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Respiratory–swallowing coordination (RSC) is well established as an essential airway‐protective mechanism. Previous studies have used nasal airflow and/or kinematic rib cage and abdominal measures to assess respiration surrounding swallowing, meaning that the direct influence of oral respiration on RSC remains unknown. This study used a partitioned oronasal facemask to compare respiratory phase patterns measured using isolated nasal airflow with those measured using combined oronasal airflow during non‐ingestive and ingestive swallowing tasks. Twenty‐four healthy individuals with no respiratory or swallowing disorders were assessed at rest and during cued dry, 10 mL water, continuous drinking and cracker swallowing tasks. Respiratory phase patterns were determined for discrete swallows using the nasal and combined oronasal channels separately. There was variable agreement between respiratory phase patterns according to the nasal and oronasal channels across swallowing conditions. The frequency of exhale–swallow–exhale, inhale–swallow–exhale and exhale–swallow–inhale patterns increased by 2%–3% each with the addition of oral flow data to nasal data, whereas the prevalence of inhale–swallow–inhale and ambiguous patterns decreased. This suggests that estimates of respiratory phase patterns are altered minimally by inclusion of oral respiratory estimates in a healthy sample. There were several additional findings of note, including lower within‐participant, within‐session trial consistency (test–retest reliability) than expected, suggesting high variability in respiratory phase patterns across trials. Additionally, data showed evidence of swallowing non‐respiratory flow at the beginning and end of the respiratory–swallowing pause, moving in both inward and outward directions, potentially expanding current understanding of swallowing non‐respiratory flow. Further in‐depth physiological investigations are required to improve understanding of these findings. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Objective Methods Results Conclusion The role of objective nasal airflow measures using peak nasal inspiratory flow (PNIF) and rhinospirometry in supporting clinical examination findings when offering patients septoplasty remain undefined.To explore the baseline relationships between clinical examination findings, subjective reported symptoms and objective nasal patency measures in nasal obstruction.This is a sub‐study of the NAIROS trial. Participants with nasal obstruction secondary to septal deviation were included in this NAIROS sub‐study. The side of septal deviation, enlargement of inferior turbinate (IT), the need for IT reduction if septoplasty was being performed, the area of septum deflecting into the airway and observer rated airway block (ORAB–arbitrarily divided by <50% and >50% blockage) were assessed by clinicians. The subjective score of nasal obstruction was assessed using the Double Ordinal Assessed Subjective Scale (DOASS). Objective nasal patency measures (e.g., nasal partitioning ratio, [NPR] and PNIF) were measured using PNIF and rhinospirometry.The mean NPR for left‐sided, both‐sided and right‐sided septal deviation was −0.35, −0.02 and 0.51, respectively (p < 0.001). There was very weak correlation between the requirement for IT reduction and PNIF change (0.13, p < 0.01). There was no difference in mean PNIF (94 L/min vs. 93 L/min) and mean DOASS (0.33 vs. 0.38) for participants with ORAB rated <50% and >50%. The mean NPR for participants with ORAB >50% was higher than for those with ORAB <50% (0.51 vs. 0.41, p = 0.002). There was strong correlation between the DOASS and NPR (+0.737, p < 0.001). The mean DOASS score for right‐sided, both‐sided and left‐sided septal deviation was 0.32, 0.05 and −0.29, respectively (p < 0.001).This study identified strong relationships between the clinician rated side of septal deflection, the patient reported DOASS and the objective NPR measurements. NPR and the clinician rated degree of airway blockage were concordant. [ABSTRACT FROM AUTHOR]

Highlights Environmental hazards caused by the ever‐increasing end‐of‐life (EoL) glass fiber reinforced polymer (GFRPs) composite waste is of major concern for the sustainable development of the industry. Compared to land filling or incineration, pyrolysis is one of the most promising environmentally friendly methods of disposal of EoL GFRPs. Pyrolysis not only results in recovery of clean glass fibers but other valuable products, such as oils. However, long processing time at elevated temperature leads to aggravation of already existed surface flaws along with the structural changes. Therefore, thermal conditioning of glass fibers results in severe deterioration of the strength in recovered fibers and hence limiting the use of recovered fibers to low end‐products. In this study, a new strategy was adopted where instead of complete cleaning of the fibers at pyrolysis stage, the fibers were partially oxidized and the complete removal of char from the surface of glass was done during hot alkaline etching. This strategy was opted to enhance the quality of the required fibers while reducing the processing time. The results showed ~200% increase in strength of fibers after the combined treatment of pyrolysis and post etching compared to the just pyrolyzed samples with etching time of just 1 min. End‐of‐life panels of GFRPs were pyrolyzed under inert environment of Argon. Residual char was partially removed through post oxidation under flowing air. Hot alkaline etching resulted in complete removal of char and surface defects. Partial oxidation and short etching cycles resulted in improved strength of recovered glass fibers. [ABSTRACT FROM AUTHOR]

A novel plasma reactor is being investigated for green NOx production, crucial for nitrate‐based fertilizer manufacturing. Various parameters, including air flow rates, gas ratios, ozone, and catalyst effects are explored for NO → NO2 conversion. NOx concentrations reach ~0.6 vol%, with a total production of ~9.7 gr/h and energy cost of ~3.0 mJ/mol, notably favorable for atmospheric gliding arc plasma. Selectivity (~75%) towards NO2 is achieved with ozone addition or catalytic treatment, pivotal for nitrate fertilizer and HNO3 production. [ABSTRACT FROM AUTHOR]

Direct air capture (DAC) is a negative emission technology for removing CO2 from the atmosphere to maintain the CO2 level within a reasonable range so as to address greenhouse effects. In this study, the operational optimization of lab‐scale DAC has been investigated using a crossflow air‐liquid contactor loaded with a three dimensionally printed Gyroid packing structure and a potassium sarcosinate solvent. The effects of various parameters, including feed air flow rate, liquid solvent flow rate, contactor geometry, and ambient temperature, are examined. The results demonstrate that the Gyroid packing design achieves comparable CO2 capture performance to conventional packed beds but with a significantly lower pressure drop of up to 77.8%, suggesting its potential as an efficient and cost‐effective solution for gas–liquid contactors in DAC. Additionally, the study explores the climate impact on CO2 capture performance and finds that as the air temperature increases from 35 to 95°F at a fixed relative humidity of 80%, the CO2 capture rate increased from 23.2% to 46.8% with better stability. The research highlights the importance of optimizing contactor design and operational conditions to improve the CO2 capture rate and feasibility of DAC systems as a negative emission technology for addressing greenhouse effects. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The delayed drying of newly harvested tiger nuts can lead to mold and rancidity. Timely drying is therefore important. However, few studies have analyzed the impact of hot‐air drying on the quality of tiger‐nut oil and starch, making it essential to establish optimal drying conditions.The results showed that the drying temperature was the most important factor affecting the drying speed, followed by drying airflow rate and loading capacity. A logarithmic model can describe the hot‐air drying process of tiger nuts. The oil yield of tiger nut was highest after drying at 60 °C, reaching 22.40%. Meanwhile, the starch extracted from after drying at 60 °C had the highest solubility and expansion rate, 4.77% and 9.74%, respectively. Starch has the highest viscosity after drying at 70 °C, and it forms gel easily after aging.High‐quality tiger nuts should be produced under optimal conditions: a hot‐air drying temperature of 60 °C, an airflow rate of 1.0 m s−1, and a loading capacity of 100 g. The results of this study have practical implications for the effective drying of tiger nuts. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study reports satellite evidence for the most northerly blown dust activity yet observed on Earth. A systematic inspection of high‐resolution satellite imagery identified active dust events and their sources >82°N in Peary Land, Greenland. In the absence of any local weather measurements, for all observed dust activity a focus period in April 2020 with multiple dust plumes, reanalysis climate data found the majority of dust events to be associated with wind speeds exceeding a typical threshold value for blowing sand and dust uplift. Wind direction variability points to dust‐raising by cold airflow down‐valley winds, likely from nearby ice masses. [ABSTRACT FROM AUTHOR]

