Search Results (205)

Based on experimental data regarding the local distribution of metallic impurities in raw selenium and the composition of its vapor phase, the potential composition of the vapor–droplet suspension that leads to reduced condensate quality due to impurities with low partial vapor pressures relative to selenium, as well as metals with vapor pressures comparable to selenium, has been hypothesized. Due to selenium’s high aggressiveness towards structural materials and based on economic feasibility, the use of low-alloy steel of ordinary quality for the technical design of the distillation process, instead of alloyed steel, has been thermodynamically justified. A method has been developed, and a device to refine selenium has been manufactured, which differs from existing ones by the inertial purification of the vapor phase from droplet suspension. The development is protected by a security document (patent KZ No. 37275). Based on the completed developments, an industrial prototype of such equipment has been designed and implemented in production. Full article

It is imperative to investigate the behavior of the droplet superimposed condensation of deltamethrin reagent on strawberry leaf surface, as well as the dynamic variation rule of its contact angle. A microinjector was utilized to conduct the experiment of droplet superposition and condensation. The surface tension of deltamethrin droplets was measured by means of an optical contact angle meter, and the wetting parameters, such as contact angle, volume, and spreading diameter, were obtained by observing the leaf surfaces of various parts of strawberries during the dynamic process of superimposed condensation. A model was constructed by establishing the relationship between the contact angle and the coordinates of the observation point and time through the spatial fitting interpolation method. This model is a three-dimensional dynamic trend surface model of contact angle for droplet superposition and condensation. The findings indicated that the surface tension of the deltamethrin drop was 28.92 ± 0.2 mN·m⁻¹. The interval between the superposition of two droplets and the subsequent condensation of a new droplet was found to be within 0.5 s. The time taken for a new droplet to form was found to be between 0.0356 and 0.0476 s. The change in contact angle during the processes of superposition and coalescence can be broadly categorized into three distinct stages: namely, sharp oscillation, slight decrease, and gentle stabilization. The volume of the new droplet formed by the superposition and condensation was found to be 1.05 to 1.93 times that of a lying droplet. The maximum increase in the spreading diameter of the superimposed and condensed droplets was 40.29%. The three-dimensional dynamic trend surface model can reflect the overall spatial–temporal change trend of the contact angle in the process of superposition and coalescence. The model successfully passed the overall significance F-test and each coefficient of the statistical t-test, and demonstrated a satisfactory time interpolation effect. The experimental verification demonstrates that the predicted contact angle value of the model is consistent with the measured value. Full article

PDE11A is a little-studied phosphodiesterase sub-family that breaks down cAMP/cGMP, with the PDE11A4 isoform enriched in the memory-related hippocampal formation. Age-related increases in PDE11A expression occur in human and rodent hippocampus and cause age-related cognitive decline of social memories. Interestingly, age-related increases in PDE11A4 protein ectopically accumulate in spherical clusters that group together in the brain to form linear filamentous patterns termed “PDE11A4 ghost axons”. The biophysical/physiochemical mechanisms underlying this age-related clustering are not known. Here, we determine if age-related clustering of PDE11A4 reflects liquid–liquid phase separation (LLPS; biomolecular condensation), and if PDE11A inhibitors can reverse this LLPS. We show human and mouse PDE11A4 exhibit several LLPS-promoting sequence features, including intrinsically disordered regions, non-covalent pi–pi interactions, and prion-like domains that were particularly enriched in the N-terminal regulatory region. Further, multiple bioinformatic tools predict PDE11A4 undergoes LLPS. Consistent with these predictions, aging-like PDE11A4 clusters in HT22 hippocampal neuronal cells were membraneless spherical droplets that progressively fuse over time in a concentration-dependent manner. Deletion of the N-terminal intrinsically disordered region prevented PDE11A4 LLPS despite equal protein expression between WT and mutant constructs. 1,6-hexanediol, along with tadalafil and BC11-38 that inhibit PDE11A4, reversed PDE11A4 LLPS in HT22 hippocampal neuronal cells. Interestingly, PDE11A4 inhibitors reverse PDE11A4 LLPS independently of increasing cAMP/cGMP levels via catalytic inhibition. Importantly, orally dosed tadalafil reduced PDE11A4 ghost axons in old mouse ventral hippocampus by 50%. Thus, PDE11A4 exhibits the four defining criteria of LLPS, and PDE11A inhibitors reverse this age-related phenotype both in vitro and in vivo. Full article

