Relative Humidity Research Articles

Research on humidity field and freezing resistance of green recycled ceramic internal cured concrete at early age

In cold and drought environment, concrete shrinkage cracking caused by water loss is serious, and thus the freezing resistance of concrete is deteriorated. The waste ceramic particles were used as internal curing materials to prepare concrete, based on this background. Then, the influence of internal curing with ceramic particles on humidity field and temperature of concrete is analyzed by using temperature and humidity sensor. Based on the change mechanism of the internal humidity of concrete, the relationship between the curvature radius of liquid surface and the relative humidity is revealed. Taking water loss and water loss rate as the index, the water transfer law of concrete surface under ceramic particle internal curing was defined. Through the drying shrinkage test, the mechanism of improving the drying shrinkage of concrete by internal curing in ceramic particles was mastered. Finally, the effects of ceramic internal curing on cement hydration, interfacial transition zone (ITZ) and freezing resistance of concrete were studied. The results show that the relative humidity, water loss and water loss rate of concrete increase with the increase of ceramic particle content, and the dry shrinkage value decreases with the increase of ceramic particle content. Compared with ordinary concrete, when the ceramic particle content is 10%, 15%, 20%, 25% and 30%, and the test period is 10 days, the internal relative humidity of concrete increases by 0.52%, 0.67%, 1.55%, 2.55% and 3.05%, respectively. The drying shrinkage values decreased by 3.42%, 7.69%, 10.26%, 15.17% and 30.13%, respectively. When the test period was 1032 hours, the water loss increased by 1.08%, 5.15%, 7.90%, 12.69% and 14.49%, respectively. Furthermore, when the ceramic particle content is 20%, the initial normalized heat flow of concrete increases by 2.74 mW/g, and the normalized heat flow minimum increases by 0.324 mW/g. The minimum ITZ microhardness increased by 2.64 MPa, the ITZ width decreased by 5 μm, and the maximum crack width at the contact between ITZ and aggregate decreased by 0.89 μm. At the same time, when the ceramic particle content is less than 20%, the effect of internal curing on the freezing resistance of concrete increases with an increase in ceramic particle content.

Avaliação do conforto térmico em instalação de processamento de rapadura por meio do índice IBUTG

ABSTRACT The production process of non-centrifuged cane sugar (NCS) involves a significant release of steam and heat due to the evaporation of cane juices in saucepans over a solid fuel oven. This results in a warm and moisture-saturated environment, which can be suffocating for workers. This study aimed to evaluate the bioclimatic behavior of an NCS processing facility, based on the wet bulb globe temperature (WBGT) index. In addition, solutions are suggested to mitigate possible adverse effects of heat stress. This evaluation utilized computational simulations to determine the thermal comfort perceived by the workers. The accuracy of simulations was verified against temperature and relative air humidity data collected from the facility. Bioclimatic simulations encompassed twelve treatments, involving modifications to the enclosure on the walls and lantern window, incorporating three types of roof material. The WBGT index was determined by considering the effects of the radiant heat generated by the oven and the natural ventilation area on the facility’s temperature and relative air humidity. This helps to assess the comfort experienced by the workers. The thermal zone of the oven presented heat stress conditions; therefore, rest periods and mechanical ventilation were suggested when dissipating heat and steam through natural ventilation is not possible. For workers exposed to high temperatures and thermal radiation, the use of an aluminized apron and infrared goggles for eye protection was recommended.

Energy forecast for a cogeneration system using dynamic factor models

Cogeneration is used in different sectors of industry and it allows that two types of energy to be efficiently obtained from a single source. Accurate predictions are fundamental to optimize energy production, considering the variability that occurs in the daily market. This study adjusts and predicts cogeneration using real data from a Spanish energy technology center, using dynamic factor analysis methodology and incorporating covariates such as temperature and relative humidity. A comparative analysis is performed to evaluate the improvements achieved by implementing cluster-structured dynamic models versus other methods. Furthermore, a robust interpolation method has been implemented to handle missing data in both the main variable and the covariates.