As the important component to guide the airflow in the classifier, installation position of the guide vane determines the width of the classification annular region and influences the flow field distribution. The influence of the guide vane positioning on the flow field in the annular region is analyzed through numerical simulation. The simulation results show the tangential velocities near the inner edge of the guide vanes increase, and the tangential velocity gradient decreases with decrease of the width of the annular region. The increases of turbulent dissipation rate near the guide vanes are beneficial to powder dispersion. However, the increases of turbulent dissipation rate near the rotor cage aren′t conducive to uniformity of the flow field. In case of the narrow annular region, the cut size gradually increases when the width of the annular region increases. However, when the width of the annular region continues to increase, the particle′s residence time become long, and the solid concentration increases significantly to increase the probability of particle aggregation. The reasonable range of the installation diameter of the guide vane in the classifier is between 504 mm and 524 mm. [ABSTRACT FROM AUTHOR]

This study aimed to assess the technical feasibility of incorporating selenized Lactobacillus spp. microencapsulated via spray drying into cattle feed. Gum Arabic and maltodextrin were used as encapsulating agents. The encapsulation process was carried out with a drying air flow rate of 1.75 m3/min, inlet air temperature of 90°C, and outlet air temperature of 75°C. The viability of the encapsulated microorganisms and the technological characteristics of the obtained microparticles were evaluated. Microorganisms were incorporated into beef cattle feed to supplement their diet with up to 0.3 mg of Se per kilogram of feed. The encapsulated particles, consisting of a 50/50 ratio of gum Arabic/maltodextrin at a 1:20 proportion of selenized biomass to encapsulant mixture, exhibited superior technical viability for application in beef cattle feed. Supplemented feeds displayed suitable moisture, water activity, and hygroscopicity values, ensuring the preservation of viable microorganisms for up to 5 months of storage, with an approximate count of 4.5 log CFU/g. Therefore, supplementing beef cattle feed with selenized and microencapsulated lactic acid bacteria represents a viable technological alternative, contributing to increased animal protein productivity through proper nutrition. [ABSTRACT FROM AUTHOR]

Humidification and dehumidification (HDH) desalination units compared with the other thermal desalination systems have relative advantages due to working under ambient pressure and low temperatures and are more attractive. In this research, the application of an HDH desalination unit with indirect‐contact of air and water streams in a steam power plant is investigated. To increase the energy efficiency of the system, a closed air cycle has been considered. Also, by application of the closed water cycle in the humidifier, the recovery rate of the desalination unit increases according to the concentration of discharge flow. The flow rate of boilers blowdown in the studied steam power plant is around 2.2 kg/s and can be used as a unique source of required thermal energy in the desalination system to produce freshwater from power plant chemical effluents. On the basis of the available cooling water (30 m3/day), this stream is considered as the limiting flow in the modeling. The detailed design of different parts of the desalination unit, including the humidification tower, condensers, wet air circulation fans, the required pumps, and the heat exchanger, is presented in this study. The maximum production of freshwater and the minimum energy intensity are obtained for the circulating air flow rate of 4 kg/s. By 14% recovery of lost steam in the power plant, 20.8 m3/h of desalinated water is produced. The gain output ratio and the energy intensity of the system are 1.025 and 2201 kJ/L, respectively. The production cost with the proposed indirect‐constant HDH system is equal to 0.56 $/m3 of freshwater. [ABSTRACT FROM AUTHOR]

The goal of the current study is to determine how the SST k−ω$$ k-\omega $$ and the standard k−ɛ$$ k-\varepsilon $$ turbulence models prediction on PCM with cylindrical configuration affect AC performance and PCM discharging when coupled with an AC unit. For simulation, 308.15 K and 318.15 K, the inflow air temperature has been considered with a fixed 33.6 L/s intake air flow rate. The low outside temperature charges the PCMs during the night. During the daytime, heated ambient air is cooled by the PCM heat exchanger before passing over the unit condenser. The present outcomes show that using the standard k−ε$$ k-\varepsilon $$ model, the cylindrical PCM has the lowest time of complete melting. The temperature contours demonstrate that turbulence occurs, particularly at higher temperatures, in the PCM melting zone within the solid region. This implies that there is increased convection in this area. The maximum improved percentage in COP increases as the rising input air temperature for both turbulence models increases. The average power saving of AC at 308.15 K of an input air temperature for 83.33 min is predicted by both the standard k−ɛ$$ k-\varepsilon $$ and the SST k−ω$$ k-\omega $$ to be 14.0905 W and 14.1089 W, respectively. [ABSTRACT FROM AUTHOR]

Considering that nearly 39% of the total CO2 emission released into the atmosphere today are thought to be due to the energy consumed by buildings, the importance of taking measures through buildings to combat global warming is evident. Therefore, the concept of nearly zero‐energy buildings (NZEB) is come to the forefront. Building integrated photovoltaic thermal (BIPV/T) systems are used to enable buildings to generate their own energy. However, buildings have limited facade and roof areas required for BIPV/T systems. Therefore, in this study, various configurations of bifacial (double‐sided) and monofacial (single‐sided) panels were compared to investigate ways to enhance the efficiency of BIPV/T systems. Different air flow velocities and varying air gap distances were tested for both panel types. By placing a reflective surface on the wall behind the bifacial panel, the electrical efficiency of the bifacial panel was increased and proven through PVsyst analysis. Both panels provided maximum heat efficiency at the shortest air gap distance under high air flow conditions. In addition, it was shown in both the experimental setup and Comsol CFD analysis that it provides significant benefit in the thermal energy load of the building when heating the interior environment in winter. In terms of electrical power production surplus, the bifacial panel outperformed the monofacial panel in all configurations, with a minimum advantage of 8.33% and a maximum of 12.73%. Additionally, the maximum electrical efficiency was obtained from the bifacial panel in configurations with the longest air gap distance. Using the bifacial panel in the BIPV/T system with the shortest air gap distance during the heating season and the longest air gap distance during other seasons can provide the highest efficiency for the building throughout the year. [ABSTRACT FROM AUTHOR]

The practical application of fiber membranes prepared by electrostatic spinning requires a uniform thickness. However, the parameters involved in the spinning process are highly complex, particularly when it comes to precise control over membrane thickness. Hence, achieving a consistent and homogeneous thickness for fiber membranes has posed significant challenges thus far. To accurately predict membrane thickness during the spinning process and ensure consistent outcomes, this study employed polyvinylidene fluoride as the raw material and optimized electrostatic spinning preparation using an innovative airflow‐assisted strategy. The as‐proposed preparation strategy effectively enhances the volatilization of solvents within the jet, also promotes jet stretching through assistance from airflow, resulting in a more stable and homogeneous fiber diameter. Additionally, COMSOL simulations were utilized to provide rational explanations for these findings. By collecting multiple process parameters, including positive voltage, liquid supply speed, winding speed, and solution concentration, this study has successfully developed an artificial neural network (ANN) that exhibits reliable predictive capabilities for membrane thickness. Notably, the model demonstrates a remarkable goodness‐of‐fit with an R2 value of 0.9981. Through the integration of ANN with electrostatic spinning technology, significant advancements have been achieved in accurately predicting and controlling the uniformity of electrostatically spun polymer fiber membranes. [ABSTRACT FROM AUTHOR]

