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A femtosecond laser induced photofragmentation fluorescence (fs-LIPF) scheme for the sensitive detection and imaging of water vapor is presented. Two photons of 244.3 nm excite water to the D ̃ state and produce hydroxyl radicals in the fluorescing A ̃ state. Two more photons promote electrons from the D ̃ state to a neutral Rydberg state of the (1b2)−1 ionic core through a 2 + 2 doubly resonant process. The resulting high-lying Rydberg state undergoes neutral dissociation, and the energetic hydrogen fragments are detected from their Balmer series fluorescence. These channels (in the low-pressure limit) have detection sensitivities around 1012 molecules per cubic centimeters, orders of magnitude more sensitive than laser-induced fluorescence based approaches, allowing for sensitive non-invasive detection and imaging of water density for many important processes. [ABSTRACT FROM AUTHOR]

Molecular-level nucleation has not been clearly understood due to the complexity of multi-body potentials and the stochastic, rare nature of the process. This work utilizes molecular dynamics (MD) simulations, incorporating a first-principles-based deep neural network (DNN) potential model, to investigate homogeneous water vapor condensation. The nucleation rates and critical nucleus sizes predicted by the DNN model are compared against commonly used semi-empirical models, namely extended simple point charge (SPC/E), TIP4P, and OPC, in addition to classical nucleation theory (CNT). The nucleation rates from the DNN model are comparable with those from the OPC model yet surpass the rates from the SPC/E and TIP4P models, a discrepancy that could mainly arise from the overestimated bulk free energy by SPC/E and TIP4P. The surface free energy predicted by CNT is lower than that in MD simulations, while its bulk free energy is higher than that in MD simulations, irrespective of the potential model used. Further analysis of cluster properties with the DNN model unveils pronounced variations of O–H bond length and H–O–H bond angle, along with averaged bond lengths and angles that are enlarged during embryonic cluster formation. Properties such as cluster surface free energy and liquid-to-vapor density transition profiles exhibit significant deviations from CNT assumptions. [ABSTRACT FROM AUTHOR]

We have developed an experimental and analytical setup for thermal desorption spectroscopy of solid water films on surfaces. We obtain the coverage-dependent desorption kinetics of water molecules from a well-defined ultra-thin alumina/NiAl(110) surface in the coverage range of 0–2 monolayers. We use a novel deconvolution technique to eliminate the pumping delay of water vapor in the vacuum system, which has previously hindered the accurate estimation of desorption kinetic parameters, such as activation energy and pre-exponential factor. The coverage-dependent Arrhenius analysis reveals that the desorption activation energy decreases with increasing coverage in the sub-monolayer range, indicating that the water–water interaction is not attractive. We also find that the pre-exponential factor for the second layer is higher than that for the sub-monolayer. We explain this difference in terms of transition state theory and propose that entropic effects play a significant role in water desorption kinetics. [ABSTRACT FROM AUTHOR]

This article presents methodological advances in the state-of-the-art for making time-dependent, thermochemical measurements within kilogram-scale explosive post-detonation fireballs utilizing tunable laser absorption spectroscopy. This measurement capability is critical for validating multi-scale, multi-physics models of post-detonation dynamics. The technique is based on hardened gauges built around rapidly-tunable lasers and custom post-processing algorithms that provide quantitative thermochemical data interior to large and opaque explosive fireballs. The authors present a holistic overview of the technique including gauge design, the laser absorption diagnostic, and the custom data processing algorithms. Additionally, fielding high-bandwidth laser absorption probes at stand-off ranges presents new challenges in data processing that must compensate for long distance signal transmission effects. We highlight representative data from a hardened gauge measurement at 0.81 m stand-off from a 2.78 kg LX-14 explosive charge detonated in an outdoor test arena. We discuss progress in all-optical measurement of temperature, pressure, and water vapor number density at a 100 kHz repetition rate during the first 10 ms of the fireball evolution. We conclude the article with a brief discussion on our current approach for comparing hardened gauge measurements with computational fluid dynamic simulations. [ABSTRACT FROM AUTHOR]

Using adiabatic molecular dynamics coupled with the fluid dynamics equations, we model nucleation in an expanding beam of water vapor and argon on a microsecond scale. The size distribution of clusters, their temperature, and pickup cross sections in dependence on velocity are investigated and compared to the geometric cross sections and the experiment. The clusters are warmer than the expanding gas because of the time scale of relaxation processes. We also suggest that their translational and rotational kinetic energies are modified due to evaporative cooling. The pickup cross sections determined for the final clusters using molecules of the same kind increase with decreasing velocity, still obeying the (a + b N 1 / 3 ) 2 law. [ABSTRACT FROM AUTHOR]

The growing concern regarding widespread plastic pollution has propelled the development of sustainable self‐healing plastics. Although considerable efforts have been dedicated to fabricating self‐healing plastics, achieving rapid healing at room temperature is extremely challenging. Herein, we have developed an ultra‐fast‐healing glassy polyurethane (UGPU) by designing a hyperbranched molecular structure with a high density of multiple hydrogen bonds (H‐bonds) on compliant acyclic heterochains and introducing trace water to form water bridge across the fractured surfaces. The compliant acyclic heterochains allow the dense multiple hydrogen bonds to form a frozen network, enabling tensile strength of up to 70 MPa and storage modulus of 2.5 GPa. The hyperbranched structure can drive the reorganization of the H‐bonding network through the high mobility of the branched chains and terminals, thereby leading to self‐healing ability at room temperature. Intriguingly, the presence of trace water vapor facilitates the formation of activated layers and the rearrangement of networks across the fractured UGPU sections, thereby enabling ultra‐fast self‐healing at room temperature. Consequently, the restored tensile strength after healing for 1 minute achieves a historic‐record of 26.4 MPa. Furthermore, the high transparency (>90 %) and ultra‐fast healing property of UGPU make it an excellent candidate for advanced optical and structural materials. [ABSTRACT FROM AUTHOR]

Two new cyano-bridged coordination polymers, {[Ni(bpe)(H2O)2][Ni(CN)4]·2H2O}n (1) and {[Cu(bpe)(H2O)2][Ni(CN)4]·ethanol}n (2) (bpe = 1,2-bis(4-pyridyl)ethane) were synthesized and characterized. This was part of a study attempting to rationalize the formation of Hofmann coordination polymers over their aqua-derivatives, in which we found that the length of the ligand does not control the outcome of the synthesis. In the initial phase of thermogravimetric analysis, compound 1 lost the guest water molecule while compound 2 lost its guest ethanol. Single crystal X-ray diffraction revealed that both compounds crystallize in P1¯ with similar unit cell parameters. In both compounds, the Ni(II) ion is coordinated with four cyanide–carbon atoms in a square planar geometry and Cu(II) or the second Ni(II) ion adopts a distorted octahedral coordination by two bpe ligands, two bridging cyano groups, and two water molecules. In both structures, chains composed of adjacent [Ni(C12H12N2)(H2O)2]2+ (for 1) or [Cu(C12H12N2)(H2O)2]2+ (for 2) are further linked together via [Ni(CN)4]2− units and extend to generate a two-dimensional framework. The presence of disordered terminal cyanide moieties in 1 could be attributed to a larger volume available to this moiety in the structure of 1. The BET surface areas of the activated phases 1′ of 1 and 2′ of 2 are 28 m2 g−1 and 5 m2 g−1, respectively, and originally, they have no pores to accommodate gas molecules at low pressure (1 atm). 1′ does not adsorb carbon dioxide at 195 K (0.30 mmol g−1), 273 K (0.086 mmol g−1) and 298 K (0.056 mmol g−1), or hydrogen at 77 K, but it shows an affinity to adsorb nitrogen (around 2.5 mmol g−1) at 77 K and water vapor molecules (around 0.95 mmol g−1) at 298 K with typical type-II isotherms. 2′ adsorbs a small quantity of water vapor (around 0.20 mmol g−1) at 298 K and does not adsorb carbon dioxide at 195 K (0.125 mmol g−1), 273 K (0.069 mmol g−1) and 298 K (0.062 mmol g−1), or hydrogen at 77 K, but shows more affinity to adsorb nitrogen (around 1.2 mmol g−1) at 77 K. [ABSTRACT FROM AUTHOR]

