High Air Temperature Research Articles

A thermal performance curve perspective explains decades of disagreements over how air temperature affects the flight metabolism of honey bees.

While multiple studies have shown that honey bees and some other flying insects lower their flight metabolic rates when flying at high air temperatures, critics have suggested such patterns result from poor experimental methods as, theoretically, air temperature should not appreciably affect aerodynamic force requirements. Here, we show that apparently contradictory studies can be reconciled by considering the thermal performance curve of flight muscle. We show that prior studies that found no effects of air temperature on flight metabolism of honey bees achieved flight muscle temperatures that were near or on equal, opposite sides of the thermal performance curve. Honey bees vary their wing kinematics and metabolic heat production to thermoregulate, and how air temperature affects the flight metabolic rate of honey bees is predictable using a non-linear thermal performance perspective of honey bee flight muscle.

Increased heat stress for the population of urbanized areas against the background of global climate change

The combination of high temperature and relative humidity of the atmospheric air creates heat stress, which has a serious impact on the environment, society and the health of the population in urban areas. Using the example of the city of Kyiv, the paper investigated long-term changes in heat stress depending on global climate changes. Averaged monthly long-term climate data of the urban environment were studied, starting from 1981, based on monitoring data using the Copernicus Climate Change Service toolkit and data from the Borys Sreznevsky Central Geophysical Observatory. Predictive dynamics of temperature by conventional and wet bulb was investigated using OriginPro8 software. Data on the dependence of the frequency and unevenness of precipitation during the last decades are presented. The dependences of the value of the heat index (NI) on the temperature and air humidity for different observation periods were obtained. Over the past decade, Kyiv has seen a significant increase in average heat stress and the frequency of days and events with extreme heat stress. According to the obtained forecast estimates, in 2050 the heat index should increase by almost 30%, and the risk to the health of the population in the surrounding area and for workers in the open air will be interpreted as "high" levels at a relative humidity of 80%; "moderate" at a relative humidity of 50% and "low" at a relative humidity of 20%. The forecast temperature dynamics according to the conventional and according to the wet thermometer in the month of July at the end of different years is: 2021–2030 – 24.136°С and 26.24°С; 2030–2050 – 26.371°С and 28.918°С, respectively, with other equal conditions of the urban environment. An additional possibility of influence on the thermal dome appears already at the design stage, thanks to the variability of the placement of the projected buildings on the general plan, and the formation of individual buildings, in the correct area ratio green plantings to stone surfaces of facades and paving. The research data will be useful for the possible reduction of the size of the thermal dome over the city during the planning and reconstruction of the housing stock and the development of climate neutrality measures for the cities of Ukraine.

A prenatal acoustic signal of heat reduces a biomarker of chronic stress at adulthood across seasons.

During development, phenotype can be adaptively modulated by environmental conditions, sometimes in the long-term. However, with weather variability increasing under climate change, the potential for maladaptive long-term responses to environmental variations may increase. In the arid-adapted zebra finch, parents emit "heat-calls" when experiencing heat during incubation, which adaptively affects offspring growth in the heat, and adult heat tolerance. This suggests that heat-call exposure may adjust individual phenotype to hot conditions, potentially compromising individual sensitivity to cool weather conditions. To test this hypothesis, we manipulated individual prenatal acoustic and postnatal thermal experiences during development, and sought to assess subsequent chronic responses to thermal fluctuations at adulthood. We thus measured heterophil to lymphocyte (H/L) ratios in adults, when held in outdoor aviaries during two summers and two winters. We found that birds exposed to heat-calls as embryos, had consistently lower H/L ratios than controls at adulthood, indicative of lower chronic stress, irrespective of the season. Nonetheless, in all birds, the H/L ratio did vary with short-term weather fluctuations (2, 5 or 7days), increasing at more extreme (low and high) air temperatures. In addition, the H/L ratio was higher in males than females. Overall, while H/L ratio may reflect how individuals were being impacted by temperature, heat-call exposed individuals did not show a stronger chronic response in winter, and instead appeared more resilient to thermal variability than control individuals. Our findings therefore suggest that heat-call exposure did not compromise individual sensitivity to low temperatures at adulthood. Our study also reveals that prenatal sound can lead to long-term differences in individual physiology or quality/condition, as reflected by H/L ratios, which are consistent with previously-demonstrated reproductive fitness differences.