Background: Computed tomography (CT) offers pulmonary volumetric quantification but is not commonly used in healthy individuals due to radiation concerns. Chronic airflow limitation (CAL) is one of the diagnostic criteria for chronic obstructive pulmonary disease (COPD), where early diagnosis is important. Our aim was to present reference values for chest CT volumetric and radiodensity measurements and explore their potential in detecting early signs of CAL. Methods: From the population‐based Swedish CArdioPulmonarybioImage Study (SCAPIS), 294 participants aged 50–64, were categorized into non‐CAL (n = 258) and CAL (n = 36) groups based on spirometry. From inspiratory and expiratory CT images we compared lung volumes, mean lung density (MLD), percentage of low attenuation volume (LAV%) and LAV cluster volume between groups, and against reference values from static pulmonary function test (PFT). Results: The CAL group exhibited larger lung volumes, higher LAV%, increased LAV cluster volume and lower MLD compared to the non‐CAL group. Lung volumes significantly deviated from PFT values. Expiratory measurements yielded more reliable results for identifying CAL compared to inspiratory. Using a cut‐off value of 0.6 for expiratory LAV%, we achieved sensitivity, specificity and positive/negative predictive values of 72%, 85% and 40%/96%, respectively. Conclusion: We present volumetric reference values from inspiratory and expiratory chest CT images for a middle‐aged healthy cohort. These results are not directly comparable to those from PFTs. Measures of MLD and LAV can be valuable in the evaluation of suspected CAL. Further validation and refinement are necessary to demonstrate its potential as a decision support tool for early detection of COPD. [ABSTRACT FROM AUTHOR]

This study aimed to explore the variability in nasal airflow patterns among different sexes and populations using computational fluid dynamics (CFD). We focused on evaluating the universality and applicability of dimensionless parameters R (bilateral nasal resistance) and ϕ (nasal flow asymmetry), initially established in a Caucasian Spanish cohort, across a broader spectrum of human populations to assess normal breathing function in healthy airways. In this retrospective study, CT scans from Cambodia (20 males, 20 females), Russia (20 males, 18 females), and Spain (19 males, 19 females) were analyzed. A standardized CFD workflow was implemented to calculate R‐ϕ parameters from these scans. Statistical analyses were conducted to assess and compare these parameters across different sexes and populations, emphasizing their distribution and variances. Our results indicated no significant sex‐based differences in the R parameter across the populations. However, moderate sexual dimorphism in the ϕ parameter was observed in the Cambodian group. Notably, no geographical differences were found in either R or ϕ parameters, suggesting consistent nasal airflow characteristics across the diverse human groups studied. The study also emphasized the importance of using dimensionless variables to effectively analyze the relationships between form and function in nasal airflow. The observed consistency of R‐ϕ parameters across various populations highlights their potential as reliable indicators in both medical practice and further CFD research, particularly in diverse human populations. Our findings suggest the potential applicability of dimensionless CFD parameters in analyzing nasal airflow, highlighting their utility across diverse demographic and geographic contexts. This research advances our understanding of nasal airflow dynamics and underscores the need for additional studies to validate these parameters in broader population cohorts. The approach of employing dimensionless parameters paves the way for future research that eliminates confounding size effects, enabling more accurate comparisons across different populations and sexes. The implications of this study are significant for the advancement of personalized medicine and the development of diagnostic tools that accommodate individual variations in nasal airflow. [ABSTRACT FROM AUTHOR]

This experimental investigation aimed to analyze the impact of a unique design of swirl generator airflow on the performance of a tubular heat exchanger operating with axial flow. To conduct the experiment, we utilized a custom‐built apparatus containing eight sawtooth air deflectors with differing space height ratios (e/h). These deflectors were oriented in a uniform manner (shutter type) and positioned at various inclination angles. Circular baffle plates, housing these deflectors, were equidistantly spaced at different pitch ratios. The arrangement of tubes within the heat exchanger remained constant throughout the study, while the Reynolds number ranged from 16,000 to 30,000. In addition, a consistent heat flux condition was maintained on the surface of the tubes. The research outcomes indicated that incorporating a deflector baffle plate with an inclination angle of 30°, an e/h ratio of 0.4, and a pitch ratio of 1.2 led to an average increase of 1.36 in the thermal enhancement factor when compared to a heat exchanger lacking a baffle plate, tested under similar conditions. [ABSTRACT FROM AUTHOR]

Background and Objective: The use of small airway parameters generated by spirometry, namely forced expiratory flow between 25% and 75% of forced vital capacity (FVC) (FEF25%–75%) and forced expiratory flow at 50% and 75% of FVC (FEF50% and FEF75%, respectively), is widely discussed. We evaluated the importance of these spirometric parameters in a large Chinese population. Methods: We conducted a cross‐sectional observational study in which spirometry and bronchodilator responsiveness (BDR) data were collected in a healthcare centre from May 2021 to August 2022 and in a tertiary hospital from January 2017 to March 2022. Discordance was assessed between the classification of test results by the large airway parameters of forced expiratory volume in 1 second (FEV1) and FEV1/FVC ratio and by the small airway parameters of FEF25%–75%, FEF75% and FEF50%. The predictive power of Z‐scores of spirometric parameters for airflow limitation and BDR was assessed using receiver operating characteristic curves. Results: Our study included 26,658 people. Among people with a normal FVC (n = 14,688), 3.7%, 4.5% and 3.6% of cases exhibited normal FEV1/FVC ratio but impaired FEF25%–75%, FEF75% and FEF50%, respectively, while 6.8%–7.0% of people exhibited normal FEV1 but impaired FEF25%–75%, FEF75% and FEF50%. Using the Z‐scores of combining both large and small airway parameters in spirometry showed the best area under the curve for predicting airflow limitation (0.90; 95% CI 0.87–0.94) and predicting BDR (0.72; 95% CI 0.71–0.73). Conclusion: It is important to consider both large and small airway parameters in spirometry to avoid missing a diagnosis of airflow obstruction. [ABSTRACT FROM AUTHOR]

To study the air‐suction separation mechanism of fresh tea leaves, this article adopts the coupling simulation method of discrete elements and computational fluid dynamics to conduct numerical simulation and experimental research on the movement of fresh tea leaves adsorbed by negative pressure air flow. In the gas–solid coupling model, three‐dimensional scanning technology is applied to establish a three‐dimensional model of fresh tea leaves with one bud and two leaves. Through the Fluent module in CFD, the negative pressure adsorption gas phase of the simulation process was established, bench tests were established, and parameters of the coupling model were optimized. Finally, the minimum error between the simulated value and the test value was 2.85% and the maximum error was 7.43%, indicating that the coupling model established had certain accuracy and could be theoretically analyzed according to the coupling model established. It is found that when the static pressure values of the adsorption surface are −120 Pa, −340 Pa, and −500 Pa respectively, the initial distance from the adsorption surface is 250–550 mm. It is found that fresh tea leaves with one bud and two leaves all fall to the pipe before adsorption, and then move to the adsorption surface. Under the same static pressure value of the adsorption surface, the initial falling distance of tea particles from the adsorption surface (250–550 mm) has a linear function relationship with the distance between the turning point and the adsorption surface. When the initial distance between falling tea particles and the adsorption surface is the same, the distance between the turning point and the adsorption surface is an exponential function when the initial position is 250–350 mm from the adsorption surface, and the distance between the turning point and the adsorption surface is a linear function when the initial position is 400–550 mm from the adsorption surface. [ABSTRACT FROM AUTHOR]

Barchan dunes do not often coexist with grasslands. However, in Gonghe Basin, north‐eastern part in Qinghai‐Tibetan Plateau (QTP), China, many barchan dunes are distributed on the grassland at high altitude. Identifying celerity and morphodynamics of barchan dunes and exploring the interaction between barchans and grassland landscape can help us better understand aeolian system sand mitigate damages. In this work, we tracked dune celerity and observed three‐dimensional changes of symmetrical and asymmetrical barchan dunes in Ertala based on high‐resolution UAV‐SfM reconstruction in short‐term monitoring and discussed the factors influencing dune celerity and deformation at high altitude. The results revealed that the barchan dunes are highly mobile with an average celerity of 0.85 m/M for the whole study area. Based on observations of dune morphology and dynamics, we found the following: (1) The dune deformation degree in a short time is not large but is widespread, especially in the elongated arm of asymmetric dune. The deformation of symmetric dune is symmetrical, whereas that of dune with extended horn is asymmetrical; (2) the sand supply, vegetation and airflow at low air density all influence the celerity and deformation degree in the development of barchan dunes; (3) the asymmetric airflow and sediment supply are important cause of dune asymmetry. The above results help us understand the deformation of barchan dune from the three‐dimensional, especially the difference reflected by the symmetry of barchan dune at high altitude. [ABSTRACT FROM AUTHOR]