Polysaccharide-based packaging and its ever-increasing applications in response to the need for sustainable and safe packaging have prompted researchers to investigate the development of antimicrobial biopolymer-based packaging for shelf-life enhancement of food samples. A film made by blending chitosan and pectin had goodmechanical properties, that is, a tensile strength of 7.43 MPa and an elongation at break of 23.033%. To produce active packaging, thyme essential oil (TEO) was added to the blend at concentrations of 10%, 15%, and 20%. The developed film was characterized for its techno-functional and antimicrobial properties. Further the developed films were employed in an active food packaging system for milk cake. Films with added TEO showed significant enhancements in elongation at break (28.22%) and water vapor barrier properties (30.08 g/h.m²). Additionally, the microstructure of the film was also improved, as demonstrated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements. Fourier transform infrared spectroscopy (FTIR) indicated the interaction of blended matrix (chitosan and pectin) and TEO as observed from the formation of hydrogen bonds with the addition of TEO owing to the OH functional groups. The use of TEO in pectin and chitosan-based film and its application for milk cake packaging showed delayed microbiological contamination and hardness of milk cake samples. The shelf life of milk cake packaged in pectin and chitosan blend film with 20% TEO was enhanced by > 10 days. [ABSTRACT FROM AUTHOR]

Rainfall in East Asia is affected by two rain‐bearing systems: tropical cyclones and monsoon‐related frontal systems. Distinguishing typhoon rainfall (TR) and non‐typhoon rainfall (non‐TR) helps to understand the evolution process of regional rainfall at different timescales. Taking Fujian Province in the southeast coast of China as an example, based on the fixed box approach of separating TR, the method of determining the size of fixed box is explored. TR and non‐TR are separated in Fujian Province, and the spatial variations of TR and non‐TR at different timescales (annual, monthly, day of annual‐maximum‐rain) are analysed. The results showed that (1) according to the relationship between the sizes of fixed box and the rate of change of TR, the size of fixed box could be reasonably determined; thus, the expended size of fixed box suitable for separating TR in Fujian was 3.5°, namely the range of 20°–31.8°N and 112.3°–124.2°E. (2) The spatial variations of TR at different timescales in Fujian were similar: TR decreased from the coast to the inland, and the northeast coast of Fujian was the high‐value region. Due to the difference of water vapour sources, non‐TR in March–June increased from the coast to the inland, but the high value of non‐TR in July–September was distributed in the eastern coast. (3) The contribution rates of average TR to the total rainfall of the year, July–September and 1 day were 12.8%, 34.6% and 35.7%, respectively. In eastern coast, TR in July–September accounted for 1/3–1/2 of total rainfall, and the rainfall in a day was mainly affected by TR; while in western inland, rainfall was mainly non‐TR and the influence of TR was less than 1/4. [ABSTRACT FROM AUTHOR]

Air sensitivity remains a substantial barrier to the commercialization of sodium (Na)-layered oxides (NLOs). This problem has puzzled the community for decades because of the complexity of interactions between air components and their impact on both bulk and surfaces of NLOs. We show here that water vapor plays a pivotal role in initiating destructive acid and oxidative degradations of NLOs only when coupled with carbon dioxide or oxygen, respectively. Quantification analysis revealed that reducing the defined cation competition coefficient (h), which integrates the effects of ionic potential and sodium content, and increasing the particle size can enhance the resistance to acid attack, whereas using high-potential redox couples can eliminate oxidative degradation. These findings elucidate the underlying air deterioration mechanisms and rationalize the design of air-stable NLOs. [ABSTRACT FROM AUTHOR]

In the atmosphere, the interrelationship between dynamics and chemistry results in mutual influence and interaction. The behavior of internal gravity waves is influenced by the thermal effects caused by chemical components present in the atmosphere. In this investigation, the equations determining gravity waves are coupled with those characterizing the behavior of ozone and water vapor. To investigate the coupled equations, numerical analyses are conducted, and the resulting numerical results are presented. Internal gravity waves have been observed to influence the distribution of ozone and water vapor within the Earth's atmosphere. It has been demonstrated, based on our findings, that wave fluctuations play a significant role in exerting a substantial effect. In addition, it has been observed that the influence of ozone and water vapor-induced heating on gravity waves is significant, particularly near the critical level where the mean flow induced by gravity waves plays a significant role. [ABSTRACT FROM AUTHOR]

With urbanization, anthropogenic water vapor emissions have become a significant component of the urban atmosphere. Fossil fuel combustion‐derived vapor (CDV) is a primary source of these emissions. Owing to the notably low CDV d‐excess, stable hydrogen and oxygen isotopes are promising for distinguishing CDV from natural sources. Considering the limitations of in situ observations, this study aims to explore the feasibility of using IsoRSM, an isotopically enabled regional atmospheric model, to simulate CDV emissions in urban areas in winter. Two experiments were conducted: one in Salt Lake City (SLC) in January 2017 and another in Beijing in January 2007. The simulation results showed that the CDV addition significantly reduced the water vapor d‐excess, particularly when the boundary layer was stable. The simulation with CDV emissions aligned better with the time series of in situ observations in SLC. The modification led to a more pronounced positive correlation between vapor d‐excess and specific humidity, which was similar to the observation of SLC. The CDV inclusion significantly increased the vapor d‐excess variability with varying wind directions in both sites. However, in Beijing, the underestimation of d‐excess variation from natural sources caused a bigger discrepancy between the observed and simulated d‐excess and CDV fraction. Thus, though there were still biases, the inclusion of CDV could improve the accuracy of isotopic simulation in the urban regions where CDV was one of the controlling factors of vapor d‐excess. Plain Language Summary: Combustion‐derived vapor (CDV) generated from fossil fuel is one of the main sources of anthropogenic water emissions in urban areas. Water d‐excess, which is calculated with the water isotopes of oxygen (δ18O) and hydrogen (δ2H), is usually used to distinguish the water from different sources. Due to the extremely low d‐excess of CDV, we can use the water isotopes to partition CDV from naturally evaporative water. Different from previous researches on CDV based on the in situ observed data, this study aims to simulate the isotopic composition of CDV in urban areas with the atmospheric model. The results of experiments in Salt Lake City and Beijing indicates that CDV can be one of the controlling factors of the vapor d‐excess in some urban regions, and the inclusion of CDV in the model will improve the accuracy of simulation in these regions. Therefore, this approach has great potential for research of water isotopes on a global scale with the impact of anthropogenic emissions. Key Points: The emission of combustion‐derived vapor (CDV) was simulated with the isotopic‐enable regional spectral modelThe CDV addition reduced the water vapor d‐excess and made the simulation align better with the observations in Salt Lake CityThe CDV inclusion significantly increased the vapor d‐excess variability with varying wind directions [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) provides vital water resources for downstream regions, with spring precipitation contributing considerably to the annual totals over the southeastern TP. The added value of convection‐permitting modeling in simulating the spring climate over the TP is uncertain. Here, we conducted and compared decade‐long regional convection‐permitting (3.3 km) and convection‐parameterized (13.2 km) Icosahedral Nonhydrostatic Weather and Climate Model (ICON) simulations to reproduce the atmospheric water cycle in spring over the TP. Results indicated that 3.3 km mesh ICON (ICON_3.3 km) exhibited notable added value in simulating the spring atmospheric water cycle over the TP. ICON_3.3 km reduced the wet biases of precipitation in the ERA5 reanalysis and 13.2 km mesh ICON (ICON_13.2 km) simulations, and improved the simulation of surface evaporation over the central and eastern TP. The reduction in the simulated precipitation in ICON_3.3 km was primarily followed by a decrease in surface evaporation from March to May, second by a reduction in water vapor flux convergence in May due to decreased water vapor inflow from the southeastern TP. Furthermore, compared to ICON_13.2 km, ICON_3.3 km alleviated the "drizzling" bias, leading to drier surface soils and decreased evaporation, and lead to 3% decrease in the fraction of evaporation converted into precipitation. Sensitivity experiments conducted at resolution of 13.2 km but turning off the convection parameterization demonstrated that both explicit representation of convection and enhanced horizontal resolution were crucial for accurately representing the spring atmospheric water cycle over the TP. Our results highlighted the need to develop kilometer‐scale models for successfully reproducing the climate characteristics across the TP. Plain Language Summary: Climate modeling is evolving toward kilometer‐scale or convective‐permitting model (CPM). The added value of regional CPM in simulating the spring climate over the Tibetan Plateau (TP), known as "Asian Water Tower," is unknown. Here, we have performed and compared two decade‐long regional climate simulations at two horizontal resolutions: convection permitting (3.3 km) and convection parameterized (13.2 km), to reproduce the atmospheric water cycle in spring over the TP. Results indicated that the CPM reduced the wet biases in the latest reanalysis data and the convection‐parameterized model over the central and eastern TP. The reduction of wet biases was mainly followed by the decreased surface evaporation, which was associated with the alleviation of "drizzling" bias in CPM. We further showed evidences that both explicit representation of convection and enhanced horizontal resolution were crucial for accurately representing the spring climate over the TP. Our findings highlight the importance of developing high‐efficiency kilometer‐scale (<4 km) models for reproducing all the climate characteristics across the TP region. Key Points: Regional convection permitting model exhibited evident added value in simulating the spring atmospheric water cycle over the Tibetan Plateau (TP)Reduced precipitation by convective‐permitting model was mainly followed by decrease in surface evaporation, associated with the alleviation of drizzling biasesBoth explicit convection and enhanced resolution were crucial for well representing the spring atmospheric water cycle over the TP [ABSTRACT FROM AUTHOR]

