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A mathematical model and numerical framework are presented for computing multi-physics multi-layer coating flow dynamics, with applications to the leveling of multi-layer paint films. The algorithm combines finite difference level set methods and high-order accurate sharp-interface implicit mesh discontinuous Galerkin methods to capture a complex set of multi-physics, incorporating Marangoni-driven multi-phase interfacial flow and the transport, mixing, and evaporation of multiple dissolved species. In particular, we develop several numerical methods for this multi-physics problem, including: high-order local discontinuous Galerkin methods for Poisson problems with Robin boundary conditions on implicitly-defined domains, to capture solvent evaporation; finite difference surface gradient methods, to robustly and accurately incorporate Marangoni stresses; and a coupled multi-physics time stepping approach, to incorporate all the different solvers at play including quasi-Newtonian fluid flow. The framework is applicable to an arbitrary number of layers and dissolved species; here, we apply it in a variety of settings, including multi-solvent evaporative paint dynamics, the flow and leveling of multi-layer automobile paint coatings in both 2D and 3D, and an examination of interfacial turbulence within a multi-layer matter cascade. Our results reproduce several phenomena observed in experiment, such as the formation of Marangoni plumes and Bénard cells. We also use the model to study the impact of long-wave deformational surface modes on immersed interfaces as well as the emergence of the final multi-layer film profile.

A multi-component blend of highly volatile ethanol with low volatile hydrogenated biodiesel and diesel is the subject of study. The internal vapor bubble dynamics and evaporation characteristics of individual droplets at high temperatures were investigated. The evaporation characteristics of droplet normalized square diameter and droplet lifetime of the blends of hydrogenated biodiesel, ethanol, and diesel were captured by means of the hanging droplet method and high-speed microscopic imaging in a constant temperature heating furnace. It is revealed that the rise in ambient temperature contributes to increasing the evaporation rate of fuel droplets and intensifies the micro explosion during evaporation and shortens the evaporation of droplets to a certain extent; Compared to diesel, the inhibition effect of evaporation is stronger with the increase of hydrogenated biodiesel in binary fuels and compared with binary fuels, ethanol in ternary fuels promotes micro explosions and shortens droplet evaporation; The droplet evaporation of binary fuels shows three typical phases of ethanol domination, ethanol, and diesel co-domination and co-evaporation of all three in sequence. [ABSTRACT FROM AUTHOR]

AbstractUltrasonic atomization, a powerful method using high-frequency sound waves, has gained notable significance across diverse industries due to its capacity to disintegrate liquids into very fine droplets. The use of ultrasonic vibrations for spray formation can effectively address the challenges associated with conventional methods, including the requirement for high temperatures and high-pressure fluids. Compared to conventional methods, ultrasonic atomizers can deliver a spray with lower velocity, operate at lower temperatures, produce smaller particle sizes, achieve high evaporation rates, and impose low mechanical stress. The radial jet reattachment (RJR) nozzle is a unique design to modify a jet’s flow and improve its transport characteristics, especially in air drying and cooling processes. In this paper, a novel technology is utilized with the combination of an RJR nozzle and ultrasonic atomization to atomize most liquids. The corresponding atomization rate, mist droplet size distribution, and mist droplet velocity distribution, influenced by liquid properties, temperature change, transducer mesh pore size, and applied voltage have been investigated in this paper. The energy consumption ratios, defined as the ratio of thermal energy required to evaporate liquid divided by ultrasonic energy, are analyzed based on atomization rate and applied power, showing very promising results among atomizing methods. Furthermore, the results in terms of the droplet average diameter and mean velocity as well as the resultant volumetric flow rate under different operating conditions and for all working fluids considered have been correlated with the aid of non-dimensional parameters. In addition, certain potential applications based on the remarkable characteristics of the ultrasonic-assisted RJR atomizer such as misting liquids and spray drying are highlighted. [ABSTRACT FROM AUTHOR]

In this study, the effect of different arrangements of injectors on the injection of liquid water into the hot supersonic crossflow of cylindrical geometry on the performance and the rate of evaporation has been studied using a numerical method. The crossflow has a Mach of about 2 and a total temperature of 800 K. At first, the penetration height and droplets produced by atomization in the supersonic flow are validated using the Lagrangian technique, and the results have been compared with the experiments. The usage of heat transfer equations and the evaporation model for the spray evaporation of droplets in the hot flow is also performed in the validation process, and the results are compared with the experimental results. Then, the injection into the examined geometry with four, six and eight injectors in three different arrangements was evaluated. The results indicate that employing an arrangement of eight injectors leads to the most significant reduction in total temperature, with average total temperatures decreasing to below 550 K. The results demonstrate a 40% decrease in total pressure, with a decrease in Mach number to about 1 at the end of the cylinder. Additionally, the evaporation rate shows higher evaporation of water in the eight-injector arrangement compared to other arrangements. [ABSTRACT FROM AUTHOR]

The processes responsible for the isotopic compositions and abundances of volatile elements in the early solar system remain highly debated. Orders of magnitude variation of (highly) volatile elements exist between different magmatic iron meteorite groups, but it is unclear to what extent their depletions can be explained by evaporation from metal melts during parent body accretion and/or subsequent break up. To this end, we present 86 new evaporation experiments with the aim of constraining the volatility of most volatile metals from metallic melts. The results confirm the previously proposed important effects of S in metal melt on the volatility of the elements of interest governed by their S-loving or S-phobic behavior. Nominally S-loving elements In, Sn, Te, Pb and Bi are significantly more volatile in Fe melt relative to FeS liquid, whereas nominally S-avoiding elements Ga and Sb are more volatile in FeS liquid relative to Fe melt, at a given pressure and temperature. The newly derived volatility sequences for S-free/poor and S-rich metallic melts were also compared with commonly used volatility models based on condensation temperatures. The results indicate significant differences between the latter, including the much more volatile behavior of Te, relative to Se, in both explored bulk compositions, which are traditionally assumed to be equally volatile. The (minimum) degree of volatile element depletion due to evaporation was quantified using the new experimental results and models. A comparison between the volatile element depletions in magmatic iron meteorites and the predicted depletions appropriate for evaporation from Fe melts shows that the latter depletions can be easily reconciled with (an) evaporation event(s). Altogether, the new data and models will provide an important framework when more accurate and precise estimates of magmatic iron meteorite bulk volatile element contents are available. [ABSTRACT FROM AUTHOR]