In this paper, a novel air‐cooled supercapacitor thermal management system (STMS) based on the corner deflectors and the inclined inlet and outlet was proposed. The temperature and velocity fields were simulated and analyzed by CFD. Moreover, the heat dissipation effect of different STMSs was analyzed against each other. The results showed that the STMS proposed had a better heat dissipation effect when the inclined angle of inlet and outlet was appropriate, in which the maximum temperature (Tmax) and the maximum temperature difference (ΔTmax) of the module could be reduced by 10.3% and 34.6%. And it is shown that the structure with inclined inlet and outlet plays an important role for the heat dissipation capability of the STMS proposed. And it has experimentally proven its heat dissipation ability. Consequently, the impacts of inclined angle (α), monomer spacing (dc), and the distance between monomer and module shell (dx, dy, and dz) on the heat dissipation effect were deeply analyzed. For the STMS arranged in four rows and three columns, it had a better heat dissipation effect when inclined angle was in the range of 40° to 50°. The results showed that the structural parameters had a large influence on the Tmax and ΔTmax. Besides, it had shown that the temperature curves of the Tmax and ΔTmax had a main trend of “decreasing and then increasing” when the monomer spacing as well as the distance between monomer and module shell are taken from 1 mm to 5 mm. It implies that a small spacing (1 mm to 2 mm) will hinder the air circulation and reduce heat dissipation, and a large spacing (3 mm to 5 mm) will reduce the average flow rate of air and reduce the efficiency of heat transfer. [ABSTRACT FROM AUTHOR]

The airport line plays an important role in the airport landside traffic connection, which greatly relieves the urban road pressure. Studying the characteristics and laws of the time and space distribution of the airport line passenger flow will provide basic support for the airport line's capacity configuration, passenger flow control, and air‐track coordinated operation, and will also provide quantitative basis for the layout of urban terminal buildings. This paper proposes a method to analyse the temporal and spatial distribution characteristics of airport line passenger flow based on AFC card swiping data. By mining and extracting the travel behaviour data of subway airport line air passengers, the distribution characteristics of airport line passenger flow are analysed and visualized from two aspects of passenger travel time and space. Finally, a case study is carried out based on the actual data of Daxing airport express. The results show that: (1) the travel time of departure and return passengers is concentrated in 60–90 min; (2) The departure and arrival points of passengers are concentrated within the Fourth Ring Road, and a large number of air passenger flows are gathered and evacuated at hubs such as Beijing South Railway Station and Beijing West Railway Station. [ABSTRACT FROM AUTHOR]

The efficiency and dynamic response of air compressors are crucial for stability and lifespan of hydrogen fuel cells. A predictive control scheme with surge‐ and choke‐constrained awareness is proposed to ensure safe and efficient operation of air compressors in this study. The proposed scheme consists of an efficiency enhancement model predictive control (EE‐MPC), and an improved active disturbance rejection control (IADRC). Surge‐ and choke‐constrained awareness is achieved by comparing predicted air flow with surge and choke limitations. Simultaneously, the EE‐MPC is constrained with oxygen excess ratio (OER) and obtains optimal solution by searching active set. The reference flow and supply manifold pressure trajectories for IADRC are generated by EE‐MPC. A designed piecewise differentiable nonlinear smoothing function is embedded in IADRC. The disturbances are estimated for coordinating flow and pressure control. Under China heavy‐duty commercial vehicle test cycle for bus conditions, root‐mean‐squared errors (RMSEs) of flow and pressure are 3.27 g s−1 and 1.88 × 103 Pa, respectively, and the mean efficiency can be enhanced by 13.4% compared to the MPC with fixed OER. Finally, a controller hardware‐in‐the‐loop test is conducted, with flow and pressure RMSEs of 2.48 g s−1 and 4.28 × 103 Pa between the test and simulation, respectively. [ABSTRACT FROM AUTHOR]

For shallow buried mines, the cracks generated due to the mining activities will connect the surface ground and the working face through the gob, which may result in the gas exchange between the surface and underground. In this study, we proposed the gob gas flow model and verified its applicability based on the measured data on site in our previous research and discussed the effect of delay time of pressure variation between working face and surface ground on the airflow direction according to the simulation. The results suggest that the delay time of pressure variation is the main factor affecting the pressure difference between surface and working face and airflow direction. Due to the characteristics of the surface pressure changes, the effect of delay time on airflow in gob is small in a short time, but this effect gradually increases with time. According to the airflow law in a cycle of pressure variation, the airflow direction in the gob is predictable when the delay time reaches a certain value, which can be interpreted clearly on the surface pressure variation diagram. This research may provide references for the measures taken against mine disasters caused by different airflow directions. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The present study focuses on heat transfer in ventilated caves for which the airflow is driven by the temperature contrast between the cave and the external atmosphere. We use a numerical model that couples the convective heat transfer due to the airflow in a single karst conduit with the conductive heat transfer in the rock mass. Assuming dry air and a simplified geometry, we investigate the propagation of thermal perturbations inside the karst massif. We perform a parametric study to identify general trends regarding the effect of the air flowrate and conduit size on the amplitude and spatial extent of thermal perturbations. Numerical results support the partition of a cave into three regions: (a) a short (few meters) diffusive region, where heat mainly propagates from the external atmosphere by conduction in the rock mass; (b) a convective region where heat is mainly transported by the air flow; (c) a deep karst region characterized by quasi‐constant temperatures throughout the year. Numerical simulations show that the length of the convective region is approximately proportional to the amplitude of the flowrate annual fluctuations divided by the square root of the cave radius. This result is tested against field data from a mine tunnel and two caves. Our study provides first estimates to identify climate sensitive regions for speleothem science and/or ecosystemic studies. Plain Language Summary: Karsts are landscapes formed from the dissolution of soluble rocks. The chemical erosion due to rainwater results in the formation of an extensive network of caves traversed by air and water flows. Understanding heat transfer in karst is a key issue in many fields, as diverse as study of underground biota or paleoclimate reconstruction. The present work focuses on heat transfer in ventilated caves for which the airflow is driven by the temperature contrast between the cave and the external atmosphere. In winter, the air inside the massif is hotter (and thus lighter) than the air outside. This situation results in an upward airflow as in a chimney. The airflow is reversed in summer (colder and thus heavier air inside the massif). Assuming a simplified geometry, we investigate by numerical simulations the propagation of thermal perturbations inside a single ventilated conduit. The results of the numerical simulations are tested against field data from a mine and two caves. We show that in ventilated caves, the airflow can propagate the annual temperature fluctuations over distances from the entrance ranging from a few tens to a few hundreds of meters. In extreme cases, it could go up to kilometers. Our study provides first estimates to identify climate sensitive regions for speleothem science and/or ecosystemic studies. Key Points: A numerical model was developed to investigate heat transfer inside ventilated caves driven by chimney effectThe airflow can propagate annual temperature fluctuations over a few tens to a few hundreds of meters from the cave entrance (over kilometers in extreme cases)The distance of propagation (the convection length) is approximately proportional to the airflow rate and inversely proportional to the square root of the cave diameter [ABSTRACT FROM AUTHOR]

