Adverse events such as fires pose a significant threat to air quality in urban areas, with both immediate and long-term impacts on public health and the environment. This study examines the effects of a major fire that occurred in Rome in 2024, affecting an industrial area and resulting in a substantial release of atmospheric pollutants. Using monitoring sensors and dispersion models, we measured the increase in fine particulate matter (PM2.5 and PM10) during and after the incident. The collected data were compared with standard air quality levels, highlighting a critical exceedance of safety thresholds. Furthermore, the study evaluates the effectiveness of the measures taken to contain pollution and reduce public exposure, proposing preventive and management solutions to minimize the impact of future events. The results emphasize the need to improve response strategies to such phenomena and to strengthen the alert system to ensure better protection of air quality and urban health.

This study introduces an innovative method for the recovery and reuse of unsintered powder in the Selective Laser Sintering (SLS) process, widely used in additive manufacturing for creating complex components with a broad range of powder materials. The main challenge in this process is the effective management of unsintered powder, particularly the separation of aggregates formed during the sintering phase, to avoid compromising the properties of the reused material. The proposed fluidized bed system employs a gas flow to fluidize the powder, effectively separating the aggregates and restoring the powder's granularity to a quality similar to its original state. This process not only improves material efficiency by reducing waste but also maintains the desired properties of the powder for continuous reuse in the SLS process. Experimental results demonstrate that the powder recovered through this method retains its essential characteristics, such as particle size distribution and flow properties, enabling its direct reuse in the SLS process work chamber. This approach represents a significant step toward sustainability and economic efficiency in additive manufacturing, providing a viable solution for powder reuse and reducing the environmental impact associated with the production of new powder.

Supercritical PArticle Formation has been proposed for the entrapment of ferrous sulphate in liposomes, overcoming drawbacks linked to conventional processes, such as residual solvents and low versatility. The innovation of this process was the combined integration of supercritical assisted production with drying techniques (freeze and spray-drying) and final drum-grinding, being effective in preserving active ingredients while eliminating liquid content. Liposomes powder was stable over 24 months, mean size down to 3.5 mu m was achieved, with a Drug to Lipid Ratio of 6. Encapsulation efficiency up to 94 +/- 4 % was obtained without significant loss during drying. Supernatant and lipidic solids were separated and analyzed, demonstrating presence of lightweight floating liposomes in the aqueous part and larger lipo-complexes among the solids. During the production of a pilot-scale batch of 25 kg, liquid-to-powder yield of 0.179 kg/L was obtained. Drying was successful to produce narrow vesicles in absence of pesticides, bacteria and heavy metals.

A good understanding of temperature-dependent material properties and the associated process parameters is required to successfully model the heat transfer in laser powder bed fusion (LPBF). To quantify the temperature distribution along the depth and top surface, a stationary laser sintering experimental set-up equipped with two infrared cameras is constructed in this study. A shallow bed of polymeric powder is spread on infrared-transparent Zinc Selenide (ZnSe) glass, so that one of the thermal cameras can see the heat transfer along the depth from the bottom. Two carbon black powders of treated polyamide (PA12 CB of 60 μm and PA6 CB of 80 μm) are used. A 3D finite-element heat transfer model is developed considering conductive, convective, radiative heat transfer, and phase change. Temperature-dependent material properties, such as thermal conductivity, density, specific heat, and emissivity, are estimated and considered. The model's accuracy is validated by comparing the temperature data along XYZ directions with the experimental values. The PA6 CB powder exhibits higher laser absorption and thermal conductivity than PA12 CB. This finding is evident from the rapid heating of PA6 CB due to higher laser absorption and faster cooling rate due to higher thermal conductivity. The emissivity of the powder bed is nearly uniform with the temperature for both powders and drastically increases at the melt pool. This change in emissivity is captured in the model.