Realistic estimates of evaporation from unsaturated soils, which are important for many geotechnical and geoenvironmental applications, need to be considered in the context of soil settlement, and require thermohydromechanical (THM) analysis. Evaporation also depends on environmental parameters, including air temperature, air relative humidity, net radiation, and wind speed. Therefore, a consideration of atmospheric coupling in predicting evaporation is also necessary. In this study, the two-dimensional model EVAP1––which numerically estimates evaporation from unsaturated soil using THM and employing a soil–atmosphere model––was used to conduct a parametric study in order to investigate the effects of variation in environmental parameters and to study the effects of climate change on potential and actual evaporation and soil settlement. We found that the evaporation rate increased nonlinearly with increases in air temperature, net radiation, and wind speed, but decreases with an increase in relative humidity. However, the effect of a change in wind speed was less than the effect of a change in the three other environmental parameters. In addition, the change in evaporation rate differed in different regions with different air temperatures. For example, the temperature change had more of an effect on the evaporation rate at higher temperatures. In addition, neglecting soil settlement led to an overestimation of evaporation, albeit the amount of evaporation was almost the same whether soil settlement was considered or not, both at the beginning of the evaporation process, when potential evaporation was dominant, and at the end, when the water content in both cases had decreased almost to the residual water content, and the evaporation was minimized. The difference in the amount of evaporation was greater in the middle of the evaporation process, when actual evaporation dominated. [ABSTRACT FROM AUTHOR]

The Particle Image Velocity method was used to investigate the velocity fields when the liquid layer height changed from 0.6 to 5.1 mm. The loss of stability of the velocity field during local heating is realized at the Bond number (Bo) 0.01–0.02, which is 10–20 times lower than the critical value of Bo(cr) compared to heat exchange at a uniform wall temperature. The Marangoni flow depends both on the height and the layer diameter. The critical height of the layer 2–2.5 mm leads to a sharp change in the flow pattern. [ABSTRACT FROM AUTHOR]

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The increase in demand for water has caused attention to non-traditional methods for water supply in many places. Solar still is a simple, economical and suitable technology for providing drinking water from salt water that can be used even in remote areas. The challenge facing these technologies is to increase their performance, which is possible through three ways: environmental, design and operational parameters. This research has investigated the potential and location of Iran for the installation of solar still using environmental parameters. The three parameters of ambient temperature, solar radiation intensity and wind velocity are the most important environmental parameters affecting the performance of solar still; hence, they were used to investigate the potential of Iran to install solar still. The long-term information of the desired environmental parameters was prepared using field and telemetry methods; then, by averaging each parameter in ArcGIS software, a map was prepared for the ease of analysis and review. The results show that Iran has a high potential for using solar still in terms of environmental conditions affecting the performance of solar still and having brackish water resources and the provinces of Sistan and Baluchistan, Hormozgan, Fars, Kerman and Bushehr are the most favorable places in the country. Iran has been investigated for the installation of solar still based on three parameters. Also, the results show that the provinces of Sistan and Baluchistan (2196 kWh/m2), Fars (2148 kWh/m2), Hormozgan (2136 kWh/m2), Kerman (2116 kWh/m2), and Kohkiloyeh and Boyer-Ahmad (2098 kWh/m2), are the regions with highest potentials for installation of solar based water desalination systems in Iran. [ABSTRACT FROM AUTHOR]

In this work, we explore the intricacies of the potential‐temperature variance budget in coastal fog. We propose an improvement to the theoretical framework of the budget, whereby we include the heat exchange due to water‐phase changes. We then show this framework's consistency with a real‐world case study from the Coastal Fog (C‐FOG) Research Program. Results show that the presence of intermittent energy bursts is driven by the sudden turbulent injection of heat into the environment caused by the condensation of water vapour, and the improved theoretical framework proves satisfactory in detailing the observed process. The heat excess is transported vertically, creating a two‐term balance of high‐order moments. A bulk parametrization of this balance is also proposed to provide a simplified representation of the phase‐change process and suggest that it could be used for operational purposes. Finally, the length‐scales of the processes are evaluated from the parametrizations. The analysis indicates that the scales of the phase change of water vapour are consistent with the buoyancy production and Taylor scales. [ABSTRACT FROM AUTHOR]

This study uses idealized simulations to investigate the impact of cloud condensation nuclei (CCN) on a cumulus congestus. Thirteen cases with the initial CCN_C, which is the CCN concentration at 1% supersaturation with respect to water, from 10 to 10,000 cm−3 are simulated. The analysis focuses on the liquid phase due to the negligible ice phase in this study. A non-monotonic response of cloud properties and precipitation to CCN concentration is observed. When CCN_C is increased from 10 to 50 cm−3, the enhanced condensation due to the more numerous droplets invigorates the cumulus congestus. The delayed precipitation formation due to the smaller droplets also facilitates the cloud development. The two processes together lead to a higher liquid water path (LWP), higher cloud top, and heavier precipitation. The cumulus congestus has the highest cloud top, the strongest updraft, and the most accumulated precipitation and at CCN_C = 50 cm−3. When CCN_C is increased from 50 to 500 cm−3, the condensation near the cloud base is further enhanced and the precipitation is further delayed, both of which lead to more liquid water remaining in the cloud, and thus an even higher LWP and heavier precipitation rate in the later stage. However, the significantly enhanced evaporation near the cloud top limits the vertical development of the cumulus congestus, leading to a lower cloud top. When CCN_C is further increased to be higher than 1000 cm−3, the cumulus congestus is strongly suppressed, and no precipitation forms. The ratio of the precipitation production rate to vertical cloud water flux in the updraft is not a constant, as is generally assumed in cumulus parameterization schemes, but decreases significantly with increasing CCN concentration. It is also found that the CCN effect on the cumulus congestus relies on which parameters are used to describe the cloud strength. In this study, as CCN_C increases, the LWP and the maximum precipitation rate peak at CCN_C = 500 cm−3, while the cloud top height, maximum updraft, and accumulated precipitation amount peak at CCN_C = 50 cm−3. [ABSTRACT FROM AUTHOR]

The heat transfer limit of heat pipes is investigated by pool boiling experiments in a standard apparatus with a capillary layer placed on a copper tube. The capillary layer is a hollow cylinder made of bronze with a wall thickness of 2 mm and the test fluids are methanol and n‐pentane. The setting is comparable to high‐flux tubes already investigated in the literature. In dependence on the heat flux, three to four sections with different characteristics are identified. Compared to plain copper tubes, the heat transfer is partially increased by a factor of 12 until the limit is reached at around 70 kW m−2. [ABSTRACT FROM AUTHOR]

Endotherms vary widely in their capacity to defend sublethal body temperature (Tb) during acute heat exposure. Interspecific variation in the upper thermal limits of small mammals remains poorly studied, particularly in taxa other than bats. We hypothesised that rupicolous elephant shrews (Macroscelidae), on account of their occupancy of above-ground rock crevices in hot habitats and rapid cursorial locomotion, have evolved pronounced heat tolerance capacities. To test this hypothesis, we quantified relationships between Tb, resting metabolic rate (RMR) and evaporative water loss (EWL) in western rock elephant shrews (Elephantulus rupestris) exposed to air temperature (Tair) approaching or exceeding Tb under conditions of low humidity representative of the study population's arid, winter-rainfall habitat in western South Africa. Our data revealed a pronounced capacity to tolerate Tair > Tb, with E. rupestris tolerating Tair up to 48.0 ± 0.1 °C while defending Tb > 7 °C below Tair (maximum Tb = 41.64 ± 0.16 °C). Three behavioural pathways were employed to dissipate heat: open mouth panting, flattening their body posture, and nose-licking. At the highest experimental Tair values achieved, EWL increased 15.05-fold relative to normothermic levels and heat was dissipated evaporatively at rates equivalent to 174%—240% of metabolic heat production. The heat tolerance limit of Tair = 48 °C in E. rupestris is one of the highest yet recorded in a non-volant small mammal, and our data support the notion that elephant shrews possess a pronounced capacity to avoid lethal hyperthermia during acute heat exposure. [ABSTRACT FROM AUTHOR]

