Increase In Temperature Research Articles

Synthesis and characterization of titanium oxynitride catalyst via direct ammonia nitridation of titanium polyacrylate for oxygen reduction reaction

AbstractA titanium oxynitride catalyst for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cells was synthesized through the direct ammonia nitridation of titanium complexes. Titanium polyacrylate was employed as the catalyst precursor, and the effect of the calcination temperature between 600 and 1000 °C on the catalyst structure was studied. The catalysts were characterized via X-ray diffraction, X-ray absorption spectroscopy, transmission electron microscopy, cyclic voltammetry, and powder electrical resistivity measurements. The formation of titanium oxynitride particles and deposited carbon was observed for all the samples; however, significant variations in the catalyst structure and catalytic activity were also observed. With an increase in the calcination temperature, nitridation of titanium oxynitride progressed, and the conductivity of the catalyst powder increased. The highest rest potential and ORR current density were achieved with calcination at 800 °C. Importantly, the results suggest that maintaining an optimal nitrogen doping level within the catalyst particles, along with ensuring the formation of electroconductive deposited carbon, is essential for achieving a high ORR current. This work introduces the direct ammonia nitridation of metal complexes as a promising process for designing metal oxynitride catalysts.

Extreme ultra-short-term changes in air temperature in January in southern Poland (the example of Sosnowiec) against the background of atmospheric circulation conditions

Abstract Large short-term changes in air temperature affect the functioning of living organisms in the environment and human activities. For this reason, a study of extreme positive and negative 10 min temperature changes and their causes related to atmospheric circulation was undertaken. Air temperature data for January in the period 2001–2017 in southern Poland (Sosnowiec) were analysed. Extreme ultra-short-term temperature changes were considered to be values less than or equal to 0.1 percentile (extreme temperature drops) and greater than or equal to 99.9 percentile (extreme temperature increases). The extreme ultra-short-term negative air temperature change was − 7.2°C/10 min, while the positive change was + 3.5 °C/10 min. Extreme ultra-short-term negative air temperature changes in southern Poland in January occur most frequently with the advection of air from the west (43% of cases), the inflow of maritime Polar old (transformed) air over Poland (25% of cases), western cyclonic (Wc) and north-western cyclonic (NWc) situations, a total of 34% of cases), the passage of the atmospheric front over southern Poland (59% of cases), especially a cold front (68% of cases with a front). Extreme ultra-short-term positive changes of air temperature in southern Poland in January occur most frequently with the advection of air from the south-west (43% of cases), the inflow of continental Polar air (42% of cases), anticyclonic situations (72% of cases), the occurrence of a high-pressure wedge over southern Poland (26% of cases), situations without atmospheric front (80% of cases). The direction of advection plays a secondary role in determining the values of extreme short-term changes in air temperature. More important is the speed of the influx of this air mass. Extreme ultra-short-term temperature changes are partly explained by circulation conditions. Rapid temperature changes can also occur as a result of small-scale processes in the atmosphere.

Interdisciplinary Research for the Delimitation of Catchment Areas of Large Deep Karstic Aquifers: Origin of the Thermal Springs of Alhama de Aragon and Jaraba (Spain)

The integration of different sources of geological and hydrogeological information and the application of interdisciplinary methods have informed the origin of the thermal springs of Alhama de Aragón and Jaraba, as well as other associated semi thermal springs (1200 L/s of combined flow, 711 L/s at over 30 °C), which is the main objective of this article. These springs come mainly from the autogenous recharge that occurs in the Cretaceous calcareous outcrops that border the Almazán Basin to the north, both in the Ebro Basin (Jalón Valley) and in the Duero Basin. The aquifer, shaped by upper Cretaceous limestones under the Palaeogene and Neogene rocks of the Almazán Basin, has extensive depths of more than 4000 m in the NE sector. This hydrostratigraphic unit has been affected by a generalized pre-Paleogene karstification that provides the main porosity to the aquifer. The underground flow moves in a NW–SE direction, crossing the Duero–Ebro divide, favoured by the topographic difference in elevation between the two basins. The regional flow is coherent with the progressive increase in temperature, infiltrating recharge water age (about 20–25 years in the semi-thermal springs, and more than 60 years in the Alhama and Jaraba springs), mineralization, and flow of the springs through which the system discharges. This issue is key to being able to design any sustainable conservation strategy in terms of quantity and quality of resources within the recharge area of the most important thermal springs in Spain. The Jaraba and Alhama de Aragón hot springs share the same or similar temperature, chemical composition, and geological contact of the spring. Their tritium isotopic composition and its evolution over time are practically the same. Their isotopic composition in D and 18O is also very similar. Both springs share the same recharge zone of similar altitude and constitute the end of flow tubes of similar length and flow rate.