The Supercritical Particle Formation (SPAF) process represents a significant advancement in the development of drug delivery systems for both pharmaceutical and nutraceutical applications. Traditional manufacturing methods often face challenges such as residual solvent contamination, low reproducibility, and limited versatility in bioactives encapsulation. On the contrary, SPAF exploits the benefits deriving from the use of supercritical fluids to remove solvent residue, thus resulting in a highly efficient, eco-friendly process, guaranteeing the coupling of several hydrophilic and lipophilic compounds with polymeric or lipidic carriers. This technique improves the yield at industrial level, without losing control over particle size distribution and morphology, release profile and cell bioavailability of active ingredients. The improved stability of SPAF products is guaranteed by the addition of a process unit, made of several freeze-dryers working in parallel, to transform the liquid suspension of carriers into powder stable over 2 years. The synergy between supercritical particle formation and lyophilization offers a successful platform to produce high-quality, ready-to-market drug delivery systems with improved pharmacokinetic properties. This study highlights yield, profit and environmental benefits of SPAF, positioning it as a valid alternative to conventional production techniques nowadays utilized by companies.

In the present study the concentration of some air pollutants (nitrogen dioxide, sulphur dioxide, hydrogen sulphide, ammonia and BTEX, i.e. benzene, toluene, ethylbenzene and xylene) was monitored inside and outside the Sanctuary of the Beata Vergine dei Miracoli (Saronno, Italy) by passive air sampling (using radial samplers), during two sampling periods in 2022 (April 27-May 11 and May 11-May 25). Concurrently, particulate matter (PM10 and PM2.5) concentration was determined by using sensors based on laser scattering technology. Moreover, we took advantage of the location of this sanctuary (proximity to an air monitoring central unit) to evaluate the performance of a new axial-type sampler for nitrogen dioxide. Sulphur dioxide concentration was in the range 0.8-3.1 mu g/m(3), with outdoor values higher than indoor ones, whereas no detectable concentrations of hydrogen sulphide were found (<0.1 g/m(3)). A different trend was observed for ammonia, where indoor concentrations were higher than outdoor ones (3.6-5.5 vs 2.7-3.1 mu g/m(3)). Among BTEX, only for benzene statistical differences (p-value < 0.05) between the indoor and outdoor concentrations were found, suggesting additional indoor sources for this hydrocarbon. Toluene results as the most abundant among these hydrocarbons (1.7-2.3 g/m(3)) in outdoor environments, whereas, in indoor environments, benzene has the higher concentration (6-9 mu g/m(3)). The indoor concentrations of NO2 (15.4-22.2 mu g/m(3) for radial samplers and 48-60 mu g/m(3) for axial samplers) are not only much higher than the recommended limit values to guarantee proper conservation of artefacts (5 mu g/m(3)), but also close to the values for human health preservation (40 mu g/m(3)), suggesting the need of proper strategy to improve indoor air quality inside the Sanctuary. The preliminary results obtained for the new axial-type sampler for nitrogen dioxide are very encouraging, given the closeness of the obtained concentration data to those measured by monitoring central unit, even though further experiments will have to be carried out to validate this sampler.

A Discrete Element Method model, including interparticle cohesive forces, was calibrated and validated to develop a tool to predict the powder layer’s quality in the powder bed fusion process. An elastic contact model was used to describe cohesive interparticle interactions. The surface energy of the model particles was estimated by assuming that the pull-off force should provide the strength of the material evaluated at low consolidation with shear test experiments. The particle rolling friction was calibrated considering the bulk density of the layer produced by the spreading tool. The model was validated with the experiments by comparing the wavelet power spectra obtained with the simulations with those of the experimental layers illuminated by grazing light. The calibration proposed in this study demonstrated superior performance compared to our previous methods, which relied on measuring the angle of repose and unconfined yield strength.

