Hot Environment Research Articles

Impacts of urban expansion on air temperature and humidity during 2022 mega-heatwave over the Yangtze River Delta, China

The Yangtze River Delta (YRD) experienced record-breaking heat in the summer of 2022. However, the urban heat pattern and the role of urban expansion over the last two decades in this hot summer have not been explored. Using the advanced mesoscale Weather Research and Forecasting (WRF) model, we reproduced the fine spatial features and investigated the urban heat island (UHI) and dry island (UDI) effects during the two identified heatwaves in 2022. We further replace the current (2020) land use with the historical (2001) land use in WRF to evaluate the impacts of urban expansion from 2001 to 2020 on air temperature and moisture. Our finding revealed that the conversion of land use resulted in near-surface warming and drying, with pronounced diurnal variations, especially during the July heatwave. The analysis of surface energy balance demonstrated that the substantial decrease in evapotranspiration (ET) was the primary driver of daytime warming, elevating temperatures by 7 °C (July heatwave) and 2 °C (August heatwave). This ET reduction also led to the strong daytime coupling of warming and drying effects over new urban areas. At night, the release of stored heat resulted in the temperature increase of 2 °C (1 °C) during July (August) heatwave, highlighting the nighttime as a critical period for heightened thermal risk. Additionally, urban expansion at the periphery contributed modestly to the warming of urban cores, exacerbating conditions in an already hot environment. This study enhances understanding of the impacts of urban expansion on air temperature and humidity during extreme heatwaves, thereby supporting targeted adaptation and mitigation for extreme events within large cities.

Evaluation of physiological and thermal comfort effectiveness of ceiling fan and table fan during a heat wave

Heat waves are becoming a significant global concern as they have substantial repercussions on human health. Further, the adverse impact of heat waves on health will likely worsen globally. The use of electric fans is an energy-saving and sustainable cooling strategy against heat waves, but current health guidelines discourage fan use during heat waves. Previous research has shown that health guidelines underestimated the evaporative cooling impact of fans. These studies mainly focused on the effects of table fans on various physiological parameters of occupants in hot environments. Nevertheless, the air movement produced by both table fans and ceiling fans may influence the occupants’ physiological and perceptual responses significantly. Hence, the present study investigated the effectiveness of no-fan, table-fan and ceiling-fan conditions during heat waves through an experimental approach. Sixteen healthy young participants were exposed to an air temperature of 41.0 ± 0.5 °C and relative humidity of 35 ± 2 % for 2 hours. The participants’ physiological parameters and perceptual responses were collected. We found that both table and ceiling fans delay the changes in thermoregulatory and cardiovascular strain compared to the no-fan scenario. Moreover, table fans minimize physiological strain and provide greater comfort than ceiling fans. Hence, people should opt for table fans over ceiling fans during heat waves.

Detection Dogs Working in Hot Climates: The Influence on Thermoregulation and Fecal Consistency.

Body temperature is an important physiological parameter that influences the performance of working dogs. The main cooling mechanism in dogs is panting to support evaporative cooling, which reduces the dog's ability to detect scents. In this study, we investigated the general body condition of four detection dogs searching for cheetah scats in a hot environment in northern Kenya. We evaluated the effect on the dog's body temperature post-work in the short term (within hours) and long term (12-24 h). The fecal consistency and mean body temperature of the investigated dogs differed significantly between individuals but not between locations (moderate Nairobi and hot Samburu). On the morning after fieldwork, the dogs showed a significantly increased body temperature (37.9 ± 0.8 °C) compared to resting days (37.5 ± 2.2 °C). In the short term, on the first day of fieldwork, the dog's body temperature (n = 2) decreased after 10 min of rest. On the second consecutive day of fieldwork, the 10-min recovery period was too short, and the body temperature did not decrease significantly. Our data showed that the use of detection dogs in hot conditions is possible and useful but requires increased attention to prevent heat-related illness.

Exploring GVS as a display modality: signal amplitude and polarity, in various environments, impacts on posture, and with dual-tasking.