Characterization of Groundwater Geochemistry in an Esker Aquifer in Western Finland Based on Three Years of Monitoring Data

This study investigated the hydrogeochemistry of a shallow Quaternary sedimentary aquifer in an esker deposition in western Finland, where distinct spatial and temporal variability in groundwater hydrogeochemistry has been observed. Field investigation and hydrogeochemical data were obtained from autumn 2010 to autumn 2013. The data were analyzed using the multivariate statistical methods principal component analysis (PCA) and hierarchical cluster analysis (HCA), in conjunction with groundwater classification based on the main ionic composition. The stable isotope ratios of δ18O and δD were used to determine the origin of the groundwater and its connection to surface water bodies. The groundwater geochemistry is characterized by distinct redox zones caused by the influence of organic matter, pyrite oxidation, and preferential flow pathways due to different hydrogeological conditions. The groundwater is of the Ca-HCO3 type and locally of the Ca-HCO3-SO4 type, with low TDS, alkalinity, and pH, but elevated Fe and Mn concentrations, KMnO4 consumption, and, occasionally, Ni concentrations. The decomposition of organic matter adds CO2 to the groundwater, and in this study, the dissolution of CO2 was found to increase the pH and enhance the buffering capacity of the groundwater. The mobility of redox-sensitive elements and trace metals is controlled by pH and redox conditions, which are affected by the pumping rate, precipitation, and temperature. With the expected future increases in precipitation and temperature, the buffering capacity of the aquifer system will enhance the balance between alkalinity from bioactivity and acidity from recharge and pyrite oxidation.

Investigation into Recycling of Iron Oxide Scale on H13 Steel by Low‐Temperature Carbothermal Reduction Method

The current method for recovering iron oxide scale in the steel industry is not economically optimal, especially for high‐alloy scales found in alloyed steel. This study focuses on iron oxide scale containing valuable metals like chromium (Cr), molybdenum (Mo), and vanadium (V). The required carbon addition is calculated based on the iron and chromium oxides in the scale. The effects of varying carbon additions and reduction temperatures on reduction efficiency are thoroughly examined. Kinetic studies show that as temperature and carbon increase, the rate‐limiting step shifts from interfacial diffusion to interfacial reaction. Reduction experiments assess carbon utilization, metallization rate, deoxidation rate, and removal of harmful elements. Results show that high temperatures hinder sulfur (S) and phosphorus (P) removal, and excess carbon reduces carbon utilization efficiency. Optimal conditions are a carbon ratio of 0.2174 and a temperature of 1150 °C. The carbothermic reduction product requires further refinement through conventional ladle slag systems to meet the quality standards for metallic materials. Over 65% of alloying elements are recovered, though phosphorus content remains slightly higher than in finished alloy steel. The materials from this study are suitable as high‐quality intermediates for alloy steel production.

Soil microfauna mediate multifunctionality under multilevel warming in a primary forest

Abstract Soil microfauna play a crucial role in maintaining multiple functions associated with soil phosphorous, nitrogen and carbon cycling. Although both soil microfauna diversity and multifunctionality are strongly affected by climate warming, it remains unclear how their relationships respond to different levels of warming. We conducted a 3‐year multilevel warming experiment with five warming treatments in a subtropical primary forest. Using infrared heating systems, the soil surface temperature in plots was maintained at 0.8, 1.5, 3.0 and 4.2°C above ambient temperature (control). Our findings indicated that low‐level warming (+0.8–1.5°C) increased soil multifunctionality, as well as nematode and protist diversity, compared with the control. In contrast, high‐level warming (+4.2°C) significantly reduced these variables. We also identified significant positive correlations between soil multifunctionality and nematode and protist diversity in the 0–10 cm soil layer. Notably, we found that soil multifunctionality and protist diversity did not change significantly under 3.0°C warming treatment. Our results imply that a temperature increase of around 3°C may represent a critical threshold in subtropical forests, which is of great importance for identifying response measures to global warming from the perspective of microfauna in the surface soil. Our findings provide new evidence on how soil microfauna regulate multifunctionality under varying degrees of warming in primary forests.