Vegetable tanning compounds have recently gathered attention as an environment-friendly, sustainable alternative to basic chromium sulfate in leather manufacturing. This study used different solvents such as water, methanol, and ethanol to extract tannins from Cassia fistula bark, a waste part of a tree. Ethanol proved the most effective solvent, yielding an extraction efficiency of 21.4 ± 0.61%. The bark extract was characterized with Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis spectrophotometry, and Reverse Phase High Performance Liquid Chromatography (RP-HPLC). Gallic acid and rutin were discovered at high levels of tannins and polyphenolic compounds, including gallic acid (114.29 mg/100 g dry extract) and rutin (45.71 mg/100 g dry extract) whereas catechol and cinnamic were absent. The extracted bark exhibited a pH of 4.01 ± 0.04 and a moisture content of 4.89 ± 0.17%. Full vegetable, semi-chrome, and chrome re-tanned upper leathers were prepared using Cassia fistula bark extract to assess the tanning performance. Full vegetable leather displayed a reasonable shrinkage temperature of 85.77 ± 1.83 °C. All three types of upper leather met the United Nations Industrial Development Organization (UNIDO) standards of different parameters such as tensile, tear, and grain cracking strength, elongation, distention at grain crack, and flexing endurance. Field Emission Scanning Electron Microscope (FESEM) analysis revealed high fiber dispersion, indicating a higher cross-linking reaction within the leathers. Overall, the results suggested that Cassia fistula bark tannin may serve as a viable and renewable substitute for chrome tanning agents, providing a sustainable source of natural tanning material for leather manufacture. [ABSTRACT FROM AUTHOR]

The article presents a kinetic model describing the lead vapor oxidation in the vapor bubble volume to produce lead oxide and hydrogen with their subsequent dissolution in the lead melt volume. The model is implemented in the approximation of homogeneous distribution of reagents and oxidation reaction products in the bubble volume. An analytical solution for stationary oxidation conditions is obtained. It is shown that vapor bubbles in the lead melt volume are a sort of chemical "microreactors" producing lead oxide and hydrogen, which subsequently dissolve in the melt volume. However, such hydrogen generation mechanism does not pose any threat for the primary coolant circuit of fast lead cooled reactors in terms of hydrogen accumulation and explosion hazard in view of essentially low intensity of the hydrogen generation source. The article presents the results of water to hydrogen conversion assessments carried out with the use of a homogeneous kinetic model for interaction of water vapor with lead vapor in the vapor bubble volume. The model incorporates mechanisms governing lead evaporation into the bubble volume, oxidation of lead vapor as it interacts with water vapor in the bubble volume, and dissolution of reaction products in the lead melt surrounding the bubble. One more important result of equilibrium thermodynamic computations is connected with a possible change in the composition of iron oxides in the melt after the injection of water from the steam generator leak into the melt. The ingress of water into the lead melt may cause a change in the composition of iron oxides, thereby increasing the fraction of hematite and decreasing the fraction of magnetite. This may entail a change in the composition of the protective oxide film on the structural steel surface to make it more brittle. [ABSTRACT FROM AUTHOR]

The high surface area of porous media enhances its efficacy for evaporative cooling, however, the evaporation of pure substances often encounters issues including local overheating and unstable heat transfer. To address these challenges, a volume of fluid (VOF) model integrated with a species transport model was developed to predict the evaporation processes of ternary mixtures (water, glycerol, and 1,2-propylene glycol) in porous ceramics in this study. It reveals that the synergistic effects of thermal conduction and convective heat transfer significantly influence the mixtures evaporation, causing the fluctuations in evaporation rates. The obtained result shows a significant increase in water evaporation rates with decreasing the microcolumn size. At a pore size of 30 μm and a porosity of 30%, an optimal balance between capillary forces and flow resistance yields a peak water release rate of 96.0%. Furthermore, decreasing the glycerol content from 70% to 60% enhances water release by 10.6%. The findings in this work propose the approaches to optimize evaporative cooling technologies by controlling the evaporation of mixtures in porous media. [ABSTRACT FROM AUTHOR]

The exploration of performance and prediction of environmentally friendly refrigerant physical properties represents a critical endeavor. Equilibrium molecular dynamics simulations were employed to investigate the density and transport properties of propane and ethane at ultra-low temperatures under evaporative pressure conditions. The results of the density simulation of the evaporation conditions of the blends proved the validity of the simulation method. Under identical temperature and pressure conditions, increasing the proportion of R170 in the refrigerant blends leads to a density decrease while the temperature range in which the gas-liquid phase transition occurs is lower. The analysis of simulated results pertaining to viscosity, thermal conductivity, and self-diffusion coefficient reveals heightened deviation levels within the phase transition temperature zone. This increase in deviation attributed to intensified molecular activity. In terms of uncovering the physical mechanism of gas-liquid phase transition, the work illustrates the macroscopic phenomenon of the intensified existing disorder during phase transitions at the molecular level. Molecular dynamics simulations analyzing the thermophysical properties of refrigerant blends from a microscopic point of view can deepen the comprehension of the thermal optimization of refrigeration processes. [ABSTRACT FROM AUTHOR]

The reduction of frictional power losses in power transmitting gears takes a crucial role in the design of energy- and resource-efficient drivetrains. Water-containing lubricants like glycerol and polyalkylene glycols have shown great potential in achieving friction within the superlubricity regime with coefficients of friction lower than 0.01 under elastohydrodynamic lubrication. Additionally, a bio-based production of the base stocks can lead to the development of green lubricants. However, one challenge associated with the application of water-containing lubricants to gearboxes is the evaporation of water and its impact on the lubricant properties. In this study, the influence of water evaporation on elastohydrodynamic friction and film thickness was investigated for three water-containing polyalkylene glycols. Two nominal water contents of 20 wt% and 40 wt% and two viscosities were considered. The results show that the friction increases continuously with higher evaporated water content, while the overall friction level remains low in nearly water-free states. A similar trend is observed for film thickness, where the strong increase in viscosity results in a notable increase in film thickness. Nevertheless, the sensitivity of friction and film thickness to water evaporation is low for small amounts of evaporated water. This allows generous thresholds for permissible variations in water content. [ABSTRACT FROM AUTHOR]

