Strong Solar Radiation Research Articles

Tibetan Plateau is vulnerable to aromatic-related photochemical pollution and health threats: A case study in Lhasa

Anthropogenic aromatics play a key role in photochemical pollution and pose a serious threat to human health. Current knowledge on source characteristics of aromatics in the urban region of the Tibetan Plateau (TP), the “Third Pole” and ecologically sensitive area, remains limited. In this study, an intensive observation of 17 aromatic hydrocarbons was conducted in Lhasa, the cultural and economic center of TP, during the second Tibetan Plateau Scientific Expedition and Research in summer 2020. The results showed that the average concentration of aromatics in Lhasa (7.6 ± 7.4 ppbv) was unexpectedly higher than those in megacities such as Beijing, Shanghai, and Guangzhou. Tripled concentrations and corresponding ozone formation potential during pollution episodes were recorded. Further source apportionment using positive matrix factorization revealed that solvent usage (60.0 %) was the dominant source, which may be due to the extremely low atmospheric pressure. Vehicle exhaust (15.4 %), industrial emissions (12.8 %), fuel evaporation (6.2 %), and burning emissions (5.7 %) were also important sources. The concentration weighted trajectory analysis revealed that the observed high levels of aromatics were mainly driven by local anthropogenic emissions, rather than the regional transport by the Indian summer monsoon. Long-term exposure to aromatics in Lhasa was assessed to pose carcinogenic risks to the population, with the risks of benzene and ethylbenzene 5 times the criteria. Our results suggest that, given the magnified emissions of aromatics in this extreme environment (low atmospheric pressure and strong solar radiation), the implementation of targeted pollution controls is urgently needed to mitigate the aromatic-related photochemical pollution and health threats in TP.

Refined Analysis of the Transient Temperature Effect during the Closing Process of a Cross-Sea Bridge

In order to study the transient temperature effect during the construction of a cross-sea bridge off the coast, based on the Hong Kong-Zhuhai-Macao Bridge-Pipe Bridge Crossing Cliff 13-1 Gas Field, a refined analysis was conducted and the prediction of transient temperature gradient and structural response was carried out under the conditions of strong solar radiation and atmospheric convection using the method of combining theoretical research and numerical simulation. Firstly, the partial differential equation of uniform heat flux density on the outer surface of the main girder under the action of solar radiation and atmospheric convection was established. The equation was realized by calculating the solar radiation intensity and the comprehensive heat transfer coefficient, as well as fitting the atmospheric temperature on the outer surface of the main girder, and the equivalent comprehensive temperature at any time on the main girder was obtained. Secondly, a numerical analysis model of the heat conduction of the main girder section was established, and the equivalent comprehensive temperature was input into the numerical model as the temperature field boundary to solve the transient temperature gradient of the section, and the result was verified in comparison with the measured data. Finally, the transient temperature gradient was applied to the girder, and the temperature effect of the main girder during the closing process was also calculated. Construction control measures were also discussed. The research results show that the predicted value of the transient temperature gradient is consistent with the measured value (the maximum deviation is less than 2 °C), and the predicted value is slightly larger than the measured value, which makes the structure safer. During the closing process, the temperature gradient of the main girder has obvious non-linear characteristics: the temperature gradient is relatively high within 0.4 m of the top surface of the roof while tending to zero outside 0.4 m. The best closing time for the main girder is from 21:00 in the evening of the closing day to 6:00 a.m. the next day. For the small angles at both ends of the closure segment during the best closing time, temporary adjustment jacks and temporary counterweights can be adopted to eliminate the small angles at both ends of the closure segment in order to facilitate the welding construction and meet the smoothness requirements of bridge alignment.

