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Efficiently breaking the oxide layer and rapidly diffusing of elements at low-temperature has been a longstanding goal in the diffusion bonding (DB) of Al alloys. To break the interfacial oxide layers and accelerate atomic diffusion, ultrasound energy was introduced during the DB of 6063Al. A full Zn–Al eutectoid joint was manufactured via a pure Zn interlayer at 360 °C in atmospheric by an ultrasonic-assisted diffusion bonding (U-DB) at only an ultrasonic vibration of10 min. During U-DB, brittle cracks were formed in the interfacial oxide layers due to high strain rate induced by ultrasonic action. Zn diffused into Al alloy through the brittle cracks in oxide layers via "subcutaneous diffusion," forming a Zn–Al eutectoid diffusion region between the Al alloy and oxide layer. The oxide fragments irregularly migrated to the center of the joint due to Kirkendall effect and ultrasonic action, finally dispersed in the bonded metal. The bonded metal finally transformed as a full Zn–Al eutectoid phase after consuming interlayer. The shear strength of the Zn–Al eutectoid joint reached 82.6 MPa. The Zn–Al mutual diffusion coefficient of U-DB at 360 °C was ∼0.6 μm2/s, which was about 20 times higher than the thermal diffusion coefficient under same temperature condition. Additionally, the mechanism of ultrasonic-assisted diffusion based on the strain-driven diffusion mode was discussed in detail. [ABSTRACT FROM AUTHOR]

Four severe nuclear accident scenarios have been identified for operating nuclear power plants (ONPPs). However, there is a research gap in predicting the mid–long-term radiation doses for these scenarios. This study aims to address this gap by proposing a novel approach for predicting the mid–long-term radiation dose in the case of a hypothetical short-term station blackout (STSBO) scenario, one of the aforementioned scenarios. Firstly, the Weather Research and Forecasting (WRF) model was coupled with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) (WRF-HYSPLIT) model to establish an atmospheric transport and diffusion model for airborne radionuclides, and the regularity of the atmospheric transport and diffusion for the airborne radionuclides was determined. Subsequently, the Residual Radioactive Material Guidelines (RESRAD) OFFSITE (RESRAD-OFFSITE) code was utilized to establish a radiation dose model for predicting the mid–long-term radiation dose resulting from the airborne radionuclides, and the evolution of the mid–long-term radiation dose was analyzed. Finally, the proposed approach was applied to an ONPP, and the results were used to predict the mid–long-term public radiation dose. The results indicated that the total radiation dose would be lower than the dose limit recommended by the International Commission on Radiological Protection (1 mSv/yr) from the second month to the 100th year after the hypothetical STSBO nuclear accident, and the total radiation dose would decrease slowly over time. Recommendations are made for offsite emergency response measures. These research findings can assist ONPPs in analyzing their environmental impacts in the event of an STSBO scenario. [ABSTRACT FROM AUTHOR]

A simple and flexible mass balance approach was applied to observations of XCH4 from TROPOMI to estimate CH4 emissions over Shanxi Province, including the impacts of advective transport, pressure transport, and atmospheric diffusion. High-frequency eddy-covariance flux observations were used to constrain the driving terms of the mass balance equation. This equation was then used to calculate day-to-day and 5 km × 5 km grided CH4 emissions from May 2018 to July 2022 based on TROPOMI RPRO column CH4 observations. The Shanxi-wide emissions of CH4, 126 ± 58.8 ug/m2/s, shows a fat tail distribution and high variability on a daily time scale (the 90th percentile is 2.14 times the mean and 2.74 times the median). As the number of days in the rolling average increases, the change in the variation decreases to 128 ± 35.7 ug/m2/s at 10-day, 128 ± 19.8 ug/m2/s at 30-day and 127 ± 13.9 ug/m2/s at 90-day. The range of values of the annual mean emissions on coal mine grids within Shanxi for the years 2018 to 2022 was 122 ± 58.2, 131 ± 71.2, 111 ± 63.6, 129 ± 87.1, and 138 ± 63.4 ug/m2/s, respectively. The 5-year average emissions from TROPOMI are 131 ± 68.0 ug/m2/s versus 125 ± 94.6 ug/m2/s on the grids where the EDGAR bottom-up database also has data, indicating that those pixels with mines dominate the overall emissions in terms of both magnitude and variability. The results show that high-frequency observation-based campaigns can produce a less biased result in terms of both the spatial and temporal distribution of CH4 emissions as compared with approaches using either low-frequency data or bottom-up databases, that coal mines dominate the sources of CH4 in Shanxi, and that the observed fat tail distribution can be accounted for using this approach. [ABSTRACT FROM AUTHOR]

Images captured under severe weather conditions, such as haze and fog, suffer from image quality degradation caused by atmospheric particle diffusion. This degradation manifests as color fading, reduced contrast, and adversely affects the performance of various computer vision tasks. To address this, this paper presents an end-to-end feature fusion attention network (FFA-Net) designed to directly restore haze-free images. By incorporating the SSIM loss into the original loss function, the proposed method effectively captures the visual disparities between the estimated defogged image and the authentic haze-free image. Additionally, it mitigates the color distortion problem inherent in the original algorithm. To address the challenge of low brightness in input images, a low illumination enhancement module is introduced, seamlessly integrated with the FFA-Net defogging method. Subsequently, a comparative analysis of different defogging algorithms is conducted using two distinct foggy datasets. Multiple evaluation metrics are employed to assess the performance of these algorithms. The findings indicate that our algorithm significantly outperforms others in terms of objective indicators such as PSNR and SSIM, as well as visual effects. [ABSTRACT FROM AUTHOR]

In order to address the impact of nuclear accident on the atmospheric environment, an analysis method for the atmospheric diffusion characteristics of radionuclides at different scales was established, which was based on the regional scale weather prediction model weather research forecasting model ( WRF). Taking multiple nuclear power plants in the eastern region as the research object, the atmospheric diffusion distribution characteristics of radionuclides released from nuclear accident in the eastern region and in the nuclear power plant surrounding region were studied. The WRF model was used, which was driven by final reanalysis data (FNL) reanalysis meteorological data, combined with the Gaussian atmospheric diffusion model. The results show that the maximum atmospheric diffusion factor at the regional scale mainly distributes in the western region of the calculation area, and it shows a decreasing trend with increasing distance. The difference of the maximum atmospheric diffusion factor at distances of 500 m and 5 000 m is about one order of magnitude. The maximum atmospheric diffusion factor of nuclear power plant surrounding region scale is one order of magnitude lower than that of the regional scale. The difference of the maximum atmospheric diffusion factor at distances of 500 m and 5 000 m is about one order of magnitude for other nuclear power plants,except Qinshan Nuclear Power Plant. There are significant differences of the direction of the maximum atmospheric diffusion factor among different nuclear power plants due to the influence of meteorological conditions of the plant site. The atmospheric diffusion capacity in eastern coastal region is stronger than that in inland region, which is conducive to the atmospheric transport of radioactive radionuclides. [ABSTRACT FROM AUTHOR]