Green structures, such as green roofs or green façades, are great examples of climate change mitigation. Their impact is mainly focused on roofs in the area of overheating reduction. In this paper, initial measurement results of a green façade experimental test setup are provided. The green façade uses an innovative board from recycled materials with vegetation rooted directly on the board. The tested green façade is divided into three segments. These segments differ from each other in their watering regimes, which are crucial for cooling effectiveness. Watering operates with the assistance of gravity; water flows from the top gutter through the boards. In this paper, these three segments are compared to each other with respect to temperatures on the surface of a regular external thermal insulation composite system façade (ETICS) during two summer days. The green façade showed an impact on the temperature in the ventilated air gap, where the temperature is almost the same as the outdoor air temperature in the morning with direct solar radiation on the façade and lower than the outdoor air temperature in the afternoon. At the peaks, the surface temperatures within the air cavity surface are up to 8 °C lower than those on a new white ETICS coating. This demonstrates a cooling potential, although the surface temperatures are always higher than the outdoor air temperatures during daylight hours. [ABSTRACT FROM AUTHOR]

Cavernous weathering forms have long been studied and discussed as enigmas in geomorphology. Recently, their evolution has been shown to be controlled by moisture patterns, which are still poorly understood. For the first time, capillary water and vapor fluxes were characterized in detail at tafone in a temperate climate of central Europe using a wide range of methods adapted from soil hydrology. Time domain reflectometry showed that moisture flows from the rock interior to the evaporation front in the shallow subsurface of both — the backwalls and the outer surface. When overland flow occurs on the outer surfaces (after heavy rains), 10 mm/day can infiltrate and flow toward the backwalls. The main sources of water for tafone are the influx of water from the rock interior and the infiltration of overland flow after heavy rains, while condensation of air humidity is a minor source. Influx from the rock interior is coupled to the evaporation rate, which varies between 100 and 300 kg/m2/year in summer and less than 15 kg/m2/year in winter. More water evaporates from the backwall of the tafone than from the outer surface, and more salt is deposited in the backwalls, resulting in predominant salt weathering in the backwalls. The tafoni studied thus evolve, and the cavities deepen. Tafoni in arid and semi‐arid environments generally show a much higher contrast between evaporation rates from backwalls and outer surfaces than tafoni and honeycombs in temperate and coastal environments. Tafoni in temperate settings are therefore more susceptible to degradation when evaporation decreases or inflow to the tafone increases. This study also shows that microtensiometers can be used to determine moisture content with high spatial resolution, while time domain reflectometry allows accurate characterization of moisture patterns with depth. [ABSTRACT FROM AUTHOR]

Swimming pools are key assets in the hotel industry. With climate change and water stress, more sustainable pools are needed in tourist areas. The study examines the relationship between hotel categories and the consumption of water in swimming pools in a Mediterranean coastal region facing water scarcity. The study focuses on the Costa Brava, with a focus on Lloret de Mar, a popular tourist destination. The research employs a combination of data analysis and the utilisation of evaporation models in order to estimate the consumption of water by swimming pools. The findings indicate that hotels in the higher categories, particularly those with three or four stars, contribute a notable proportion of the total water consumption due to their larger pool sizes and higher guest numbers. The study underscores the necessity for the implementation of sustainable water management strategies, particularly in the context of climate change. It recommends the utilisation of pool water-saving technologies as potential solutions. Furthermore, the paper highlights the broader environmental impact of tourism infrastructure on water resources and suggests policy measures to mitigate these effects. The research aligns with global sustainability goals such as the European Green Deal and the 2030 Agenda. [ABSTRACT FROM AUTHOR]

The study investigates the drying behavior and desalination effectiveness of porous ceramic tiles made from fired clay materials like bricks or pottery on soil columns initially saturated with saline solution. Evaporation kinetics experiments compared the drying of saline soil with and without a ceramic tile. For soil without a ceramic cover, salt precipitation formed an efflorescent crust that initially (t ∼ 30 h) reduced the evaporation rate. However, with continued drying, the tensile stress caused cracks in the crust, allowing increased evaporation through the cracks (t > 200 h). When covered with a ceramic poultice, the saline solution was wicked into the porous ceramic by capillary action. Rapid salt efflorescence was observed on the ceramic surface. The ceramic layer initially reduced the soil evaporation rate due to pore clogging caused by salt precipitation. The pore structure characteristics of the ceramics significantly impacted their desalination performance. After an initial fast drying period controlled by evaporation, a reduced drying rate was observed as salt clogging effects became dominant, especially for the low porosity ceramic (t ∼20 h). The porous ceramic poultices could effectively extract salts from the soil, but their desalination efficiency depended critically on their pore structure properties. An industrial-based clay ceramic with large and more connected pores (porosity 0.33) was found to be around 62% more efficient in removing NaCl than a handmade pottery with small pores (porosity 0.18). [ABSTRACT FROM AUTHOR]

Droplet evaporation occurs in many natural phenomena and industrial processes; hence, several studies have been conducted on droplet evaporation. In many applications, a group of droplets evaporate and the interaction between them affects the evaporation process. In this paper, the front-tracking method is used to simulate the droplets groups evaporation. Since the front-tracking method uses a Lagrangian grid for each droplet, this method offers good accuracy in predicting the shape, the displacement and the evaporation rate of droplets. The numerical method has been developed to simulate the evaporation of binary droplets. The fluid surrounding the droplets is modeled as a gas mixture, so the numerical method can be used to simulate multiphase-multicomponent problems. The front-tracking method requires very fine grid resolution to simulate flows at high-density ratios; therefore, the method is rarely used at high-density ratios. In this paper, a two-step method is used to move the front at high-density ratios without requiring a very fine grid resolution. First, a static droplet evaporation is simulated, and the results are compared with the analytical solutions; evaporation of a Decane droplet is then simulated, and the results are compared with the experimental data. Subsequently, the evaporation of a binary droplet is modeled. The evaporation of a group of static droplets is also simulated, and the effect of droplets interaction is investigated. Next, the evaporation of three injected droplets is simulated, and the effect of some parameters on droplets interaction is probed. The evaporation rate and displacement of each droplet are calculated and compared with the single droplet. Finally, the evaporation of the groups of droplets is simulated, and the effect of different arrangements of droplets on the evaporation rate is studied. Understanding the droplets interactions is helpful in predicting droplet spray behavior and developing numerical methods. Thus, the presented results are useful to achieve a better understanding of the droplets interaction phenomenon, its outcomes, and the parameters affecting evaporation rate. [ABSTRACT FROM AUTHOR]