This study investigates the spreadability behaviour of four different polymeric materials, namely Polyamide 6, Polyamide 6 Black, Polypropylene, and Thermoplastic Polyurethane, under different spreading speeds (30 and 3 mm/s) and powder bed temperatures (25, 80, 110 degrees C) using a purposely developed experimental apparatus. Macroscopic and microscopic images of the powder layer were taken after completing the powder spreading step. A thresholding-based image processing method was utilised to evaluate the fraction of the bed area not covered by particles (NCF), and the standard deviation of pixel intensities in grayscale images (SDG) was calculated to evaluate powder layer quality in macroscopic images. NCF and SDG can provide quantitative evaluation of the quality of the spread layer, NCF in a logarithmic scale ranking and SDG in a linear scale ranking. A wavelet analysis technique was developed on microscopic panorama images obtained with grazing light to characterise the surface roughness of the layer. Results indicate that the spreadability generally worsens much more significantly than powder flow properties at increasing temperatures and, remarkably, that flowability and spreadability are unrelated. As expected, the temperature effect on powder spreading changes for the different powders are mostly governed by the approach to the powder melting temperature. Minor effects on the final layer quality were also observed at changing spreading speed. (c) 2024 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.

The quantity of the main pollutants present in the atmosphere (particulate matter, ozone, sulfur dioxide, nitrogen dioxide) and meteorological events (rain) can cause permanent or catastrophic damage to plant growth. This study was conducted for the environmental assessment of the Italian territory, in the cities of Palermo, Bari, Ferrara, Padua, and Venice, which respectively represent southern, central, and northern Italy, in order to have a territory global environmental view. The aim of this research is to analyze the relationship between air pollution (PM10, O3, NO2, SO2) and crops (durum and common wheat, corn) as a basis for the subsequent definition of an agronomic model. Later, meteorological events were also added to the analysis, to have a complete overview for the evaluation, since meteorological events contribute to the pollutants’ behavior and favor the deposition of the latter on the vegetation, increasing the negative and toxic effect on crops. The analyses showed that pollutants have a significant effect on crops and in particular ozone appears to be the most influential parameter.

In this study, a Discrete Element Method (DEM)-based model was developed to simulate the powder spreading process in Powder bed Fusion (PBF) for Polyamide 6 (PA6) powder, which considered the spreading speed (3 mm/s and 30 mm/s) and temperature (25 degrees C and 110 degrees C) as parameters affecting the final spreading powder layer quality. The particle horizontal and vertical velocities were analysed in regions near the spreading blade, where at the lower spreading speed, particle velocities are far less compared to the higher spreading speed. The lower particle velocities lead to gently settling down and rearranging particles during spreading on the bed, allowing a uniform powder layer to form. Increasing the spreading speed led to an increase in shear stress and inertia number. At higher temperatures, shear stresses also rise while the inertia number is slightly reduced due to the greater cohesion between particles. The generated powder layer by the DEM model was analysed using the wavelet analysis technique and compared to experiments. The spreadability index of experiments can be estimated with less than 5% error using DEM simulations, though in an approximately consistent manner that captures the experimental trends of spreading speed and temperature. The packing fraction of simulated powder layers was investigated in the spreading direction. The DEM simulations show that packing fraction decreases as temperature or spreading speed are increased, with its variation across the bed increasing for higher spreading speeds. Increasing the spreading speed leads to greater motion and inertia number of particles and, consequently, it intensifies the particle ejection and results in many unfilled areas in the spread powder layer. Increasing temperature leads to an increase in cohesivity between particles, resulting in aggregates forming on the spread powder layer.

This study focuses on the assessment of air quality in the industrial sector of Solofra, particularly within the tanning industry, known for its intensive activities and potential environmental impact. The main objective is to monitor the presence of atmospheric pollutants such as particulate matter (dust), nitrogen dioxide (NO2) and carbon monoxide (CO), due to their relevance in the industrial context of Solofra and their known adverse effects on human health and the environment. Through advanced monitoring methods, the study identified and quantified these pollutants, revealing a significant correlation between the activities of the tanning sector and high levels of NO2. Additionally, the detected concentrations of particulate matter and CO indicate the influence of industrial processes and combustion. The results provide a detailed mapping of pollution sources, laying the groundwork for the development of mitigation strategies and the implementation of more effective environmental policies. This study represents a crucial step towards understanding and managing the environmental impact of industrial activities in Solofra, contributing to the protection of public health and the integrity of the local ecosystem.

