Positively charged nanoparticles to be used as substrates for surface-enhanced Raman scattering (SERS) were prepared by coating citrate-reduced silver nanoparticles with the cationic polymer poly-l-lysine. The average diameter of the coated nanoparticles is 75 nm, and their zeta potential is +62.3 ± 1.7 mV. UV-vis spectrophotometry and dynamic light scattering measurements show that no aggregation occurs during the coating process. As an example of their application, the so-obtained positively charged coated particles were employed to detect nanomolar concentrations of the anionic chromophore bilirubin using SERS. Because of their opposite charge, bilirubin molecules interact with the coated nanoparticles, allowing SERS detection. The SERS intensity increases linearly with concentration in a range from 10 to 200 nM, allowing quantitative analysis of bilirubin aqueous solutions.

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This paper presents a literature overview of the acoustic studies dedicated to lightweight wooden constructions. The reviewed articles contain prediction models, laboratory and field measurements, finite element or computational investigations as well as subjective survey describing the vibro-acoustic behaviour of a large range of wooden structures. The review analyses different type of timber constructions and investigates the acoustic research methodologies highlighting the following aspects: airborne sound insulation, impact noise reduction, flanking transmissions, human perceptions and pros and cons of the presented methods. Furthermore, an in-depth analysis of impact noise of bare floors focuses on how impact sound reduction could not be as efficient as in heavyweight constructions; the comparison between the different approaches on prediction of airborne sound insulation of multilayer timber partitions compared to traditional heavy building materials is shown. Finally a subjective method survey is provided, underlining the weakest point of timber buildings: low frequency sound insulation

In recent years, building technologies have been developed in order to improve comfort and energy saving. European institutions and single countries firmly invite individuals to choose high energy-saving strategies in order to decrease carbon emissions and energy consumption. Examples could be found in thermal insulators added to façades and improvement of glazing performance. At present, two technologies are the most used in construction realization: traditional (concrete, masonry or in general heavyweight structure) or wood (timber, crosslam or in general timber lightweight structure). Designers, scientists and builders have their own opinions on these two topics, but good insulation performance are achievable with both of them. Nevertheless, for lay people as well as for designers, wooden structures seem more comfortable, reliable and insulated. Therefore, an international survey was realized in order to investigate what individuals expect from these two different construction technologies in terms of insulation performance. Results indicate that timber buildings stereotypes are confirmed for acoustic and thermal insulation and show how scientific communication may help to deal with new or untraditional constructions.