Cfd-based optimization of Direct evaporative cooling systems for canarian greenhouses in Semi-Arid regions

Direct Evaporative Cooling Systems (DECS) offer a promising solution for mitigating heat stress in greenhouses located in arid and semi-arid regins. To implement DECS efficiently in these regions, it is crucial to understand their impact on greenhouse microclimate parameters. This study investigates the influence of DECS on the microclimate within a canarian greenhouse and identifies key factors affecting their efficiency. Through Computational Fluid Dynamics (CFD) simulations using Ansys, we examined the effects of DECS on temperature, relative humidity, and air velocity within the greenhouse under semi-arid conditions.The results indicate that DECS efficiency is affected by several factors, including fan placement, evaporative pad height, fan spacing, and inlet air fan speed. Higher fan placement cools the upper canopy but increases humidity near the ceiling, whereas lower placement improves temperature uniformity but may require additional humidification. Closer fan spacing results in uneven air velocity, while wider spacing leads to stagnant zones within the greenhouse. Optimal placement of the the evaporative pad is crucial for maximizing the cooling coverage area and minimizes the temperature gradients. Inlet air fan speed also significantly impacts the microclimate, with higher speeds reducing both temperature and humidity. By optimizing these parameters, the DECS system was able to significantly decrease air temperature, increase humidity, and improve air velocity inside the greenhouse. With a pad height of 1.5 m, fans positioned at a height of 2 m, a distance of 6 m between each fan, and an air speed of 1.5 m/s at the entrance – the DECS enhances the local climate. Under these conditions, the mean air temperature drops from 40°C −in greenhouse with natural ventilation- to 21 °C using DECS, while relative humidity increases from 23 % −in greenhouse with natural ventilation- to 67 % using DECS, creating a more favorable environment for plant growth and potentially increasing crop yield and quality. Additionally, energy and environmental analyses show that implementing DECS in Canarian greenhouses, instead of traditional electrical cooling systems, results in substantial energy savings of 123,818.112 kWh/year annually and reduces carbon dioxide emissions by approximately 1.785 tons/year over a 20-year operational lifespan in a semi-arid climate.

Future Changes in the Vertical Structure of Severe Convective Storm Environments over the U.S. Central Great Plains

Abstract The effect of warming on severe convective storm potential is commonly explained in terms of changes in vertically integrated (“bulk”) environmental parameters, such as CAPE and 0–6-km shear. However, such events are known to depend on the details of the vertical structure of the thermodynamic and kinematic environment that can change independently of these bulk parameters. This work examines how warming may affect the complete vertical structure of these environments for fixed ranges of values of high CAPE and bulk shear, using data over the central Great Plains from two high-performing climate models (CNRM and MPI). To first order, projected changes in the vertical sounding structure are consistent between the two models: the environment warms approximately uniformly with height at constant relative humidity, and the shear profile remains relatively constant. The boundary layer becomes slightly drier (−2% to 6% relative humidity) while the free troposphere becomes slightly moister (+1% to 3%), with a slight increase in moist static energy deficit aloft with stronger magnitude in CNRM. CNRM indicates enhanced low-level shear and storm-relative helicity associated with stronger hodograph curvature in the lowest 2 km, whereas MPI shows near-zero change. Both models strongly underestimate shear below 1 km compared to ERA5, indicating large uncertainty in projecting subtle changes in the low-level flow structure in climate models. The evaluation of the net effect of these modest thermodynamic and kinematic changes on severe convective storm outcomes cannot be ascertained here but could be explored in simulation experiments. Significance Statement Severe thunderstorms and tornadoes cause substantial damage and loss of life each year, which raise concerns about how they may change as the world warms. We typically use a small number of common atmospheric parameters to understand how these localized events may change with climate change. However, climate change may alter the weather patterns that produce these events in ways not captured by these parameters. This work examines how climate change may alter the complete vertical structure of temperature, moisture, and wind and discusses the potential implications of these changes for future severe thunderstorms and tornadoes.