Efficiency of weed control in winter pea in the Right Bank Forest Steppe of Ukraine

Purpose. To analyze the features of weed control in winter pea in the Right Bank Forest Steppe of Ukraine. Methods. The research was conducted at the Salyvonky State Enterprise of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences of Ukraine (Bila Tserkva district, Kyiv region) in 2020–2023. The agronomic practices used in the experiment were conventional for the zone of insufficient moisture of the Right Bank Forest Steppe of Ukraine, with the exception of the studied elements. Results. The development of the concept of autumn weed control for winter pea from requires a fairly competent selection of herbicides, taking into account weather forecasts, the specifics of the effect of active substances on weeds and cultivated plants, etc., as conditions for sowing winter pea do not allow to effectively apply conventional weed control system with the use of soil tillage and, if necessary, the limited application of herbicides during the vegetation season. This is explained by the fact that the terms for soil preparation and sowing are quite limited, and soil herbicides at high air temperatures work unpredictably and have limited efficiency in case of moisture deficit. Herbicide Corum, developed by combination of active substances bentazone (480 g/l) and imazomox (22 g/l), had better indicators in terms of total efficiency at an increased application rate (1.5 l/ha) – 92.9% in the BBCH 12 and 91.7% in the BBCH 14. At the same time, the efficiency of an application rate of 1.25 l/ha was within 80%. The latter is probably related not only to the autumn conditions of application of the [reparation, but also to the fact that such species as Fumaria officinalis, Sinapis arvensis, Solanum nigrum and thistles sprouted later, when the main mass of weeds was already in a development stage that was less sensitive to low rates of the herbicide. Conclusions. The application of Corum herbicide in the BBCH 12 at an application rate of 1.25 l/ha contributed to the destruction of 73.8% and an application rate of 1.5 l/ha resulted in 86.7% of weeds. When the herbicide was applied in BBCH 14, the total efficiency of crop treatment at an application rate of 1.25 l/ha was higher by 2.4% and at a rate of 1.5 l/ha it was higher by 1.2% compared to application in the BBCH 12. This is due to the fact that Chenopodium album, Amaranthus retroflexus, Polygonum convolvulus, Persicaria maculosa, Solanum nigrum, Polygonum lapathifolium and thistles sprouted in the pea crops, and the herbicide was highly effective against them. On the other hand, weed plants that sprouted earlier continued to vegetate and were already less sensitive even to increased application rates of herbicide. The application of the maximum recommended application rates was, for the most part, the most effective measure to reduce the number of weeds in winter pea crops. At the same time, such rates affected crop plants, causing stress, especially in the late periods of growth and development, which further affected the formation of pea yield. Therefore, the use of herbicides in the late phases of crop development should be avoided.

Summer drought weakens land surface cooling of tundra vegetation

Siberia experienced a prolonged heatwave in the spring of 2020, resulting in extreme summer drought and major wildfires in the North-Eastern Siberian lowland tundra. In the Arctic tundra, plants play a key role in regulating the summer land surface energy budget by contributing to land surface cooling through evapotranspiration. Yet we know little about how drought conditions impact land surface cooling by tundra plant communities, potentially contributing to high air temperatures through a positive plant-mediated feedback. Here we used high-resolution land surface temperature and vegetation maps based on drone imagery to determine the impact of an extreme summer drought on land surface cooling in the lowland tundra of North-Eastern Siberia. We found that land surface cooling differed strongly among plant communities between the drought year 2020 and the reference year 2021. Further, we observed a decrease in the normalized land surface cooling (measured as water deficit index) in the drought year 2020 across all plant communities. This indicates a shift towards an energy budget dominated by sensible heat fluxes, contributing to land surface warming. Overall, our findings suggest significant variation in land surface cooling among common Arctic plant communities in the North-Eastern Siberian lowland tundra and a pronounced effect of drought on all community types. Based on our results, we suggest discriminating between functional tundra plant communities when predicting the drought impacts on energy flux related processes such as land surface cooling, permafrost thaw and wildfires.