This study develops a two-dimensional (z-x direction) atmospheric dynamics model based on a set of simplified atmospheric motion equations, designed for rapid simulation of atmospheric flow characteristics over complex terrains. The model effectively captures the influence of topography on the atmospheric flow field, offering a new research tool for the in-depth investigation of atmospheric dynamic phenomena under complex terrain conditions. Furthermore, the model takes into account water vapor transport and condensation processes, and employs a simplified algorithm for the conversion of cloud droplets to raindrops to estimate the intensity and spatial distribution of precipitation. The innovative use of the z-coordinate system allows for a focused simulation of dynamic processes in complex terrains, capable of real-time computation of the temporal variations in precipitation processes. The model exhibits high simulation precision and has a wide range of potential practical applications. Full article

As desertification intensifies, greenhouses in arid regions are increasingly challenged by severe water scarcity and low water utilization efficiency. Traditional greenhouse HVAC systems are often inadequate in efficiently recovering condensate water. This study addressed these challenges by investigating, through wind tunnel experiments, the fin angle and inlet wind speed for optimal condensation and heat transfer performance of a straight-fin heat exchanger in desert greenhouse environments. The experimental findings revealed that under low-temperature conditions, vertical fins facilitated gravity-driven droplet removal, resulting in a maximum condensate amount of 524.2 g within 120 min. Conversely, under high-temperature conditions, a fin angle of 45° optimally balanced turbulent disturbances and liquid film stability, producing a condensate amount of up to 887.1 g in the same timeframe. Additionally, wind speed tests at a 45° fin angle identified a critical wind speed of 1.5 m/s, beyond which the condensate amount significantly decreased. Furthermore, when the fin inclination reached or exceeded 60°, flow separation occurred, reducing the effective heat transfer area and negatively impacting the exchanger efficiency. Overall, the study provides significant insights into water conservation and sustainable environmental utilization by enhancing condensate recovery efficiency. Full article

During the conventional biomass fractionation, the degradation and dissolution of lignin and hemicellulose result in a complex extract which remains very challenging for the thorough separation and purification of a wide variety of fractionated products, limiting their further utilization. Herein, we proposed a facile and efficient strategy for fractionating biomass and simultaneously in situ converting of both lignin and hemicellulose into single products using a formic acid–phloroglucinol system. The introduced phloroglucinol could react with lignin fragments and hemicellulose-derived products, and the generated intermediate product from hemicellulose can be further condensed with lignin fragments, finally forming single lignin-based functional biopolymers containing heterocyclic structures. Only small amounts of hemicellulosic derivatives, such as oligosaccharides, monosaccharides, furfural, and 5-HMF, were detected in the extracted solution, indicating a highly directional and effective in situ conversion process of hemicellulose. The constructed specific structures on fabric surfaces by using the chelation between lignin-based functional biopolymers and metal ions achieved the preparation of functional fabrics with stable hydrophobicity. The dynamic contact angle of water droplets on the surface of prepared fabric only decreased from 122° to 116.8° over 30 min. This work strategy provides an ideal route to maximize the utilization of both lignin and hemicellulose without involving complex separation and purification procedures. This strategy is the first demonstration of using the targeted fractionation system to achieve the simultaneous conversion of hemicellulose and lignin into single functional biopolymers directly from lignocellulosic biomass. Full article