The presence of fermentative hotspots in municipal waste dumps has been reported for several decades, but no study has focused on their size and shape. The uncontrolled landfill of Soub Sekt, covering an area of about 8 hectares in the Tadla plain in Morocco, is the source of a permanent pollution plume in the groundwater, detected by self-potential (SP) measurements. The study aims to detect and characterize these hotspots as well as the leachates that form within them. These hotspots are typically circular and smaller than 3 m in size, and they are concentrated within recent waste deposits. Intense electron transfer activities, particularly during redox reactions leading to metal solubilization, result in very low SP values (down to −60 mV), facilitating their detection. Several successive field campaigns suggest that they are active for 2–3 weeks. Due to the low permeability of the soils, highly mineralized leachates (average Electrical Conductivity 45 mS cm−1) rich in organic ions accumulate on the soil surface at the base of the waste windrows. There, they evolve by concentration due to evaporation and oxidation due to slow diffusion of atmospheric O2. Despite the small size of the hotspots generating the leachates, the accumulation of leachates in ponds and the low soil permeability limits the percolation rate, resulting in moderate but permanent groundwater pollution. [ABSTRACT FROM AUTHOR]

The study aims to develop and apply the WRF-uEMEP model to simulate air quality at the city scale, with a focus on Foshan, the city with the highest industrial density. The interaction between atmospheric diffusion and chemical reactions in different regions further complicates the modeling process. Therefore, this study proposes a multi-scale approach to build an urban air quality model with a resolution of 250 meters by integrating different models. The model takes into account the effects of urban structure and takes into account atmospheric diffusion and chemical reactions in different regions. The research process included model development, calibration, and validation using existing air quality data in Foshan. The study shows that the WRF-uEMEP model effectively captures the impact of urban structure on air pollutant processes. The simulation results reveal the spatial and temporal distribution of air pollutants in Foshan, providing valuable insights for urban air quality management. [ABSTRACT FROM AUTHOR]

In order to investigate the impact of environmental temperature and atmospheric humidity on the leakage and diffusion of hydrogen fluoride (HF) gas, this study focused on the real scenario of an HF chemical industrial park. Based on the actual dispersion scenario of HF gas, a proportionally scaled-down experimental platform for HF gas leakage was established to validate the accuracy and feasibility of numerical simulations under complex conditions. Using the validated model, the study calculated the complex scenarios of HF leakage and diffusion within the temperature range of 293 K to 313 K and the humidity range of 0% to 100%. The simulation results indicated that different environmental temperatures had a relatively small impact on the hazardous areas (the lethal area, severe injury area, light injury area, and maximum allowable concentration (MAC) area) formed by HF gas leakage. At 600 s of dispersion, the fluctuation range of hazardous area sizes under different temperature conditions was between 3.11% and 13.07%. In contrast to environmental temperature, atmospheric relative humidity had a more significant impact on the dispersion trend of HF leakage. Different relative humidity levels mainly affected the areas of the lethal zone, light injury zone, and MAC zone. When HF continued to leak and disperse for 600 s, compared to 0% relative humidity, 100% relative humidity reduced the lethal area by 35.7%, while increasing the light injury area and MAC area by 27.26% and 111.6%, respectively. The impact on the severe injury area was relatively small, decreasing by 1.68%. The results of this study are crucial for understanding the dispersion patterns of HF gas under different temperature and humidity conditions. [ABSTRACT FROM AUTHOR]

Nitrogen dioxide (NO2) is an important contributor to the formation of acid rain, photochemical smog and aerosol particles, which seriously endangers public health. At present, remote sensing of polar-orbiting satellites is a conventional means to obtain large-scale NO2 distribution, but it cannot capture the rapid change because of long revisit periods. The Advanced Himawari Imager (AHI) on the Himawari-8 geostationary satellite has the advantage of high time resolution, which makes it possible to realize near-real-time atmospheric monitoring. Here, based on the absorption characteristics of NO2 in infrared radiation, hourly near-surface NO2 concentrations are retrieved based on the brightness temperature from AHI and auxiliary information such as meteorology and aerosol. The results of 10-fold cross-validation show that NO2 estimations from satellite are in good agreement with in-situ measurements, and their determination coefficient (R2) can reach 0.79. Due to different emission and atmospheric diffusion conditions at different time, the model performance presents a diurnal variation of high accuracy in the noon and afternoon but low accuracy in the morning. Based on the retrieval dataset, it is found that high NO2 concentrations are mainly concentrated in the densely populated and industrial areas such as the North China area. In addition, NO2 pollution mainly occurs in autumn and winter, and the average NO2 concentration in winter is about 1.63 times that in summer in 2021. This study provides a new insight for satellite retrieval of NO2, which is of great significance for real-time pollution monitoring and public health protection. [ABSTRACT FROM AUTHOR]

The long half‐life of 129I makes it useful for dating marine sediments aged 2–90 Ma. However, the lack of initial value dating hinders its application for dating terrestrial sediments. A large scatter of 129I/127I in prenuclear terrestrial samples has been reported; however, the key influencing factors remain unclear. This study presented iodine isotope data from three Argentine Entisol profiles and developed an iodine‐source model to determine the influence of the source on iodine isotopic composition. The temporal patterns demonstrated clear climate modulations in natural terrestrial iodine isotopes over the last ∼15 Kyr. The model identified rock weathering as a major source of iodine in continental sediments. Higher 129I/127I ratios at mid‐high latitudes arise from weak geomagnetic shielding of cosmic rays and thus a high production rate, implying limited meridional diffusion of atmospheric iodine. These findings reveal that environmental factors are significant for constraining the initial value of terrestrial 129I. Plain Language Summary: In terrestrial sediments, the absence of a specific initial value poses a challenge for 129I dating. Through examination of three profiles of Argentine Entisols, this study investigated how changes in the environment over the past 15 Kyr affected iodine isotopic composition. The climate modulations of iodine isotopes were indicated by comparing them with climatic proxies. A simple multi‐source model of iodine suggested that "old" iodine from catchment rock weathering was a major iodine provider, and decreased 129I/127I with the enhanced South American Summer Monsoon and South Westerly Wind indicated a low‐129I iodine input. The deviant 129I/127I of the most southern site was hypothesized to be caused by a greater cosmogenic 129I production rate at high latitudes than at mid‐low latitudes. Key Points: Natural 129I/127I was for the first time found to co‐vary with the summer monsoon and westerlies in South AmericaRock weathering contributes more iodine to terrestrial sediments than oceanic emissionsHigh 129I/127I values at mid‐high latitudes imply low geomagnetic shielding and limited meridional diffusion of atmospheric iodine [ABSTRACT FROM AUTHOR]