The study is concerned with the rate of evaporation from porous rock, including the second stage of evaporation characterised by the existence of a dry surface layer separated from the wet capillary zone by a sharp evaporation front. The main objective is to investigate the relationship between the depth of evaporation front and the rate of evaporation as the drying process progresses, and to compare measured evaporation rate with the corresponding calculated values. Sandstone core samples saturated with water were allowed to dry naturally under room conditions, while the changes in the evaporation rate and the depth of evaporation front, among other quantities, were measured. We demonstrate that the evaporation rate can be very accurately determined from the depth of the evaporation front and the ambient air temperature and relative humidity using Fick's law for water-vapor diffusion. During the second stage of evaporation, the diffusion flux through the dry surface layer is computed using the water-vapor diffusion coefficient of the rock, determined from a separate wet cup experiment. In order to cover the first stage of evaporation, an additional parameter characterising the diffusion layer of air above the surface is required, either determined by the best fit to the measured evaporation rates, or adopted from previous studies. The calculated evaporation rate was in good agreement with measurements, with Pearson correlation coefficient 0.98 and relative error of the calculations averaging 15% over the evaporation front depths ranging from 0 to 29 mm. A workflow for determining the evaporation rate from sandstone outcrops is suggested, along with possible applications in sandstone weathering research. [ABSTRACT FROM AUTHOR]

The primary objective of this study is to evaluate soil evaporation in arid regions using a minimal set of readily accessible parameters, which are represented through a nomogram. This work explores the relationships between soil evaporation, soil water deficit, and air temperature. Evaporation is a critical factor influencing the soil water regime. Irrigation artificially adjusts soil moisture to maintain it within optimal limits for vegetation. This regulation can only be effectively managed if the principles of soil-water balance are thoroughly understood. In arid and semi-arid regions, where water quality is often poor (high salinity), prolonged excessive irrigation can lead to soil salinization, thereby reducing agricultural productivity. In this study, ten lysimeters were used to measure soil evaporation at different levels of soil water saturation. The highest evaporation rate was recorded in fully saturated soil, peaking at 548 mm. This rate decreased as the soil water saturation decreased. Therefore, a good knowledge of the evaporation value is necessary to establish appropriate irrigation and soil leaching rates and consequently, an adequate water balance. [ABSTRACT FROM AUTHOR]

In the present work, direct contact the refrigerant and the cells was employed for thermal management. This study experimentally investigates cooling the battery pack by allowing the refrigerant to directly contact the cells. Furthermore, it presents the first experimental evaluation of combining this approach with various active and passive cooling methods. According to the results, the cells' maximum temperature decreased by 34°C at the end of the discharge. In the proposed system, the heatsink served as the only heat transfer path to the environment, where. heat transfer occurred via free convection. To enhance heat dissipation from the heatsink, the system was combined with active or passive Battery Thermal Management Systems (BTMSs). Using hydrogel between the fins of the heatsink decreased the cells' maximum temperature by 0.5°C. However, the use of forced airflow between the fins of the heatsink did not affect the cells' maximum temperature. The proposed system was also combined with an active forced liquid cooling system, and various water flow rates were investigated. At a flow rate of 200 LPH, the cells' maximum temperature was reduced by 1.5°C compared to the mode without forced water flow. Additionally, different inlet water temperatures were examined, revealing that increasing the inlet water temperature leads to a significant rise in the cells' maximum temperature. [ABSTRACT FROM AUTHOR]

The composition of the gas phase was identified for the first time up to a temperature of 2200 K by the Knudsen effusion mass spectrometric method, and the partial pressures of the vapor species during the evaporation of hydroxyapatite were determined. Ca10(PO4)6(OH)2 was evaporated from a Knudsen effusion cell made of tungsten. In the temperature range 1200–1300 K, Ca10(PO4)6(OH)2 undergoes dehydration, forming Ca3P2O8, which evaporates in the form of PO, atomic calcium, and oxygen when the temperature further increases to 1750–2200 K. [ABSTRACT FROM AUTHOR]

The evaporation of Y2O3 in the presence of carbon was studied by high-temperature differential mass spectrometry. In the temperature range 1950–2200 K, the vapor above the Y2O3–C system contains YO and atomic yttrium. At elevated temperatures, the partial pressure of YO vapor over the Y2O3–C system decreases compared to the partial pressure of YO vapor over individual Y2O3, leading to a decrease in the activity of yttrium oxide in the system. [ABSTRACT FROM AUTHOR]

Sea surface salinity (SSS) can change as a result of surface freshwater forcing (FWF) or internal ocean processes such as upwelling or advection. SSS should follow FWF by ¼ cycle, or 3 months, if FWF is the primary process controlling it at the seasonal scale. In this paper, we compare the phase relationship between SSS and FWF (i.e., evaporation minus precipitation over mixed layer depth) over the global (non-Arctic) ocean using in situ SSS and satellite evaporation and precipitation. We found that, instead of the expected 3-month delay between SSS and FWF, the delay is mostly closer to 1–2 months, with SSS peaking too soon relative to FWF. We then computed monthly vertical entrainment and horizontal advection terms of the upper ocean salinity balance equation and added their contributions to the phase of the FWF. The addition of these processes to the seasonal upper ocean salinity balance leads to the phase difference between SSS and the forcing processes being closer to the expected value. We conducted a similar computation with the amplitude of the seasonal SSS and the forcing terms, with less definitive results. The results of this study highlight the important role that ocean processes play in the global freshwater cycle at the seasonal scale. [ABSTRACT FROM AUTHOR]

Evapotranspiration (ET) $(ET)$ is a key process in the hydrological cycle that can help mitigate urban heat. ET $ET$ depends on the surface cover, as the surface affects the partitioning of precipitation between runoff and evapotranspiration. In urban neighborhoods, this surface cover is highly heterogeneous. The resulting neighborhood‐scale ET $ET$ can be observed with eddy‐covariance systems. However, these observations represent the signal from wind‐ and stability‐dependent footprints resulting in a continuously changing contribution of surface cover types to the observation. This continuous change prevents quantifying the contribution of the surface cover types to neighborhood ET $ET$ and their hourly dynamics. Here, we disentangle this neighborhood‐scale ET $ET$ at two sites in Berlin attributing the patch‐scale ET $ET$ dynamics to the four major surface cover types in the footprint: impervious surfaces, low vegetation, high vegetation, and open water. From the bottom‐up, we reconstruct neighborhood ET $ET$ based on patch‐scale observations and conceptual models. Alternatively, we start top‐down and attribute neighborhood ET $ET$ to the surface cover types solving a system of equations for three eddy‐covariance systems. Although data requirements for the bottom‐up approach are met more frequently, both approaches indicate that vegetation is responsible for more ET $ET$ than proportional to its surface fraction in the footprint related to the large evaporating surface compared to the ground surface. Evaporation from impervious surfaces cannot be neglected, although it is less than from vegetation due to limited water availability. The limited water availability causes impervious surfaces to cease evaporation hours after rainfall, while vegetation and open water sustain ET $ET$ for extended periods. Plain Language Summary: Different types of surfaces, like grass, trees, pavement, and open water, affect how rainwater is divided between evaporation and runoff. In cities with lots of pavement and buildings, more water runs off than in natural areas leaving less water for evaporation. Measurement towers have been observing the evaporation from whole neighborhoods, but separating the effects of different surfaces is hard. In our study, we figure out how much each surface type contributes to evaporation with two methods: one starting from the separate surfaces and rebuilding the neighborhood evaporation, and the other starting with the neighborhood evaporation and breaking it down into evaporation from each surface. Both ways showed that plants evaporate more than proportionally to their surface area, but even built surfaces like pavement evaporate. Our findings confirm that more plants lead to more evaporation, but built surfaces cannot be ignored. This information can help urban planners create cities that manage water better, making cities nicer places to live. Key Points: Neighborhood ET is reconstructed from patch‐scale data (bottom‐up) and disentangled attributing ET to four surface types (top‐down)The neighborhood and patch scale are connected through half‐hourly‐varying eddy‐covariance footprintsET dynamics after rainfall reveal that water limitation drives differences between surface cover types [ABSTRACT FROM AUTHOR]

