Development of paints with infrared radiation reflective properties

AbstractLarge buildings situated in hot regions of the Globe need to be agreeable to their residents. Air conditioning is extensively used to make these buildings comfortable, with consequent energy consumption. Absorption of solar visible and infrared radiations are responsible for heating objects on the surface of the Earth, including houses and buildings. To avoid excessive energy consumption, it is possible to use coatings formulated with special pigments that are able to reflect the radiation in the near- infrared, NIR, spectrum. To evaluate this phenomenon an experimental study about the reflectivity of paints containing infrared-reflective pigments has been made. By irradiating with an IR source and by measuring the surface temperatures of the samples we evaluated: color according to ASTM D 2244-14, UV/VIS/NIR reflectance according to ASTM E 903-12 and thermal performance. Additionally, the spectral reflectance and the IR emittance were measured and the solar reflectance of the samples were calculated. The results showed that plates coated with paints containing IR-reflecting pigments displayed lower air temperature on the opposite side as compared to conventional coatings, indicating that they can be effective to reflect NIR and decrease the temperature of buildings when used in roofs and walls.</p

Highlighting metabolic indicators of olive oil during storage by the AComDim method

International audienceLipid oxidation during olive oil storage induces changes in the metabolite content of the oil, which can be measured using so-called quality indices. High values indicate poor quality oils that should be labeled accordingly or removed from the market. Based on quality indices measured over two years for two olive oils, the AComDim method was used to highlight the influence of five factors (olive oil type, oxygen, light, temperature and storage time) on oxidative stability during storage. To identify the significant factors, two full factorial experimental designs were built, each containing four of the five factors examined. The results showed that all five factors, as well as some two-factor interactions, were significant. Phenols and hydroperoxides were identified as being the most sensitive to these factors, and potential markers for the ageing of olive oil

AComDim as a multivariate tool to analyse experimental design application to γ-irradiated and leached ion exchange resins

International audienceLeaching MIR spectroscopy Ion exchange resin γ-Irradiations of ion exchange resins were carried out under various experimental conditions, selected using an experimental design, to simulate the ageing of such nuclear wastes. Those resins are a commercial mixed bed, constituted of 75 wt.% of a cationic resin and 25 wt.% of an anionic resin, and both are pure cationic and anionic resins. Then, irradiated samples were leached, at two different temperatures (20 °C and 50 °C). Solid matrices were characterized by a spectroscopic technique and spectral data were analysed by the ANOVA Common Dimensions (AComDim) method to detect and highlight influential factors and interactions. Four factors were studied (absorbed dose under irradiation, atmosphere during irradiation, dose rate, leaching temperature and resin type) with several levels for each. In a first study of the separate resins, the absorbed dose and the irradiation atmosphere appeared as the most influencing factors for the anionic resin. The leaching temperature was significant but only in interaction with other factors, while this parameter was significant for the cationic and mixed bed resins. In a global study of all the spectral data, the resin type appeared as the most influential factor for the radiolysis of resins

Discrimination of olive oil by cultivar, geographical origin and quality using potentiometric electronic tongue fingerprints

Legal regulations are set for protecting claims regarding olive oil geographical denomination. When meteorological or agroecological factors similarly affect different regions, the origin identification is a challenging task. This study demonstrated the use of a potentiometric electronic tongue coupled with linear discriminant analysis to discriminate the geographical origin of monovarietal Tunisian olive oil produced from local cv Chemlali (Kairouan, Sidi Bouzid or Sfax regions) and cv Sahli (Kairouan, Mahdia or Sousse regions). The potentiometric fingerprints of 12 or eight lipid sensors (for Chemlali and Sahli, respectively), selected using a simulated annealing meta-heuristic algorithm, allowed the correct prediction (repeated K-fold cross-validation) of the geographic production region with sensitivities of 92 ± 7% (Chemlali) and 97 ± 8% (Sahli). It was also confirmed the electronic tongue capability to classify Tunisian olive oil according to olive cultivar or quality grade. The results indicated the possible use of potentiometric fingerprints as a promising innovative strategy for olive oil analysis allowing assessing geographical origin, olive cultivar and quality grade, which are key factors determining olive oil price and consumers preference.This work was financially supported by Project POCI-01–0145-FEDER-006984 - Associate Laboratory LSRE-LCM, Project UID/QUI/00616/2013 - CQ-VR, and UID/AGR/00690/2013 - CIMO all funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) - and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/ BD/104038/2014). Souheib Oueslati is also grateful for the support of the Tunisian Ministry of Agriculture.info:eu-repo/semantics/publishedVersio