Additional Moisture Research Articles

Investigation of the hygrothermal effects on in-plane failure mechanisms of fine Z-pinned laminates

Hygrothermal effect on the in-plane behavior of fine Z-pinned laminates were studied and the failure mechanisms were explained. Artificial seawater aging experiments were carried out on Z-pinned laminates prepared by ultrasonic vibration equipment. A compression progressive damage numerical model of fine Z-pinned laminates based on moisture-induced interface degradation was proposed to analyze the damage initialization and development of composites. The mechanical results show that the unpinned and Φ0.11 mm Z-pinned laminates have similar in-plane strength retention after 6 months of aging, and the tensile and compressive strengths decrease by 20% and 29%, respectively. EDS analysis confirms that Z-pin provides an additional moisture channel, leading to more elements with high relative atomic mass inside the laminates. It is found through the simulation studies that moisture leads to matrix compression and interlaminar interfacial damage regions to localized areas, weakening the interlayer effect of Z-pins and leading to the decrease of the ultimate bearing capacity of laminates. It denotes that Φ0.11 mm fine Z-pin has the potential to be used in composite marine structures.

ОРГАНИЗАЦИЯ СЕМЕНОВОДСТВА СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР НА ОРОШЕНИИ И ТЕХНИКА ПОЛИВА (НА ПРИМЕРЕ ЯРОВОЙ ПШЕНИЦЫ)

his paper presents a brief summary of research work carried out in 2012-2022. on the irrigated fields of the peasant farm of IP "Vafin R.K." Laishevsky and LLC AF "Kyrlay" Arsky municipal districts of the Republic of Tatarstan on the selection of short-stemmed, resistant to lodging, diseases and pests, highly responsive to additional moisture of such spring wheat varieties as Zlata, Kazanskaya Yubileynaya, Omskaya 33 and varietal technology for their cultivation. It was found that when placing spring wheat on a layer of irrigated perennial grasses and after spring rapeseed, optimizing nutrition backgrounds, using modern biologics and seed protectants, high-quality basic and pre-sowing soil preparation, compliance with sowing methods and timing, intensification of crop care techniques, including digital technologies for determining the timing and quality of irrigation, provides more than 6.0 tons/ ha of grain with a yield of commercial seeds at the level of 65-76%, with a mass of 1000 seeds of 40 or more g corresponding to the second class of quality in terms of gluten, protein, vitreous and grain nature.

The Influence of the Morphological Characteristics of Mining-Induced Ground Fissures on the Spatiotemporal Distribution of Soil Moisture

In order to study the influence of fissure morphology on soil moisture-content changes under different fissure types, this study established HYDRUS 2.0 numerical models of stepped fissures and planar fissures with different fissure widths and depths based on the experimental condition parameters obtained from physical simulation tests. Then, we simulated the spatial and temporal variation rules of soil moisture around the fissures. The results showed a high level of agreement between the HYDRUS numerical simulations and actual measurements, indicating that the model accurately reflects the movement of soil moisture near fissures. The study found that ground fissures affected the spatial distribution of soil moisture, leading to an increased rate of moisture loss in the deep soil near the fissure walls. Moreover, larger fissures had greater horizontal and vertical effects on soil moisture. The soil moisture content is lower closer to the fissure walls. As the soil depth increased, the influence of the fissures gradually diminished. For planar fissure with a depth of 50 cm, the soil moisture content was 30.6%, 17.8%, and 8.4% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. For a stepped fissure with a depth of 50 cm, the soil moisture content was 29.2%, 20.9%, and 13.9% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. Under the same conditions of fissure width and depth, stepped fissures exhibit faster moisture loss, and the larger the fissure, the more significant the additional moisture loss compared to planar fissures.