Surface solar radiation is fundamental for terrestrial life. It provides warmth to make our planet habitable, drives atmospheric circulation, the hydrological cycle and photosynthesis. Europe has experienced an increase in surface solar radiation, termed "brightening," since the 1980s. This study investigates the causative factors behind this brightening. A novel algorithm from the EUMETSAT satellite application facility on climate monitoring (CM SAF) provides the unique opportunity to simulate surface solar radiation under various atmospheric conditions for clouds (clear‐sky or all‐sky), aerosol optical depth (time‐varying or climatological averages) and water vapor content (with or without its direct influence on surface solar radiation). Through a multiple linear regression approach, the study attributes brightening trends to changes in these atmospheric parameters. Analyzing 61 locations distributed across Europe from 1983 to 2020, aerosols emerge as key driver during 1983–2002, with Southern Europe and high elevations showing subdued effects (0%/decade–1%/decade) versus more pronounced impacts in Northern and Eastern Europe (2%/decade–6%/decade). Cloud effects exhibit spatial variability, inducing a negative effect on surface solar radiation (−3%/decade–−2%/decade) at most investigated locations in the same period. In the period 2001–2020, aerosol effects are much smaller, while cloud effects dominate the observed brightening (2%/decade–5%/decade). This study therefore finds a substantial decrease in the cloud radiative effect over Europe in the first two decades of the 21st century. Water vapor exerts negligible influence in both sub‐periods. Plain Language Summary: This study explores the recent increase in surface solar radiation in Europe, commonly referred to as "brightening," which began in the mid‐1980s. Surface solar radiation is crucial for life on Earth, fostering warmth, shaping wind patterns, and fueling the hydrological cycle and photosynthesis. Utilizing data derived from satellites, we simulated surface solar radiation under different atmospheric conditions regarding clouds, aerosols, and water vapor. This allowed us to separate the individual effects and analyze their contributions to the observed brightening across 61 locations in Europe from 1983 to 2020. We find that the decrease in aerosols was the dominant driver for the brightening during the initial period from 1983 to 2002. Southern Europe and high‐elevation areas showed modest aerosol effects, while Northern and Eastern Europe experienced higher values. Cloud effects were predominantly negative (decreasing surface solar radiation) at most locations. However, between 2001 and 2020 the aerosol effect resulted much smaller and the brightening was mostly attributed to a decrease in cloudiness during that sub‐period. Water vapor was found to have a negligible impact on surface solar radiation trends. Key Points: Satellite application facility on climate monitoring (CM SAF) Land Flux v1.0 surface solar radiation data agree well with station‐based measurements over Europe, also at high‐altitude locationsThe direct aerosol effect was the main driver of the European brightening from 1983 to 2002. Changes in cloudiness rather counteracted itFrom 2001 to 2020 the brightening in Europe was dominated by the cloud effect and the aerosol effect resulted much smaller [ABSTRACT FROM AUTHOR]

Accurate surface longwave downward radiation (SLDR) is crucial for understanding mountain climate dynamics. While existing algorithms notably improve the accuracy of clear‐sky SLDR, a terrain correction algorithm that can correct remotely sensed and model‐simulated all‐sky SLDR on a large scale remains largely unexplored. Here, we propose a parameterization scheme for estimating all‐sky SLDR in rugged terrain. We primarily improve the estimation of nearby terrain thermal contribution by considering topographic asymmetry and incorporate the effects of ice cloud thermal scattering under low water vapor conditions. We validate the reliability of our model using the Discrete Anisotropic Radiative Transfer (DART) model, demonstrating a good agreement with a bias value of −12.8 W/m2 and a RMSE value of 28.2 W/m2. Further evaluation against the Essential Thermal Infrared Remote Sensing (ELITE) SLDR product at three TIPEX‐III in situ sites, located near the bottom of deep valleys with predominantly flat surfaces, indicates significant improvement in our model, reducing the mean bias by 7.4 W/m2 and the mean RMSE by 4.1 W/m2. Post‐terrain correction, the ELITE SLDR difference map exhibits a spatial pattern of "small in the northwest and large in the southeast" in the study area, with the maximum differences reaching 67 W/m2 in the daytime and 54 W/m2 at nighttime. Comparison with existing methods reveals similar improvements due to the consideration of terrain effects. Overall, our SLDR correction model shows enormous potential for correcting remotely sensed and model‐simulated SLDR products on a large scale. Plain Language Summary: Accurate measurement of surface longwave downward radiation (SLDR) is essential for understanding the climate in mountainous areas. However, current methods struggle to correct all sky SLDR data on a large scale when using remote sensing technology. We develop a new method to better estimate nearby terrain thermal contribution considering the effects of uneven terrain. Additionally, we take into account the impact of ice cloud scattering when there is low water vapor. We utilize the ELITE product as a reference to test our model at three locations from the TIPEX‐III project. Our model showed significant improvements, reducing the average bias by 7.4 W/m2 and the RMSE by 4.1 W/m2 When comparing ELITE SLDR data with our corrected SLDR maps, we observed a pattern of lower values in the northwest and higher values in the southeast of the study area. The differences reached up to 67 W/m2 during the day and 54 W/m2 at night. Our method, which includes the effects of terrain, showed similar improvements to other methods designed for rugged terrain. Overall, our SLDR correction model has strong potential for enhancing the accuracy of SLDR measurements over mountainous regions. Key Points: We propose a method for correcting all‐sky surface longwave downward radiation (SLDR) in rugged terrain, with mainly improving the estimate of nearby terrain thermal contributionThe reliability of our model is demonstrated through comprehensive comparisons with Discrete Anisotropic Radiative Transfer (DART) simulations and in situ observationsOur method exhibits significant capability in correcting remotely sensed and model‐simulated SLDRs across extensive geographic scales [ABSTRACT FROM AUTHOR]

The current‐state of polymer‐based humidity sensors faces numerous limitations, including energy‐costly synthesis, low sensitivity, and slow response times. This study presents innovative approach to overcome these challenges, based on a robust all‐water‐borne in situ miniemulsion polymerization. The use of water throughout the entire process mitigates the negative environmental impact. Thiol‐ene polymers reinforced with reduced graphene oxide (rGO) with concentrations ranging from 0.2–1.0 wt% are selected to fabricate these chemoresistive sensors. The selected thiol‐enes present high hydrophobicity and a semicrystalline nature, suggesting resistance to early delamination even under prolonged exposure to humidity. Incorporating rGO not only imparts electrical conductivity but also enhances mechanical and water resistance of the composite films. The 0.6% rGO composite exhibits optimal resistance for humidity sensing, demonstrating rapid and consistent responses across three exposure cycles to water vapor concentrations ranging 800–5000 ppm. Moreover, the sensor exhibits remarkable selectivity toward water vapors over these of toluene, propanol, and 4‐methyl‐2‐pentanol, attributed to the high surface hydrophilicity and inherent porosity of the waterborne film, and network structuring of rGO platelets within the matrix. In summary, this study pioneers a novel approach to polymer‐based humidity sensing, addressing key limitations while offering enhanced sensitivity, rapid response times, and superior selectivity. [ABSTRACT FROM AUTHOR]