Design and assessment of an adapted absorber solar air collector tailored for sustainable drying applications

The design of a relevant solar air collector (SAC) is imperative to make the drying industries self-reliant and sustainable in terms of energy. However, the literature doesn’t describe the coherent design assessment of SAC, and its viability for a drying system provided the scale-up opportunity for commercial applications. Hence, the present work was devoted to estimating the heat load for a particular drying condition, a methodological understanding of SAC design, and an investigation of the performance of the newly developed solar collector. The essential design criteria were the moisture content of fresh and intended dried items, physical attributes of items, dryer capacity, preferred drying temperature, projected drying duration, required air speed (based on dryer type), and local climate (solar radiation, ambient temperature and relative humidity). The regular semi-hexagonal shape aluminium (Al) sheet was chosen to introduce air turbulence while maximizing the surface area available for heat transfer. The regular semi-hexagonal absorber was outfitted with helical springs to generate air turbulence and augment heat transfer. A double glazing (polycarbonate) of 5 mm apart was mounted to impede radiation heat loss. Three successive days of the experimental study showed that the average temperature increases of air passing through SAC were 36.02 °C, 37 °C, and 39.2 °C. The optimal tilt angle with the horizontal surface was found to be 35° in a south-facing direction for the month of January. The highest energy efficiency was found to be 40.5 %, while the lowest was found to be 24.73 %. The sustainability index of the SAC was found to be 1.02. The experimental results clearly demonstrate that the designed SAC was capable of supplying adequate heat energy (at the minimum of 155.86 W/hr.) to meet the necessary heat load (125.82 W/hr.) for agro-products drying at the designed capacity.

Moisture ageing effects on the mechanical performance of eco-friendly sandwich panels made of aluminium skins, bamboo ring core and bio-based adhesives

Recent research has been focused on developing high-performance sandwich structures using renewable resources. The adoption of bamboo rings as a core material and bio-based adhesives has emerged as a promising sustainable design solution for panel construction. It is therefore critical to conduct accelerated ageing tests on these materials to evaluate the impact of environmental humidity on their degradation and durability. This study assessed the effects of moisture ageing on the physic-mechanical properties of eco-friendly sandwich panels and their constituents (aluminium skins, bamboo ring core and castor oil bio-adhesive). Mechanical evaluations of sandwich panels with compacted and spaced bamboo ring cores were performed under varying humidity conditions. Bamboo rings exhibited variable bulk density due to swelling and loss of organic material over time. They also demonstrated increased compressive properties after 2 years of natural ageing but reduced performance after 30 days at 100% relative humidity. The mechanical properties of the bio-based polymer were enhanced through water-ageing exposure. Sandwich panels constructed with compacted bamboo ring cores exhibited higher bending properties than those with spaced ring core architecture, with the latter showing failures characterised by a wrinkling effect on both skins followed by debonding.

The Effect of a Synthetic-Grass Sport Surface on Physiology and Perception During Intermittent Exercise in Hot Conditions.

The current study aimed to determine the effect of a synthetic-grass sport surface on core body temperature, skin temperature, heart rate, thermal sensation, thermal comfort, and rating of perceived exertion (RPE)during intermittent exercise in hot conditions. Using a randomized crossover design, 13 trained/developmental team-sport athletes completed two 50-minute standardized intermittent running protocols on a synthetic and anatural-grass surface, on separate days (control-condition air temperature 32.6 °C [1.3 °C], relative humidity 43.2% [5.3%]). Final skin temperature was significantly higher on synthetic compared with natural grass at the calf (40.1 °C [2.5 °C] vs 33.4 °C [0.6 °C]; P < .001), shoulder (36.6 °C [1.7 °C] vs 33.7 °C [0.7 °C]; P < .001), and chest (33.2 °C [1.1 °C] vs 31.8 °C [1.2 °C]; P = .02). Thermal sensation (median: 2.3; interquartile range [0.5] vs 2.2 [0.5], P = .03) and sweat rate (1.5 [0.4]L·h-1 vs 1.2 [0.3]L·h-1; P = .02) were also significantly higher on synthetic grass. While final core body temperature was significantly higher on the natural than synthetic grass (38.4 °C [0.3 °C] vs 38.2 °C [0.4 °C]),there were no significant differences in delta core temperature, as well as heart rate, thermal comfort, or RPE. Higher skin temperatures, thermal sensation, and sweat rates suggest that exercising on synthetic grass in hot conditions may increase some markers of heat strain during exercise. However, delta core body temperature, heart rate, thermal comfort, and RPE remained unaffected.