Summary: We investigate the transmission of aerosol particles in an airplane cabin with a joint approach using experiments and simulation. Experiments were conducted in a realistic aircraft cabin with heated dummies acting as passengers. A Sheffield head with an aerosol generator was used to emulate an infected passenger and particle numbers were measured at different locations throughout the cabin to quantify the exposure of other passengers. The same setting was simulated with a computational fluid dynamics model consisting of a Lagrange continuous phase for capturing the air flow, coupled with a Lagrange suspended discrete phase to represent the aerosols. Virtual measurements were derived from the simulation and compared with the experiments. Our main results are: the experimental setup provides good measurements well suited for model validation, the simulation does correctly reproduce the fundamental mechanisms of aerosol dispersion and simulations can help to improve the understanding of aerosol transmission for example by visualizing particle distributions. Furthermore, with findings from the simulation it was possible to crucially improve the experimental setup, proving that feedback between the numerical and the hardware world is indeed beneficial. [ABSTRACT FROM AUTHOR]

Corn that are not properly dried can result in a lot of waste. Therefore, in this study, the corn pile was used as porous medium for hot air drying, and the coupling method of multiple physical fields was used to simulate and analyze the corn air‐drying silo with different initial conditions and different sizes. The results show that increasing the temperature of hot air could increase the temperature gradient inside corns and promote the evaporation of water. The higher the wind speed, the better the convective heat transfer effect between corn and air, thus improving the drying efficiency. The smaller the ratio of height to diameter of air‐drying silo, the more corn dried in the direction of hot air flow, resulting in poor drying effect. Increasing the inner diameter of the air‐drying silo will reduce the heat transfer efficiency. The lower the bed of the air‐drying silo, the closer the corns are to the hot air inlet, the faster the heating rate and the better the drying effect. The model has good performance and can be used as a mathematical tool to predict the change of maize wet heat field. Practical applications: In order to solve the integral problem of corn drying, the model uses corn grain pile as porous medium for hot air drying. The model investigated the changes of temperature field and humidity field during the drying process of grain pile in corn air‐drying silo. In addition, the characteristics of the model introduced in this study may qualify it for automatic control of corn air‐drying silo and online prediction of drying times to achieve the desired drying effect. [ABSTRACT FROM AUTHOR]

Using large eddy simulation, we investigate the combined effect of terrain and surface sensible heat flux (SHF) heterogeneity on the development of afternoon deep moist convection (DMC). We implement an analytically derived, two‐dimensional terrain and SHF variations transformed from a κ−3 (where κ is the wavenumber) spectrum spanning wavelengths from 32 to 0.2 km. By separately coupling multiscale terrain with a homogeneous SHF field and the multiscale SHF field with flat terrain, we discern the individual impacts of these κ−3‐spectrum forcings on DMC. Our specific forcing configuration demonstrates that the multiscale terrain had a greater influence on DMC development compared to the multiscale SHF field. While the solely surface SHF heterogeneity forcing results in a wider pool of high relative humidity above the boundary layer, its significance is relatively lower in the mountainous terrain cases due to the shorter interaction time between highly buoyant thermals and the surrounding environment. However, when the multiscale terrain and SHF field are synchronized, DMC develops rapidly within a time frame of 4.5 hr, which is facilitated by enhanced surface buoyancy fluxes, the presence of highly buoyant thermals, and the persistence of mesoscale structures such as near‐surface convergence and mesoscale updrafts. Our study highlights the importance of the synergistic effects between multiscale terrain and surface SHF heterogeneity in DMC development. Additionally, our multiscale analyses of atmospheric variables reveal distinct atmospheric regimes between the pre‐storm and DMC periods. These findings contribute to a better understanding of the complex dynamics involved in the formation of afternoon DMC. Plain Language Summary: Our research used a high‐resolution model to explore how clouds and precipitation form in the afternoon in response to spatial variations in surface thermal properties and terrain height. Specifically, we analyze the effects of multiscale terrain height variation and surface thermal variation that is warmer and drier over higher terrain and cooler and moister over lower terrain. This is a realistic representation of how summits and valleys are differently heated in a mountainous area. Air flow moving up toward higher terrain is caused by both the difference in pressure between the summit and valley, as well as the varying thermal properties across the surface. To see the effects of each factor, we ran two additional simulations with a flat surface and homogeneous thermal properties. On the surface with thermal properties covarying with terrain height, a storm with rain quickly formed by 1500 local time. This study suggests that the contrasting thermal properties of warm summits and cool valleys greatly increase the chances of severe thunderstroms forming. Key Points: Multiscale surface‐thermal variation in phase with terrain has a stronger impact on moist convection than any single variationAn air pool of high humidity above the boundary layer has a lesser effect over mountainous terrain compared to surface thermal variationMesoscale variance of atmospheric variables significantly rises post onset of deep moist convection [ABSTRACT FROM AUTHOR]

Accurate measurement of complicated multiphase flow is crucial to the safety and efficiency of petroleum and chemical industrial facilities. However, the existing multiphase flow detection techniques are not applicable to pipelines in remote regions including deserts or deep seas, due to the high cost of providing a stable power supply. Herein, a self‐powered multiphase flow sensor, composed of a liquid‐driven triboelectric nanogenerator (TENG) ‐based signal generator, a ring‐type transmitter, and a string‐type receiver, is proposed. Theoretical modeling of displacement current between transmitter and receiver implies that the received current signal can accurately reflect the wetting state of the receiver, validated by a combined experimental (accuracy above 97%) and simulation study. Coupling with a quantitative analysis algorithm, a multiphase flow detection system with numerous receiver measurement points is developed to precisely monitor various flow parameters, including slug frequency (one point), slug length (two points), and flow pattern (four points), which is verified by spontaneous high‐speed camera recordings of water–air flow. The present work provides a paradigm‐shift way to develop a self‐powered, inexpensive, and accurate technique to detect multiphase flow at remote industrial facilities. [ABSTRACT FROM AUTHOR]

There are many factors that may affect the longevity of or guide the use of canine training aids. Literature to date has mainly focused on identifying the headspace volatiles associated with training aids or odors and only minimal research exists into how different variables may alter those volatiles. The current study examines several factors affecting canine training aids: humidity, air flow, transportation, and operational deployment, using the triacetone triperoxide polymer odor capture-and-release canine training aid (TATP POCR) as the target. The TATP POCR is an absorption-based canine training aid developed to be used to safely train canines to detect the odor of the explosive TATP in operational settings. Comparisons of the TATP POCR to neat TATP are made throughout the manuscript. First, humidity increased the background components of the POCR matrix, as well as the amount of TATP recovered was above the POCR. Humidity thus affected the amount of TATP detected but did not prevent detection. Second, air flow lessened the lifetime of the TATP POCR. Third, the practice of using primary and secondary containment successfully prevented contamination, cross-contamination, and significant target loss, thereby maintaining kit integrity. Finally, the absorption of background odors from training environments was not observed. TATP headspace concentrations between a Deployed and Control POCR kit were not significantly different at time 0 (i.e., upon opening), which suggests that the operational use does not affect the function of the TATP POCR system. This information provides pivotal evidence for explosives detection canine handlers or trainers who utilize the TATP POCR. [ABSTRACT FROM AUTHOR]