Highlights: Pre-fermentative cryogenic treatments as a tool to increase the varietal thiol levels in Sauvignon blanc and Chenin blanc wines. Cryogenic pre treatment technologies as an innovative method for wine production. Low-temperature treatments preceding alcoholic fermentation are becoming increasingly popular and have been used in winemaking as a tool to improve wine colour, aroma, and quality. Additionally, the pre-fermentative treatment of grapes with cryogenic agents protects the grape juice (must) from oxidation by reducing the diffusion of atmospheric oxygen into the liquid phase during the winemaking process. Resultant wines were reported to have enhanced varietal aromas, increased complexity, and higher thiol levels. Indications are that increased contact time between skin and juice improves the extraction of the compounds and/or precursors. Recently, there has been considerable interest in the production of wines with enhanced varietal aromas and improved quality by applying innovative winemaking technologies. This review aims to provide an overview of the aroma and organoleptic quality of Sauvignon blanc and Chenin blanc wines produced from grapes that were subjected to pre-fermentative cryogenic treatments including the impact aroma compounds, i.e., volatile thiols and methoxypyrazines. [ABSTRACT FROM AUTHOR]

With the increasing temperature and pressure in the cylinder of the diesel engine, the in-cylinder environment gradually exceeded the thermodynamic critical point of hydrocarbon fuel. Compared with subcritical spray, the phase transformation mechanism of supercritical spray is essentially changed. In this paper, the n-heptane fuel sprays in three conditions case 1 (T1 = 400 K P1 = 2 MPa), case 2 (T2 = 600 K P2 = 2 MPa), and case 3 (T3 = 800 K P3 = 6 MPa) were obtained by high-speed digital schlieren method on the test platform of a constant volume combustion bomb. The spray liquid phase, liquid–gas mixed layer, and mixture were divided, and the variation rules of the spray cone angle, the liquid phase length, maximum interface thickness, and liquid– gas mixed layer area were discussed. The results showed that the higher the ambient temperature and pressure, the more severe the fragmentation of the spray. Compared with the subcritical condition, the spray penetration distance in the supercritical condition tended to be flat faster. Compared with 400 K, 2 MPa condition, the spray cone angle was about 33° and 50% larger at 800 K, 6 MPa condition. The liquid core area at 800 K, 6 MPa condition was 60 cm², reduced by 75% compared with 400 K, 2 MPa condition, resulting in better spray diffusion and mixing with atmospheric gas. The sensitivity analysis of ambient temperature and pressure on spray characteristic parameters shows that temperature has a greater impact on the interface mixing layer area (VIP = 1.23), and pressure has a greater on penetration distance and spray penetration rate (VIP = 1.23). When the environmental conditions exceed the thermodynamic critical point, the area of the liquid–gas mixed layer increases due to the transformation of spray from evaporation to diffusion and the phenomenon of interfacial layer enrichment. In summary, the supercritical condition promotes the mixing of spray and environment and has a positive effect on spray diffusion and atomization. [ABSTRACT FROM AUTHOR]

The Burgers–Huxley equation is important because it involves the phenomena of accumulation, drag, diffusion, and the generation or decay of species, which are common in various problems in science and engineering, such as heat transmission, the diffusion of atmospheric contaminants, etc. On the other hand, the mathematical technique of nondimensionalisation has proven to be very useful in the appropriate grouping of the variables involved in a physical–chemical phenomenon and in obtaining universal solutions to different complex engineering problems. Therefore, a deep analysis using this technique of the Burgers–Huxley equation and its possible boundary conditions can facilitate a common understanding of these problems through the appropriate grouping of variables and propose common universal solutions. Thus, in this case, the technique is applied to obtain a universal solution for Dirichlet and symmetric boundary conditions. The validation of the methodology is carried out by comparing different cases, where the coefficients or the value of the boundary condition are varied, with the results obtained through a numerical simulation. Furthermore, one of the cases presented presents a boundary condition that changes at a certain time. Finally, after applying the technique, it is studied which phenomenon is predominant, concluding that from a certain value diffusion predominates, with the rest being practically negligible. [ABSTRACT FROM AUTHOR]

Copyright of Uranium Mining & Metallurgy is the property of Uranium Mining & Metallurgy Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of urbanization on the frequent winter aerosol pollution events in Northeast China is not fully understood. The Weather Research and Forecasting Model with Chemistry (WRF–Chem) coupled with urban canopy (UC) models was used to simulate the impact of urbanization on an aerosol pollution process in the Central Liaoning city cluster (CLCC), China. To investigate the main mechanisms of urban expansion and UC on the winter atmospheric environment and the atmospheric diffusion capacity (ADC) in the CLCC, three simulation cases were designed using land-use datasets from different periods and different UC schemes. A comparative analysis of the simulation results showed that the land-use change (LU) and both LU and UC (LUUC) effects lead to higher surface temperature and lower relative humidity and wind speed in the CLCC by decreasing surface albedo, increasing sensible heat flux, and increasing surface roughness, with a spatial distribution similar to the distribution of LU. The thermal effect leads to an increase in atmospheric instability, an increase in boundary layer height and diffusion coefficient, and an increase in the ADC. The LU and LUUC effects lead to a significant decrease in near-surface PM2.5 concentrations in the CLCC due to changes in meteorological conditions and ADC within the boundary layer. The reduction in surface PM2.5 concentrations due to the LU effect is stronger at night than during daytime, while the LUUC effect leads to a greater reduction in surface PM2.5 concentrations during the day, mainly due to stronger diffusion and dilution caused by the effect of urban turbulence within different levels caused by the more complex UC scheme. In this study, the LU and LUUC effects result in greater thermal than dynamic effects, and both have a negative impact on surface PM2.5 concentrations, but redistribute pollutants from the lower urban troposphere to higher altitudes. [ABSTRACT FROM AUTHOR]