Responses of summer mesoscale convective systems to irrigation over the North China Plain based on convection-permitting model simulations

Extensive irrigation activities in the North China Plain (NCP) significantly influence regional weather and climate. However, previous studies focusing on the NCP were primarily based on coarse-resolution models, which are unable to explicitly resolve convection systems, causing large uncertainty in precipitation simulations. In this study, a convection-permitting model coupled with a dynamic irrigation scheme is utilized to investigate the impacts of irrigation on summertime mesoscale convective systems (MCSs) over the NCP. Sensitivity experiments with irrigation off and on are conducted for 5 summers and an MCS identification and tracking algorithm is applied to both satellite observations and model simulations. We find that incorporating irrigation in the model increases MCS precipitation, which agrees more with observations. The probability distributions of MCS lifetime, area, propagation speed, and intensity are all better simulated with irrigation. Irrigation increases the occurrence frequency of MCSs throughout the entire day. The nighttime increase is partly because of more frequent local initiation of MCS developed from isolated deep convection, while the daytime increase is mainly attributed to the changes in MCSs initiating elsewhere and then propagating to the NCP. On average, irrigation induces additional moisture that is more thermodynamically favorable for precipitation, but this effect is partially offset by the weakened ascending air motion primarily caused by irrigation surface cooling. Compared to weak MCS precipitation events, strong MCS precipitation events experience greater enhancement in precipitation intensity when including irrigation because the offset effect from the change in large-scale ascending air motion is insignificant. In addition, irrigation makes the variation of MCS precipitation intensity more correlated with the variation in ascending motion but less correlated with that in atmospheric moisture. Our results suggest the pronounced impacts of irrigation on MCSs over the NCP which should be included in numerical models to improve regional precipitation simulation and prediction.

Study of moisture sorption thermodynamic in canola oilseed and drying energy requirement considerations

AbstractThe objective of this study is to derive the thermodynamic characteristics from sorption isotherm data for canola. The semi‐gravimetric method was utilized at three different temperatures (25, 40, and 55°C) and seven air relative humidity levels within the range of 11%–90%. The observed data indicated that the equilibrium moisture content of the sample decreased as the temperature increased. The “GAB and BET” models were applied to fit the empirical data, which demonstrated a Type III isotherm, and the monolayer water content was subsequently determined using these models. Thermodynamic properties such as “isosteric heat,” “net isosteric heat,” “differential entropy,” “net integral entropy,” and “net integral enthalpy” were determined from isothermal sorption curves. The results show that as moisture content increases, both the sorption isosteric heat and the differential entropy of sorption decrease. This indicates that at higher moisture levels, the energy required for additional moisture adsorption and the changes in entropy are reduced. Similarly, the net isosteric heat of sorption and the net integral enthalpy of sorption also decrease with increasing moisture content, consistent with the observed reductions in isosteric heat and differential entropy. The specific absorption surface area for each temperature was determined by calculating the monolayer moisture content using both the “GAB and BET models.” The net integral entropy had an increasing trend in the range of 4%–4.5% (db%), while it decreased in the range of 4.5%–6.8% of moisture content. In addition, the spreading pressure at three levels of temperature was reported. Finally, an empirical relation was employed to illustrate the cumulative energy requirement for drying versus moisture content. The results indicated that at low moisture content levels, the drying process required significantly higher energy.Practical applicationsMoisture sorption isotherms are essential for understanding the interaction between water and food ingredients. This knowledge is vital for improving food processing methods such as drying, mixing, cooling, and storage. In industry, isotherms can help determine the best drying method to maintain food quality, identify the optimal mixing conditions to ensure consistency, establish cooling protocols to prevent spoilage, and set storage guidelines to extend shelf life. In addition, understanding thermodynamic properties is crucial for regulating moisture absorption and release, achieving the desired food texture, managing surface characteristics, and calculating the energy needed for effective dehydration processes.

Orbital modulation of subtropical versus subantarctic moisture sources in the southeast Pacific mid-latitudes

Reconstructing rainfall variability and moisture sources is a critical aspect to understand past and future hydroclimate dynamics. Here, we use changes in the deuterium content of land-plant leaf waxes from two marine sediment cores located off Chile to reconstruct changes in rainfall amount and variation in moisture sources over the last ~50 ka. The records indicate increased moisture in central Chile during precession maxima, but an obliquity modulation is evident in southern Chile. While the southern westerly winds are the dominant factor of precipitation in southern Chile by bringing moisture and perturbations from the extratropics, the subtropics represent an additional moisture source during precession maxima due to a stronger subtropical jet increasing moisture transport from the tropics to the mid-latitudes. These findings imply that a combination of orbital modulation of moisture sources and rainfall amount explains the last glacial moisture maximum and early Holocene moisture minimum in south-central Chile.