Galvanic Vestibular Stimulation (GVS) has been proposed as an alternative display modality to relay information without increasing demands on the visual or auditory sensory modalities of the wearer or in environments where those modalities cannot be used (e.g., covert night operations). We further investigated this concept with four experiments designed to test: (1) thresholds at which subjects could distinguish between different GVS current amplitudes and polarities, (2) thresholds at which different bipolar (i.e., sinusoidal waveform with current oscillating between left and right directions) current frequencies were distinguishable among room temperature, hot, cold, and windy environments, (3) effects of unipolar (i.e., sinusoidal waveform with current occurring in only the left or right direction) currents on balance performance, and (4) dual-task performance among frequency and polarity modulated GVS conditions during a concordant visual search task. Subjects reliably distinguished between current amplitudes that varied from a pedestal of ± 0.6mA by a median of 0.03mA (range of 0.02-0.32mA) and between unipolar currents at a median amplitude of 0.55mA (range of 0.32-0.83mA). GVS frequency thresholds were robust to the environment conditions tested, with no statistical differences found. Sway and balance errors were increased with unipolar currents. GVS thresholds were not impacted by the dual-task paradigm, but the visual search scores were slightly elevated when congruently performing a polarity thresholding task. Overall findings continue to support GVS use as a display modality, but some limitations are noted, such as the use of unipolar currents under scenarios where postural control is important.

Heat strain differences walking in hot-dry and warm-wet environments of equivalent wet bulb globe temperature

ABSTRACT Wet bulb globe temperature (WBGT) is a commonly used measure to predict heat strain in workers. Different combinations of environmental conditions can create equivalent WBGT, yet it remains unknown whether biophysical, physiological, and perceptual responses vary when working in different but equivalent hot conditions. The purpose of the study was to compare body heat storage and physiological and perceptual strain during walking in hot-dry and warm-wet conditions of the same WBGT. Twelve subjects (age: 22 ± 2 y) walked for 90 min at 60% maximum heart rate in a 27.8°C WBGT environment of hot-dry (HD: 40°C, 19% relative humidity) or warm-wet (WW: 30°C, 77% relative humidity) conditions. Partitional calorimetry was used to estimate heat storage. Core temperature at 90 min (HD: 38.5 ± 0.5°C; WW: 38.4 ± 0.3°C, p = 0.244) and cumulative heat storage (HD: 115 ± 531 Kj; WW: 333 ± 269 Kj, p = 0.242) were not different. At 90 min, heart rate was not different (HD: 160 ± 19 bpm; WW: 154 ± 15 bpm, p = 0.149) but skin temperature (HD: 36.6 ± 0.9°C; WW: 34.7 ± 0.6°C, p < 0.001), thirst (HD: 6.8 a.u.; WW: 5.3 a.u. p = 0.043), and sweat rate (HD: 15.1 ± 4.4 g·min−1; WW: 10.0 ± 4.1 g·min−1, p < 0.001) were greater in HD compared to WW. Hot environments of equivalent 27.8°C WBGT created equivalent core temperature despite differences in physiological strain during exercise, including earlier onset of cardiovascular strain, greater sweat rate, and higher skin temperature compared to a WW environment. ClinicalTrials.gov ID NCT04624919.

Ingesting carbonated water post-exercise in the heat transiently ameliorates hypotension and enhances mood state.

