Acceleration and Deflection Analysis for Class C Edge Protection Systems in Construction Work

The requirements for edge protection systems on most sloped work surfaces (class C, according to EN 13374-2013 code) in construction works are studied in this paper. Maximum deceleration suffered by a falling body and maximum deflection of the protection system were analyzed through finite-element models and confirmed through full-scale experiments. The aim of this work is to determine which value for deflection system entails a safe deceleration for the human body. This value is compared with the requirements given by the current version of EN 13374-2013. An additional series of experiments were done to determine the acceleration linked to minimum deflection required by code (200 mm) during the retention process. According to the obtained results, a modification of this value is recommended. Additionally, a simple design formula for this falling protection system is proposed as a quick tool for the initial steps of design.

Modulation of the Silica Sol–Gel Composition for the Promotion of Direct Electron Transfer to Encapsulated Cytochrome c

The direct electron transfer between indium–tin oxide electrodes (ITO) and cytochrome c encapsulated in different sol–gel silica networks was studied. Cyt c@silica modified electrodes were synthesized by a two-step encapsulation method mixing a phosphate buffer solution with dissolved cytochrome c and a silica sol prepared by the alcohol-free sol–gel route. These modified electrodes were characterized by cyclic voltammetry, UV–vis spectroscopy, and in situ UV–vis spectroelectrochemistry. The electrochemical response of encapsulated protein is influenced by the terminal groups of the silica pores. Cyt c does not present electrochemical response in conventional silica (hydroxyl terminated) or phenyl terminated silica. Direct electron transfer to encapsulated cytochrome c and ITO electrodes only takes place when the protein is encapsulated in methyl modified silica networks.