frequencies at each site. There was no significant correlation between sediment and benthic communities. However, Palythoa caribaeorum usually occur in high sediment deposition areas. Our results did not corroborate previous data that suggested that a 10 mg cm-2 day-1 would be a "critical limit for coral survival". Some coral reefs may be associated with high sedimentation environments including carbonatic fractions, but which does not per se hinder the development of southwestern Atlantic coral reef communities

Revisão sistemática dos Octocorallia (Coelenterata, Anthozoa) dos recifes de Abrolhos, BA, Brasil

Systematic studies were developed on shallow water Octocorallia (Coelenterata, Anthozoa) from the Abrolhos area, Bahia, Brazil. These studies were based on material from collections in Brazilian and American institutions. The specimens from Abrolhos were compared with specimens of other localities to determine the variation ocurring within each species. Sclerites of every species were illustrated; most using Scanning Electron Microscopy (SEM). Six species were reported: Carijoa riisei (Duchassaing & Michelotti, 1860); Muriceopsis sulphurea (Donovan, 1825); Plexaurella grandiflora (Verrill, 1912); Plexaurella sp.; Olindagorgia gracilis (Verrill, 1912); e Phyllogorgia dilatata (Esper, 1806). Four of these species (P. grandiflora, Plexaurella sp., Q. gracilis e P. dilatata) are endemic in Brazilian territory and two (Plexaurella sp. e Q. gracilis) occur only in the Abrolhos area. The description of each species includes synonyms, type depository, type locality and geographical distribution.CAPESRevisão sistemática das espécies de Octocorallia (Coelenterata, Anthozoa) coletadas em águas rasas na região de Abrolhos, BA, Brasil. Utilizou-se material de coleções de instituições brasileiras e norte-americanas. Os exemplares da área foram comparados com espécimes de outros locais, para a observação das variações existentes nas espécies. Foram feitas ilustrações dos escleritos de todas as espécies estudadas, sendo que a maioria teve seus escleritos fotografados em microscópio eletrônico de varredura ("'SEM"). Foram consideradas válidas seis espécies pertencentes a quatro gêneros: Carijoa riisei (Duchasssaing & Michellotti, 1860); Muriceopsis sulphurea (Donovan, 1825); Plexaurella grandiflora Verrill, 1912; Plexaurella sp. ind.; Olindagorgia gracilis (Verrill, 1912); e Phyllogorgia dilatata (Esper, 1806). Dessas, quatro (P. grandiflora, Plexaurella sp., Q. gracilis e P. dilatata) são endêmicas em águas brasileiras e duas (Plexaurella sp. e Q. gracilis) ocorrem apenas na região de Abrolhos. A descrição de cada espécie inclui: lista sinonímica, instituição depositária, localidade-tipo e distribuição geográfica

Cosmological tests of coupled Galileons

We investigate the cosmological properties of Galileon models which admit Minkowski space as a stable solution in vacuum. This is motivated by stable, positive tension brane world constructions that give rise to Galileons. We include both conformal and disformal couplings to matter and focus on constraints on the theory that arise because of these couplings. The disformal coupling to baryonic matter is extremely constrained by astrophysical and particle physics effects. The disformal coupling to photons induces a cosmological variation of the speed of light and therefore distorsions of the Cosmic Microwave Background spectrum which are known to be very small. The conformal coupling to baryons leads to a variation of particle masses since Big Bang Nucleosynthesis which is also tightly constrained. We consider the background cosmology of Galileon models coupled to Cold Dark Matter (CDM), photons and baryons and impose that the speed of light and particle masses respect the observational bounds on cosmological time scales. We find that requiring that the equation of state for the Galileon models must be close to -1 now restricts severely their parameter space and can only be achieved with a combination of the conformal and disformal couplings. This leads to large variations of particle masses and the speed of light which are not compatible with observations. As a result, we find that cosmological Galileon models are viable dark energy theories coupled to dark matter but their couplings, both disformal and conformal, to baryons and photons must be heavily suppressed making them only sensitive to CDM

Super-sample covariance of the power spectrum, bispectrum, halos, voids, and their cross-covariances

We study the effect of super-sample covariance (SSC) on the power spectrum and higher-order statistics: bispectrum, halo mass function, and void size function. We also investigate the effect of SSC on the cross-covariance between the statistics. We consider both the matter and halo fields. Higher-order statistics of the large-scale structure contain additional cosmological information beyond the power spectrum and are a powerful tool to constrain cosmology. They are a promising probe for ongoing and upcoming high precision cosmological surveys such as DESI, PFS, Rubin Observatory LSST, Euclid, SPHEREx, SKA, and Roman Space Telescope. Cosmological simulations used in modeling and validating these statistics often have sizes that are much smaller than the observed Universe. Density fluctuations on scales larger than the simulation box, known as super-sample modes, are not captured by the simulations and in turn can lead to inaccuracies in the covariance matrix. We compare the covariance measured using simulation boxes containing super-sample modes to those without. We also compare with the Separate Universe approach. We find that while the power spectrum, bispectrum and halo mass function show significant scale- or mass-dependent SSC, the void size function shows relatively small SSC. We also find significant SSC contributions to the cross-covariances between the different statistics, implying that future joint-analyses will need to carefully take into consideration the effect of SSC.Comment: 8+2 pages, 4 figure

Avocado and its by-products: natural sources of nutrients, phytochemical compounds and functional properties

Avocado (Persea americana Mill.) is a tropical and subtropical fruit that is native to Mexico and Central America. This fruit is gaining increasing worldwide acceptance and has received extensive marketing and a wide distribution due to its relevant nutritional benefits for human health. This work presents relevant information on the production, composition and application of avocado, with an emphasis on its by-products, focusing on the proper use of waste and the possibility of monetizing waste for nutritional and environmental purposes. The entire avocado is rich in bioactive compounds (pulp, peel and seed) and presents several health benefits, such as antimicrobial, antioxidant and anticancer activities, as well as dermatological uses and others. Therefore, several food grade ingredients can be obtained from avocado wastes, particularly premium-grade fats or extracts with a high functional power. Studies should continue to identify the profiles and phytochemicals available to the business sector, which can also be implemented to valorize the nutritional and functional potential of avocado seeds and peels.info:eu-repo/semantics/publishedVersio