Search Results (3)

Multilayer objects with different interfaces are quite typical for architectural heritage, and from them may be inferred the age, production process, and deterioration mechanism through analyzing characteristic compositions with advanced analytical techniques. The Meiwu ceiling in the Hall of Mental Cultivation of the Palace Museum was found to contain many paper-based layers during conservation. Once several surface strata were detached, a colorful layer of printed fabric textile was discovered integrally. Through microscopic observation and micro-attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) imaging, the overall structure consisted of 11 layers, namely, bast paper, cotton wiring, xuan paper, cotton printed fabric, two yellow board papers, bamboo paper, three wood pulp paper and surface coatings, and starch was considered as an organic adhesive. For identification of the printed fabric’s color palette, ultra-performance liquid chromatography (UPLC) combined with high-resolution quadrupole time-of-flight (QTOF) technology, non-invasive macro X-ray fluorescence (MA-XRF) and desorption electrospray ionization mass spectrometry imaging (DESI-MSI) were applied in situ. Seven industrial synthetic dyes, including auramine O, malachite green, and eosin Y with corresponding by-products, as well as chromium-based pigments considered as dark draft line, were confirmed. By X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), and micro Fourier transform infrared spectroscopy (micro FTIR, other results showed chalk soil and talc for the outermost coating. According to the synthetic time of industrial dyes and degradation degree of paper, there were at least four occurrences and their specific time periods were speculated. Full article

This paper reports on a pilot study that was conducted during a technical trial of a new ePortfolio system at a large Australian university. Students from a large (n = 325) first-year educational technology course were given the opportunity to use the new ePortfolio system weekly as part of their reflective practice at the end of the hands-on tutorial classes and also through a blogging assignment that required six posts throughout the semester. Although the students reflecting on their work and ePortfolios themselves are not new concepts, this paper reports how assessment practices can be improved using ePortfolios and how students can improve their reflective practice through simple and regular use throughout the 12-week semester that the study was conducted. From the class, 208 students responded to the survey with the results being positive. The students were able to use the system easily and did not report many problems with crashing or freezing. The lessons learnt form an important part of this study for future iterations with these reported in the paper. Full article

Ventilation-controlled fires tend to be the worst for toxicity, because they produce large amounts of fire effluent containing high yields of toxic products. In order to examine the dependence of the amount of chosen few main combustion gases under ventilation-controlled conditions, a PVC-insulated copper electric wire with unknown composition (PVC filled with chalk) was studied by mean of a steady state tube furnace. For the tested wire, lower values of CO₂ yields at different ventilation conditions were obtained than for the reference pure polymer unplasticized PVC and additionally tested pure LDPE, the yields were higher three times in the case of PVC and two times in the case of LDPE than those received for wire at the same ventilation conditions, which pointed out decreasing contribution of hyperventilation effect to human during cable fire. In contrast, higher values of toxic CO yields, four times higher, were obtained for the PVC-insulated electric wire rather than for the pure polymers. The maximum value of CO yield (0.57 g/g) was determined in the case of 5 L/min of primary airflow and decreased with increasing ventilation. The measured yields of hydrocarbons were similar to the reference values except for the equivalence ratio ϕ = 0.27, where hydrocarbon yield was equal to 0.45 g/g. The HCl yield of fire effluents from the PVC-insulated wire was shown to be independent of ventilation conditions. The corrosive reaction between copper and the HCl species and the flame-retardant mechanisms of the additives, caused the lower values of HCl in the fire effluent of the PVC-insulated copper wire than for pure polymer. Full article