A Coaxial Line Fixture Based on a Hybrid PSO-NLR Model for in Situ Dielectric Permittivity Determination of Carasau Bread Dough

Food quality is crucial in today's processing industry. The organoleptic properties of most food materials are known to depend on their water content. The monitoring of food quality and moisture content calls for engineering solutions. To this aim, given their nondestructive nature and cost-effective features, microwave sensors are a valuable tool. However, for some peculiar food processing industries, suitable engineered microwave devices must be designed. Therein, we will focus on the case of the Carasau bread industry. Carasau bread is a typical food product from Sardinia (IT). In this work, we will present the design, realization, and characterization of a coaxial fixture, working between 0.5 and 3 GHz, for the determination of the complex dielectric permittivity of Carasau bread dough. Through a nonlinear regression model based on a particle swarm optimization routine, the scattering parameters are used to retrieve the electromagnetic properties of bread doughs. By making a comparison with the complex dielectric permittivity measured with an open-ended coaxial probe, an average error of 3% for the real part and 6% for the imaginary part has been found. The proposed device is driven by a Raspberry Pi that controls the acquisition of a pocket-vector network analyzer (VNA), thus representing a cost-effective electronic system for industrial applications

A Low-profile Shared Aperture Antenna for FR1 and FR2 5G Frequency Bands

Shared-aperture antennas are attracting a wide interest in last of years, due to their inherent compactness and low-profile layout. More specifically, in this work a shared-aperture antenna for FR1 and FR2 frequency bands is proposed. The difference in size between the radiating elements operating the two frequency bands can be exploited to embed different antennas in the same area. A 4×4 patch array for FR2 is embedded inside a FR1 shaped patch antenna. The antenna system is designed by preserving a low-profile architecture suitable for planar technology. The performance of the antenna system are evaluated for both the bands achieving a 10-dB bandwidth equal to 0.14 GHz (3.8 %) for FR1 and to 2.32 GHz (8.6 %) for FR2. In FR2, a ±30° steering capability along the H plane is shown

Design of a Low-Profile Dual Linearly Polarized Antenna Array for mm-Wave 5G

This work proposes a dual linearly polarized antenna array for 5G mm-wave band, which is designed to be compatible with planar printed circuit board technology. The proposed antenna is engineered with a focus on simplifying the antenna geometry and eliminating any critical issues that may arise in antenna manufacturing. The proposed antenna has been evaluated, finding a 7% impedance bandwidth centered around 27.28 GHz. Additionally, the beam steering capability of the antenna is found to cover a ±30% angular width for both linear polarizations. These findings highlight the potential of the proposed antenna for use in 5G mm-wave band applications, where compatibility with planar printed circuit board technology and simplified antenna geometry are essential design requirements

Monitor and sensors 2.0 for exposure assessment to airborne pollutants

In recent years, the issue of exposure assessment to airborne pollutants has become increasingly popular, both in the occupational and environmental fields. The increasingly stringent national and international air quality standards and exposure limit values both for indoor environments and occupational exposure limit values have been developed with the aim of protecting the health of the general population and workers. On the other hand, this requires a considerable and continuous development of the technologies used to monitor the concentrations of the pollutants to ensure the reliability of the exposure assessment studies. In this regard, one of the most interesting aspects is certainly the development of “new generation” instrumentation for monitoring airborne pollutants (“Next Generation Monitors and Sensors” – NGMS). The main purpose of this work is to analyze the state of the art regarding the afore-mentioned instrumentation, to be able to investigate any practical applications within exposure assessment studies. In this regard, a systematic review of the scientific literature was carried out using three different databases (Scopus, PubMed and Web of Knowledge) and the results were analyzed in terms of the objectives set out above. What emerged is the fact that the use of NGMSs is increasingly growing within the scientific community for exposure assessment studies applied to the occupational and environmental context. The investigated studies have emphasized that NGMSs cannot be considered, in terms of the reliability of the results, to be equal to the reference measurement tools and techniques (i.e., those defined in recognized methods used for regulatory purposes), but they can certainly be integrated into the internal exposure assessment studies to improve their spatial-temporal resolution. These tools have the potential to be easily adapted to different types of studies, are characterized by a small size, which allows them to be worn comfortably without affecting the normal activities of workers or citizens, and by a relatively low cost. Despite this, there is certainly a gap with respect to the reference instrumentation, regarding the measurement performance and quality of the data provided; the objective to be set, however, is not to replace the traditional instrumentation with NGMSs but to integrate and combine the two typologies of instruments to benefit from the strengths of both, therefore, the desirable future developments in this sense has been discussed in this work