Drivers of anomalous surface melting over Ingrid Christensen Coast, East Antarctica

Antarctica contains 90% of the Earth's ice; if it melts, it can significantly contribute to the rise in global sea levels. Over Antarctica, short-term atmospheric warming events have led to significant surface melt in summer. Understanding the conditions of such warming events and subsequent surface melt is highly prioritized in Polar Research. The austral summer of 2016-17 witnessed the largest melt duration of the 21st century over Ingrid Christensen Coast (ICC), East Antarctica. Being situated on the grounded ice near four research stations, understanding the melt over the region has both scientific and operational importance. Here, we investigate the drivers of four major melt events identified over ICC for the austral summer of 2016-17 using the reanalysis dataset, ERA5. The first melt event, coinciding with the season's highest air temperature, was triggered by high turbulent heat flux from strong katabatic winds, while the rest of the events were triggered by low-level, liquid cloud-induced longwave radiation. During the melt events, anomalous high pressure ridges were present over the continent causing low pressure systems to remain stationary for an extended period and direct warm, moist air towards the ICC, facilitating melting. The present study observed melting occurring above the grounding zone, and if such melting extends to a larger scale beyond ice shelves, it could raise significant concerns regarding the hydrodynamics and stability of ice sheets in the future.

Impact of Foodborne Disease in Taiwan during the COVID-19 Pandemic.

Background and Objectives: The coronavirus disease 2019 (COVID-19) pandemic originated in Wuhan, China, in December 2019, the first case diagnosed since January 2020 in Taiwan. The study about the potential impact of the COVID-19 pandemic on event, location, food source, and pathogens of foodborne disease (FBD) is limited in Taiwan. Our aim in this study is to investigate FBD in the context of the COVID-19 pandemic. Materials and Methods: We collected publicly available annual summary data from the FBD dataset in the Taiwan Food and Drug Administration and Certifiable Disease on reported FBD in Taiwan from 2019 to 2020. We used logistic regression to evaluate changes in the occurrence or likelihood of FBD cases and Poisson regression to examine the relative risk (RR) between FBD and climate factors. Results: Similar events occurred in 2019 and 2020, but the total number of FBD cases decreased from 6935 in 2019 to 4920 in 2020. The places where FBD decreased were in schools, hospitals, outdoors, vendors, and exteriors. The top place in FBD shifted from schools to restaurants. The top food source for FBD has changed from boxed food to compound food. Bacillus cereus and Salmonella emerged as the top two observed bacterial pathogens causing FBD. The risk of FBD cases increased with a higher air temperature, with an RR of 1.055 (1.05-1.061, p < 0.001) every 1 °C. Conclusion: The incidence of FBD decreased significantly during the COVID-19 pandemic in Taiwan. This decline may be attributed to protective measures implemented to control the spread of the virus. This shift in locations could be influenced by changes in public behavior, regulations, or other external factors. The study emphasizes the importance of understanding the sources and effectiveness of severe infection prevention policies. The government can use these findings to formulate evidence-based policies aimed at reducing FBD cases and promoting public health. Consumers can reduce the risk of FBD by following safe food handling and preparation recommendations.

