The existing stock of institutional buildings constructed before current thermal regulation codes is known to be high-energy consuming. To make energy savings, retrofitting solutions have to deal with important transformations of those buildings (e.g. envelope, energy systems) and with better-suited management solutions. Such technical solutions quite often neglect occupants' comfort. The present work aims to develop and implement an energy audit protocol to tackle simultaneously the questions of thermal comfort and energy efficiency for higher education buildings. Our transverse approach allowed us to achieve a complementary view of the building under examination, including its operating conditions. At any rate, capturing the full complexity of a building-system (building energy devices, management strategies, and occupancy and behaviours impacts) requires a broad perspective and points to the limits of key-in-hand audits and solutions.

Six new nickel (II) complexes with a series of tetrazole derivatives functionalized by different substituents {5-(2-(1-Benzyltetrazol-5-yl) phenyl)-2-ethyl-4-methylthiazole (L 1), 1-Benzyl-5-(2-(1methylpyrrol-2-yl)phenyl) tetrazole (L 2), 5-(2-(1-Pivalyltetrazol-5-yl)phenyl)-2-ethyl-4methylthiazole (L 3), 5-(2-(1-Methylpyrrol-2-yl) phenyl)-1-pivalyltetrazole (L 4), 2-Ethyl-4-methyl-5-(2-(1 methyltetrazol-5-yl) phenyl) thiazole (L 5) and 1-Methyl-5-(2-(1-methylpyrrol-2-yl)phenyl) tetrazole (L 6)} have been synthesized and characterized by analytical and spectral methods. The data clearly indicated that the nickel (II) complexes are coordinated to the monodentate tetrazole derivatives via nitrogen (N3) atom of the tetrazole ring. The octahedral geometry is observed for all the complexes. The thermogravimetric analysis revealed the presence of coordinated and hydrated water molecules in the coordination sphere. The DFT calculations performed on both the ligands and the complexes allowed to optimize the structures, the stability and to explain the electrochemical behavior and the biological activities of the nickel (II) complexes. The study of the substituents effects on the redox properties of the ligands and their nickel (II) complexes were discussed via cyclic voltammograms. Electron donating substituents shift the reduction potentials toward negative values, while anodic shift of the oxidation potentials is manifested by the substituents having an electron withdrawing effect. The in vitro antimicrobial activities of the ligands and their corresponding nickel (II) complexes have been evaluated against four bacterial and two fungal strains.

The COVID-19 health crisis highlighted the correlation between air exchange efficiency and virus airborne transmission. Air exchange efficiency is a performance index able to characterize ventilation effectiveness in buildings. Some standards, such as ASHRAE 129, clearly define assessment procedures of air exchange efficiency for mechanical ventilation, adopting tracer gas techniques. However, standardized procedures are based on measurements at the exhaust and cannot be adopted for natural and mixed mode ventilation strategies. In the ‘80s, Sandberg suggested that tracer gas decay technique enables to measure simultaneously the nominal time constant (through air change rate measurements) and the mean age of air in several points of the ventilated zone. This paper aims to present practical issues and uncertainty analysis related to the implementation of this approach, in a new commissioning protocol. For this purpose, we compare the new procedure, based on Sandberg’s observation, with the ASHRAE 129 protocol for mechanical ventilation. Results coming from field campaigns show that the difference between air exchange efficiency values obtained using ASHRAE 129 protocol (51.8 %) and the new procedure (47.4 %) are usually negligible in low airflow rate, considering an average uncertainty of ±7.0 %. Results show that the procedure is robust and that it is technically possible to implement it to natural and mixed-mode ventilation.