Preparation of high temperature proton exchange membrane through covalent organic framework doped polyvinylidene fluoride nanofibers

Covalent organic framework (COF) exhibits the great potential to promote proton conduction under low relative humidity for proton exchange membranes (PEMs). In this research, quick and stable proton conduction has been achieved since the prepared COF and polyvinylidene fluoride (PVDF) nanofibers are believed to constitute successive proton conduction channels. The PVDF-COF nanofibers membrane is prepared through the in-situ growth of COF along PVDF nanofibers. The fine compatibility can drive the stable combination of COF with the PVDF nanofibers in PVDF-COF nanofibers. Most importantly, the fibrous PVDF nanofibers accelerate proton conduction through confining the proton conduction pathways. Additionally, ionic liquids of 1-butyl-3-methylimidazolium chloride (BmimCl) and 1-butyl-3-methylimidazole hexafluorophosphate (BmimPF6) as proton conduction carriers have been introduced to accelerate proton conduction in the prepared PVDF-COF/BmimCl/PA and PVDF-COF/BmimPF6/PA membranes. Phosphoric acid (PA) molecules are combined by COF and ionic liquid cations with the formation of intermolecular hydrogen bonds. As a result, the PVDF-COF/BmimPF6/PA membrane exhibits the proton conductivity of (1.81 ± 0.07) × 10−1 S/cm at 160 °C. The long-term proton conductivity stability is determined, deriving from the proton conductivities of 1.77×10−2 S/cm at 80 °C and 1.42×10−2 S/cm at 110 °C in the 400 h non-stop measurement. The single fuel cell equipped with the PVDF-COF/BmimPF6/PA membrane represents the open circuit voltage of 0.927 V and the peak power density of 178.8 mW/cm2 at 100 °C, 0.907 V and 326.5 mW/cm2 at 120 °C.

Distribution of Air pollutant Concentration and Ammonium conversion rate in Livestock Areas: Focusing on Boryeong

Objectives:The association between the generation of fine particulate matter (PM2.5) and ammonia is well-established, highlighting the importance of managing ammonia as a primary means to reduce particulate matter. However, domestic research on ammonia emissions, particularly in livestock areas, which are major sources of ammonia, is insufficient. This study aims to contribute to pollutant management on a national scale by conducting air pollutant measurements and analyses in livestock areas. Methods:Real-time analysis and monitoring of air and weather conditions were carried out in Boryeong, Chungcheongnam-do, from 2021 to 2022. Statistical analysis was then employed to investigate the correlation between observed air pollutants (ammonia, nitrogen oxides, sulfur oxides, ozone and particle matters) and PM2.5. Results and Discussion:As a result of the analysis, the concentration of air pollutants in Boryeong showed a seasonal tendancy to decrease in summer and increase after that. Most substances such as NO2, SO2, and PM10 were observed within the standard values. In the case of ammonia, domestic air environment standards are not in place, but the annual average was found to be 61.5 ± 55.3 ppb, higher than in other research results. This discrepancy is attributed to the influence of nearby livestock houses. It was also observed that PM2.5 exceeded the annual standard value of 15 μg/m3 in spring (30.1 μg/m3), summer (18.3 μg/m3), autumn (25.3 μg/m3) and winter (31.7 μg/m3), respectively. During this period, ammonium (NH4+, 32.8%), nitrate (NO3-, 35.9%), and sulfate (SO42-, 19.7%) comprised the majority of particulate pollutants in PM2.5. The ammonia-ammonium conversion rate (NHR) was 0.08 annual average, and it was found that gas/ion phase changes were affected by seasonal weather conditions (temperature and relative humidity). As a result of analyzing the NHR according to the PM2.5 concentration, it was found that the higher the PM2.5 concentration, the higher the NHR. Furthermore, although the measurement area of this study exhibited high ammonia concentration, the NHR was low. This suggests that the contribution rate of ammonia to PM2.5 was relatively low compared to the other studies.Conclusion:As a result, there is a need for measures to reduce the high concentrations of ammonia in livestock areas. Simultaneously, considering the diverse mechanisms involved in particulate matter formation, it is suggested that management of pollutants such as nitrogen oxides, sulfur oxides including ammonia should be implemented.