Comparison of carbon and water fluxes and the drivers of ecosystem water use efficiency in a temperate rainforest and a peatland in southern South America

Abstract. The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For 8 years (2015–2022), we measured carbon dioxide net ecosystem exchange (NEE) and evapotranspiration (ET) using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. NEE was partitioned into gross primary productivity (GPP) and ecosystem respiration (Reco), while ET was partitioned into evaporation (E) and transpiration (T) and used to estimate different expressions of ecosystem WUE. We then used the correlation between detrended time series and structural equation modelling to identify the main environmental drivers of WUE, GPP, ET, E and T. The results showed that the forest was a consistent carbon sink (−486 ± 23 g C m−2 yr−1), while the peatland was, on average, a small source (33 ± 21 g C m−2 yr−1). WUE is low in both ecosystems and likely explained by the high annual precipitation in this region (∼ 2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable, accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation and higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e. mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e. anisohydric tree species in the forest). The observed increase in potential ET in the last 2 decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant.

Filling structure design and cooling mechanism study of the heat-not-burn cigarettes with sidewall openings

The smoke temperature of heat-not-burn cigarettes is usually high, which affects the user experience. This study investigates the application of filled structures in the cooling process of heat-not-burn cigarette smoke through experiments and numerical simulations. A cigarette structure that can effectively reduce the smoke temperature is identified. The temperature distribution characteristics and flow process of heat-not-burn cigarettes with straight and filled multifluid structures were investigated by numerical simulation. The mixing mechanism between high-temperature smoke and air inside them was revealed. The low-temperature air and high-temperature smoke are centrally mixed in the straight structure and are concentrated in the center of the structure under the effect of shear flow. In the multi-flow channel structure, the low-temperature air and high-temperature smoke diffuse to the wall due to the structural inflow and the pressure in the center return area, which is the decentralized mixing mode. The decentralized mixing method can promote the mixing between low-temperature air and high-temperature smoke and effectively reduce the temperature of the smoke. It has a 7 K cooling effect on the smoke compared to the straight structure, which can provide a new solution for exploring healthier and superior heat-not-burn cigarettes.

LysipheN: a gravimetric IoT device for near real-time high-frequency crop phenotyping: a case study on common beans

Climate instability directly affects agro-environments. Water scarcity, high air temperature, and changes in soil biota are some factors caused by environmental changes. Verified and precise phenotypic traits are required for assessing the impact of various stress factors on crop performance while keeping phenotyping costs at a reasonable level. Experiments which use a lysimeter method to measure transpiration efficiency are often expensive and require complex infrastructures. This study presents the development and testing process of an automated, reliable, small, and low-cost prototype system using IoT with high-frequency potential in near-real time. Because of its waterproofness, our device—LysipheN—assesses each plant individually and can be deployed for experiments in different environmental conditions (farm, field, greenhouse, etc.). LysipheN integrates multiple sensors, automatic irrigation according to desired drought scenarios, and a remote, wireless connection to monitor each plant and device performance via a data platform. During testing, LysipheN proved to be sensitive enough to detect and measure plant transpiration, from early to ultimate plant developmental stages. Even though the results were generated on common beans, the LysipheN can be scaled up/adapted to other crops. This tool serves to screen transpiration, transpiration efficiency, and transpiration-related physiological traits. Because of its price, endurance, and waterproof design, LysipheN will be useful in screening populations in a realistic ecological and breeding context. It operates by phenotyping the most suitable parental lines, characterizing genebank accessions, and allowing breeders to make a target-specific selection using functional traits (related to the place where LysipheN units are located) in line with a realistic agronomic background.

Single droplet drying with stepwise changing temperature-time trajectories: Influence on heat sensitive constituents

Optimization procedures for industrial spray drying processes mainly rely on empirical understanding. Mechanistic understanding of the process is limited, but can be enhanced by studying the drying of single droplets. We here report on a new sessile single droplet drying platform, using two air streams to represent the inlet and outlet air of a spray dryer to simulate changing conditions in a spray dryer. Accurate temperature measurements confirmed the temperature profiles and their imposition onto a drying droplet. Single droplets of solutions containing β-galactosidase and maltodextrin were dried with different temperature-time trajectories, with the inactivation of the enzyme as indicator for the thermal load on the droplet. The locking point is found to be an important parameter: the air temperature before this point does not influence the enzyme inactivation much, but a high air temperature after the locking point results in significant inactivation. The β-galactosidase inactivation was also successfully predicted with a coupled drying and inactivation model.