Effects of orientation and dimensions of shading structures on thermal comfort

Shading structures can block strong solar radiation and improve pedestrians' thermal comfort in subtropical regions. However, the type, size, and orientation of such structures affect their shading performance. This study explored the effects of the dimensions and orientations of shading structures on pedestrians’ thermal comfort in subtropical Taiwan.In this study, the high accuracy of the Ladybug simulation tool was confirmed through comparison of its results with field measurements. After accuracy confirmation, this tool was used to calculate the physiological equivalent temperature (PET) under shading structures with various dimensions and orientations during the day in summer. The effective aspect ratio (eAR) was developed in this study as a dimensional parameter for shading structures.The simulation results indicated that within the eAR range of 0.22–4.0, lower eAR values were associated with higher average PET values and a greater proportion of time spent by pedestrians under the shading structures in discomfort in summer. The shading orientation also affected thermal comfort. Formulas for predicting PET from eAR were developed in this study, and a simple reference table that indicates the relationships of the dimensions and orientation of shading structures with thermal comfort was created. This table provides a reference for shading-related policy making and shading structure design. The results of this study have been applied to local building codes in Tainan City, Taiwan.

Thermodynamic and economic analysis of a multi-energy complementary distributed CCHP system coupled with solar thermochemistry and active energy storage regulation process

The combination of distributed energy systems (DES) and solar energy is considered a vital measure to save the usage of fossil energy. A new distributed combined cooling, heating and power (CCHP) system integrated with solar thermochemistry (STC) and energy storage (ES) units is proposed. The methane steam reforming (MSR) reaction is driven by solar energy to produce hydrogen-rich syngas, which is fed with high-efficiency solid oxide fuel cell (SOFC) – micro gas turbine (MGT) to produce electricity. The residual heat of the flue gas drives a double effect lithium bromide unit for cooling and a heat exchanger for heating, while a parabolic trough collector (PTC) is used to supplement cooling and heating supply. Under different weather conditions and user load demands, simulation analysis of the matching between system outputs and user loads is conducted, and the thermodynamic and economic performance are analyzed. The results show that through active energy storage regulation, the new system outputs can meet the hourly user loads with a matching degree of 1. The total exergy efficiencies of the system on typical summer, transition and winter days are 69.93%, 62.03%, and 52.28%, respectively, and the specific CO2 emission rates are 152.57 g/kWh, 191.75 g/kWh, and 234.16 g/kWh, respectively, indicating that the system has higher exergy efficiency and is more environmentally friendly under strong solar radiation. Economic analysis indicates that the capital investment cost is 779.34 k$, and the revenue begins in the 9-th year.

Experimental study on the influence of embankment slope direction on near-surface thermal conditions in permafrost region, Qinghai-Tibet Plateau

Heterogeneous ground thermal conditions caused by slope orientation are significant in Qinghai-Tibet Plateau because of the high altitude and strong solar radiation. Variation in solar radiation may result in contrasting thermal and upper boundary conditions, causing engineering problems at infrastructure with sloped embankments. Quantitative research on conditions on different man-made slopes is insufficient in permafrost regions, and consequently, planning for long-term effects on linear infrastructure is challenging. Net radiation, heat flux, near-surface temperature, soil moisture content, were recorded for one whole year (2021) at a field platform with eight slopes. Slope orientation affected net radiation (Rn) and ground heat flux (G), resulting in different energy balances between slopes. The north facing slope had a lowest Rn (174 W m-2), while the south slope had a maximum (239.8 W m-2). The north slope had a negative annual heat flux (-0.7 W m-2), while a maximum positive flux (1.5 W m-2) was recorded on the southeast slope. The annual mean surface temperature (Ts) was highest on the south slope and lowest on the north slope. The maximum difference of ground temperatures (within 30 cm depth) (Tg), was close to differences in Ts of over 4 °C. The maximum difference in soil moisture content during the thawing season (May–October) was 11% between the W and E slopes. Due to the different ground temperatures and soil moisture conditions, the annual number of freeze-thaw cycles was variable, and the maximum freeze-thaw cycles were 106 times in south slope and the minimum were 18 times in west slope. Those different thermal conditions between different slope orientations were significant, and pertinent to planning and maintenance of infrastructure. The results provide accurate boundary conditions for modeling to support development of new infrastructure that have embankment slopes in any direction, and for ensuring the stability of existing structures on Qinghai-Tibet Plateau.