The objective was to assess if post-exercise ingestion of carbonated water in a hot environment ameliorates hypotension, enhances cerebral blood flow and heat loss responses, and positively modulates perceptions and mood states. Twelve healthy, habitually active young adults (five women) performed 60min of cycling at 45% peak oxygen uptake in a hot climate (35°C). Subsequently, participants consumed 4°C carbonated or non-carbonated (control) water (150 and 100mL for males and females regardless of drink type) at 20 and 40min into post-exercise periods. Mean arterial pressure decreased post-exercise at 20min only (P=0.032) compared to the pre-exercise baseline. Both beverages transiently (∼1min) increased mean arterial pressure and middle cerebral artery mean blood velocity (cerebral blood flow index) regardless of post-exercise periods (all P ≤ 0.015). Notably, carbonated water ingestion led to greater increases in mean arterial pressure (2.3±2.8mmHg vs. 6.6±4.4mmHg, P<0.001) and middle cerebral artery mean blood velocity (1.6±2.5cm/s vs. 3.8±4.1cm/s, P=0.046) at 20min post-exercise period compared to non-carbonated water ingestion. Both beverages increased mouth exhilaration and reduced sleepiness regardless of post-exercise periods, but these responses were more pronounced with carbonated water ingestion at 40min post-exercise (mouth exhilaration: 3.1±1.4vs. 4.7±1.7, P=0.001; sleepiness: -0.7±0.91vs. -1.9±1.6, P=0.014). Heat loss responses and other perceptions were similar between the two conditions throughout (all P ≥ 0.054). We show that carbonated water ingestion temporarily ameliorates hypotension and increases the cerebral blood flow index during the early post-exercise phase in a hot environment, whereas it enhances mouth exhilaration and reduces sleepiness during the late post-exercise phase.

Effect of Shell Cover Color on Solar Absorptance and Environmental Heating of Cricket Helmets: A Pilot Study

The objective of this pilot study was to quantify and describe the effect of shell cover color on solar absorptance, a1 (%; mean ± SD) and the temperature of the cricket helmet shell covers, Thsc (°C; mean ± SD) during exposure to a hot outdoor environment (WBGT 32.5 ± 1.9 °C; ACSM Heat Index Black; Extreme Danger STOP). We measured and recorded a1 in yellow, red and black cricket helmets using a micro-solarimeter. Thermographic imaging was used to quantify differential Thsc . Variations in shell cover color had a statistically significant (p&lt;0.0002) 2-fold effect on a1 . At the end of 30-minute trials, variations in color and a1 resulted in 3.6 to 6.0 °C difference in Thsc between helmets. Although speculative, the color of cricket helmet shell covers may have a functionally significant effect of exertional heat illnesses, EHIs (ranging from dehydration to heat stroke). Incorporating reflective nanocomposites particles into the material used in the construction of the Lycra® shell covers and XENOY™ shells may facilitate passive cooling of cricket helmets and ultimately reduce EHIs.

Evaluating the influence of ambient conditions in the cooking space of railway pantry car using selected thermal indices and physiological parameter.

Hot and humid indoor environment of the kitchen affects worker performance. The Indian Railway's pantry car culinary is one of them that cooks food for the on-board passengers, which could be bothered by the hot indoor climate. The current study aimed to identify the indoor working environment of the railway "pantry car" using heat stress indices such as "Universal Thermal Climate Index-UTCI," "Wet-Bulb Globe Temperature-WBGT," "Discomfort Index-DI," "Tropical Summer Index-TSI," "Heat Index-HI," and Heart Rate-HR with clothing insulation. METHODS: The study was performed in 2018 (August-summer season) to collect field survey data on 6 railway pantry cars. Measurements were carried out during peak cooking times such as morning "7 : 00 am", day "11 : 30 am", evening "4 : 00 pm," and night "6 : 30 pm". This study's descriptive and Pearson's correlation analysis was accomplished using SPSS version 2016 software. The analysis results revealed that the average values were for UTCI (37.77±5.26°C), WBGT (30.42±2.28°C), DI (30.05±2.70°C), TSI (33.21±2.90°C), HI (48.53±4.86°C), correspondingly. During analysis, the strongest correlation association was observed between "TSI and DI" (r = 0.985, p < 0.000) and WBGT and TSI (r = 0.958, p < 0.000). A "significant correlation" was found between UTCI and HI (r = 0.637, p < 0.05). While no signification correlation was found between "heat stress indices and physiological parameters (p > 0.05)". In this study, all the heat stress index limit values showed highly harsh working conditions inside the pantry car, which created unfavorable circumstances for the culinarians. Inappropriate "ventilation design" could be a reason for discomfort in the railway pantry car.