The height of the stable boundary layer is a key parameter in atmospheric transmission and diffusion, air quality, emergency response, wind energy, and numerical weather prediction models. Existing methods mainly determine the stable boundary layer height via a threshold or minimum value of the wind speed variance under a low-level jet. Based on multi-meteorological element data from a meteorological gradient observation tower, this paper revealed the limitations of existing methods from the perspective of dynamic and thermal effects. In this paper, it is demonstrated that there were four types of shapes of the wind speed variance profile under the low-level jet and a method for using the shape of the variance profile to retrieve the height of the stable boundary layer was proposed. This method distinguished different types of wind speed variance profiles and solved the problems of the misjudgment and omissions (about 34%) present in existing methods. Our experiment showed that the average absolute error of the proposed method was less than 18 m and the average relative error was less than 9%. The results showed that the proposed inversion method was extended to all kinds of wind field detection equipment for inversion of the stable boundary layer height and has very high universality. [ABSTRACT FROM AUTHOR]

Hazardous gas release can pose severe hazards to the ecological environment and public safety. The source-term estimation of hazardous gas leakage serves a crucial role in emergency response and safety management practices. Nevertheless, the precision of a forward diffusion model and atmospheric diffusion conditions have a significant impact on the performance of the method for estimating source terms. This work proposes the particle swarm optimization (PSO) algorithm coupled with the Gaussian dispersion model for estimating leakage source parameters. The method is validated using experimental cases of the prairie grass field dispersion experiment with various atmospheric stability classes. The results prove the effectiveness of this method. The effects of atmospheric diffusion conditions on estimation outcomes are also investigated. The estimated effect in extreme atmospheric diffusion conditions is not as good as in other diffusion conditions. Accordingly, the Gaussian dispersion model is improved by adding linear and polynomial correction coefficients to it for its inapplicability under extreme diffusion conditions. Finally, the PSO method coupled with improved models is adapted for the source-term parameter estimation. The findings demonstrate that the estimation performance of the PSO method coupled with improved models is significantly improved. It was also found that estimated performances of source parameters of two correction models were significantly distinct under various atmospheric stability classes. There is no single optimal model; however, the model can be selected according to practical diffusion conditions to enhance the estimated precision of source-term parameters. [ABSTRACT FROM AUTHOR]

This work aims to determine the maximum concentration and downwind distance at the earth's surface in two methods Briggs and standard for two conditions are slightly unstable and neutral by using the Gaussian equation at different effective heights and wind seeped at (8.9, 8.5 and 8 m/s) under lateral and vertical dispersion coefficient measurement. [ABSTRACT FROM AUTHOR]

Simultaneous application of multi-channel laser-induced incandescence (LII) and shifted vibrational coherent anti-Stokes Raman scattering (SV-CARS) to study sooting flames is demonstrated for the first time. The potential of this diagnostics combination is evaluated on the basis of characterization of soot particles and correlation of soot presence with temperature. For that purpose, a sooting swirl flame operated at three bars has been employed with ethylene as fuel. The novel combination of CARS and time-resolved LII (TiRe LII) enables the estimation of particle size and correlation of this quantity with local gas temperature; simultaneously acquired 2D LII images provide information on the soot distribution in the ambience of the measurement volume which is used by CARS and TiRe LII. Even if the used LII model is approximative in some respect, the detected LII decay times indicate very small particle size throughout the flame relative to an atmospheric laminar diffusion flame which was used for comparison. In most instances, soot presence relates to local gas temperatures in a range between 1600 and 2400 K. Rare soot events at cooler temperatures occur near the nozzle exit and are attributed to transported soot. Comparison of the peak soot temperatures during the LII process shows a significant decrease in the turbulent pressurized flame relative to the laminar atmospheric reference flame. This is attributed to a less-efficient LII heat-up process at turbulent pressurized conditions due to beam steering. The background blackbody temperature, which can be derived by evaluating the signal captured in the different color channels of the LII system towards the end of the LII process, has been identified to be mostly controlled by hotter soot filaments between the laser plane and the detector. Thus, the LII signal tail is not a good measure of the local gas temperature in the measurement volume for this type of configuration. [ABSTRACT FROM AUTHOR]

Urban green and blue space (GBS) significantly impacts the diffusion range of atmospheric particulate matter. By determining the diffusion distance of atmospheric particulate matter (PM2.5 and PM10) in Shanghai, combined with the GBS landscape pattern index, this study completed a stepwise multiple regression equation and correlation analysis to explore the relationship between the morphological structure and spatial configuration of GBS on the diffusion distance of atmospheric particles. The results show that the landscape shape index (LSI) and the number of patches (NP) of GBS have a significant positive correlation with the diffusion distance of atmospheric particles, while the coefficient of the percent of landscape (PLAND), as a key influencing factor, has a negative correlation. The mean Euclidean nearest neighbor distance (ENN_MN) and splitting index (SPLIT) in the spatial configuration metrics positively affect the diffusion distance. Studies have proved that complex and dispersed GBS will lead to the weakening of its purification ability, thereby increasing the pollution range of atmospheric particulate matter. The order of the influence of different GBS types on the diffusion distance of atmospheric particles is as follows: DT > BS > LP > ST > WA. Therefore, high-density GBS with simple shapes and concentrated distribution should be considered in the future construction of new cities. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal Of Sichuan University (Natural Sciences Division) / Sichuan Daxue Xuebao-Ziran Kexueban is the property of Editorial Department of Journal of Sichuan University Natural Science Edition and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Crop planting scheme was developed to remove the dioxins from the soil. • Optimum healthy dietary plan reduced 58.13% dioxins risk to sensitive populations. • Fertilizer schemes improved the degradation of dioxin by rhizosphere microorganisms. • Dioxins' ground-level concentration (2.283 × 10−8–1.362 × 10−4ng TEQ/m3) was estimated. Based on a domestic waste incineration power generation project, the dioxin emission from the waste incineration plant (WIP), phytoextraction and microbial degradation of dioxins, and dioxins human health risks reduction were investigated through in-silico methods. Based on the dioxins concentrations in soil (9.97 × 10−9–7.00 × 10−5ng/g) predicted by atmospheric dispersion model system and the Level-III fugacity model, planting schemes under different wind directions were designed considering the dioxin absorption capacity and the economic benefits for crops (i.e., barley, peanut, pea, maize and wheat). The dioxins in soils can be further degraded by five crops' rhizosphere microorganisms and fertilizers, simulated through molecular dynamic simulations. The enhanced degradation rates of dioxin by rhizosphere microorganisms of five crops reached 15.70 %–28.66 %. Finally, healthy dietary plans were developed to reduce the risk of dioxin exposure to the sensitive populations living around WIP. Results showed that the consumption of maize, fungus, mushroom and bamboo fungus could effectively reduce dioxins toxicity to humans by 58.13 %. The systematic approach developed in this study provided theoretical support for soil remediation and human health risk control of dioxins-contaminated sites. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The inverse problems of the convection-diffusion equation (ICDE) have received extensive attention in incomplete boundary conditions and uncertain source terms. They can be applied in thermally stratified pipe elbows and so on. Many algorithms need to combine with optimization algorithms to repeatedly calculate the direct problem in the solution process. To solve such problems, this paper employs a boundary-type algorithm named the half-boundary method (HBM). The HBM does not require additional repeated optimization of the direct problem. To test the performance of the method, the numerical simulations of some problems have been carried out, including the inverse problems of heat convection, river pollution and air pollution. The results show that the HBM has the desired accuracy by comparing with the exact solution. If there are errors in the measurement process, the solution doesn't generate a large deviation from the result. It is worth noting that the placement of internal measurement points minimally impacts the numerical results within the solution domain. And the method is also able to handle with discontinuous problems. Because the Gaussian plume model verifies the accuracy of HBM, the HBM can quickly calculate the atmospheric diffusion of the non-Gaussian plume model. [ABSTRACT FROM AUTHOR]