As global demand for energy-efficient cooling technologies grows, optimizing window air conditioners (WACs) is crucial. This study integrates computational fluid dynamics (CFD) and experimental fluid dynamics (EFD) to analyze condensate transport induced by the slinger ring in a WAC system. To investigate condensate behavior, the WAC domain is divided into six regions based on the slinger ring’s rotational direction and impact. In the initial impact zone, large liquid structures adhere to the slinger ring before breaking into ligaments. In the upward transport region, condensate films rise along the wall due to centrifugal forces, forming short ligaments. In the rebound region, condensate impacts the top surface and transitions into droplets. In the accumulation zone, droplet coalescence occurs in a confined space, leading to localized mass buildup. In the dispersion region, condensate spreads widely due to increased rotational speed. In the splash zone, splashing and wave-like structures form near the reservoir surface. A newly identified mechanism of condensate mass discharge shows that mass ejection is concentrated in four key regions near the condenser coils. These findings offer insights into optimizing a slinger ring design for improved condensate dispersion. Future research should explore airflow variations and alternative slinger ring configurations to enhance WAC performance. Full article

Unveiling the heat transfer behavior of solar collectors in concentrating solar thermochemical energy storage is crucial for harnessing full-spectrum solar light. In this study, a glass Flat Tube-Shaped Heat Pipe (FT-SHP) was developed, and a visualization experimental platform was established to investigate its internal operation mechanisms and heat transfer characteristics. The results revealed that the liquid filling ratio (FR) significantly affects the heat transfer performance, with an optimal value identified as 25%. As the heat flow temperature in the evaporation section increased, both the Bubble Growing Frequency (BGF) and Droplet Condensation Reflux Period (DCRP) decreased, leading to a reduction in thermal resistance. Conversely, an increase in the cooling flow rate resulted in opposite trends in BGF and DCRP within the tube, while both the Reynolds (Re) number and thermal resistance decreased. As such, an empirical correlation between thermal resistance and Re number was derived, demonstrating a nonlinear relationship between thermal resistance, BGF, and DCRP. These findings provide important insights for the design of heat pipes, with the potential to enhance the efficiency and reliability of solar collectors. Full article

In this study, a novel macromolecular flame retardant (MFR) with a phosphine oxide structure is successfully synthesized to improve the flame retardancy of polyamide 6 (PA6). Following this, the flame-retardant polyamide 6 (FR–PA6) is prepared via melt blending the MFR with PA6. Results indicate that the introduction of MFR has little effect on the melting and crystallization temperature of FR–PA6. While it slightly reduces the thermal stability of PA6, MFR significantly enhances its flame retardancy. The limiting oxygen index of FR–PA6 increases from 21.8% to 28.2%, and it successfully passes the UL-94 V-0 rating when it contains 0.5 wt% of phosphorus. Compared with pure PA6, the av-EHC of FR–PA6 is reduced by 32.2% and the SEA is increased by 66.7%. The MFR showed a flame-retardant mechanism in both the gas phase and the condensed phase. In the gas phase, the decomposition of MFR releases phosphorus-containing free radicals to interrupt the combustion chain reaction and reduces the concentration of the combustible caprolactam. In the condensed phase, the MFR promotes faster formation of melt droplets during combustion, taking heat away from the burning PA6 timely. Full article

Earias insulana Boisd. (Lepidoptera: Nolidae) is a major pest of cotton and other crops in Egypt, and the widespread use of insecticides has led to resistance. This study evaluates, for the first time, the bioactivity of Croton tiglium (Malpighiales: Euphorbiaceae) oil and its nano-emulsion (CTNE) against 25 newly hatched larvae of E. insulana Boisd. We assessed their biological effects across different developmental stages and performed histological and ultrastructural examinations. Gas–liquid chromatography (GLC) identified several bioactive compounds in C. tiglium oil crushed dry seeds, including fatty acids, hydrocarbons, and sterols. CTNE showed excellent quality with a zeta potential of −17.7 mV, an average particle size of 54.28 nm, and spherical droplets of 42.42 nm in diameter. The LC₅₀ values for C. tiglium oil and CTNE were 9.02% and 2.70%, respectively. Both treatments significantly impacted the biological characteristics of E. insulana Boisd., including reduced larval and pupal weight, lower adult emergence, decreased fecundity, and increased mortality. Histologically, there was epithelial cell hypotrophy and detachment, while ultrastructural damage included chromatin condensation, nuclear envelope folding, and mitochondrial damage, indicating apoptotic degeneration. These findings suggest C. tiglium oil and CTNE as potential, safe alternatives to chemical insecticides. Full article