Significance of anthropogenic black carbon in modulating atmospheric and cloud properties through aerosol-radiation interaction during a winter-time fog-haze

The present study investigated the aerosol-radiation-cloud interaction of anthropogenic black carbon (BC) during a severe fog-haze event by utilizing WRF-Chem, multi-satellite and in-situ observations, reanalyses datasets, and HYSPLIT model. The WRF-Chem model adequately captured the regional distribution of aerosol, cloud, and meteorological variables over the study domain. The maximum BC surface concentration (≥7 μg m−3) was predominantly evident over densely populated central and lower Indo-Gangetic Plain (IGP) regions. Although smoke aerosols usually persisted within 4 km above the surface at daylight hours, they reached as high as 6 km during nighttime, specifically over the central IGP regions. The heavily influenced areas by BC aerosols expanded to almost the entire landmass and the continental outflow region upon doubling the anthropogenic emission. The geographical distribution of maximum perturbations in net shortwave radiation flux at the surface closely matched the spatial patterns of the highest BC concentration, indicating a crucial role of BC in directly preventing the incoming sunlight from reaching the surface. Consequently, the reduced solar radiation at the ground might result in substantial surface cooling (between −0.3 and −0.5 °C), eventually prohibiting surface evapotranspiration and diminishing the outgoing sensible and latent heat fluxes. Also, more amplified cooling in the polluted atmosphere can prevent further development of the planetary boundary layer (PBL), increasing particle entrapment near the surface via an ‘aerosol-radiation-PBL’ feedback loop. However, the most striking contrast between the two scenarios (typical and polluted) was the prolonged and intensified warming (0.5–0.8 °C) in the mid-troposphere, causing a remarkable drop in moisture (more than two to three times) and hence burn-off of liquid cloud droplets due to the semi-direct effect of increased BC aerosols. The intense mid-tropospheric heating could remarkably enhance the updraft velocity, supporting the vertical transport of the additional moisture to higher altitudes, forming more ice clouds at night. Therefore, the current study highlighted the urgency of mitigating anthropogenic BC emissions in highly polluted regions since increased emissions could considerably worsen severe fog-haze conditions and influence both liquid water and ice clouds, depending on the atmospheric conditions.

The diffusion process of different moisture sources in the radiant cooling room and the condensation risk assessment

The condensation phenomenon severely limits the widespread application of radiant cooling systems. Although a series of anti-condensation methods have been proposed, it is more important to explore the diffusion process of moisture sources that cause condensation in the radiant cooling room, only in this way can targeted anti-condensation measures be carried out. In this regard, the numerical simulation method is used to explore the diffusion process of additional moisture caused by the increase in occupancy rate and window opening behavior, while monitoring the state of the air on the surface of the radiant terminal (ASRT) to determine whether condensation occurs and evaluate the condensation risk. The results indicate that the moisture emitted by the increased personnel will diffuse along the direction of their surface hot air flow when the occupancy rate increases, and the moisture in the outdoor air will diffuse along its flow direction after the window is opened. However, the change of moisture is accompanied by the change of heat and the condensation phenomenon will not occur first in the place with a large humidity ratio, but rather in areas with lower surface air temperatures in these two situations. In addition, condensation will not occur in all cases after the occupancy rate increases, and the minimum condensation time is still more than 20 min when the occupancy rate is maximum, which has sufficient time for human intervention to avoid condensation. Condensation occurs in all cases after the window is opened, with a minimum condensation time of 68 s. Window opening behavior carries a high condensation risk and should be avoided during the operation of the radiant cooling system. This study can provide a basis for adopting corresponding anti-condensation strategies.

Особенности высокорослого среднеспелого сорта сои Ягуар с признаком ускоренного прироста надземной биомассы

The tall, middle maturing soybean cultivar Jaguar with a trait of accelerated formation of aboveground biomass was obtained as a result of individual selection in F4 from the hybrid combination Vilana × D-7/10 by tall growth (> 150 cm) of the stem, large seeds, middle maturity and lodging resistance. Based on the results of variety testing in 2020–2023, the soybean cultivar Jaguar exceeded the standard cultivar Vilana by 0.26 t/ha of yield. With an average vegetative period of 123 days at the latitude of Krasnodar (45°), the height of plants of this cultivar is 138 cm, varying over the years from 120 to 154 cm. In optimal moisture conditions, the weight of 1000 seeds is 160–190 g. The phenomenon of accelerated formation of aboveground biomass of plants of the cultivar Jaguar y in optimal cultivation conditions is confirmed by a 44% more intense daily increase in plant height and a 55% more intense daily increase in aboveground biomass compared to these indicators for the standard cultivar Vilana. The new tall, middle maturing soybean variety Jaguar, with a trait of accelerated formation of aboveground biomass, is characterized by increased responsiveness to additional moisture by increasing the plant height to ultra-high, increasing the number of nodes, beans and seeds, seed size and weight, and yield. It has increased resistance of tall plants to tilting and lodging due to excessive moisture due to the increased mechanical strength of the stem. Due to its tall growth and high positive response to additional moisture supply, it is suitable for cultivation in the southern foothill and central zones of the Krasnodar region, with irrigation throughout the North Caucasus and Lower Volga regions of the Russian Federation, as well as in the republics of Central Asia and Transcaucasia.