Nitrogen dioxide (NO2) is an air pollutant highly impacting on human health, and its measurement is crucial for air quality assessment. Use of passive samplers for long-term large-scale monitoring is a reasonably reliable and economic alternative to more sophisticated and expensive equipment employed in active air sampling by environmental control authorities. In recent years the Citizen Science approach, based on low-cost devices, is spreading more and more in environmental control. Passive samplers available on the market (like the consolidated “Palmes” tubes) are often used in community-based monitoring campaigns. We describe validation of a new cheap axial diffusion tube for NO2 monitoring, used in combination with a new user-friendly App for smartphone that represents an innovation to speed up recording of geo-localization and exposition period data. Affordability and availability of materials, simple construction protocol and easy App procedure, allow possible self-production by school students and non-expert users, making the proposed tube a potential tool to realize extended Citizen Science monitoring campaigns. Accuracy within 25% and precision within 20%, evidenced in validation, show comparability of the tube performance with Palmes-type tubes and agreement with the official monitoring station results. Two small-scale trial monitoring campaigns, involving high school students, were performed to test the efficacy of the proposed “tube-App” system in combining educational impact and community value of air quality monitoring.

Climate change, driven by elevated atmospheric CO2 levels, is recognized as a persistent and significant issue of the 21st century. Consequently, the creation of effective and suitable methods to decrease atmospheric CO2 emissions is urgently and critically needed. Various techniques, including membrane separation, chemical absorption, and adsorption, are currently employed to capture CO2. In particular, processes based on physisorption are noted for their energy efficiency and cost-effectiveness, making the choice of an effective adsorbent essential. Metal-organic frameworks (MOFs), which are porous structures formed from metal ions and organic linkers, have emerged as promising and adaptable solutions for advanced CO2 capture initiatives. These materials hold potential for application across a broad spectrum of domains, including gas adsorption and separation, catalysis, electron luminescence, magnetism, as well as in drug delivery and the health sciences. So far, MOFs have mainly been developed as promising materials for CO2 adsorption due to their large capacity for adsorption of gases and easy tailor ability of their structures, and metal sites. In this study, the fabrication of specific devise for controlling environmental remediation of CO2 through CCS techniques has been described also highlighting their potential utility for CO2 adsorption purposes. First of all, the synthesis of HKUST-1, a solid belonging to the class of copper-based MOF has been described and in particular ([Cu3(btc)2(H2O)3]-H2O), directly deposited on ceramic foam. A characterisation of the samples obtained under different synthetic conditions through X ray analysis, thermogravimetric analysis, porosimetry and electron scanning microscopy (SEM) has been shown. Ultimately, the degree of MOF coating on the supports was assessed, and their ability to adsorb CO2 was examined through experimental trials that tested the capture process under precise temperature and pressure conditions using a 10 mol% mixture of air and CO2. A fixed bed system, structured with coated foams, exhibited a CO2 capture capability of 0.40 mmol/gMOF, minimal pressure drops, and low temperatures for reactivation, all critical requirements for industrial applications.

Air pollution is a problem that affects both human health and the state of historical artifacts.The interaction between pollutants and historical artifacts leads to a material degradation and therefore to the ruin of the artistic heritage.To define the impact of air quality on historic artifacts, it is necessary to measure these levels through an air quality measurement system.In this study the levels of particulate matter, PM10, PM2.5 and PM1, measured in the historic sanctuary of the Beata Vergine dei Miracoli in Saronno (Varese) were analysed using two measuring devices.Two air quality sensors, operating 24/24h and 7/7 days, were installed inside the sanctuary near the "Last Supper" wooden sculptural group realized during Renaissance period by Andrea da Corbetta and decorated by Alberto da Lodi.Similar concentration values and trends were observed with the two devices.Particulate matter levels were often above the recommended values for conservation and this may pose a threat to the artifacts present in the sanctuary.The two sensors return similar values in both trends and measured concentrations.From the analysis of the particulate matter levels it can be seen that they are high and sensitive to the activities, such as religious services, that take place in the sanctuary.