Experimental and numerical study on indoor thermal environment of solar Trombe walls with different air-channel thicknesses in plateau

Trombe wall is an effective method for passively absorbing solar energy and providing heat to buildings. This paper conducts a comparative experiment between Trombe wall buildings and glass curtain wall buildings during the winter season in Songpan County, western Sichuan. The climate characteristics of the western Sichuan plateau are analyzed, and the potential applications of these two building types in the region are investigated. To further understand the heat transfer mechanism of Trombe wall buildings, numerical simulations are carried out to analyze the indoor thermal environment of buildings with varying air channel thicknesses. The results show that Trombe wall buildings are more effective at delaying heat loss compared to glass curtain wall buildings, due to the thermal storage of the Trombe wall providing heat at night. This makes Trombe wall buildings well-suited for regions with strong solar radiation and large temperature differences between day and night, such as the alpine region. However, excessively small air channel thickness can lead to excessive air flow speed during the day, causing more heat loss and weaker insulation at night. Conversely, excessively large air channel thickness reduces air flow temperature difference and diminishes the heat brought into the room. Among different air channels, a thickness of 100 mm performs best with a temperature difference between the inlet and outlet of about 45 °C. At 13:00 o ‘clock, the maximum airflow rate of approximately 5.8 L/s is achieved for a thickness of 100 mm, whereas for thicknesses of 150 mm and 50 mm, the corresponding values are 4.9 L/s and 4.1 L/s, respectively. It is important to note that blindly increasing air channel thickness to raise indoor temperature is not a practical or reasonable engineering solution. The measured and numerical results can provide valuable reference value for the improvement and development of Trombe wall buildings in the future.

Effects of boundary layer dynamics and meteorology on ultrafine particle formation and growth

It is currently not well understood how the planetary boundary layer (PBL) dynamics affects the formation and growth of ultrafine particles in the atmosphere, because of the limited co-located aerosol size distributions and lidar measurements. Here we show, from long-term in-situ observations, a clear link between boundary layer processes and surface aerosol dynamics. Aerosol size distributions in the diameter range from 7 to 300 nm were measured with a scanning mobility particle sizer (SMPS) at the University of Alabama Huntsville campus in 2016, 2017, and 2022. The backscatter of larger aerosols was measured using a co-located lidar ceilometer. Meteorological surface parameters including temperature, relative humidity, station pressure, wind speed and direction, solar radiation, and precipitation were also measured. New particle formation (NPF) and long growth (over 12 h) events occurred most frequently during the winter, unlike many other locations where NPF events occur more frequently in spring and fall, indicating that cooler temperatures play important roles in ultrafine particle formation in the warm subtropical environment. During the summer with strong solar radiation, there were more short-time growth events (less than 6 h), likely associated with convection within the boundary layer. Our observations also show cold fronts affect the measured aerosol size distributions because the combination of precipitation scavenging and cleaner air can provide thermodynamic conditions favorable for NPF and aerosol growth. These results highlight the importance of meteorology on aerosol formation and growth.

Solar Air Conditioning Case Studies for Qatar Climate Conditions

Abstract Air conditioning (AC) is crucial for comfortable living in countries with challenging desert climates like Qatar. In the face of such harsh conditions, cooling applications account for up to 70% of energy consumption in residential buildings. Given the high-energy demand for cooling and the region's abundant solar resources, rooftop photovoltaics (PVs) can offer an ideal sustainable solution, as peak solar supply closely aligns with the electricity demand. This study aims to enhance the feasibility, effectiveness, and system design for solar ACs in Qatar's climate conditions. A simulation model is developed to evaluate different setups of solar AC systems, utilizing local historical weather data. Optimization strategies are explored and validated for the purpose of minimizing the need for costly battery storage. Results demonstrate the efficacy of these techniques, with potential reductions in battery capacity needs of up to 15% through heat inertia management and matching of energy supply and demand. The complete elimination of battery storage is found to be possible but would be at the expense of slight compromises in end-of-day indoor comfort, which can be addressed by cooling storage solutions.