A Regionally Refined and Mass‐Consistent Atmospheric and Hydrological De‐Aliasing Product for GRACE, GRACE‐FO and Future Gravity Missions

AbstractDe‐aliasing products are used in the estimation process of satellite‐based gravity field computation to reduce errors from high‐frequency mass variations that alias into monthly gravity fields. The latest official product is AOD1B RL07 and describes non‐tidal atmosphere and oceanic mass variations at 3‐hourly resolution. However, the model‐based de‐aliasing products are inevitably incomplete and prone to temporally and spatially correlated errors that substantially contribute to errors in the estimated gravity fields. Here, we investigate possible enhancement of current de‐aliasing products by nesting a regional high‐resolution atmospheric reanalysis over Europe into a global reanalysis. As further novelty we include almost mass consistent terrestrial water storage variability from a regional hydrological model nested into a global model as additional component of the de‐aliasing product. While we find in agreement with earlier studies only minor contributions from increasing the temporal resolution beyond 3‐hourly data, our investigations suggest that contributions from continental hydrology and from regional non‐hydrostatic atmospheric modeling to sub‐monthly mass variations could be relevant already for gravity fields estimated from current gravity missions. Moreover, in the context of extreme events, we find regionally contributions from additional moisture fields, such as cloud liquid water, in the order of a few mm over Europe. We suggest this needs to be taken into account when preparing data analysis schemes for future space gravimetric missions.

Improving land surface feedbacks to the atmosphere in convection-permitting climate simulations for Europe

We investigated positive temperature (warm) and negative precipitation (dry) biases in convection-permitting model (CPM) simulations for Europe (2.2 km grid spacing) that were considerably larger than in equivalent regional climate model (RCM) simulations (12 km grid spacing). We found that improvements in dry biases could be made by (1) using a more complex runoff scheme which takes into account topography and groundwater, (2) delaying the onset of water stress in vegetation to enhance transpiration, (3) changing the microphysics scheme to CASIM (Cloud AeroSol Interacting Microphysics) which also decreases heavy rainfall and increases light rainfall. Increasing soil moisture to the critical point can remove dry precipitation biases in southern Europe but not in northern areas, indicating that soil moisture limitation is a key contributor to precipitation biases in the south only. Instead, in the north, changing the cloud scheme of the model has more impact on precipitation biases. We found that the more intense and intermittent nature of rainfall in the CPM, which is more realistic leads to different canopy interception compared to the RCM. This can impact canopy evaporation, evapotranspiration and feed back on precipitation. Increasing rainfall storage in the canopy only leads to small improvements in warm biases, since it still fills rapidly with intense CPM rainfall, suggesting the need for an additional moisture store via improved groundwater modelling or surface pooling. Overall, this work highlights the challenge of correctly capturing land surface feedbacks in CPMs, which play an important role in future climate projections in some regions.

Influence of the Pacific Decadal Oscillation on Winter Temperatures and Precipitation Over the Southern Tibetan Plateau