Change in interleukin (IL)-6, 8, and 10 and its association with an increase in core temperature following a 7-mile running race in the warm weather

ABSTRACT The purposes of this study were 1) to investigate if cytokines were increased following a running road-race, and 2) to examine associations between cytokines and hyperthermia. Seventy-seven recreational runners participated in this study which occurred at the 7-mile race in the heat (ambient temperature, 25.0–26.7°C; %RH, 56.7–79.0 ± 5.0%). Before and following the race, blood draws were performed to measure circulating inflammatory cytokines. Core temperature was measured using an ingestible thermistor throughout the race. Core temperature was significantly higher at post-race (39.5 ± 0.7°C) than pre-race (36.9 ± 0.4°C, p < 0.001). IL-6, IL-8, and IL-10 significantly increased at post-race (IL-6, 48.0 ± 22.3 pg⋅ml−1; IL-8, 63.8 ± 23.9 pg⋅ml−1; IL-10, 29.2 ± 20.0 pg⋅ml−1) compared to pre-race (IL-6, 28.4 ± 13.6 pg⋅ml−1; IL-8, 53.2 ± 19.4 pg⋅ml−1; IL-10, 18.6 ± 11.9 pg⋅ml−1, p < 0.001). A greater increase in core temperature pre- to post-race was predicted by the faster finish time, a greater increase in IL-6, and greater body mass loss during the race (r2 = 0.298, p < 0.001). Small associations were found between IL-8 and core temperature at post-race (r = 0.255, p = 0.025). In conclusion, cytokines concentrations and core temperature increased following the race. Moreover, post-race hyperthermia is associated with increased IL-6, faster finish times, and higher body mass losses.

Influence of Solid Solution Treatment on Microstructure and Mechanical Properties of 20CrNiMo/Incoloy 825 Composite Materials

The utilization of 20CrNiMo/Incoloy 825 composite materials as high-pressure pipe manifold steel can not only improve the strength and hardness of the steel, but also improve its corrosion resistance. However, research on the heat treatment of 20CrNiMo/Incoloy 825 composite materials is still scarce. Thus, the aim of this study was to investigate the influence of solid solution treatment on the microstructure and properties of 20CrNiMo/Incoloy 825 composite materials. Firstly, the composite materials were subjected to solid solution treatment at temperatures ranging from 850 to 1100 °C with varied holding times of 1 h, 4 h, and 6 h. Microstructural analysis revealed that the solid solution treatment temperature had a more pronounced effect than the treatment time on the interface decarburization layer, carburization layer, and grain size. It was observed that the carburized layer thickness decreased while the decarburized layer thickness increased with an increase in the solid solution treatment temperature, oil cooling was found to enhance the hardness of the base layer of the composite materials, and the size of the original austenite grains of 20CrNiMo steel and Incoloy 825 increased with an increase in the solid solution treatment temperature. Secondly, the tensile properties, microhardness, and fracture morphology were evaluated after the composite materials underwent solid solution treatment at temperatures between 950 °C and 1100 °C for 1 h. The results indicated that increasing the solution temperature initially led to an increase in tensile strength and elongation after fracture, followed by a decrease; furthermore, the hardness of Incoloy 825 exhibited a declining trend, while the hardness of 20CrNiMo first decreased then increased. Thirdly, the shear properties and interfacial element diffusion of the composite materials were analyzed following solid solution treatment in a temperature range of 950 °C to 1100 °C for 1 h. The findings demonstrated that higher solid solution treatment temperatures induced full diffusion of Cr, Ni, and Fe atoms at the interface and softened the matrix, leading to an increase in the thickness of the diffusion layer and toughening of the composite interface. Therefore, the shear strength increased with an increase in the solid solution treatment temperature. Finally, the optimal solid solution treatment process for 20CrNiMo/Incoloy 825 composite materials was determined to be 1050 °C/1 h oil cooling, following which the composite materials had good comprehensive mechanical properties.

Hypothermia-Prevalence and risk factors in neonates admitted to a neonatal unit in Tanzania.

