Climate change is a significant problem that many countries are currently facing, and green roofs (GRs) are one of the suitable choices to confront it and decrease its impacts. The advantages of GRs are numerous, such as stormwater management, thermal need reduction, runoff quality, and life quality improvement. However, there are some limitations, including the weight, limits in water retention, irrigation in the drought period, suitability of harvested water for building usages, installation on sloped roofs, and high cost. Therefore, developing a novel system and design for GRs with higher efficiency and fewer negative points seems necessary and is the main scope of this research. In this regard, a novel multipurpose self-irrigated green roof with an innovative drainage layer combined with specific multilayer filters has been developed. The application of the proposed system in terms of water retention capacity, water storage volume, runoff treatment performance, irrigation system, drainage layer, application of the harvested water for domestic purposes, and some other aspects has been analyzed and compared with the conventional systems with a focus on extensive green roofs. The results demonstrate that this novel green roof would have many advantages including less weight due to the replacement of the gravel drainage layer with a pipeline network for water storage, higher water retention capacity due to the specific design, higher impacts on runoff treatment due to the existence of multilayer filters that can be changed periodically, easier installation on flat and sloped roofs, the possibility of using the collected rainfall for domestic use, and fewer irrigation water demands due to the sub-surface self-irrigation system.

The outbreak of the new Coronavirus (COVID-19) pandemic has prompted investigations on various aspects. This research aims to study the possible correlation between the numbers of swab tests and the trend of confirmed cases of infection, while paying particular attention to the sickness level. The study is carried out in relation to the Italian case, but the result is of more general importance, particularly for countries with limited ICU (intensive care units) availability. The statistical analysis showed that, by increasing the number of tests, the trend of home isolation cases was positive. However, the trend of mild cases admitted to hospitals, intensive case cases, and daily deaths were all negative. The result of the statistical analysis provided the basis for an AI study by ANN. In addition, the results were validated using a multivariate linear regression (MLR) approach. Our main result was to identify a significant statistical effect of a reduction of pressure on the health care system due to an increase in tests. The relevance of this result is not confined to the COVID-19 outbreak, because the high demand of hospitalizations and ICU treatments due to this pandemic has an indirect effect on the possibility of guaranteeing an adequate treatment for other high-fatality diseases, such as, e.g., cardiological and oncological ones. Our results show that swab testing may play a significant role in decreasing stress on the health system. Therefore, this case study is relevant, in particular, for plans to control the pandemic in countries with a limited capacity for admissions to ICU units.

The growing use of microfluidic-based devices necessitates an analysis of flow characteristics through both experimental methods and computational fluid dynamic (CFD) simulations. CFD simulations facilitate the investigation of various devices, including medical sensors, by providing detailed insights into flow behavior. In this study, we conducted experimental and CFD analysis of the microfluidic flow in three devices: a COVID-19 rapid test kit, a blood glucose kit, and a PDMS kit. Our findings revealed that the changes in wall adhesion (contact angles) during the capillary flow could cause significant deviation from theoretical flow speed predictions. A hemodynamic analysis of the blood glucose kit and PDMS kit showed that capillary filling decreased in length, and flow speed could depend on the microchannel diameter. CFD results indicated the prominent role of porosity in the simulation of porous media material such as the COVID-19 test kit, as well as surface tension coefficients and wall adhesion (contact angles) in blood glucose kits and PDMS kits. Therefore, considering adaptive dynamic contact angles in CFD simulation software such as Ansys-Fluent 2024 could result in a more accurate prediction than simplified theoretical techniques, which is useful for sensor optimization and development.

The advantages of green roofs and solar panels are numerous, but in dry periods, green roofs can place urban water resources under pressure, and the efficiency of solar panels can be affected negatively by high temperatures. In this context, our analysis investigated the advantages of bio-solar green roofs and evaluated the impact of green roofs on solar panel electricity production and solar panels on green roof water consumption. The assessment was conducted through simulation in a selected case study located in Cosenza, a city with a Mediterranean climate, with solar panels covering 10% to 60% of the green roof. Analyses were performed on the power outputs of four kinds of photovoltaic panels: polycrystalline, monocrystalline, bifacial, and Passivated Emitter and Rear Contact (PERC). The energy production and shade frequencies were simulated using PVGIS 5.3 and PVSOL 2024 R3. The impact of photovoltaic (PV) shade on the water consumption of green roofs was evaluated by image processing of a developed code in MATLAB R2024b. Moreover, water–energy interconnections in bio-solar green roof systems were assessed using the developed dynamic model in Vensim PLE 10.2.1. The results revealed that the water consumption by the green roof was reduced by 30.8% with a bio-solar coverage area of 60%. However, the electricity production by the PV panel was enhanced by about 4% with bio-solar green roofs and was at its maximum at a coverage rate of 50%. This investigation demonstrates the benefits of bio-solar green roofs, which can generate more electricity and require less irrigation.

In recent years, the application of microfluidic devices has increased, and three-dimensional (3D) printers for fabricating microdevices could be considered a suitable technique but, in some cases, may confront some issues. The main issues include channel roughness values, print orientation due to the 3D printer’s setup, filament materials, nozzle specifications, and condition. This study aims to analyze the capillary-driven flow in microdevices produced by 3D printers. Therefore, four 3D printer-based microchannels were investigated, and the capillary-driven flow of five liquids with different viscosities and contact angles was evaluated experimentally. The experimental results were compared with theoretical calculations using the Lucas−Washburn equation, and the impact of the width, length, and closed and open microchannel on flow behaviors was explored. The experimental results showed that the peak velocity for open and closed microchannels decreases with the length. Moreover, there were differences in flow behavior between open and closed microchannels. For the former, the maximum average velocity appeared in the microchannel with a width of 400 μm, while for the latter, it was for a width of 1000 μm. In addition, the flow velocity decreased when the viscosity increased, regardless of microchannel width. The decrease was more pronounced for the lower-viscosity liquids (ethanol and water) and smaller for the higher-viscosity ones (coffee and olive oil). Finally, the advantages and challenges of 3D printer-based microdevices are presented.

Nature-based solutions (NBSs), such as green roofs, are among the most effective ways to manage urban stormwater, improve building energy efficiency, and adapt to climate change. However, conventional green roofs confront several restrictions related to stormwater drainage, retention capacity, irrigation demand, and pressure on urban water networks during dry periods. This study proposes and experimentally validates a novel system applicable to green roofs and other NBS, including streetside planting systems and vegetated sports grounds. The novelty of the proposed system lies in a double-layer design, the integration of filters within soil substrate to enhance short-term stormwater retention and controlled drainage, and passive subsurface capillary irrigation with cords to improve irrigation efficiency. Infiltration tests showed that filter hydraulic conductivity strongly depends on pore size, with measured infiltration rates ranging from 0.01 mm/min (ceramic, 0.1 μm) to 20 mm/min (polypropylene, 50 μm). The results showed that filter material and pore size significantly influence infiltration behaviour and short-term storage capacity. When integrated with the soil substrate, the combined system exhibited infiltration rates of 0.8–2.0 mm/min, decreasing as hydraulic head declined. Capillary rise experiments demonstrated a maximum vertical rise of 32 cm and horizontal rise of 39 cm for polyester cords (6 mm width), confirming the feasibility of passive subsurface irrigation through stored runoff reuse without external energy. The experiments were conducted at a laboratory scale (25 × 25 cm) as a proof-of-concept validation. Finally, the study results demonstrate the feasibility of the proposed system as a multifunctional NBS solution that enhances stormwater retention while enabling passive irrigation using retained runoff.