AbstractWe used observational data and a long‐term piControl simulation from the Community Earth System Model Version 2 to investigate the influence of the Pacific Decadal Oscillation (PDO) on the winter climate over the Tibetan Plateau. The results showed that changes in the phase of the PDO have a significant effect on winter temperatures and precipitation over the southern Tibetan Plateau. Changes in the sea surface temperature (SST) during the positive PDO can weaken the Walker circulation and increase the SST in the Indian Ocean. Our analyses of the moist static energy showed that warming of the tropical troposphere over the Indian Ocean caused by the increased SST has resulted in the horizontal advection of anomalous moist enthalpy by the climatological zonal winds, which was responsible for anomalous ascending motion over the Tibetan Plateau. The additional moisture budget suggests that enhanced vertical motion contributes to the increase in winter precipitation and related total cloud cover over the Tibetan Plateau, leading to the increase of snow depth. The increased total cloud cover and snow depth, in turn, reduces net surface shortwave radiation. The surface air temperature of the Tibetan Plateau is then decreased as a result of the reduction in the net surface shortwave radiation. The PDO therefore has an important modulating role in the interdecadal variability of the winter climate over the Tibetan Plateau. We therefore need to focus on changes in the PDO in research related to the decadal prediction of the climate over the Tibetan Plateau.

Historical and ecological aspects of hydro-reclamation research at the Kirov Meadow-Swamp Experimental Station (<i>to the 105th anniversary of the Station's formation</i>)

The article presents the history of the origin and development of hydromodule research at the Kirov Meadow-Swamp Experimental Station, their practical implementation and ecological significance in the development of the principles of a saving, soil-protective and environment-forming system of agriculture on organic soils in the conditions of the North-East of the European part of the Russian Federation. The main object of long-term research is a typical lowland peatland «Gadovskoye», located on the territory of the Kotelnich peat base of the Kirov region. Special attention is paid to the search for the most effective ways to regulate the water regime of drained swamps used in feed production. It has been established that the most operational, efficient and environmentally friendly method is sluicing, when additional moisture is supplied to the root layer from below. The most optimal range of groundwater regime for annual and perennial forage grasses is shown. The correlation dependence of yield on the degree of drainage of peat deposits is presented. A significant contribution to the reclamation science was made by hydromodule studies on the cutover bogs of the Kirov region. The chemical composition of groundwater and waste swamp waters has been studied on the «Gadovskoye», «Zenginskoye», «Bakhtinskoye», «Pishchalskoye» peatlands, and others, the relationship of the water-physical properties and water regime of the residual deposit with food and temperature regimes, as well as with the coefficient of water consumption of plants and the bearing capacity of the soil of cutover bogs has been established. Agroecological monitoring of the developed peatlands, which have been in culture for more than 40−60 years, shows that during the operation of these facilities there is a gradual decrease in their productivity, due to a decrease in the total agricultural background, partial and even complete violation of the hydrological functions of the drainage network. In order not to completely lose these anthropogenic formations from the sphere of cultural nature management, it is necessary, first of all, periodic repairs of the entire drainage system. Further restructuring within the landscape shell will make it possible to construct fundamentally new post-swamp forest-meadow agroecosystems, where other alternative fields to forage production (hunting, forestry activity, berry-officinal, mushroom, etc.) can be provided.

Parameters affecting the development of capillary barriers due to conventional geotextiles

The objective of this study is to assess the formation of capillary barriers on unsaturated soils in contact with geotextiles that have been placed with the primary function of acting as a separator between soil or drainage layers, including the geotextile component of a geocomposite. A comprehensive experimental program involving soil column infiltration tests was conducted using a variety of material combinations to assess the hydraulic performance of interfaces between unsaturated clay and geotextiles. Soil moisture was recorded using time domain reflectometers. Custom made acrylic soil columns were comparatively small (20 cm diameter and 33 cm tall) in order to facilitate test setup and reduce total testing time. Multiple column tests were conducted, which included woven and nonwoven geotextiles selected to identify which geotextile characteristics may affect the formation of a capillary barrier. Other tests were conducted to assess the effect of varying relative compaction and inflow rate on the hydraulic performance. Based on data from the moisture sensors, all tests were found to clearly show the formation of a capillary barrier, which resulted in additional moisture storage in the overlying finegrained soil layer. The test results show that currently available conventional geotextiles create a capillary barrier and restrict moisture flow into the underlying soil or drainage layer until the overlying fine-grained soil has become essentially saturated. This includes nonwoven geotextiles that are commonly used as the top layer in geocomposite drainage products or as separators between a soil layer and an underlying gravel drainage layer. The strength of the capillary barrier was found to be similar for the multiple conventional polypropylene geotextiles investigated in this study.