VARIATIONS OF δ18О AND δ2H VALUES OF PRECIPITATION IN MOSCOW FROM 2017 TO 2019

To reveal variations in the iso topic composition of O and H in the atmospheric precipitation in Moscow and the processes influencing the isotope composition, all events of precipitation in 2017-2019 were sampled at the Meteorological Observatory of the Moscow State University: 158 samples in 2017, 119 samples in 2018 and 143 samples in 2019. The study is a prolongation of continuous measurements of the isotope composition of precipitation, started by authors in 2014. The study of the isotope composition of precipitation at the MSU Meteorological Observatory was supported by the IAEA and became a part of the Global Network of Isotopes in Precipitation (GNIP) database. It has been found that the intra-annual variability of the isotop e composition of precipitation has a pronounced seasonality. The most isotopically heavy precipitation falls from May to August, and the most isotop ically light precipitation at December-February, mainly due to seasonal air temperature variations. The ratio of the average monthly δ18O values in precipitation and air temperature for the study period varied from 0.34 to 0.39‰/°C, which is consistent with the previously obtained data for precipitation in Moscow. The δ2H-δ18O ratio in precipitation was clos e to that of the Global Meteoric Water Line, pointing to the equilibrium conditions during precipitation formation. It was established that in the summer months isotopic composition is significantly influenced by undercloud evaporation. The deuterium excess va lues in precipitation are not markedly seasonal; however, lower dexc values (below the 3-year average of 11‰) are typical for the summer months (July-August). It is most likely due to undercloud evaporation in conditions of low relative humidity and high air temperatures. Higher dexc values (above 11‰) prevailed from October to April.

Microclimatic study under wheat, mustard and chickpea crops in western plain zone of Uttar Pradesh

The present study to quantify the variations in microclimate under wheat, mustard and chickpea crops was conducted at ICAR-Indian Institute of Farming Systems Research, Modipuram, Meerut (U.P.), India. Air temperature, relative humidity, CO2 concentration below and above the canopies of wheat, mustard and chickpea were recorded at hourly interval from 07:30 to 17:30 hours at different heights (0.5 m, 1.0 m and 2.0 m) from the ground. CO2 probes like GMP-343, (Diffusion aspiration) was used to record data of CO2 concentration and HPM-75 probes was used to capture the observation of air temperature and relative humidity. Results revealed that diurnal air temperature was continuously increasing from morning to afternoon hrs and highest air temperature was recorded at 13:30 hrs (afternoon). Thereafter, air temperature decreased and reached to the lowest at 17:30 hrs irrespective of crops and height from the ground. Analysis of diurnal air temperature variations at different height clearly showed that tall statured crop such as wheat and mustard reached higher air temperature regime early (13.30 hrs) compared to short statured crop like chickpea at 15.30 hrs. Highest relative humidity was observed at 07.30 hrs and lowest relative humidity was recorded either at 13:30 hrs or at 15:30 hrs. As per study maximum CO2 concentration was found at 07:30 hrs morning and minimum at 15:30 hrs. The lowest concentration of CO2 (624 ppm) was recorded from the chickpea field and highest from the mustard field (630 ppm) at the same point of observation during vegetative phase of crops.

The impact of well spacing on three-dimensional in situ extraction of oil shale using high-temperature air injection

To explore the impact of well spacing on the in situ high-temperature air injection for three-dimensional shale oil recovery, this study constructed six different well-spacing physical models of shale oil for investigation. By comparing factors such as temperature distribution, cumulative oil production volume, heating rate factor, and specific energy consumption per unit volume of shale oil among the six different well-spacing models, the influence of well spacing on the in situ high-temperature air injection for three-dimensional shale oil recovery was analyzed. The results showed that all six shale oil models exhibited a ripple pattern, advancing along the fractured fissures from the heating well to the production well. Model I, Model II, Model III, Model IV, Model V, and Model VI completed the full decomposition of the shale region at 2610, 1530, 1800, 3510, 4050, and 6660 days, respectively. The heating rate factor reached its peak at 1800, 900, 1440, 2340, 3240, and 3960 days. Model III had the lowest specific energy consumption per unit volume of shale oil, which was 905.41 kW/m3. Using Model III for three-dimensional shale oil injection with high-temperature air in situ recovery will shorten the heating time and reduce heat loss.