Weakened Subtropical Westerlies Reduced Early Spring Precipitation in the Southeast Tibetan Plateau

Abstract The Southeast Tibetan Plateau (SETP) is a major region where many low-latitude glaciers are located, with spring precipitation being a major input of the glacier mass balance. This study shows that early spring precipitation has decreased significantly since 1999, which is attributed to declined moisture contribution from the far-field sources (west of 70°E) induced by the weakened subtropical westerlies. The possible physical mechanism underlying this change has also been revealed. It is found that snow-cover extent (SCE) in March reduced in midlatitude Eurasia after 1999; meanwhile, strong solar radiation during this month may have exacerbated snow melting through snow albedo–radiation interactions. These two processes led to warming and caused a strong anticyclone over midlatitude Eurasia that weakened the subtropical westerlies near 30°N. This decadal change in the subtropical westerlies led to a decrease in moisture transport upstream. As a result, the windward slopes of large terrain along the latitudinal belt near 30°N received less precipitation, and the decrease in SETP precipitation was part of this change. A further analysis shows that the positive correlation between the westerlies and precipitation has weakened since 1999. Significance Statement The purpose of this study is to reveal the decreased early spring precipitation and explore its possible physical mechanism in the Southeast Tibetan Plateau (SETP), which is crucial to understand the shrinkage of the local glacier. Our results indicate that the reduction of snow cover in midlatitude Eurasia since 1999 and the strong solar radiation in March contributed to the weakening subtropical westerlies, which further resulted in the decreasing precipitation in the SETP and other windward slopes of large terrain along the latitudinal 30°N belt in Eurasia.

Cenderawasih Hot Pool: The Frequent High Sea Surface Temperature Phenomena At Cenderawasih Bay, Papua

The term “warm pool” refers to a body of water with the characteristic of SST exceeding 28°C within a particular area and a relatively long period in an annual circle. However, there are regions with an annual mean SST measured above 30°C, and we classified them as hot pools because of the conditions of intense solar radiation and low wind speed. One of the Hot Pool spots was found in Indonesia, in Cenderawasih Bay. The present study examines the existence of the Cenderawasih Hot Pool using long-term observation of satellite SST data. In order to learn more about their mechanisms, we also analyzed surface wind, surface heat flux, and surface current data. The results show that SSTs in Cenderawasih Bay have a 50% chance of exceeding 30°C within the 13 years of study (2013-2015). Heat input comes from strong solar radiation, i.e., 50% of solar radiation is more than 200 W/m2. The location is also dominated by low wind speed, i.e., 80% wind speed of lower than 4 m/s, which caused the low latent loss in Cenderawasih Bay. Cenderawasih Bay is fully separated from surface currents during the dry and wet seasons since the easterly subsurface water flow does not enter the bay. The absence of strong currents prevents the mixing process, maintaining the high temperature in the surface layer. Those processes are discovered and they serve as compelling evidence to support Cenderawasih Bay as one of the Hot Pool areas within the Indonesian seas.

Assessing the synergies between heat waves and urban heat islands of different local climate zones in Guangzhou, China

Urban heat island (UHI) effects and heat waves (HWs) increase, posing a threat to human health and urban ecological systems. However, the synergistic mechanisms of UHI and HWs are yet to be fully elucidated. This study aims to assess the characteristics of UHI under HWs in different Local Climate Zones (LCZs) using temperature observations from Guangzhou, China. Fixed-point measurements were employed to simultaneously collect air temperature from nine LCZs in 2021. The results showed a localised interplay between HWs and UHI. During HWs, the UHI effect was significantly amplified in built-type LCZ, where the UHI intensity (UHII) was amplified by 0.1–0.5 °C throughout the day, 0.4–1 °C at night, but slightly reduced by 0–0.4 °C during daytime. The UHII was significantly reduced in land-cover type LCZ, and the urban cold effect was amplified during HWs. Furthermore, with strong solar radiation and low wind speed in HWs, the daily maximum UHII of LCZs increased 0.4–1.1 °C. Finally, correlations between UHII and morphological characteristics of LCZs are examined in HWs and non-heat waves (NHWs). During HWs, the increase in impervious surface fraction (ISF) and building surface fraction (BSF) and the decrease in sky view factor (SVF) exacerbate UHII, particularly at night. The augment in surface vegetation fraction (Fveg), does not significantly contribute to reducing the UHI and is less effective than NHWs at night. Therefore, different measures should be taken in different LCZs to mitigate UHII amplification during HWs. This study can serve as a reference for preventing responses to climate extremes.