Abstract We present accurate and mathematically consistent formulations of a diffuse-interface model for two-phase flow problems involving rapid evaporation. The model addresses challenges including discontinuities in the density field by several orders of magnitude, leading to high velocity and pressure jumps across the liquid–vapor interface, along with dynamically changing interface topologies. To this end, we integrate an incompressible Navier–Stokes solver combined with a conservative level-set formulation and a regularized, i.e., diffuse, representation of discontinuities into a matrix-free adaptive finite element framework. The achievements are three-fold: First, we propose mathematically consistent definitions for the level-set transport velocity in the diffuse interface region by extrapolating the velocity from the liquid or gas phase. They exhibit superior prediction accuracy for the evaporated mass and the resulting interface dynamics compared to a local velocity evaluation, especially for strongly curved interfaces.Second, we show that accurate prediction of the evaporation-induced pressure jump requires a consistent, namely a reciprocal, density interpolation across the interface, which satisfies local mass conservation. Third, the combination of diffuse interface models for evaporation with standard Stokes-type constitutive relations for viscous flows leads to significant pressure artifacts in the diffuse interface region. To mitigate these, we propose to introduce a correction term for such constitutive model types. Through selected analytical and numerical examples, the aforementioned properties are validated. The presented model promises new insights in simulation-based prediction of melt–vapor interactions in thermal multiphase flows such as in laser-based powder bed fusion of metals.

The primary objective of this study is to evaluate soil evaporation in arid regions using a minimal set of readily accessible parameters, which are represented through a nomogram. This work explores the relationships between soil evaporation, soil water deficit, and air temperature. Evaporation is a critical factor influencing the soil water regime. Irrigation artificially adjusts soil moisture to maintain it within optimal limits for vegetation. This regulation can only be effectively managed if the principles of soil-water balance are thoroughly understood. In arid and semi-arid regions, where water quality is often poor (high salinity), prolonged excessive irrigation can lead to soil salinization, thereby reducing agricultural productivity. In this study, ten lysimeters were used to measure soil evaporation at different levels of soil water saturation. The highest evaporation rate was recorded in fully saturated soil, peaking at 548 mm. This rate decreased as the soil water saturation decreased. Therefore, a good knowledge of the evaporation value is necessary to establish appropriate irrigation and soil leaching rates and consequently, an adequate water balance.

The importance of marine transportation of crude oil and petroleum products significantly increases in the context of geopolitical tensions. Marine transportation of oil involves losses from evaporation during loading and unloading of tankers at marine terminals, as well as during transshipment from ship to ship. It is difficult to predict the volume and quantity of the resulting multi-component mixture of gases because of the uncertainty in the initial data. Gas-dynamic processes occurring inside the tanker and in the pipelines of gas phase affect the efficiency of oil and oil products vapor recovery systems. The paper proposes a model that allows to determine the parameters of these processes during tanker loading. Under conditions of high ambient temperatures of 25.-30 0C, it is experimentally determined that the concentration of hydrocarbons can reach up to 0.6 kg/m³ during vaporization of gasoline. The paper presents the calculation of distances for which the vapor recovery unit can accept vapors simple by pressure without using a gas blower. The developed model was verified on the basis of real loading data on the territory of a large port in the Russian Federation during gasoline transshipment. It was shown that for an operating marine terminal with a vapor recovery unit located 300 m away from the tanker, the gas blower can be turned off without the risk of opening the discharge valve. [ABSTRACT FROM AUTHOR]

[Display omitted] Evaporation of small water droplets on solids is hindered because surface tension pulls the droplet into a spherical cap that has a small perimeter. Our solution is to coat a solid with a very thin, porous layer into which the droplet flows to create a large-area disk with concomitant high rate of evaporation. We investigate evaporation by varying factors that have not been previously considered: pore size and distribution, contact angle, temperature, and relative humidity (RH). A larger pore size resulted in faster evaporation, which we explain through faster transport within the coating. Even faster evaporation occurred for a bilayer structure with small particles on the air side and larger particles on the solid side. The water advancing contact angle had an insignificant effect in the range from < 10° through to 60°. Our results for different pore sizes, temperature, humidity, and contact angle all collapse onto a single curve when appropriately normalized. This validates an equation that can be used for the evaporation from a homogeneous coating that depends only one empirical factor and the droplet volume. Since the volume is often user-controlled, we envisage that this equation can be used to predict evaporation and guide design of fast-drying coatings. [ABSTRACT FROM AUTHOR]

The Patearoa saline site in Maniototo basin has developed on variably clay-altered Otago Schist. Decomposition and sedimentary redistribution of schist outcrop components has led to formation of bare soil-free substrates (upper metre scale) with contrasting permeability to rain and shallow groundwater percolation. Relatively impermeable clay-rich substrates, with a surface crust (cm scale) of detrital clay and muscovite, are saline with electrical conductivity (EC) of 1–35 mS/cm and locally hyperalkaline (pH > 10), with evaporative mineral accumulations. These saline substrates are downslope of more permeable substrates consisting of coarse schist debris and fractured outcrops, which have lower salinity (EC < 1 mS/cm) and lower pH (<7). A salt line can be mapped at metre scale between these substrate types on hillsides. The geochemical contrasts across the salt line have strong effects on plant communities that are colonising bare ground. Initial colonisation of bare saline substrates by some plants changes the geochemical signatures of the surficial few centimetres to form proto-soil with lower EC and pH. Proto-soil development facilitates further colonisation by pasture grasses, but the underlying substrates remain saline and highly alkaline. Salt lines similar to the one at Patearoa are mappable elsewhere in the Otago area and constitute fundamental geoecological boundaries. [ABSTRACT FROM AUTHOR]