First in-Lab Testing of a Cost-Effective Prototype for PM2.5 Monitoring: The P.ALP Assessment

The goal of the present research was to assess, under controlled laboratory conditions, the accuracy and precision of a prototype device (named ‘P.ALP’: Ph.D. Air-quality Low-cost Project) developed for PM2.5 concentration level monitoring. Indeed, this study follows a complementary manuscript (previously published) focusing on the in-field evaluation of the device’s performance. Four P.ALP prototypes were co-located with the reference instrument in a calm-air aerosol chamber at the NIOSH laboratories in Pittsburgh, PA (USA), used by the Center for Direct Reading and Sensor Technologies. The devices were tested for 10 monitoring days under several exposure conditions. To evaluate the performance of the prototypes, different approaches were employed. After the data from the devices were stored and prepared for analysis, to assess the accuracy (comparing the reference instrument with the prototypes) and the precision (comparing all the possible pairs of devices) of the P.ALPs, linear regression analysis was performed. Moreover, to find out the applicability field of this device, the US EPA’s suggested criteria were adopted, and to assess error trends of the prototype in the process of data acquisition, Bland–Altman plots were built. The findings show that, by introducing ad hoc calibration factors, the P.ALP’s performance needs to be further implemented, but the device can monitor the concentration trend variations with satisfying accuracy. Overall, the P.ALP can be involved in and adapted to a wide range of applications because of the inexpensive nature of the components, the small dimensions, and the high data storage capacity

Smart-working VS office work: how does personal exposure to different air pollutants change?

The COVID-19 pandemic is raging all over the world, with possible structural effects on the work: the smart-working (WFH -Working From Home) role is therefore emphasized by the fact that it could become a traditional way of working in many work sectors. Several scientific papers have recently analyzed the WFH phenomenon under different aspects, but scientific studies have not yet been conducted considering the differences between WFH and WFO (Working From Office), in terms of evaluation of personal exposure assessment to selected airborne pollutants. This study, therefore, aims to evaluate, using portable monitors, the differences in terms of personal exposure to selected airborne pollutants, during different working conditions (WFO vs WFH), over long periods of time (from days to weeks), extending the results to even longer periods (years), to adhere to the approach proposed by the concept of the exposome. The preliminary results of this study refer to three separate phases of the work (i) re-analyses of literature data via Monte Carlo simulation, and assessment of personal exposure to different air pollutants during different working conditions, during (ii) “long term” campaign and (iii) a “short term” monitoring campaign. During the two different measurement campaigns, portable instrumentation was used, because of the ability of these kinds of instruments to obtain data characterized by a high spatial and temperature resolution. The re-elaborations of the data obtained from the literature show how, under different conditions, the exposure concentrations to different PM fractions are statistically lower in WFH working conditions, compared to WFO conditions. These results are in contrast with the preliminary results obtained from exploratory monitoring (both for the “long term” and for the “short term” campaigns). The results obtained from these exploratory monitoring show that the WFH condition has a greater impact on the daily exposure of the monitored subjects, compared to the WFO condition

An In-Field Assessment of the P.ALP Device in Four Different Real Working Conditions: A Performance Evaluation in Particulate Matter Monitoring

This study aimed to assess the performance, in terms of precision and accuracy, of a prototype (called “P.ALP”—Ph.D. Air Quality Low-cost Project) developed for monitoring PM2.5 concentration levels. Four prototypes were co-located with reference instrumentation in four different microenvironments simulating real-world and working conditions, namely (i) office, (ii) home, (iii) outdoor, and (iv) occupational environments. The devices were evaluated for a total of 20 monitoring days (approximately 168 h) under a wide range of PM2.5 concentrations. The performances of the prototypes (based on the light-scattering working principle) were tested through different statistical methods. After the data acquisition and data cleaning processes, a linear regression analysis was performed to assess the precision (by comparing all possible pairs of devices) and the accuracy (by comparing the prototypes against the reference instrumentation) of the P.ALP. Moreover, the United States Environmental Protection Agency (US EPA) criteria were applied to assess the possible usage of this instrumentation, and to evaluate the eventual error trends of the P.ALP in the data storage process, Bland–Altman plots were also adopted. The outcomes of this study underlined that the P.ALP performed differently depending on the microenvironment in which it was tested and, consequently, on the PM2.5 concentrations. The device can monitor PM2.5 variations with acceptable results, but the performance cannot be considered satisfactory at extremely low and remarkably high PM2.5 concentrations. Thanks to modular components and open-source software, the tested device has the potential to be customized and adapted to better fit specific study design needs, but it must be implemented with ad hoc calibration factors depending on the application before being used in field