Adaptive thermal sensation evaluation model in tents for Western Sichuan Plateau of China: A field study

The Western Sichuan Plateau (WSP), which is located in the eastern margin of the Qinghai–Tibet Plateau, exhibits a unique climate featuring high altitude, thin air, low air temperature, and strong solar radiation. The local residents have developed a unique thermal sensation as a result of climatic adaptation, which cannot be accurately described using existing thermal sensation evaluation models. Therefore, we conducted a field study of the thermal sensation of the herdsmen living in tents in two typical areas located in the WSP. We measured the thermal environment parameters (air temperature, relative humidity, air speed, and black-globe temperature) on site and simultaneously conducted a questionnaire regarding the activity level, clothing insulation, and thermal sensation of the residents. A statistical regression analysis was performed, and the results showed a difference of 5.7 °C and 3.2 °C between the actual and predicted thermal neutral temperatures of the residents in the WSP during winter and summer, respectively. To improve the prediction accuracy, an adaptive predicted mean vote (aPMV) model incorporated with an adaptive coefficient was established for the WSP. The aPMV model can accurately predicted the thermal sensation levels of the local herdsmen living in tents.

Characteristics of O3 Production in the Western Suburb of Hefei in Summer Based on the Observation of Total Peroxy Radical

In August 2020, the observations of total peroxy radical concentrations were carried out in the western suburb site of Hefei using a peroxy radical chemical amplifier (PERCA) instrument. The ozone production and its sensitivity were characterized with the measured O3 and its precursors. The results showed that the daily variation in total peroxy radical concentrations exhibited an obvious convex tend, with the highest value at approximately 12:00; the average peak peroxy radical concentration was 43.8×10-12; and the concentrations of the peroxy radical and ozone were driven by strong solar radiation and high temperature. The photochemical ozone production rate could be determined with peroxy radical and NO concentration. The average ozone peak production rate in summer was 10.6×10-9 h-1, which was more sensitive to NO concentration. Based on the ratio of the radical loss rate due to reactions with NOx to the radical loss rate (Ln/Q), the characteristics of O3 production in the western suburb of Hefei in summer were analyzed. The results showed that O3 production sensitivity varied greatly during the day. The summer O3 production regime shifted from the VOC-sensitive chemistry in the early morning to NOx-sensitive chemistry in the afternoon, and this regime transition typically occurred in the morning.

Development and Application of a Mathematical Simulation Model to Evaluate Environmental Performance of Greenhouses Using Physical and Climatic Indicators

This study was conducted to determine and apply a mathematical model to simulate the environmental and climatic parameters to evaluate the performance of different greenhouses in three areas within the Khartoum North – Sudan (Date Palm Technology Company., Abu Halima Center and Khartoum University). The assessment method depends on development of a computer simulation model to generate from house physical characteristics and climate data ten environmental performance evaluation indicators (Relative moisture efficiency; Cooling effectiveness, Moisture saturation efficiency; Water consumption rate; House overall efficiency; House ventilation rate, Optimum internal temperature and internal relative humidity).The result of application of the evaluation model for nine greenhouses in three different locations in Khartoum North reveals that there is no significant differences (P = 0.05) in evaluation indicators between the three studied areas. The study concluded that additional work is needed to upgrade the mode of running greenhouse crop cultivation system with regards to: using sustainable and energy efficient cooling and ventilation technologies, adopting new techniques to conserve water and its efficient utilization, introducing properly adapted materials for high temperatures and strong solar radiation, and accessibility of technologies such as automation systems. In the current system moisture use efficiency in particular found to be lower than expected and measures to improvement are critically needed. With respect to the system efficiency and utility of fan and pad greenhouse the effectiveness of cooling system is function of internal environmental parameter (temperature and relative humidity with negative relation). The evaluation model shows that cooling efficiency tends to go up in the areas with low relative humidity.