The evaporation rate of disinfestants when sprayed on production surfaces is expected to vary under different weather conditions, but it is unknown how that affects efficacy. This study was an initial investigation into how the evaporation rates of water and six commercial disinfestants vary under eight weather condition categories. Additionally, an empirical model was developed on the evaporation rate of water in response to air temperature, relative humidity, solar radiation, vapor pressure deficit, and wind speed under the same eight weather condition categories. Isopropyl alcohol lost more weight due to evaporation over 4 h (P < 0.0001) than all other disinfestant solutions, and no differences (P = 0.05) existed between the other five disinfestant solutions and water. Isopropyl alcohol had a mean percentage weight loss of 71% under hot and sunny conditions, 43% under cool and cloudy conditions, and 6% under indoor laboratory conditions. Water, hypochlorite, quaternary ammonium, and peroxy disinfestant solutions evaporated at a similar rate over 4 h, with an approximate mean percentage weight loss of 17% under hot and sunny conditions, 6% under cool and cloudy conditions, and 1% under indoor laboratory conditions. The regression model that best explained the influence of weather on evaporation included the variables solar radiation, temperature, and wind speed (P < 0.0001, R2 = 0.5603). This information will be used further to model the evaporative rate of disinfestants under the same range of weather conditions when applied to multiple types of substrate materials that represent common horticultural plant production surfaces. [Figure: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.

One method used to estimate the evaporation rate involves employing various types of evaporation pans, including the standard Colorado Sunken and Class A evaporation pans. This study aimed to investigate and compare the evaporation rates from two pans, Class A and Colorado Sunken, in Semnan City. The Colorado Sunken evaporation pan was utilized as the test pan, and the test was conducted in an open space near the Faculty of Civil Engineering at Semnan University, located in Semnan City. Evaporation measurements were recorded daily for 123 days, from June 1, 2017, to September 31, 2017. The evaporation amount from the Class A pan was obtained from the synoptic station of Semnan city, situated 2.39 km away from the test site, and was subsequently analyzed. Meteorological data, including maximum and minimum temperature, maximum and minimum relative humidity, wind speed, sunshine hours, and air pressure, were also collected from the Semnan synoptic station and compared with the experimental evaporation data. The results indicated no significant difference in the daily evaporation amount between the Class A pan and the Colorado Sunken pan during the tested periods. The best statistical distribution, based on Kolmogorov–Smirnov test, for the Class A evaporation pan and the buried Colorado pan, were selected as Error with (k-s=0.05019) and Gamma with (k-s=0.05552). The coefficient of determination between the two pans was estimated to be approximately 93%. Further analysis revealed that the rate of evaporation is most closely associated with the maximum daily temperature. Pearson's correlation coefficient for the maximum temperature with the Class A evaporation pan and the Colorado Sunken pan was found to be 0.623 and 0.647, respectively.

Palladium is now frequently utilized in fuel cells, electroplating, electronics, and catalysis. Due to their rarity and high cost, precious metal recovery has taken on a significant role. The extraction method frequently utilized in polymer inclusion membranes (PIMs) is both efficient and simple since it has been demonstrated that precious metal adsorption on the membrane significantly controls the mechanism of chemical adsorption. In this study, polyvinyl chloride (PVC) as a polymer, A336 as a plasticizer, and trioctylamine (TOA) as a carrier were used to produce a PIM by evaporation. After the production of PIMs, palladium extract was studied. The stripping phase, palladium concentration in the feed phase, and components of the membrane were changed to determine the optimum condition with better extraction ability. When 0.5 M of HCl was used, higher kinetic parameter results and higher than 85% extraction efficiency were achieved compared to other concen- trations. When the EDX results were examined, 3.3% palladium was retained on the membrane surface. When the palladium concentration was selected at 2.5 ppm, higher kinetic parameters were observed, and the extraction efficiency was over 90%. The best membrane was the PIM containing 40% PVC–40% A336–20% TOA. HIGHLIGHTS Palladium metal recovery is very important to reduce the depletion of natural resources.; PIMs are preferred because of their physical and chemical properties.; The polymer inclusion membrane is the most innovative extraction method.; PVC as a polymer can be used for the production of PIMs containing different ratios of plasticizers and carriers.;

The creation of modern production is impossible without the use of information measuring systems that allow optimizing production processes, increasing enterprise productivity and improving the quality of finished products by controlling a set of characteristic parameters. The study considered the issue of assessing the moisture content of manufactured products, which is a characteristic parameter that is decisive for the quality of finished products in many areas of industry. Without violating the generality of conclusions, the research is conducted on the basis of technological processes with evaporation. During its implementation, determining measurements are performed, the purpose of which is to carry out the calibration process based on test samples in order to create calibration tables, and control measurements carried out directly during the production process in order to adjust (according to the created tables) the influential controlled parameters to the value of the characteristic parameter. The study described the methodology of obtaining a relative grading characteristic for processes that directly or indirectly correspond to the subtraction model equation. The structural organization is given for grading the values of the characteristic parameter of the finished product depending on the size of the influential factors. The uncertainty of moisture estimation based on the results of the control measurement is analyzed. The study established that the presence of instrumental correlation leads to an increase in the estimation accuracy when using the subtraction operation. Moreover, with the increase in the difference between the input parameters, the accuracy of estimating the moisture content of the finished product also increases.

Qinghai Lake is not only the largest lake in China but also an important part of the national ecological security strategy.Under the background of global warming， the water level of Qinghai Lake changes rapidly， which has great effects on the surrounding traffic facilities， residents' safety and the development of animal husbandry， etc.Therefore， it is necessary to study the water level evolution characteristics of Qinghai Lake and its water balance under climate change.Based on the hydrological data of Buha River hydrology station and Xiashe hydrology station， meteorological data of Gangcha meteorological station and CMFD， and water balance equation， this paper first analyzes the inter-annual and intra-year water level evolution characteristics of Qinghai Lake from 1956 to 2020， and the water balance components， such as runoff into the lake （Rs）， precipitation （P） and evaporation （E）.The second reveals that the changes in water level values calculated in the same months are synchronized with the changes in Rs， P， and E.Finally， the ridge regression method is employed to quantitatively calculate the contribution rates of Rs， P， and E to the water level change of Qinghai Lake based on calculations made for December.The results show that the annual average water level declined at a rate of 0.8 m·（10a）-1 from 1956 to 2004， of which the main reason for the decrease between 1979 and 2004 was that E exceeded the sum of P and Rs.However， from 2004 to 2020， the water level increased at a rate of 1.9 m·（10a）-1， of which the main reason for the increase between 2004 and 2018 was the increase of P and Rs.Qinghai Lake exhibits evident intra-annual variations， with the water level starting to rise in May and reaching its peak in September， which aligns with the monthly variations of Rs， P， and E.Furthermore， the impact of the current year's P， Rs， and E changes on the annual water level change for the same months of September to December is greater than that of the previous year.Specifically， the contributions of the current year's P， Rs， and E changes to the water level change calculated based on December data are 10%， 70%， and 20%， respectively.