We aimed to study the prevalence of hpyothermia among neonates, the association between admission temperature and neonatal mortality, and the impact of radiant warmers. In an observational prospective study, we included 1988 neonates born at Haydom Lutheran Hospital, Tanzania, and admitted to the neonatal unit from 1 January 2018 to 31 December 2022. We explored risk factors for hypothermia (<36.0°C, primary outcome) and newborn mortality by admission temperature (secondary outcome) with adjusted odds ratios (aOR) and 95% confidence intervals (CI) for birth weight and bag and mask ventilation. Hypothermia was present in 47.0% (n = 935) at admission, 46.9% (n = 932) were normothermic or mildly hypothermic (36.0-37.5°C), and 6.1% (n = 121) hyperthermic. Of those admitted to the neonatal unit, 217 (10.9%) died. For every 1°C increase in temperature, neonatal mortality decreased by 31% (aOR 0.69, 95% CI 0.59-0.82). Admission temperature <34.5°C was strongly associated with mortality (aOR 3.56, 1.87-6.79). Mild hypothermia (36.0-36.5°C) was not associated with mortality (aOR 1.30, 0.72-2.37). Risk factors for hypothermia were bag and mask ventilation (aOR 2.53, 2.07-3.11) and low birth weight. The introduction of radiant warmers from 1 May 2022 was associated with a decrease in hypothermia (aOR 0.54, 0.41-0.72). Hypothermia is prevalent even in tropical settings and maintaining normothermia after birth is critical and achievable for reducing neonatal mortality.

Summer High-Altitude Diurnal Rainfall Change in the Three Rivers Source Region and Associated Mechanism

Abstract The Tibetan Plateau (TP), a crucial area influencing global climatic patterns and water resources, is experiencing a unique climatic paradox, particularly evident in the Three Rivers Source Region (TRSR). A striking summer asymmetry in the increases of near-surface temperature and precipitation is observed from 1989 to 2018: the rate of daily minimum temperature (0.64°C decade−1) surpasses the daily maximum temperature (0.52°C decade−1), while the daytime precipitation intensity (0.40 mm day−1 decade−1) increases at a faster rate compared to nighttime (0.30 mm day−1 decade−1). Despite these trends, the summer mean nighttime precipitation intensity consistently remains higher than the daytime average. Notably, this pattern is accompanied by an increasing trend of moisture transport during both daytime and nighttime in TRSR. This paper deciphers the thermodynamic and dynamic processes behind this trend. The daytime warmth not only alters the stability of atmosphere but also modulates convective inhibition (CIN), thereby reshaping precipitation mechanics and potentially dampening or delaying daytime convection. Thermodynamically, a shift from unstable to stable anomalies in the summer troposphere suppresses precipitation development. The combination of increased CIN during those period leads to fewer but more intense rainy days. Dynamically, the shift from a consistent downward motion anomaly throughout troposphere to an upward motion anomaly becomes dominant during nighttime, exhibiting a similar transition but only below 500 hPa during daytime. These findings reveal the complex interplay between thermodynamics, dynamics, and precipitation, highlighting the need for refined climatic models that can accurately simulate these summer diurnal processes.

Model Test on Thermomechanical Behavior of Deeply Buried Pipe Energy Pile Under Different Temperature Loads and Mechanical Loads

Deeply buried pipe energy pile (DBP-EP) offers the capability to harness geothermal energy from significantly deeper subterranean layers than those available inside buried pipe energy pile (IBP-EP). Despite its potential, there is a notable scarcity of research on the thermomechanical behavior of DBP-EP. This study meticulously observed the thermal variations in the soil surrounding the DBP-EP, the mechanical response of the pile itself, the earth pressure at the pile toe, and the displacement occurring at the pile’s top during the heating phase across various operational conditions. The findings show that for every 1 °C increase in inlet temperature, the temperature difference between the inlet and outlet increases by about 0.27 °C. The method of load application at the pile top during heating markedly influences the frictional resistance along the pile’s sides. Furthermore, When the pile top load rises from 0.26 kN to 0.78 kN, the observed vertical load at the pile foot decreases by 2.2–8.51%. This indicates that the increase in the pile top load reduces the downdrag effect on the sandy soil near the pile toe. This reduction subsequently diminishes the impact of vertical loads on the pile toe. Notably, after continuous operation for 8 h, the rate of increase in pile top displacement for DBP-EP shows a decline. Additionally, for every 1 °C rise in the inlet water temperature, the final displacement at the pile top diminishes by approximately 0.03‰D. This research endeavors to furnish a robust theoretical foundation for the structural design and practical engineering applications for DBP-EP.