A Comparative Study on the Behaviour of Various Methods of Curing Concrete

Abstract: The properties of cement-based products, especially their durability, are predominantly influenced by curing, since it has a remarkable effect on the hydration of the cement. Proper curing of cement-based products is crucial to obtaining design strength and maximum durability. The curing period depends on the type of cement works, the purpose for which it is to be used and the surrounding atmosphere, namely temperature and relative humidity. Curing is designed primarily to maintain the moisture, by avoiding the loss of moisture from the period in which it is gaining strength. Curing may be applied in a number of different processes and the mass appropriate means of curing may be directed by the site or the construction method. In this critique, a paper struggle has been made to understand the working and efficiency of curing system which are generally adopted in the construction industry and compared with the standard water curing method.

Distribution of air quality data across stratified areas of Port Harcourt metropolis

Distribution of Air Quality Data across seven stratified areas of Port Harcourt Metropolis was carried out. The study utilized a total of 18 parameters from four different air quality datasets obtained from 24 sampling points during field data collection. The sampling points were structured and stratified into residential, industrial, commercial, recreational, transport, dumpsite and abattoir areas. Air quality data were acquired using a multi-digital potable tool, Aerosol Gas Monitor and TESTO Gas Analyser for meteorological data, particulate matters (PM), gaseous emissions and heavy metals. Results showed that the concentrations of air quality data were not evenly distributed across the seven stratified areas, an indication of the influence of location-based activities on the distribution of air quality parameters. The minimum and maximum values of wind speed, temperature and relative humidity were obtained within Residential and Transport Areas, Abattoir and Dumpsite Areas, and, Industrial and Recreational Areas with numerical values of 1.1ms-1 and 3.7ms-1, 27.20C and 350C, and, 67.8% and 923% for wind speed, temperature and relative humidity respectively. The values of TSP, PM2.5 and PM10 ranged from 53 to 255 μg/m3, 13 to 90 μg/m3 and 40 to 169μg/m3 for TSP, PM2.5 and PM10 respectively with the lowest and highest values obtained within Residential and Dumpsite Areas respectively. The concentrations of NO2 and SO2 exceeded the standards of WHO, NAAQS and FMEnv in Industrial, Dumpsite and Abattoir Areas. Lead ( Pb) showed very high values within Dumpsite Area (0.954mg/kg), Industrial Area (0.372mg/kg) and Transport Area (0.077mg/kg).

Population dynamics of the main necrophagous Diptera in the sub-Sudanese zone of Côte d’Ivoire