Spray technology is an innovative salt production process technology that is able to increase seawater salinity and accelerate the salt production process. This study aims to determine the effect of variations in the amount of spray and discharge in spray technology on increasing seawater salinity. The experimental method was carried out by varying the spray and water discharge amount in spray technology according to the variables. This research has been successfully carried out to increase the salinity of synthetic seawater where to increase from the initial seawater salinity of 2.5 °Be to 24 °Be. It takes 16 hours taken in 3 days using the number of sprays as much as 5 sprays with a seawater flow rate of 0.2424 m³/hour in an evaporation pond of 15í—7 m. The use of the spray method proved effective in accelerating the rate of increase in salinity of synthetic seawater, which was tested to increase the salinity of synthetic seawater from 2.5 °Be to 12 °Be with an evaporation time in traditional methods of 15 days to only 11 hours. This can also happen because the temperature, humidity and wind speed were relatively stable when the research took place.

In this study, we conducted the extraction of silver nitrate (AgNO3) using the chemical reduction evaporation method, involving silver metal (Ag) with a molarity of 7.716 M and nitric acid (HNO3). The heating process via evaporation was carried out at 85oC for 2 hours. Subsequently, the synthesis of silver nanowires (AgNWs) was performed using a 0.3 M of AgNO3 solution in ethylene glycol (EG), polyvinyl pyrrolidone (PVP), and Iron (III) Chloride hexahydrate (FeCl36H2O). XRD analysis of the AgNO3 sample revealed an orthorhombic crystal structure with a single AgNO3 phase peak. In AgNWs, three crystalline phases were observed, with the Ag phase being the most dominant. The average crystal size of AgNO3 and AgNWs was 109.42 nm and 22.06 nm, respectively. The average crystal size of the AgNO3 sample may be influenced by the aggregation between crystal nuclei during the heating process. XRF analysis indicated a 98.84% Ag concentration in AgNO3. SEM-EDS analysis showed that the AgNO3 sample had a non-aggregated morphological structure, with particle size measuring 49.46 μm and an overall AgNO3 purity of 92.68%. The SEM image of the AgNWs sample displayed a very homogeneous diameter of ∼200 nm with a length of around 10-20 μm. Meanwhile, AgNWs exhibited a morphology resembling rod-shaped wires with a purity of 68% for Ag.

Abstract Various environmental factors could induce groundwater hydrochemical evolution, which should be considered when addressing groundwater environmental issues. However, the complex interactions among the environmental controls remain unknown for a groundwater flow system spanning multiple geological units. To fill this gap, we conducted a study on the groundwater hydrochemical evolution in the fluvial corridor of the Fen River, Northern China, utilizing a combination of hydrogeochemical and multiple isotope methods. Results reveal that the groundwater in the corridor has significantly degraded due to high concentrations of $${\text{SO}}_{4}^{2 - }$$ SO 4 2 - , $${\text{NO}}_{3}^{ - }$$ NO 3 - , Cl−, or F−. We find an unordered evolution of the hydrochemical composition of groundwater along this corridor. These evolutions are driven by mineral dissolution/precipitation, dedolomitization, and cation exchange processes. Human activities play a significant role, with notable contributions including $${\text{NO}}_{3}^{ - }$$ NO 3 - fluxes from agricultural fertilizers, manure, and sewage, as well as $${\text{SO}}_{4}^{2 - }$$ SO 4 2 - fluxes arising from coal mining activities. The combination between karst spring areas and faults/uplifts, between coal-bearing strata and mining activities fosters the mixing of karst water/mine water with shallow groundwater, promoting dramatic hydrochemical evolution of groundwater. The flat terrain and the natural blockage formed by mountains significantly enhance water–rock interactions and groundwater evaporation by slowing groundwater flow. The contribution of evaporation on groundwater salinity ranges from ~ 0.2% to 4.8%, highlighting its importance in the groundwater hydrochemical evolution. This study unravels the multifaceted nature of groundwater hydrochemical evolution. It emphasizes the four types of environmental controls, including hydrogeochemical processes, climate factors, human activities, and variations in geological settings, can be equally important, which is usually ignored. The findings enrich our understanding of groundwater evolution and highlight the challenges encountered in regions composed of diverse geological units.

The paper considers the peculiarities of the climate change influence on the dynamics of drought development in Ukraine. The analysis was performed for average long-term climatic conditions during the growing season (1981–2020) and under climate change scenarios RCP 4.5 and RCP 8.5 for the period of 2021–2050 (for the period as a whole and by the decades: 2021-2030, 2031-2040, 2041-2050). The drought development was studied over relatively short periods of time (ten days) at the main agroclimatic regions of Ukraine (Polissia, Forest-Steppe, Northern and Southern Steppe). The assessment of the aridity of ten-day periods was accomplished by means of a set of aridity indicators by Selyaninov, Shashko, Budagovskiy and Bova, which corrects and supplements each other; this made it possible to consider in detail the genesis of climate-induced drought in the agroclimatic regions of Ukraine. Analysis of the study results showed that the development of drought conditions in all agroclimatic regions is expected as early as in the first decade (2021-2030). According to both scenarios, from 4-6 in Polissia to 16-17 severe and very severe droughts in the Southern Steppe are expected. In the second decade (2031-2040), under RCP4.5, improvement in moistening conditions is expected in Polissia and Forest-Steppe and under RCP8.5, an increase in the level of aridity is expected in these agroclimatic regions. In the Northern Steppe and Southern Steppe the number of moderately, very and extremely dry ten-day periods will increase (from 9 to 17). In the third decade (2041-2050), under the RCP4.5 scenario, very severe aridity conditions are assumed in all agroclimatic regions. Under RCP8.5, good moistening conditions and, according to both criteria, a small number of dry ten-day periods are expected in Polissia and Forest-Steppe. As for the conditions at the Northern and Southern Steppes very severe drought conditions are expected (from 8 to 17 ten-day periods with moderate, severe and very severe drought). For 2021-2050 on the whole, there will be an increase in aridity during the growing season in all agroclimatic regions of Ukraine.

Attaching DNA oligonucleotides to gold nanoparticles (AuNPs) to prepare spherical nucleic acids (SNAs) has offered tremendous insights into surface chemistry with resulting bioconjugates serving as critical reagents in biosensors and nanotechnology. While thiolated DNA is generally required to achieve stable conjugates, we herein communicate that using a thermal drying method, a high DNA density and excellent SNA stability was achieved using nonthiolated DNA, rivaling the performance of thiolated DNA such as surviving 1 M NaCl, 2 month stability in 0.3 M NaCl and working in 50 % serum. A poly‐adenine block with as few as two consecutive terminal adenine bases is sufficient for anchoring on AuNPs. By side‐by‐side comparison with the salt‐aging method, the conjugation mechanism was attributed to competitive adenine adsorption at high temperature along with an extremely high DNA concentration upon drying. Bioanalytical applications of nonthiolated SNAs were validated in both solution and paper‐based sensor platforms, facilitating cost‐effective applications for SNAs. [ABSTRACT FROM AUTHOR]