UTILIZATION OF CASSAVA PEEL AND CHITOSAN FOR THE PRODUCTION OF HYDROGEL AS A SUSTAINABLE SOLUTION FOR DOMESTIC WASTEWATER TREATMENT

Water pollution is a significant environmental issue, especially in developing countries where domestic wastewater often contains a high concentration of pollutants, posing risks to public health and the environment. Hydrogel from cassava peel and chitosan shows promise as a bioadsorbent for domestic wastewater treatment, but its capacity and optimal production temperature have not been fully studied. The study aimed to investigate the characteristics of hydrogel from cassava peel and chitosan, the optimal temperature for hydrogel production, and the efficacy of hydrogel as a bioadsorbent for domestic wastewater treatment. The study involved four stages: cellulose isolation, hydrogel preparation, wastewater treatment experimentation, and data analysis. The results showed that chitosan hydrogel synthesized at 750C had superior efficiency, achieving an optimal outcome of 88% in the treatment of household wastewater using a triad of chitosan hydrogel pellets. The degree of cross-linking in chitosan hydrogel diminished with an increase in heating temperature

Products Distribution and Reaction Kinetics from Co-Pyrolysis of Pinewood and Polypropylene under Non-Catalytic and Catalytic Reaction Conditions

Abstract Co-pyrolysis technology offers vital pathways for efficient utilization of plastics and biomass resources to help reduce the environmental problems and energy resources issues. The pyrolysis characteristics of pinewood and polypropylene (PP) mixtures were analyzed using TGA. The results showed a decrease in first peak of the mixture with increase in PP in the mixture, while the second peak increased with an increase in PP in the mixture. The addition of a catalyst decreased the DTG peak heights. The reduction in the first peak with different catalysts was in the order: CaO/ZSM-5 &amp;gt;CaO &amp;gt;ZSM-5, while for the second peak showed: CaO &amp;gt;CaO/ZSM-5 &amp;gt;ZSM-5. The activation energy, calculated by Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Friedman models, revealed that ZSM-5 reduced the activation energy, whereas CaO/ZSM-5 increased the activation energy, as compared to no catalyst case. Increase of co-pyrolysis temperature reduced the yield of aldehydes, ketones, acids and esters, but increased the yield of hydrocarbons. The addition of CaO reduced the yield of ketones, phenols, esters, and acids, while it increased the yield of alcohols. The addition of ZSM-5 also decreased the yield of ketones, phenols, acids and hydrocarbons, but increased the yield of furans and alcohols. The addition of CaO/ZSM-5 specifically reduced the yield of aldehydes and alcohols. The results show the important role of the specific catalysts examined on the resulting products distribution for the same reaction condition.

Characterizing Long-term Astroclimate Parameters at the Muztagh-Ata Site in the Pamir Plateau with ERA5 and MERRA-2 Data

Abstract The Muztagh-Ata site, an excellent high-altitude ground-based astronomical observing site was discovered and monitored in the eastern part of the Pamir Plateau in the southwestern Xinjiang Uygur Autonomous Region of China. This site has been systematically monitored using various observational parameters since the spring of 2017. Yet, the site lacks long-term monitoring and statistical characterization of key variables such as: precipitable water vapour (PWV) and air temperature. These factors directly influence whether a site is suitable for hosting large ground-based telescopes across optical, infrared, submillimeter, and millimeter wavelengths in later stages. In this study, we utilized atmospheric reanalysis datasets from the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and ERA5, the fifth edition of the European Centre for Medium-Range Weather Forecasts (ECMWF). These datasets were combined with local observations from the weather station at the Muztagh-Ata site. Following the validation of ground-based and satellite data, we conducted a comparative analysis of PWV and temperature trends at the Muztagh-Ata site over a period of 24 years. The weighted annual mean nighttime temperature and PWV increase at rates of 0.18 ∼ 0.38 ○C decade−1 and 0.02 ∼ 0.15 mm decade−1, respectively. The nighttime PWV slightly decrease during the winter with rates of −0.01 ∼ −0.03 mm decade−1. This findings reveal that the PWV and temperature variation patterns at the Muztagh-Ata site are consistently stable, particularly in the results derived from the ERA5 dataset. The comprehensive conditions at this site are highly suitable and advantageous for hosting large optical, infrared, submillimeter, and millimeter wavelengths telescope installations.

