The experimental characterization of the overall thermal transmittance of homogeneous, moderately-and non-homogeneous walls, windows, and construction elements with innovative materials is very important to predict their thermal performance. It is also important to evaluate if the standard calculation methods to estimate the U-value of new and existing walls can be applied to more complex configurations, since the correct estimation of this value is a critical requirement when performing building energy simulations or energy audit. This paper provides a survey on the main methods to measure the thermal transmittance and thermal behaviour of construction elements, considering laboratory conditions and in-situ non-destructive measurements. Five methods are described: the heat flow meter (HFM); the guarded hot plate (GHP); the hot box (HB), considering the guarded HB (GHB) and the calibrated HB (CHB); and the infrared thermography (IRT). Then, previous studies dedicated to the assessment of the thermal performance of different heavy-and light-weight walls are discussed. Particular attention is devoted to the measurement of the U-value of nonhomogeneous walls, including the effect of thermal bridging caused by steel framing or mortar joints, and the presence of PCMs or new insulation materials in the configuration of the walls. hot box; calibrated hot box; infrared thermography. Highlights: -Review on the main methods to measure the U-value of non-homogeneous walls. -Methods: heat flow meter, guarded hot plate, guarded and calibrated hot box, infrared thermography. -Standards framework and discussion of the main advantages and drawbacks of each method. -Description of methodologies and working principles of laboratory and in-situ measurements. -Measurement of the thermal transmittance of different heavy-and light-weight walls.

In building applications (e.g. industrial, offices and residential), the use of lightweight steel-framed structural elements is increasing given its advantages, such as exceptional strength-to-weight relation, great potential for recycling and reuse, humidity shape stability, easy prefabrication and rapid on-site erection. However, the high thermal conductivity of steel presents a drawback, which may lead to thermal bridges if not well designed and executed. Furthermore, given the high number of steel profiles and its reduced thickness, it is not an easy task to accurately predict its thermal performance in laboratory and even less in situ. In a previous article, the authors studied the importance of flaking heat loss in lightweight steel-framed walls. This article discusses several thermal bridges mitigation strategies to improve a lightweight steel-framed wall model, which increase its thermal performance and reduce the energy consumption. The implementation of those mitigation strategies leads to a reduction of 8.3% in the U-value, comparatively to the reference case. An optimization of the wall module insulation layers is also performed (e.g. making use of new insulation materials: aerogel and vacuum insulation panels), which combined with the mitigation approaches allows a decrease of 68% in the U-value, also relatively to the reference case. Some design rules for lightweight steel-framed elements are also presented.

The thermal performance of a modular lightweight steel framed wall was measured and calculated with three-dimensional finite element method model. The focus of this article is on the effect of flanking thermal losses. The calculated heat flux values varied from 222% (external surface) to + 50% (internal surface) when flanking loss was set to 0 as a reference case, thermal transmittance equal to 0.30 W/(m 2 ÁK). Other critical parameters were the existence of fixing 'L'-shaped steel elements and the perimeter thermal insulation (10 cm XPS).

Given the great influence of the thermal transmittance of the building envelope on the overall thermal performance and energy efficiency of the building, it is essential to accurately determine the U-value of the main building envelope elements. Due to the great heterogeneity of the thermal conductivity of the elements presented in a lightweight steelframed (LSF) wall, and to the geometric complexity of some steel framed structures, a reliable estimation of the thermal transmittance of LSF elements is even more challenging. Indeed, thermal bridging originated by steel studs must be considered in the assessment of the thermal transmittance of LSF walls. In this work, the thermal transmittance (U-value) of three LSF walls with different configurations will be investigated based on four different approaches: experimental laboratorial measurements based on the Heat Flow Meter (HFM) method; 3D finite element method (FEM) simulations using ANSYS CFX ® software; 2D FEM-based simulations using THERM software; analytical estimations based on the ISO 6946 procedure for building components with inhomogeneous layers. Several verification procedures were performed to ensure the reliability of the results. It was found that a secondary wood stud can mitigate the thermal bridging effect of the steel frame and improve the LSF thermal performance, which is more noticeable when there is no thermal insulation. Furthermore, a good agreement was found between the results of the 2D FEM and the analytical ISO 6946 approaches for the LSF wall with only vertical steel studs.