Очень высокорослый среднеспелый сорт сои Мамонт

A very tall, middle maturing soybean cultivar Mamont, with traits of gigantism, was obtained as a result of individual selection in F4 from the hybrid combination Vilana × Pin GD for the characteristics of tall growth (> 160 cm) of the stem, large seeds, mid-ripening and non-lodging ability. Based on the results of variety testing 2020–2022, the soybean cultivar Mamont exceeded the standard cultivar Vilana by 0.18 t/ha by yield. The height of plants at the latitude of Krasnodar (45°) is 152–174 cm. In optimal cultivation conditions for moisture supply, the weight of 1000 seeds of this cultivar is 165–195 g. The phenomenon of the gigantism in plants of the Mamont cultivar in optimal growing conditions is confirmed to be 48 % more intense daily increase in plant height, and a 71% more intense daily increase in aboveground biomass compared to these indicators for the standard cultivar Vilana. The new very tall middle maturing soybean cultivar Mamont, with traits of gigantism, is distinguished by increased responsiveness to additional moisture by increasing the traits of plant height to ultra-high, increasing the number of nodes, beans and seeds, seed size and weight, and yield. It has increased resistance of tall plants to tilting and lodging due to excessive moisture due to the increased mechanical strength of the stem. Due to its tall growth and high positive response to additional moisture supply, it is suitable for cultivation in the southern foothill and central zones of the Krasnodar region and on irrigated plot throughout the North Caucasus and Lower Volga regions of the Russian Federation.

Effect of hygrothermal aging on compression behavior of CFRP material with different layups

This study investigates the mechanical degradation mechanism and statistical analysis of residual compressive strength of three lay-up laminates under more than one-year seawater environment. Fick and Langmuir model were used to describe the moisture absorption process with a maximum moisture equilibrium content of 3.78% and various characterization methods were used to reveal the microstructural evolution of CFRP during aging. Experimental results demonstrate that the multiple fiber directions in the MD specimens provide additional moisture absorption channels, leading to a stronger wicking effect and a higher equilibrium moisture content. The layups can significantly affect the compression failure mode after long-term aging. The compressive strength of the cross-ply and multidirectional laminates decreased by 50% while that of unidirectional laminates decreased by 28%, and surface cracking is easily observed in the aged specimens. An empirical prediction model based on the Langmuir model and experimental data was proposed and verified by the data from the literature, with at least a 10% improvement in prediction accuracy. Meanwhile the three-parameter Weibull distribution was used to describe the residual compressive strength after hygrothermal aging and tested by Kolmogorov-Smirnov test. It is expected to provide insight for the application of CFRP in seawater environment.

Precipitation Efficiencies in a Climatology of Southern Ocean Extratropical Cyclones

AbstractPrecipitation efficiency refers to the amount of water that is lost from the atmosphere through precipitation compared to the available water vapor in the atmosphere. This metric plays a critical role in understanding precipitation patterns. However, calculating precipitation efficiency for extratropical cyclones can be challenging because cyclones are dynamic and move through the atmosphere as they evolve. To overcome this challenge, our study uses ERA5 reanalysis data to estimate precipitation efficiencies for 400 Southern Ocean cyclones, with a frame of reference that moves with the individual cyclones. Our findings indicate that at maximum intensity, average precipitation efficiencies reach a maximum of 60%/6 hr near the warm front where ascent rates are the largest. Typically, within 24–36 hr after cyclogenesis, all of the initial water vapor available within 500 km of a cyclone center is lost due to precipitation. However, a cyclone's precipitating phase is prolonged due to local evaporation and moisture flux convergence (MFC), which replenish the moisture lost via precipitation. Close to the cyclone center, MFC provides additional moisture from the environment into which cyclones are traveling. On average, this extends a cyclone's precipitation phase to over 60 hr after cyclogenesis. Thus, while moisture from the genesis location is quickly removed from the cyclone via precipitation, cyclones are replenished by moisture along their track, which doubles the timescale for a cyclone's precipitating phase.

Effect of moisture content on charging and triboelectrostatic separation of coal gasification fine ash

Resource utilization of coal gasification fine ash is restricted by moisture content. Drying and dewatering are indispensable in triboelectrostatic separation. The study aims to determine the minimum required moisture content for effective gasification fine ash separation. Thereinto, experiments reveal a profound influence of moisture content on the electrical properties of gasification fine ash, subsequently impacting the separation process. With higher moisture content, the resistivity and relative dielectric constant of gasification fine ash decrease and increase, respectively. The electrical conductivity of gasification fine ash is enhanced by moisture, but the ability to retain charge is reduced, resulting in a decline in the charge-to-mass ratio. Additionally, severely agglomerated particles and poor separation will be generated by a high moisture content. Comprehensive triboelectrostatic separation experiments demonstrate that gasification fine ash with an additional moisture content of 10% could still be effectively separated yielding carbon-enriched and ash-enriched products with a LOI of 37.17% and 12.47%, respectively. Remarkably, the carbon recovery rate reaches a high of 78.44%. To a certain extent, the drying energy consumption is reduced. This paper provides significant inspiration for resource utilization of coal gasification fine ash.