In the European Union, Regulation (EU) No 305/2011, in force since 2017 as CPR, requires the classification of cables permanently installed in buildings for reaction to fire, smoke, flaming droplets, and acidity. The latter is an additional classification evaluated through EN 60754-2, involving pH and conductivity measurements. Acidity is the weak point of a PVC cable due to the release of HCl during the combustion. Low-smoke acidity compounds, containing potent acid scavengers at high temperatures, are developed to reduce the acidity of the smoke. In order to design proper HCl scavengers to be used in PVC low-smoke acidity compounds, it becomes essential to evaluate the main actors affecting acidity and conductivity. In this paper, different cable PVC compounds were tested carrying out EN 60754-2 at different temperatures and temperature regimes: measurements of pH and conductivity were compared with ions’ concentration determined by ion chromatography, according to ISO 10304-1 and ISO 14911 for anions and cations, and inductively coupled plasma–optical emission spectrometry, according to ISO 11885. The conclusive results emphasize that HCl from PVC compounds’ thermal decomposition is the primary driver of pH and conductivity, and the contribution from the evaporation and or decomposition of additives and by-products from combustion is found to be negligible in most of the tested PVC compounds for cables. The findings highlight the effectiveness of ion chromatography and inductively coupled plasma–optical emission spectrometry as powerful analytical tools for developing efficient acid scavengers capable of maintaining performance at elevated temperatures. A further outcome regards the experimental demonstration of the limits and incongruencies of EN 60754-2 as an instrument for assessing the additional classification for acidity for cables. Finally, a statistical method to understand through pH and conductivity measurements if the scavenging mechanism acts in the condensed phase is presented. Full article

Non-equilibrium condensation involves intricate physics, making it crucial to thoroughly investigate the factors that influence it. Understanding these factors is essential for optimizing the system performance and minimizing the negative effects associated with non-equilibrium condensation. This study focused on examining the impact of various operational conditions in a saturated mode on non-equilibrium condensation within a supersonic nozzle. The operation conditions under investigation involved pressures of 25 kPa, 50 kPa, 75 kPa, and 100 kPa. Each saturation state was examined to assess its effect on various parameters, such as temperature, pressure, liquid mass fraction, droplet radius, nucleation rate, Mach number, and droplet count. A consistent pattern emerged across all samples. As the gas accelerated through the converging section of the nozzle, both pressure and temperature gradually decreased. However, upon reaching the throat and entering the divergent section, a phenomenon known as condensation shock occurred. This shock wave caused a sudden and significant spike in both pressure and temperature. Following the shock, both parameters resumed their downward trend along the remaining length of the nozzle. Interestingly, increasing the initial pressure of the gas led to a less intense condensation shock. Additionally, raising the saturation pressure at the nozzle inlet resulted in larger droplets and a higher concentration of liquid within the gas flow. By quadrupling the inlet saturation pressure from 25 to 100 kPa, a substantial 106.9% increase in droplet radius and a 9.65% increase in liquid mass fraction were observed at the nozzle outlet. Full article

Insecticides are used commonly in agricultural production to defend plants, including legumes, from insect pests. It is a known fact that insecticides can have a harmful effect on the legume–rhizobial symbiosis. In this study, the effects of systemic seed treatment insecticide Imidor Pro (imidacloprid) and foliar insecticide Faskord (alpha-cypermethrin) on the structural organization of pea (Pisum sativum L.) nodules and their transcriptomic activity were investigated. The plants were treated as recommended by the manufacturer (10 mg/mL for Imidor Pro and 50 µg/mL for Faskord) and twofold concentrations were used for both insecticides. Insecticides had no visible effect on the growth of pea plants. The nodules also showed no visible changes, except for the variant treated with twofold concentration of Imidor Pro. However, the dry weight of shoots and roots differed significantly in insecticide-treated plants compared to untreated plants in almost all treatments. The number of nodules decreased in variants with Imidor Pro treatment. At the ultrastructural level, both insecticides caused cell wall deformation, poly-β-hydroxybutyrate accumulation in bacteroids, expansion of the peribacteroid space in symbiosomes, and inclusions in vacuoles. Treatment with Faskord caused chromatin condensation in nucleus. Imidor Pro treatment caused hypertrophy of infection droplets by increasing the amount of matrix, as confirmed by immunofluorescence analysis of extensins. Transcriptome analysis revealed upregulation of expression of a number of extensin-like protein-coding genes in nodules after the Imidor Pro treatment. Overall, both insecticides caused some minor changes in the legume–rhizobial system when used at recommended doses, but Faskord, an enteric contact insecticide, has fewer negative effects on symbiotic nodules and legume plants; of these two insecticides, it is preferred in pea agricultural production. Full article

