Chiara Burattini

Colorimetric variation of zinc–titanium alloy coatings

The purpose of this work is to characterise the colours obtained on the surface of zinc–titanium alloy coatings. Hot dip galvanising samples were prepared at temperatures in the range of 560–640°C. Seven colours were observed and objectively measured by means of reflectance curves and CIELab coordinates. Experimental results show that, after the extraction from the bath, the colours of the galvanised coating change continuously during the cooling and then stabilise after a few seconds. The colour uniformity on the surface of each sample was evaluated according to ASTM standard. Results show little colour differences in two specimens and acceptable colour uniformity in the other five.

A quantitative evaluation of the mutual influences among Smart strategies applied at district level

Cities play an important role in reducing greenhouse gas emissions and improving energy efficiency. The Smart City concept, applied at different territorial levels, is one of most famous frameworks for improving the performance of cities. Smart planning models should allow to identify solutions in a coordinated and holistic way. Starting from these considerations, in this paper the authors focused on the quantitative evaluation of the mutual influences among Smart strategies applied at district level. An ideal sustainable district was analyzed and two improved scenarios (Smart interventions on buildings and green areas) were carried out. The aim is to evaluate if and to what extent these actions would have an impact form energy, environment end economy points of view compared to the base case scenario. Simulation results of the three scenarios show significant differences from energy, environmental and economic perspectives.

Colour resistance of Zn–Ti coatings to corrosive environments

Adding titanium to a hot-dip galvanising bath, a coloured oxide film due to interference effect was obtained on iron samples; different colours were achieved varying the bath temperature in the range of 520–600°C. In this paper, the resistance of three colours (yellow, purple and light blue) to four corrosive environments (urban, marine, industrial and rural) has been investigated by means of an experimental approach: two specimens of each colour with titanium percentage of 0.2% were exposed for 1 year in each environment and colour measurements in CIE Lab coordinates have been recorded at fixed time intervals. Modification of colours on samples due to corrosion effects of different chemical agents was evaluated calculating CIE colour difference. Results demonstrated that the colour of the coatings have a good resistance to all kinds of atmospheres tested; so the performance of this galvanising bath resulted adequate for architectural application.

Adaptive control for lighting, shading and HVAC systems in near zero energy buildings

Due to the increasing amount of energy consumption and CO2 emissions, Building Automation Systems have been developed in order to increase energy performance in buildings and guarantee indoor comfort at the same time. However, along with the development of the hardware itself, the need to develop also suitable control systems and methods for improving the management of smart buildings, is arising. In this framework, fuzzy logic may be a valuable tool for developing suitable control systems. In this paper, fuzzy logic has been used in order to optimize comfort features and energy demand in an office. Starting from the model defined in a previous work, the aim of the paper is to simulate different configurations of the room and compare the results in order to evaluate the impact of room variations (window geometry, glass properties and wall reflectance) on the fuzzy control system. Given the same solar radiation inputs, it was noticed that different room configurations require a diversified management of the shading systems and artificial lighting control in order to achieve a good balance between comfort and energy consumption.

Exploring the daylight simulation of filter panels in a pre-tunnel structure

The study of a pre-tunnel structure that filters the daylight has been carried out by means of 3D daylight simulation software. The 1:1 scale model of the tunnel and the pre-tunnel has been realized and two different sequences of filtering panels have been simulated. The first sequence reproduces the panels experimented in a previous study with a real scale model; the second sequence is aimed to optimize the filter effect, acting on the grid of the panels.

The pedestrian's perspective: How do illuminance variations affect reassurance?

The Economist Intelligence Unit Safe Cities Index summarizes the primary issues of Safety as being digital security, health security, infrastructure safety and personal safety. The biggest challenge for cities is to identify all the issues that actually impact on public safety and comprehend the real perceptions — or misconceptions — that citizens may have. Reassurance describes the confidence a pedestrian might gain from road lighting (and other factors) to walk along a footpath or road after dark, and is intended to describe both perceived safety and fear of crime. Past studies have demonstrated that the presence, level and quality of lighting affect human perception of safety. This article describes a field survey of reassurance carried out in Rome to investigate methods for measuring how changes in illuminance affect reassurance. These results confirm that the reassurance of participants can be put in relation with street lighting since changes in illuminance levels were highly perceived by test participants. It was also found that reassurance is more related to the mean horizontal illuminance than to the minimum illuminance or minimum/average uniformity.

LED lighting effect on sleep, sleepiness, mood and vigor

Several scientific studies indicate that blue light exposure at night reduces the melatonin secretion, improving vigilance and diminishing sleepiness; moreover has been demonstrated that a blue light dose administered in the evening has a positive effect for shift workers. In this study the effect of cool LED lighting exposure during daily hours has been investigated in two experiments: self-reported sleep, sleepiness, mood and physical vigor have been assessed prior and post light exposure using bipolar scales (KSS and GVAS) and sleep diary. In the first investigation (E1) the experimental light condition consisted in a 4000 K LED light and the control condition was the halogen lighting (2800 K); while in the experiment 2 (E2) a 6800 K LED lighting has been compared with a warm 3000 K LED light condition. In both experimental studies the cool light exposure duration was about 1 hour. Results of E1 indicated that the experimental light condition had a positive effect on night sleep latency; in E2 shorter awakenings and longer sleep time have been observed for participants exposed to cool LED lighting.