Effects of Accumulated Growing Degree Days (GDDs) on Sesame (Sesamum indicum) Growth and Yield under Greenhouse Condition in the Mekong Delta, Vietnam

Sesame has high nutritional value, sesame seeds contain oil, protein, sugar, water, ash, and two kinds of oleic acid and linoleic acid; sesame is commonly used in the diet or as a vegetable oil. Sesame is grown in many tropical countries, and the optimum temperature for sesame growth is 25-30 °C. Due to climate change, the temperature is increasing, in the Mekong Delta of Vietnam, the temperature in summer can reach nearly 35 °C. The research question is whether high air temperature affects sesame growth and yield. To answer the above question, the study was conducted in greenhouse conditions in An Giang province with different temperature conditions, including 3 extreme chambers from 32.7, 32.9, and 34°C; automatic fan and a misting system for to control temperature. Black sesame plants were grown in 42 pot (34 x 28 x 28cm), each chamber with 4 plants per pot. All pots were filled with the same amount of alluvial soil (Fluvi Mollic Gleysols). Results showed that accumulated growing degree days in chambers 1, 2, and 3 were 2115, 2019, and 1994 GDDs, respectively. At 2115 GDDs gave the highest value of fresh biomass (1417g/pot), dry biomass (276 g/pot), dry weight capsule (109 g/pot), and dry seeds (51 g/pot). Regarding harvest index, chamber 3 with 1994 GDDs gave the highest harvest index of 0.22; the other chambers were in the range of harvest index of 0.18-0.20. In conclusion, under greenhouse conditions with 2115 GDDs is ideal for the growth and yield performance of black sesame.

Numerical simulation of sound attenuation in an acoustically lined duct in high-temperature air flows

Noise reduction structures are important for the vibration and noise reduction design of aerospace engines. The design of noise-reducing structures often needs to be quickly evaluated via numerical simulations. Hence, the simulation results of the corresponding system are very important for guiding the design of noise-reducing structures. High temperature is one of the key environmental factors that need to be considered when evaluating the sound attenuation process via numerical methods. In this study, numerical simulations of acoustic wave propagation on an acoustic liner structure considering air temperature variations are carried out by using compressible Navier–Stokes equations and the ideal gas equation of state. The results showed that the effect of temperature on sound attenuation under grazing flow conditions is complex. Moreover, an increase in temperature will reduce the transmission loss of the acoustic liner in the grazing flow at high air speed.

Transport cross sections and collision integrals for N(4S)–O(3P) and N(4S)–O(1D) interactions in high-temperature air plasmas

Collisions between nitrogen (N) and oxygen (O) play a crucial role in determining transport coefficients in high-temperature atmospheres of Earth and planetary. In this study, the momentum transfer, viscosity, third-moment, and fourth-moment transport cross sections for the N(4S)–O(3P) and N(4S)–O(1D) interactions are reported in the collision energy range of 10−6–10 Hartree based on the classical and semiclassical methods. The new and accurate potential energy curves for N–O interactions, which are used to provide the input for calculations of the cross sections, are calculated based on the state-of-the-art ab initio method. The classical and semiclassical collision integrals are provided at 300–50 000 K, and the results support the calculation of transport coefficients in a third-order approximation. In particular, the collision data for the N(4S)–O(1D) interaction based on ab initio points are reported for the first time. The calculated transport cross sections and collision integrals are helpful for studies of modeling the high-temperature air plasmas.