The objective of this work was to identify the population variation of the main necrophagous Diptera in the sub-Sudanese zone of Côte d'Ivoire. Three traps, inspired by Upton's and using pig liver and viscera as bait were placed on the site of the Botanical Garden of Peleforo Gon Coulibaly University and Lataha located 10 km from the Botanical Garden. Weekly captures were taken from October 4, 2018 to October 3, 2019. In total, 194,853 individuals from the Calliphoridae, Sarcophagidae and Muscidae were collected. Calliphoridae represented 48%, Sarcophagidae 24% and Muscidae 28% in the Botanical Garden site and in Lataha, Calliphoridae presented 52%, Sarcophagidae 27% and Muscidae 21%. Chrysomya albiceps, Sarcophaga carnaria and Musca domestica were the majority species. The numbers of these three species were higher at relative humidity levels reaching 70 to 85%. A correlation between relative humidity and the numbers of these three species was observed. Apart from relative humidity, these results show that other climatic parameters have a weak influence on the activity of Chrysomya albiceps, Sarcophaga carnaria and Musca domestica. During this study, temperature and rainfall had little influence on the variation in the numbers of these three main species of necrophagous insects. However, the numbers of the three species were correlated with relative humidity levels.

Development of craquelure patterns in paintings on canvas

Canvas paintings are layered structures composed of canvas support sized with animal glue, a preparatory layer of the ground, and paint and varnish layers on the top. Preventing or limiting humidity-induced stresses in these structures requires an understanding of the relevant processes and risks. A three-dimensional model of a canvas painting was used to analyse stresses and crack development in the two-layer structure comprised of a glue-sized canvas on a wooden stretcher with a layer of stiff chalk-glue ground representing a pictorial layer in historic canvas paintings. The model was subjected to a large relative humidity fall which induced shrinkage of the glue-sized canvas. The modelling revealed that when a stretcher with flexible wooden bars is considered, high tensile stresses arise in the ground layer at the corners of the painting, and cracks are formed in these areas in the direction perpendicular to the painting’s diagonal. Ratios of critical distances between cracks to the ground layer thickness for which stresses in the midpoints between the cracks dropped to below the level inducing fracture in the material were estimated for various magnitudes of the relative humidity drop and thicknesses of the ground layer. Increasing ground layer thickness limits the hygric response of the sized canvas and makes the paintings less vulnerable to humidity variations. The ratio of stress along the diagonal calculated for painting with one crack to the solution without cracks was described by the double Lorentz function. A simple procedure of calculating stress variations along the diagonal—using the function—on a sequential addition of cracks was developed. Cracks in central parts of canvas painting were found to be induced by permanent cumulative drying shrinkage of the oil-based paints and grounds due to the evolution of the molecular composition of the oil binder. The outcome of the modelling indicated that the risk of cracking of the pictorial layers in canvas paintings due to drops in ambient relative humidity was small.

Impact of temperature and humidity on airway obstruction in a cohort of elderly women

Abstract Background Temperature and relative humidity (RH) impact human health. However, little is known about the combined association between temperature and RH on respiratory health in the elderly. In this study, we evaluated the interactive associations of temperature and RH on airway obstruction in elderly German women. Methods Using data from the second follow-up (2007-2010) of the German SALIA cohort study, we assessed the short-term (Lag0-8) combined association between maximum and minimum temperature (Tmax, Tmin) and RH on airway obstruction. Airway obstruction was defined as the ratio of first second of forced expiration (FEV1) / forced vital capacity (FVC) &amp;lt; 0.70. Multivariable logistic regression with a distributed lag non-linear model (DLNM) was constructed for the interaction between temperature and RH and adjusted for a single pollutant, location, socioeconomic status and smoking status. Results 735 elderly women with an average (±SD) age of 73.46 (±3.09) years were included. Around 16.73% of them had airway obstruction. For non-linear antagonistic Tmax and RH interaction models, we found a U-shaped relationship from Lag 0-8, with an immediate adverse association from Lag0-1 and a significant delayed adverse association from Lag7-8. For non-linear antagonistic Tmin and RH interaction models, the relationship was U-shaped and showed an immediate adverse association from Lag0-1, while there was also a significant delayed association from Lag6-8. Conclusions Climate change increases the likelihood of exposure to adverse temperatures and weather conditions. Vulnerable populations like the elderly are more susceptible to the adverse associations of climate change. In this epidemiological study, we found that exposure to Tmax/Tmin and RH had immediate and delayed adverse associations by increasing respiratory obstruction in elderly women. Increasing public awareness of the danger of interactions between non-optimum temperature and RH on respiratory health is crucial. Key messages • Elderly women’s respiratory health is impacted by temperature and humidity interactions, requiring awareness and proactive measures. • Climate change heightens risk for vulnerable groups, emphasising the need to address environmental impacts on health.