Influence of light radiation on performance-structure of tricalcium silicate (C3S) hydration products

In this work, high-power Xenon radiation is used to simulate real sunlight radiation and calcium silicate hydrate is prepared by hydration of tricalcium silicate (C3S) with two water-to-solids (w/s) ratios of 0.5 and 10. The absorbance, compositions, silicate chain structure, pore structure and micromorphology of C3S hydration products (C3S-H) after exposure to Xenon radiation were determined using XRD, TG, FITR, 29Si solid-stated NMR, BET and SEM. First of all, fibrous and needle-like calcium silicate hydrate is observed in C3S-H/10 while flaky and honeycomb-like shape is observed in C3S-H/0.5. Although there are remarkable differences in the micromorphology of calcium silicate hydrate in C3S-H with different w/s ratios, Xenon radiation reduces the amount of bound water, increases the polymerization of silicate chain and refines the nanopore structure of calcium silicate hydrate. The underlying mechanism for the re-organization of chemical structure is attributed to improved polymerization of silicate chains. In addition, the refinement on the nanopore structure is due to the coupling actions of shrinking and polymerization of calcium silicate hydrate sheets. The findings could provide basic knowledge regarding the durability of cement-based materials serviced in atmospheric environments especially with strong solar radiation.

Spectral emissivity measurement of free-falling particle groups

A solar energy receiver is a device that absorbs solar radiation and transfers the generated heat energy to a heat transfer medium. As a heat transfer medium in solar energy receivers, solid particles can safely absorb strong solar radiation flux and achieve a higher operating temperature. Hence, they have attracted considerable research interest. The emissivity of particles is an important parameter in numerical simulation and efficiency analysis of solid particle receivers. However, it is rarely reported, especially for dispersed particles flowing in receivers. In this study, a measurement system for the normal spectral emissivity of free-falling particles is designed and developed. The system is based on the energy method and uses an FTIR spectrometer as a radiation measurement device, which can achieve measurement in the wavelength range of 2.5–16 µm below 800 °C. The emissivity of the sheet SiC material is measured to verify the reliability of the system. The results are in good agreement with the data published in NIST. Furthermore, the effects of the particle material, temperature, and particle group thickness on the particle group emissivity are studied. It is found that the emissivity of gray ceramic sand particles is not sensitive to the temperature, whereas that of alumina ceramic particles is positively correlated with the temperature. The emissivity of the two particles increases rapidly with the release width of the particle group, which is related to the increase in the mass flow rate of the particle group. Finally, uncertainty analysis of the measurement system is performed. The results measured in this paper can provide the original emissivity data for heat transfer simulation and efficiency evaluation in the receiver.

PLTS sebagai Backup Supply pada Plant Hidroponik Nutrient Film Tehcnique (NFT) Berbasis IoT

Indonesia is geographically located on the equator, which has very strong solar radiation and high rainfall, making it suitable for farming. Hydroponics is used as a growing medium for planting without using large areas of land by utilizing water and prioritizing the nutritional needs of plants. NFT is a hydroponic method that is easy to implement and is quite effective for plants. However, this method requires a cycle that cannot be stopped, so it requires a pump that must be on all the time. Therefore, a backup supply is needed that can guarantee the availability or continuity of the supply of electricity to the load by using an Automatic Transfer Switch (ATS) which keeps the system running if the PLN goes out by using PLTS and can be monitored and controlled at any time using Internet of things (IoT) technology. ). From the results of trials and analysis carried out that the performance of the system when in automatic mode, that is, when the battery reaches a value of 11.3 Volts, it will switch to the PLN supply. The supply from PLTS will change to PLN's supply automatically with a predetermined time, namely from 09.00 WIB to 15.00 WIB. If PLN experiences a blackout, it will switch to the PLTS source until PLN is back on.