Present wearable sensors are able to measure the frequency of vital signs such as respiration rate and heartbeat rate, but unable to measure those quantitatively, e.g. respiratory volume and heartbeat strength. Meanwhile, airflow at mouth contains both the respiration and the heartbeat quantitative signals. In this study, we propose a calibration method for a wearable vital sensor attached on the chest using the airflow at the mouth for quantitative respiration monitoring. An artificial ventilator and an experimental animal were introduced as test benches prior to human clinical experiment. As a proof of concept, a micro‐electro mechanical systems (MEMS) airflow sensor and a wearable accelerometer were implemented to both the test benches. The velocity output of the piston motion measured by the wearable sensor conformed with the airflow rate output, and the obtained results indicated that the wearable sensor can monitor not only the frequency of vital signs but also quantitative magnitudes such as the respiratory volume. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Respiratory diseases, including the cronic obstructive pulmonary disease (COPD) are among the leading causes of death worldwide. To date, there is no physical examination procedure that can quantify important parameters within a specific lesion area inside the lung. In this study, we propose a novel sensor probe system consisting of a basket forceps and 2 pressure sensors to simultaneously measure the expiratory airflow and the static pressure inside the pulmonary airway. A Pitot tube mechanism using 2 pressure sensors is introduced in the system for measuring both the physical quantities. Small fiber‐optic pressure sensors with 0.3 mm diameter were utilized, and both the airflow rate and the static pressure characteristics were evaluated for obtaining the calibration curves. Finally, the proposed sensor system was implemented to measure both the airflow and pressure in an artificial ventilator and an experimental animal. The measurement of expired airflow and static pressure inside the airway of a rat with the diameter of 1.8 mm were demonstrated. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper aims to explore machine learning techniques for post‐processing high‐resolution Numerical Weather Prediction (NWP) products for the early detection of convection. Data from the Arome Ensemble Prediction System and satellite observations from the Rapidly Developing Thunderstorm (RDT) product by Météo‐France are used to train a recurrent neural network model to predict areas of total convection and moderate convection. The learning task is formulated as a binary classification problem using a long short‐term memory (LSTM) network architecture. Results from the LSTM model are compared with an object‐based probabilistic approach to forecast convection using metrics such as a receiver operating characteristics (ROC) curve, the Brier score and reliability. Results indicate that the LSTM model performs similarly to the object‐based probabilistic benchmark when classifying moderate convection areas and shows improved skill when classifying areas of total convective. Finally, the LSTM model results are presented within an air traffic management context to showcase the potential use of machine learning models within an operational application. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is a semi‐crystalline polymer that displays simple manufacturing, high stiffness, lightweight, chemical resistance, and inexpensive. However, PP has significant drawbacks, such as poor brittleness at low temperatures, high shrinkage ratio, and low impact resistance, which limit its development. Thermoplastic polyurethane (TPU) possesses recyclable and eco‐friendly characteristics, along with the elasticity of rubber and exceptional mechanical properties. In this study, a flexible and high‐filtration performance PP‐TPU textile material was developed by melt‐blowing for filtering PM0.3 aerosols. For the first time, a melt‐blown PP‐TPU nonwoven was used as an air filter. The fiber morphological studies exhibited that addition of 10 and 20 wt.% TPU into PP resulted in a fiber diameter increment from 0.94 to 1.24 μm. Also, melt‐blown PP‐TPU forms helical fibers, which are different from fibers noticed in melt‐blown PP. Corona‐charged double‐layer 80PP‐20TPU nonwovens have a filtration efficiency of 99.25% and quality factor (QF) of 0.13 mm H2O−1 at an air flow rate of 95 L/min. Moreover, PP's tensile strength was increased by 72.22%, and elongation was raised by 38.1% with the addition of 20 wt.% TPU. Thus, PP‐TPU melt‐blown composites may bring novel perspectives into the design and development of high‐performance filtering materials for a variety of applications. [ABSTRACT FROM AUTHOR]

Purpose: Various parameters of regional lung ventilation can be estimated using phase‐resolved functional lung (PREFUL)‐MRI. The parameter "ventilation correlation coefficient (Vent‐CC)" was shown advantageous because it assesses the dynamics of regional air flow. Calculating Vent‐CC depends on a voxel‐wise comparison to a healthy reference flow curve. This work examines the effect of placing a reference region of interest (ROI) in various lung quadrants or in different coronal slices. Furthermore, algorithms for automated ROI selection are presented and compared in terms of test–retest repeatability. Methods: Twenty‐eight healthy subjects and 32 chronic obstructive pulmonary disease (COPD) patients were scanned twice using PREFUL‐MRI. Retrospective analyses examined the homogeneity of air flow curves of various reference ROIs using cross‐correlation. Vent‐CC and ventilation defect percentage (VDP) calculated using various reference ROIs were compared using one‐way analysis of variance (ANOVA). The coefficient of variation was calculated for Vent‐CC and VDP when using different reference selection algorithms. Results: Flow‐volume curves were highly correlated between ROIs placed at various lung quadrants in the same coronal slice (r > 0.97) with no differences in Vent‐CC and VDP (ANOVA: p > 0.5). However, ROIs placed at different coronal slices showed lower correlation coefficients and resulted in significantly different Vent‐CC and VDP values (ANOVA: p < 0.001). Vent‐CC and VDP showed higher repeatability when calculated using the presented new algorithm. Conclusion: In COPD and healthy cohorts, assessing regional ventilation dynamics using PREFUL‐MRI in terms of the Vent‐CC metric showed higher repeatability using a new algorithm for selecting a homogenous reference ROI from the same slice. [ABSTRACT FROM AUTHOR]

The role of coherent airflow structures capable of setting gravel‐sized particles in motion is studied theoretically and experimentally. Specifically, a micromechanical model based on energy conservation is proposed to describe the incipient motion of large‐particles ranging from rocking (incomplete entrainment) to incipient rolling (full entrainment). Wind tunnel experiments were conducted on an aerodynamically rough bed surface under near‐threshold airflow conditions. Synchronous signals of airflow velocities upwind of the test particles and particle displacement are measured using a hot film anemometer and a laser distance sensor, respectively, from which coherent airflow structures (extracted via quadrant analysis) and particle movements are interlinked. It is suggested that the incipient motion of gravel‐sized particles (rocking and rolling) may result from sufficiently energetic sweep events corresponding to aerodynamic drag forces in excess of the local micro‐topography resistance. However, full entrainment in rolling mode should satisfy the presented work‐based criterion. Furthermore, using an appropriate probabilistic frame, the proposed criterion may be suitable for describing processes of energy transfer from the wind to the granular soil surface, ranging from the creep transport of gravels to the "mechanical sieving" of mega‐ripples, as well as the transport of light anthropogenic debris (such as plastics). Plain Language Summary: Entrainment of particles from a particle bed is a key problem in wind‐driven sediment transport. Most existing models define critical entrainment conditions as those at which a bed particle begins to move. Such conditions are typically met during the passing of turbulent flow structures. However, the energy transferred from the structure to the particle may not be sufficient to leapfrog over neighboring bed grains. In this case, the particle will eventually fall back into its bed pocket. Here, we experimentally evaluate an alternative work‐based criterion for particle entrainment during the passing of turbulent flow structures. Our results indicate that sweeps of sufficient turbulent energy are predominantly responsible for particle entrainment. Key Points: Coherent airflow sweep structures exerting sufficient drag force can set coarse particles in motionA work‐based criterion has been established to define the full aerodynamic entrainment of coarse particlesThe proposed criterion agrees with wind tunnel experimental observations [ABSTRACT FROM AUTHOR]

This article presents a novel airflow rate sensing method based on the principle of a hot‐film flow sensing device with data‐driven machine learning (ML) models. In addition, to combine the two signals of the sensor (the resistance changes of the heaters) and predict the output (airflow rate), three different ML multivariate regression models, i.e., multiple linear regression (MLR), k‐nearest neighbor (KNN), and deep neural network (DNN) models, are trained and compared using 8400 experimentally obtained data. Using sensor fusion techniques, the average mean absolute error (MAE) and mean squared error (MSE) of the KNN model are determined to be 0.01522 and 0.00132, respectively, in the range of 0–5.07 standard liters per minute. Compared with the average results obtained using only a single input, those obtained using a dual input indicate a significant decrease in the MAE and MSE by 85.69% and 96.68%, respectively. Furthermore, a transient analysis of the ML‐based flow sensor is conducted to investigate the response time and transient characteristics of the MLR, KNN, and DNN models. The results of this study contribute to the advancement of airflow management systems for various industrial applications, such as building ventilation, gas leakage detection, and energy systems. [ABSTRACT FROM AUTHOR]