• A new Transformer is proposed for air quality spatiotemporal prediction. • MGSFformer full fuses multi-granularity and spatiotemporal correlations of data. • The proposed model can outperform 11 SOTA models on 3 datasets. Air quality spatiotemporal prediction can provide technical support for environmental governance and sustainable city development. As a classic multi-source spatiotemporal data, effective multi-source information fusion is key to achieving accurate air quality predictions. However, due to not fully fusing two pieces of information, classical deep learning models struggle to achieve satisfactory prediction results: (1) Multi-granularity: each air monitoring station collects air quality data at different sampling intervals, which show distinct time series patterns. (2) Spatiotemporal correlation: due to human activities and atmospheric diffusion, there exist correlations between air quality data from different air monitoring stations, necessitating the consideration of other air monitoring stations' influences when modeling each air quality time series. In this study, to achieve satisfactory prediction results, we propose the Multi-Granularity Spatiotemporal Fusion Transformer, comprised of the residual de-redundant block, spatiotemporal attention block, and dynamic fusion block. Specifically, the residual de-redundant block eliminates information redundancy between data with different granularities and prevents the model from being misled by redundant information. The spatiotemporal attention block captures the spatiotemporal correlation of air quality data and facilitates prediction modeling. The dynamic fusion block evaluates the importance of data with different granularities and integrates the prediction results. Experimental results demonstrate that the proposed model surpasses 11 baselines by 5% in performance on three real-world datasets. [ABSTRACT FROM AUTHOR]

The results of development of a software tool for assessing the dynamics of the absorbed dose rate of external β- and γ-radiation by the height of the pine stands during first year after accidental radioactive fallout, taking into account the dynamics of their redistribution between compartments of the "crown surface of woody plants–surface soil layer" system, are presented. The main assumptions of the software implementation using mathematical modeling methods are formulated. The estimation of radionuclide deposition on the Earth's surface is based on the Gaussian model of atmospheric diffusion. The model (compartment) approach to the dynamics of redistribution of radionuclide activity from the composition of radioactive emissions is represented by a system of linear differential equations of the first order. The calculation of the absorbed dose rate is based on integration of the dose attenuation function of a point source. The determining contribution of β-radiation from radionuclides located on surface of the studied components of the system is established. A methodical approach that takes into account the dynamics of the distribution of radionuclides in the "crown surface of woody plants–surface soil layer" system and the associated doses of external β- and γ-irradiation by the height of pine stands during the first year after accidental radioactive fallout is implemented as a software tool and can be applied in solving problems of ensuring the radiation safety of the environment. [ABSTRACT FROM AUTHOR]

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BackgroundAtmospheric diffusion is often accompanied by complex meteorological conditions of inversion temperature.MethodsIn response to the emergency needs for rapid consequence assessment of nuclear accidents under these complex meteorological conditions, a Gaussian diffusion-based model of radionuclide is developed with mixed layer modification. The inhibition effect of the inversion temperature on the diffusion of radionuclides is modified in the vertical direction. The intensity of the radionuclide source is modified by the decay constant.ResultsThe results indicate that the enhancement effect of the mixed layer on the concentration of radionuclides is reflected. The shorter the half-life of the radionuclide, the greater the effect of reducing the diffusion concentration. The Kincaid dataset validation in the Model Validation Kit (MVK) shows that, compared to the non-modified model, predictions of the modified model have an enhancement effect beyond 5 km, modulating the prediction values to be closer to the observation values.ConclusionsThis development is consistent with the modification effects of the mixed layer. The statistical indicators show that the criteria of the modified model meet the criteria of the recommended model.

Air pollution as one of the major environmental issues in modern society, has already brought severe impact to human life and production, thus it is an urgent task for studying environmental and ecological science to solve this issue that has bothered human society for the last centuries. Scientists have endeavored to figure out the laws of atmospheric pollutant diffusion using various mathematical models and statistical models, and drawn some precious conclusions. This paper explored the basic model of atmospheric diffusion--modeling and solution of Gaussian Diffusion Model, clarify its principles and operation forms, then applied the model into the PM2.5 atmospheric diffusion cases, make the program planning base on the results of model calculation, and get the final conclusion. [ABSTRACT FROM AUTHOR]

The sudden increase in air temperature associated with strong gusty winds of northerly direction is a phenomenon occasionally observed during the cold season in the central region of Rio Grande do Sul (RS) state, located in extreme southern Brazil. This geophysical flow, which is known as Vento Norte (VNOR; Portuguese for "North Wind"), promotes temperature variations that depart significantly from the local cold-season climatology. In this study, eleven years of surface meteorological observations collected at seven weather stations distributed over central RS are employed to investigate the regional extension of the effects of the VNOR windstorm. The analysis revealed that the sharp increase in temperature and in wind magnitude caused by VNOR is observed over a rather wide region of central RS. However, it is in the vicinities of the city of Santa Maria, located just south of an abrupt drop in terrain elevation, that the most intense VNOR effects are observed suggesting a downslope enhancement of the windstorm. A detailed investigation of the meteorological data also showed that the duration of the VNOR windstorm is well correlated with the magnitude of the maximum wind gusts, with the most intense VNOR events also lasting longer. VNOR events occur more frequently in the period between the morning (0700 LST) and early afternoon (1400 LST). The onset of the windstorm is detected predominantly during overnight and morning hours, with 70% of VNOR cases initiating between 0000 and 1000 LST. Regarding the VNOR demise, 66% of the windstorms dissipate between early afternoon and early evening hours (1200–1900 LST). Results from this study are applicable in the areas of atmospheric diffusion and local weather forecasting. [ABSTRACT FROM AUTHOR]