Prospective Evolution of Meteorological Drought in the Haihe River Basin and Its Connection With Large‐Scale Atmospheric Circulations Using CMIP6 Multimodel Ensemble

AbstractClimate change modifies monsoon rainfall patterns, leading to significant impacts on future meteorological droughts. This study investigated the spatiotemporal pattern of future precipitation, drought features, and the dynamic mechanisms governing their evolution induced by teleconnected atmospheric circulation in the Haihe River Basin, situated in the north China monsoon region. The investigation was conducted under SSP1‐2.6, SSP2‐4.5, and SSP5‐8.5 scenarios of CMIP6, utilizing the Standardized Precipitation Index and an improved run theory at seasonal and annual scales. The findings revealed that high‐emission scenarios cause a wetter climate trend, particularly in autumn and winter, related to the attenuation of the East Asian Trough from climate warming. The uneven intra‐annual precipitation patterns within the basin, induced by the Asian monsoon climate, are expected to improve in the far future, particularly under the SSP2‐4.5 scenarios. The drought frequency, intensity, and duration of future meteorological drought are expected to improve compared to historical conditions under all three scenarios. SSP2‐4.5 shows the shortest duration and lightest intensity of annual droughts. Extreme droughts are primarily driven by strong subsidence with low‐level moisture divergence. However, in the far future, the eastward shift of the western Pacific subtropical high results in reducing moisture transport from the western Pacific, leading to increasing contribution of advection term to atmospheric drying, particularly under the SSP1‐2.6. In winter, the increase in radiative forcing leads to enhanced evapotranspiration from the Eurasian continent, providing additional moisture and alleviating drought, especially in the far future under the SSP1‐2.6 and SSP2‐4.5 scenarios.

Climate-oriented breeding of spring barley in arid regions

The article presents the results of the study of collection samples of spring barley. The aim of the research was to assess the prospects of breeding lines of spring barley for the agro-industrial complex of regions with different climate aridity. The studies were carried in 2011-2021 out at the Krasnokutskaya breeding experimental station (experimental field coordinates 50.914000, 47.068300, Krasnokutsky district of the Saratov region). Predecessor - fallow, accounting area of plots - 25 sq.m. During the period of study of the material, 2012, 2013, 2014, 2015 and 2018 were dry years (the total precipitation during the growing season was 42.8-50.3 mm, HTC 0.30-0.46). In 2019, spring barley crops almost died due to a severe frost in the three-leaf phase and the subsequent severe drought (only 4.9 mm of precipitation fell during the growing season, the HTC was 0.03), so data for this year are not provided. As relatively favorable, 2011, 2016, 2017, 2020 and 2021 can be distinguished (the total precipitation for the growing season is 81.0-135 mm, HTC 0.61-0.97). During 2011-2021 indicators of productivity, plasticity, stability and drought resistance of spring barley varieties bred over a 100-year period at the Krasnokutsk breeding experimental station were evaluated. It was revealed that the average productivity of barley varieties increased by 57.9%, and in the years of acute droughts it almost doubled. Analysis by the same parameters of 5 promising lines in 2017-2021. made it possible to differentiate their potential for regions with different aridity. In the zone with low aridity (more than 7 million hectares of arable land in the Right Bank of the Saratov, Penza and Samara, Volgograd, Ulyanovsk regions), the Nutans 244 and Medicum 276 lines, which are responsive to additional moisture, have the greatest potential. In areas with moderate aridity (about 10 million hectares arable land in the Lower Volga region), samples Nutans 296 and Medicum 247 will have an advantage. In areas with high aridity (more than 6 million hectares of arable land in the Left Bank of the Saratov, Volgograd, Astrakhan regions, Kalmykia), the Medicum 270 line can show high efficiency. These features will be taken into account during further transfer to variety testing.