Association between temperatures and type 2 diabetes: A prospective study in UK Biobank

ObjectiveThis study aims to prospectively examine the association between temperatures and the occurrence of type 2 diabetes (T2D). MethodsWe used the CPH models to analyze 103,215 non-diabetic participants in the UK Biobank cohort who answered questions about workplace temperature, to evaluate the survival relationship, and the interaction effects of working environmental temperature and T2D-related genetic risk scores (GRS) on the occurrence of T2D. The occurrence of T2D was assessed by hospital inpatient records. The weighted T2D-related GRS were calculated. ResultsDuring 1,355,200.6 person-years follow-up, a total of 2436 participants were documented as having diagnosed T2D. After adjustment, compared to the comfortable group, the participants working in non-comfortable environmental temperature had greater risk of T2D (HR: 1.27, 95 %CI: 1.04 to 1.55, for cold; HR: 1.32, 95 %CI: 1.17 to 1.48 for hot; HR: 1.51, 95 %CI: 1.38 to 1.65 for alternate). Similarly, individuals exposed to different levels of genetic risk scores in alternating hot and cold work environments had a higher risk of developing type 2 diabetes. ConclusionsThis study found working in single non-comfortable environmental temperatures was associated with greater risk of T2D occurrence, and exposure to alternating environmental temperatures had the highest risk of range and severity.

Effects of cooling vest and personal protective equipment removal on thermoregulation in wildland firefighters during progressive thermal loads.

Wildland firefighters (WFFs) regularly face demanding physical and environmental conditions during their duties, such as high ambient temperatures, challenging terrains, heavy equipment and protective gear. These conditions can strain thermoregulatory responses, leading to increased fatigue and posing risks to their health and safety. This study examined the effectiveness of two cooling interventions during physical activity in hot environments. Eight active male WFFs participated, comparing the effects of wearing a cooling vest (VEST) and personal protective equipment removal (PASSIVE) against a control condition (PPE). Participants walked on a treadmill at a speed of 6 km·h-1 for approximately 75-min under hot conditions (30°C and 30% relative humidity). Incremental slope increases were introduced every 15 min after the initial 20 min of activity, with 5-min passive recovery between each increment. Physiological and perceptual parameters were monitored throughout the protocol. Significant main effects (p < 0.05) were observed in skin temperature (36.3 ± 0.2, 36.2 ± 0.4 and 35.4 ± 0.6°C in PPE, PASSIVE and VEST, respectively), physiological strain index (5.2 ± 0.4, 5.6 ± 1.1 and 4.3 ± 1.4 in PPE, PASSIVE and VEST) and thermal sensation (6.6 ± 0.6, 6.4 ± 0.7 and 5.3 ± 0.7 in PPE, PASSIVE, and VEST). However, no significant effects of the cooling strategies were observed on heart rate, gastrointestinal temperature or performance. Despite the observed effects on physiological responses, neither cooling strategy effectively mitigated thermal strain in WFFs under the experimental conditions tested.

A survey of nocturnality and risk for savanna chimpanzees at Assirik, Senegal.

Chimpanzees (Pan troglodytes) in Senegal may use nocturnality to mitigate hyperthermia risk in semi-arid environments but the degree of nocturnality for such chimpanzees also in sympatry with large carnivores remains uncertain. We compared diel activity among chimpanzees and their potential predators at Assirik in Niokolo-Koba National Park and contextualized these findings relative to other unit-groups in savanna landscapes. From 2015-2018, we generated a predator inventory using multi-modal methods and monitored the diel activity of chimpanzees and predators with camera traps [ N = 2092 camera trap (CT) days]. From 2015-2023, we also surveyed for evidence of predation during recce walks. Six potential nonhuman predators occur at Assirik, including lions (Panthera leo), leopards (Panthera pardus), spotted hyenas (Crocuta crocuta), African wild dogs (Lycaon pictus), Nile crocodiles (Crocodylus niloticus), and rock pythons (Python sebae). We documented one suspected case of a predator killing a chimpanzee. Nocturnality comprised 12.7% of CT events for chimpanzees and these events were more concentrated at twilight. Chimpanzees were more active during the day, predators were more active at night, and there was substantial temporal overlap among chimpanzees and potential predators during twilight intervals. Our findings support the hypothesis that savanna chimpanzees in Senegal are active at night in response to the extremely hot environment. We hypothesize that Assirik chimpanzees experience a tension between decreasing hyperthermia and increasing predation risk during nocturnality.