Summary: Plant leaf temperatures can differ from ambient air temperatures. A temperature gradient in a gas mixture gives rise to a phenomenon known as thermodiffusion, which operates in addition to ordinary diffusion. Whilst transpiration is generally understood to be driven solely by the ordinary diffusion of water vapour along a concentration gradient, we consider the implications of thermodiffusion for transpiration.We develop a new modelling framework that introduces the effects of thermodiffusion on the transpiration rate, E.By applying this framework, we quantify the proportion of E attributable to thermodiffusion for a set of physiological and environmental conditions, varied over a wide range.Thermodiffusion is found to be most significant (in some cases > 30% of E) when a leaf‐to‐air temperature difference coincides with a relatively small water vapour concentration difference across the boundary layer; a boundary layer conductance that is large as compared to the stomatal conductance; or a relatively low transpiration rate. Thermodiffusion also alters the conditions required for the onset of reverse transpiration, and the rate at which this water vapour uptake occurs. See also the Commentary on this article by Vesala, 243: 1281–1283. [ABSTRACT FROM AUTHOR]

Water vapor scale height reflects the vertical distribution of water vapor in the atmosphere, which is a vital parameter in tropospheric zenith wet delay (ZWD) modeling and GNSS meteorology. This study accurately calculated the long-term water vapor scale height using 89 radiosonde stations in China, analyzed the characteristics in temporal and spatial variations and explored the impact factors of the water vapor scale height from the perspective of the climate zones. The numerical results indicate that the water vapor scale height in China exhibits annual and semiannual variations with a rising-then-decreasing trend across the four seasons. A relatively larger value for the water vapor scale height were observed in the subtropical monsoon climate and the temperate continental climate zone, in which the values are greater than 2.35 km, while the values in temperate monsoon climate and the alpine plateau climate zone are relatively small. In addition, the water vapor scale height in different climate zones shows different trends, with a downward trend appeared in the subtropical monsoon climate and the alpine plateau climate zone, while an upward trend was observed in the temperate monsoon climate and the temperate continental climate zone. Furthermore, a positive correlation between water vapor scale height and temperature, pressure, and atmospheric precipitable water was found in China, with a varied degree of correlation in different climate zones. [ABSTRACT FROM AUTHOR]

Gradient environmental barrier coatings (EBCs) were fabricated via atmospheric plasma spraying to deposit Yb 2 Si 2 O 7 -Yb 2 SiO 5 onto a laser-sculpted SiC substrate, with varying mass ratios. Experimental results reveal that the gradient coating exhibited remarkable integrity, showing no signs of cracking even after exposure to 90% H 2 O-10% O 2 (g) water vapor corrosion at 1300 ℃ for 100 h. Besides, the thickness of the thermally grown oxide (TGO) layer was minimal (18.53 ± 1.08 μm) compared to 75Yb 2 Si 2 O 7 -25Yb 2 SiO 5 single layer EBCs (24.93 ± 1.62 μm) with similar integrity under water vapor environment for 100 h. The superior performance of the gradient coating against water vapor corrosion can be attributed to the outmost layer containing more Yb 2 SiO 5 with excellent vapor corrosion resistance, while the innermost layer primarily comprises Yb 2 Si 2 O 7 , providing significant damage resistance and resilience to thermal shock. These favorable attributes make the gradient coating a promising candidate for EBC application in aerospace. [ABSTRACT FROM AUTHOR]

To reduce the influence of TGO on EBCs performance, the Yb 2 SiO 5 -Yb 2 O 3 -Si-SiC ceramic was prepared by tape casting and reactive melt infiltration in this paper. During high-temperature water vapor corrosion, the ceramic formed a unique layered oxide layer structure to protect the material. On one hand, TGO is consumed by the reaction of Yb 2 O 3 and Yb 2 SiO 5 with SiO 2 ; On the other, the structure makes no TGO layer between the oxidized and unoxidized regions, which means that even if the TGO layer is stripped, the material still has a dense Yb 2 Si 2 O 7 and Yb 2 SiO 5 mixed layer as a protective barrier. [ABSTRACT FROM AUTHOR]

High-pressure water vapor annealing (HWA) was recently demonstrated as a method that can substantially improve the photoluminescence quantum yield (PLQY) of silicon quantum dots (Si QDs) with the oxide shell. In this Letter, the mechanism of this enhancement is studied optically on a single-dot level. HWA treatment is performed on Si QDs formed on a silicon-on-insulator wafer, and their photoluminescence (PL) properties were examined before and after the treatment. Our experiments show a 2.5 time enhancement in the average blinking duty cycle of Si QDs after 2.6 MPa HWA treatment without changing the average ON-state PL intensity. This observation proves the carrier trapping process is suppressed on the HWA-built Si/SiO2 interface. We also discussed the mechanism behind the PLQY enhancement of HWA-treated Si QDs by comparing single-dot-level data to reported ensemble PL Si QDs results. HWA treatment is found to mainly brighten "grey" (not 100% efficient) QDs, a mechanism different from changing dark (non-emitting) to bright (100% efficient) Si QDs by ligand passivation. [ABSTRACT FROM AUTHOR]

The present study elucidates new perspectives regarding the Pt−CeO2 system for CO oxidation. The successful deposition of highly dispersed Pt−CeO2 species onto the surface of multiwalled carbon nanotubes (MWCNTs) led to the formation of abnormally active and water‐resistant catalysts. The catalysts were investigated by structural (XRD, TEM), spectral (XPS), and kinetic (TPR‐CO+O2, TPR‐CO, TPR‐H2) methods. The application of TPR‐CO+O2 revealed the remarkably high activity of all Pt−CeO2/MWCNTs catalysts at temperatures below 0 °C. The study of the catalysts at ambient temperature demonstrated high CO conversion in the presence of water vapor at a concentration of 100 ppm CO. The experimental findings suggest that active sites, comprising platinum structures stabilized directly on the surface of MWCNTs, play a pivotal role in the oxidation of CO under humid conditions. A dual‐site approach was employed to develop a kinetic model that effectively describes the experimental data. This model provides valuable insights into the mechanism of wet CO oxidation. [ABSTRACT FROM AUTHOR]

Moisture ingress in photovoltaic (PV) modules is a critical factor for performance degradation, therefore, a low water vapor transmission rate (WVTR) is highly desirable for polymers used to embed the solar cells, including backsheets, frontsheets, and encapsulants. With the advent of glass‐free modules for integration in building envelopes and vehicles, there is growing interest in polymer composite structures with embedded glass fibers to enhance rigidity. Furthermore, due to environmental concerns, there is increased interest in fluorine‐free polymers for PV applications. In this work, 21 samples with different base polymers, coatings, and/or surface treatments are investigated and their WVTRs are measured. The results show no good alternatives to existing fluoride‐based polymers/coatings for reducing WVTRs of backsheets and frontsheets among the investigated samples. In addition, glass fibers embedded within polymers to provide increased stability to backsheets or in composites for lightweight PV are shown to significantly increase WVTRs, especially, when fibers are not properly embedded, providing additional diffusion pathways for moisture ingress. [ABSTRACT FROM AUTHOR]

The 2022 eruption of the Hunga submarine volcano injected an unprecedented volume of water vapor into the stratosphere, presenting a unique, natural experiment for ascertaining the influence of stratospheric water vapor within the global radiation budget. This study examines the radiative forcings of the Hunga stratospheric water vapor enhancement, comparing stratosphere-adjusted radiative forcing derived from offline methods to an effective radiative forcing derived from Earth System Model simulations. Assuming a uniform 2 parts per million mass mixing ratio increase of water vapor in the Southern Hemisphere stratosphere, we estimated the instantaneous, stratosphere-adjusted, and overall effective radiative forcing to be -0.04, 0.08, and 0.05 W m-2, respectively. The lower magnitude of the positive volcanic stratospheric water vapor effective radiative forcing is due to compensating effects from atmospheric adjustments. Ensemble simulations of a coupled atmosphere-ocean model suggest a surface warming of 0.05 K, affirming a limited influence on global mean surface temperature from the volcanic stratospheric water vapor injection. [ABSTRACT FROM AUTHOR]