Proton transfer driven by the fluctuation of water molecules in chitin film.

Proton-transfer mechanisms and hydration states were investigated in chitin films possessing the functionality of fuel-cell electrolytes. The absolute hydration number per chitin molecule (N) as a function of relative humidity (RH) was determined from the OH stretching bands of H2O molecules, and the proton conductivity was found to enhance above N = 2 (80%RH). The FIR spectrum at 500-900cm-1 for 20%RH (N < 1) together with first-principles calculations clearly shows that the w1 site has the same hydration strength as the w2 site. The molecular dynamics simulations for N = 2 demonstrate that H2O molecules with tiny fluctuations are localized on w1 and w2, and the hydrogen-bond (HB) network is formed via the CH2OH group of chitin molecules. Shrinkage of the O-O distance (dOO), which synchronizes with the barrier height, is required for proton transfer from H3O+ to adjacent CH2OH groups or H2O molecules. Nevertheless, dOO is hardly modulated for N = 2 because H2O molecules are strongly constrained on w1 and w2, and therefore, the transfer probability becomes small. For N = 3, novel HBs emerged between the additional H2O molecules broadly distributed on the w3 site and H2O molecules on w1 and w2. The transfer probability is enhanced because large fluctuations and diffusions in the whole H2O molecule yield large modulations of dOO. Consequently, long-range proton hopping is driven by the Zundel-type protonated hydrates in the water network.

Transfer Learning‐Assisted Porous Polymer Humidity Sensor for Powered Air‐Purifying Mask

Masks protect respiratory health in the coal, oil, and gas industries. However, prolonged exposure to high humidity inside masks can cause discomfort and increase the risk of respiratory diseases. To address the issue, in this work, a porous polymer humidity sensor suitable for monitoring respiratory changes in high humidity environment is prepared and integrated into the power air‐purifying mask. Combined with the transfer learning algorithm, the problem with respiratory resistance caused by delayed air supply due to signal processing in the traditional power air‐purifying mask is overcome, and the respiratory signal is effectively predicted in advance, so as to achieve real‐time on‐demand air supply. The brief process is as follows: A porous polymer humidity sensor with fast response/recovery times (2.94/4.86 s) at 95% relative humidity (RH) is developed for monitoring respiratory rate changes in high humidity environments. By integrating this sensor with a powered air‐purifying system and employing a transfer learning algorithm, the system predicts respiratory signals and adjusts the air supply in real‐time. This reduces mask humidity from 95% RH to 40–50% RH in 1.8 s, ensuring comfortable, low‐resistance breathing for workers.This work will be conductive to the development of comfortable poweredair‐purifying respirators with low resistance and humidity.

How to promote health in indoor living and working spaces: quali-quantitative analysis to evaluate the indoor air quality through users’ perception and low-cost sensors

Abstract It is well-known that humans spend most of their time in indoor spaces: what it is sometimes underestimated; however, is how much the space in which someone is can affect their abilities, feelings and even their mental and physical health. A team developed a methodology to allow the collection of useful data and giving rise to management strategies for guaranteeing healthy spaces, in terms of Indoor Environmental Quality (IEQ). In particular, the methodology is based on a quali-quantitative analysis of Indoor Air Quality (IAQ) supported by a questionnaire on users’ perception and well-being, based on a scoping review, and low-cost sensors for IAQ monitoring air contaminants (carbon dioxide, temperature, relative humidity, volatile organic compounds, etc.). In particular, for the quantitative analysis, the team adopted a method that considers the location of the sensors in different typology of settings with various solar exposures, ventilation systems, human occupancy, type of activity, etc. with the scope of testing the trends in different seasons. As well as the qualitative data collect several information about the users’ perceived comfort and the symptoms (headache, fatigue, etc.) during their stay. The data analysis highlights how the different users’ perceptions affect the conditions of the environmental units, in particular in crowded rooms (4-6 people). Adequate lifestyles, such as door and window-openings, regular air-changes, etc. can highly affect the performances and the productivity, as well as the quality of the spaces. In that sense the use of low-cost sensors with light signals can be helpful as strategy for informing the user of the state of the air and any actions to be implemented. In conclusion, starting from the methodology, the team gives rise to a decalogue of strategies and good habits that permits -through the support of low-cost sensors - to inform the users on how to guarantee healthy living and working spaces.