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Increasing interest in n-type silicon (Si) solar cells due to the high-quality material properties of the n-Si wafers, their relatively low sensitivity to donor-like impurities like iron and their resistance to light-induced degradation brings more recent attention to the studies on the p+ emitter and its metal contact. In this work, we investigate the effect of the Boron doping profile on the quality of p+ emitter and their contacts with screen-printed Ag/Al metal fingers. The emitters within the scope of this study are created with BBr 3 diffusion in an atmospheric diffusion furnace on n-type Si wafers and also applied to n-PERT Si cells to analyze their effects on device performance. Our results highlight the significance of the doping profile for solar cell performance, as it considerably affects the contact resistivity at the emitter-metal interface and the saturation current densities for emitter (J 0, emitter) and Ag/Al metal contacts (J 0, AgAl). Reducing the Boron concentration within the emitter leads to a decrease in carrier recombination in the non-contacted region of the emitter, which in turn decreases J 0, emitter. However, this reduction increases the recombination in the contacted areas of the emitter, consequently elevating the J 0, AgAl , and increasing the contact resistance values. Besides, the power loss analysis and simulation results based on experimental values obtained for our best solar cells group show how much J 0, emitter and J 0, AgAl values contribute to and would improve solar cell efficiency. The manuscript presents a case study of experimental emitter doping profile optimization applicable to similar n-type PERT or TOPCon cells with varying design parameters. • The effects of the doping profile on the quality of Boron-doped emitters and the quality of screen-printed Ag/Al metal contacts on these emitters were investigated. • The impact of three distinct emitter profiles was investigated on the overall device performance of n-type passivated emitter, rear totally-diffused silicon solar cells without selective doping. • Reducing Boron concentration within the emitter led to a decrease in carrier recombination in the non-contacted region of the emitter while causing an increase in metal recombination and contact resistance values. • The Quokka-3 simulations indicated that reducing the metal recombination would yield greater benefits than reducing the emitter recombination and potentially that implementing floating busbars would improve efficiency further. [ABSTRACT FROM AUTHOR]

The importance of turbulence-radiation interaction for the calculation of mean (total-TRI) and filtered (subfilter-scale TRI) radiative quantities across the wavenumber spectrum is investigated. The analysis is based on time and space series of scalar fluctuations generated at DNS-level resolution using a stochastic model along optical paths that cross a methane-air diffusion flame. A narrow band correlated- k model is employed for determining the radiative properties of the medium. Errors in the mean, narrow band-integrated intensity arising from neglecting turbulent fluctuations are highly dependent on the spectral position, especially for total-TRI. There is also a trend of errors increasing towards higher wavenumbers, although large errors at the tail-end of the spectrum have no effect on the total intensity. Correlation coefficients, defined for each narrow band, are also assessed across the wavenumber spectrum. Due to the functional dependence of the Planck function on temperature and wavenumber, the temperature self-correlation dominates emission-TRI as one moves towards higher wavenumbers. However, for the narrow bands more relevant for the radiative transfer, all correlations within the radiative emission term are relevant. Absorption-TRI is less important than emission-TRI, but it is not always negligible, particularly for strongly-absorbing bands. The validity of the optically-thin fluctuations approximation is verified across most of the spectrum for total-TRI, and across all of it for subfilter-scale TRI (for adequately-sized filter widths). • Turbulence-radiation interaction (TRI) is studied at a narrow-band level. • A stochastic model is used to generate time and space series of scalar fluctuations. • Studied configurations: atmospheric and high-pressure diffusion flames. • Narrow-band TRI correlations are identified across the radiation spectrum. • Correlations relevant to both RANS and LES are assessed. [ABSTRACT FROM AUTHOR]

[Display omitted] Clogging of staked-in-needle prefilled syringes (PFS) is a sporadic and scarcely predictable event, which occurs particularly in highly concentrated protein solutions and can result in the injection of incomplete doses, especially if autoinjector devices are used for administration. A systematic screening of possible causes and triggers was performed in order to find the crucial factors of influence, the underlying mechanisms and possible measures for prevention. An essential prerequisite for the formation of a solidified clog in the needle is the ingress of liquid from the barrel, which was investigated and quantified by means of neutron imaging after storage of prefilled syringes under various conditions. The needle filling ratio increases with both the storage temperature and the storage period, as a result of atmospheric gas diffusion through the needle shield. While the air pocket in the needle is reduced by this process, diffusion of water vapor does not affect the filling ratio but instead increases the protein concentration in the needle lumen, leading to an exponential rise of the viscosity and finally to the solidification of the protein solution. Maintaining the air pocket in the needle by avoiding any diffusion promoting pressure gradient is therefore the most effective protection from clogging. [ABSTRACT FROM AUTHOR]

Research on the enhanced control and emission-reduction measures to improve air quality during major events could provide data theory and scientific support for air-quality improvement during non-activities. Based on the air-quality data published by the China Environmental Monitoring Station and the meteorological elements and weather conditions released by the China Meteorological Administration, this paper explored the characteristics of air-quality evolution in Beijing from 5 August to 18 September 2015 and the weather situation during the Military Parade. The results showed that: (1) Emission-reduction measures implemented for air quality by Beijing and its surrounding area were induced, and we explored the contribution of these measures to pollutants or AQI in the locality. (2) During the 2015 Military Parade, Beijing was in the front or lower part of the high-pressure system. Due to the strong effect of North or Northeast winds, the weather situation was conducive to the diffusion of pollutants. When before or after the implementation, once the atmospheric diffusion was poor, the pollutants would accumulate gradually. Thus, it can be seen that the weather situation had a great impact on air quality. (3) During the implementation, PM2.5, PM10, NO2 and other pollutants decreased significantly, of which the concentration of PM10 decreased the most, from 109 μg·m−3 down to 34 μg·m−3, and the concentration of PM2.5 decreased by 72.73%. According to the changes between before and during the implementation or during and after the implementation, the concentration of PM10 and PM2.5 increased when the implementation of the emission-reduction measures had been finished, indicating that the enhanced control measures made a great contribution to the emission reduction in particles. (4) In addition, the annual average of AQI in the three years is 87.49, and the average value of a normal year was the average value of 2013 and 2014. The average value of the normal year during the military parade is 64.63, which was 70.40% lower than the average value of AQI during the military parade. The goal of reaching the secondary standard of GB-3095-2012 was achieved, and there was still a long way to go from the primary standard. In a few words, in order to achieve the goal of better air quality throughout the year, all parties still needed to coordinate control and make joint efforts. [ABSTRACT FROM AUTHOR]