At ualmente, as legislações nacionais voltadas à saúde do trabalhador exigem que a audição seja monitorada apenas quando há exposição ocupacional ao ruído, não sendo considerada, assim, a exposição a produtos químicos. Entretanto, na literatura científica, é bastante clara a preocupação sobre os efeitos do chumbo no sistema auditivo, uma vez que foram observados efeitos negativos após a exposição ocupacional a este metal. Objetivo: O presente estudo teve como objetivo analisar a amplitude das emissões otoacústicas evocadas por produto de distorção, em indivíduos com histórico de exposição ao chumbo e ruído. Forma de estudo: Coorte Transversal. Material e método: Foram avaliados 69 indivíduos subdivididos em 3 grupos: Grupo I (GI): composto por 29 trabalhadores expostos ao chumbo com exposição simultânea ao ruído, em seu ambiente de trabalho; Grupo II (GII): composto por 11 trabalhadores expostos ao ruído ocupacional sem exposição simultânea ou pregressa a outros agentes nocivos à audição; e Grupo III (GIII): composto por 11 indivíduos com audição normal, sem histórico de exposição ao ruído ocupacional ou de outros fatores de risco para a ocorrência de perda auditiva. Resultado: Os resultados obtidos não evidenciaram o efeito tóxico do chumbo nos resultados das emissões otoacústicas, visto que as menores amplitudes das EOEPD foram observadas no grupo exposto somente ao ruído, mesmo considerando que os indivíduos expostos ao chumbo com exposição simultânea ao ruído apresentavam longo período de exposição a este metal bem como ampla variação do nível de chumbo sérico. Current ly, legislations concerning worker's health only require periodic monitoring of individuals who are noiseexposed at work, and exposure to chemicals are not taken into consideration. However, the scientific literature indicates a very clear concern regarding the effects of lead on the auditory system, demonstrating that there are negative effects to the auditory system following occupational exposure to this metal. Aim: The aim of this study was to evaluate the amplitude of distortion product otoacoustic emissions (DPOAEs) among individuals with a history of exposure to lead and noise. Study design: Transversal Cohort. Material and method: We evaluated 69 individuals divided in 3 groups: Group I (GI): composed by 29 workers occupationally exposed to both lead and noise; Group II (GII): composed by 11 noise-exposed workers with no other exposure to ototraumatic, and Group III (GIII): composed by 11 individuals with normal hearing and no history of exposure to noise or lead. Results: The results showed no effect of lead exposure on the otoacoustic emission results, since the smaller EOEPD amplitudes were observed in the noise-exposed group, despite the fact that the lead and noise exposed workers had a long history of lead exposure, and a wide variability in blood lead levels.Palavras-chave: chumbo, emissões otoacústicas, ruído, perda auditiva.

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In this study a novel gellan gum/pullulan bilayer film containing silibinin-loaded nanocapsules was developed for topical treatment of atopic dermatitis (AD). The bilayer films were produced by applying a pullulan layer on a gellan gum layer incorporated with silibinin nanocapsules by two-step solvent casting method. The bilayer formation was confirmed by microscopic analysis. In vitro studies showed that pullulan imparts bioadhesitvity for the films and the presence of nanocapsules increased their occlusion factor almost 2-fold. Besides, the nano-based film presented a slow silibinin release and high affinity for cutaneous tissue. Moreover, this film presented high scavenger capacity and non-hemolytic property. In the in vivo study, interestingly, the treatments with vehicle film attenuated the scratching behavior and the ear edema in mice induced by 2,4-dinitrochlorobenzene (DNCB). However, the nano-based film containing silibinin modulated the inflammatory and oxidative parameters in a similar or more pronounced way than silibinin solution and vehicle film, as well as than hydrocortisone, a classical treatment of AD. In conclusion, these data suggest that itself gellan gum/pullulan bilayer film might attenuate the effects induced by DNCB, acting together with silibinin-loaded nanocapsules, which protected the skin from oxidative damage, improving the therapeutic effect in this AD-model.