Equivalent Heat Source Model of Thermal Relay Contact Based on Surface Roughness of Silver–Magnesium–Nickel Contact

In a sealed electromagnetic relay, the change in the surface roughness mainly depends on the collision wear between the contact and the moving reed and the ablation effect of the arc on the contact surface based on the strong correlation between the contact resistance and the surface roughness of the Ag-Mg-Ni contact. With a change in contact resistance, the contact temperature increase in a hermetically sealed electromagnetic relay (HSER) is greatly affected. Under extreme overload conditions, the contact surface is severely ablated by the arc, and the roughness increases rapidly with the number of cycles, which greatly affects the contact resistance of the contact surface and the reliability of the relay. A thermal model of a relay contact system based on the surface roughness of Ag-Mg-Ni contacts was established in this paper by analyzing the effect of an arc on the surface roughness of Ag-Mg-Ni contacts under heavy overload conditions. The arc image of the Ag-Mg-Ni contact was recorded using a double-axis arc photographing platform, and the moving track of the arc center under overload conditions was drawn. This paper explored the patterns of arc center movement on the contact surface and the effects of the arc on the surface roughness of the contacts by analyzing the probabilities of the arc center appearing in various locations. A mathematical model correlating the number of contact cycles with contact resistance was established. Subsequently, a finite element simulation model for the equivalent heat source of the contact was developed. The theoretical model error was less than 10%. The accuracy of the equivalent heat source model was verified by comparing the measured data with the simulation results.

EARLY FLOWERING 3 alleles affect the temperature responsiveness of the circadian clock in Chinese cabbage.

Temperature is an environmental cue that entrains the circadian clock, adapting it to local thermal and photoperiodic conditions that characterize different geographic regions. Circadian clock thermal adaptation in leafy vegetables such as Chinese cabbage (Brassica rapa ssp. pekinensis) is poorly understood but essential to sustain and increase vegetable production under changing climates. We investigated circadian rhythmicity in natural Chinese cabbage accessions grown at 14, 20, and 28 °C. The circadian period was significantly shorter at 20 °C than at either 14 or 28 °C, and the responses to increasing temperature and temperature compensation (Q10) were associated with population structure. Genome-wide association studies mapping identified variation responsible for temperature compensation as measured by Q10 value for temperature increase from 20 to 28 °C. Haplotype analysis indicated that B. rapa EARLY FLOWERING 3 H1 Allele (BrELF3H1) conferred a significantly higher Q10 value at 20 to 28 °C than BrELF3H2. Co-segregation analyses of an F2 population derived from a BrELF3H1 × BrELF3H2 cross revealed that variation among BrELF3 alleles determined variation in the circadian period of Chinese cabbage at 20 °C. However, their differential impact on circadian oscillation was attenuated at 28 °C. Transgenic complementation in Arabidopsis thaliana elf3-8 mutants validated the involvement of BrELF3 in the circadian clock response to thermal cues, with BrELF3H1 conferring a higher Q10 value than BrELF3 H2 at 20 to 28 °C. Thus, BrELF3 is critical to the circadian clock response to ambient temperature in Chinese cabbage. These findings have clear implications for breeding new varieties with enhanced resilience to extreme temperatures.

Design and demonstration of a simple, low-cost transparent solar absorber for glass window applications

Windows are a major source of heat loss from buildings in cold climates. Developing coatings for windows that retain high visible transparency and strongly absorbs solar energy in the near infrared region can help reduce energy consumption and cost for indoor heating. Nanophotonic structures based on metasurface and metamaterials have shown great potential for such applications. Unfortunately, most of the designs proposed so far are difficult to fabricate or expensive. In this work, we report the experimental demonstration of a low-cost alternative based on Ni/SiO2/Ni multilayer structure. The device provides a large increase in temperature under solar illumination while retaining high visible transmission. Our optical and thermal measurements reveal that the performance of the device remains stable over a long period. The combination of low cost, ease of fabrication, good optical and thermal performance, and long-term stability makes it a promising design for passive heating of windows in cold climates.

Nanodomains and Their Temperature Dependence in a Phosphonium-Based Ionic Liquid: A Single-Molecule Tracking Study.