Small uncrewed aircraft systems (sUxS) are now being routinely used not only for sampling atmospheric boundary layer (ABL) processes and land-atmosphere interactions but also have significant potential to improve weather forecasting at National Weather Service (NWS) Weather Forecast Offices (WFOs). In the present study, we used observations obtained from a Meteomatics Meteodrone SSE sUxS flown on 31 days between 20 August and 10 December 2020 near Oliver Springs, Tennessee, located 35 km northwest of Knoxville, Tennessee. We flew the sUxS up to 700 m above ground level, starting around sunrise and continuing every half hour until 3.5-4.0 hours past sunrise under synoptically quiescent, fair weather conditions. These datasets were provided in real time to the local NWS WFO in Morristown, Tennessee and used by forecasters there to assist with short-term operational forecasting needs. The sUxS profiles also provided finescale details on the early-morning transition over complex terrain and how this evolution varied during the late summer to winter period, which can be used to support the initialization of numerical weather prediction models. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The accurate numerical prediction of soot formation in practical combustion devices remains a challenge. Several new quadrature-based moment closures based on fractional-order moments of soot particle volume are proposed for the prediction of soot formation in laminar diffusion flames at atmospheric and elevated pressures. Both univariate Quadrature Method of Moments (QMOM) models based on a classical particle volume formulation and bivariate Conditional Quadrature Method of Moments (CQMOM) models based on a new particle volume/primary particle number formulation are proposed. The soot models include detailed gas-phase chemistry along with nucleation, surface growth, oxidation, and coalescence/coagulation soot chemistry source terms. Initial comparisons to predictions of a sectional method for space homogeneous simulations illustrate well the improved predictions of soot number density and volume fraction are provided by the fractional-order moment closures compared to integer-order moment approaches. Furthermore, additional comparisons of soot prediction of methane/ethanol laminar diffusion flames at elevated pressures indicate that the proposed bivariate CQMOM, with a specified soot inception size, offer significantly improved results when compared to the other variants and available experimental data. [ABSTRACT FROM AUTHOR]

Investigations of the physicochemical characteristics of low-enriched uranium hexafluoride stored for up to 12 years in 1 m3 containers confirmed the stability of its isotopic composition and activity reduction of γ-emitting products of uranium fission. It was shown that the gas pressure in the vessels increases by 4.5%/yr due to radiolysis and hydrolysis of the product. The rate of radiolysis of uranium hexafluoride was found to be 0.009%/yr, and elemental fluorine accumulates in vessels as a result; hydrolysis at 0.001%/yr confirms very weak diffusion of atmospheric air through the seal material of a vessel. Total product losses are equal to about 0.01%/yr. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) is the primary air pollutant in northern China. The PM2.5/PM10 ratio has been used increasingly as an indicator to reflect anthropogenic PM pollution, but its advantages compared with individual PM2.5 or PM10 concentrations have not been proven sufficiently by experimental data. By dividing Hebei Province (China) into seven natural ecological regions, this study investigated the spatial characteristics of the PM2.5/PM10 ratio and its relationships with PM2.5, PM10, economic density, and wind speed. Results showed that the PM2.5/PM10 ratio decreased from east to west and from south to north, with an annual average value in 2019 of 0.439–0.559. The characteristics of the spatial variation of the PM2.5/PM10 ratio were different to those of either PM2.5 or PM10 concentration, indicating that PM pollution reflected by the PM2.5/PM10 ratio is not entirely consistent with that by PM2.5 and PM10 concentrations. In comparison with PM2.5 or PM10 concentration, the PM2.5/PM10 ratio had higher (lower) correlation with economic density (wind speed), indicating that the PM2.5/PM10 ratio is a better indicator used to reflect the intensity of anthropogenic emissions of PM pollutants. According to the characteristics of the spatial variations of the PM2.5/PM10 ratio and the PM2.5 and PM10 concentrations, the seven ecological regions of Hebei Province were categorized into four different types of atmospheric PM pollution: "three low regions," "three high regions," "one high and two low regions," and "one low and two high regions." This reflects the comprehensive effect of the intensity of anthropogenic PM emissions and the atmospheric diffusion conditions. [ABSTRACT FROM AUTHOR]

Kinetics of isothermal (500, 600, and 650°C) oxidation of YCu1-хGax (0 ≤ x ≤ 0.3) solid solution powders (50 μm of size) on the base of YCu compound is studied by the periodic weighment method as well as by XRD phase analysis. Features of oxidation mechanism of these intermetallic powders are revealed, including two stages of oxidation process. The initial stage of oxidation is characterized by the decomposition of the YCu1-хGax solid solution into Y(Cu, Ga)2 phase and individual metals with gradual formation of a stable oxide scale (containing Y2O3 mainly). The second stage of oxidation is characterized by oxidation of the Y(Cu, Ga)2 phase with formation of both copper and gallium oxides. This polyphase oxide scale forms significantly retards either the diffusion of atmospheric oxygen atoms along the grain boundaries or the oxidation. In a whole, the oxidation rate of the YCu1-xGax solid solution decreases with an increase in the gallium content, while the apparent activation energy of oxidation increases. That is, gallium dopants increase the resistance to high-temperature oxidation of the YCu phase under its annealing at 500-650°C in air. [ABSTRACT FROM AUTHOR]