Limestone-gypsum wet flue gas desulfurization (WFGD) played a key role in SOx removal and clean emissions. However, it would also affect the condensable particulate matter (CPM) removal and compositions. The effects of the WFGD system on the removal of CPM and the contents of soluble ions in CPM were investigated in a spray desulfurization tower at varied conditions. The results indicate that the emission concentration of CPM decreased from 7.5 mg/Nm³ to 3.7 mg/Nm³ following the introduction of cold water spray and hot alkali droplet spray systems. This resulted in a CPM reduction rate of approximately 51%, reducing the percentage of CPM in total particulate matter and solving the problem of substandard particulate matter emission concentrations in some coal-fired power plants. The concentrations of NO₃⁻, SO₄²⁻, and Cl⁻ among the soluble ions decreased by 41–66.6%. As the liquid-to-gas ratio of the cold water spray and hot alkali droplet spray increased, CPM came into contact with more spray, which accelerated dissolution and chemical reactions. Consequently, the CPM emission concentration decreased by 17.4–19%. The liquid-to-gas ratio has a great effect on the ion concentrations of NO₃⁻, SO₄²⁻, Cl⁻ and NH₄⁺, with a decrease of 28–66%. The temperatures of the cold water spray and the hot alkali droplet spray primarily affect the ionic concentrations of SO₄²⁻ and Ca²⁺, leading to a decrease of 32.3–51%. When the SO₂ concentration increased from 0 mg/Nm³ to 1500 mg/Nm³, large amounts of SO₂ reacted with the desulfurization slurry to form new CPM and its precursors, the CPM emission concentration increased by 57–68.4%. This study addresses the issue of high Concentration of CPM emissions from coal-fired power plants in a straightforward and efficient manner, which is significant for enhancing the air quality and reducing hazy weather conditions. Also, it provides a theoretical basis and technical foundation for the efficient removal of CPM from actual coal-fired flue gas. Full article

This paper aims to discuss the internal flow and cavitation characteristics of petal bionic nozzle holes under different injection pressures to improve the atomization effect of methanol. The FLUENT (v2022 R1) software is used for simulation. The Schnerr-Sauer cavitation model in the Mixture multiphase flow model is adopted, considering the evaporation and condensation processes of methanol fuel to accurately simulate cavitation and internal flow performance. The new nozzle hole is compared with the ordinary circular nozzle hole for analysis to ensure research reliability. The results show that the cavitation of the petal bionic nozzle hole mainly occurs at the outlet, which can enhance the atomization effect. In terms of turbulent kinetic energy, the internal turbulent kinetic energy of the petal bionic nozzle hole is greater under the same pressure. At 1 MPa, its outlet turbulent kinetic energy is 38.37 m²/s², which is about 2.3 times that of the ordinary circular nozzle hole. When the injection pressure is from 0.2 MPa to 1 MPa, the maximum temperature of the ordinary circular nozzle hole increases by about 33.4%, while that of the petal bionic nozzle hole only increases by 12.3%. The intensity of internal convection and vortex is significantly reduced. The outlet velocity and turbulent kinetic energy distribution of the petal bionic nozzle hole are more uniform. In general, the internal flow performance of the petal bionic nozzle hole is more stable, which is beneficial to the collision and fragmentation of droplets and has better uniformity of droplet distribution. It has a positive effect on improving the atomization effect of methanol injection in the intake port of methanol-diesel dual-fuel engines. Full article