Palm leaf manuscripts, which are crucial carriers of historical, religious, scientific, and artistic information in East and Southeast Asia, specifically encapsulate significant aspects of Buddhist culture and thus require comprehensive research and preservation efforts. The base material of palm leaf manuscripts is processed palm leaves, which are hygroscopic and profoundly affected by environmental humidity. Currently, there is a research gap regarding the impact of traditional processing crafts and natural aging on the hygroscopicity of palm leaf manuscripts. Utilizing dynamic water vapor sorption (DVS), the hygroscopic properties of palm leaves from various years were assessed before and after traditional processing in Yunnan Province, China. The results show that traditional processing slightly increases the equilibrium moisture content (EMC) in environments with 0 to 60% relative humidity (RH), but significantly lowers EMC in high humidity environments, with reductions up to 19.01%. Additionally, hysteresis doubled post-processing, indicating enhanced stability under fluctuating humidity conditions. Sorption models suggest that traditional processing increases the number of adsorption sites while reducing physical adsorption or capillary condensation. FT-IR (Fourier-transform infrared spectroscopy) analysis indicates that the relative contents of cellulose and hemicellulose were reduced by 39.90% and 3.97%, respectively. Degradation occurring in both the crystalline and amorphous regions of cellulose. After natural aging, the hygroscopicity of processed palm leaves improved across the entire humidity range of 0 to 95%, and there was a slight increase in hysteresis. This is due to the increase in both adsorption sites and physical adsorption capabilities. FT-IR results also indicate that the relative contents of cellulose and hemicellulose were decreased by 57.52% and 19.83% after nature aging, respectively. These findings confirm that traditional processing improves the writability and humidity resilience of the leaves, while natural aging enhances their overall hygroscopic properties. This research contributes to our understanding of how humidity damages palm leaf manuscripts. aids in determining optimal RH ranges for storage, and assesses the effectiveness of consolidation treatments in their long–term preservation. [ABSTRACT FROM AUTHOR]

Highlights Poly(butylene adipate‐co‐terephthalate) (PBAT) is popular because of its low cost, biodegradability, good processing properties, flexibility, and mechanical features. In this study, we explore the potential of PBAT‐based bioplastics by adding AgVO3 nanorods with PBAT to reduce costs. We produced nanocomposite films of PBAT reinforced with 1, 3, and 5 wt% of AgVO3 nanorods using solvent casting. The inclusion of AgVO3 in the structure of PBAT was investigated through Fourier transform infrared spectroscopy, x‐ray diffraction, and scanning electron microscopy. The nanocomposite films demonstrate excellent properties, surpassing those of single‐component blends, enhancing mechanical properties, and improving the barrier properties of nanocomposite films. The water vapor transmission rate of AgVO3 reinforced (5 wt%) nanocomposite films improved by 42.45% compared to pure PBAT films. The tensile strength of the PBA‐3 film was 37.19 MPa, exhibiting higher strength than the films produced from clean PBAT (19.73 MPa). The AgVO3‐reinforced films demonstrated increased resistance to moisture and water, as indicated by their higher water contact angle values (88.04°). Food‐borne bacteria like Staphylococcus aureus and Escherichia coli have been stable to the antibacterial activity of the nanocomposites on the addition of AgVO3.The potential applications of these nanocomposite films in food packaging are promising, offering a sustainable and effective solution to food preservation. The AgVO3‐filled poly(butylene adipate‐co‐terephthalate) (PBAT) nanocomposite films exhibit superior mechanical, barrier, and resistance to moisture and water compared to neat PBAT films. The water vapor transmission rate of the film is significantly enhanced, with a 42.45% enhancement in films reinforced with 5 wt% AgVO3. AgVO3‐filled PBAT nanocomposites demonstrate effective antibacterial activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Streamflow in source region of Yellow River (SRYR) matters with regard to the adjacent and downstream water resources. Intraseasonal oscillation (ISO) in the streamflow in SRYR is of great significance to the sub-seasonal prediction of streamflow in SRYR, but is unknown. Here, we first report a 30–60-day ISO in the streamflow in SRYR, which is regulated by the atmospheric 30–60-day ISO at mid-high latitude over North Eurasia. The 30–60-day ISO in atmosphere is featured by a Rossby wavetrain, and the wave energy propagates southward onto the TP, which causes anomalous wind response over TP. The leading anomalous high (low) with anti-cyclonic (cyclonic) wind anomalies over the TP favors dry (wet) air in lower troposphere in SRYR, via enhancing the water vapor divergence (convergence). Dry (wet) air always results in strong (weak) evaporation from the Yellow River, which causes the later streamflow valley (peak) and thereby the 30–60-day ISO in the streamflow in SRYR. [ABSTRACT FROM AUTHOR]

This work investigates the effects of spermidine (SPD) on the properties of hemp‐based biopolymers developed in the absence or presence of glycerol (GLY). The mechanical properties of the biopolymer show that the tensile strength and Young's module significantly increase when the film is prepared with SPD alone (10 mm). However, the GLY plasticized films with the same concentration of 10 mm SPD have the highest elongation at break compared to the other films. The film moisture content, water solubility, and swelling ratio improve by the incorporation of SPD, resulting in the development of more hydrophobic biopolymers. However, the hydrophobicity and barrier properties to gases and water vapor of the biopolymers are higher when prepared with SPD alone. [ABSTRACT FROM AUTHOR]

Water vapour diffusion resistance of solid wood panels and laminated veneer lumber panels The material composition of wood and adhesive is influenced by numerous factors during the bonding process, which is why the water vapour diffusion resistance (WVDR) of wood‐based panels is subject to a certain degree of variation. In this work, self and industrially produced panels were tested for their WVDR in dry and humid test climates. The tests show that the results are highly dependent on the corresponding adhesive system, the adhesive quantity and the board thickness. Additional evaluations of the adhesive joint formation using a microscope show a correlation between the WVDR and the thickness of the pure adhesive film. A comparison of the measured values with the information in the data sheets reveals a considerable difference. It can be concluded from this that in future the normative regulation for determining the WVDR for the product declaration should not be determined using list values, but rather measured for each product in accordance with standard EN ISO 12572. [ABSTRACT FROM AUTHOR]

In situ measurements of water vapour isotopic composition in polar regions has provided needed constrains of post-deposition processes involved in the archiving of the climatic signal in ice core records. During polar winter, the temperatures, and thus the specific humidity, are so low that current commercial techniques are not able to measure the vapour isotopic composition with enough precision. Here, we make use of new developments in infrared spectroscopy and combine an optical-feedback frequency-stabilised laser source (OFFS technique) using a V-shaped cavity optical feedback (VCOF) cavity and a high-finesse cavity ring-down spectroscopy (CRDS) cavity to increase the signal-to-noise ratio while measuring absorption transitions of water isotopes. We present a laboratory infrared spectrometer leveraging all these techniques dedicated to measure water vapour isotopic composition at low humidity levels. At 400 ppmv , the instrument demonstrates a precision of 0.01 ‰ and 0.1 ‰ in δ18O and d-excess, respectively, for an integration time of 2 min. This set-up yields an isotopic composition precision below 1 ‰ at water mixing ratios down to 4 ppmv , which suggests an extrapolated precision in δ18O of 1.5 ‰ at 1 ppmv. Indeed, thanks to the stabilisation of the laser by the VCOF, the instrument exhibits extremely low drift and very high signal-to-noise ratio. The instrument is not hindered by a strong isotope–humidity response which at low humidity can create extensive biases on commercial instruments. [ABSTRACT FROM AUTHOR]