Solar radiation plays a crucial role in the formation of sea-land breeze (SLB) circulation in coastal areas, and the SLB circulation in turn influences the atmospheric diffusion of pollutants in coastal cities. Therefore, the characteristics of the SLB and its impacts on the pollutant distributions in Shanghai, China, are numerically investigated for three (low, medium, and high) daily solar radiation intensities (DSRIs). The results show that the pollutant dispersion is affected by both the horizontal flow of SLB circulation and the vertical thermal plume (TP). The SLB only transports pollutants within the near-ground layer, while TP removes pollutants from the boundary layer and then improves near-ground air quality. Both the intensities of the SLB and TP increase with the increase of DSRI, however, the relative strength of the two are different at different DSRIs. When the DSRI is high (28.35 MJ/m2/day) or low (9.45 MJ/m2/day) during the daytime, the sea breeze (SB) is much stronger than the TP, so the prevailing flow direction on the land is horizontal, causing large amounts of pollutants to be blown inland. For the medium DSRI (18.90 MJ/m2/day), the TP is more powerful in the early stage of the SB period, so the airflow across the land is dominated by the rising TP. Pollutants are mainly transported to the upper atmosphere and the best air quality can be achieved in the residential region. At night, the worst air quality occurs at low DSRI, because when the DSRI is low, the speed of the land breeze is also low and this decelerates the diffusion of pollutants to the sea by the wind. [Display omitted] • Effect of daily solar radiation intensity (DSRI) on the sea-land breeze (SLB) is studied. • Pollutant dispersion patterns for different SLB intensities are compared. • The height of the low-speed region (i.e., pollutant accumulation) depends on DSRI. • Thermal plume facilitates the pollutant vertical transport at medium DSRI. • Pollutants accumulated on the sea surface are re-blown to land only in case of low DSRI. [ABSTRACT FROM AUTHOR]

In this paper, we use an analysis function for gas diffusion known as the Research Institute for Applied Mechanics, Kyushu University, Computational Prediction of Airflow over Complex Terrain (RIAM-COMPACT), which was developed for complex terrain, in Airflow Analyst software, and apply it to the spread and dissipation of a fluid layer (assuming the fluid layer contains COVID-19 particles). First, to verify the prediction accuracy of the gas diffusion using RIAM-COMPACT, comparisons with past wind tunnel test results conducted on simple and complex terrains are presented under neutral atmospheric stability. The results of the numerical simulations carried out in this study show good agreement with the wind tunnel experiments for both simple and complex terrains. Next, a model of the Japan National Stadium (Tokyo Olympic Stadium) was constructed using 3D detailed topographic Advanced World 3D Map (AW3D) data generated by combining high-resolution satellite images. We tried to reproduce the hypothetical spread and dissipation of the fluid layer (assuming the fluid layer contains COVID-19 particles) inside and outside of the Japan National Stadium using Airflow Analyst implemented with the RIAM-COMPACT analysis function for gas diffusion. We paid special attention to the effect of wind ventilation driven by natural wind. The numerical results under various scenarios show that ventilation driven by natural wind is very effective for the Japan National Stadium. [ABSTRACT FROM AUTHOR]

In this paper, we propose an efficient and practical implementation of the ensemble Kalman filter via shrinkage covariance matrix estimation. Our filter implementation combines information brought by an ensemble of model realizations, and that based on our prior knowledge about the dynamical system of interest. We perform the combination of both sources of information via optimal shrinkage factors. The method exploits the rank-deficiency of ensemble covariance matrices to provide an efficient and practical implementation of the analysis step in EnKF based formulations. Localization and inflation aspects are discussed, as well. Experimental tests are performed to assess the accuracy of our proposed filter implementation by employing an Advection Diffusion Model and an Atmospheric General Circulation Model. The experimental results reveal that the use of our proposed filter implementation can mitigate the impact of sampling noise, and even more, it can avoid the impact of spurious correlations during assimilation steps. [ABSTRACT FROM AUTHOR]

Consideration is given to a promising approach to heat treatment of biofuel, viz. oxidative torrefaction in a layer of mineral filler. The key features of the proposed technique are the uniformity of heating up the specimen and the possibility of controlling oxidizing processes in the specimen by changing the height of the mineral filler. Based on design-theoretical analysis, an investigation has been made of the thermal and kinetic processes accompanying torrefaction in a layer of mineral filler. It is shown that the presence of the mineral layer ensures a high degree of uniformity for heating up a biofuel specimen in the process of torrefaction. The influence of the mineral filler layer on the diffusion flows of atmospheric oxygen and volatile compounds released during heating up the specimen is shown. [ABSTRACT FROM AUTHOR]

Soil flooding is a compound abiotic stress that alters soil properties and limits atmospheric gas diffusion (O2 and CO2) to the roots. The involvement of abscisic acid (ABA) in the regulation of soil flooding-specific genetic and metabolic responses has been scarcely studied despite its key importance as regulator in other abiotic stress conditions. To attain this objective, wild type and ABA-deficient tomatoes were subjected to short-term (24 h) soil waterlogging. After this period, gas exchange parameters were reduced in the wild type but not in ABA-deficient plants that always had higher E and g s . Transcript and metabolite alterations were more intense in waterlogged tissues, with genotype-specific variations. Waterlogging reduced the ABA levels in the roots while inducing PYR/PYL/RCAR ABA receptors and ABA-dependent transcription factor transcripts, of which induction was less pronounced in the ABA-deficient genotype. Ethylene/O2-dependent genetic responses (ERFVIIs, plant anoxia survival responses, and genes involved in the N-degron pathway) were induced in hypoxic tissues independently of the genotype. Interestingly, genes encoding a nitrate reductase and a phytoglobin involved in NO biosynthesis and scavenging and ERFVII stability were induced in waterlogged tissues, but to a lower extent in ABA-deficient tomato. At the metabolic level, flooding-induced accumulation of Ala was enhanced in ABA-deficient lines following a differential accumulation of Glu and Asp in both hypoxic and aerated tissues, supporting their involvement as sources of oxalacetate to feed the tricarboxylic acid cycle in waterlogged tissues and constituting a potential advantage upon long periods of soil waterlogging. The promoter analysis of upregulated genes indicated that the production of oxalacetate from Asp via Asp oxidase, energy processes such as acetyl-CoA, ATP, and starch biosynthesis, and the lignification process were likely subjected to ABA regulation. Taken together, these data indicate that ABA depletion in waterlogged tissues acts as a positive signal, inducing several specific genetic and metabolic responses to soil flooding. [ABSTRACT FROM AUTHOR]

We present an investigation of polar cap plasma structure lifetimes. We analyze both simulated data from ionospheric models (International Reference Ionosphere model and Mass Spectrometer Incoherent Scatter model) and in situ data from the Swarm satellite mission (the 16 Hz Advanced Plasma Density dataset). We find that the theoretical prediction that E-region conductance is a predictor of F-region polar cap plasma structure lifetimes is indeed supported by both in situ-based observations and by ionospheric models. In situ plasma structure lifetimes correlate well with the ratio of F- to E-region conductance. We present explicit predictions of small scale (~1 km) structure lifetimes, which range from less than 1 h during local summer to around 3 h during local winter. We highlight a large discrepancy between the observational and theoretical scale-dependency of decay due to diffusion. [ABSTRACT FROM AUTHOR]