Ionic liquids (ILs) exhibit a unique nanoscale structure (i.e., nanodomains) characterized by their organization into distinct domains. We present evidence of nanodomains in trihexyl(tetradecyl)phosphonium chloride, [P66614][Cl], using single-molecule tracking (SMT) and the maximum entropy method (MEM) to analyze single-molecule trajectories. The diffusion properties of ATTO 647N were assessed as the temperature of [P66614][Cl] increased from 20 °C (4020 cP), 35 °C (1239 cP), 45 °C (599 cP) to 50 °C (439 cP). The MEM analysis revealed a distinct two-population distribution of diffusion coefficients representing nanodomains in [P66614][Cl] at 20 °C (4020 cP). The slow population accounts for 16%, with a diffusion coefficient of 0.104 μm2/s, while the fast population constitutes 84% with a diffusion coefficient of 0.634 μm2/s. Two diffusing populations were also measured for the chemically different probes ATTO 647N, DiD, and Nile Blue chloride in [P66614][Cl] at 20 °C. In contrast, only a single fast population was measured in [P66614][Cl] at 50 °C. At a similar viscosity (640 cP) but a lower temperature of 20 °C, trihexyl(tetradecyl)phosphonium bis[(trifluoromethyl)-sulfonyl]imide, [P66614][NTf2], also showed only a single diffusing population. The elimination of the slow population and the presence of a single diffusing population in [P66614][Cl] as the temperature increases and the viscosity decreases is consistent with liquid-liquid phase separation (LLPS) as a mechanism of nanodomain formation. In addition, the measurement of two diffusing populations for three fluorophores with different chemical structures is also consistent with a physical mechanism, and not a chemical mechanism, for nanodomain formation.

A Thermal Impedance Model for IGBT Modules Considering the Nonlinear Thermal Characteristics of Chips and Ceramic Materials

The traditional method of calculating junction temperature does not consider the dependence of a material’s thermal conductivity on temperature, in which the thermal conductivity changes with temperature. However, with an increase in junction temperature, the temperature sensitivity (TS) will have a more significant impact on the actual temperature of chips. This study established an improved IGBT equivalent thermal impedance model that considers the nonlinear characteristics of the TS of chips and ceramic materials. The Fourier series analysis method was used to obtain the heat flux density curve, and then the heat diffusion angles of each layer were solved. Moreover, iterations were performed until the thermal conductivity and temperature of the chip and ceramic layers matched the nonlinear characteristics of the TS. When the power loss was less than 200 W, the maximum error of the junction temperature calculated by the proposed method considering TS was 3%, while the maximum error of the method without considering TS was 9.5%. Compared with the finite element simulation, the proposed method has a faster solving speed and high accuracy. The proposed method only requires the input material parameters, size parameters, and boundary conditions to solve the junction temperature, which has strong practicality and high accuracy.

Effects of different water temperatures on the ovarian development and biochemical composition of Portunus trituberculatus after mating (Decapoda, Portunidae)

Abstract This study investigated the effects of different water temperatures (20, 23, 26 and 29°C) on the ovarian development and biochemical composition of Portunus trituberculatus (a swimming crab) after mating. The results showed that the higher the water temperature was, the faster the ovarian development, especially the GSI in the 29°C group was significantly higher than that in the 20°C and 23°C groups (). The hepatosomatic index (HSI) decreased with increasing water temperature, but there was no significant difference between the groups at different water temperatures (). The muscle yield (MY) was basically maintained at approximately 34%. The condition factor (CF) of the crab reached 0.62 in the 29°C group, which was significantly higher than that in the 20°C and 23°C groups (). Histological observation revealed that the number of lipid droplets and the degree of homogenization of yolk granules in ovarian oocytes gradually increased with the increase of the water temperature. From the perspective of conventional biochemical composition, the moisture and crude protein contents in muscle and the crude fat content in hepatopancreas did not change much among the groups, but the crude protein content in the ovary of the 29°C group was as high as 24.65%, which was significantly higher than that in the other three groups (). In terms of fatty acid composition, there was little difference in the fatty acid content in the ovaries of the different water temperature groups. The contents of C22 : 2n6 and C18 : 3n3 in polyunsaturated fatty acids were significantly higher in the 29°C group than in the other three groups (). In the hepatopancreas, the contents of C22 : 5n3 (DPA) and C22 : 6n3 (DHA) in the 20°C group were the lowest, 0.07% and 0.15%, respectively, which were significantly lower values than in the 29°C group (). The change of amino acid content is mainly reflected in ovarian tissues, showing a gradual upward trend as a whole. Furthermore, the essential amino acid score (EAAS) and average score of the two tissues in the 20°C and 23°C groups were relatively close, and both reached the highest score in the 29°C group. Overall, with increasing water temperature, the rate of ovarian development significantly accelerated, and the nutritional quality of the tissues improved in these swimming crabs.