Predicting the thermophysiological response in hot environment when using protective clothing

Predicting the thermophysiological response in hot environment when using protective clothing

Comprehensive investigation of daytime radiative cooling technology for sustainable grain storage: A combined approach of field measurement and CFD simulations

Ensuring the thermal-safety of grain storage while achieving an ecologically friendly, energy-efficient solution that contributes to carbon reduction strategy is the future direction for grain storage systems. The application of Radiative Cooling (RC) technology in long-term grain storage is a promising solution in this regard. This study investigates the energy storage and heat transfer properties of the Daytime Radiative Cooling (DRC) metafilm, a type of RC material, in grain storage settings from spring to summer by performing a field measurement on a grain storage of ∼500 m2 rooftop and corresponding Computational Fluid Dynamics (CFD) simulations. The results highlight that the DRC metafilm applied to the outer roof surface achieves a peak cooling rate of 38.3 % under direct sunlight, which is a 50.6 % improvement over the non-filmed condition, providing effective heat dissipation and ensuring a continuous passive cooling process in hot environments. Especially in high-temperature summer conditions, the DRC metafilm ensures that both the average grain temperature throughout the storage and the central grain pile temperature meet the standards for quasi-low-temperature grain storage with zero energy consumption. Additionally, during the peak solar radiation intensity of summer, the DRC film acts as an efficient heat dissipator, facilitating negligible surface heat flux on the exterior roof, with localized regions exhibiting positive cooling effects. Consequently, using DRC material engenders tangible economic and substantial environmental benefits for grain storage cooling.

Factors associated with pityriasis versicolor in a large national database.

Pityriasis versicolor (PV), a cutaneous fungal infection, most commonly affects adolescents and young adults and is associated with hyperhidrosis and humid weather. Understanding other factors associated with PV might help improve diagnostic and treatment practices. PV's associations with patient demographics, comorbidities and medication exposures were assessed using the All of Us Database, a large, diverse, national database from the United States. A case-control study with multivariable analysis was performed. We identified 456 PV case-patients and 1368 control-patients. PV case-patients (vs. control-patients) were younger (median age [years] (standard deviation): 48.7 (15.4) vs. 61.9 (15.5); OR: 0.95, CI: 0.94-0.96) and more likely to be men versus women (42.8% vs. 33.9%, OR: 1.45, CI: 1.16-1.79) and Black (19.5% vs. 15.8%, OR: 1.35, 95% CI: 1.02-1.80) or Asian (4.6% vs. 2.7%, OR: 1.86, CI: 1.07-3.24) versus White. PV case-patients more frequently had acne (5.3% vs. ≤1.5%, OR: 5.37, CI: 2.76-10.48) and less frequently had type 2 diabetes mellitus (T2DM) (14.7% vs. 24.7%, OR: 0.52, CI: 0.39-0.70) and hypothyroidism (OR: 10.3% vs. 16.4%, OR: 0.59, CI: 0.42-0.82). In multivariable analysis, PV odds were significantly higher in those with acne and lower in those with T2DM, older age and female sex. Our results may be used as a basis for future studies evaluating whether acne treatment may decrease PV risk. Physicians could educate patients with acne about PV, including strategies to control modifiable PV risk factors, such as avoidance of hot and humid environments and avoidance of use of topical skin oils.