Studies on Air Pollution and Air Quality in Rural and Agricultural Environments: A Systematic Review

Studies on air quality in rural environments are fundamental to obtain first-hand data for the determination of base emissions of air pollutants, to assess the impact of rural-specific airborne pollutants, to model pollutant dispersion, and to develop proper pollution mitigation technologies. The literature lacks a systematic review based on the evaluation of the techniques and methods used for the sampling/monitoring (S/M) of atmospheric pollutants in rural and agricultural settings, which highlights the shortcomings in this field and the need for future studies. This work aims to review the study design applied for on-field monitoring campaigns of airborne pollutants in rural environments and discuss the possible needs and future developments in this field. The results of this literature review, based on the revision of 23 scientific papers, allowed us to determine (i) the basic characteristics related to the study design that should always be reported; (ii) the main techniques and analyses used in exposure assessment studies conducted in this type of setting; and (iii) contextual parameters and descriptors of the S/M site that should be considered to best support the results obtained from the different studies. Future studies carried out to monitor the airborne pollution in rural/agriculture areas should (i) include the use of multiparametric monitors for the contextual measurement of different atmospheric pollutants (as well as meteorological parameters) and (ii) consider the most important boundary information, to better characterize the S/M site

Ancient pathogen-driven adaptation triggers increased susceptibility to non-celiac wheat sensitivity in present-day European populations

Details of sequence profiles for each NCWS subject. (XLSX 47 kb

Indoor air pollution impacts cardiovascular autonomic control during sleep and the inflammatory profile

The present study explores the modifications of cardiovascular autonomic control (CAC) during wake and sleep time and the systemic inflammatory profile associated with exposure to indoor air pollution (IAP) in a cohort of healthy subjects. Twenty healthy volunteers were enrolled. Indoor levels of fine particulate matter (PM2.5), nitrogen dioxide (NO2) and volatile organic compounds (VOCs) were monitored using a portable detector for 7 days. Together, a 7-day monitoring was performed through a wireless patch that continuously recorded electrocardiogram, respiratory activity and actigraphy. Indexes of CAC during wake and sleep time were derived from the biosignals: heart rate and low-frequency to high-frequency ratio (LF/HF), index of sympathovagal balance with higher values corresponding to a predominance of the sympathetic branch. Cyclic variation of heart rate index (CVHRI events/hour) during sleep, a proxy for the evaluation of sleep apnea, was assessed for each night. After the monitoring, blood samples were collected to assess the inflammatory profile. Regression and correlation analyses were performed. A positive association between VOC exposure and the CVHRI (Δ% = +0.2% for 1 μg/m3 VOCs, p = 0.008) was found. The CVHRI was also positively associated with LF/HF during sleep, thus higher CVHRI values corresponded to a shift of the sympathovagal balance towards a sympathetic predominance (r = 0.52; p = 0.018). NO2 exposure was positively associated with both the pro-inflammatory biomarker TREM-1 and the anti-inflammatory biomarker IL-10 (Δ% = +1.2% and Δ% = +2.4%, for 1 μg/m3 NO2; p = 0.005 and p = 0.022, respectively). The study highlights a possible causal relationship between IAP exposure and higher risk of sleep apnea events, associated with impaired CAC during sleep, and a pro-inflammatory state counterbalanced by an increased anti-inflammatory response in healthy subjects. This process may be disrupted in vulnerable populations, leading to a harmful chronic pro-inflammatory profile. Thus, IAP may emerge as a critical and often neglected risk factor for the public health that can be addressed through targeted preventive interventions