Subjective perceived risk factors of exertional heat exhaustion-related symptoms in male collegiate athletes in Japan: a case-control study.

The purpose of this study was to investigate associations between lifestyle habits, health factors, athletic activity conditions, and exertional heat exhaustion (EHE)-related symptoms among male college athletes in Japan based on a self-completed questionnaire. The paper-based questionnaires were distributed to 11 universities in Japan, and 2006 respondents completed the survey. Data of personal characteristics (age, body mass), lifestyle habits (sleep duration, use of air-conditioner while sleeping, and practice duration), perceived health factors (loss of appetite, sleep deprivation, sickness, dehydration, accumulated fatigue, and mental stress), perceived athletic activity (insufficient rest breaks, high ambient temperature, excessive humidity, strong solar radiation, lack of ambient wind, and clothing discomfort), and EHE-related symptoms (dizziness, headaches, nausea, and malaise) were collected. The association between lifestyle habits, health factors, athletic activity conditions (explanatory variables), and EHE-related symptoms (objective variables) was analyzed using the partial-proportional odds model. "Perceived dehydration" (odds ratios [ORs] 1.70-2.31, p < 0.002)," "sickness" (ORs 1.35-1.76), p < 0.001), "perceived accumulated fatigue" (ORs 1.13-1.31, p ≤ 0.001), "perceived mental stress" (ORs 1.17-1.31, p < 0.019), "lack of ambient wind" (ORs 1.12-1.19, p < 0.022), "loss of appetite" (ORs 1.16-1.23, p < 0.037), and "sleep deprivation" (ORs 1.15-1.17, p < 0.025) were positively associated with EHE-related symptoms, whereas "using an air conditioner during sleeping" (ORs 0.91, p = 0.047) during summer seasons was negatively associated. These findings suggest that athletes should be allowed to postpone or downregulate exercise intensity and/or volume based on their perceptions of dehydration, sickness, accumulated fatigue, mental stress, loss of appetite, and/or sleep deprivation in the summer to prevent heat illness.

Evaluation of Fire Hazard in Electrical Installations Due to Unfavorable Ambient Thermal Conditions

Evaluation of fire hazard caused by electrical installations is a difficult and important topic, and it limits the possibility of loss of life or health of people, as well as the occurrence of significant property damage. In particular, this hazard was caused by power cables and especially photovoltaic (PV) installations. The authors proved that power cables directly exposed to strong solar radiation are likely to exceed maximum permissible temperature in unfavorable ambient conditions. Overheated and damaged cable insulation can be a source of electric shock and a strong leakage current causing fire. In the case of typical PV connectors (MC4 connectors), the main problem is poor contact at the connections of the PV cables. A poor connection can even cause the connector to melt, as shown in this study. In the paper, the authors present a computer simulation regarding critical thermal points of electrical installations, in particular, of the PV type. It may be an indication of what should be paid attention to when designing and implementing such installations. This is important for the safety of people and buildings.

Comparative analysis of environmental standards to install a rooftop temperature monitoring station

Urban climate influences economic activities and the health and safety of urban residents. Therefore, monitoring temperature in urban areas is important. However, owing to the lack of space for an appropriate observation site, an automatic weather station (AWS) was installed on a building rooftop. The rooftop installation can indicate temperature differences depending on the intensity of strong solar radiation and radiant heat of the building, and wind speed. Therefore, in this study, we aimed to provide observation standards for measuring rooftop temperature according to the optimal rooftop material and observation height. Specifically, an AWS was installed on the rooftop of the Gochang Standard Weather Station (GSWO), Jeollabuk-do Province, to observe the urban climate in South Korea and establish suitable weather standards. Different temperatures, optimum surface materials, and optimum heights for measuring the temperature at the rooftop of GSWO were investigated and compared over 1 year. The temperature recorded after installing a palm mat on the rooftop was more similar to that observed in the grassland. Furthermore, the installation height of the temperature sensor of 2.5–3.0 m for the palm mat and 3.5–4.0 m for concrete was found to be the optimal height for observing temperature at the rooftop.