In order to deepen the knowledge of the seasonal variation in total cloud cover (TCC) in Xinjiang, China (XJ), a typical arid region, and to broaden the understanding of the seasonal variation in cloud type (CLT) in the region, we used TCC and CLT datasets from the latest generation of the geostationary satellite Fengyun 4A (FY-4A) from 2018 to 2022 to investigate the seasonal variation characteristics of TCC and CLT in XJ. Meanwhile, to verify the accuracy of TCC from FY-4A, ground observation (GROB) TCC datasets from 105 national meteorological stations (NMSs) in XJ and TCC datasets from ERA5 during the same period were used. In addition, the correlation between TCC from FY-4A and meteorological factors from ERA5 was also analyzed in this study. The TCC from FY-4A, GROB, and ERA5 can all well reflect the significant seasonal variation in TCC in XJ, with the highest (lowest) mean TCC and a distribution pattern of high in the southwest (northwest) and low in the northeast (southeast) in spring (fall) in XJ. Although the mean TCC from FY-4A in all four seasons was lower than that from GROB, the two were comparable in spring (44.09% and 47.32%) and summer (42.88% and 43.17%), while there was a significant difference between the two in fall (27.86% and 40.19%) and winter (30.58% and 46.93%) for 105 NMSs in XJ. The TCC from FY-4A was lower (higher) than that from GROB in spring and summer at most NMSs in northern (southern) XJ, while the TCC from FY-4A was lower than that from GROB for the vast majority of NMSs in fall and winter, especially in northern XJ. The seasonal variation in the spatial distribution of different CLTs (clear, water-type, supercooled-type, mixed-type, ice-type, cirrus-type, and overlap-type) from FY-4A exhibited diverse variation characteristics. Water-type (supercooled-water-type) had a high-frequency center of over 30% in the Tarim Basin (Kunlun Mountains) during summer. Mixed-type (ice-type and cirrus-type) had the highest frequency in winter (spring), while overlap-type had the highest frequency in summer. The correlation between TCC and water vapor conditions (total column vertically integrated water vapor, specific humidity at 250 hPa, 500 hPa, and 700 hPa) was positive in XJ. [ABSTRACT FROM AUTHOR]

The ignition and combustion behaviors of single-particle aluminum in a water vapor environment are among the most important basic research aspects of metal fuels and solid propulsion technologies. In this paper, the ignition and combustion behaviors of aluminum particles in a water vapor environment were modeled based on a traditional aluminum particle ignition model and the finite difference method. In addition, a metal single-particle ignition combustion test system was used to carry out relevant validation experiments. The validation results showed that the average error of the model remained within 10%. In addition, an initial oxide layer fusion module was established in conjunction with the results of a material mechanics study of Al/Al2O3. Moreover, the model was used to calculate the ignition behavioral parameters (ignition delay time and ignition temperature) of the aluminum particles under different initial parameters. Finally, an intrinsic mechanism model was created to evaluate the influences of the relevant parameters on the ignition behaviors of the aluminum particles. The model results showed that the initial oxide layer ruptured during the aluminum melting stage, the phase transition stress was the main factor leading to oxide layer rupture, the ambient temperature had a great influence on the ignition temperature, and all four initial parameters were negatively correlated with the ignition delay time. [ABSTRACT FROM AUTHOR]

Winter extreme cold events (ECEs) have profound impacts on human health, transportation, energy consumption and the economy, particularly associated with high‐humidity conditions. Recent research has indicated a growing interest in extreme temperature events that account for the presence of water vapour. However, the characteristics of humidity‐related ECEs (HECEs) remain unclear. Given the rise in atmospheric moisture due to global warming, understanding the influence of water vapour on HECEs becomes crucial. This study examined variations in HECEs identified using the wet‐bulb globe temperature (WBGT) in China during 1959–2020 and quantified the impacts of water vapour. The results revealed a decrease in the intensity and frequency of HECEs in China during this period, except for in northern China, where the intensity increased, which contrasts with the trends in traditional ECEs. Furthermore, strong HECEs were found to exhibit greater frequency, duration and intensity in northern China than weak HECEs. Additionally, the specific humidity for all categories of HECEs in China exhibited an upward trend, with a more rapid increase for strong HECEs. The findings indicated that the intensity of HECEs is positively correlated with the increase in water vapour. Defining a water vapour amplification factor revealed amplified intensity and duration at most grid points, particularly across northern China. Therefore, while winter warming reduces traditional ECEs, HECEs persist and even intensify as humidity increases, confirming significant amplification by water vapour. Our results emphasized the importance of increasing water vapour, driven by global warming, which may increase the risk of HECEs in the future. [ABSTRACT FROM AUTHOR]

Rapid progresses concerning wearable electronics call for stretchable batteries. Owing to the merits of high energy density and wide operating voltage range, organic electrolyte‐based lithium‐ion batteries (LIBs) take a large proportion in the powering markets. Due to the high sensitivity to moisture and oxygen, it is difficult to obtain long‐term reliable stretchable organic electrolyte‐based LIBs when they are directly exposed to the air. Benefiting from the outstanding gas impermeability of liquid metal (LM) and relatively good barrier properties for reactive acid gas molecules by polyisobutylene (PIB), an LM‐PIB seal is demonstrated for organic electrolyte‐based LIBs. In the seal, LM can prevent the inward permeation of oxygen and water vapor, and PIB can block the outward permeation of hydrolysis acid generated from the side reactions during the operation of the organic electrolyte‐based LIBs, which helps prevent the detrimental interaction between the hydrolysis acid and LM. A specific capacity of over 120 mAh g−1 is achieved and the battery shows consistent electrochemical performances under multiple deformations. This study offers a different design approach for long‐term operation of stretchable organic electrolyte‐based LIBs. [ABSTRACT FROM AUTHOR]

Potential vorticity (PV) is one of the most important quantities in atmospheric science. In the absence of dissipative processes, the PV of each fluid parcel is known to be conserved, for a dry atmosphere. However, a parcel's PV is not conserved if clouds or phase changes of water occur. Recently, PV conservation laws were derived for a cloudy atmosphere, where each parcel's PV is not conserved but parcel‐integrated PV is conserved, for integrals over certain volumes that move with the flow. Hence a variety of different statements are now possible for moist PV conservation and non‐conservation, and in comparison to the case of a dry atmosphere, the situation for moist PV is more complex. Here, in light of this complexity, several different definitions of moist PV are compared for a cloudy atmosphere. Numerical simulations are shown for a rising thermal, both before and after the formation of a cloud. These simulations include the first computational illustration of the parcel‐integrated, moist PV conservation laws. The comparisons, both theoretical and numerical, serve to clarify and highlight the different statements of conservation and non‐conservation that arise for different definitions of moist PV. [ABSTRACT FROM AUTHOR]

The Asian summer monsoon anticyclone (ASMA) plays a vital role in the transport and redistribution of the tracers in the upper troposphere and lower stratosphere during transient monsoon conditions. The ASMA can be identified using various diagnostics such as winds and divergence, potential vorticity, the Montgomery stream function or geopotential height. Its representation based on the commonly‐used existing method that takes a climatological range of the geopotential height (GPH) at a given pressure level is not robust and fails in several circumstances. In this study, we propose a new GPH method to define the ASMA for the active and break phases of the monsoon based on the GPH values at the tropical easterly jet (TEJ) and subtropical westerly jet (STJ) locations. The proposed method compares the GPH values at the locations corresponding to the wind speed maxima of TEJ and STJ at 100 hPa with the maximum GPH at 100 hPa and selects the one with the minimum difference to define the ASMA extent. The same procedures were applied to obtain the ASMA extent at 150 hPa. The ASMA extents are obtained using the method proposed here and the existing fixed GPH method for the 30 active and 27 break phases from 2005 to 2023. The fixed GPH method provides a larger ASMA extent for 24 active and 21 break phases, which appears to be an unrealistic estimation compared to the proposed method. Our proposed method identifies the ASMA extent that is larger and centred around the Iranian side during the active phases while it is smaller and centred around the Tibetan side during the break phases. Furthermore, the minimum concentration of ozone (O3), and maximum concentrations of carbon monoxide (CO) and water vapour (H2O) are also found to be centred near the Iranian side during the active phases and on the Tibetan side during the break phases. The tracer concentrations are generally higher for CO, H2O and O3 during the active phase than in the break phase. Tracer concentrations within the ASMA extent using the fixed GPH method are higher for O3 while lesser for CO and H2O when compared to the proposed method. [ABSTRACT FROM AUTHOR]