Heat dissipation performance is crucial for the operational reliability of industrial equipment, which can be monitored by detecting the wind or airflow temperature of the radiator. The emergence of triboelectric nanogenerators (TENGs) provides new routes for wind energy harvesting and self‐powered sensing. Herein, a rotary wind‐driven triboelectric nanogenerator (RW‐TENG) with soft‐contact working mode is newly designed to achieve tunable contact areas by utilizing the reliable thermal response of NiTi shape memory alloy (SMA) to air/wind temperature. The RW‐TENG can generate different triboelectric outputs under air stimulation with different speeds or temperatures, which is demonstrated as a power source for online monitoring sensors, self‐powered wind speed sensing, and airflow temperature monitoring. Specifically, a self‐powered sensor of wind speed is demonstrated with a sensitivity of 0.526 µA m−1 s between 2.2 and 19.6 m s−1, and a self‐powered monitoring device of high airflow temperature, which show relatively short response time (109 s), strong anti‐interference ability and outstanding long‐term durability. This study introduces an innovative route for real‐time detection of airflow temperature in wind‐cooled industrial equipment, showing broad application prospects for information perception and intelligent sensing of the industrial IoTs. [ABSTRACT FROM AUTHOR]

In this research, an angular contact ball bearing with two‐half inner rings is used as a carrier. Considering the two‐phase flow characteristics of oil and air in the bearing, the flow characteristics of lubricating oil inside the bearing with under‐race lubrication are studied. Based on the volume of fluid (VOF) method and the standard k–ε turbulent flow model, the characteristics of oil and air two‐phase flow inside the ball bearing are analysed. The bearing internal pressure field distribution, streamline distribution, and other flow properties for the different radial working clearances, pocket clearances and guide clearances are determined. The distribution of the lubricating oil in key areas is observed. The oil phase volume fraction of the key lubrication areas, such as the cage pocket surface and the inner and outer ring surfaces is used to evaluate the influence of different structural parameters on the bearing lubrication performance. The lubrication influences of the inner and outer guides of the cage are evaluated, and the internal flow characteristics of the bearing are analysed with different guide clearances. The results show that with the radial working clearance range from 0.100 to 0.145 mm, the pressure in the working contact area of the bearing decreases 26%. The pocket clearance ranges from 0.48 to 0.28 mm, and the pressure in the working contact area of the bearing significant increases from 0.642 to 1.165 MPa. From this perspective, the larger the radial working clearance and pocket clearance are, the more favourable it is for bearing lubrication. For bearings with under‐ring lubrication, when the bearing adopts outer guidance, the distribution of lubricating oil in the key areas of the bearing is worse than that for internal guidance. However, the pressure in the working contact area of the bearing slightly increases from 0.642 to 0.759 MPa with the inner guide clearance increasing from 0.4 to 0.8 mm. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of the full transverse exhaust method for smoke extraction in tunnel fires. It examines factors such as the number and layout of air supply and exhaust outlets, analyzing their impact on smoke spread, tunnel temperature, visibility, and airflow. The results demonstrate that the full transverse exhaust method effectively controls smoke emissions in raised highway tunnels. It limits smoke spread, reduces tunnel temperature, and effectively controls the fire‐affected area. The number and layout of outlets significantly influence smoke dispersion, with fewer exhaust outlets providing better smoke control and optimizing the tunnel environment. However, insufficient outlets disrupt gas flow stability. The position of exhaust outlets affects smoke distribution, and caution is advised to prevent directing fresh air flow toward the fire. Opening an equal number of exhaust outlets on one side of the fire source yields superior smoke extraction results, reducing tunnel ceiling temperatures and minimizing risks to personnel and structures. Though stabilization may take longer, this configuration proves advantageous. The study offers valuable insights and practical guidelines for implementing the full transverse smoke control method in real‐world scenarios. [ABSTRACT FROM AUTHOR]

Flow‐induced vibrations are common occurrences in various fluid–solid interaction systems existing in nature. One way to transform this vibrational mechanical energy into a usable form is through energy harvesters. This study examines the performance of a piezoelectric energy harvester, where mechanical oscillations result from the fluttering flags made of various fabrics. Flags, made of commonly encountered fabrics, are attached to a cantilever beam inside a wind tunnel with a 30 × 30 cm test section, allowing the airflow to be adjusted between 0 and 10 m s−1. The alpaca flag, with dimensions corresponding to an aspect ratio of 2, can produce meaningful electricity even at a wind speed as low as ≈3.8 m s−1. As the wind speed increases, the fluttering frequency of this flag configuration becomes 10.9 Hz at a wind speed of 5 m s−1, coinciding with the natural frequency of the first mode shape. In this specific arrangement, the structural deformation of the piezoelectric patch on the beam surface is maximized, allowing the harvester system to produce a root mean square voltage of 5 V with a relatively high maximum power of 98 μW. [ABSTRACT FROM AUTHOR]

fThe traditional solar air heater (SAH) has poor thermal performance due to low heat transfer coefficient. Artificial roughness, flow passage alteration, absorber modification, etc. can enhance it. Thus, an experimental investigation is performed to study the thermohydraulic characteristics of a reverse flow SAH with perforated absorber and delta wing (DW) structure. The present study investigates the effect of attack angle (15°–75°) at constant streamwise pitch (35 mm), transverse pitch (70 mm), height (h), and width (w) of DW 20 mm, under Reynolds number (Re) ranging from 4000 to 20 000. The perforation index (PI = ADW/Aap) for inline and staggered arrangements are 9.52 and 4.76, respectively. The results indicate that the concept of perforated absorber and DW leads to enhanced heat transfer, reduced pressure drops, and enhanced utilization of solar energy. The Nusselt number (Nu), friction factor (f), and thermohydraulic performance enhance about 6.6, 9.4, and 3.06 times, respectively, at attack angle 75o for inline arrangement of DW over the smooth duct. Thermohydraulic performance of reversed‐flow SAH is compared with previously published works, and it highlights that the full‐length inline and staggered arrangement of the DW offers the most significant improvements in heat transfer and friction factor. [ABSTRACT FROM AUTHOR]

See relatedarticle [ABSTRACT FROM AUTHOR]

On the cover: Pots housed within individual containers designed to maintain microarthropod treatments while allowing air flow and light for the oats. To see how this experiment was used to explore the interactive effects of microarthropods and fertilizers on crop productivity, see the article "Microarthropods improve oat nutritional quality and mediate fertilizer effects on soil biological activity" by Jernigan et al. in this issue of the journal. Photo by Ashley Jernigan, Virginia Tech.. [Extracted from the article]

Aiming at the problem that the droplet re‐entrainment in the intake filtration components affects the gas intake quality and the safe operation of gas turbines, the characteristics and mechanism of the re‐entrainment in a marine double‐hook inertial stage filter are studied, and the distribution of liquid film and re‐entrainment under different inlet air velocities and droplet size distributions are compared. The results show that, due to the influence of inertia and turbulent dispersion, droplets tend to deposit on draining hooks and the lower surface of the leeward side of the blade to form a liquid film. Film stripping is the main form of re‐entrainment under ship‐driving conditions. Due to the high airflow velocity and the large film thickness, hook peaks are the most prone to film stripping, and the critical airflow for film stripping velocity is 14.8 m/s. With the increase of the inlet air velocity, the film thickness at the draining hooks increased first and then decreased, and the film stripping positions were extended from the hook peaks to the rear. Different droplet size distributions mainly affect the liquid film thickness at the draining hook and leeward side of the blade, which in turn affects the film stripping mass. [ABSTRACT FROM AUTHOR]