High-temperature properties of dry air used as arc quenching medium and its mixture with vaporized C2F4 : reaction products and critical reduced electric field strength at 300–3000 K

Recently, electric power equipment manufacturers released a joint statement with the aim of developing high-voltage electrical equipment completely free of fluorinated gases such as fluoroketones and fluoronitriles, which are considered as alternatives to SF6 and artificially produced compounds of F. This paper considers air as a typical gas present naturally in the environment to investigate its high-temperature properties, including an air mixture with C2F4 vapor injected from a polytetrafluoroethylene nozzle, for application as an arc-quenching medium in a high-voltage circuit breaker equipped with a nozzle. Chemical composition results for the reaction products at 300–3000 K show that the admixture of C2F4 vapor causes a decrease in the molar number of O2 contained in the air, owing to the production of O-containing compounds such as CO2 and CO . Additionally, the results reveal that the admixture of C2F4 vapor lead to the production of CF4 as the predominant F-containing compound. Furthermore, the boundary condition for O2 production in terms of O2 molar number XO2 and C2F4 molar number XC2F4 is formulated. Such evaluation of the mixture composition enables the determination of a reduced effective collision ionization coefficient αˉ/N and a critical reduced electric field strength Ecr/N , resulting in αˉ/N = 0. The strength Ecr/N for the mixture with 30%–100% C2F4 molar fraction rises to approximately 150 Td (1 Td = 1 ×10−21 V m2) over 300–3000 K, which is 20–50 Td higher than that for high-temperature air unmixed with C2F4 vapor. The variation in Ecr/N is discussed in terms of predominant electron impact processes and the electron energy distribution function in the mixture.

In Situ Real-Time Atomic Force Microscopy Observations of Chain Mobility at Polymer/Water Interfaces of Poly(methyl methacrylate), Poly(2-hydroxyethyl methacrylate), and Poly(2-methoxyethyl methacrylate) Films in Water.

Polymer materials are widely used in water or in contact with an aqueous environment. However, evaluating the chain mobility, a crucial parameter, at a polymer-water interface is challenging. In this study, we, for the first time, observed poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), and poly(2-methoxyethyl methacrylate) (PMEMA) film surfaces in water via in situ real-time atomic force microscopy (AFM) in tapping mode and quantified the chain mobility. The average displacement between adjacent images (nm/8.75 min) was evaluated using particle image velocimetry. The displacement of PMMA, which has a high bulk glass-transition temperature (Tg) (108 °C) and exhibits limited water absorption, was low both in air (0.54 nm/8.75 min) and water (0.86), while PHEMA, which has a high bulk Tg (99 °C) and exhibits high water absorption, exhibited low mobility in air (0.40) but two orders of magnitude higher mobility in water (60). PMEMA, which has a low bulk Tg (14 °C) and exhibits limited water absorption, already started to move in air (4.5), and its mobility moderately increased in water (20). These behaviors were reasonable, considering the bulk Tg and water absorption characteristics of the polymers. Further, the chain mobility in water was compared with that of dried samples at high temperatures in air. The mobility of PMMA, PHEMA, and PMEMA in water corresponded to that of the dried samples observed in air below the surface Tg (97 °C) for PMMA, at ∼125 °C for PHEMA, and at ∼35 °C for PMEMA. In situ real-time AFM analysis of polymer materials in water is an effective method for evaluating the chain mobility at the polymer/water interface.

Evaporative cooling strategy using cooling pad material made from stove wicks in walk-up flat in the humid tropical climate of Surabaya

Generally, the thermal conditions in simple flats for rent are still not within a comfortable range. There is no implementation of artificial ventilation (Air Conditioner) with adjustable air temperature, so passive strategies still need to be pursued. In this case, the strategy pursued is Direct Evaporative Cooling (DEC) system with cooling pads made from stove wicks. Experimental methods were conducted in one of the apartment buildings in Surabaya, namely Indrapura Walk-up Flat. The research results indicate that at relatively high outdoor air temperatures from 12:00 to 15:00 local time, ranging from 27.9 to 32oC, the implementation of DEC was able to reduce the air temperature by 1.94-2.08oC