When a copper billet is heated in the rolling reheating furnace, certain oxides that affect the surface quality may persist on the substrate. This study investigates the effects of heating atmosphere compositions (N2, O2, CO2, and H2O) and contents on the micro-morphology and phase evolution of the copper oxides. The results revealed that O2 is the primary factor contributing to the formation of nodules on the copper surface. The primary phase of the exfoliated oxides was CuO attached to Cu2O, and the nodular oxides also consisted of CuO that directly adhere to copper matrix. Additionally, water vapor can increase the number of Cu2O particles on the interface between exfoliated oxide and copper matrix, effectively reducing the number of residual nodular oxides. Finally, water vapor and its dissociation products effectively eliminated the pores within the oxide layer and at the oxide–matrix interface, while CO2 increased the porosity within the oxide layer. [ABSTRACT FROM AUTHOR]

Currently, there is a significant demand in forensic toxicology for biomarkers of cannabis exposure that, unlike ∆9-tetrahydrocannabinol, can reliably indicate time and frequency of use, be sampled with relative ease, and correlate with impairment. Oral fluid (OF) and exhaled breath condensate (EBC) are alternative, non-invasive sample matrices that hold promise for identifying cannabis exposure biomarkers. OF, produced by salivary glands, is increasingly utilized in drug screening due to its non-invasive collection and is being explored as an alternative matrix for cannabinoid analysis. EBC is an aqueous specimen consisting of condensed water vapor containing water-soluble volatile and non-volatile components present in exhaled breath. Despite potential advantages, there are no reports on the use of EBC for cannabinoid detection. This study developed a supported liquid extraction approach and LC-QqQ-MS dMRM analytical method for quantification of 25 major and minor cannabinoids and metabolites in OF and EBC. The method was validated according to the ANSI/ASB 036 standard and other published guidelines. LOQ ranged from 0.5 to 6.0 ng/mL for all cannabinoids in both matrices. Recoveries for most analytes were 60–90%, with generally higher values for EBC compared to OF. Matrix effects were observed with some cannabinoids, with effects mitigated by use of matrix-matched calibration. Bias and precision were within ± 25%. Method applicability was demonstrated by analyzing ten authentic OF and EBC samples, with positive detections of multiple analytes in both matrices. The method will facilitate comprehensive analysis of cannabinoids in non-invasive sample matrices for the development of reliable cannabis exposure biomarkers. [ABSTRACT FROM AUTHOR]

Recycled moisture is an important indicator of the renewal capacity of regional water resources. Due to the existence of Yulong Snow Mountain, Lijiang in Yunnan Province, southeast of the Qinghai-Tibet Plateau, China, is the closest ocean glacier area to the equator in Eurasia. Daily precipitation samples were collected from 2017 to 2018 in Lijiang to quantify the effect of sub-cloud evaporation and recycled moisture on precipitation combined with the d-excess model during monsoon and non-monsoon periods. The results indicated that the d-excess values of precipitation fluctuated between −35.6‰ and 16.0‰, with an arithmetic mean of 3.5‰. The local meteoric water line (LMWL) was δD = 7.91δ18O + 2.50, with a slope slightly lower than the global meteoric water line (GMWL). Sub-cloud evaporation was higher during the non-monsoon season than during the monsoon season. It tended to peak in March and was primarily influenced by the relative humidity. The source of the water vapour affected the proportion of recycled moisture. According to the results of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the main sources of water vapour in Lijiang area during the monsoon period were the southwest and southeast monsoons. During the non-monsoon period, water vapour was transported by a southwesterly flow. The recycled moisture in Lijiang area between March and October 2017 was 10.62%. Large variations were observed between the monsoon and non-monsoon seasons, with values of 5.48% and 25.65%, respectively. These differences were primarily attributed to variations in the advection of water vapour. The recycled moisture has played a supplementary role in the precipitation of Lijiang area [ABSTRACT FROM AUTHOR]

Six types of γ-polyglutamic acid (γ-PGA)/cold water-soluble starch (St) composite film models were constructed using molecular dynamics simulation, and their properties were investigated and compared with the corresponding experimental values. The compatibility between the composite film components was analyzed using the radial distribution function and mean square displacement (MSD). The hydrogen-bond number and bond energy were used to track the film-formation process. The mechanical property data of the films were extracted, and MSD was used to analyze the permeability of the film to carbon dioxide, oxygen, water vapor, and carbon-16 saturated fatty acids. Finally, the simulated values of mechanical properties and permeability were compared with the experimental values. The results demonstrated that γ-PGA is well compatible with St. The intramolecular and intermolecular hydrogen bonds of γ-PGA and St did not change considerably during the film-formation process. The simulated values of the mechanical properties exhibited a similar trend as the experimental values; however, in terms of permeability, a difference was observed between the initial values of the simulated design and actual material parameters, as well as the complexity of the experiment. [ABSTRACT FROM AUTHOR]

Summary: Potato flour/gelatine films in different ratios (6:0, 5:1, 4:1, 3:1, 2:1 and 1:1) were prepared and their properties were examined in this study. Potato flour film‐forming dispersion without gelatine showed the highest particle size and apparent viscosity. As the gelatine concentration increased, the composite films became smoother and more transparent. Gelatine incorporated with potato flour films reduced the retrogradation enthalpy and glass transition temperature, leading to the low tensile strength and high elongation at break. Although water content and water solubility index increased with the higher gelatine concentration, water vapour permeability of composite films decreased from 14.59 × 10−13 gm−1s−1Pa−1 to 5.83 × 10−13 gm−1s−1Pa−1. In addition, it was noted that water contact angle increased from 24.50° to 102.33° as gelatine concentration increased from 0% (6:0) to 50% (1:1). According to these findings, potato flour film with the presence of gelatine showed the better moisture barrier properties. [ABSTRACT FROM AUTHOR]

The variability of stratospheric water vapor (SWV) plays a crucial role in stratospheric chemistry and Earth's energy budget, strongly influenced by sea surface temperature (SST). In this study, we systematically investigate the response of lower-SWV (LSWV) to regional sea surface temperature changes using idealized SST patch experiments within a climate model. The results indicate that LSWV is most sensitive to tropical sea surface temperature, with the strongest response occurring in late autumn and early winter. Warming of the tropical Indian Ocean and western Pacific (WP) leads to stratospheric drying, while warming of the tropical Atlantic (TA) and eastern Pacific results in stratospheric moistening. The drying impact on LSWV due to warming in the western Pacific Ocean exceeds the wet effect in the eastern Pacific Ocean by approximately 60%. The variations in tropical SST influence LSWV by modulating the temperature at the tropical tropopause layer, especially over the Indo-Pacific warm pool through Matsuno–Gill responses. Furthermore, the response of LSWV to tropical SST changes exhibits nonnegligible nonlinearity, which indicates the importance of nonlinearity in determining the LSWV response to global surface warming. Significance Statement: In this study, we explore how changes in the temperature of the ocean's surface can affect the amount of water vapor in the stratosphere, a layer of Earth's atmosphere. Understanding this relationship is important because water vapor in the stratosphere can influence both our climate and the chemistry of the atmosphere. Using a climate model, we found that water vapor in the lower stratosphere is especially responsive to temperature changes in tropical ocean regions. Specifically, when the Indian Ocean and the western Pacific get warmer, the stratosphere tends to get drier. On the other hand, warming in the Atlantic and eastern Pacific leads to more moisture in the stratosphere. The way these changes add up is complex and not simply a sum of individual parts, especially in tropical warm pool regions. Our findings have implications for how we understand and predict the impacts of climate change on stratospheric water vapor. [ABSTRACT FROM AUTHOR]

A heterogeneous condensation process facilitates the growth of fine particulate matter, making it more easily removable. The aim of this study was to effectively eliminate pre-existing fine particles in the atmosphere by investigating the growth characteristics of particles in turbulent water vapor environments using experimental and numerical methods. The results reveal that the presence of soluble and hydrophilic particles in atmospheric fine particulate matter enhances their growth compared to coal particles. Increasing temperature differences, reducing particle number concentrations, and elevating the proportion of soluble particle components contribute to particle growth. When the temperature difference is below 10K, particle growth is less effective. The beneficial impact of particle collision and coagulation, partly offsetting water vapor competition, was observed with an increase in particle number concentration. The addition of soluble and hydrophilic components promoted particle activation, further fostering particle growth. The region near the wall exhibited more significant particle growth due to higher supersaturation and lower flow velocity. These findings theoretically support the application of heterogeneous condensation processes in atmospheric purification. [ABSTRACT FROM AUTHOR]