Reversible airflow fixed bed dryer (RAFBD) is an energy‐efficient, cost‐effective, and dependable dryer for using renewable energy sources in parboiling mills. In this study, a medium‐sized and high‐moisture parboiled paddy, ASD‐16, was dried in the RAFBD to determine its deep drying characteristics and thermodynamic properties. The chosen paddy variety is a commonly cultivated paddy in the southern region of Tamil Nadu, India. The RAFBD experimental setup was designed to dry 30 kg of parboiled paddy. For the statistical analysis, the experimental data for the deep‐bed drying at hot air temperatures 50–80°C and velocities of 0.1 and 0.15 m/s were used at constant specific humidity. To predict drying characteristics, 12 drying models were compared. Based on their statistical parameters, the Midilli et al. model was selected. For the tested conditions, the coefficients for effective moisture diffusion, heat transfer, and mass transfer were between 9.82 × 10−8 and 2.13 × 10−7 m2/s, 0.3802 and 1.325 W/m2 K, and 0.375 × 10−4 and 1.26 × 10−4 m/s, respectively. Furthermore, the determined activation energy ranged from 20.4964 to 20.4390 kJ/mol. Practical Applications: ASD‐16 is one of the popular paddy varieties cultivated and used in parboiling mills in the study region. The outcome of this research can contribute to the application of a cost‐effective dryer for drying high‐moisture paddy. Furthermore, the drying time and bed height proposed in this work can reduce the drying time in the mills and improve energy efficiency. The drying kinetics and suitability of the models found in this study will contribute to the design and development of low‐cost dryers for the local parboiling industries. As rice husk, which is a waste from paddy processing, is used for the heating process, industries can reduce the cost of energy for closed‐roof drying. This study provides a clear insight to the researchers and designers in standardizing the capacity of the dryer, drying temperature, and airflow rate for any similar kind of paddy variety. [ABSTRACT FROM AUTHOR]

The purpose of this research was to confirm the suitability of allulose to produce crystallized fruits under nonthermal conditions and the suitability of UV‐A light dehydration to concentrate the osmotic solutions. Mangoes and apples were subjected to osmotic drying with either sucrose or allulose, which was followed by an air‐drying step at room temperature to further concentrate the crystallized fruits. There was no significant difference in the dehydration kinetics parameters between the two sugars in each crystallized fruit. Color evaluations showed that allulose was able to better preserve the color of the original raw fruits in the final crystallized samples. Electron microscopy images suggested a more uniform diffusion of allulose as compared to sucrose for both fruits. Similarly, liquid chromatography and infrared spectroscopy analyses confirmed the successful absorption of both sugars into both fruits, with allulose having a final higher concentration in both mango and apple (51.7 ± 5.6% and 70.8 ± 7.7% w/w, respectively) as compared to sucrose (48.6 ± 2.9% and 58.3 ± 3.4% w/w, respectively). UV‐A light dehydration showed to be able to increase the recovery of the sugars from osmotic solutions better than in conditions without UV‐A light exposure. When only air flow was used, it was possible to remove 85.3 ± 4.6% and 78.6 ± 0.6% of the original moisture in the sucrose and allulose solutions, respectively. In contrast, under UV‐A light dehydration, the percentage of the original water removed from the sucrose and allulose solutions was 95.2 ± 1.8% and 83.1 ± 1.9%, respectively. Practical applications: There is an increasing trend toward producing foods that are healthier for the general population. The use of rare sugars like allulose offers a promising alternative to accomplishing this. In addition, it has become imperative to develop processes that are more sustainable. The use of air‐drying at room temperature can represent an effective approach to develop more sustainable food manufacturing processes. More specifically, the use of UV‐A light dehydration (which is a non‐thermal food dehydration technique) for the recovery of solutes or the concentration of osmotic solutions can also represent an effective aid in this type of processes. [ABSTRACT FROM AUTHOR]

Energy and exergy performance of simple vapor compression refrigeration unit is investigated experimentally with and without coupling heat exchanger of phase change material before the condenser. The hot outside air is cooled before entering the condenser throughout the day by flowing over the cooled phase change material structure that previously solidified during nighttime. Phase change material SP24 is employed because its melting/freezing range is suitable for most selected countries' climates. An experimental set‐up of an air‐phase change material heat exchanger coupled with the unit is constructed to examine its performance, including pressure–enthalpy curve, coefficient of performance, exergy performance, and power consumption including inflow air temperatures and flow rates impacts. Results affirm that the coefficient of performance, cooling capacity, power usage, and exergy destruction are improved by using phase change material. Compared to the unmodified unit, the maximum percentage of saved power and exergy destruction enhancement for the modified refrigeration unit with phase change material is about 8.8% and 10%, respectively. The maximum coefficient of performance and exergy efficiency rise is about 15.1% and 14.2%, respectively. Increasing the temperature differential across the phase change material heat exchanger, either by increasing inlet temperature or decreasing airflow, enhances the refrigeration unit power saving. [ABSTRACT FROM AUTHOR]

In the present study, an experimental test was conducted to investigate the energetic performance of a novel designed solar air heaters (SAHs), with, and without phase change material (PCM). Two identical SAHs were fabricated and tested to compare their performance. The first heater is a jacket‐tube solar air heater (SAH 1), while the second heater is similar to the first but filled with PCM (SAH 2). Experimental results showed that increasing air flow rate increases the daily thermal efficiency. Thermal energy during day hours can be stored in the PCM and used after sunset. SAH 2 gave an additional operating time after sunset for 4 hours at 0.01 kg/s, 2.5 hours at 0.035 kg/s, and 1 hour at 0.06 kg/s. Maximum improvement in the daily thermal efficiency was 15% at SAH 2, more than SAH 1 at 0.01 kg/s air flow rate. Employing PCM, as so as increasing air flow rate can reduce the daily thermal losses. [ABSTRACT FROM AUTHOR]

In this study, a comprehensive simulation study was carried out to obtain detailed battery temperature behaviors. The influences of air inlet temperature, air flow rate, C‐rate, and free stream temperature were investigated on the temperature uniformity and maximal battery temperature. Taguchi design is implemented to investigate the main effects of four control parameters in the battery thermal management process. Results indicated that as the free stream temperature (delta = 7.3366) was the most influential factor for the temperature uniformity, the air inlet temperature (delta = 0.2679) was the most efficient factor for the maximal battery temperature. The contribution of the air inlet temperature was 28% and 38% for temperature uniformity and maximal battery temperature, respectively. Additionally, the free stream temperature contributed 32% to temperature uniformity and 25% to the maximum battery temperature. The airflow rate was found to be the least effective factor for temperature uniformity (delta = 2.8672) and maximal battery temperature (delta = 0.0506). The results could be helpful in the design of a lithium‐ion battery thermal management process to improve temperature uniformity and maximal battery temperature. [ABSTRACT FROM AUTHOR]

Objective: Total laryngectomy (TL) patients are good models in which to evaluate the effects of nasal airflow cessation on the sinonasal tract. Here, we evaluated changes in sinonasal structures and association with sinus opacification in the computed tomography (CT) images 3 years post‐TL. Methods: Patients who underwent TL from 2005 to 2017 in a teaching academic center were reviewed retrospectively. Patients with a final follow‐up CT taken less than 3 years after TL, tracheoesophageal puncture, inadequate CT image, or history of sinonasal surgery were excluded. The control group included patients who underwent a partial laryngectomy or hypopharyngectomy without requiring a tracheotomy for more than a month. Altogether, 45 TL patients and 38 controls were selected. The volume of all four paranasal sinuses, inferior turbinate soft tissue volume (ITSTV), maxillary sinus natural ostium (MSNO) mucosal width, and Lund–Mackay scores (LMS) were measured on preoperative and postoperative CT scans. Results: The mean duration between surgery and the final CT scan was 6.3 ± 2.4 and 5.5 ± 2.3 years for the TL and control groups, respectively. Neither group showed significant changes in the four paranasal sinuses' volume or MSNO mucosa width. The ITSTV decreased significantly, from 4.6 ± 1.3 to 2.8 ± 1.1 mL (p <.001), in the TL group, regardless of the presence of nasal septal deviation, showing ITSTV reduction on both concave and convex sides. By contrast, the control group showed no significant changes in ITSTV. Postoperative LMS changes in both groups were insignificant. The number of patients with LMS aggravation or alleviation was the same in both groups, regardless of preoperative sinus opacification. Conclusions: Paranasal sinus structures and sinus opacification are not affected significantly by nasal airflow cessation; however, the inferior turbinate mucosa is affected by long‐term discontinuation of nasal airflow. Level of Evidence: 4 (case–control study). [ABSTRACT FROM AUTHOR]