The monitoring of the concentration of harmful air pollutants is mandatory to prevent the deterioration of cultural heritage and, at the same time, safeguard the health of visitors and workers.The present study is focused on the determination of the concentration of specific air pollutants (nitrogen dioxide and aromatic hydrocarbons, precisely benzene, toluene, ethylbenzene and xylene) in the Sanctuary of the Beata Vergine dei Miracoli (Saronno, Italy) by passive air sampling.The results of this monitoring suggest that indoor concentration of NO2 and benzene are always higher than outdoor ones.Further investigations should be performed to assess the effective concentrations to which, not only the works of art, but also people are exposed.

Different integration methods were tested to integrate data from a dynamic road network (ROM) in which pollution measurement sensors were mounted over delivery vans. Two methods were purposely developed, the isoelliptical expansion - ISOE - method accounting for the wind convective transport of pollutants and the modified isoelliptical expansion - MISOE - method in which, furthermore, local specific deviation of the pollution are estimated from historical sequences of pollution levels. The results obtained by these methods were compared with the well-known inverse distance weighted - IDW - method, which is only based on the distance from the interpolation sources. The comparison of the errors between the estimated values and the available measures reveals that the MISOE model provides more accurate estimated values with a low associated error. The ISOE model is more complicate than the IDW but provides better estimations in windy days. The maps of the local adjusting coefficients estimated month by months are able to identify critical areas to address in local environmental policy decisions.

According to the literature, the microscopic quality of the powder layer produced in the Selective Laser Sintering (SLS) process is related to the onset of macroscopic defects of the produced powder. This study proposes an experimental procedure able to quantify the quality of the powder layer obtained in the spreading step of the SLS process. A dedicated experimental set-up was developed, able to mimic the powder spreading step of the SLS process and to allow the photographic analysis of its surface. Four commercial polymeric powders for SLS applications were tested at two different speeds of the recoater. An image processing analysis was developed, converting a series of microscopic images of layer surface in grey level profiles along the spreading direction. The grey level profiles were further analysed with a wavelet analysis tool, and the major features of the wavelet powder spectral density were used to calculate specific indicators of the powder layer quality. The different indicators provide consistent results comparing the tested powders and the testing conditions. The powder ranking according to spreadability indexes differs from the one obtained using flowability indexes. This finding confirms that spreadability cannot be directly related to flowability.

Mold temperature is the key parameter in determining the morphology of molded parts. Uneven temperature distribution could induce significant effects on part performances. In such cases, uneven temperature is induced to analyze the morphology developed in the molded specimens. The technology used for controlling mold temperature during the process is crucial to maintain the short processing time. This paper proposed a strategy for controlling mold temperature during the process, avoiding a significant increase in processing time. A thin electrical heater is designed and adapted below the cavity surface, allowing for the increase of the cavity surface temperature soon after the mold closure, and the fast decrease of the mold temperature soon after the filling. The effect of several heating powers and heating durations on the molecular orientation was analyzed and exploited considering the temperature and flow field realized during the process.

The Special Issue entitled “Air Quality Monitoring for Smart Cities and Industrial Applications” addresses the pressing concern of environmental pollution, particularly air pollution, and its impact on global well-being [...]

Air pollution is a serious problem for the preservation of cultural heritage.In fact, the iteration works of art with atmospheric pollutants leads to their degradation.To define the impact of air quality on artifacts, it is necessary to measure the pollutants' levels through an air quality measurement system.In this study, the levels of particulate matter (PM10, PM2.5 and PM1) near the Amalfi Cathedral (Amalfi, Salerno, Italy) were measured by using the Sensy sensor.The analysis of the data recorded by the Sensy sensor was useful in identifying the air quality in an area that is very crowded with tourists from around the world.By analyzing the data collected by the sensor, researchers were able to assess the air quality in the area and evaluate the potential impact of air pollution on the cultural heritage sites in the region.