Asymmetrical surface-modified polyester/cotton fabrics for temperature-adaptive moisture and thermal management of human body

Personal moisture and thermal management fabrics that can regulate skin temperature are highly desired for improving human comfort and performance. Here, a symmetric surface modified polyester/cotton fabric (Janus T/C fabric) exhibiting exceptional temperature-adaptive personal moisture and thermal managements was developed. This was achieved by integrating two distinct temperature-sensitive hydrophobic/hydrophilic transition materials through single-sided spray coating technique and in-situ ultraviolet-induced free radical polymerization in 60/40 polyester/cotton blend fabric (T/C fabric, composed of 60 % cotton and 40 % polyester fibers). 2-(2-methoxyethoxy) ethoxyethyl-methacrylate (MEO2MA) was utilized to create lower critical solution temperature (LCST) polymer, while N, N-dimethyl (methacryloylethyl) ammonium propane sulfonate (DMAPS) formed an upper critical solution temperature (UCST) polymer on T/C fabric surface. Fabric’s surface demonstrated a reversible transition in hydrophobicity/hydrophilicity in response to environmental temperature changes. The distinct hydrophobic and hydrophilic surfaces configuration resulted in a remarkable wettability gradient, significantly increased moisture permeability to 6792.5 g/m2·24 h—an increase of 1132.1 g/m2·24 h compared to the 60/40 T/C fabric at 40 °C. Moreover, the Janus T/C fabric provided practical temperature adaptation benefits, offering a cooling effect of approximately 1.2 °C in hot environments and a warming effect of approximately 1.0 °C in cold conditions. These thermal responsive properties make the asymmetric surface-modified polyester/cotton fabric an ideal choice for personalized moisture and thermal management, ensuring optimal comfort across varying temperatures.

Bioinspired Multilayered Knitted Fabric with Directional Water Transport and Collection for Personal Sweat Management.

Effective sweat management fabric for sportswear facilitates sweat removal from the skin and elevates the comfort for human. However, when the body is in a strong hot and humid environment or after strenuous exercise, the sweat management fabric will be totally wetted and saturated quickly. As a result, excess sweat cannot be absorbed effectively by the garment, which creates obvious stickiness and heaviness. In this paper, a directional water transport and collection multilayered knitted fabric (DWTCF) is prepared by plasma pretreatment technology and screen coating. The treelike water transport network inspired from nature is designed in order to drive the liquid flow along the channels. By surface modification, branched hydrophilic flow paths are fabricated, and other regions are hydrophobic. As a demonstration, DWTCF has been injected with water to observe the liquid transport behavior. During the experiment, 76.7% liquid is collected by DWTCF, but there is just 0.06% collected by an ordinary knitted fabric. The weight increase of the ordinary fabric is 555.4% larger than that of DWTCF. Specifically, DWTCF utilizes the wetting and pressure-gradient-induced interfacial tension as well as the gravitational effect to facilitate the fluid motion along the hydrophilic channel, in addition to the capillarity present in the fabric structure. This study provides a new idea to develop directional water transport and collection fabric to solve the moisture absorption saturation problem of the fabric, especially for conditions requiring intense sweating.

Geochemistry of Middle Jurassic Coals from the Dananhu Mine, Xinjiang: Emphasis on Sediment Source and Control Factors of Critical Metals

In recent years, coal-type critical metal deposits have become a research hotspot in coal geology. As a major coal-accumulating basin in the Xinjiang area, the Turpan-Hami Basin contains abundant coal resources and has the potential to become a large coal-type critical metal deposit. However, previous studies on the enrichment characteristics of critical metal elements in coal are few and need further research. Based on SEM-EDS, XRF, and ICP-MS experiments, this study investigates the coal petrology, mineralogy, and geochemistry of the No. 22 coal of the Xishanyao Formation from the Dananhu Coal Mine, Xinjiang, to identify the sediment source, depositional environment, and controlling factors of the critical metal elements of the No. 22 coal. The results showed that the Dananhu coals are characterized by a low ash yield, low total sulfur content, high volatile yield, and high inertinite proportions. Quartz, kaolinite, and illite are the main minerals in the coal. Compared with the world’s low-rank coals, Ni, Co, Mo, and Ta are slightly enriched, Li, Rb, Cs, Ba, Tl, Bi, and Ge are depleted, and the concentrations of other trace elements are comparable to the average values of the world’s low-rank coals. The REY of the Dannanhu coals exhibited high fractionation, with its enrichment patterns characterized by the H-type and M-H-type. Although most of the critical metals are not enriched in the Dannanhu coals, the Ga, Zr (Hf), and Nb (Ta) concentrations in the coal ash of the Dannanhu coals have reached the economic cut-off grade and have the potential to be a substitute for rare metal resources. The terrigenous detrital sources of the Dannanhu coals mainly come from the Paleozoic dacite, andesite, and a small amount of granite from the Harik Mountain and Eastern Bogda Mountain in the Turpan-Hami Basin. The Dannanhu coals are generally in a dry and hot depositional environment, with high salinity and weak reduction-oxidation. The low source input and weak reduction-oxidation environment have resulted in low concentrations of critical metal of the No. 22 coal from the Dananhu Coal Mine.