• A review dedicated to the state on compression high-temperature heat pump steam systems. • The refrigerant and compressor that can be used in compression high-temperature heat pump steam systems are reviewed. • Research trend and the main technical problems of compression high-temperature heat pump steam systems to be solved are proposed. • The progress in developing, manufacturing, and optimizing high-temperature, high-pressure ratio compressors is summarized. • The primary technique for lowering discharge temperature in water vapor compressors is indicated. Compression high-temperature heat pump steam system (HTHPSS) has higher energy efficiency than electric, coal-fired and gas boilers for steam production. The system efficiently recovers waste heat from the factory and the CO 2 emissions can be reduced depending on the driving electricity mix, which is in line with the carbon neutral energy saving and environmental protection development strategy. However, there are few reviews published in the existing literature that specifically address the status of research on HTHPSS. This work not only reviews the status of research on compression HTHPSS in two directions: increasing the efficiency of high-temperature heat pump (HTHP) and increasing the steam temperature, respectively, but also indicates the future development trend of HTHPSS. The key to the research of HTHP is the development of high-temperature refrigerant and high compression ratio compressors. In this work, the refrigerants that can be used in HTHP are reviewed. Natural refrigerants R718 show promise as HTHP refrigerants because they have zero ozone depletion potential (ODP), zero global warming potential (GWP) and a high critical temperature. In addition, the research status of high-temperature and high-pressure compressor with a focus on their design and strategies for reducing the discharge temperature of scroll, piston, and screw compressors. The future focus of research is to develop a high compression ratio for the compressor. Moreover, the three main water vapor compressors, centrifugal, Roots and screw compressors, are introduced respectively. Finally, according to the operational requirements of the compression HTHPSS, research trend and the technical problems to be solved are proposed. [ABSTRACT FROM AUTHOR]

This study analyzes the oxidation behavior of FeCrAl–(0.0, 0.5, 1.0, 2.0, and 4.0) wt% Sc alloys prepared through vacuum hot‐press sintering in a water vapor environment. Sc diffuses via short‐circuit diffusion from the oxide scale/alloy interface to the oxide scale surface. Subsequently, Sc is segregated at the aluminum oxide scale interface, preventing Al ions from diffusing outward to combine with the oxygen in the water vapor and reducing the growth rate of the oxide scale. Compared to a pure oxygen atmosphere, the water vapor atmosphere affects the adhesion of the oxide scale, shedding the oxide scale and leading to secondary oxidation. Sc doping transforms the oxide scale from a state of easily curved, poorly bonded, and full voids into a flat, bonded, dense, and protective scale. A dopant content of 0.5 wt% Sc is low and has a minor effect on the oxidation resistance of FeCrAl alloys. Samples containing 2.0 and 4.0 wt% Sc are excessively doped, causing considerable internal oxidation. In this experiment, 1.0 wt% Sc doping is found to be the most appropriate, demonstrating a low mass gain of 2.59 ± 0.12 mg cm−2 and a slow oxidation rate (Kp = 0.7131 mg cm−2 · hn). [ABSTRACT FROM AUTHOR]

Featured Application: Thermal hydraulics related to hydrogen safety in a nuclear reactor containment can be simulated by the 3D CFD code with validated steam condensation and hydrogen recombination models. In a pressurized water reactor (PWR) during a loss of coolant accident (LOCA) or a station blackout (SBO) accident, water and steam are released into the containment building. The water vapor mixes with the atmosphere, partially condensing into droplets or condensing on the containment walls. Although a significant amount of water vapor condenses, it coexists with hydrogen generated by the reactor core oxidation. As water vapor condenses, the volume fraction of hydrogen increases, raising the risk of explosion or flame acceleration. As such, water vapor's behavior directly affects hydrogen distribution. To conservatively evaluate hydrogen safety in a PWR during a severe accident, lumped-parameter codes have been heavily used. As a best-estimate approach for hydrogen safety analysis in a PWR containment, a turbulence-resolved CFD code called contain3D has been developed. This paper presents the validation results of the code and simulation results of hydrogen behavior affected by water vapor condensation and hydrogen removal by passive autocatalytic recombiners (PARs) in the APR1400 containment. The results provide insight into the three-dimensional behaviors of the hydrogen in the containment. [ABSTRACT FROM AUTHOR]

In this study, the optimal ratio of starch and polyvinyl alcohol (PVA) was successfully selected by response surface method. The novel packaging films were fabricated by immobilizing Kyoho skin extract (KSE) within starch/PVA composite film by the casting method. The mechanical property, PH sensitivity, and other properties of films with different KSE content (1–5 mL) were studied. The starch/PVA film with 3 mL KSE (SPK3.0 film) showed more uniform structure than the starch/PVA film in microscope. At the same time, the film has strong mechanical properties and low water barrier capacity. Infrared analysis of the film further revealed hydrogen bond interaction between film matrix and KSE. The smart packaging film displayed distinguishable changes of color from purple to green in pH (1–13). Furthermore, the smart films possessed excellent antioxidant. Therefore, the SPK films had the potential application potential in the field of packaging. Highlights: Barrier properties and antioxidant activity were enhanced significantly by the addition of KSE.The film components are connected by hydrogen bonds so that they have good compatibility.The functional film shows different colors in the range of pH 1–13. [ABSTRACT FROM AUTHOR]

Any change in a meteorological variable can affect an environmental element's evapotranspiration over time. This paper studies the dynamic causal relationships between evapotranspiration and meteorological parameters, which have long-term equilibrium relationships in Lahore, Pakistan, during the period from October 2004 to March 2020. The Augmented Dicky Fuller test reveals that the ARDL Approach to Cointegration is used for forecasting ET (kg m−2 s−1). The results depicted that geopotential height, surface air temperature, relative humidity at the surface, surface wind speed, tropopause height, surface skin temperature, and water vapor mass mixing ratio have a statistically significant long-run relationship with evapotranspiration. The results also revealed that cloud fraction, relative humidity at the surface, surface air temperature, total surface precipitation, water vapor mass mixing ratio, and tropopause height have a statistically significant short-run relationship with evapotranspiration. The CF (t - 1) has the strongest effect on ET (kg m−2 s−1) in the short and long run. Speed of adjustment ( ECT t - 1 ) shows a highly significant and negative relation, which indicates that after a 1 unit increase in the period, evapotranspiration (kg m−2 s−1) will go toward long-run equilibrium with a rate of 66.4%. The forecasted evapotranspiration time plot shows a long-term trend with seasonal components from April 2020 to March 2025. [ABSTRACT FROM AUTHOR]

Desert regions have emerged as ideal places for GW utility‐scale photovoltaic (PV) module installations because of their ultra‐large spaces, abundance of high‐irradiance sunshine hours, and clear sky. However, the harsh desert climate presents challenges to the reliability and bankability of PV modules. This review provides an in‐depth understanding of the unique desert parameters impact, desert‐induced degradation modes, status, and required properties of the bill of materials (BOMs) and suggestions for the development of desert standards. The review reveals that the climatic conditions in the desert are considerably harsher than those in the moderate climate. The main degradation mechanisms caused by the desert are ultraviolet (UV)‐induced discoloration, thermomechanical flaws of interconnects, and glass abrasion (because of soiling). The development of desert modules may necessitate the use of new‐generation modules with low‐temperature coefficients, high efficiency, high bifaciality, stability under UV light, and elevated temperatures. For the desert module application, options include advanced back sheets and encapsulants that are thermally and UV stable, free of acetic acid groups, and have a low water vapor transfer rate. The degradation modes induced by desert climate are not sufficiently addressed by the present environmental and safety standards through accelerated aging tests. As a result, this article provides a summary of current standards and recommends creating a new testing proposal called the "Hot Desert Test Cycle (HDTC)" sequence that is specific to the desert climate. This comprehensive review catalyzes the PV community to explore novel designs and develop desert PV modules while adhering to localized standards. [ABSTRACT FROM AUTHOR]