Impact of the Indian Ocean Dipole Mode on Planetary Boundary Layer Ozone in China

AbstractThe Indian Ocean Dipole (IOD) mode exerts distinct impacts on the climate in China and can further affect tropospheric ozone. Using long‐term GEOS‐Chem simulations, we found distinct changes in planetary boundary layer ozone throughout China during positive and negative phases of IOD. In summer, ozone shows synchronized increases except in southern China during positive IOD; the ozone increases are dominated by chemical production and transport in northern and western China, respectively. The increased precursor from biogenic emissions contributed to ozone chemical formation in the northern region, and the increased precipitation and decreased solar radiation hindered ozone production in southern China. Ozone changes show good symmetry over most regions during negative IOD. In autumn, the ozone reduction in southern China shares the same reason as summer, while the chemical increase over northern China is affected more by changes in solar radiation and relative humidity than in the precursor emission.

A data-driven framework for the definition of heat in CV research for better comprehension of climate changes on human health

Abstract Background Recent literature has identified numerous combinations of meteorological indicators, methods and comparison thresholds to define heat in order to analyse its impact on adverse cardiovascular (CV) events. In fact, despite increasing attention to the issue due to ongoing climate change, there is no standardised definition of heat nor guidelines for its establishment, and in studies often little attention is given to the selected definition, despite its impact on the results. Purpose To fill this gap, our aim was to propose a data-driven framework for selecting the temperature threshold for defining heat in the context of studies on adverse CV outcomes, combining the most common approaches identified in the literature. Methods The following five-step framework is proposed: 1) Selection of temperature lags based on the contour plot obtained by the distributed lag non-linear model (DLNM); 2) Estimation of the relative risk (RR) of having a CV emergency in heat versus non-heat days by Poisson regression considering the 90th-99th percentile (%ile) of the temperature distribution for each lag; 3) Selection of the final lag based on the curvatures of the 10 included %iles; 4) Calculation of the % change in RR from %ile i to %ile i+1; 5) Selection of the heat threshold, defined as the %ile from which all the next %iles are associated with a higher % change, or, if not existing, the %ile preceding the one with the highest % change. We tested this framework, for each year, on retrospective CV emergencies in May-September 2017-2022 in Milan, Italy, using the apparent temperature data, accounting for air temperature, relative humidity and wind speed. Results The contour plot of the DLNM, controlled for air pollution, seasonality and long-term trend, showed that lags 0 and 1 were characterised by an increased RR for a CV emergency. The RR estimated for each %ile for each considered lag (i.e., heat on day i, heat on day i or on day i-1, and heat on day i and on day i-1), produced a similar curvature, so first lag option was arbitrarily selected. For Milan, the 95th %ile was the point from which all the subsequent %iles were associated to progressively higher % changes, resulting in a RR of having a CV emergency compared to non-heat days equal to 1.113 (95% CI: 1.087-1.139). The mean daily apparent temperature values associated to such %ile, varying from 27.7 °C to 29.9 °C depending on the year, should then be considered as the heat threshold in the examined context. Conclusion We proposed a flexible data-driven framework for the definition of heat that could easily be extended to similar scenarios. Although the framework still requires some arbitrary choices to be made, and the need of validation on other real-world data, it could provide a valuable guideline for relevant research, and could contribute to the standardization of heat definition for CV health research aiming at a better comprehension of climate changes on human health.