Transcritical Cycles With CO2-based Mixtures for CSP Applications: An Overview of the SCARABEUS Findings

This work summarizes the methodology developed within the H2020 EU project SCARABEUS for the analysis of innovative CO2-based mixtures used as working fluid in transcritical cycles for CSP applications. By adding a specific quantity of carefully selected dopant to CO2 it is possible to reach a high mixture critical temperature, suitable for air cooled cycles at very high minimum temperature in hot environments with high efficiencies. Along the methodology, some results related to the design of the turbine and the heat exchangers for the innovative mixtures are presented, including a focus on the system integration between the power block and the solar plant: as such, these results can be considered as interesting research outcomes to widen the knowledge on innovative solutions for efficient power cycles. The new power cycles are foreseen to drastically increase the profitability and cut the specific cost of CSP systems with respect to the state-of-the-art

Interfacial Study of Steel Joints Prepared with a Catechol-Modified Epoxy Adhesive with Enhanced Bonding Performance and Durability.

Bonding is widely used in aircraft and vehicles due to its light weight and simple process, but its strength decreases sharply in hot and humid environments. Anodization treatment, used for enhancing aging performance, is environmentally harmful and unsuitable for steel. In this study, a catechol-modified epoxy adhesive (CMEA) was prepared on a hectogram scale. Comparative analysis with phenol-modified epoxy adhesive (PMEA) and pristine epoxy adhesive (EA) revealed that the underwater bonding of CMEA (13.0 MPa) on stainless steel (SS) significantly outperformed the two control groups. Moreover, after 32 days of hydrothermal aging at 50 °C, CMEA preserved 73.9% of its initial bonding strength, while PMEA and EA retained 59.8 and 11.4%, respectively. Furthermore, X-ray photoelectron spectroscopy (XPS) etching at different times to analyze the interface between adhesives and the SS substrate indicated a marked increase in the O-H/O2- value at the interface between CMEA and the SS substrate compared to the two control groups. The above results demonstrated that the catechol-modified adhesive enhanced the bonding and aging properties of the adhesive, possibly due to the formation of a higher density of hydroxyl groups at the interface between the adhesive and the SS substrate. These findings contribute to the understanding of the enhancement mechanism of catechol in improving the bonding and aging properties of adhesives and suggest a feasible direction for designing adhesives with high bonding strength and high durability.

Wpływ mikroklimatu gorącego na funkcje psychomotoryczne pracowników

The effect of hot microclimate on psychomotor functions of employees For several years now, one of the most important harmful factors related to the work environment has been a hot microclimate. Additionally, due to climate changes, including an increase in the average air temperature, especially in summer, attention should be paid to people working in open spaces. Microclimate parameters affect not only on physiological responses of the human body, but also psychomotor efficiency, which translates into the number of errors made during work, and thus the safety of oneself and one's colleagues. The aim of the article is to indicate the impact of a hot microclimate (and so a high air temperature) on the psychomotor functions of workers. Expanding knowledge in this area may contribute to improving safety at work in hot microclimates. Keywords: air temperature, hot environment, hot microclimate, thermal load, psychomotor performance, cognitive function